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/* NetworkListen for SysmoBTS management daemon */
/*
* (C) 2014 by Holger Hans Peter Freyther
*
* 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 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 "misc/sysmobts_mgr.h"
#include "misc/sysmobts_misc.h"
#include "misc/sysmobts_nl.h"
#include "misc/sysmobts_par.h"
#include <osmo-bts/logging.h>
#include <osmocom/gsm/protocol/ipaccess.h>
#include <osmocom/core/msgb.h>
#include <osmocom/core/socket.h>
#include <osmocom/core/select.h>
#include <arpa/inet.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <errno.h>
#include <string.h>
static struct osmo_fd nl_fd;
/*
* The TLV structure in IPA messages in UDP packages is a bit
* weird. First the header appears to have an extra NULL byte
* and second the L16 of the L16TV needs to include +1 for the
* tag. The default msgb/tlv and libosmo-abis routines do not
* provide this.
*/
static void ipaccess_prepend_header_quirk(struct msgb *msg, int proto)
{
struct ipaccess_head *hh;
/* prepend the ip.access header */
hh = (struct ipaccess_head *) msgb_push(msg, sizeof(*hh) + 1);
hh->len = htons(msg->len - sizeof(*hh) - 1);
hh->proto = proto;
}
static void quirk_l16tv_put(struct msgb *msg, uint16_t len, uint8_t tag,
const uint8_t *val)
{
uint8_t *buf = msgb_put(msg, len + 2 + 1);
*buf++ = (len + 1) >> 8;
*buf++ = (len + 1) & 0xff;
*buf++ = tag;
memcpy(buf, val, len);
}
/*
* We don't look at the content of the request yet and lie
* about most of the responses.
*/
static void respond_to(struct sockaddr_in *src, struct osmo_fd *fd,
uint8_t *data, size_t len)
{
static int fetched_info = 0;
static char mac_str[20] = { };
static char *model_name;
struct sockaddr_in loc_addr;
int rc;
char loc_ip[INET_ADDRSTRLEN];
struct msgb *msg = msgb_alloc_headroom(512, 128, "ipa get response");
if (!msg) {
LOGP(DFIND, LOGL_ERROR, "Failed to allocate msgb\n");
return;
}
if (!fetched_info) {
uint8_t mac[6];
/* fetch the MAC */
sysmobts_par_get_buf(SYSMOBTS_PAR_MAC, mac, sizeof(mac));
snprintf(mac_str, sizeof(mac_str), "%.2x:%.2x:%.2x:%.2x:%.2x:%.2x",
mac[0], mac[1], mac[2],
mac[3], mac[4], mac[5]);
/* fetch the model and trx number */
switch(sysmobts_bts_type()) {
case 0:
case 0xffff:
case 1002:
model_name = "sysmoBTS 1002";
break;
case 2050:
if (sysmobts_trx_number() == 0)
model_name = "sysmoBTS 2050 (master)";
else if (sysmobts_trx_number() == 1)
model_name = "sysmoBTS 2050 (slave)";
else
model_name = "sysmoBTS 2050 (unknown)";
break;
default:
model_name = "Unknown";
break;
}
fetched_info = 1;
}
if (source_for_dest(&src->sin_addr, &loc_addr.sin_addr) != 0) {
LOGP(DFIND, LOGL_ERROR, "Failed to determine local source\n");
return;
}
msgb_put_u8(msg, IPAC_MSGT_ID_RESP);
/* append MAC addr */
quirk_l16tv_put(msg, strlen(mac_str) + 1, IPAC_IDTAG_MACADDR, (uint8_t *) mac_str);
/* append ip address */
inet_ntop(AF_INET, &loc_addr.sin_addr, loc_ip, sizeof(loc_ip));
quirk_l16tv_put(msg, strlen(loc_ip) + 1, IPAC_IDTAG_IPADDR, (uint8_t *) loc_ip);
/* abuse some flags */
quirk_l16tv_put(msg, strlen(model_name) + 1, IPAC_IDTAG_UNIT, (uint8_t *) model_name);
/* ip.access nanoBTS would reply to port==3006 */
ipaccess_prepend_header_quirk(msg, IPAC_PROTO_IPACCESS);
rc = sendto(fd->fd, msg->data, msg->len, 0, (struct sockaddr *)src, sizeof(*src));
if (rc != msg->len)
LOGP(DFIND, LOGL_ERROR,
"Failed to send with rc(%d) errno(%d)\n", rc, errno);
}
static int ipaccess_bcast(struct osmo_fd *fd, unsigned int what)
{
uint8_t data[2048];
char src[INET_ADDRSTRLEN];
struct sockaddr_in addr = {};
socklen_t len = sizeof(addr);
int rc;
rc = recvfrom(fd->fd, data, sizeof(data), 0,
(struct sockaddr *) &addr, &len);
if (rc <= 0) {
LOGP(DFIND, LOGL_ERROR,
"Failed to read from socket errno(%d)\n", errno);
return -1;
}
LOGP(DFIND, LOGL_DEBUG,
"Received request from: %s size %d\n",
inet_ntop(AF_INET, &addr.sin_addr, src, sizeof(src)), rc);
if (rc < 6)
return 0;
if (data[2] != IPAC_PROTO_IPACCESS || data[4] != IPAC_MSGT_ID_GET)
return 0;
respond_to(&addr, fd, data + 6, rc - 6);
return 0;
}
int sysmobts_mgr_nl_init(void)
{
int rc;
nl_fd.cb = ipaccess_bcast;
rc = osmo_sock_init_ofd(&nl_fd, AF_INET, SOCK_DGRAM, IPPROTO_UDP,
"0.0.0.0", 3006, OSMO_SOCK_F_BIND);
if (rc < 0) {
perror("Socket creation");
return -1;
}
return 0;
}
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