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

   1 /* -*-c-*-
   2  *
   3  * $Id: qmail-checkspam.c,v 1.2 2004/04/08 01:36:26 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 /*----- Header files ------------------------------------------------------*/
  28
  29 #include <ctype.h>
  30 #include <errno.h>
  31 #include <limits.h>
  32 #include <stdio.h>
  33 #include <stdlib.h>
  34 #include <string.h>
  35
  36 #include <sys/types.h>
  37 #include <sys/unistd.h>
  38
  39 #include <libspamc.h>
  40
  41 /*----- Main code ---------------------------------------------------------*/
  42
  43 static const char *strenv(const char *e, const char *d)
  44 {
  45   const char *p = getenv(e);
  46   if (!p) return (d);
  47   return (p);
  48 }
  49
  50 static double dblenv(const char *e, double d)
  51 {
  52   const char *p = getenv(e);
  53   char *q;
  54   int err = errno;
  55   double f;
  56   if (!p) return (d);
  57   errno = 0;
  58   f = strtod(p, &q);
  59   if (errno) return (d);
  60   errno = err;
  61   return (f);
  62 }
  63
  64 static int intenv(const char *e, int d)
  65 {
  66   const char *p = getenv(e);
  67   char *q;
  68   int err = errno;
  69   long l;
  70   if (!p) return (d);
  71   errno = 0;
  72   l = strtol(p, &q, 0);
  73   if (errno) return (d);
  74   errno = err;
  75   if (l < 0 || l > INT_MAX) return (d);
  76   return ((int)l);
  77 }
  78
  79 int shovel(int from, int to)
  80 {
  81   char buf[4096];
  82   ssize_t n;
  83   char *p;
  84   size_t r;
  85
  86   for (;;) {
  87     n = read(from, buf, sizeof(buf));
  88     if (n < 0 && errno != EINTR && errno != EAGAIN)
  89       return (-1);
  90     else if (!n)
  91       return (0);
  92     p = buf;
  93     r = n;
  94     while (r) {
  95       n = write(to, p, n);
  96       if (n <= 0 && errno != EINTR && errno != EAGAIN)
  97         return (-1);
  98       r -= n;
  99       p += n;
 100     }
 101   }
 102 }
 103
 104 int main(int argc, char *argv[])
 105 {
 106   struct sockaddr sa;
 107   struct message m;
 108   int fd_m[2], fd_e[2];
 109   pid_t kid;
 110   const char *qmq;
 111   int rc;
 112
 113   if (getenv("RELAYCLIENT")) goto exec;
 114   m.max_len = intenv("QMAIL_CHECKSPAM_MAXLEN", 2 * 1024 * 1024);
 115   m.timeout = intenv("QMAIL_CHECKSPAM_TIMEOUT", 300);
 116   rc = message_read(0, 0, &m);
 117   if (rc != 0 && rc != EX_TOOBIG)
 118     return (54);
 119   if (!rc) {
 120     if (lookup_host(strenv("QMAIL_CHECKSPAM_SPAMDHOST", "localhost"),
 121                     intenv("QMAIL_CHECKSPAM_SPAMDPORT", 783),
 122                     &sa))
 123       return (56);
 124     if (message_filter(&sa, "spamd", 0, &m))
 125       return (74);
 126     if (m.score >= dblenv("QMAIL_CHECKSPAM_THRESH", m.threshold))
 127       return (31);
 128   }
 129   if (pipe(fd_m) || pipe(fd_e))
 130     return (56);
 131   if ((kid = fork()) < 0)
 132     return (56);
 133   if (!kid) {
 134     close(fd_m[0]);
 135     close(fd_e[0]);
 136     if (message_write(fd_m[1], &m) < 0)
 137       _exit(127);
 138     if (rc == EX_TOOBIG && shovel(0, fd_m[1]))
 139       _exit(127);
 140     close(fd_m[1]);
 141     if (shovel(1, fd_e[1]))
 142       _exit(127);
 143     close(fd_e[1]);
 144     _exit(0);
 145   }
 146
 147   dup2(fd_m[0], 0);
 148   dup2(fd_e[0], 1);
 149   close(fd_m[0]);
 150   close(fd_e[0]);
 151   close(fd_m[1]);
 152   close(fd_e[1]);
 153 exec:
 154   qmq = strenv("QMAIL_CHECKSPAM_QUEUE", "/var/qmail/bin/qmail-queue");
 155   execlp(qmq, qmq, (char *)0);
 156   fprintf(stderr, "failed to exec: %s\n", strerror(errno));
 157   return (56);
 158 }
 159
 160 /*----- That's all, folks -------------------------------------------------*/