* Add a little review of rspamd

* Add local_scan.c from Anton Nekhoroshikh for exim MTA

1 files changed, 702 insertions, 0 deletions

diff --git a/contrib/exim/local_scan.c b/contrib/exim/local_scan.c
new file mode 100644
index 000000000..6761c2840
--- /dev/null
+++ b/contrib/exim/local_scan.c
@@ -0,0 +1,702 @@
+/*
+    This program is RSPAMD agent for use with 
+    exim (http://www.exim.org) MTA by its local_scan feature.
+
+    To enable exim local scan please copy this file to exim source tree
+    Local/local_scan.c, edit Local/Makefile to add  
+    
+    LOCAL_SCAN_SOURCE=Local/local_scan.c 
+    LOCAL_SCAN_HAS_OPTIONS=yes
+    
+    and compile exim. 
+    
+    Comment out RSPAM_UNIXSOCKET definition below if you have remote RSPAMD
+    daemon
+    
+    AND
+    
+    use Exim parameters daemonIP and daemonPort to configure remote
+    RSPAMD daemon.
+    
+    For exim compilation with local scan feature details please visit 
+    http://www.exim.org/exim-html-4.50/doc/html/spec_toc.html#TOC333
+    
+    For RSPAMD details please visit
+    http://cebka.pp.ru/trac/
+*/
+
+/* Comment out the row below to use socket type AF_INET
+   to connect RSPAMD daemon */
+//#define RSPAM_UNIXSOCKET
+
+#include <stdio.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <netinet/in.h>
+#include <stdlib.h>
+
+#include "local_scan.h"
+
+extern uschar *sender_helo_name;
+extern int     message_size;
+
+#define READ_FAIL(x)    ((x) < 0)
+#define RSPAMD_FAILURE_HDR 	"X-Spam-Flag"
+#define RSPAMD_SCORE_HDR 	"X-Spam-Status"
+#define REJECT_ON_ERROR 0
+
+static int _OK = 0;
+static int ERR_WRITE = 53;
+static int ERR_READ  = 54;
+static int MAX_FAILS_C = 256;
+static int MAX_PATH  = 256;
+static int MAX_SIZE_FILE = 64*1024;
+
+static uschar *daemonIP = US"127.0.0.1";
+static int daemonPort = 11333;
+static uschar *temp_dir = US"/var/tmp";
+static uschar *socket_name = US"/var/run/rspamd.sock";
+static int strange = 0;
+
+optionlist local_scan_options[] = 
+{ 
+    {"rspam_ip", opt_stringptr, &daemonIP}, 
+    {"rspam_port", opt_int, &daemonPort},
+    {"rspam_tmp", opt_stringptr, &temp_dir},
+    {"rspam_sock", opt_stringptr, &socket_name},
+    
+};
+
+int local_scan_options_count = sizeof (local_scan_options) / sizeof (optionlist);
+
+typedef int socket_t;
+static socket_t sock = -1;
+
+int iFdInp;
+struct sockaddr_un	ssun;
+struct sockaddr_in	ssin;
+
+static int mOpenTmp (char *pszDir, char *pszPrefix, char *pszPath)
+{
+    int iLen;
+    int iFd = -1;
+    char *pszSep = "";
+
+    iLen = (int)strlen(pszDir);
+    if (iLen > MAX_PATH)
+        return -1;
+
+    if (pszDir[iLen - 1] != '/')
+        pszSep = "/";
+
+    sprintf (pszPath, "%s%s%sXXXXXX", pszDir, pszSep, pszPrefix);
+    iFd = mkstemp (pszPath);
+
+    if (iFd < 0)
+        log_write (0, LOG_MAIN, "rspam-exim: Temp file create error %d", errno);
+
+    return iFd;
+}
+
+static int ReadFd (int iFdMsg, int fd)
+{
+    char psMsg [MAX_SIZE_FILE]; /* max size SO can swallow */
+    int iLen, result = _OK;
+
+    if ((iLen = read (fd, psMsg, sizeof (psMsg))) > 0) 
+    {
+        if (write (iFdMsg, psMsg, (unsigned int) iLen) != iLen) 
+            result = ERR_WRITE;
+    }
+    else
+        result = ERR_READ;
+
+    close (iFdMsg);
+
+    return result;
+}
+
+
