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authorDave Barach <dave@barachs.net>2019-03-06 11:14:03 -0500
committerFlorin Coras <florin.coras@gmail.com>2019-03-06 17:19:22 +0000
commita55df1081762b4e40698ef7d9196551851be646a (patch)
treeeb1867e1de1fc78d18da9067d04423dfdb199cd1 /src/plugins/ct6/ct6_in2out.c
parente275bed64d12009726fcf43943f1684195cd1e5d (diff)
ipv6 connection tracking plugin
A security feature: drop unsolicited global unicast traffic. Change-Id: I421da7d52e08b7acf40c62a1f6e2a6caac349e7e Signed-off-by: Dave Barach <dave@barachs.net>
Diffstat (limited to 'src/plugins/ct6/ct6_in2out.c')
-rw-r--r--src/plugins/ct6/ct6_in2out.c362
1 files changed, 362 insertions, 0 deletions
diff --git a/src/plugins/ct6/ct6_in2out.c b/src/plugins/ct6/ct6_in2out.c
new file mode 100644
index 00000000000..b28d349dd29
--- /dev/null
+++ b/src/plugins/ct6/ct6_in2out.c
@@ -0,0 +1,362 @@
+/*
+ * ct6_in2out.c - ip6 connection tracker, inside-to-outside path
+ *
+ * Copyright (c) 2019 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 <vlib/vlib.h>
+#include <vnet/vnet.h>
+#include <vnet/pg/pg.h>
+#include <vppinfra/error.h>
+#include <ct6/ct6.h>
+
+typedef struct
+{
+ u32 sw_if_index;
+ u32 next_index;
+ u32 session_index;
+} ct6_in2out_trace_t;
+
+#ifndef CLIB_MARCH_VARIANT
+
+/* packet trace format function */
+static u8 *
+format_ct6_in2out_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 *);
+ ct6_in2out_trace_t *t = va_arg (*args, ct6_in2out_trace_t *);
+
+ s = format (s, "CT6_IN2OUT: sw_if_index %d, next index %d session %d\n",
+ t->sw_if_index, t->next_index, t->session_index);
+ return s;
+}
+
+vlib_node_registration_t ct6_in2out_node;
+
+#endif /* CLIB_MARCH_VARIANT */
+
+#define foreach_ct6_in2out_error \
+_(PROCESSED, "ct6 packets processed") \
+_(CREATED, "ct6 sessions created") \
+_(RECYCLED, "ct6 sessions recycled")
+
+typedef enum
+{
+#define _(sym,str) CT6_IN2OUT_ERROR_##sym,
+ foreach_ct6_in2out_error
+#undef _
+ CT6_IN2OUT_N_ERROR,
+} ct6_in2out_error_t;
+
+#ifndef CLIB_MARCH_VARIANT
+static char *ct6_in2out_error_strings[] = {
+#define _(sym,string) string,
+ foreach_ct6_in2out_error
+#undef _
+};
+#endif /* CLIB_MARCH_VARIANT */
+
+typedef enum
+{
+ CT6_IN2OUT_NEXT_DROP,
+ CT6_IN2OUT_N_NEXT,
+} ct6_next_t;
+
+#ifndef CLIB_MARCH_VARIANT
+ct6_session_t *
+ct6_create_or_recycle_session (ct6_main_t * cmp,
+ clib_bihash_kv_48_8_t * kvpp, f64 now,
+ u32 my_thread_index, u32 * recyclep,
+ u32 * createp)
+{
+ ct6_session_t *s0;
+
+ /* Empty arena? */
+ if (PREDICT_FALSE (cmp->last_index[my_thread_index] == ~0))
+ goto alloc0;
+
+ /* Look at the least-recently-used session */
+ s0 = pool_elt_at_index (cmp->sessions[my_thread_index],
+ cmp->last_index[my_thread_index]);
+
+ if (s0->expires < now)
+ clib_warning ("session %d expired %.2f time now %.2f",
+ s0 - cmp->sessions[my_thread_index], s0->expires, now);
+
+ if (pool_elts (cmp->sessions[my_thread_index]) >=
+ cmp->max_sessions_per_worker)
+ clib_warning ("recycle session %d have %d max %d",
+ s0 - cmp->sessions[my_thread_index],
+ pool_elts (cmp->sessions[my_thread_index]),
+ cmp->max_sessions_per_worker);
+
+ /* Session expired, or we have as many sessions as is allowed by law? */
+ if ((s0->expires < now) || (pool_elts (cmp->sessions[my_thread_index])
+ >= cmp->max_sessions_per_worker))
+ {
+ /* recycle the session */
