diff options
Diffstat (limited to 'src/plugins/nat/nat.c')
-rwxr-xr-x | src/plugins/nat/nat.c | 265 |
1 files changed, 240 insertions, 25 deletions
diff --git a/src/plugins/nat/nat.c b/src/plugins/nat/nat.c index c3583cabc21..d4c266a2b16 100755 --- a/src/plugins/nat/nat.c +++ b/src/plugins/nat/nat.c @@ -178,9 +178,27 @@ vlib_node_registration_t nat44_ed_classify_node; vlib_node_registration_t nat44_det_classify_node; vlib_node_registration_t nat44_handoff_classify_node; +#define foreach_nat44_classify_error \ +_(MAX_REASS, "Maximum reassemblies exceeded") \ +_(MAX_FRAG, "Maximum fragments per reassembly exceeded") + +typedef enum { +#define _(sym,str) NAT44_CLASSIFY_ERROR_##sym, + foreach_nat44_classify_error +#undef _ + NAT44_CLASSIFY_N_ERROR, +} nat44_classify_error_t; + +static char * nat44_classify_error_strings[] = { +#define _(sym,string) string, + foreach_nat44_classify_error +#undef _ +}; + typedef enum { NAT44_CLASSIFY_NEXT_IN2OUT, NAT44_CLASSIFY_NEXT_OUT2IN, + NAT44_CLASSIFY_NEXT_DROP, NAT44_CLASSIFY_N_NEXT, } nat44_classify_next_t; @@ -438,6 +456,7 @@ nat_ed_session_alloc (snat_main_t *sm, snat_user_t *u, u32 thread_index) typedef struct { u8 next_in2out; + u8 cached; } nat44_classify_trace_t; static u8 * format_nat44_classify_trace (u8 * s, va_list * args) @@ -447,9 +466,13 @@ static u8 * format_nat44_classify_trace (u8 * s, va_list * args) nat44_classify_trace_t *t = va_arg (*args, nat44_classify_trace_t *); char *next; - next = t->next_in2out ? "nat44-in2out" : "nat44-out2in"; - - s = format (s, "nat44-classify: next %s", next); + if (t->cached) + s = format (s, "nat44-classify: fragment cached"); + else + { + next = t->next_in2out ? "nat44-in2out" : "nat44-out2in"; + s = format (s, "nat44-classify: next %s", next); + } return s; } @@ -466,6 +489,8 @@ nat44_classify_node_fn_inline (vlib_main_t * vm, snat_static_mapping_t *m; u32 thread_index = vm->thread_index; snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index]; + u32 *fragments_to_drop = 0; + u32 *fragments_to_loopback = 0; from = vlib_frame_vector_args (frame); n_left_from = frame->n_vectors; @@ -489,6 +514,8 @@ nat44_classify_node_fn_inline (vlib_main_t * vm, clib_bihash_kv_8_8_t kv0, value0; clib_bihash_kv_16_8_t ed_kv0, ed_value0; udp_header_t *udp0; + nat_reass_ip4_t *reass0; + u8 cached0 = 0; /* speculatively enqueue b0 to the current next frame */ bi0 = from[0]; @@ -502,17 +529,102 @@ nat44_classify_node_fn_inline (vlib_main_t * vm, ip0 = vlib_buffer_get_current (b0); udp0 = ip4_next_header (ip0); - if (is_ed) + if (is_ed && ip0->protocol != IP_PROTOCOL_ICMP) { - sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX]; - rx_fib_index0 = - fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4, - sw_if_index0); - make_ed_kv (&ed_kv0, &ip0->src_address, &ip0->dst_address, - ip0->protocol, rx_fib_index0, udp0->src_port, - udp0->dst_port); - if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &ed_kv0, &ed_value0)) - goto enqueue0; + if (!ip4_is_fragment (ip0) || ip4_is_first_fragment (ip0)) + { + /* process leading fragment/whole packet (with L4 header) */ + sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX]; + rx_fib_index0 = + fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4, + sw_if_index0); + make_ed_kv (&ed_kv0, &ip0->src_address, &ip0->dst_address, + ip0->protocol, rx_fib_index0, udp0->src_port, + udp0->dst_port); + if (ip4_is_fragment (ip0)) + { + reass0 = nat_ip4_reass_find_or_create (ip0->src_address, + ip0->dst_address, + ip0->fragment_id, + ip0->protocol, + 1, + &fragments_to_drop); + if (PREDICT_FALSE (!reass0)) + { + next0 = NAT44_CLASSIFY_NEXT_DROP; + b0->error = node->errors[NAT44_CLASSIFY_ERROR_MAX_REASS]; + nat_log_notice ("maximum reassemblies exceeded"); + goto enqueue0; + } + if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &ed_kv0, + &ed_value0)) + { + /* session exists so classify as IN2OUT, + * save