Harald Welte | 0df904d | 2018-12-03 11:00:04 +0100 | [diff] [blame] | 1 | /* (C) 2018-2019 by sysmocom s.f.m.c. GmbH |
| 2 | * All Rights Reserved |
| 3 | * |
| 4 | * Author: Harald Welte, Philipp Maier |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU Affero General Public License as published by |
| 8 | * the Free Software Foundation; either version 3 of the License, or |
| 9 | * (at your option) any later version. |
| 10 | * |
| 11 | * This program is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | * GNU Affero General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU Affero General Public License |
| 17 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 18 | * |
| 19 | */ |
| 20 | |
Neels Hofmeyr | c4628a3 | 2018-12-07 14:47:34 +0100 | [diff] [blame] | 21 | #include <errno.h> |
| 22 | |
Harald Welte | 0df904d | 2018-12-03 11:00:04 +0100 | [diff] [blame] | 23 | #include <osmocom/msc/sgs_iface.h> |
| 24 | #include <osmocom/msc/debug.h> |
| 25 | #include <osmocom/msc/sgs_server.h> |
| 26 | #include <osmocom/core/utils.h> |
| 27 | #include <osmocom/core/socket.h> |
| 28 | #include <osmocom/core/select.h> |
| 29 | #include <osmocom/netif/stream.h> |
| 30 | #include <netinet/sctp.h> |
| 31 | |
| 32 | #define LOGSGC(sgc, lvl, fmt, args...) \ |
| 33 | LOGP(DSGS, lvl, "%s: " fmt, (sgc)->sockname, ## args) |
| 34 | |
| 35 | /* call-back when data arrives on SGs */ |
| 36 | static int sgs_conn_readable_cb(struct osmo_stream_srv *conn) |
| 37 | { |
| 38 | struct osmo_fd *ofd = osmo_stream_srv_get_ofd(conn); |
| 39 | struct sgs_connection *sgc = osmo_stream_srv_get_data(conn); |
| 40 | struct msgb *msg = gsm29118_msgb_alloc(); |
| 41 | struct sctp_sndrcvinfo sinfo; |
| 42 | int flags = 0; |
Vadim Yanitskiy | 48a24cd | 2019-05-10 21:18:05 +0700 | [diff] [blame] | 43 | int rc = 0; |
Harald Welte | 0df904d | 2018-12-03 11:00:04 +0100 | [diff] [blame] | 44 | |
| 45 | /* we cannot use osmo_stream_srv_recv() here, as we might get some out-of-band info from |
| 46 | * SCTP. FIXME: add something like osmo_stream_srv_recv_sctp() to libosmo-netif and use |
| 47 | * it here as well as in libosmo-sigtran */ |
| 48 | rc = sctp_recvmsg(ofd->fd, msgb_data(msg), msgb_tailroom(msg), NULL, NULL, &sinfo, &flags); |
| 49 | if (rc < 0) { |
| 50 | osmo_stream_srv_destroy(conn); |
| 51 | rc = -EBADF; |
| 52 | goto out; |
| 53 | } else if (rc == 0) { |
| 54 | osmo_stream_srv_destroy(conn); |
| 55 | rc = -EBADF; |
| 56 | goto out; |
| 57 | } else { |
| 58 | msgb_put(msg, rc); |
| 59 | } |
| 60 | |
| 61 | if (flags & MSG_NOTIFICATION) { |
| 62 | union sctp_notification *notif = (union sctp_notification *)msgb_data(msg); |
| 63 | |
| 64 | switch (notif->sn_header.sn_type) { |
| 65 | case SCTP_SHUTDOWN_EVENT: |
| 66 | osmo_stream_srv_destroy(conn); |
| 67 | rc = -EBADF; |
| 68 | break; |
| 69 | case SCTP_ASSOC_CHANGE: |
| 70 | /* FIXME: do we have to notify the SGs code about this? */ |
| 71 | break; |
| 72 | default: |
| 73 | break; |
| 74 | } |
Harald Welte | 0df904d | 2018-12-03 11:00:04 +0100 | [diff] [blame] | 75 | goto out; |
| 76 | } |
| 77 | |
| 78 | /* set l2 header, as that's what we use in SGs code */ |
| 79 | msg->l2h = msgb_data(msg); |
| 80 | |
| 81 | if (msgb_sctp_ppid(msg) != 0) { |
| 82 | LOGSGC(sgc, LOGL_NOTICE, "Ignoring SCTP PPID %ld (spec violation)\n", msgb_sctp_ppid(msg)); |
| 83 | msgb_free(msg); |
| 84 | return 0; |
| 85 | } |
| 86 | |
| 87 | /* handle message */ |
| 88 | sgs_iface_rx(sgc, msg); |
| 89 | |
| 90 | return 0; |
| 91 | out: |
| 92 | msgb_free(msg); |
| 93 | return rc; |
| 94 | } |
| 95 | |
| 96 | /* call-back when new connection is closed ed on SGs */ |
