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>
35 format_ip_frag_trace (u8 * s, va_list * args)
37 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
38 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
39 ip_frag_trace_t *t = va_arg (*args, ip_frag_trace_t *);
40 s = format (s, "IPv%s mtu: %u fragments: %u next: %d",
41 t->ipv6 ? "6" : "4", t->mtu, t->n_fragments, t->next);
45 static u32 running_fragment_id;
48 frag_set_sw_if_index (vlib_buffer_t * to, vlib_buffer_t * from)
50 vnet_buffer (to)->sw_if_index[VLIB_RX] =
51 vnet_buffer (from)->sw_if_index[VLIB_RX];
52 vnet_buffer (to)->sw_if_index[VLIB_TX] =
53 vnet_buffer (from)->sw_if_index[VLIB_TX];
55 /* Copy adj_index in case DPO based node is sending for the
56 * fragmentation, the packet would be sent back to the proper
57 * DPO next node and Index
59 vnet_buffer (to)->ip.adj_index[VLIB_RX] =
60 vnet_buffer (from)->ip.adj_index[VLIB_RX];
61 vnet_buffer (to)->ip.adj_index[VLIB_TX] =
62 vnet_buffer (from)->ip.adj_index[VLIB_TX];
65 if (PREDICT_TRUE (from->flags & VNET_BUFFER_F_QOS_DATA_VALID))
67 vnet_buffer2 (to)->qos = vnet_buffer2 (from)->qos;
68 to->flags |= VNET_BUFFER_F_QOS_DATA_VALID;
72 static vlib_buffer_t *
73 frag_buffer_alloc (vlib_buffer_t * org_b, u32 * bi)
75 vlib_main_t *vm = vlib_get_main ();
76 if (vlib_buffer_alloc (vm, bi, 1) != 1)
79 vlib_buffer_t *b = vlib_get_buffer (vm, *bi);
80 VLIB_BUFFER_TRACE_TRAJECTORY_INIT (b);
81 vlib_buffer_copy_trace_flag (vm, org_b, *bi);
87 * Limitation: Does follow buffer chains in the packet to fragment,
88 * but does not generate buffer chains. I.e. a fragment is always
89 * contained with in a single buffer and limited to the max buffer
91 * from_bi: current pointer must point to IPv4 header
94 ip4_frag_do_fragment (vlib_main_t * vm, u32 from_bi, u16 mtu,
95 u16 l2unfragmentablesize, u32 ** buffer)
97 vlib_buffer_t *from_b;
99 u16 len, max, rem, ip_frag_id, ip_frag_offset;
100 u8 *org_from_packet, more;
102 from_b = vlib_get_buffer (vm, from_bi);
103 org_from_packet = vlib_buffer_get_current (from_b);
104 ip4 = vlib_buffer_get_current (from_b) + l2unfragmentablesize;
106 rem = clib_net_to_host_u16 (ip4->length) - sizeof (ip4_header_t);
108 (clib_min (mtu, vlib_buffer_get_default_data_size (vm)) -
109 sizeof (ip4_header_t)) & ~0x7;
112 (vlib_buffer_length_in_chain (vm, from_b) - sizeof (ip4_header_t)))
114 return IP_FRAG_ERROR_MALFORMED;
117 if (mtu < sizeof (ip4_header_t))
119 return IP_FRAG_ERROR_CANT_FRAGMENT_HEADER;
122 if (ip4->flags_and_fragment_offset &
123 clib_host_to_net_u16 (IP4_HEADER_FLAG_DONT_FRAGMENT))
125 return IP_FRAG_ERROR_DONT_FRAGMENT_SET;
128 if (ip4_is_fragment (ip4))
130 ip_frag_id = ip4->fragment_id;
131 ip_frag_offset = ip4_get_fragment_offset (ip4);
133 !(!(ip4->flags_and_fragment_offset &
134 clib_host_to_net_u16 (IP4_HEADER_FLAG_MORE_FRAGMENTS)));
138 ip_frag_id = (++running_fragment_id);
143 u8 *from_data = (void *) (ip4 + 1);
144 vlib_buffer_t *org_from_b = from_b;
146 u16 left_in_from_buffer =
147 from_b->current_length - (l2unfragmentablesize + sizeof (ip4_header_t));
150 /* Do the actual fragmentation */
155 ip4_header_t *to_ip4;
158 len = (rem > max ? max : rem);
159 if (len != rem) /* Last fragment does not need to divisible by 8 */
161 if ((to_b = frag_buffer_alloc (org_from_b, &to_bi)) == 0)
163 return IP_FRAG_ERROR_MEMORY;
165 vec_add1 (*buffer, to_bi);
166 frag_set_sw_if_index (to_b, org_from_b);
168 /* Copy ip4 header */
169 to_data = vlib_buffer_get_current (to_b);
170 clib_memcpy_fast (to_data, org_from_packet,
171 l2unfragmentablesize + sizeof (ip4_header_t));
172 to_ip4 = (ip4_header_t *) (to_data + l2unfragmentablesize);
173 to_data = (void *) (to_ip4 + 1);
174 vnet_buffer (to_b)->l3_hdr_offset = to_b->current_data;
175 vlib_buffer_copy_trace_flag (vm, from_b, to_bi);
176 to_b->flags |= VNET_BUFFER_F_L3_HDR_OFFSET_VALID;
178 if (from_b->flags & VNET_BUFFER_F_L4_HDR_OFFSET_VALID)
180 vnet_buffer (to_b)->l4_hdr_offset =
181 (vnet_buffer (to_b)->l3_hdr_offset +
182 (vnet_buffer (from_b)->l4_hdr_offset -
183 vnet_buffer (from_b)->l3_hdr_offset));
184 to_b->flags |= VNET_BUFFER_F_L4_HDR_OFFSET_VALID;
187 /* Spin through from buffers filling up the to buffer */
188 u16 left_in_to_buffer = len, to_ptr = 0;
193 /* Figure out how many bytes we can safely copy */
194 bytes_to_copy = left_in_to_buffer <= left_in_from_buffer ?
