doc: add doxygen comment for parse_packet()

Author: cejkato2

input/parser.hpp

@@ -66,6 +66,23 @@ typedef struct parser_opt_s {
    int datalink;
 } parser_opt_t;
 
+/**
+ * \brief Parse one packet and update output metadata in `opt`, and statistics in `stats`.
+ *
+ * The function updates the metadata (using `opt->pblock->cnt` index) when the
+ * packet is successfully parsed.  On error, the packet metadata at
+ * `opt->pblock->cnt` index are invalid and the index points to the same place.
+ * The caller must ensure `opt->pblock->size` is higher the `opt->pblock->cnt`;
+ * this is checked and in case of no free space, `parse_packet()` returns
+ * without any action.
+
+ * \param [out] opt Pointer to the structure with an output list of parsed packet metadata.
+ * \param [out] stats Structure with the ipfixprobe statistics counters.
+ * \param [in] ts Timestamp of the current packet
+ * \param [in] data  Input data, i.e., pointer to beginning of the packet header.
+ * \param [in] len   Original size of the packet to process.
+ * \param [in] caplen   Capture length - actual size of the packet, i.e., number of bytes that are available in data.
+ */
 void parse_packet(parser_opt_t *opt, ParserStats& stats, struct timeval ts, const uint8_t *data, uint16_t len, uint16_t caplen);
 
 }