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 fip4 = (ip4_header_t *) (vlib_buffer_get_current (b) + offset);
136 //Copy offset and ip4 header
137 clib_memcpy (b->data, packet, offset + sizeof (*ip4));
139 clib_memcpy (((u8 *) (fip4)) + sizeof (*fip4),
140 packet + offset + sizeof (*fip4) + ptr, len);
142 b->current_length = offset + len + sizeof (*fip4);
144 fip4->fragment_id = ip_frag_id;
145 fip4->flags_and_fragment_offset =
146 clib_host_to_net_u16 ((ptr >> 3) + ip_frag_offset);
147 fip4->flags_and_fragment_offset |=
148 clib_host_to_net_u16 (((len != rem) || more) << 13);
149 // ((len0 != rem0) || more0) << 13 is optimization for
150 // ((len0 != rem0) || more0) ? IP4_HEADER_FLAG_MORE_FRAGMENTS : 0
151 fip4->length = clib_host_to_net_u16 (len + sizeof (*fip4));
152 fip4->checksum = ip4_header_checksum (fip4);
154 if (vnet_buffer (p)->ip_frag.flags & IP_FRAG_FLAG_IP4_HEADER)
156 //Encapsulating ipv4 header
157 ip4_header_t *encap_header4 =
158 (ip4_header_t *) vlib_buffer_get_current (b);
159 encap_header4->length = clib_host_to_net_u16 (b->current_length);
160 encap_header4->checksum = ip4_header_checksum (encap_header4);
162 else if (vnet_buffer (p)->ip_frag.flags & IP_FRAG_FLAG_IP6_HEADER)
164 //Encapsulating ipv6 header
165 ip6_header_t *encap_header6 =
166 (ip6_header_t *) vlib_buffer_get_current (b);
167 encap_header6->payload_length =
168 clib_host_to_net_u16 (b->current_length -
169 sizeof (*encap_header6));
178 ip_frag_set_vnet_buffer (vlib_buffer_t * b, u16 offset, u16 mtu,
179 u8 next_index, u8 flags)
181 vnet_buffer (b)->ip_frag.header_offset = offset;
182 vnet_buffer (b)->ip_frag.mtu = mtu;
183 vnet_buffer (b)->ip_frag.next_index = next_index;
184 vnet_buffer (b)->ip_frag.flags = flags;
188 ip4_frag (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
190 u32 n_left_from, *from, next_index, *to_next, n_left_to_next;
191 vlib_node_runtime_t *error_node =
192 vlib_node_get_runtime (vm, ip4_frag_node.index);
193 from = vlib_frame_vector_args (frame);
194 n_left_from = frame->n_vectors;
195 next_index = node->cached_next_index;
196 u32 frag_sent = 0, small_packets = 0;
199 while (n_left_from > 0)
201 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
203 while (n_left_from > 0 && n_left_to_next > 0)
205 u32 pi0, *frag_from, frag_left;
207 ip_frag_error_t error0;
208 ip4_frag_next_t next0;
210 //Note: The packet is not enqueued now.
211 //It is instead put in a vector where other fragments
212 //will be put as well.
216 error0 = IP_FRAG_ERROR_NONE;
218 p0 = vlib_get_buffer (vm, pi0);
219 ip4_frag_do_fragment (vm, pi0, &buffer, &error0);
221 if (PREDICT_FALSE (p0->flags & VLIB_BUFFER_IS_TRACED))
223 ip_frag_trace_t *tr =
224 vlib_add_trace (vm, node, p0, sizeof (*tr));
225 tr->header_offset = vnet_buffer (p0)->ip_frag.header_offset;
226 tr->mtu = vnet_buffer (p0)->ip_frag.mtu;
228 tr->n_fragments = vec_len (buffer);
229 tr->next = vnet_buffer (p0)->ip_frag.next_index;
232 if (error0 == IP_FRAG_ERROR_DONT_FRAGMENT_SET)
234 icmp4_error_set_vnet_buffer (p0, ICMP4_destination_unreachable,
235 ICMP4_destination_unreachable_fragmentation_needed_and_dont_fragment_set,
236 vnet_buffer (p0)->ip_frag.mtu);
237 vlib_buffer_advance (p0,
238 vnet_buffer (p0)->ip_frag.header_offset);
239 next0 = IP4_FRAG_NEXT_ICMP_ERROR;
244 next0 = (error0 == IP_FRAG_ERROR_NONE) ? vnet_buffer (p0)->
245 ip_frag.next_index : IP4_FRAG_NEXT_DROP;
249 if (error0 == IP_FRAG_ERROR_NONE)
251 frag_sent += vec_len (buffer);
252 small_packets += (vec_len (buffer) == 1);
255 vlib_error_count (vm, ip4_frag_node.index, error0, 1);
257 //Send fragments that were added in the frame
259 frag_left = vec_len (buffer);
261 while (frag_left > 0)
263 while (frag_left > 0 && n_left_to_next > 0)
