2 * Copyright (c) 2017 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.
18 * @brief IPv4 Reassembly.
20 * This file contains the source code for IPv4 reassembly.
23 #include <vppinfra/vec.h>
24 #include <vnet/vnet.h>
25 #include <vnet/ip/ip.h>
26 #include <vppinfra/bihash_16_8.h>
27 #include <vnet/ip/ip4_reassembly.h>
29 #define MSEC_PER_SEC 1000
30 #define IP4_REASS_TIMEOUT_DEFAULT_MS 100
31 #define IP4_REASS_EXPIRE_WALK_INTERVAL_DEFAULT_MS 10000 // 10 seconds default
32 #define IP4_REASS_MAX_REASSEMBLIES_DEFAULT 1024
33 #define IP4_REASS_HT_LOAD_FACTOR (0.75)
35 #define IP4_REASS_DEBUG_BUFFERS 0
36 #if IP4_REASS_DEBUG_BUFFERS
37 #define IP4_REASS_DEBUG_BUFFER(bi, what) \
41 printf (#what "buffer %u", _bi); \
42 vlib_buffer_t *_b = vlib_get_buffer (vm, _bi); \
43 while (_b->flags & VLIB_BUFFER_NEXT_PRESENT) \
45 _bi = _b->next_buffer; \
46 printf ("[%u]", _bi); \
47 _b = vlib_get_buffer (vm, _bi); \
54 #define IP4_REASS_DEBUG_BUFFER(...)
60 IP4_REASS_RC_INTERNAL_ERROR,
81 ip4_reass_buffer_get_data_offset (vlib_buffer_t * b)
83 vnet_buffer_opaque_t *vnb = vnet_buffer (b);
84 return vnb->ip.reass.range_first - vnb->ip.reass.fragment_first;
88 ip4_reass_buffer_get_data_len (vlib_buffer_t * b)
90 vnet_buffer_opaque_t *vnb = vnet_buffer (b);
91 return clib_min (vnb->ip.reass.range_last, vnb->ip.reass.fragment_last) -
92 (vnb->ip.reass.fragment_first + ip4_reass_buffer_get_data_offset (b)) + 1;
99 // time when last packet was received
101 // internal id of this reassembly
103 // buffer index of first buffer in this reassembly context
105 // last octet of packet, ~0 until fragment without more_fragments arrives
106 u32 last_packet_octet;
107 // length of data collected so far
109 // trace operation counter
110 u32 trace_op_counter;
111 // next index - used by non-feature node
113 // minimum fragment length for this reassembly - used to estimate MTU
114 u16 min_fragment_length;
123 clib_spinlock_t lock;
124 } ip4_reass_per_thread_t;
131 u32 expire_walk_interval_ms;
135 clib_bihash_16_8_t hash;
137 ip4_reass_per_thread_t *per_thread_data;
140 vlib_main_t *vlib_main;
141 vnet_main_t *vnet_main;
143 // node index of ip4-drop node
145 u32 ip4_reass_expire_node_idx;
148 ip4_reass_main_t ip4_reass_main;
152 IP4_REASSEMBLY_NEXT_INPUT,
153 IP4_REASSEMBLY_NEXT_DROP,
154 IP4_REASSEMBLY_N_NEXT,
164 } ip4_reass_trace_operation_e;
174 } ip4_reass_range_trace_t;
178 ip4_reass_trace_operation_e action;
180 ip4_reass_range_trace_t trace_range;
189 ip4_reass_trace_details (vlib_main_t * vm, u32 bi,
190 ip4_reass_range_trace_t * trace)
192 vlib_buffer_t *b = vlib_get_buffer (vm, bi);
193 vnet_buffer_opaque_t *vnb = vnet_buffer (b);
194 trace->range_first = vnb->ip.reass.range_first;
195 trace->range_last = vnb->ip.reass.range_last;
196 trace->data_offset = ip4_reass_buffer_get_data_offset (b);
197 trace->data_len = ip4_reass_buffer_get_data_len (b);
198 trace->range_bi = bi;
202 format_ip4_reass_range_trace (u8 * s, va_list * args)
204 ip4_reass_range_trace_t *trace = va_arg (*args, ip4_reass_range_trace_t *);
205 s = format (s, "range: [%u, %u], off %d, len %u, bi %u", trace->range_first,
206 trace->range_last, trace->data_offset, trace->data_len,
212 format_ip4_reass_trace (u8 * s, va_list * args)
214 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
215 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
216 ip4_reass_trace_t *t = va_arg (*args, ip4_reass_trace_t *);
217 s = format (s, "reass id: %u, op id: %u ", t->reass_id, t->op_id);
218 u32 indent = format_get_indent (s);
219 s = format (s, "first bi: %u, data len: %u, ip/fragment[%u, %u]",
220 t->trace_range.first_bi, t->total_data_len, t->fragment_first,
225 s = format (s, "\n%Ushrink %U by %u", format_white_space, indent,
226 format_ip4_reass_range_trace, &t->trace_range,
230 s = format (s, "\n%Udiscard %U", format_white_space, indent,
231 format_ip4_reass_range_trace, &t->trace_range);
234 s = format (s, "\n%Unew %U", format_white_space, indent,
235 format_ip4_reass_range_trace, &t->trace_range);
238 s = format (s, "\n%Uoverlapping/ignored %U", format_white_space, indent,
239 format_ip4_reass_range_trace, &t->trace_range);
242 s = format (s, "\n%Ufinalize reassembly", format_white_space, indent);
249 ip4_reass_add_trace (vlib_main_t * vm, vlib_node_runtime_t * node,
250 ip4_reass_main_t * rm, ip4_reass_t * reass, u32 bi,
251 ip4_reass_trace_operation_e action, u32 size_diff)
253 vlib_buffer_t *b = vlib_get_buffer (vm, bi);
254 vnet_buffer_opaque_t *vnb = vnet_buffer (b);
255 if (pool_is_free_index (vm->trace_main.trace_buffer_pool, b->trace_index))
257 // this buffer's trace is gone
258 b->flags &= ~VLIB_BUFFER_IS_TRACED;
261 ip4_reass_trace_t *t = vlib_add_trace (vm, node, b, sizeof (t[0]));
262 t->reass_id = reass->id;
264 ip4_reass_trace_details (vm, bi, &t->trace_range);
265 t->size_diff = size_diff;
