Harald Welte | 59b0468 | 2009-06-10 05:40:52 +0800 | [diff] [blame] | 1 | #include <stdio.h> |
| 2 | #include <openbsc/tlv.h> |
| 3 | |
| 4 | int tlv_dump(struct tlv_parsed *dec) |
| 5 | { |
| 6 | int i; |
| 7 | |
| 8 | for (i = 0; i <= 0xff; i++) { |
| 9 | if (!dec->lv[i].val) |
| 10 | continue; |
| 11 | printf("T=%02x L=%d\n", i, dec->lv[i].len); |
| 12 | } |
| 13 | return 0; |
| 14 | } |
| 15 | |
| 16 | /* dec: output: a caller-allocated pointer to a struct tlv_parsed, |
| 17 | * def: input: a structure defining the valid TLV tags / configurations |
| 18 | * buf: input: the input data buffer to be parsed |
| 19 | * buf_len: input: the length of the input data buffer |
| 20 | * lv_tag: input: an initial LV tag at the start of the buffer |
| 21 | * lv_tag2: input: a second initial LV tag following lv_tag |
| 22 | */ |
| 23 | int tlv_parse(struct tlv_parsed *dec, const struct tlv_definition *def, |
| 24 | const u_int8_t *buf, int buf_len, u_int8_t lv_tag, |
| 25 | u_int8_t lv_tag2) |
| 26 | { |
| 27 | u_int8_t tag, len = 1; |
| 28 | const u_int8_t *pos = buf; |
| 29 | int num_parsed = 0; |
| 30 | |
| 31 | memset(dec, 0, sizeof(*dec)); |
| 32 | |
| 33 | if (lv_tag) { |
| 34 | if (pos > buf + buf_len) |
| 35 | return -1; |
| 36 | dec->lv[lv_tag].val = pos+1; |
| 37 | dec->lv[lv_tag].len = *pos; |
| 38 | len = dec->lv[lv_tag].len + 1; |
| 39 | if (pos + len > buf + buf_len) |
| 40 | return -2; |
| 41 | num_parsed++; |
| 42 | pos += len; |
| 43 | } |
| 44 | if (lv_tag2) { |
| 45 | if (pos > buf + buf_len) |
| 46 | return -1; |
| 47 | dec->lv[lv_tag2].val = pos+1; |
| 48 | dec->lv[lv_tag2].len = *pos; |
| 49 | len = dec->lv[lv_tag2].len + 1; |
| 50 | if (pos + len > buf + buf_len) |
| 51 | return -2; |
| 52 | num_parsed++; |
| 53 | pos += len; |
| 54 | } |
| 55 | |
| 56 | for (; pos < buf+buf_len; pos += len) { |
| 57 | tag = *pos; |
| 58 | /* FIXME: use tables for knwon IEI */ |
| 59 | switch (def->def[tag].type) { |
| 60 | case TLV_TYPE_T: |
| 61 | /* GSM TS 04.07 11.2.4: Type 1 TV or Type 2 T */ |
| 62 | dec->lv[tag].val = pos; |
| 63 | dec->lv[tag].len = 0; |
| 64 | len = 1; |
| 65 | num_parsed++; |
| 66 | break; |
| 67 | case TLV_TYPE_TV: |
| 68 | dec->lv[tag].val = pos+1; |
| 69 | dec->lv[tag].len = 1; |
| 70 | len = 2; |
| 71 | num_parsed++; |
| 72 | break; |
| 73 | case TLV_TYPE_FIXED: |
| 74 | dec->lv[tag].val = pos+1; |
| 75 | dec->lv[tag].len = def->def[tag].fixed_len; |
| 76 | len = def->def[tag].fixed_len + 1; |
| 77 | num_parsed++; |
| 78 | break; |
| 79 | case TLV_TYPE_TLV: |
| 80 | /* GSM TS 04.07 11.2.4: Type 4 TLV */ |
| 81 | if (pos + 1 > buf + buf_len) |
| 82 | return -1; |
| 83 | dec->lv[tag].val = pos+2; |
| 84 | dec->lv[tag].len = *(pos+1); |
| 85 | len = dec->lv[tag].len + 2; |
| 86 | if (pos + len > buf + buf_len) |
| 87 | return -2; |
| 88 | num_parsed++; |
| 89 | break; |
| 90 | case TLV_TYPE_TL16V: |
| 91 | if (pos + 2 > buf + buf_len) |
| 92 | return -1; |
| 93 | dec->lv[tag].val = pos+3; |
| 94 | dec->lv[tag].len = *(pos+1) << 8 | *(pos+2); |
| 95 | len = dec->lv[tag].len + 3; |
| 96 | if (pos + len > buf + buf_len) |
| 97 | return -2; |
| 98 | num_parsed++; |
| 99 | break; |
| 100 | } |
| 101 | } |
| 102 | //tlv_dump(dec); |
| 103 | return num_parsed; |
| 104 | } |
| 105 | |