*
*/
-#ifdef DLL_EXPORT
-#define IN_LIBCIT
-#endif
-
#include "sysdep.h"
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
+#include <ctype.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <limits.h>
#include <netdb.h>
#include <string.h>
+#include <libcitadel.h>
#include "citadel.h"
#include "server.h"
-#include "dynloader.h"
#include "locate_host.h"
#include "sysdep_decls.h"
#include "config.h"
-#include "tools.h"
+#include "domain.h"
+
+#ifdef HAVE_RESOLV_H
+#include <arpa/nameser.h>
+#ifdef HAVE_ARPA_NAMESER_COMPAT_H
+#include <arpa/nameser_compat.h>
+#endif
+#include <resolv.h>
+#endif
+
+
+/* Hacks to work around nameser.h declarations missing on OpenBSD
+ * see also: http://search.cpan.org/src/MIKER/Net-DNS-ToolKit-0.30/ToolKit.h
+ */
+
+#ifndef NS_INT16SZ
+# ifdef INT16SZ
+# define NS_INT16SZ INT16SZ
+# endif
+#endif
-void locate_host(char *tbuf, size_t n, const struct in_addr *addr)
+#ifndef NS_INT32SZ
+# ifdef INT32SZ
+# define NS_INT32SZ INT32SZ
+# endif
+#endif
+
+#ifndef NS_GET16
+# ifdef GETSHORT
+# define NS_GET16 GETSHORT
+# endif
+#endif
+
+
+/***************************************************************************/
+
+
+void locate_host(char *tbuf, size_t n,
+ char *abuf, size_t na,
+ const struct in_addr *addr)
{
struct hostent *ch;
- char *i;
+ const char *i;
+ char *j;
int a1, a2, a3, a4;
+ char address_string[SIZ];
- lprintf(9, "locate_host() called\n");
#ifdef HAVE_NONREENTRANT_NETDB
begin_critical_section(S_NETDB);
#endif
- if ((ch = gethostbyaddr((char *) addr, sizeof(*addr), AF_INET)) ==
- NULL) {
- bad_dns:
- i = (char *) addr;
- a1 = ((*i++) & 0xff);
- a2 = ((*i++) & 0xff);
- a3 = ((*i++) & 0xff);
- a4 = ((*i++) & 0xff);
- snprintf(tbuf, n, "%d.%d.%d.%d", a1, a2, a3, a4);
+ 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 */
}
/* check if the forward DNS agrees; if not, they're spoofing */
- i = strdoop(ch->h_name);
- ch = gethostbyname(i);
- phree(i);
+ j = strdup(ch->h_name);
+ ch = gethostbyname(j);
+ free(j);
if (ch == NULL)
goto bad_dns;
#endif
tbuf[63] = 0;
- lprintf(9, "locate_host() exiting\n");
+}
+
+
+/*
+ * RBL check written by Edward S. Marshall [http://rblcheck.sourceforge.net]
+ */
+#define RESULT_SIZE 4096 /* What is the longest result text we support? */
+int rblcheck_backend(char *domain, char *txtbuf, int txtbufsize) {
+ int a, b, c;
+ char *result = NULL;
+ u_char fixedans[ PACKETSZ ];
+ u_char *answer;
+ int need_to_free_answer = 0;
+ const u_char *cp;
+ u_char *rp;
+ const u_char *cend;
+ const u_char *rend;
+ int len;
+ char *p = NULL;
+
+ /* Make our DNS query. */
+ //res_init();
+ answer = fixedans;
+ len = res_query( domain, C_IN, T_A, answer, PACKETSZ );
+
+ /* Was there a problem? If so, the domain doesn't exist. */
+ if( len == -1 ) {
+ if (txtbuf != NULL) {
+ strcpy(txtbuf, "");
+ }
+ return(0);
+ }
+
+ if( len > PACKETSZ )
+ {
+ answer = malloc( len );
+ need_to_free_answer = 1;
+ len = res_query( domain, C_IN, T_A, answer, len );
+ if( len == -1 ) {
+ if (txtbuf != NULL) {
+ snprintf(txtbuf, txtbufsize,
+ "Message rejected due to known spammer source IP address");
+ }
+ if (need_to_free_answer) free(answer);
+ return(1);
+ }
+ }
+
+ result = ( char * )malloc( RESULT_SIZE );
+ result[ 0 ] = '\0';
+
+
+ /* Make another DNS query for textual data; this shouldn't
+ be a performance hit, since it'll now be cached at the
+ nameserver we're using. */
+ res_init();
+ len = res_query( domain, C_IN, T_TXT, answer, PACKETSZ );
+
+ /* Just in case there's no TXT record... */
+ if( len == -1 )
+ {
+ if (txtbuf != NULL) {
+ snprintf(txtbuf, txtbufsize,
+ "Message rejected due to known spammer source IP address");
+ }
+ if (need_to_free_answer) free(answer);
+ free(result);
+ return(1);
+ }
+
+ /* Skip the header and the address we queried. */
+ cp = answer + sizeof( HEADER );
+ while( *cp != '\0' )
+ {
+ a = *cp++;
+ while( a-- )
+ cp++;
+ }
+
+ /* This seems to be a bit of magic data that we need to
+ skip. I wish there were good online documentation
+ for programming for libresolv, so I'd know what I'm
+ skipping here. Anyone reading this, feel free to
+ enlighten me. */
+ cp += 1 + NS_INT16SZ + NS_INT32SZ;
+
+ /* Skip the type, class and ttl. */
+ cp += ( NS_INT16SZ * 2 ) + NS_INT32SZ;
+
+ /* Get the length and end of the buffer. */
+ NS_GET16( c, cp );
+ cend = cp + c;
+
+ /* Iterate over any multiple answers we might have. In
+ this context, it's unlikely, but anyway. */
+ rp = (u_char *) result;
+ rend = (u_char *) result + RESULT_SIZE - 1;
+ while( cp < cend && rp < rend )
+ {
+ a = *cp++;
+ if( a != 0 )
+ for( b = a; b > 0 && cp < cend && rp < rend;
+ b-- )
+ {
+ if( *cp == '\n' || *cp == '"' ||
+ *cp == '\\' )
+ {
+ *rp++ = '\\';
+ }
+ *rp++ = *cp++;
+ }
+ }
+ *rp = '\0';
+ if (txtbuf != NULL) {
+ snprintf(txtbuf, txtbufsize, "%s", result);
+ }
+ /* Remove nonprintable characters */
+ for (p=txtbuf; *p; ++p) {
+ if (!isprint(*p)) strcpy(p, p+1);
+ }
+ if (need_to_free_answer) free(answer);
+ free(result);
+ return(1);
+}
+
+
+/*
+ * 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];
+ char txt_answer[1024];
+
+ 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 (rblcheck_backend(tbuf, txt_answer, sizeof txt_answer)) {
+ sprintf(message_to_spammer, "5.7.1 %s", txt_answer);
+ lprintf(CTDL_INFO, "RBL: %s\n", txt_answer);
+ 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 */
+
+ len = 0;
+ memset (&sin, 0, sizeof (struct sockaddr_in));
+ 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);
}
projects / citadel.git / blobdiff