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-rw-r--r--src/plugins/cnat/cnat_node_snat.c237
1 files changed, 237 insertions, 0 deletions
diff --git a/src/plugins/cnat/cnat_node_snat.c b/src/plugins/cnat/cnat_node_snat.c
new file mode 100644
index 00000000000..cc1421be084
--- /dev/null
+++ b/src/plugins/cnat/cnat_node_snat.c
@@ -0,0 +1,237 @@
+/*
+ * 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_snat.h>
+
+typedef enum cnat_snat_next_
+{
+ CNAT_SNAT_NEXT_DROP,
+ CNAT_SNAT_N_NEXT,
+} cnat_snat_next_t;
+
+typedef struct cnat_snat_trace_
+{
+ u32 found;
+ cnat_session_t session;
+} cnat_snat_trace_t;
+
+vlib_node_registration_t cnat_snat_ip4_node;
+vlib_node_registration_t cnat_snat_ip6_node;
+
+static u8 *
+format_cnat_snat_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_snat_trace_t *t = va_arg (*args, cnat_snat_trace_t *);
+
+ if (t->found)
+ s = format (s, "found: %U", format_cnat_session, &t->session, 1);
+ else
+ s = format (s, "not found");
+ return s;
+}
+
+/* CNat sub for source NAT as a feature arc on ip[46]-unicast
+ This node's sub shouldn't apply to the same flows as
+ cnat_vip_inline */
+always_inline uword
+cnat_snat_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)
+{
+ cnat_main_t *cm = &cnat_main;
+ ip4_header_t *ip4;
+ ip_protocol_t iproto;
+ ip6_header_t *ip6;
+ udp_header_t *udp0;
+ u32 arc_next0;
+ u16 next0;
+ u16 sport;
+
+ 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);
+ }
+
+ /* By default don't follow previous next0 */
+ vnet_feature_next (&arc_next0, b);
+ next0 = arc_next0;
+
+ if (iproto != IP_PROTOCOL_UDP && iproto != IP_PROTOCOL_TCP)
+ {
+ /* Dont translate */
+ goto trace;
+ }
+
+ if (!rv)
+ {
+ /* session table hit */
+ cnat_timestamp_update (session->value.cs_ts_index, ctx->now);
+ }
+ else
+ {
+ ip46_address_t ip46_dst_address;
+ if (AF_IP4 == ctx->af)
+ ip46_address_set_ip4 (&ip46_dst_address, &ip4->dst_address);
+ else
+ ip46_address_set_ip6 (&ip46_dst_address, &ip6->dst_address);
+ rv = cnat_search_snat_prefix (&ip46_dst_address, ctx->af);
+ if (!rv)
+ {
+ /* Prefix table hit, we shouldn't source NAT */
+ goto trace;
+ }
+ /* New flow, create the sessions if necessary. session will be a snat
+ session, and rsession will be a dnat session
+ Note: packet going through this path are going to the outside,
+ so they will never hit the NAT again (they are not going towards
+ a VIP) */
+ if (AF_IP4 == ctx->af)
+ {
+ ip46_address_set_ip4 (&session->value.cs_ip[VLIB_RX],
+ &cm->snat_ip4);
+ ip46_address_set_ip4 (&session->value.cs_ip[VLIB_TX],
+ &ip4->dst_address);
+ }
+ else
+ {
+ ip46_address_set_ip6 (&session->value.cs_ip[VLIB_RX],
+ &cm->snat_ip6);
+ ip46_address_set_ip6 (&session->value.cs_ip[VLIB_TX],
+ &ip6->dst_address);
+ }
+
+ /* Port allocation, first try to use the original port, allocate one
+ if it is already used */
+ sport = udp0->src_port;
+ rv = cnat_allocate_port (cm, &sport);
+ if (rv)
+ {
+ vlib_node_increment_counter (vm, cnat_snat_ip4_node.index,
+ CNAT_ERROR_EXHAUSTED_PORTS, 1);
+ next0 = CNAT_SNAT_NEXT_DROP;
+ goto trace;
+ }
+
+ session->value.cs_port[VLIB_RX] = sport;
+ session->value.cs_port[VLIB_TX] = udp0->dst_port;
+ session->value.cs_lbi = INDEX_INVALID;
+ session->value.flags =
+ CNAT_SESSION_FLAG_NO_CLIENT | CNAT_SESSION_FLAG_ALLOC_PORT;
+
+ cnat_session_create (session, ctx, CNAT_SESSION_FLAG_HAS_SNAT);
+ }
+
+
+ if (AF_IP4 == ctx->af)
+ cnat_translation_ip4 (session, ip4, udp0);
+ else
+ cnat_translation_ip6 (session, ip6, udp0);
+
+trace:
+ if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
+ {
+ cnat_snat_trace_t *t;
+
+ t = vlib_add_trace (vm, node, b, sizeof (*t));
+
+ if (NULL != session)
+ clib_memcpy (&t->session, session, sizeof (t->session));
+ }
+ return next0;
+}
+
+VLIB_NODE_FN (cnat_snat_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_snat_inline, AF_IP4,
+ 1 /* do_trace */ );
+ return cnat_node_inline (vm, node, frame, cnat_snat_inline, AF_IP4,
+ 0 /* do_trace */ );
+}
+
+VLIB_NODE_FN (cnat_snat_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_snat_inline, AF_IP6,
+ 1 /* do_trace */ );
+ return cnat_node_inline (vm, node, frame, cnat_snat_inline, AF_IP6,
+ 0 /* do_trace */ );
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (cnat_snat_ip4_node) =
+{
+ .name = "ip4-cnat-snat",
+ .vector_size = sizeof (u32),
+ .format_trace = format_cnat_snat_trace,
+ .type = VLIB_NODE_TYPE_INTERNAL,
+ .n_errors = CNAT_N_ERROR,
+ .error_strings = cnat_error_strings,
+ .n_next_nodes = CNAT_SNAT_N_NEXT,
+ .next_nodes =
+ {
+ [CNAT_SNAT_NEXT_DROP] = "ip4-drop",
+ }
+};
+
+VLIB_REGISTER_NODE (cnat_snat_ip6_node) =
+{
+ .name = "ip6-cnat-snat",
+ .vector_size = sizeof (u32),
+ .format_trace = format_cnat_snat_trace,
+ .type = VLIB_NODE_TYPE_INTERNAL,
+ .n_errors = CNAT_N_ERROR,
+ .error_strings = cnat_error_strings,
+ .n_next_nodes = CNAT_SNAT_N_NEXT,
+ .next_nodes =
+ {
+ [CNAT_SNAT_NEXT_DROP] = "ip6-drop",
+ }
+};
+/* *INDENT-ON* */
+
+
+VNET_FEATURE_INIT (cnat_snat_ip4_node, static) =
+{
+.arc_name = "ip4-unicast",.node_name = "ip4-cnat-snat",};
+
+VNET_FEATURE_INIT (cnat_snat_ip6_node, static) =
+{
+.arc_name = "ip6-unicast",.node_name = "ip6-cnat-snat",};
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */