diff options
Diffstat (limited to '1.4.23-rc4/main/srv.c')
| -rw-r--r-- | 1.4.23-rc4/main/srv.c | 246 |
1 files changed, 0 insertions, 246 deletions
diff --git a/1.4.23-rc4/main/srv.c b/1.4.23-rc4/main/srv.c deleted file mode 100644 index cf99ef3ec..000000000 --- a/1.4.23-rc4/main/srv.c +++ /dev/null @@ -1,246 +0,0 @@ -/* - * Asterisk -- An open source telephony toolkit. - * - * Copyright (C) 1999 - 2005, Digium, Inc. - * - * Mark Spencer <markster@digium.com> - * - * Funding provided by nic.at - * - * See http://www.asterisk.org for more information about - * the Asterisk project. Please do not directly contact - * any of the maintainers of this project for assistance; - * the project provides a web site, mailing lists and IRC - * channels for your use. - * - * This program is free software, distributed under the terms of - * the GNU General Public License Version 2. See the LICENSE file - * at the top of the source tree. - */ - -/*! \file - * - * \brief DNS SRV Record Lookup Support for Asterisk - * - * \author Mark Spencer <markster@digium.com> - * - * \arg See also \ref AstENUM - * - * \note Funding provided by nic.at - */ - -#include "asterisk.h" - -ASTERISK_FILE_VERSION(__FILE__, "$Revision$") - -#include <sys/types.h> -#include <netinet/in.h> -#include <arpa/nameser.h> -#if __APPLE_CC__ >= 1495 -#include <arpa/nameser_compat.h> -#endif -#include <resolv.h> -#include <stdio.h> -#include <string.h> -#include <unistd.h> - -#include "asterisk/channel.h" -#include "asterisk/logger.h" -#include "asterisk/srv.h" -#include "asterisk/dns.h" -#include "asterisk/options.h" -#include "asterisk/utils.h" -#include "asterisk/linkedlists.h" - -#ifdef __APPLE__ -#undef T_SRV -#define T_SRV 33 -#endif - -struct srv_entry { - unsigned short priority; - unsigned short weight; - unsigned short port; - unsigned int weight_sum; - AST_LIST_ENTRY(srv_entry) list; - char host[1]; -}; - -struct srv_context { - unsigned int have_weights:1; - AST_LIST_HEAD_NOLOCK(srv_entries, srv_entry) entries; -}; - -static int parse_srv(unsigned char *answer, int len, unsigned char *msg, struct srv_entry **result) -{ - struct srv { - unsigned short priority; - unsigned short weight; - unsigned short port; - } __attribute__((__packed__)) *srv = (struct srv *) answer; - - int res = 0; - char repl[256] = ""; - struct srv_entry *entry; - - if (len < sizeof(*srv)) - return -1; - - answer += sizeof(*srv); - len -= sizeof(*srv); - - if ((res = dn_expand(msg, answer + len, answer, repl, sizeof(repl) - 1)) <= 0) { - ast_log(LOG_WARNING, "Failed to expand hostname\n"); - return -1; - } - - /* the magic value "." for the target domain means that this service - is *NOT* available at the domain we searched */ - if (!strcmp(repl, ".")) - return -1; - - if (!(entry = ast_calloc(1, sizeof(*entry) + strlen(repl)))) - return -1; - - entry->priority = ntohs(srv->priority); - entry->weight = ntohs(srv->weight); - entry->port = ntohs(srv->port); - strcpy(entry->host, repl); - - *result = entry; - - return 0; -} - -static int srv_callback(void *context, unsigned char *answer, int len, unsigned char *fullanswer) -{ - struct srv_context *c = (struct srv_context *) context; - struct srv_entry *entry = NULL; - struct srv_entry *current; - - if (parse_srv(answer, len, fullanswer, &entry)) - return -1; - - if (entry->weight) - c->have_weights = 1; - - AST_LIST_TRAVERSE_SAFE_BEGIN(&c->entries, current, list) { - /* insert