266 i = to_next[0] = frag_from[0];
272 vlib_get_buffer (vm, i)->error = error_node->errors[error0];
273 vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
274 to_next, n_left_to_next, i,
277 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
278 vlib_get_next_frame (vm, node, next_index, to_next,
281 vec_reset_length (buffer);
283 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
287 vlib_node_increment_counter (vm, ip4_frag_node.index,
288 IP_FRAG_ERROR_FRAGMENT_SENT, frag_sent);
289 vlib_node_increment_counter (vm, ip4_frag_node.index,
290 IP_FRAG_ERROR_SMALL_PACKET, small_packets);
292 return frame->n_vectors;
297 ip6_frag_do_fragment (vlib_main_t * vm, u32 pi, u32 ** buffer,
298 ip_frag_error_t * error)
301 ip6_header_t *ip6_hdr;
302 ip6_frag_hdr_t *frag_hdr;
303 u8 *payload, *next_header;
305 p = vlib_get_buffer (vm, pi);
307 //Parsing the IPv6 headers
309 vlib_buffer_get_current (p) + vnet_buffer (p)->ip_frag.header_offset;
310 payload = (u8 *) (ip6_hdr + 1);
311 next_header = &ip6_hdr->protocol;
312 if (*next_header == IP_PROTOCOL_IP6_HOP_BY_HOP_OPTIONS)
314 next_header = payload;
315 payload += payload[1] * 8;
318 if (*next_header == IP_PROTOCOL_IP6_DESTINATION_OPTIONS)
320 next_header = payload;
321 payload += payload[1] * 8;
324 if (*next_header == IP_PROTOCOL_IPV6_ROUTE)
326 next_header = payload;
327 payload += payload[1] * 8;
331 (payload >= (u8 *) vlib_buffer_get_current (p) + p->current_length))
333 //A malicious packet could set an extension header with a too big size
334 //and make us modify another vlib_buffer
335 *error = IP_FRAG_ERROR_MALFORMED;
341 if (*next_header == IP_PROTOCOL_IPV6_FRAGMENTATION)
343 //The fragmentation header is already there
344 frag_hdr = (ip6_frag_hdr_t *) payload;
345 has_more = ip6_frag_hdr_more (frag_hdr);
346 initial_offset = ip6_frag_hdr_offset (frag_hdr);
350 //Insert a fragmentation header in the packet
351 u8 nh = *next_header;
352 *next_header = IP_PROTOCOL_IPV6_FRAGMENTATION;
353 vlib_buffer_advance (p, -sizeof (*frag_hdr));
354 u8 *start = vlib_buffer_get_current (p);
355 memmove (start, start + sizeof (*frag_hdr),
356 payload - (start + sizeof (*frag_hdr)));
357 frag_hdr = (ip6_frag_hdr_t *) (payload - sizeof (*frag_hdr));
358 frag_hdr->identification = ++running_fragment_id;
359 frag_hdr->next_hdr = nh;
364 payload = (u8 *) (frag_hdr + 1);
366 u16 headers_len = payload - (u8 *) vlib_buffer_get_current (p);
367 u16 max_payload = vnet_buffer (p)->ip_frag.mtu - headers_len;
368 u16 rem = p->current_length - headers_len;
373 *error = IP_FRAG_ERROR_CANT_FRAGMENT_HEADER;
381 u16 len = (rem > max_payload) ? (max_payload & ~0x7) : rem;
386 if (!vlib_buffer_alloc (vm, &bi, 1))
388 *error = IP_FRAG_ERROR_MEMORY;
391 b = vlib_get_buffer (vm, bi);
392 vnet_buffer (b)->sw_if_index[VLIB_RX] =
393 vnet_buffer (p)->sw_if_index[VLIB_RX];
394 vnet_buffer (b)->sw_if_index[VLIB_TX] =
395 vnet_buffer (p)->sw_if_index[VLIB_TX];
396 clib_memcpy (vlib_buffer_get_current (b),
397 vlib_buffer_get_current (p), headers_len);
398 clib_memcpy (vlib_buffer_get_current (b) + headers_len,
401 vlib_buffer_get_current (b) + headers_len - sizeof (*frag_hdr);
406 b = vlib_get_buffer (vm, bi);
407 //frag_hdr already set here
411 vlib_buffer_get_current (b) + vnet_buffer (p)->ip_frag.header_offset;
412 frag_hdr->fragment_offset_and_more =
413 ip6_frag_hdr_offset_and_more (initial_offset + (ptr >> 3),
415 b->current_length = headers_len + len;
416 ip6_hdr->payload_length =
417 clib_host_to_net_u16 (b->current_length -
418 vnet_buffer (p)->ip_frag.header_offset -
421 if (vnet_buffer (p)->ip_frag.flags & IP_FRAG_FLAG_IP4_HEADER)
423 //Encapsulating ipv4 header
424 ip4_header_t *encap_header4 =