+void CleanupInp (char *sName)
+{
+    if (sName) unlink (sName); 
+
+    close (iFdInp);
+    return;
+}
+
+
+int FakeSMTPCommand (socket_t sock,
+                     char *command,
+                     char *value,
+                     char *sName,
+                     int Cleanup,
+            	     int wa)
+{
+    char sCommand[1024];
+    char answ [3];
+    int  Len;
+
+    sprintf (sCommand, "%s %s\r\n", command, value);
+
+    if (send (sock, sCommand, strlen (sCommand), 0) != (int) strlen (sCommand))
+    {
+        log_write (0, LOG_MAIN, "rspam-exim: socket sending '%s' error %d", sCommand, errno);
+        if (Cleanup)
+            CleanupInp (sName);
+        return ERR_WRITE;
+    }
+
+    if(wa) {
+	memset (answ, '\0', sizeof (answ));
+        Len = read (sock, answ, sizeof (answ));
+	if (READ_FAIL (Len))
+	{
+    	    log_write (0, LOG_MAIN, "rspam-exim: read() error %d, len=%d", errno, Len);
+    	    if (Cleanup)
+        	CleanupInp (sName);
+    	    return ERR_WRITE;
+	}
+
+	if (strncmp (answ, "OK", 2) != 0)
+	{
+    	    log_write (0, LOG_MAIN, "rspam-exim: server did not confirm, answ=%s", answ);
+    	    if (Cleanup)
+        	CleanupInp (sName);
+    	    return ERR_WRITE;	/* Cannot read message error code */
+	}
+    }
+
+    return OK;
+}
+
+
+static int writen (socket_t fd, const char *vptr, int n)
+{
+    size_t nleft;
+    int nwritten;
+    const char *ptr;
+      
+    ptr = vptr;
+    nleft = n;
+    while (nleft > 0)
+    {
+        if ((nwritten = send (fd, ptr, nleft, 0)) <= 0)
+        {
+            if (errno == EINTR)
+                nwritten = 0;
+            else
+                return (-1);
+        }
+    
+        nleft -= nwritten;
+        ptr += nwritten;
+    }
+    
+    return (n);
+}
+
+
+static int SendEnvelope (char *sFile)
+{
+    int i;
+    char str [256], *rh;
+    void *psBuf;
+    int fd, bytesRead;
+
+    if(message_size > MAX_SIZE_FILE) {
+	log_write (0, LOG_MAIN, "rspam-exim: file %s is great %d bytes", sFile, MAX_SIZE_FILE);
+        return ERR_WRITE;
+    }
+    
+    /* send greeting */
+//    if(FakeSMTPCommand(sock, "PROCESS", "RSPAMC/1.0", sFile, 1, 0) != _OK)
+//        return ERR_WRITE;
+    if(FakeSMTPCommand(sock, "SYMBOLS", "RSPAMC/1.1", sFile, 1, 0) != _OK)
+//    if(FakeSMTPCommand(sock, "CHECK", "RSPAMC/1.0", sFile, 1, 0) != _OK)
+        return ERR_WRITE;
+	
+	
+
+    /* sender IP */
+    if (FakeSMTPCommand (sock, "IP:", sender_host_address, sFile, 1, 0) != _OK)
+        return ERR_WRITE;
+
+    /* mail from */
+    if (FakeSMTPCommand (sock, "From:", 
+                         strlen (sender_address) == 0 ?  "MAILER-DAEMON" : (char*) sender_address, sFile, 1, 0) != _OK)
+        return ERR_WRITE;
+
+    /* send helo */
+    if (FakeSMTPCommand (sock, "Helo:", sender_helo_name, sFile, 1, 0) != _OK)
+        return ERR_WRITE;
+
+    /* send helo */
+    sprintf(str, "%d", message_size);
+    if (FakeSMTPCommand (sock, "Content-Length:", str, sFile, 1, 0) != _OK)
+        return ERR_WRITE;
+
+    /* number of recipient */
+    sprintf(str, "%d", recipients_count);
+    if (FakeSMTPCommand (sock, "Recipient-Number:", str, sFile, 1, 0) != _OK)
+        return ERR_WRITE;
+    
+    /* envelope rcpto */
+    for (i = 0; i < recipients_count; i ++)