+ if (clib_bihash_add_del_48_8 (&cmp->session_hash,
+ (clib_bihash_kv_48_8_t *) s0,
+ 0 /* is_add */ ) < 0)
+ clib_warning ("session %d not found in hash?",
+ s0 - cmp->sessions[my_thread_index]);
+
+ ct6_lru_remove (cmp, s0);
+ *recyclep += 1;
+ }
+ else
+ {
+ alloc0:
+ /* Allocate a fresh session */
+ pool_get (cmp->sessions[my_thread_index], s0);
+ *createp += 1;
+ }
+
+ /* Sesison setup */
+ memset (s0, 0, sizeof (*s0));
+ clib_memcpy_fast (s0, kvpp, sizeof (ct6_session_key_t));
+ s0->thread_index = my_thread_index;
+ s0->expires = now + cmp->session_timeout_interval;
+ kvpp->value = s0 - cmp->sessions[my_thread_index];
+ clib_bihash_add_del_48_8 (&cmp->session_hash, kvpp, 1 /* is_add */ );
+ ct6_lru_add (cmp, s0, now);
+ return s0;
+}
+#endif /* CLIB_MARCH_VARIANT */
+
+always_inline uword
+ct6_in2out_inline (vlib_main_t * vm,
+ vlib_node_runtime_t * node, vlib_frame_t * frame,
+ int is_trace)
+{
+ u32 n_left_from, *from;
+ vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
+ u16 nexts[VLIB_FRAME_SIZE], *next;
+ ct6_main_t *cmp = &ct6_main;
+ u32 my_thread_index = vm->thread_index;
+ f64 now = vlib_time_now (vm);
+ u32 created = 0;
+ u32 recycled = 0;
+
+ from = vlib_frame_vector_args (frame);
+ n_left_from = frame->n_vectors;
+
+ vlib_get_buffers (vm, from, bufs, n_left_from);
+ b = bufs;
+ next = nexts;
+
+#if 0
+ while (n_left_from >= 4)
+ {
+ /* Prefetch next iteration. */
+ if (PREDICT_TRUE (n_left_from >= 8))
+ {
+ vlib_prefetch_buffer_header (b[4], STORE);
+ vlib_prefetch_buffer_header (b[5], STORE);
+ vlib_prefetch_buffer_header (b[6], STORE);
+ vlib_prefetch_buffer_header (b[7], STORE);
+ CLIB_PREFETCH (b[4]->data, CLIB_CACHE_LINE_BYTES, STORE);
+ CLIB_PREFETCH (b[5]->data, CLIB_CACHE_LINE_BYTES, STORE);
+ CLIB_PREFETCH (b[6]->data, CLIB_CACHE_LINE_BYTES, STORE);
+ CLIB_PREFETCH (b[7]->data, CLIB_CACHE_LINE_BYTES, STORE);
+ }
+
+ /* $$$$ process 4x pkts right here */
+ next[0] = 0;
+ next[1] = 0;
+ next[2] = 0;
+ next[3] = 0;
+
+ if (is_trace)
+ {
+ if (b[0]->flags & VLIB_BUFFER_IS_TRACED)
+ {
+ ct6_trace_t *t = vlib_add_trace (vm, node, b[0], sizeof (*t));
+ t->next_index = next[0];
+ t->sw_if_index = vnet_buffer (b[0])->sw_if_index[VLIB_RX];
+ }
+ if (b[1]->flags & VLIB_BUFFER_IS_TRACED)
+ {
+ ct6_trace_t *t = vlib_add_trace (vm, node, b[1], sizeof (*t));
+ t->next_index = next[1];
+ t->sw_if_index = vnet_buffer (b[1])->sw_if_index[VLIB_RX];
+ }
+ if (b[2]->flags & VLIB_BUFFER_IS_TRACED)
+ {
+ ct6_trace_t *t = vlib_add_trace (vm, node, b[2], sizeof (*t));
+ t->next_index = next[2];
+ t->sw_if_index = vnet_buffer (b[2])->sw_if_index[VLIB_RX];
+ }
+ if (b[3]->flags & VLIB_BUFFER_IS_TRACED)
+ {
+ ct6_trace_t *t = vlib_add_trace (vm, node, b[3], sizeof (*t));
+ t->next_index = next[3];
+ t->sw_if_index = vnet_buffer (b[3])->sw_if_index[VLIB_RX];
+ }
+ }
+
+ b += 4;
+ next += 4;
+ n_left_from -= 4;
+ }
+#endif
+
+ while (n_left_from > 0)
+ {
+ clib_bihash_kv_48_8_t kvp0;
+ ct6_session_key_t *key0;
+ ct6_session_t *s0;
+ u32 session_index0 = ~0;
+ u32 next0, delta0;
+ ethernet_header_t *e0;
+
+ ip6_header_t *ip0;
+ udp_header_t *udp0;
+
+ /* $$$ Set to 0 for pg testing */
+ if (1)
+ {
+ vnet_feature_next (&next0, b[0]);
+ next[0] = next0;
+ }
+ else
+ next[0] = CT6_IN2OUT_NEXT_DROP;
+
+ /*
+ * This is an output feature which runs at the last possible
+ * moment. Assume an ethernet header.
