1 /*---------------------------------------------------------------------------
2 * Copyright (c) 2009-2014 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.
14 *---------------------------------------------------------------------------
17 * IPv4 Fragmentation Node
24 #include <vnet/ip/ip.h>
37 format_ip_frag_trace (u8 * s, va_list * args)
39 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
40 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
41 ip_frag_trace_t *t = va_arg (*args, ip_frag_trace_t *);
42 s = format (s, "IPv%s offset: %u mtu: %u fragments: %u",
43 t->ipv6 ? "6" : "4", t->header_offset, t->mtu, t->n_fragments);
47 static u32 running_fragment_id;
50 ip4_frag_do_fragment (vlib_main_t * vm, u32 pi, u32 ** buffer,
51 ip_frag_error_t * error)
55 u16 mtu, ptr, len, max, rem, offset, ip_frag_id, ip_frag_offset;
58 vec_add1 (*buffer, pi);
59 p = vlib_get_buffer (vm, pi);
60 offset = vnet_buffer (p)->ip_frag.header_offset;
61 mtu = vnet_buffer (p)->ip_frag.mtu;
62 packet = (u8 *) vlib_buffer_get_current (p);
63 ip4 = (ip4_header_t *) (packet + offset);
65 rem = clib_net_to_host_u16 (ip4->length) - sizeof (*ip4);
67 max = (mtu - sizeof (*ip4) - vnet_buffer (p)->ip_frag.header_offset) & ~0x7;
69 if (rem < (p->current_length - offset - sizeof (*ip4)))
71 *error = IP_FRAG_ERROR_MALFORMED;
75 if (mtu < sizeof (*ip4))
77 *error = IP_FRAG_ERROR_CANT_FRAGMENT_HEADER;
81 if (ip4->flags_and_fragment_offset &
82 clib_host_to_net_u16 (IP4_HEADER_FLAG_DONT_FRAGMENT))
84 *error = IP_FRAG_ERROR_DONT_FRAGMENT_SET;
88 if (ip4_is_fragment (ip4))
90 ip_frag_id = ip4->fragment_id;
91 ip_frag_offset = ip4_get_fragment_offset (ip4);
93 !(!(ip4->flags_and_fragment_offset &
94 clib_host_to_net_u16 (IP4_HEADER_FLAG_MORE_FRAGMENTS)));
98 ip_frag_id = (++running_fragment_id);
103 //Do the actual fragmentation
112 (mtu - sizeof (*ip4) -
113 vnet_buffer (p)->ip_frag.header_offset)) ? max : rem;
119 fip4 = (ip4_header_t *) (vlib_buffer_get_current (b) + offset);
123 if (!vlib_buffer_alloc (vm, &bi, 1))
125 *error = IP_FRAG_ERROR_MEMORY;
128 vec_add1 (*buffer, bi);
129 b = vlib_get_buffer (vm, bi);
130 vnet_buffer (b)->sw_if_index[VLIB_RX] =
131 vnet_buffer (p)->sw_if_index[VLIB_RX];
132 vnet_buffer (b)->sw_if_index[VLIB_TX] =
133 vnet_buffer (p)->sw_if_index[VLIB_TX];
134 /* Copy Adj_index in case DPO based node is sending for the fragmentation,
135 the packet would be sent back to the proper DPO next node and Index */
136 vnet_buffer (b)->ip.adj_index[VLIB_RX] =
137 vnet_buffer (p)->ip.adj_index[VLIB_RX];
138 vnet_buffer (b)->ip.adj_index[VLIB_TX] =
139 vnet_buffer (p)->ip.adj_index[VLIB_TX];
140 fip4 = (ip4_header_t *) (vlib_buffer_get_current (b) + offset);
142 //Copy offset and ip4 header
143 clib_memcpy (b->data, packet, offset + sizeof (*ip4));
145 clib_memcpy (((u8 *) (fip4)) + sizeof (*fip4),
146 packet + offset + sizeof (*fip4) + ptr, len);
148 b->current_length = offset + len + sizeof (*fip4);
150 fip4->fragment_id = ip_frag_id;
151 fip4->flags_and_fragment_offset =
152 clib_host_to_net_u16 ((ptr >> 3) + ip_frag_offset);
153 fip4->flags_and_fragment_offset |=
154 clib_host_to_net_u16 (((len != rem) || more) << 13);
155 // ((len0 != rem0) || more0) << 13 is optimization for
156 // ((len0 != rem0) || more0) ? IP4_HEADER_FLAG_MORE_FRAGMENTS : 0
157 fip4->length = clib_host_to_net_u16 (len + sizeof (*fip4));
158 fip4->checksum = ip4_header_checksum (fip4);
160 if (vnet_buffer (p)->ip_frag.flags & IP_FRAG_FLAG_IP4_HEADER)
162 //Encapsulating ipv4 header
