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>
27 * Copy the mpls header if present.
28 * The current is pointing to the ip header.
29 * Adjust the buffer and point to the mpls headers on these fragments
30 * before sending the packet back to mpls-output node.
33 copy_mpls_hdr (vlib_buffer_t * to_b, vlib_buffer_t * from_b)
35 if ((vnet_buffer (from_b)->ip_frag.flags) & IP_FRAG_FLAG_MPLS_HEADER)
37 u8 mpls_hdr_length = vnet_buffer (from_b)->mpls.mpls_hdr_length;
38 u8 *org_from_mpls_packet =
39 from_b->data + (from_b->current_data - mpls_hdr_length);
40 clib_memcpy_fast ((to_b->data - mpls_hdr_length), org_from_mpls_packet,
42 vlib_buffer_advance (to_b, -vnet_buffer (to_b)->mpls.mpls_hdr_length);
55 format_ip_frag_trace (u8 * s, va_list * args)
57 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
58 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
59 ip_frag_trace_t *t = va_arg (*args, ip_frag_trace_t *);
60 s = format (s, "IPv%s mtu: %u fragments: %u next: %d",
61 t->ipv6 ? "6" : "4", t->mtu, t->n_fragments, t->next);
65 static u32 running_fragment_id;
68 frag_set_sw_if_index (vlib_buffer_t * to, vlib_buffer_t * from)
70 vnet_buffer (to)->sw_if_index[VLIB_RX] =
71 vnet_buffer (from)->sw_if_index[VLIB_RX];
72 vnet_buffer (to)->sw_if_index[VLIB_TX] =
73 vnet_buffer (from)->sw_if_index[VLIB_TX];
75 /* Copy adj_index in case DPO based node is sending for the
76 * fragmentation, the packet would be sent back to the proper
77 * DPO next node and Index
79 vnet_buffer (to)->ip.adj_index[VLIB_RX] =
80 vnet_buffer (from)->ip.adj_index[VLIB_RX];
81 vnet_buffer (to)->ip.adj_index[VLIB_TX] =
82 vnet_buffer (from)->ip.adj_index[VLIB_TX];
85 if (PREDICT_TRUE (from->flags & VNET_BUFFER_F_QOS_DATA_VALID))
87 vnet_buffer2 (to)->qos = vnet_buffer2 (from)->qos;
88 to->flags |= VNET_BUFFER_F_QOS_DATA_VALID;
91 /* Copy mpls opaque data */
92 if ((vnet_buffer (from)->ip_frag.flags) & IP_FRAG_FLAG_MPLS_HEADER)
94 vnet_buffer (to)->mpls.pyld_proto = vnet_buffer (from)->mpls.pyld_proto;
95 vnet_buffer (to)->mpls.mpls_hdr_length =
96 vnet_buffer (from)->mpls.mpls_hdr_length;
100 static vlib_buffer_t *
101 frag_buffer_alloc (vlib_buffer_t * org_b, u32 * bi)
103 vlib_main_t *vm = vlib_get_main ();
104 if (vlib_buffer_alloc (vm, bi, 1) != 1)
107 vlib_buffer_t *b = vlib_get_buffer (vm, *bi);
108 VLIB_BUFFER_TRACE_TRAJECTORY_INIT (b);
109 vlib_buffer_copy_trace_flag (vm, org_b, *bi);
115 * Limitation: Does follow buffer chains in the packet to fragment,
116 * but does not generate buffer chains. I.e. a fragment is always
117 * contained with in a single buffer and limited to the max buffer
121 ip4_frag_do_fragment (vlib_main_t * vm, u32 from_bi, u32 ** buffer,
122 ip_frag_error_t * error)
124 vlib_buffer_t *from_b;
126 u16 mtu, len, max, rem, ip_frag_id, ip_frag_offset;
127 u8 *org_from_packet, more;
129 from_b = vlib_get_buffer (vm, from_bi);
130 mtu = vnet_buffer (from_b)->ip_frag.mtu;
