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-rw-r--r--src/vnet/ip/ip4_source_check.c573
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diff --git a/src/vnet/ip/ip4_source_check.c b/src/vnet/ip/ip4_source_check.c
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+++ b/src/vnet/ip/ip4_source_check.c
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+/*
+ * Copyright (c) 2015 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.
+ */
+/*
+ * ip/ip4_source_check.c: IP v4 check source address (unicast RPF check)
+ *
+ * Copyright (c) 2008 Eliot Dresselhaus
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <vnet/ip/ip.h>
+#include <vnet/fib/ip4_fib.h>
+#include <vnet/fib/fib_urpf_list.h>
+#include <vnet/dpo/load_balance.h>
+
+/**
+ * @file
+ * @brief IPv4 Unicast Source Check.
+ *
+ * This file contains the IPv4 interface unicast source check.
+ */
+
+
+typedef struct
+{
+ u8 packet_data[64];
+ index_t urpf;
+} ip4_source_check_trace_t;
+
+static u8 *
+format_ip4_source_check_trace (u8 * s, va_list * va)
+{
+ CLIB_UNUSED (vlib_main_t * vm) = va_arg (*va, vlib_main_t *);
+ CLIB_UNUSED (vlib_node_t * node) = va_arg (*va, vlib_node_t *);
+ ip4_source_check_trace_t *t = va_arg (*va, ip4_source_check_trace_t *);
+
+ s = format (s, "%U",
+ format_ip4_header, t->packet_data, sizeof (t->packet_data));
+
+ return s;
+}
+
+typedef enum
+{
+ IP4_SOURCE_CHECK_NEXT_DROP,
+ IP4_SOURCE_CHECK_N_NEXT,
+} ip4_source_check_next_t;
+
+typedef enum
+{
+ IP4_SOURCE_CHECK_REACHABLE_VIA_RX,
+ IP4_SOURCE_CHECK_REACHABLE_VIA_ANY,
+} ip4_source_check_type_t;
+
+typedef union
+{
+ u32 fib_index;
+} ip4_source_check_config_t;
+
+always_inline uword
+ip4_source_check_inline (vlib_main_t * vm,
+ vlib_node_runtime_t * node,
+ vlib_frame_t * frame,
+ ip4_source_check_type_t source_check_type)
+{
+ u32 n_left_from, *from, *to_next;
+ u32 next_index;
+ vlib_node_runtime_t *error_node =
+ vlib_node_get_runtime (vm, ip4_input_node.index);
+
+ from = vlib_frame_vector_args (frame);
+ n_left_from = frame->n_vectors;
+ next_index = node->cached_next_index;
+
+ if (node->flags & VLIB_NODE_FLAG_TRACE)
+ vlib_trace_frame_buffers_only (vm, node, from, frame->n_vectors,
+ /* stride */ 1,
+ sizeof (ip4_source_check_trace_t));
+
+ while (n_left_from > 0)
+ {
+ u32 n_left_to_next;
+
+ vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+
+ while (n_left_from >= 4 && n_left_to_next >= 2)
+ {
+ vlib_buffer_t *p0, *p1;
+ ip4_header_t *ip0, *ip1;
+ ip4_fib_mtrie_t *mtrie0, *mtrie1;
+ ip4_fib_mtrie_leaf_t leaf0, leaf1;
+ ip4_source_check_config_t *c0, *c1;
+ const load_balance_t *lb0, *lb1;
+ u32 pi0, next0, pass0, lb_index0;
+ u32 pi1, next1, pass1, lb_index1;
+
+ /* Prefetch next iteration. */
+ {
+ vlib_buffer_t *p2, *p3;
+
+ p2 = vlib_get_buffer (vm, from[2]);
+ p3 = vlib_get_buffer (vm, from[3]);
+
+ vlib_prefetch_buffer_header (p2, LOAD);
