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-rw-r--r--src/libmsc/mncc_sock.c337
1 files changed, 337 insertions, 0 deletions
diff --git a/src/libmsc/mncc_sock.c b/src/libmsc/mncc_sock.c
new file mode 100644
index 00000000..2eef7c86
--- /dev/null
+++ b/src/libmsc/mncc_sock.c
@@ -0,0 +1,337 @@
+/* mncc_sock.c: Tie the MNCC interface to a unix domain socket */
+
+/* (C) 2008-2010 by Harald Welte <laforge@gnumonks.org>
+ * (C) 2009 by Andreas Eversberg <Andreas.Eversberg@versatel.de>
+ * All Rights Reserved
+ *
+ * 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 2 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, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <assert.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+
+#include <osmocore/talloc.h>
+#include <osmocore/select.h>
+#include <osmocore/protocol/gsm_04_08.h>
+
+#include <openbsc/debug.h>
+#include <openbsc/mncc.h>
+#include <openbsc/gsm_data.h>
+
+struct mncc_sock_state {
+ struct gsm_network *net;
+ struct bsc_fd listen_bfd; /* fd for listen socket */
+ struct bsc_fd conn_bfd; /* fd for connection to lcr */
+};
+
+/* FIXME: avoid this */
+static struct mncc_sock_state *g_state;
+
+/* input from CC code into mncc_sock */
+int mncc_sock_from_cc(struct gsm_network *net, struct msgb *msg)
+{
+ struct gsm_mncc *mncc_in = (struct gsm_mncc *) msgb_data(msg);
+ int msg_type = mncc_in->msg_type;
+
+ /* Check if we currently have a MNCC handler connected */
+ if (g_state->conn_bfd.fd < 0) {
+ LOGP(DMNCC, LOGL_ERROR, "mncc_sock receives %s for external CC app "
+ "but socket is gone\n", get_mncc_name(msg_type));
+ if (msg_type != GSM_TCHF_FRAME &&
+ msg_type != GSM_TCHF_FRAME_EFR) {
+ /* release the request */
+ struct gsm_mncc mncc_out;
+ memset(&mncc_out, 0, sizeof(mncc_out));
+ mncc_out.callref = mncc_in->callref;
+ mncc_set_cause(&mncc_out, GSM48_CAUSE_LOC_PRN_S_LU,
+ GSM48_CC_CAUSE_TEMP_FAILURE);
+ mncc_tx_to_cc(net, MNCC_REL_REQ, &mncc_out);
+ }
+ /* free the original message */
+ msgb_free(msg);
+ return -1;
+ }
+
+ /* FIXME: check for some maximum queue depth? */
+
+ /* Actually enqueue the message and mark socket write need */
+ msgb_enqueue(&net->upqueue, msg);
+ g_state->conn_bfd.when |= BSC_FD_WRITE;
+ return 0;
+}
+
+void mncc_sock_write_pending(void)
+{
+ g_state->conn_bfd.when |= BSC_FD_WRITE;
+}
+
+/* FIXME: move this to libosmocore */
+int osmo_unixsock_listen(struct bsc_fd *bfd, int type, const char *path);
+
+static void mncc_sock_close(struct mncc_sock_state *state)
+{
+ struct bsc_fd *bfd = &state->conn_bfd;
+
+ LOGP(DMNCC, LOGL_NOTICE, "MNCC Socket has LOST connection\n");
+
+ close(bfd->fd);
+ bfd->fd = -1;
+ bsc_unregister_fd(bfd);
+
+ /* re-enable the generation of ACCEPT for new connections */
+ state->listen_bfd.when |= BSC_FD_READ;
+
+ /* FIXME: make sure we don't enqueue anymore */
+
+ /* release all exisitng calls */
+ gsm0408_clear_all_trans(state->net, GSM48_PDISC_CC);
+
+ /* flush the queue */
+ while (!llist_empty(&state->net->upqueue)) {
+ struct msgb *msg = msgb_dequeue(&state->net->upqueue);
+ msgb_free(msg);
+ }
+}
+
+static int mncc_sock_read(struct bsc_fd *bfd)
+{
+ struct mncc_sock_state *state = (struct mncc_sock_state *)bfd->data;
+ struct gsm_mncc *mncc_prim;
+ struct msgb *msg;
+ int rc;
+
+ msg = msgb_alloc(sizeof(*mncc_prim)+256, "mncc_sock_rx");
+ if (!msg)
+ return -ENOMEM;
+
+ mncc_prim = (struct gsm_mncc *) msg->tail;
+
+ rc = recv(bfd->fd, msg->tail, msgb_tailroom(msg), 0);
+ if (rc == 0)
+ goto close;
+
+ if (rc < 0) {
+ if (errno == EAGAIN)
+ return 0;
+ goto close;
+ }
+
+ rc = mncc_tx_to_cc(state->net, mncc_prim->msg_type, mncc_prim);
+
+ /* as we always synchronously process the message in mncc_send() and
+ * its callbacks, we can free the message here. */
+ msgb_free(msg);
+
+ return rc;
+
+close:
+ msgb_free(msg);
+ mncc_sock_close(state);
+ return -1;
+}
+
+static int mncc_sock_write(struct bsc_fd *bfd)
+{
+ struct mncc_sock_state *state = bfd->data;
+ struct gsm_network *net = state->net;
+ int rc;
+
+ while (!llist_empty(&net->upqueue)) {
