1 files changed, 581 insertions, 0 deletions

diff --git a/src/smtp_proxy.c b/src/smtp_proxy.c
new file mode 100644
index 000000000..fa9da971a
--- /dev/null
+++ b/src/smtp_proxy.c
@@ -0,0 +1,581 @@
+/* Copyright (c) 2010-2012, Vsevolod Stakhov
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *       * Redistributions of source code must retain the above copyright
+ *         notice, this list of conditions and the following disclaimer.
+ *       * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED ''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 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.
+ */
+
+#include "config.h"
+#include "main.h"
+#include "cfg_file.h"
+#include "cfg_xml.h"
+#include "util.h"
+#include "smtp_proto.h"
+#include "map.h"
+#include "message.h"
+#include "settings.h"
+#include "dns.h"
+#include "upstream.h"
+#include "proxy.h"
+
+/*
+ * SMTP proxy is a simple smtp proxy worker for dns resolving and
+ * load balancing. It uses XCLIENT command and is designed for MTA
+ * that supports that (postfix and exim).
+ */
+
+/* Upstream timeouts */
+#define DEFAULT_UPSTREAM_ERROR_TIME 10
+#define DEFAULT_UPSTREAM_DEAD_TIME 300
+#define DEFAULT_UPSTREAM_MAXERRORS 10
+
+static sig_atomic_t                    wanna_die = 0;
+
+/* Init functions */
+gpointer init_smtp_proxy ();
+void start_smtp_proxy (struct rspamd_worker *worker);
+
+worker_t smtp_proxy_worker = {
+	"smtp_proxy",				/* Name */
+	init_smtp_proxy,			/* Init function */
+	start_smtp_proxy,			/* Start function */
+	TRUE,						/* Has socket */
+	FALSE,						/* Non unique */
+	FALSE,						/* Non threaded */
+	TRUE						/* Killable */
+};
+
+struct smtp_proxy_ctx {
+	struct smtp_upstream upstreams[MAX_SMTP_UPSTREAMS];
+	size_t upstream_num;
+	gchar *upstreams_str;
+
+	memory_pool_t *pool;
+	guint32 smtp_delay;
+	guint32 delay_jitter;
+	guint32 smtp_timeout_raw;
+	struct timeval smtp_timeout;
+
+	struct rspamd_dns_resolver *resolver;
+	struct event_base *ev_base;
+};
+
+enum rspamd_smtp_proxy_state {
+	SMTP_PROXY_STATE_RESOLVE_REVERSE = 0,
+	SMTP_PROXY_STATE_RESOLVE_NORMAL,
+	SMTP_PROXY_STATE_DELAY
+};
+
+struct smtp_proxy_session {
+	struct smtp_proxy_ctx *ctx;
+	memory_pool_t *pool;
+
+	enum rspamd_smtp_proxy_state state;
+	struct rspamd_worker *worker;
+	struct in_addr client_addr;
+	gchar *hostname;
+	gchar *error;
+	gchar *temp_name;
+	gint sock;
+	gint upstream_sock;
+
+	struct rspamd_async_session *s;
+	rspamd_io_dispatcher_t *dispatcher;
+
+	rspamd_proxy_t *proxy;
+
+	struct smtp_upstream *upstream;
+
+	struct event *delay_timer;
+
+	gboolean resolved;
+	struct rspamd_dns_resolver *resolver;
+	struct event_base *ev_base;
+};
+
+#ifndef HAVE_SA_SIGINFO
+static void
+sig_handler (gint signo)
+#else
+static void
+sig_handler (gint signo, siginfo_t *info, void *unused)
+#endif
+{
+	struct timeval                  tv;
+
+	switch (signo) {
+	case SIGINT:
+	case SIGTERM:
+		if (!wanna_die) {
+			wanna_die = 1;
+			tv.tv_sec = 0;
+			tv.tv_usec = 0;
+			event_loopexit (&tv);
+
+#ifdef WITH_GPERF_TOOLS
+			ProfilerStop ();
+#endif
+		}
+		break;
+	}
+}
+
+/*
+ * Config reload is designed by sending sigusr to active workers and pending shutdown of them
+ */
+static void
