| /* C-ARES DNS resolver integration */ |
| |
| /* |
| * (C) 2015 by Holger Hans Peter Freyther |
| * All Rights Reserved |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU Affero 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 Affero General Public License for more details. |
| * |
| * You should have received a copy of the GNU Affero General Public License |
| * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| * |
| */ |
| |
| #include <openbsc/sgsn.h> |
| #include <openbsc/debug.h> |
| |
| #include <netdb.h> |
| |
| struct cares_event_fd { |
| struct llist_head head; |
| struct osmo_fd fd; |
| }; |
| |
| struct cares_cb_data { |
| ares_host_callback cb; |
| void *data; |
| }; |
| |
| static void osmo_ares_reschedule(struct sgsn_instance *sgsn); |
| static void ares_cb(void *_arg, int status, int timeouts, struct hostent *hostent) |
| { |
| struct cares_cb_data *arg = _arg; |
| |
| arg->cb(arg->data, status, timeouts, hostent); |
| osmo_ares_reschedule(sgsn); |
| talloc_free(arg); |
| } |
| |
| static int ares_osmo_fd_cb(struct osmo_fd *fd, unsigned int what) |
| { |
| LOGP(DGPRS, LOGL_DEBUG, "C-ares fd(%d) ready(%d)\n", fd->fd, what); |
| |
| ares_process_fd(sgsn->ares_channel, |
| (what & BSC_FD_READ) ? fd->fd : ARES_SOCKET_BAD, |
| (what & BSC_FD_WRITE) ? fd->fd : ARES_SOCKET_BAD); |
| osmo_ares_reschedule(sgsn); |
| return 0; |
| } |
| |
| static void ares_timeout_cb(void *data) |
| { |
| struct sgsn_instance *sgsn = data; |
| |
| LOGP(DGPRS, LOGL_DEBUG, "C-ares triggering timeout\n"); |
| ares_process_fd(sgsn->ares_channel, ARES_SOCKET_BAD, ARES_SOCKET_BAD); |
| osmo_ares_reschedule(sgsn); |
| } |
| |
| static void osmo_ares_reschedule(struct sgsn_instance *sgsn) |
| { |
| struct timeval *timeout, tv; |
| |
| osmo_timer_del(&sgsn->ares_timer); |
| timeout = ares_timeout(sgsn->ares_channel, NULL, &tv); |
| if (timeout) { |
| sgsn->ares_timer.cb = ares_timeout_cb; |
| sgsn->ares_timer.data = sgsn; |
| |
| LOGP(DGPRS, LOGL_DEBUG, "C-ares scheduling timeout %llu.%llu\n", |
| (unsigned long long) tv.tv_sec, |
| (unsigned long long) tv.tv_usec); |
| osmo_timer_schedule(&sgsn->ares_timer, tv.tv_sec, tv.tv_usec); |
| } |
| } |
| |
| static void setup_ares_osmo_fd(void *data, int fd, int read, int write) |
| { |
| struct cares_event_fd *ufd, *tmp; |
| |
| /* delete the entry */ |
| if (read == 0 && write == 0) { |
| llist_for_each_entry_safe(ufd, tmp, &sgsn->ares_fds, head) { |
| if (ufd->fd.fd != fd) |
| continue; |
| |
| LOGP(DGPRS, LOGL_DEBUG, |
| "Removing C-ares watched fd (%d)\n", fd); |
| osmo_fd_unregister(&ufd->fd); |
| llist_del(&ufd->head); |
| talloc_free(ufd); |
| return; |
| } |
| } |
| |
| /* Search for the fd or create a new one */ |
| llist_for_each_entry(ufd, &sgsn->ares_fds, head) { |
| if (ufd->fd.fd != fd) |
| continue; |
| |
| LOGP(DGPRS, LOGL_DEBUG, "Updating C-ares fd (%d)\n", fd); |
| goto update_fd; |
| } |
| |
| LOGP(DGPRS, LOGL_DEBUG, "Registering C-ares fd (%d)\n", fd); |
| ufd = talloc_zero(tall_bsc_ctx, struct cares_event_fd); |
| ufd->fd.fd = fd; |
| ufd->fd.cb = ares_osmo_fd_cb; |
| ufd->fd.data = data; |
| if (osmo_fd_register(&ufd->fd) != 0) |
| LOGP(DGPRS, LOGL_ERROR, "Failed to register C-ares fd (%d)\n", fd); |
| llist_add(&ufd->head, &sgsn->ares_fds); |
| |
| update_fd: |
| if (read) |
| ufd->fd.when |= BSC_FD_READ; |
| else |
| ufd->fd.when &= ~BSC_FD_READ; |
| |
| if (write) |
| ufd->fd.when |= BSC_FD_WRITE; |
| else |
| ufd->fd.when &= ~BSC_FD_WRITE; |
| |
| osmo_ares_reschedule(sgsn); |
| } |
| |
| int sgsn_ares_query(struct sgsn_instance *sgsn, const char *name, |
| ares_host_callback cb, void *data) |
| { |
| struct cares_cb_data *cb_data; |
| |
| cb_data = talloc_zero(tall_bsc_ctx, struct cares_cb_data); |
| cb_data->cb = cb; |
| cb_data->data = data; |
| ares_gethostbyname(sgsn->ares_channel, name, AF_INET, ares_cb, cb_data); |
| osmo_ares_reschedule(sgsn); |
| return 0; |
| } |
| |
| int sgsn_ares_init(struct sgsn_instance *sgsn) |
| { |
| struct ares_options options; |
| int optmask; |
| int rc; |
| |
| INIT_LLIST_HEAD(&sgsn->ares_fds); |
| memset(&options, 0, sizeof(options)); |
| options.sock_state_cb = setup_ares_osmo_fd; |
| options.sock_state_cb_data = sgsn; |
| |
| optmask = ARES_OPT_FLAGS | ARES_OPT_SOCK_STATE_CB | ARES_OPT_DOMAINS; |
| |
| if (sgsn->ares_servers) |
| optmask |= ARES_OPT_SERVERS; |
| |
| ares_library_init(ARES_LIB_INIT_ALL); |
| rc = ares_init_options(&sgsn->ares_channel, &options, optmask); |
| if (rc != ARES_SUCCESS) |
| return rc; |
| |
| if (sgsn->ares_servers) |
| rc = ares_set_servers(sgsn->ares_channel, sgsn->ares_servers); |
| |
| return rc; |
| } |
| |
| osmo_static_assert(ARES_SUCCESS == 0, ares_success_zero); |