summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
-rw-r--r--openbsc/configure.in1
-rw-r--r--openbsc/src/Makefile.am2
-rw-r--r--openbsc/src/proxy/Makefile.am7
-rw-r--r--openbsc/src/proxy/ipaccess-bts_if.c838
-rw-r--r--openbsc/src/proxy/proxy.txt57
5 files changed, 905 insertions, 0 deletions
diff --git a/openbsc/configure.in b/openbsc/configure.in
index 94fb15f..8665160 100644
--- a/openbsc/configure.in
+++ b/openbsc/configure.in
@@ -39,6 +39,7 @@ AC_OUTPUT(
include/vty/Makefile
include/Makefile
src/Makefile
+ src/proxy/Makefile
tests/Makefile
tests/debug/Makefile
tests/timer/Makefile
diff --git a/openbsc/src/Makefile.am b/openbsc/src/Makefile.am
index ed63c8e..5ed5d8c 100644
--- a/openbsc/src/Makefile.am
+++ b/openbsc/src/Makefile.am
@@ -1,6 +1,8 @@
INCLUDES = $(all_includes) -I$(top_srcdir)/include
AM_CFLAGS=-Wall
+SUBDIRS = proxy
+
sbin_PROGRAMS = bsc_hack bs11_config ipaccess-find ipaccess-config isdnsync
noinst_LIBRARIES = libbsc.a libvty.a
noinst_HEADERS = vty/cardshell.h
diff --git a/openbsc/src/proxy/Makefile.am b/openbsc/src/proxy/Makefile.am
new file mode 100644
index 0000000..6fe1291
--- /dev/null
+++ b/openbsc/src/proxy/Makefile.am
@@ -0,0 +1,7 @@
+INCLUDES = $(all_includes) -I$(top_srcdir)/include
+AM_CFLAGS=-Wall
+
+sbin_PROGRAMS = ipaccess-proxy
+
+ipaccess_proxy_SOURCES = ipaccess-bts_if.c \
+ ../msgb.c ../select.c ../talloc.c ../debug.c ../timer.c
diff --git a/openbsc/src/proxy/ipaccess-bts_if.c b/openbsc/src/proxy/ipaccess-bts_if.c
new file mode 100644
index 0000000..879b0b8
--- /dev/null
+++ b/openbsc/src/proxy/ipaccess-bts_if.c
@@ -0,0 +1,838 @@
+/* OpenBSC Abis/IP proxy ip.access nanoBTS */
+
+/* (C) 2009 by Harald Welte <laforge@gnumonks.org>
+ *
+ * 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 <errno.h>
+#include <string.h>
+#include <time.h>
+#include <sys/fcntl.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/ioctl.h>
+#include <arpa/inet.h>
+#include <netinet/in.h>
+
+#include <openbsc/gsm_data.h>
+#include <openbsc/select.h>
+#include <openbsc/tlv.h>
+#include <openbsc/msgb.h>
+#include <openbsc/debug.h>
+#include <openbsc/ipaccess.h>
+#include <openbsc/talloc.h>
+
+/* one instance of an ip.access protocol proxy */
+struct ipa_proxy {
+ /* socket where we listen for incoming OML from BTS */
+ struct bsc_fd oml_listen_fd;
+ /* socket where we listen for incoming RSL from BTS */
+ struct bsc_fd rsl_listen_fd;
+ /* list of BTS's (struct ipa_bts_conn */
+ struct llist_head bts_list;
+};
+
+/* global pointer to the proxy structure */
+static struct ipa_proxy *ipp;
+
+struct ipa_proxy_conn {
+ struct bsc_fd fd;
+ struct llist_head tx_queue;
+ struct ipa_bts_conn *bts_conn;
+};
+
+/* represents a particular BTS in our proxy */
+struct ipa_bts_conn {
+ /* list of BTS's (ipa_proxy->bts_list) */
+ struct llist_head list;
+ /* the unit ID as determined by CCM */
+ struct {
+ u_int16_t site_id;
+ u_int16_t bts_id;
+ u_int16_t trx_id;
+ } unit_id;
+
+ /* incoming connections from BTS */
+ struct ipa_proxy_conn *oml_conn;
+ struct ipa_proxy_conn *rsl_conn;
