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.
19 #define DEBUG_TLV_DUMP 0 /* 1=> dump TLV's to stdout while processing them */
22 * ported from an unspecified Cisco cdp implementation.
23 * Compute / return in HOST byte order. 0 => good checksum.
26 cdp_checksum (void *p, int count)
41 sum += *(char *) data;
45 sum = (sum & 0xFFFF) + (sum >> 16);
52 /* TLV handler table */
61 static tlv_handler_t tlv_handlers[];
63 /* Display a generic TLV as a set of hex bytes */
65 format_generic_tlv (u8 * s, va_list * va)
67 cdp_tlv_t *t = va_arg (*va, cdp_tlv_t *);
68 tlv_handler_t *h = &tlv_handlers[t->t];
70 s = format (s, "%s(%d): %U\n", h->name,
71 t->t, format_hex_bytes, t->v, t->l - sizeof (*t));
75 /* Ignore / skip a TLV we don't support */
77 process_generic_tlv (cdp_main_t * cm, cdp_neighbor_t * n, cdp_tlv_t * t)
79 #if DEBUG_TLV_DUMP > 0
80 fformat (stdout, "%U", format_generic_tlv, t);
83 return CDP_ERROR_NONE;
86 /* print a text tlv */
88 format_text_tlv (u8 * s, va_list * va)
90 cdp_tlv_t *t = va_arg (*va, cdp_tlv_t *);
91 tlv_handler_t *h = &tlv_handlers[t->t];
94 s = format (s, "%s(%d): ", h->name, t->t);
98 for (i = 0; i < (t->l - sizeof (*t)); i++)
99 vec_add1 (s, t->v[i]);
106 #if DEBUG_TLV_DUMP == 0
107 /* gcc warning be gone */
108 CLIB_UNUSED (static cdp_error_t
109 process_text_tlv (cdp_main_t * cm, cdp_neighbor_t * n,
113 /* process / skip a generic text TLV that we don't support */
115 process_text_tlv (cdp_main_t * cm, cdp_neighbor_t * n, cdp_tlv_t * t)
117 #if DEBUG_TLV_DUMP > 0
118 fformat (stdout, "%U\n", format_text_tlv, t);
121 return CDP_ERROR_NONE;
124 /* per-TLV format function definitions */
125 #define format_unused_tlv format_generic_tlv
126 #define format_device_name_tlv format_text_tlv
127 #define format_address_tlv format_generic_tlv
128 #define format_port_id_tlv format_text_tlv
129 #define format_capabilities_tlv format_generic_tlv
130 #define format_version_tlv format_text_tlv
131 #define format_platform_tlv format_text_tlv
132 #define format_ipprefix_tlv format_generic_tlv
133 #define format_hello_tlv format_generic_tlv
134 #define format_vtp_domain_tlv format_generic_tlv
135 #define format_native_vlan_tlv format_generic_tlv
136 #define format_duplex_tlv format_generic_tlv
137 #define format_appl_vlan_tlv format_generic_tlv
138 #define format_trigger_tlv format_generic_tlv
139 #define format_power_tlv format_generic_tlv
140 #define format_mtu_tlv format_generic_tlv
141 #define format_trust_tlv format_generic_tlv
142 #define format_cos_tlv format_generic_tlv
143 #define format_sysname_tlv format_generic_tlv
144 #define format_sysobject_tlv format_generic_tlv
145 #define format_mgmt_addr_tlv format_generic_tlv
146 #define format_physical_loc_tlv format_generic_tlv
147 #define format_mgmt_addr2_tlv format_generic_tlv
148 #define format_power_requested_tlv format_generic_tlv
149 #define format_power_available_tlv format_generic_tlv
150 #define format_port_unidirectional_tlv format_generic_tlv
151 #define format_unknown_28_tlv format_generic_tlv
152 #define format_energywise_tlv format_generic_tlv
153 #define format_unknown_30_tlv format_generic_tlv
154 #define format_spare_poe_tlv format_generic_tlv
156 /* tlv ID=0 is a mistake */
158 process_unused_tlv (cdp_main_t * cm, cdp_neighbor_t * n, cdp_tlv_t * t)
160 return CDP_ERROR_BAD_TLV;
163 /* list of text TLV's that we snapshoot */
164 #define foreach_text_to_struct_tlv \
165 _(device_name,DEBUG_TLV_DUMP) \