266 t->op_id = reass->trace_op_counter;
267 ++reass->trace_op_counter;
268 t->fragment_first = vnb->ip.reass.fragment_first;
269 t->fragment_last = vnb->ip.reass.fragment_last;
270 t->trace_range.first_bi = reass->first_bi;
271 t->total_data_len = reass->data_len;
274 s = format (s, "%U", format_ip4_reass_trace, NULL, NULL, t);
275 printf ("%.*s\n", vec_len (s), s);
277 vec_reset_length (s);
282 ip4_reass_free (ip4_reass_main_t * rm, ip4_reass_per_thread_t * rt,
285 clib_bihash_kv_16_8_t kv;
286 kv.key[0] = reass->key.as_u64[0];
287 kv.key[1] = reass->key.as_u64[1];
288 clib_bihash_add_del_16_8 (&rm->hash, &kv, 0);
289 pool_put (rt->pool, reass);
294 ip4_reass_on_timeout (vlib_main_t * vm, ip4_reass_main_t * rm,
295 ip4_reass_t * reass, u32 ** vec_drop_timeout)
297 u32 range_bi = reass->first_bi;
298 vlib_buffer_t *range_b;
299 vnet_buffer_opaque_t *range_vnb;
300 while (~0 != range_bi)
302 range_b = vlib_get_buffer (vm, range_bi);
303 range_vnb = vnet_buffer (range_b);
307 vec_add1 (*vec_drop_timeout, bi);
308 vlib_buffer_t *b = vlib_get_buffer (vm, bi);
309 if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
312 b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
319 range_bi = range_vnb->ip.reass.next_range_bi;
324 ip4_reass_find_or_create (vlib_main_t * vm, ip4_reass_main_t * rm,
325 ip4_reass_per_thread_t * rt,
326 ip4_reass_key_t * k, u32 ** vec_drop_timeout)
328 ip4_reass_t *reass = NULL;
329 f64 now = vlib_time_now (rm->vlib_main);
330 clib_bihash_kv_16_8_t kv, value;
331 kv.key[0] = k->as_u64[0];
332 kv.key[1] = k->as_u64[1];
334 if (!clib_bihash_search_16_8 (&rm->hash, &kv, &value))
336 reass = pool_elt_at_index (rt->pool, value.value);
337 if (now > reass->last_heard + rm->timeout)
339 ip4_reass_on_timeout (vm, rm, reass, vec_drop_timeout);
340 ip4_reass_free (rm, rt, reass);
347 reass->last_heard = now;
351 if (rt->reass_n >= rm->max_reass_n)
358 pool_get (rt->pool, reass);
359 clib_memset (reass, 0, sizeof (*reass));
361 ((u64) os_get_thread_index () * 1000000000) + rt->id_counter;
363 reass->first_bi = ~0;
364 reass->last_packet_octet = ~0;
369 reass->key.as_u64[0] = kv.key[0] = k->as_u64[0];
370 reass->key.as_u64[1] = kv.key[1] = k->as_u64[1];
371 kv.value = reass - rt->pool;
372 reass->last_heard = now;
374 if (clib_bihash_add_del_16_8 (&rm->hash, &kv, 1))
376 ip4_reass_free (rm, rt, reass);
383 always_inline ip4_reass_rc_t
384 ip4_reass_finalize (vlib_main_t * vm, vlib_node_runtime_t * node,
385 ip4_reass_main_t * rm, ip4_reass_per_thread_t * rt,
386 ip4_reass_t * reass, u32 * bi0, u32 * next0,
387 u32 * error0, u32 ** vec_drop_compress,
388 u32 ** vec_drop_overlap, bool is_feature)
390 vlib_buffer_t *first_b = vlib_get_buffer (vm, reass->first_bi);
391 vlib_buffer_t *last_b = NULL;
392 u32 sub_chain_bi = reass->first_bi;
393 u32 total_length = 0;
398 u32 tmp_bi = sub_chain_bi;
399 vlib_buffer_t *tmp = vlib_get_buffer (vm, tmp_bi);
400 ip4_header_t *ip = vlib_buffer_get_current (tmp);
401 vnet_buffer_opaque_t *vnb = vnet_buffer (tmp);
402 if (!(vnb->ip.reass.range_first >= vnb->ip.reass.fragment_first) &&
403 !(vnb->ip.reass.range_last > vnb->ip.reass.fragment_first))
405 return IP4_REASS_RC_INTERNAL_ERROR;
408 u32 data_len = ip4_reass_buffer_get_data_len (tmp);
410 ip4_header_bytes (ip) + ip4_reass_buffer_get_data_offset (tmp);
412 vlib_buffer_length_in_chain (vm, tmp) - trim_front - data_len;
413 if (tmp_bi == reass->first_bi)
415 /* first buffer - keep ip4 header */
416 if (0 != ip4_reass_buffer_get_data_offset (tmp))
418 return IP4_REASS_RC_INTERNAL_ERROR;
421 trim_end = vlib_buffer_length_in_chain (vm, tmp) - data_len -
422 ip4_header_bytes (ip);
423 if (!(vlib_buffer_length_in_chain (vm, tmp) - trim_end > 0))
425 return IP4_REASS_RC_INTERNAL_ERROR;
429 vlib_buffer_length_in_chain (vm, tmp) - trim_front - trim_end;
435 if (trim_front > tmp->current_length)
437 /* drop whole buffer */
438 vec_add1 (*vec_drop_compress, tmp_bi);
440 trim_front -= tmp->current_length;
441 if (!(tmp->flags & VLIB_BUFFER_NEXT_PRESENT))
443 return IP4_REASS_RC_INTERNAL_ERROR;
445 tmp->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
446 tmp_bi = tmp->next_buffer;
447 tmp = vlib_get_buffer (vm, tmp_bi);
452 vlib_buffer_advance (tmp, trim_front);
460 last_b->flags |= VLIB_BUFFER_NEXT_PRESENT;
461 last_b->next_buffer = tmp_bi;
464 if (keep_data <= tmp->current_length)
466 tmp->current_length = keep_data;
471 keep_data -= tmp->current_length;
472 if (!(tmp->flags & VLIB_BUFFER_NEXT_PRESENT))
474 return IP4_REASS_RC_INTERNAL_ERROR;
477 total_length += tmp->current_length;
481 vec_add1 (*vec_drop_overlap, tmp_bi);
482 if (reass->first_bi == tmp_bi)
484 return IP4_REASS_RC_INTERNAL_ERROR;
488 if (tmp->flags & VLIB_BUFFER_NEXT_PRESENT)
490 tmp_bi = tmp->next_buffer;
491 tmp = vlib_get_buffer (vm, tmp->next_buffer);
499 vnet_buffer (vlib_get_buffer (vm, sub_chain_bi))->ip.