163 ip4_header_t *encap_header4 =
164 (ip4_header_t *) vlib_buffer_get_current (b);
165 encap_header4->length = clib_host_to_net_u16 (b->current_length);
166 encap_header4->checksum = ip4_header_checksum (encap_header4);
168 else if (vnet_buffer (p)->ip_frag.flags & IP_FRAG_FLAG_IP6_HEADER)
170 //Encapsulating ipv6 header
171 ip6_header_t *encap_header6 =
172 (ip6_header_t *) vlib_buffer_get_current (b);
173 encap_header6->payload_length =
174 clib_host_to_net_u16 (b->current_length -
175 sizeof (*encap_header6));
184 ip_frag_set_vnet_buffer (vlib_buffer_t * b, u16 offset, u16 mtu,
185 u8 next_index, u8 flags)
187 vnet_buffer (b)->ip_frag.header_offset = offset;
188 vnet_buffer (b)->ip_frag.mtu = mtu;
189 vnet_buffer (b)->ip_frag.next_index = next_index;
190 vnet_buffer (b)->ip_frag.flags = flags;
194 ip4_frag (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
196 u32 n_left_from, *from, next_index, *to_next, n_left_to_next;
197 vlib_node_runtime_t *error_node =
198 vlib_node_get_runtime (vm, ip4_frag_node.index);
199 from = vlib_frame_vector_args (frame);
200 n_left_from = frame->n_vectors;
201 next_index = node->cached_next_index;
202 u32 frag_sent = 0, small_packets = 0;
205 while (n_left_from > 0)
207 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
209 while (n_left_from > 0 && n_left_to_next > 0)
211 u32 pi0, *frag_from, frag_left;
213 ip_frag_error_t error0;
214 ip4_frag_next_t next0;
216 //Note: The packet is not enqueued now.
217 //It is instead put in a vector where other fragments
218 //will be put as well.
222 error0 = IP_FRAG_ERROR_NONE;
224 p0 = vlib_get_buffer (vm, pi0);
225 ip4_frag_do_fragment (vm, pi0, &buffer, &error0);
227 if (PREDICT_FALSE (p0->flags & VLIB_BUFFER_IS_TRACED))
229 ip_frag_trace_t *tr =
230 vlib_add_trace (vm, node, p0, sizeof (*tr));
231 tr->header_offset = vnet_buffer (p0)->ip_frag.header_offset;
232 tr->mtu = vnet_buffer (p0)->ip_frag.mtu;
234 tr->n_fragments = vec_len (buffer);
235 tr->next = vnet_buffer (p0)->ip_frag.next_index;
238 if (error0 == IP_FRAG_ERROR_DONT_FRAGMENT_SET)
240 icmp4_error_set_vnet_buffer (p0, ICMP4_destination_unreachable,
241 ICMP4_destination_unreachable_fragmentation_needed_and_dont_fragment_set,
242 vnet_buffer (p0)->ip_frag.mtu);
243 vlib_buffer_advance (p0,
244 vnet_buffer (p0)->ip_frag.header_offset);
245 next0 = IP4_FRAG_NEXT_ICMP_ERROR;
250 next0 = (error0 == IP_FRAG_ERROR_NONE) ? vnet_buffer (p0)->
251 ip_frag.next_index : IP4_FRAG_NEXT_DROP;
255 if (error0 == IP_FRAG_ERROR_NONE)
257 frag_sent += vec_len (buffer);
258 small_packets += (vec_len (buffer) == 1);
261 vlib_error_count (vm, ip4_frag_node.index, error0, 1);
263 //Send fragments that were added in the frame
265 frag_left = vec_len (buffer);
267 while (frag_left > 0)
269 while (frag_left > 0 && n_left_to_next > 0)
272 i = to_next[0] = frag_from[0];
278 vlib_get_buffer (vm, i)->error = error_node->errors[error0];
279 vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
280 to_next, n_left_to_next, i,
283 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
284 vlib_get_next_frame (vm, node, next_index, to_next,
287 vec_reset_length (buffer);
289 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
293 vlib_node_increment_counter (vm, ip4_frag_node.index,
294 IP_FRAG_ERROR_FRAGMENT_SENT, frag_sent);
295 vlib_node_increment_counter (vm, ip4_frag_node.index,
296 IP_FRAG_ERROR_SMALL_PACKET, small_packets);
298 return frame->n_vectors;
303 ip6_frag_do_fragment (vlib_main_t * vm, u32 pi, u32 ** buffer,
304 ip_frag_error_t * error)