166 _(version,DEBUG_TLV_DUMP) \
167 _(platform,DEBUG_TLV_DUMP) \
168 _(port_id,DEBUG_TLV_DUMP)
172 cdp_error_t process_##z##_tlv (cdp_main_t *cm, cdp_neighbor_t *n, \
177 fformat(stdout, "%U\n", format_text_tlv, t); \
180 _vec_len(n->z) = 0; \
182 for (i = 0; i < (t->l - sizeof (*t)); i++) \
183 vec_add1(n->z, t->v[i]); \
187 return CDP_ERROR_NONE; \
190 foreach_text_to_struct_tlv
192 #define process_address_tlv process_generic_tlv
193 #define process_capabilities_tlv process_generic_tlv
194 #define process_ipprefix_tlv process_generic_tlv
195 #define process_hello_tlv process_generic_tlv
196 #define process_vtp_domain_tlv process_generic_tlv
197 #define process_native_vlan_tlv process_generic_tlv
198 #define process_duplex_tlv process_generic_tlv
199 #define process_appl_vlan_tlv process_generic_tlv
200 #define process_trigger_tlv process_generic_tlv
201 #define process_power_tlv process_generic_tlv
202 #define process_mtu_tlv process_generic_tlv
203 #define process_trust_tlv process_generic_tlv
204 #define process_cos_tlv process_generic_tlv
205 #define process_sysname_tlv process_generic_tlv
206 #define process_sysobject_tlv process_generic_tlv
207 #define process_mgmt_addr_tlv process_generic_tlv
208 #define process_physical_loc_tlv process_generic_tlv
209 #define process_mgmt_addr2_tlv process_generic_tlv
210 #define process_power_requested_tlv process_generic_tlv
211 #define process_power_available_tlv process_generic_tlv
212 #define process_port_unidirectional_tlv process_generic_tlv
213 #define process_unknown_28_tlv process_generic_tlv
214 #define process_energywise_tlv process_generic_tlv
215 #define process_unknown_30_tlv process_generic_tlv
216 #define process_spare_poe_tlv process_generic_tlv
217 static tlv_handler_t tlv_handlers[] = {
218 #define _(a) {#a, CDP_TLV_##a, format_##a##_tlv, process_##a##_tlv},
223 #if DEBUG_TLV_DUMP == 0
224 CLIB_UNUSED (static u8 * format_cdp_hdr (u8 * s, va_list * va));
228 format_cdp_hdr (u8 * s, va_list * va)
230 cdp_hdr_t *h = va_arg (*va, cdp_hdr_t *);
232 s = format (s, "version %d, ttl %d(secs), cksum 0x%04x\n",
233 h->version, h->ttl, h->checksum);
238 process_cdp_hdr (cdp_main_t * cm, cdp_neighbor_t * n, cdp_hdr_t * h)
240 #if DEBUG_TLV_DUMP > 0
241 fformat (stdout, "%U", format_cdp_hdr, h);
244 if (h->version != 1 && h->version != 2)
245 return CDP_ERROR_PROTOCOL_VERSION;
247 n->ttl_in_seconds = h->ttl;
249 return CDP_ERROR_NONE;
252 /* scan a cdp packet; header, then tlv's */
254 cdp_packet_scan (cdp_main_t * cm, cdp_neighbor_t * n)
256 u8 *end, *cur = n->last_rx_pkt;
259 cdp_error_t e = CDP_ERROR_NONE;
260 tlv_handler_t *handler;
261 cdp_error_t (*fp) (cdp_main_t *, cdp_neighbor_t *, cdp_tlv_t *);
262 u16 computed_checksum;
264 computed_checksum = cdp_checksum (cur, vec_len (cur));
266 if (computed_checksum)
267 return CDP_ERROR_CHECKSUM;
269 h = (cdp_hdr_t *) cur;
271 e = process_cdp_hdr (cm, n, h);
276 if (vec_len (n->last_rx_pkt) <= 0)
277 return CDP_ERROR_BAD_TLV;
279 cur = (u8 *) (h + 1);
280 end = n->last_rx_pkt + vec_len (n->last_rx_pkt) - 1;
282 // look ahead 4 bytes (u16 tlv->t + u16 tlv->l)
283 while (cur + 3 <= end)
285 tlv = (cdp_tlv_t *) cur;
286 tlv->t = ntohs (tlv->t);
287 tlv->l = ntohs (tlv->l);
289 /* tlv length includes t, l and v */
292 return CDP_ERROR_BAD_TLV;
296 return CDP_ERROR_BAD_TLV;
299 * Only process known TLVs. In practice, certain
300 * devices send tlv->t = 0xFF, perhaps as an EOF of sorts.
