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 static vlib_buffer_t *
67 frag_buffer_alloc (vlib_buffer_t * org_b, u32 * bi)
69 vlib_main_t *vm = vlib_get_main ();
70 if (vlib_buffer_alloc (vm, bi, 1) != 1)
73 vlib_buffer_t *b = vlib_get_buffer (vm, *bi);
74 vlib_buffer_free_list_t *fl =
75 vlib_buffer_get_free_list (vm, VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX);
76 vlib_buffer_init_for_free_list (b, fl);
77 VLIB_BUFFER_TRACE_TRAJECTORY_INIT (b);
78 vlib_buffer_copy_trace_flag (vm, org_b, *bi);
84 * Limitation: Does follow buffer chains in the packet to fragment,
85 * but does not generate buffer chains. I.e. a fragment is always
86 * contained with in a single buffer and limited to the max buffer
90 ip4_frag_do_fragment (vlib_main_t * vm, u32 from_bi, u32 ** buffer,
91 ip_frag_error_t * error)
93 vlib_buffer_t *from_b;
95 u16 mtu, len, max, rem, ip_frag_id, ip_frag_offset;
96 u8 *org_from_packet, more;
98 from_b = vlib_get_buffer (vm, from_bi);
99 mtu = vnet_buffer (from_b)->ip_frag.mtu;
100 org_from_packet = vlib_buffer_get_current (from_b);
101 ip4 = (ip4_header_t *) vlib_buffer_get_current (from_b);
103 rem = clib_net_to_host_u16 (ip4->length) - sizeof (ip4_header_t);
105 (clib_min (mtu, VLIB_BUFFER_DATA_SIZE) - sizeof (ip4_header_t)) & ~0x7;
108 (vlib_buffer_length_in_chain (vm, from_b) - sizeof (ip4_header_t)))
110 *error = IP_FRAG_ERROR_MALFORMED;
114 if (mtu < sizeof (ip4_header_t))
116 *error = IP_FRAG_ERROR_CANT_FRAGMENT_HEADER;
120 if (ip4->flags_and_fragment_offset &
121 clib_host_to_net_u16 (IP4_HEADER_FLAG_DONT_FRAGMENT))
123 *error = IP_FRAG_ERROR_DONT_FRAGMENT_SET;
127 if (ip4_is_fragment (ip4))
129 ip_frag_id = ip4->fragment_id;
130 ip_frag_offset = ip4_get_fragment_offset (ip4);
132 !(!(ip4->flags_and_fragment_offset &
133 clib_host_to_net_u16 (IP4_HEADER_FLAG_MORE_FRAGMENTS)));
137 ip_frag_id = (++running_fragment_id);
142 u8 *from_data = (void *) (ip4 + 1);
143 vlib_buffer_t *org_from_b = from_b;
145 u16 left_in_from_buffer = from_b->current_length - sizeof (ip4_header_t);
148 /* Do the actual fragmentation */
153 ip4_header_t *to_ip4;
156 len = (rem > max ? max : rem);
157 if (len != rem) /* Last fragment does not need to divisible by 8 */
159 if ((to_b = frag_buffer_alloc (org_from_b, &to_bi)) == 0)
161 *error = IP_FRAG_ERROR_MEMORY;
164 vec_add1 (*buffer, to_bi);
165 frag_set_sw_if_index (to_b, org_from_b);
167 /* Copy ip4 header */
168 clib_memcpy_fast (to_b->data, org_from_packet, sizeof (ip4_header_t));
169 to_ip4 = vlib_buffer_get_current (to_b);
170 to_data = (void *) (to_ip4 + 1);
172 /* Spin through from buffers filling up the to buffer */
173 u16 left_in_to_buffer = len, to_ptr = 0;
178 /* Figure out how many bytes we can safely copy */
179 bytes_to_copy = left_in_to_buffer <= left_in_from_buffer ?
