2 * Copyright (c) 2016 Cisco and/or its affiliates.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at:
7 * http://www.apache.org/licenses/LICENSE-2.0
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
16 * An adjacency is a representation of an attached L3 peer.
18 * Adjacency Sub-types:
19 * - neighbour: a representation of an attached L3 peer.
20 * Key:{addr,interface,link/ether-type}
22 * - glean: used to drive ARP/ND for packets destined to a local sub-net.
23 * 'glean' mean use the packet's destination address as the target
24 * address in the ARP packet.
25 * UNSHARED. Only one per-interface.
26 * - midchain: a nighbour adj on a virtual/tunnel interface.
28 * The API to create and update the adjacency is very sub-type specific. This
29 * is intentional as it encourages the user to carefully consider which adjacency
30 * sub-type they are really using, and hence assign it data in the appropriate
31 * sub-type space in the union of sub-types. This prevents the adj becoming a
32 * disorganised dumping group for 'my features needs a u16 somewhere' data. It
33 * is important to enforce this approach as space in the adjacency is a premium,
34 * as we need it to fit in 1 cache line.
36 * the API is also based around an index to an ajdacency not a raw pointer. This
37 * is so the user doesn't suffer the same limp inducing firearm injuries that
38 * the author suffered as the adjacenices can realloc.
44 #include <vnet/adj/adj_types.h>
45 #include <vnet/adj/adj_nbr.h>
46 #include <vnet/adj/adj_glean.h>
47 #include <vnet/adj/rewrite.h>
49 /** @brief Common (IP4/IP6) next index stored in adjacency. */
52 /** Adjacency to drop this packet. */
54 /** Adjacency to punt this packet. */
57 /** This packet is for one of our own IP addresses. */
60 /** This packet matches an "incomplete adjacency" and packets
61 need to be passed to ARP to find rewrite string for
65 /** This packet matches an "interface route" and packets
66 need to be passed to ARP to find rewrite string for
70 /** This packet is to be rewritten and forwarded to the next
71 processing node. This is typically the output interface but
72 might be another node for further output processing. */
73 IP_LOOKUP_NEXT_REWRITE,
75 /** This packets follow a mid-chain adjacency */
76 IP_LOOKUP_NEXT_MIDCHAIN,
78 /** This packets needs to go to ICMP error */
79 IP_LOOKUP_NEXT_ICMP_ERROR,
81 /** Multicast Adjacency. */
85 } __attribute__ ((packed)) ip_lookup_next_t;
89 IP4_LOOKUP_N_NEXT = IP_LOOKUP_N_NEXT,
94 /* Hop-by-hop header handling */
95 IP6_LOOKUP_NEXT_HOP_BY_HOP = IP_LOOKUP_N_NEXT,
96 IP6_LOOKUP_NEXT_ADD_HOP_BY_HOP,
97 IP6_LOOKUP_NEXT_POP_HOP_BY_HOP,
101 #define IP4_LOOKUP_NEXT_NODES { \
102 [IP_LOOKUP_NEXT_DROP] = "ip4-drop", \
103 [IP_LOOKUP_NEXT_PUNT] = "ip4-punt", \
104 [IP_LOOKUP_NEXT_LOCAL] = "ip4-local", \
105 [IP_LOOKUP_NEXT_ARP] = "ip4-arp", \
106 [IP_LOOKUP_NEXT_GLEAN] = "ip4-glean", \
107 [IP_LOOKUP_NEXT_REWRITE] = "ip4-rewrite", \
108 [IP_LOOKUP_NEXT_MCAST] = "ip4-rewrite-mcast", \
109 [IP_LOOKUP_NEXT_MIDCHAIN] = "ip4-midchain", \
110 [IP_LOOKUP_NEXT_ICMP_ERROR] = "ip4-icmp-error", \
113 #define IP6_LOOKUP_NEXT_NODES { \
114 [IP_LOOKUP_NEXT_DROP] = "ip6-drop", \
115 [IP_LOOKUP_NEXT_PUNT] = "ip6-punt", \
116 [IP_LOOKUP_NEXT_LOCAL] = "ip6-local", \
117 [IP_LOOKUP_NEXT_ARP] = "ip6-discover-neighbor", \
118 [IP_LOOKUP_NEXT_GLEAN] = "ip6-glean", \
119 [IP_LOOKUP_NEXT_REWRITE] = "ip6-rewrite", \
120 [IP_LOOKUP_NEXT_MCAST] = "ip6-rewrite-mcast", \
121 [IP_LOOKUP_NEXT_MIDCHAIN] = "ip6-midchain", \
122 [IP_LOOKUP_NEXT_ICMP_ERROR] = "ip6-icmp-error", \
123 [IP6_LOOKUP_NEXT_HOP_BY_HOP] = "ip6-hop-by-hop", \
124 [IP6_LOOKUP_NEXT_ADD_HOP_BY_HOP] = "ip6-add-hop-by-hop", \
125 [IP6_LOOKUP_NEXT_POP_HOP_BY_HOP] = "ip6-pop-hop-by-hop", \
131 struct ip_adjacency_t_;
134 * @brief A function type for post-rewrite fixups on midchain adjacency
136 typedef void (*adj_midchain_fixup_t) (vlib_main_t * vm,
137 struct ip_adjacency_t_ * adj,
141 * @brief Flags on an IP adjacency
143 typedef enum ip_adjacency_flags_t_
148 * Currently a sync walk is active. Used to prevent re-entrant walking
150 ADJ_FLAG_SYNC_WALK_ACTIVE = (1 << 0),
153 * Packets TX through the midchain do not increment the interface
154 * counters. This should be used when the adj is associated with an L2
155 * interface and that L2 interface is in a bridege domain. In that case
156 * the packet will have traversed the interface's TX node, and hence have
157 * been counted, before it traverses ths midchain
159 ADJ_FLAG_MIDCHAIN_NO_COUNT = (1 << 1),
160 } __attribute__ ((packed)) adj_flags_t;
163 * @brief IP unicast adjacency.
