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>
36 format_ip_frag_trace (u8 * s, va_list * args)
38 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
39 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
40 ip_frag_trace_t *t = va_arg (*args, ip_frag_trace_t *);
41 s = format (s, "IPv%s mtu: %u fragments: %u",
42 t->ipv6 ? "6" : "4", t->mtu, t->n_fragments);
46 static u32 running_fragment_id;
49 frag_set_sw_if_index (vlib_buffer_t * to, vlib_buffer_t * from)
51 vnet_buffer (to)->sw_if_index[VLIB_RX] =
52 vnet_buffer (from)->sw_if_index[VLIB_RX];
53 vnet_buffer (to)->sw_if_index[VLIB_TX] =
54 vnet_buffer (from)->sw_if_index[VLIB_TX];
56 /* Copy adj_index in case DPO based node is sending for the
57 * fragmentation, the packet would be sent back to the proper
58 * DPO next node and Index
60 vnet_buffer (to)->ip.adj_index[VLIB_RX] =
61 vnet_buffer (from)->ip.adj_index[VLIB_RX];
62 vnet_buffer (to)->ip.adj_index[VLIB_TX] =
63 vnet_buffer (from)->ip.adj_index[VLIB_TX];
66 if (PREDICT_TRUE (from->flags & VNET_BUFFER_F_QOS_DATA_VALID))
68 vnet_buffer2 (to)->qos = vnet_buffer2 (from)->qos;
69 to->flags |= VNET_BUFFER_F_QOS_DATA_VALID;
73 static vlib_buffer_t *
74 frag_buffer_alloc (vlib_buffer_t * org_b, u32 * bi)
76 vlib_main_t *vm = vlib_get_main ();
77 if (vlib_buffer_alloc (vm, bi, 1) != 1)
80 vlib_buffer_t *b = vlib_get_buffer (vm, *bi);
81 VLIB_BUFFER_TRACE_TRAJECTORY_INIT (b);
82 vlib_buffer_copy_trace_flag (vm, org_b, *bi);
88 * Limitation: Does follow buffer chains in the packet to fragment,
89 * but does not generate buffer chains. I.e. a fragment is always
90 * contained with in a single buffer and limited to the max buffer
94 ip4_frag_do_fragment (vlib_main_t * vm, u32 from_bi, u32 ** buffer,
95 ip_frag_error_t * error)
97 vlib_buffer_t *from_b;
99 u16 mtu, 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 mtu = vnet_buffer (from_b)->ip_frag.mtu;
104 org_from_packet = vlib_buffer_get_current (from_b);
105 ip4 = (ip4_header_t *) vlib_buffer_get_current (from_b);
107 rem = clib_net_to_host_u16 (ip4->length) - sizeof (ip4_header_t);
109 (clib_min (mtu, vlib_buffer_get_default_data_size (vm)) -
110 sizeof (ip4_header_t)) & ~0x7;
113 (vlib_buffer_length_in_chain (vm, from_b) - sizeof (ip4_header_t)))
115 *error = IP_FRAG_ERROR_MALFORMED;
119 if (mtu < sizeof (ip4_header_t))
121 *error = IP_FRAG_ERROR_CANT_FRAGMENT_HEADER;
125 if (ip4->flags_and_fragment_offset &
126 clib_host_to_net_u16 (IP4_HEADER_FLAG_DONT_FRAGMENT))
128 *error = IP_FRAG_ERROR_DONT_FRAGMENT_SET;
132 if (ip4_is_fragment (ip4))
134 ip_frag_id = ip4->fragment_id;
135 ip_frag_offset = ip4_get_fragment_offset (ip4);
137 !(!(ip4->flags_and_fragment_offset &
138 clib_host_to_net_u16 (IP4_HEADER_FLAG_MORE_FRAGMENTS)));
142 ip_frag_id = (++running_fragment_id);
147 u8 *from_data = (void *) (ip4 + 1);
148 vlib_buffer_t *org_from_b = from_b;
150 u16 left_in_from_buffer = from_b->current_length - sizeof (ip4_header_t);
153 /* Do the actual fragmentation */
158 ip4_header_t *to_ip4;
161 len = (rem > max ? max : rem);
162 if (len != rem) /* Last fragment does not need to divisible by 8 */
164 if ((to_b = frag_buffer_alloc (org_from_b, &to_bi)) == 0)
166 *error = IP_FRAG_ERROR_MEMORY;
169 vec_add1 (*buffer, to_bi);
170 frag_set_sw_if_index (to_b, org_from_b);
172 /* Copy ip4 header */
173 clib_memcpy_fast (to_b->data, org_from_packet, sizeof (ip4_header_t));
174 to_ip4 = vlib_buffer_get_current (to_b);
175 to_data = (void *) (to_ip4 + 1);
177 /* Spin through from buffers filling up the to buffer */
178 u16 left_in_to_buffer = len, to_ptr = 0;
183 /* Figure out how many bytes we can safely copy */
184 bytes_to_copy = left_in_to_buffer <= left_in_from_buffer ?
