2 * Copyright (c) 2011-2016 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.
15 #include <vnet/cdp/cdp_node.h>
19 #define DEBUG_TLV_DUMP 0 /* 1=> dump TLV's to stdout while processing them */
21 /* Reliable multicast messages we use to keep peers updated */
22 mc_serialize_msg_t serialize_cdp_neighbor_msg;
23 mc_serialize_msg_t serialize_cdp_keepalive_msg;
26 * ported from an unspecified Cisco cdp implementation.
27 * Compute / return in HOST byte order. 0 => good checksum.
29 u16 cdp_checksum (void *p, int count)
46 sum = (sum & 0xFFFF) + (sum >> 16);
53 /* TLV handler table */
61 static tlv_handler_t tlv_handlers [];
63 /* Display a generic TLV as a set of hex bytes */
64 static u8 * format_generic_tlv (u8 * s, va_list * va)
66 cdp_tlv_t *t = va_arg (*va, cdp_tlv_t *);
67 tlv_handler_t *h = &tlv_handlers[t->t];
69 s = format (s, "%s(%d): %U\n", h->name,
70 t->t, format_hex_bytes, t->v, t->l - sizeof (*t));
74 /* Ignore / skip a TLV we don't support */
75 static cdp_error_t process_generic_tlv (cdp_main_t *cm, cdp_neighbor_t *n,
78 #if DEBUG_TLV_DUMP > 0
79 fformat(stdout, "%U", format_generic_tlv, t);
82 return CDP_ERROR_NONE;
85 /* print a text tlv */
86 static u8 * format_text_tlv (u8 * s, va_list * va)
88 cdp_tlv_t *t = va_arg (*va, cdp_tlv_t *);
89 tlv_handler_t *h = &tlv_handlers[t->t];
92 s = format (s, "%s(%d): ", h->name, t->t);
94 for (i = 0; i < (t->l - sizeof (*t)); i++)
101 #if DEBUG_TLV_DUMP == 0
102 /* gcc warning be gone */
103 CLIB_UNUSED (static cdp_error_t
104 process_text_tlv (cdp_main_t *cm, cdp_neighbor_t *n,
108 /* process / skip a generic text TLV that we don't support */
109 static cdp_error_t process_text_tlv (cdp_main_t *cm, cdp_neighbor_t *n,
112 #if DEBUG_TLV_DUMP > 0
113 fformat(stdout, "%U\n", format_text_tlv, t);
116 return CDP_ERROR_NONE;
119 /* per-TLV format function definitions */
120 #define format_unused_tlv format_generic_tlv
121 #define format_device_name_tlv format_text_tlv
122 #define format_address_tlv format_generic_tlv
123 #define format_port_id_tlv format_text_tlv
124 #define format_capabilities_tlv format_generic_tlv
125 #define format_version_tlv format_text_tlv
126 #define format_platform_tlv format_text_tlv
127 #define format_ipprefix_tlv format_generic_tlv
128 #define format_hello_tlv format_generic_tlv
129 #define format_vtp_domain_tlv format_generic_tlv
130 #define format_native_vlan_tlv format_generic_tlv
131 #define format_duplex_tlv format_generic_tlv
132 #define format_appl_vlan_tlv format_generic_tlv
133 #define format_trigger_tlv format_generic_tlv
134 #define format_power_tlv format_generic_tlv
135 #define format_mtu_tlv format_generic_tlv
136 #define format_trust_tlv format_generic_tlv
137 #define format_cos_tlv format_generic_tlv
138 #define format_sysname_tlv format_generic_tlv
139 #define format_sysobject_tlv format_generic_tlv
140 #define format_mgmt_addr_tlv format_generic_tlv
141 #define format_physical_loc_tlv format_generic_tlv
142 #define format_mgmt_addr2_tlv format_generic_tlv
143 #define format_power_requested_tlv format_generic_tlv
144 #define format_power_available_tlv format_generic_tlv
145 #define format_port_unidirectional_tlv format_generic_tlv
146 #define format_unknown_28_tlv format_generic_tlv
147 #define format_energywise_tlv format_generic_tlv
148 #define format_unknown_30_tlv format_generic_tlv
149 #define format_spare_poe_tlv format_generic_tlv
151 /* tlv ID=0 is a mistake */
152 static cdp_error_t process_unused_tlv (cdp_main_t *cm, cdp_neighbor_t *n,
155 return CDP_ERROR_BAD_TLV;
158 /* list of text TLV's that we snapshoot */
159 #define foreach_text_to_struct_tlv \
160 _(device_name,DEBUG_TLV_DUMP) \
161 _(version,DEBUG_TLV_DUMP) \
162 _(platform,DEBUG_TLV_DUMP) \
163 _(port_id,DEBUG_TLV_DUMP)
167 cdp_error_t process_##z##_tlv (cdp_main_t *cm, cdp_neighbor_t *n, \
172 fformat(stdout, "%U\n", format_text_tlv, t); \
175 _vec_len(n->z) = 0; \
177 for (i = 0; i < (t->l - sizeof (*t)); i++) \
178 vec_add1(n->z, t->v[i]); \
182 return CDP_ERROR_NONE; \
185 foreach_text_to_struct_tlv
188 #define process_address_tlv process_generic_tlv
189 #define process_capabilities_tlv process_generic_tlv
190 #define process_ipprefix_tlv process_generic_tlv
