From 11a4d9dd91216fe353e94bfdbbab53bc4f891c0d Mon Sep 17 00:00:00 2001 From: Stefan Sperling Date: Thu, 15 Feb 2018 18:28:04 +0100 Subject: support for more cell ID list types in libosmocore Introduce gsm0808_dec_cell_id_list2() with supports additional types of cell identifier lists. The new parsing routines are based on similar routines used by the paging code in osmo-bsc's osmo_bsc_bssap.c. Likewise, introduce gsm0808_enc_cell_id_list2() with support for the same additional types of cell identifier lists. The old API using struct gsm0808_cell_id_list is deprecated. The previous definition was insufficient because it assumed that all decoded cell ID types could be represented with a single uint16_t. It was declared in a GSM protocol header (gsm/protocol/gsm_08_08.h) despite being a host-side representation of data in an IE. The only user I am aware of is in osmo-msc, where this struct is used for one local variable. osmo-msc releases >= 1.1.0 make use of this API. While here, fix a small bug in a test: test_gsm0808_enc_dec_cell_id_list_bss() set the cell ID type to 'LAC' but obviously wants to use type 'BSS'. Change-Id: Ib7e754f538df0c83298a3c958b4e15a32fcb8abb Related: OS#2847 --- src/gsm/gsm0808.c | 36 ++++++- src/gsm/gsm0808_utils.c | 258 ++++++++++++++++++++++++++++++++++++++++++++++++ src/gsm/libosmogsm.map | 3 + 3 files changed, 292 insertions(+), 5 deletions(-) (limited to 'src/gsm') diff --git a/src/gsm/gsm0808.c b/src/gsm/gsm0808.c index b43e0e63..3003284b 100644 --- a/src/gsm/gsm0808.c +++ b/src/gsm/gsm0808.c @@ -521,16 +521,16 @@ struct msgb *gsm0808_create_clear_rqst(uint8_t cause) * \param[in] cil Cell Identity List (where to page) * \param[in] chan_needed Channel Type needed * \returns callee-allocated msgb with BSSMAP PAGING message */ -struct msgb *gsm0808_create_paging(const char *imsi, const uint32_t *tmsi, - const struct gsm0808_cell_id_list *cil, - const uint8_t *chan_needed) +struct msgb *gsm0808_create_paging2(const char *imsi, const uint32_t *tmsi, + const struct gsm0808_cell_id_list2 *cil, + const uint8_t *chan_needed) { struct msgb *msg; uint8_t mid_buf[GSM48_MI_SIZE + 2]; int mid_len; uint32_t tmsi_sw; - /* Mandatory emelents! */ + /* Mandatory elements! */ OSMO_ASSERT(imsi); OSMO_ASSERT(cil); @@ -558,7 +558,7 @@ struct msgb *gsm0808_create_paging(const char *imsi, const uint32_t *tmsi, /* Cell Identifier List 3.2.2.27 */ if (cil) - gsm0808_enc_cell_id_list(msg, cil); + gsm0808_enc_cell_id_list2(msg, cil); /* Channel Needed 3.2.2.36 */ if (chan_needed) { @@ -573,6 +573,32 @@ struct msgb *gsm0808_create_paging(const char *imsi, const uint32_t *tmsi, return msg; } +/*! DEPRECATED: Use gsm0808_create_paging2 instead. + * Create BSSMAP PAGING message. + * \param[in] imsi Mandatory paged IMSI in string representation + * \param[in] tmsi Optional paged TMSI + * \param[in] cil Cell Identity List (where to page) + * \param[in] chan_needed Channel Type needed + * \returns callee-allocated msgb with BSSMAP PAGING message */ +struct msgb *gsm0808_create_paging(const char *imsi, const uint32_t *tmsi, + const struct gsm0808_cell_id_list *cil, + const uint8_t *chan_needed) +{ + struct