citadel/serv_spam.c

   1 /*
   2  * $Id$
   3  *
   4  * Reject incoming SMTP messages containing strings that tell us that the
   5  * message is probably spam.
   6  *
   7  */
   8
   9
  10 #include "sysdep.h"
  11 #include <stdlib.h>
  12 #include <unistd.h>
  13 #include <stdio.h>
  14 #include <fcntl.h>
  15 #include <signal.h>
  16 #include <pwd.h>
  17 #include <errno.h>
  18 #include <sys/types.h>
  19
  20 #if TIME_WITH_SYS_TIME
  21 # include <sys/time.h>
  22 # include <time.h>
  23 #else
  24 # if HAVE_SYS_TIME_H
  25 #  include <sys/time.h>
  26 # else
  27 #  include <time.h>
  28 # endif
  29 #endif
  30
  31 #include <sys/wait.h>
  32 #include <string.h>
  33 #include <limits.h>
  34 #include <sys/socket.h>
  35 #include "citadel.h"
  36 #include "server.h"
  37 #include "sysdep_decls.h"
  38 #include "citserver.h"
  39 #include "support.h"
  40 #include "config.h"
  41 #include "control.h"
  42 #include "dynloader.h"
  43 #include "room_ops.h"
  44 #include "user_ops.h"
  45 #include "policy.h"
  46 #include "database.h"
  47 #include "msgbase.h"
  48 #include "tools.h"
  49 #include "internet_addressing.h"
  50 #include "clientsocket.h"
  51
  52
  53
  54 #ifdef ___NOT_CURRENTLY_IN_USE___
  55 /* Scan a message for spam */
  56 int spam_filter(struct CtdlMessage *msg) {
  57         int spam_strings_found = 0;
  58         struct spamstrings_t *sptr;
  59         char *ptr;
  60
  61         /* Bail out if there's no message text */
  62         if (msg->cm_fields['M'] == NULL) return(0);
  63
  64
  65         /* Scan! */
  66         ptr = msg->cm_fields['M'];
  67         while (ptr++[0] != 0) {
  68                 for (sptr = spamstrings; sptr != NULL; sptr = sptr->next) {
  69                         if (!strncasecmp(ptr, sptr->string,
  70                            strlen(sptr->string))) {
  71                                 ++spam_strings_found;
  72                         }
  73                 }
  74         }
  75
  76         if (spam_strings_found) {
  77                 if (msg->cm_fields['0'] != NULL) {
  78                         phree(msg->cm_fields['0']);
  79                 }
  80                 msg->cm_fields['0'] = strdoop("Unsolicited spam rejected");
  81                 return(spam_strings_found);
  82         }
  83
  84         return(0);
  85 }
  86 #endif
  87
  88
  89
  90 /*
  91  * Connect to the SpamAssassin server and scan a message.
  92  */
  93 int spam_assassin(struct CtdlMessage *msg) {
  94         int sock = (-1);
  95         char buf[SIZ];
  96         int is_spam = 0;
  97
  98 #define SPAMASSASSIN_HOST       "127.0.0.1"
  99 #define SPAMASSASSIN_PORT       "783"
 100
 101         /* Connect to the SpamAssassin server */
 102         lprintf(9, "Connecting to SpamAssassin\n");
 103         sock = sock_connect(SPAMASSASSIN_HOST, SPAMASSASSIN_PORT, "tcp");
 104         if (sock < 0) {
 105                 /* If the service isn't running, just pass the mail
 106                  * through.  Potentially throwing away mails isn't good.
 107                  */
 108                 return(0);
 109         }
 110
 111         /* Command */
 112         lprintf(9, "Transmitting command\n");
 113         sprintf(buf, "CHECK SPAMC/1.2\r\n\r\n");
 114         lprintf(9, buf);
 115         lprintf(9, "sock_write() returned %d\n",
 116                 sock_write(sock, buf, strlen(buf))
 117         );
 118
 119         /* Message */
 120         CtdlRedirectOutput(NULL, sock);
 121         CtdlOutputPreLoadedMsg(msg, 0L, MT_RFC822, 0, 0, 1);
 122         CtdlRedirectOutput(NULL, -1);
 123
 124         /* Close one end of the socket connection; this tells SpamAssassin
 125          * that we're done.
 126          */
 127         lprintf(9, "sock_shutdown() returned %d\n",
 128                 sock_shutdown(sock, SHUT_WR)
 129         );
 130
 131         /* Response */
 132         lprintf(9, "Awaiting response\n");
 133         if (sock_gets(sock, buf) < 0) {
 134                 goto bail;
 135         }
 136         lprintf(9, "<%s\n", buf);
 137         if (strncasecmp(buf, "SPAMD", 5)) {
 138                 goto bail;
 139         }
 140         if (sock_gets(sock, buf) < 0) {
 141                 goto bail;
 142         }
 143         lprintf(9, "<%s\n", buf);
 144         if (!strncasecmp(buf, "Spam: True", 10)) {
 145                 is_spam = 1;
 146         }
 147
 148         if (is_spam) {
 149                 if (msg->cm_fields['0'] != NULL) {
 150                         phree(msg->cm_fields['0']);
 151                 }
 152                 msg->cm_fields['0'] = strdoop(
 153                         "Message rejected by SpamAssassin");
 154         }
 155
 156 bail:   close(sock);
 157         return(is_spam);
 158 }
 159
 160
 161
 162 char *Dynamic_Module_Init(void)
 163 {
 164
 165 /* ** This one isn't in use.  It's a spam filter I wrote, but we're going to
 166       try the SpamAssassin stuff instead.
 167         CtdlRegisterMessageHook(spam_filter, EVT_SMTPSCAN);
 168  */
 169
 170
 171         CtdlRegisterMessageHook(spam_assassin, EVT_SMTPSCAN);
 172
 173
 174         return "$Id$";
 175 }