+    {
+        if (FakeSMTPCommand (sock, "Rcpt:", recipients_list[i].address, sFile, 1, 0) != _OK)
+            return ERR_WRITE;
+    }
+
+    psBuf = store_get (MAX_SIZE_FILE);
+
+    fd = open (sFile, O_RDONLY);
+    if (fd > 0)
+    {
+        bytesRead = read (fd, psBuf, MAX_SIZE_FILE);
+        close (fd);
+
+        if (FakeSMTPCommand (sock, "\r\n", "", sFile, 1, 0) != _OK)
+            return ERR_WRITE;
+            
+        if (writen (sock, psBuf, bytesRead) != bytesRead)
+            return ERR_WRITE;
+    }
+    else
+    {
+        log_write (0, LOG_MAIN, "rspam-exim: file %s open error %d", sFile, errno);
+        return ERR_WRITE;
+    }
+
+    return _OK;
+}
+
+
+int GetFiles (char *pInpFile, int local_scan_fd)
+{
+    /*
+        Returns OK if no errors, else error code.
+        On succesful return, pEnvFile points to Envelope file name and
+        pInpFile points to Message filename
+    */
+    int iStatus;
+    struct header_line *h_line;
+            
+    iFdInp = mOpenTmp ((char *)temp_dir, "sp-inp", pInpFile);
+    if (iFdInp == -1) 
+    {
+        return ERR_WRITE;
+    }
+
+    /* Emit headers */
+    h_line = header_list;
+    while (h_line != NULL)
+    {
+        if (h_line->type == '*') /* internal header */
+        {
+            h_line = h_line->next;
+            continue;
+        }
+        
+        if (write (iFdInp, h_line->text, strlen (h_line->text)) != strlen (h_line->text))
+        {
+            CleanupInp ("");
+            return ERR_WRITE;
+        }
+        h_line = h_line->next;
+    }
+    if (write (iFdInp, "\n", 1) != 1)
+    {
+        CleanupInp ("");
+        return ERR_WRITE;
+    }
+    
+    /* Read msg */
+    if ((iStatus = ReadFd (iFdInp, local_scan_fd))) 
+    {
+        return iStatus;
+    }
+
+    /* Return success */
+    return _OK;
+}
+
+
+int GetAndTransferMessage (int fd, char *sFile)
+{
+    char answ [4];
+    int	 iStatus;
+    int	 Len, ccnt;
+
+    iStatus = GetFiles ((char *)sFile, fd);
+
+    if (iStatus != _OK)
+    {
+        log_write (0, LOG_MAIN, "rspam-exim: Error %d getting message", iStatus);
+        close (sock);
+        return iStatus;
+    }
+
+    for (ccnt = 0; ccnt <= MAX_FAILS_C; ccnt ++)
+    {
+#ifdef RSPAM_UNIXSOCKET
+        if (connect (sock, (struct sockaddr *) &ssun, sizeof (struct sockaddr_un)) < 0)
+#else
+        if (connect (sock, (struct sockaddr *) &ssin, sizeof (struct sockaddr_in)) < 0)
+#endif
+        {
+            if (ccnt < MAX_FAILS_C)
+                usleep (1000);
+            else
+            {
+                close (sock);
+#ifdef RSPAM_UNIXSOCKET
+                log_write (0, LOG_MAIN, "rspam-exim: socket connect to %s failed", (char *)socket_name);
+#else
+                log_write (0, LOG_MAIN, "rspam-exim: socket connect to %s:%u failed", daemonIP, daemonPort);
+#endif
+		return REJECT_ON_ERROR ? LOCAL_SCAN_TEMPREJECT:LOCAL_SCAN_ACCEPT;
+            }
+        }
+        else
+            break;
+    }
+    
+    iStatus = SendEnvelope (sFile);
+    if (iStatus != _OK)
+    {
+        log_write (0, LOG_MAIN, "rspam-exim: error %d sending envelope data", iStatus);
+        close (sock);
+        return iStatus;
+    }
+    
+    /* fprintf (stderr, "Transmit OK\n"); */
+    return _OK;
