diff options
Diffstat (limited to 'src/ipaccess/ipaccess-proxy.c')
| -rw-r--r-- | src/ipaccess/ipaccess-proxy.c | 1226 |
1 files changed, 1226 insertions, 0 deletions
diff --git a/src/ipaccess/ipaccess-proxy.c b/src/ipaccess/ipaccess-proxy.c new file mode 100644 index 000000000..d3674426c --- /dev/null +++ b/src/ipaccess/ipaccess-proxy.c @@ -0,0 +1,1226 @@ +/* OpenBSC Abis/IP proxy ip.access nanoBTS */ + +/* (C) 2009 by Harald Welte <laforge@gnumonks.org> + * (C) 2010 by On-Waves + * (C) 2010 by Holger Hans Peter Freyther <zecke@selfish.org> + * + * 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 <stdio.h> +#include <unistd.h> +#include <stdlib.h> +#include <errno.h> +#include <string.h> +#include <signal.h> +#include <time.h> +#include <sys/fcntl.h> +#include <sys/socket.h> +#include <sys/ioctl.h> +#include <arpa/inet.h> +#include <netinet/in.h> + +#define _GNU_SOURCE +#include <getopt.h> + +#include <openbsc/gsm_data.h> +#include <osmocom/core/application.h> +#include <osmocom/core/select.h> +#include <osmocom/gsm/tlv.h> +#include <osmocom/core/msgb.h> +#include <osmocom/gsm/ipa.h> +#include <osmocom/abis/ipa.h> +#include <osmocom/abis/ipaccess.h> +#include <openbsc/debug.h> +#include <openbsc/ipaccess.h> +#include <openbsc/socket.h> +#include <osmocom/core/talloc.h> + +/* one instance of an ip.access protocol proxy */ +struct ipa_proxy { + /* socket where we listen for incoming OML from BTS */ + struct osmo_fd oml_listen_fd; + /* socket where we listen for incoming RSL from BTS */ + struct osmo_fd rsl_listen_fd; + /* list of BTS's (struct ipa_bts_conn */ + struct llist_head bts_list; + /* the BSC reconnect timer */ + struct osmo_timer_list reconn_timer; + /* global GPRS NS data */ + struct in_addr gprs_addr; + struct in_addr listen_addr; +}; + +/* global pointer to the proxy structure */ +static struct ipa_proxy *ipp; + +struct ipa_proxy_conn { + struct osmo_fd fd; + struct llist_head tx_queue; + struct ipa_bts_conn *bts_conn; +}; +#define MAX_TRX 4 + +/* represents a particular BTS in our proxy */ +struct ipa_bts_conn { + /* list of BTS's (ipa_proxy->bts_list) */ + struct llist_head list; + /* back pointer to the proxy which we belong to */ + struct ipa_proxy *ipp; + /* the unit ID as determined by CCM */ + struct { + uint16_t site_id; + uint16_t bts_id; + } unit_id; + + /* incoming connections from BTS */ + struct ipa_proxy_conn *oml_conn; + struct ipa_proxy_conn *rsl_conn[MAX_TRX]; + + /* outgoing connections to BSC */ + struct ipa_proxy_conn *bsc_oml_conn; + struct ipa_proxy_conn *bsc_rsl_conn[MAX_TRX]; + + /* UDP sockets for BTS and BSC injection */ + struct osmo_fd udp_bts_fd; + struct osmo_fd udp_bsc_fd; + + /* NS data */ + struct in_addr bts_addr; + struct osmo_fd gprs_ns_fd; + int gprs_local_port; + uint16_t gprs_orig_port; + uint32_t gprs_orig_ip; + + char *id_tags[256]; + uint8_t *id_resp; + unsigned int id_resp_len; +}; + +enum ipp_fd_type { + OML_FROM_BTS = 1, + RSL_FROM_BTS = 2, + OML_TO_BSC = 3, + RSL_TO_BSC = 4, + UDP_TO_BTS = 5, + UDP_TO_BSC = 6, +}; + +/* some of the code against we link from OpenBSC needs this */ +void *tall_bsc_ctx; + +static char *listen_ipaddr; +static char *bsc_ipaddr; +static char *gprs_ns_ipaddr; + +static int gprs_ns_cb(struct osmo_fd *bfd, unsigned int what); + +#define PROXY_ALLOC_SIZE 1200 + +static struct ipa_bts_conn *find_bts_by_unitid(struct ipa_proxy *ipp, + uint16_t site_id, + uint16_t bts_id) +{ + struct ipa_bts_conn *ipbc; + + llist_for_each_entry(ipbc, &ipp->bts_list, list) { + if (ipbc->unit_id.site_id == site_id && + ipbc->unit_id.bts_id == bts_id) + return ipbc; + } + + return NULL; +} + +struct ipa_proxy_conn *alloc_conn(void) +{ + struct ipa_proxy_conn *ipc; + + ipc = talloc_zero(tall_bsc_ctx, struct ipa_proxy_conn); + if (!ipc) + return NULL; + + INIT_LLIST_HEAD(&ipc->tx_queue); + + return ipc; +} + +static int store_idtags(struct ipa_bts_conn *ipbc, struct tlv_parsed *tlvp) +{ + unsigned int i, len; + + for (i = 0; i <= 0xff; i++) { + if (!TLVP_PRESENT(tlvp, i)) + continue; + + len = TLVP_LEN(tlvp, i); +#if 0 + if (!ipbc->id_tags[i]) + ipbc->id_tags[i] = talloc_size(tall_bsc_ctx, len); + else +#endif + ipbc->id_tags[i] = talloc_realloc_size(ipbc, + ipbc->id_tags[i], len); + if (!ipbc->id_tags[i]) + return -ENOMEM; + + memset(ipbc->id_tags[i], 0, len); + //memcpy(ipbc->id_tags[i], TLVP_VAL(tlvp, i), len); + } + return 0; +} + + +static struct ipa_proxy_conn *connect_bsc(struct sockaddr_in *sa, int priv_nr, void *data); + +#define logp_ipbc_uid(ss, lvl, ipbc, trx_id) _logp_ipbc_uid(ss, lvl, __FILE__, __LINE__, ipbc, trx_id) + +static void _logp_ipbc_uid(unsigned int ss, unsigned int lvl, char *file, int line, + struct ipa_bts_conn *ipbc, uint8_t trx_id) +{ + if (ipbc) + logp2(ss, lvl, file, line, 0, "(%u/%u/%u) ", ipbc->unit_id.site_id, + ipbc->unit_id.bts_id, trx_id); + else + logp2(ss, lvl, file, line, 0, "unknown "); +} + +static int handle_udp_read(struct osmo_fd *bfd) +{ + struct ipa_bts_conn *ipbc = bfd->data; + struct ipa_proxy_conn *other_conn = NULL; + struct msgb *msg = msgb_alloc(PROXY_ALLOC_SIZE, "Abis/IP UDP"); + struct ipaccess_head *hh; + int ret; + + /* with UDP sockets, we cannot read partial packets but have to read + * all of it in one go */ + hh = (struct ipaccess_head *) msg->data; + ret = recv(bfd->fd, msg->data, msg->data_len, 0); + if (ret < 0) { + if (errno != EAGAIN) + LOGP(DLINP, LOGL_ERROR, "recv error %s\n", strerror(errno)); + msgb_free(msg); + return ret; + } + if (ret == 0) { + DEBUGP(DLINP, "UDP peer disappeared, dead socket\n"); + osmo_fd_unregister(bfd); + close(bfd->fd); + bfd->fd = -1; + msgb_free(msg); + return -EIO; + } + if (ret < sizeof(*hh)) { + DEBUGP(DLINP, "could not even read header!?!\n"); + msgb_free(msg); + return -EIO; + } + msgb_put(msg, ret); + msg->l2h = msg->data + sizeof(*hh); + DEBUGP(DLMI, "UDP RX: %s\n", osmo_hexdump(msg->data, msg->len)); + + if (hh->len != msg->len - sizeof(*hh)) { + DEBUGP(DLINP, "length (%u/%u) disagrees with header(%u)\n", + msg->len, msg->len - 3, hh->len); + msgb_free(msg); + return -EIO; + } + + switch (bfd->priv_nr & 0xff) { + case UDP_TO_BTS: + /* injection towards BTS */ + switch (hh->proto) { + case IPAC_PROTO_RSL: + /* FIXME: what to do about TRX > 0 */ + other_conn = ipbc->rsl_conn[0]; + break; + default: + DEBUGP(DLINP, "Unknown protocol 0x%02x, sending to " + "OML FD\n", hh->proto); + /* fall through */ + case IPAC_PROTO_IPACCESS: + case IPAC_PROTO_OML: + other_conn = ipbc->oml_conn; + break; + } + break; + case UDP_TO_BSC: + /* injection towards BSC */ + switch (hh->proto) { + case IPAC_PROTO_RSL: + /* FIXME: what to do about TRX > 0 */ + other_conn = ipbc->bsc_rsl_conn[0]; + break; + default: + DEBUGP(DLINP, "Unknown protocol 0x%02x, sending to " + "OML FD\n", hh->proto); + /* fall through */ + case IPAC_PROTO_IPACCESS: + case IPAC_PROTO_OML: + other_conn = ipbc->bsc_oml_conn; + break; + } + break; + default: + DEBUGP(DLINP, "Unknown filedescriptor priv_nr=%04x\n", bfd->priv_nr); + break; + } + + if (other_conn) { + /* enqueue the message for TX on the respective FD */ + msgb_enqueue(&other_conn->tx_queue, msg); + other_conn->fd.when |= BSC_FD_WRITE; + } else + msgb_free(msg); + + return 0; +} + +static int handle_udp_write(struct osmo_fd *bfd) +{ + /* not implemented yet */ + bfd->when &= ~BSC_FD_WRITE; + + return -EIO; +} + +/* callback from select.c in case one of the fd's can be read/written */ +static int udp_fd_cb(struct osmo_fd *bfd, unsigned int what) +{ + int rc = 0; + + if (what & BSC_FD_READ) + rc = handle_udp_read(bfd); + if (what & BSC_FD_WRITE) + rc = handle_udp_write(bfd); + + return rc; +} + + +static int ipbc_alloc_connect(struct ipa_proxy_conn *ipc, struct osmo_fd *bfd, + uint16_t site_id, uint16_t bts_id, + uint16_t trx_id, struct tlv_parsed *tlvp, + struct msgb *msg) +{ + struct ipa_bts_conn *ipbc; + uint16_t udp_port; + int ret = 0; + struct sockaddr_in sin; + + memset(&sin, 0, sizeof(sin)); + sin.sin_family = AF_INET; + inet_aton(bsc_ipaddr, &sin.sin_addr); + + DEBUGP(DLINP, "(%u/%u/%u) New BTS connection: ", + site_id, bts_id, trx_id); + + /* OML needs to be established before RSL */ + if ((bfd->priv_nr & 0xff) != OML_FROM_BTS) { + DEBUGPC(DLINP, "Not a OML connection ?!?