+sigusr2_handler (gint fd, short what, void *arg)
+{
+	struct rspamd_worker           *worker = (struct rspamd_worker *)arg;
+	/* Do not accept new connections, preparing to end worker's process */
+	struct timeval                  tv;
+	if (! wanna_die) {
+		tv.tv_sec = SOFT_SHUTDOWN_TIME;
+		tv.tv_usec = 0;
+		event_del (&worker->sig_ev_usr1);
+		event_del (&worker->sig_ev_usr2);
+		event_del (&worker->bind_ev);
+		msg_info ("worker's shutdown is pending in %d sec", SOFT_SHUTDOWN_TIME);
+		event_loopexit (&tv);
+	}
+	return;
+}
+
+/*
+ * Reopen log is designed by sending sigusr1 to active workers and pending shutdown of them
+ */
+static void
+sigusr1_handler (gint fd, short what, void *arg)
+{
+	struct rspamd_worker           *worker = (struct rspamd_worker *) arg;
+
+	reopen_log (worker->srv->logger);
+
+	return;
+}
+
+static void
+free_smtp_proxy_session (gpointer arg)
+{
+	struct smtp_proxy_session            *session = arg;
+
+	if (session) {
+		if (session->dispatcher) {
+			rspamd_remove_dispatcher (session->dispatcher);
+		}
+
+		close (session->sock);
+		memory_pool_delete (session->pool);
+		g_free (session);
+	}
+}
+
+static void
+smtp_proxy_err_proxy (GError * err, void *arg)
+{
+	struct smtp_proxy_session            *session = arg;
+
+	msg_info ("abnormally closing connection, error: %s", err->message);
+	/* Free buffers */
+	destroy_session (session->s);
+}
+
+static gboolean
+create_smtp_proxy_upstream_connection (struct smtp_proxy_session *session)
+{
+	struct smtp_upstream              *selected;
+	struct sockaddr_un                *un;
+
+	/* Try to select upstream */
+	selected = (struct smtp_upstream *)get_upstream_round_robin (session->ctx->upstreams,
+			session->ctx->upstream_num, sizeof (struct smtp_upstream),
+			time (NULL), DEFAULT_UPSTREAM_ERROR_TIME, DEFAULT_UPSTREAM_DEAD_TIME, DEFAULT_UPSTREAM_MAXERRORS);
+	if (selected == NULL) {
+		msg_err ("no upstreams suitable found");
+		return FALSE;
+	}
+
+	session->upstream = selected;
+
+	/* Now try to create socket */
+	if (selected->is_unix) {
+		un = alloca (sizeof (struct sockaddr_un));
+		session->upstream_sock = make_unix_socket (selected->name, un, FALSE, TRUE);
+	}
+	else {
+		session->upstream_sock = make_tcp_socket (&selected->addr, selected->port, FALSE, TRUE);
+	}
+	if (session->upstream_sock == -1) {
+		msg_err ("cannot make a connection to %s", selected->name);
+		upstream_fail (&selected->up, time (NULL));
+		return FALSE;
+	}
+	/* Create a proxy for upstream connection */
+	rspamd_dispatcher_pause (session->dispatcher);
+	session->proxy = rspamd_create_proxy (session->sock, session->upstream_sock, session->pool,
+			session->ev_base, BUFSIZ, &session->ctx->smtp_timeout, smtp_proxy_err_proxy, session);
+
+	return TRUE;
+}
+
+/* Resolving and delay handlers */
+/*
+ * Return from a delay
+ */
+static void
+smtp_delay_handler (gint fd, short what, void *arg)
+{
+	struct smtp_proxy_session *session = arg;
+
+	remove_normal_event (session->s, (event_finalizer_t) event_del,
+			session->delay_timer);
+	if (session->state == SMTP_PROXY_STATE_DELAY) {
+		/* TODO: Create upstream connection here */
+		create_smtp_proxy_upstream_connection (session);
+	}
+	else {
