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authorNeale Ranns <nranns@cisco.com>2020-05-19 07:17:19 +0000
committerAndrew Yourtchenko <ayourtch@gmail.com>2020-08-31 09:23:32 +0000
commit29f3c7d2ecac2f9d80bb33e91bd5d1f9d434768a (patch)
tree66d7c69f2c24959ef4f6ef67b7c56dba11d8be29 /src/plugins/cnat/cnat_node_vip.c
parent133c91c1c06e7c773ba675181901ba0dcf955ae6 (diff)
cnat: Destination based NAT
Type: feature Signed-off-by: Neale Ranns <nranns@cisco.com> Change-Id: I64a99a4fbc674212944247793fd5c1fb701408cb
Diffstat (limited to 'src/plugins/cnat/cnat_node_vip.c')
-rw-r--r--src/plugins/cnat/cnat_node_vip.c308
1 files changed, 308 insertions, 0 deletions
diff --git a/src/plugins/cnat/cnat_node_vip.c b/src/plugins/cnat/cnat_node_vip.c
new file mode 100644
index 00000000000..afabed08f1a
--- /dev/null
+++ b/src/plugins/cnat/cnat_node_vip.c
@@ -0,0 +1,308 @@
+/*
+ * Copyright (c) 2020 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vlibmemory/api.h>
+#include <cnat/cnat_node.h>
+#include <cnat/cnat_translation.h>
+
+#include <vnet/dpo/load_balance.h>
+#include <vnet/dpo/load_balance_map.h>
+
+typedef struct cnat_translation_trace_t_
+{
+ cnat_session_t session;
+ cnat_translation_t tr;
+ u32 found_session;
+ u32 created_session;
+ u32 has_tr;
+} cnat_translation_trace_t;
+
+typedef enum cnat_translation_next_t_
+{
+ CNAT_TRANSLATION_NEXT_DROP,
+ CNAT_TRANSLATION_NEXT_LOOKUP,
+ CNAT_TRANSLATION_N_NEXT,
+} cnat_translation_next_t;
+
+vlib_node_registration_t cnat_vip_ip4_node;
+vlib_node_registration_t cnat_vip_ip6_node;
+
+static u8 *
+format_cnat_translation_trace (u8 * s, va_list * args)
+{
+ CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
+ CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
+ cnat_translation_trace_t *t =
+ va_arg (*args, cnat_translation_trace_t *);
+
+ if (t->found_session)
+ s = format (s, "found: %U", format_cnat_session, &t->session, 1);
+ else if (t->created_session)
+ s = format (s, "created: %U\n tr: %U",
+ format_cnat_session, &t->session, 1,
+ format_cnat_translation,
+ &t->tr, 0);
+ else if (t->has_tr)
+ s = format (s, "tr pass: %U", format_cnat_translation,
+ &t->tr, 0);
+ else
+ s = format (s, "not found");
+ return s;
+}
+
+/* CNat sub for NAT behind a fib entry (VIP or interposed real IP) */
+always_inline uword
+cnat_vip_inline (vlib_main_t * vm,
+ vlib_node_runtime_t * node,
+ vlib_buffer_t * b,
+ cnat_node_ctx_t * ctx, int rv, cnat_session_t * session)
+{
+ vlib_combined_counter_main_t *cntm = &cnat_translation_counters;
+ cnat_main_t *cm = &cnat_main;
+ const cnat_translation_t *ct = NULL;
+ ip4_header_t *ip4;
+ ip_protocol_t iproto;
+ ip6_header_t *ip6;
+ udp_header_t *udp0;
+ cnat_client_t *cc;
+ u16 next0;
+ index_t cti;
+ int created_session = 0;
+ if (AF_IP4 == ctx->af)
+ {
+ ip4 = vlib_buffer_get_current (b);
+ iproto = ip4->protocol;
+ udp0 = (udp_header_t *) (ip4 + 1);
+ }
+ else
+ {
+ ip6 = vlib_buffer_get_current (b);
+ iproto = ip6->protocol;