\n"); + return -EIO; + } + + /* allocate new BTS connection data structure */ + ipbc = talloc_zero(tall_bsc_ctx, struct ipa_bts_conn); + if (!ipbc) { + ret = -ENOMEM; + goto err_out; + } + + DEBUGPC(DLINP, "Created BTS Conn data structure\n"); + ipbc->ipp = ipp; + ipbc->unit_id.site_id = site_id; + ipbc->unit_id.bts_id = bts_id; + ipbc->oml_conn = ipc; + ipc->bts_conn = ipbc; + + /* store the content of the ID TAGS for later reference */ + store_idtags(ipbc, tlvp); + ipbc->id_resp_len = msg->len; + ipbc->id_resp = talloc_size(tall_bsc_ctx, ipbc->id_resp_len); + memcpy(ipbc->id_resp, msg->data, ipbc->id_resp_len); + + /* Create OML TCP connection towards BSC */ + sin.sin_port = htons(IPA_TCP_PORT_OML); + ipbc->bsc_oml_conn = connect_bsc(&sin, OML_TO_BSC, ipbc); + if (!ipbc->bsc_oml_conn) { + ret = -EIO; + goto err_bsc_conn; + } + + DEBUGP(DLINP, "(%u/%u/%u) OML Connected to BSC\n", + site_id, bts_id, trx_id); + + /* Create UDP socket for BTS packet injection */ + udp_port = 10000 + (site_id % 1000)*100 + (bts_id % 100); + ret = make_sock(&ipbc->udp_bts_fd, IPPROTO_UDP, INADDR_ANY, udp_port, + UDP_TO_BTS, udp_fd_cb, ipbc); + if (ret < 0) + goto err_udp_bts; + DEBUGP(DLINP, "(%u/%u/%u) Created UDP socket for injection " + "towards BTS at port %u\n", site_id, bts_id, trx_id, udp_port); + + /* Create UDP socket for BSC packet injection */ + udp_port = 20000 + (site_id % 1000)*100 + (bts_id % 100); + ret = make_sock(&ipbc->udp_bsc_fd, IPPROTO_UDP, INADDR_ANY, udp_port, + UDP_TO_BSC, udp_fd_cb, ipbc); + if (ret < 0) + goto err_udp_bsc; + DEBUGP(DLINP, "(%u/%u/%u) Created UDP socket for injection " + "towards BSC at port %u\n", site_id, bts_id, trx_id, udp_port); + + + /* GPRS NS related code */ + if (gprs_ns_ipaddr) { + struct sockaddr_in sock; + socklen_t len = sizeof(sock); + struct in_addr addr; + uint32_t ip; + + inet_aton(listen_ipaddr, &addr); + ip = ntohl(addr.s_addr); /* make_sock() needs host byte order */ + ret = make_sock(&ipbc->gprs_ns_fd, IPPROTO_UDP, ip, 0, 0, + gprs_ns_cb, ipbc); + if (ret < 0) { + LOGP(DLINP, LOGL_ERROR, "Creating the GPRS socket failed.\n"); + goto err_udp_bsc; + } + + ret = getsockname(ipbc->gprs_ns_fd.fd, (struct sockaddr* ) &sock, &len); + ipbc->gprs_local_port = ntohs(sock.sin_port); + LOGP(DLINP, LOGL_NOTICE, + "Created GPRS NS Socket. Listening on: %s:%d\n", + inet_ntoa(sock.sin_addr), ipbc->gprs_local_port); + + ret = getpeername(bfd->fd, (struct sockaddr* ) &sock, &len); + ipbc->bts_addr = sock.sin_addr; + } + + llist_add(&ipbc->list, &ipp->bts_list); + + return 0; + +err_udp_bsc: + osmo_fd_unregister(&ipbc->udp_bts_fd); +err_udp_bts: + osmo_fd_unregister(&ipbc->bsc_oml_conn->fd); + close(ipbc->bsc_oml_conn->fd.fd); + talloc_free(ipbc->bsc_oml_conn); + ipbc->bsc_oml_conn = NULL; +err_bsc_conn: + talloc_free(ipbc->id_resp); + talloc_free(ipbc); +#if 0 + osmo_fd_unregister(bfd); + close(bfd->fd); + talloc_free(bfd); +#endif +err_out: + return ret; +} + +static int ipaccess_rcvmsg(struct ipa_proxy_conn *ipc, struct msgb *msg, + struct osmo_fd *bfd) +{ + struct tlv_parsed tlvp; + uint8_t msg_type = *(msg->l2h); + struct ipaccess_unit unit_data; + struct ipa_bts_conn *ipbc; + int ret = 0; + + switch (msg_type) { + case IPAC_MSGT_PING: + ret = ipa_ccm_send_pong(bfd->fd); + break; + case IPAC_MSGT_PONG: + DEBUGP(DLMI, "PONG!\n"); + break; + case IPAC_MSGT_ID_RESP: + DEBUGP(DLMI, "ID_RESP "); + /* parse tags, search for Unit ID */ + ipa_ccm_idtag_parse(&tlvp, (uint8_t *)msg->l2h + 2, + msgb_l2len(msg)-2); + DEBUGP(DLMI, "\n"); + + if (!TLVP_PRESENT(&tlvp, IPAC_IDTAG_UNIT)) { + LOGP(DLINP, LOGL_ERROR, "No Unit ID in ID RESPONSE !?!