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/* (C) 2014 by sysmocom s.f.m.c. GmbH
*
* 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 <osmo-bts/msg_utils.h>
#include <osmo-bts/logging.h>
#include <osmo-bts/oml.h>
#include <osmocom/gsm/protocol/ipaccess.h>
#include <osmocom/gsm/protocol/gsm_12_21.h>
#include <osmocom/gsm/abis_nm.h>
#include <osmocom/core/msgb.h>
#include <arpa/inet.h>
static int check_fom(struct abis_om_hdr *omh, size_t len)
{
if (omh->length != len) {
LOGP(DL1C, LOGL_ERROR, "Incorrect OM hdr length value %d %zu\n",
omh->length, len);
return -1;
}
if (len < sizeof(struct abis_om_fom_hdr)) {
LOGP(DL1C, LOGL_ERROR, "FOM header insufficient space %zu %zu\n",
len, sizeof(struct abis_om_fom_hdr));
return -1;
}
return 0;
}
static int check_manuf(struct msgb *msg, struct abis_om_hdr *omh, size_t msg_size)
{
int type;
size_t size;
if (msg_size < 1) {
LOGP(DL1C, LOGL_ERROR, "No ManId Length Indicator %zu\n",
msg_size);
return -1;
}
if (omh->data[0] >= msg_size - 1) {
LOGP(DL1C, LOGL_ERROR,
"Insufficient message space for this ManId Length %d %zu\n",
omh->data[0], msg_size - 1);
return -1;
}
if (omh->data[0] == sizeof(abis_nm_ipa_magic) &&
strncmp(abis_nm_ipa_magic, (const char *)omh->data + 1,
sizeof(abis_nm_ipa_magic)) == 0) {
type = OML_MSG_TYPE_IPA;
size = sizeof(abis_nm_ipa_magic) + 1;
} else if (omh->data[0] == sizeof(abis_nm_osmo_magic) &&
strncmp(abis_nm_osmo_magic, (const char *) omh->data + 1,
sizeof(abis_nm_osmo_magic)) == 0) {
type = OML_MSG_TYPE_OSMO;
size = sizeof(abis_nm_osmo_magic) + 1;
} else {
LOGP(DL1C, LOGL_ERROR, "Manuf Label Unknown\n");
return -1;
}
/* we have verified that the vendor string fits */
msg->l3h = omh->data + size;
if (check_fom(omh, msgb_l3len(msg)) != 0)
return -1;
return type;
}
/**
* Return 0 in case the IPA structure is okay and in this
* case the l2h will be set to the beginning of the data.
*/
int msg_verify_ipa_structure(struct msgb *msg)
{
struct ipaccess_head *hh;
if (msgb_l1len(msg) < sizeof(struct ipaccess_head)) {
LOGP(DL1C, LOGL_ERROR,
"Ipa header insufficient space %d %d\n",
msgb_l1len(msg), sizeof(struct ipaccess_head));
return -1;
}
hh = (struct ipaccess_head *) msg->l1h;
if (ntohs(hh->len) != msgb_l1len(msg) - sizeof(struct ipaccess_head)) {
LOGP(DL1C, LOGL_ERROR,
"Incorrect ipa header msg size %d %d\n",
ntohs(hh->len), msgb_l1len(msg) - sizeof(struct ipaccess_head));
return -1;
}
if (hh->proto == IPAC_PROTO_OSMO) {
struct ipaccess_head_ext *hh_ext = (struct ipaccess_head_ext *) hh->data;
if (ntohs(hh->len) < sizeof(*hh_ext)) {
LOGP(DL1C, LOGL_ERROR, "IPA length shorter than OSMO header\n");
return -1;
}
msg->l2h = hh_ext->data;
} else
msg->l2h = hh->data;
return 0;
}
/**
* \brief Verify the structure of the OML message and set l3h
*
* This function verifies that the data in \param in msg is a proper
* OML message. This code assumes that msg->l2h points to the
* beginning of the OML message. In the successful case the msg->l3h
* will be set and will point to the FOM header. The value is undefined
* in all other cases.
*
* \param msg The message to analyze starting from msg->l2h.
* \return In case the structure is correct a positive number will be
* returned and msg->l3h will point to the FOM. The number is a
* classification of the vendor type of the message.
*/
int msg_verify_oml_structure(struct msgb *msg)
{
struct abis_om_hdr *omh;
if (msgb_l2len(msg) < sizeof(*omh)) {
LOGP(DL1C, LOGL_ERROR, "Om header insufficient space %d %d\n",
msgb_l2len(msg), sizeof(*omh));
return -1;
}
omh = (struct abis_om_hdr *) msg->l2h;
if (omh->mdisc != ABIS_OM_MDISC_FOM &&
omh->mdisc != ABIS_OM_MDISC_MANUF) {
LOGP(DL1C, LOGL_ERROR, "Incorrect om mdisc value %x\n",
omh->mdisc);
return -1;
}
if (omh->placement != ABIS_OM_PLACEMENT_ONLY) {
LOGP(DL1C, LOGL_ERROR, "Incorrect om placement value %x %x\n",
omh->placement, ABIS_OM_PLACEMENT_ONLY);
return -1;
}
if (omh->sequence != 0) {
LOGP(DL1C, LOGL_ERROR, "Incorrect om sequence value %d\n",
omh->sequence);
return -1;
}
if (omh->mdisc == ABIS_OM_MDISC_MANUF)
return check_manuf(msg, omh, msgb_l2len(msg) - sizeof(*omh));
msg->l3h = omh->data;
if (check_fom(omh, msgb_l3len(msg)) != 0)
return -1;
return OML_MSG_TYPE_ETSI;
}
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