diff options
Diffstat (limited to 'source3/libsmb/namecache.c')
-rw-r--r-- | source3/libsmb/namecache.c | 480 |
1 files changed, 480 insertions, 0 deletions
diff --git a/source3/libsmb/namecache.c b/source3/libsmb/namecache.c new file mode 100644 index 0000000..eb59b9e --- /dev/null +++ b/source3/libsmb/namecache.c @@ -0,0 +1,480 @@ +/* + Unix SMB/CIFS implementation. + + NetBIOS name cache module on top of gencache mechanism. + + Copyright (C) Tim Potter 2002 + Copyright (C) Rafal Szczesniak 2002 + Copyright (C) Jeremy Allison 2007 + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +#include "includes.h" +#include "lib/gencache.h" +#include "libsmb/namequery.h" + +#define IPSTR_LIST_SEP "," +#define IPSTR_LIST_CHAR ',' + +/** + * Allocate and initialise an ipstr list using samba_sockaddr ip addresses + * passed as arguments. + * + * @param ctx TALLOC_CTX to use + * @param ip_list array of ip addresses to place in the list + * @param ip_count number of addresses stored in ip_list + * @return pointer to allocated ip string + **/ + +static char *ipstr_list_make_sa(TALLOC_CTX *ctx, + const struct samba_sockaddr *sa_list, + size_t ip_count) +{ + char *ipstr_list = NULL; + size_t i; + + /* arguments checking */ + if (sa_list == NULL) { + return NULL; + } + + /* process ip addresses given as arguments */ + for (i = 0; i < ip_count; i++) { + char addr_buf[INET6_ADDRSTRLEN]; + char *new_str = NULL; + + print_sockaddr(addr_buf, + sizeof(addr_buf), + &sa_list[i].u.ss); + + if (sa_list[i].u.ss.ss_family == AF_INET) { + /* IPv4 - port no longer used, store 0 */ + new_str = talloc_asprintf(ctx, + "%s:%d", + addr_buf, + 0); + } else { + /* IPv6 - port no longer used, store 0 */ + new_str = talloc_asprintf(ctx, + "[%s]:%d", + addr_buf, + 0); + } + if (new_str == NULL) { + TALLOC_FREE(ipstr_list); + return NULL; + } + + if (ipstr_list == NULL) { + /* First ip address. */ + ipstr_list = new_str; + } else { + /* + * Append the separator "," and then the new + * ip address to the existing list. + * + * The efficiency here is horrible, but + * ip_count should be small enough we can + * live with it. + */ + char *tmp = talloc_asprintf(ctx, + "%s%s%s", + ipstr_list, + IPSTR_LIST_SEP, + new_str); + if (tmp == NULL) { + TALLOC_FREE(new_str); + TALLOC_FREE(ipstr_list); + return NULL; + } + TALLOC_FREE(new_str); + TALLOC_FREE(ipstr_list); + ipstr_list = tmp; + } + } + + return ipstr_list; +} + +/** + * Parse given ip string list into array of ip addresses + * (as ip_service structures) + * e.g. [IPv6]:port,192.168.1.100:389,192.168.1.78, ... + * + * @param ipstr ip string list to be parsed + * @param ip_list pointer to array of ip addresses which is + * talloced by this function and must be freed by caller + * @return number of successfully parsed addresses + **/ + +static int ipstr_list_parse(TALLOC_CTX *ctx, + const char *ipstr_list, + struct samba_sockaddr **sa_list_out) +{ + TALLOC_CTX *frame = talloc_stackframe(); + struct samba_sockaddr *sa_list = NULL; + char *token_str = NULL; + size_t count; + size_t array_size; + + *sa_list_out = NULL; + + array_size = count_chars(ipstr_list, IPSTR_LIST_CHAR) + 1; + sa_list = talloc_zero_array(frame, + struct samba_sockaddr, + array_size); + if (sa_list == NULL) { + TALLOC_FREE(frame); + return 0; + } + + count = 0; + while (next_token_talloc(frame, + &ipstr_list, + &token_str, + IPSTR_LIST_SEP)) { + bool ok; + char *s = token_str; + char *p = strrchr(token_str, ':'); + struct sockaddr_storage ss; + + /* Ensure we don't overrun. */ + if (count >= array_size) { + break; + } + + if (p) { + *p = 0; + /* We now ignore the port. */ + } + + /* convert single token to ip address */ + if (token_str[0] == '[') { + /* IPv6 address. */ + s++; + p = strchr(token_str, ']'); + if (!p) { + continue; + } + *p = '\0'; + } + ok = interpret_string_addr(&ss, s, AI_NUMERICHOST); + if (!ok) { + continue; + } + ok = sockaddr_storage_to_samba_sockaddr(&sa_list[count], + &ss); + if (!ok) { + continue; + } + count++; + } + if (count > 0) { + *sa_list_out = talloc_move(ctx, &sa_list); + } + TALLOC_FREE(frame); + return count; +} + +#define NBTKEY_FMT "NBT/%s#%02X" + +/** + * Generates a key for netbios name lookups on basis of + * netbios name and type. + * The caller must free returned key string when finished. + * + * @param name netbios name string (case insensitive) + * @param name_type netbios type of the name being looked up + * + * @return string consisted of uppercased name and appended + * type number + */ + +static char *namecache_key(TALLOC_CTX *ctx, + const char *name, + int name_type) +{ + return talloc_asprintf_strupper_m(ctx, + NBTKEY_FMT, + name, + name_type); +} + +/** + * Store a name(s) in the name cache - samba_sockaddr version. + * + * @param name netbios names array + * @param name_type integer netbios name type + * @param num_names number of names being stored + * @param ip_list array of in_addr structures containing + * ip addresses being stored + **/ + +bool namecache_store(const char *name, + int name_type, + size_t num_names, + struct samba_sockaddr *sa_list) +{ + time_t expiry; + char *key = NULL; + char *value_string = NULL; + size_t i; + bool ret = false; + TALLOC_CTX *frame = talloc_stackframe(); + + if (name_type > 255) { + /* Don't store non-real name types. */ + goto out; + } + + if ( DEBUGLEVEL >= 5 ) { + char *addr = NULL; + + DBG_INFO("storing %zu address%s for %s#%02x: ", + num_names, num_names == 1 ? "": "es", name, name_type); + + for (i = 0; i < num_names; i++) { + addr = print_canonical_sockaddr(frame, + &sa_list[i].u.ss); + if (!addr) { + continue; + } + DEBUGADD(5, ("%s%s", addr, + (i == (num_names - 1) ? "" : ","))); + + } + DEBUGADD(5, ("\n")); + } + + key = namecache_key(frame, name, name_type); + if (!key) { + goto out; + } + + expiry = time(NULL) + lp_name_cache_timeout(); + + /* + * Generate string representation of ip addresses list + */ + value_string = ipstr_list_make_sa(frame, sa_list, num_names); + if (value_string == NULL) { + goto out; + } + + /* set the entry */ + ret = gencache_set(key, value_string, expiry); + + out: + + TALLOC_FREE(key); + TALLOC_FREE(value_string); + TALLOC_FREE(frame); + return ret; +} + +/** + * Look up a name in the cache. + * + * @param name netbios name to look up for + * @param name_type netbios name type of @param name + * @param ip_list talloced list of IP addresses if found in the cache, + * NULL otherwise + * @param num_names number of entries found + * + * @return true upon successful fetch or + * false if name isn't found in the cache or has expired + **/ + +bool namecache_fetch(TALLOC_CTX *ctx, + const char *name, + int name_type, + struct samba_sockaddr **sa_list, + size_t *num_names) +{ + char *key, *value; + time_t timeout; + + if (name_type > 255) { + return false; /* Don't fetch non-real name types. */ + } + + *num_names = 0; + + /* + * Use gencache interface - lookup the key + */ + key = namecache_key(talloc_tos(), name, name_type); + if (!key) { + return false; + } + + if (!gencache_get(key, talloc_tos(), &value, &timeout)) { + DBG_INFO("no entry for %s#%02X found.