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

[citadel.git] / citadel / locate_host.c

diff --git a/citadel/locate_host.c b/citadel/locate_host.c
index d3c194adc2a5658f6a025f0a0732ee2894b9a487..a3ff5c028529102ac7f926f3b9de46fd1193475a 100644 (file)
--- a/citadel/locate_host.c
+++ b/citadel/locate_host.c
@@ -1,7 +1,11 @@
 /*
+ * $Id$
+ *
  * locate the originating host
+ *
  */
 
+#include "sysdep.h"
 #include <stdlib.h>
 #include <unistd.h>
 #include <stdio.h>
@@ -9,40 +13,158 @@
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
+#include <limits.h>
 #include <netdb.h>
 #include <string.h>
-#include <pthread.h>
-#include "sysdep.h"
 #include "citadel.h"
 #include "server.h"
+#include "serv_extensions.h"
+#include "locate_host.h"
+#include "sysdep_decls.h"
+#include "config.h"
+#include "tools.h"
+#include "domain.h"
 
-struct config config;
-
-void locate_host(char *tbuf)
+void locate_host(char *tbuf, size_t n,
+               char *abuf, size_t na,
+               const struct in_addr *addr)
 {
-       struct sockaddr_in      cs;     
-       struct hostent      *   ch;        
-       int                     len;     
-       char *i;
-       int a1,a2,a3,a4;
-       
-    len = sizeof(cs);   
-    if (getpeername(CC->client_socket, (struct sockaddr *)&cs,&len) < 0){   
-       strcpy(tbuf,config.c_fqdn);
-       return;
+       struct hostent *ch;
+       const char *i;
+       char *j;
+       int a1, a2, a3, a4;
+       char address_string[SIZ];
+
+       lprintf(CTDL_DEBUG, "locate_host() called\n");
+
+#ifdef HAVE_NONREENTRANT_NETDB
+       begin_critical_section(S_NETDB);
+#endif
+
+       i = (const char *) addr;
+       a1 = ((*i++) & 0xff);
+       a2 = ((*i++) & 0xff);
+       a3 = ((*i++) & 0xff);
+       a4 = ((*i++) & 0xff);
+       sprintf(address_string, "%d.%d.%d.%d", a1, a2, a3, a4);
+
+       if (abuf != NULL) {
+               safestrncpy(abuf, address_string, na);
+       }
+
+       if ((ch = gethostbyaddr((const char *) addr,
+          sizeof(*addr), AF_INET)) == NULL) {
+bad_dns:
+               safestrncpy(tbuf, address_string, n);
+               goto end;       /* because we might need to end the critical
+                                  section */
        }
-     
-    if((ch = gethostbyaddr((char *) &cs.sin_addr, sizeof(cs.sin_addr),  
-         AF_INET)) == NULL) { 
-               i = (char *) &cs.sin_addr;
-               a1 = ((*i++)&0xff);
-               a2 = ((*i++)&0xff);
-               a3 = ((*i++)&0xff);
-               a4 = ((*i++)&0xff);
-               sprintf(tbuf,"%d.%d.%d.%d",a1,a2,a3,a4);
-               return;
+       /* check if the forward DNS agrees; if not, they're spoofing */
+       j = strdup(ch->h_name);
+       ch = gethostbyname(j);
+       free(j);
+       if (ch == NULL)
+               goto bad_dns;
+
+       /* check address for consistency */
+       for (; *ch->h_addr_list; ch->h_addr_list++)
+               if (!memcmp(*ch->h_addr_list, addr,
+                           sizeof *addr)) {
+                       safestrncpy(tbuf, ch->h_name, 63);
+                       goto end;
                }
+       goto bad_dns;           /* they were spoofing. report a numeric IP
+                                  address. */
+
+      end:
+
+#ifdef HAVE_NONREENTRANT_NETDB
+       end_critical_section(S_NETDB);
+#endif
+
+       tbuf[63] = 0;
+       lprintf(CTDL_DEBUG, "locate_host() exiting\n");
+}
+
+
+/*
+ * Check to see if a host is on some sort of spam list (RBL)
+ * If spammer, returns nonzero and places reason in 'message_to_spammer'
+ */
+int rbl_check_addr(struct in_addr *addr, char *message_to_spammer)
+{
+       const char *i;
+       int a1, a2, a3, a4;
+       char tbuf[256];
+       int rbl;
+       int num_rbl;
+       char rbl_domains[SIZ];
 
-       strncpy(tbuf,ch->h_name, 24);
-       tbuf[24] = 0;
+       strcpy(message_to_spammer, "ok");
+
+       i = (const char *) addr;
+       a1 = ((*i++) & 0xff);
+       a2 = ((*i++) & 0xff);
+       a3 = ((*i++) & 0xff);
+       a4 = ((*i++) & 0xff);
+
+       /* See if we have any RBL domains configured */
+       num_rbl = get_hosts(rbl_domains, "rbl");
+       if (num_rbl < 1) return(0);
+
+       /* Try all configured RBL's */
+        for (rbl=0; rbl<num_rbl; ++rbl) {
+               snprintf(tbuf, sizeof tbuf,
+                       "%d.%d.%d.%d.",
+                       a4, a3, a2, a1);
+                extract_token(&tbuf[strlen(tbuf)], rbl_domains, rbl, '|', (sizeof tbuf - strlen(tbuf)));
+
+               if (gethostbyname(tbuf) != NULL) {
+                       strcpy(message_to_spammer,
+                               "5.7.1 Message rejected due to known spammer source IP address"
+                       );
+                       return(1);
+               }
        }
+
+       return(0);
+}
+                       
+
+/*
+ * Check to see if the client host is on some sort of spam list (RBL)
+ * If spammer, returns nonzero and places reason in 'message_to_spammer'
+ */
+int rbl_check(char *message_to_spammer) {
+       struct sockaddr_in sin;
+       int len;        /* should be socklen_t but doesn't work on Macintosh */
+
+       if (!getpeername(CC->client_socket, (struct sockaddr *) &sin, (socklen_t *)&len)) {
+               return(rbl_check_addr(&sin.sin_addr, message_to_spammer));
+       }
+       return(0);
+}
+
+/*
+ * Convert a host name to a dotted quad address. 
+ * Returns zero on success or nonzero on failure.
+ */
+int hostname_to_dotted_quad(char *addr, char *host) {
+       struct hostent *ch;
+       const char *i;
+       int a1, a2, a3, a4;
+
+       ch = gethostbyname(host);
+       if (ch == NULL) {
+               strcpy(addr, "0.0.0.0");
+               return(1);
+       }
+
+       i = (const char *) ch->h_addr_list[0];
+       a1 = ((*i++) & 0xff);
+       a2 = ((*i++) & 0xff);
+       a3 = ((*i++) & 0xff);
+       a4 = ((*i++) & 0xff);
+       sprintf(addr, "%d.%d.%d.%d", a1, a2, a3, a4);
+       return(0);
+}