Nino Der Kinderen / Mbed 2 deprecated InetTest

Embedded C project:18/12/2014

Dependencies:   DS1307 TextLCD mbed

NetServices/lwip/core/ipv4/ip_frag.c@0:8d87bc453349, 2014-12-18 (annotated)

Committer:
ninoderkinderen
Date:
Thu Dec 18 09:35:49 2014 +0000
Revision:
0:8d87bc453349
Programma embedded C

Who changed what in which revision?

UserRevisionLine numberNew contents of line
ninoderkinderen 0:8d87bc453349 1 /**
ninoderkinderen 0:8d87bc453349 2 * @file
ninoderkinderen 0:8d87bc453349 3 * This is the IPv4 packet segmentation and reassembly implementation.
ninoderkinderen 0:8d87bc453349 4 *
ninoderkinderen 0:8d87bc453349 5 */
ninoderkinderen 0:8d87bc453349 6
ninoderkinderen 0:8d87bc453349 7 /*
ninoderkinderen 0:8d87bc453349 8 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
ninoderkinderen 0:8d87bc453349 9 * All rights reserved.
ninoderkinderen 0:8d87bc453349 10 *
ninoderkinderen 0:8d87bc453349 11 * Redistribution and use in source and binary forms, with or without modification,
ninoderkinderen 0:8d87bc453349 12 * are permitted provided that the following conditions are met:
ninoderkinderen 0:8d87bc453349 13 *
ninoderkinderen 0:8d87bc453349 14 * 1. Redistributions of source code must retain the above copyright notice,
ninoderkinderen 0:8d87bc453349 15 * this list of conditions and the following disclaimer.
ninoderkinderen 0:8d87bc453349 16 * 2. Redistributions in binary form must reproduce the above copyright notice,
ninoderkinderen 0:8d87bc453349 17 * this list of conditions and the following disclaimer in the documentation
ninoderkinderen 0:8d87bc453349 18 * and/or other materials provided with the distribution.
ninoderkinderen 0:8d87bc453349 19 * 3. The name of the author may not be used to endorse or promote products
ninoderkinderen 0:8d87bc453349 20 * derived from this software without specific prior written permission.
ninoderkinderen 0:8d87bc453349 21 *
ninoderkinderen 0:8d87bc453349 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
ninoderkinderen 0:8d87bc453349 23 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
ninoderkinderen 0:8d87bc453349 24 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
ninoderkinderen 0:8d87bc453349 25 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
ninoderkinderen 0:8d87bc453349 26 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
ninoderkinderen 0:8d87bc453349 27 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
ninoderkinderen 0:8d87bc453349 28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
ninoderkinderen 0:8d87bc453349 29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
ninoderkinderen 0:8d87bc453349 30 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
ninoderkinderen 0:8d87bc453349 31 * OF SUCH DAMAGE.
ninoderkinderen 0:8d87bc453349 32 *
ninoderkinderen 0:8d87bc453349 33 * This file is part of the lwIP TCP/IP stack.
ninoderkinderen 0:8d87bc453349 34 *
ninoderkinderen 0:8d87bc453349 35 * Author: Jani Monoses <jani@iv.ro>
ninoderkinderen 0:8d87bc453349 36 * Simon Goldschmidt
ninoderkinderen 0:8d87bc453349 37 * original reassembly code by Adam Dunkels <adam@sics.se>
ninoderkinderen 0:8d87bc453349 38 *
ninoderkinderen 0:8d87bc453349 39 */
ninoderkinderen 0:8d87bc453349 40
ninoderkinderen 0:8d87bc453349 41 #include "lwip/opt.h"
ninoderkinderen 0:8d87bc453349 42 #include "lwip/ip_frag.h"
ninoderkinderen 0:8d87bc453349 43 #include "lwip/def.h"
ninoderkinderen 0:8d87bc453349 44 #include "lwip/inet_chksum.h"
ninoderkinderen 0:8d87bc453349 45 #include "lwip/netif.h"
ninoderkinderen 0:8d87bc453349 46 #include "lwip/snmp.h"
ninoderkinderen 0:8d87bc453349 47 #include "lwip/stats.h"
ninoderkinderen 0:8d87bc453349 48 #include "lwip/icmp.h"
ninoderkinderen 0:8d87bc453349 49
ninoderkinderen 0:8d87bc453349 50 #include <string.h>
ninoderkinderen 0:8d87bc453349 51
ninoderkinderen 0:8d87bc453349 52 #if IP_REASSEMBLY
ninoderkinderen 0:8d87bc453349 53 /**
ninoderkinderen 0:8d87bc453349 54 * The IP reassembly code currently has the following limitations:
ninoderkinderen 0:8d87bc453349 55 * - IP header options are not supported
ninoderkinderen 0:8d87bc453349 56 * - fragments must not overlap (e.g. due to different routes),
ninoderkinderen 0:8d87bc453349 57 * currently, overlapping or duplicate fragments are thrown away
ninoderkinderen 0:8d87bc453349 58 * if IP_REASS_CHECK_OVERLAP=1 (the default)!
ninoderkinderen 0:8d87bc453349 59 *
ninoderkinderen 0:8d87bc453349 60 * @todo: work with IP header options
ninoderkinderen 0:8d87bc453349 61 */
ninoderkinderen 0:8d87bc453349 62
ninoderkinderen 0:8d87bc453349 63 /** Setting this to 0, you can turn off checking the fragments for overlapping
ninoderkinderen 0:8d87bc453349 64 * regions. The code gets a little smaller. Only use this if you know that
ninoderkinderen 0:8d87bc453349 65 * overlapping won't occur on your network! */
ninoderkinderen 0:8d87bc453349 66 #ifndef IP_REASS_CHECK_OVERLAP
ninoderkinderen 0:8d87bc453349 67 #define IP_REASS_CHECK_OVERLAP 1
ninoderkinderen 0:8d87bc453349 68 #endif /* IP_REASS_CHECK_OVERLAP */
ninoderkinderen 0:8d87bc453349 69
ninoderkinderen 0:8d87bc453349 70 /** Set to 0 to prevent freeing the oldest datagram when the reassembly buffer is
ninoderkinderen 0:8d87bc453349 71 * full (IP_REASS_MAX_PBUFS pbufs are enqueued). The code gets a little smaller.
ninoderkinderen 0:8d87bc453349 72 * Datagrams will be freed by timeout only. Especially useful when MEMP_NUM_REASSDATA
ninoderkinderen 0:8d87bc453349 73 * is set to 1, so one datagram can be reassembled at a time, only. */
ninoderkinderen 0:8d87bc453349 74 #ifndef IP_REASS_FREE_OLDEST
ninoderkinderen 0:8d87bc453349 75 #define IP_REASS_FREE_OLDEST 1
ninoderkinderen 0:8d87bc453349 76 #endif /* IP_REASS_FREE_OLDEST */
ninoderkinderen 0:8d87bc453349 77
ninoderkinderen 0:8d87bc453349 78 #define IP_REASS_FLAG_LASTFRAG 0x01
ninoderkinderen 0:8d87bc453349 79
ninoderkinderen 0:8d87bc453349 80 /** This is a helper struct which holds the starting
ninoderkinderen 0:8d87bc453349 81 * offset and the ending offset of this fragment to
ninoderkinderen 0:8d87bc453349 82 * easily chain the fragments.
