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);
37 /* convert to network byte order */
41 if (net == INADDR_NONE || mask == INADDR_NONE) {
42 DEBUG(0,("access: bad net/mask access control: %s\n", tok));
46 return ((addr & mask) == (net & mask));
49 /* string_match - match string against token */
50 static BOOL string_match(const char *tok,const char *s, char *invalid_char)
58 /* Return True if a token has the magic value "ALL". Return
59 * FAIL if the token is "FAIL". If the token starts with a "."
60 * (domain name), return True if it matches the last fields of
61 * the string. If the token has the magic value "LOCAL",
62 * return True if the string does not contain a "."
63 * character. If the token ends on a "." (network number),
64 * return True if it matches the first fields of the
65 * string. If the token begins with a "@" (netgroup name),
66 * return True if the string is a (host) member of the
67 * netgroup. Return True if the token fully matches the
68 * string. If the token is a netnumber/netmask pair, return
69 * True if the address is a member of the specified subnet.
72 if (tok[0] == '.') { /* domain: match last fields */
73 if ((str_len = strlen(s)) > (tok_len = strlen(tok))
74 && strequal(tok, s + str_len - tok_len))
76 } else if (tok[0] == '@') { /* netgroup: look it up */
78 static char *mydomain = NULL;
79 char *hostname = NULL;
80 BOOL netgroup_ok = False;
83 yp_get_default_domain(&mydomain);
86 DEBUG(0,("Unable to get default yp domain. Try without it.\n"));
88 if (!(hostname = SMB_STRDUP(s))) {
89 DEBUG(1,("out of memory for strdup!\n"));
93 netgroup_ok = innetgr(tok + 1, hostname, (char *) 0, mydomain);
95 DEBUG(5,("looking for %s of domain %s in netgroup %s gave %s\n",
97 mydomain?mydomain:"(ANY)",
99 BOOLSTR(netgroup_ok)));
106 DEBUG(0,("access: netgroup support is not configured\n"));
109 } else if (strequal(tok, "ALL")) { /* all: match any */
111 } else if (strequal(tok, "FAIL")) { /* fail: match any */
113 } else if (strequal(tok, "LOCAL")) { /* local: no dots */
114 if (strchr_m(s, '.') == 0 && !strequal(s, "unknown"))
116 } else if (strequal(tok, s)) { /* match host name or address */
118 } else if (tok[(tok_len = strlen(tok)) - 1] == '.') { /* network */
119 if (strncmp(tok, s, tok_len) == 0)
121 } else if ((cut = strchr_m(tok, '/')) != 0) { /* netnumber/netmask */
122 if (isdigit((int)s[0]) && masked_match(tok, cut, s))
124 } else if (strchr_m(tok, '*') != 0) {
126 } else if (strchr_m(tok, '?') != 0) {
132 /* client_match - match host name and address against token */
133 static BOOL client_match(const char *tok, const char *item)
135 const char **client = (const char **)item;
137 char invalid_char = '\0';
140 * Try to match the address first. If that fails, try to match the host
144 if ((match = string_match(tok, client[1], &invalid_char)) == 0) {
146 DEBUG(0,("client_match: address match failing due to invalid character '%c' found in \
147 token '%s' in an allow/deny hosts line.\n", invalid_char, tok ));
149 if (client[0][0] != 0)
150 match = string_match(tok, client[0], &invalid_char);
153 DEBUG(0,("client_match: address match failing due to invalid character '%c' found in \
154 token '%s' in an allow/deny hosts line.\n", invalid_char, tok ));
160 /* list_match - match an item against a list of tokens with exceptions */
161 static BOOL list_match(const char **list,const char *item,
162 BOOL (*match_fn)(const char *, const char *))
170 * Process tokens one at a time. We have exhausted all possible matches
171 * when we reach an "EXCEPT" token or the end of the list. If we do find
172 * a match, look for an "EXCEPT" list and recurse to determine whether
173 * the match is affected by any exceptions.
