| #include <stdio.h> |
| #include <openbsc/tlv.h> |
| |
| int tlv_dump(struct tlv_parsed *dec) |
| { |
| int i; |
| |
| for (i = 0; i <= 0xff; i++) { |
| if (!dec->lv[i].val) |
| continue; |
| printf("T=%02x L=%d\n", i, dec->lv[i].len); |
| } |
| return 0; |
| } |
| |
| /* dec: output: a caller-allocated pointer to a struct tlv_parsed, |
| * def: input: a structure defining the valid TLV tags / configurations |
| * buf: input: the input data buffer to be parsed |
| * buf_len: input: the length of the input data buffer |
| * lv_tag: input: an initial LV tag at the start of the buffer |
| * lv_tag2: input: a second initial LV tag following lv_tag |
| */ |
| int tlv_parse(struct tlv_parsed *dec, const struct tlv_definition *def, |
| const u_int8_t *buf, int buf_len, u_int8_t lv_tag, |
| u_int8_t lv_tag2) |
| { |
| u_int8_t tag, len = 1; |
| const u_int8_t *pos = buf; |
| int num_parsed = 0; |
| |
| memset(dec, 0, sizeof(*dec)); |
| |
| if (lv_tag) { |
| if (pos > buf + buf_len) |
| return -1; |
| dec->lv[lv_tag].val = pos+1; |
| dec->lv[lv_tag].len = *pos; |
| len = dec->lv[lv_tag].len + 1; |
| if (pos + len > buf + buf_len) |
| return -2; |
| num_parsed++; |
| pos += len; |
| } |
| if (lv_tag2) { |
| if (pos > buf + buf_len) |
| return -1; |
| dec->lv[lv_tag2].val = pos+1; |
| dec->lv[lv_tag2].len = *pos; |
| len = dec->lv[lv_tag2].len + 1; |
| if (pos + len > buf + buf_len) |
| return -2; |
| num_parsed++; |
| pos += len; |
| } |
| |
| for (; pos < buf+buf_len; pos += len) { |
| tag = *pos; |
| /* FIXME: use tables for knwon IEI */ |
| switch (def->def[tag].type) { |
| case TLV_TYPE_T: |
| /* GSM TS 04.07 11.2.4: Type 1 TV or Type 2 T */ |
| dec->lv[tag].val = pos; |
| dec->lv[tag].len = 0; |
| len = 1; |
| num_parsed++; |
| break; |
| case TLV_TYPE_TV: |
| dec->lv[tag].val = pos+1; |
| dec->lv[tag].len = 1; |
| len = 2; |
| num_parsed++; |
| break; |
| case TLV_TYPE_FIXED: |
| dec->lv[tag].val = pos+1; |
| dec->lv[tag].len = def->def[tag].fixed_len; |
| len = def->def[tag].fixed_len + 1; |
| num_parsed++; |
| break; |
| case TLV_TYPE_TLV: |
| /* GSM TS 04.07 11.2.4: Type 4 TLV */ |
| if (pos + 1 > buf + buf_len) |
| return -1; |
| dec->lv[tag].val = pos+2; |
| dec->lv[tag].len = *(pos+1); |
| len = dec->lv[tag].len + 2; |
| if (pos + len > buf + buf_len) |
| return -2; |
| num_parsed++; |
| break; |
| case TLV_TYPE_TL16V: |
| if (pos + 2 > buf + buf_len) |
| return -1; |
| dec->lv[tag].val = pos+3; |
| dec->lv[tag].len = *(pos+1) << 8 | *(pos+2); |
| len = dec->lv[tag].len + 3; |
| if (pos + len > buf + buf_len) |
| return -2; |
| num_parsed++; |
| break; |
| } |
| } |
| //tlv_dump(dec); |
| return num_parsed; |
| } |
| |