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 int masked_match(char *tok, char *slash, char *s)
24 if ((addr = interpret_addr(s)) == INADDR_NONE)
27 net = interpret_addr(tok);
30 if (strlen(slash + 1) > 2) {
31 mask = interpret_addr(slash + 1);
33 mask = (uint32)((ALLONES << atoi(slash + 1)) ^ ALLONES);
36 if (net == INADDR_NONE || mask == INADDR_NONE) {
37 DEBUG(0,("access: bad net/mask access control: %s\n", tok));
40 return ((addr & mask) == net);
43 /* string_match - match string against token */
44 static int string_match(char *tok,char *s, char *invalid_char)
52 /* Return True if a token has the magic value "ALL". Return
53 * FAIL if the token is "FAIL". If the token starts with a "."
54 * (domain name), return True if it matches the last fields of
55 * the string. If the token has the magic value "LOCAL",
56 * return True if the string does not contain a "."
57 * character. If the token ends on a "." (network number),
58 * return True if it matches the first fields of the
59 * string. If the token begins with a "@" (netgroup name),
60 * return True if the string is a (host) member of the
61 * netgroup. Return True if the token fully matches the
62 * string. If the token is a netnumber/netmask pair, return
63 * True if the address is a member of the specified subnet.
66 if (tok[0] == '.') { /* domain: match last fields */
67 if ((str_len = strlen(s)) > (tok_len = strlen(tok))
68 && strcasecmp(tok, s + str_len - tok_len) == 0)
70 } else if (tok[0] == '@') { /* netgroup: look it up */
72 static char *mydomain = NULL;
73 char *hostname = NULL;
74 BOOL netgroup_ok = False;
76 if (!mydomain) yp_get_default_domain(&mydomain);
79 DEBUG(0,("Unable to get default yp domain.\n"));
82 if (!(hostname = strdup(s))) {
83 DEBUG(1,("out of memory for strdup!\n"));
87 netgroup_ok = innetgr(tok + 1, hostname, (char *) 0, mydomain);
89 DEBUG(5,("looking for %s of domain %s in netgroup %s gave %s\n",
93 BOOLSTR(netgroup_ok)));
97 if (netgroup_ok) return(True);
99 DEBUG(0,("access: netgroup support is not configured\n"));
102 } else if (strcasecmp(tok, "ALL") == 0) { /* all: match any */
104 } else if (strcasecmp(tok, "FAIL") == 0) { /* fail: match any */
106 } else if (strcasecmp(tok, "LOCAL") == 0) { /* local: no dots */
107 if (strchr_m(s, '.') == 0 && strcasecmp(s, "unknown") != 0)
109 } else if (!strcasecmp(tok, s)) { /* match host name or address */
111 } else if (tok[(tok_len = strlen(tok)) - 1] == '.') { /* network */
112 if (strncmp(tok, s, tok_len) == 0)
114 } else if ((cut = strchr_m(tok, '/')) != 0) { /* netnumber/netmask */
115 if (isdigit((int)s[0]) && masked_match(tok, cut, s))
117 } else if (strchr_m(tok, '*') != 0) {
119 } else if (strchr_m(tok, '?') != 0) {
126 /* client_match - match host name and address against token */
127 static int client_match(char *tok,char *item)
129 char **client = (char **)item;
131 char invalid_char = '\0';
134 * Try to match the address first. If that fails, try to match the host
138 if ((match = string_match(tok, client[1], &invalid_char)) == 0) {
140 DEBUG(0,("client_match: address match failing due to invalid character '%c' found in \
141 token '%s' in an allow/deny hosts line.\n", invalid_char, tok ));
143 if (client[0][0] != 0)
144 match = string_match(tok, client[0], &invalid_char);
147 DEBUG(0,("client_match: address match failing due to invalid character '%c' found in \
148 token '%s' in an allow/deny hosts line.\n", invalid_char, tok ));
154 /* list_match - match an item against a list of tokens with exceptions */
155 static int list_match(char **list,char *item, int (*match_fn)(char *, char *))
159 if (!list) return False;
162 * Process tokens one at a time. We have exhausted all possible matches
163 * when we reach an "EXCEPT" token or the end of the list. If we do find
164 * a match, look for an "EXCEPT" list and recurse to determine whether
165 * the match is affected by any exceptions.
