/*
- * $Id$
+ * Functions which handle hostname/address lookups and resolution
*
- * locate the originating host
+ * Copyright (c) 1987-2019 by the citadel.org team
*
+ * This program is open source software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 3.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
*/
#include "sysdep.h"
-#include <stdlib.h>
-#include <unistd.h>
+#include <string.h>
#include <stdio.h>
+#include <syslog.h>
#include <ctype.h>
-#include <signal.h>
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <netinet/in.h>
-#include <limits.h>
#include <netdb.h>
-#include <string.h>
-#include "citadel.h"
-#include "server.h"
-#include "locate_host.h"
-#include "sysdep_decls.h"
-#include "config.h"
-#include "tools.h"
-#include "domain.h"
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <libcitadel.h>
+#include "context.h"
#ifdef HAVE_RESOLV_H
#include <arpa/nameser.h>
#ifdef HAVE_ARPA_NAMESER_COMPAT_H
#include <resolv.h>
#endif
+#include "domain.h"
+#include "locate_host.h"
-/* 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
+/* START: some missing macros on OpenBSD 3.9 */
+#ifndef NS_CMPRSFLGS
+#define NS_CMPRSFLGS 0xc0
#endif
-
-#ifndef NS_INT32SZ
-# ifdef INT32SZ
-# define NS_INT32SZ INT32SZ
-# endif
+#if !defined(NS_MAXCDNAME) && defined (MAXCDNAME)
+#define NS_MAXCDNAME MAXCDNAME
+#endif
+#if !defined(NS_INT16SZ) && defined(INT16SZ)
+#define NS_INT16SZ INT16SZ
+#define NS_INT32SZ INT32SZ
#endif
-
#ifndef NS_GET16
-# ifdef GETSHORT
# define NS_GET16 GETSHORT
-# endif
#endif
+/* END: some missing macros on OpenBSD 3.9 */
-/***************************************************************************/
-
-
-void locate_host(char *tbuf, size_t n,
- char *abuf, size_t na,
- const struct in_addr *addr)
+/*
+ * Given an open client socket, return the host name and IP address at the other end.
+ * (IPv4 and IPv6 compatible)
+ */
+void locate_host(char *tbuf, size_t n, char *abuf, size_t na, int client_socket)
{
- struct hostent *ch;
- const char *i;
- char *j;
- int a1, a2, a3, a4;
- char address_string[SIZ];
-
-
-#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 */
+ struct sockaddr_in6 clientaddr;
+ unsigned int addrlen = sizeof(clientaddr);
+
+ tbuf[0] = 0;
+ abuf[0] = 0;
+
+ getpeername(client_socket, (struct sockaddr *)&clientaddr, &addrlen);
+ getnameinfo((struct sockaddr *)&clientaddr, addrlen, tbuf, n, NULL, 0, 0);
+ getnameinfo((struct sockaddr *)&clientaddr, addrlen, abuf, na, NULL, 0, NI_NUMERICHOST);
+
+ /* Convert IPv6-mapped IPv4 addresses back to traditional dotted quad.
+ *
+ * Other code here, such as the RBL check, will expect IPv4 addresses to be represented
+ * as dotted-quad, even if they come in over a hybrid IPv6/IPv4 socket.
+ */
+ if ( (strlen(abuf) > 7) && (!strncasecmp(abuf, "::ffff:", 7)) ) {
+ if (!strcmp(abuf, tbuf)) strcpy(tbuf, &tbuf[7]);
+ strcpy(abuf, &abuf[7]);
}
- /* 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;
}
const u_char *rend;
int len;
char *p = NULL;
+ static int res_initted = 0;
+
+ if (!res_initted) { /* only have to do this once */
+ res_init();
+ res_initted = 1;
+ }
/* Make our DNS query. */
- //res_init();
answer = fixedans;
- len = res_query( domain, C_IN, T_A, answer, PACKETSZ );
+ if (server_shutting_down) {
+ if (txtbuf != NULL) {
+ snprintf(txtbuf, txtbufsize, "System shutting down");
+ }
+ return (1);
+ }
+ 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 (len == -1) {
if (txtbuf != NULL) {
strcpy(txtbuf, "");
}
return(0);
}
- if( len > PACKETSZ )
- {
- answer = malloc( len );
+ if (len > PACKETSZ) {
+ answer = malloc(len);
need_to_free_answer = 1;
- len = res_query( domain, C_IN, T_A, answer, len );
+ 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");
+ snprintf(txtbuf, txtbufsize, "Message rejected due to known spammer source IP address");
}
if (need_to_free_answer) free(answer);
return(1);
}
}
+ if (server_shutting_down) {
+ if (txtbuf != NULL) {
+ snprintf(txtbuf, txtbufsize, "System shutting down");
+ }
+ if (need_to_free_answer) free(answer);
+ return (1);
+ }
- result = ( char * )malloc( RESULT_SIZE );
- result[ 0 ] = '\0';
-
+ 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 );
+ * be a performance hit, since it'll now be cached at the
+ * nameserver we're using.
+ */
+ len = res_query(domain, C_IN, T_TXT, answer, PACKETSZ);
+ if (server_shutting_down) {
+ if (txtbuf != NULL) {
+ snprintf(txtbuf, txtbufsize, "System shutting down");
+ }
+ if (need_to_free_answer) free(answer);
+ free(result);
+ return (1);
+ }
/* Just in case there's no TXT record... */
- if( len == -1 )
- {
+ if (len ==(-1)) {
if (txtbuf != NULL) {
- snprintf(txtbuf, txtbufsize,
- "Message rejected due to known spammer source IP address");
+ snprintf(txtbuf, txtbufsize, "Message rejected due to known spammer source IP address");
}
if (need_to_free_answer) free(answer);
free(result);
/* Skip the header and the address we queried. */
cp = answer + sizeof( HEADER );
- while( *cp != '\0' )
- {
+ 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. */
+ * 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;
+ cp += (NS_INT16SZ * 2) + NS_INT32SZ;
/* Get the length and end of the buffer. */
- NS_GET16( c, cp );
+ NS_GET16(c, cp);
cend = cp + c;
/* Iterate over any multiple answers we might have. In
- this context, it's unlikely, but anyway. */
+ * this context, it's unlikely, but anyway.