\n"); + return -EIO; + } + + /* lookup BTS, create sign_link, ... */ + memset(&unit_data, 0, sizeof(unit_data)); + ipa_parse_unitid((char *)TLVP_VAL(&tlvp, IPAC_IDTAG_UNIT), + &unit_data); + ipbc = find_bts_by_unitid(ipp, unit_data.site_id, unit_data.bts_id); + if (!ipbc) { + /* We have not found an ipbc (per-bts proxy instance) + * for this BTS yet. The first connection of a new BTS must + * be a OML connection. We allocate the associated data structures, + * and try to connect to the remote end */ + + return ipbc_alloc_connect(ipc, bfd, unit_data.site_id, + unit_data.bts_id, + unit_data.trx_id, &tlvp, msg); + /* if this fails, the caller will clean up bfd */ + } else { + struct sockaddr_in sin; + memset(&sin, 0, sizeof(sin)); + sin.sin_family = AF_INET; + inet_aton(bsc_ipaddr, &sin.sin_addr); + + DEBUGP(DLINP, "Identified BTS %u/%u/%u\n", + unit_data.site_id, unit_data.bts_id, unit_data.trx_id); + + if ((bfd->priv_nr & 0xff) != RSL_FROM_BTS) { + LOGP(DLINP, LOGL_ERROR, "Second OML connection from " + "same BTS ?!?\n"); + return 0; + } + + if (unit_data.trx_id >= MAX_TRX) { + LOGP(DLINP, LOGL_ERROR, "We don't support more " + "than %u TRX\n", MAX_TRX); + return -EINVAL; + } + + ipc->bts_conn = ipbc; + /* store TRX number in higher 8 bit of the bfd private number */ + bfd->priv_nr |= unit_data.trx_id << 8; + ipbc->rsl_conn[unit_data.trx_id] = ipc; + + /* Create RSL TCP connection towards BSC */ + sin.sin_port = htons(IPA_TCP_PORT_RSL); + ipbc->bsc_rsl_conn[unit_data.trx_id] = + connect_bsc(&sin, RSL_TO_BSC | (unit_data.trx_id << 8), ipbc); + if (!ipbc->bsc_oml_conn) + return -EIO; + DEBUGP(DLINP, "(%u/%u/%u) Connected RSL to BSC\n", + unit_data.site_id, unit_data.bts_id, unit_data.trx_id); + } + break; + case IPAC_MSGT_ID_GET: + DEBUGP(DLMI, "ID_GET\n"); + if ((bfd->priv_nr & 0xff) != OML_TO_BSC && + (bfd->priv_nr & 0xff) != RSL_TO_BSC) { + DEBUGP(DLINP, "IDentity REQuest from BTS ?!?\n"); + return -EIO; + } + ipbc = ipc->bts_conn; + if (!ipbc) { + DEBUGP(DLINP, "ID_GET from BSC before we have ID_RESP from BTS\n"); + return -EIO; + } + ret = write(bfd->fd, ipbc->id_resp, ipbc->id_resp_len); + if (ret != ipbc->id_resp_len) { + LOGP(DLINP, LOGL_ERROR, "Partial write: %d of %d\n", + ret, ipbc->id_resp_len); + return -EIO; + } + ret = 0; + break; + case IPAC_MSGT_ID_ACK: + DEBUGP(DLMI, "ID_ACK? -> ACK!\n"); + ret = ipa_ccm_send_id_ack(bfd->fd); + break; + default: + LOGP(DLMI, LOGL_ERROR, "Unhandled IPA type; %d\n", msg_type); + return 1; + break; + } + return ret; +} + +struct msgb *ipaccess_proxy_read_msg(struct osmo_fd *bfd, int *error) +{ + struct msgb *msg = msgb_alloc(PROXY_ALLOC_SIZE, "Abis/IP"); + struct ipaccess_head *hh; + int len, ret = 0; + + if (!msg) { + *error = -ENOMEM; + return NULL; + } + + /* first read our 3-byte header */ + hh = (struct ipaccess_head *) msg->data; + ret = recv(bfd->fd, msg->data, 3, 0); + if (ret < 0) { + if (errno != EAGAIN) + LOGP(DLINP, LOGL_ERROR, "recv error: %s\n", strerror(errno)); + msgb_free(msg); + *error = ret; + return NULL; + } else if (ret == 0) { + msgb_free(msg); + *error = ret; + return NULL; + } + + msgb_put(msg, ret); + + /* then read te length as specified in header */ + msg->l2h = msg->data + sizeof(*hh); + len = ntohs(hh->len); + ret = recv(bfd->fd, msg->l2h, len, 0); + if (ret < len) { + LOGP(DLINP, LOGL_ERROR, "short read!\n"); + msgb_free(msg); + *error = -EIO; + return NULL; + } + msgb_put(msg, ret); + + return msg; +} + +static struct ipa_proxy_conn *ipc_by_priv_nr(struct ipa_bts_conn *ipbc, + unsigned int priv_nr) +{ + struct ipa_proxy_conn *bsc_conn; + unsigned int trx_id = priv_nr >> 8; + + switch (priv_nr & 0xff) { + case OML_FROM_BTS: /* incoming OML data from BTS, forward to BSC OML */ + bsc_conn = ipbc->bsc_oml_conn; + break; + case RSL_FROM_BTS: /* incoming RSL data from BTS, forward to BSC RSL */ + bsc_conn = ipbc->bsc_rsl_conn[trx_id]; + break; + case OML_TO_BSC: /* incoming OML data from BSC, forward to BTS OML */ + bsc_conn = ipbc->oml_conn; + break; + case RSL_TO_BSC: /* incoming RSL data from BSC, forward to BTS RSL */ + bsc_conn = ipbc->rsl_conn[trx_id]; + break; + default: + bsc_conn = NULL; + break; + } + return bsc_conn; +} + +static void reconn_tmr_cb(void *data) +{ + struct ipa_proxy *ipp = data; + struct ipa_bts_conn *ipbc; + struct sockaddr_in sin; + int i; + + DEBUGP(DLINP, "Running reconnect timer\n"); + + memset(&sin, 0, sizeof(sin)); + sin.sin_family = AF_INET; + inet_aton(bsc_ipaddr, &sin.sin_addr); + + llist_for_each_entry(ipbc, &ipp->bts_list, list) { + /* if OML to BSC is dead, try to restore it */ + if (ipbc->oml_conn && !ipbc->bsc_oml_conn) { + sin.sin_port = htons(IPA_TCP_PORT_OML); + logp_ipbc_uid(DLINP, LOGL_NOTICE, ipbc, 0); + LOGPC(DLINP, LOGL_NOTICE, "OML Trying to reconnect\n"); + ipbc->bsc_oml_conn = connect_bsc(&sin, OML_TO_BSC, ipbc); + if (!ipbc->bsc_oml_conn) + goto reschedule; + logp_ipbc_uid(DLINP, LOGL_NOTICE, ipbc, 0); + LOGPC(DLINP, LOGL_NOTICE, "OML Reconnected\n"); + } + /* if we (still) don't have a OML connection, skip RSL */ + if (!ipbc->oml_conn || !ipbc->bsc_oml_conn) + continue; + + for (i = 0; i < ARRAY_SIZE(ipbc->rsl_conn); i++) { + unsigned int priv_nr; + /* don't establish RSL links which we don't have */ + if (!ipbc->rsl_conn[i]) + continue; + if (ipbc->bsc_rsl_conn[i]) + continue; + priv_nr = ipbc->rsl_conn[i]->fd.priv_nr; + priv_nr &= ~0xff; + priv_nr |= RSL_TO_BSC; + sin.sin_port = htons(IPA_TCP_PORT_RSL); + logp_ipbc_uid(DLINP, LOGL_NOTICE, ipbc, priv_nr >> 8); + LOGPC(DLINP, LOGL_NOTICE, "RSL Trying to reconnect\n"); + ipbc->bsc_rsl_conn[i] = connect_bsc(&sin, priv_nr, ipbc); + if (!ipbc->bsc_rsl_conn[i]) + goto reschedule; + logp_ipbc_uid(DLINP, LOGL_NOTICE, ipbc, priv_nr >> 8); + LOGPC(DLINP, LOGL_NOTICE, "RSL Reconnected\n"); + } + } + return; + +reschedule: + osmo_timer_schedule(&ipp->reconn_timer, 5, 0); +} + +static void handle_dead_socket(struct osmo_fd *bfd) +{ + struct ipa_proxy_conn *ipc = bfd->data; /* local conn */ + struct ipa_proxy_conn *bsc_conn; /* remote conn */ + struct ipa_bts_conn *ipbc = ipc->bts_conn; + unsigned int trx_id = bfd->priv_nr >> 8; + struct msgb *msg, *msg2; + + osmo_fd_unregister(bfd); + close(bfd->fd); + bfd->fd = -1; + + /* FIXME: clear tx_queue, remove all references, etc. */ + llist_for_each_entry_safe(msg, msg2, &ipc->tx_queue, list) + msgb_free(msg); + + switch (bfd->priv_nr & 0xff) { + case OML_FROM_BTS: /* incoming OML data from BTS, forward to BSC OML */ + /* The BTS started a connection with us but we got no + * IPAC_MSGT_ID_RESP message yet, in that scenario we did not + * allocate the ipa_bts_conn structure. */ + if (ipbc == NULL) + break; + ipbc->oml_conn = NULL; + bsc_conn = ipbc->bsc_oml_conn; + /* close the connection to the BSC */ + osmo_fd_unregister(&bsc_conn->fd); + close(bsc_conn->fd.fd); + llist_for_each_entry_safe(msg, msg2, &bsc_conn->tx_queue, list) + msgb_free(msg); + talloc_free(bsc_conn); + ipbc->bsc_oml_conn = NULL; + /* FIXME: do we need to delete the entire ipbc ? */ + break; + case RSL_FROM_BTS: /* incoming RSL data from BTS, forward to BSC RSL */ + ipbc->rsl_conn[trx_id] = NULL; + bsc_conn = ipbc->bsc_rsl_conn[trx_id]; + /* close the connection to the BSC */ + osmo_fd_unregister(&bsc_conn->fd); + close(bsc_conn->fd.fd); + llist_for_each_entry_safe(msg, msg2, &bsc_conn->tx_queue, list) + msgb_free(msg); + talloc_free(bsc_conn); + ipbc->bsc_rsl_conn[trx_id] = NULL; + break; + case OML_TO_BSC: /* incoming OML data from BSC, forward to BTS OML */ + ipbc->bsc_oml_conn = NULL; + bsc_conn = ipbc->oml_conn; + /* start reconnect timer */ + osmo_timer_schedule(&ipp->reconn_timer, 5, 0); + break; + case RSL_TO_BSC: /* incoming RSL data from BSC, forward to BTS RSL */ + ipbc->bsc_rsl_conn[trx_id] = NULL; + bsc_conn = ipbc->rsl_conn[trx_id]; + /* start reconnect timer */ + osmo_timer_schedule(&ipp->reconn_timer, 5, 0); + break; + default: + bsc_conn = NULL; + break; + } + + talloc_free(ipc); +} + +static void patch_gprs_msg(struct ipa_bts_conn *ipbc, int priv_nr, struct msgb *msg) +{ + uint8_t *nsvci; + + if ((priv_nr & 0xff) != OML_FROM_BTS && (priv_nr & 