ninoderkinderen 0:8d87bc453349 83 * It has the same packing requirements as the IP header, since it replaces
ninoderkinderen 0:8d87bc453349 84 * the IP header in memory in incoming fragments (after copying it) to keep
ninoderkinderen 0:8d87bc453349 85 * track of the various fragments. (-> If the IP header doesn't need packing,
ninoderkinderen 0:8d87bc453349 86 * this struct doesn't need packing, too.)
ninoderkinderen 0:8d87bc453349 87 */
ninoderkinderen 0:8d87bc453349 88 #ifdef PACK_STRUCT_USE_INCLUDES
ninoderkinderen 0:8d87bc453349 89 # include "arch/bpstruct.h"
ninoderkinderen 0:8d87bc453349 90 #endif
ninoderkinderen 0:8d87bc453349 91 PACK_STRUCT_BEGIN
ninoderkinderen 0:8d87bc453349 92 struct ip_reass_helper {
ninoderkinderen 0:8d87bc453349 93 PACK_STRUCT_FIELD(struct pbuf *next_pbuf);
ninoderkinderen 0:8d87bc453349 94 PACK_STRUCT_FIELD(u16_t start);
ninoderkinderen 0:8d87bc453349 95 PACK_STRUCT_FIELD(u16_t end);
ninoderkinderen 0:8d87bc453349 96 } PACK_STRUCT_STRUCT;
ninoderkinderen 0:8d87bc453349 97 PACK_STRUCT_END
ninoderkinderen 0:8d87bc453349 98 #ifdef PACK_STRUCT_USE_INCLUDES
ninoderkinderen 0:8d87bc453349 99 # include "arch/epstruct.h"
ninoderkinderen 0:8d87bc453349 100 #endif
ninoderkinderen 0:8d87bc453349 101
ninoderkinderen 0:8d87bc453349 102 #define IP_ADDRESSES_AND_ID_MATCH(iphdrA, iphdrB) \
ninoderkinderen 0:8d87bc453349 103 (ip_addr_cmp(&(iphdrA)->src, &(iphdrB)->src) && \
ninoderkinderen 0:8d87bc453349 104 ip_addr_cmp(&(iphdrA)->dest, &(iphdrB)->dest) && \
ninoderkinderen 0:8d87bc453349 105 IPH_ID(iphdrA) == IPH_ID(iphdrB)) ? 1 : 0
ninoderkinderen 0:8d87bc453349 106
ninoderkinderen 0:8d87bc453349 107 /* global variables */
ninoderkinderen 0:8d87bc453349 108 static struct ip_reassdata *reassdatagrams;
ninoderkinderen 0:8d87bc453349 109 static u16_t ip_reass_pbufcount;
ninoderkinderen 0:8d87bc453349 110
ninoderkinderen 0:8d87bc453349 111 /* function prototypes */
ninoderkinderen 0:8d87bc453349 112 static void ip_reass_dequeue_datagram(struct ip_reassdata *ipr, struct ip_reassdata *prev);
ninoderkinderen 0:8d87bc453349 113 static int ip_reass_free_complete_datagram(struct ip_reassdata *ipr, struct ip_reassdata *prev);
ninoderkinderen 0:8d87bc453349 114
ninoderkinderen 0:8d87bc453349 115 /**
ninoderkinderen 0:8d87bc453349 116 * Reassembly timer base function
ninoderkinderen 0:8d87bc453349 117 * for both NO_SYS == 0 and 1 (!).
ninoderkinderen 0:8d87bc453349 118 *
ninoderkinderen 0:8d87bc453349 119 * Should be called every 1000 msec (defined by IP_TMR_INTERVAL).
ninoderkinderen 0:8d87bc453349 120 */
ninoderkinderen 0:8d87bc453349 121 void
ninoderkinderen 0:8d87bc453349 122 ip_reass_tmr(void)
ninoderkinderen 0:8d87bc453349 123 {
ninoderkinderen 0:8d87bc453349 124 struct ip_reassdata *r, *prev = NULL;
ninoderkinderen 0:8d87bc453349 125
ninoderkinderen 0:8d87bc453349 126 r = reassdatagrams;
ninoderkinderen 0:8d87bc453349 127 while (r != NULL) {
ninoderkinderen 0:8d87bc453349 128 /* Decrement the timer. Once it reaches 0,
ninoderkinderen 0:8d87bc453349 129 * clean up the incomplete fragment assembly */
ninoderkinderen 0:8d87bc453349 130 if (r->timer > 0) {
ninoderkinderen 0:8d87bc453349 131 r->timer--;
ninoderkinderen 0:8d87bc453349 132 LWIP_DEBUGF(IP_REASS_DEBUG, ("ip_reass_tmr: timer dec %"U16_F"\n",(u16_t)r->timer));
ninoderkinderen 0:8d87bc453349 133 prev = r;
ninoderkinderen 0:8d87bc453349 134 r = r->next;
ninoderkinderen 0:8d87bc453349 135 } else {
ninoderkinderen 0:8d87bc453349 136 /* reassembly timed out */
ninoderkinderen 0:8d87bc453349 137 struct ip_reassdata *tmp;
ninoderkinderen 0:8d87bc453349 138 LWIP_DEBUGF(IP_REASS_DEBUG, ("ip_reass_tmr: timer timed out\n"));
ninoderkinderen 0:8d87bc453349 139 tmp = r;
ninoderkinderen 0:8d87bc453349 140 /* get the next pointer before freeing */
ninoderkinderen 0:8d87bc453349 141 r = r->next;
ninoderkinderen 0:8d87bc453349 142 /* free the helper struct and all enqueued pbufs */
ninoderkinderen 0:8d87bc453349 143 ip_reass_free_complete_datagram(tmp, prev);
ninoderkinderen 0:8d87bc453349 144 }
ninoderkinderen 0:8d87bc453349 145 }
ninoderkinderen 0:8d87bc453349 146 }
ninoderkinderen 0:8d87bc453349 147
ninoderkinderen 0:8d87bc453349 148 /**
ninoderkinderen 0:8d87bc453349 149 * Free a datagram (struct ip_reassdata) and all its pbufs.
ninoderkinderen 0:8d87bc453349 150 * Updates the total count of enqueued pbufs (ip_reass_pbufcount),
ninoderkinderen 0:8d87bc453349 151 * SNMP counters and sends an ICMP time exceeded packet.
ninoderkinderen 0:8d87bc453349 152 *
ninoderkinderen 0:8d87bc453349 153 * @param ipr datagram to free
ninoderkinderen 0:8d87bc453349 154 * @param prev the previous datagram in the linked list
ninoderkinderen 0:8d87bc453349 155 * @return the number of pbufs freed
ninoderkinderen 0:8d87bc453349 156 */
ninoderkinderen 0:8d87bc453349 157 static int
ninoderkinderen 0:8d87bc453349 158 ip_reass_free_complete_datagram(struct ip_reassdata *ipr, struct ip_reassdata *prev)
ninoderkinderen 0:8d87bc453349 159 {
ninoderkinderen 0:8d87bc453349 160 u16_t pbufs_freed = 0;
ninoderkinderen 0:8d87bc453349 161 u8_t clen;
ninoderkinderen 0:8d87bc453349 162 struct pbuf *p;
ninoderkinderen 0:8d87bc453349 163 struct ip_reass_helper *iprh;
ninoderkinderen 0:8d87bc453349 164
ninoderkinderen 0:8d87bc453349 165 LWIP_ASSERT("prev != ipr", prev != ipr);
ninoderkinderen 0:8d87bc453349 166 if (prev != NULL) {
ninoderkinderen 0:8d87bc453349 167 LWIP_ASSERT("prev->next == ipr", prev->next == ipr);
ninoderkinderen 0:8d87bc453349 168 }
ninoderkinderen 0:8d87bc453349 169
ninoderkinderen 0:8d87bc453349 170 snmp_inc_ipreasmfails();
ninoderkinderen 0:8d87bc453349 171 #if LWIP_ICMP
ninoderkinderen 0:8d87bc453349 172 iprh = (struct ip_reass_helper *)ipr->p->payload;
ninoderkinderen 0:8d87bc453349 173 if (iprh->start == 0) {
ninoderkinderen 0:8d87bc453349 174 /* The first fragment was received, send ICMP time exceeded. */
ninoderkinderen 0:8d87bc453349 175 /* First, de-queue the first pbuf from r->p. */
ninoderkinderen 0:8d87bc453349 176 p = ipr->p;
ninoderkinderen 0:8d87bc453349 177 ipr->p = iprh->next_pbuf;
ninoderkinderen 0:8d87bc453349 178 /* Then, copy the original header into it. */
ninoderkinderen 0:8d87bc453349 179 SMEMCPY(p->payload, &ipr->iphdr, IP_HLEN);
ninoderkinderen 0:8d87bc453349 180 icmp_time_exceeded(p, ICMP_TE_FRAG);
ninoderkinderen 0:8d87bc453349 181 clen = pbuf_clen(p);
ninoderkinderen 0:8d87bc453349 182 LWIP_ASSERT("pbufs_freed + clen <= 0xffff", pbufs_freed + clen <= 0xffff);
ninoderkinderen 0:8d87bc453349 183 pbufs_freed += clen;
ninoderkinderen 0:8d87bc453349 184 pbuf_free(p);
ninoderkinderen 0:8d87bc453349 185 }
ninoderkinderen 0:8d87bc453349 186 #endif /* LWIP_ICMP */
ninoderkinderen 0:8d87bc453349 187
ninoderkinderen 0:8d87bc453349 188 /* First, free all received pbufs. The individual pbufs need to be released
ninoderkinderen 0:8d87bc453349 189 separately as they have not yet been chained */
ninoderkinderen 0:8d87bc453349 190 p = ipr->p;
ninoderkinderen 0:8d87bc453349 191 while (p != NULL) {
ninoderkinderen 0:8d87bc453349 192 struct pbuf *pcur;
ninoderkinderen 0:8d87bc453349 193 iprh = (struct ip_reass_helper *)p->payload;
ninoderkinderen 0:8d87bc453349 194 pcur = p;
ninoderkinderen 0:8d87bc453349 195 /* get the next pointer before freeing */
ninoderkinderen 0:8d87bc453349 196 p = iprh->next_pbuf;
ninoderkinderen 0:8d87bc453349 197 clen = pbuf_clen(pcur);
ninoderkinderen 0:8d87bc453349 198 LWIP_ASSERT("pbufs_freed + clen <= 0xffff", pbufs_freed + clen <= 0xffff);
ninoderkinderen 0:8d87bc453349 199 pbufs_freed += clen;
ninoderkinderen 0:8d87bc453349 200 pbuf_free(pcur);
ninoderkinderen 0:8d87bc453349 201 }
ninoderkinderen 0:8d87bc453349 202 /* Then, unchain the struct ip_reassdata from the list and free it. */
ninoderkinderen 0:8d87bc453349 203 ip_reass_dequeue_datagram(ipr, prev);
ninoderkinderen 0:8d87bc453349 204 LWIP_ASSERT("ip_reass_pbufcount >= clen", ip_reass_pbufcount >= pbufs_freed);
ninoderkinderen 0:8d87bc453349 205 ip_reass_pbufcount -= pbufs_freed;
ninoderkinderen 0:8d87bc453349 206
ninoderkinderen 0:8d87bc453349 207 return pbufs_freed;
ninoderkinderen 0:8d87bc453349 208 }
ninoderkinderen 0:8d87bc453349 209
ninoderkinderen 0:8d87bc453349 210 #if IP_REASS_FREE_OLDEST
ninoderkinderen 0:8d87bc453349 211 /**
ninoderkinderen 0:8d87bc453349 212 * Free the oldest datagram to make room for enqueueing new fragments.
ninoderkinderen 0:8d87bc453349 213 * The datagram 'fraghdr' belongs to is not freed!
ninoderkinderen 0:8d87bc453349 214 *
ninoderkinderen 0:8d87bc453349 215 * @param fraghdr IP header of the current fragment
ninoderkinderen 0:8d87bc453349 216 * @param pbufs_needed number of pbufs needed to enqueue
ninoderkinderen 0:8d87bc453349 217 * (used for freeing other datagrams if not enough space)
ninoderkinderen 0:8d87bc453349 218 * @return the number of pbufs freed
ninoderkinderen 0:8d87bc453349 219 */
ninoderkinderen 0:8d87bc453349 220 static int
ninoderkinderen 0:8d87bc453349 221 ip_reass_remove_oldest_datagram(struct ip_hdr *fraghdr, int pbufs_needed)
ninoderkinderen 0:8d87bc453349 222 {
ninoderkinderen 0:8d87bc453349 223 /* @todo Can't we simply remove the last datagram in the
ninoderkinderen 0:8d87bc453349 224 * linked list behind reassdatagrams?
ninoderkinderen 0:8d87bc453349 225 */
ninoderkinderen 0:8d87bc453349 226 struct ip_reassdata *r, *oldest, *prev;
ninoderkinderen 0:8d87bc453349 227 int pbufs_freed = 0, pbufs_freed_current;
ninoderkinderen 0:8d87bc453349 228 int other_datagrams;
ninoderkinderen 0:8d87bc453349 229
ninoderkinderen 0:8d87bc453349 230 /* Free datagrams until being allowed to enqueue 'pbufs_needed' pbufs,
ninoderkinderen 0:8d87bc453349 231 * but don't free the datagram that 'fraghdr' belongs to! */
ninoderkinderen 0:8d87bc453349 232 do {
ninoderkinderen 0:8d87bc453349 233 oldest = NULL;
ninoderkinderen 0:8d87bc453349 234 prev = NULL;
ninoderkinderen 0:8d87bc453349 235 other_datagrams = 0;
ninoderkinderen 0:8d87bc453349 236 r = reassdatagrams;
ninoderkinderen 0:8d87bc453349 237 while (r != NULL) {
ninoderkinderen 0:8d87bc453349 238 if (!IP_ADDRESSES_AND_ID_MATCH(&r->iphdr, fraghdr)) {
ninoderkinderen 0:8d87bc453349 239 /* Not the same datagram as fraghdr */
ninoderkinderen 0:8d87bc453349 240 other_datagrams++;
ninoderkinderen 0:8d87bc453349 241 if (oldest == NULL) {
ninoderkinderen 0:8d87bc453349 242 oldest = r;
ninoderkinderen 0:8d87bc453349 243 } else if (r->timer <= oldest->timer) {
ninoderkinderen 0:8d87bc453349 244 /* older than the previous oldest */
ninoderkinderen 0:8d87bc453349 245 oldest = r;
ninoderkinderen 0:8d87bc453349 246 }
ninoderkinderen 0:8d87bc453349 247 }
ninoderkinderen 0:8d87bc453349 248 if (r->next != NULL) {
ninoderkinderen 0:8d87bc453349 249 prev = r;
ninoderkinderen 0:8d87bc453349 250 }
ninoderkinderen 0:8d87bc453349 251 r = r->next;
ninoderkinderen 0:8d87bc453349 252 }
ninoderkinderen 0:8d87bc453349 253 if (oldest != NULL) {
ninoderkinderen 0:8d87bc453349 254 pbufs_freed_current = ip_reass_free_complete_datagram(oldest, prev);
ninoderkinderen 0:8d87bc453349 255 pbufs_freed += pbufs_freed_current;
ninoderkinderen 0:8d87bc453349 256 }
ninoderkinderen 0:8d87bc453349 257 } while ((pbufs_freed < pbufs_needed) && (other_datagrams > 1));
ninoderkinderen 0:8d87bc453349 258 return pbufs_freed;
ninoderkinderen 0:8d87bc453349 259 }
ninoderkinderen 0:8d87bc453349 260 #endif /* IP_REASS_FREE_OLDEST */
ninoderkinderen 0:8d87bc453349 261
ninoderkinderen 0:8d87bc453349 262 /**
ninoderkinderen 0:8d87bc453349 263 * Enqueues a new fragment into the fragment queue
ninoderkinderen 0:8d87bc453349 264 * @param fraghdr points to the new fragments IP hdr
ninoderkinderen 0:8d87bc453349 265 * @param clen number of pbufs needed to enqueue (used for freeing other datagrams if not enough space)
ninoderkinderen 0:8d87bc453349 266 * @return A pointer to the queue location into which the fragment was enqueued
ninoderkinderen 0:8d87bc453349 267 */
ninoderkinderen 0:8d87bc453349 268 static struct ip_reassdata*
ninoderkinderen 0:8d87bc453349 269 ip_reass_enqueue_new_datagram(struct ip_hdr *fraghdr, int clen)
ninoderkinderen 0:8d87bc453349 270 {
ninoderkinderen 0:8d87bc453349 271 struct ip_reassdata* ipr;
ninoderkinderen 0:8d87bc453349 272 /* No matching previous fragment found, allocate a new reassdata struct */
ninoderkinderen 0:8d87bc453349 273 ipr = (struct ip_reassdata *)memp_malloc(MEMP_REASSDATA);
ninoderkinderen 0:8d87bc453349 274 if (ipr == NULL) {
ninoderkinderen 0:8d87bc453349 275 #if IP_REASS_FREE_OLDEST
ninoderkinderen 0:8d87bc453349 276 if (ip_reass_remove_oldest_datagram(fraghdr, clen) >= clen) {
ninoderkinderen 0:8d87bc453349 277 ipr = (struct ip_reassdata *)memp_malloc(MEMP_REASSDATA);
ninoderkinderen 0:8d87bc453349 278 }
ninoderkinderen 0:8d87bc453349 279 if (ipr == NULL)
ninoderkinderen 0:8d87bc453349 280 #endif /* IP_REASS_FREE_OLDEST */
ninoderkinderen 0:8d87bc453349 281 {
ninoderkinderen 0:8d87bc453349 282 IPFRAG_STATS_INC(ip_frag.memerr);
ninoderkinderen 0:8d87bc453349 283 LWIP_DEBUGF(IP_REASS_DEBUG,("Failed to alloc reassdata struct\n"));
ninoderkinderen 0:8d87bc453349 284 return NULL;
ninoderkinderen 0:8d87bc453349 285 }
ninoderkinderen 0:8d87bc453349 286 }
ninoderkinderen 0:8d87bc453349 287 memset(ipr, 0, sizeof(struct ip_reassdata));
ninoderkinderen 0:8d87bc453349 288 ipr->timer = IP_REASS_MAXAGE;
ninoderkinderen 0:8d87bc453349 289
ninoderkinderen 0:8d87bc453349 290 /* enqueue the new structure to the front of the list */
ninoderkinderen 0:8d87bc453349 291 ipr->next = reassdatagrams;
ninoderkinderen 0:8d87bc453349 292 reassdatagrams = ipr;
ninoderkinderen 0:8d87bc453349 293 /* copy the ip header for later tests and input */
ninoderkinderen 0:8d87bc453349 294 /* @todo: no ip options supported? */
ninoderkinderen 0:8d87bc453349 295 SMEMCPY(&(ipr->iphdr), fraghdr, IP_HLEN);
ninoderkinderen 0:8d87bc453349 296 return ipr;
ninoderkinderen 0:8d87bc453349 297 }
ninoderkinderen 0:8d87bc453349 298
ninoderkinderen 0:8d87bc453349 299 /**
ninoderkinderen 0:8d87bc453349 300 * Dequeues a datagram from the datagram queue. Doesn't deallocate the pbufs.
ninoderkinderen 0:8d87bc453349 301 * @param ipr points to the queue entry to dequeue
ninoderkinderen 0:8d87bc453349 302 */
ninoderkinderen 0:8d87bc453349 303 static void
ninoderkinderen 0:8d87bc453349 304 ip_reass_dequeue_datagram(struct ip_reassdata *ipr, struct ip_reassdata *prev)
ninoderkinderen 0:8d87bc453349 305 {
ninoderkinderen 0:8d87bc453349 306
ninoderkinderen 0:8d87bc453349 307 /* dequeue the reass struct */
ninoderkinderen 0:8d87bc453349 308 if (reassdatagrams == ipr) {
ninoderkinderen 0:8d87bc453349 309 /* it was the first in the list */
ninoderkinderen 0:8d87bc453349 310 reassdatagrams = ipr->next;
ninoderkinderen 0:8d87bc453349 311 } else {
ninoderkinderen 0:8d87bc453349 312 /* it wasn't the first, so it must have a valid 'prev' */
ninoderkinderen 0:8d87bc453349 313 LWIP_ASSERT("sanity check linked list", prev != NULL);
ninoderkinderen 0:8d87bc453349 314 prev->next = ipr->next;
ninoderkinderen 0:8d87bc453349 315 }
ninoderkinderen 0:8d87bc453349 316
ninoderkinderen 0:8d87bc453349 317 /* now we can free the ip_reass struct */
ninoderkinderen 0:8d87bc453349 318 memp_free(MEMP_REASSDATA, ipr);
ninoderkinderen 0:8d87bc453349 319 }
ninoderkinderen 0:8d87bc453349 320
ninoderkinderen 0:8d87bc453349 321 /**
ninoderkinderen 0:8d87bc453349 322 * Chain a new pbuf into the pbuf list that composes the datagram. The pbuf list
ninoderkinderen 0:8d87bc453349 323 * will grow over time as new pbufs are rx.
ninoderkinderen 0:8d87bc453349 324 * Also checks that the datagram passes basic continuity checks (if the last
ninoderkinderen 0:8d87bc453349 325 * fragment was received at least once).
ninoderkinderen 0:8d87bc453349 326 * @param root_p points to the 'root' pbuf for the current datagram being assembled.
