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-rw-r--r--source3/lib/access.c415
1 files changed, 415 insertions, 0 deletions
diff --git a/source3/lib/access.c b/source3/lib/access.c
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--- /dev/null
+++ b/source3/lib/access.c
@@ -0,0 +1,415 @@
+/*
+ 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
+
+ Updated for IPv6 by Jeremy Allison (C) 2007.
+*/
+
+#include "includes.h"
+
+#define NAME_INDEX 0
+#define ADDR_INDEX 1
+
+/* masked_match - match address against netnumber/netmask */
+static bool masked_match(const char *tok, const char *slash, const char *s)
+{
+ struct sockaddr_storage ss_mask;
+ struct sockaddr_storage ss_tok;
+ struct sockaddr_storage ss_host;
+ char *tok_copy = NULL;
+
+ if (!interpret_string_addr(&ss_host, s, 0)) {
+ return false;
+ }
+
+ if (*tok == '[') {
+ /* IPv6 address - remove braces. */
+ tok_copy = SMB_STRDUP(tok+1);
+ if (!tok_copy) {
+ return false;
+ }
+ /* Remove the terminating ']' */
+ tok_copy[PTR_DIFF(slash,tok)-1] = '\0';
+ } else {
+ tok_copy = SMB_STRDUP(tok);
+ if (!tok_copy) {
+ return false;
+ }
+ /* Remove the terminating '/' */
+ tok_copy[PTR_DIFF(slash,tok)] = '\0';
+ }
+
+ if (!interpret_string_addr(&ss_tok, tok_copy, 0)) {
+ SAFE_FREE(tok_copy);
+ return false;
+ }
+
+ SAFE_FREE(tok_copy);
+
+ if (strlen(slash + 1) > 2) {
+ if (!interpret_string_addr(&ss_mask, slash+1, 0)) {
+ return false;
+ }
+ } else {
+ char *endp = NULL;
+ unsigned long val = strtoul(slash+1, &endp, 0);
+ if (slash+1 == endp || (endp && *endp != '\0')) {
+ return false;
+ }
+ if (!make_netmask(&ss_mask, &ss_tok, val)) {
+ return false;
+ }
+ }
+
+ return same_net(&ss_host, &ss_tok, &ss_mask);
+}
+
+/* string_match - match string s against token tok */
+static bool string_match(const char *tok,const char *s)
+{
+ size_t tok_len;
+ size_t str_len;
+ const char *cut;
+
+ /* Return true if a token has the magic value "ALL". Return
+ * true 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
+ DATA_BLOB tmp;
+ char *mydomain = NULL;
+ char *hostname = NULL;
+ bool netgroup_ok = false;
+
+ if (memcache_lookup(
+ NULL, SINGLETON_CACHE,
+ data_blob_string_const("yp_default_domain"),
+ &tmp)) {
+
+ SMB_ASSERT(tmp.length > 0);
+ mydomain = (tmp.data[0] == '\0')
+ ? NULL : (char *)tmp.data;
+ }
+ else {
+ yp_get_default_domain(&mydomain);
+
+ memcache_add(
+ NULL, SINGLETON_CACHE,
+ data_blob_string_const("yp_default_domain"),
+ data_blob_string_const(mydomain?mydomain:""));
+ }
+
+ if (!mydomain) {
+ DEBUG(0,("Unable to get default yp domain. "
+ "Try without it.\n"));
+ }
+ if (!(hostname = SMB_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?mydomain:"(ANY)",
+ 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 true;
+ } 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(s[0]) && strchr_m(tok, '.') != NULL) ||
+ (tok[0] == '[' && cut > tok && cut[-1] == ']') ||
+ ((isxdigit(s[0]) || s[0] == ':') &&
+ strchr_m(tok, ':') != NULL)) {
+ /* IPv4/netmask or
+ * [IPv6:addr]/netmask or IPv6:addr/netmask */
+ return masked_match(tok, cut, s);
+ }
+ } else if (strchr_m(tok, '*') != 0 || strchr_m(tok, '?')) {
+ return unix_wild_match(tok, s);
+ }
+ return false;
+}
+
+/* client_match - match host name and address against token */
+bool client_match(const char *tok, const void *item)
+{
+ const char **client = (const char **)item;
+
+ /*
+ * Try to match the address first. If that fails, try to match the host
+ * name if available.
+ */
+
+ if (string_match(tok, client[ADDR_INDEX])) {
+ return true;
+ }
+
+ if (strnequal(client[ADDR_INDEX],"::ffff:",7) &&
+ !strnequal(tok, "::ffff:",7)) {
+ /* client[ADDR_INDEX] is an IPv4 mapped to IPv6, but
+ * the list item is not. Try and match the IPv4 part of
+ * address only. This will happen a lot on IPv6 enabled
+ * systems with IPv4 allow/deny lists in smb.conf.
+ * Bug #5311. JRA.
+ */
+ if (string_match(tok, (client[ADDR_INDEX])+7)) {
+ return true;
+ }
+ }
+
+ if (client[NAME_INDEX][0] != 0) {
+ if (string_match(tok, client[NAME_INDEX])) {
+ return true;
+ }
+ }
+
+ return false;
+}
+
+/* list_match - match an item against a list of tokens with exceptions */
+bool list_match(const char **list,const void *item,
+ bool (*match_fn)(const char *, const void *))
+{
+ 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[NAME_INDEX] = cname;
+ client[ADDR_INDEX] = caddr;
+
+ /* if it is loopback then always allow unless specifically denied */
+ if (strcmp(caddr, "127.0.0.1") == 0 || strcmp(caddr, "::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,client,client_match) &&
+ (!allow_list ||
+ !list_match(allow_list,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,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,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
+name lookup 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) {
+ char addr[INET6_ADDRSTRLEN];
+
+ /* Bypass name resolution 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,addr,sizeof(addr)));
+ } 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,addr,sizeof(addr)));
+ }
+
+ if (ret) {
+ DEBUG(2,("Allowed connection from %s (%s)\n",
+ only_ip ? "" : get_peer_name(sock,true),
+ get_peer_addr(sock,addr,sizeof(addr))));
+ } else {
+ DEBUG(0,("Denied connection from %s (%s)\n",
+ only_ip ? "" : get_peer_name(sock,true),
+ get_peer_addr(sock,addr,sizeof(addr))));
+ }
+ }
+
+ return(ret);
+}
generated by cgit (git 2.34.1) at 2025-01-14 17:27:31 +0000