mdw@git.distorted.org.uk Git - misc/blob - qmail-checkspam.c

   1 /* -*-c-*-
   2  *
   3  * $Id: qmail-checkspam.c,v 1.1 2003/10/01 00:08:57 mdw Exp $
   4  *
   5  * Filter messages for spam
   6  *
   7  * (c) 2003 Mark Wooding
   8  */
   9
  10 /*----- Licensing notice --------------------------------------------------*
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software Foundation,
  24  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  25  */
  26
  27 /*----- Revision history --------------------------------------------------*
  28  *
  29  * $Log: qmail-checkspam.c,v $
  30  * Revision 1.1  2003/10/01 00:08:57  mdw
  31  * Collection of miscellaneous ill-documented tools.
  32  *
  33  */
  34
  35 /*----- Header files ------------------------------------------------------*/
  36
  37 #include <ctype.h>
  38 #include <errno.h>
  39 #include <stdio.h>
  40 #include <stdlib.h>
  41 #include <string.h>
  42
  43 #include <sys/types.h>
  44 #include <sys/unistd.h>
  45
  46 #include <libspamc.h>
  47
  48 /*----- Main code ---------------------------------------------------------*/
  49
  50 static const char *strenv(const char *e, const char *d)
  51 {
  52   const char *p = getenv(e);
  53   if (!p) return (d);
  54   return (p);
  55 }
  56
  57 static double dblenv(const char *e, double d)
  58 {
  59   const char *p = getenv(e);
  60   char *q;
  61   int err = errno;
  62   double f;
  63   if (!p) return (d);
  64   errno = 0;
  65   f = strtod(p, &q);
  66   if (errno) return (d);
  67   errno = err;
  68   return (f);
  69 }
  70
  71 static int intenv(const char *e, int d)
  72 {
  73   const char *p = getenv(e);
  74   char *q;
  75   int err = errno;
  76   long l;
  77   if (!p) return (d);
  78   errno = 0;
  79   l = strtol(p, &q, 0);
  80   if (errno) return (d);
  81   errno = err;
  82   if (l < 0 || l > INT_MAX) return (d);
  83   return ((int)l);
  84 }
  85
  86 int shovel(int from, int to)
  87 {
  88   char buf[4096];
  89   ssize_t n;
  90   char *p;
  91   size_t r;
  92
  93   for (;;) {
  94     n = read(from, buf, sizeof(buf));
  95     if (n < 0 && errno != EINTR && errno != EAGAIN)
  96       return (-1);
  97     else if (!n)
  98       return (0);
  99     p = buf;
 100     r = n;
 101     while (r) {
 102       n = write(to, p, n);
 103       if (n <= 0 && errno != EINTR && errno != EAGAIN)
 104         return (-1);
 105       r -= n;
 106       p += n;
 107     }
 108   }
 109 }
 110
 111 int main(int argc, char *argv[])
 112 {
 113   struct sockaddr sa;
 114   struct message m;
 115   int fd_m[2], fd_e[2];
 116   pid_t kid;
 117   int rc;
 118
 119   m.max_len = intenv("QMAIL_CHECKSPAM_MAXLEN", 2 * 1024 * 1024);
 120   m.timeout = intenv("QMAIL_CHECKSPAM_TIMEOUT", 300);
 121   rc = message_read(0, 0, &m);
 122   if (rc != 0 && rc != EX_TOOBIG)
 123     return (54);
 124   if (!rc) {
 125     if (lookup_host(strenv("QMAIL_CHECKSPAM_SPAMDHOST", "localhost"),
 126                     intenv("QMAIL_CHECKSPAM_SPAMDPORT", 783),
 127                     &sa))
 128       return (56);
 129     if (message_filter(&sa, "spamd", 0, &m))
 130       return (74);
 131     if (m.score >= dblenv("QMAIL_CHECKSPAM_THRESH", m.threshold))
 132       return (31);
 133   }
 134   if (pipe(fd_m) || pipe(fd_e))
 135     return (56);
 136   if ((kid = fork()) < 0)
 137     return (56);
 138   if (!kid) {
 139     close(fd_m[0]);
 140     close(fd_e[0]);
 141     if (message_write(fd_m[1], &m) < 0)
 142       _exit(127);
 143     if (rc == EX_TOOBIG && shovel(0, fd_m[1]))
 144       _exit(127);
 145     close(fd_m[1]);
 146     if (shovel(1, fd_e[1]))
 147       _exit(127);
 148     close(fd_e[1]);
 149     _exit(0);
 150   }
 151
 152   dup2(fd_m[0], 0);
 153   dup2(fd_e[0], 1);
 154   close(fd_m[0]);
 155   close(fd_e[0]);
 156   close(fd_m[1]);
 157   close(fd_e[1]);
 158   execlp(strenv("QMAIL_CHECKSPAM_QUEUE", "/var/qmail/bin/qmail-queue"),
 159          (char *)0);
 160   fprintf(stderr, "failed to exec: %s\n", strerror(errno));
 161   return (56);
 162 }
 163
 164 /*----- That's all, folks -------------------------------------------------*/