+
+ /* outgoing connections to BSC */
+ struct ipa_proxy_conn *bsc_oml_conn;
+ struct ipa_proxy_conn *bsc_rsl_conn;
+
+ /* UDP sockets for BTS and BSC injection */
+ struct bsc_fd udp_bts_fd;
+ struct bsc_fd udp_bsc_fd;
+
+ char *id_tags[0xff];
+ u_int8_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;
+
+#define PROXY_ALLOC_SIZE 300
+
+static const u_int8_t pong[] = { 0, 1, IPAC_PROTO_IPACCESS, IPAC_MSGT_PONG };
+static const u_int8_t id_ack[] = { 0, 1, IPAC_PROTO_IPACCESS, IPAC_MSGT_ID_ACK };
+static const u_int8_t id_req[] = { 0, 17, IPAC_PROTO_IPACCESS, IPAC_MSGT_ID_GET,
+ 0x01, IPAC_IDTAG_UNIT,
+ 0x01, IPAC_IDTAG_MACADDR,
+ 0x01, IPAC_IDTAG_LOCATION1,
+ 0x01, IPAC_IDTAG_LOCATION2,
+ 0x01, IPAC_IDTAG_EQUIPVERS,
+ 0x01, IPAC_IDTAG_SWVERSION,
+ 0x01, IPAC_IDTAG_UNITNAME,
+ 0x01, IPAC_IDTAG_SERNR,
+ };
+
+static const char *idtag_names[] = {
+ [IPAC_IDTAG_SERNR] = "Serial_Number",
+ [IPAC_IDTAG_UNITNAME] = "Unit_Name",
+ [IPAC_IDTAG_LOCATION1] = "Location_1",
+ [IPAC_IDTAG_LOCATION2] = "Location_2",
+ [IPAC_IDTAG_EQUIPVERS] = "Equipment_Version",
+ [IPAC_IDTAG_SWVERSION] = "Software_Version",
+ [IPAC_IDTAG_IPADDR] = "IP_Address",
+ [IPAC_IDTAG_MACADDR] = "MAC_Address",
+ [IPAC_IDTAG_UNIT] = "Unit_ID",
+};
+
+static const char *ipac_idtag_name(int tag)
+{
+ if (tag >= ARRAY_SIZE(idtag_names))
+ return "unknown";
+
+ return idtag_names[tag];
+}
+
+static int ipac_idtag_parse(struct tlv_parsed *dec, unsigned char *buf, int len)
+{
+ u_int8_t t_len;
+ u_int8_t t_tag;
+ u_int8_t *cur = buf;
+
+ while (cur < buf + len) {
+ t_len = *cur++;
+ t_tag = *cur++;
+
+ DEBUGPC(DMI, "%s='%s' ", ipac_idtag_name(t_tag), cur);
+
+ dec->lv[t_tag].len = t_len;
+ dec->lv[t_tag].val = cur;
+
+ cur += t_len;
+ }
+ return 0;
+}
+
+static int parse_unitid(const char *str, u_int16_t *site_id, u_int16_t *bts_id,
+ u_int16_t *trx_id)
+{
+ unsigned long ul;
+ char *endptr;
+ const char *nptr;
+
+ nptr = str;
+ ul = strtoul(nptr, &endptr, 10);
+ if (endptr <= nptr)
+ return -EINVAL;
+ if (site_id)
+ *site_id = ul & 0xffff;
+
+ if (*endptr++ != '/')
+ return -EINVAL;
+
+ nptr = endptr;
+ ul = strtoul(nptr, &endptr, 10);
+ if (endptr <= nptr)
+ return -EINVAL;
+ if (bts_id)
+ *bts_id = ul & 0xffff;
+
+ if (*endptr++ != '/')
+ return -EINVAL;
+
+ nptr = endptr;
+ ul = strtoul(nptr, &endptr, 10);
+ if (endptr <= nptr)
+ return -EINVAL;
+ if (trx_id)
+ *trx_id = ul & 0xffff;
+
+ return 0;
+}
+
+static struct ipa_bts_conn *find_bts_by_unitid(struct ipa_proxy *ipp,
+ u_int16_t site_id,
+ u_int16_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(tall_bsc_ctx,
+ 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);
+
+/* UDP socket handling */
+
+static int make_sock(struct bsc_fd *bfd, u_int16_t port, int proto, int priv_nr,
+ int (*cb)(struct bsc_fd *fd, unsigned int what),
+ void *data)
+{
+ struct sockaddr_in addr;
+ int ret, on = 1;
+
+ bfd->fd = socket(AF_INET, SOCK_DGRAM, proto);
+ bfd->cb = cb;
+ bfd->when = BSC_FD_READ;
+ bfd->data = data;
+ bfd->priv_nr = priv_nr;
+
