diff options
| -rw-r--r-- | include/osmocom/gsm/tlv.h | 50 | ||||
| -rw-r--r-- | src/gsm/libosmogsm.map | 5 | ||||
| -rw-r--r-- | src/gsm/tlv_parser.c | 105 |
3 files changed, 159 insertions, 1 deletions
diff --git a/include/osmocom/gsm/tlv.h b/include/osmocom/gsm/tlv.h index 254c21bc..a307b3de 100644 --- a/include/osmocom/gsm/tlv.h +++ b/include/osmocom/gsm/tlv.h @@ -620,4 +620,54 @@ int osmo_match_shift_tlv(uint8_t **data, size_t *data_len, int osmo_shift_lv(uint8_t **data, size_t *data_len, uint8_t **value, size_t *value_len); +#define MSG_DEF(name, mand_ies, flags) { name, mand_ies, ARRAY_SIZE(mand_ies), flags } + +struct osmo_tlv_prot_msg_def { + /*! human-readable name of message type (optional) */ + const char *name; + /*! array of mandatory IEs */ + const uint8_t *mand_ies; + /*! number of entries in 'mand_ies' above */ + uint8_t mand_count; + /*! user-defined flags (like uplink/downlink/...) */ + uint32_t flags; +}; +struct osmo_tlv_prot_ie_def { + /*! minimum length of IE value part, in octets */ + uint16_t min_len; + /*! huamn-readable name (optional) */ + const char *name; +}; + +/*! Osmocom TLV protocol definition */ +struct osmo_tlv_prot_def { + /*! human-readable name of protocol */ + const char *name; + /*! TLV parser definition (optional) */ + const struct tlv_definition *tlv_def; + /*! definition of each message (8-bit message type) */ + struct osmo_tlv_prot_msg_def msg_def[256]; + /*! definition of IE for each 8-bit tag */ + struct osmo_tlv_prot_ie_def ie_def[256]; + /*! value_string array of message type names (legacy, if not populated in msg_def) */ + const struct value_string *msgt_names; +}; + +const char *osmo_tlv_prot_msg_name(const struct osmo_tlv_prot_def *pdef, uint8_t msg_type); +const char *osmo_tlv_prot_ie_name(const struct osmo_tlv_prot_def *pdef, uint8_t iei); + +int osmo_tlv_prot_validate_tp(const struct osmo_tlv_prot_def *pdef, uint8_t msg_type, + const struct tlv_parsed *tp, int log_subsys, const char *log_pfx); + +int osmo_tlv_prot_parse(const struct osmo_tlv_prot_def *pdef, + struct tlv_parsed *dec, unsigned int dec_multiples, uint8_t msg_type, + const uint8_t *buf, unsigned int buf_len, uint8_t lv_tag, uint8_t lv_tag2, + int log_subsys, const char *log_pfx); + +static inline uint32_t osmo_tlv_prot_msgt_flags(const struct osmo_tlv_prot_def *pdef, uint8_t msg_type) +{ + return pdef->msg_def[msg_type].flags; +} + + /*! @} */ diff --git a/src/gsm/libosmogsm.map b/src/gsm/libosmogsm.map index f339120c..bcded1ce 100644 --- a/src/gsm/libosmogsm.map +++ b/src/gsm/libosmogsm.map @@ -580,6 +580,11 @@ osmo_shift_tlv; osmo_match_shift_tlv; osmo_shift_lv; +osmo_tlv_prot_msg_name; +osmo_tlv_prot_ie_name; +osmo_tlv_prot_validate_tp; +osmo_tlv_prot_parse; + gan_msgt_vals; gan_pdisc_vals; diff --git a/src/gsm/tlv_parser.c b/src/gsm/tlv_parser.c index 159b42bd..24edd0cf 100644 --- a/src/gsm/tlv_parser.c +++ b/src/gsm/tlv_parser.c @@ -1,4 +1,4 @@ -/* (C) 2008-2017 by Harald Welte <laforge@gnumonks.org> +/* (C) 2008-2020 by Harald Welte <laforge@gnumonks.org> * (C) 2016-2017 by sysmocom - s.f.m.c. GmbH * * All Rights Reserved @@ -24,6 +24,7 @@ #include <stdint.h> #include <errno.h> #include <osmocom/core/utils.h> +#include <osmocom/core/logging.h> #include <osmocom/gsm/tlv.h> /*! \addtogroup tlv @@ -627,4 +628,106 @@ fail: return -1; } +static __thread char ienamebuf[32]; +static __thread char msgnamebuf[32]; + +/*! get the message name for given msg_type in protocol pdef */ +const char *osmo_tlv_prot_msg_name(const struct