502 while (~0 != sub_chain_bi);
506 return IP4_REASS_RC_INTERNAL_ERROR;
508 last_b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
509 rt->buffers_n -= buf_cnt - dropped_cnt;
510 if (total_length < first_b->current_length)
512 return IP4_REASS_RC_INTERNAL_ERROR;
514 total_length -= first_b->current_length;
515 first_b->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
516 first_b->total_length_not_including_first_buffer = total_length;
517 ip4_header_t *ip = vlib_buffer_get_current (first_b);
518 ip->flags_and_fragment_offset = 0;
519 ip->length = clib_host_to_net_u16 (first_b->current_length + total_length);
520 ip->checksum = ip4_header_checksum (ip);
521 u32 before = vec_len (*vec_drop_compress);
522 vlib_buffer_chain_compress (vm, first_b, vec_drop_compress);
523 rt->buffers_n += vec_len (*vec_drop_compress) - before;
525 if (PREDICT_FALSE (first_b->flags & VLIB_BUFFER_IS_TRACED))
527 ip4_reass_add_trace (vm, node, rm, reass, reass->first_bi, FINALIZE, 0);
529 // following code does a hexdump of packet fragments to stdout ...
532 u32 bi = reass->first_bi;
536 vlib_buffer_t *b = vlib_get_buffer (vm, bi);
537 s = format (s, "%u: %U\n", bi, format_hexdump,
538 vlib_buffer_get_current (b), b->current_length);
539 if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
548 printf ("%.*s\n", vec_len (s), s);
555 *bi0 = reass->first_bi;
558 *next0 = IP4_REASSEMBLY_NEXT_INPUT;
562 *next0 = reass->next_index;
564 vnet_buffer (first_b)->ip.reass.estimated_mtu = reass->min_fragment_length;
565 *error0 = IP4_ERROR_NONE;
566 ip4_reass_free (rm, rt, reass);
568 return IP4_REASS_RC_OK;
572 ip4_reass_get_buffer_chain_length (vlib_main_t * vm, vlib_buffer_t * b)
578 if (PREDICT_FALSE (b->flags & VLIB_BUFFER_NEXT_PRESENT))
580 b = vlib_get_buffer (vm, b->next_buffer);
590 always_inline ip4_reass_rc_t
591 ip4_reass_insert_range_in_chain (vlib_main_t * vm,
592 ip4_reass_main_t * rm,
593 ip4_reass_per_thread_t * rt,
595 u32 prev_range_bi, u32 new_next_bi)
597 vlib_buffer_t *new_next_b = vlib_get_buffer (vm, new_next_bi);
598 vnet_buffer_opaque_t *new_next_vnb = vnet_buffer (new_next_b);
599 if (~0 != prev_range_bi)
601 vlib_buffer_t *prev_b = vlib_get_buffer (vm, prev_range_bi);
602 vnet_buffer_opaque_t *prev_vnb = vnet_buffer (prev_b);
603 new_next_vnb->ip.reass.next_range_bi = prev_vnb->ip.reass.next_range_bi;
604 prev_vnb->ip.reass.next_range_bi = new_next_bi;
608 if (~0 != reass->first_bi)
610 new_next_vnb->ip.reass.next_range_bi = reass->first_bi;
612 reass->first_bi = new_next_bi;
614 vnet_buffer_opaque_t *vnb = vnet_buffer (new_next_b);
615 if (!(vnb->ip.reass.range_first >= vnb->ip.reass.fragment_first) &&
616 !(vnb->ip.reass.range_last > vnb->ip.reass.fragment_first))
618 return IP4_REASS_RC_INTERNAL_ERROR;
620 reass->data_len += ip4_reass_buffer_get_data_len (new_next_b);
621 rt->buffers_n += ip4_reass_get_buffer_chain_length (vm, new_next_b);
622 return IP4_REASS_RC_OK;
625 always_inline ip4_reass_rc_t
626 ip4_reass_remove_range_from_chain (vlib_main_t * vm,
627 vlib_node_runtime_t * node,
628 ip4_reass_main_t * rm,
629 u32 ** vec_drop_overlap,
630 ip4_reass_t * reass, u32 prev_range_bi,
633 vlib_buffer_t *discard_b = vlib_get_buffer (vm, discard_bi);
634 vnet_buffer_opaque_t *discard_vnb = vnet_buffer (discard_b);
635 if (~0 != prev_range_bi)
637 vlib_buffer_t *prev_b = vlib_get_buffer (vm, prev_range_bi);
638 vnet_buffer_opaque_t *prev_vnb = vnet_buffer (prev_b);
639 if (!(prev_vnb->ip.reass.next_range_bi == discard_bi))
641 return IP4_REASS_RC_INTERNAL_ERROR;
643 prev_vnb->ip.reass.next_range_bi = discard_vnb->ip.reass.next_range_bi;
647 reass->first_bi = discard_vnb->ip.reass.next_range_bi;
649 vnet_buffer_opaque_t *vnb = vnet_buffer (discard_b);
650 if (!(vnb->ip.reass.range_first >= vnb->ip.reass.fragment_first) &&
651 !(vnb->ip.reass.range_last > vnb->ip.reass.fragment_first))
653 return IP4_REASS_RC_INTERNAL_ERROR;
655 reass->data_len -= ip4_reass_buffer_get_data_len (discard_b);
658 vec_add1 (*vec_drop_overlap, discard_bi);
659 if (PREDICT_FALSE (discard_b->flags & VLIB_BUFFER_IS_TRACED))
661 ip4_reass_add_trace (vm, node, rm, reass, discard_bi, RANGE_DISCARD,
