1 | /**
|
---|
2 | * @file
|
---|
3 | * This is the IPv4 packet segmentation and reassembly implementation.
|
---|
4 | *
|
---|
5 | */
|
---|
6 |
|
---|
7 | /*
|
---|
8 | * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
|
---|
9 | * All rights reserved.
|
---|
10 | *
|
---|
11 | * Redistribution and use in source and binary forms, with or without modification,
|
---|
12 | * are permitted provided that the following conditions are met:
|
---|
13 | *
|
---|
14 | * 1. Redistributions of source code must retain the above copyright notice,
|
---|
15 | * this list of conditions and the following disclaimer.
|
---|
16 | * 2. Redistributions in binary form must reproduce the above copyright notice,
|
---|
17 | * this list of conditions and the following disclaimer in the documentation
|
---|
18 | * and/or other materials provided with the distribution.
|
---|
19 | * 3. The name of the author may not be used to endorse or promote products
|
---|
20 | * derived from this software without specific prior written permission.
|
---|
21 | *
|
---|
22 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
|
---|
23 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
|
---|
24 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
|
---|
25 | * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
|
---|
26 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
|
---|
27 | * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
---|
28 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
---|
29 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
|
---|
30 | * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
|
---|
31 | * OF SUCH DAMAGE.
|
---|
32 | *
|
---|
33 | * This file is part of the lwIP TCP/IP stack.
|
---|
34 | *
|
---|
35 | * Author: Jani Monoses <jani@iv.ro>
|
---|
36 | * Simon Goldschmidt
|
---|
37 | * original reassembly code by Adam Dunkels <adam@sics.se>
|
---|
38 | *
|
---|
39 | */
|
---|
40 |
|
---|
41 | #include "lwip/opt.h"
|
---|
42 | #include "lwip/ip_frag.h"
|
---|
43 | #include "lwip/def.h"
|
---|
44 | #include "lwip/inet_chksum.h"
|
---|
45 | #include "lwip/netif.h"
|
---|
46 | #include "lwip/snmp.h"
|
---|
47 | #include "lwip/stats.h"
|
---|
48 | #include "lwip/icmp.h"
|
---|
49 |
|
---|
50 | #include <string.h>
|
---|
51 |
|
---|
52 | #if IP_REASSEMBLY
|
---|
53 | /**
|
---|
54 | * The IP reassembly code currently has the following limitations:
|
---|
55 | * - IP header options are not supported
|
---|
56 | * - fragments must not overlap (e.g. due to different routes),
|
---|
57 | * currently, overlapping or duplicate fragments are thrown away
|
---|
58 | * if IP_REASS_CHECK_OVERLAP=1 (the default)!
|
---|
59 | *
|
---|
60 | * @todo: work with IP header options
|
---|
61 | */
|
---|
62 |
|
---|
63 | /** Setting this to 0, you can turn off checking the fragments for overlapping
|
---|
64 | * regions. The code gets a little smaller. Only use this if you know that
|
---|
65 | * overlapping won't occur on your network! */
|
---|
66 | #ifndef IP_REASS_CHECK_OVERLAP
|
---|
67 | #define IP_REASS_CHECK_OVERLAP 1
|
---|
68 | #endif /* IP_REASS_CHECK_OVERLAP */
|
---|
69 |
|
---|
70 | /** Set to 0 to prevent freeing the oldest datagram when the reassembly buffer is
|
---|
71 | * full (IP_REASS_MAX_PBUFS pbufs are enqueued). The code gets a little smaller.
|
---|
72 | * Datagrams will be freed by timeout only. Especially useful when MEMP_NUM_REASSDATA
|
---|
73 | * is set to 1, so one datagram can be reassembled at a time, only. */
|
---|
74 | #ifndef IP_REASS_FREE_OLDEST
|
---|
75 | #define IP_REASS_FREE_OLDEST 1
|
---|
76 | #endif /* IP_REASS_FREE_OLDEST */
|
---|
77 |
|
---|
78 | #define IP_REASS_FLAG_LASTFRAG 0x01
|
---|
79 |
|
---|
80 | /** This is a helper struct which holds the starting
|
---|
81 | * offset and the ending offset of this fragment to
|
---|
82 | * easily chain the fragments.
|
---|
83 | * It has the same packing requirements as the IP header, since it replaces
|
---|
84 | * the IP header in memory in incoming fragments (after copying it) to keep
|
---|
85 | * track of the various fragments. (-> If the IP header doesn't need packing,
|
---|
86 | * this struct doesn't need packing, too.)
|
---|
87 | */
|
---|
88 | #ifdef PACK_STRUCT_USE_INCLUDES
|
---|
89 | # include "arch/bpstruct.h"
|
---|
90 | #endif
|
---|
91 | PACK_STRUCT_BEGIN
|
---|
92 | struct ip_reass_helper {
|
---|
93 | PACK_STRUCT_FIELD(struct pbuf *next_pbuf);
|
---|
94 | PACK_STRUCT_FIELD(u16_t start);
|
---|
95 | PACK_STRUCT_FIELD(u16_t end);
|
---|
96 | } PACK_STRUCT_STRUCT;
|
---|
97 | PACK_STRUCT_END
|
---|
98 | #ifdef PACK_STRUCT_USE_INCLUDES
|
---|
99 | # include "arch/epstruct.h"
|
---|
100 | #endif
|
---|
101 |
|
---|
102 | #define IP_ADDRESSES_AND_ID_MATCH(iphdrA, iphdrB) \
|
---|
103 | (ip_addr_cmp(&(iphdrA)->src, &(iphdrB)->src) && \
|
---|
104 | ip_addr_cmp(&(iphdrA)->dest, &(iphdrB)->dest) && \
|
---|
105 | IPH_ID(iphdrA) == IPH_ID(iphdrB)) ? 1 : 0
|
---|
106 |
|
---|
107 | /* global variables */
|
---|
108 | static struct ip_reassdata *reassdatagrams;
|
---|
109 | static u16_t ip_reass_pbufcount;
|
---|
110 |
|
---|
111 | /* function prototypes */
|
---|
112 | static void ip_reass_dequeue_datagram(struct ip_reassdata *ipr, struct ip_reassdata *prev);
|
---|
113 | static int ip_reass_free_complete_datagram(struct ip_reassdata *ipr, struct ip_reassdata *prev);
|
---|
114 |
|
---|
115 | /**
|
---|
116 | * Reassembly timer base function
|
---|
117 | * for both NO_SYS == 0 and 1 (!).