307 ip6_header_t *ip6_hdr;
308 ip6_frag_hdr_t *frag_hdr;
309 u8 *payload, *next_header;
311 p = vlib_get_buffer (vm, pi);
313 //Parsing the IPv6 headers
315 vlib_buffer_get_current (p) + vnet_buffer (p)->ip_frag.header_offset;
316 payload = (u8 *) (ip6_hdr + 1);
317 next_header = &ip6_hdr->protocol;
318 if (*next_header == IP_PROTOCOL_IP6_HOP_BY_HOP_OPTIONS)
320 next_header = payload;
321 payload += payload[1] * 8;
324 if (*next_header == IP_PROTOCOL_IP6_DESTINATION_OPTIONS)
326 next_header = payload;
327 payload += payload[1] * 8;
330 if (*next_header == IP_PROTOCOL_IPV6_ROUTE)
332 next_header = payload;
333 payload += payload[1] * 8;
337 (payload >= (u8 *) vlib_buffer_get_current (p) + p->current_length))
339 //A malicious packet could set an extension header with a too big size
340 //and make us modify another vlib_buffer
341 *error = IP_FRAG_ERROR_MALFORMED;
347 if (*next_header == IP_PROTOCOL_IPV6_FRAGMENTATION)
349 //The fragmentation header is already there
350 frag_hdr = (ip6_frag_hdr_t *) payload;
351 has_more = ip6_frag_hdr_more (frag_hdr);
352 initial_offset = ip6_frag_hdr_offset (frag_hdr);
356 //Insert a fragmentation header in the packet
357 u8 nh = *next_header;
358 *next_header = IP_PROTOCOL_IPV6_FRAGMENTATION;
359 vlib_buffer_advance (p, -sizeof (*frag_hdr));
360 u8 *start = vlib_buffer_get_current (p);
361 memmove (start, start + sizeof (*frag_hdr),
362 payload - (start + sizeof (*frag_hdr)));
363 frag_hdr = (ip6_frag_hdr_t *) (payload - sizeof (*frag_hdr));
364 frag_hdr->identification = ++running_fragment_id;
365 frag_hdr->next_hdr = nh;
370 payload = (u8 *) (frag_hdr + 1);
372 u16 headers_len = payload - (u8 *) vlib_buffer_get_current (p);
373 u16 max_payload = vnet_buffer (p)->ip_frag.mtu - headers_len;
374 u16 rem = p->current_length - headers_len;
379 *error = IP_FRAG_ERROR_CANT_FRAGMENT_HEADER;
387 u16 len = (rem > max_payload) ? (max_payload & ~0x7) : rem;
392 if (!vlib_buffer_alloc (vm, &bi, 1))
394 *error = IP_FRAG_ERROR_MEMORY;
397 b = vlib_get_buffer (vm, bi);
398 vnet_buffer (b)->sw_if_index[VLIB_RX] =
399 vnet_buffer (p)->sw_if_index[VLIB_RX];
400 vnet_buffer (b)->sw_if_index[VLIB_TX] =
401 vnet_buffer (p)->sw_if_index[VLIB_TX];
403 /* Copy Adj_index in case DPO based node is sending for the fragmentation,
404 the packet would be sent back to the proper DPO next node and Index */
405 vnet_buffer (b)->ip.adj_index[VLIB_RX] =
406 vnet_buffer (p)->ip.adj_index[VLIB_RX];
407 vnet_buffer (b)->ip.adj_index[VLIB_TX] =
408 vnet_buffer (p)->ip.adj_index[VLIB_TX];
410 clib_memcpy (vlib_buffer_get_current (b),
411 vlib_buffer_get_current (p), headers_len);
412 clib_memcpy (vlib_buffer_get_current (b) + headers_len,
415 vlib_buffer_get_current (b) + headers_len - sizeof (*frag_hdr);
420 b = vlib_get_buffer (vm, bi);
421 //frag_hdr already set here
425 vlib_buffer_get_current (b) + vnet_buffer (p)->ip_frag.header_offset;
426 frag_hdr->fragment_offset_and_more =
427 ip6_frag_hdr_offset_and_more (initial_offset + (ptr >> 3),
429 b->current_length = headers_len + len;
430 ip6_hdr->payload_length =
431 clib_host_to_net_u16 (b->current_length -
432 vnet_buffer (p)->ip_frag.header_offset -
435 if (vnet_buffer (p)->ip_frag.flags & IP_FRAG_FLAG_IP4_HEADER)
437 //Encapsulating ipv4 header
438 ip4_header_t *encap_header4 =
439 (ip4_header_t *) vlib_buffer_get_current (b);
440 encap_header4->length = clib_host_to_net_u16 (b->current_length);
441 encap_header4->checksum = ip4_header_checksum (encap_header4);
