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 | |
Sylvain Munaut | 1ebac14 | 2009-10-26 20:19:59 +0100 | [diff] [blame] | 19 | /* o_tag: output: tag found |
| 20 | * o_len: output: length of the data |
| 21 | * o_val: output: pointer to the data |
| 22 | * def: input: a structure defining the valid TLV tags / configurations |
| 23 | * buf: input: the input data buffer to be parsed |
| 24 | * buf_len: input: the length of the input data buffer |
| 25 | * |
| 26 | * Also, returns the number of bytes consumed by the TLV entry |
| 27 | */ |
| 28 | int tlv_parse_one(u_int8_t *o_tag, u_int16_t *o_len, const u_int8_t **o_val, |
| 29 | const struct tlv_definition *def, |
| 30 | const u_int8_t *buf, int buf_len) |
| 31 | { |
| 32 | u_int8_t tag; |
| 33 | int len; |
| 34 | |
| 35 | tag = *buf; |
| 36 | *o_tag = tag; |
| 37 | |
| 38 | /* FIXME: use tables for knwon IEI */ |
| 39 | switch (def->def[tag].type) { |
| 40 | case TLV_TYPE_T: |
| 41 | /* GSM TS 04.07 11.2.4: Type 1 TV or Type 2 T */ |
| 42 | *o_val = buf; |
| 43 | *o_len = 0; |
| 44 | len = 1; |
| 45 | break; |
| 46 | case TLV_TYPE_TV: |
| 47 | *o_val = buf+1; |
| 48 | *o_len = 1; |
| 49 | len = 2; |
| 50 | break; |
| 51 | case TLV_TYPE_FIXED: |
| 52 | *o_val = buf+1; |
| 53 | *o_len = def->def[tag].fixed_len; |
| 54 | len = def->def[tag].fixed_len + 1; |
| 55 | break; |
| 56 | case TLV_TYPE_TLV: |
| 57 | /* GSM TS 04.07 11.2.4: Type 4 TLV */ |
| 58 | if (buf + 1 > buf + buf_len) |
| 59 | return -1; |
| 60 | *o_val = buf+2; |
| 61 | *o_len = *(buf+1); |
| 62 | len = *o_len + 2; |
| 63 | if (len > buf_len) |
| 64 | return -2; |
| 65 | break; |
| 66 | case TLV_TYPE_TvLV: |
| 67 | if (*(buf+1) & 0x80) { |
| 68 | /* like TLV, but without highest bit of len */ |
| 69 | if (buf + 1 > buf + buf_len) |
| 70 | return -1; |
| 71 | *o_val = buf+2; |
| 72 | *o_len = *(buf+1) & 0x7f; |
| 73 | len = *o_len + 2; |
| 74 | if (len > buf_len) |
| 75 | return -2; |
| 76 | break; |
| 77 | } |
| 78 | /* like TL16V, fallthrough */ |
| 79 | case TLV_TYPE_TL16V: |
| 80 | if (2 > buf_len) |
| 81 | return -1; |
| 82 | *o_val = buf+3; |
| 83 | *o_len = *(buf+1) << 8 | *(buf+2); |
| 84 | len = *o_len + 3; |
| 85 | if (len > buf_len) |
| 86 | return -2; |
| 87 | break; |
| 88 | default: |
| 89 | return -3; |
| 90 | } |
| 91 | |
| 92 | return len; |
| 93 | } |
| 94 | |
Harald Welte | 59b0468 | 2009-06-10 05:40:52 +0800 | [diff] [blame] | 95 | /* dec: output: a caller-allocated pointer to a struct tlv_parsed, |
| 96 | * def: input: a structure defining the valid TLV tags / configurations |
| 97 | * buf: input: the input data buffer to be parsed |
| 98 | * buf_len: input: the length of the input data buffer |
| 99 | * lv_tag: input: an initial LV tag at the start of the buffer |
| 100 | * lv_tag2: input: a second initial LV tag following lv_tag |
| 101 | */ |
| 102 | int tlv_parse(struct tlv_parsed *dec, const struct tlv_definition *def, |
| 103 | const u_int8_t *buf, int buf_len, u_int8_t lv_tag, |
