On Thu, Jul 14, 2022 at 12:24:39PM +0300, Magnus Armholt wrote: > Strip the IEC62439-3 PRP trailer if it is present > to support PTP over PRP. > The implementation is very pedantic about > trailing bytes and will indicate bad message if the > PRP trailer bytes are present when parsing the PTP message.
> +static int has_prp_trailer(unsigned char *ptr, int cnt, int eth_hlen, int > *trailer_len) > +{ > + unsigned short suffix_id, lane_size_field, lsdu_size; > + struct ptp_header* hdr; > + int ptp_msg_len, trailer_start, padding_len; Just some minor coding style issues. Please order the declarations by length (reverse christmas tree) and write hdr as "*hdr" instead of "* hdr". > + /* try to parse like a PTP message to find out the message length */ > + if (cnt < sizeof(struct ptp_header)) > + return 0; > + > + hdr = (struct ptp_header*)ptr; "ptp_header *". > + lane_size_field = ntohs(*(unsigned short*)(ptr + (trailer_start + 2))); Unnecessary parenthesis around "trailer_start + 2". > + lsdu_size = (lane_size_field & 0x0FFF); Same here. > + if (lsdu_size != cnt) > + return 0; > + > + /* Verify the suffix */ > + suffix_id = ntohs(*(unsigned short*)(ptr + (trailer_start + 4))); And here. > + if (suffix_id == ETH_P_PRP) > + { > + *trailer_len = PRP_TRAILER_LEN + padding_len; > + return 1; Is it necessary to return the padding length here? If I understand it correctly it's not specific to PRP. It's just the original Ethernet minimum length of 64 plus 6 bytes for the trailer. If you remove the padding_len variable, the function can be simplified a bit. -- Miroslav Lichvar _______________________________________________ Linuxptp-devel mailing list Linuxptp-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxptp-devel