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-rw-r--r--source/lib/access.c333
1 files changed, 333 insertions, 0 deletions
diff --git a/source/lib/access.c b/source/lib/access.c
new file mode 100644
index 00000000000..f03f5daf333
--- /dev/null
+++ b/source/lib/access.c
@@ -0,0 +1,333 @@
+/*
+ This module is an adaption of code from the tcpd-1.4 package written
+ by Wietse Venema, Eindhoven University of Technology, The Netherlands.
+
+ The code is used here with permission.
+
+ The code has been considerably changed from the original. Bug reports
+ should be sent to samba@samba.org
+*/
+
+#include "includes.h"
+
+#define FAIL (-1)
+
+#define ALLONES ((uint32)0xFFFFFFFF)
+
+/* masked_match - match address against netnumber/netmask */
+static BOOL masked_match(const char *tok, const char *slash, const char *s)
+{
+ uint32 net;
+ uint32 mask;
+ uint32 addr;
+ fstring tok_cpy;
+
+ if ((addr = interpret_addr(s)) == INADDR_NONE)
+ return (False);
+
+ fstrcpy(tok_cpy, tok);
+ tok_cpy[PTR_DIFF(slash,tok)] = '\0';
+ net = interpret_addr(tok_cpy);
+ tok_cpy[PTR_DIFF(slash,tok)] = '/';
+
+ if (strlen(slash + 1) > 2) {
+ mask = interpret_addr(slash + 1);
+ } else {
+ mask = (uint32)((ALLONES >> atoi(slash + 1)) ^ ALLONES);
+ /* convert to network byte order */
+ mask = htonl(mask);
+ }
+
+ if (net == INADDR_NONE || mask == INADDR_NONE) {
+ DEBUG(0,("access: bad net/mask access control: %s\n", tok));
+ return (False);
+ }
+
+ return ((addr & mask) == (net & mask));
+}
+
+/* string_match - match string against token */
+static BOOL string_match(const char *tok,const char *s, char *invalid_char)
+{
+ size_t tok_len;
+ size_t str_len;
+ const char *cut;
+
+ *invalid_char = '\0';
+
+ /* Return True if a token has the magic value "ALL". Return
+ * FAIL if the token is "FAIL". If the token starts with a "."
+ * (domain name), return True if it matches the last fields of
+ * the string. If the token has the magic value "LOCAL",
+ * return True if the string does not contain a "."
+ * character. If the token ends on a "." (network number),
+ * return True if it matches the first fields of the
+ * string. If the token begins with a "@" (netgroup name),
+ * return True if the string is a (host) member of the
+ * netgroup. Return True if the token fully matches the
+ * string. If the token is a netnumber/netmask pair, return
+ * True if the address is a member of the specified subnet.
+ */
+
+ if (tok[0] == '.') { /* domain: match last fields */
+ if ((str_len = strlen(s)) > (tok_len = strlen(tok))
+ && strequal(tok, s + str_len - tok_len))
+ return (True);
+ } else if (tok[0] == '@') { /* netgroup: look it up */
+#ifdef HAVE_NETGROUP
+ static char *mydomain = NULL;
+ char *hostname = NULL;
+ BOOL netgroup_ok = False;
+
+ if (!mydomain)
+ yp_get_default_domain(&mydomain);
+
+ if (!mydomain) {
+ DEBUG(0,("Unable to get default yp domain.\n"));
+ return False;
+ }
+ if (!(hostname = strdup(s))) {
+ DEBUG(1,("out of memory for strdup!\n"));
+ return False;
+ }
+
+ netgroup_ok = innetgr(tok + 1, hostname, (char *) 0, mydomain);
+
+ DEBUG(5,("looking for %s of domain %s in netgroup %s gave %s\n",
+ hostname,
+ mydomain,
+ tok+1,
+ BOOLSTR(netgroup_ok)));
+
+ SAFE_FREE(hostname);