302 if (tlv->t < ARRAY_LEN (tlv_handlers))
304 handler = &tlv_handlers[tlv->t];
305 fp = handler->process;
306 e = (*fp) (cm, n, tlv);
312 // did not process all tlvs or none tlv processed
313 if ((cur - 1) != end)
314 return CDP_ERROR_BAD_TLV;
316 return CDP_ERROR_NONE;
323 cdp_input (vlib_main_t * vm, vlib_buffer_t * b0, u32 bi0)
325 cdp_main_t *cm = &cdp_main;
329 uword last_packet_signature;
331 /* find or create a neighbor pool entry for the (sw) interface
332 upon which we received this pkt */
333 p = hash_get (cm->neighbor_by_sw_if_index,
334 vnet_buffer (b0)->sw_if_index[VLIB_RX]);
338 pool_get (cm->neighbors, n);
339 clib_memset (n, 0, sizeof (*n));
340 n->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
341 n->packet_template_index = (u8) ~ 0;
342 hash_set (cm->neighbor_by_sw_if_index, n->sw_if_index,
347 n = pool_elt_at_index (cm->neighbors, p[0]);
351 * typical clib idiom. Don't repeatedly allocate and free
352 * the per-neighbor rx buffer. Reset its apparent length to zero
357 _vec_len (n->last_rx_pkt) = 0;
359 /* cdp disabled on this interface, we're done */
361 return CDP_ERROR_DISABLED;
364 * Make sure the per-neighbor rx buffer is big enough to hold
365 * the data we're about to copy
367 vec_validate (n->last_rx_pkt, vlib_buffer_length_in_chain (vm, b0) - 1);
370 * Coalesce / copy e the buffer chain into the per-neighbor
373 nbytes = vlib_buffer_contents (vm, bi0, n->last_rx_pkt);
374 ASSERT (nbytes <= vec_len (n->last_rx_pkt));
377 * Compute Jenkins hash of the new packet, decide if we need to
378 * actually parse through the TLV's. CDP packets are all identical,
379 * so unless we time out the peer, we don't need to process the packet.
381 last_packet_signature =
382 hash_memory (n->last_rx_pkt, vec_len (n->last_rx_pkt), 0xd00b);
384 if (n->last_packet_signature_valid &&
385 n->last_packet_signature == last_packet_signature)
387 e = CDP_ERROR_CACHE_HIT;
391 /* Actually scan the packet */
392 e = cdp_packet_scan (cm, n);
393 n->last_packet_signature_valid = 1;
394 n->last_packet_signature = last_packet_signature;
397 if (e == CDP_ERROR_NONE)
399 n->last_heard = vlib_time_now (vm);
406 * setup neighbor hash table
408 static clib_error_t *
409 cdp_input_init (vlib_main_t * vm)
411 cdp_main_t *cm = &cdp_main;
414 cm->vnet_main = vnet_get_main ();
415 cm->neighbor_by_sw_if_index = hash_create (0, sizeof (uword));
421 VLIB_INIT_FUNCTION (cdp_input_init) =
423 .runs_after = VLIB_INITS("cdp_periodic_init"),
429 format_cdp_neighbors (u8 * s, va_list * va)
431 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*va, vlib_main_t *);
432 cdp_main_t *cm = va_arg (*va, cdp_main_t *);
433 vnet_main_t *vnm = &vnet_main;
435 vnet_hw_interface_t *hw;
438 "%=25s %=25s %=25s %=10s\n",
439 "Our Port", "Peer System", "Peer Port", "Last Heard");
442 pool_foreach (n, cm->neighbors,
444 hw = vnet_get_sup_hw_interface (vnm, n->sw_if_index);
446 if (n->disabled == 0)
447 s = format (s, "%=25v %=25s %=25s %=10.1f\n",
448 hw->name, n->device_name, n->port_id,
455 static clib_error_t *
456 show_cdp (vlib_main_t * vm,
457 unformat_input_t * input, vlib_cli_command_t * cmd)
459 cdp_main_t *cm = &cdp_main;
461 if (cm->enabled == 0)
462 vlib_cli_output (vm, "CDP is not enabled...");
464 vlib_cli_output (vm, "%U\n", format_cdp_neighbors, vm, cm);
470 VLIB_CLI_COMMAND (show_cdp_command, static) = {
472 .short_help = "Show cdp command",
473 .function = show_cdp,
479 * packet trace format function, very similar to
480 * cdp_packet_scan except that we call the per TLV format
481 * functions instead of the per TLV processing functions
484 cdp_input_format_trace (u8 * s, va_list * args)
486 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
487 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
488 cdp_input_trace_t *t = va_arg (*args, cdp_input_trace_t *);
492 tlv_handler_t *handler;
493 u8 *(*fp) (cdp_tlv_t *);
497 h = (cdp_hdr_t *) cur;
498 s = format (s, "%U", format_cdp_hdr, h);
500 cur = (u8 *) (h + 1);
502 while (cur < t->data + t->len)
504 tlv = (cdp_tlv_t *) cur;
505 tlv->t = ntohs (tlv->t);
506 tlv->l = ntohs (tlv->l);
507 if (tlv->t >= ARRAY_LEN (tlv_handlers))
509 s = format (s, "BAD_TLV\n");
512 handler = &tlv_handlers[tlv->t];
513 fp = handler->format;
514 s = format (s, " %U", fp, tlv);
515 /* tlv length includes (t, l) */
523 * fd.io coding-style-patch-verification: ON
526 * eval: (c-set-style "gnu")