+ struct msgb *msg, *msg2;
+ struct gsm_mncc *mncc_prim;
+
+ /* peek at the beginning of the queue */
+ msg = llist_entry(net->upqueue.next, struct msgb, list);
+ mncc_prim = (struct gsm_mncc *)msg->data;
+
+ bfd->when &= ~BSC_FD_WRITE;
+
+ /* try to send it over the socket */
+ rc = write(bfd->fd, msgb_data(msg), msgb_length(msg));
+ if (rc == 0)
+ goto close;
+ if (rc < 0) {
+ if (errno == EAGAIN) {
+ bfd->when |= BSC_FD_WRITE;
+ break;
+ }
+ goto close;
+ }
+ /* _after_ we send it, we can deueue */
+ msg2 = msgb_dequeue(&net->upqueue);
+ assert(msg == msg2);
+ msgb_free(msg);
+ }
+ return 0;
+
+close:
+ mncc_sock_close(state);
+
+ return -1;
+}
+
+static int mncc_sock_cb(struct bsc_fd *bfd, unsigned int flags)
+{
+ int rc = 0;
+
+ if (flags & BSC_FD_READ)
+ rc = mncc_sock_read(bfd);
+ if (rc < 0)
+ return rc;
+
+ if (flags & BSC_FD_WRITE)
+ rc = mncc_sock_write(bfd);
+
+ return rc;
+}
+
+/* accept a new connection */
+static int mncc_sock_accept(struct bsc_fd *bfd, unsigned int flags)
+{
+ struct mncc_sock_state *state = (struct mncc_sock_state *)bfd->data;
+ struct bsc_fd *conn_bfd = &state->conn_bfd;
+ struct sockaddr_un un_addr;
+ socklen_t len;
+ int rc;
+
+ len = sizeof(un_addr);
+ rc = accept(bfd->fd, (struct sockaddr *) &un_addr, &len);
+ if (rc < 0) {
+ LOGP(DMNCC, LOGL_ERROR, "Failed to accept a new connection\n");
+ return -1;
+ }
+
+ if (conn_bfd->fd >= 0) {
+ LOGP(DMNCC, LOGL_NOTICE, "MNCC app connects but we already have "
+ "another active connection ?!?\n");
+ /* We already have one MNCC app connected, this is all we support */
+ state->listen_bfd.when &= ~BSC_FD_READ;
+ close(rc);
+ return 0;
+ }
+
+ conn_bfd->fd = rc;
+ conn_bfd->when = BSC_FD_READ;
+ conn_bfd->cb = mncc_sock_cb;
+ conn_bfd->data = state;
+
+ if (bsc_register_fd(conn_bfd) != 0) {
+ LOGP(DMNCC, LOGL_ERROR, "Failed to register new connection fd\n");
+ close(conn_bfd->fd);
+ conn_bfd->fd = -1;
+ state->listen_bfd.when |= ~BSC_FD_READ;
+ return -1;
+ }
+
+ LOGP(DMNCC, LOGL_NOTICE, "MNCC Socket has connection with external "
+ "call control application\n");
+
+ return 0;
+}
+
+
+int mncc_sock_init(struct gsm_network *net)
+{
+ struct mncc_sock_state *state;
+ struct bsc_fd *bfd;
+ int rc;
+
+ state = talloc_zero(tall_bsc_ctx, struct mncc_sock_state);
+ if (!state)
+ return -ENOMEM;
+
+ state->net = net;
+ state->conn_bfd.fd = -1;
+
+ bfd = &state->listen_bfd;
+
+ rc = osmo_unixsock_listen(bfd, SOCK_SEQPACKET, "/tmp/bsc_mncc");
+ if (rc < 0) {
+ LOGP(DMNCC, LOGL_ERROR, "Could not create unix socket: %s\n",
+ strerror(errno));
+ talloc_free(state);
+ return rc;
+ }
+
+ bfd->when = BSC_FD_READ;
+ bfd->cb = mncc_sock_accept;
+ bfd->data = state;
+
+ rc = bsc_register_fd(bfd);
+ if (rc < 0) {
+ LOGP(DMNCC, LOGL_ERROR, "Could not register listen fd: %d\n", rc);
+ close(bfd->fd);
+ talloc_free(state);
+ return rc;
+ }
+
+ g_state = state;
+
+ return 0;
+}
+
+/* FIXME: move this to libosmocore */
+int osmo_unixsock_listen(struct bsc_fd *bfd, int type, const char *path)
+{
+ struct sockaddr_un local;
+ unsigned int namelen;
+ int rc;
+
+ bfd->fd = socket(AF_UNIX, type, 0);
+
+ if (bfd->fd < 0) {
+ fprintf(stderr, "Failed to create Unix Domain Socket.\n");
+ return -1;
+ }
+
+ local.sun_family = AF_UNIX;
+ strncpy(local.sun_path, path, sizeof(local.sun_path));
+ local.sun_path[sizeof(local.sun_path) - 1] = '\0';
+ unlink(local.sun_path);
+
+ /* we use the same magic that X11 uses in Xtranssock.c for
+ * calculating the proper length of the sockaddr */
+#if defined(BSD44SOCKETS) || defined(__UNIXWARE__)
+ local.sun_len = strlen(local.sun_path);
+#endif
+#if defined(BSD44SOCKETS) || defined(SUN_LEN)
+ namelen = SUN_LEN(&local);
+#else
+ namelen = strlen(local.sun_path) +
+ offsetof(struct sockaddr_un, sun_path);
+#endif
+
+ rc = bind(bfd->fd, (struct sockaddr *) &local, namelen);
+ if (rc != 0) {
+ fprintf(stderr, "Failed to bind the unix domain socket. '%s'\n",
+ local.sun_path);
+ return -1;
+ }
+
+ if (listen(bfd->fd, 0) != 0) {
+ fprintf(stderr, "Failed to listen.\n");
+ return -1;
+ }
+
+ return 0;
+}