176 for (; *list ; list++) {
177 if (strequal(*list, "EXCEPT")) /* EXCEPT: give up */
179 if ((match = (*match_fn) (*list, item))) /* True or FAIL */
182 /* Process exceptions to True or FAIL matches. */
184 if (match != False) {
185 while (*list && !strequal(*list, "EXCEPT"))
188 for (; *list; list++) {
189 if ((*match_fn) (*list, item)) /* Exception Found */
197 /* return true if access should be allowed */
198 static BOOL allow_access_internal(const char **deny_list,const char **allow_list,
199 const char *cname, const char *caddr)
201 const char *client[2];
206 /* if it is loopback then always allow unless specifically denied */
207 if (strcmp(caddr, "127.0.0.1") == 0) {
209 * If 127.0.0.1 matches both allow and deny then allow.
210 * Patch from Steve Langasek vorlon@netexpress.net.
213 list_match(deny_list,(const char *)client,client_match) &&
215 !list_match(allow_list,(const char *)client, client_match))) {
221 /* if theres no deny list and no allow list then allow access */
222 if ((!deny_list || *deny_list == 0) &&
223 (!allow_list || *allow_list == 0)) {
227 /* if there is an allow list but no deny list then allow only hosts
229 if (!deny_list || *deny_list == 0)
230 return(list_match(allow_list,(const char *)client,client_match));
232 /* if theres a deny list but no allow list then allow
233 all hosts not on the deny list */
234 if (!allow_list || *allow_list == 0)
235 return(!list_match(deny_list,(const char *)client,client_match));
237 /* if there are both types of list then allow all hosts on the
239 if (list_match(allow_list,(const char *)client,client_match))
242 /* if there are both types of list and it's not on the allow then
243 allow it if its not on the deny */
244 if (list_match(deny_list,(const char *)client,client_match))
250 /* return true if access should be allowed */
251 BOOL allow_access(const char **deny_list, const char **allow_list,
252 const char *cname, const char *caddr)
255 char *nc_cname = smb_xstrdup(cname);
256 char *nc_caddr = smb_xstrdup(caddr);
258 ret = allow_access_internal(deny_list, allow_list, nc_cname, nc_caddr);
265 /* return true if the char* contains ip addrs only. Used to avoid
266 gethostbyaddr() calls */
268 static BOOL only_ipaddrs_in_list(const char** list)
275 for (; *list ; list++) {
276 /* factor out the special strings */
277 if (strequal(*list, "ALL") || strequal(*list, "FAIL") ||
278 strequal(*list, "EXCEPT")) {
282 if (!is_ipaddress(*list)) {
284 * if we failed, make sure that it was not because the token
285 * was a network/netmask pair. Only network/netmask pairs
288 if ((strchr_m(*list, '/')) == NULL) {
290 DEBUG(3,("only_ipaddrs_in_list: list has non-ip address (%s)\n", *list));
299 /* return true if access should be allowed to a service for a socket */
300 BOOL check_access(int sock, const char **allow_list, const char **deny_list)
303 BOOL only_ip = False;
305 if ((!deny_list || *deny_list==0) && (!allow_list || *allow_list==0))
309 /* bypass gethostbyaddr() calls if the lists only contain IP addrs */
310 if (only_ipaddrs_in_list(allow_list) && only_ipaddrs_in_list(deny_list)) {
312 DEBUG (3, ("check_access: no hostnames in host allow/deny list.\n"));
313 ret = allow_access(deny_list,allow_list, "", get_peer_addr(sock));
315 DEBUG (3, ("check_access: hostnames in host allow/deny list.\n"));
316 ret = allow_access(deny_list,allow_list, get_peer_name(sock,True),
317 get_peer_addr(sock));
321 DEBUG(2,("Allowed connection from %s (%s)\n",
322 only_ip ? "" : get_peer_name(sock,True),
323 get_peer_addr(sock)));
325 DEBUG(0,("Denied connection from %s (%s)\n",
326 only_ip ? "" : get_peer_name(sock,True),
327 get_peer_addr(sock)));