+
+ return s;
+}
+
+static snat_session_t *
+snat_in2out_lb (snat_main_t *sm,
+ vlib_buffer_t * b,
+ ip4_header_t * ip,
+ u32 rx_fib_index,
+ u32 thread_index,
+ f64 now,
+ vlib_main_t * vm,
+ vlib_node_runtime_t * node)
+{
+ nat_ed_ses_key_t key;
+ clib_bihash_kv_16_8_t s_kv, s_value;
+ udp_header_t *udp = ip4_next_header (ip);
+ tcp_header_t *tcp = (tcp_header_t *) udp;
+ snat_session_t *s = 0;
+ snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
+ u32 old_addr, new_addr;
+ u16 new_port, old_port;
+ ip_csum_t sum;
+ u32 proto = ip_proto_to_snat_proto (ip->protocol);
+ snat_session_key_t e_key, l_key;
+ clib_bihash_kv_8_8_t kv, value;
+ snat_user_key_t u_key;
+ snat_user_t *u;
+ dlist_elt_t *head, *elt;
+
+ old_addr = ip->src_address.as_u32;
+
+ key.l_addr = ip->src_address;
+ key.r_addr = ip->dst_address;
+ key.fib_index = rx_fib_index;
+ key.proto = ip->protocol;
+ key.rsvd = 0;
+ key.l_port = udp->src_port;
+ s_kv.key[0] = key.as_u64[0];
+ s_kv.key[1] = key.as_u64[1];
+
+ if (!clib_bihash_search_16_8 (&sm->in2out_ed, &s_kv, &s_value))
+ {
+ s = pool_elt_at_index (tsm->sessions, s_value.value);
+ }
+ else
+ {
+ if (PREDICT_FALSE (maximum_sessions_exceeded (sm, thread_index)))
+ {
+ b->error = node->errors[SNAT_IN2OUT_ERROR_MAX_SESSIONS_EXCEEDED];
+ return 0;
+ }
+
+ l_key.addr = ip->src_address;
+ l_key.port = udp->src_port;
+ l_key.protocol = proto;
+ l_key.fib_index = rx_fib_index;
+ if (snat_static_mapping_match(sm, l_key, &e_key, 0, 0))
+ return 0;
+
+ u_key.addr = ip->src_address;
+ u_key.fib_index = rx_fib_index;
+ kv.key = u_key.as_u64;
+
+ /* Ever heard of the "user" = src ip4 address before? */
+ if (clib_bihash_search_8_8 (&tsm->user_hash, &kv, &value))
+ {
+ /* no, make a new one */
+ pool_get (tsm->users, u);
+ memset (u, 0, sizeof (*u));
+ u->addr = ip->src_address;
+ u->fib_index = rx_fib_index;
+
+ pool_get (tsm->list_pool, head);
+ u->sessions_per_user_list_head_index = head - tsm->list_pool;
+
+ clib_dlist_init (tsm->list_pool,
+ u->sessions_per_user_list_head_index);
+
+ kv.value = u - tsm->users;
+
+ /* add user */
+ if (clib_bihash_add_del_8_8 (&tsm->user_hash, &kv, 1))
+ clib_warning ("user key add failed");
+ }
+ else
+ {
+ u = pool_elt_at_index (tsm->users, value.value);
+ }
+
+ /* Create a new session */
+ pool_get (tsm->sessions, s);
+ memset (s, 0, sizeof (*s));
+
+ s->ext_host_addr.as_u32 = ip->dst_address.as_u32;
+ s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
+ s->flags |= SNAT_SESSION_FLAG_LOAD_BALANCING;
+ s->outside_address_index = ~0;
+ s->in2out = l_key;
+ s->out2in = e_key;
+ u->nstaticsessions++;
+
+ /* Create list elts */
+ pool_get (tsm->list_pool, elt);
+ clib_dlist_init (tsm->list_pool, elt - tsm->list_pool);
+ elt->value = s - tsm->sessions;
+ s->per_user_index = elt - tsm->list_pool;
+ s->per_user_list_head_index = u->sessions_per_user_list_head_index;
+ clib_dlist_addtail (tsm->list_pool, s->per_user_list_head_index,
+ s->per_user_index);
+
+ /* Add to lookup tables */
+ s_kv.value = s - tsm->sessions;
+ if (clib_bihash_add_del_16_8 (&sm->in2out_ed, &s_kv, 1))
+ clib_warning ("in2out-ed key add failed");
+
+ key.l_addr = e_key.addr;
+ key.fib_index = e_key.fib_index;
+ key.l_port = e_key.port;
+ s_kv.key[0] = key.as_u64[0];
+ s_kv.key[1] = key.as_u64[1];
+ if (clib_bihash_add_del_16_8 (&sm->out2in_ed, &s_kv, 1))
+ clib_warning ("out2in-ed key add failed");
+ }
+
+ new_addr = ip->src_address.as_u32 = s->out2in.addr.as_u32;
+
+ /* Update IP checksum */
+ sum = ip->checksum;
+ sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, src_address);
+ ip->checksum = ip_csum_fold (sum);
+
+ if (PREDICT_TRUE(proto == SNAT_PROTOCOL_TCP))
+ {
+ old_port = tcp->src_port;
+ tcp->src_port = s->out2in.port;
+ new_port = tcp->src_port;
+
+ sum = tcp->checksum;
+ sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, src_address);
+ sum = ip_csum_update (sum, old_port, new_port, ip4_header_t, length);
+ tcp->checksum = ip_csum_fold(sum);
+ }
+ else
+ {
+ udp->src_port = s->out2in.port;
+ udp->checksum = 0;
+ }
+
+ if (vnet_buffer(b)->sw_if_index[VLIB_TX] == ~0)
+ vnet_buffer(b)->sw_if_index[VLIB_TX] = sm->outside_fib_index;
+
+ /* Accounting */
+ s->last_heard = now;
+ s->total_pkts++;
+ s->total_bytes += vlib_buffer_length_in_chain (vm, b);
+ return s;