| /* (C) 2018-2019 by sysmocom s.f.m.c. GmbH |
| * All Rights Reserved |
| * |
| * Author: Harald Welte, Philipp Maier |
| * |
| * 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 <errno.h> |
| |
| #include <osmocom/msc/sgs_iface.h> |
| #include <osmocom/msc/debug.h> |
| #include <osmocom/msc/sgs_server.h> |
| #include <osmocom/core/utils.h> |
| #include <osmocom/core/socket.h> |
| #include <osmocom/core/select.h> |
| #include <osmocom/netif/stream.h> |
| #include <netinet/sctp.h> |
| |
| #define LOGSGC(sgc, lvl, fmt, args...) \ |
| LOGP(DSGS, lvl, "%s: " fmt, (sgc)->sockname, ## args) |
| |
| /* call-back when data arrives on SGs */ |
| static int sgs_conn_readable_cb(struct osmo_stream_srv *conn) |
| { |
| struct osmo_fd *ofd = osmo_stream_srv_get_ofd(conn); |
| struct sgs_connection *sgc = osmo_stream_srv_get_data(conn); |
| struct msgb *msg = gsm29118_msgb_alloc(); |
| struct sctp_sndrcvinfo sinfo; |
| int flags = 0; |
| int rc = 0; |
| |
| /* we cannot use osmo_stream_srv_recv() here, as we might get some out-of-band info from |
| * SCTP. FIXME: add something like osmo_stream_srv_recv_sctp() to libosmo-netif and use |
| * it here as well as in libosmo-sigtran */ |
| rc = sctp_recvmsg(ofd->fd, msgb_data(msg), msgb_tailroom(msg), NULL, NULL, &sinfo, &flags); |
| if (rc < 0) { |
| osmo_stream_srv_destroy(conn); |
| rc = -EBADF; |
| goto out; |
| } else if (rc == 0) { |
| osmo_stream_srv_destroy(conn); |
| rc = -EBADF; |
| goto out; |
| } else { |
| msgb_put(msg, rc); |
| } |
| |
| if (flags & MSG_NOTIFICATION) { |
| union sctp_notification *notif = (union sctp_notification *)msgb_data(msg); |
| |
| switch (notif->sn_header.sn_type) { |
| case SCTP_SHUTDOWN_EVENT: |
| osmo_stream_srv_destroy(conn); |
| rc = -EBADF; |
| break; |
| case SCTP_ASSOC_CHANGE: |
| /* FIXME: do we have to notify the SGs code about this? */ |
| break; |
| default: |
| break; |
| } |
| goto out; |
| } |
| |
| /* set l2 header, as that's what we use in SGs code */ |
| msg->l2h = msgb_data(msg); |
| |
| if (msgb_sctp_ppid(msg) != 0) { |
| LOGSGC(sgc, LOGL_NOTICE, "Ignoring SCTP PPID %ld (spec violation)\n", msgb_sctp_ppid(msg)); |
| msgb_free(msg); |
| return 0; |
| } |
| |
| /* handle message */ |
| sgs_iface_rx(sgc, msg); |
| |
| return 0; |
| out: |
| msgb_free(msg); |
| return rc; |
| } |
| |
| /* call-back when new connection is closed ed on SGs */ |
| static int sgs_conn_closed_cb(struct osmo_stream_srv *conn) |
| { |
| struct sgs_connection *sgc = osmo_stream_srv_get_data(conn); |
| |
| LOGSGC(sgc, LOGL_NOTICE, "Connection lost\n"); |
| if (sgc->mme) { |
| /* unlink ourselves from the MME context */ |
| if (sgc->mme->conn == sgc) |
| sgc->mme->conn = NULL; |
| } |
| llist_del(&sgc->entry); |
| return 0; |
| } |
| |
| /* call-back when new connection is accept() ed on SGs */ |
| static int sgs_accept_cb(struct osmo_stream_srv_link *link, int fd) |
| { |
| struct sgs_state *sgs = osmo_stream_srv_link_get_data(link); |
| struct sgs_connection *sgc = talloc_zero(link, struct sgs_connection); |
| OSMO_ASSERT(sgc); |
| sgc->sgs = sgs; |
| osmo_sock_get_name_buf(sgc->sockname, sizeof(sgc->sockname), fd); |
| sgc->srv = osmo_stream_srv_create(sgc, link, fd, sgs_conn_readable_cb, sgs_conn_closed_cb, sgc); |
| if (!sgc->srv) { |
| talloc_free(sgc); |
| return -1; |
| } |
| LOGSGC(sgc, LOGL_INFO, "Accepted new SGs connection\n"); |
| llist_add_tail(&sgc->entry, &sgs->conn_list); |
| |
| return 0; |
| } |
| |
| static struct sgs_state *sgs_state_alloc(void *ctx) |
| { |
| struct sgs_state *sgs = talloc_zero(ctx, struct sgs_state); |
| |
| INIT_LLIST_HEAD(&sgs->mme_list); |
| INIT_LLIST_HEAD(&sgs->conn_list); |
| |
| memcpy(sgs->cfg.timer, sgs_state_timer_defaults, sizeof(sgs->cfg.timer)); |
| memcpy(sgs->cfg.counter, sgs_state_counter_defaults, sizeof(sgs->cfg.counter)); |
| sgs->cfg.local_port = SGS_PORT_DEFAULT; |
| osmo_strlcpy(sgs->cfg.local_addr, DEFAULT_SGS_SERVER_IP, sizeof(sgs->cfg.local_addr)); |
| osmo_strlcpy(sgs->cfg.vlr_name, DEFAULT_SGS_SERVER_VLR_NAME, sizeof(sgs->cfg.vlr_name)); |
| |
| return sgs; |
| } |
| |
| /*! allocate SGs new sgs state |
| * \param[in] ctx talloc context |
| * \returns returns allocated sgs state, NULL in case of error. */ |
| struct sgs_state *sgs_server_alloc(void *ctx) |
| { |
| struct sgs_state *sgs; |
| struct osmo_stream_srv_link *link; |
| |
| sgs = sgs_state_alloc(ctx); |
| if (!sgs) |
| return NULL; |
| |
| sgs->srv_link = link = osmo_stream_srv_link_create(ctx); |
| if (!sgs->srv_link) |
| return NULL; |
| |
| osmo_stream_srv_link_set_nodelay(link, true); |
| osmo_stream_srv_link_set_addr(link, sgs->cfg.local_addr); |
| osmo_stream_srv_link_set_port(link, sgs->cfg.local_port); |
| osmo_stream_srv_link_set_proto(link, IPPROTO_SCTP); |
| osmo_stream_srv_link_set_data(link, sgs); |
| osmo_stream_srv_link_set_accept_cb(link, sgs_accept_cb); |
| |
| return sgs; |
| } |
| |
| /*! (re)open SGs interface (SCTP) |
| * \param[in] sgs associated sgs state |
| * \returns 0 in case of success, -EINVAL in case of error. */ |
| int sgs_server_open(struct sgs_state *sgs) |
| { |
| int rc; |
| struct osmo_fd *ofd = osmo_stream_srv_link_get_ofd(sgs->srv_link); |
| |
| rc = osmo_stream_srv_link_open(sgs->srv_link); |
| if (rc < 0) { |
| LOGP(DSGS, LOGL_ERROR, "SGs socket cannot be opened: %s\n", strerror(errno)); |
| return -EINVAL; |
| } |
| |
| LOGP(DSGS, LOGL_NOTICE, "SGs socket bound to %s\n", osmo_sock_get_name2(ofd->fd)); |
| return 0; |
| } |