|
---|
118 | *
|
---|
119 | * Should be called every 1000 msec (defined by IP_TMR_INTERVAL).
|
---|
120 | */
|
---|
121 | void
|
---|
122 | ip_reass_tmr(void)
|
---|
123 | {
|
---|
124 | struct ip_reassdata *r, *prev = NULL;
|
---|
125 |
|
---|
126 | r = reassdatagrams;
|
---|
127 | while (r != NULL) {
|
---|
128 | /* Decrement the timer. Once it reaches 0,
|
---|
129 | * clean up the incomplete fragment assembly */
|
---|
130 | if (r->timer > 0) {
|
---|
131 | r->timer--;
|
---|
132 | LWIP_DEBUGF(IP_REASS_DEBUG, ("ip_reass_tmr: timer dec %"U16_F"\n",(u16_t)r->timer));
|
---|
133 | prev = r;
|
---|
134 | r = r->next;
|
---|
135 | } else {
|
---|
136 | /* reassembly timed out */
|
---|
137 | struct ip_reassdata *tmp;
|
---|
138 | LWIP_DEBUGF(IP_REASS_DEBUG, ("ip_reass_tmr: timer timed out\n"));
|
---|
139 | tmp = r;
|
---|
140 | /* get the next pointer before freeing */
|
---|
141 | r = r->next;
|
---|
142 | /* free the helper struct and all enqueued pbufs */
|
---|
143 | ip_reass_free_complete_datagram(tmp, prev);
|
---|
144 | }
|
---|
145 | }
|
---|
146 | }
|
---|
147 |
|
---|
148 | /**
|
---|
149 | * Free a datagram (struct ip_reassdata) and all its pbufs.
|
---|
150 | * Updates the total count of enqueued pbufs (ip_reass_pbufcount),
|
---|
151 | * SNMP counters and sends an ICMP time exceeded packet.
|
---|
152 | *
|
---|
153 | * @param ipr datagram to free
|
---|
154 | * @param prev the previous datagram in the linked list
|
---|
155 | * @return the number of pbufs freed
|
---|
156 | */
|
---|
157 | static int
|
---|
158 | ip_reass_free_complete_datagram(struct ip_reassdata *ipr, struct ip_reassdata *prev)
|
---|
159 | {
|
---|
160 | u16_t pbufs_freed = 0;
|
---|
161 | u8_t clen;
|
---|
162 | struct pbuf *p;
|
---|
163 | struct ip_reass_helper *iprh;
|
---|
164 |
|
---|
165 | LWIP_ASSERT("prev != ipr", prev != ipr);
|
---|
166 | if (prev != NULL) {
|
---|
167 | LWIP_ASSERT("prev->next == ipr", prev->next == ipr);
|
---|
168 | }
|
---|
169 |
|
---|
170 | snmp_inc_ipreasmfails();
|
---|
171 | #if LWIP_ICMP
|
---|
172 | iprh = (struct ip_reass_helper *)ipr->p->payload;
|
---|
173 | if (iprh->start == 0) {
|
---|
174 | /* The first fragment was received, send ICMP time exceeded. */
|
---|
175 | /* First, de-queue the first pbuf from r->p. */
|
---|
176 | p = ipr->p;
|
---|
177 | ipr->p = iprh->next_pbuf;
|
---|
178 | /* Then, copy the original header into it. */
|
---|
179 | SMEMCPY(p->payload, &ipr->iphdr, IP_HLEN);
|
---|
180 | icmp_time_exceeded(p, ICMP_TE_FRAG);
|
---|
181 | clen = pbuf_clen(p);
|
---|
182 | LWIP_ASSERT("pbufs_freed + clen <= 0xffff", pbufs_freed + clen <= 0xffff);
|
---|
183 | pbufs_freed += clen;
|
---|
184 | pbuf_free(p);
|
---|
185 | }
|
---|
186 | #endif /* LWIP_ICMP */
|
---|
187 |
|
---|
188 | /* First, free all received pbufs. The individual pbufs need to be released
|
---|
189 | separately as they have not yet been chained */
|
---|
190 | p = ipr->p;
|
---|
191 | while (p != NULL) {
|
---|
192 | struct pbuf *pcur;
|
---|
193 | iprh = (struct ip_reass_helper *)p->payload;
|
---|
194 | pcur = p;
|
---|
195 | /* get the next pointer before freeing */
|
---|
196 | p = iprh->next_pbuf;
|
---|
197 | clen = pbuf_clen(pcur);
|
---|
198 | LWIP_ASSERT("pbufs_freed + clen <= 0xffff", pbufs_freed + clen <= 0xffff);
|
---|
199 | pbufs_freed += clen;
|
---|
200 | pbuf_free(pcur);
|
---|
201 | }
|
---|
202 | /* Then, unchain the struct ip_reassdata from the list and free it. */
|
---|
203 | ip_reass_dequeue_datagram(ipr, prev);
|
---|
204 | LWIP_ASSERT("ip_reass_pbufcount >= clen", ip_reass_pbufcount >= pbufs_freed);
|
---|
205 | ip_reass_pbufcount -= pbufs_freed;
|
---|
206 |
|
---|
207 | return pbufs_freed;
|
---|
208 | }
|
---|
209 |
|
---|
210 | #if IP_REASS_FREE_OLDEST
|
---|
211 | /**
|
---|
212 | * Free the oldest datagram to make room for enqueueing new fragments.
|
---|
213 | * The datagram 'fraghdr' belongs to is not freed!
|
---|
214 | *
|
---|
215 | * @param fraghdr IP header of the current fragment
|
---|
216 | * @param pbufs_needed number of pbufs needed to enqueue
|
---|
217 | * (used for freeing other datagrams if not enough space)
|
---|
218 | * @return the number of pbufs freed
|
---|
219 | */
|
---|
220 | static int
|
---|
221 | ip_reass_remove_oldest_datagram(struct ip_hdr *fraghdr, int pbufs_needed)
|
---|
222 | {
|
---|
223 | /* @todo Can't we simply remove the last datagram in the
|
---|
224 | * linked list behind reassdatagrams?
