277 lines
7.5 KiB
C
277 lines
7.5 KiB
C
/* Iu interface specific helper functions */
|
|
|
|
/* (C) 2015 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 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 <stdint.h>
|
|
#include <string.h>
|
|
#include <errno.h>
|
|
#include <arpa/inet.h>
|
|
#include "asn1helpers.h"
|
|
#include <osmocom/core/utils.h>
|
|
#include <osmocom/core/socket.h>
|
|
#include <osmocom/core/bit16gen.h>
|
|
|
|
#include <osmocom/ranap/RANAP_IuTransportAssociation.h>
|
|
#include <osmocom/ranap/RANAP_TransportLayerAddress.h>
|
|
#include <osmocom/ranap/RANAP_TransportLayerInformation.h>
|
|
|
|
/* decode a BCD-string as used inside ASN.1 encoded Iu interface protocols */
|
|
int ranap_bcd_decode(char *out, size_t out_len, const uint8_t *in, size_t in_len)
|
|
{
|
|
const uint8_t *ch;
|
|
char *outch = out;
|
|
|
|
for (ch = in; ch < in + in_len; ch++) {
|
|
char c = osmo_bcd2char(*ch & 0xF);
|
|
*outch++ = c;
|
|
if (outch + 1 >= out + out_len)
|
|
break;
|
|
c = osmo_bcd2char(*ch >> 4);
|
|
/* skip padding nibble at end */
|
|
if (c == 'F')
|
|
break;
|
|
*outch++ = c;
|
|
}
|
|
*outch++ = '\0';
|
|
return outch - out;
|
|
}
|
|
|
|
/* decode an IMSI as used inside ASN.1 encoded Iu interface protocols */
|
|
int ranap_imsi_encode(uint8_t *out, size_t out_len, const char *in)
|
|
{
|
|
unsigned int len = strlen(in);
|
|
unsigned int octlen;
|
|
uint8_t odd = (len & 0x01) == 1;
|
|
unsigned int off = 0;
|
|
unsigned int i;
|
|
|
|
octlen = len/2;
|
|
if (odd)
|
|
octlen++;
|
|
|
|
for (i = 0; i < octlen; i++) {
|
|
uint8_t lower, upper;
|
|
|
|
lower = osmo_char2bcd(in[off++]) & 0x0f;
|
|
if (odd && off == len)
|
|
upper = 0x0f;
|
|
else
|
|
upper = osmo_char2bcd(in[off++]) & 0x0f;
|
|
|
|
out[i] = (upper << 4) | lower;
|
|
}
|
|
return i;
|
|
}
|
|
|
|
/* decode a network port as used inside ASN.1 encoded Iu interface protocols */
|
|
int ranap_transp_assoc_decode(uint16_t *port, const RANAP_IuTransportAssociation_t *transp_assoc)
|
|
{
|
|
uint32_t result;
|
|
|
|
if (!transp_assoc)
|
|
return -EINVAL;
|
|
|
|
result = asn1bitstr_to_u32((BIT_STRING_t *) & transp_assoc->choice.bindingID);
|
|
|
|
/* The lower 16 bits should be zero, otherwise the decoding may
|
|
* have yielded some odd result */
|
|
if (result & 0xFFFF)
|
|
return -EINVAL;
|
|
|
|
*port = (uint16_t) ((result >> 16) & 0xFFFF);
|
|
|
|
if (*port == 0)
|
|
return -EINVAL;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* decode a network address as used inside ASN.1 encoded Iu interface protocols */
|
|
int ranap_transp_layer_addr_decode(char *addr, unsigned int addr_len,
|
|
const RANAP_TransportLayerAddress_t *trasp_layer_addr)
|
|
{
|
|
unsigned char *buf;
|
|
int len;
|
|
const char *rc;
|
|
|
|
buf = trasp_layer_addr->buf;
|
|
len = trasp_layer_addr->size;
|
|
|
|
if (len >= 7 && buf[0] == 0x35)
|
|
rc = inet_ntop(AF_INET, buf + 3, addr, addr_len);
|
|
else if (len > 3)
|
|
rc = inet_ntop(AF_INET, buf, addr, addr_len);
|
|
else
|
|
return -EINVAL;
|
|
|
|
if (!rc)
|
|
return -EINVAL;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* (same as ranap_transp_layer_addr_decode, but AF agnostic) */
|
|
int ranap_transp_layer_addr_decode2(struct osmo_sockaddr *addr, bool *uses_x213_nsap,
|
|
const RANAP_TransportLayerAddress_t *trasp_layer_addr)
|
|
{
|
|
unsigned char *buf;
|
|
int len;
|
|
bool x213_nsap = false;
|
|
uint16_t icp;
|
|
|
|
buf = trasp_layer_addr->buf;
|
|
len = trasp_layer_addr->size;
|
|
|
|
memset(addr, 0, sizeof(*addr));
|
|
|
|
if (len == 20 && buf[0] == 0x35) {
|
|
/* For an X.213 NSAP encoded address we expect a buffer of exactly 20 bytes (3 bytes IDP + 17 bytes
|
|
* DSP). we also expect AFI = 0x35, which means that two byte IDI and an IP address follows. (see also
|
|
* comments in function ranap_new_transp_layer_addr below) */
|
|
x213_nsap = true;
|
|
icp = osmo_load16be(&buf[1]);
|
|
switch (icp) {
|
|
case 0x0000:
|
|