664 if (discard_b->flags & VLIB_BUFFER_NEXT_PRESENT)
666 discard_b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
667 discard_bi = discard_b->next_buffer;
668 discard_b = vlib_get_buffer (vm, discard_bi);
675 return IP4_REASS_RC_OK;
678 always_inline ip4_reass_rc_t
679 ip4_reass_update (vlib_main_t * vm, vlib_node_runtime_t * node,
680 ip4_reass_main_t * rm, ip4_reass_per_thread_t * rt,
681 ip4_reass_t * reass, u32 * bi0, u32 * next0,
682 u32 * error0, u32 ** vec_drop_overlap,
683 u32 ** vec_drop_compress, bool is_feature)
685 ip4_reass_rc_t rc = IP4_REASS_RC_OK;
687 vlib_buffer_t *fb = vlib_get_buffer (vm, *bi0);
688 ip4_header_t *fip = vlib_buffer_get_current (fb);
689 vnet_buffer_opaque_t *fvnb = vnet_buffer (fb);
690 reass->next_index = fvnb->ip.reass.next_index; // store next_index before it's overwritten
691 const u32 fragment_first = ip4_get_fragment_offset_bytes (fip);
692 const u32 fragment_length =
693 clib_net_to_host_u16 (fip->length) - ip4_header_bytes (fip);
694 const u32 fragment_last = fragment_first + fragment_length - 1;
695 fvnb->ip.reass.fragment_first = fragment_first;
696 fvnb->ip.reass.fragment_last = fragment_last;
697 int more_fragments = ip4_get_fragment_more (fip);
698 u32 candidate_range_bi = reass->first_bi;
699 u32 prev_range_bi = ~0;
700 fvnb->ip.reass.range_first = fragment_first;
701 fvnb->ip.reass.range_last = fragment_last;
702 fvnb->ip.reass.next_range_bi = ~0;
705 reass->last_packet_octet = fragment_last;
707 if (~0 == reass->first_bi)
709 // starting a new reassembly
711 ip4_reass_insert_range_in_chain (vm, rm, rt, reass, prev_range_bi,
713 if (IP4_REASS_RC_OK != rc)
717 if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
719 ip4_reass_add_trace (vm, node, rm, reass, *bi0, RANGE_NEW, 0);
722 reass->min_fragment_length = clib_net_to_host_u16 (fip->length);
723 return IP4_REASS_RC_OK;
725 reass->min_fragment_length = clib_min (clib_net_to_host_u16 (fip->length),
726 fvnb->ip.reass.estimated_mtu);
727 while (~0 != candidate_range_bi)
729 vlib_buffer_t *candidate_b = vlib_get_buffer (vm, candidate_range_bi);
730 vnet_buffer_opaque_t *candidate_vnb = vnet_buffer (candidate_b);
731 if (fragment_first > candidate_vnb->ip.reass.range_last)
733 // this fragments starts after candidate range
734 prev_range_bi = candidate_range_bi;
735 candidate_range_bi = candidate_vnb->ip.reass.next_range_bi;
736 if (candidate_vnb->ip.reass.range_last < fragment_last &&
737 ~0 == candidate_range_bi)
739 // special case - this fragment falls beyond all known ranges
741 ip4_reass_insert_range_in_chain (vm, rm, rt, reass,
742 prev_range_bi, *bi0);
743 if (IP4_REASS_RC_OK != rc)
752 if (fragment_last < candidate_vnb->ip.reass.range_first)
754 // this fragment ends before candidate range without any overlap
756 ip4_reass_insert_range_in_chain (vm, rm, rt, reass, prev_range_bi,
758 if (IP4_REASS_RC_OK != rc)
766 if (fragment_first >= candidate_vnb->ip.reass.range_first &&
767 fragment_last <= candidate_vnb->ip.reass.range_last)
769 // this fragment is a (sub)part of existing range, ignore it
770 if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
772 ip4_reass_add_trace (vm, node, rm, reass, *bi0,
777 int discard_candidate = 0;
778 if (fragment_first < candidate_vnb->ip.reass.range_first)
781 fragment_last - candidate_vnb->ip.reass.range_first + 1;
782 if (overlap < ip4_reass_buffer_get_data_len (candidate_b))
784 candidate_vnb->ip.reass.range_first += overlap;
785 if (reass->data_len < overlap)
787 return IP4_REASS_RC_INTERNAL_ERROR;
789 reass->data_len -= overlap;
790 if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
792 ip4_reass_add_trace (vm, node, rm, reass,
793 candidate_range_bi, RANGE_SHRINK,
797 ip4_reass_insert_range_in_chain (vm, rm, rt, reass,
798 prev_range_bi, *bi0);
799 if (IP4_REASS_RC_OK != rc)
807 discard_candidate = 1;
810 else if (fragment_last > candidate_vnb->ip.reass.range_last)
813 candidate_vnb->ip.reass.range_last - fragment_first + 1;
814 if (overlap < ip4_reass_buffer_get_data_len (candidate_b))
816 fvnb->ip.reass.range_first += overlap;
817 if (~0 != candidate_vnb->ip.reass.next_range_bi)
819 prev_range_bi = candidate_range_bi;
821 candidate_vnb->ip.reass.next_range_bi;
