diff options
| -rw-r--r-- | include/osmocom/gsm/tlv.h | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/include/osmocom/gsm/tlv.h b/include/osmocom/gsm/tlv.h index 5bf4a87b..8654893b 100644 --- a/include/osmocom/gsm/tlv.h +++ b/include/osmocom/gsm/tlv.h @@ -90,13 +90,24 @@ static inline uint8_t *lv_put(uint8_t *buf, uint8_t len, return buf + len; } -/*! put (append) a TLV field */ +/*! Append a TLV field, a Tag-Length-Value field. + * \param[out] buf Location in a buffer to append TLV at. + * \param[in] tag Tag id to write. + * \param[in] len Length field to write and amount of bytes to append. + * \param[in] val Pointer to data to append, or NULL to append zero data. + * Always append tag and length. Append \a len bytes read from \a val. If val is NULL, append \a len zero + * bytes instead. If \a len is zero, do not append any data apart from tag and length. */ static inline uint8_t *tlv_put(uint8_t *buf, uint8_t tag, uint8_t len, const uint8_t *val) { *buf++ = tag; *buf++ = len; - memcpy(buf, val, len); + if (len) { + if (val) + memcpy(buf, val, len); + else + memset(buf, 0, len); + } return buf + len; } |