diff options
Diffstat (limited to 'src/gsm')
| -rw-r--r-- | src/gsm/libosmogsm.map | 6 | ||||
| -rw-r--r-- | src/gsm/tlv_parser.c | 171 |
2 files changed, 177 insertions, 0 deletions
diff --git a/src/gsm/libosmogsm.map b/src/gsm/libosmogsm.map index 21d3c293..8bd0dbfe 100644 --- a/src/gsm/libosmogsm.map +++ b/src/gsm/libosmogsm.map @@ -278,6 +278,12 @@ tlv_parse_one; tvlv_att_def; vtvlv_gan_att_def; +osmo_shift_v_fixed; +osmo_match_shift_tv_fixed; +osmo_shift_tlv; +osmo_match_shift_tlv; +osmo_shift_lv; + gan_msgt_vals; gan_pdisc_vals; diff --git a/src/gsm/tlv_parser.c b/src/gsm/tlv_parser.c index 19d0c84d..e84edd97 100644 --- a/src/gsm/tlv_parser.c +++ b/src/gsm/tlv_parser.c @@ -225,4 +225,175 @@ static __attribute__((constructor)) void on_dso_load_tlv(void) vtvlv_gan_att_def.def[i].type = TLV_TYPE_vTvLV_GAN; } +/*! Advance the data pointer, subtract length and assign value pointer + * \param data pointer to the pointer to data + * \param data_len pointer to size_t containing \arg data length + * \param[in] len the length that we expect the fixed IE to hav + * \param[out] value pointer to pointer of value part of IE + * \returns length of IE value; negative in case of error + */ +int osmo_shift_v_fixed(uint8_t **data, size_t *data_len, + size_t len, uint8_t **value) +{ + if (len > *data_len) + goto fail; + + if (value) + *value = *data; + + *data += len; + *data_len -= len; + + return len; + +fail: + *data += *data_len; + *data_len = 0; + return -1; +} + +/*! Match tag, check length and assign value pointer + * \param data pointer to the pointer to data + * \param data_len pointer to size_t containing \arg data length + * \param[in] tag the tag (IEI) that we expect at \arg data + * \param[in] len the length that we expect the fixed IE to have + * \param[out] value pointer to pointer of value part of IE + * \returns length of IE value; negative in case of error + */ +int osmo_match_shift_tv_fixed(uint8_t **data, size_t *data_len, + uint8_t tag, size_t len, + uint8_t **value) +{ + size_t ie_len; + + if (*data_len == 0) + goto fail; + + if ((*data)[0] != tag) + return 0; + + if (len > *data_len - 1) + goto fail; + + if (value) + *value = *data + 1; + + ie_len = len + 1; + *data += ie_len; + *data_len -= ie_len; + + return ie_len; + +fail: + *data += *data_len; + *data_len = 0; + return -1; +} + +/*! Verify TLV header and advance data / subtract length + * \param data pointer to the pointer to data + * \param data_len pointer to size_t containing \arg data length + * \param[in] expected_tag the tag (IEI) that we expect at \arg data + * \param[out] value pointer to pointer of value part of IE + * \param[out] value_len pointer to length of \arg value + * \returns length of IE value; negative in case of error + */ +int osmo_match_shift_tlv(uint8_t **data, size_t *data_len, + uint8_t expected_tag, uint8_t **value, + size_t *value_len) +{ + int rc; + uint8_t tag; + uint8_t *old_data = *data; + size_t old_data_len = *data_len; + + rc = osmo_shift_tlv(data, data_len, &tag, value, value_len); + + if (rc > 0 && tag != expected_tag) { + *data = old_data; + *data_len = old_data_len; + return 0; + } + + return rc; +} + +/*! Extract TLV and advance data pointer + subtract length + * \param data pointer to the pointer to data + * \param data_len pointer to size_t containing \arg data lengt + * \param[out] tag extract the tag (IEI) at start of \arg data + * \param[out] value extracted pointer to value part of TLV + * \param[out] value_len extracted length of \arg value + * \returns number of bytes subtracted + */ +int osmo_shift_tlv(uint8_t **data, size_t *data_len, + uint8_t *tag, uint8_t **value, size_t *value_len) +{ + size_t len; + size_t ie_len; + + if (*data_len < 2) + goto fail; + + len = (*data)[1]; + if (len > *data_len - 2) + goto fail; + + if (tag) + *tag = (*data)[0]; + if (value) + *value = *data + 2; + if (value_len) + *value_len = len; + + ie_len = len + 2; + + *data += ie_len; + *data_len -= ie_len; + + return ie_len; + +fail: + *data += *data_len; + *data_len = 0; + return -1; +} + +/*! Extract LV and advance data pointer + subtract length + * \param data pointer to the pointer to data + * \param data_len pointer to size_t containing \arg data lengt + * \param[out] value extracted pointer to value part of TLV + * \param[out] value_len extracted length of \arg value + * \returns number of bytes subtracted + */ +int osmo_shift_lv(uint8_t **data, size_t *data_len, + uint8_t **value, size_t *value_len) +{ + size_t len; + size_t ie_len; + + if (*data_len < 1) + goto fail; + + len = (*data)[0]; + if (len > *data_len - 1) + goto fail; + + if (value) + *value = *data + 1; + if (value_len) + *value_len = len; + + ie_len = len + 1; + *data += ie_len; + *data_len -= ie_len; + + return ie_len; + +fail: + *data += *data_len; + *data_len = 0; + return -1; +} + /*! @} */ |