From: Vsevolod Stakhov Date: Sat, 3 Aug 2013 20:00:35 +0000 (+0100) Subject: Remove unused code. X-Git-Tag: 0.6.0~255 X-Git-Url: https://source.dussan.org/?a=commitdiff_plain;h=cbc0fe933b987333b7162457362330c2104ab87c;p=rspamd.git Remove unused code. --- diff --git a/src/evdns/CMakeLists.txt b/src/evdns/CMakeLists.txt deleted file mode 100644 index fff890e59..000000000 --- a/src/evdns/CMakeLists.txt +++ /dev/null @@ -1,9 +0,0 @@ -# Evdns port to support TXT records -SET(EVDNSSRC evdns.c) - -ADD_LIBRARY(rspamd_evdns STATIC ${EVDNSSRC}) -IF(CMAKE_COMPILER_IS_GNUCC) -SET_TARGET_PROPERTIES(rspamd_evdns PROPERTIES COMPILE_FLAGS "-fno-strict-aliasing -DRSPAMD_LIB") -ELSE -SET_TARGET_PROPERTIES(rspamd_evdns PROPERTIES COMPILE_FLAGS "-DRSPAMD_LIB") -ENDIF(CMAKE_COMPILER_IS_GNUCC) diff --git a/src/evdns/evdns.c b/src/evdns/evdns.c deleted file mode 100644 index ce7c0b429..000000000 --- a/src/evdns/evdns.c +++ /dev/null @@ -1,3328 +0,0 @@ -/* $Id: evdns.c 6979 2006-08-04 18:31:13Z nickm $ */ - -/* The original version of this module was written by Adam Langley; for - * a history of modifications, check out the subversion logs. - * - * When editing this module, try to keep it re-mergeable by Adam. Don't - * reformat the whitespace, add Tor dependencies, or so on. - * - * TODO: - * - Support IPv6 and PTR records. - * - Replace all externally visible magic numbers with #defined constants. - * - Write doccumentation for APIs of all external functions. - */ - -/* Async DNS Library - * Adam Langley - * http://www.imperialviolet.org/eventdns.html - * Public Domain code - * - * This software is Public Domain. To view a copy of the public domain dedication, - * visit http://creativecommons.org/licenses/publicdomain/ or send a letter to - * Creative Commons, 559 Nathan Abbott Way, Stanford, California 94305, USA. - * - * I ask and expect, but do not require, that all derivative works contain an - * attribution similar to: - * Parts developed by Adam Langley - * - * You may wish to replace the word "Parts" with something else depending on - * the amount of original code. - * - * (Derivative works does not include programs which link against, run or include - * the source verbatim in their source distributions) - * - * Version: 0.1b - */ - -#include "../config.h" -#include "../main.h" -#include "evdns.h" - -/* According to SUSv2 */ -#ifndef HOST_NAME_MAX -#define HOST_NAME_MAX 255 -#endif - -/* for strtok_r */ -#define _REENTRANT - -#undef MIN -#define MIN(a,b) ((a)<(b)?(a):(b)) - -#ifdef __USE_ISOC99B -/* libevent doesn't work without this */ -typedef unsigned int uint; -#endif - -#define u64 uint64_t -#define u32 uint32_t -#define u16 uint16_t -#define u8 uint8_t - -#ifdef WIN32 -#define open _open -#define read _read -#define close _close -#endif - -#define MAX_ADDRS 32 /* maximum number of addresses from a single packet */ -/* which we bother recording */ - -#define TYPE_A EVDNS_TYPE_A -#define TYPE_CNAME 5 -#define TYPE_TXT EVDNS_TYPE_TXT -#define TYPE_MX EVDNS_TYPE_MX -#define TYPE_PTR EVDNS_TYPE_PTR -#define TYPE_AAAA EVDNS_TYPE_AAAA - -#define CLASS_INET EVDNS_CLASS_INET - -#define EVUTIL_SOCKET_ERROR() (errno) -#define EVUTIL_SET_SOCKET_ERROR(errcode) \ - do { errno = (errcode); } while (0) -#define evutil_socket_geterror(sock) (errno) -#define evutil_socket_error_to_string(errcode) (strerror(errcode)) - -#define evtimer_assign(ev, b, cb, arg) event_assign(ev, b, -1, 0, cb, arg) - - -#define EVUTIL_UPCAST(ptr, type, field) \ - ((type *)((char*)ptr) - offsetof(type, field)) - - - -struct evdns_request { - u8 *request; /* the dns packet data */ - unsigned int request_len; - int reissue_count; - int tx_count; /* the number of times that this packet has been sent */ - unsigned int request_type; /* TYPE_PTR or TYPE_A */ - void *user_pointer; /* the pointer given to us for this request */ - evdns_callback_type user_callback; - struct nameserver *ns; /* the server which we last sent it */ - - /* elements used by the searching code */ - int search_index; - struct search_state *search_state; - char *search_origname; /* needs to be free()ed */ - int search_flags; - - /* these objects are kept in a circular list */ - struct evdns_request *next, *prev; - - struct event timeout_event; - - u16 trans_id; /* the transaction id */ - char request_appended; /* true if the request pointer is data which follows this struct */ - char transmit_me; /* needs to be transmitted */ - - struct evdns_base *base; -}; - -struct reply { - unsigned int type; - unsigned int have_answer; - union { - struct { - u32 addrcount; - u32 addresses[MAX_ADDRS]; - } a; - struct { - u32 addrcount; - struct in6_addr addresses[MAX_ADDRS]; - } aaaa; - struct { - char name[HOST_NAME_MAX]; - } ptr; - struct { - char name[HOST_NAME_MAX]; - u32 priority; - } mx; - /* TXT field may be longer than 508 bytes, but UDP packets are limited to 512 octets */ - struct { - char data[508]; - } txt; - } data; -}; - -struct nameserver { - int socket; /* a connected UDP socket */ - struct sockaddr_storage address; - socklen_t addrlen; - int failed_times; /* number of times which we have given this server a chance */ - int timedout; /* number of times in a row a request has timed out */ - struct event event; - /* these objects are kept in a circular list */ - struct nameserver *next, *prev; - struct event timeout_event; /* used to keep the timeout for */ - /* when we next probe this server. */ - /* Valid if state == 0 */ - /* Outstanding probe request for this nameserver, if any */ - struct evdns_request *probe_request; - char state; /* zero if we think that this server is down */ - char choked; /* true if we have an EAGAIN from this server's socket */ - char write_waiting; /* true if we are waiting for EV_WRITE events */ - struct evdns_base *base; -}; - - -/* Represents a local port where we're listening for DNS requests. Right now, */ -/* only UDP is supported. */ -struct evdns_server_port { - int socket; /* socket we use to read queries and write replies. */ - int refcnt; /* reference count. */ - char choked; /* Are we currently blocked from writing? */ - char closing; /* Are we trying to close this port, pending writes? */ - evdns_request_callback_fn_type user_callback; /* Fn to handle requests */ - void *user_data; /* Opaque pointer passed to user_callback */ - struct event event; /* Read/write event */ - /* circular list of replies that we want to write. */ - struct server_request *pending_replies; - struct event_base *event_base; - -}; - -/* Represents part of a reply being built. (That is, a single RR.) */ -struct server_reply_item { - struct server_reply_item *next; /* next item in sequence. */ - char *name; /* name part of the RR */ - u16 type; /* The RR type */ - u16 class; /* The RR class (usually CLASS_INET) */ - u32 ttl; /* The RR TTL */ - char is_name; /* True iff data is a label */ - u16 datalen; /* Length of data; -1 if data is a label */ - void *data; /* The contents of the RR */ -}; - -/* Represents a request that we've received as a DNS server, and holds */ -/* the components of the reply as we're constructing it. */ -struct server_request { - /* Pointers to the next and previous entries on the list of replies */ - /* that we're waiting to write. Only set if we have tried to respond */ - /* and gotten EAGAIN. */ - struct server_request *next_pending; - struct server_request *prev_pending; - - u16 trans_id; /* Transaction id. */ - struct evdns_server_port *port; /* Which port received this request on? */ - struct sockaddr_storage addr; /* Where to send the response */ - socklen_t addrlen; /* length of addr */ - - int n_answer; /* how many answer RRs have been set? */ - int n_authority; /* how many authority RRs have been set? */ - int n_additional; /* how many additional RRs have been set? */ - - struct server_reply_item *answer; /* linked list of answer RRs */ - struct server_reply_item *authority; /* linked list of authority RRs */ - struct server_reply_item *additional; /* linked list of additional RRs */ - - /* Constructed response. Only set once we're ready to send a reply. */ - /* Once this is set, the RR fields are cleared, and no more should be set. */ - char *response; - size_t response_len; - - /* Caller-visible fields: flags, questions. */ - struct evdns_server_request base; -}; - -struct evdns_base { - /* An array of n_req_heads circular lists for inflight requests. - * Each inflight request req is in req_heads[req->trans_id % n_req_heads]. - */ - struct evdns_request **req_heads; - /* A circular list of requests that we're waiting to send, but haven't - * sent yet because there are too many requests inflight */ - struct evdns_request *req_waiting_head; - /* A circular list of nameservers. */ - struct nameserver *server_head; - int n_req_heads; - - struct event_base *event_base; - - /* The number of good nameservers that we have */ - int global_good_nameservers; - - /* inflight requests are contained in the req_head list */ - /* and are actually going out across the network */ - int global_requests_inflight; - /* requests which aren't inflight are in the waiting list */ - /* and are counted here */ - int global_requests_waiting; - - int global_max_requests_inflight; - - struct timeval global_timeout; /* 5 seconds */ - int global_max_reissues; /* a reissue occurs when we get some errors from the server */ - int global_max_retransmits; /* number of times we'll retransmit a request which timed out */ - /* number of timeouts in a row before we consider this server to be down */ - int global_max_nameserver_timeout; - /* true iff we will use the 0x20 hack to prevent poisoning attacks. */ - int global_randomize_case; - - /** Port to bind to for outgoing DNS packets. */ - struct sockaddr_storage global_outgoing_address; - /** socklen_t for global_outgoing_address. 0 if it isn't set. */ - socklen_t global_outgoing_addrlen; - - struct search_state *global_search_state; - -#ifndef _EVENT_DISABLE_THREAD_SUPPORT - void *lock; - int lock_count; -#endif -}; - -static struct evdns_base *current_base = NULL; - -/* Given a pointer to an evdns_server_request, get the corresponding */ -/* server_request. */ -#define TO_SERVER_REQUEST(base_ptr) \ - ((struct server_request*) \ - (((char*)(base_ptr) - offsetof(struct server_request, base)))) - -#define REQ_HEAD(base, id) ((base)->req_heads[id % (base)->n_req_heads]) - -/* These are the timeout values for nameservers. If we find a nameserver is down */ -/* we try to probe it at intervals as given below. Values are in seconds. */ -static const struct timeval global_nameserver_timeouts[] = {{10, 0}, {60, 0}, {300, 0}, {900, 0}, {3600, 0}}; -static const int global_nameserver_timeouts_length = sizeof(global_nameserver_timeouts)/sizeof(struct timeval); - -static struct nameserver *nameserver_pick(struct evdns_base *base); -static void evdns_request_insert(struct evdns_request *req, struct evdns_request **head); -static void evdns_request_remove(struct evdns_request *req, struct evdns_request **head); -static void nameserver_ready_callback(int fd, short events, void *arg); -static int evdns_transmit(struct evdns_base *base); -static int evdns_request_transmit(struct evdns_request *req); -static void nameserver_send_probe(struct nameserver *const ns); -static void search_request_finished(struct evdns_request *const); -static int search_try_next(struct evdns_request *const req); -static struct evdns_request *search_request_new(struct evdns_base *base, int type, const char *const name, int flags, evdns_callback_type user_callback, void *user_arg); -static void evdns_requests_pump_waiting_queue(struct evdns_base *base); -static u16 transaction_id_pick(struct evdns_base *base); -static struct evdns_request *request_new(struct evdns_base *base, int type, const char *name, int flags, evdns_callback_type callback, void *ptr); -static void request_submit(struct evdns_request *const req); - -static int server_request_free(struct server_request *req); -static void server_request_free_answers(struct server_request *req); -static void server_port_free(struct evdns_server_port *port); -static void server_port_ready_callback(int fd, short events, void *arg); -static int evdns_base_resolv_conf_parse_impl(struct evdns_base *base, int flags, const char *const filename); -static int evdns_base_set_option_impl(struct evdns_base *base, - const char *option, const char *val, int flags); -static void evdns_base_free_and_unlock(struct evdns_base *base, int fail_requests); - -static int strtoint(const char *const str); - -#define CLOSE_SOCKET(s) close(s) - - -static int -evutil_parse_sockaddr_port(const char *ip_as_string, struct sockaddr *out, int *outlen) -{ - int port; - char buf[128]; - const char *cp, *addr_part, *port_part; - int is_ipv6; - /* recognized formats are: - * [ipv6]:port - * ipv6 - * [ipv6] - * ipv4:port - * ipv4 - */ - - cp = strchr(ip_as_string, ':'); - if (*ip_as_string == '[') { - int len; - if (!(cp = strchr(ip_as_string, ']'))) { - return -1; - } - len = cp-(ip_as_string + 1); - if (len > (int)sizeof(buf)-1) { - return -1; - } - memcpy(buf, ip_as_string+1, len); - buf[len] = '\0'; - addr_part = buf; - if (cp[1] == ':') - port_part = cp+2; - else - port_part = NULL; - is_ipv6 = 1; - } else if (cp && strchr(cp+1, ':')) { - is_ipv6 = 1; - addr_part = ip_as_string; - port_part = NULL; - } else if (cp) { - is_ipv6 = 0; - if (cp - ip_as_string > (int)sizeof(buf)-1) { - return -1; - } - memcpy(buf, ip_as_string, cp-ip_as_string); - buf[cp-ip_as_string] = '\0'; - addr_part = buf; - port_part = cp+1; - } else { - addr_part = ip_as_string; - port_part = NULL; - is_ipv6 = 0; - } - - if (port_part == NULL) { - port = 0; - } else { - port = atoi(port_part); - if (port <= 0 || port > 65535) { - return -1; - } - } - - if (!addr_part) - return -1; /* Should be impossible. */ - - struct sockaddr_in sin; - memset(&sin, 0, sizeof(sin)); - sin.sin_family = AF_INET; - sin.sin_port = htons(port); - if (1 != inet_pton(AF_INET, addr_part, &sin.sin_addr)) - return -1; - if (sizeof(sin) > *outlen) - return -1; - memset(out, 0, *outlen); - memcpy(out, &sin, sizeof(sin)); - *outlen = sizeof(sin); - return 0; -} - -static int -evutil_sockaddr_cmp(const struct sockaddr *sa1, const struct sockaddr *sa2, - int include_port) -{ - int r; - if (0 != (r = (sa1->sa_family - sa2->sa_family))) - return r; - - if (sa1->sa_family == AF_INET) { - const struct sockaddr_in *sin1, *sin2; - sin1 = (const struct sockaddr_in *)sa1; - sin2 = (const struct sockaddr_in *)sa2; - if (sin1->sin_addr.s_addr < sin2->sin_addr.s_addr) - return -1; - else if (sin1->sin_addr.s_addr > sin2->sin_addr.s_addr) - return 1; - else if (include_port && - (r = ((int)sin1->sin_port - (int)sin2->sin_port))) - return r; - else - return 0; - } - return 1; -} - -static void -event_assign(struct event *ev, struct event_base *base, int fd, short events, void (*cb)(int, short, void *), void *arg) -{ - event_set(ev, fd, events, cb, arg); - if (base != NULL) - g_assert(event_base_set(base, ev) == 0); -} - - -static const char * -debug_ntoa(u32 address) -{ - static char buf[32]; - u32 a = ntohl(address); - snprintf(buf, sizeof(buf), "%d.