+}
+
+void header_del (uschar *hdr)
+{
+    struct header_line *h_line;
+
+    h_line = header_list;
+    while (h_line != NULL)
+    {
+        if (h_line->type == '*') /* internal header */
+        {
+            h_line = h_line->next;
+            continue;
+        }
+        
+        if (strncasecmp (h_line->text, hdr, strlen(hdr)) == 0)
+        {
+            h_line->type = '*';
+            while (h_line->next && 
+                   (*h_line->next->text == ' ' || *h_line->next->text == '\t'))
+            {
+                h_line = h_line->next;
+                h_line->type = '*';
+            }
+        }
+        h_line = h_line->next;
+    }
+}
+
+void AlterSubject (char *label)
+{
+    struct header_line *h_line;
+    char *subject, *strP;
+
+    h_line = header_list;
+    
+    while (h_line != NULL)
+    {
+        if (h_line->type == '*') /* internal header */
+        {
+            h_line = h_line->next;
+            continue;
+        }
+        
+        if (strncasecmp (h_line->text, "Subject", strlen("Subject")) == 0)
+        {
+            strP = strchr (h_line->text, ':');
+            subject = string_copy (++strP);
+            while (h_line->next &&
+                   (*h_line->next->text == ' ' || *h_line->next->text == '\t'))
+            {
+                h_line = h_line->next;
+		subject = string_sprintf ("%s\n%s", subject, h_line->text);
+            }
+            header_del (US "Subject");
+            break;
+        }
+
+        h_line = h_line->next;
+    }
+    header_add (' ', "Subject: %s%s", label, subject ? subject : "");
+}
+
+int 
+io_read(int fd, char *buf, size_t size)
+{
+    int nfd, next = 0, rcount = 15;
+    size_t len = 0;
+    fd_set fds;
+    struct timeval tv;
+    
+    if((sock < 0) || (buf == NULL))
+	return -1;
+	
+    FD_ZERO(&fds);
+
+repeat_read:
+
+    tv.tv_sec = 5;
+    tv.tv_usec = 0;
+    FD_SET(fd, &fds);
+    
+//    log_write(0, LOG_MAIN, "rspam-exim: before select");
+
+    if((nfd=select(fd+1, &fds, NULL, NULL, &tv)) == -1) {
+//	log_write(0, LOG_MAIN, "rspam-exim: select error: %s", strerror(errno));
+	return -1;
+    }
+
+//    log_write(0, LOG_MAIN, "rspam-exim: select return %d fds, rcount %d, next %d", nfd, rcount, next);
+    
+    if((nfd>0) && (FD_ISSET(fd, &fds))) {
+	next += len = read(fd, buf + next, size - next);
+//        log_write(0, LOG_MAIN, "rspam-exim: read %d bytes", len);
+//	if(next<size) 
+//	    goto repeat_read;
+    }
+    rcount--;
+    if(rcount>0)
+	goto repeat_read;
+
+    return next;
+}
+
+int WaitForScanResult (uschar **resStr)
+{
+    int Len, i;
+    int rej, result = LOCAL_SCAN_ACCEPT, answer_size, spm = 0, code = 0, ns = 0, smb = 0, urf = 0;
+    char *strP, *tok, *tmp;
+    char *hdr = NULL, *hdrv = NULL, *spmStr = NULL, *symbols=NULL, *urls=NULL;
+    char answ [4096], state[6], metric[128], back;
+    float sm=0, smd=0, smr=0;
+    
+    memset (answ, '\0', sizeof (answ));
+//    log_write(0, LOG_MAIN, "rspam-exim: before read from %d", sock);
+//    Len = read (sock, answ, sizeof (answ) - 1);
+    Len = io_read(sock, answ, sizeof (answ) - 1);
+    log_write(0, LOG_MAIN, "rspam-exim: read %d bytes", Len);
+
+    if (strncmp (answ, "RSPAMD/1.1 ", 11) == 0)
+    {
+        strP = (char *)answ;