191 #define process_hello_tlv process_generic_tlv
192 #define process_vtp_domain_tlv process_generic_tlv
193 #define process_native_vlan_tlv process_generic_tlv
194 #define process_duplex_tlv process_generic_tlv
195 #define process_appl_vlan_tlv process_generic_tlv
196 #define process_trigger_tlv process_generic_tlv
197 #define process_power_tlv process_generic_tlv
198 #define process_mtu_tlv process_generic_tlv
199 #define process_trust_tlv process_generic_tlv
200 #define process_cos_tlv process_generic_tlv
201 #define process_sysname_tlv process_generic_tlv
202 #define process_sysobject_tlv process_generic_tlv
203 #define process_mgmt_addr_tlv process_generic_tlv
204 #define process_physical_loc_tlv process_generic_tlv
205 #define process_mgmt_addr2_tlv process_generic_tlv
206 #define process_power_requested_tlv process_generic_tlv
207 #define process_power_available_tlv process_generic_tlv
208 #define process_port_unidirectional_tlv process_generic_tlv
209 #define process_unknown_28_tlv process_generic_tlv
210 #define process_energywise_tlv process_generic_tlv
211 #define process_unknown_30_tlv process_generic_tlv
212 #define process_spare_poe_tlv process_generic_tlv
214 static tlv_handler_t tlv_handlers [] =
216 #define _(a) {#a, CDP_TLV_##a, format_##a##_tlv, process_##a##_tlv},
221 #if DEBUG_TLV_DUMP == 0
222 CLIB_UNUSED(static u8 * format_cdp_hdr (u8 * s, va_list * va));
225 static u8 * format_cdp_hdr (u8 * s, va_list * va)
227 cdp_hdr_t *h = va_arg (*va, cdp_hdr_t *);
229 s = format (s, "version %d, ttl %d(secs), cksum 0x%04x\n",
230 h->version, h->ttl, h->checksum);
234 static cdp_error_t process_cdp_hdr (cdp_main_t *cm, cdp_neighbor_t *n,
237 #if DEBUG_TLV_DUMP > 0
238 fformat(stdout, "%U", format_cdp_hdr, h);
241 if (h->version != 1 && h->version != 2)
242 return CDP_ERROR_PROTOCOL_VERSION;
244 n->ttl_in_seconds = h->ttl;
246 return CDP_ERROR_NONE;
249 /* scan a cdp packet; header, then tlv's */
250 static int cdp_packet_scan (cdp_main_t *cm, cdp_neighbor_t *n)
252 u8 *cur = n->last_rx_pkt;
255 cdp_error_t e = CDP_ERROR_NONE;
256 tlv_handler_t *handler;
257 cdp_error_t (*fp)(cdp_main_t *, cdp_neighbor_t *, cdp_tlv_t *);
258 u16 computed_checksum;
260 computed_checksum = cdp_checksum (cur, vec_len(cur));
262 if (computed_checksum)
263 return CDP_ERROR_CHECKSUM;
265 h = (cdp_hdr_t *)cur;
267 e = process_cdp_hdr (cm, n, h);
273 while (cur < n->last_rx_pkt + vec_len (n->last_rx_pkt) - 1) {
274 tlv = (cdp_tlv_t *)cur;
275 tlv->t = ntohs(tlv->t);
276 tlv->l = ntohs(tlv->l);
277 if (tlv->t >= ARRAY_LEN(tlv_handlers))
278 return CDP_ERROR_BAD_TLV;
279 handler = &tlv_handlers[tlv->t];
280 fp = handler->process;
281 e = (*fp)(cm, n, tlv);
284 /* tlv length includes (t, l) */
288 return CDP_ERROR_NONE;
294 cdp_error_t cdp_input (vlib_main_t *vm, vlib_buffer_t * b0, u32 bi0)
296 cdp_main_t * cm = &cdp_main;
300 uword last_packet_signature;
302 /* find or create a neighbor pool entry for the (sw) interface
303 upon which we received this pkt */
304 p = hash_get (cm->neighbor_by_sw_if_index,
305 vnet_buffer(b0)->sw_if_index[VLIB_RX]);
308 pool_get (cm->neighbors, n);
309 memset (n, 0, sizeof (*n));
310 n->sw_if_index = vnet_buffer(b0)->sw_if_index[VLIB_RX];
311 n->packet_template_index = (u8)~0;
312 hash_set (cm->neighbor_by_sw_if_index, n->sw_if_index,
315 n = pool_elt_at_index (cm->neighbors, p[0]);
319 * typical clib idiom. Don't repeatedly allocate and free
320 * the per-neighbor rx buffer. Reset its apparent length to zero
325 _vec_len (n->last_rx_pkt) = 0;
327 /* cdp disabled on this interface, we're done */
329 return CDP_ERROR_DISABLED;
332 * Make sure the per-neighbor rx buffer is big enough to hold
333 * the data we're about to copy
335 vec_validate (n->last_rx_pkt, vlib_buffer_length_in_chain (vm, b0)-1);
338 * Coalesce / copy e the buffer chain into the per-neighbor
341 nbytes = vlib_buffer_contents (vm, bi0, n->last_rx_pkt);
342 ASSERT(nbytes <= vec_len (n->last_rx_pkt));
345 * Compute Jenkins hash of the new packet, decide if we need to
346 * actually parse through the TLV's. CDP packets are all identical,
347 * so unless we time out the peer, we don't need to process the packet.