+ memset(&addr, 0, sizeof(addr));
+ addr.sin_family = AF_INET;
+ addr.sin_port = htons(port);
+ addr.sin_addr.s_addr = INADDR_ANY;
+
+ setsockopt(bfd->fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
+
+ ret = bind(bfd->fd, (struct sockaddr *) &addr, sizeof(addr));
+ if (ret < 0) {
+ fprintf(stderr, "could not bind l2 socket %s\n",
+ strerror(errno));
+ return -EIO;
+ }
+
+ ret = bsc_register_fd(bfd);
+ if (ret < 0) {
+ perror("register UDP fd");
+ return ret;
+ }
+ return 0;
+}
+
+static int handle_udp_read(struct bsc_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) {
+ DEBUGP(DINP, "recv error %s\n", strerror(errno));
+ msgb_free(msg);
+ return ret;
+ }
+ if (ret == 0) {
+ DEBUGP(DINP, "UDP peer disappeared, dead socket\n");
+ bsc_unregister_fd(bfd);
+ close(bfd->fd);
+ bfd->fd = -1;
+ msgb_free(msg);
+ return -EIO;
+ }
+ if (ret < sizeof(*hh)) {
+ DEBUGP(DINP, "could not even read header!?!\n");
+ msgb_free(msg);
+ return -EIO;
+ }
+ msgb_put(msg, ret);
+ msg->l2h = msg->data + sizeof(*hh);
+ DEBUGP(DMI, "UDP RX: %s\n", hexdump(msg->data, msg->len));
+
+ if (hh->len != msg->len - sizeof(*hh)) {
+ DEBUGP(DMI, "length (%u/%u) disagrees with header(%u)\n",
+ msg->len, msg->len - 3, hh->len);
+ msgb_free(msg);
+ return -EIO;
+ }
+
+ switch (bfd->priv_nr) {
+ case UDP_TO_BTS:
+ /* injection towards BTS */
+ switch (hh->proto) {
+ case IPAC_PROTO_RSL:
+ other_conn = ipbc->rsl_conn;
+ break;
+ default:
+ DEBUGP(DINP, "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:
+ other_conn = ipbc->bsc_rsl_conn;
+ break;
+ default:
+ DEBUGP(DINP, "Unknown protocol 0x%02x, sending to "
+ "OML FD\n", hh->proto);
+ case IPAC_PROTO_IPACCESS:
+ case IPAC_PROTO_OML:
+ other_conn = ipbc->bsc_oml_conn;
+ break;
+ }
+ break;
+ default:
+ DEBUGP(DINP, "Unknown filedescriptor priv_nr=%u\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 bsc_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 bsc_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 ipaccess_rcvmsg(struct ipa_proxy_conn *ipc, struct msgb *msg,
+ struct bsc_fd *bfd)
+{
+ struct sockaddr_in sin;
+ struct tlv_parsed tlvp;
+ u_int8_t msg_type = *(msg->l2h);
+ u_int16_t site_id, bts_id, trx_id;
+ struct ipa_bts_conn *ipbc;
+ int ret = 0;
+
+ memset(&sin, 0, sizeof(sin));
+ sin.sin_family = AF_INET;
+ inet_aton(bsc_ipaddr, &sin.sin_addr.s_addr);
+
+ switch (msg_type) {
+ case IPAC_MSGT_PING:
+ ret = write(bfd->fd, pong, sizeof(pong));
+ if (ret < 0)
+ return ret;
+ if (ret < sizeof(pong)) {
+ DEBUGP(DINP, "short write\n");
+ return -EIO;
+ }
+ break;
+ case IPAC_MSGT_PONG:
+ DEBUGP(DMI, "PONG!\n");
+ break;
+ case IPAC_MSGT_ID_RESP:
+ DEBUGP(DMI, "ID_RESP ");
+ /* parse tags, search for Unit ID */
+ ipac_idtag_parse(&tlvp, (u_int8_t *)msg->l2h + 2,
+ msgb_l2len(msg)-2);
+ DEBUGP(DMI, "\n");
+
+ if (!TLVP_PRESENT(&tlvp, IPAC_IDTAG_UNIT)) {
+ DEBUGP(DINP, "No Unit ID in ID RESPONSE !?!\n");
+ return -EIO;
+ }
+
+ /* lookup BTS, create sign_link, ... */
+ parse_unitid((char *)TLVP_VAL(&tlvp, IPAC_IDTAG_UNIT),
+ &site_id, &bts_id, &trx_id);