|
---|
225 | */
|
---|
226 | struct ip_reassdata *r, *oldest, *prev;
|
---|
227 | int pbufs_freed = 0, pbufs_freed_current;
|
---|
228 | int other_datagrams;
|
---|
229 |
|
---|
230 | /* Free datagrams until being allowed to enqueue 'pbufs_needed' pbufs,
|
---|
231 | * but don't free the datagram that 'fraghdr' belongs to! */
|
---|
232 | do {
|
---|
233 | oldest = NULL;
|
---|
234 | prev = NULL;
|
---|
235 | other_datagrams = 0;
|
---|
236 | r = reassdatagrams;
|
---|
237 | while (r != NULL) {
|
---|
238 | if (!IP_ADDRESSES_AND_ID_MATCH(&r->iphdr, fraghdr)) {
|
---|
239 | /* Not the same datagram as fraghdr */
|
---|
240 | other_datagrams++;
|
---|
241 | if (oldest == NULL) {
|
---|
242 | oldest = r;
|
---|
243 | } else if (r->timer <= oldest->timer) {
|
---|
244 | /* older than the previous oldest */
|
---|
245 | oldest = r;
|
---|
246 | }
|
---|
247 | }
|
---|
248 | if (r->next != NULL) {
|
---|
249 | prev = r;
|
---|
250 | }
|
---|
251 | r = r->next;
|
---|
252 | }
|
---|
253 | if (oldest != NULL) {
|
---|
254 | pbufs_freed_current = ip_reass_free_complete_datagram(oldest, prev);
|
---|
255 | pbufs_freed += pbufs_freed_current;
|
---|
256 | }
|
---|
257 | } while ((pbufs_freed < pbufs_needed) && (other_datagrams > 1));
|
---|
258 | return pbufs_freed;
|
---|
259 | }
|
---|
260 | #endif /* IP_REASS_FREE_OLDEST */
|
---|
261 |
|
---|
262 | /**
|
---|
263 | * Enqueues a new fragment into the fragment queue
|
---|
264 | * @param fraghdr points to the new fragments IP hdr
|
---|
265 | * @param clen number of pbufs needed to enqueue (used for freeing other datagrams if not enough space)
|
---|
266 | * @return A pointer to the queue location into which the fragment was enqueued
|
---|
267 | */
|
---|
268 | static struct ip_reassdata*
|
---|
269 | ip_reass_enqueue_new_datagram(struct ip_hdr *fraghdr, int clen)
|
---|
270 | {
|
---|
271 | struct ip_reassdata* ipr;
|
---|
272 | /* No matching previous fragment found, allocate a new reassdata struct */
|
---|
273 | ipr = (struct ip_reassdata *)memp_malloc(MEMP_REASSDATA);
|
---|
274 | if (ipr == NULL) {
|
---|
275 | #if IP_REASS_FREE_OLDEST
|
---|
276 | if (ip_reass_remove_oldest_datagram(fraghdr, clen) >= clen) {
|
---|
277 | ipr = (struct ip_reassdata *)memp_malloc(MEMP_REASSDATA);
|
---|
278 | }
|
---|
279 | if (ipr == NULL)
|
---|
280 | #endif /* IP_REASS_FREE_OLDEST */
|
---|
281 | {
|
---|
282 | IPFRAG_STATS_INC(ip_frag.memerr);
|
---|
283 | LWIP_DEBUGF(IP_REASS_DEBUG,("Failed to alloc reassdata struct\n"));
|
---|
284 | return NULL;
|
---|
285 | }
|
---|
286 | }
|
---|
287 | memset(ipr, 0, sizeof(struct ip_reassdata));
|
---|
288 | ipr->timer = IP_REASS_MAXAGE;
|
---|
289 |
|
---|
290 | /* enqueue the new structure to the front of the list */
|
---|
291 | ipr->next = reassdatagrams;
|
---|
292 | reassdatagrams = ipr;
|
---|
293 | /* copy the ip header for later tests and input */
|
---|
294 | /* @todo: no ip options supported? */
|
---|
295 | SMEMCPY(&(ipr->iphdr), fraghdr, IP_HLEN);
|
---|
296 | return ipr;
|
---|
297 | }
|
---|
298 |
|
---|
299 | /**
|
---|
300 | * Dequeues a datagram from the datagram queue. Doesn't deallocate the pbufs.
|
---|
301 | * @param ipr points to the queue entry to dequeue
|
---|
302 | */
|
---|
303 | static void
|
---|
304 | ip_reass_dequeue_datagram(struct ip_reassdata *ipr, struct ip_reassdata *prev)
|
---|
305 | {
|
---|
306 |
|
---|
307 | /* dequeue the reass struct */
|
---|
308 | if (reassdatagrams == ipr) {
|
---|
309 | /* it was the first in the list */
|
---|
310 | reassdatagrams = ipr->next;
|
---|
311 | } else {
|
---|
312 | /* it wasn't the first, so it must have a valid 'prev' */
|
---|
313 | LWIP_ASSERT("sanity check linked list", prev != NULL);
|
---|
314 | prev->next = ipr->next;
|
---|
315 | }
|
---|
316 |
|
---|
317 | /* now we can free the ip_reass struct */
|
---|
318 | memp_free(MEMP_REASSDATA, ipr);
|
---|
319 | }
|
---|
320 |
|
---|
321 | /**
|
---|
322 | * Chain a new pbuf into the pbuf list that composes the datagram. The pbuf list
|
---|
323 | * will grow over time as new pbufs are rx.
|
---|
324 | * Also checks that the datagram passes basic continuity checks (if the last
|
---|
325 | * fragment was received at least once).
|
---|
326 | * @param root_p points to the 'root' pbuf for the current datagram being assembled.