%d.%d.%d", - (int)(u8)((a>>24)&0xff), - (int)(u8)((a>>16)&0xff), - (int)(u8)((a>>8 )&0xff), - (int)(u8)((a )&0xff)); - return buf; -} - -static const char * -debug_ntop(const struct sockaddr *sa) -{ - if (sa->sa_family == AF_INET) { - struct sockaddr_in *sin = (struct sockaddr_in *) sa; - return debug_ntoa(sin->sin_addr.s_addr); - } -#ifdef AF_INET6 - if (sa->sa_family == AF_INET6) { - static char buf[128]; - struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) sa; - const char *result; - result = inet_ntop(AF_INET6, &sin6->sin6_addr, buf, sizeof(buf)); - return result ? result : "unknown"; - } -#endif - return ""; -} - - - -/* This walks the list of inflight requests to find the */ -/* one with a matching transaction id. Returns NULL on */ -/* failure */ -static struct evdns_request * -request_find_from_trans_id(struct evdns_base *base, u16 trans_id) { - struct evdns_request *req = REQ_HEAD(base, trans_id); - struct evdns_request *const started_at = req; - - if (req) { - do { - if (req->trans_id == trans_id) return req; - req = req->next; - } while (req != started_at); - } - - return NULL; -} - -/* a libevent callback function which is called when a nameserver */ -/* has gone down and we want to test if it has came back to life yet */ -static void -nameserver_prod_callback(int fd, short events, void *arg) { - struct nameserver *const ns = (struct nameserver *) arg; - (void)fd; - (void)events; - - nameserver_send_probe(ns); -} - -/* a libevent callback which is called when a nameserver probe (to see if */ -/* it has come back to life) times out. We increment the count of failed_times */ -/* and wait longer to send the next probe packet. */ -static void -nameserver_probe_failed(struct nameserver *const ns) { - const struct timeval * timeout; - - (void) evtimer_del(&ns->timeout_event); - if (ns->state == 1) { - /* This can happen if the nameserver acts in a way which makes us mark */ - /* it as bad and then starts sending good replies. */ - return; - } - - timeout = - &global_nameserver_timeouts[MIN(ns->failed_times, - global_nameserver_timeouts_length - 1)]; - ns->failed_times++; - - if (evtimer_add(&ns->timeout_event, (struct timeval *) timeout) < 0) { - msg_warn( - "Error from libevent when adding timer event for %s", - debug_ntop((struct sockaddr *)&ns->address)); - /* ???? Do more? */ - } -} - -/* called when a nameserver has been deemed to have failed. For example, too */ -/* many packets have timed out etc */ -static void -nameserver_failed(struct nameserver *const ns, const char *msg) { - struct evdns_request *req, *started_at; - struct evdns_base *base = ns->base; - int i; - - /* if this nameserver has already been marked as failed */ - /* then don't do anything */ - if (!ns->state) return; - - base->global_good_nameservers--; - g_assert(base->global_good_nameservers >= 0); - - ns->state = 0; - ns->failed_times = 1; - - if (evtimer_add(&ns->timeout_event, (struct timeval *) &global_nameserver_timeouts[0]) < 0) { - msg_warn( - "Error from libevent when adding timer event for %s", - debug_ntop((struct sockaddr*)&ns->address)); - /* ???? Do more? */ - } - - /* walk the list of inflight requests to see if any can be reassigned to */ - /* a different server. Requests in the waiting queue don't have a */ - /* nameserver assigned yet */ - - /* if we don't have *any* good nameservers then there's no point */ - /* trying to reassign requests to one */ - if (!base->global_good_nameservers) return; - - for (i = 0; i < base->n_req_heads; ++i) { - req = started_at = base->req_heads[i]; - if (req) { - do { - if (req->tx_count == 0 && req->ns == ns) { - /* still waiting to go out, can be moved */ - /* to another server */ - req->ns = nameserver_pick(base); - } - req = req->next; - } while (req != started_at); - } - } -} - -static void -nameserver_up(struct nameserver *const ns) { - if (ns->state) return; - evtimer_del(&ns->timeout_event); - if (ns->probe_request) { - evdns_cancel_request(ns->base, ns->probe_request); - ns->probe_request = NULL; - } - ns->state = 1; - ns->failed_times = 0; - ns->timedout = 0; - ns->base->global_good_nameservers++; -} - -static void -request_trans_id_set(struct evdns_request *const req, const u16 trans_id) { - req->trans_id = trans_id; - *((u16 *) req->request) = htons(trans_id); -} - -/* Called to remove a request from a list and dealloc it. */ -/* head is a pointer to the head of the list it should be */ -/* removed from or NULL if the request isn't in a list. */ -static void -request_finished(struct evdns_request *const req, struct evdns_request **head) { - struct evdns_base *base = req->base; - int was_inflight = (head != &base->req_waiting_head); - if (head) - evdns_request_remove(req, head); - - search_request_finished(req); - if (was_inflight) { - evtimer_del(&req->timeout_event); - base->global_requests_inflight--; - } else { - base->global_requests_waiting--; - } - - if (!req->request_appended) { - /* need to free the request data on it's own */ - g_free(req->request); - } else { - /* the request data is appended onto the header */ - /* so everything gets free()ed when we: */ - } - - g_free(req); - - evdns_requests_pump_waiting_queue(base); -} - -/* This is called when a server returns a funny error code. */ -/* We try the request again with another server. */ -/* */ -/* return: */ -/* 0 ok */ -/* 1 failed/reissue is pointless */ -static int -request_reissue(struct evdns_request *req) { - const struct nameserver *const last_ns = req->ns; - /* the last nameserver should have been marked as failing */ - /* by the caller of this function, therefore pick will try */ - /* not to return it */ - req->ns = nameserver_pick(req->base); - if (req->ns == last_ns) { - /* ... but pick did return it */ - /* not a lot of point in trying again with the */ - /* same server */ - return 1; - } - - req->reissue_count++; - req->tx_count = 0; - req->transmit_me = 1; - - return 0; -} - -/* this function looks for space on the inflight queue and promotes */ -/* requests from the waiting queue if it can. */ -static void -evdns_requests_pump_waiting_queue(struct evdns_base *base) { - while (base->global_requests_inflight < base->global_max_requests_inflight && - base->global_requests_waiting) { - struct evdns_request *req; - /* move a request from the waiting queue to the inflight queue */ - g_assert(base->req_waiting_head); - req = base->req_waiting_head; - evdns_request_remove(req, &base->req_waiting_head); - - base->global_requests_waiting--; - base->global_requests_inflight++; - - req->ns = nameserver_pick(base); - request_trans_id_set(req, transaction_id_pick(base)); - - evdns_request_insert(req, &REQ_HEAD(base, req->trans_id)); - evdns_request_transmit(req); - evdns_transmit(base); - } -} - -static void -reply_callback(struct evdns_request *const req, u32 ttl, u32 err, struct reply *reply) { - switch (req->request_type) { - case TYPE_A: - if (reply) - req->user_callback(DNS_ERR_NONE, DNS_IPv4_A, - reply->data.a.addrcount, ttl, - reply->data.a.addresses, - req->user_pointer); - else - req->user_callback(err, 0, 0, 0, NULL, req->user_pointer); - return; - case TYPE_PTR: - if (reply) { - char *name = reply->data.ptr.name; - req->user_callback(DNS_ERR_NONE, DNS_PTR, 1, ttl, - &name, req->user_pointer); - } else { - req->user_callback(err, 0, 0, 0, NULL, - req->user_pointer); - } - return; - case TYPE_AAAA: - if (reply) - req->user_callback(DNS_ERR_NONE, DNS_IPv6_AAAA, - reply->data.aaaa.addrcount, ttl, - reply->data.aaaa.addresses, - req->user_pointer); - else - req->user_callback(err, 0, 0, 0, NULL, req->user_pointer); - return; - case TYPE_TXT: - if (reply) { - char *data = reply->data.txt.data; - req->user_callback(DNS_ERR_NONE, DNS_TXT, 1, ttl, - &data, req->user_pointer); - } - else { - req->user_callback(err, 0, 0, 0, NULL, req->user_pointer); - } - return; - case TYPE_MX: - if (reply) { - struct evdns_mx mx; - mx.host = reply->data.mx.name; - mx.priority = reply->data.mx.priority; - req->user_callback(DNS_ERR_NONE, DNS_MX, 1, ttl, - &mx, req->user_pointer); - } - else { - req->user_callback(err, 0, 0, 0, NULL, req->user_pointer); - } - return; - } - g_assert(0); -} - -/* this processes a parsed reply packet */ -static void -reply_handle(struct evdns_request *const req, u16 flags, u32 ttl, struct reply *reply) { - int error; - static const int error_codes[] = { - DNS_ERR_FORMAT, DNS_ERR_SERVERFAILED, DNS_ERR_NOTEXIST, - DNS_ERR_NOTIMPL, DNS_ERR_REFUSED - }; - - - if (flags & 0x020f || !reply || !reply->have_answer) { - /* there was an error */ - if (flags & 0x0200) { - error = DNS_ERR_TRUNCATED; - } else { - u16 error_code = (flags & 0x000f) - 1; - if (error_code > 4) { - error = DNS_ERR_UNKNOWN; - } else { - error = error_codes[error_code]; - } - } - - switch(error) { - case DNS_ERR_NOTIMPL: - case DNS_ERR_REFUSED: - /* we regard these errors as marking a bad nameserver */ - if (req->reissue_count < req->base->global_max_reissues) { - char msg[64]; - snprintf(msg, sizeof(msg), "Bad response %d (%s)", - error, evdns_err_to_string(error)); - nameserver_failed(req->ns, msg); - if (!request_reissue(req)) return; - } - break; - case DNS_ERR_SERVERFAILED: - /* rcode 2 (servfailed) sometimes means "we - * are broken" and sometimes (with some binds) - * means "that request was very confusing." - * Treat this as a timeout, not a failure. - */ - break; - default: - /* we got a good reply from the nameserver */ - nameserver_up(req->ns); - } - - if (req->search_state && req->request_type != TYPE_PTR) { - /* if we have a list of domains to search in, - * try the next one */ - if (!search_try_next(req)) { - /* a new request was issued so this - * request is finished and */ - /* the user callback will be made when - * that request (or a */ - /* child of it) finishes. */ - request_finished(req, &REQ_HEAD(req->base, req->trans_id)); - return; - } - } - - /* all else failed. Pass the failure up */ - reply_callback(req, 0, error, NULL); - request_finished(req, &REQ_HEAD(req->base, req->trans_id)); - } else { - /* all ok, tell the user */ - reply_callback(req, ttl, 0, reply); - if (req == req->ns->probe_request) - req->ns->probe_request = NULL; /* Avoid double-free */ - nameserver_up(req->ns); - request_finished(req, &REQ_HEAD(req->base, req->trans_id)); - } -} - -static int -name_parse(u8 *packet, int length, int *idx, char *name_out, int name_out_len) { - int name_end = -1; - int j = *idx; - int ptr_count = 0; -#define GET32(x) do { if (j + 4 > length) goto err; memcpy(&_t32, packet + j, 4); j += 4; x = ntohl(_t32); } while(0) -#define GET16(x) do { if (j + 2 > length) goto err; memcpy(&_t, packet + j, 2); j += 2; x = ntohs(_t); } while(0) -#define GET8(x) do { if (j >= length) goto err; x = packet[j++]; } while(0) - - char *cp = name_out; - const char *const end = name_out + name_out_len; - - /* Normally, names are a series of length prefixed strings terminated */ - /* with a length of 0 (the lengths are u8's < 63). */ - /* However, the length can start with a pair of 1 bits and that */ - /* means that the next 14 bits are a pointer within the current */ - /* packet. */ - - for(;;) { - u8 label_len; - if (j >= length) return -1; - GET8(label_len); - if (!label_len) break; - if (label_len & 0xc0) { - u8 ptr_low; - GET8(ptr_low); - if (name_end < 0) name_end = j; - j = (((int)label_len & 0x3f) << 8) + ptr_low; - /* Make sure that the target offset is in-bounds. */ - if (j < 0 || j >= length) return -1; - /* If we've jumped more times than there are characters in the - * message, we must have a loop. */ - if (++ptr_count > length) return -1; - continue; - } - if (label_len > 63) return -1; - if (cp != name_out) { - if (cp + 1 >= end) return -1; - *cp++ = '.'; - } - if (cp + label_len >= end) return -1; - memcpy(cp, packet + j, label_len); - cp += label_len; - j += label_len; - } - if (cp >= end) return -1; - *cp = '\0'; - if (name_end < 0) - *idx = j; - else - *idx = name_end; - return 0; - err: - return -1; -} - -/* parses a raw request from a nameserver */ -static int -reply_parse(struct evdns_base *base, u8 *packet, int length) { - int j = 0, k = 0; /* index into packet */ - u16 _t; /* used by the macros */ - u32 _t32; /* used by the macros */ - char tmp_name[256], cmp_name[256]; /* used by the macros */ - int name_matches = 0; - - u16 trans_id, questions, answers, authority, additional, datalength; - u16 flags = 0; - u32 ttl, ttl_r = 0xffffffff; - struct reply reply; - struct evdns_request *req = NULL; - unsigned int i; - - - GET16(trans_id); - GET16(flags); - GET16(questions); - GET16(answers); - GET16(authority); - GET16(additional); - (void) authority; /* suppress "unused variable" warnings. */ - (void) additional; /* suppress "unused variable" warnings. */ - - req = request_find_from_trans_id(base, trans_id); - if (!req) return -1; - g_assert(req->base == base); - - memset(&reply, 0, sizeof(reply)); - - /* If it's not an answer, it doesn't correspond to any request. */ - if (!