2 This module is an adaption of code from the tcpd-1.4 package written
3 by Wietse Venema, Eindhoven University of Technology, The Netherlands.
5 The code is used here with permission.
7 The code has been considerably changed from the original. Bug reports
8 should be sent to samba@samba.org
15 #define ALLONES ((uint32)0xFFFFFFFF)
17 /* masked_match - match address against netnumber/netmask */
18 static BOOL masked_match(const char *tok, const char *slash, const char *s)
25 if ((addr = interpret_addr(s)) == INADDR_NONE)
28 fstrcpy(tok_cpy, tok);
29 tok_cpy[PTR_DIFF(slash,tok)] = '\0';
30 net = interpret_addr(tok_cpy);
31 tok_cpy[PTR_DIFF(slash,tok)] = '/';
33 if (strlen(slash + 1) > 2) {
34 mask = interpret_addr(slash + 1);
36 mask = (uint32)((ALLONES >> atoi(slash + 1)) ^ ALLONES);
39 if (net == INADDR_NONE || mask == INADDR_NONE) {
40 DEBUG(0,("access: bad net/mask access control: %s\n", tok));
44 /* convert to network byte order */
47 return ((addr & mask) == net);
50 /* string_match - match string against token */
51 static BOOL string_match(const char *tok,const char *s, char *invalid_char)
59 /* Return True if a token has the magic value "ALL". Return
60 * FAIL if the token is "FAIL". If the token starts with a "."
61 * (domain name), return True if it matches the last fields of
62 * the string. If the token has the magic value "LOCAL",
63 * return True if the string does not contain a "."
64 * character. If the token ends on a "." (network number),
65 * return True if it matches the first fields of the
66 * string. If the token begins with a "@" (netgroup name),
67 * return True if the string is a (host) member of the
68 * netgroup. Return True if the token fully matches the
69 * string. If the token is a netnumber/netmask pair, return
70 * True if the address is a member of the specified subnet.
73 if (tok[0] == '.') { /* domain: match last fields */
74 if ((str_len = strlen(s)) > (tok_len = strlen(tok))
75 && strcasecmp(tok, s + str_len - tok_len) == 0)
77 } else if (tok[0] == '@') { /* netgroup: look it up */
79 static char *mydomain = NULL;
80 char *hostname = NULL;
81 BOOL netgroup_ok = False;
84 yp_get_default_domain(&mydomain);
87 DEBUG(0,("Unable to get default yp domain.\n"));
90 if (!(hostname = strdup(s))) {
91 DEBUG(1,("out of memory for strdup!\n"));
95 netgroup_ok = innetgr(tok + 1, hostname, (char *) 0, mydomain);
97 DEBUG(5,("looking for %s of domain %s in netgroup %s gave %s\n",
101 BOOLSTR(netgroup_ok)));
108 DEBUG(0,("access: netgroup support is not configured\n"));
111 } else if (strcasecmp(tok, "ALL") == 0) { /* all: match any */
113 } else if (strcasecmp(tok, "FAIL") == 0) { /* fail: match any */
115 } else if (strcasecmp(tok, "LOCAL") == 0) { /* local: no dots */
116 if (strchr_m(s, '.') == 0 && strcasecmp(s, "unknown") != 0)
118 } else if (!strcasecmp(tok, s)) { /* match host name or address */
120 } else if (tok[(tok_len = strlen(tok)) - 1] == '.') { /* network */
121 if (strncmp(tok, s, tok_len) == 0)
123 } else if ((cut = strchr_m(tok, '/')) != 0) { /* netnumber/netmask */
124 if (isdigit((int)s[0]) && masked_match(tok, cut, s))
126 } else if (strchr_m(tok, '*') != 0) {
128 } else if (strchr_m(tok, '?') != 0) {
134 /* client_match - match host name and address against token */
135 static BOOL client_match(const char *tok, const char *item)
137 const char **client = (const char **)item;
139 char invalid_char = '\0';
142 * Try to match the address first. If that fails, try to match the host
146 if ((match = string_match(tok, client[1], &invalid_char)) == 0) {
148 DEBUG(0,("client_match: address match failing due to invalid character '%c' found in \
149 token '%s' in an allow/deny hosts line.\n", invalid_char, tok ));
151 if (client[0][0] != 0)
152 match = string_match(tok, client[0], &invalid_char);
155 DEBUG(0,("client_match: address match failing due to invalid character '%c' found in \
156 token '%s' in an allow/deny hosts line.\n", invalid_char, tok ));
162 /* list_match - match an item against a list of tokens with exceptions */
163 static BOOL list_match(const char **list,const char *item,
164 BOOL (*match_fn)(const char *, const char *))
172 * Process tokens one at a time. We have exhausted all possible matches
173 * when we reach an "EXCEPT" token or the end of the list. If we do find
174 * a match, look for an "EXCEPT" list and recurse to determine whether
175 * the match is affected by any exceptions.