+ ipbc = find_bts_by_unitid(ipp, site_id, bts_id);
+ if (!ipbc) {
+ u_int16_t udp_port;
+
+ DEBUGP(DINP, "New BTS connection from %u/%u/%u: ",
+ site_id, bts_id, trx_id);
+
+ /* OML needs to be established before RSL */
+ if (bfd->priv_nr != OML_FROM_BTS) {
+ DEBUGPC(DINP, "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)
+ return -ENOMEM;
+
+ DEBUGPC(DINP, "Created BTS Conn data structure\n");
+ ipbc->unit_id.site_id = site_id;
+ ipbc->unit_id.bts_id = bts_id;
+ ipbc->unit_id.trx_id = trx_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(3002);
+ ipbc->bsc_oml_conn = connect_bsc(&sin, OML_TO_BSC, ipbc);
+ if (!ipbc->bsc_oml_conn)
+ return -EIO;
+ DEBUGP(DINP, "Connected OML to BSC\n");
+
+ /* Create UDP socket for BTS packet injection */
+ udp_port = 10000 + (site_id % 1000)*100 + (bts_id % 100);
+ ret = make_sock(&ipbc->udp_bts_fd, udp_port, IPPROTO_UDP,
+ UDP_TO_BTS, udp_fd_cb, ipbc);
+ if (ret < 0)
+ return ret;
+ DEBUGP(DINP, "Created UDP socket for injection "
+ "towards BTS at port %u\n", 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, udp_port, IPPROTO_UDP,
+ UDP_TO_BSC, udp_fd_cb, ipbc);
+ if (ret < 0)
+ return ret;
+ DEBUGP(DINP, "Created UDP socket for injection "
+ "towards BSC at port %u\n", udp_port);
+ llist_add(&ipbc->list, &ipp->bts_list);
+ } else {
+ DEBUGP(DINP, "Identified BTS %u/%u/%u\n",
+ site_id, bts_id, trx_id);
+
+ if (bfd->priv_nr != RSL_FROM_BTS) {
+ DEBUGP(DINP, "Second OML connection from "
+ "same BTS ?!?\n");
+ return 0;
+ }
+ ipc->bts_conn = ipbc;
+ /* FIXME: implement this for non-0 TRX */
+ ipbc->rsl_conn = ipc;
+
+ /* Create RSL TCP connection towards BSC */
+ sin.sin_port = htons(3003);
+ ipbc->bsc_rsl_conn = connect_bsc(&sin, RSL_TO_BSC, ipbc);
+ if (!ipbc->bsc_oml_conn)
+ return -EIO;
+ DEBUGP(DINP, "Connected RSL to BSC\n");
+ }
+ break;
+ case IPAC_MSGT_ID_GET:
+ DEBUGP(DMI, "ID_GET\n");
+ if (bfd->priv_nr != OML_TO_BSC && bfd->priv_nr != RSL_TO_BSC) {
+ DEBUGP(DINP, "IDentity REQuest from BTS ?!?\n");
+ return -EIO;
+ }
+ ipbc = ipc->bts_conn;
+ if (!ipbc) {
+ DEBUGP(DINP, "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);
+ break;
+ case IPAC_MSGT_ID_ACK:
+ DEBUGP(DMI, "ID_ACK? -> ACK!\n");
+ ret = write(bfd->fd, id_ack, sizeof(id_ack));
+ break;
+ }
+ return 0;
+}
+
+static int handle_tcp_read(struct bsc_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 = msgb_alloc(PROXY_ALLOC_SIZE, "Abis/IP");
+ struct ipaccess_head *hh;
+ int ret;
+ char *btsbsc;
+
+ if (!msg)
+ return -ENOMEM;
+
+ if (bfd->priv_nr <= 2)
+ btsbsc = "BTS";
+ else
+ btsbsc = "BSC";
+
+ /* first read our 3-byte header */
+ hh = (struct ipaccess_head *) msg->data;
+ ret = recv(bfd->fd, msg->data, 3, 0);
+ if (ret < 0) {
+ fprintf(stderr, "recv error %s\n", strerror(errno));
+ return ret;
+ }
+ if (ret == 0) {
+ fprintf(stderr, "%s disappeared, dead socket\n", btsbsc);
+ bsc_unregister_fd(bfd);
+ close(bfd->fd);
+ bfd->fd = -1;
+ return -EIO;
+ }
+ msgb_put(msg, ret);
+
+ /* then read the length as specified in header */