this entry just before the first existing - entry with a higher priority */ - if (current->priority <= entry->priority) - continue; - - AST_LIST_INSERT_BEFORE_CURRENT(&c->entries, entry, list); - entry = NULL; - break; - } - AST_LIST_TRAVERSE_SAFE_END; - - /* if we didn't find a place to insert the entry before an existing - entry, then just add it to the end */ - if (entry) - AST_LIST_INSERT_TAIL(&c->entries, entry, list); - - return 1; -} - -/* Do the bizarre SRV record weight-handling algorithm - involving sorting and random number generation... - - See RFC 2782 if you want know why this code does this -*/ -static void process_weights(struct srv_context *context) -{ - struct srv_entry *current; - struct srv_entries newlist = AST_LIST_HEAD_NOLOCK_INIT_VALUE; - - while (AST_LIST_FIRST(&context->entries)) { - unsigned int random_weight; - unsigned int weight_sum; - unsigned short cur_priority = AST_LIST_FIRST(&context->entries)->priority; - struct srv_entries temp_list = AST_LIST_HEAD_NOLOCK_INIT_VALUE; - weight_sum = 0; - - AST_LIST_TRAVERSE_SAFE_BEGIN(&context->entries, current, list) { - if (current->priority != cur_priority) - break; - - AST_LIST_REMOVE_CURRENT(&context->entries, list); - AST_LIST_INSERT_TAIL(&temp_list, current, list); - } - AST_LIST_TRAVERSE_SAFE_END; - - while (AST_LIST_FIRST(&temp_list)) { - weight_sum = 0; - AST_LIST_TRAVERSE(&temp_list, current, list) - current->weight_sum = weight_sum += current->weight; - - /* if all the remaining entries have weight == 0, - then just append them to the result list and quit */ - if (weight_sum == 0) { - AST_LIST_APPEND_LIST(&newlist, &temp_list, list); - break; - } - - random_weight = 1 + (unsigned int) ((float) weight_sum * (ast_random() / ((float) RAND_MAX + 1.0))); - - AST_LIST_TRAVERSE_SAFE_BEGIN(&temp_list, current, list) { - if (current->weight < random_weight) - continue; - - AST_LIST_REMOVE_CURRENT(&temp_list, list); - AST_LIST_INSERT_TAIL(&newlist, current, list); - break; - } - AST_LIST_TRAVERSE_SAFE_END; - } - - } - - /* now that the new list has been ordered, - put it in place */ - - AST_LIST_APPEND_LIST(&context->entries, &newlist, list); -} - -int ast_get_srv(struct ast_channel *chan, char *host, int hostlen, int *port, const char *service) -{ - struct srv_context context = { .entries = AST_LIST_HEAD_NOLOCK_INIT_VALUE }; - struct srv_entry *current; - int ret; - - if (chan && ast_autoservice_start(chan) < 0) - return -1; - - ret = ast_search_dns(&context, service, C_IN, T_SRV, srv_callback); - - if (context.have_weights) - process_weights(&context); - - if (chan) - ret |= ast_autoservice_stop(chan); - - /* TODO: there could be a "." entry in the returned list of - answers... if so, this requires special handling */ - - /* the list of entries will be sorted in the proper selection order - already, so we just need the first one (if any) */ - - if ((ret > 0) && (current = AST_LIST_REMOVE_HEAD(&context.entries, list))) { - ast_copy_string(host, current->host, hostlen); - *port = current->port; - ast_free(current); - if (option_verbose > 3) { - ast_verbose(VERBOSE_PREFIX_3 "ast_get_srv: SRV lookup for '%s' mapped to host %s, port %d\n", - service, host, *port); - } - } else { - host[0] = '\0'; - *port = -1; - } - - while ((current = AST_LIST_REMOVE_HEAD(&context.entries, list))) - ast_free(current); - - return ret; -} |