gsm0808_cell_id_list2 cil2 = {}; + + /* Mandatory emelents! */ + OSMO_ASSERT(cil); + + if (cil->id_list_len > GSM0808_CELL_ID_LIST2_MAXLEN) + return NULL; + + cil2.id_discr = cil->id_discr; + memcpy(cil2.id_list, cil->id_list_lac, cil->id_list_len * sizeof(cil2.id_list[0].lac)); + cil2.id_list_len = cil->id_list_len; + + return gsm0808_create_paging2(imsi, tmsi, &cil2, chan_needed); +} + /*! Prepend a DTAP header to given Message Buffer * \param[in] msgb Message Buffer * \param[in] link_id Link Identifier */ diff --git a/src/gsm/gsm0808_utils.c b/src/gsm/gsm0808_utils.c index 93e6074c..a07ef0ec 100644 --- a/src/gsm/gsm0808_utils.c +++ b/src/gsm/gsm0808_utils.c @@ -27,6 +27,8 @@ #include #include #include +#include +#include #define IP_V4_ADDR_LEN 4 #define IP_V6_ADDR_LEN 16 @@ -571,6 +573,75 @@ int gsm0808_dec_encrypt_info(struct gsm0808_encrypt_info *ei, * \param[out] msg Message Buffer to which IE is to be appended * \param[in] cil Cell ID List to be encoded * \returns number of bytes appended to \a msg */ +uint8_t gsm0808_enc_cell_id_list2(struct msgb *msg, + const struct gsm0808_cell_id_list2 *cil) +{ + uint8_t *old_tail; + uint8_t *tlv_len; + unsigned int i; + + OSMO_ASSERT(msg); + OSMO_ASSERT(cil); + + msgb_put_u8(msg, GSM0808_IE_CELL_IDENTIFIER_LIST); + tlv_len = msgb_put(msg, 1); + old_tail = msg->tail; + + msgb_put_u8(msg, cil->id_discr & 0x0f); + + OSMO_ASSERT(cil->id_list_len <= GSM0808_CELL_ID_LIST2_MAXLEN) + switch (cil->id_discr) { + case CELL_IDENT_WHOLE_GLOBAL: + for (i = 0; i < cil->id_list_len; i++) { + const struct osmo_cell_global_id *id = &cil->id_list[i].global; + struct gsm48_loc_area_id lai; + gsm48_generate_lai(&lai, id->lai.plmn.mcc, id->lai.plmn.mnc, id->lai.lac); + memcpy(msgb_put(msg, sizeof(lai)), &lai, sizeof(lai)); + msgb_put_u16(msg, id->cell_identity); + } + break; + case CELL_IDENT_LAC_AND_CI: + for (i = 0; i < cil->id_list_len; i++) { + const struct osmo_lac_and_ci_id *id = &cil->id_list[i].lac_and_ci; + msgb_put_u16(msg, id->lac); + msgb_put_u16(msg, id->ci); + } + break; + case CELL_IDENT_CI: + for (i = 0; i < cil->id_list_len; i++) + msgb_put_u16(msg, cil->id_list[i].ci); + break; + case CELL_IDENT_LAI_AND_LAC: + for (i = 0; i < cil->id_list_len; i++) { + const struct osmo_location_area_id *id = &cil->id_list[i].lai_and_lac; + struct gsm48_loc_area_id lai; + gsm48_generate_lai(&lai, id->plmn.mcc, id->plmn.mnc, id->lac); + memcpy(msgb_put(msg, sizeof(lai)), &lai, sizeof(lai)); + } + break; + case CELL_IDENT_LAC: + for (i = 0; i < cil->id_list_len; i++) + msgb_put_u16(msg, cil->id_list[i].lac); + break; + case CELL_IDENT_BSS: + case CELL_IDENT_NO_CELL: + /* Does not have any list items */ + break; + default: + /* Support for other identifier list types is not implemented. */ + OSMO_ASSERT(false); + } + + *tlv_len = (uint8_t) (msg->tail - old_tail); + return *tlv_len + 2; +} + +/*! DEPRECATED: Use gsm0808_enc_cell_id_list2 instead. + * + * Encode TS 08.08 Cell Identifier List IE + * \param[out] msg Message Buffer to which IE is to be appended + * \param[in] cil Cell ID List to be encoded + * \returns number of bytes appended to \a msg */ uint8_t