185 left_in_to_buffer : left_in_from_buffer;
186 clib_memcpy_fast (to_data + to_ptr, from_data + ptr, bytes_to_copy);
187 left_in_to_buffer -= bytes_to_copy;
188 ptr += bytes_to_copy;
189 left_in_from_buffer -= bytes_to_copy;
190 if (left_in_to_buffer == 0)
193 ASSERT (left_in_from_buffer <= 0);
195 if (!(from_b->flags & VLIB_BUFFER_NEXT_PRESENT))
197 *error = IP_FRAG_ERROR_MALFORMED;
200 from_b = vlib_get_buffer (vm, from_b->next_buffer);
201 from_data = (u8 *) vlib_buffer_get_current (from_b);
203 left_in_from_buffer = from_b->current_length;
204 to_ptr += bytes_to_copy;
207 to_b->current_length = len + sizeof (ip4_header_t);
209 to_ip4->fragment_id = ip_frag_id;
210 to_ip4->flags_and_fragment_offset =
211 clib_host_to_net_u16 ((fo >> 3) + ip_frag_offset);
212 to_ip4->flags_and_fragment_offset |=
213 clib_host_to_net_u16 (((len != rem) || more) << 13);
214 to_ip4->length = clib_host_to_net_u16 (len + sizeof (ip4_header_t));
215 to_ip4->checksum = ip4_header_checksum (to_ip4);
217 if (vnet_buffer (org_from_b)->ip_frag.flags & IP_FRAG_FLAG_IP4_HEADER)
219 /* Encapsulating ipv4 header */
220 ip4_header_t *encap_header4 =
221 (ip4_header_t *) vlib_buffer_get_current (to_b);
222 encap_header4->length = clib_host_to_net_u16 (to_b->current_length);
223 encap_header4->checksum = ip4_header_checksum (encap_header4);
225 else if (vnet_buffer (org_from_b)->
226 ip_frag.flags & IP_FRAG_FLAG_IP6_HEADER)
228 /* Encapsulating ipv6 header */
229 ip6_header_t *encap_header6 =
230 (ip6_header_t *) vlib_buffer_get_current (to_b);
231 encap_header6->payload_length =
232 clib_host_to_net_u16 (to_b->current_length -
233 sizeof (*encap_header6));
241 ip_frag_set_vnet_buffer (vlib_buffer_t * b, u16 mtu, u8 next_index, u8 flags)
243 vnet_buffer (b)->ip_frag.mtu = mtu;
244 vnet_buffer (b)->ip_frag.next_index = next_index;
245 vnet_buffer (b)->ip_frag.flags = flags;
250 frag_node_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
251 vlib_frame_t * frame, u32 node_index, bool is_ip6)
253 u32 n_left_from, *from, next_index, *to_next, n_left_to_next;
254 vlib_node_runtime_t *error_node = vlib_node_get_runtime (vm, node_index);
255 from = vlib_frame_vector_args (frame);
256 n_left_from = frame->n_vectors;
257 next_index = node->cached_next_index;
258 u32 frag_sent = 0, small_packets = 0;
261 while (n_left_from > 0)
263 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
265 while (n_left_from > 0 && n_left_to_next > 0)
267 u32 pi0, *frag_from, frag_left;
269 ip_frag_error_t error0;
273 * Note: The packet is not enqueued now. It is instead put
274 * in a vector where other fragments will be put as well.