ninoderkinderen 0:8d87bc453349 327 * @param new_p points to the pbuf for the current fragment
ninoderkinderen 0:8d87bc453349 328 * @return 0 if invalid, >0 otherwise
ninoderkinderen 0:8d87bc453349 329 */
ninoderkinderen 0:8d87bc453349 330 static int
ninoderkinderen 0:8d87bc453349 331 ip_reass_chain_frag_into_datagram_and_validate(struct ip_reassdata *ipr, struct pbuf *new_p)
ninoderkinderen 0:8d87bc453349 332 {
ninoderkinderen 0:8d87bc453349 333 struct ip_reass_helper *iprh, *iprh_tmp, *iprh_prev=NULL;
ninoderkinderen 0:8d87bc453349 334 struct pbuf *q;
ninoderkinderen 0:8d87bc453349 335 u16_t offset,len;
ninoderkinderen 0:8d87bc453349 336 struct ip_hdr *fraghdr;
ninoderkinderen 0:8d87bc453349 337 int valid = 1;
ninoderkinderen 0:8d87bc453349 338
ninoderkinderen 0:8d87bc453349 339 /* Extract length and fragment offset from current fragment */
ninoderkinderen 0:8d87bc453349 340 fraghdr = (struct ip_hdr*)new_p->payload;
ninoderkinderen 0:8d87bc453349 341 len = ntohs(IPH_LEN(fraghdr)) - IPH_HL(fraghdr) * 4;
ninoderkinderen 0:8d87bc453349 342 offset = (ntohs(IPH_OFFSET(fraghdr)) & IP_OFFMASK) * 8;
ninoderkinderen 0:8d87bc453349 343
ninoderkinderen 0:8d87bc453349 344 /* overwrite the fragment's ip header from the pbuf with our helper struct,
ninoderkinderen 0:8d87bc453349 345 * and setup the embedded helper structure. */
ninoderkinderen 0:8d87bc453349 346 /* make sure the struct ip_reass_helper fits into the IP header */
ninoderkinderen 0:8d87bc453349 347 LWIP_ASSERT("sizeof(struct ip_reass_helper) <= IP_HLEN",
ninoderkinderen 0:8d87bc453349 348 sizeof(struct ip_reass_helper) <= IP_HLEN);
ninoderkinderen 0:8d87bc453349 349 iprh = (struct ip_reass_helper*)new_p->payload;
ninoderkinderen 0:8d87bc453349 350 iprh->next_pbuf = NULL;
ninoderkinderen 0:8d87bc453349 351 iprh->start = offset;
ninoderkinderen 0:8d87bc453349 352 iprh->end = offset + len;
ninoderkinderen 0:8d87bc453349 353
ninoderkinderen 0:8d87bc453349 354 /* Iterate through until we either get to the end of the list (append),
ninoderkinderen 0:8d87bc453349 355 * or we find on with a larger offset (insert). */
ninoderkinderen 0:8d87bc453349 356 for (q = ipr->p; q != NULL;) {
ninoderkinderen 0:8d87bc453349 357 iprh_tmp = (struct ip_reass_helper*)q->payload;
ninoderkinderen 0:8d87bc453349 358 if (iprh->start < iprh_tmp->start) {
ninoderkinderen 0:8d87bc453349 359 /* the new pbuf should be inserted before this */
ninoderkinderen 0:8d87bc453349 360 iprh->next_pbuf = q;
ninoderkinderen 0:8d87bc453349 361 if (iprh_prev != NULL) {
ninoderkinderen 0:8d87bc453349 362 /* not the fragment with the lowest offset */
ninoderkinderen 0:8d87bc453349 363 #if IP_REASS_CHECK_OVERLAP
ninoderkinderen 0:8d87bc453349 364 if ((iprh->start < iprh_prev->end) || (iprh->end > iprh_tmp->start)) {
ninoderkinderen 0:8d87bc453349 365 /* fragment overlaps with previous or following, throw away */
ninoderkinderen 0:8d87bc453349 366 goto freepbuf;
ninoderkinderen 0:8d87bc453349 367 }
ninoderkinderen 0:8d87bc453349 368 #endif /* IP_REASS_CHECK_OVERLAP */
ninoderkinderen 0:8d87bc453349 369 iprh_prev->next_pbuf = new_p;
ninoderkinderen 0:8d87bc453349 370 } else {
ninoderkinderen 0:8d87bc453349 371 /* fragment with the lowest offset */
ninoderkinderen 0:8d87bc453349 372 ipr->p = new_p;
ninoderkinderen 0:8d87bc453349 373 }
ninoderkinderen 0:8d87bc453349 374 break;
ninoderkinderen 0:8d87bc453349 375 } else if(iprh->start == iprh_tmp->start) {
ninoderkinderen 0:8d87bc453349 376 /* received the same datagram twice: no need to keep the datagram */
ninoderkinderen 0:8d87bc453349 377 goto freepbuf;
ninoderkinderen 0:8d87bc453349 378 #if IP_REASS_CHECK_OVERLAP
ninoderkinderen 0:8d87bc453349 379 } else if(iprh->start < iprh_tmp->end) {
ninoderkinderen 0:8d87bc453349 380 /* overlap: no need to keep the new datagram */
ninoderkinderen 0:8d87bc453349 381 goto freepbuf;
ninoderkinderen 0:8d87bc453349 382 #endif /* IP_REASS_CHECK_OVERLAP */
ninoderkinderen 0:8d87bc453349 383 } else {
ninoderkinderen 0:8d87bc453349 384 /* Check if the fragments received so far have no wholes. */
ninoderkinderen 0:8d87bc453349 385 if (iprh_prev != NULL) {
ninoderkinderen 0:8d87bc453349 386 if (iprh_prev->end != iprh_tmp->start) {
ninoderkinderen 0:8d87bc453349 387 /* There is a fragment missing between the current
ninoderkinderen 0:8d87bc453349 388 * and the previous fragment */
ninoderkinderen 0:8d87bc453349 389 valid = 0;
ninoderkinderen 0:8d87bc453349 390 }
ninoderkinderen 0:8d87bc453349 391 }
ninoderkinderen 0:8d87bc453349 392 }
ninoderkinderen 0:8d87bc453349 393 q = iprh_tmp->next_pbuf;
ninoderkinderen 0:8d87bc453349 394 iprh_prev = iprh_tmp;
ninoderkinderen 0:8d87bc453349 395 }
ninoderkinderen 0:8d87bc453349 396
ninoderkinderen 0:8d87bc453349 397 /* If q is NULL, then we made it to the end of the list. Determine what to do now */
ninoderkinderen 0:8d87bc453349 398 if (q == NULL) {
ninoderkinderen 0:8d87bc453349 399 if (iprh_prev != NULL) {
ninoderkinderen 0:8d87bc453349 400 /* this is (for now), the fragment with the highest offset:
ninoderkinderen 0:8d87bc453349 401 * chain it to the last fragment */
ninoderkinderen 0:8d87bc453349 402 #if IP_REASS_CHECK_OVERLAP
ninoderkinderen 0:8d87bc453349 403 LWIP_ASSERT("check fragments don't overlap", iprh_prev->end <= iprh->start);
ninoderkinderen 0:8d87bc453349 404 #endif /* IP_REASS_CHECK_OVERLAP */
ninoderkinderen 0:8d87bc453349 405 iprh_prev->next_pbuf = new_p;
ninoderkinderen 0:8d87bc453349 406 if (iprh_prev->end != iprh->start) {
ninoderkinderen 0:8d87bc453349 407 valid = 0;
ninoderkinderen 0:8d87bc453349 408 }
ninoderkinderen 0:8d87bc453349 409 } else {
ninoderkinderen 0:8d87bc453349 410 #if IP_REASS_CHECK_OVERLAP
ninoderkinderen 0:8d87bc453349 411 LWIP_ASSERT("no previous fragment, this must be the first fragment!",
ninoderkinderen 0:8d87bc453349 412 ipr->p == NULL);
ninoderkinderen 0:8d87bc453349 413 #endif /* IP_REASS_CHECK_OVERLAP */
ninoderkinderen 0:8d87bc453349 414 /* this is the first fragment we ever received for this ip datagram */
ninoderkinderen 0:8d87bc453349 415 ipr->p = new_p;
ninoderkinderen 0:8d87bc453349 416 }
ninoderkinderen 0:8d87bc453349 417 }
ninoderkinderen 0:8d87bc453349 418
ninoderkinderen 0:8d87bc453349 419 /* At this point, the validation part begins: */
ninoderkinderen 0:8d87bc453349 420 /* If we already received the last fragment */
ninoderkinderen 0:8d87bc453349 421 if ((ipr->flags & IP_REASS_FLAG_LASTFRAG) != 0) {
ninoderkinderen 0:8d87bc453349 422 /* and had no wholes so far */
ninoderkinderen 0:8d87bc453349 423 if (valid) {
ninoderkinderen 0:8d87bc453349 424 /* then check if the rest of the fragments is here */
ninoderkinderen 0:8d87bc453349 425 /* Check if the queue starts with the first datagram */
ninoderkinderen 0:8d87bc453349 426 if (((struct ip_reass_helper*)ipr->p->payload)->start != 0) {
ninoderkinderen 0:8d87bc453349 427 valid = 0;
ninoderkinderen 0:8d87bc453349 428 } else {
ninoderkinderen 0:8d87bc453349 429 /* and check that there are no wholes after this datagram */
ninoderkinderen 0:8d87bc453349 430 iprh_prev = iprh;
ninoderkinderen 0:8d87bc453349 431 q = iprh->next_pbuf;
ninoderkinderen 0:8d87bc453349 432 while (q != NULL) {
ninoderkinderen 0:8d87bc453349 433 iprh = (struct ip_reass_helper*)q->payload;
ninoderkinderen 0:8d87bc453349 434 if (iprh_prev->end != iprh->start) {
ninoderkinderen 0:8d87bc453349 435 valid = 0;
ninoderkinderen 0:8d87bc453349 436 break;
ninoderkinderen 0:8d87bc453349 437 }
ninoderkinderen 0:8d87bc453349 438 iprh_prev = iprh;
ninoderkinderen 0:8d87bc453349 439 q = iprh->next_pbuf;
ninoderkinderen 0:8d87bc453349 440 }
ninoderkinderen 0:8d87bc453349 441 /* if still valid, all fragments are received
ninoderkinderen 0:8d87bc453349 442 * (because to the MF==0 already arrived */
ninoderkinderen 0:8d87bc453349 443 if (valid) {
ninoderkinderen 0:8d87bc453349 444 LWIP_ASSERT("sanity check", ipr->p != NULL);
ninoderkinderen 0:8d87bc453349 445 LWIP_ASSERT("sanity check",
ninoderkinderen 0:8d87bc453349 446 ((struct ip_reass_helper*)ipr->p->payload) != iprh);
ninoderkinderen 0:8d87bc453349 447 LWIP_ASSERT("validate_datagram:next_pbuf!=NULL",
ninoderkinderen 0:8d87bc453349 448 iprh->next_pbuf == NULL);
ninoderkinderen 0:8d87bc453349 449 LWIP_ASSERT("validate_datagram:datagram end!=datagram len",
ninoderkinderen 0:8d87bc453349 450 iprh->end == ipr->datagram_len);
ninoderkinderen 0:8d87bc453349 451 }
ninoderkinderen 0:8d87bc453349 452 }
ninoderkinderen 0:8d87bc453349 453 }
ninoderkinderen 0:8d87bc453349 454 /* If valid is 0 here, there are some fragments missing in the middle
ninoderkinderen 0:8d87bc453349 455 * (since MF == 0 has already arrived). Such datagrams simply time out if
ninoderkinderen 0:8d87bc453349 456 * no more fragments are received... */
ninoderkinderen 0:8d87bc453349 457 return valid;
ninoderkinderen 0:8d87bc453349 458 }
ninoderkinderen 0:8d87bc453349 459 /* If we come here, not all fragments were received, yet! */
ninoderkinderen 0:8d87bc453349 460 return 0; /* not yet valid! */
ninoderkinderen 0:8d87bc453349 461 #if IP_REASS_CHECK_OVERLAP
ninoderkinderen 0:8d87bc453349 462 freepbuf:
ninoderkinderen 0:8d87bc453349 463 ip_reass_pbufcount -= pbuf_clen(new_p);
ninoderkinderen 0:8d87bc453349 464 pbuf_free(new_p);
ninoderkinderen 0:8d87bc453349 465 return 0;
ninoderkinderen 0:8d87bc453349 466 #endif /* IP_REASS_CHECK_OVERLAP */
ninoderkinderen 0:8d87bc453349 467 }
ninoderkinderen 0:8d87bc453349 468
ninoderkinderen 0:8d87bc453349 469 /**
ninoderkinderen 0:8d87bc453349 470 * Reassembles incoming IP fragments into an IP datagram.
ninoderkinderen 0:8d87bc453349 471 *
ninoderkinderen 0:8d87bc453349 472 * @param p points to a pbuf chain of the fragment
ninoderkinderen 0:8d87bc453349 473 * @return NULL if reassembly is incomplete, ? otherwise
ninoderkinderen 0:8d87bc453349 474 */
ninoderkinderen 0:8d87bc453349 475 struct pbuf *
ninoderkinderen 0:8d87bc453349 476 ip_reass(struct pbuf *p)
ninoderkinderen 0:8d87bc453349 477 {
ninoderkinderen 0:8d87bc453349 478 struct pbuf *r;
ninoderkinderen 0:8d87bc453349 479 struct ip_hdr *fraghdr;
ninoderkinderen 0:8d87bc453349 480 struct ip_reassdata *ipr;
ninoderkinderen 0:8d87bc453349 481 struct ip_reass_helper *iprh;
ninoderkinderen 0:8d87bc453349 482 u16_t offset, len;
ninoderkinderen 0:8d87bc453349 483 u8_t clen;
ninoderkinderen 0:8d87bc453349 484 struct ip_reassdata *ipr_prev = NULL;
ninoderkinderen 0:8d87bc453349 485
ninoderkinderen 0:8d87bc453349 486 IPFRAG_STATS_INC(ip_frag.recv);
ninoderkinderen 0:8d87bc453349 487 snmp_inc_ipreasmreqds();
ninoderkinderen 0:8d87bc453349 488
ninoderkinderen 0:8d87bc453349 489 fraghdr = (struct ip_hdr*)p->payload;
ninoderkinderen 0:8d87bc453349 490
ninoderkinderen 0:8d87bc453349 491 if ((IPH_HL(fraghdr) * 4) != IP_HLEN) {
ninoderkinderen 0:8d87bc453349 492 LWIP_DEBUGF(IP_REASS_DEBUG,("ip_reass: IP options currently not supported!\n"));
ninoderkinderen 0:8d87bc453349 493 IPFRAG_STATS_INC(ip_frag.err);
ninoderkinderen 0:8d87bc453349 494 goto nullreturn;
ninoderkinderen 0:8d87bc453349 495 }
