| /* 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/socket.h> |
| #include <sys/un.h> |
| |
| #include <osmocom/core/talloc.h> |
| #include <osmocom/core/select.h> |
| #include <osmocom/gsm/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; |
| 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; |
| } |