0xff) != OML_TO_BSC) + return; + + if (msgb_l2len(msg) != 39) + return; + + /* + * Check if this is a IPA Set Attribute or IPA Set Attribute ACK + * and if the FOM Class is GPRS NSVC0 and then we will patch it. + * + * The patch assumes the message looks like the one from the trace + * but we only match messages with a specific size anyway... So + * this hack should work just fine. + */ + + if (msg->l2h[0] == 0x10 && msg->l2h[1] == 0x80 && + msg->l2h[2] == 0x00 && msg->l2h[3] == 0x15 && + msg->l2h[18] == 0xf5 && msg->l2h[19] == 0xf2) { + nsvci = &msg->l2h[23]; + ipbc->gprs_orig_port = *(uint16_t *)(nsvci+8); + ipbc->gprs_orig_ip = *(uint32_t *)(nsvci+10); + *(uint16_t *)(nsvci+8) = htons(ipbc->gprs_local_port); + *(uint32_t *)(nsvci+10) = ipbc->ipp->listen_addr.s_addr; + } else if (msg->l2h[0] == 0x10 && msg->l2h[1] == 0x80 && + msg->l2h[2] == 0x00 && msg->l2h[3] == 0x15 && + msg->l2h[18] == 0xf6 && msg->l2h[19] == 0xf2) { + nsvci = &msg->l2h[23]; + *(uint16_t *)(nsvci+8) = ipbc->gprs_orig_port; + *(uint32_t *)(nsvci+10) = ipbc->gprs_orig_ip; + } +} + +static int handle_tcp_read(struct osmo_fd *bfd) +{ + struct ipa_proxy_conn *ipc = bfd->data; + struct ipa_bts_conn *ipbc = ipc->bts_conn; + struct ipa_proxy_conn *bsc_conn; + struct msgb *msg; + struct ipaccess_head *hh; + int ret = 0; + char *btsbsc; + + if ((bfd->priv_nr & 0xff) <= 2) + btsbsc = "BTS"; + else + btsbsc = "BSC"; + + msg = ipaccess_proxy_read_msg(bfd, &ret); + if (!msg) { + if (ret == 0) { + logp_ipbc_uid(DLINP, LOGL_NOTICE, ipbc, bfd->priv_nr >> 8); + LOGPC(DLINP, LOGL_NOTICE, "%s disappeared, " + "dead socket\n", btsbsc); + handle_dead_socket(bfd); + } + return ret; + } + + msgb_put(msg, ret); + logp_ipbc_uid(DLMI, LOGL_DEBUG, ipbc, bfd->priv_nr >> 8); + DEBUGPC(DLMI, "RX<-%s: %s\n", btsbsc, osmo_hexdump(msg->data, msg->len)); + + hh = (struct ipaccess_head *) msg->data; + if (hh->proto == IPAC_PROTO_IPACCESS) { + ret = ipaccess_rcvmsg(ipc, msg, bfd); + if (ret < 0) { + osmo_fd_unregister(bfd); + close(bfd->fd); + bfd->fd = -1; + talloc_free(bfd); + msgb_free(msg); + return ret; + } else if (ret == 0) { + /* we do not forward parts of the CCM protocol + * through the proxy but rather terminate it ourselves. */ + msgb_free(msg); + return ret; + } + } + + if (!ipbc) { + LOGP(DLINP, LOGL_ERROR, + "received %s packet but no ipc->bts_conn?!?\n", btsbsc); + msgb_free(msg); + return -EIO; + } + + bsc_conn = ipc_by_priv_nr(ipbc, bfd->priv_nr); + if (bsc_conn) { + if (gprs_ns_ipaddr) + patch_gprs_msg(ipbc, bfd->priv_nr, msg); + /* enqueue packet towards BSC */ + msgb_enqueue(&bsc_conn->tx_queue, msg); + /* mark respective filedescriptor as 'we want to write' */ + bsc_conn->fd.when |= BSC_FD_WRITE; + } else { + logp_ipbc_uid(DLINP, LOGL_INFO, ipbc, bfd->priv_nr >> 8); + LOGPC(DLINP, LOGL_INFO, "Dropping packet from %s, " + "since remote connection is dead\n", btsbsc); + msgb_free(msg); + } + + return ret; +} + +/* a TCP socket is ready to be written to */ +static int handle_tcp_write(struct osmo_fd *bfd) +{ + struct ipa_proxy_conn *ipc = bfd->data; + struct ipa_bts_conn *ipbc = ipc->bts_conn; + struct llist_head *lh; + struct msgb *msg; + char *btsbsc; + int ret; + + if ((bfd->priv_nr & 0xff) <= 2) + btsbsc = "BTS"; + else + btsbsc = "BSC"; + + + /* get the next msg for this timeslot */ + if (llist_empty(&ipc->tx_queue)) { + bfd->when &= ~BSC_FD_WRITE; + return 0; + } + lh = ipc->tx_queue.next; + llist_del(lh); + msg = llist_entry(lh, struct msgb, list); + + logp_ipbc_uid(DLMI, LOGL_DEBUG, ipbc, bfd->priv_nr >> 8); + DEBUGPC(DLMI, "TX %04x: %s\n", bfd->priv_nr, + osmo_hexdump(msg->data, msg->len)); + + ret = send(bfd->fd, msg->data, msg->len, 0); + msgb_free(msg); + + if (ret == 0) { + logp_ipbc_uid(DLINP, LOGL_NOTICE, ipbc, bfd->priv_nr >> 8); + LOGP(DLINP, LOGL_NOTICE, "%s disappeared, dead socket\n", btsbsc); + handle_dead_socket(bfd); + } + + return ret; +} + +/* callback from select.c in case one of the fd's can be read/written */ +static int proxy_ipaccess_fd_cb(struct osmo_fd *bfd, unsigned int what) +{ + int rc = 0; + + if (what & BSC_FD_READ) { + rc = handle_tcp_read(bfd); + if (rc < 0) + return rc; + } + if (what & BSC_FD_WRITE) + rc = handle_tcp_write(bfd); + + return rc; +} + +/* callback of the listening filedescriptor */ +static int listen_fd_cb(struct osmo_fd *listen_bfd, unsigned int what) +{ + int ret; + struct ipa_proxy_conn *ipc; + struct osmo_fd *bfd; + struct sockaddr_in sa; + socklen_t sa_len = sizeof(sa); + + if (!