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-bugs@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 /* (All modifications are marked with the initials "jkf") */
152 static int list_match(char *list,char *item, int (*match_fn)(char *, char *))
155 char *listcopy; /* jkf */
159 * jkf@soton.ac.uk -- 31 August 1994 -- Stop list_match()
160 * overwriting the list given as its first parameter.
163 /* jkf -- can get called recursively with NULL list */
164 listcopy = (list == 0) ? (char *)0 : strdup(list);
167 * Process tokens one at a time. We have exhausted all possible matches
168 * when we reach an "EXCEPT" token or the end of the list. If we do find
169 * a match, look for an "EXCEPT" list and recurse to determine whether
170 * the match is affected by any exceptions.
173 for (tok = strtok(listcopy, sep); tok ; tok = strtok(NULL, sep)) {
174 if (strcasecmp(tok, "EXCEPT") == 0) /* EXCEPT: give up */
176 if ((match = (*match_fn) (tok, item))) /* True or FAIL */
179 /* Process exceptions to True or FAIL matches. */
181 if (match != False) {
182 while ((tok = strtok((char *) 0, sep)) && strcasecmp(tok, "EXCEPT"))
184 if (tok == 0 || list_match((char *) 0, item, match_fn) == False) {
185 if (listcopy != 0) free(listcopy); /* jkf */
190 if (listcopy != 0) free(listcopy); /* jkf */
195 /* return true if access should be allowed */
196 BOOL allow_access(char *deny_list,char *allow_list,
197 char *cname,char *caddr)
204 /* if it is loopback then always allow unless specifically denied */
205 if (strcmp(caddr, "127.0.0.1") == 0) {
207 list_match(deny_list,(char *)client,client_match)) {
213 /* if theres no deny list and no allow list then allow access */
214 if ((!deny_list || *deny_list == 0) &&
215 (!allow_list || *allow_list == 0)) {
219 /* if there is an allow list but no deny list then allow only hosts
221 if (!deny_list || *deny_list == 0)
222 return(list_match(allow_list,(char *)client,client_match));
224 /* if theres a deny list but no allow list then allow
225 all hosts not on the deny list */
226 if (!allow_list || *allow_list == 0)
227 return(!list_match(deny_list,(char *)client,client_match));
229 /* if there are both type of list then allow all hosts on the
231 if (list_match(allow_list,(char *)client,client_match))
234 /* if there are both type of list and it's not on the allow then
235 allow it if its not on the deny */
236 if (list_match(deny_list,(char *)client,client_match))
242 /* return true if access should be allowed to a service for a socket */
243 BOOL check_access(int sock, char *allow_list, char *deny_list)
247 if (deny_list) deny_list = strdup(deny_list);
248 if (allow_list) allow_list = strdup(allow_list);
250 if ((!deny_list || *deny_list==0) && (!allow_list || *allow_list==0)) {
255 if (allow_access(deny_list,allow_list,
256 client_name(sock),client_addr(sock))) {
257 DEBUG(2,("Allowed connection from %s (%s)\n",
258 client_name(sock),client_addr(sock)));
261 DEBUG(0,("Denied connection from %s (%s)\n",
262 client_name(sock),client_addr(sock)));
266 if (deny_list) free(deny_list);
267 if (allow_list) free(allow_list);