425 (ip4_header_t *) vlib_buffer_get_current (b);
426 encap_header4->length = clib_host_to_net_u16 (b->current_length);
427 encap_header4->checksum = ip4_header_checksum (encap_header4);
429 else if (vnet_buffer (p)->ip_frag.flags & IP_FRAG_FLAG_IP6_HEADER)
431 //Encapsulating ipv6 header
432 ip6_header_t *encap_header6 =
433 (ip6_header_t *) vlib_buffer_get_current (b);
434 encap_header6->payload_length =
435 clib_host_to_net_u16 (b->current_length -
436 sizeof (*encap_header6));
439 vec_add1 (*buffer, bi);
446 ip6_frag (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
448 u32 n_left_from, *from, next_index, *to_next, n_left_to_next;
449 vlib_node_runtime_t *error_node =
450 vlib_node_get_runtime (vm, ip6_frag_node.index);
451 from = vlib_frame_vector_args (frame);
452 n_left_from = frame->n_vectors;
453 next_index = node->cached_next_index;
454 u32 frag_sent = 0, small_packets = 0;
457 while (n_left_from > 0)
459 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
461 while (n_left_from > 0 && n_left_to_next > 0)
463 u32 pi0, *frag_from, frag_left;
465 ip_frag_error_t error0;
466 ip6_frag_next_t next0;
471 error0 = IP_FRAG_ERROR_NONE;
473 p0 = vlib_get_buffer (vm, pi0);
474 ip6_frag_do_fragment (vm, pi0, &buffer, &error0);
476 if (PREDICT_FALSE (p0->flags & VLIB_BUFFER_IS_TRACED))
478 ip_frag_trace_t *tr =
479 vlib_add_trace (vm, node, p0, sizeof (*tr));
480 tr->header_offset = vnet_buffer (p0)->ip_frag.header_offset;
481 tr->mtu = vnet_buffer (p0)->ip_frag.mtu;
483 tr->n_fragments = vec_len (buffer);
484 tr->next = vnet_buffer (p0)->ip_frag.next_index;
488 next0 = (error0 == IP_FRAG_ERROR_NONE) ? vnet_buffer (p0)->
489 ip_frag.next_index : IP6_FRAG_NEXT_DROP;
492 frag_sent += vec_len (buffer);
493 small_packets += (vec_len (buffer) == 1);
495 //Send fragments that were added in the frame
497 frag_left = vec_len (buffer);
498 while (frag_left > 0)
500 while (frag_left > 0 && n_left_to_next > 0)
503 i = to_next[0] = frag_from[0];
509 vlib_get_buffer (vm, i)->error = error_node->errors[error0];
510 vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
511 to_next, n_left_to_next, i,
514 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
515 vlib_get_next_frame (vm, node, next_index, to_next,
518 vec_reset_length (buffer);
520 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
523 vlib_node_increment_counter (vm, ip6_frag_node.index,
524 IP_FRAG_ERROR_FRAGMENT_SENT, frag_sent);
525 vlib_node_increment_counter (vm, ip6_frag_node.index,
526 IP_FRAG_ERROR_SMALL_PACKET, small_packets);
528 return frame->n_vectors;
531 static char *ip4_frag_error_strings[] = {
532 #define _(sym,string) string,
533 foreach_ip_frag_error
538 VLIB_REGISTER_NODE (ip4_frag_node) = {
539 .function = ip4_frag,
540 .name = IP4_FRAG_NODE_NAME,
541 .vector_size = sizeof (u32),
542 .format_trace = format_ip_frag_trace,
543 .type = VLIB_NODE_TYPE_INTERNAL,
545 .n_errors = IP_FRAG_N_ERROR,
546 .error_strings = ip4_frag_error_strings,
548 .n_next_nodes = IP4_FRAG_N_NEXT,
550 [IP4_FRAG_NEXT_IP4_LOOKUP] = "ip4-lookup",
551 [IP4_FRAG_NEXT_IP6_LOOKUP] = "ip6-lookup",
552 [IP4_FRAG_NEXT_ICMP_ERROR] = "ip4-icmp-error",
553 [IP4_FRAG_NEXT_DROP] = "ip4-drop"
559 VLIB_REGISTER_NODE (ip6_frag_node) = {
560 .function = ip6_frag,
561 .name = IP6_FRAG_NODE_NAME,
562 .vector_size = sizeof (u32),
563 .format_trace = format_ip_frag_trace,
564 .type = VLIB_NODE_TYPE_INTERNAL,
566 .n_errors = IP_FRAG_N_ERROR,
567 .error_strings = ip4_frag_error_strings,
569 .n_next_nodes = IP6_FRAG_N_NEXT,
571 [IP6_FRAG_NEXT_IP4_LOOKUP] = "ip4-lookup",
572 [IP6_FRAG_NEXT_IP6_LOOKUP] = "ip6-lookup",
573 [IP6_FRAG_NEXT_DROP] = "ip6-drop"
579 * fd.io coding-style-patch-verification: ON
582 * eval: (c-set-style "gnu")