ninoderkinderen 0:8d87bc453349 496
ninoderkinderen 0:8d87bc453349 497 offset = (ntohs(IPH_OFFSET(fraghdr)) & IP_OFFMASK) * 8;
ninoderkinderen 0:8d87bc453349 498 len = ntohs(IPH_LEN(fraghdr)) - IPH_HL(fraghdr) * 4;
ninoderkinderen 0:8d87bc453349 499
ninoderkinderen 0:8d87bc453349 500 /* Check if we are allowed to enqueue more datagrams. */
ninoderkinderen 0:8d87bc453349 501 clen = pbuf_clen(p);
ninoderkinderen 0:8d87bc453349 502 if ((ip_reass_pbufcount + clen) > IP_REASS_MAX_PBUFS) {
ninoderkinderen 0:8d87bc453349 503 #if IP_REASS_FREE_OLDEST
ninoderkinderen 0:8d87bc453349 504 if (!ip_reass_remove_oldest_datagram(fraghdr, clen) ||
ninoderkinderen 0:8d87bc453349 505 ((ip_reass_pbufcount + clen) > IP_REASS_MAX_PBUFS))
ninoderkinderen 0:8d87bc453349 506 #endif /* IP_REASS_FREE_OLDEST */
ninoderkinderen 0:8d87bc453349 507 {
ninoderkinderen 0:8d87bc453349 508 /* No datagram could be freed and still too many pbufs enqueued */
ninoderkinderen 0:8d87bc453349 509 LWIP_DEBUGF(IP_REASS_DEBUG,("ip_reass: Overflow condition: pbufct=%d, clen=%d, MAX=%d\n",
ninoderkinderen 0:8d87bc453349 510 ip_reass_pbufcount, clen, IP_REASS_MAX_PBUFS));
ninoderkinderen 0:8d87bc453349 511 IPFRAG_STATS_INC(ip_frag.memerr);
ninoderkinderen 0:8d87bc453349 512 /* @todo: send ICMP time exceeded here? */
ninoderkinderen 0:8d87bc453349 513 /* drop this pbuf */
ninoderkinderen 0:8d87bc453349 514 goto nullreturn;
ninoderkinderen 0:8d87bc453349 515 }
ninoderkinderen 0:8d87bc453349 516 }
ninoderkinderen 0:8d87bc453349 517
ninoderkinderen 0:8d87bc453349 518 /* Look for the datagram the fragment belongs to in the current datagram queue,
ninoderkinderen 0:8d87bc453349 519 * remembering the previous in the queue for later dequeueing. */
ninoderkinderen 0:8d87bc453349 520 for (ipr = reassdatagrams; ipr != NULL; ipr = ipr->next) {
ninoderkinderen 0:8d87bc453349 521 /* Check if the incoming fragment matches the one currently present
ninoderkinderen 0:8d87bc453349 522 in the reassembly buffer. If so, we proceed with copying the
ninoderkinderen 0:8d87bc453349 523 fragment into the buffer. */
ninoderkinderen 0:8d87bc453349 524 if (IP_ADDRESSES_AND_ID_MATCH(&ipr->iphdr, fraghdr)) {
ninoderkinderen 0:8d87bc453349 525 LWIP_DEBUGF(IP_REASS_DEBUG, ("ip_reass: matching previous fragment ID=%"X16_F"\n",
ninoderkinderen 0:8d87bc453349 526 ntohs(IPH_ID(fraghdr))));
ninoderkinderen 0:8d87bc453349 527 IPFRAG_STATS_INC(ip_frag.cachehit);
ninoderkinderen 0:8d87bc453349 528 break;
ninoderkinderen 0:8d87bc453349 529 }
ninoderkinderen 0:8d87bc453349 530 ipr_prev = ipr;
ninoderkinderen 0:8d87bc453349 531 }
ninoderkinderen 0:8d87bc453349 532
ninoderkinderen 0:8d87bc453349 533 if (ipr == NULL) {
ninoderkinderen 0:8d87bc453349 534 /* Enqueue a new datagram into the datagram queue */
ninoderkinderen 0:8d87bc453349 535 ipr = ip_reass_enqueue_new_datagram(fraghdr, clen);
ninoderkinderen 0:8d87bc453349 536 /* Bail if unable to enqueue */
ninoderkinderen 0:8d87bc453349 537 if(ipr == NULL) {
ninoderkinderen 0:8d87bc453349 538 goto nullreturn;
ninoderkinderen 0:8d87bc453349 539 }
ninoderkinderen 0:8d87bc453349 540 } else {
ninoderkinderen 0:8d87bc453349 541 if (((ntohs(IPH_OFFSET(fraghdr)) & IP_OFFMASK) == 0) &&
ninoderkinderen 0:8d87bc453349 542 ((ntohs(IPH_OFFSET(&ipr->iphdr)) & IP_OFFMASK) != 0)) {
ninoderkinderen 0:8d87bc453349 543 /* ipr->iphdr is not the header from the first fragment, but fraghdr is
ninoderkinderen 0:8d87bc453349 544 * -> copy fraghdr into ipr->iphdr since we want to have the header
ninoderkinderen 0:8d87bc453349 545 * of the first fragment (for ICMP time exceeded and later, for copying
ninoderkinderen 0:8d87bc453349 546 * all options, if supported)*/
ninoderkinderen 0:8d87bc453349 547 SMEMCPY(&ipr->iphdr, fraghdr, IP_HLEN);
ninoderkinderen 0:8d87bc453349 548 }
ninoderkinderen 0:8d87bc453349 549 }
ninoderkinderen 0:8d87bc453349 550 /* Track the current number of pbufs current 'in-flight', in order to limit
ninoderkinderen 0:8d87bc453349 551 the number of fragments that may be enqueued at any one time */
ninoderkinderen 0:8d87bc453349 552 ip_reass_pbufcount += clen;
ninoderkinderen 0:8d87bc453349 553
ninoderkinderen 0:8d87bc453349 554 /* At this point, we have either created a new entry or pointing
ninoderkinderen 0:8d87bc453349 555 * to an existing one */
ninoderkinderen 0:8d87bc453349 556
ninoderkinderen 0:8d87bc453349 557 /* check for 'no more fragments', and update queue entry*/
ninoderkinderen 0:8d87bc453349 558 if ((IPH_OFFSET(fraghdr) & PP_NTOHS(IP_MF)) == 0) {
ninoderkinderen 0:8d87bc453349 559 ipr->flags |= IP_REASS_FLAG_LASTFRAG;
ninoderkinderen 0:8d87bc453349 560 ipr->datagram_len = offset + len;
ninoderkinderen 0:8d87bc453349 561 LWIP_DEBUGF(IP_REASS_DEBUG,
ninoderkinderen 0:8d87bc453349 562 ("ip_reass: last fragment seen, total len %"S16_F"\n",
ninoderkinderen 0:8d87bc453349 563 ipr->datagram_len));
ninoderkinderen 0:8d87bc453349 564 }
ninoderkinderen 0:8d87bc453349 565 /* find the right place to insert this pbuf */
ninoderkinderen 0:8d87bc453349 566 /* @todo: trim pbufs if fragments are overlapping */
ninoderkinderen 0:8d87bc453349 567 if (ip_reass_chain_frag_into_datagram_and_validate(ipr, p)) {
ninoderkinderen 0:8d87bc453349 568 /* the totally last fragment (flag more fragments = 0) was received at least
ninoderkinderen 0:8d87bc453349 569 * once AND all fragments are received */
ninoderkinderen 0:8d87bc453349 570 ipr->datagram_len += IP_HLEN;
ninoderkinderen 0:8d87bc453349 571