+ udp0 = (udp_header_t *) (ip6 + 1);
+ }
+
+ cc = cnat_client_get (vnet_buffer (b)->ip.adj_index[VLIB_TX]);
+
+ if (iproto != IP_PROTOCOL_UDP && iproto != IP_PROTOCOL_TCP)
+ {
+ /* Dont translate & follow the fib programming */
+ next0 = cc->cc_parent.dpoi_next_node;
+ vnet_buffer (b)->ip.adj_index[VLIB_TX] = cc->cc_parent.dpoi_index;
+ goto trace;
+ }
+
+ ct = cnat_find_translation (cc->parent_cci,
+ clib_host_to_net_u16 (udp0->dst_port),
+ iproto);
+
+ if (!rv)
+ {
+ /* session table hit */
+ cnat_timestamp_update (session->value.cs_ts_index, ctx->now);
+
+ if (NULL != ct)
+ {
+ /* Translate & follow the translation given LB */
+ next0 = ct->ct_lb.dpoi_next_node;
+ vnet_buffer (b)->ip.adj_index[VLIB_TX] = session->value.cs_lbi;
+ }
+ else if (session->value.flags & CNAT_SESSION_FLAG_HAS_SNAT)
+ {
+ /* The return needs DNAT, so we need an additionnal
+ * lookup after translation */
+ next0 = CNAT_TRANSLATION_NEXT_LOOKUP;
+ }
+ else
+ {
+ /* Translate & follow the fib programming */
+ next0 = cc->cc_parent.dpoi_next_node;
+ vnet_buffer (b)->ip.adj_index[VLIB_TX] = cc->cc_parent.dpoi_index;
+ }
+ }
+ else
+ {
+ if (NULL == ct)
+ {
+ /* Dont translate & Follow the fib programming */
+ vnet_buffer (b)->ip.adj_index[VLIB_TX] = cc->cc_parent.dpoi_index;
+ next0 = cc->cc_parent.dpoi_next_node;
+ goto trace;
+ }
+
+ /* New flow, create the sessions */
+ const load_balance_t *lb0;
+ cnat_ep_trk_t *trk0;
+ u32 hash_c0, bucket0;
+ u32 rsession_flags = 0;
+ const dpo_id_t *dpo0;
+
+ lb0 = load_balance_get (ct->ct_lb.dpoi_index);
+ if (!lb0->lb_n_buckets)
+ {
+ /* Dont translate & Follow the fib programming */
+ vnet_buffer (b)->ip.adj_index[VLIB_TX] = cc->cc_parent.dpoi_index;
+ next0 = cc->cc_parent.dpoi_next_node;
+ goto trace;
+ }
+
+ /* session table miss */
+ hash_c0 = (AF_IP4 == ctx->af ?
+ ip4_compute_flow_hash (ip4, lb0->lb_hash_config) :
+ ip6_compute_flow_hash (ip6, lb0->lb_hash_config));
+ bucket0 = hash_c0 & lb0->lb_n_buckets_minus_1;
+ dpo0 = load_balance_get_fwd_bucket (lb0, bucket0);
+
+ /* add the session */
+ trk0 = &ct->ct_paths[bucket0];
+
+ ip46_address_copy (&session->value.cs_ip[VLIB_TX],
+ &trk0->ct_ep[VLIB_TX].ce_ip.ip);
+ if (ip_address_is_zero (&trk0->ct_ep[VLIB_RX].ce_ip))
+ {
+ if (AF_IP4 == ctx->af)
+ ip46_address_set_ip4 (&session->value.cs_ip[VLIB_RX],
+ &ip4->src_address);
+ else
+ ip46_address_set_ip6 (&session->value.cs_ip[VLIB_RX],
+ &ip6->src_address);
+ }
+ else
+ {
+ /* We source NAT with the translation */
+ rsession_flags |= CNAT_SESSION_FLAG_HAS_SNAT;
+ ip46_address_copy (&session->value.cs_ip[VLIB_RX],
+ &trk0->ct_ep[VLIB_RX].ce_ip.ip);
+ }
+ session->value.cs_port[VLIB_TX] =
+ clib_host_to_net_u16 (trk0->ct_ep[VLIB_TX].ce_port);
+ session->value.cs_port[VLIB_RX] =
+ clib_host_to_net_u16 (trk0->ct_ep[VLIB_RX].ce_port);
+
+ session->value.flags = 0;
+ if (!session->value.cs_port[VLIB_RX])
+ {
+ u16 sport;
+ sport = udp0->src_port;
+ /* Allocate a port only if asked and if we actually sNATed */