gsm0808_enc_cell_id_list(struct msgb *msg, const struct gsm0808_cell_id_list *cil) { @@ -606,11 +677,198 @@ uint8_t gsm0808_enc_cell_id_list(struct msgb *msg, return *tlv_len + 2; } +/* Decode 5-byte LAI list element data (see TS 08.08 3.2.2.27) into MCC/MNC/LAC. + * Return 0 if successful, negative on error. */ +static int decode_lai(const uint8_t *data, uint16_t *mcc, uint16_t *mnc, uint16_t *lac) +{ + struct gsm48_loc_area_id lai; + + /* Copy data to stack to prevent unaligned access in gsm48_decode_lai(). */ + memcpy(&lai, data, sizeof(lai)); /* don't byte swap yet */ + + return gsm48_decode_lai(&lai, mcc, mnc, lac) ? -1 : 0; +} + +static int parse_cell_id_global_list(struct osmo_cell_global_id *id_list, const uint8_t *data, size_t remain, + size_t *consumed) +{ + struct osmo_cell_global_id *id; + uint16_t *ci_be; + size_t lai_offset; + int i = 0; + const size_t elemlen = sizeof(struct gsm48_loc_area_id) + sizeof(*ci_be); + + *consumed = 0; + while (remain >= elemlen) { + if (i >= GSM0808_CELL_ID_LIST2_MAXLEN) + return -ENOSPC; + id = &id_list[i]; + lai_offset = 1 + i * elemlen; + if (decode_lai(&data[lai_offset], &id->lai.plmn.mcc, &id->lai.plmn.mnc, &id->lai.lac) != 0) + return -EINVAL; + ci_be = (uint16_t *)(&data[lai_offset + sizeof(struct gsm48_loc_area_id)]); + id->cell_identity = osmo_load16be(ci_be); + *consumed += elemlen; + remain -= elemlen; + i++; + } + + return i; +} + +static int parse_cell_id_lac_and_ci_list(struct osmo_lac_and_ci_id *id_list, const uint8_t *data, size_t remain, + size_t *consumed) +{ + uint16_t *lacp_be, *ci_be; + struct osmo_lac_and_ci_id *id; + int i = 0; + const size_t elemlen = sizeof(*lacp_be) + sizeof(*ci_be); + + *consumed = 0; + + if (remain < elemlen) + return -EINVAL; + + lacp_be = (uint16_t *)(&data[0]); + ci_be = (uint16_t *)(&data[2]); + while (remain >= elemlen) { + if (i >= GSM0808_CELL_ID_LIST2_MAXLEN) + return -ENOSPC; + id = &id_list[i]; + id->lac = osmo_load16be(lacp_be); + id->ci = osmo_load16be(ci_be); + *consumed += elemlen; + remain -= elemlen; + lacp_be++; + ci_be++; + } + + return i; +} + +static int parse_cell_id_ci_list(uint16_t *id_list, const uint8_t *data, size_t remain, size_t *consumed) +{ + const uint16_t *ci_be = (const uint16_t *)data; + int i = 0; + const size_t elemlen = sizeof(*ci_be); + + *consumed = 0; + while (remain >= elemlen) { + if (i >= GSM0808_CELL_ID_LIST2_MAXLEN) + return -ENOSPC; + id_list[i++] = osmo_load16be(ci_be++); + consumed += elemlen; + remain -= elemlen; + } + return i; +} + +static int parse_cell_id_lai_and_lac(struct osmo_location_area_id *id_list, const uint8_t *data, size_t remain, + size_t *consumed) +{ + struct osmo_location_area_id *id; + int i = 0; + const size_t elemlen = sizeof(struct gsm48_loc_area_id); + + *consumed = 0; + while (remain >= elemlen) { + if (i >= GSM0808_CELL_ID_LIST2_MAXLEN) + return -ENOSPC; + id = &id_list[i]; + if (decode_lai(&data[1 + i * elemlen], &id->plmn.mcc, &id->plmn.mnc, &id->lac) != 0) + return -EINVAL; + *consumed += elemlen; + remain -= elemlen; + i++; + } + + return i; +} + +static int parse_cell_id_lac_list(uint16_t *id_list, const uint8_t *data, size_t remain, size_t *consumed) +{ + const uint16_t *lac_be = (const uint16_t *)data; + int i = 0; + const size_t elemlen = sizeof(*lac_be); + + *consumed = 0; + while (remain >= elemlen) { + if (i >= GSM0808_CELL_ID_LIST2_MAXLEN) + return -ENOSPC; + id_list[i++] = osmo_load16be(lac_be++); + *consumed += elemlen; + remain -= elemlen; + } + return i; +} + /*! Decode Cell Identifier List IE * \param[out] cil Caller-provided memory to store Cell ID list * \param[in] elem IE value to be decoded * \param[in] len Length of \a elem in bytes * \returns number of bytes parsed; negative on error */ +int gsm0808_dec_cell_id_list2(struct gsm0808_cell_id_list2 *cil, + const uint8_t *elem, uint8_t len) +{ + uint8_t id_discr; + size_t bytes_elem = 0; + int list_len = 0; + + OSMO_ASSERT(cil); + if (!elem) + return -EINVAL; + if (len == 0) + return -EINVAL; + + memset(cil, 0, sizeof(*cil)); + + id_discr = *elem & 0x0f; + elem++; + len--; + + switch (id_discr) { + case CELL_IDENT_WHOLE_GLOBAL: + list_len = parse_cell_id_global_list(&cil->id_list[0].global, elem, len, &bytes_elem); + break; + case CELL_IDENT_LAC_AND_CI: + list_len = parse_cell_id_lac_and_ci_list(&cil->id_list[0].lac_and_ci, elem, len, &bytes_elem); + break; + case CELL_IDENT_CI: + list_len = parse_cell_id_ci_list(&cil->id_list[0].ci, elem, len, &bytes_elem); + break; + case CELL_IDENT_LAI_AND_LAC: + list_len = parse_cell_id_lai_and_lac(&cil->id_list[0].lai_and_lac, elem, len, &bytes_elem); + break; + case CELL_IDENT_LAC: + list_len = parse_cell_id_lac_list(&cil->id_list[0].lac, elem, len, &bytes_elem); + break; + case CELL_IDENT_BSS: + case CELL_IDENT_NO_CELL: + /* Does not have any list items */ + break; + default: + /* Remaining cell identification types are not implemented. */ + return -EINVAL; + } + + if (list_len < 0) /* parsing error */ + return list_len; + + cil->id_discr = id_discr; + cil->id_list_len = list_len; + + /* One byte for the cell ID discriminator + any remaining bytes in + * the IE which were consumed by the parser functions above. */ + return 1 + (int)bytes_elem; +} + +/*! DEPRECATED: Use gsm0808_dec_cell_id_list2 instead. + * + * Decode Cell Identifier List IE + * \param[out] cil Caller-provided memory to store Cell ID list + * \param[in] elem IE value to be decoded + * \param[in] len Length of \a elem in bytes + * \returns number of bytes parsed; negative on error */ int gsm0808_dec_cell_id_list(struct gsm0808_cell_id_list *cil, const uint8_t *elem, uint8_t len) { diff --git a/src/gsm/libosmogsm.map b/src/gsm/libosmogsm.map index b9035041..36a77129 100644 --- a/src/gsm/libosmogsm.map +++ b/src/gsm/libosmogsm.map @@ -151,6 +151,7 @@ gsm0808_create_clear_command; gsm0808_create_clear_complete; gsm0808_create_clear_rqst; gsm0808_create_paging; +gsm0808_create_paging2; gsm0808_create_dtap; gsm0808_create_layer3; gsm0808_create_layer3_aoip; @@ -170,7 +171,9 @@ gsm0808_dec_channel_type; gsm0808_enc_encrypt_info; gsm0808_dec_encrypt_info; gsm0808_enc_cell_id_list; +gsm0808_enc_cell_id_list2; gsm0808_dec_cell_id_list; +gsm0808_dec_cell_id_list2; gsm0808_chan_type_to_speech_codec; gsm0808_speech_codec_from_chan_type; gsm0808_speech_codec_type_names; -- cgit v1.2.3