(flags & 0x8000)) return -1; /* must be an answer */ - if (flags & 0x020f) { - /* there was an error */ - goto err; - } - /* if (!answers) return; */ /* must have an answer of some form */ - - /* This macro skips a name in the DNS reply. */ -#define SKIP_NAME \ - do { tmp_name[0] = '\0'; \ - if (name_parse(packet, length, &j, tmp_name, \ - sizeof(tmp_name))<0) \ - goto err; \ - } while(0) -#define TEST_NAME \ - do { tmp_name[0] = '\0'; \ - cmp_name[0] = '\0'; \ - k = j; \ - if (name_parse(packet, length, &j, tmp_name, \ - sizeof(tmp_name))<0) \ - goto err; \ - if (name_parse(req->request, req->request_len, &k, \ - cmp_name, sizeof(cmp_name))<0) \ - goto err; \ - if (base->global_randomize_case) { \ - if (strcmp(tmp_name, cmp_name) == 0) \ - name_matches = 1; \ - } else { \ - if (g_ascii_strcasecmp(tmp_name, cmp_name) == 0) \ - name_matches = 1; \ - } \ - } while(0) - - reply.type = req->request_type; - - /* skip over each question in the reply */ - for (i = 0; i < questions; ++i) { - /* the question looks like - * - */ - TEST_NAME; - j += 4; - if (j >= length) goto err; - } - - if (!name_matches) - goto err; - - /* now we have the answer section which looks like - * - */ - - for (i = 0; i < answers; ++i) { - u16 type, class; - - SKIP_NAME; - GET16(type); - GET16(class); - GET32(ttl); - GET16(datalength); - - if (type == TYPE_A && class == CLASS_INET) { - int addrcount, addrtocopy; - if (req->request_type != TYPE_A) { - j += datalength; continue; - } - if ((datalength & 3) != 0) /* not an even number of As. */ - goto err; - addrcount = datalength >> 2; - addrtocopy = MIN(MAX_ADDRS - reply.data.a.addrcount, (unsigned)addrcount); - - ttl_r = MIN(ttl_r, ttl); - /* we only bother with the first four addresses. */ - if (j + 4*addrtocopy > length) goto err; - memcpy(&reply.data.a.addresses[reply.data.a.addrcount], - packet + j, 4*addrtocopy); - j += 4*addrtocopy; - reply.data.a.addrcount += addrtocopy; - reply.have_answer = 1; - if (reply.data.a.addrcount == MAX_ADDRS) break; - } else if (type == TYPE_PTR && class == CLASS_INET) { - if (req->request_type != TYPE_PTR) { - j += datalength; continue; - } - if (name_parse(packet, length, &j, reply.data.ptr.name, - sizeof(reply.data.ptr.name))<0) - goto err; - ttl_r = MIN(ttl_r, ttl); - reply.have_answer = 1; - break; - } else if (type == TYPE_AAAA && class == CLASS_INET) { - int addrcount, addrtocopy; - if (req->request_type != TYPE_AAAA) { - j += datalength; continue; - } - if ((datalength & 15) != 0) /* not an even number of AAAAs. */ - goto err; - addrcount = datalength >> 4; /* each address is 16 bytes long */ - addrtocopy = MIN(MAX_ADDRS - reply.data.aaaa.addrcount, (unsigned)addrcount); - ttl_r = MIN(ttl_r, ttl); - - /* we only bother with the first four addresses. */ - if (j + 16*addrtocopy > length) goto err; - memcpy(&reply.data.aaaa.addresses[reply.data.aaaa.addrcount], - packet + j, 16*addrtocopy); - reply.data.aaaa.addrcount += addrtocopy; - j += 16*addrtocopy; - reply.have_answer = 1; - if (reply.data.aaaa.addrcount == MAX_ADDRS) break; - } else if (type == TYPE_TXT) { - if (req->request_type != TYPE_TXT) { - j += datalength; - continue; - } - memcpy(&reply.data.txt.data, packet + j + 1, MIN(sizeof(reply.data.txt.data), datalength - 1)); - j += datalength; - ttl_r = MIN(ttl_r, ttl); - reply.have_answer = 1; - break; - } else if (type == TYPE_MX) { - if (req->request_type != TYPE_MX) { - j += datalength; - continue; - } - GET16(reply.data.mx.priority); - if (name_parse(packet, length, &j, reply.data.mx.name, - sizeof(reply.data.mx.name))<0) - goto err; - ttl_r = MIN(ttl_r, ttl); - reply.have_answer = 1; - break; - } else { - /* skip over any other type of resource */ - j += datalength; - } - } - - reply_handle(req, flags, ttl_r, &reply); - return 0; - err: - if (req) - reply_handle(req, flags, 0, NULL); - return -1; -} - -/* Parse a raw request (packet,length) sent to a nameserver port (port) from */ -/* a DNS client (addr,addrlen), and if it's well-formed, call the corresponding */ -/* callback. */ -static int -request_parse(u8 *packet, int length, struct evdns_server_port *port, struct sockaddr *addr, socklen_t addrlen) -{ - int j = 0; /* index into packet */ - u16 _t; /* used by the macros */ - char tmp_name[256]; /* used by the macros */ - - int i; - u16 trans_id, flags, questions, answers, authority, additional; - struct server_request *server_req = NULL; - - - /* Get the header fields */ - GET16(trans_id); - GET16(flags); - GET16(questions); - GET16(answers); - GET16(authority); - GET16(additional); - - if (flags & 0x8000) return -1; /* Must not be an answer. */ - flags &= 0x0110; /* Only RD and CD get preserved. */ - - server_req = g_malloc(sizeof(struct server_request)); - if (server_req == NULL) return -1; - memset(server_req, 0, sizeof(struct server_request)); - - server_req->trans_id = trans_id; - memcpy(&server_req->addr, addr, addrlen); - server_req->addrlen = addrlen; - - server_req->base.flags = flags; - server_req->base.nquestions = 0; - server_req->base.questions = g_malloc(sizeof(struct evdns_server_question *) * questions); - if (server_req->base.questions == NULL) - goto err; - - for (i = 0; i < questions; ++i) { - u16 type, class; - struct evdns_server_question *q; - int namelen; - if (name_parse(packet, length, &j, tmp_name, sizeof(tmp_name))<0) - goto err; - GET16(type); - GET16(class); - namelen = strlen(tmp_name); - q = g_malloc(sizeof(struct evdns_server_question) + namelen); - if (!q) - goto err; - q->type = type; - q->dns_question_class = class; - memcpy(q->name, tmp_name, namelen+1); - server_req->base.questions[server_req->base.nquestions++] = q; - } - - /* Ignore answers, authority, and additional. */ - - server_req->port = port; - port->refcnt++; - - /* Only standard queries are supported. */ - if (flags & 0x7800) { - evdns_server_request_respond(&(server_req->base), DNS_ERR_NOTIMPL); - return -1; - } - - port->user_callback(&(server_req->base), port->user_data); - - return 0; -err: - if (server_req) { - if (server_req->base.questions) { - for (i = 0; i < server_req->base.nquestions; ++i) - g_free(server_req->base.questions[i]); - g_free(server_req->base.questions); - } - g_free(server_req); - } - return -1; - -#undef SKIP_NAME -#undef GET32 -#undef GET16 -#undef GET8 -} - -static u16 -default_transaction_id_fn(void) -{ - u16 trans_id; -#ifdef HAVE_CLOCK_GETTIME - struct timespec ts; - static int clkid = -1; - if (clkid == -1) { - clkid = CLOCK_REALTIME; - if (clock_gettime(CLOCK_MONOTONIC, &ts) != -1) - clkid = CLOCK_MONOTONIC; - } - clock_gettime(clkid, &ts); - trans_id = ts.tv_nsec & 0xffff; -#elif defined(HAVE_SYS_TIMEB_H) - struct timeb tb; - ftime(&tb); - trans_id = tb.millitm & 0xffff; -#else -# error Cannot find way to generate dns transaction id -#endif - - return trans_id; -} - -static uint16_t (*trans_id_function)(void) = default_transaction_id_fn; - -static void -default_random_bytes_fn(char *buf, size_t n) -{ - unsigned i; - for (i = 0; i < n; i += 2) { - u16 tid = trans_id_function(); - buf[i] = (tid >> 8) & 0xff; - if (i+1server_head, *picked; - if (!base->server_head) return NULL; - - /* if we don't have any good nameservers then there's no */ - /* point in trying to find one. */ - if (!base->global_good_nameservers) { - base->server_head = base->server_head->next; - return base->server_head; - } - - /* remember that nameservers are in a circular list */ - for (;;) { - if (base->server_head->state) { - /* we think this server is currently good */ - picked = base->server_head; - base->server_head = base->server_head->next; - return picked; - } - - base->server_head = base->server_head->next; - if (base->server_head == started_at) { - /* all the nameservers seem to be down */ - /* so we just return this one and hope for the */ - /* best */ - g_assert(base->global_good_nameservers == 0); - picked = base->server_head; - base->server_head = base->server_head->next; - return picked; - } - } -} - -/* this is called when a namesever socket is ready for reading */ -static void -nameserver_read(struct nameserver *ns) { - struct sockaddr_storage ss; - socklen_t addrlen = sizeof(ss); - u8 packet[1500]; - - for (;;) { - const int r = recvfrom(ns->socket, packet, sizeof(packet), 0, - (struct sockaddr*)&ss, &addrlen); - if (r < 0) { - int err = evutil_socket_geterror(ns->socket); - nameserver_failed(ns, - evutil_socket_error_to_string(err)); - return; - } - if (evutil_sockaddr_cmp((struct sockaddr*)&ss, - (struct sockaddr*)&ns->address, 0)) { - msg_warn("Address mismatch on received " - "DNS packet. Apparent source was %s", - debug_ntop((struct sockaddr*)&ss)); - return; - } - - ns->timedout = 0; - reply_parse(ns->base, packet, r); - } -} - -/* Read a packet from a DNS client on a server port s, parse it, and */ -/* act accordingly. */ -static void -server_port_read(struct evdns_server_port *s) { - u8 packet[1500]; - struct sockaddr_storage addr; - socklen_t addrlen; - int r; - - for (;;) { - addrlen = sizeof(struct sockaddr_storage); - r = recvfrom(s->socket, packet, sizeof(packet), 0, - (struct sockaddr*) &addr, &addrlen); - if (r < 0) { - int err = evutil_socket_geterror(s->socket); - msg_warn("Error %s (%d) while reading request.", - evutil_socket_error_to_string(err), err); - return; - } - request_parse(packet, r, s, (struct sockaddr*) &addr, addrlen); - } -} - -/* Try to write all pending replies on a given DNS server port. */ -static void -server_port_flush(struct evdns_server_port *port) -{ - while (port->pending_replies) { - struct server_request *req = port->pending_replies; - int r = sendto(port->socket, req->response, req->response_len, 0, - (struct sockaddr*) &req->addr, req->addrlen); - if (r < 0) { - int err = evutil_socket_geterror(port->socket); - msg_warn("Error %s (%d) while writing response to port; dropping", evutil_socket_error_to_string(err), err); - } - if (server_request_free(req)) { - /* we released the last reference to req->port. */ - return; - } - } - - /* We have no more pending requests; stop listening for 'writeable' events. */ - (void) event_del(&port->event); - event_assign(&port->event, port->event_base, - port->socket, EV_READ | EV_PERSIST, - server_port_ready_callback, port); - - if (event_add(&port->event, NULL) < 0) { - msg_warn("Error from libevent when adding event for DNS server."); - /* ???? Do more? */ - } -} - -/* set if we are waiting for the ability to write to this server. */ -/* if waiting is true then we ask libevent for EV_WRITE events, otherwise */ -/* we stop these events. */ -static void -nameserver_write_waiting(struct nameserver *ns, char waiting) { - if (ns->write_waiting == waiting) return; - - ns->write_waiting = waiting; - (void) event_del(&ns->event); - event_assign(&ns->event, ns->base->event_base, - ns->socket, EV_READ | (waiting ? EV_WRITE : 0) | EV_PERSIST, - nameserver_ready_callback, ns); - if (event_add(&ns->event, NULL) < 0) { - msg_warn("Error from libevent when adding event for %s", - debug_ntop((struct sockaddr *)&ns->address)); - /* ???? Do more? */ - } -} - -/* a callback function. Called by libevent when the kernel says that */ -/* a nameserver socket is ready for writing or reading */ -static void -nameserver_ready_callback(int fd, short events, void *arg) { - struct nameserver *ns = (struct nameserver *) arg; - (void)fd; - - if (events & EV_WRITE) { - ns->choked = 0; - if (!evdns_transmit(ns->base)) { - nameserver_write_waiting(ns, 0); - } - } - if (events & EV_READ) { - nameserver_read(ns); - } -} - -/* a callback function. Called by libevent when the kernel says that */ -/* a server socket is ready for writing or reading. */ -static void -server_port_ready_callback(int fd, short events, void *arg) { - struct evdns_server_port *port = (struct evdns_server_port *) arg; - (void) fd; - - if (events & EV_WRITE) { - port->choked = 0; - server_port_flush(port); - } - if (events & EV_READ) { - server_port_read(port); - } -} - -/* This is an inefficient representation; only use it via the dnslabel_table_* - * functions, so that is can be safely replaced with something smarter later. */ -#define MAX_LABELS 128 -/* Structures used to implement name compression */ -struct dnslabel_entry { char *v; off_t pos; }; -struct dnslabel_table { - int n_labels; /* number of current entries */ - /* map from name to position in message */ - struct dnslabel_entry labels[MAX_LABELS]; -}; - -/* Initialize dnslabel_table. */ -static void -dnslabel_table_init(struct dnslabel_table *table) -{ - table->n_labels = 0; -} - -/* Free all storage held by table, but not the table itself. */ -static void -dnslabel_clear(struct dnslabel_table *table) -{ - int i; - for (i = 0; i < table->n_labels; ++i) - g_free(table->labels[i].v); - table->n_labels = 0; -} - -/* return the position of the label in the current message, or -1 if the label */ -/* hasn't been used yet. */ -static int -dnslabel_table_get_pos(const struct dnslabel_table *table, const char *label) -{ - int i; - for (i = 0; i < table->n_labels; ++i) { - if (!strcmp(label, table->labels[i].v)) - return table->labels[i].pos; - } - return -1; -} - -/* remember that we've used the label at position pos */ -static int -dnslabel_table_add(struct dnslabel_table *table, const char *label, off_t pos) -{ - char *v; - int p; - if (table->n_labels == MAX_LABELS) - return (-1); - v = g_strdup(label); - if (v == NULL) - return (-1); - p = table->n_labels++; - table->labels[p].v = v; - table->labels[p].pos = pos; - - return (0); -} - -/* Converts a string to a length-prefixed set of DNS labels, starting */ -/* at buf[j]. name and buf must not overlap. name_len should be the length */ -/* of name. table is optional, and is used for compression. */ -/* */ -/* Input: abc.def */ -/* Output: <3>abc<3>def<0> */ -/* */ -/* Returns the first index after the encoded name, or negative on error. */ -/* -1 label was > 63 bytes */ -/* -2 name too long to fit in buffer. */ -/* */ -static off_t -dnsname_to_labels(u8 *const buf, size_t buf_len, off_t j, - const char *name, const int name_len, - struct dnslabel_table *table) { - const char *end = name + name_len; - int ref = 0; - u16 _t; - -#define APPEND16(x) do { \ - if (j + 2 > (off_t)buf_len) \ - goto overflow; \ - _t = htons(x); \ - memcpy(buf + j, &_t, 2); \ - j += 2; \ - } while (0) -#define APPEND32(x) do { \ - if (j + 4 > (off_t)buf_len) \ - goto overflow; \ - _t32 = htonl(x); \ - memcpy(buf + j, &_t32, 4); \ - j += 4; \ - } while (0) - - if (name_len > 255) return -2; - - for (;;) { - const char *const start = name; - if (table && (ref = dnslabel_table_get_pos(table, name)) >= 0) { - APPEND16(ref | 0xc000); - return j; - } - name = strchr(name, '.'); - if (!name) { - const unsigned int label_len = end - start; - if (label_len > 63) return -1; - if ((size_t)(j+label_len+1) > buf_len) return -2; - if (table) dnslabel_table_add(table, start, j); - buf[j++] = label_len; - - memcpy(buf + j, start, end - start); - j += end - start; - break; - } else { - /* append length of the label. */ - const unsigned int label_len = name - start; - if (label_len > 63) return -1; - if ((size_t)(j+label_len+1) > buf_len) return -2; - if (table) dnslabel_table_add(table, start, j); - buf[j++] = label_len; - - memcpy(buf + j, start, name - start); - j += name - start; - /* hop over the '.' */ - name++; - } - } - - /* the labels must be terminated by a 0. */ - /* It's possible that the name ended in a . */ - /* in which case the zero is already there */ - if (!j || buf[j-1]) buf[j++] = 0; - return j; - overflow: - return (-2); -} - -/* Finds the length of a dns request for a DNS name of the given */ -/* length. The actual request may be smaller than the value returned */ -/* here */ -static size_t -evdns_request_len(const size_t name_len) { - return 96 + /* length of the DNS standard header */ - name_len + 2 + - 4; /* space for the resource type */ -} - -/* build a dns request packet into buf. buf should be at least as long */ -/* as evdns_request_len told you it should be. */ -/* */ -/* Returns the amount of space used. Negative on error. */ -static int -evdns_request_data_build(const char *const name, const int name_len, - const u16 trans_id, const u16 type, const u16 class, - u8 *const buf, size_t buf_len) { - off_t j = 0; /* current offset into buf */ - u16 _t; /* used by the macros */ - - APPEND16(trans_id); - APPEND16(0x0100); /* standard query, recusion needed */ - APPEND16(1); /* one question */ - APPEND16(0); /* no answers */ - APPEND16(0); /* no authority */ - APPEND16(0); /* no additional */ - - j = dnsname_to_labels(buf, buf_len, j, name, name_len, NULL); - if (j < 0) { - return (int)j; - } - - APPEND16(type); - APPEND16(class); - - return (int)j; - overflow: - return (-1); -} - -/* exported function */ -struct evdns_server_port * -evdns_add_server_port_with_base(struct event_base *base, int socket, int is_tcp, evdns_request_callback_fn_type cb, void *user_data) -{ - struct evdns_server_port *port; - if (!