279 error0 = IP_FRAG_ERROR_NONE;
281 p0 = vlib_get_buffer (vm, pi0);
283 ip6_frag_do_fragment (vm, pi0, &buffer, &error0);
285 ip4_frag_do_fragment (vm, pi0, &buffer, &error0);
287 if (PREDICT_FALSE (p0->flags & VLIB_BUFFER_IS_TRACED))
289 ip_frag_trace_t *tr =
290 vlib_add_trace (vm, node, p0, sizeof (*tr));
291 tr->mtu = vnet_buffer (p0)->ip_frag.mtu;
292 tr->ipv6 = is_ip6 ? 1 : 0;
293 tr->n_fragments = vec_len (buffer);
294 tr->next = vnet_buffer (p0)->ip_frag.next_index;
297 if (!is_ip6 && error0 == IP_FRAG_ERROR_DONT_FRAGMENT_SET)
299 icmp4_error_set_vnet_buffer (p0, ICMP4_destination_unreachable,
300 ICMP4_destination_unreachable_fragmentation_needed_and_dont_fragment_set,
301 vnet_buffer (p0)->ip_frag.mtu);
302 next0 = IP4_FRAG_NEXT_ICMP_ERROR;
309 IP_FRAG_ERROR_NONE) ? vnet_buffer (p0)->
310 ip_frag.next_index : IP6_FRAG_NEXT_DROP;
314 IP_FRAG_ERROR_NONE) ? vnet_buffer (p0)->
315 ip_frag.next_index : IP4_FRAG_NEXT_DROP;
318 if (error0 == IP_FRAG_ERROR_NONE)
320 /* Free original buffer chain */
321 frag_sent += vec_len (buffer);
322 small_packets += (vec_len (buffer) == 1);
323 vlib_buffer_free_one (vm, pi0); /* Free original packet */
327 vlib_error_count (vm, node_index, error0, 1);
328 vec_add1 (buffer, pi0); /* Get rid of the original buffer */
331 /* Send fragments that were added in the frame */
333 frag_left = vec_len (buffer);
335 while (frag_left > 0)
337 while (frag_left > 0 && n_left_to_next > 0)
340 i = to_next[0] = frag_from[0];
346 vlib_get_buffer (vm, i)->error = error_node->errors[error0];
347 vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
348 to_next, n_left_to_next, i,
351 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
352 vlib_get_next_frame (vm, node, next_index, to_next,
355 vec_reset_length (buffer);
357 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
361 vlib_node_increment_counter (vm, node_index,
362 IP_FRAG_ERROR_FRAGMENT_SENT, frag_sent);
363 vlib_node_increment_counter (vm, node_index,
364 IP_FRAG_ERROR_SMALL_PACKET, small_packets);
366 return frame->n_vectors;
372 ip4_frag (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
374 return frag_node_inline (vm, node, frame, ip4_frag_node.index,
379 ip6_frag (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
381 return frag_node_inline (vm, node, frame, ip6_frag_node.index,
386 * Fragments the packet given in from_bi. Fragments are returned in the buffer vector.
387 * Caller must ensure the original packet is freed.
390 ip6_frag_do_fragment (vlib_main_t * vm, u32 from_bi, u32 ** buffer,
391 ip_frag_error_t * error)
393 vlib_buffer_t *from_b;
395 u16 mtu, len, max, rem, ip_frag_id;
397 from_b = vlib_get_buffer (vm, from_bi);
398 mtu = vnet_buffer (from_b)->ip_frag.mtu;
399 ip6 = (ip6_header_t *) vlib_buffer_get_current (from_b);
401 rem = clib_net_to_host_u16 (ip6->payload_length);
402 max = (mtu - sizeof (ip6_header_t) - sizeof (ip6_frag_hdr_t)) & ~0x7; // TODO: Is max correct??
405 (vlib_buffer_length_in_chain (vm, from_b) - sizeof (ip6_header_t)))
407 *error = IP_FRAG_ERROR_MALFORMED;
411 /* TODO: Look through header chain for fragmentation header */
412 if (ip6->protocol == IP_PROTOCOL_IPV6_FRAGMENTATION)
414 *error = IP_FRAG_ERROR_MALFORMED;
418 u8 *from_data = (void *) (ip6 + 1);
419 vlib_buffer_t *org_from_b = from_b;
421 u16 left_in_from_buffer = from_b->current_length - sizeof (ip6_header_t);
424 ip_frag_id = ++running_fragment_id; // Fix
426 /* Do the actual fragmentation */
431 ip6_header_t *to_ip6;
432 ip6_frag_hdr_t *to_frag_hdr;
437 (mtu - sizeof (ip6_header_t) - sizeof (ip6_frag_hdr_t)) ? max : rem);
438 if (len != rem) /* Last fragment does not need to divisible by 8 */
440 if ((to_b = frag_buffer_alloc (org_from_b, &to_bi)) == 0)
442 *error = IP_FRAG_ERROR_MEMORY;
445 vec_add1 (*buffer, to_bi);
446 frag_set_sw_if_index (to_b, org_from_b);
448 /* Copy ip6 header */
449 clib_memcpy_fast (to_b->data, ip6, sizeof (ip6_header_t));
450 to_ip6 = vlib_buffer_get_current (to_b);
451 to_frag_hdr = (ip6_frag_hdr_t *) (to_ip6 + 1);
452 to_data = (void *) (to_frag_hdr + 1);
454 /* Spin through from buffers filling up the to buffer */
455 u16 left_in_to_buffer = len, to_ptr = 0;
460 /* Figure out how many bytes we can safely copy */
461 bytes_to_copy = left_in_to_buffer <= left_in_from_buffer ?