addr->u.sa.sa_family = AF_INET6;
|
|
memcpy(addr->u.sin6.sin6_addr.s6_addr, buf + 3, sizeof(addr->u.sin6.sin6_addr.s6_addr));
|
|
break;
|
|
case 0x0001:
|
|
addr->u.sa.sa_family = AF_INET;
|
|
memcpy((uint8_t *) &addr->u.sin.sin_addr.s_addr, buf + 3, sizeof(addr->u.sin.sin_addr.s_addr));
|
|
break;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
} else if (len == 4) {
|
|
/* A non X.213 NSAP encoded IPv4 address is 4 bytes long */
|
|
addr->u.sa.sa_family = AF_INET;
|
|
memcpy((uint8_t *) &addr->u.sin.sin_addr.s_addr, buf, sizeof(addr->u.sin.sin_addr.s_addr));
|
|
} else if (len == 16) {
|
|
/* A non X.213 NSAP encoded IPv6 address is 16 bytes long */
|
|
addr->u.sa.sa_family = AF_INET6;
|
|
memcpy(addr->u.sin6.sin6_addr.s6_addr, buf, sizeof(addr->u.sin6.sin6_addr.s6_addr));
|
|
} else
|
|
return -EINVAL;
|
|
|
|
/* In case the caller is interested in the encoding method that was used */
|
|
if (uses_x213_nsap)
|
|
*uses_x213_nsap = x213_nsap;
|
|
|
|
return 0;
|
|
}
|
|
|
|
int ranap_new_transp_layer_addr(BIT_STRING_t *out, struct osmo_sockaddr *addr, bool use_x213_nsap)
|
|
{
|
|
uint8_t *buf;
|
|
unsigned int len;
|
|
size_t ip_len;
|
|
uint8_t *ip_addr;
|
|
uint16_t icp;
|
|
|
|
switch (addr->u.sa.sa_family) {
|
|
case AF_INET:
|
|
ip_len = sizeof(addr->u.sin.sin_addr.s_addr);
|
|
ip_addr = (uint8_t *) &addr->u.sin.sin_addr.s_addr;
|
|
icp = 0x0001; /* See X.213, section A.5.2.1.2.7 */
|
|
break;
|
|
case AF_INET6:
|
|
ip_len = sizeof(addr->u.sin6.sin6_addr.s6_addr);
|
|
ip_addr = addr->u.sin6.sin6_addr.s6_addr;
|
|
icp = 0x0000; /* See X.213, section A.5.2.1.2.7 */
|
|
break;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (use_x213_nsap) {
|
|
/* 3 bytes IDP (AFI+ICP) + 17 bytes DSP */
|
|
len = 3 + 17;
|
|
buf = CALLOC(len, sizeof(uint8_t));
|
|
|
|
/* 1 byte AFI to announce IANA ICP, see also X.213, table A.4 */
|
|
buf[0] = 0x35;
|
|
|
|
/* 2 byte IANA ICP IDI, see also X.213, A.5.2.1.2.7 */
|
|
osmo_store16be(icp, &buf[1]);
|
|
|
|
/* 17 byte DSP, see also X.213, table A.5 and A.5.2.1.2.7 */
|
|
memcpy(&buf[3], ip_addr, ip_len);
|
|
} else {
|
|
len = ip_len;
|
|
buf = CALLOC(len, sizeof(uint8_t));
|
|
memcpy(buf, ip_addr, ip_len);
|
|
}
|
|
out->buf = buf;
|
|
out->size = len;
|
|
out->bits_unused = 0;
|
|
|
|
return 0;
|
|
}
|
|
|
|
RANAP_TransportLayerInformation_t *ranap_new_transp_info_rtp(struct osmo_sockaddr *addr, bool use_x213_nsap)
|
|
{
|
|
RANAP_TransportLayerInformation_t *tli;
|
|
uint8_t binding_id[4] = { 0 };
|
|
int rc;
|
|
|
|
switch (addr->u.sin.sin_family) {
|
|
case AF_INET:
|
|
osmo_store16be(ntohs(addr->u.sin.sin_port), binding_id);
|
|
break;
|
|
case AF_INET6:
|
|
osmo_store16be(ntohs(addr->u.sin6.sin6_port), binding_id);
|
|
break;
|
|
default:
|
|
return NULL;
|
|
}
|
|
|
|
tli = CALLOC(1, sizeof(*tli));
|
|
rc = ranap_new_transp_layer_addr(&tli->transportLayerAddress, addr, use_x213_nsap);
|
|
if (rc < 0) {
|
|
ASN_STRUCT_FREE(asn_DEF_RANAP_TransportLayerInformation, tli);
|
|
return NULL;
|
|
}
|
|
|
|
tli->iuTransportAssociation.present = RANAP_IuTransportAssociation_PR_bindingID;
|
|
OCTET_STRING_fromBuf(&tli->iuTransportAssociation.choice.bindingID,
|
|
(const char *)binding_id, sizeof(binding_id));
|
|
|
|
return tli;
|
|
}
|
|
|
|
RANAP_TransportLayerInformation_t *ranap_new_transp_info_gtp(struct osmo_sockaddr *addr, uint32_t tei,
|
|
bool use_x213_nsap)
|
|
{
|
|
RANAP_TransportLayerInformation_t *tli = CALLOC(1, sizeof(*tli));
|
|
uint32_t binding_buf = htonl(tei);
|
|
int rc;
|
|
|
|
rc = ranap_new_transp_layer_addr(&tli->transportLayerAddress, addr, use_x213_nsap);
|
|
if (rc < 0) {
|
|
ASN_STRUCT_FREE(asn_DEF_RANAP_TransportLayerInformation, tli);
|
|
return NULL;
|
|
}
|
|
|
|
tli->iuTransportAssociation.present = RANAP_IuTransportAssociation_PR_gTP_TEI;
|
|
OCTET_STRING_fromBuf(&tli->iuTransportAssociation.choice.gTP_TEI,
|
|
(const char *)&binding_buf, sizeof(binding_buf));
|
|
|
|
return tli;
|
|
}
|