(port = g_malloc(sizeof(struct evdns_server_port)))) - return NULL; - memset(port, 0, sizeof(struct evdns_server_port)); - - g_assert(!is_tcp); /* TCP sockets not yet implemented */ - port->socket = socket; - port->refcnt = 1; - port->choked = 0; - port->closing = 0; - port->user_callback = cb; - port->user_data = user_data; - port->pending_replies = NULL; - port->event_base = base; - - event_assign(&port->event, port->event_base, - port->socket, EV_READ | EV_PERSIST, - server_port_ready_callback, port); - if (event_add(&port->event, NULL) < 0) { - g_free(port); - return NULL; - } - return port; -} - -struct evdns_server_port * -evdns_add_server_port(int socket, int is_tcp, evdns_request_callback_fn_type cb, void *user_data) -{ - return evdns_add_server_port_with_base(NULL, socket, is_tcp, cb, user_data); -} - -/* exported function */ -void -evdns_close_server_port(struct evdns_server_port *port) -{ - if (--port->refcnt == 0) { - server_port_free(port); - } else { - port->closing = 1; - } -} - -/* exported function */ -int -evdns_server_request_add_reply(struct evdns_server_request *_req, int section, const char *name, int type, int class, int ttl, int datalen, int is_name, const char *data) -{ - struct server_request *req = TO_SERVER_REQUEST(_req); - struct server_reply_item **itemp, *item; - int *countp; - int result = -1; - - if (req->response) /* have we already answered? */ - goto done; - - switch (section) { - case EVDNS_ANSWER_SECTION: - itemp = &req->answer; - countp = &req->n_answer; - break; - case EVDNS_AUTHORITY_SECTION: - itemp = &req->authority; - countp = &req->n_authority; - break; - case EVDNS_ADDITIONAL_SECTION: - itemp = &req->additional; - countp = &req->n_additional; - break; - default: - goto done; - } - while (*itemp) { - itemp = &((*itemp)->next); - } - item = g_malloc(sizeof(struct server_reply_item)); - if (!item) - goto done; - item->next = NULL; - if (!(item->name = g_strdup(name))) { - g_free(item); - goto done; - } - item->type = type; - item->dns_question_class = class; - item->ttl = ttl; - item->is_name = is_name != 0; - item->datalen = 0; - item->data = NULL; - if (data) { - if (item->is_name) { - if (!(item->data = g_strdup(data))) { - g_free(item->name); - g_free(item); - goto done; - } - item->datalen = (u16)-1; - } else { - if (!(item->data = g_malloc(datalen))) { - g_free(item->name); - g_free(item); - goto done; - } - item->datalen = datalen; - memcpy(item->data, data, datalen); - } - } - - *itemp = item; - ++(*countp); - result = 0; -done: - return result; -} - -/* exported function */ -int -evdns_server_request_add_a_reply(struct evdns_server_request *req, const char *name, int n, void *addrs, int ttl) -{ - return evdns_server_request_add_reply( - req, EVDNS_ANSWER_SECTION, name, TYPE_A, CLASS_INET, - ttl, n*4, 0, addrs); -} - -/* exported function */ -int -evdns_server_request_add_aaaa_reply(struct evdns_server_request *req, const char *name, int n, void *addrs, int ttl) -{ - return evdns_server_request_add_reply( - req, EVDNS_ANSWER_SECTION, name, TYPE_AAAA, CLASS_INET, - ttl, n*16, 0, addrs); -} - -/* exported function */ -int -evdns_server_request_add_ptr_reply(struct evdns_server_request *req, struct in_addr *in, const char *inaddr_name, const char *hostname, int ttl) -{ - u32 a; - char buf[32]; - g_assert(in || inaddr_name); - g_assert(!(in && inaddr_name)); - if (in) { - a = ntohl(in->s_addr); - snprintf(buf, sizeof(buf), "%d.%d.%d.%d.in-addr.arpa", - (int)(u8)((a )&0xff), - (int)(u8)((a>>8 )&0xff), - (int)(u8)((a>>16)&0xff), - (int)(u8)((a>>24)&0xff)); - inaddr_name = buf; - } - return evdns_server_request_add_reply( - req, EVDNS_ANSWER_SECTION, inaddr_name, TYPE_PTR, CLASS_INET, - ttl, -1, 1, hostname); -} - -/* exported function */ -int -evdns_server_request_add_cname_reply(struct evdns_server_request *req, const char *name, const char *cname, int ttl) -{ - return evdns_server_request_add_reply( - req, EVDNS_ANSWER_SECTION, name, TYPE_CNAME, CLASS_INET, - ttl, -1, 1, cname); -} - -/* exported function */ -void -evdns_server_request_set_flags(struct evdns_server_request *exreq, int flags) -{ - struct server_request *req = TO_SERVER_REQUEST(exreq); - req->base.flags &= ~(EVDNS_FLAGS_AA|EVDNS_FLAGS_RD); - req->base.flags |= flags; -} - -static int -evdns_server_request_format_response(struct server_request *req, int err) -{ - unsigned char buf[1500]; - size_t buf_len = sizeof(buf); - off_t j = 0, r; - u16 _t; - u32 _t32; - int i; - u16 flags; - struct dnslabel_table table; - - if (err < 0 || err > 15) return -1; - - /* Set response bit and error code; copy OPCODE and RD fields from - * question; copy RA and AA if set by caller. */ - flags = req->base.flags; - flags |= (0x8000 | err); - - dnslabel_table_init(&table); - APPEND16(req->trans_id); - APPEND16(flags); - APPEND16(req->base.nquestions); - APPEND16(req->n_answer); - APPEND16(req->n_authority); - APPEND16(req->n_additional); - - /* Add questions. */ - for (i=0; i < req->base.nquestions; ++i) { - const char *s = req->base.questions[i]->name; - j = dnsname_to_labels(buf, buf_len, j, s, strlen(s), &table); - if (j < 0) { - dnslabel_clear(&table); - return (int) j; - } - APPEND16(req->base.questions[i]->type); - APPEND16(req->base.questions[i]->dns_question_class); - } - - /* Add answer, authority, and additional sections. */ - for (i=0; i<3; ++i) { - struct server_reply_item *item; - if (i==0) - item = req->answer; - else if (i==1) - item = req->authority; - else - item = req->additional; - while (item) { - r = dnsname_to_labels(buf, buf_len, j, item->name, strlen(item->name), &table); - if (r < 0) - goto overflow; - j = r; - - APPEND16(item->type); - APPEND16(item->dns_question_class); - APPEND32(item->ttl); - if (item->is_name) { - off_t len_idx = j, name_start; - j += 2; - name_start = j; - r = dnsname_to_labels(buf, buf_len, j, item->data, strlen(item->data), &table); - if (r < 0) - goto overflow; - j = r; - _t = htons( (short) (j-name_start) ); - memcpy(buf+len_idx, &_t, 2); - } else { - APPEND16(item->datalen); - if (j+item->datalen > (off_t)buf_len) - goto overflow; - memcpy(buf+j, item->data, item->datalen); - j += item->datalen; - } - item = item->next; - } - } - - if (j > 512) { -overflow: - j = 512; - buf[2] |= 0x02; /* set the truncated bit. */ - } - - req->response_len = j; - - if (!(req->response = g_malloc(req->response_len))) { - server_request_free_answers(req); - dnslabel_clear(&table); - return (-1); - } - memcpy(req->response, buf, req->response_len); - server_request_free_answers(req); - dnslabel_clear(&table); - return (0); -} - -/* exported function */ -int -evdns_server_request_respond(struct evdns_server_request *_req, int err) -{ - struct server_request *req = TO_SERVER_REQUEST(_req); - struct evdns_server_port *port = req->port; - int r = -1; - - if (!req->response) { - if ((r = evdns_server_request_format_response(req, err))<0) - goto done; - } - - r = sendto(port->socket, req->response, req->response_len, 0, - (struct sockaddr*) &req->addr, req->addrlen); - if (r<0) { - if (port->pending_replies) { - req->prev_pending = port->pending_replies->prev_pending; - req->next_pending = port->pending_replies; - req->prev_pending->next_pending = - req->next_pending->prev_pending = req; - } else { - req->prev_pending = req->next_pending = req; - port->pending_replies = req; - port->choked = 1; - - (void) event_del(&port->event); - event_assign(&port->event, port->event_base, port->socket, (port->closing?0:EV_READ) | EV_WRITE | EV_PERSIST, server_port_ready_callback, port); - - if (event_add(&port->event, NULL) < 0) { - msg_warn("Error from libevent when adding event for DNS server"); - } - - } - - r = 1; - goto done; - } - if (server_request_free(req)) { - r = 0; - goto done; - } - - if (port->pending_replies) - server_port_flush(port); - - r = 0; -done: - return r; -} - -/* Free all storage held by RRs in req. */ -static void -server_request_free_answers(struct server_request *req) -{ - struct server_reply_item *victim, *next, **list; - int i; - for (i = 0; i < 3; ++i) { - if (i==0) - list = &req->answer; - else if (i==1) - list = &req->authority; - else - list = &req->additional; - - victim = *list; - while (victim) { - next = victim->next; - g_free(victim->name); - if (victim->data) - g_free(victim->data); - g_free(victim); - victim = next; - } - *list = NULL; - } -} - -/* Free all storage held by req, and remove links to it. */ -/* return true iff we just wound up freeing the server_port. */ -static int -server_request_free(struct server_request *req) -{ - int i, rc=1, lock=0; - if (req->base.questions) { - for (i = 0; i < req->base.nquestions; ++i) - g_free(req->base.questions[i]); - g_free(req->base.questions); - } - - if (req->port) { - lock=1; - if (req->port->pending_replies == req) { - if (req->next_pending) - req->port->pending_replies = req->next_pending; - else - req->port->pending_replies = NULL; - } - rc = --req->port->refcnt; - } - - if (req->response) { - g_free(req->response); - } - - server_request_free_answers(req); - - if (req->next_pending && req->next_pending != req) { - req->next_pending->prev_pending = req->prev_pending; - req->prev_pending->next_pending = req->next_pending; - } - - if (rc == 0) { - server_port_free(req->port); - g_free(req); - return (1); - } - g_free(req); - return (0); -} - -/* Free all storage held by an evdns_server_port. Only called when */ -static void -server_port_free(struct evdns_server_port *port) -{ - g_assert(port); - g_assert(!port->refcnt); - g_assert(!port->pending_replies); - if (port->socket > 0) { - CLOSE_SOCKET(port->socket); - port->socket = -1; - } - (void) event_del(&port->event); - g_free(port); -} - -/* exported function */ -int -evdns_server_request_drop(struct evdns_server_request *_req) -{ - struct server_request *req = TO_SERVER_REQUEST(_req); - server_request_free(req); - return 0; -} - -/* exported function */ -int -evdns_server_request_get_requesting_addr(struct evdns_server_request *_req, struct sockaddr *sa, int addr_len) -{ - struct server_request *req = TO_SERVER_REQUEST(_req); - if (addr_len < (int)req->addrlen) - return -1; - memcpy(sa, &(req->addr), req->addrlen); - return req->addrlen; -} - -#undef APPEND16 -#undef APPEND32 - -/* this is a libevent callback function which is called when a request */ -/* has timed out. */ -static void -evdns_request_timeout_callback(int fd, short events, void *arg) { - struct evdns_request *const req = (struct evdns_request *) arg; - (void) fd; - (void) events; - - - req->ns->timedout++; - if (req->ns->timedout > req->base->global_max_nameserver_timeout) { - req->ns->timedout = 0; - nameserver_failed(req->ns, "request timed out."); - } - - if (req->tx_count >= req->base->global_max_retransmits) { - /* this request has failed */ - reply_callback(req, 0, DNS_ERR_TIMEOUT, NULL); - request_finished(req, &REQ_HEAD(req->base, req->trans_id)); - } else { - /* retransmit it */ - (void) evtimer_del(&req->timeout_event); - evdns_request_transmit(req); - } -} - -/* try to send a request to a given server. */ -/* */ -/* return: */ -/* 0 ok */ -/* 1 temporary failure */ -/* 2 other failure */ -static int -evdns_request_transmit_to(struct evdns_request *req, struct nameserver *server) { - int r; - r = sendto(server->socket, req->request, req->request_len, 0, - (struct sockaddr *)&server->address, server->addrlen); - if (r < 0) { - int err = evutil_socket_geterror(server->socket); - nameserver_failed(req->ns, evutil_socket_error_to_string(err)); - return 2; - } else if (r != (int)req->request_len) { - return 1; /* short write */ - } else { - return 0; - } -} - -/* try to send a request, updating the fields of the request */ -/* as needed */ -/* */ -/* return: */ -/* 0 ok */ -/* 1 failed */ -static int -evdns_request_transmit(struct evdns_request *req) { - int retcode = 0, r; - - /* if we fail to send this packet then this flag marks it */ - /* for evdns_transmit */ - req->transmit_me = 1; - if (req->trans_id == 0xffff) abort(); - - if (req->ns->choked) { - /* don't bother trying to write to a socket */ - /* which we have had EAGAIN from */ - return 1; - } - - r = evdns_request_transmit_to(req, req->ns); - switch (r) { - case 1: - /* temp failure */ - req->ns->choked = 1; - nameserver_write_waiting(req->ns, 1); - return 1; - case 2: - /* failed to transmit the request entirely. */ - retcode = 1; - /* fall through: we'll set a timeout, which will time out, - * and make us retransmit the request anyway. */ - default: - /* all ok */ - if (evtimer_add(&req->timeout_event, &req->base->global_timeout) < 0) { - msg_warn( - "Error from libevent when adding timer for request %lx", - (unsigned long) req); - /* ???? Do more? */ - } - req->tx_count++; - req->transmit_me = 0; - return retcode; - } -} - -static void -nameserver_probe_callback(int result, char type, int count, int ttl, void *addresses, void *arg) { - struct nameserver *const ns = (struct nameserver *) arg; - (void) type; - (void) count; - (void) ttl; - (void) addresses; - - ns->probe_request = NULL; - if (result == DNS_ERR_CANCEL) { - /* We canceled this request because the nameserver came up - * for some other reason. Do not change our opinion about - * the nameserver. */ - } else if (result == DNS_ERR_NONE || result == DNS_ERR_NOTEXIST) { - /* this is a good reply */ - nameserver_up(ns); - } else { - nameserver_probe_failed(ns); - } -} - -static void -nameserver_send_probe(struct nameserver *const ns) { - struct evdns_request *req; - /* here we need to send a probe to a given nameserver */ - /* in the hope that it is up now. */ - - - req = request_new(ns->base, TYPE_A, "google.com", DNS_QUERY_NO_SEARCH, nameserver_probe_callback, ns); - if (!req) return; - ns->probe_request = req; - /* we force this into the inflight queue no matter what */ - request_trans_id_set(req, transaction_id_pick(ns->base)); - req->ns = ns; - request_submit(req); -} - -/* returns: */ -/* 0 didn't try to transmit anything */ -/* 1 tried to transmit something */ -static int -evdns_transmit(struct evdns_base *base) { - char did_try_to_transmit = 0; - int i; - - for (i = 0; i < base->n_req_heads; ++i) { - if (base->req_heads[i]) { - struct evdns_request *const started_at = base->req_heads[i], *req = started_at; - /* first transmit all the requests which are currently waiting */ - do { - if (req->transmit_me) { - did_try_to_transmit = 1; - evdns_request_transmit(req); - } - - req = req->next; - } while (req != started_at); - } - } - - return did_try_to_transmit; -} - -/* exported function */ -int -evdns_base_count_nameservers(struct evdns_base *base) -{ - const struct nameserver *server; - int n = 0; - - server = base->server_head; - if (!server) - goto done; - do { - ++n; - server = server->next; - } while (server != base->server_head); -done: - return n; -} - -int -evdns_count_nameservers(void) -{ - return evdns_base_count_nameservers(current_base); -} - -/* exported function */ -int -evdns_base_clear_nameservers_and_suspend(struct evdns_base *base) -{ - struct nameserver *server, *started_at; - int i; - - server = base->server_head; - started_at = base->server_head; - if (!server) { - return 0; - } - while (1) { - struct nameserver *next = server->next; - (void) event_del(&server->event); - if (evtimer_initialized(&server->timeout_event)) - (void) evtimer_del(&server->timeout_event); - if (server->socket >= 0) - CLOSE_SOCKET(server->socket); - g_free(server); - if (next == started_at) - break; - server = next; - } - base->server_head = NULL; - base->global_good_nameservers = 0; - - for (i = 0; i < base->n_req_heads; ++i) { - struct evdns_request *req, *req_started_at; - req = req_started_at = base->req_heads[i]; - while (req) { - struct evdns_request *next = req->next; - req->tx_count = req->reissue_count = 0; - req->ns = NULL; - /* ???? What to do about searches? */ - (void) evtimer_del(&req->timeout_event); - req->trans_id = 0; - req->transmit_me = 0; - - base->global_requests_waiting++; - evdns_request_insert(req, &base->req_waiting_head); - /* We want to insert these suspended elements at the front of - * the waiting queue, since they were pending before any of - * the waiting entries were added. This is a circular list, - * so we can just shift the start back by one.