this information for future fragments and set + * past fragments to be looped over and reprocessed */ + reass0->sess_index = ed_value0.value; + reass0->classify_next = NAT_REASS_IP4_CLASSIFY_NEXT_IN2OUT; + nat_ip4_reass_get_frags (reass0, + &fragments_to_loopback); + goto enqueue0; + } + else + { + /* session doesn't exist so continue in the code, + * save this information for future fragments and set + * past fragments to be looped over and reprocessed */ + reass0->flags |= NAT_REASS_FLAG_CLASSIFY_ED_CONTINUE; + nat_ip4_reass_get_frags (reass0, + &fragments_to_loopback); + } + } + else + { + /* process whole packet */ + if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &ed_kv0, + &ed_value0)) + goto enqueue0; + /* session doesn't exist so continue in code */ + } + } + else + { + /* process non-first fragment */ + reass0 = nat_ip4_reass_find_or_create (ip0->src_address, + ip0->dst_address, + ip0->fragment_id, + ip0->protocol, + 1, + &fragments_to_drop); + if (PREDICT_FALSE (!reass0)) + { + next0 = NAT44_CLASSIFY_NEXT_DROP; + b0->error = node->errors[NAT44_CLASSIFY_ERROR_MAX_REASS]; + nat_log_notice ("maximum reassemblies exceeded"); + goto enqueue0; + } + /* check if first fragment has arrived */ + if (reass0->classify_next == NAT_REASS_IP4_CLASSIFY_NONE && + !(reass0->flags & NAT_REASS_FLAG_CLASSIFY_ED_CONTINUE)) + { + /* first fragment still hasn't arrived, cache this fragment */ + if (nat_ip4_reass_add_fragment (reass0, bi0, + &fragments_to_drop)) + { + b0->error = node->errors[NAT44_CLASSIFY_ERROR_MAX_FRAG]; + nat_log_notice ("maximum fragments per reassembly exceeded"); + next0 = NAT44_CLASSIFY_NEXT_DROP; + goto enqueue0; + } + cached0 = 1; + goto enqueue0; + } + if (reass0->classify_next == NAT_REASS_IP4_CLASSIFY_NEXT_IN2OUT) + goto enqueue0; + /* flag NAT_REASS_FLAG_CLASSIFY_ED_CONTINUE is set + * so keep the default next0 and continue in code to + * potentially find other classification for this packet */ + } } vec_foreach (ap, sm->addresses) @@ -531,21 +643,86 @@ nat44_classify_node_fn_inline (vlib_main_t * vm, m_key0.protocol = 0; m_key0.fib_index = 0; kv0.key = m_key0.as_u64; - if (!clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv0, &value0)) + /* try to classify the fragment based on IP header alone */ + if (!clib_bihash_search_8_8 (&sm->static_mapping_by_external, + &kv0, &value0)) { m = pool_elt_at_index (sm->static_mappings, value0.value); if (m->local_addr.as_u32 != m->external_addr.as_u32) next0 = NAT44_CLASSIFY_NEXT_OUT2IN; goto enqueue0; } - m_key0.port = clib_net_to_host_u16 (udp0->dst_port); - m_key0.protocol = ip_proto_to_snat_proto (ip0->protocol); - kv0.key = m_key0.as_u64; - if (!clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv0, &value0)) + if (!ip4_is_fragment (ip0) || ip4_is_first_fragment (ip0)) { - m = pool_elt_at_index (sm->static_mappings, value0.value); - if (m->local_addr.as_u32 != m->external_addr.as_u32) + /* process leading fragment/whole packet (with L4 header) */ + m_key0.port = clib_net_to_host_u16 (udp0->dst_port); + m_key0.protocol = ip_proto_to_snat_proto (ip0->protocol); + kv0.key = m_key0.as_u64; + if (!clib_bihash_search_8_8 (&sm->static_mapping_by_external, + &kv0, &value0)) + { + m = pool_elt_at_index (sm->static_mappings, value0.value); + if (m->local_addr.as_u32 != m->external_addr.as_u32) + next0 = NAT44_CLASSIFY_NEXT_OUT2IN; + } + if (ip4_is_fragment (ip0)) + { + reass0 = nat_ip4_reass_find_or_create (ip0->src_address, + ip0->dst_address, + ip0->fragment_id, + ip0->protocol, + 1, + &fragments_to_drop); + if (PREDICT_FALSE (!reass0)) + { + next0 = NAT44_CLASSIFY_NEXT_DROP; + b0->error = node->errors[NAT44_CLASSIFY_ERROR_MAX_REASS]; + nat_log_notice ("maximum reassemblies exceeded"); + goto enqueue0; + } + /* save classification for future fragments and set past + * fragments to be looped over and reprocessed */ + if (next0 == NAT44_CLASSIFY_NEXT_OUT2IN) + reass0->classify_next = NAT_REASS_IP4_CLASSIFY_NEXT_OUT2IN; + else + reass0->classify_next = NAT_REASS_IP4_CLASSIFY_NEXT_IN2OUT; + nat_ip4_reass_get_frags (reass0, &fragments_to_loopback); + } + } + else + { + /* process non-first fragment */ + reass0 = nat_ip4_reass_find_or_create (ip0->src_address, + ip0->dst_address, + ip0->fragment_id, + ip0->protocol, + 1, + &fragments_to_drop); + if (PREDICT_FALSE (!reass0)) + { + next0 = NAT44_CLASSIFY_NEXT_DROP; + b0->error = node->errors[NAT44_CLASSIFY_ERROR_MAX_REASS]; + nat_log_notice ("maximum reassemblies exceeded"); + goto enqueue0; + } + if (reass0->classify_next == NAT_REASS_IP4_CLASSIFY_NONE) + /* first fragment still hasn't arrived */ + { + if (nat_ip4_reass_add_fragment (reass0, bi0, + &fragments_to_drop)) + { + b0->error = node->errors[NAT44_CLASSIFY_ERROR_MAX_FRAG]; + nat_log_notice ("maximum fragments per reassembly exceeded"); + next0 = NAT44_CLASSIFY_NEXT_DROP; + goto enqueue0; + } + cached0 = 1; + goto enqueue0; + } + else if (reass0->classify_next == NAT_REASS_IP4_CLASSIFY_NEXT_OUT2IN) next0 = NAT44_CLASSIFY_NEXT_OUT2IN; + else if (reass0->classify_next == NAT_REASS_IP4_CLASSIFY_NEXT_IN2OUT) + next0 = NAT44_CLASSIFY_NEXT_IN2OUT; } } @@ -555,18 +732,50 @@ nat44_classify_node_fn_inline (vlib_main_t * vm, { nat44_classify_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t)); - t->next_in2out = next0 == NAT44_CLASSIFY_NEXT_IN2OUT ? 1 : 0; + t->cached = cached0; + if (!cached0) + t->next_in2out = next0 == NAT44_CLASSIFY_NEXT_IN2OUT ? 1 : 0; } - /* verify speculative enqueue, maybe switch current next frame */ - vlib_validate_buffer_enqueue_x1 (vm, node, next_index, - to_next, n_left_to_next, - bi0, next0); + if (cached0) + { + n_left_to_next++; + to_next--; + } + else + /* verify speculative enqueue, maybe switch current next frame */ + vlib_validate_buffer_enqueue_x1 (vm, node, next_index, + to_next, n_left_to_next, + bi0, next0); + + if (n_left_from == 0 && vec_len (fragments_to_loopback)) + { + from = vlib_frame_vector_args (frame); + u32 len = vec_len (fragments_to_loopback); + if (len <= VLIB_FRAME_SIZE) + { + clib_memcpy (from, fragments_to_loopback, sizeof (u32) * len); + n_left_from = len; + vec_reset_length (fragments_to_loopback); + } + else + { + clib_memcpy (from, + fragments_to_loopback + (len - VLIB_FRAME_SIZE), + sizeof (u32) * VLIB_FRAME_SIZE); + n_left_from = VLIB_FRAME_SIZE; + _vec_len (fragments_to_loopback) = len - VLIB_FRAME_SIZE; + } + } } vlib_put_next_frame (vm, node, next_index, n_left_to_next); } + nat_send_all_to_node (vm, fragments_to_drop, node, 0, NAT44_CLASSIFY_NEXT_DROP); + + vec_free (fragments_to_drop); + return frame->n_vectors; } @@ -584,10 +793,13 @@ VLIB_REGISTER_NODE (nat44_classify_node) = { .vector_size = sizeof (u32), .format_trace = format_nat44_classify_trace, .type = VLIB_NODE_TYPE_INTERNAL, + .n_errors = ARRAY_LEN(nat44_classify_error_strings), + .error_strings = nat44_classify_error_strings, .n_next_nodes = NAT44_CLASSIFY_N_NEXT, .next_nodes = { [NAT44_CLASSIFY_NEXT_IN2OUT] = "nat44-in2out", [NAT44_CLASSIFY_NEXT_OUT2IN] = "nat44-out2in", + [NAT44_CLASSIFY_NEXT_DROP] = "error-drop", }, }; @@ -611,6 +823,7 @@ VLIB_REGISTER_NODE (nat44_ed_classify_node) = { .next_nodes = { [NAT44_CLASSIFY_NEXT_IN2OUT] = "nat44-ed-in2out", [NAT44_CLASSIFY_NEXT_OUT2IN] = "nat44-ed-out2in", + [NAT44_CLASSIFY_NEXT_DROP] = "error-drop", }, }; @@ -635,6 +848,7 @@ VLIB_REGISTER_NODE (nat44_det_classify_node) = { .next_nodes = { [NAT44_CLASSIFY_NEXT_IN2OUT] = "nat44-det-in2out", [NAT44_CLASSIFY_NEXT_OUT2IN] = "nat44-det-out2in", + [NAT44_CLASSIFY_NEXT_DROP] = "error-drop", }, }; @@ -659,6 +873,7 @@ VLIB_REGISTER_NODE (nat44_handoff_classify_node) = { .next_nodes = { [NAT44_CLASSIFY_NEXT_IN2OUT] = "nat44-in2out-worker-handoff", [NAT44_CLASSIFY_NEXT_OUT2IN] = "nat44-out2in-worker-handoff", + [NAT44_CLASSIFY_NEXT_DROP] = "error-drop", }, }; |