349 last_packet_signature =
350 hash_memory (n->last_rx_pkt, vec_len (n->last_rx_pkt), 0xd00b);
352 if (n->last_packet_signature_valid &&
353 n->last_packet_signature == last_packet_signature) {
354 e = CDP_ERROR_CACHE_HIT;
356 /* Actually scan the packet */
357 e = cdp_packet_scan (cm, n);
358 n->last_packet_signature_valid = 1;
359 n->last_packet_signature = last_packet_signature;
362 if (e == CDP_ERROR_NONE) {
363 n->last_heard = vlib_time_now (vm);
370 * setup neighbor hash table
372 static clib_error_t *cdp_init (vlib_main_t *vm)
374 clib_error_t * error;
375 cdp_main_t *cm = &cdp_main;
376 void vnet_cdp_node_reference(void);
378 vnet_cdp_node_reference();
380 if ((error = vlib_call_init_function (vm, cdp_periodic_init)))
384 cm->vnet_main = vnet_get_main();
385 cm->neighbor_by_sw_if_index = hash_create (0, sizeof (uword));
390 VLIB_INIT_FUNCTION (cdp_init);
393 static u8 * format_cdp_neighbors (u8 * s, va_list * va)
395 CLIB_UNUSED(vlib_main_t *vm) = va_arg (*va, vlib_main_t *);
396 cdp_main_t *cm = va_arg (*va, cdp_main_t *);
397 vnet_main_t * vnm = & vnet_main;
399 vnet_hw_interface_t *hw;
402 "%=25s %=15s %=25s %=10s\n",
403 "Our Port", "Peer System", "Peer Port", "Last Heard");
405 pool_foreach (n, cm->neighbors,
407 hw = vnet_get_sup_hw_interface (vnm, n->sw_if_index);
409 if (n->disabled == 0)
410 s = format (s, "%=25s %=15s %=25s %=10.1f\n",
411 hw->name, n->device_name, n->port_id,
418 static clib_error_t *
419 show_cdp (vlib_main_t * vm,
420 unformat_input_t * input,
421 vlib_cli_command_t * cmd)
423 cdp_main_t *cm = &cdp_main;
425 vlib_cli_output (vm, "%U\n", format_cdp_neighbors, vm, cm);
430 VLIB_CLI_COMMAND (show_cdp_command, static) = {
432 .short_help = "Show cdp command",
433 .function = show_cdp,
438 * packet trace format function, very similar to
439 * cdp_packet_scan except that we call the per TLV format
440 * functions instead of the per TLV processing functions
442 u8 * cdp_input_format_trace (u8 * s, va_list * args)
444 CLIB_UNUSED(vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
445 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
446 cdp_input_trace_t * t = va_arg (*args, cdp_input_trace_t *);
450 tlv_handler_t *handler;
451 u8 * (*fp)(cdp_tlv_t *);
455 h = (cdp_hdr_t *)cur;
456 s = format (s, "%U", format_cdp_hdr, h);
460 while (cur < t->data + t->len) {
461 tlv = (cdp_tlv_t *)cur;
462 tlv->t = ntohs(tlv->t);
463 tlv->l = ntohs(tlv->l);
464 if (tlv->t > ARRAY_LEN(tlv_handlers)) {
465 s = format (s, "BAD_TLV\n");
468 handler = &tlv_handlers[tlv->t];
469 fp = handler->format;
470 s = format (s, " %U", fp, tlv);
471 /* tlv length includes (t, l) */