+        for (tok = strtok (strP, "\n"); tok; tok = strtok (NULL, "\n"))
+        {
+//            log_write(0, LOG_MAIN, "rspam-exim: process line '%s'", tok);
+
+            if (strncmp (tok, "RSPAMD/1.1 ", 11) == 0)
+            {
+                if (sscanf (tok, "%*s %d %s", &code, state) == 2)
+                {
+//                    log_write(0, LOG_MAIN, "rspam-exim: daemon reports code %d %s", code, state);
+            	    if ((code == 0) && (strcmp(state,"OK")==0)) {
+                	    header_del ((uschar *) RSPAMD_FAILURE_HDR);
+                	    header_add (' ', "%s: SKIP\n", RSPAMD_FAILURE_HDR);
+                	    strange = 1;
+            		    continue;
+            	    } else {
+                	    header_del ((uschar *) RSPAMD_FAILURE_HDR);
+                	    header_add (' ', "%s: SKIP\n", RSPAMD_FAILURE_HDR);
+                            log_write(0, LOG_MAIN, "rspam-exim: daemon reports code %d %s", code, state);
+                    	    return LOCAL_SCAN_ACCEPT;
+            	    }
+                }
+                continue;
+            }
+
+	    /* Metric: default; False; 6.00 / 10.00 */           
+            /* Process metric */
+            if (strncmp (tok, "Metric:", 7) == 0)
+            {
+        	tmp = tok;
+        	while(	(*tmp++) && 
+        		((*tmp!='\r') || (*tmp!='\n'))
+        		);
+        	back = *tmp;
+        	*tmp = '\0';
+                if (sscanf (tok, "Metric: %[^';']; %[^';']; %f / %f / %f", metric, state, &sm, &smd, &smr) == 5) {
+            		log_write(0, LOG_MAIN, "rspam-exim: metric: %s; %s; %f / %f / %f", metric, state, sm, smd, smr );
+            		if(strcasecmp(state,"true")==0) {
+                		header_del ((uschar *) RSPAMD_FAILURE_HDR);
+                		header_add (' ', "%s: %s\n", RSPAMD_FAILURE_HDR, "Yes");
+            		} else if(strcasecmp(state,"skip")==0) {
+                		header_del ((uschar *) RSPAMD_FAILURE_HDR);
+                		header_add (' ', "%s: %s\n", RSPAMD_FAILURE_HDR, "Skip");
+            		} else {
+                		header_del ((uschar *) RSPAMD_FAILURE_HDR);
+                		header_add (' ', "%s: %s\n", RSPAMD_FAILURE_HDR, "No");
+            		}
+                	header_del ((uschar *) RSPAMD_SCORE_HDR);
+                	header_add (' ', "%s: %.2f / %.2f / %.2f\n", RSPAMD_SCORE_HDR, sm, smd, smr);
+                	strange = 0;
+        	}
+		*tmp = back;
+                continue;
+            }
+            
+            if (strncmp (tok, "Symbol:", 7) == 0)
+            {
+        	tmp = tok;
+        	while(	(*tmp++) && 
+        		((*tmp!='\r') || (*tmp!='\n'))
+        		);
+        	back = *tmp;
+        	*tmp = '\0';
+		if(smb>0) {
+		    tok[0] = tok[1]= tok[2]= tok[3]= tok[4]= tok[5]= tok[6]= ' ';
+		    symbols = string_sprintf ("%s\n%s", symbols, tok+5);    
+		} else {
+		    tok += 7;
+		    while(*tok && isspace(*tok)) tok++;
+		    symbols = string_copy (tok);
+		}
+        	smb = 1;
+		*tmp = back;
+        	continue;
+	    }
+
+            if (strncmp (tok, "Urls:", 5) == 0)
+            {
+        	tmp = tok;
+        	while(	(*tmp++) && 
+        		((*tmp!='\r') || (*tmp!='\n'))
+        		);
+        	back = *tmp;
+        	*tmp = '\0';
+		if(urf>0) {
+		    tok[0] = tok[1]= tok[2]= tok[3]= tok[4] = ' ';