+ vlib_prefetch_buffer_header (p3, LOAD);
+
+ CLIB_PREFETCH (p2->data, sizeof (ip0[0]), LOAD);
+ CLIB_PREFETCH (p3->data, sizeof (ip1[0]), LOAD);
+ }
+
+ pi0 = to_next[0] = from[0];
+ pi1 = to_next[1] = from[1];
+ from += 2;
+ to_next += 2;
+ n_left_from -= 2;
+ n_left_to_next -= 2;
+
+ p0 = vlib_get_buffer (vm, pi0);
+ p1 = vlib_get_buffer (vm, pi1);
+
+ ip0 = vlib_buffer_get_current (p0);
+ ip1 = vlib_buffer_get_current (p1);
+
+ c0 =
+ vnet_feature_next_with_data (vnet_buffer (p0)->sw_if_index
+ [VLIB_RX], &next0, p0,
+ sizeof (c0[0]));
+ c1 =
+ vnet_feature_next_with_data (vnet_buffer (p1)->sw_if_index
+ [VLIB_RX], &next1, p1,
+ sizeof (c1[0]));
+
+ mtrie0 = &ip4_fib_get (c0->fib_index)->mtrie;
+ mtrie1 = &ip4_fib_get (c1->fib_index)->mtrie;
+
+ leaf0 = leaf1 = IP4_FIB_MTRIE_LEAF_ROOT;
+
+ leaf0 =
+ ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address, 0);
+ leaf1 =
+ ip4_fib_mtrie_lookup_step (mtrie1, leaf1, &ip1->src_address, 0);
+
+ leaf0 =
+ ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address, 1);
+ leaf1 =
+ ip4_fib_mtrie_lookup_step (mtrie1, leaf1, &ip1->src_address, 1);
+
+ leaf0 =
+ ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address, 2);
+ leaf1 =
+ ip4_fib_mtrie_lookup_step (mtrie1, leaf1, &ip1->src_address, 2);
+
+ leaf0 =
+ ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address, 3);
+ leaf1 =
+ ip4_fib_mtrie_lookup_step (mtrie1, leaf1, &ip1->src_address, 3);
+
+ lb_index0 = ip4_fib_mtrie_leaf_get_adj_index (leaf0);
+ lb_index1 = ip4_fib_mtrie_leaf_get_adj_index (leaf1);
+
+ lb0 = load_balance_get (lb_index0);
+ lb1 = load_balance_get (lb_index1);
+
+ /* Pass multicast. */
+ pass0 = ip4_address_is_multicast (&ip0->src_address)
+ || ip0->src_address.as_u32 == clib_host_to_net_u32 (0xFFFFFFFF);
+ pass1 = ip4_address_is_multicast (&ip1->src_address)
+ || ip1->src_address.as_u32 == clib_host_to_net_u32 (0xFFFFFFFF);
+
+ if (IP4_SOURCE_CHECK_REACHABLE_VIA_RX == source_check_type)
+ {
+ pass0 |= fib_urpf_check (lb0->lb_urpf,
+ vnet_buffer (p0)->sw_if_index
+ [VLIB_RX]);
+ pass1 |=
+ fib_urpf_check (lb1->lb_urpf,
+ vnet_buffer (p1)->sw_if_index[VLIB_RX]);
+ }
+ else
+ {
+ pass0 |= fib_urpf_check_size (lb0->lb_urpf);
+ pass1 |= fib_urpf_check_size (lb1->lb_urpf);
+ }
+ next0 = (pass0 ? next0 : IP4_SOURCE_CHECK_NEXT_DROP);
+ next1 = (pass1 ? next1 : IP4_SOURCE_CHECK_NEXT_DROP);
+
+ p0->error =
+ error_node->errors[IP4_ERROR_UNICAST_SOURCE_CHECK_FAILS];
+ p1->error =
+ error_node->errors[IP4_ERROR_UNICAST_SOURCE_CHECK_FAILS];
+
+ vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
+ to_next, n_left_to_next,
+ pi0, pi1, next0, next1);
+ }
+
+ while (n_left_from > 0 && n_left_to_next > 0)
+ {
+ vlib_buffer_t *p0;
+ ip4_header_t *ip0;
+ ip4_fib_mtrie_t *mtrie0;
+ ip4_fib_mtrie_leaf_t leaf0;
+ ip4_source_check_config_t *c0;
+ u32 pi0, next0, pass0, lb_index0;
