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
13 extern int DEBUGLEVEL;
15 /* Delimiters for lists of daemons or clients. */
16 static char *sep = ", \t";
20 /* masked_match - match address against netnumber/netmask */
21 static int masked_match(char *tok, char *slash, char *s)
27 if ((addr = interpret_addr(s)) == INADDR_NONE)
30 net = interpret_addr(tok);
32 if (net == INADDR_NONE ||
33 (mask = interpret_addr(slash + 1)) == INADDR_NONE) {
34 DEBUG(0,("access: bad net/mask access control: %s\n", tok));
37 return ((addr & mask) == net);
40 /* string_match - match string against token */
41 static int string_match(char *tok,char *s, char *invalid_char)
49 /* Return True if a token has the magic value "ALL". Return
50 * FAIL if the token is "FAIL". If the token starts with a "."
51 * (domain name), return True if it matches the last fields of
52 * the string. If the token has the magic value "LOCAL",
53 * return True if the string does not contain a "."
54 * character. If the token ends on a "." (network number),
55 * return True if it matches the first fields of the
56 * string. If the token begins with a "@" (netgroup name),
57 * return True if the string is a (host) member of the
58 * netgroup. Return True if the token fully matches the
59 * string. If the token is a netnumber/netmask pair, return
60 * True if the address is a member of the specified subnet. */
62 if (tok[0] == '.') { /* domain: match last fields */
63 if ((str_len = strlen(s)) > (tok_len = strlen(tok))
64 && strcasecmp(tok, s + str_len - tok_len) == 0)
66 } else if (tok[0] == '@') { /* netgroup: look it up */
68 static char *mydomain = NULL;
69 char *hostname = NULL;
70 BOOL netgroup_ok = False;
72 if (!mydomain) yp_get_default_domain(&mydomain);
75 DEBUG(0,("Unable to get default yp domain.\n"));
78 if (!(hostname = strdup(s))) {
79 DEBUG(1,("out of memory for strdup!\n"));
83 netgroup_ok = innetgr(tok + 1, hostname, (char *) 0, mydomain);
85 DEBUG(5,("looking for %s of domain %s in netgroup %s gave %s\n",
89 BOOLSTR(netgroup_ok)));
93 if (netgroup_ok) return(True);
95 DEBUG(0,("access: netgroup support is not configured\n"));
98 } else if (strcasecmp(tok, "ALL") == 0) { /* all: match any */
100 } else if (strcasecmp(tok, "FAIL") == 0) { /* fail: match any */
102 } else if (strcasecmp(tok, "LOCAL") == 0) { /* local: no dots */
103 if (strchr(s, '.') == 0 && strcasecmp(s, "unknown") != 0)
105 } else if (!strcasecmp(tok, s)) { /* match host name or address */
107 } else if (tok[(tok_len = strlen(tok)) - 1] == '.') { /* network */
108 if (strncmp(tok, s, tok_len) == 0)
110 } else if ((cut = strchr(tok, '/')) != 0) { /* netnumber/netmask */
111 if (isdigit((int)s[0]) && masked_match(tok, cut, s))
113 } else if (strchr(tok, '*') != 0) {
115 } else if (strchr(tok, '?') != 0) {
122 /* client_match - match host name and address against token */
123 static int client_match(char *tok,char *item)
125 char **client = (char **)item;
127 char invalid_char = '\0';
130 * Try to match the address first. If that fails, try to match the host
134 if ((match = string_match(tok, client[1], &invalid_char)) == 0) {
136 DEBUG(0,("client_match: address match failing due to invalid character '%c' found in \
137 token '%s' in an allow/deny hosts line.\n", invalid_char, tok ));
139 if (client[0][0] != 0)
140 match = string_match(tok, client[0], &invalid_char);
143 DEBUG(0,("client_match: address match failing due to invalid character '%c' found in \
144 token '%s' in an allow/deny hosts line.\n", invalid_char, tok ));
150 /* list_match - match an item against a list of tokens with exceptions */
151 static int list_match(char **list,char *item, int (*match_fn)(char *, char *))
155 if (!list) return False;
158 * Process tokens one at a time. We have exhausted all possible matches
159 * when we reach an "EXCEPT" token or the end of the list. If we do find
160 * a match, look for an "EXCEPT" list and recurse to determine whether
161 * the match is affected by any exceptions.