+ msg->l2h = msg->data + sizeof(*hh);
+ ret = recv(bfd->fd, msg->l2h, hh->len, 0);
+ if (ret < hh->len) {
+ fprintf(stderr, "short read!\n");
+ msgb_free(msg);
+ return -EIO;
+ }
+ msgb_put(msg, ret);
+ DEBUGP(DMI, "RX<-%s: %s\n", btsbsc, hexdump(msg->data, msg->len));
+
+ if (hh->proto == IPAC_PROTO_IPACCESS) {
+ ret = ipaccess_rcvmsg(ipc, msg, bfd);
+ if (ret < 0) {
+ bsc_unregister_fd(bfd);
+ close(bfd->fd);
+ bfd->fd = -1;
+ }
+ /* we do not forward the CCM protocol through the
+ * proxy but rather terminate it ourselves */
+ msgb_free(msg);
+ return ret;
+ }
+
+ if (!ipbc) {
+ DEBUGP(DINP, "received %s packet but no ipc->bts_conn?!?\n",
+ btsbsc);
+ msgb_free(msg);
+ return -EIO;
+ }
+
+ switch (bfd->priv_nr) {
+ 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;
+ 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;
+ break;
+ default:
+ bsc_conn = NULL;
+ break;
+ }
+
+ if (bsc_conn) {
+ /* 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
+ msgb_free(msg);
+
+ return ret;
+}
+
+/* a TCP socket is ready to be written to */
+static int handle_tcp_write(struct bsc_fd *bfd)
+{
+ struct ipa_proxy_conn *ipc = bfd->data;
+ struct llist_head *lh;
+ struct msgb *msg;
+ int ret;
+
+ /* 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);
+
+ DEBUGP(DMI, "TX %u: %s\n", bfd->priv_nr, hexdump(msg->data, msg->len));
+
+ ret = send(bfd->fd, msg->data, msg->len, 0);
+ msgb_free(msg);
+
+ return ret;
+}
+
+/* callback from select.c in case one of the fd's can be read/written */
+static int ipaccess_fd_cb(struct bsc_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 bsc_fd *listen_bfd, unsigned int what)
+{
+ int ret;
+ struct ipa_proxy_conn *ipc;
+ struct bsc_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(DINP, "accept()ed new %s link from %s\n",
+ listen_bfd->priv_nr == 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 = ipaccess_fd_cb;
+ bfd->when = BSC_FD_READ;
+ ret = bsc_register_fd(bfd);
+ if (ret < 0) {
+ fprintf(stderr, "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 = write(bfd->fd, id_req, sizeof(id_req));
+
+ return 0;
+}
+
+static int make_listen_sock(struct bsc_fd *bfd, u_int16_t port, int priv_nr,
+ int (*cb)(struct bsc_fd *fd, unsigned int what))
+{
+ struct sockaddr_in addr;
+ int ret, on = 1;
+
+ bfd->fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
+ bfd->cb = cb;
+ bfd->when = BSC_FD_READ;
+ bfd->priv_nr = priv_nr;
+
+ memset(&addr, 0, sizeof(addr));
+ addr.sin_family = AF_INET;
+ addr.sin_port = htons(port);
+ if (!listen_ipaddr)
+ addr.sin_addr.s_addr = INADDR_ANY;
+ else
+ inet_aton(listen_ipaddr, &addr.sin_addr);
+
+ setsockopt(bfd->fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
+
+ ret = bind(bfd->fd, (struct sockaddr *) &addr, sizeof(addr));
+ if (ret < 0) {
+ fprintf(stderr, "could not bind l2 socket %s\n",
+ strerror(errno));
+ return -EIO;
+ }
+
+ ret = listen(bfd->fd, 1);
+ if (ret < 0) {
+ perror("listen");
+ return ret;
+ }
+
+ ret = bsc_register_fd(bfd);
+ if (ret < 0) {
+ perror("register_listen_fd");
+ return ret;
+ }