826 // special case - last range discarded
828 ip4_reass_insert_range_in_chain (vm, rm, rt, reass,
831 if (IP4_REASS_RC_OK != rc)
840 discard_candidate = 1;
845 discard_candidate = 1;
847 if (discard_candidate)
849 u32 next_range_bi = candidate_vnb->ip.reass.next_range_bi;
850 // discard candidate range, probe next range
852 ip4_reass_remove_range_from_chain (vm, node, rm,
853 vec_drop_overlap, reass,
856 if (IP4_REASS_RC_OK != rc)
860 if (~0 != next_range_bi)
862 candidate_range_bi = next_range_bi;
867 // special case - last range discarded
869 ip4_reass_insert_range_in_chain (vm, rm, rt, reass,
870 prev_range_bi, *bi0);
871 if (IP4_REASS_RC_OK != rc)
883 if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
885 ip4_reass_add_trace (vm, node, rm, reass, *bi0, RANGE_NEW, 0);
888 if (~0 != reass->last_packet_octet &&
889 reass->data_len == reass->last_packet_octet + 1)
891 return ip4_reass_finalize (vm, node, rm, rt, reass, bi0, next0, error0,
892 vec_drop_compress, vec_drop_overlap,
903 *next0 = IP4_REASSEMBLY_NEXT_DROP;
904 *error0 = IP4_ERROR_REASS_DUPLICATE_FRAGMENT;
911 ip4_reassembly_inline (vlib_main_t * vm,
912 vlib_node_runtime_t * node,
913 vlib_frame_t * frame, bool is_feature)
915 u32 *from = vlib_frame_vector_args (frame);
916 u32 n_left_from, n_left_to_next, *to_next, next_index;
917 ip4_reass_main_t *rm = &ip4_reass_main;
918 ip4_reass_per_thread_t *rt = &rm->per_thread_data[os_get_thread_index ()];
919 clib_spinlock_lock (&rt->lock);
921 n_left_from = frame->n_vectors;
922 next_index = node->cached_next_index;
923 static u32 *vec_drop_timeout = NULL; // indexes of buffers which timed out
924 static u32 *vec_drop_overlap = NULL; // indexes of buffers which were discarded due to overlap
925 static u32 *vec_drop_internal_error = NULL; // indexes of buffers which were discarded due to internal errors
926 static u32 *vec_drop_compress = NULL; // indexes of buffers dicarded due to buffer compression
927 while (n_left_from > 0 || vec_len (vec_drop_timeout) > 0
928 || vec_len (vec_drop_overlap) > 0 || vec_len (vec_drop_compress) > 0
929 || vec_len (vec_drop_internal_error) > 0)
931 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
933 while (vec_len (vec_drop_timeout) > 0 && n_left_to_next > 0)
935 u32 bi = vec_pop (vec_drop_timeout);
936 vlib_buffer_t *b = vlib_get_buffer (vm, bi);
937 b->error = node->errors[IP4_ERROR_REASS_TIMEOUT];
941 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
943 IP4_REASSEMBLY_NEXT_DROP);
944 IP4_REASS_DEBUG_BUFFER (bi, enqueue_drop_timeout);
948 while (vec_len (vec_drop_overlap) > 0 && n_left_to_next > 0)
950 u32 bi = vec_pop (vec_drop_overlap);
951 vlib_buffer_t *b = vlib_get_buffer (vm, bi);
952 b->error = node->errors[IP4_ERROR_REASS_DUPLICATE_FRAGMENT];
956 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
958 IP4_REASSEMBLY_NEXT_DROP);
959 IP4_REASS_DEBUG_BUFFER (bi, enqueue_drop_duplicate_fragment);
963 while (vec_len (vec_drop_compress) > 0 && n_left_to_next > 0)
965 u32 bi = vec_pop (vec_drop_compress);
966 vlib_buffer_t *b = vlib_get_buffer (vm, bi);
967 b->error = node->errors[IP4_ERROR_NONE];
971 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
973 IP4_REASSEMBLY_NEXT_DROP);
974 IP4_REASS_DEBUG_BUFFER (bi, enqueue_drop_compress);
977 while (vec_len (vec_drop_internal_error) > 0 && n_left_to_next > 0)
979 u32 bi = vec_pop (vec_drop_internal_error);
980 vlib_buffer_t *b = vlib_get_buffer (vm, bi);
981 b->error = node->errors[IP4_ERROR_REASS_INTERNAL_ERROR];
985 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
987 IP4_REASSEMBLY_NEXT_DROP);
988 IP4_REASS_DEBUG_BUFFER (bi, enqueue_drop_internal_error);
991 while (n_left_from > 0 && n_left_to_next > 0)
996 u32 error0 = IP4_ERROR_NONE;
999 b0 = vlib_get_buffer (vm, bi0);
1001 ip4_header_t *ip0 = vlib_buffer_get_current (b0);
1002 if (!ip4_get_fragment_more (ip0) && !ip4_get_fragment_offset (ip0))
1004 // this is a whole packet - no fragmentation
1007 next0 = IP4_REASSEMBLY_NEXT_INPUT;
1011 next0 = vnet_buffer (b0)->ip.reass.next_index;
1016 const u32 fragment_first = ip4_get_fragment_offset_bytes (ip0);
1017 const u32 fragment_length =
1018 clib_net_to_host_u16 (ip0->length) - ip4_header_bytes (ip0);