(what & BSC_FD_READ)) + return 0; + + ret = accept(listen_bfd->fd, (struct sockaddr *) &sa, &sa_len); + if (ret < 0) { + perror("accept"); + return ret; + } + DEBUGP(DLINP, "accept()ed new %s link from %s\n", + (listen_bfd->priv_nr & 0xff) == OML_FROM_BTS ? "OML" : "RSL", + inet_ntoa(sa.sin_addr)); + + ipc = alloc_conn(); + if (!ipc) { + close(ret); + return -ENOMEM; + } + + bfd = &ipc->fd; + bfd->fd = ret; + bfd->data = ipc; + bfd->priv_nr = listen_bfd->priv_nr; + bfd->cb = proxy_ipaccess_fd_cb; + bfd->when = BSC_FD_READ; + ret = osmo_fd_register(bfd); + if (ret < 0) { + LOGP(DLINP, LOGL_ERROR, "could not register FD\n"); + close(bfd->fd); + talloc_free(ipc); + return ret; + } + + /* Request ID. FIXME: request LOCATION, HW/SW VErsion, Unit Name, Serno */ + ret = ipa_ccm_send_id_req(bfd->fd); + + return 0; +} + +static void send_ns(int fd, const char *buf, int size, struct in_addr ip, int port) +{ + int ret; + struct sockaddr_in addr; + socklen_t len = sizeof(addr); + memset(&addr, 0, sizeof(addr)); + + addr.sin_family = AF_INET; + addr.sin_port = htons(port); + addr.sin_addr = ip; + + ret = sendto(fd, buf, size, 0, (struct sockaddr *) &addr, len); + if (ret < 0) { + LOGP(DLINP, LOGL_ERROR, "Failed to forward GPRS message.\n"); + } +} + +static int gprs_ns_cb(struct osmo_fd *bfd, unsigned int what) +{ + struct ipa_bts_conn *bts; + char buf[4096]; + int ret; + struct sockaddr_in sock; + socklen_t len = sizeof(sock); + + /* 1. get the data... */ + ret = recvfrom(bfd->fd, buf, sizeof(buf), 0, (struct sockaddr *) &sock, &len); + if (ret < 0) { + LOGP(DLINP, LOGL_ERROR, "Failed to recv GPRS NS msg: %s.\n", strerror(errno)); + return -1; + } + + bts = bfd->data; + + /* 2. figure out where to send it to */ + if (memcmp(&sock.sin_addr, &ipp->gprs_addr, sizeof(sock.sin_addr)) == 0) { + LOGP(DLINP, LOGL_DEBUG, "GPRS NS msg from network.\n"); + send_ns(bfd->fd, buf, ret, bts->bts_addr, 23000); + } else if (memcmp(&sock.sin_addr, &bts->bts_addr, sizeof(sock.sin_addr)) == 0) { + LOGP(DLINP, LOGL_DEBUG, "GPRS NS msg from BTS.\n"); + send_ns(bfd->fd, buf, ret, ipp->gprs_addr, 23000); + } else { + LOGP(DLINP, LOGL_ERROR, "Unknown GPRS source: %s\n", inet_ntoa(sock.sin_addr)); + } + + return 0; +} + +/* Actively connect to a BSC. */ +static struct ipa_proxy_conn *connect_bsc(struct sockaddr_in *sa, int priv_nr, void *data) +{ + struct ipa_proxy_conn *ipc; + struct osmo_fd *bfd; + int ret, on = 1; + + ipc = alloc_conn(); + if (!ipc) + return NULL; + + ipc->bts_conn = data; + + bfd = &ipc->fd; + bfd->fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); + bfd->cb = ipaccess_fd_cb; + bfd->when = BSC_FD_READ | BSC_FD_WRITE; + bfd->data = ipc; + bfd->priv_nr = priv_nr; + + if (bfd->fd < 0) { + LOGP(DLINP, LOGL_ERROR, "Could not create socket: %s\n", + strerror(errno)); + talloc_free(ipc); + return NULL; + } + + ret = setsockopt(bfd->fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)); + if (ret < 0) { + LOGP(DLINP, LOGL_ERROR, "Could not set socket option\n"); + close(bfd->fd); + talloc_free(ipc); + return NULL; + } + + ret = connect(bfd->fd, (struct sockaddr *) sa, sizeof(*sa)); + if (ret < 0) { + LOGP(DLINP, LOGL_ERROR, "Could not connect socket: %s\n", + inet_ntoa(sa->sin_addr)); + close(bfd->fd); + talloc_free(ipc); + return NULL; + } + + /* pre-fill tx_queue with identity request */ + ret = osmo_fd_register(bfd); + if (ret < 0) { + close(bfd->fd); + talloc_free(ipc); + return NULL; + } + + return ipc; +} + +static int ipaccess_proxy_setup(void) +{ + int ret; + + ipp = talloc_zero(tall_bsc_ctx, struct ipa_proxy); + if (!ipp) + return -ENOMEM; + INIT_LLIST_HEAD(&ipp->bts_list); + osmo_timer_setup(&ipp->reconn_timer, reconn_tmr_cb, ipp); + + /* Listen for OML connections */ + ret = make_sock(&ipp->oml_listen_fd, IPPROTO_TCP, INADDR_ANY, + IPA_TCP_PORT_OML, OML_FROM_BTS, listen_fd_cb, NULL); + if (ret < 0) + return ret; + + /* Listen for RSL connections */ + ret = make_sock(&ipp->rsl_listen_fd, IPPROTO_TCP, INADDR_ANY, + IPA_TCP_PORT_RSL, RSL_FROM_BTS, listen_fd_cb, NULL); + + if (ret < 0) + return ret; + + /* Connect the GPRS NS Socket */ + if (gprs_ns_ipaddr) { + inet_aton(gprs_ns_ipaddr, &ipp->gprs_addr); + inet_aton(listen_ipaddr, &ipp->listen_addr); + } + + return ret; +} + +static void signal_handler(int signal) +{ + fprintf(stdout, "signal %u received\n", signal); + + switch (signal) { + case SIGABRT: + /* in case of abort, we want to obtain a talloc report + * and then return to the caller, who will abort the process */ + case SIGUSR1: + talloc_report_full(tall_bsc_ctx, stderr); + break; + default: + break; + } +} + +static void print_help(void) +{ + printf(" ipaccess-proxy is a proxy BTS.\n"); + printf(" -h --help. This help text.\n"); + printf(" -l --listen IP. The ip to listen to.\n"); + printf(" -b --bsc IP. The BSC IP address.\n"); + printf(" -g --gprs IP. Take GPRS NS from that IP.\n"); + printf("\n"); + printf(" -s --disable-color. Disable the color inside the logging message.\n"); + printf(" -e --log-level number. Set the global loglevel.\n"); + printf(" -T --timestamp. Prefix every log message with a timestamp.\n"); + printf(" -V --version. Print the version of OpenBSC.\n"); +} + +static void print_usage(void) +{ + printf("Usage: ipaccess-proxy [options]\n"); +} + +enum { + IPA_PROXY_OPT_LISTEN_NONE = 0, + IPA_PROXY_OPT_LISTEN_IP = (1 << 0), + IPA_PROXY_OPT_BSC_IP = (1 << 1), +}; + +static void handle_options(int argc, char** argv) +{ + int options_mask = 0; + + /* disable explicit missing arguments error output from getopt_long */ + opterr = 0; + + while (1) { + int option_index = 0, c; + static struct option long_options[] = { + {"help", 0, 0, 'h'}, + {"disable-color", 0, 0, 's'}, + {"timestamp", 0, 0, 'T'}, + {"log-level", 1, 0, 'e'}, + {"listen", 1, 0, 'l'}, + {"bsc", 1, 0, 'b'}, + {0, 0, 0, 0} + }; + + c = getopt_long(argc, argv, "hsTe:l:b:g:", + long_options, &option_index); + if (c == -1) + break; + + switch (c) { + case 'h': + print_usage(); + print_help(); + exit(0); + case 'l': + listen_ipaddr = optarg; + options_mask |= IPA_PROXY_OPT_LISTEN_IP; + break; + case 'b': + bsc_ipaddr = optarg; + options_mask |= IPA_PROXY_OPT_BSC_IP; + break; + case 'g': + gprs_ns_ipaddr = optarg; + break; + case 's': + log_set_use_color(osmo_stderr_target, 0); + break; + case 'T': + log_set_print_timestamp(osmo_stderr_target, 1); + break; + case 'e': + log_set_log_level(osmo_stderr_target, atoi(optarg)); + break; + case '?': + if (optopt) { + printf("ERROR: missing mandatory argument " + "for `%s' option\n", argv[optind-1]); + } else { + printf("ERROR: unknown option `%s'\n", + argv[optind-1]); + } + print_usage(); + print_help(); + exit(EXIT_FAILURE); + break; + default: + /* ignore */ + break; + } + } + if ((options_mask & (IPA_PROXY_OPT_LISTEN_IP | IPA_PROXY_OPT_BSC_IP)) + != (IPA_PROXY_OPT_LISTEN_IP | IPA_PROXY_OPT_BSC_IP)) { + printf("ERROR: You have to specify `--listen' and `--bsc' " + "options at least.\n"); + print_usage(); + print_help(); + exit(EXIT_FAILURE); + } +} + +int main(int argc, char **argv) +{ + int rc; + + tall_bsc_ctx = talloc_named_const(NULL, 1, "ipaccess-proxy"); + msgb_talloc_ctx_init(tall_bsc_ctx, 0); + + osmo_init_logging(&log_info); + log_parse_category_mask(osmo_stderr_target, "DLINP:DLMI"); + + handle_options(argc, argv); + + rc = ipaccess_proxy_setup(); + if (rc < 0) + exit(1); + + signal(SIGUSR1, &signal_handler); + signal(SIGABRT, &signal_handler); + osmo_init_ignore_signals(); + + while (1) { + osmo_select_main(0); + } +} |