+		/* TODO: Write error here */
+		if (rspamd_dispatcher_write (session->dispatcher,
+				make_smtp_error (session->pool, 550, "%s Improper use of SMTP command pipelining", "5.5.0"),
+				0, FALSE, TRUE)) {
+			destroy_session (session->s);
+		}
+	}
+}
+
+/*
+ * Make delay for a client
+ */
+static void
+smtp_make_delay (struct smtp_proxy_session *session)
+{
+	struct event *tev;
+	struct timeval *tv;
+	gint32 jitter;
+
+	if (session->ctx->smtp_delay != 0 && session->state == SMTP_PROXY_STATE_DELAY) {
+		tev = memory_pool_alloc (session->pool, sizeof(struct event));
+		tv = memory_pool_alloc (session->pool, sizeof(struct timeval));
+		if (session->ctx->delay_jitter != 0) {
+			jitter = g_random_int_range (0, session->ctx->delay_jitter);
+			msec_to_tv (session->ctx->smtp_delay + jitter, tv);
+		}
+		else {
+			msec_to_tv (session->ctx->smtp_delay, tv);
+		}
+
+		evtimer_set (tev, smtp_delay_handler, session);
+		evtimer_add (tev, tv);
+		register_async_event (session->s, (event_finalizer_t) event_del, tev,
+				g_quark_from_static_string ("smtp proxy"));
+		session->delay_timer = tev;
+	}
+	else if (session->state == SMTP_PROXY_STATE_DELAY) {
+		/* TODO: Create upstream connection here */
+		create_smtp_proxy_upstream_connection (session);
+	}
+}
+
+/*
+ * Handle DNS replies
+ */
+static void
+smtp_dns_cb (struct rspamd_dns_reply *reply, void *arg)
+{
+	struct smtp_proxy_session *session = arg;
+	gint res = 0;
+	union rspamd_reply_element *elt;
+	GList *cur;
+
+	switch (session->state)
+	{
+	case SMTP_PROXY_STATE_RESOLVE_REVERSE:
+		/* Parse reverse reply and start resolve of this ip */
+		if (reply->code != DNS_RC_NOERROR) {
+			rspamd_conditional_debug (rspamd_main->logger,
+					session->client_addr.s_addr, __FUNCTION__, "DNS error: %s",
+					dns_strerror (reply->code));
+
+			if (reply->code == DNS_RC_NXDOMAIN) {
+				session->hostname = memory_pool_strdup (session->pool,
+						XCLIENT_HOST_UNAVAILABLE);
+			}
+			else {
+				session->hostname = memory_pool_strdup (session->pool,
+						XCLIENT_HOST_TEMPFAIL);
+			}
+			session->state = SMTP_PROXY_STATE_DELAY;
+			smtp_make_delay (session);
+		}
+		else {
+			if (reply->elements) {
+				elt = reply->elements->data;
+				session->hostname = memory_pool_strdup (session->pool,
+						elt->ptr.name);
+				session->state = SMTP_PROXY_STATE_RESOLVE_NORMAL;
+				make_dns_request (session->resolver, session->s, session->pool,
+						smtp_dns_cb, session, DNS_REQUEST_A, session->hostname);
+
+			}
+		}
+		break;
+	case SMTP_PROXY_STATE_RESOLVE_NORMAL:
+		if (reply->code != DNS_RC_NOERROR) {
+			rspamd_conditional_debug (rspamd_main->logger,
+					session->client_addr.s_addr, __FUNCTION__, "DNS error: %s",
+					dns_strerror (reply->code));
+
+			if (reply->code == DNS_RC_NXDOMAIN) {
+				session->hostname = memory_pool_strdup (session->pool,
+						XCLIENT_HOST_UNAVAILABLE);
+			}
+			else {
+				session->hostname = memory_pool_strdup (session->pool,
+						XCLIENT_HOST_TEMPFAIL);
+			}
+			session->state = SMTP_PROXY_STATE_DELAY;
+			smtp_make_delay (session);
+		}
+		else {
+			res = 0;
+			cur = reply->elements;
+			while (cur) {
+				elt = cur->data;
+				if (memcmp (&session->client_addr, &elt->a.addr[0],