1019 const u32 fragment_last = fragment_first + fragment_length - 1;
1020 if (fragment_first > fragment_last || fragment_first + fragment_length > UINT16_MAX - 20 || (fragment_length < 8 && ip4_get_fragment_more (ip0))) // 8 is minimum frag length per RFC 791
1022 next0 = IP4_REASSEMBLY_NEXT_DROP;
1023 error0 = IP4_ERROR_REASS_MALFORMED_PACKET;
1029 (u64) vnet_buffer (b0)->sw_if_index[VLIB_RX] |
1030 (u64) ip0->src_address.as_u32 << 32;
1032 (u64) ip0->dst_address.as_u32 |
1033 (u64) ip0->fragment_id << 32 | (u64) ip0->protocol << 48;
1035 ip4_reass_t *reass =
1036 ip4_reass_find_or_create (vm, rm, rt, &k,
1041 switch (ip4_reass_update
1042 (vm, node, rm, rt, reass, &bi0, &next0, &error0,
1043 &vec_drop_overlap, &vec_drop_compress,
1046 case IP4_REASS_RC_OK:
1047 /* nothing to do here */
1049 case IP4_REASS_RC_INTERNAL_ERROR:
1050 /* drop everything and start with a clean slate */
1051 ip4_reass_on_timeout (vm, rm, reass,
1052 &vec_drop_internal_error);
1053 ip4_reass_free (rm, rt, reass);
1060 next0 = IP4_REASSEMBLY_NEXT_DROP;
1061 error0 = IP4_ERROR_REASS_LIMIT_REACHED;
1065 b0->error = node->errors[error0];
1072 n_left_to_next -= 1;
1073 if (is_feature && IP4_ERROR_NONE == error0)
1075 b0 = vlib_get_buffer (vm, bi0);
1076 vnet_feature_next (&next0, b0);
1078 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1079 n_left_to_next, bi0, next0);
1080 IP4_REASS_DEBUG_BUFFER (bi0, enqueue_next);
1088 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1091 clib_spinlock_unlock (&rt->lock);
1092 return frame->n_vectors;
1095 static char *ip4_reassembly_error_strings[] = {
1096 #define _(sym, string) string,
1102 ip4_reassembly (vlib_main_t * vm, vlib_node_runtime_t * node,
1103 vlib_frame_t * frame)
1105 return ip4_reassembly_inline (vm, node, frame, false /* is_feature */ );
1109 VLIB_REGISTER_NODE (ip4_reass_node, static) = {
1110 .function = ip4_reassembly,
1111 .name = "ip4-reassembly",
1112 .vector_size = sizeof (u32),
1113 .format_trace = format_ip4_reass_trace,
1114 .n_errors = ARRAY_LEN (ip4_reassembly_error_strings),
1115 .error_strings = ip4_reassembly_error_strings,
1116 .n_next_nodes = IP4_REASSEMBLY_N_NEXT,
1119 [IP4_REASSEMBLY_NEXT_INPUT] = "ip4-input",
1120 [IP4_REASSEMBLY_NEXT_DROP] = "ip4-drop",
1125 VLIB_NODE_FUNCTION_MULTIARCH (ip4_reass_node, ip4_reassembly);
1128 ip4_reassembly_feature (vlib_main_t * vm,
1129 vlib_node_runtime_t * node, vlib_frame_t * frame)
1131 return ip4_reassembly_inline (vm, node, frame, true /* is_feature */ );
1135 VLIB_REGISTER_NODE (ip4_reass_node_feature, static) = {
1136 .function = ip4_reassembly_feature,
1137 .name = "ip4-reassembly-feature",
1138 .vector_size = sizeof (u32),
1139 .format_trace = format_ip4_reass_trace,
1140 .n_errors = ARRAY_LEN (ip4_reassembly_error_strings),
1141 .error_strings = ip4_reassembly_error_strings,
1142 .n_next_nodes = IP4_REASSEMBLY_N_NEXT,
1145 [IP4_REASSEMBLY_NEXT_INPUT] = "ip4-input",
1146 [IP4_REASSEMBLY_NEXT_DROP] = "ip4-drop",
1151 VLIB_NODE_FUNCTION_MULTIARCH (ip4_reass_node_feature, ip4_reassembly_feature);
1154 VNET_FEATURE_INIT (ip4_reassembly_feature, static) = {
1155 .arc_name = "ip4-unicast",
1156 .node_name = "ip4-reassembly-feature",
1157 .runs_before = VNET_FEATURES ("ip4-lookup"),
1163 ip4_reass_get_nbuckets ()
1165 ip4_reass_main_t *rm = &ip4_reass_main;
1169 nbuckets = (u32) (rm->max_reass_n / IP4_REASS_HT_LOAD_FACTOR);
1171 for (i = 0; i < 31; i++)
1172 if ((1 << i) >= nbuckets)
1181 IP4_EVENT_CONFIG_CHANGED = 1,
1182 } ip4_reass_event_t;
1187 clib_bihash_16_8_t *new_hash;
1188 } ip4_rehash_cb_ctx;
1191 ip4_rehash_cb (clib_bihash_kv_16_8_t * kv, void *_ctx)
1193 ip4_rehash_cb_ctx *ctx = _ctx;
1194 if (clib_bihash_add_del_16_8 (ctx->new_hash, kv, 1))
1201 ip4_reass_set_params (u32 timeout_ms, u32 max_reassemblies,
1202 u32 expire_walk_interval_ms)
1204 ip4_reass_main.timeout_ms = timeout_ms;
1205 ip4_reass_main.timeout = (f64) timeout_ms / (f64) MSEC_PER_SEC;
1206 ip4_reass_main.max_reass_n = max_reassemblies;
1207 ip4_reass_main.expire_walk_interval_ms = expire_walk_interval_ms;
1211 ip4_reass_set (u32 timeout_ms, u32 max_reassemblies,
1212 u32 expire_walk_interval_ms)