+ const load_balance_t *lb0;
+
+ pi0 = from[0];
+ to_next[0] = pi0;
+ from += 1;
+ to_next += 1;
+ n_left_from -= 1;
+ n_left_to_next -= 1;
+
+ p0 = vlib_get_buffer (vm, pi0);
+ ip0 = vlib_buffer_get_current (p0);
+
+ c0 =
+ vnet_feature_next_with_data (vnet_buffer (p0)->sw_if_index
+ [VLIB_RX], &next0, p0,
+ sizeof (c0[0]));
+
+ mtrie0 = &ip4_fib_get (c0->fib_index)->mtrie;
+
+ leaf0 = IP4_FIB_MTRIE_LEAF_ROOT;
+
+ leaf0 =
+ ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address, 0);
+
+ leaf0 =
+ ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address, 1);
+
+ leaf0 =
+ ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address, 2);
+
+ leaf0 =
+ ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address, 3);
+
+ lb_index0 = ip4_fib_mtrie_leaf_get_adj_index (leaf0);
+
+ lb0 = load_balance_get (lb_index0);
+
+ /* Pass multicast. */
+ pass0 = ip4_address_is_multicast (&ip0->src_address)
+ || ip0->src_address.as_u32 == clib_host_to_net_u32 (0xFFFFFFFF);
+
+ if (IP4_SOURCE_CHECK_REACHABLE_VIA_RX == source_check_type)
+ {
+ pass0 |= fib_urpf_check (lb0->lb_urpf,
+ vnet_buffer (p0)->sw_if_index
+ [VLIB_RX]);
+ }
+ else
+ {
+ pass0 |= fib_urpf_check_size (lb0->lb_urpf);
+ }
+
+ next0 = (pass0 ? next0 : IP4_SOURCE_CHECK_NEXT_DROP);
+ p0->error =
+ error_node->errors[IP4_ERROR_UNICAST_SOURCE_CHECK_FAILS];
+
+ vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
+ to_next, n_left_to_next,
+ pi0, next0);
+ }
+
+ vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+ }
+
+ return frame->n_vectors;
+}
+
+static uword
+ip4_source_check_reachable_via_any (vlib_main_t * vm,
+ vlib_node_runtime_t * node,
+ vlib_frame_t * frame)
+{
+ return ip4_source_check_inline (vm, node, frame,
+ IP4_SOURCE_CHECK_REACHABLE_VIA_ANY);
+}
+
+static uword
+ip4_source_check_reachable_via_rx (vlib_main_t * vm,
+ vlib_node_runtime_t * node,
+ vlib_frame_t * frame)
+{
+ return ip4_source_check_inline (vm, node, frame,
+ IP4_SOURCE_CHECK_REACHABLE_VIA_RX);
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (ip4_check_source_reachable_via_any) = {
+ .function = ip4_source_check_reachable_via_any,
+ .name = "ip4-source-check-via-any",
+ .vector_size = sizeof (u32),
+
+ .n_next_nodes = IP4_SOURCE_CHECK_N_NEXT,
+ .next_nodes = {
+ [IP4_SOURCE_CHECK_NEXT_DROP] = "error-drop",
+ },
+
+ .format_buffer = format_ip4_header,
+ .format_trace = format_ip4_source_check_trace,
+};
+/* *INDENT-ON* */
+
+VLIB_NODE_FUNCTION_MULTIARCH (ip4_check_source_reachable_via_any,
+ ip4_source_check_reachable_via_any);
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (ip4_check_source_reachable_via_rx) = {
+ .function = ip4_source_check_reachable_via_rx,
+ .name = "ip4-source-check-via-rx",
+ .vector_size = sizeof (u32),
+
+ .n_next_nodes = IP4_SOURCE_CHECK_N_NEXT,
+ .next_nodes = {
+ [IP4_SOURCE_CHECK_NEXT_DROP] = "error-drop",
+ },