+						sizeof(struct in_addr)) == 0) {
+					res = 1;
+					session->resolved = TRUE;
+					break;
+				}
+				cur = g_list_next (cur);
+			}
+
+			if (res == 0) {
+				msg_info(
+						"cannot find address for hostname: %s, ip: %s", session->hostname, inet_ntoa (session->client_addr));
+				session->hostname = memory_pool_strdup (session->pool,
+						XCLIENT_HOST_UNAVAILABLE);
+			}
+			session->state = SMTP_PROXY_STATE_DELAY;
+			smtp_make_delay (session);
+		}
+		break;
+	default:
+		/* TODO: write something about pipelining */
+		break;
+	}
+}
+
+/*
+ * Callback that is called when there is data to read in buffer
+ */
+static                          gboolean
+smtp_proxy_read_socket (f_str_t * in, void *arg)
+{
+	struct smtp_proxy_session            *session = arg;
+
+	/* This can be called only if client is using invalid pipelining */
+	if (rspamd_dispatcher_write (session->dispatcher,
+			make_smtp_error (session->pool, 550, "%s Improper use of SMTP command pipelining", "5.5.0"),
+			0, FALSE, TRUE)) {
+		destroy_session (session->s);
+	}
+	else {
+		return FALSE;
+	}
+
+	return TRUE;
+}
+
+/*
+ * Called if something goes wrong
+ */
+static void
+smtp_proxy_err_socket (GError * err, void *arg)
+{
+	struct smtp_proxy_session            *session = arg;
+
+	msg_info ("abnormally closing connection, error: %s", err->message);
+	/* Free buffers */
+	destroy_session (session->s);
+}
+
+/*
+ * Accept new connection and construct session
+ */
+static void
+accept_socket (gint fd, short what, void *arg)
+{
+	struct rspamd_worker           *worker = (struct rspamd_worker *)arg;
+	union sa_union                  su;
+	struct smtp_proxy_session      *session;
+	struct smtp_proxy_ctx          *ctx;
+
+	socklen_t                       addrlen = sizeof (su.ss);
+	gint                            nfd;
+
+	if ((nfd = accept_from_socket (fd, (struct sockaddr *)&su.ss, &addrlen)) == -1) {
+		msg_warn ("accept failed: %s", strerror (errno));
+		return;
+	}
+	/* Check for EAGAIN */
+	if (nfd == 0) {
+		return;
+	}
+
+	ctx = worker->ctx;
+	session = g_slice_alloc0 (sizeof (struct smtp_proxy_session));
+	session->pool = memory_pool_new (memory_pool_get_size ());
+
+	if (su.ss.ss_family == AF_UNIX) {
+		msg_info ("accepted connection from unix socket");
+		session->client_addr.s_addr = INADDR_NONE;
+	}
+	else if (su.ss.ss_family == AF_INET) {
+		msg_info ("accepted connection from %s port %d", inet_ntoa (su.s4.sin_addr), ntohs (su.s4.sin_port));
+		memcpy (&session->client_addr, &su.s4.sin_addr, sizeof (struct in_addr));
+	}
+
+	session->sock = nfd;
+	session->worker = worker;
+	session->ctx = ctx;
+	session->resolver = ctx->resolver;
+	session->ev_base = ctx->ev_base;
+	worker->srv->stat->connections_count++;
+
+	/* Resolve client's addr */
+	/* Set up async session */
+	session->s = new_async_session (session->pool, NULL, NULL, free_smtp_proxy_session, session);
+	session->state = SMTP_PROXY_STATE_RESOLVE_REVERSE;
+	if (! make_dns_request (session->resolver, session->s, session->pool,
+			smtp_dns_cb, session, DNS_REQUEST_PTR, &session->client_addr)) {
+		msg_err ("cannot resolve %s", inet_ntoa (session->client_addr));
+		g_slice_free1 (sizeof (struct smtp_proxy_session), session);
