Harald Welte | 59b0468 | 2009-06-10 05:40:52 +0800 | [diff] [blame] | 1 | #include <stdio.h> |
| 2 | #include <openbsc/tlv.h> |
Harald Welte | 724ddb8 | 2009-10-24 10:04:02 +0200 | [diff] [blame^] | 3 | #include <openbsc/gsm_data.h> |
| 4 | |
| 5 | struct tlv_definition tvlv_att_def; |
Harald Welte | 59b0468 | 2009-06-10 05:40:52 +0800 | [diff] [blame] | 6 | |
| 7 | int tlv_dump(struct tlv_parsed *dec) |
| 8 | { |
| 9 | int i; |
| 10 | |
| 11 | for (i = 0; i <= 0xff; i++) { |
| 12 | if (!dec->lv[i].val) |
| 13 | continue; |
| 14 | printf("T=%02x L=%d\n", i, dec->lv[i].len); |
| 15 | } |
| 16 | return 0; |
| 17 | } |
| 18 | |
| 19 | /* dec: output: a caller-allocated pointer to a struct tlv_parsed, |
| 20 | * def: input: a structure defining the valid TLV tags / configurations |
| 21 | * buf: input: the input data buffer to be parsed |
| 22 | * buf_len: input: the length of the input data buffer |
| 23 | * lv_tag: input: an initial LV tag at the start of the buffer |
| 24 | * lv_tag2: input: a second initial LV tag following lv_tag |
| 25 | */ |
| 26 | int tlv_parse(struct tlv_parsed *dec, const struct tlv_definition *def, |
| 27 | const u_int8_t *buf, int buf_len, u_int8_t lv_tag, |
| 28 | u_int8_t lv_tag2) |
| 29 | { |
| 30 | u_int8_t tag, len = 1; |
| 31 | const u_int8_t *pos = buf; |
| 32 | int num_parsed = 0; |
| 33 | |
| 34 | memset(dec, 0, sizeof(*dec)); |
| 35 | |
| 36 | if (lv_tag) { |
| 37 | if (pos > buf + buf_len) |
| 38 | return -1; |
| 39 | dec->lv[lv_tag].val = pos+1; |
| 40 | dec->lv[lv_tag].len = *pos; |
| 41 | len = dec->lv[lv_tag].len + 1; |
| 42 | if (pos + len > buf + buf_len) |
| 43 | return -2; |
| 44 | num_parsed++; |
| 45 | pos += len; |
| 46 | } |
| 47 | if (lv_tag2) { |
| 48 | if (pos > buf + buf_len) |
| 49 | return -1; |
| 50 | dec->lv[lv_tag2].val = pos+1; |
| 51 | dec->lv[lv_tag2].len = *pos; |
| 52 | len = dec->lv[lv_tag2].len + 1; |
| 53 | if (pos + len > buf + buf_len) |
| 54 | return -2; |
| 55 | num_parsed++; |
| 56 | pos += len; |
| 57 | } |
| 58 | |
| 59 | for (; pos < buf+buf_len; pos += len) { |
| 60 | tag = *pos; |
| 61 | /* FIXME: use tables for knwon IEI */ |
| 62 | switch (def->def[tag].type) { |
| 63 | case TLV_TYPE_T: |
| 64 | /* GSM TS 04.07 11.2.4: Type 1 TV or Type 2 T */ |
| 65 | dec->lv[tag].val = pos; |
| 66 | dec->lv[tag].len = 0; |
| 67 | len = 1; |
| 68 | num_parsed++; |
| 69 | break; |
| 70 | case TLV_TYPE_TV: |
| 71 | dec->lv[tag].val = pos+1; |
| 72 | dec->lv[tag].len = 1; |
| 73 | len = 2; |
| 74 | num_parsed++; |
| 75 | break; |
| 76 | case TLV_TYPE_FIXED: |
| 77 | dec->lv[tag].val = pos+1; |
| 78 | dec->lv[tag].len = def->def[tag].fixed_len; |
| 79 | len = def->def[tag].fixed_len + 1; |
| 80 | num_parsed++; |
| 81 | break; |
| 82 | case TLV_TYPE_TLV: |
| 83 | /* GSM TS 04.07 11.2.4: Type 4 TLV */ |
| 84 | if (pos + 1 > buf + buf_len) |
| 85 | return -1; |
| 86 | dec->lv[tag].val = pos+2; |
| 87 | dec->lv[tag].len = *(pos+1); |
| 88 | len = dec->lv[tag].len + 2; |
| 89 | if (pos + len > buf + buf_len) |
| 90 | return -2; |
| 91 | num_parsed++; |
| 92 | break; |
Harald Welte | 724ddb8 | 2009-10-24 10:04:02 +0200 | [diff] [blame^] | 93 | case TLV_TYPE_TvLV: |
| 94 | if (*(pos+1) & 0x80) { |
| 95 | /* like TLV, but without highest bit of len */ |
| 96 | if (pos + 1 > buf + buf_len) |
| 97 | return -1; |
| 98 | dec->lv[tag].val = pos+2; |
| 99 | dec->lv[tag].len = *(pos+1) & 0x7f; |
| 100 | len = dec->lv[tag].len + 2; |
| 101 | if (pos + len > buf + buf_len) |
| 102 | return -2; |
| 103 | num_parsed++; |
| 104 | break; |
| 105 | } |
| 106 | /* like TL16V, fallthrough */ |
Harald Welte | 59b0468 | 2009-06-10 05:40:52 +0800 | [diff] [blame] | 107 | case TLV_TYPE_TL16V: |
| 108 | if (pos + 2 > buf + buf_len) |
| 109 | return -1; |
| 110 | dec->lv[tag].val = pos+3; |
| 111 | dec->lv[tag].len = *(pos+1) << 8 | *(pos+2); |
| 112 | len = dec->lv[tag].len + 3; |
| 113 | if (pos + len > buf + buf_len) |
| 114 | return -2; |
| 115 | num_parsed++; |
| 116 | break; |
| 117 | } |
| 118 | } |
| 119 | //tlv_dump(dec); |
| 120 | return num_parsed; |
| 121 | } |
| 122 | |
Harald Welte | 724ddb8 | 2009-10-24 10:04:02 +0200 | [diff] [blame^] | 123 | static __attribute__((constructor)) void on_dso_load_tlv(void) |
| 124 | { |
| 125 | int i; |
| 126 | for (i = 0; i < ARRAY_SIZE(tvlv_att_def.def); i++) |
| 127 | tvlv_att_def.def[i].type = TLV_TYPE_TvLV; |
| 128 | } |