1214 u32 old_nbuckets = ip4_reass_get_nbuckets ();
1215 ip4_reass_set_params (timeout_ms, max_reassemblies,
1216 expire_walk_interval_ms);
1217 vlib_process_signal_event (ip4_reass_main.vlib_main,
1218 ip4_reass_main.ip4_reass_expire_node_idx,
1219 IP4_EVENT_CONFIG_CHANGED, 0);
1220 u32 new_nbuckets = ip4_reass_get_nbuckets ();
1221 if (ip4_reass_main.max_reass_n > 0 && new_nbuckets > old_nbuckets)
1223 clib_bihash_16_8_t new_hash;
1224 clib_memset (&new_hash, 0, sizeof (new_hash));
1225 ip4_rehash_cb_ctx ctx;
1227 ctx.new_hash = &new_hash;
1228 clib_bihash_init_16_8 (&new_hash, "ip4-reass", new_nbuckets,
1229 new_nbuckets * 1024);
1230 clib_bihash_foreach_key_value_pair_16_8 (&ip4_reass_main.hash,
1231 ip4_rehash_cb, &ctx);
1234 clib_bihash_free_16_8 (&new_hash);
1239 clib_bihash_free_16_8 (&ip4_reass_main.hash);
1240 clib_memcpy_fast (&ip4_reass_main.hash, &new_hash,
1241 sizeof (ip4_reass_main.hash));
1248 ip4_reass_get (u32 * timeout_ms, u32 * max_reassemblies,
1249 u32 * expire_walk_interval_ms)
1251 *timeout_ms = ip4_reass_main.timeout_ms;
1252 *max_reassemblies = ip4_reass_main.max_reass_n;
1253 *expire_walk_interval_ms = ip4_reass_main.expire_walk_interval_ms;
1257 static clib_error_t *
1258 ip4_reass_init_function (vlib_main_t * vm)
1260 ip4_reass_main_t *rm = &ip4_reass_main;
1261 clib_error_t *error = 0;
1266 rm->vnet_main = vnet_get_main ();
1268 vec_validate (rm->per_thread_data, vlib_num_workers ());
1269 ip4_reass_per_thread_t *rt;
1270 vec_foreach (rt, rm->per_thread_data)
1272 clib_spinlock_init (&rt->lock);
1273 pool_alloc (rt->pool, rm->max_reass_n);
1276 node = vlib_get_node_by_name (vm, (u8 *) "ip4-reassembly-expire-walk");
1278 rm->ip4_reass_expire_node_idx = node->index;
1280 ip4_reass_set_params (IP4_REASS_TIMEOUT_DEFAULT_MS,
1281 IP4_REASS_MAX_REASSEMBLIES_DEFAULT,
1282 IP4_REASS_EXPIRE_WALK_INTERVAL_DEFAULT_MS);
1284 nbuckets = ip4_reass_get_nbuckets ();
1285 clib_bihash_init_16_8 (&rm->hash, "ip4-reass", nbuckets, nbuckets * 1024);
1287 node = vlib_get_node_by_name (vm, (u8 *) "ip4-drop");
1289 rm->ip4_drop_idx = node->index;
1294 VLIB_INIT_FUNCTION (ip4_reass_init_function);
1297 ip4_reass_walk_expired (vlib_main_t * vm,
1298 vlib_node_runtime_t * node, vlib_frame_t * f)
1300 ip4_reass_main_t *rm = &ip4_reass_main;
1301 uword event_type, *event_data = 0;
1305 vlib_process_wait_for_event_or_clock (vm,
1306 (f64) rm->expire_walk_interval_ms
1307 / (f64) MSEC_PER_SEC);
1308 event_type = vlib_process_get_events (vm, &event_data);
1312 case ~0: /* no events => timeout */
1313 /* nothing to do here */
1315 case IP4_EVENT_CONFIG_CHANGED:
1318 clib_warning ("BUG: event type 0x%wx", event_type);
1321 f64 now = vlib_time_now (vm);
1324 u32 *vec_drop_timeout = NULL;
1325 int *pool_indexes_to_free = NULL;
1327 uword thread_index = 0;
1329 const uword nthreads = vlib_num_workers () + 1;
1330 for (thread_index = 0; thread_index < nthreads; ++thread_index)
1332 ip4_reass_per_thread_t *rt = &rm->per_thread_data[thread_index];
1333 clib_spinlock_lock (&rt->lock);
1335 vec_reset_length (pool_indexes_to_free);
1337 pool_foreach_index (index, rt->pool, ({
1338 reass = pool_elt_at_index (rt->pool, index);
1339 if (now > reass->last_heard + rm->timeout)
1341 vec_add1 (pool_indexes_to_free, index);
1347 vec_foreach (i, pool_indexes_to_free)
1349 ip4_reass_t *reass = pool_elt_at_index (rt->pool, i[0]);
1350 u32 before = vec_len (vec_drop_timeout);
1351 vlib_buffer_t *b = vlib_get_buffer (vm, reass->first_bi);
1352 if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
1354 if (pool_is_free_index (vm->trace_main.trace_buffer_pool,
1357 /* the trace is gone, don't trace this buffer anymore */
1358 b->flags &= ~VLIB_BUFFER_IS_TRACED;
1361 ip4_reass_on_timeout (vm, rm, reass, &vec_drop_timeout);
1362 u32 after = vec_len (vec_drop_timeout);
1363 rt->buffers_n -= (after - before);
1364 ip4_reass_free (rm, rt, reass);
1368 clib_spinlock_unlock (&rt->lock);
1371 while (vec_len (vec_drop_timeout) > 0)
1373 vlib_frame_t *f = vlib_get_frame_to_node (vm, rm->ip4_drop_idx);
1374 u32 *to_next = vlib_frame_vector_args (f);
1375 u32 n_left_to_next = VLIB_FRAME_SIZE - f->n_vectors;
1376 int trace_frame = 0;