180 left_in_to_buffer : left_in_from_buffer;
181 clib_memcpy_fast (to_data + to_ptr, from_data + ptr, bytes_to_copy);
182 left_in_to_buffer -= bytes_to_copy;
183 ptr += bytes_to_copy;
184 left_in_from_buffer -= bytes_to_copy;
185 if (left_in_to_buffer == 0)
188 ASSERT (left_in_from_buffer <= 0);
190 if (!(from_b->flags & VLIB_BUFFER_NEXT_PRESENT))
192 *error = IP_FRAG_ERROR_MALFORMED;
195 from_b = vlib_get_buffer (vm, from_b->next_buffer);
196 from_data = (u8 *) vlib_buffer_get_current (from_b);
198 left_in_from_buffer = from_b->current_length;
199 to_ptr += bytes_to_copy;
202 to_b->current_length = len + sizeof (ip4_header_t);
204 to_ip4->fragment_id = ip_frag_id;
205 to_ip4->flags_and_fragment_offset =
206 clib_host_to_net_u16 ((fo >> 3) + ip_frag_offset);
207 to_ip4->flags_and_fragment_offset |=
208 clib_host_to_net_u16 (((len != rem) || more) << 13);
209 to_ip4->length = clib_host_to_net_u16 (len + sizeof (ip4_header_t));
210 to_ip4->checksum = ip4_header_checksum (to_ip4);
212 if (vnet_buffer (org_from_b)->ip_frag.flags & IP_FRAG_FLAG_IP4_HEADER)
214 /* Encapsulating ipv4 header */
215 ip4_header_t *encap_header4 =
216 (ip4_header_t *) vlib_buffer_get_current (to_b);
217 encap_header4->length = clib_host_to_net_u16 (to_b->current_length);
218 encap_header4->checksum = ip4_header_checksum (encap_header4);
220 else if (vnet_buffer (org_from_b)->
221 ip_frag.flags & IP_FRAG_FLAG_IP6_HEADER)
223 /* Encapsulating ipv6 header */
224 ip6_header_t *encap_header6 =
225 (ip6_header_t *) vlib_buffer_get_current (to_b);
226 encap_header6->payload_length =
227 clib_host_to_net_u16 (to_b->current_length -
228 sizeof (*encap_header6));
236 ip_frag_set_vnet_buffer (vlib_buffer_t * b, u16 mtu, u8 next_index, u8 flags)
238 vnet_buffer (b)->ip_frag.mtu = mtu;
239 vnet_buffer (b)->ip_frag.next_index = next_index;
240 vnet_buffer (b)->ip_frag.flags = flags;
245 frag_node_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
246 vlib_frame_t * frame, u32 node_index, bool is_ip6)
248 u32 n_left_from, *from, next_index, *to_next, n_left_to_next;
249 vlib_node_runtime_t *error_node = vlib_node_get_runtime (vm, node_index);
250 from = vlib_frame_vector_args (frame);
251 n_left_from = frame->n_vectors;
252 next_index = node->cached_next_index;
253 u32 frag_sent = 0, small_packets = 0;
256 while (n_left_from > 0)
258 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
260 while (n_left_from > 0 && n_left_to_next > 0)
262 u32 pi0, *frag_from, frag_left;
264 ip_frag_error_t error0;
268 * Note: The packet is not enqueued now. It is instead put
269 * in a vector where other fragments will be put as well.