+ */
rp = (u_char *) result;
rend = (u_char *) result + RESULT_SIZE - 1;
- while( cp < cend && rp < rend )
- {
+ 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 == '\\' )
- {
+ 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);
+ long len;
+ len = snprintf(txtbuf, txtbufsize, "%s", result);
+
+ /* Remove nonprintable characters */
+ for (p = txtbuf; *p != '\0'; p++) {
+ if (!isprint(*p)) {
+ memmove (p,
+ p + 1,
+ len - (p - txtbuf) - 1);
+ }
+ }
}
if (need_to_free_answer) free(answer);
free(result);
/*
- * Check to see if a host is on some sort of spam list (RBL)
+ * 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_addr(struct in_addr *addr, char *message_to_spammer)
+int rbl_check(char *cs_addr, char *message_to_spammer)
{
- const char *i;
- int a1, a2, a3, a4;
- char tbuf[256];
+ char tbuf[256] = "";
+ int suffix_pos = 0;
int rbl;
+ int rc;
int num_rbl;
char rbl_domains[SIZ];
char txt_answer[1024];
+ struct timeval tx_start;
+ struct timeval tx_finish;
+ rc = 0;
strcpy(message_to_spammer, "ok");
+ gettimeofday(&tx_start, NULL); /* start a stopwatch for performance timing */
- i = (const char *) addr;
- a1 = ((*i++) & 0xff);
- a2 = ((*i++) & 0xff);
- a3 = ((*i++) & 0xff);
- a4 = ((*i++) & 0xff);
+ if ((strchr(cs_addr, '.')) && (!strchr(cs_addr, ':'))) {
+ int a1, a2, a3, a4;
+
+ sscanf(cs_addr, "%d.%d.%d.%d", &a1, &a2, &a3, &a4);
+ snprintf(tbuf, sizeof tbuf, "%d.%d.%d.%d.", a4, a3, a2, a1);
+ suffix_pos = strlen(tbuf);
+ }
+ else if ((!strchr(cs_addr, '.')) && (strchr(cs_addr, ':'))) {
+ int num_colons = 0;
+ int i = 0;
+ char workbuf[sizeof tbuf];
+ char *ptr;
+
+ /* tedious code to expand and reverse an IPv6 address */
+ safestrncpy(tbuf, cs_addr, sizeof tbuf);
+ num_colons = haschar(tbuf, ':');
+ if ((num_colons < 2) || (num_colons > 7))
+ goto finish_rbl; /* badly formed address */
+
+ /* expand the "::" shorthand */
+ while (num_colons < 7) {
+ ptr = strstr(tbuf, "::");
+ if (!ptr)
+ goto finish_rbl; /* badly formed address */
+
+ ++ptr;
+ strcpy(workbuf, ptr);
+ strcpy(ptr, ":");
+ strcat(ptr, workbuf);
+ ++num_colons;
+ }
+
+ /* expand to 32 hex characters with no colons */
+ strcpy(workbuf, tbuf);
+ strcpy(tbuf, "00000000000000000000000000000000");
+ for (i=0; i<8; ++i) {
+ char tokbuf[5];
+ extract_token(tokbuf, workbuf, i, ':', sizeof tokbuf);
+ memcpy(&tbuf[ (i*4) + (4-strlen(tokbuf)) ], tokbuf, strlen(tokbuf) );
+ }
+ if (strlen(tbuf) != 32) {
+ goto finish_rbl;
+ }
+
+ /* now reverse it and add dots */
+ strcpy(workbuf, tbuf);
+ for (i=0; i<32; ++i) {
+ tbuf[i*2] = workbuf[31-i];
+ tbuf[(i*2)+1] = '.';
+ }
+ tbuf[64] = 0;
+ suffix_pos = 64;
+ }
+ else {
+ goto finish_rbl; /* unknown address format */
+ }
/* See if we have any RBL domains configured */
num_rbl = get_hosts(rbl_domains, "rbl");
- if (num_rbl < 1) return(0);
+ if (num_rbl < 1)
+ {
+ goto finish_rbl;
+ }
/* 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)));
+ extract_token(&tbuf[suffix_pos], rbl_domains, rbl, '|', (sizeof tbuf - suffix_pos));
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);
+ strcpy(message_to_spammer, txt_answer);
+ syslog(LOG_INFO, "RBL: %s %s", cs_addr, txt_answer);
+ rc = 1;
}
}
-
- return(0);
+finish_rbl:
+ /* How long did this transaction take? */
+ gettimeofday(&tx_finish, NULL);
+
+ syslog(LOG_WARNING, "rbl: %s [%ld.%06ld] %s",
+ cs_addr,
+ ((tx_finish.tv_sec*1000000 + tx_finish.tv_usec) - (tx_start.tv_sec*1000000 + tx_start.tv_usec)) / 1000000,
+ ((tx_finish.tv_sec*1000000 + tx_finish.tv_usec) - (tx_start.tv_sec*1000000 + tx_start.tv_usec)) % 1000000,
+ (rc)?"found":"none found"
+ );
+
+ return rc;
}
-/*
- * 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.
+ *
+ * FIXME this is obviously not IPv6 compatible.
*/
int hostname_to_dotted_quad(char *addr, char *host) {
struct hostent *ch;
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