diff options
Diffstat (limited to 'src/gprs/sgsn_ares.c')
| -rw-r--r-- | src/gprs/sgsn_ares.c | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/src/gprs/sgsn_ares.c b/src/gprs/sgsn_ares.c new file mode 100644 index 000000000..d94d184a3 --- /dev/null +++ b/src/gprs/sgsn_ares.c @@ -0,0 +1,173 @@ +/* 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) { + 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_setup(&sgsn->ares_timer, ares_timeout_cb, sgsn); + 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); |