|
---|
327 | * @param new_p points to the pbuf for the current fragment
|
---|
328 | * @return 0 if invalid, >0 otherwise
|
---|
329 | */
|
---|
330 | static int
|
---|
331 | ip_reass_chain_frag_into_datagram_and_validate(struct ip_reassdata *ipr, struct pbuf *new_p)
|
---|
332 | {
|
---|
333 | struct ip_reass_helper *iprh, *iprh_tmp, *iprh_prev=NULL;
|
---|
334 | struct pbuf *q;
|
---|
335 | u16_t offset,len;
|
---|
336 | struct ip_hdr *fraghdr;
|
---|
337 | int valid = 1;
|
---|
338 |
|
---|
339 | /* Extract length and fragment offset from current fragment */
|
---|
340 | fraghdr = (struct ip_hdr*)new_p->payload;
|
---|
341 | len = ntohs(IPH_LEN(fraghdr)) - IPH_HL(fraghdr) * 4;
|
---|
342 | offset = (ntohs(IPH_OFFSET(fraghdr)) & IP_OFFMASK) * 8;
|
---|
343 |
|
---|
344 | /* overwrite the fragment's ip header from the pbuf with our helper struct,
|
---|
345 | * and setup the embedded helper structure. */
|
---|
346 | /* make sure the struct ip_reass_helper fits into the IP header */
|
---|
347 | LWIP_ASSERT("sizeof(struct ip_reass_helper) <= IP_HLEN",
|
---|
348 | sizeof(struct ip_reass_helper) <= IP_HLEN);
|
---|
349 | iprh = (struct ip_reass_helper*)new_p->payload;
|
---|
350 | iprh->next_pbuf = NULL;
|
---|
351 | iprh->start = offset;
|
---|
352 | iprh->end = offset + len;
|
---|
353 |
|
---|
354 | /* Iterate through until we either get to the end of the list (append),
|
---|
355 | * or we find on with a larger offset (insert). */
|
---|
356 | for (q = ipr->p; q != NULL;) {
|
---|
357 | iprh_tmp = (struct ip_reass_helper*)q->payload;
|
---|
358 | if (iprh->start < iprh_tmp->start) {
|
---|
359 | /* the new pbuf should be inserted before this */
|
---|
360 | iprh->next_pbuf = q;
|
---|
361 | if (iprh_prev != NULL) {
|
---|
362 | /* not the fragment with the lowest offset */
|
---|
363 | #if IP_REASS_CHECK_OVERLAP
|
---|
364 | if ((iprh->start < iprh_prev->end) || (iprh->end > iprh_tmp->start)) {
|
---|
365 | /* fragment overlaps with previous or following, throw away */
|
---|
366 | goto freepbuf;
|
---|
367 | }
|
---|
368 | #endif /* IP_REASS_CHECK_OVERLAP */
|
---|
369 | iprh_prev->next_pbuf = new_p;
|
---|
370 | } else {
|
---|
371 | /* fragment with the lowest offset */
|
---|
372 | ipr->p = new_p;
|
---|
373 | }
|
---|
374 | break;
|
---|
375 | } else if(iprh->start == iprh_tmp->start) {
|
---|
376 | /* received the same datagram twice: no need to keep the datagram */
|
---|
377 | goto freepbuf;
|
---|
378 | #if IP_REASS_CHECK_OVERLAP
|
---|
379 | } else if(iprh->start < iprh_tmp->end) {
|
---|
380 | /* overlap: no need to keep the new datagram */
|
---|
381 | goto freepbuf;
|
---|
382 | #endif /* IP_REASS_CHECK_OVERLAP */
|
---|
383 | } else {
|
---|
384 | /* Check if the fragments received so far have no wholes. */
|
---|
385 | if (iprh_prev != NULL) {
|
---|
386 | if (iprh_prev->end != iprh_tmp->start) {
|
---|
387 | /* There is a fragment missing between the current
|
---|
388 | * and the previous fragment */
|
---|
389 | valid = 0;
|
---|
390 | }
|
---|
391 | }
|
---|
392 | }
|
---|
393 | q = iprh_tmp->next_pbuf;
|
---|
394 | iprh_prev = iprh_tmp;
|
---|
395 | }
|
---|
396 |
|
---|
397 | /* If q is NULL, then we made it to the end of the list. Determine what to do now */
|
---|
398 | if (q == NULL) {
|
---|
399 | if (iprh_prev != NULL) {
|
---|
400 | /* this is (for now), the fragment with the highest offset:
|
---|
401 | * chain it to the last fragment */
|
---|
402 | #if IP_REASS_CHECK_OVERLAP
|
---|
403 | LWIP_ASSERT("check fragments don't overlap", iprh_prev->end <= iprh->start);
|
---|
404 | #endif /* IP_REASS_CHECK_OVERLAP */
|
---|
405 | iprh_prev->next_pbuf = new_p;
|
---|
406 | if (iprh_prev->end != iprh->start) {
|
---|
407 | valid = 0;
|
---|
408 | }
|
---|
409 | } else {
|
---|
410 | #if IP_REASS_CHECK_OVERLAP
|
---|
411 | LWIP_ASSERT("no previous fragment, this must be the first fragment!",
|
---|
412 | ipr->p == NULL);
|
---|
413 | #endif /* IP_REASS_CHECK_OVERLAP */
|
---|
414 | /* this is the first fragment we ever received for this ip datagram */
|
---|
415 | ipr->p = new_p;
|
---|
416 | }
|
---|
417 | }
|
---|
418 |
|
---|
419 | /* At this point, the validation part begins: */
|
---|
420 | /* If we already received the last fragment */
|
---|
421 | if ((ipr->flags & IP_REASS_FLAG_LASTFRAG) != 0) {
|
---|
422 | /* and had no wholes so far */
|
---|
423 | if (valid) {
|
---|
424 | /* then check if the rest of the fragments is here */
|
---|
425 | /* Check if the queue starts with the first datagram */
|
---|
426 | if (((struct ip_reass_helper*)ipr->p->payload)->start != 0) {
|
---|
427 | valid = 0;
|
---|
428 | } else {
|
---|
429 | /* and check that there are no wholes after this datagram */
|
---|
430 | iprh_prev = iprh;
|
---|
431 | q = iprh->next_pbuf;
|
---|
432 | while (q != NULL) {
|
---|
433 | iprh = (struct ip_reass_helper*)q->payload;
|
---|
434 | if (iprh_prev->end != iprh->start) {
|
---|
435 | valid = 0;
|
---|
436 | break;
|
---|
437 | }
|
---|
438 | iprh_prev = iprh;
|
---|
439 | q = iprh->next_pbuf;
|
---|
440 | }
|
---|
441 | /* if still valid, all fragments are received
|
---|
442 | * (because to the MF==0 already arrived */
|
---|
443 | if (valid) {
|
---|
444 | LWIP_ASSERT("sanity check", ipr->p != NULL);
|
---|
445 | LWIP_ASSERT("sanity check",
|
---|
446 | ((struct ip_reass_helper*)ipr->p->payload) != iprh);
|
---|
447 | LWIP_ASSERT("validate_datagram:next_pbuf!=NULL",
|
---|
448 | iprh->next_pbuf == NULL);
|
---|
449 | LWIP_ASSERT("validate_datagram:datagram end!=datagram len",
|
---|
450 | iprh->end == ipr->datagram_len);
|
---|
451 | }
|
---|
452 | }
|
---|
453 | }
|
---|
454 | /* If valid is 0 here, there are some fragments missing in the middle
|
---|
455 | * (since MF == 0 has already arrived). Such datagrams simply time out if
|
---|
456 | * no more fragments are received... */
|
---|
457 | return valid;
|
---|
458 | }
|
---|
459 | /* If we come here, not all fragments were received, yet! */
|
---|
460 | return 0; /* not yet valid! */
|
---|
461 | #if IP_REASS_CHECK_OVERLAP
|
---|
462 | freepbuf:
|
---|
463 | ip_reass_pbufcount -= pbuf_clen(new_p);
|
---|
464 | pbuf_free(new_p);
|
---|
465 | return 0;
|
---|
466 | #endif /* IP_REASS_CHECK_OVERLAP */
|
---|
467 | }
|
---|
468 |
|
---|
469 | /**
|
---|
470 | * Reassembles incoming IP fragments into an IP datagram.