+
+ .format_buffer = format_ip4_header,
+ .format_trace = format_ip4_source_check_trace,
+};
+/* *INDENT-ON* */
+
+VLIB_NODE_FUNCTION_MULTIARCH (ip4_check_source_reachable_via_rx,
+ ip4_source_check_reachable_via_rx);
+
+static clib_error_t *
+set_ip_source_check (vlib_main_t * vm,
+ unformat_input_t * input, vlib_cli_command_t * cmd)
+{
+ unformat_input_t _line_input, *line_input = &_line_input;
+ vnet_main_t *vnm = vnet_get_main ();
+ ip4_main_t *im = &ip4_main;
+ clib_error_t *error = 0;
+ u32 sw_if_index, is_del;
+ ip4_source_check_config_t config;
+ char *feature_name = "ip4-source-check-via-rx";
+
+ sw_if_index = ~0;
+ is_del = 0;
+
+ if (!unformat_user (input, unformat_line_input, line_input))
+ return 0;
+
+ while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
+ {
+ if (unformat_user
+ (line_input, unformat_vnet_sw_interface, vnm, &sw_if_index))
+ ;
+ else if (unformat (line_input, "del"))
+ is_del = 1;
+ else if (unformat (line_input, "loose"))
+ feature_name = "ip4-source-check-via-any";
+ else
+ {
+ error = unformat_parse_error (line_input);
+ goto done;
+ }
+ }
+
+ if (~0 == sw_if_index)
+ {
+ error = clib_error_return (0, "unknown interface `%U'",
+ format_unformat_error, line_input);
+ goto done;
+ }
+
+ config.fib_index = im->fib_index_by_sw_if_index[sw_if_index];
+ vnet_feature_enable_disable ("ip4-unicast", feature_name, sw_if_index,
+ is_del == 0, &config, sizeof (config));
+done:
+ return error;
+}
+
+/*?
+ * This command adds the 'ip4-source-check-via-rx' graph node for
+ * a given interface. By adding the IPv4 source check graph node to
+ * an interface, the code verifies that the source address of incoming
+ * unicast packets are reachable over the incoming interface. Two flavours
+ * are supported (the default is strict):
+ * - loose: accept ingress packet if there is a route to reach the source
+ * - strict: accept ingress packet if it arrived on an interface which
+ * the route to the source uses. i.e. an interface that the source
+ * is reachable via.
+ *
+ * @cliexpar
+ * @parblock
+ * Example of graph node before range checking is enabled:
+ * @cliexstart{show vlib graph ip4-source-check-via-rx}
+ * Name Next Previous
+ * ip4-source-check-via-rx error-drop [0]
+ * @cliexend
+ *
+ * Example of how to enable unicast source checking on an interface:
+ * @cliexcmd{set interface ip source-check GigabitEthernet2/0/0 loose}
+ *
+ * Example of graph node after range checking is enabled:
+ * @cliexstart{show vlib graph ip4-source-check-via-rx}
+ * Name Next Previous
+ * ip4-source-check-via-rx error-drop [0] ip4-input-no-checksum
+ * ip4-source-and-port-range- ip4-input
+ * @cliexend
+ *
+ * Example of how to display the feature enabed on an interface:
+ * @cliexstart{show ip interface features GigabitEthernet2/0/0}
+ * IP feature paths configured on GigabitEthernet2/0/0...