168 for (; *list ; list++) {
169 if (strcasecmp(*list, "EXCEPT") == 0) /* EXCEPT: give up */
171 if ((match = (*match_fn) (*list, item))) /* True or FAIL */
174 /* Process exceptions to True or FAIL matches. */
176 if (match != False) {
177 while (*list && strcasecmp(*list, "EXCEPT"))
180 for (; *list; list++) {
181 if ((*match_fn) (*list, item)) /* Exception Found */
190 /* return true if access should be allowed */
191 BOOL allow_access(char **deny_list,char **allow_list,
192 char *cname,char *caddr)
199 /* if it is loopback then always allow unless specifically denied */
200 if (strcmp(caddr, "127.0.0.1") == 0) {
202 * If 127.0.0.1 matches both allow and deny then allow.
203 * Patch from Steve Langasek vorlon@netexpress.net.
206 list_match(deny_list,(char *)client,client_match) &&
208 !list_match(allow_list,(char *)client, client_match))) {
214 /* if theres no deny list and no allow list then allow access */
215 if ((!deny_list || *deny_list == 0) &&
216 (!allow_list || *allow_list == 0)) {
220 /* if there is an allow list but no deny list then allow only hosts
222 if (!deny_list || *deny_list == 0)
223 return(list_match(allow_list,(char *)client,client_match));
225 /* if theres a deny list but no allow list then allow
226 all hosts not on the deny list */
227 if (!allow_list || *allow_list == 0)
228 return(!list_match(deny_list,(char *)client,client_match));
230 /* if there are both types of list then allow all hosts on the
232 if (list_match(allow_list,(char *)client,client_match))
235 /* if there are both types of list and it's not on the allow then
236 allow it if its not on the deny */
237 if (list_match(deny_list,(char *)client,client_match))
243 /* return true if the char* contains ip addrs only. Used to avoid
244 gethostbyaddr() calls */
245 static BOOL only_ipaddrs_in_list(char** list)
249 if (!list) return True;
251 for (; *list ; list++)
253 /* factor out the special strings */
254 if (!strcasecmp(*list, "ALL") || !strcasecmp(*list, "FAIL") ||
255 !strcasecmp(*list, "EXCEPT"))
260 if (!is_ipaddress(*list))
264 * if we failed, make sure that it was not because the token
265 * was a network/netmask pair. Only network/netmask pairs
268 if ((p=strchr_m(*list, '/')) == NULL)
271 DEBUG(3,("only_ipaddrs_in_list: list has non-ip address (%s)\n", *list));
280 /* return true if access should be allowed to a service for a socket */
281 BOOL check_access(int sock, char **allow_list, char **deny_list)
284 BOOL only_ip = False;
286 if ((!deny_list || *deny_list==0) && (!allow_list || *allow_list==0))
293 /* bypass gethostbyaddr() calls if the lists only contain IP addrs */
294 if (only_ipaddrs_in_list(allow_list) && only_ipaddrs_in_list(deny_list))
297 DEBUG (3, ("check_access: no hostnames in host allow/deny list.\n"));
298 ret = allow_access(deny_list,allow_list, "", get_socket_addr(sock));
302 DEBUG (3, ("check_access: hostnames in host allow/deny list.\n"));
303 ret = allow_access(deny_list,allow_list, get_socket_name(sock),
304 get_socket_addr(sock));
309 DEBUG(2,("Allowed connection from %s (%s)\n",
310 only_ip ? "" : get_socket_name(sock),
311 get_socket_addr(sock)));
315 DEBUG(0,("Denied connection from %s (%s)\n",
316 only_ip ? "" : get_socket_name(sock),
317 get_socket_addr(sock)));