*/ - base->req_waiting_head = base->req_waiting_head->prev; - - if (next == req_started_at) - break; - req = next; - } - base->req_heads[i] = NULL; - } - - base->global_requests_inflight = 0; - - return 0; -} - -int -evdns_clear_nameservers_and_suspend(void) -{ - return evdns_base_clear_nameservers_and_suspend(current_base); -} - - -/* exported function */ -int -evdns_base_resume(struct evdns_base *base) -{ - evdns_requests_pump_waiting_queue(base); - return 0; -} - -int -evdns_resume(void) -{ - return evdns_base_resume(current_base); -} - -static int -_evdns_nameserver_add_impl(struct evdns_base *base, const struct sockaddr *address, int addrlen) { - /* first check to see if we already have this nameserver */ - - const struct nameserver *server = base->server_head, *const started_at = base->server_head; - struct nameserver *ns; - int err = 0; - - if (server) { - do { - if (!evutil_sockaddr_cmp((struct sockaddr*)&server->address, address, 1)) return 3; - server = server->next; - } while (server != started_at); - } - if (addrlen > (int)sizeof(ns->address)) { - return 2; - } - - ns = (struct nameserver *) g_malloc(sizeof(struct nameserver)); - if (!ns) return -1; - - memset(ns, 0, sizeof(struct nameserver)); - ns->base = base; - - evtimer_assign(&ns->timeout_event, ns->base->event_base, nameserver_prod_callback, ns); - - ns->socket = socket(PF_INET, SOCK_DGRAM, 0); - if (ns->socket < 0) { err = 1; goto out1; } - make_socket_nonblocking(ns->socket); - - if (base->global_outgoing_addrlen) { - if (bind(ns->socket, - (struct sockaddr*)&base->global_outgoing_address, - base->global_outgoing_addrlen) < 0) { - msg_warn("Couldn't bind to outgoing address"); - err = 2; - goto out2; - } - } - - memcpy(&ns->address, address, addrlen); - ns->addrlen = addrlen; - ns->state = 1; - event_assign(&ns->event, ns->base->event_base, ns->socket, EV_READ | EV_PERSIST, nameserver_ready_callback, ns); - if (event_add(&ns->event, NULL) < 0) { - err = 2; - goto out2; - } - - - /* insert this nameserver into the list of them */ - if (!base->server_head) { - ns->next = ns->prev = ns; - base->server_head = ns; - } else { - ns->next = base->server_head->next; - ns->prev = base->server_head; - base->server_head->next = ns; - if (base->server_head->prev == base->server_head) { - base->server_head->prev = ns; - } - } - - base->global_good_nameservers++; - - return 0; - -out2: - CLOSE_SOCKET(ns->socket); -out1: - g_free(ns); - msg_warn("error %d", debug_ntop(address), err); - return err; -} - -/* exported function */ -int -evdns_base_nameserver_add(struct evdns_base *base, - unsigned long int address) -{ - struct sockaddr_in sin; - int res; - sin.sin_addr.s_addr = address; - sin.sin_port = htons(53); - sin.sin_family = AF_INET; - res = _evdns_nameserver_add_impl(base, (struct sockaddr*)&sin, sizeof(sin)); - return res; -} - -int -evdns_nameserver_add(unsigned long int address) { - if (!current_base) - current_base = evdns_base_new(NULL, 0); - return evdns_base_nameserver_add(current_base, address); -} - -/* exported function */ -int -evdns_base_nameserver_ip_add(struct evdns_base *base, const char *ip_as_string) { - struct sockaddr_storage ss; - struct sockaddr *sa; - int len = sizeof(ss); - int res; - if (evutil_parse_sockaddr_port(ip_as_string, (struct sockaddr *)&ss, - &len)) { - msg_warn("Unable to parse nameserver address %s", - ip_as_string); - return 4; - } - sa = (struct sockaddr *) &ss; - if (sa->sa_family == AF_INET) { - struct sockaddr_in *sin = (struct sockaddr_in *)sa; - if (sin->sin_port == 0) - sin->sin_port = htons(53); - } -#ifdef AF_INET6 - else if (sa->sa_family == AF_INET6) { - struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sa; - if (sin6->sin6_port == 0) - sin6->sin6_port = htons(53); - } -#endif - else - return -1; - - res = _evdns_nameserver_add_impl(base, sa, len); - return res; -} - -int -evdns_nameserver_ip_add(const char *ip_as_string) { - if (!current_base) - current_base = evdns_base_new(NULL, 0); - return evdns_base_nameserver_ip_add(current_base, ip_as_string); -} - -/* remove from the queue */ -static void -evdns_request_remove(struct evdns_request *req, struct evdns_request **head) -{ - -#if 0 - { - struct evdns_request *ptr; - int found = 0; - g_assert(*head != NULL); - - ptr = *head; - do { - if (ptr == req) { - found = 1; - break; - } - ptr = ptr->next; - } while (ptr != *head); - g_assert(found); - - g_assert(req->next); - } -#endif - - if (req->next == req) { - /* only item in the list */ - *head = NULL; - } else { - req->next->prev = req->prev; - req->prev->next = req->next; - if (*head == req) *head = req->next; - } - req->next = req->prev = NULL; -} - -/* insert into the tail of the queue */ -static void -evdns_request_insert(struct evdns_request *req, struct evdns_request **head) { - if (!*head) { - *head = req; - req->next = req->prev = req; - return; - } - - req->prev = (*head)->prev; - req->prev->next = req; - req->next = *head; - (*head)->prev = req; -} - -static int -string_num_dots(const char *s) { - int count = 0; - while ((s = strchr(s, '.'))) { - s++; - count++; - } - return count; -} - -static struct evdns_request * -request_new(struct evdns_base *base, int type, const char *name, int flags, - evdns_callback_type callback, void *user_ptr) { - - const char issuing_now = - (base->global_requests_inflight < base->global_max_requests_inflight) ? 1 : 0; - - const size_t name_len = strlen(name); - const size_t request_max_len = evdns_request_len(name_len); - const u16 trans_id = issuing_now ? transaction_id_pick(base) : 0xffff; - /* the request data is alloced in a single block with the header */ - struct evdns_request *const req = - g_malloc(sizeof(struct evdns_request) + request_max_len); - int rlen; - char namebuf[256]; - (void) flags; - - - if (!req) return NULL; - - if (name_len >= sizeof(namebuf)) { - free(req); - return NULL; - } - - memset(req, 0, sizeof(struct evdns_request)); - req->base = base; - - evtimer_assign(&req->timeout_event, req->base->event_base, evdns_request_timeout_callback, req); - - if (base->global_randomize_case) { - unsigned i; - char randbits[(sizeof(namebuf)+7)/8]; - rspamd_strlcpy(namebuf, name, sizeof(namebuf)); - rand_bytes_function(randbits, (name_len+7)/8); - for (i = 0; i < name_len; ++i) { - if (g_ascii_isalpha(namebuf[i])) { - if ((randbits[i >> 3] & (1<<(i & 7)))) - namebuf[i] |= 0x20; - else - namebuf[i] &= ~0x20; - } - } - name = namebuf; - } - - /* request data lives just after the header */ - req->request = ((u8 *) req) + sizeof(struct evdns_request); - /* denotes that the request data shouldn't be free()ed */ - req->request_appended = 1; - rlen = evdns_request_data_build(name, name_len, trans_id, - type, CLASS_INET, req->request, request_max_len); - if (rlen < 0) - goto err1; - - req->request_len = rlen; - req->trans_id = trans_id; - req->tx_count = 0; - req->request_type = type; - req->user_pointer = user_ptr; - req->user_callback = callback; - req->ns = issuing_now ? nameserver_pick(base) : NULL; - req->next = req->prev = NULL; - - return req; -err1: - g_free(req); - return NULL; -} - -static void -request_submit(struct evdns_request *const req) { - struct evdns_base *base = req->base; - if (req->ns) { - /* if it has a nameserver assigned then this is going */ - /* straight into the inflight queue */ - evdns_request_insert(req, &REQ_HEAD(base, req->trans_id)); - base->global_requests_inflight++; - evdns_request_transmit(req); - } else { - evdns_request_insert(req, &base->req_waiting_head); - base->global_requests_waiting++; - } -} - -/* exported function */ -void -evdns_cancel_request(struct evdns_base *base, struct evdns_request *req) -{ - if (!base) - base = req->base; - - reply_callback(req, 0, DNS_ERR_CANCEL, NULL); - if (req->ns) { - /* remove from inflight queue */ - request_finished(req, &REQ_HEAD(base, req->trans_id)); - } else { - /* remove from global_waiting head */ - request_finished(req, &base->req_waiting_head); - } -} - -/* exported function */ -struct evdns_request * -evdns_base_resolve_ipv4(struct evdns_base *base, const char *name, int flags, - evdns_callback_type callback, void *ptr) { - struct evdns_request *req; - if (flags & DNS_QUERY_NO_SEARCH) { - req = - request_new(base, TYPE_A, name, flags, callback, ptr); - if (req) - request_submit(req); - } else { - req = search_request_new(base, TYPE_A, name, flags, callback, ptr); - } - return req; -} - -int evdns_resolve_ipv4(const char *name, int flags, - evdns_callback_type callback, void *ptr) -{ - return evdns_base_resolve_ipv4(current_base, name, flags, callback, ptr) - ? 0 : -1; -} - - -/* exported function */ -struct evdns_request * -evdns_base_resolve_ipv6(struct evdns_base *base, - const char *name, int flags, - evdns_callback_type callback, void *ptr) -{ - struct evdns_request *req; - if (flags & DNS_QUERY_NO_SEARCH) { - req = request_new(base, TYPE_AAAA, name, flags, callback, ptr); - if (req) - request_submit(req); - } else { - req = search_request_new(base,TYPE_AAAA, name, flags, callback, ptr); - } - return req; -} - -int evdns_resolve_ipv6(const char *name, int flags, - evdns_callback_type callback, void *ptr) { - return evdns_base_resolve_ipv6(current_base, name, flags, callback, ptr) - ? 0 : -1; -} - -struct evdns_request * -evdns_base_resolve_reverse(struct evdns_base *base, const struct in_addr *in, int flags, evdns_callback_type callback, void *ptr) { - char buf[32]; - struct evdns_request *req; - u32 a; - g_assert(in); - a = ntohl(in->s_addr); - snprintf(buf, sizeof(buf), "%d.%d.%d.%d.in-addr.arpa", - (int)(u8)((a )&0xff), - (int)(u8)((a>>8 )&0xff), - (int)(u8)((a>>16)&0xff), - (int)(u8)((a>>24)&0xff)); - req = request_new(base, TYPE_PTR, buf, flags, callback, ptr); - if (req) - request_submit(req); - return (req); -} - -int evdns_resolve_reverse(const struct in_addr *in, int flags, evdns_callback_type callback, void *ptr) { - return evdns_base_resolve_reverse(current_base, in, flags, callback, ptr) - ? 0 : -1; -} - -struct evdns_request * -evdns_base_resolve_reverse_ipv6(struct evdns_base *base, const struct in6_addr *in, int flags, evdns_callback_type callback, void *ptr) { - /* 32 nybbles, 32 periods, "ip6.arpa", NUL. */ - char buf[73]; - char *cp; - struct evdns_request *req; - int i; - g_assert(in); - cp = buf; - for (i=15; i >= 0; --i) { - u8 byte = in->s6_addr[i]; - *cp++ = "0123456789abcdef"[byte & 0x0f]; - *cp++ = '.'; - *cp++ = "0123456789abcdef"[byte >> 4]; - *cp++ = '.'; - } - g_assert(cp + strlen("ip6.arpa") < buf+sizeof(buf)); - memcpy(cp, "ip6.arpa", strlen("ip6.arpa")+1); - req = request_new(base, TYPE_PTR, buf, flags, callback, ptr); - if (req) - request_submit(req); - return (req); -} - -int evdns_resolve_reverse_ipv6(const struct in6_addr *in, int flags, evdns_callback_type callback, void *ptr) { - return evdns_base_resolve_reverse_ipv6(current_base, in, flags, callback, ptr) - ? 0 : -1; -} - -int -evdns_resolve_txt(const char *in, int flags, evdns_callback_type callback, void *ptr) { - struct evdns_request *req; - g_assert(in); - req = request_new(current_base, TYPE_TXT, in, flags, callback, ptr); - if (!req) return 1; - request_submit(req); - return 0; -} - -int -evdns_resolve_mx(const char *in, int flags, evdns_callback_type callback, void *ptr) { - struct evdns_request *req; - g_assert(in); - req = request_new(current_base, TYPE_MX, in, flags, callback, ptr); - if (!req) return 1; - request_submit(req); - return 0; -} - - -/*/////////////////////////////////////////////////////////////////// */ -/* Search support */ -/* */ -/* the libc resolver has support for searching a number of domains */ -/* to find a name. If nothing else then it takes the single domain */ -/* from the gethostname() call. */ -/* */ -/* It can also be configured via the domain and search options in a */ -/* resolv.conf. */ -/* */ -/* The ndots option controls how many dots it takes for the resolver */ -/* to decide that a name is non-local and so try a raw lookup first. */ - -struct search_domain { - int len; - struct search_domain *next; - /* the text string is appended to this structure */ -}; - -struct search_state { - int refcount; - int ndots; - int num_domains; - struct search_domain *head; -}; - -static void -search_state_decref(struct search_state *const state) { - if (!state) return; - state->refcount--; - if (!state->refcount) { - struct search_domain *next, *dom; - for (dom = state->head; dom; dom = next) { - next = dom->next; - g_free(dom); - } - g_free(state); - } -} - -static struct search_state * -search_state_new(void) { - struct search_state *state = (struct search_state *) g_malloc(sizeof(struct search_state)); - if (!state) return NULL; - memset(state, 0, sizeof(struct search_state)); - state->refcount = 1; - state->ndots = 1; - - return state; -} - -static void -search_postfix_clear(struct evdns_base *base) { - search_state_decref(base->global_search_state); - - base->global_search_state = search_state_new(); -} - -/* exported function */ -void -evdns_base_search_clear(struct evdns_base *base) -{ - search_postfix_clear(base); -} - -void -evdns_search_clear(void) { - evdns_base_search_clear(current_base); -} - -static void -search_postfix_add(struct evdns_base *base, const char *domain) { - int domain_len; - struct search_domain *sdomain; - while (domain[0] == '.') domain++; - domain_len = strlen(domain); - - if (!base->global_search_state) base->global_search_state = search_state_new(); - if (!base->global_search_state) return; - base->global_search_state->num_domains++; - - sdomain = (struct search_domain *) g_malloc(sizeof(struct search_domain) + domain_len); - if (!sdomain) return; - memcpy( ((u8 *) sdomain) + sizeof(struct search_domain), domain, domain_len); - sdomain->next = base->global_search_state->head; - sdomain->len = domain_len; - - base->global_search_state->head = sdomain; -} - -/* reverse the order of members in the postfix list. This is needed because, */ -/* when parsing resolv.conf we push elements in the wrong order */ -static void -search_reverse(struct evdns_base *base) { - struct search_domain *cur, *prev = NULL, *next; - cur = base->global_search_state->head; - while (cur) { - next = cur->next; - cur->next = prev; - prev = cur; - cur = next; - } - - base->global_search_state->head = prev; -} - -/* exported function */ -void -evdns_base_search_add(struct evdns_base *base, const char *domain) { - search_postfix_add(base, domain); -} -void -evdns_search_add(const char *domain) { - evdns_base_search_add(current_base, domain); -} - -/* exported function */ -void -evdns_base_search_ndots_set(struct evdns_base *base, const int ndots) { - if (!base->global_search_state) base->global_search_state = search_state_new(); - if (base->global_search_state) - base->global_search_state->ndots = ndots; -} -void -evdns_search_ndots_set(const int ndots) { - evdns_base_search_ndots_set(current_base, ndots); -} - -static void -search_set_from_hostname(struct evdns_base *base) { - char hostname[HOST_NAME_MAX + 1], *domainname; - - search_postfix_clear(base); - if (gethostname(hostname, sizeof(hostname))) return; - domainname = strchr(hostname, '.'); - if (!domainname) return; - search_postfix_add(base, domainname); -} - -/* warning: returns malloced string */ -static char * -search_make_new(const struct search_state *const state, int n, const char *const base_name) { - const int base_len = strlen(base_name); - const char need_to_append_dot = base_name[base_len - 1] == '.' ? 