+ *
+ * ipv4 unicast:
+ * ip4-source-check-via-rx
+ * ip4-lookup
+ *
+ * ipv4 multicast:
+ * ip4-lookup-multicast
+ *
+ * ipv4 multicast:
+ * interface-output
+ *
+ * ipv6 unicast:
+ * ip6-lookup
+ *
+ * ipv6 multicast:
+ * ip6-lookup
+ *
+ * ipv6 multicast:
+ * interface-output
+ * @cliexend
+ *
+ * Example of how to disable unicast source checking on an interface:
+ * @cliexcmd{set interface ip source-check GigabitEthernet2/0/0 del}
+ * @endparblock
+?*/
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (set_interface_ip_source_check_command, static) = {
+ .path = "set interface ip source-check",
+ .function = set_ip_source_check,
+ .short_help = "set interface ip source-check <interface> [strict|loose] [del]",
+};
+/* *INDENT-ON* */
+
+static clib_error_t *
+ip_source_check_accept (vlib_main_t * vm,
+ unformat_input_t * input, vlib_cli_command_t * cmd)
+{
+ unformat_input_t _line_input, *line_input = &_line_input;
+ fib_prefix_t pfx = {
+ .fp_proto = FIB_PROTOCOL_IP4,
+ };
+ clib_error_t *error = NULL;
+ u32 table_id, is_add, fib_index;
+
+ is_add = 1;
+ table_id = ~0;
+
+ /* Get a line of input. */
+ if (!unformat_user (input, unformat_line_input, line_input))
+ return 0;
+
+ while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
+ {
+ if (unformat (line_input, "table %d", &table_id))
+ ;
+ else if (unformat (line_input, "del"))
+ is_add = 0;
+ else if (unformat (line_input, "add"))
+ is_add = 1;
+ else if (unformat (line_input, "%U/%d",
+ unformat_ip4_address, &pfx.fp_addr.ip4, &pfx.fp_len))
+ pfx.fp_proto = FIB_PROTOCOL_IP4;
+ else
+ {
+ error = unformat_parse_error (line_input);
+ goto done;
+ }
+ }
+
+ if (~0 != table_id)
+ {
+ fib_index = fib_table_id_find_fib_index (pfx.fp_proto, table_id);
+ if (~0 == fib_index)
+ {
+ error = clib_error_return (0, "Nonexistent table id %d", table_id);
+ goto done;
+ }
+ }
+ else
+ {
+ fib_index = 0;
+ }
+
+ if (is_add)
+ {
+ fib_table_entry_special_add (fib_index,
+ &pfx,
+ FIB_SOURCE_URPF_EXEMPT,
+ FIB_ENTRY_FLAG_DROP, ADJ_INDEX_INVALID);
+ }
+ else
+ {
+ fib_table_entry_special_remove (fib_index,
+ &pfx, FIB_SOURCE_URPF_EXEMPT);
+ }
+
+done:
+ return (error);
+}
+
+/*?
+ * Add an exemption for a prefix to pass the Unicast Reverse Path
+ * Forwarding (uRPF) loose check. This is for testing purposes only.
+ * If the '<em>table</em>' is not enter it is defaulted to 0. Default
+ * is to '<em>add</em>'. VPP always performs a loose uRPF check for
+ * for-us traffic.
+ *
+ * @cliexpar
+ * Example of how to add a uRPF exception to a FIB table to pass the
+ * loose RPF tests:
+ * @cliexcmd{ip urpf-accept table 7 add}
+?*/
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (ip_source_check_accept_command, static) = {
+ .path = "ip urpf-accept",
+ .function = ip_source_check_accept,
+ .short_help = "ip urpf-accept [table <table-id>] [add|del]",
+};
+/* *INDENT-ON* */
+
+
+/* Dummy init function to get us linked in. */
+clib_error_t *
+ip4_source_check_init (vlib_main_t * vm)
+{
+ return 0;
+}
+
+VLIB_INIT_FUNCTION (ip4_source_check_init);
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */