| /* 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/ranap/RANAP_IuTransportAssociation.h> |
| #include <osmocom/ranap/RANAP_TransportLayerAddress.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 (buf[0] == 0x35 && len == 7) |
| 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; |
| } |