diff options
Diffstat (limited to 'proto_ipv6_hop_by_hop.c')
| -rw-r--r-- | proto_ipv6_hop_by_hop.c | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/proto_ipv6_hop_by_hop.c b/proto_ipv6_hop_by_hop.c new file mode 100644 index 0000000..b0c5a0d --- /dev/null +++ b/proto_ipv6_hop_by_hop.c @@ -0,0 +1,100 @@ +/* + * netsniff-ng - the packet sniffing beast + * Copyright 2012 Markus Amend <markus@netsniff-ng.org>, Deutsche Flugsicherung GmbH + * Subject to the GPL, version 2. + * + * IPv6 Hop-By-Hop Header described in RFC2460 + */ + +#include <stdio.h> +#include <stdint.h> +#include <netinet/in.h> /* for ntohs() */ + +#include "proto.h" +#include "protos.h" +#include "dissector_eth.h" +#include "built_in.h" +#include "pkt_buff.h" + +struct hop_by_hophdr { + uint8_t h_next_header; + uint8_t hdr_len; +} __packed; + +static void dissect_opt_hop (struct pkt_buff *pkt, ssize_t *opt_len) +{ + /* Have to been upgraded. + * http://tools.ietf.org/html/rfc2460#section-4.2 + * Look also for proto_ipv6_dest_opts.h, it needs + * dissect_opt(), too. + */ + if (*opt_len) + tprintf(", Option(s) recognized "); + + /* If adding dissector reduce opt_len for each using of pkt_pull + * to the same size. + */ +} + +static void hop_by_hop(struct pkt_buff *pkt) +{ + uint16_t hdr_ext_len; + ssize_t opt_len; + struct hop_by_hophdr *hop_ops; + + hop_ops = (struct hop_by_hophdr *) pkt_pull(pkt, sizeof(*hop_ops)); + if (hop_ops == NULL) + return; + + /* Total Header Length in Bytes */ + hdr_ext_len = (hop_ops->hdr_len + 1) * 8; + /* Options length in Bytes */ + opt_len = hdr_ext_len - sizeof(*hop_ops); + + tprintf("\t [ Hop-by-Hop Options "); + tprintf("NextHdr (%u), ", hop_ops->h_next_header); + if (opt_len > pkt_len(pkt) || opt_len < 0){ + tprintf("HdrExtLen (%u, %u Bytes, %s)", hop_ops->hdr_len, + hdr_ext_len, colorize_start_full(black, red) + "invalid" colorize_end()); + return; + } + tprintf("HdrExtLen (%u, %u Bytes)", hop_ops->hdr_len, + hdr_ext_len); + + dissect_opt_hop(pkt, &opt_len); + + tprintf(" ]\n"); + + pkt_pull(pkt, opt_len); + pkt_set_proto(pkt, ð_lay3, hop_ops->h_next_header); +} + +static void hop_by_hop_less(struct pkt_buff *pkt) +{ + uint16_t hdr_ext_len; + ssize_t opt_len; + struct hop_by_hophdr *hop_ops; + + hop_ops = (struct hop_by_hophdr *) pkt_pull(pkt, sizeof(*hop_ops)); + if (hop_ops == NULL) + return; + + /* Total Header Length in Bytes */ + hdr_ext_len = (hop_ops->hdr_len + 1) * 8; + /* Options length in Bytes */ + opt_len = hdr_ext_len - sizeof(*hop_ops); + if (opt_len > pkt_len(pkt) || opt_len < 0) + return; + + tprintf(" Hop Ops"); + + pkt_pull(pkt, opt_len); + pkt_set_proto(pkt, ð_lay3, hop_ops->h_next_header); +} + +struct protocol ipv6_hop_by_hop_ops = { + .key = 0x0, + .print_full = hop_by_hop, + .print_less = hop_by_hop_less, +}; |