164 * @note cache aligned.
166 * An adjacency is a represenation of a peer on a particular link.
168 typedef struct ip_adjacency_t_
170 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
173 * Linkage into the FIB node grpah. First member since this type
174 * has 8 byte alignment requirements.
179 * Next hop after ip4-lookup.
180 * This is not accessed in the rewrite nodes.
183 ip_lookup_next_t lookup_next_index;
192 * The protocol of the neighbor/peer. i.e. the protocol with
193 * which to interpret the 'next-hop' attirbutes of the sub-types.
196 fib_protocol_t ia_nh_proto;
199 * Flags on the adjacency
202 adj_flags_t ia_flags;
207 * IP_LOOKUP_NEXT_ARP/IP_LOOKUP_NEXT_REWRITE
209 * neighbour adjacency sub-type;
213 ip46_address_t next_hop;
216 * IP_LOOKUP_NEXT_MIDCHAIN
218 * A nbr adj that is also recursive. Think tunnels.
219 * A nbr adj can transition to be of type MDICHAIN
220 * so be sure to leave the two structs with the next_hop
226 * The recursive next-hop.
227 * This field MUST be at the same memory location as
228 * sub_type.nbr.next_hop
230 ip46_address_t next_hop;
232 * The next DPO to use
236 * A function to perform the post-rewrite fixup
238 adj_midchain_fixup_t fixup_func;
241 * IP_LOOKUP_NEXT_GLEAN
243 * Glean the address to ARP for from the packet's destination.
244 * Technically these aren't adjacencies, i.e. they are not a
245 * representation of a peer. One day we might untangle this coupling
246 * and use a new Glean DPO.
250 ip46_address_t receive_addr;
254 CLIB_CACHE_LINE_ALIGN_MARK (cacheline1);
256 /* Rewrite in second/third cache lines */
257 vnet_declare_rewrite (VLIB_BUFFER_PRE_DATA_SIZE);
260 STATIC_ASSERT ((STRUCT_OFFSET_OF (ip_adjacency_t, cacheline0) == 0),
261 "IP adjacency cachline 0 is not offset");
262 STATIC_ASSERT ((STRUCT_OFFSET_OF (ip_adjacency_t, cacheline1) ==
263 CLIB_CACHE_LINE_BYTES),
264 "IP adjacency cachline 1 is more than one cachline size offset");
268 * Take a reference counting lock on the adjacency
270 extern void adj_lock(adj_index_t adj_index);
273 * Release a reference counting lock on the adjacency
275 extern void adj_unlock(adj_index_t adj_index);
279 * Add a child dependent to an adjacency. The child will
280 * thus be informed via its registerd back-walk function
281 * when the adjacency state changes.
283 extern u32 adj_child_add(adj_index_t adj_index,
284 fib_node_type_t type,
285 fib_node_index_t child_index);
288 * Remove a child dependent
290 extern void adj_child_remove(adj_index_t adj_index,
294 * @brief Walk the Adjacencies on a given interface
296 extern void adj_walk (u32 sw_if_index,
301 * @brief Return the link type of the adjacency
303 extern vnet_link_t adj_get_link_type (adj_index_t ai);
306 * @brief Return the sw interface index of the adjacency.
308 extern u32 adj_get_sw_if_index (adj_index_t ai);
311 * @brief Return the link type of the adjacency
313 extern const u8* adj_get_rewrite (adj_index_t ai);
316 * @brief Notify the adjacency subsystem that the features settings for
317 * an interface have changed
319 extern void adj_feature_update (u32 sw_if_index, u8 arc_index, u8 is_enable);
323 * The global adjacnecy pool. Exposed for fast/inline data-plane access
325 extern ip_adjacency_t *adj_pool;
329 * Adjacency packet counters
331 extern vlib_combined_counter_main_t adjacency_counters;
334 * @brief Global Config for enabling per-adjacency counters
335 * This is configurable because it comes with a non-negligible
336 * performance cost. */
337 extern int adj_per_adj_counters;
341 * Get a pointer to an adjacency object from its index
343 static inline ip_adjacency_t *
344 adj_get (adj_index_t adj_index)
346 return (vec_elt_at_index(adj_pool, adj_index));
350 * @brief Get the global configuration option for enabling per-adj counters
353 adj_are_counters_enabled (void)
355 return (adj_per_adj_counters);