2 * Routines to authenticate access to a daemon (hosts allow/deny).
4 * Copyright (C) 1998 Andrew Tridgell
5 * Copyright (C) 2004-2009 Wayne Davison
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 3 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License along
18 * with this program; if not, visit the http://fsf.org website.
23 static int allow_forward_dns;
25 extern const char undetermined_hostname[];
27 static int match_hostname(const char **host_ptr, const char *addr, const char *tok)
31 const char *host = *host_ptr;
36 /* First check if the reverse-DNS-determined hostname matches. */
37 if (iwildmatch(tok, host))
40 if (!allow_forward_dns)
43 /* Fail quietly if tok is an address or wildcarded entry, not a simple hostname. */
44 if (!tok[strspn(tok, ".0123456789")] || tok[strcspn(tok, ":/*?[")])
47 /* Now try forward-DNS on the token (config-specified hostname) and see if the IP matches. */
48 if (!(hp = gethostbyname(tok)))
51 for (i = 0; hp->h_addr_list[i] != NULL; i++) {
52 if (strcmp(addr, inet_ntoa(*(struct in_addr*)(hp->h_addr_list[i]))) == 0) {
53 /* If reverse lookups are off, we'll use the conf-specified
54 * hostname in preference to UNDETERMINED. */
55 if (host == undetermined_hostname) {
56 if (!(*host_ptr = strdup(tok)))
57 *host_ptr = undetermined_hostname;
66 static int match_binary(const char *b1, const char *b2, const char *mask, int addrlen)
70 for (i = 0; i < addrlen; i++) {
71 if ((b1[i] ^ b2[i]) & mask[i])
78 static void make_mask(char *mask, int plen, int addrlen)
86 memset(mask, 0xff, w);
88 mask[w] = 0xff & (0xff<<(8-b));
90 memset(mask+w+1, 0, addrlen-w-1);
95 static int match_address(const char *addr, const char *tok)
98 struct addrinfo hints, *resa, *rest;
108 char *a = NULL, *t = NULL;
117 /* Fail quietly if tok is a hostname, not an address. */
118 if (tok[strspn(tok, ".0123456789")] && strchr(tok, ':') == NULL) {
124 memset(&hints, 0, sizeof(hints));
125 hints.ai_family = PF_UNSPEC;
126 hints.ai_socktype = SOCK_STREAM;
127 #ifdef AI_NUMERICHOST
128 hints.ai_flags = AI_NUMERICHOST;
131 if (getaddrinfo(addr, NULL, &hints, &resa) != 0) {
137 gai = getaddrinfo(tok, NULL, &hints, &rest);
141 rprintf(FLOG, "error matching address %s: %s\n",
142 tok, gai_strerror(gai));
147 if (rest->ai_family != resa->ai_family) {
152 switch(resa->ai_family) {
154 a = (char *)&((struct sockaddr_in *)resa->ai_addr)->sin_addr;
155 t = (char *)&((struct sockaddr_in *)rest->ai_addr)->sin_addr;
163 struct sockaddr_in6 *sin6a, *sin6t;
165 sin6a = (struct sockaddr_in6 *)resa->ai_addr;
166 sin6t = (struct sockaddr_in6 *)rest->ai_addr;
168 a = (char *)&sin6a->sin6_addr;
169 t = (char *)&sin6t->sin6_addr;
173 #ifdef HAVE_SOCKADDR_IN6_SCOPE_ID
174 if (sin6t->sin6_scope_id &&
175 sin6a->sin6_scope_id != sin6t->sin6_scope_id) {
185 rprintf(FLOG, "unknown family %u\n", rest->ai_family);
192 if (inet_pton(resa->ai_addr->sa_family, p, mask) <= 0) {
200 bits = strtol(p, &ep, 10);
202 rprintf(FLOG, "malformed mask in %s\n", tok);
207 for (pp = (unsigned char *)p; *pp; pp++) {
208 if (!isascii(*pp) || !isdigit(*pp)) {
209 rprintf(FLOG, "malformed mask in %s\n", tok);
220 if (bits < 0 || bits > (addrlen << 3)) {
221 rprintf(FLOG, "malformed mask in %s\n", tok);
231 make_mask(mask, bits, addrlen);
233 ret = match_binary(a, t, mask, addrlen);
241 static int access_match(const char *list, const char *addr, const char **host_ptr)
244 char *list2 = strdup(list);
247 out_of_memory("access_match");
251 for (tok = strtok(list2, " ,\t"); tok; tok = strtok(NULL, " ,\t")) {
252 if (match_hostname(host_ptr, addr, tok) || match_address(addr, tok)) {
262 int allow_access(const char *addr, const char **host_ptr, int i)
264 const char *allow_list = lp_hosts_allow(i);
265 const char *deny_list = lp_hosts_deny(i);
267 if (allow_list && !*allow_list)
269 if (deny_list && !*deny_list)
272 allow_forward_dns = lp_forward_lookup(i);
274 /* If we match an allow-list item, we always allow access. */
276 if (access_match(allow_list, addr, host_ptr))
278 /* For an allow-list w/o a deny-list, disallow non-matches. */
283 /* If we match a deny-list item (and got past any allow-list
284 * items), we always disallow access. */
285 if (deny_list && access_match(deny_list, addr, host_ptr))
288 /* Allow all other access. */