131 org_from_packet = vlib_buffer_get_current (from_b);
132 ip4 = (ip4_header_t *) vlib_buffer_get_current (from_b);
134 rem = clib_net_to_host_u16 (ip4->length) - sizeof (ip4_header_t);
136 (clib_min (mtu, vlib_buffer_get_default_data_size (vm)) -
137 sizeof (ip4_header_t)) & ~0x7;
140 (vlib_buffer_length_in_chain (vm, from_b) - sizeof (ip4_header_t)))
142 *error = IP_FRAG_ERROR_MALFORMED;
146 if (mtu < sizeof (ip4_header_t))
148 *error = IP_FRAG_ERROR_CANT_FRAGMENT_HEADER;
152 if (ip4->flags_and_fragment_offset &
153 clib_host_to_net_u16 (IP4_HEADER_FLAG_DONT_FRAGMENT))
155 *error = IP_FRAG_ERROR_DONT_FRAGMENT_SET;
159 if (ip4_is_fragment (ip4))
161 ip_frag_id = ip4->fragment_id;
162 ip_frag_offset = ip4_get_fragment_offset (ip4);
164 !(!(ip4->flags_and_fragment_offset &
165 clib_host_to_net_u16 (IP4_HEADER_FLAG_MORE_FRAGMENTS)));
169 ip_frag_id = (++running_fragment_id);
174 u8 *from_data = (void *) (ip4 + 1);
175 vlib_buffer_t *org_from_b = from_b;
177 u16 left_in_from_buffer = from_b->current_length - sizeof (ip4_header_t);
180 /* Do the actual fragmentation */
185 ip4_header_t *to_ip4;
188 len = (rem > max ? max : rem);
189 if (len != rem) /* Last fragment does not need to divisible by 8 */
191 if ((to_b = frag_buffer_alloc (org_from_b, &to_bi)) == 0)
193 *error = IP_FRAG_ERROR_MEMORY;
196 vec_add1 (*buffer, to_bi);
197 frag_set_sw_if_index (to_b, org_from_b);
199 /* Copy ip4 header */
200 clib_memcpy_fast (to_b->data, org_from_packet, sizeof (ip4_header_t));
201 to_ip4 = vlib_buffer_get_current (to_b);
202 to_data = (void *) (to_ip4 + 1);
204 /* Spin through from buffers filling up the to buffer */
205 u16 left_in_to_buffer = len, to_ptr = 0;
210 /* Figure out how many bytes we can safely copy */
211 bytes_to_copy = left_in_to_buffer <= left_in_from_buffer ?
212 left_in_to_buffer : left_in_from_buffer;
213 clib_memcpy_fast (to_data + to_ptr, from_data + ptr, bytes_to_copy);
214 left_in_to_buffer -= bytes_to_copy;
215 ptr += bytes_to_copy;
216 left_in_from_buffer -= bytes_to_copy;
217 if (left_in_to_buffer == 0)
220 ASSERT (left_in_from_buffer <= 0);
222 if (!(from_b->flags & VLIB_BUFFER_NEXT_PRESENT))
224 *error = IP_FRAG_ERROR_MALFORMED;
227 from_b = vlib_get_buffer (vm, from_b->next_buffer);
228 from_data = (u8 *) vlib_buffer_get_current (from_b);
230 left_in_from_buffer = from_b->current_length;
231 to_ptr += bytes_to_copy;
234 to_b->current_length = len + sizeof (ip4_header_t);
236 to_ip4->fragment_id = ip_frag_id;
237 to_ip4->flags_and_fragment_offset =
238 clib_host_to_net_u16 ((fo >> 3) + ip_frag_offset);
239 to_ip4->flags_and_fragment_offset |=
240 clib_host_to_net_u16 (((len != rem) || more) << 13);
241 to_ip4->length = clib_host_to_net_u16 (len + sizeof (ip4_header_t));
242 to_ip4->checksum = ip4_header_checksum (to_ip4);
244 if (vnet_buffer (org_from_b)->ip_frag.flags & IP_FRAG_FLAG_IP4_HEADER)
246 /* Encapsulating ipv4 header */
247 ip4_header_t *encap_header4 =