| 104 | u_int8_t lv_tag2) |
| 105 | { |
Sylvain Munaut | 1ebac14 | 2009-10-26 20:19:59 +0100 | [diff] [blame] | 106 | int ofs = 0, num_parsed = 0; |
| 107 | u_int16_t len; |
Harald Welte | 59b0468 | 2009-06-10 05:40:52 +0800 | [diff] [blame] | 108 | |
| 109 | memset(dec, 0, sizeof(*dec)); |
| 110 | |
| 111 | if (lv_tag) { |
Sylvain Munaut | 1ebac14 | 2009-10-26 20:19:59 +0100 | [diff] [blame] | 112 | if (ofs > buf_len) |
Harald Welte | 59b0468 | 2009-06-10 05:40:52 +0800 | [diff] [blame] | 113 | return -1; |
Sylvain Munaut | 1ebac14 | 2009-10-26 20:19:59 +0100 | [diff] [blame] | 114 | dec->lv[lv_tag].val = &buf[ofs+1]; |
| 115 | dec->lv[lv_tag].len = buf[ofs]; |
Harald Welte | 59b0468 | 2009-06-10 05:40:52 +0800 | [diff] [blame] | 116 | len = dec->lv[lv_tag].len + 1; |
Sylvain Munaut | 1ebac14 | 2009-10-26 20:19:59 +0100 | [diff] [blame] | 117 | if (ofs + len > buf_len) |
Harald Welte | 59b0468 | 2009-06-10 05:40:52 +0800 | [diff] [blame] | 118 | return -2; |
| 119 | num_parsed++; |
Sylvain Munaut | 1ebac14 | 2009-10-26 20:19:59 +0100 | [diff] [blame] | 120 | ofs += len; |
Harald Welte | 59b0468 | 2009-06-10 05:40:52 +0800 | [diff] [blame] | 121 | } |
| 122 | if (lv_tag2) { |
Sylvain Munaut | 1ebac14 | 2009-10-26 20:19:59 +0100 | [diff] [blame] | 123 | if (ofs > buf_len) |
Harald Welte | 59b0468 | 2009-06-10 05:40:52 +0800 | [diff] [blame] | 124 | return -1; |
Sylvain Munaut | 1ebac14 | 2009-10-26 20:19:59 +0100 | [diff] [blame] | 125 | dec->lv[lv_tag2].val = &buf[ofs+1]; |
| 126 | dec->lv[lv_tag2].len = buf[ofs]; |
Harald Welte | 59b0468 | 2009-06-10 05:40:52 +0800 | [diff] [blame] | 127 | len = dec->lv[lv_tag2].len + 1; |
Sylvain Munaut | 1ebac14 | 2009-10-26 20:19:59 +0100 | [diff] [blame] | 128 | if (ofs + len > buf_len) |
Harald Welte | 59b0468 | 2009-06-10 05:40:52 +0800 | [diff] [blame] | 129 | return -2; |
| 130 | num_parsed++; |
Sylvain Munaut | 1ebac14 | 2009-10-26 20:19:59 +0100 | [diff] [blame] | 131 | ofs += len; |
Harald Welte | 59b0468 | 2009-06-10 05:40:52 +0800 | [diff] [blame] | 132 | } |
| 133 | |
Sylvain Munaut | 1ebac14 | 2009-10-26 20:19:59 +0100 | [diff] [blame] | 134 | while (ofs < buf_len) { |
| 135 | int rv; |
| 136 | u_int8_t tag; |
| 137 | const u_int8_t *val; |
| 138 | |
| 139 | rv = tlv_parse_one(&tag, &len, &val, def, |
| 140 | &buf[ofs], buf_len-ofs); |
| 141 | if (rv < 0) |
| 142 | return rv; |
| 143 | dec->lv[tag].val = val; |
| 144 | dec->lv[tag].len = len; |
| 145 | ofs += rv; |
| 146 | num_parsed++; |
Harald Welte | 59b0468 | 2009-06-10 05:40:52 +0800 | [diff] [blame] | 147 | } |
| 148 | //tlv_dump(dec); |
| 149 | return num_parsed; |
| 150 | } |
| 151 | |
Harald Welte | 724ddb8 | 2009-10-24 10:04:02 +0200 | [diff] [blame] | 152 | static __attribute__((constructor)) void on_dso_load_tlv(void) |
| 153 | { |
| 154 | int i; |
| 155 | for (i = 0; i < ARRAY_SIZE(tvlv_att_def.def); i++) |
| 156 | tvlv_att_def.def[i].type = TLV_TYPE_TvLV; |
| 157 | } |