+
+ if (netgroup_ok)
+ return(True);
+#else
+ DEBUG(0,("access: netgroup support is not configured\n"));
+ return (False);
+#endif
+ } else if (strequal(tok, "ALL")) { /* all: match any */
+ return (True);
+ } else if (strequal(tok, "FAIL")) { /* fail: match any */
+ return (FAIL);
+ } else if (strequal(tok, "LOCAL")) { /* local: no dots */
+ if (strchr_m(s, '.') == 0 && !strequal(s, "unknown"))
+ return (True);
+ } else if (strequal(tok, s)) { /* match host name or address */
+ return (True);
+ } else if (tok[(tok_len = strlen(tok)) - 1] == '.') { /* network */
+ if (strncmp(tok, s, tok_len) == 0)
+ return (True);
+ } else if ((cut = strchr_m(tok, '/')) != 0) { /* netnumber/netmask */
+ if (isdigit((int)s[0]) && masked_match(tok, cut, s))
+ return (True);
+ } else if (strchr_m(tok, '*') != 0) {
+ *invalid_char = '*';
+ } else if (strchr_m(tok, '?') != 0) {
+ *invalid_char = '?';
+ }
+ return (False);
+}
+
+/* client_match - match host name and address against token */
+static BOOL client_match(const char *tok, const char *item)
+{
+ const char **client = (const char **)item;
+ BOOL match;
+ char invalid_char = '\0';
+
+ /*
+ * Try to match the address first. If that fails, try to match the host
+ * name if available.
+ */
+
+ if ((match = string_match(tok, client[1], &invalid_char)) == 0) {
+ if(invalid_char)
+ DEBUG(0,("client_match: address match failing due to invalid character '%c' found in \
+token '%s' in an allow/deny hosts line.\n", invalid_char, tok ));
+
+ if (client[0][0] != 0)
+ match = string_match(tok, client[0], &invalid_char);
+
+ if(invalid_char)
+ DEBUG(0,("client_match: address match failing due to invalid character '%c' found in \
+token '%s' in an allow/deny hosts line.\n", invalid_char, tok ));
+ }
+
+ return (match);
+}
+
+/* list_match - match an item against a list of tokens with exceptions */
+static BOOL list_match(const char **list,const char *item,
+ BOOL (*match_fn)(const char *, const char *))
+{
+ BOOL match = False;
+
+ if (!list)
+ return False;
+
+ /*
+ * Process tokens one at a time. We have exhausted all possible matches
+ * when we reach an "EXCEPT" token or the end of the list. If we do find
+ * a match, look for an "EXCEPT" list and recurse to determine whether
+ * the match is affected by any exceptions.
+ */
+
+ for (; *list ; list++) {
+ if (strequal(*list, "EXCEPT")) /* EXCEPT: give up */
+ break;
+ if ((match = (*match_fn) (*list, item))) /* True or FAIL */
+ break;
+ }
+ /* Process exceptions to True or FAIL matches. */
+
+ if (match != False) {
+ while (*list && !strequal(*list, "EXCEPT"))
+ list++;
+
+ for (; *list; list++) {
+ if ((*match_fn) (*list, item)) /* Exception Found */
+ return False;
+ }
+ }
+
+ return (match);
+}
+
+/* return true if access should be allowed */
+static BOOL allow_access_internal(const char **deny_list,const char **allow_list,
+ const char *cname, const char *caddr)
+{
+ const char *client[2];
+
+ client[0] = cname;
+ client[1] = caddr;
+
+ /* if it is loopback then always allow unless specifically denied */
+ if (strcmp(caddr, "127.0.0.1") == 0) {
+ /*
+ * If 127.0.0.1 matches both allow and deny then allow.
+ * Patch from Steve Langasek vorlon@netexpress.net.
