diff options
| -rw-r--r-- | include/osmocom/gsm/gsm0480.h | 2 | ||||
| -rw-r--r-- | src/gsm/gsm0480.c | 88 | ||||
| -rw-r--r-- | src/gsm/libosmogsm.map | 1 | ||||
| -rw-r--r-- | tests/ussd/ussd_test.c | 75 | ||||
| -rw-r--r-- | tests/ussd/ussd_test.ok | 6 |
5 files changed, 172 insertions, 0 deletions
diff --git a/include/osmocom/gsm/gsm0480.h b/include/osmocom/gsm/gsm0480.h index b0b6aa29..b31f8a71 100644 --- a/include/osmocom/gsm/gsm0480.h +++ b/include/osmocom/gsm/gsm0480.h @@ -91,6 +91,8 @@ struct ss_request { uint8_t invoke_id; }; +int gsm0480_extract_ie_by_tag(const struct gsm48_hdr *hdr, uint16_t msg_len, + uint8_t **ie, uint16_t *ie_len, uint8_t ie_tag); int gsm0480_decode_ss_request(const struct gsm48_hdr *hdr, uint16_t len, struct ss_request *request); diff --git a/src/gsm/gsm0480.c b/src/gsm/gsm0480.c index 5c73e5b8..dfd98773 100644 --- a/src/gsm/gsm0480.c +++ b/src/gsm/gsm0480.c @@ -33,6 +33,7 @@ #include <osmocom/gsm/protocol/gsm_04_80.h> #include <string.h> +#include <errno.h> static inline unsigned char *msgb_wrap_with_TL(struct msgb *msgb, uint8_t tag) { @@ -214,6 +215,93 @@ static int parse_ss_for_bs_req(const uint8_t *ss_req_data, uint16_t length, struct ss_request *req); +/*! Get pointer to the IE of a given type + * \param[in] hdr Pointer to the message starting from header + * \param[in] msg_len Length of the whole message + header + * \param[out] ie External pointer to be set + * \param[out] ie_len External IE length variable + * \param[in] ie_tag Tag value of the required IE + * \returns 0 in case of success, otherwise -ERRNO + * + * This function iterates over existing IEs within a given + * message (depending on its type), and looks for the one with + * given \ref ie_tag value. If the IE is found, the external + * pointer pointed by \ref ie will be set to its value part + * (omitting TL), and \ref ie_len will be set to the length. + * Otherwise, e.g. in case of parsing error, both \ref ie + * and \ref ie_len are set to NULL and 0 respectively. + */ +int gsm0480_extract_ie_by_tag(const struct gsm48_hdr *hdr, uint16_t msg_len, + uint8_t **ie, uint16_t *ie_len, uint8_t ie_tag) +{ + uint8_t pdisc, msg_type; + uint8_t *tlv, len; + + /* Init external variables */ + *ie_len = 0; + *ie = NULL; + + /* Drop incomplete / corrupted messages */ + if (msg_len < sizeof(*hdr)) + return -EINVAL; + + pdisc = gsm48_hdr_pdisc(hdr); + msg_type = gsm48_hdr_msg_type(hdr); + + /* Drop non-SS related messages */ + if (pdisc != GSM48_PDISC_NC_SS) + return -EINVAL; + + len = msg_len - sizeof(*hdr); + tlv = (uint8_t *) hdr->data; + + /* Parse a message depending on its type */ + switch (msg_type) { + /* See table 2.5: RELEASE COMPLETE message content */ + case GSM0480_MTYPE_RELEASE_COMPLETE: + /* See tables 2.3 and 2.4: REGISTER message content */ + case GSM0480_MTYPE_REGISTER: + /* Iterate over TLV-based IEs */ + while (len > 2) { + if (tlv[0] == ie_tag) { + *ie_len = tlv[1]; + *ie = tlv + 2; + return 0; + } + + len -= tlv[1] + 2; + tlv += tlv[1] + 2; + continue; + } + + /* The Facility IE is mandatory for REGISTER */ + if (msg_type == GSM0480_MTYPE_REGISTER) + if (ie_tag == GSM0480_IE_FACILITY) + return -EINVAL; + break; + + /* See table 2.2: FACILITY message content */ + case GSM0480_MTYPE_FACILITY: + /* There is no other IEs */ + if (ie_tag != GSM0480_IE_FACILITY) + break; + + /* Mandatory LV-based Facility IE */ + if (len < 2) + return -EINVAL; + + *ie_len = tlv[0]; + *ie = tlv + 1; + return 0; + + default: + /* Wrong message type, out of specs */ + return -EINVAL; + } + + return 0; +} + /* Decode a mobile-originated USSD-request message */ int gsm0480_decode_ussd_request(const struct gsm48_hdr *hdr, uint16_t len, struct ussd_request *req) diff --git a/src/gsm/libosmogsm.map b/src/gsm/libosmogsm.map index 117cecfa..4aaed46e 100644 --- a/src/gsm/libosmogsm.map +++ b/src/gsm/libosmogsm.map @@ -89,6 +89,7 @@ gsm0480_create_unstructuredSS_Notify; gsm0480_create_ussd_resp; gsm0480_create_ussd_notify; gsm0480_create_ussd_release_complete; +gsm0480_extract_ie_by_tag; gsm0480_decode_ussd_request; gsm0480_decode_ss_request; gsm0480_wrap_facility; diff --git a/tests/ussd/ussd_test.c b/tests/ussd/ussd_test.c index 1f79063b..23fd7393 100644 --- a/tests/ussd/ussd_test.c +++ b/tests/ussd/ussd_test.c @@ -34,6 +34,17 @@ static const uint8_t ussd_request[] = { 0x01, 0x7f, 0x01, 0x00 }; +static const uint8_t ussd_facility[] = { + 0x1b, 0x3a, 0x12, 0xa2, 0x10, 0x02, 0x01, 0x01, + 0x30, 0x0b, 0x02, 0x01, 0x3c, 0x30, 0x06, 0x04, + 0x01, 0x0f, 0x04, 0x01, 0x32 +}; + +static const uint8_t ussd_release[] = { + 0x8b, 0x2a, 0x1c, 0x08, 0xa3, 0x06, 0x02, 0x01, + 0x05, 0x02, 0x01, 0x24 +}; + static const uint8_t interrogate_ss[] = { 0x0b, 0x7b, 0x1c, 0x0d, 0xa1, 0x0b, 0x02, 0x01, 0x03, 0x02, 0x01, 0x0e, 0x30, 0x03, 0x04, 0x01, @@ -116,6 +127,67 @@ static void test_7bit_ussd(const char *text, const char *encoded_hex, const char } } +static void test_extract_ie_by_tag(void) +{ + uint16_t ie_len; + uint8_t *ie; + int rc; + + printf("[i] Testing gsm0480_extract_ie_by_tag()\n"); + + /* REGISTER message with Facility IE */ + rc = gsm0480_extract_ie_by_tag((struct gsm48_hdr *) ussd_request, + sizeof(ussd_request), &ie, &ie_len, GSM0480_IE_FACILITY); + OSMO_ASSERT(rc == 0); + OSMO_ASSERT(ie != NULL && ie_len > 0); + printf("[?] REGISTER message with Facility IE " + "(len=%u): %s\n", ie_len, osmo_hexdump(ie, ie_len)); + + /* REGISTER message with SS version IE */ + rc = gsm0480_extract_ie_by_tag((struct gsm48_hdr *) ussd_request, + sizeof(ussd_request), &ie, &ie_len, GSM0480_IE_SS_VERSION); + OSMO_ASSERT(rc == 0); + OSMO_ASSERT(ie != NULL && ie_len > 0); + printf("[?] REGISTER message with SS version IE " + "(len=%u): %s\n", ie_len, osmo_hexdump(ie, ie_len)); + + /* REGISTER message with unknown IE */ + rc = gsm0480_extract_ie_by_tag((struct gsm48_hdr *) ussd_request, + sizeof(ussd_request), &ie, &ie_len, 0xff); + OSMO_ASSERT(rc == 0); + OSMO_ASSERT(ie == NULL && ie_len == 0); + + /* FACILITY message with Facility IE */ + rc = gsm0480_extract_ie_by_tag((struct gsm48_hdr *) ussd_facility, + sizeof(ussd_facility), &ie, &ie_len, GSM0480_IE_FACILITY); + OSMO_ASSERT(rc == 0); + OSMO_ASSERT(ie != NULL && ie_len > 0); + printf("[?] FACILITY message with Facility IE " + "(len=%u): %s\n", ie_len, osmo_hexdump(ie, ie_len)); + + /* FACILITY message with unknown IE */ + rc = gsm0480_extract_ie_by_tag((struct gsm48_hdr *) ussd_facility, + sizeof(ussd_facility), &ie, &ie_len, 0xff); + OSMO_ASSERT(rc == 0); + OSMO_ASSERT(ie == NULL && ie_len == 0); + + /* RELEASE COMPLETE message with Facility IE */ + rc = gsm0480_extract_ie_by_tag((struct gsm48_hdr *) ussd_release, + sizeof(ussd_release), &ie, &ie_len, GSM0480_IE_FACILITY); + OSMO_ASSERT(rc == 0); + OSMO_ASSERT(ie != NULL && ie_len > 0); + printf("[?] RELEASE COMPLETE message with Facility IE " + "(len=%u): %s\n", ie_len, osmo_hexdump(ie, ie_len)); + + /* RELEASE COMPLETE message without Facility IE */ + rc = gsm0480_extract_ie_by_tag((struct gsm48_hdr *) ussd_release, + sizeof(struct gsm48_hdr), &ie, &ie_len, GSM0480_IE_FACILITY); + OSMO_ASSERT(rc == 0); + OSMO_ASSERT(ie == NULL && ie_len == 0); + + printf("\n"); +} + int main(int argc, char **argv) { struct ss_request req; @@ -126,6 +198,9 @@ int main(int argc, char **argv) osmo_init_logging2(ctx, &info); + /* Test gsm0480_extract_ie_by_tag() */ + test_extract_ie_by_tag(); + memset(&req, 0, sizeof(req)); gsm0480_decode_ss_request((struct gsm48_hdr *) ussd_request, sizeof(ussd_request), &req); diff --git a/tests/ussd/ussd_test.ok b/tests/ussd/ussd_test.ok index aff383eb..8fa4348f 100644 --- a/tests/ussd/ussd_test.ok +++ b/tests/ussd/ussd_test.ok @@ -1,3 +1,9 @@ +[i] Testing gsm0480_extract_ie_by_tag() +[?] REGISTER message with Facility IE (len=21): a1 13 02 01 03 02 01 3b 30 0b 04 01 0f 04 06 2a d5 4c 16 1b 01 +[?] REGISTER message with SS version IE (len=1): 00 +[?] FACILITY message with Facility IE (len=18): a2 10 02 01 01 30 0b 02 01 3c 30 06 04 01 0f 04 01 32 +[?] RELEASE COMPLETE message with Facility IE (len=8): a3 06 02 01 05 02 01 24 + Tested if it still works. Text was: **321# interrogateSS CFU text..'' code 33 Testing parsing a USSD request and truncated versions |