274 error0 = IP_FRAG_ERROR_NONE;
276 p0 = vlib_get_buffer (vm, pi0);
278 ip6_frag_do_fragment (vm, pi0, &buffer, &error0);
280 ip4_frag_do_fragment (vm, pi0, &buffer, &error0);
282 if (PREDICT_FALSE (p0->flags & VLIB_BUFFER_IS_TRACED))
284 ip_frag_trace_t *tr =
285 vlib_add_trace (vm, node, p0, sizeof (*tr));
286 tr->mtu = vnet_buffer (p0)->ip_frag.mtu;
287 tr->ipv6 = is_ip6 ? 1 : 0;
288 tr->n_fragments = vec_len (buffer);
289 tr->next = vnet_buffer (p0)->ip_frag.next_index;
292 if (!is_ip6 && error0 == IP_FRAG_ERROR_DONT_FRAGMENT_SET)
294 icmp4_error_set_vnet_buffer (p0, ICMP4_destination_unreachable,
295 ICMP4_destination_unreachable_fragmentation_needed_and_dont_fragment_set,
296 vnet_buffer (p0)->ip_frag.mtu);
297 next0 = IP4_FRAG_NEXT_ICMP_ERROR;
304 IP_FRAG_ERROR_NONE) ? vnet_buffer (p0)->
305 ip_frag.next_index : IP6_FRAG_NEXT_DROP;
309 IP_FRAG_ERROR_NONE) ? vnet_buffer (p0)->
310 ip_frag.next_index : IP4_FRAG_NEXT_DROP;
313 if (error0 == IP_FRAG_ERROR_NONE)
315 /* Free original buffer chain */
316 frag_sent += vec_len (buffer);
317 small_packets += (vec_len (buffer) == 1);
318 vlib_buffer_free_one (vm, pi0); /* Free original packet */
322 vlib_error_count (vm, node_index, error0, 1);
323 vec_add1 (buffer, pi0); /* Get rid of the original buffer */
326 /* Send fragments that were added in the frame */
328 frag_left = vec_len (buffer);
330 while (frag_left > 0)
332 while (frag_left > 0 && n_left_to_next > 0)
335 i = to_next[0] = frag_from[0];
341 vlib_get_buffer (vm, i)->error = error_node->errors[error0];
342 vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
343 to_next, n_left_to_next, i,
346 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
347 vlib_get_next_frame (vm, node, next_index, to_next,
350 vec_reset_length (buffer);
352 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
356 vlib_node_increment_counter (vm, node_index,
357 IP_FRAG_ERROR_FRAGMENT_SENT, frag_sent);
358 vlib_node_increment_counter (vm, node_index,
359 IP_FRAG_ERROR_SMALL_PACKET, small_packets);
361 return frame->n_vectors;
367 ip4_frag (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
369 return frag_node_inline (vm, node, frame, ip4_frag_node.index,
374 ip6_frag (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
376 return frag_node_inline (vm, node, frame, ip6_frag_node.index,
381 * Fragments the packet given in from_bi. Fragments are returned in the buffer vector.
382 * Caller must ensure the original packet is freed.
385 ip6_frag_do_fragment (vlib_main_t * vm, u32 from_bi, u32 ** buffer,
386 ip_frag_error_t * error)
388 vlib_buffer_t *from_b;
390 u16 mtu, len, max, rem, ip_frag_id;
392 from_b = vlib_get_buffer (vm, from_bi);
393 mtu = vnet_buffer (from_b)->ip_frag.mtu;
394 ip6 = (ip6_header_t *) vlib_buffer_get_current (from_b);
396 rem = clib_net_to_host_u16 (ip6->payload_length);
397 max = (mtu - sizeof (ip6_header_t) - sizeof (ip6_frag_hdr_t)) & ~0x7; // TODO: Is max correct??
400 (vlib_buffer_length_in_chain (vm, from_b) - sizeof (ip6_header_t)))
402 *error = IP_FRAG_ERROR_MALFORMED;
406 /* TODO: Look through header chain for fragmentation header */
407 if (ip6->protocol == IP_PROTOCOL_IPV6_FRAGMENTATION)
409 *error = IP_FRAG_ERROR_MALFORMED;
413 u8 *from_data = (void *) (ip6 + 1);
414 vlib_buffer_t *org_from_b = from_b;
416 u16 left_in_from_buffer = from_b->current_length - sizeof (ip6_header_t);
419 ip_frag_id = ++running_fragment_id; // Fix
421 /* Do the actual fragmentation */
426 ip6_header_t *to_ip6;
427 ip6_frag_hdr_t *to_frag_hdr;
432 (mtu - sizeof (ip6_header_t) - sizeof (ip6_frag_hdr_t)) ? max : rem);
433 if (len != rem) /* Last fragment does not need to divisible by 8 */
435 if ((to_b = frag_buffer_alloc (org_from_b, &to_bi)) == 0)
437 *error = IP_FRAG_ERROR_MEMORY;
440 vec_add1 (*buffer, to_bi);
441 frag_set_sw_if_index (to_b, org_from_b);
443 /* Copy ip6 header */
444 clib_memcpy_fast (to_b->data, ip6, sizeof (ip6_header_t));
445 to_ip6 = vlib_buffer_get_current (to_b);
446 to_frag_hdr = (ip6_frag_hdr_t *) (to_ip6 + 1);
447 to_data = (void *) (to_frag_hdr + 1);
449 /* Spin through from buffers filling up the to buffer */
450 u16 left_in_to_buffer = len, to_ptr = 0;
455 /* Figure out how many bytes we can safely copy */
456 bytes_to_copy = left_in_to_buffer <= left_in_from_buffer ?
