diff options
Diffstat (limited to 'tap.c')
| -rw-r--r-- | tap.c | 52 |
1 files changed, 52 insertions, 0 deletions
@@ -879,6 +879,58 @@ append: return in->count; } +#define IPV6_NH_OPT(nh) \ + ((nh) == 0 || (nh) == 43 || (nh) == 44 || (nh) == 50 || \ + (nh) == 51 || (nh) == 60 || (nh) == 135 || (nh) == 139 || \ + (nh) == 140 || (nh) == 253 || (nh) == 254) + +/** + * ipv6_l4hdr() - Find pointer to L4 header in IPv6 packet and extract protocol + * @data: IPv6 packet + * @proto: Filled with L4 protocol number + * @dlen: Data length (payload excluding header extensions), set on return + * + * Return: true if the L4 header is found and @data, @proto, @dlen are set, + * false on error. Outputs are indeterminate on failure. + */ +static bool ipv6_l4hdr(struct iov_tail *data, uint8_t *proto, size_t *dlen) +{ + struct ipv6_opt_hdr o_storage; + const struct ipv6_opt_hdr *o; + struct ipv6hdr ip6h_storage; + const struct ipv6hdr *ip6h; + int hdrlen; + uint8_t nh; + + ip6h = IOV_REMOVE_HEADER(data, ip6h_storage); + if (!ip6h) + return false; + + nh = ip6h->nexthdr; + if (!IPV6_NH_OPT(nh)) + goto found; + + while ((o = IOV_PEEK_HEADER(data, o_storage))) { + nh = o->nexthdr; + hdrlen = (o->hdrlen + 1) * 8; + + if (IPV6_NH_OPT(nh)) + iov_drop_header(data, hdrlen); + else + goto found; + } + + return false; + +found: + if (nh == IPPROTO_NONE) + return false; + + *dlen = iov_tail_size(data); + *proto = nh; + return true; +} + /** * tap6_handler() - IPv6 packet handler for tap file descriptor * @c: Execution context |