+		close (nfd);
+		return;
+	}
+	else {
+		session->dispatcher = rspamd_create_dispatcher (session->ev_base, nfd, BUFFER_ANY,
+								smtp_proxy_read_socket, NULL, smtp_proxy_err_socket,
+								&session->ctx->smtp_timeout, session);
+		session->dispatcher->peer_addr = session->client_addr.s_addr;
+	}
+}
+
+gpointer
+init_smtp_proxy (void)
+{
+	struct smtp_proxy_ctx         		*ctx;
+	GQuark								type;
+
+	type = g_quark_try_string ("smtp_proxy");
+
+	ctx = g_malloc0 (sizeof (struct smtp_worker_ctx));
+	ctx->pool = memory_pool_new (memory_pool_get_size ());
+
+	/* Set default values */
+	ctx->smtp_timeout_raw = 300000;
+	ctx->smtp_delay = 0;
+
+	register_worker_opt (type, "upstreams", xml_handle_string, ctx,
+				G_STRUCT_OFFSET (struct smtp_proxy_ctx, upstreams_str));
+	register_worker_opt (type, "timeout", xml_handle_seconds, ctx,
+					G_STRUCT_OFFSET (struct smtp_proxy_ctx, smtp_timeout_raw));
+	register_worker_opt (type, "delay", xml_handle_seconds, ctx,
+					G_STRUCT_OFFSET (struct smtp_proxy_ctx, smtp_delay));
+	register_worker_opt (type, "jitter", xml_handle_seconds, ctx,
+						G_STRUCT_OFFSET (struct smtp_proxy_ctx, delay_jitter));
+
+	return ctx;
+}
+
+/* Make post-init configuration */
+static gboolean
+config_smtp_proxy_worker (struct rspamd_worker *worker)
+{
+	struct smtp_proxy_ctx         *ctx = worker->ctx;
+	gchar                         *value;
+
+	/* Init timeval */
+	msec_to_tv (ctx->smtp_timeout_raw, &ctx->smtp_timeout);
+
+	/* Init upstreams */
+	if ((value = ctx->upstreams_str) != NULL) {
+		if (!parse_upstreams_line (ctx->pool, ctx->upstreams, value, &ctx->upstream_num)) {
+			return FALSE;
+		}
+	}
+	else {
+		msg_err ("no upstreams defined, don't know what to do");
+		return FALSE;
+	}
+
+	return TRUE;
+}
+
+/*
+ * Start worker process
+ */
+void
+start_smtp_proxy (struct rspamd_worker *worker)
+{
+	struct sigaction                signals;
+	struct smtp_worker_ctx         *ctx = worker->ctx;
+
+	gperf_profiler_init (worker->srv->cfg, "worker");
+
+	worker->srv->pid = getpid ();
+	ctx->ev_base = event_init ();
+
+	/* Set smtp options */
+	if ( !config_smtp_proxy_worker (worker)) {
+		msg_err ("cannot configure smtp worker, exiting");
+		exit (EXIT_SUCCESS);
+	}
+
+	init_signals (&signals, sig_handler);
+	sigprocmask (SIG_UNBLOCK, &signals.sa_mask, NULL);
+
+	/* SIGUSR2 handler */
+	signal_set (&worker->sig_ev_usr2, SIGUSR2, sigusr2_handler, (void *) worker);
+	event_base_set (ctx->ev_base, &worker->sig_ev_usr2);
+	signal_add (&worker->sig_ev_usr2, NULL);
+
+	/* SIGUSR1 handler */
+	signal_set (&worker->sig_ev_usr1, SIGUSR1, sigusr1_handler, (void *) worker);
+	event_base_set (ctx->ev_base, &worker->sig_ev_usr1);
+	signal_add (&worker->sig_ev_usr1, NULL);
+
+	/* Accept event */
+	event_set (&worker->bind_ev, worker->cf->listen_sock, EV_READ | EV_PERSIST, accept_socket, (void *)worker);
+	event_base_set (ctx->ev_base, &worker->bind_ev);
+	event_add (&worker->bind_ev, NULL);
+
+	/* DNS resolver */
+	ctx->resolver = dns_resolver_init (ctx->ev_base, worker->srv->cfg);
+
+	/* Set umask */
+	umask (S_IWGRP | S_IWOTH | S_IROTH | S_IRGRP);
+
+	event_base_loop (ctx->ev_base, 0);
+
+	close_log (rspamd_main->logger);
+	exit (EXIT_SUCCESS);
+}
+