1377 while (vec_len (vec_drop_timeout) > 0 && n_left_to_next > 0)
1379 u32 bi = vec_pop (vec_drop_timeout);
1380 vlib_buffer_t *b = vlib_get_buffer (vm, bi);
1381 if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
1383 if (pool_is_free_index (vm->trace_main.trace_buffer_pool,
1386 /* the trace is gone, don't trace this buffer anymore */
1387 b->flags &= ~VLIB_BUFFER_IS_TRACED;
1394 b->error = node->errors[IP4_ERROR_REASS_TIMEOUT];
1398 n_left_to_next -= 1;
1399 IP4_REASS_DEBUG_BUFFER (bi, enqueue_drop_timeout_walk);
1401 f->frame_flags |= (trace_frame * VLIB_FRAME_TRACE);
1402 vlib_put_frame_to_node (vm, rm->ip4_drop_idx, f);
1405 vec_free (pool_indexes_to_free);
1406 vec_free (vec_drop_timeout);
1409 _vec_len (event_data) = 0;
1416 static vlib_node_registration_t ip4_reass_expire_node;
1419 VLIB_REGISTER_NODE (ip4_reass_expire_node, static) = {
1420 .function = ip4_reass_walk_expired,
1421 .type = VLIB_NODE_TYPE_PROCESS,
1422 .name = "ip4-reassembly-expire-walk",
1423 .format_trace = format_ip4_reass_trace,
1424 .n_errors = ARRAY_LEN (ip4_reassembly_error_strings),
1425 .error_strings = ip4_reassembly_error_strings,
1431 format_ip4_reass_key (u8 * s, va_list * args)
1433 ip4_reass_key_t *key = va_arg (*args, ip4_reass_key_t *);
1434 s = format (s, "xx_id: %u, src: %U, dst: %U, frag_id: %u, proto: %u",
1435 key->xx_id, format_ip4_address, &key->src, format_ip4_address,
1436 &key->dst, clib_net_to_host_u16 (key->frag_id), key->proto);
1441 format_ip4_reass (u8 * s, va_list * args)
1443 vlib_main_t *vm = va_arg (*args, vlib_main_t *);
1444 ip4_reass_t *reass = va_arg (*args, ip4_reass_t *);
1446 s = format (s, "ID: %lu, key: %U\n first_bi: %u, data_len: %u, "
1447 "last_packet_octet: %u, trace_op_counter: %u\n",
1448 reass->id, format_ip4_reass_key, &reass->key, reass->first_bi,
1449 reass->data_len, reass->last_packet_octet,
1450 reass->trace_op_counter);
1451 u32 bi = reass->first_bi;
1455 vlib_buffer_t *b = vlib_get_buffer (vm, bi);
1456 vnet_buffer_opaque_t *vnb = vnet_buffer (b);
1457 s = format (s, " #%03u: range: [%u, %u], bi: %u, off: %d, len: %u, "
1458 "fragment[%u, %u]\n",
1459 counter, vnb->ip.reass.range_first,
1460 vnb->ip.reass.range_last, bi,
1461 ip4_reass_buffer_get_data_offset (b),
1462 ip4_reass_buffer_get_data_len (b),
1463 vnb->ip.reass.fragment_first, vnb->ip.reass.fragment_last);
1464 if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
1466 bi = b->next_buffer;
1476 static clib_error_t *
1477 show_ip4_reass (vlib_main_t * vm, unformat_input_t * input,
1478 CLIB_UNUSED (vlib_cli_command_t * lmd))
1480 ip4_reass_main_t *rm = &ip4_reass_main;
1482 vlib_cli_output (vm, "---------------------");
1483 vlib_cli_output (vm, "IP4 reassembly status");
1484 vlib_cli_output (vm, "---------------------");
1485 bool details = false;
1486 if (unformat (input, "details"))
1491 u32 sum_reass_n = 0;
1492 u64 sum_buffers_n = 0;
1495 const uword nthreads = vlib_num_workers () + 1;
1496 for (thread_index = 0; thread_index < nthreads; ++thread_index)
1498 ip4_reass_per_thread_t *rt = &rm->per_thread_data[thread_index];
1499 clib_spinlock_lock (&rt->lock);
1503 pool_foreach (reass, rt->pool, {
1504 vlib_cli_output (vm, "%U", format_ip4_reass, vm, reass);
1508 sum_reass_n += rt->reass_n;
1509 sum_buffers_n += rt->buffers_n;
1510 clib_spinlock_unlock (&rt->lock);
1512 vlib_cli_output (vm, "---------------------");
1513 vlib_cli_output (vm, "Current IP4 reassemblies count: %lu\n",
1514 (long unsigned) sum_reass_n);
1515 vlib_cli_output (vm,
1516 "Maximum configured concurrent IP4 reassemblies per worker-thread: %lu\n",
1517 (long unsigned) rm->max_reass_n);
1518 vlib_cli_output (vm, "Buffers in use: %lu\n",
1519 (long unsigned) sum_buffers_n);
1524 VLIB_CLI_COMMAND (show_ip4_reassembly_cmd, static) = {
1525 .path = "show ip4-reassembly",
1526 .short_help = "show ip4-reassembly [details]",
1527 .function = show_ip4_reass,
1532 ip4_reass_enable_disable (u32 sw_if_index, u8 enable_disable)
1534 return vnet_feature_enable_disable ("ip4-unicast", "ip4-reassembly-feature",
1535 sw_if_index, enable_disable, 0, 0);
1539 * fd.io coding-style-patch-verification: ON
1542 * eval: (c-set-style "gnu")