0 : 1; - struct search_domain *dom; - - for (dom = state->head; dom; dom = dom->next) { - if (!n--) { - /* this is the postfix we want */ - /* the actual postfix string is kept at the end of the structure */ - const u8 *const postfix = ((u8 *) dom) + sizeof(struct search_domain); - const int postfix_len = dom->len; - char *const newname = (char *) g_malloc(base_len + need_to_append_dot + postfix_len + 1); - if (!newname) return NULL; - memcpy(newname, base_name, base_len); - if (need_to_append_dot) newname[base_len] = '.'; - memcpy(newname + base_len + need_to_append_dot, postfix, postfix_len); - newname[base_len + need_to_append_dot + postfix_len] = 0; - return newname; - } - } - - /* we ran off the end of the list and still didn't find the requested string */ - abort(); - return NULL; /* unreachable; stops warnings in some compilers. */ -} - -static struct evdns_request * -search_request_new(struct evdns_base *base, int type, const char *const name, int flags, evdns_callback_type user_callback, void *user_arg) { - g_assert(type == TYPE_A || type == TYPE_AAAA); - if ( ((flags & DNS_QUERY_NO_SEARCH) == 0) && - base->global_search_state && - base->global_search_state->num_domains) { - /* we have some domains to search */ - struct evdns_request *req; - if (string_num_dots(name) >= base->global_search_state->ndots) { - req = request_new(base, type, name, flags, user_callback, user_arg); - if (!req) return NULL; - req->search_index = -1; - } else { - char *const new_name = search_make_new(base->global_search_state, 0, name); - if (!new_name) return NULL; - req = request_new(base, type, new_name, flags, user_callback, user_arg); - g_free(new_name); - if (!req) return NULL; - req->search_index = 0; - } - req->search_origname = g_strdup(name); - req->search_state = base->global_search_state; - req->search_flags = flags; - base->global_search_state->refcount++; - request_submit(req); - return req; - } else { - struct evdns_request *const req = request_new(base, type, name, flags, user_callback, user_arg); - if (!req) return NULL; - request_submit(req); - return req; - } -} - -/* if it is part of a search and, if so, try the next name in the list */ -/* returns: */ -/* 0 another request has been submitted */ -/* 1 no more requests needed */ -static int -search_try_next(struct evdns_request *const req) { - struct evdns_base *base = req->base; - if (req->search_state) { - /* it is part of a search */ - char *new_name; - struct evdns_request *newreq; - req->search_index++; - if (req->search_index >= req->search_state->num_domains) { - /* no more postfixes to try, however we may need to try */ - /* this name without a postfix */ - if (string_num_dots(req->search_origname) < req->search_state->ndots) { - /* yep, we need to try it raw */ - newreq = request_new(base, req->request_type, req->search_origname, req->search_flags, req->user_callback, req->user_pointer); - if (newreq) { - request_submit(newreq); - return 0; - } - } - return 1; - } - - new_name = search_make_new(req->search_state, req->search_index, req->search_origname); - if (!new_name) return 1; - newreq = request_new(base, req->request_type, new_name, req->search_flags, req->user_callback, req->user_pointer); - g_free(new_name); - if (!newreq) return 1; - newreq->search_origname = req->search_origname; - req->search_origname = NULL; - newreq->search_state = req->search_state; - newreq->search_flags = req->search_flags; - newreq->search_index = req->search_index; - newreq->search_state->refcount++; - request_submit(newreq); - return 0; - } - return 1; -} - -static void -search_request_finished(struct evdns_request *const req) { - if (req->search_state) { - search_state_decref(req->search_state); - req->search_state = NULL; - } - if (req->search_origname) { - g_free(req->search_origname); - req->search_origname = NULL; - } -} - -/*/////////////////////////////////////////////////////////////////// */ -/* Parsing resolv.conf files */ - -static void -evdns_resolv_set_defaults(struct evdns_base *base, int flags) { - /* if the file isn't found then we assume a local resolver */ - if (flags & DNS_OPTION_SEARCH) search_set_from_hostname(base); - if (flags & DNS_OPTION_NAMESERVERS) evdns_base_nameserver_ip_add(base,"127.0.0.1"); -} - - -/* helper version of atoi which returns -1 on error */ -static int -strtoint(const char *const str) -{ - char *endptr; - const int r = strtol(str, &endptr, 10); - if (*endptr) return -1; - return r; -} - -/* Parse a number of seconds into a timeval; return -1 on error. */ -static int -strtotimeval(const char *const str, struct timeval *out) -{ - double d; - char *endptr; - d = strtod(str, &endptr); - if (*endptr) return -1; - out->tv_sec = (int) d; - out->tv_usec = (int) ((d - (int) d)*1000000); - return 0; -} - -/* helper version of atoi that returns -1 on error and clips to bounds. */ -static int -strtoint_clipped(const char *const str, int min, int max) -{ - int r = strtoint(str); - if (r == -1) - return r; - else if (rmax) - return max; - else - return r; -} - -static int -evdns_base_set_max_requests_inflight(struct evdns_base *base, int maxinflight) -{ - int old_n_heads = base->n_req_heads, n_heads; - struct evdns_request **old_heads = base->req_heads, **new_heads, *req; - int i; - - if (maxinflight < 1) - maxinflight = 1; - n_heads = (maxinflight+4) / 5; - g_assert(n_heads > 0); - new_heads = g_malloc(n_heads * sizeof(struct evdns_request*)); - if (!new_heads) - return (-1); - for (i=0; i < n_heads; ++i) - new_heads[i] = NULL; - if (old_heads) { - for (i = 0; i < old_n_heads; ++i) { - while (old_heads[i]) { - req = old_heads[i]; - evdns_request_remove(req, &old_heads[i]); - evdns_request_insert(req, &new_heads[req->trans_id % n_heads]); - } - } - g_free(old_heads); - } - base->req_heads = new_heads; - base->n_req_heads = n_heads; - base->global_max_requests_inflight = maxinflight; - return (0); -} - -/* exported function */ -int -evdns_base_set_option(struct evdns_base *base, - const char *option, const char *val, int flags) -{ - int res; - res = evdns_base_set_option_impl(base, option, val, flags); - return res; -} - -static int -evdns_base_set_option_impl(struct evdns_base *base, - const char *option, const char *val, int flags) -{ - if (!strncmp(option, "ndots:", 6)) { - const int ndots = strtoint(val); - if (ndots == -1) return -1; - if (!(flags & DNS_OPTION_SEARCH)) return 0; - if (!base->global_search_state) base->global_search_state = search_state_new(); - if (!base->global_search_state) return -1; - base->global_search_state->ndots = ndots; - } else if (!strncmp(option, "timeout:", 8)) { - struct timeval tv; - if (strtotimeval(val, &tv) == -1) return -1; - if (!(flags & DNS_OPTION_MISC)) return 0; - memcpy(&base->global_timeout, &tv, sizeof(struct timeval)); - } else if (!strncmp(option, "max-timeouts:", 12)) { - const int maxtimeout = strtoint_clipped(val, 1, 255); - if (maxtimeout == -1) return -1; - if (!(flags & DNS_OPTION_MISC)) return 0; - base->global_max_nameserver_timeout = maxtimeout; - } else if (!strncmp(option, "max-inflight:", 13)) { - const int maxinflight = strtoint_clipped(val, 1, 65000); - if (maxinflight == -1) return -1; - if (!(flags & DNS_OPTION_MISC)) return 0; - evdns_base_set_max_requests_inflight(base, maxinflight); - } else if (!strncmp(option, "attempts:", 9)) { - int retries = strtoint(val); - if (retries == -1) return -1; - if (retries > 255) retries = 255; - if (!(flags & DNS_OPTION_MISC)) return 0; - base->global_max_retransmits = retries; - } else if (!strncmp(option, "randomize-case:", 15)) { - int randcase = strtoint(val); - if (!(flags & DNS_OPTION_MISC)) return 0; - base->global_randomize_case = randcase; - } else if (!strncmp(option, "bind-to:", 8)) { - /* XXX This only applies to successive nameservers, not - * to already-configured ones. We might want to fix that. */ - int len = sizeof(base->global_outgoing_address); - if (!(flags & DNS_OPTION_NAMESERVERS)) return 0; - if (evutil_parse_sockaddr_port(val, - (struct sockaddr*)&base->global_outgoing_address, &len)) - return -1; - base->global_outgoing_addrlen = len; - } - return 0; -} - -int -evdns_set_option(const char *option, const char *val, int flags) -{ - return evdns_base_set_option(current_base, option, val, flags); -} - -static void -resolv_conf_parse_line(struct evdns_base *base, char *const start, int flags) { - char *strtok_state; - static const char *const delims = " \t"; -#define NEXT_TOKEN strtok_r(NULL, delims, &strtok_state) - - - char *const first_token = strtok_r(start, delims, &strtok_state); - if (!first_token) return; - - if (!strcmp(first_token, "nameserver") && (flags & DNS_OPTION_NAMESERVERS)) { - const char *const nameserver = NEXT_TOKEN; - - evdns_base_nameserver_ip_add(base, nameserver); - } else if (!strcmp(first_token, "domain") && (flags & DNS_OPTION_SEARCH)) { - const char *const domain = NEXT_TOKEN; - if (domain) { - search_postfix_clear(base); - search_postfix_add(base, domain); - } - } else if (!strcmp(first_token, "search") && (flags & DNS_OPTION_SEARCH)) { - const char *domain; - search_postfix_clear(base); - - while ((domain = NEXT_TOKEN)) { - search_postfix_add(base, domain); - } - search_reverse(base); - } else if (!strcmp(first_token, "options")) { - const char *option; - while ((option = NEXT_TOKEN)) { - const char *val = strchr(option, ':'); - evdns_base_set_option(base, option, val ? val+1 : "", flags); - } - } -#undef NEXT_TOKEN -} - -/* exported function */ -/* returns: */ -/* 0 no errors */ -/* 1 failed to open file */ -/* 2 failed to stat file */ -/* 3 file too large */ -/* 4 out of memory */ -/* 5 short read from file */ -int -evdns_base_resolv_conf_parse(struct evdns_base *base, int flags, const char *const filename) { - int res; - res = evdns_base_resolv_conf_parse_impl(base, flags, filename); - return res; -} - -static int -evdns_base_resolv_conf_parse_impl(struct evdns_base *base, int flags, const char *const filename) { - struct stat st; - int fd, n, r; - u8 *resolv; - char *start; - int err = 0; - - - fd = open(filename, O_RDONLY); - if (fd < 0) { - evdns_resolv_set_defaults(base, flags); - return 1; - } - - if (fstat(fd, &st)) { err = 2; goto out1; } - if (!st.st_size) { - evdns_resolv_set_defaults(base, flags); - err = (flags & DNS_OPTION_NAMESERVERS) ? 6 : 0; - goto out1; - } - if (st.st_size > 65535) { err = 3; goto out1; } /* no resolv.conf should be any bigger */ - - resolv = (u8 *) g_malloc((size_t)st.st_size + 1); - if (!resolv) { err = 4; goto out1; } - - n = 0; - while ((r = read(fd, resolv+n, (size_t)st.st_size-n)) > 0) { - n += r; - if (n == st.st_size) - break; - g_assert(n < st.st_size); - } - if (r < 0) { err = 5; goto out2; } - resolv[n] = 0; /* we malloced an extra byte; this should be fine. */ - - start = (char *) resolv; - for (;;) { - char *const newline = strchr(start, '\n'); - if (!newline) { - resolv_conf_parse_line(base, start, flags); - break; - } else { - *newline = 0; - resolv_conf_parse_line(base, start, flags); - start = newline + 1; - } - } - - if (!base->server_head && (flags & DNS_OPTION_NAMESERVERS)) { - /* no nameservers were configured. */ - evdns_base_nameserver_ip_add(base, "127.0.0.1"); - err = 6; - } - if (flags & DNS_OPTION_SEARCH && (!base->global_search_state || base->global_search_state->num_domains == 0)) { - search_set_from_hostname(base); - } - -out2: - g_free(resolv); -out1: - close(fd); - return err; -} - -int -evdns_resolv_conf_parse(int flags, const char *const filename) { - return evdns_base_resolv_conf_parse(current_base, flags, filename); -} - -struct evdns_base * -evdns_base_new(struct event_base *event_base, int initialize_nameservers) -{ - struct evdns_base *base; - base = g_malloc(sizeof(struct evdns_base)); - if (base == NULL) - return (NULL); - memset(base, 0, sizeof(struct evdns_base)); - base->req_waiting_head = NULL; - - - /* Set max requests inflight and allocate req_heads. */ - base->req_heads = NULL; - - evdns_base_set_max_requests_inflight(base, 64); - - base->server_head = NULL; - base->event_base = event_base; - base->global_good_nameservers = base->global_requests_inflight = - base->global_requests_waiting = 0; - - base->global_timeout.tv_sec = 5; - base->global_timeout.tv_usec = 0; - base->global_max_reissues = 1; - base->global_max_retransmits = 3; - base->global_max_nameserver_timeout = 3; - base->global_search_state = NULL; - base->global_randomize_case = 1; - - if (initialize_nameservers) { - int r; - r = evdns_base_resolv_conf_parse(base, DNS_OPTIONS_ALL, "/etc/resolv.conf"); - if (r == -1) { - evdns_base_free_and_unlock(base, 0); - return NULL; - } - } - return base; -} - -int -evdns_init(void) -{ - struct evdns_base *base = evdns_base_new(NULL, 1); - if (base) { - current_base = base; - return 0; - } else { - return -1; - } -} - -const char * -evdns_err_to_string(int err) -{ - switch (err) { - case DNS_ERR_NONE: return "no error"; - case DNS_ERR_FORMAT: return "misformatted query"; - case DNS_ERR_SERVERFAILED: return "server failed"; - case DNS_ERR_NOTEXIST: return "name does not exist"; - case DNS_ERR_NOTIMPL: return "query not implemented"; - case DNS_ERR_REFUSED: return "refused"; - - case DNS_ERR_TRUNCATED: return "reply truncated or ill-formed"; - case DNS_ERR_UNKNOWN: return "unknown"; - case DNS_ERR_TIMEOUT: return "request timed out"; - case DNS_ERR_SHUTDOWN: return "dns subsystem shut down"; - case DNS_ERR_CANCEL: return "dns request canceled"; - default: return "[Unknown error code]"; - } -} - -static void -evdns_base_free_and_unlock(struct evdns_base *base, int fail_requests) -{ - struct nameserver *server, *server_next; - struct search_domain *dom, *dom_next; - int i; - - /* Requires that we hold the lock. */ - - /* TODO(nickm) we might need to refcount here. */ - - for (i = 0; i < base->n_req_heads; ++i) { - while (base->req_heads[i]) { - if (fail_requests) - reply_callback(base->req_heads[i], 0, DNS_ERR_SHUTDOWN, NULL); - request_finished(base->req_heads[i], &REQ_HEAD(base, base->req_heads[i]->trans_id)); - } - } - while (base->req_waiting_head) { - if (fail_requests) - reply_callback(base->req_waiting_head, 0, DNS_ERR_SHUTDOWN, NULL); - request_finished(base->req_waiting_head, &base->req_waiting_head); - } - base->global_requests_inflight = base->global_requests_waiting = 0; - - for (server = base->server_head; server; server = server_next) { - server_next = server->next; - if (server->socket >= 0) - CLOSE_SOCKET(server->socket); - (void) event_del(&server->event); - if (server->state == 0) - (void) event_del(&server->timeout_event); - g_free(server); - if (server_next == base->server_head) - break; - } - base->server_head = NULL; - base->global_good_nameservers = 0; - - if (base->global_search_state) { - for (dom = base->global_search_state->head; dom; dom = dom_next) { - dom_next = dom->next; - g_free(dom); - } - g_free(base->global_search_state); - base->global_search_state = NULL; - } - - g_free(base); -} - -void -evdns_base_free(struct evdns_base *base, int fail_requests) -{ - evdns_base_free_and_unlock(base, fail_requests); -} - -void -evdns_shutdown(int fail_requests) -{ - if (current_base) { - struct evdns_base *b = current_base; - current_base = NULL; - evdns_base_free(b, fail_requests); - } -} diff --git a/src/evdns/evdns.h b/src/evdns/evdns.h deleted file mode 100644 index ded48f2ac..000000000 --- a/src/evdns/evdns.h +++ /dev/null @@ -1,774 +0,0 @@ -/* - * Copyright (c) 2000-2007 Niels Provos - * Copyright (c) 2007-2009 Niels Provos and Nick Mathewson - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * 1. Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * 2. Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in the - * documentation and/or other materials provided with the distribution. - * 3. The name of the author may not be used to endorse or promote products - * derived from this software without specific prior written permission. - * - * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR - * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES - * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. - * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, - * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT - * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, - * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY - * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT - * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF - * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. - */ -#ifndef _EVDNS_H_ -#define _EVDNS_H_ - -#include "../config.h" - -/** Error codes 0-5 are as described in RFC 1035. */ -#define DNS_ERR_NONE 0 -/** The name server was unable to interpret the query */ -#define DNS_ERR_FORMAT 1 -/** The name server was unable to process this query due to a problem with the - * name server */ -#define DNS_ERR_SERVERFAILED 2 -/** The domain name does not exist */ -#define DNS_ERR_NOTEXIST 3 -/** The name server does not support the requested kind of query */ -#define DNS_ERR_NOTIMPL 4 -/** The name server refuses to reform the specified operation for policy - * reasons */ -#define DNS_ERR_REFUSED 5 -/** The reply was truncated or ill-formatted */ -#define DNS_ERR_TRUNCATED 65 -/** An unknown error occurred */ -#define DNS_ERR_UNKNOWN 66 -/** Communication with the server timed out */ -#define DNS_ERR_TIMEOUT 67 -/** The request was canceled because the DNS subsystem was shut down. */ -#define DNS_ERR_SHUTDOWN 68 -/** The request was canceled via a call to evdns_cancel_request */ -#define DNS_ERR_CANCEL 69 - -#define DNS_IPv4_A 1 -#define DNS_PTR 2 -#define DNS_IPv6_AAAA 3 -#define DNS_TXT 4 -#define DNS_MX 15 - -#define DNS_QUERY_NO_SEARCH 1 - -#define DNS_OPTION_SEARCH 1 -#define DNS_OPTION_NAMESERVERS 2 -#define DNS_OPTION_MISC 4 -#define DNS_OPTIONS_ALL 7 - -/** - * The callback that contains the results from a lookup. - * - type is either DNS_IPv4_A or DNS_PTR or DNS_IPv6_AAAA - * - count contains the number of addresses of form type - * - ttl is the number of seconds the resolution may be cached for. - * - addresses needs to be cast according to type - */ -typedef void (*evdns_callback_type) (int result, char type, int count, int ttl, void *addresses, void *arg); - -struct evdns_base; -struct event_base; - -struct evdns_mx { - char *host; - int priority; -}; - -/** - Initialize the asynchronous DNS library. - - This function initializes support for non-blocking name resolution by - calling evdns_resolv_conf_parse() on UNIX and - evdns_config_windows_nameservers() on Windows. - - @param event_base the event base to associate the dns client with - @param initialize_nameservers 1 if resolve.conf processing should occur - @return 0 if successful, or -1 if an error occurred - @see evdns_base_free() - */ -struct evdns_base * evdns_base_new(struct event_base *event_base, int initialize_nameservers); - - -/** - Shut down the asynchronous DNS resolver and terminate all active requests. - - If the 'fail_requests' option is enabled, all active requests will return - an empty result with the error flag set to DNS_ERR_SHUTDOWN. Otherwise, - the requests will be silently discarded. - - @param evdns_base the evdns base to free - @param fail_requests if zero, active requests will be aborted; if non-zero, - active requests will return DNS_ERR_SHUTDOWN. - @see evdns_base_new() - */ -void evdns_base_free(struct evdns_base *base, int fail_requests); - -/** - Convert a DNS error code to a string. - - @param err the DNS error code - @return a string containing an explanation of the error code -*/ -const char *evdns_err_to_string(int err); - - -/** - Add a nameserver. - - The address should be an IPv4 address in network byte order. - The type of address is chosen so that it matches in_addr.s_addr. - - @param base the evdns_base to which to add the name server - @param address an IP address in network byte order - @return 0 if successful, or -1 if an error occurred - @see evdns_base_nameserver_ip_add() - */ -int evdns_base_nameserver_add(struct evdns_base *base, - unsigned long int address); - -/** - Get the number of configured nameservers. - - This returns the number of configured nameservers (not necessarily the - number of running nameservers). This is useful for double-checking - whether our calls to the various nameserver configuration functions - have been successful. - - @param base the evdns_base to which to apply this operation - @return the number of configured nameservers - @see evdns_base_nameserver_add() - */ -int evdns_base_count_nameservers(struct evdns_base *base); - -/** - Remove all configured nameservers, and suspend all pending resolves. - - Resolves will not necessarily be re-attempted until evdns_resume() is called. - - @param base the evdns_base to which to apply this operation - @return 0 if successful, or -1 if an error occurred - @see evdns_base_resume() - */ -int evdns_base_clear_nameservers_and_suspend(struct evdns_base *base); - - -/** - Resume normal operation and continue any suspended resolve requests. - - Re-attempt resolves left in limbo after an earlier call to - evdns_clear_nameservers_and_suspend(). - - @param base the evdns_base to which to apply this operation - @return 0 if successful, or -1 if an error occurred - @see evdns_base_clear_nameservers_and_suspend() - */ -int evdns_base_resume(struct evdns_base *base); - -/** - Add a nameserver. - - This function parses a n IPv4 or IPv6 address from a string and adds it as a - nameserver. It supports the following formats: - - [IPv6Address]:port - - [IPv6Address] - - IPv6Address - - IPv4Address:port - - IPv4Address - - If no port is specified, it defaults to 53. - - @param base the evdns_base to which to apply this operation - @return 0 if successful, or -1 if an error occurred - @see evdns_base_nameserver_add() - */ -int evdns_base_nameserver_ip_add(struct evdns_base *base, - const char *ip_as_string); - -struct evdns_request; - -/** - Lookup an A record for a given name. - - @param base the evdns_base to which to apply this operation - @param name a DNS hostname - @param flags either 0, or DNS_QUERY_NO_SEARCH to disable searching for this query. - @param callback a callback function to invoke when the request is completed - @param ptr an argument to pass to the callback function - @return an evdns_request object if successful, or NULL if an error occurred. - @see evdns_resolve_ipv6(), evdns_resolve_reverse(), evdns_resolve_reverse_ipv6(), evdns_cancel_request() - */ -struct evdns_request *evdns_base_resolve_ipv4(struct evdns_base *base, const char *name, int flags, evdns_callback_type callback, void *ptr); - -/** - Lookup an AAAA record for a given name. - - @param base the evdns_base to which to apply this operation - @param name a DNS hostname - @param flags either 0, or DNS_QUERY_NO_SEARCH to disable searching for this query. - @param callback a callback function to invoke when the request is completed - @param ptr an argument to pass to the callback function - @return an evdns_request object if successful, or NULL if an error occurred. - @see evdns_resolve_ipv4(), evdns_resolve_reverse(), evdns_resolve_reverse_ipv6(), evdns_cancel_request() - */ -struct evdns_request *evdns_base_resolve_ipv6(struct evdns_base *base, const char *name, int flags, evdns_callback_type callback, void *ptr); - -struct in_addr; -struct in6_addr; - -/** - Lookup a PTR record for a given IP address. - - @param base the evdns_base to which to apply this operation - @param in an IPv4 address - @param flags either 0, or DNS_QUERY_NO_SEARCH to disable searching for this query. - @param callback a callback function to invoke when the request is completed - @param ptr an argument to pass to the callback function - @return an evdns_request object if successful, or NULL if an error occurred. - @see evdns_resolve_reverse_ipv6(), evdns_cancel_request() - */ -struct evdns_request *evdns_base_resolve_reverse(struct evdns_base *base, const struct in_addr *in, int flags, evdns_callback_type callback, void *ptr); - - -/** - Lookup a PTR record for a given IPv6 address. - - @param base the evdns_base to which to apply this operation - @param in an IPv6 address - @param flags either 0, or DNS_QUERY_NO_SEARCH to disable searching for this query. - @param callback a callback function to invoke when the request is completed - @param ptr an argument to pass to the callback function - @return an evdns_request object if successful, or NULL if an error occurred. - @see evdns_resolve_reverse_ipv6(), evdns_cancel_request() - */ -struct evdns_request *evdns_base_resolve_reverse_ipv6(struct evdns_base *base, const struct in6_addr *in, int flags, evdns_callback_type callback, void *ptr); - -/** - Cancels a pending DNS resolution request. - - @param base the evdns_base that was used to make the request - @param req the evdns_request that was returned by calling a resolve function - @see evdns_base_resolve_ip4(), evdns_base_resolve_ipv6, evdns_base_resolve_reverse -*/ -void evdns_cancel_request(struct evdns_base *base, struct evdns_request *req); - -/** - Set the value of a configuration option. - - The currently available configuration options are: - - ndots, timeout, max-timeouts, max-inflight, attempts, randomize-case, - bind-to. - - The option name needs to end with a colon. - - @param base the evdns_base to which to apply this operation - @param option the name of the configuration option to be modified - @param val the value to be set - @param flags either 0 | DNS_OPTION_SEARCH | DNS_OPTION_MISC - @return 0 if successful, or -1 if an error occurred - */ -int evdns_base_set_option(struct evdns_base *base, const char *option, const char *val, int flags); - - -/** - Parse a resolv.conf file. - - The 'flags' parameter determines what information is parsed from the - resolv.conf file. See the man page for resolv.conf for the format of this - file. - - The following directives are not parsed from the file: sortlist, rotate, - no-check-names, inet6, debug. - - If this function encounters an error, the possible return values are: 1 = - failed to open file, 2 = failed to stat file, 3 = file too large, 4 = out of - memory, 5 = short read from file, 6 = no nameservers listed in the file - - @param base the evdns_base to which to apply this operation - @param flags any of DNS_OPTION_NAMESERVERS|DNS_OPTION_SEARCH|DNS_OPTION_MISC| - DNS_OPTIONS_ALL - @param filename the path to the resolv.conf file - @return 0 if successful, or various positive error codes if an error - occurred (see above) - @see resolv.conf(3), evdns_config_windows_nameservers() - */ -int evdns_base_resolv_conf_parse(struct evdns_base *base, int flags, const char *const filename); - - -/** - Obtain nameserver information using the Windows API. - - Attempt to configure a set of nameservers based on platform settings on - a win32 host. Preferentially tries to use GetNetworkParams; if that fails, - looks in the registry. - - @return 0 if successful, or -1 if an error occurred - @see evdns_resolv_conf_parse() - */ -#ifdef WIN32 -int evdns_base_config_windows_nameservers(struct evdns_base *); -#define EVDNS_BASE_CONFIG_WINDOWS_NAMESERVERS_IMPLEMENTED -#endif - - -/** - Clear the list of search domains. - */ -void evdns_base_search_clear(struct evdns_base *base); - - -/** - Add a domain to the list of search domains - - @param domain the domain to be added to the search list - */ -void evdns_base_search_add(struct evdns_base *base, const char *domain); - - -/** - Set the 'ndots' parameter for searches. - - Sets the number of dots which, when found in a name, causes - the first query to be without any search domain. - - @param ndots the new ndots parameter - */ -void evdns_base_search_ndots_set(struct evdns_base *base, const int ndots); - -/** - A callback that is invoked when a log message is generated - - @param is_warning indicates if the log message is a 'warning' - @param msg the content of the log message - */ -typedef void (*evdns_debug_log_fn_type)(int is_warning, const char *msg); - - -/** - Set the callback function to handle log messages. - - @param fn the callback to be invoked when a log message is generated - */ -void evdns_set_log_fn(evdns_debug_log_fn_type fn); - -/** - Set a callback that will be invoked to generate transaction IDs. By - default, we pick transaction IDs based on the current clock time, which - is bad for