+ 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 bsc_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;
+
+ setsockopt(bfd->fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
+
+ ret = connect(bfd->fd, (struct sockaddr *) sa, sizeof(*sa));
+ if (ret < 0) {
+ fprintf(stderr, "could not connect socket\n");
+ close(bfd->fd);
+ talloc_free(ipc);
+ return NULL;
+ }
+
+ /* pre-fill tx_queue with identity request */
+ ret = bsc_register_fd(bfd);
+ if (ret < 0) {
+ close(bfd->fd);
+ talloc_free(ipc);
+ return NULL;
+ }
+
+ return ipc;
+}
+
+int ipaccess_setup(void)
+{
+ int ret;
+
+ ipp = talloc_zero(tall_bsc_ctx, struct ipa_proxy);
+ if (!ipp)
+ return -ENOMEM;
+ INIT_LLIST_HEAD(&ipp->bts_list);
+
+ /* Listen for OML connections */
+ ret = make_listen_sock(&ipp->oml_listen_fd, 3002, OML_FROM_BTS, listen_fd_cb);
+ if (ret < 0)
+ return ret;
+
+ /* Listen for RSL connections */
+ ret = make_listen_sock(&ipp->rsl_listen_fd, 3003, RSL_FROM_BTS, listen_fd_cb);
+
+ return ret;
+}
+
+
+int main(int argc, char **argv)
+{
+ listen_ipaddr = "172.27.8.9";
+ bsc_ipaddr = "192.168.100.102";
+
+ debug_parse_category_mask("DMI:DINP");
+
+ ipaccess_setup();
+
+ while (1) {
+ bsc_select_main(0);
+ }
+}
diff --git a/openbsc/src/proxy/proxy.txt b/openbsc/src/proxy/proxy.txt
new file mode 100644
index 0000000..e80a65b
--- /dev/null
+++ b/openbsc/src/proxy/proxy.txt
@@ -0,0 +1,57 @@
+OpenBSC ip.access Abis/IP proxy design
+======================================================================
+
+== the big picture ==
+
+* behave as BSC
+ * listen for BTS OML connections (TCP port 3002, primary OML)
+ * listen for BTS RSL connections (TCP port 3003)
+ * actively connect to BTS (TCP port 3006, 2ndary OML)
+
+* behave as BTS
+ * actively connect OML to BSC (TCP port 3002)
+ * actively connect RSL to BSC (TCP port 3003)
+
+* provide UDP interface for packet injection
+ * packet format inside UDP is exactly the same as ip.access
+ * provide one port for each direction:
+ * UDP port 5001: message to BTS
+ * IDP port 5002: message to BSC
+
+== use cases ==
+
+* transparent proxy
+ * simply pass all messages from BTS to BSC and vice-versa
+
+* injection proxy
+ * provide UDP (packet-based) interface for tools like scapy
+
+== misc ==
+
+* keep-alive is handled independently, i.e. connections to BTS / BSC are always
+ kept open
+
+
+== code architecture ==
+
+=== incoming TCP connection ===
+* connect TCP to BSC
+* create 2 UDP sockets for packet injection
+
+=== incoming TCP data from BTS ===
+* determine if OML or RSL fd
+* copy data to tx_queue of corresponding BSC fd
+
+=== incoming TCP data from BSC ===
+* determine if OML or RSL fd
+* copy data to tx_queue of corresponding BTS fd
+
+=== incoming UDP data ===
+* determine OML or RSL and direction based on port number
+* copy data to apropriate tx_queue
+
+=== termination of TCP connection ===
+* no matter if BSC or BTS disconnect, keep other TCP session open
+* make sure upon re-connection, the correct pairs of connections
+ are matched up
+