195 left_in_to_buffer : left_in_from_buffer;
196 clib_memcpy_fast (to_data + to_ptr, from_data + ptr, bytes_to_copy);
197 left_in_to_buffer -= bytes_to_copy;
198 ptr += bytes_to_copy;
199 left_in_from_buffer -= bytes_to_copy;
200 if (left_in_to_buffer == 0)
203 ASSERT (left_in_from_buffer <= 0);
205 if (!(from_b->flags & VLIB_BUFFER_NEXT_PRESENT))
207 return IP_FRAG_ERROR_MALFORMED;
209 from_b = vlib_get_buffer (vm, from_b->next_buffer);
210 from_data = (u8 *) vlib_buffer_get_current (from_b);
212 left_in_from_buffer = from_b->current_length;
213 to_ptr += bytes_to_copy;
216 to_b->flags |= VNET_BUFFER_F_IS_IP4;
217 to_b->current_length =
218 len + sizeof (ip4_header_t) + l2unfragmentablesize;
220 to_ip4->fragment_id = ip_frag_id;
221 to_ip4->flags_and_fragment_offset =
222 clib_host_to_net_u16 ((fo >> 3) + ip_frag_offset);
223 to_ip4->flags_and_fragment_offset |=
224 clib_host_to_net_u16 (((len != rem) || more) << 13);
225 to_ip4->length = clib_host_to_net_u16 (len + sizeof (ip4_header_t));
226 to_ip4->checksum = ip4_header_checksum (to_ip4);
228 /* we've just done the IP checksum .. */
229 to_b->flags &= ~VNET_BUFFER_F_OFFLOAD_IP_CKSUM;
235 return IP_FRAG_ERROR_NONE;
239 ip_frag_set_vnet_buffer (vlib_buffer_t * b, u16 mtu, u8 next_index, u8 flags)
241 vnet_buffer (b)->ip_frag.mtu = mtu;
242 vnet_buffer (b)->ip_frag.next_index = next_index;
243 vnet_buffer (b)->ip_frag.flags = flags;
248 frag_node_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
249 vlib_frame_t * frame, u32 node_index, bool is_ip6)
251 u32 n_left_from, *from, next_index, *to_next, n_left_to_next;
252 vlib_node_runtime_t *error_node = vlib_node_get_runtime (vm, node_index);
253 from = vlib_frame_vector_args (frame);
254 n_left_from = frame->n_vectors;
255 next_index = node->cached_next_index;
256 u32 frag_sent = 0, small_packets = 0;
259 while (n_left_from > 0)
261 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
263 while (n_left_from > 0 && n_left_to_next > 0)
265 u32 pi0, *frag_from, frag_left;
267 ip_frag_error_t error0;
271 * Note: The packet is not enqueued now. It is instead put
272 * in a vector where other fragments will be put as well.
278 p0 = vlib_get_buffer (vm, pi0);
279 u16 mtu = vnet_buffer (p0)->ip_frag.mtu;
281 error0 = ip6_frag_do_fragment (vm, pi0, mtu, 0, &buffer);
283 error0 = ip4_frag_do_fragment (vm, pi0, mtu, 0, &buffer);
285 if (PREDICT_FALSE (p0->flags & VLIB_BUFFER_IS_TRACED))
287 ip_frag_trace_t *tr =
288 vlib_add_trace (vm, node, p0, sizeof (*tr));
290 tr->ipv6 = is_ip6 ? 1 : 0;
291 tr->n_fragments = vec_len (buffer);
292 tr->next = vnet_buffer (p0)->ip_frag.next_index;
295 if (!is_ip6 && error0 == IP_FRAG_ERROR_DONT_FRAGMENT_SET)
297 icmp4_error_set_vnet_buffer (p0, ICMP4_destination_unreachable,
298 ICMP4_destination_unreachable_fragmentation_needed_and_dont_fragment_set,
299 vnet_buffer (p0)->ip_frag.mtu);
300 next0 = IP_FRAG_NEXT_ICMP_ERROR;
304 next0 = (error0 == IP_FRAG_ERROR_NONE ?
