* extract_token() now expects to be supplied with the size of the

[citadel.git] / citadel / serv_spam.c

diff --git a/citadel/serv_spam.c b/citadel/serv_spam.c
index 21dfb6068d84d0928ae083d7e6530ff95513a568..8cdca5648ba1551767a6dfff89609a82eb246705 100644 (file)
--- a/citadel/serv_spam.c
+++ b/citadel/serv_spam.c
@@ -1,11 +1,13 @@
 /*
  * $Id$
  *
- * Reject incoming SMTP messages containing strings that tell us that the
- * message is probably spam.
- *
+ * This module allows Citadel to use SpamAssassin to filter incoming messages
+ * arriving via SMTP.  For more information on SpamAssassin, visit
+ * http://www.spamassassin.org (the SpamAssassin project is not in any way
+ * affiliated with the Citadel project).
  */
 
+#define SPAMASSASSIN_PORT       "783"
 
 #include "sysdep.h"
 #include <stdlib.h>
@@ -31,6 +33,7 @@
 #include <sys/wait.h>
 #include <string.h>
 #include <limits.h>
+#include <sys/socket.h>
 #include "citadel.h"
 #include "server.h"
 #include "sysdep_decls.h"
@@ -38,7 +41,7 @@
 #include "support.h"
 #include "config.h"
 #include "control.h"
-#include "dynloader.h"
+#include "serv_extensions.h"
 #include "room_ops.h"
 #include "user_ops.h"
 #include "policy.h"
@@ -46,8 +49,17 @@
 #include "msgbase.h"
 #include "tools.h"
 #include "internet_addressing.h"
+#include "domain.h"
+#include "clientsocket.h"
+
 
 
+/* 
+ * This is a scanner I had started writing before deciding to just farm the
+ * job out to SpamAssassin.  It *does* work but it's not in use.  We've
+ * commented it out so it doesn't even compile.
+ */
+#ifdef ___NOT_CURRENTLY_IN_USE___
 /* Scan a message for spam */
 int spam_filter(struct CtdlMessage *msg) {
        int spam_strings_found = 0;
@@ -71,19 +83,118 @@ int spam_filter(struct CtdlMessage *msg) {
 
        if (spam_strings_found) {
                if (msg->cm_fields['0'] != NULL) {
-                       phree(msg->cm_fields['0']);
+                       free(msg->cm_fields['0']);
                }
-               msg->cm_fields['0'] = strdoop("Unsolicited spam rejected");
+               msg->cm_fields['0'] = strdup("Unsolicited spam rejected");
                return(spam_strings_found);
        }
 
        return(0);
 }
+#endif
+
+
+
+/*
+ * Connect to the SpamAssassin server and scan a message.
+ */
+int spam_assassin(struct CtdlMessage *msg) {
+       int sock = (-1);
+       char sahosts[SIZ];
+       int num_sahosts;
+       char buf[SIZ];
+       int is_spam = 0;
+       int sa;
+       char *msgtext;
+       size_t msglen;
+
+       /* For users who have authenticated to this server we never want to
+        * apply spam filtering, because presumably they're trustworthy.
+        */
+       if (CC->logged_in) return(0);
+
+       /* See if we have any SpamAssassin hosts configured */
+       num_sahosts = get_hosts(sahosts, "spamassassin");
+       if (num_sahosts < 1) return(0);
+
+       /* Try them one by one until we get a working one */
+        for (sa=0; sa<num_sahosts; ++sa) {
+                extract_token(buf, sahosts, sa, '|', sizeof buf);
+                lprintf(CTDL_INFO, "Connecting to SpamAssassin at <%s>\n", buf);
+                sock = sock_connect(buf, SPAMASSASSIN_PORT, "tcp");
+                if (sock >= 0) lprintf(CTDL_DEBUG, "Connected!\n");
+        }
+
+       if (sock < 0) {
+               /* If the service isn't running, just pass the mail
+                * through.  Potentially throwing away mails isn't good.
+                */
+               return(0);
+       }
+
+       /* Command */
+       lprintf(CTDL_DEBUG, "Transmitting command\n");
+       sprintf(buf, "CHECK SPAMC/1.2\r\n\r\n");
+       sock_write(sock, buf, strlen(buf));
+
+       /* Message */
+       CC->redirect_buffer = malloc(SIZ);
+       CC->redirect_len = 0;
+       CC->redirect_alloc = SIZ;
+       CtdlOutputPreLoadedMsg(msg, 0L, MT_RFC822, HEADERS_ALL, 0, 1);
+       msgtext = CC->redirect_buffer;
+       msglen = CC->redirect_len;
+       CC->redirect_buffer = NULL;
+       CC->redirect_len = 0;
+       CC->redirect_alloc = 0;
+
+       sock_write(sock, msgtext, msglen);
+       free(msgtext);
+
+       /* Close one end of the socket connection; this tells SpamAssassin
+        * that we're done.
+        */
+       sock_shutdown(sock, SHUT_WR);
+       
+       /* Response */
+       lprintf(CTDL_DEBUG, "Awaiting response\n");
+        if (sock_gets(sock, buf) < 0) {
+                goto bail;
+        }
+        lprintf(CTDL_DEBUG, "<%s\n", buf);
+       if (strncasecmp(buf, "SPAMD", 5)) {
+               goto bail;
+       }
+        if (sock_gets(sock, buf) < 0) {
+                goto bail;
+        }
+        lprintf(CTDL_DEBUG, "<%s\n", buf);
+       if (!strncasecmp(buf, "Spam: True", 10)) {
+               is_spam = 1;
+       }
+
+       if (is_spam) {
+               if (msg->cm_fields['0'] != NULL) {
+                       free(msg->cm_fields['0']);
+               }
+               msg->cm_fields['0'] = strdup(
+                       "5.7.1 Message rejected by SpamAssassin");
+       }
+
+bail:  close(sock);
+       return(is_spam);
+}
 
 
 
-char *Dynamic_Module_Init(void)
+char *serv_spam_init(void)
 {
+
+/* (disabled built-in scanner, see above)
        CtdlRegisterMessageHook(spam_filter, EVT_SMTPSCAN);
+ */
+
+       CtdlRegisterMessageHook(spam_assassin, EVT_SMTPSCAN);
+
         return "$Id$";
 }