248 (ip4_header_t *) vlib_buffer_get_current (to_b);
249 encap_header4->length = clib_host_to_net_u16 (to_b->current_length);
250 encap_header4->checksum = ip4_header_checksum (encap_header4);
252 else if (vnet_buffer (org_from_b)->
253 ip_frag.flags & IP_FRAG_FLAG_IP6_HEADER)
255 /* Encapsulating ipv6 header */
256 ip6_header_t *encap_header6 =
257 (ip6_header_t *) vlib_buffer_get_current (to_b);
258 encap_header6->payload_length =
259 clib_host_to_net_u16 (to_b->current_length -
260 sizeof (*encap_header6));
263 /* Copy mpls header if present */
264 copy_mpls_hdr (to_b, org_from_b);
272 ip_frag_set_vnet_buffer (vlib_buffer_t * b, u16 mtu, u8 next_index, u8 flags)
274 vnet_buffer (b)->ip_frag.mtu = mtu;
275 vnet_buffer (b)->ip_frag.next_index = next_index;
276 vnet_buffer (b)->ip_frag.flags = flags;
281 frag_node_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
282 vlib_frame_t * frame, u32 node_index, bool is_ip6)
284 u32 n_left_from, *from, next_index, *to_next, n_left_to_next;
285 vlib_node_runtime_t *error_node = vlib_node_get_runtime (vm, node_index);
286 from = vlib_frame_vector_args (frame);
287 n_left_from = frame->n_vectors;
288 next_index = node->cached_next_index;
289 u32 frag_sent = 0, small_packets = 0;
292 while (n_left_from > 0)
294 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
296 while (n_left_from > 0 && n_left_to_next > 0)
298 u32 pi0, *frag_from, frag_left;
300 ip_frag_error_t error0;
304 * Note: The packet is not enqueued now. It is instead put
305 * in a vector where other fragments will be put as well.
310 error0 = IP_FRAG_ERROR_NONE;
312 p0 = vlib_get_buffer (vm, pi0);
314 ip6_frag_do_fragment (vm, pi0, &buffer, &error0);
316 ip4_frag_do_fragment (vm, pi0, &buffer, &error0);
318 if (PREDICT_FALSE (p0->flags & VLIB_BUFFER_IS_TRACED))
320 ip_frag_trace_t *tr =
321 vlib_add_trace (vm, node, p0, sizeof (*tr));
322 tr->mtu = vnet_buffer (p0)->ip_frag.mtu;
323 tr->ipv6 = is_ip6 ? 1 : 0;
324 tr->n_fragments = vec_len (buffer);
325 tr->next = vnet_buffer (p0)->ip_frag.next_index;
328 if (!is_ip6 && error0 == IP_FRAG_ERROR_DONT_FRAGMENT_SET)
330 icmp4_error_set_vnet_buffer (p0, ICMP4_destination_unreachable,
331 ICMP4_destination_unreachable_fragmentation_needed_and_dont_fragment_set,
332 vnet_buffer (p0)->ip_frag.mtu);
333 next0 = IP4_FRAG_NEXT_ICMP_ERROR;
340 IP_FRAG_ERROR_NONE) ? vnet_buffer (p0)->
341 ip_frag.next_index : IP6_FRAG_NEXT_DROP;
345 IP_FRAG_ERROR_NONE) ? vnet_buffer (p0)->
346 ip_frag.next_index : IP4_FRAG_NEXT_DROP;
349 if (error0 == IP_FRAG_ERROR_NONE)
351 /* Free original buffer chain */
352 frag_sent += vec_len (buffer);
353 small_packets += (vec_len (buffer) == 1);
354 vlib_buffer_free_one (vm, pi0); /* Free original packet */
358 vlib_error_count (vm, node_index, error0, 1);
359 vec_add1 (buffer, pi0); /* Get rid of the original buffer */
362 /* Send fragments that were added in the frame */
364 frag_left = vec_len (buffer);
