move openbsc/* to repos root

This is the first step in creating this repository from the legacy openbsc.git.

Like all other Osmocom repositories, keep the autoconf and automake files in
the repository root. openbsc.git has been the sole exception, which ends now.

Change-Id: I9c6f2a448d9cb1cc088cf1cf6918b69d7e69b4e7

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);