|
---|
471 | *
|
---|
472 | * @param p points to a pbuf chain of the fragment
|
---|
473 | * @return NULL if reassembly is incomplete, ? otherwise
|
---|
474 | */
|
---|
475 | struct pbuf *
|
---|
476 | ip_reass(struct pbuf *p)
|
---|
477 | {
|
---|
478 | struct pbuf *r;
|
---|
479 | struct ip_hdr *fraghdr;
|
---|
480 | struct ip_reassdata *ipr;
|
---|
481 | struct ip_reass_helper *iprh;
|
---|
482 | u16_t offset, len;
|
---|
483 | u8_t clen;
|
---|
484 | struct ip_reassdata *ipr_prev = NULL;
|
---|
485 |
|
---|
486 | IPFRAG_STATS_INC(ip_frag.recv);
|
---|
487 | snmp_inc_ipreasmreqds();
|
---|
488 |
|
---|
489 | fraghdr = (struct ip_hdr*)p->payload;
|
---|
490 |
|
---|
491 | if ((IPH_HL(fraghdr) * 4) != IP_HLEN) {
|
---|
492 | LWIP_DEBUGF(IP_REASS_DEBUG,("ip_reass: IP options currently not supported!\n"));
|
---|
493 | IPFRAG_STATS_INC(ip_frag.err);
|
---|
494 | goto nullreturn;
|
---|
495 | }
|
---|
496 |
|
---|
497 | offset = (ntohs(IPH_OFFSET(fraghdr)) & IP_OFFMASK) * 8;
|
---|
498 | len = ntohs(IPH_LEN(fraghdr)) - IPH_HL(fraghdr) * 4;
|
---|
499 |
|
---|
500 | /* Check if we are allowed to enqueue more datagrams. */
|
---|
501 | clen = pbuf_clen(p);
|
---|
502 | if ((ip_reass_pbufcount + clen) > IP_REASS_MAX_PBUFS) {
|
---|
503 | #if IP_REASS_FREE_OLDEST
|
---|
504 | if (!ip_reass_remove_oldest_datagram(fraghdr, clen) ||
|
---|
505 | ((ip_reass_pbufcount + clen) > IP_REASS_MAX_PBUFS))
|
---|
506 | #endif /* IP_REASS_FREE_OLDEST */
|
---|
507 | {
|
---|
508 | /* No datagram could be freed and still too many pbufs enqueued */
|
---|
509 | LWIP_DEBUGF(IP_REASS_DEBUG,("ip_reass: Overflow condition: pbufct=%d, clen=%d, MAX=%d\n",
|
---|
510 | ip_reass_pbufcount, clen, IP_REASS_MAX_PBUFS));
|
---|
511 | IPFRAG_STATS_INC(ip_frag.memerr);
|
---|
512 | /* @todo: send ICMP time exceeded here? */
|
---|
513 | /* drop this pbuf */
|
---|
514 | goto nullreturn;
|
---|
515 | }
|
---|
516 | }
|
---|
517 |
|
---|
518 | /* Look for the datagram the fragment belongs to in the current datagram queue,
|
---|
519 | * remembering the previous in the queue for later dequeueing. */
|
---|
520 | for (ipr = reassdatagrams; ipr != NULL; ipr = ipr->next) {
|
---|
521 | /* Check if the incoming fragment matches the one currently present
|
---|
522 | in the reassembly buffer. If so, we proceed with copying the
|
---|
523 | fragment into the buffer. */
|
---|
524 | if (IP_ADDRESSES_AND_ID_MATCH(&ipr->iphdr, fraghdr)) {
|
---|
525 | LWIP_DEBUGF(IP_REASS_DEBUG, ("ip_reass: matching previous fragment ID=%"X16_F"\n",
|
---|
526 | ntohs(IPH_ID(fraghdr))));
|
---|
527 | IPFRAG_STATS_INC(ip_frag.cachehit);
|
---|
528 | break;
|
---|
529 | }
|
---|
530 | ipr_prev = ipr;
|
---|
531 | }
|
---|
532 |
|
---|
533 | if (ipr == NULL) {
|
---|
534 | /* Enqueue a new datagram into the datagram queue */
|
---|
535 | ipr = ip_reass_enqueue_new_datagram(fraghdr, clen);
|
---|
536 | /* Bail if unable to enqueue */
|
---|
537 | if(ipr == NULL) {
|
---|
538 | goto nullreturn;
|
---|
539 | }
|
---|
540 | } else {
|
---|
541 | if (((ntohs(IPH_OFFSET(fraghdr)) & IP_OFFMASK) == 0) &&
|
---|
542 | ((ntohs(IPH_OFFSET(&ipr->iphdr)) & IP_OFFMASK) != 0)) {
|
---|
543 | /* ipr->iphdr is not the header from the first fragment, but fraghdr is
|
---|
544 | * -> copy fraghdr into ipr->iphdr since we want to have the header
|
---|
545 | * of the first fragment (for ICMP time exceeded and later, for copying
|
---|
546 | * all options, if supported)*/
|
---|
547 | SMEMCPY(&ipr->iphdr, fraghdr, IP_HLEN);
|
---|
548 | }
|
---|
549 | }
|
---|
550 | /* Track the current number of pbufs current 'in-flight', in order to limit
|
---|
551 | the number of fragments that may be enqueued at any one time */
|
---|
552 | ip_reass_pbufcount += clen;
|
---|
553 |
|
---|
554 | /* At this point, we have either created a new entry or pointing
|
---|
555 | * to an existing one */
|
---|
556 |
|
---|
557 | /* check for 'no more fragments', and update queue entry*/
|
---|
558 | if ((IPH_OFFSET(fraghdr) & PP_NTOHS(IP_MF)) == 0) {
|
---|
559 | ipr->flags |= IP_REASS_FLAG_LASTFRAG;