security. - - @param fn the new callback, or NULL to use the default. - */ -void evdns_set_transaction_id_fn(uint16_t (*fn)(void)); - -/** - Set a callback used to generate random bytes. By default, we use - the same function as passed to evdns_set_transaction_id_fn to generate - bytes two at a time. If a function is provided here, it's also used - to generate transaction IDs. -*/ -void evdns_set_random_bytes_fn(void (*fn)(char *, size_t)); - -#define DNS_NO_SEARCH 1 - -/* - * Functions used to implement a DNS server. - */ - -struct evdns_server_request; -struct evdns_server_question; - -/** - A callback to implement a DNS server. The callback function receives a DNS - request. It should then optionally add a number of answers to the reply - using the evdns_server_request_add_*_reply functions, before calling either - evdns_server_request_respond to send the reply back, or - evdns_server_request_drop to decline to answer the request. - - @param req A newly received request - @param user_data A pointer that was passed to - evdns_add_server_port_with_base(). - */ -typedef void (*evdns_request_callback_fn_type)(struct evdns_server_request *, void *); -#define EVDNS_ANSWER_SECTION 0 -#define EVDNS_AUTHORITY_SECTION 1 -#define EVDNS_ADDITIONAL_SECTION 2 - -#define EVDNS_TYPE_A 1 -#define EVDNS_TYPE_NS 2 -#define EVDNS_TYPE_CNAME 5 -#define EVDNS_TYPE_SOA 6 -#define EVDNS_TYPE_PTR 12 -#define EVDNS_TYPE_MX 15 -#define EVDNS_TYPE_TXT 16 -#define EVDNS_TYPE_AAAA 28 - -#define EVDNS_QTYPE_AXFR 252 -#define EVDNS_QTYPE_ALL 255 - -#define EVDNS_CLASS_INET 1 - -/* flags that can be set in answers; as part of the err parameter */ -#define EVDNS_FLAGS_AA 0x400 -#define EVDNS_FLAGS_RD 0x080 - -/** Create a new DNS server port. - - @param base The event base to handle events for the server port. - @param socket A UDP socket to accept DNS requests. - @param is_tcp Always 0 for now. - @param callback A function to invoke whenever we get a DNS request - on the socket. - @param user_data Data to pass to the callback. - @return an evdns_server_port structure for this server port. - */ -struct evdns_server_port *evdns_add_server_port_with_base(struct event_base *base, int socket, int is_tcp, evdns_request_callback_fn_type callback, void *user_data); -/** Close down a DNS server port, and free associated structures. */ -void evdns_close_server_port(struct evdns_server_port *port); - -/** Sets some flags in a reply we're building. - Allows setting of the AA or RD flags - */ -void evdns_server_request_set_flags(struct evdns_server_request *req, int flags); - -/* Functions to add an answer to an in-progress DNS reply. - */ -int evdns_server_request_add_reply(struct evdns_server_request *req, int section, const char *name, int type, int dns_class, int ttl, int datalen, int is_name, const char *data); -int evdns_server_request_add_a_reply(struct evdns_server_request *req, const char *name, int n, void *addrs, int ttl); -int evdns_server_request_add_aaaa_reply(struct evdns_server_request *req, const char *name, int n, void *addrs, int ttl); -int evdns_server_request_add_ptr_reply(struct evdns_server_request *req, struct in_addr *in, const char *inaddr_name, const char *hostname, int ttl); -int evdns_server_request_add_cname_reply(struct evdns_server_request *req, const char *name, const char *cname, int ttl); - -/** - Send back a response to a DNS request, and free the request structure. -*/ -int evdns_server_request_respond(struct evdns_server_request *req, int err); -/** - Free a DNS request without sending back a reply. -*/ -int evdns_server_request_drop(struct evdns_server_request *req); -struct sockaddr; -/** - Get the address that made a DNS request. - */ -int evdns_server_request_get_requesting_addr(struct evdns_server_request *_req, struct sockaddr *sa, int addr_len); - -/* - * Structures used to implement a DNS server. - */ - -struct evdns_server_request { - int flags; - int nquestions; - struct evdns_server_question **questions; -}; -struct evdns_server_question { - int type; -#ifdef __cplusplus - int dns_question_class; -#else - /* You should refer to this field as "dns_question_class". The - * name "class" works in C for backward compatibility, and will be - * removed in a future version. (1.5 or later). */ - int class; -#define dns_question_class class -#endif - char name[1]; -}; - -/** - Initialize the asynchronous DNS library. - - This function initializes support for non-blocking name resolution by - calling evdns_resolv_conf_parse() on UNIX and - evdns_config_windows_nameservers() on Windows. - - @deprecated This function is deprecated because it always uses the current - event base, and is easily confused by multiple calls to event_init(), and - so is not safe for multithreaded use. Additionally, it allocates a global - structure that only one thread can use. The replacement is - evdns_base_new(). - - @return 0 if successful, or -1 if an error occurred - @see evdns_shutdown() - */ -int evdns_init(void); - -/** - Shut down the asynchronous DNS resolver and terminate all active requests. - - If the 'fail_requests' option is enabled, all active requests will return - an empty result with the error flag set to DNS_ERR_SHUTDOWN. Otherwise, - the requests will be silently discarded. - - @deprecated This function is deprecated because it does not allow the - caller to specify which evdns_base it applies to. The recommended - function is evdns_base_shutdown(). - - @param fail_requests if zero, active requests will be aborted; if non-zero, - active requests will return DNS_ERR_SHUTDOWN. - @see evdns_init() - */ -void evdns_shutdown(int fail_requests); - -/** - Add a nameserver. - - The address should be an IPv4 address in network byte order. - The type of address is chosen so that it matches in_addr.s_addr. - - @deprecated This function is deprecated because it does not allow the - caller to specify which evdns_base it applies to. The recommended - function is evdns_base_nameserver_add(). - - @param address an IP address in network byte order - @return 0 if successful, or -1 if an error occurred - @see evdns_nameserver_ip_add() - */ -int evdns_nameserver_add(unsigned long int address); - -/** - Get the number of configured nameservers. - - This returns the number of configured nameservers (not necessarily the - number of running nameservers). This is useful for double-checking - whether our calls to the various nameserver configuration functions - have been successful. - - @deprecated This function is deprecated because it does not allow the - caller to specify which evdns_base it applies to. The recommended - function is evdns_base_count_nameservers(). - - @return the number of configured nameservers - @see evdns_nameserver_add() - */ -int evdns_count_nameservers(void); - -/** - Remove all configured nameservers, and suspend all pending resolves. - - Resolves will not necessarily be re-attempted until evdns_resume() is called. - - @deprecated This function is deprecated because it does not allow the - caller to specify which evdns_base it applies to. The recommended - function is evdns_base_clear_nameservers_and_suspend(). - - @return 0 if successful, or -1 if an error occurred - @see evdns_resume() - */ -int evdns_clear_nameservers_and_suspend(void); - -/** - Resume normal operation and continue any suspended resolve requests. - - Re-attempt resolves left in limbo after an earlier call to - evdns_clear_nameservers_and_suspend(). - - @deprecated This function is deprecated because it does not allow the - caller to specify which evdns_base it applies to. The recommended - function is evdns_base_resume(). - - @return 0 if successful, or -1 if an error occurred - @see evdns_clear_nameservers_and_suspend() - */ -int evdns_resume(void); - -/** - Add a nameserver. - - This wraps the evdns_nameserver_add() function by parsing a string as an IP - address and adds it as a nameserver. - - @deprecated This function is deprecated because it does not allow the - caller to specify which evdns_base it applies to. The recommended - function is evdns_base_nameserver_ip_add(). - - @return 0 if successful, or -1 if an error occurred - @see evdns_nameserver_add() - */ -int evdns_nameserver_ip_add(const char *ip_as_string); - -/** - Lookup an A record for a given name. - - @deprecated This function is deprecated because it does not allow the - caller to specify which evdns_base it applies to. The recommended - function is evdns_base_resolve_ipv4(). - - @param name a DNS hostname - @param flags either 0, or DNS_QUERY_NO_SEARCH to disable searching for this query. - @param callback a callback function to invoke when the request is completed - @param ptr an argument to pass to the callback function - @return 0 if successful, or -1 if an error occurred - @see evdns_resolve_ipv6(), evdns_resolve_reverse(), evdns_resolve_reverse_ipv6() - */ -int evdns_resolve_ipv4(const char *name, int flags, evdns_callback_type callback, void *ptr); - -/** - Lookup an AAAA record for a given name. - - @param name a DNS hostname - @param flags either 0, or DNS_QUERY_NO_SEARCH to disable searching for this query. - @param callback a callback function to invoke when the request is completed - @param ptr an argument to pass to the callback function - @return 0 if successful, or -1 if an error occurred - @see evdns_resolve_ipv4(), evdns_resolve_reverse(), evdns_resolve_reverse_ipv6() - */ -int evdns_resolve_ipv6(const char *name, int flags, evdns_callback_type callback, void *ptr); - -struct in_addr; -struct in6_addr; - -/** - Lookup a PTR record for a given IP address. - - @deprecated This function is deprecated because it does not allow the - caller to specify which evdns_base it applies to. The recommended - function is evdns_base_resolve_reverse(). - - @param in an IPv4 address - @param flags either 0, or DNS_QUERY_NO_SEARCH to disable searching for this query. - @param callback a callback function to invoke when the request is completed - @param ptr an argument to pass to the callback function - @return 0 if successful, or -1 if an error occurred - @see evdns_resolve_reverse_ipv6() - */ -int evdns_resolve_reverse(const struct in_addr *in, int flags, evdns_callback_type callback, void *ptr); - -/** - Lookup a PTR record for a given IPv6 address. - - @deprecated This function is deprecated because it does not allow the - caller to specify which evdns_base it applies to. The recommended - function is evdns_base_resolve_reverse_ipv6(). - - @param in an IPv6 address - @param flags either 0, or DNS_QUERY_NO_SEARCH to disable searching for this query. - @param callback a callback function to invoke when the request is completed - @param ptr an argument to pass to the callback function - @return 0 if successful, or -1 if an error occurred - @see evdns_resolve_reverse_ipv6() - */ -int evdns_resolve_reverse_ipv6(const struct in6_addr *in, int flags, evdns_callback_type callback, void *ptr); - -/** - Lookup a TXT entry for a specified DNS name. - @param name a DNS name - @param flags either 0, or DNS_QUERY_NO_SEARCH to disable searching for this query. - @param callback a callback function to invoke when the request is completed - @param ptr an argument to pass to the callback function - @return 0 if successful, or -1 if an error occurred -*/ -int evdns_resolve_txt(const char *in, int flags, evdns_callback_type callback, void *ptr); - -/** - Lookup a MX entry for a specified DNS name. - @param name a DNS name - @param flags either 0, or DNS_QUERY_NO_SEARCH to disable searching for this query. - @param callback a callback function to invoke when the request is completed - @param ptr an argument to pass to the callback function - @return 0 if successful, or -1 if an error occurred -*/ -int evdns_resolve_mx(const char *in, int flags, evdns_callback_type callback, void *ptr); - - -/** - Set the value of a configuration option. - - The currently available configuration options are: - - ndots, timeout, max-timeouts, max-inflight, and attempts - - @deprecated This function is deprecated because it does not allow the - caller to specify which evdns_base it applies to. The recommended - function is evdns_base_set_option(). - - @param option the name of the configuration option to be modified - @param val the value to be set - @param flags either 0 | DNS_OPTION_SEARCH | DNS_OPTION_MISC - @return 0 if successful, or -1 if an error occurred - */ -int evdns_set_option(const char *option, const char *val, int flags); - -/** - Parse a resolv.conf file. - - The 'flags' parameter determines what information is parsed from the - resolv.conf file. See the man page for resolv.conf for the format of this - file. - - The following directives are not parsed from the file: sortlist, rotate, - no-check-names, inet6, debug. - - If this function encounters an error, the possible return values are: 1 = - failed to open file, 2 = failed to stat file, 3 = file too large, 4 = out of - memory, 5 = short read from file, 6 = no nameservers listed in the file - - @deprecated This function is deprecated because it does not allow the - caller to specify which evdns_base it applies to. The recommended - function is evdns_base_resolv_conf_parse(). - - @param flags any of DNS_OPTION_NAMESERVERS|DNS_OPTION_SEARCH|DNS_OPTION_MISC| - DNS_OPTIONS_ALL - @param filename the path to the resolv.conf file - @return 0 if successful, or various positive error codes if an error - occurred (see above) - @see resolv.conf(3), evdns_config_windows_nameservers() - */ -int evdns_resolv_conf_parse(int flags, const char *const filename); - -/** - Clear the list of search domains. - - @deprecated This function is deprecated because it does not allow the - caller to specify which evdns_base it applies to. The recommended - function is evdns_base_search_clear(). - */ -void evdns_search_clear(void); - -/** - Add a domain to the list of search domains - - @deprecated This function is deprecated because it does not allow the - caller to specify which evdns_base it applies to. The recommended - function is evdns_base_search_add(). - - @param domain the domain to be added to the search list - */ -void evdns_search_add(const char *domain); - -/** - Set the 'ndots' parameter for searches. - - Sets the number of dots which, when found in a name, causes - the first query to be without any search domain. - - @deprecated This function is deprecated because it does not allow the - caller to specify which evdns_base it applies to. The recommended - function is evdns_base_search_ndots_set(). - - @param ndots the new ndots parameter - */ -void evdns_search_ndots_set(const int ndots); - -/** - As evdns_server_new_with_base. - - @deprecated This function is deprecated because it does not allow the - caller to specify which even_base it uses. The recommended - function is evdns_add_server_port_with_base(). - -*/ -struct evdns_server_port *evdns_add_server_port(int socket, int is_tcp, evdns_request_callback_fn_type callback, void *user_data); - - -#endif /* _EVDNS_H_ */