462 left_in_to_buffer : left_in_from_buffer;
463 clib_memcpy_fast (to_data + to_ptr, from_data + ptr, bytes_to_copy);
464 left_in_to_buffer -= bytes_to_copy;
465 ptr += bytes_to_copy;
466 left_in_from_buffer -= bytes_to_copy;
467 if (left_in_to_buffer == 0)
470 ASSERT (left_in_from_buffer <= 0);
472 if (!(from_b->flags & VLIB_BUFFER_NEXT_PRESENT))
474 *error = IP_FRAG_ERROR_MALFORMED;
477 from_b = vlib_get_buffer (vm, from_b->next_buffer);
478 from_data = (u8 *) vlib_buffer_get_current (from_b);
480 left_in_from_buffer = from_b->current_length;
481 to_ptr += bytes_to_copy;
484 to_b->current_length =
485 len + sizeof (ip6_header_t) + sizeof (ip6_frag_hdr_t);
486 to_ip6->payload_length =
487 clib_host_to_net_u16 (len + sizeof (ip6_frag_hdr_t));
488 to_ip6->protocol = IP_PROTOCOL_IPV6_FRAGMENTATION;
489 to_frag_hdr->fragment_offset_and_more =
490 ip6_frag_hdr_offset_and_more ((fo >> 3), len != rem);
491 to_frag_hdr->identification = ip_frag_id;
492 to_frag_hdr->next_hdr = ip6->protocol;
493 to_frag_hdr->rsv = 0;
500 static char *ip4_frag_error_strings[] = {
501 #define _(sym,string) string,
502 foreach_ip_frag_error
507 VLIB_REGISTER_NODE (ip4_frag_node) = {
508 .function = ip4_frag,
509 .name = IP4_FRAG_NODE_NAME,
510 .vector_size = sizeof (u32),
511 .format_trace = format_ip_frag_trace,
512 .type = VLIB_NODE_TYPE_INTERNAL,
514 .n_errors = IP_FRAG_N_ERROR,
515 .error_strings = ip4_frag_error_strings,
517 .n_next_nodes = IP4_FRAG_N_NEXT,
519 [IP4_FRAG_NEXT_IP4_REWRITE] = "ip4-rewrite",
520 [IP4_FRAG_NEXT_IP4_LOOKUP] = "ip4-lookup",
521 [IP4_FRAG_NEXT_IP6_LOOKUP] = "ip6-lookup",
522 [IP4_FRAG_NEXT_ICMP_ERROR] = "ip4-icmp-error",
523 [IP4_FRAG_NEXT_DROP] = "ip4-drop"
529 VLIB_REGISTER_NODE (ip6_frag_node) = {
530 .function = ip6_frag,
531 .name = IP6_FRAG_NODE_NAME,
532 .vector_size = sizeof (u32),
533 .format_trace = format_ip_frag_trace,
534 .type = VLIB_NODE_TYPE_INTERNAL,
536 .n_errors = IP_FRAG_N_ERROR,
537 .error_strings = ip4_frag_error_strings,
539 .n_next_nodes = IP6_FRAG_N_NEXT,
541 [IP6_FRAG_NEXT_IP6_REWRITE] = "ip6-rewrite",
542 [IP6_FRAG_NEXT_IP4_LOOKUP] = "ip4-lookup",
543 [IP6_FRAG_NEXT_IP6_LOOKUP] = "ip6-lookup",
544 [IP6_FRAG_NEXT_DROP] = "ip6-drop"
550 * fd.io coding-style-patch-verification: ON
553 * eval: (c-set-style "gnu")