366 while (frag_left > 0)
368 while (frag_left > 0 && n_left_to_next > 0)
371 i = to_next[0] = frag_from[0];
377 vlib_get_buffer (vm, i)->error = error_node->errors[error0];
378 vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
379 to_next, n_left_to_next, i,
382 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
383 vlib_get_next_frame (vm, node, next_index, to_next,
386 vec_reset_length (buffer);
388 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
392 vlib_node_increment_counter (vm, node_index,
393 IP_FRAG_ERROR_FRAGMENT_SENT, frag_sent);
394 vlib_node_increment_counter (vm, node_index,
395 IP_FRAG_ERROR_SMALL_PACKET, small_packets);
397 return frame->n_vectors;
403 ip4_frag (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
405 return frag_node_inline (vm, node, frame, ip4_frag_node.index,
410 ip6_frag (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
412 return frag_node_inline (vm, node, frame, ip6_frag_node.index,
417 * Fragments the packet given in from_bi. Fragments are returned in the buffer vector.
418 * Caller must ensure the original packet is freed.
421 ip6_frag_do_fragment (vlib_main_t * vm, u32 from_bi, u32 ** buffer,
422 ip_frag_error_t * error)
424 vlib_buffer_t *from_b;
426 u16 mtu, len, max, rem, ip_frag_id;
428 from_b = vlib_get_buffer (vm, from_bi);
429 mtu = vnet_buffer (from_b)->ip_frag.mtu;
430 ip6 = (ip6_header_t *) vlib_buffer_get_current (from_b);
432 rem = clib_net_to_host_u16 (ip6->payload_length);
433 max = (mtu - sizeof (ip6_header_t) - sizeof (ip6_frag_hdr_t)) & ~0x7; // TODO: Is max correct??
436 (vlib_buffer_length_in_chain (vm, from_b) - sizeof (ip6_header_t)))
438 *error = IP_FRAG_ERROR_MALFORMED;
442 /* TODO: Look through header chain for fragmentation header */
443 if (ip6->protocol == IP_PROTOCOL_IPV6_FRAGMENTATION)
445 *error = IP_FRAG_ERROR_MALFORMED;
449 u8 *from_data = (void *) (ip6 + 1);
450 vlib_buffer_t *org_from_b = from_b;
452 u16 left_in_from_buffer = from_b->current_length - sizeof (ip6_header_t);
455 ip_frag_id = ++running_fragment_id; // Fix
457 /* Do the actual fragmentation */
462 ip6_header_t *to_ip6;
463 ip6_frag_hdr_t *to_frag_hdr;
468 (mtu - sizeof (ip6_header_t) - sizeof (ip6_frag_hdr_t)) ? max : rem);
469 if (len != rem) /* Last fragment does not need to divisible by 8 */
471 if ((to_b = frag_buffer_alloc (org_from_b, &to_bi)) == 0)
473 *error = IP_FRAG_ERROR_MEMORY;
476 vec_add1 (*buffer, to_bi);
477 frag_set_sw_if_index (to_b, org_from_b);
479 /* Copy ip6 header */
480 clib_memcpy_fast (to_b->data, ip6, sizeof (ip6_header_t));
481 to_ip6 = vlib_buffer_get_current (to_b);
482 to_frag_hdr = (ip6_frag_hdr_t *) (to_ip6 + 1);
483 to_data = (void *) (to_frag_hdr + 1);
485 /* Spin through from buffers filling up the to buffer */
486 u16 left_in_to_buffer = len, to_ptr = 0;
491 /* Figure out how many bytes we can safely copy */
492 bytes_to_copy = left_in_to_buffer <= left_in_from_buffer ?