+ if ((ct->flags & CNAT_TRANSLATION_FLAG_ALLOCATE_PORT)
+ && (rsession_flags & CNAT_SESSION_FLAG_HAS_SNAT)) {
+ sport = 0; /* force allocation */
+ session->value.flags |= CNAT_SESSION_FLAG_ALLOC_PORT;
+ rv = cnat_allocate_port (cm, &sport);
+ if (rv)
+ {
+ vlib_node_increment_counter (vm, cnat_vip_ip4_node.index,
+ CNAT_ERROR_EXHAUSTED_PORTS, 1);
+ next0 = CNAT_TRANSLATION_NEXT_DROP;
+ goto trace;
+ }
+ }
+
+ session->value.cs_port[VLIB_RX] = sport;
+ }
+ session->value.cs_lbi = dpo0->dpoi_index;
+
+ cnat_client_cnt_session (cc);
+ cnat_session_create (session, ctx, rsession_flags);
+ created_session = 1;
+
+ next0 = ct->ct_lb.dpoi_next_node;
+ vnet_buffer (b)->ip.adj_index[VLIB_TX] = session->value.cs_lbi;
+ }
+
+
+ if (AF_IP4 == ctx->af)
+ cnat_translation_ip4 (session, ip4, udp0);
+ else
+ cnat_translation_ip6 (session, ip6, udp0);
+
+ if (NULL != ct)
+ {
+ cti = ct - cnat_translation_pool;
+ vlib_increment_combined_counter (cntm, ctx->thread_index, cti, 1,
+ vlib_buffer_length_in_chain (vm, b));
+ }
+
+trace:
+ if (PREDICT_FALSE (ctx->do_trace))
+ {
+ cnat_translation_trace_t *t;
+
+ t = vlib_add_trace (vm, node, b, sizeof (*t));
+
+ t->found_session = !rv;
+ t->created_session = created_session;
+ if (t->found_session || t->created_session)
+ clib_memcpy (&t->session, session, sizeof (t->session));
+ t->has_tr = (NULL != ct);
+ if (t->has_tr)
+ clib_memcpy (&t->tr, ct, sizeof (cnat_translation_t));
+ }
+ return next0;
+}
+
+VLIB_NODE_FN (cnat_vip_ip4_node) (vlib_main_t * vm,
+ vlib_node_runtime_t * node,
+ vlib_frame_t * frame)
+{
+ if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)))
+ return cnat_node_inline (vm, node, frame, cnat_vip_inline, AF_IP4,
+ 1 /* do_trace */ );
+ return cnat_node_inline (vm, node, frame, cnat_vip_inline, AF_IP4,
+ 0 /* do_trace */ );
+}
+
+VLIB_NODE_FN (cnat_vip_ip6_node) (vlib_main_t * vm,
+ vlib_node_runtime_t * node,
+ vlib_frame_t * frame)
+{
+ if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)))
+ return cnat_node_inline (vm, node, frame, cnat_vip_inline, AF_IP6,
+ 1 /* do_trace */ );
+ return cnat_node_inline (vm, node, frame, cnat_vip_inline, AF_IP6,
+ 0 /* do_trace */ );
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (cnat_vip_ip4_node) =
+{
+ .name = "ip4-cnat-tx",
+ .vector_size = sizeof (u32),
+ .format_trace = format_cnat_translation_trace,
+ .type = VLIB_NODE_TYPE_INTERNAL,
+ .n_errors = 0,
+ .n_next_nodes = CNAT_TRANSLATION_N_NEXT,
+ .next_nodes =
+ {
+ [CNAT_TRANSLATION_NEXT_DROP] = "ip4-drop",
+ [CNAT_TRANSLATION_NEXT_LOOKUP] = "ip4-lookup",
+ }
+};
+VLIB_REGISTER_NODE (cnat_vip_ip6_node) =
+{
+ .name = "ip6-cnat-tx",
+ .vector_size = sizeof (u32),
+ .format_trace = format_cnat_translation_trace,
+ .type = VLIB_NODE_TYPE_INTERNAL,
+ .n_errors = 0,
+ .n_next_nodes = CNAT_TRANSLATION_N_NEXT,
+ .next_nodes =
+ {
+ [CNAT_TRANSLATION_NEXT_DROP] = "ip6-drop",
+ [CNAT_TRANSLATION_NEXT_LOOKUP] = "ip6-lookup",
+ }
+};
+/* *INDENT-ON* */
+