+++ /dev/null
-/*
- * Functions which handle hostname/address lookups and resolution
- *
- * Copyright (c) 1987-2011 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 as published by
- * the Free Software Foundation; either version 3 of the License, or
- * (at your option) any later version.
- *
- * 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.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- */
-
-#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 <netinet/in.h>
-#include <arpa/inet.h>
-#include <limits.h>
-#include <netdb.h>
-#include <string.h>
-#include <errno.h>
-#include <syslog.h>
-#include <libcitadel.h>
-#include "citadel.h"
-#include "server.h"
-#include "locate_host.h"
-#include "sysdep_decls.h"
-#include "config.h"
-#include "domain.h"
-#include "context.h"
-#include "ctdl_module.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
-
-/** START:some missing macros on OpenBSD 3.9 */
-#ifndef NS_CMPRSFLGS
-#define NS_CMPRSFLGS 0xc0
-#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
-# define NS_GET16 GETSHORT
-#endif
-
-/** END:some missing macros on OpenBSD 3.9 */
-
-/*
- * 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 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]);
- }
-}
-
-
-/*
- * 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;
- static int res_initted = 0;
-
- if (!res_initted) { /* only have to do this once */
- res_init();
- res_initted = 1;
- }
-
- /* Make our DNS query. */
- answer = fixedans;
- 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 (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);
- }
- }
- 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';
-
-
- /* 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.
- */
- 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 (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 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)
-{
- char tbuf[256] = "";
- int suffix_pos = 0;
- int rbl;
- int num_rbl;
- char rbl_domains[SIZ];
- char txt_answer[1024];
-
- strcpy(message_to_spammer, "ok");
-
- if ((strchr(CC->cs_addr, '.')) && (!strchr(CC->cs_addr, ':'))) {
- int a1, a2, a3, a4;
-
- sscanf(CC->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(CC->cs_addr, '.')) && (strchr(CC->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, CC->cs_addr, sizeof tbuf);
- num_colons = haschar(tbuf, ':');
- if ((num_colons < 2) || (num_colons > 7)) return(0); /* badly formed address */
-
- /* expand the "::" shorthand */
- while (num_colons < 7) {
- ptr = strstr(tbuf, "::");
- if (!ptr) return(0); /* 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) return(0);
-
- /* 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 {
- return(0); /* unknown address format */
- }
-
- /* 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) {
- extract_token(&tbuf[suffix_pos], rbl_domains, rbl, '|', (sizeof tbuf - suffix_pos));
-
- if (rblcheck_backend(tbuf, txt_answer, sizeof txt_answer)) {
- strcpy(message_to_spammer, txt_answer);
- syslog(LOG_INFO, "RBL: %s\n", txt_answer);
- return(1);
- }
- }
-
- 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;
- 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