493 left_in_to_buffer : left_in_from_buffer;
494 clib_memcpy_fast (to_data + to_ptr, from_data + ptr, bytes_to_copy);
495 left_in_to_buffer -= bytes_to_copy;
496 ptr += bytes_to_copy;
497 left_in_from_buffer -= bytes_to_copy;
498 if (left_in_to_buffer == 0)
501 ASSERT (left_in_from_buffer <= 0);
503 if (!(from_b->flags & VLIB_BUFFER_NEXT_PRESENT))
505 *error = IP_FRAG_ERROR_MALFORMED;
508 from_b = vlib_get_buffer (vm, from_b->next_buffer);
509 from_data = (u8 *) vlib_buffer_get_current (from_b);
511 left_in_from_buffer = from_b->current_length;
512 to_ptr += bytes_to_copy;
515 to_b->current_length =
516 len + sizeof (ip6_header_t) + sizeof (ip6_frag_hdr_t);
517 to_ip6->payload_length =
518 clib_host_to_net_u16 (len + sizeof (ip6_frag_hdr_t));
519 to_ip6->protocol = IP_PROTOCOL_IPV6_FRAGMENTATION;
520 to_frag_hdr->fragment_offset_and_more =
521 ip6_frag_hdr_offset_and_more ((fo >> 3), len != rem);
522 to_frag_hdr->identification = ip_frag_id;
523 to_frag_hdr->next_hdr = ip6->protocol;
524 to_frag_hdr->rsv = 0;
526 /* Copy mpls header if present */
527 copy_mpls_hdr (to_b, org_from_b);
534 static char *ip4_frag_error_strings[] = {
535 #define _(sym,string) string,
536 foreach_ip_frag_error
541 VLIB_REGISTER_NODE (ip4_frag_node) = {
542 .function = ip4_frag,
543 .name = IP4_FRAG_NODE_NAME,
544 .vector_size = sizeof (u32),
545 .format_trace = format_ip_frag_trace,
546 .type = VLIB_NODE_TYPE_INTERNAL,
548 .n_errors = IP_FRAG_N_ERROR,
549 .error_strings = ip4_frag_error_strings,
551 .n_next_nodes = IP4_FRAG_N_NEXT,
553 [IP4_FRAG_NEXT_IP4_REWRITE] = "ip4-rewrite",
554 [IP4_FRAG_NEXT_IP4_LOOKUP] = "ip4-lookup",
555 [IP4_FRAG_NEXT_IP6_LOOKUP] = "ip6-lookup",
556 [IP4_FRAG_NEXT_MPLS_OUTPUT] = "mpls-output",
557 [IP4_FRAG_NEXT_ICMP_ERROR] = "ip4-icmp-error",
558 [IP4_FRAG_NEXT_DROP] = "ip4-drop"
564 VLIB_REGISTER_NODE (ip6_frag_node) = {
565 .function = ip6_frag,
566 .name = IP6_FRAG_NODE_NAME,
567 .vector_size = sizeof (u32),
568 .format_trace = format_ip_frag_trace,
569 .type = VLIB_NODE_TYPE_INTERNAL,
571 .n_errors = IP_FRAG_N_ERROR,
572 .error_strings = ip4_frag_error_strings,
574 .n_next_nodes = IP6_FRAG_N_NEXT,
576 [IP6_FRAG_NEXT_IP6_REWRITE] = "ip6-rewrite",
577 [IP6_FRAG_NEXT_IP4_LOOKUP] = "ip4-lookup",
578 [IP6_FRAG_NEXT_IP6_LOOKUP] = "ip6-lookup",
579 [IP6_FRAG_NEXT_MPLS_OUTPUT] = "mpls-output",
580 [IP6_FRAG_NEXT_DROP] = "ip6-drop"
586 * fd.io coding-style-patch-verification: ON
589 * eval: (c-set-style "gnu")