443 else if (vnet_buffer (p)->ip_frag.flags & IP_FRAG_FLAG_IP6_HEADER)
445 //Encapsulating ipv6 header
446 ip6_header_t *encap_header6 =
447 (ip6_header_t *) vlib_buffer_get_current (b);
448 encap_header6->payload_length =
449 clib_host_to_net_u16 (b->current_length -
450 sizeof (*encap_header6));
453 vec_add1 (*buffer, bi);
460 ip6_frag (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
462 u32 n_left_from, *from, next_index, *to_next, n_left_to_next;
463 vlib_node_runtime_t *error_node =
464 vlib_node_get_runtime (vm, ip6_frag_node.index);
465 from = vlib_frame_vector_args (frame);
466 n_left_from = frame->n_vectors;
467 next_index = node->cached_next_index;
468 u32 frag_sent = 0, small_packets = 0;
471 while (n_left_from > 0)
473 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
475 while (n_left_from > 0 && n_left_to_next > 0)
477 u32 pi0, *frag_from, frag_left;
479 ip_frag_error_t error0;
480 ip6_frag_next_t next0;
485 error0 = IP_FRAG_ERROR_NONE;
487 p0 = vlib_get_buffer (vm, pi0);
488 ip6_frag_do_fragment (vm, pi0, &buffer, &error0);
490 if (PREDICT_FALSE (p0->flags & VLIB_BUFFER_IS_TRACED))
492 ip_frag_trace_t *tr =
493 vlib_add_trace (vm, node, p0, sizeof (*tr));
494 tr->header_offset = vnet_buffer (p0)->ip_frag.header_offset;
495 tr->mtu = vnet_buffer (p0)->ip_frag.mtu;
497 tr->n_fragments = vec_len (buffer);
498 tr->next = vnet_buffer (p0)->ip_frag.next_index;
502 next0 = (error0 == IP_FRAG_ERROR_NONE) ? vnet_buffer (p0)->
503 ip_frag.next_index : IP6_FRAG_NEXT_DROP;
506 frag_sent += vec_len (buffer);
507 small_packets += (vec_len (buffer) == 1);
509 //Send fragments that were added in the frame
511 frag_left = vec_len (buffer);
512 while (frag_left > 0)
514 while (frag_left > 0 && n_left_to_next > 0)
517 i = to_next[0] = frag_from[0];
523 vlib_get_buffer (vm, i)->error = error_node->errors[error0];
524 vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
525 to_next, n_left_to_next, i,
528 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
529 vlib_get_next_frame (vm, node, next_index, to_next,
532 vec_reset_length (buffer);
534 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
537 vlib_node_increment_counter (vm, ip6_frag_node.index,
538 IP_FRAG_ERROR_FRAGMENT_SENT, frag_sent);
539 vlib_node_increment_counter (vm, ip6_frag_node.index,
540 IP_FRAG_ERROR_SMALL_PACKET, small_packets);
542 return frame->n_vectors;
545 static char *ip4_frag_error_strings[] = {
546 #define _(sym,string) string,
547 foreach_ip_frag_error
552 VLIB_REGISTER_NODE (ip4_frag_node) = {
553 .function = ip4_frag,
554 .name = IP4_FRAG_NODE_NAME,
555 .vector_size = sizeof (u32),
556 .format_trace = format_ip_frag_trace,
557 .type = VLIB_NODE_TYPE_INTERNAL,
559 .n_errors = IP_FRAG_N_ERROR,
560 .error_strings = ip4_frag_error_strings,
562 .n_next_nodes = IP4_FRAG_N_NEXT,
564 [IP4_FRAG_NEXT_IP4_LOOKUP] = "ip4-lookup",
565 [IP4_FRAG_NEXT_IP6_LOOKUP] = "ip6-lookup",
566 [IP4_FRAG_NEXT_ICMP_ERROR] = "ip4-icmp-error",
567 [IP4_FRAG_NEXT_DROP] = "ip4-drop"
573 VLIB_REGISTER_NODE (ip6_frag_node) = {
574 .function = ip6_frag,
575 .name = IP6_FRAG_NODE_NAME,
576 .vector_size = sizeof (u32),
577 .format_trace = format_ip_frag_trace,
578 .type = VLIB_NODE_TYPE_INTERNAL,
580 .n_errors = IP_FRAG_N_ERROR,
581 .error_strings = ip4_frag_error_strings,
583 .n_next_nodes = IP6_FRAG_N_NEXT,
585 [IP6_FRAG_NEXT_IP4_LOOKUP] = "ip4-lookup",
586 [IP6_FRAG_NEXT_IP6_LOOKUP] = "ip6-lookup",
587 [IP6_FRAG_NEXT_DROP] = "ip6-drop"
593 * fd.io coding-style-patch-verification: ON
596 * eval: (c-set-style "gnu")