+ */
+
+ e0 = vlib_buffer_get_current (b[0]);
+ delta0 = sizeof (*e0);
+ delta0 += (e0->type == clib_net_to_host_u16 (ETHERNET_TYPE_VLAN))
+ ? 4 : 0;
+ delta0 += (e0->type == clib_net_to_host_u16 (ETHERNET_TYPE_DOT1AD))
+ ? 8 : 0;
+
+ ip0 = (ip6_header_t *) (vlib_buffer_get_current (b[0]) + delta0);
+
+ /*
+ * Pass non-global unicast traffic
+ */
+ if (PREDICT_FALSE (!ip6_address_is_global_unicast (&ip0->src_address)
+ ||
+ !ip6_address_is_global_unicast (&ip0->src_address)))
+ goto trace0;
+ /* Pass non-udp, non-tcp traffic */
+ if (PREDICT_FALSE (ip0->protocol != IP_PROTOCOL_TCP &&
+ ip0->protocol != IP_PROTOCOL_UDP))
+ goto trace0;
+
+ udp0 = ip6_next_header (ip0);
+
+ /*
+ * See if we know about this flow.
+ * Key set up for the out2in path, the performant case
+ */
+ key0 = (ct6_session_key_t *) & kvp0;
+ clib_memcpy_fast (&key0->src, &ip0->dst_address,
+ sizeof (ip6_address_t));
+ clib_memcpy_fast (&key0->dst, &ip0->src_address,
+ sizeof (ip6_address_t));
+ key0->as_u64[4] = 0;
+ key0->as_u64[5] = 0;
+ key0->sport = udp0->dst_port;
+ key0->dport = udp0->src_port;
+ key0->proto = ip0->protocol;
+
+ /* Need to create a new session? */
+ if (clib_bihash_search_48_8 (&cmp->session_hash, &kvp0, &kvp0) < 0)
+ {
+ s0 =
+ ct6_create_or_recycle_session (cmp, &kvp0, now, my_thread_index,
+ &recycled, &created);
+ session_index0 = kvp0.value;
+ }
+ else
+ {
+ s0 = pool_elt_at_index (cmp->sessions[my_thread_index], kvp0.value);
+ session_index0 = kvp0.value;
+ ct6_update_session_hit (cmp, s0, now);
+ }
+
+ trace0:
+ if (is_trace)
+ {
+ if (b[0]->flags & VLIB_BUFFER_IS_TRACED)
+ {
+ ct6_in2out_trace_t *t =
+ vlib_add_trace (vm, node, b[0], sizeof (*t));
+ t->next_index = next[0];
+ t->sw_if_index = vnet_buffer (b[0])->sw_if_index[VLIB_RX];
+ t->session_index = session_index0;
+ }
+ }
+
+ b += 1;
+ next += 1;
+ n_left_from -= 1;
+ }
+
+ vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
+
+ vlib_node_increment_counter (vm, node->node_index,
+ CT6_IN2OUT_ERROR_PROCESSED, frame->n_vectors);
+ vlib_node_increment_counter (vm, node->node_index,
+ CT6_IN2OUT_ERROR_CREATED, created);
+ vlib_node_increment_counter (vm, node->node_index,
+ CT6_IN2OUT_ERROR_RECYCLED, recycled);
+
+ return frame->n_vectors;
+}
+
+VLIB_NODE_FN (ct6_in2out_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
+ vlib_frame_t * frame)
+{
+ if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
+ return ct6_in2out_inline (vm, node, frame, 1 /* is_trace */ );
+ else
+ return ct6_in2out_inline (vm, node, frame, 0 /* is_trace */ );
+}
+
+/* *INDENT-OFF* */
+#ifndef CLIB_MARCH_VARIANT
+VLIB_REGISTER_NODE (ct6_in2out_node) =
+{
+ .name = "ct6-in2out",
+ .vector_size = sizeof (u32),
+ .format_trace = format_ct6_in2out_trace,
+ .type = VLIB_NODE_TYPE_INTERNAL,
+
+ .n_errors = ARRAY_LEN(ct6_in2out_error_strings),
+ .error_strings = ct6_in2out_error_strings,
+
+ .n_next_nodes = CT6_IN2OUT_N_NEXT,
+
+ /* edit / add dispositions here */
+ .next_nodes = {
+ [CT6_IN2OUT_NEXT_DROP] = "error-drop",
+ },
+ .unformat_buffer = unformat_ethernet_header,
+};
+#endif /* CLIB_MARCH_VARIANT */
+/* *INDENT-ON* */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */