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osmo-bsc/src/ipaccess/ipaccess-proxy.c

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/* 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);
}
}
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