+		    urls = string_sprintf ("%s\n%s", urls, tok+3);    
+		} else {
+		    tok += 5;
+		    while(*tok && isspace(*tok)) tok++;
+		    urls = string_copy (tok);
+		}
+        	urf = 1;
+		*tmp = back;
+        	continue;
+	    }
+        }
+
+        
+        /* do not forget the symbols */
+        if (symbols != NULL && strlen(symbols))
+        {
+    	    i = 0;
+    	    tmp = tok = string_copy(symbols);
+            header_del ((uschar *) "X-Spam-Sybmols");
+            header_add (' ', "%s: %s\n", "X-Spam-Sybmols", symbols);
+            while(*tmp!='\0') {
+        	if((*tmp == '\n') || (*tmp == '\r')) {
+        	    tmp++;
+        	    continue;
+        	}
+        	if ((*tmp == ' ') && (*(tmp+1)==' ')) {
+        	    tok[i++] = ',';
+        	    tmp += 2;
+        	    continue;
+        	}
+        	tok[i] = *tmp;
+        	i++;
+        	tmp++;
+            }
+	    tok[i] = '\0';
+            log_write(0, LOG_MAIN, "rspam-exim: symbols: %s", tok);
+        }
+
+        /* do not forget the urls */
+        if (urls != NULL && strlen(urls))
+        {
+            log_write(0, LOG_MAIN, "rspam-exim: urls: %s", urls);
+            header_del ((uschar *) "X-Spam-Urls");
+            header_add (' ', "%s: %s\n", "X-Spam-Urls", urls);
+        }
+        
+        log_write (0, LOG_MAIN, "rspam-exim: For message from %s will return %s, mailfrom: <%s>, rcpto: <%s>", sender_host_address, rej == 2 ? "DISCARD" : rej == 1 ? "REJECT" : "ACCEPT", sender_address, recipients_list[0].address);
+        
+    }
+    else
+    {
+        result = LOCAL_SCAN_ACCEPT;
+        log_write(0, LOG_MAIN, "rspam-exim: wrong signature in answer: %s", answ);
+    }
+
+    if((sm>0) && (smr>0) && (sm>=smr)) {
+	result = LOCAL_SCAN_REJECT;
+    }        
+    return result;
+}
+
+
+int
+local_scan(int fd, uschar **return_text)
+{
+    int 	retval = _OK;
+    char sFileInp [MAX_PATH + 81];
+
+    /* Socket stuff */
+
+    strange = 0;
+#ifdef RSPAM_UNIXSOCKET
+    if ((sock = socket (AF_UNIX, SOCK_STREAM, 0)) < 0)
+    {
+        log_write(0, LOG_MAIN, "rspam-exim: socket() failed");
+        exit (1);    
+    }
+    memset (&ssun, '\0', sizeof (struct sockaddr_un));
+    ssun.sun_family = AF_UNIX;
+    if (sizeof (socket_name) > sizeof (ssun.sun_path))
+    {
+        close (sock);
+        log_write(0, LOG_MAIN, "rspam-exim: UNIX socket name %s too long", socket_name);
+        exit (1);
+    }
+    strcpy (ssun.sun_path, socket_name);
+#else
+    if ((sock = socket (AF_INET, SOCK_STREAM, 0)) < 0)
+    {
+        log_write(0, LOG_MAIN, "rspam-exim: socket() failed");
+        exit (1);    
+    }
+    memset (&ssin, '\0', sizeof (struct sockaddr_in));
+    ssin.sin_family = AF_INET;
+    ssin.sin_addr.s_addr = inet_addr (daemonIP);
+    ssin.sin_port = htons (daemonPort);
+#endif
+
+    if (GetAndTransferMessage (fd, (char *)sFileInp) != _OK)
+    {
+        close (sock);
+        unlink (sFileInp);
+        SPOOL_DATA_START_OFFSET;
+	return REJECT_ON_ERROR ? LOCAL_SCAN_TEMPREJECT:LOCAL_SCAN_ACCEPT;
+    }
+    
+    retval = WaitForScanResult (return_text);
+
+    if(!strange)
+	unlink (sFileInp);
+    close (sock);
+    SPOOL_DATA_START_OFFSET;
+    
+    return retval;
+}
+
+/* End of local_scan.c */