|
---|
560 | ipr->datagram_len = offset + len;
|
---|
561 | LWIP_DEBUGF(IP_REASS_DEBUG,
|
---|
562 | ("ip_reass: last fragment seen, total len %"S16_F"\n",
|
---|
563 | ipr->datagram_len));
|
---|
564 | }
|
---|
565 | /* find the right place to insert this pbuf */
|
---|
566 | /* @todo: trim pbufs if fragments are overlapping */
|
---|
567 | if (ip_reass_chain_frag_into_datagram_and_validate(ipr, p)) {
|
---|
568 | /* the totally last fragment (flag more fragments = 0) was received at least
|
---|
569 | * once AND all fragments are received */
|
---|
570 | ipr->datagram_len += IP_HLEN;
|
---|
571 |
|
---|
572 | /* save the second pbuf before copying the header over the pointer */
|
---|
573 | r = ((struct ip_reass_helper*)ipr->p->payload)->next_pbuf;
|
---|
574 |
|
---|
575 | /* copy the original ip header back to the first pbuf */
|
---|
576 | fraghdr = (struct ip_hdr*)(ipr->p->payload);
|
---|
577 | SMEMCPY(fraghdr, &ipr->iphdr, IP_HLEN);
|
---|
578 | IPH_LEN_SET(fraghdr, htons(ipr->datagram_len));
|
---|
579 | IPH_OFFSET_SET(fraghdr, 0);
|
---|
580 | IPH_CHKSUM_SET(fraghdr, 0);
|
---|
581 | /* @todo: do we need to set calculate the correct checksum? */
|
---|
582 | IPH_CHKSUM_SET(fraghdr, inet_chksum(fraghdr, IP_HLEN));
|
---|
583 |
|
---|
584 | p = ipr->p;
|
---|
585 |
|
---|
586 | /* chain together the pbufs contained within the reass_data list. */
|
---|
587 | while(r != NULL) {
|
---|
588 | iprh = (struct ip_reass_helper*)r->payload;
|
---|
589 |
|
---|
590 | /* hide the ip header for every succeding fragment */
|
---|
591 | pbuf_header(r, -IP_HLEN);
|
---|
592 | pbuf_cat(p, r);
|
---|
593 | r = iprh->next_pbuf;
|
---|
594 | }
|
---|
595 | /* release the sources allocate for the fragment queue entry */
|
---|
596 | ip_reass_dequeue_datagram(ipr, ipr_prev);
|
---|
597 |
|
---|
598 | /* and adjust the number of pbufs currently queued for reassembly. */
|
---|
599 | ip_reass_pbufcount -= pbuf_clen(p);
|
---|
600 |
|
---|
601 | /* Return the pbuf chain */
|
---|
602 | return p;
|
---|
603 | }
|
---|
604 | /* the datagram is not (yet?) reassembled completely */
|
---|
605 | LWIP_DEBUGF(IP_REASS_DEBUG,("ip_reass_pbufcount: %d out\n", ip_reass_pbufcount));
|
---|
606 | return NULL;
|
---|
607 |
|
---|
608 | nullreturn:
|
---|
609 | LWIP_DEBUGF(IP_REASS_DEBUG,("ip_reass: nullreturn\n"));
|
---|
610 | IPFRAG_STATS_INC(ip_frag.drop);
|
---|
611 | pbuf_free(p);
|
---|
612 | return NULL;
|
---|
613 | }
|
---|
614 | #endif /* IP_REASSEMBLY */
|
---|
615 |
|
---|
616 | #if IP_FRAG
|
---|
617 | #if IP_FRAG_USES_STATIC_BUF
|
---|
618 | static u8_t buf[LWIP_MEM_ALIGN_SIZE(IP_FRAG_MAX_MTU + MEM_ALIGNMENT - 1)];
|
---|
619 | #else /* IP_FRAG_USES_STATIC_BUF */
|
---|
620 |
|
---|
621 | #if !LWIP_NETIF_TX_SINGLE_PBUF
|
---|
622 | /** Allocate a new struct pbuf_custom_ref */
|
---|
623 | static struct pbuf_custom_ref*
|
---|
624 | ip_frag_alloc_pbuf_custom_ref(void)
|
---|
625 | {
|
---|
626 | return (struct pbuf_custom_ref*)memp_malloc(MEMP_FRAG_PBUF);
|
---|
627 | }
|
---|
628 |
|
---|
629 | /** Free a struct pbuf_custom_ref */
|
---|
630 | static void
|
---|
631 | ip_frag_free_pbuf_custom_ref(struct pbuf_custom_ref* p)
|
---|
632 | {
|
---|
633 | LWIP_ASSERT("p != NULL", p != NULL);
|
---|
634 | memp_free(MEMP_FRAG_PBUF, p);
|
---|
635 | }
|
---|
636 |
|
---|
637 | /** Free-callback function to free a 'struct pbuf_custom_ref', called by
|
---|
638 | * pbuf_free. */
|
---|
639 | static void
|
---|
640 | ipfrag_free_pbuf_custom(struct pbuf *p)
|
---|
641 | {
|
---|
642 | struct pbuf_custom_ref *pcr = (struct pbuf_custom_ref*)p;
|
---|
643 | LWIP_ASSERT("pcr != NULL", pcr != NULL);
|
---|
644 | LWIP_ASSERT("pcr == p", (void*)pcr == (void*)p);
|
---|
645 | if (pcr->original != NULL) {
|
---|
646 | pbuf_free(pcr->original);
|
---|
647 | }
|
---|
648 | ip_frag_free_pbuf_custom_ref(pcr);
|
---|
649 | }
|
---|
650 | #endif /* !LWIP_NETIF_TX_SINGLE_PBUF */
|
---|
651 | #endif /* IP_FRAG_USES_STATIC_BUF */
|
---|
652 |
|
---|
653 | /**
|
---|
654 | * Fragment an IP datagram if too large for the netif.