| 97 | static int sgs_conn_closed_cb(struct osmo_stream_srv *conn) |
| 98 | { |
| 99 | struct sgs_connection *sgc = osmo_stream_srv_get_data(conn); |
| 100 | |
| 101 | LOGSGC(sgc, LOGL_NOTICE, "Connection lost\n"); |
| 102 | if (sgc->mme) { |
| 103 | /* unlink ourselves from the MME context */ |
| 104 | if (sgc->mme->conn == sgc) |
| 105 | sgc->mme->conn = NULL; |
| 106 | } |
| 107 | llist_del(&sgc->entry); |
| 108 | return 0; |
| 109 | } |
| 110 | |
| 111 | /* call-back when new connection is accept() ed on SGs */ |
| 112 | static int sgs_accept_cb(struct osmo_stream_srv_link *link, int fd) |
| 113 | { |
| 114 | struct sgs_state *sgs = osmo_stream_srv_link_get_data(link); |
| 115 | struct sgs_connection *sgc = talloc_zero(link, struct sgs_connection); |
| 116 | OSMO_ASSERT(sgc); |
| 117 | sgc->sgs = sgs; |
| 118 | osmo_sock_get_name_buf(sgc->sockname, sizeof(sgc->sockname), fd); |
| 119 | sgc->srv = osmo_stream_srv_create(sgc, link, fd, sgs_conn_readable_cb, sgs_conn_closed_cb, sgc); |
| 120 | if (!sgc->srv) { |
| 121 | talloc_free(sgc); |
| 122 | return -1; |
| 123 | } |
| 124 | LOGSGC(sgc, LOGL_INFO, "Accepted new SGs connection\n"); |
| 125 | llist_add_tail(&sgc->entry, &sgs->conn_list); |
| 126 | |
| 127 | return 0; |
| 128 | } |
| 129 | |
| 130 | static struct sgs_state *sgs_state_alloc(void *ctx) |
| 131 | { |
| 132 | struct sgs_state *sgs = talloc_zero(ctx, struct sgs_state); |
| 133 | |
| 134 | INIT_LLIST_HEAD(&sgs->mme_list); |
| 135 | INIT_LLIST_HEAD(&sgs->conn_list); |
| 136 | |
| 137 | memcpy(sgs->cfg.timer, sgs_state_timer_defaults, sizeof(sgs->cfg.timer)); |
| 138 | memcpy(sgs->cfg.counter, sgs_state_counter_defaults, sizeof(sgs->cfg.counter)); |
| 139 | sgs->cfg.local_port = SGS_PORT_DEFAULT; |
| 140 | osmo_strlcpy(sgs->cfg.local_addr, DEFAULT_SGS_SERVER_IP, sizeof(sgs->cfg.local_addr)); |
| 141 | osmo_strlcpy(sgs->cfg.vlr_name, DEFAULT_SGS_SERVER_VLR_NAME, sizeof(sgs->cfg.vlr_name)); |
| 142 | |
| 143 | return sgs; |
| 144 | } |
| 145 | |
| 146 | /*! allocate SGs new sgs state |
| 147 | * \param[in] ctx talloc context |
| 148 | * \returns returns allocated sgs state, NULL in case of error. */ |
| 149 | struct sgs_state *sgs_server_alloc(void *ctx) |
| 150 | { |
| 151 | struct sgs_state *sgs; |
| 152 | struct osmo_stream_srv_link *link; |
| 153 | |
| 154 | sgs = sgs_state_alloc(ctx); |
| 155 | if (!sgs) |
| 156 | return NULL; |
| 157 | |
| 158 | sgs->srv_link = link = osmo_stream_srv_link_create(ctx); |
| 159 | if (!sgs->srv_link) |
| 160 | return NULL; |
| 161 | |
| 162 | osmo_stream_srv_link_set_nodelay(link, true); |
| 163 | osmo_stream_srv_link_set_addr(link, sgs->cfg.local_addr); |
| 164 | osmo_stream_srv_link_set_port(link, sgs->cfg.local_port); |
| 165 | osmo_stream_srv_link_set_proto(link, IPPROTO_SCTP); |
| 166 | osmo_stream_srv_link_set_data(link, sgs); |
| 167 | osmo_stream_srv_link_set_accept_cb(link, sgs_accept_cb); |
| 168 | |
| 169 | return sgs; |
| 170 | } |
| 171 | |
| 172 | /*! (re)open SGs interface (SCTP) |
| 173 | * \param[in] sgs associated sgs state |
| 174 | * \returns 0 in case of success, -EINVAL in case of error. */ |
| 175 | int sgs_server_open(struct sgs_state *sgs) |
| 176 | { |
| 177 | int rc; |
| 178 | struct osmo_fd *ofd = osmo_stream_srv_link_get_ofd(sgs->srv_link); |
| 179 | |
| 180 | rc = osmo_stream_srv_link_open(sgs->srv_link); |
| 181 | if (rc < 0) { |
| 182 | LOGP(DSGS, LOGL_ERROR, "SGs socket cannot be opened: %s\n", strerror(errno)); |
| 183 | return -EINVAL; |
| 184 | } |
| 185 | |
| 186 | LOGP(DSGS, LOGL_NOTICE, "SGs socket bound to %s\n", osmo_sock_get_name2(ofd->fd)); |
| 187 | return 0; |
| 188 | } |