457 left_in_to_buffer : left_in_from_buffer;
458 clib_memcpy_fast (to_data + to_ptr, from_data + ptr, bytes_to_copy);
459 left_in_to_buffer -= bytes_to_copy;
460 ptr += bytes_to_copy;
461 left_in_from_buffer -= bytes_to_copy;
462 if (left_in_to_buffer == 0)
465 ASSERT (left_in_from_buffer <= 0);
467 if (!(from_b->flags & VLIB_BUFFER_NEXT_PRESENT))
469 *error = IP_FRAG_ERROR_MALFORMED;
472 from_b = vlib_get_buffer (vm, from_b->next_buffer);
473 from_data = (u8 *) vlib_buffer_get_current (from_b);
475 left_in_from_buffer = from_b->current_length;
476 to_ptr += bytes_to_copy;
479 to_b->current_length =
480 len + sizeof (ip6_header_t) + sizeof (ip6_frag_hdr_t);
481 to_ip6->payload_length =
482 clib_host_to_net_u16 (len + sizeof (ip6_frag_hdr_t));
483 to_ip6->protocol = IP_PROTOCOL_IPV6_FRAGMENTATION;
484 to_frag_hdr->fragment_offset_and_more =
485 ip6_frag_hdr_offset_and_more ((fo >> 3), len != rem);
486 to_frag_hdr->identification = ip_frag_id;
487 to_frag_hdr->next_hdr = ip6->protocol;
488 to_frag_hdr->rsv = 0;
495 static char *ip4_frag_error_strings[] = {
496 #define _(sym,string) string,
497 foreach_ip_frag_error
502 VLIB_REGISTER_NODE (ip4_frag_node) = {
503 .function = ip4_frag,
504 .name = IP4_FRAG_NODE_NAME,
505 .vector_size = sizeof (u32),
506 .format_trace = format_ip_frag_trace,
507 .type = VLIB_NODE_TYPE_INTERNAL,
509 .n_errors = IP_FRAG_N_ERROR,
510 .error_strings = ip4_frag_error_strings,
512 .n_next_nodes = IP4_FRAG_N_NEXT,
514 [IP4_FRAG_NEXT_IP4_REWRITE] = "ip4-rewrite",
515 [IP4_FRAG_NEXT_IP4_LOOKUP] = "ip4-lookup",
516 [IP4_FRAG_NEXT_IP6_LOOKUP] = "ip6-lookup",
517 [IP4_FRAG_NEXT_ICMP_ERROR] = "ip4-icmp-error",
518 [IP4_FRAG_NEXT_DROP] = "ip4-drop"
524 VLIB_REGISTER_NODE (ip6_frag_node) = {
525 .function = ip6_frag,
526 .name = IP6_FRAG_NODE_NAME,
527 .vector_size = sizeof (u32),
528 .format_trace = format_ip_frag_trace,
529 .type = VLIB_NODE_TYPE_INTERNAL,
531 .n_errors = IP_FRAG_N_ERROR,
532 .error_strings = ip4_frag_error_strings,
534 .n_next_nodes = IP6_FRAG_N_NEXT,
536 [IP6_FRAG_NEXT_IP6_REWRITE] = "ip6-rewrite",
537 [IP6_FRAG_NEXT_IP4_LOOKUP] = "ip4-lookup",
538 [IP6_FRAG_NEXT_IP6_LOOKUP] = "ip6-lookup",
539 [IP6_FRAG_NEXT_DROP] = "ip6-drop"
545 * fd.io coding-style-patch-verification: ON
548 * eval: (c-set-style "gnu")