|
---|
655 | *
|
---|
656 | * Chop the datagram in MTU sized chunks and send them in order
|
---|
657 | * by using a fixed size static memory buffer (PBUF_REF) or
|
---|
658 | * point PBUF_REFs into p (depending on IP_FRAG_USES_STATIC_BUF).
|
---|
659 | *
|
---|
660 | * @param p ip packet to send
|
---|
661 | * @param netif the netif on which to send
|
---|
662 | * @param dest destination ip address to which to send
|
---|
663 | *
|
---|
664 | * @return ERR_OK if sent successfully, err_t otherwise
|
---|
665 | */
|
---|
666 | err_t
|
---|
667 | ip_frag(struct pbuf *p, struct netif *netif, ip_addr_t *dest)
|
---|
668 | {
|
---|
669 | struct pbuf *rambuf;
|
---|
670 | #if IP_FRAG_USES_STATIC_BUF
|
---|
671 | struct pbuf *header;
|
---|
672 | #else
|
---|
673 | #if !LWIP_NETIF_TX_SINGLE_PBUF
|
---|
674 | struct pbuf *newpbuf;
|
---|
675 | #endif
|
---|
676 | struct ip_hdr *original_iphdr;
|
---|
677 | #endif
|
---|
678 | struct ip_hdr *iphdr;
|
---|
679 | u16_t nfb;
|
---|
680 | u16_t left, cop;
|
---|
681 | u16_t mtu = netif->mtu;
|
---|
682 | u16_t ofo, omf;
|
---|
683 | u16_t last;
|
---|
684 | u16_t poff = IP_HLEN;
|
---|
685 | u16_t tmp;
|
---|
686 | #if !IP_FRAG_USES_STATIC_BUF && !LWIP_NETIF_TX_SINGLE_PBUF
|
---|
687 | u16_t newpbuflen = 0;
|
---|
688 | u16_t left_to_copy;
|
---|
689 | #endif
|
---|
690 |
|
---|
691 | /* Get a RAM based MTU sized pbuf */
|
---|
692 | #if IP_FRAG_USES_STATIC_BUF
|
---|
693 | /* When using a static buffer, we use a PBUF_REF, which we will
|
---|
694 | * use to reference the packet (without link header).
|
---|
695 | * Layer and length is irrelevant.
|
---|
696 | */
|
---|
697 | rambuf = pbuf_alloc(PBUF_LINK, 0, PBUF_REF);
|
---|
698 | if (rambuf == NULL) {
|
---|
699 | LWIP_DEBUGF(IP_REASS_DEBUG, ("ip_frag: pbuf_alloc(PBUF_LINK, 0, PBUF_REF) failed\n"));
|
---|
700 | return ERR_MEM;
|
---|
701 | }
|
---|
702 | rambuf->tot_len = rambuf->len = mtu;
|
---|
703 | rambuf->payload = LWIP_MEM_ALIGN((void *)buf);
|
---|
704 |
|
---|
705 | /* Copy the IP header in it */
|
---|
706 | iphdr = (struct ip_hdr *)rambuf->payload;
|
---|
707 | SMEMCPY(iphdr, p->payload, IP_HLEN);
|
---|
708 | #else /* IP_FRAG_USES_STATIC_BUF */
|
---|
709 | original_iphdr = (struct ip_hdr *)p->payload;
|
---|
710 | iphdr = original_iphdr;
|
---|
711 | #endif /* IP_FRAG_USES_STATIC_BUF */
|
---|
712 |
|
---|
713 | /* Save original offset */
|
---|
714 | tmp = ntohs(IPH_OFFSET(iphdr));
|
---|
715 | ofo = tmp & IP_OFFMASK;
|
---|
716 | omf = tmp & IP_MF;
|
---|
717 |
|
---|
718 | left = p->tot_len - IP_HLEN;
|
---|
719 |
|
---|
720 | nfb = (mtu - IP_HLEN) / 8;
|
---|
721 |
|
---|
722 | while (left) {
|
---|
723 | last = (left <= mtu - IP_HLEN);
|
---|
724 |
|
---|
725 | /* Set new offset and MF flag */
|
---|
726 | tmp = omf | (IP_OFFMASK & (ofo));
|
---|
727 | if (!last) {
|
---|
728 | tmp = tmp | IP_MF;
|
---|
729 | }
|
---|
730 |
|
---|
731 | /* Fill this fragment */
|
---|
732 | cop = last ? left : nfb * 8;
|
---|
733 |
|
---|
734 | #if IP_FRAG_USES_STATIC_BUF
|
---|
735 | poff += pbuf_copy_partial(p, (u8_t*)iphdr + IP_HLEN, cop, poff);
|
---|
736 | #else /* IP_FRAG_USES_STATIC_BUF */
|
---|
737 | #if LWIP_NETIF_TX_SINGLE_PBUF
|
---|
738 | rambuf = pbuf_alloc(PBUF_IP, cop, PBUF_RAM);
|
---|
739 | if (rambuf == NULL) {
|
---|
740 | return ERR_MEM;
|
---|
741 | }
|
---|
742 | LWIP_ASSERT("this needs a pbuf in one piece!",
|
---|
743 | (rambuf->len == rambuf->tot_len) && (rambuf->next == NULL));
|
---|
744 | poff += pbuf_copy_partial(p, rambuf->payload, cop, poff);
|
---|
745 | /* make room for the IP header */
|
---|
746 | if(pbuf_header(rambuf, IP_HLEN)) {
|
---|
747 | pbuf_free(rambuf);
|
---|
748 | return ERR_MEM;
|
---|
749 | }
|
---|
750 | /* fill in the IP header */
|
---|
751 | SMEMCPY(rambuf->payload, original_iphdr, IP_HLEN);
|
---|
752 | iphdr = rambuf->payload;
|
---|
753 | #else /* LWIP_NETIF_TX_SINGLE_PBUF */
|
---|
754 | /* When not using a static buffer, create a chain of pbufs.