+ */
+ if (deny_list &&
+ list_match(deny_list,(const char *)client,client_match) &&
+ (!allow_list ||
+ !list_match(allow_list,(const char *)client, client_match))) {
+ return False;
+ }
+ return True;
+ }
+
+ /* if theres no deny list and no allow list then allow access */
+ if ((!deny_list || *deny_list == 0) &&
+ (!allow_list || *allow_list == 0)) {
+ return(True);
+ }
+
+ /* if there is an allow list but no deny list then allow only hosts
+ on the allow list */
+ if (!deny_list || *deny_list == 0)
+ return(list_match(allow_list,(const char *)client,client_match));
+
+ /* if theres a deny list but no allow list then allow
+ all hosts not on the deny list */
+ if (!allow_list || *allow_list == 0)
+ return(!list_match(deny_list,(const char *)client,client_match));
+
+ /* if there are both types of list then allow all hosts on the
+ allow list */
+ if (list_match(allow_list,(const char *)client,client_match))
+ return (True);
+
+ /* if there are both types of list and it's not on the allow then
+ allow it if its not on the deny */
+ if (list_match(deny_list,(const char *)client,client_match))
+ return (False);
+
+ return (True);
+}
+
+/* return true if access should be allowed */
+BOOL allow_access(const char **deny_list, const char **allow_list,
+ const char *cname, const char *caddr)
+{
+ BOOL ret;
+ char *nc_cname = smb_xstrdup(cname);
+ char *nc_caddr = smb_xstrdup(caddr);
+
+ ret = allow_access_internal(deny_list, allow_list, nc_cname, nc_caddr);
+
+ SAFE_FREE(nc_cname);
+ SAFE_FREE(nc_caddr);
+ return ret;
+}
+
+/* return true if the char* contains ip addrs only. Used to avoid
+gethostbyaddr() calls */
+
+static BOOL only_ipaddrs_in_list(const char** list)
+{
+ BOOL only_ip = True;
+
+ if (!list)
+ return True;
+
+ for (; *list ; list++) {
+ /* factor out the special strings */
+ if (strequal(*list, "ALL") || strequal(*list, "FAIL") ||
+ strequal(*list, "EXCEPT")) {
+ continue;
+ }
+
+ if (!is_ipaddress(*list)) {
+ /*
+ * if we failed, make sure that it was not because the token
+ * was a network/netmask pair. Only network/netmask pairs
+ * have a '/' in them
+ */
+ if ((strchr_m(*list, '/')) == NULL) {
+ only_ip = False;
+ DEBUG(3,("only_ipaddrs_in_list: list has non-ip address (%s)\n", *list));
+ break;
+ }
+ }
+ }
+
+ return only_ip;
+}
+
+/* return true if access should be allowed to a service for a socket */
+BOOL check_access(int sock, const char **allow_list, const char **deny_list)
+{
+ BOOL ret = False;
+ BOOL only_ip = False;
+
+ if ((!deny_list || *deny_list==0) && (!allow_list || *allow_list==0))
+ ret = True;
+
+ if (!ret) {
+ /* bypass gethostbyaddr() calls if the lists only contain IP addrs */
+ if (only_ipaddrs_in_list(allow_list) && only_ipaddrs_in_list(deny_list)) {
+ only_ip = True;
+ DEBUG (3, ("check_access: no hostnames in host allow/deny list.\n"));
+ ret = allow_access(deny_list,allow_list, "", get_peer_addr(sock));
+ } else {
+ DEBUG (3, ("check_access: hostnames in host allow/deny list.\n"));
+ ret = allow_access(deny_list,allow_list, get_peer_name(sock,True),
+ get_peer_addr(sock));
+ }
+
+ if (ret) {
+ DEBUG(2,("Allowed connection from %s (%s)\n",
+ only_ip ? "" : get_peer_name(sock,True),
+ get_peer_addr(sock)));
+ } else {
+ DEBUG(0,("Denied connection from %s (%s)\n",
+ only_ip ? "" : get_peer_name(sock,True),
+ get_peer_addr(sock)));
+ }
+ }
+
+ return(ret);
+}
generated by cgit (git 2.34.1) at 2025-10-04 05:46:20 +0000