178 for (; *list ; list++) {
179 if (strcasecmp(*list, "EXCEPT") == 0) /* EXCEPT: give up */
181 if ((match = (*match_fn) (*list, item))) /* True or FAIL */
184 /* Process exceptions to True or FAIL matches. */
186 if (match != False) {
187 while (*list && strcasecmp(*list, "EXCEPT"))
190 for (; *list; list++) {
191 if ((*match_fn) (*list, item)) /* Exception Found */
199 /* return true if access should be allowed */
200 static BOOL allow_access_internal(const char **deny_list,const char **allow_list,
201 const char *cname, const char *caddr)
203 const char *client[2];
208 /* if it is loopback then always allow unless specifically denied */
209 if (strcmp(caddr, "127.0.0.1") == 0) {
211 * If 127.0.0.1 matches both allow and deny then allow.
212 * Patch from Steve Langasek vorlon@netexpress.net.
215 list_match(deny_list,(const char *)client,client_match) &&
217 !list_match(allow_list,(const char *)client, client_match))) {
223 /* if theres no deny list and no allow list then allow access */
224 if ((!deny_list || *deny_list == 0) &&
225 (!allow_list || *allow_list == 0)) {
229 /* if there is an allow list but no deny list then allow only hosts
231 if (!deny_list || *deny_list == 0)
232 return(list_match(allow_list,(const char *)client,client_match));
234 /* if theres a deny list but no allow list then allow
235 all hosts not on the deny list */
236 if (!allow_list || *allow_list == 0)
237 return(!list_match(deny_list,(const char *)client,client_match));
239 /* if there are both types of list then allow all hosts on the
241 if (list_match(allow_list,(const char *)client,client_match))
244 /* if there are both types of list and it's not on the allow then
245 allow it if its not on the deny */
246 if (list_match(deny_list,(const char *)client,client_match))
252 /* return true if access should be allowed */
253 BOOL allow_access(const char **deny_list, const char **allow_list,
254 const char *cname, const char *caddr)
257 char *nc_cname = smb_xstrdup(cname);
258 char *nc_caddr = smb_xstrdup(caddr);
260 ret = allow_access_internal(deny_list, allow_list, nc_cname, nc_caddr);
267 /* return true if the char* contains ip addrs only. Used to avoid
268 gethostbyaddr() calls */
270 static BOOL only_ipaddrs_in_list(const char** list)
277 for (; *list ; list++) {
278 /* factor out the special strings */
279 if (!strcasecmp(*list, "ALL") || !strcasecmp(*list, "FAIL") ||
280 !strcasecmp(*list, "EXCEPT")) {
284 if (!is_ipaddress(*list)) {
287 * if we failed, make sure that it was not because the token
288 * was a network/netmask pair. Only network/netmask pairs
291 if ((p=strchr_m(*list, '/')) == NULL) {
293 DEBUG(3,("only_ipaddrs_in_list: list has non-ip address (%s)\n", *list));
302 /* return true if access should be allowed to a service for a socket */
303 BOOL check_access(int sock, const char **allow_list, const char **deny_list)
306 BOOL only_ip = False;
308 if ((!deny_list || *deny_list==0) && (!allow_list || *allow_list==0))
312 /* bypass gethostbyaddr() calls if the lists only contain IP addrs */
313 if (only_ipaddrs_in_list(allow_list) && only_ipaddrs_in_list(deny_list)) {
315 DEBUG (3, ("check_access: no hostnames in host allow/deny list.\n"));
316 ret = allow_access(deny_list,allow_list, "", get_socket_addr(sock));
318 DEBUG (3, ("check_access: hostnames in host allow/deny list.\n"));
319 ret = allow_access(deny_list,allow_list, get_socket_name(sock,True),
320 get_socket_addr(sock));
324 DEBUG(2,("Allowed connection from %s (%s)\n",
325 only_ip ? "" : get_socket_name(sock,True),
326 get_socket_addr(sock)));
328 DEBUG(0,("Denied connection from %s (%s)\n",
329 only_ip ? "" : get_socket_name(sock,True),
330 get_socket_addr(sock)));