-/* Compute flow hash. We'll use it to select which Sponge to use for this
- flow. And other things. */
-always_inline u32
-ip6_compute_flow_hash (const ip6_header_t * ip,
- flow_hash_config_t flow_hash_config)
-{
- tcp_header_t *tcp;
- u64 a, b, c;
- u64 t1, t2;
- uword is_tcp_udp = 0;
- u8 protocol = ip->protocol;
-
- if (PREDICT_TRUE
- ((ip->protocol == IP_PROTOCOL_TCP)
- || (ip->protocol == IP_PROTOCOL_UDP)))
- {
- is_tcp_udp = 1;
- tcp = (void *) (ip + 1);
- }
- else if (ip->protocol == IP_PROTOCOL_IP6_HOP_BY_HOP_OPTIONS)
- {
- ip6_hop_by_hop_header_t *hbh = (ip6_hop_by_hop_header_t *) (ip + 1);
- if ((hbh->protocol == IP_PROTOCOL_TCP) ||
- (hbh->protocol == IP_PROTOCOL_UDP))
- {
- is_tcp_udp = 1;
- tcp = (tcp_header_t *) ((u8 *) hbh + ((hbh->length + 1) << 3));
- }
- protocol = hbh->protocol;
- }
-
- t1 = (ip->src_address.as_u64[0] ^ ip->src_address.as_u64[1]);
- t1 = (flow_hash_config & IP_FLOW_HASH_SRC_ADDR) ? t1 : 0;
-
- t2 = (ip->dst_address.as_u64[0] ^ ip->dst_address.as_u64[1]);
- t2 = (flow_hash_config & IP_FLOW_HASH_DST_ADDR) ? t2 : 0;
-
- a = (flow_hash_config & IP_FLOW_HASH_REVERSE_SRC_DST) ? t2 : t1;
- b = (flow_hash_config & IP_FLOW_HASH_REVERSE_SRC_DST) ? t1 : t2;
- b ^= (flow_hash_config & IP_FLOW_HASH_PROTO) ? protocol : 0;
-
- t1 = is_tcp_udp ? tcp->src : 0;
- t2 = is_tcp_udp ? tcp->dst : 0;
-
- t1 = (flow_hash_config & IP_FLOW_HASH_SRC_PORT) ? t1 : 0;
- t2 = (flow_hash_config & IP_FLOW_HASH_DST_PORT) ? t2 : 0;
-
- c = (flow_hash_config & IP_FLOW_HASH_REVERSE_SRC_DST) ?
- ((t1 << 16) | t2) : ((t2 << 16) | t1);
-
- hash_mix64 (a, b, c);
- return (u32) c;
-}
-
-/* ip6_locate_header
- *
- * This function is to search for the header specified by the protocol number
- * in find_hdr_type.
- * This is used to locate a specific IPv6 extension header
- * or to find transport layer header.
- * 1. If the find_hdr_type < 0 then it finds and returns the protocol number and
- * offset stored in *offset of the transport or ESP header in the chain if
- * found.
- * 2. If a header with find_hdr_type > 0 protocol number is found then the
- * offset is stored in *offset and protocol number of the header is
- * returned.
- * 3. If find_hdr_type is not found or packet is malformed or
- * it is a non-first fragment -1 is returned.
- */
-always_inline int
-ip6_locate_header (vlib_buffer_t * p0,
- ip6_header_t * ip0, int find_hdr_type, u32 * offset)
-{
- u8 next_proto = ip0->protocol;
- u8 *next_header;
- u8 done = 0;
- u32 cur_offset;
- u8 *temp_nxthdr = 0;
- u32 exthdr_len = 0;
-
- next_header = ip6_next_header (ip0);
- cur_offset = sizeof (ip6_header_t);
- while (1)
- {
- done = (next_proto == find_hdr_type);
- if (PREDICT_FALSE
- (next_header >=
- (u8 *) vlib_buffer_get_current (p0) + p0->current_length))
- {
- //A malicious packet could set an extension header with a too big size
- return (-1);
- }
- if (done)
- break;
- if ((!ip6_ext_hdr (next_proto)) || next_proto == IP_PROTOCOL_IP6_NONXT)
- {
- if (find_hdr_type < 0)
- break;
- return -1;
- }
- if (next_proto == IP_PROTOCOL_IPV6_FRAGMENTATION)
- {
- ip6_frag_hdr_t *frag_hdr = (ip6_frag_hdr_t *) next_header;
- u16 frag_off = ip6_frag_hdr_offset (frag_hdr);
- /* Non first fragment return -1 */
- if (frag_off)
- return (-1);
- exthdr_len = sizeof (ip6_frag_hdr_t);
- temp_nxthdr = next_header + exthdr_len;
- }
- else if (next_proto == IP_PROTOCOL_IPSEC_AH)
- {
- exthdr_len =
- ip6_ext_authhdr_len (((ip6_ext_header_t *) next_header));
- temp_nxthdr = next_header + exthdr_len;
- }
- else
- {
- exthdr_len =
- ip6_ext_header_len (((ip6_ext_header_t *) next_header));
- temp_nxthdr = next_header + exthdr_len;
- }
- next_proto = ((ip6_ext_header_t *) next_header)->next_hdr;
- next_header = temp_nxthdr;
- cur_offset += exthdr_len;
- }
-
- *offset = cur_offset;
- return (next_proto);
-}
-