osmo_tlv_prot_def *pdef, uint8_t msg_type) +{ + if (pdef->msg_def[msg_type].name) { + return pdef->msg_def[msg_type].name; + } else if (pdef->msgt_names) { + return get_value_string(pdef->msgt_names, msg_type); + } else { + snprintf(msgnamebuf, sizeof(msgnamebuf), "Unknown msg_type 0x%02x", msg_type); + return msgnamebuf; + } +} + +/*! get the IE name for given IEI in protocol pdef */ +const char *osmo_tlv_prot_ie_name(const struct osmo_tlv_prot_def *pdef, uint8_t iei) +{ + if (pdef->ie_def[iei].name) { + return pdef->ie_def[iei].name; + } else { + snprintf(ienamebuf, sizeof(ienamebuf), "Unknown IEI 0x%02x", iei); + return ienamebuf; + } +} + +/*! Validate an already TLV-decoded message against the protocol definition. + * \param[in] pdef protocol definition of given protocol + * \param[in] msg_type message type of the parsed message + * \param[in] tp TLV parser result + * \param[in] log_subsys logging sub-system for log messages + * \param[in] log_pfx prefix for log messages + * \returns 0 in case of success; negative osmo_tlv_parser_error in case of error + */ +int osmo_tlv_prot_validate_tp(const struct osmo_tlv_prot_def *pdef, uint8_t msg_type, + const struct tlv_parsed *tp, int log_subsys, const char *log_pfx) +{ + const struct osmo_tlv_prot_msg_def *msg_def= &pdef->msg_def[msg_type]; + unsigned int num_err = 0; + unsigned int i; + + if (msg_def->mand_ies) { + for (i = 0; i < msg_def->mand_count; i++) { + uint8_t iei = msg_def->mand_ies[i]; + if (!TLVP_PRESENT(tp, iei)) { + LOGP(log_subsys, LOGL_ERROR, "%s %s %s: Missing Mandatory IE: %s\n", + log_pfx, pdef->name, osmo_tlv_prot_msg_name(pdef, msg_type), + osmo_tlv_prot_ie_name(pdef, iei)); + num_err++; + } + } + } + + for (i = 0; i < ARRAY_SIZE(tp->lv); i++) { + uint16_t min_len; + + if (!TLVP_PRESENT(tp, i)) + continue; + + min_len = pdef->ie_def[i].min_len; + if (TLVP_LEN(tp, i) < min_len) { + LOGP(log_subsys, LOGL_ERROR, "%s %s %s: Short IE %s: %u < %u\n", log_pfx, + pdef->name, osmo_tlv_prot_msg_name(pdef, msg_type), + osmo_tlv_prot_ie_name(pdef, i), TLVP_LEN(tp, i), min_len); + num_err++; + } + } + + return -num_err; +} + +/*! Parse + Validate a TLV-encoded message against the protocol definition. + * \param[in] pdef protocol definition of given protocol + * \param[out] dec caller-allocated pointer to \ref tlv_parsed + * \param[in] dec_multiples length of the tlv_parsed[] in \a dec. + * \param[in] msg_type message type of the parsed message + * \param[in] buf the input data buffer to be parsed + * \param[in] buf_len length of the input data buffer + * \param[in] lv_tag an initial LV tag at the start of the buffer + * \param[in] lv_tag2 a second initial LV tag following the \a lv_tag + * \param[in] log_subsys logging sub-system for log messages + * \param[in] log_pfx prefix for log messages + * \returns 0 in case of success; negative osmo_tlv_parser_error in case of error + */ +int osmo_tlv_prot_parse(const struct osmo_tlv_prot_def *pdef, + struct tlv_parsed *dec, unsigned int dec_multiples, uint8_t msg_type, + const uint8_t *buf, unsigned int buf_len, uint8_t lv_tag, uint8_t lv_tag2, + int log_subsys, const char *log_pfx) +{ + int rc; + + rc = tlv_parse2(dec, dec_multiples, pdef->tlv_def, buf, buf_len, lv_tag, lv_tag2); + if (rc < 0) { + LOGP(log_subsys, LOGL_ERROR, "%s %s %s: TLV parser error %d\n", log_pfx, + pdef->name, osmo_tlv_prot_msg_name(pdef, msg_type), rc); + return rc; + } + + return osmo_tlv_prot_validate_tp(pdef, msg_type, dec, log_subsys, log_pfx); +} + /*! @} */ |