|
---|
755 | * The first will be a PBUF_RAM holding the link and IP header.
|
---|
756 | * The rest will be PBUF_REFs mirroring the pbuf chain to be fragged,
|
---|
757 | * but limited to the size of an mtu.
|
---|
758 | */
|
---|
759 | rambuf = pbuf_alloc(PBUF_LINK, IP_HLEN, PBUF_RAM);
|
---|
760 | if (rambuf == NULL) {
|
---|
761 | return ERR_MEM;
|
---|
762 | }
|
---|
763 | LWIP_ASSERT("this needs a pbuf in one piece!",
|
---|
764 | (p->len >= (IP_HLEN)));
|
---|
765 | SMEMCPY(rambuf->payload, original_iphdr, IP_HLEN);
|
---|
766 | iphdr = (struct ip_hdr *)rambuf->payload;
|
---|
767 |
|
---|
768 | /* Can just adjust p directly for needed offset. */
|
---|
769 | p->payload = (u8_t *)p->payload + poff;
|
---|
770 | p->len -= poff;
|
---|
771 |
|
---|
772 | left_to_copy = cop;
|
---|
773 | while (left_to_copy) {
|
---|
774 | struct pbuf_custom_ref *pcr;
|
---|
775 | newpbuflen = (left_to_copy < p->len) ? left_to_copy : p->len;
|
---|
776 | /* Is this pbuf already empty? */
|
---|
777 | if (!newpbuflen) {
|
---|
778 | p = p->next;
|
---|
779 | continue;
|
---|
780 | }
|
---|
781 | pcr = ip_frag_alloc_pbuf_custom_ref();
|
---|
782 | if (pcr == NULL) {
|
---|
783 | pbuf_free(rambuf);
|
---|
784 | return ERR_MEM;
|
---|
785 | }
|
---|
786 | /* Mirror this pbuf, although we might not need all of it. */
|
---|
787 | newpbuf = pbuf_alloced_custom(PBUF_RAW, newpbuflen, PBUF_REF, &pcr->pc, p->payload, newpbuflen);
|
---|
788 | if (newpbuf == NULL) {
|
---|
789 | ip_frag_free_pbuf_custom_ref(pcr);
|
---|
790 | pbuf_free(rambuf);
|
---|
791 | return ERR_MEM;
|
---|
792 | }
|
---|
793 | pbuf_ref(p);
|
---|
794 | pcr->original = p;
|
---|
795 | pcr->pc.custom_free_function = ipfrag_free_pbuf_custom;
|
---|
796 |
|
---|
797 | /* Add it to end of rambuf's chain, but using pbuf_cat, not pbuf_chain
|
---|
798 | * so that it is removed when pbuf_dechain is later called on rambuf.
|
---|
799 | */
|
---|
800 | pbuf_cat(rambuf, newpbuf);
|
---|
801 | left_to_copy -= newpbuflen;
|
---|
802 | if (left_to_copy) {
|
---|
803 | p = p->next;
|
---|
804 | }
|
---|
805 | }
|
---|
806 | poff = newpbuflen;
|
---|
807 | #endif /* LWIP_NETIF_TX_SINGLE_PBUF */
|
---|
808 | #endif /* IP_FRAG_USES_STATIC_BUF */
|
---|
809 |
|
---|
810 | /* Correct header */
|
---|
811 | IPH_OFFSET_SET(iphdr, htons(tmp));
|
---|
812 | IPH_LEN_SET(iphdr, htons(cop + IP_HLEN));
|
---|
813 | IPH_CHKSUM_SET(iphdr, 0);
|
---|
814 | IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, IP_HLEN));
|
---|
815 |
|
---|
816 | #if IP_FRAG_USES_STATIC_BUF
|
---|
817 | if (last) {
|
---|
818 | pbuf_realloc(rambuf, left + IP_HLEN);
|
---|
819 | }
|
---|
820 |
|
---|
821 | /* This part is ugly: we alloc a RAM based pbuf for
|
---|
822 | * the link level header for each chunk and then
|
---|
823 | * free it.A PBUF_ROM style pbuf for which pbuf_header
|
---|
824 | * worked would make things simpler.
|
---|
825 | */
|
---|
826 | header = pbuf_alloc(PBUF_LINK, 0, PBUF_RAM);
|
---|
827 | if (header != NULL) {
|
---|
828 | pbuf_chain(header, rambuf);
|
---|
829 | netif->output(netif, header, dest);
|
---|
830 | IPFRAG_STATS_INC(ip_frag.xmit);
|
---|
831 | snmp_inc_ipfragcreates();
|
---|
832 | pbuf_free(header);
|
---|
833 | } else {
|
---|
834 | LWIP_DEBUGF(IP_REASS_DEBUG, ("ip_frag: pbuf_alloc() for header failed\n"));
|
---|
835 | pbuf_free(rambuf);
|
---|
836 | return ERR_MEM;
|
---|
837 | }
|
---|
838 | #else /* IP_FRAG_USES_STATIC_BUF */
|
---|
839 | /* No need for separate header pbuf - we allowed room for it in rambuf
|
---|
840 | * when allocated.
|
---|
841 | */
|
---|
842 | netif->output(netif, rambuf, dest);
|
---|
843 | IPFRAG_STATS_INC(ip_frag.xmit);
|
---|
844 |
|
---|
845 | /* Unfortunately we can't reuse rambuf - the hardware may still be
|
---|
846 | * using the buffer. Instead we free it (and the ensuing chain) and
|
---|
847 | * recreate it next time round the loop. If we're lucky the hardware
|
---|
848 | * will have already sent the packet, the free will really free, and
|
---|
849 | * there will be zero memory penalty.
|
---|
850 | */
|
---|
851 |
|
---|
852 | pbuf_free(rambuf);
|
---|
853 | #endif /* IP_FRAG_USES_STATIC_BUF */
|
---|
854 | left -= cop;
|
---|
855 | ofo += nfb;
|
---|
856 | }
|
---|
857 | #if IP_FRAG_USES_STATIC_BUF
|
---|
858 | pbuf_free(rambuf);
|
---|
859 | #endif /* IP_FRAG_USES_STATIC_BUF */
|
---|
860 | snmp_inc_ipfragoks();
|
---|
861 | return ERR_OK;
|
---|
862 | }
|
---|
863 | #endif /* IP_FRAG */
|
---|