305 vnet_buffer (p0)->ip_frag.next_index :
309 if (error0 == IP_FRAG_ERROR_NONE)
311 /* Free original buffer chain */
312 frag_sent += vec_len (buffer);
313 small_packets += (vec_len (buffer) == 1);
314 vlib_buffer_free_one (vm, pi0); /* Free original packet */
318 vlib_error_count (vm, node_index, error0, 1);
319 vec_add1 (buffer, pi0); /* Get rid of the original buffer */
322 /* Send fragments that were added in the frame */
324 frag_left = vec_len (buffer);
326 while (frag_left > 0)
328 while (frag_left > 0 && n_left_to_next > 0)
331 i = to_next[0] = frag_from[0];
337 vlib_get_buffer (vm, i)->error = error_node->errors[error0];
338 vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
339 to_next, n_left_to_next, i,
342 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
343 vlib_get_next_frame (vm, node, next_index, to_next,
346 vec_reset_length (buffer);
348 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
352 vlib_node_increment_counter (vm, node_index,
353 IP_FRAG_ERROR_FRAGMENT_SENT, frag_sent);
354 vlib_node_increment_counter (vm, node_index,
355 IP_FRAG_ERROR_SMALL_PACKET, small_packets);
357 return frame->n_vectors;
363 ip4_frag (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
365 return frag_node_inline (vm, node, frame, ip4_frag_node.index,
370 ip6_frag (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
372 return frag_node_inline (vm, node, frame, ip6_frag_node.index,
377 * Fragments the packet given in from_bi. Fragments are returned in the buffer vector.
378 * Caller must ensure the original packet is freed.
379 * from_bi: current pointer must point to IPv6 header
382 ip6_frag_do_fragment (vlib_main_t * vm, u32 from_bi, u16 mtu,
383 u16 l2unfragmentablesize, u32 ** buffer)
385 vlib_buffer_t *from_b;
387 u16 len, max, rem, ip_frag_id;
390 from_b = vlib_get_buffer (vm, from_bi);
391 org_from_packet = vlib_buffer_get_current (from_b);
392 ip6 = vlib_buffer_get_current (from_b) + l2unfragmentablesize;
394 rem = clib_net_to_host_u16 (ip6->payload_length);
395 max = (mtu - sizeof (ip6_header_t) - sizeof (ip6_frag_hdr_t)) & ~0x7; // TODO: Is max correct??
398 (vlib_buffer_length_in_chain (vm, from_b) - sizeof (ip6_header_t)))
400 return IP_FRAG_ERROR_MALFORMED;
403 /* TODO: Look through header chain for fragmentation header */
404 if (ip6->protocol == IP_PROTOCOL_IPV6_FRAGMENTATION)
406 return IP_FRAG_ERROR_MALFORMED;
409 u8 *from_data = (void *) (ip6 + 1);
410 vlib_buffer_t *org_from_b = from_b;
412 u16 left_in_from_buffer =
413 from_b->current_length - (l2unfragmentablesize + sizeof (ip6_header_t));
416 ip_frag_id = ++running_fragment_id; // Fix
418 /* Do the actual fragmentation */
423 ip6_header_t *to_ip6;
424 ip6_frag_hdr_t *to_frag_hdr;
429 (mtu - sizeof (ip6_header_t) - sizeof (ip6_frag_hdr_t)) ? max : rem);
430 if (len != rem) /* Last fragment does not need to divisible by 8 */
432 if ((to_b = frag_buffer_alloc (org_from_b, &to_bi)) == 0)
434 return IP_FRAG_ERROR_MEMORY;
436 vec_add1 (*buffer, to_bi);
437 frag_set_sw_if_index (to_b, org_from_b);
439 /* Copy ip6 header */
440 clib_memcpy_fast (to_b->data, org_from_packet,
441 l2unfragmentablesize + sizeof (ip6_header_t));
442 to_ip6 = vlib_buffer_get_current (to_b);
443 to_frag_hdr = (ip6_frag_hdr_t *) (to_ip6 + 1);
444 to_data = (void *) (to_frag_hdr + 1);
446 vnet_buffer (to_b)->l3_hdr_offset = to_b->current_data;
447 to_b->flags |= VNET_BUFFER_F_L3_HDR_OFFSET_VALID;
449 if (from_b->flags & VNET_BUFFER_F_L4_HDR_OFFSET_VALID)
451 vnet_buffer (to_b)->l4_hdr_offset =
452 (vnet_buffer (to_b)->l3_hdr_offset +
453 (vnet_buffer (from_b)->l4_hdr_offset -
454 vnet_buffer (from_b)->l3_hdr_offset));
455 to_b->flags |= VNET_BUFFER_F_L4_HDR_OFFSET_VALID;
457 to_b->flags |= VNET_BUFFER_F_IS_IP6;
459 /* Spin through from buffers filling up the to buffer */
460 u16 left_in_to_buffer = len, to_ptr = 0;
465 /* Figure out how many bytes we can safely copy */
466 bytes_to_copy = left_in_to_buffer <= left_in_from_buffer ?