164 for (; *list ; list++) {
165 if (strcasecmp(*list, "EXCEPT") == 0) /* EXCEPT: give up */
167 if ((match = (*match_fn) (*list, item))) /* True or FAIL */
170 /* Process exceptions to True or FAIL matches. */
172 if (match != False) {
173 while (*list && strcasecmp(*list, "EXCEPT"))
176 for (; *list; list++) {
177 if ((*match_fn) (*list, item)) /* Exception Found */
186 /* return true if access should be allowed */
187 BOOL allow_access(char **deny_list,char **allow_list,
188 char *cname,char *caddr)
195 /* if it is loopback then always allow unless specifically denied */
196 if (strcmp(caddr, "127.0.0.1") == 0) {
198 list_match(deny_list,(char *)client,client_match)) {
204 /* if theres no deny list and no allow list then allow access */
205 if ((!deny_list || *deny_list == 0) &&
206 (!allow_list || *allow_list == 0)) {
210 /* if there is an allow list but no deny list then allow only hosts
212 if (!deny_list || *deny_list == 0)
213 return(list_match(allow_list,(char *)client,client_match));
215 /* if theres a deny list but no allow list then allow
216 all hosts not on the deny list */
217 if (!allow_list || *allow_list == 0)
218 return(!list_match(deny_list,(char *)client,client_match));
220 /* if there are both type of list then allow all hosts on the
222 if (list_match(allow_list,(char *)client,client_match))
225 /* if there are both type of list and it's not on the allow then
226 allow it if its not on the deny */
227 if (list_match(deny_list,(char *)client,client_match))
233 /* return true if the char* contains ip addrs only. Used to avoid
234 gethostbyaddr() calls */
235 static BOOL only_ipaddrs_in_list(char** list)
239 if (!list) return True;
241 for (; *list ; list++)
243 /* factor out the special strings */
244 if (!strcasecmp(*list, "ALL") || !strcasecmp(*list, "FAIL") ||
245 !strcasecmp(*list, "EXCEPT"))
250 if (!is_ipaddress(*list))
254 * if we failed, make sure that it was not because the token
255 * was a network/netmask pair. Only network/netmask pairs
258 if ((p=strchr(*list, '/')) == NULL)
261 DEBUG(3,("only_ipaddrs_in_list: list has non-ip address (%s)\n", *list));
270 /* return true if access should be allowed to a service for a socket */
271 BOOL check_access(int sock, char **allow_list, char **deny_list)
274 BOOL only_ip = False;
276 if ((!deny_list || *deny_list==0) && (!allow_list || *allow_list==0))
283 /* bypass gethostbyaddr() calls if the lists only contain IP addrs */
284 if (only_ipaddrs_in_list(allow_list) && only_ipaddrs_in_list(deny_list))
287 DEBUG (3, ("check_access: no hostnames in host allow/deny list.\n"));
288 ret = allow_access(deny_list,allow_list, "", get_socket_addr(sock));
292 DEBUG (3, ("check_access: hostnames in host allow/deny list.\n"));
293 ret = allow_access(deny_list,allow_list, get_socket_name(sock),
294 get_socket_addr(sock));
299 DEBUG(2,("Allowed connection from %s (%s)\n",
300 only_ip ? "" : get_socket_name(sock),
301 get_socket_addr(sock)));
305 DEBUG(0,("Denied connection from %s (%s)\n",
306 only_ip ? "" : get_socket_name(sock),
307 get_socket_addr(sock)));