\n", name, name_type); + TALLOC_FREE(key); + return false; + } + + DBG_INFO("name %s#%02X found.\n", name, name_type); + + /* + * Split up the stored value into the list of IP addresses + */ + *num_names = ipstr_list_parse(ctx, value, sa_list); + + TALLOC_FREE(key); + TALLOC_FREE(value); + + return *num_names > 0; /* true only if some ip has been fetched */ +} + +/** + * Remove a namecache entry. Needed for site support. + * + **/ + +bool namecache_delete(const char *name, int name_type) +{ + bool ret; + char *key; + + if (name_type > 255) { + return false; /* Don't fetch non-real name types. */ + } + + key = namecache_key(talloc_tos(), name, name_type); + if (!key) { + return false; + } + ret = gencache_del(key); + TALLOC_FREE(key); + return ret; +} + +/** + * Delete single namecache entry. Look at the + * gencache_iterate definition. + * + **/ + +static void flush_netbios_name(const char *key, + const char *value, + time_t timeout, + void *dptr) +{ + gencache_del(key); + DBG_INFO("Deleting entry %s\n", key); +} + +/** + * Flush all names from the name cache. + * It's done by gencache_iterate() + * + * @return true upon successful deletion or + * false in case of an error + **/ + +void namecache_flush(void) +{ + /* + * iterate through each NBT cache's entry and flush it + * by flush_netbios_name function + */ + gencache_iterate(flush_netbios_name, NULL, "NBT/*"); + DBG_INFO("Namecache flushed\n"); +} + +/* Construct a name status record key. */ + +static char *namecache_status_record_key(TALLOC_CTX *ctx, + const char *name, + int name_type1, + int name_type2, + const struct sockaddr_storage *keyip) +{ + char addr[INET6_ADDRSTRLEN]; + + print_sockaddr(addr, sizeof(addr), keyip); + return talloc_asprintf_strupper_m(ctx, + "NBT/%s#%02X.%02X.%s", + name, + name_type1, + name_type2, + addr); +} + +/* Store a name status record. */ + +bool namecache_status_store(const char *keyname, int keyname_type, + int name_type, const struct sockaddr_storage *keyip, + const char *srvname) +{ + char *key; + time_t expiry; + bool ret; + + key = namecache_status_record_key(talloc_tos(), + keyname, + keyname_type, + name_type, + keyip); + if (!key) + return false; + + expiry = time(NULL) + lp_name_cache_timeout(); + ret = gencache_set(key, srvname, expiry); + + if (ret) { + DBG_INFO("entry %s -> %s\n", key, srvname); + } else { + DBG_INFO("entry %s store failed.\n", key); + } + + TALLOC_FREE(key); + return ret; +} + +/* Fetch a name status record. */ + +bool namecache_status_fetch(const char *keyname, + int keyname_type, + int name_type, + const struct sockaddr_storage *keyip, + char *srvname_out) +{ + char *key = NULL; + char *value = NULL; + time_t timeout; + + key = namecache_status_record_key(talloc_tos(), + keyname, + keyname_type, + name_type, + keyip); + if (!key) + return false; + + if (!gencache_get(key, talloc_tos(), &value, &timeout)) { + DBG_INFO("no entry for %s found.\n", key); + TALLOC_FREE(key); + return false; + } else { + DBG_INFO("key %s -> %s\n", key, value); + } + + strlcpy(srvname_out, value, 16); + TALLOC_FREE(key); + TALLOC_FREE(value); + return true; +} |