467 left_in_to_buffer : left_in_from_buffer;
468 clib_memcpy_fast (to_data + to_ptr, from_data + ptr, bytes_to_copy);
469 left_in_to_buffer -= bytes_to_copy;
470 ptr += bytes_to_copy;
471 left_in_from_buffer -= bytes_to_copy;
472 if (left_in_to_buffer == 0)
475 ASSERT (left_in_from_buffer <= 0);
477 if (!(from_b->flags & VLIB_BUFFER_NEXT_PRESENT))
479 return IP_FRAG_ERROR_MALFORMED;
481 from_b = vlib_get_buffer (vm, from_b->next_buffer);
482 from_data = (u8 *) vlib_buffer_get_current (from_b);
484 left_in_from_buffer = from_b->current_length;
485 to_ptr += bytes_to_copy;
488 to_b->current_length =
489 len + sizeof (ip6_header_t) + sizeof (ip6_frag_hdr_t);
490 to_ip6->payload_length =
491 clib_host_to_net_u16 (len + sizeof (ip6_frag_hdr_t));
492 to_ip6->protocol = IP_PROTOCOL_IPV6_FRAGMENTATION;
493 to_frag_hdr->fragment_offset_and_more =
494 ip6_frag_hdr_offset_and_more ((fo >> 3), len != rem);
495 to_frag_hdr->identification = ip_frag_id;
496 to_frag_hdr->next_hdr = ip6->protocol;
497 to_frag_hdr->rsv = 0;
503 return IP_FRAG_ERROR_NONE;
506 static char *ip4_frag_error_strings[] = {
507 #define _(sym,string) string,
508 foreach_ip_frag_error
513 VLIB_REGISTER_NODE (ip4_frag_node) = {
514 .function = ip4_frag,
515 .name = IP4_FRAG_NODE_NAME,
516 .vector_size = sizeof (u32),
517 .format_trace = format_ip_frag_trace,
518 .type = VLIB_NODE_TYPE_INTERNAL,
520 .n_errors = IP_FRAG_N_ERROR,
521 .error_strings = ip4_frag_error_strings,
523 .n_next_nodes = IP_FRAG_N_NEXT,
525 [IP_FRAG_NEXT_IP_REWRITE] = "ip4-rewrite",
526 [IP_FRAG_NEXT_IP_REWRITE_MIDCHAIN] = "ip4-midchain",
527 [IP_FRAG_NEXT_IP4_LOOKUP] = "ip4-lookup",
528 [IP_FRAG_NEXT_IP6_LOOKUP] = "ip6-lookup",
529 [IP_FRAG_NEXT_ICMP_ERROR] = "ip4-icmp-error",
530 [IP_FRAG_NEXT_DROP] = "ip4-drop"
536 VLIB_REGISTER_NODE (ip6_frag_node) = {
537 .function = ip6_frag,
538 .name = IP6_FRAG_NODE_NAME,
539 .vector_size = sizeof (u32),
540 .format_trace = format_ip_frag_trace,
541 .type = VLIB_NODE_TYPE_INTERNAL,
543 .n_errors = IP_FRAG_N_ERROR,
544 .error_strings = ip4_frag_error_strings,
546 .n_next_nodes = IP_FRAG_N_NEXT,
548 [IP_FRAG_NEXT_IP_REWRITE] = "ip6-rewrite",
549 [IP_FRAG_NEXT_IP_REWRITE_MIDCHAIN] = "ip6-midchain",
550 [IP_FRAG_NEXT_IP4_LOOKUP] = "ip4-lookup",
551 [IP_FRAG_NEXT_IP6_LOOKUP] = "ip6-lookup",
552 [IP_FRAG_NEXT_ICMP_ERROR] = "error-drop",
553 [IP_FRAG_NEXT_DROP] = "ip6-drop"
559 * fd.io coding-style-patch-verification: ON
562 * eval: (c-set-style "gnu")