ninoderkinderen 0:8d87bc453349 572 /* save the second pbuf before copying the header over the pointer */
ninoderkinderen 0:8d87bc453349 573 r = ((struct ip_reass_helper*)ipr->p->payload)->next_pbuf;
ninoderkinderen 0:8d87bc453349 574
ninoderkinderen 0:8d87bc453349 575 /* copy the original ip header back to the first pbuf */
ninoderkinderen 0:8d87bc453349 576 fraghdr = (struct ip_hdr*)(ipr->p->payload);
ninoderkinderen 0:8d87bc453349 577 SMEMCPY(fraghdr, &ipr->iphdr, IP_HLEN);
ninoderkinderen 0:8d87bc453349 578 IPH_LEN_SET(fraghdr, htons(ipr->datagram_len));
ninoderkinderen 0:8d87bc453349 579 IPH_OFFSET_SET(fraghdr, 0);
ninoderkinderen 0:8d87bc453349 580 IPH_CHKSUM_SET(fraghdr, 0);
ninoderkinderen 0:8d87bc453349 581 /* @todo: do we need to set calculate the correct checksum? */
ninoderkinderen 0:8d87bc453349 582 IPH_CHKSUM_SET(fraghdr, inet_chksum(fraghdr, IP_HLEN));
ninoderkinderen 0:8d87bc453349 583
ninoderkinderen 0:8d87bc453349 584 p = ipr->p;
ninoderkinderen 0:8d87bc453349 585
ninoderkinderen 0:8d87bc453349 586 /* chain together the pbufs contained within the reass_data list. */
ninoderkinderen 0:8d87bc453349 587 while(r != NULL) {
ninoderkinderen 0:8d87bc453349 588 iprh = (struct ip_reass_helper*)r->payload;
ninoderkinderen 0:8d87bc453349 589
ninoderkinderen 0:8d87bc453349 590 /* hide the ip header for every succeding fragment */
ninoderkinderen 0:8d87bc453349 591 pbuf_header(r, -IP_HLEN);
ninoderkinderen 0:8d87bc453349 592 pbuf_cat(p, r);
ninoderkinderen 0:8d87bc453349 593 r = iprh->next_pbuf;
ninoderkinderen 0:8d87bc453349 594 }
ninoderkinderen 0:8d87bc453349 595 /* release the sources allocate for the fragment queue entry */
ninoderkinderen 0:8d87bc453349 596 ip_reass_dequeue_datagram(ipr, ipr_prev);
ninoderkinderen 0:8d87bc453349 597
ninoderkinderen 0:8d87bc453349 598 /* and adjust the number of pbufs currently queued for reassembly. */
ninoderkinderen 0:8d87bc453349 599 ip_reass_pbufcount -= pbuf_clen(p);
ninoderkinderen 0:8d87bc453349 600
ninoderkinderen 0:8d87bc453349 601 /* Return the pbuf chain */
ninoderkinderen 0:8d87bc453349 602 return p;
ninoderkinderen 0:8d87bc453349 603 }
ninoderkinderen 0:8d87bc453349 604 /* the datagram is not (yet?) reassembled completely */
ninoderkinderen 0:8d87bc453349 605 LWIP_DEBUGF(IP_REASS_DEBUG,("ip_reass_pbufcount: %d out\n", ip_reass_pbufcount));
ninoderkinderen 0:8d87bc453349 606 return NULL;
ninoderkinderen 0:8d87bc453349 607
ninoderkinderen 0:8d87bc453349 608 nullreturn:
ninoderkinderen 0:8d87bc453349 609 LWIP_DEBUGF(IP_REASS_DEBUG,("ip_reass: nullreturn\n"));
ninoderkinderen 0:8d87bc453349 610 IPFRAG_STATS_INC(ip_frag.drop);
ninoderkinderen 0:8d87bc453349 611 pbuf_free(p);
ninoderkinderen 0:8d87bc453349 612 return NULL;
ninoderkinderen 0:8d87bc453349 613 }
ninoderkinderen 0:8d87bc453349 614 #endif /* IP_REASSEMBLY */
ninoderkinderen 0:8d87bc453349 615
ninoderkinderen 0:8d87bc453349 616 #if IP_FRAG
ninoderkinderen 0:8d87bc453349 617 #if IP_FRAG_USES_STATIC_BUF
ninoderkinderen 0:8d87bc453349 618 static u8_t buf[LWIP_MEM_ALIGN_SIZE(IP_FRAG_MAX_MTU + MEM_ALIGNMENT - 1)];
ninoderkinderen 0:8d87bc453349 619 #else /* IP_FRAG_USES_STATIC_BUF */
ninoderkinderen 0:8d87bc453349 620
ninoderkinderen 0:8d87bc453349 621 #if !LWIP_NETIF_TX_SINGLE_PBUF
ninoderkinderen 0:8d87bc453349 622 /** Allocate a new struct pbuf_custom_ref */
ninoderkinderen 0:8d87bc453349 623 static struct pbuf_custom_ref*
ninoderkinderen 0:8d87bc453349 624 ip_frag_alloc_pbuf_custom_ref(void)
ninoderkinderen 0:8d87bc453349 625 {
ninoderkinderen 0:8d87bc453349 626 return (struct pbuf_custom_ref*)memp_malloc(MEMP_FRAG_PBUF);
ninoderkinderen 0:8d87bc453349 627 }
ninoderkinderen 0:8d87bc453349 628
ninoderkinderen 0:8d87bc453349 629 /** Free a struct pbuf_custom_ref */
ninoderkinderen 0:8d87bc453349 630 static void
ninoderkinderen 0:8d87bc453349 631 ip_frag_free_pbuf_custom_ref(struct pbuf_custom_ref* p)
ninoderkinderen 0:8d87bc453349 632 {
ninoderkinderen 0:8d87bc453349 633 LWIP_ASSERT("p != NULL", p != NULL);
ninoderkinderen 0:8d87bc453349 634 memp_free(MEMP_FRAG_PBUF, p);
ninoderkinderen 0:8d87bc453349 635 }
ninoderkinderen 0:8d87bc453349 636
ninoderkinderen 0:8d87bc453349 637 /** Free-callback function to free a 'struct pbuf_custom_ref', called by
ninoderkinderen 0:8d87bc453349 638 * pbuf_free. */
ninoderkinderen 0:8d87bc453349 639 static void
ninoderkinderen 0:8d87bc453349 640 ipfrag_free_pbuf_custom(struct pbuf *p)
ninoderkinderen 0:8d87bc453349 641 {
ninoderkinderen 0:8d87bc453349 642 struct pbuf_custom_ref *pcr = (struct pbuf_custom_ref*)p;
ninoderkinderen 0:8d87bc453349 643 LWIP_ASSERT("pcr != NULL", pcr != NULL);
ninoderkinderen 0:8d87bc453349 644 LWIP_ASSERT("pcr == p", (void*)pcr == (void*)p);
ninoderkinderen 0:8d87bc453349 645 if (pcr->original != NULL) {
ninoderkinderen 0:8d87bc453349 646 pbuf_free(pcr->original);
ninoderkinderen 0:8d87bc453349 647 }
ninoderkinderen 0:8d87bc453349 648 ip_frag_free_pbuf_custom_ref(pcr);
ninoderkinderen 0:8d87bc453349 649 }
ninoderkinderen 0:8d87bc453349 650 #endif /* !LWIP_NETIF_TX_SINGLE_PBUF */
ninoderkinderen 0:8d87bc453349 651 #endif /* IP_FRAG_USES_STATIC_BUF */
ninoderkinderen 0:8d87bc453349 652
ninoderkinderen 0:8d87bc453349 653 /**
ninoderkinderen 0:8d87bc453349 654 * Fragment an IP datagram if too large for the netif.
ninoderkinderen 0:8d87bc453349 655 *
ninoderkinderen 0:8d87bc453349 656 * Chop the datagram in MTU sized chunks and send them in order
ninoderkinderen 0:8d87bc453349 657 * by using a fixed size static memory buffer (PBUF_REF) or
ninoderkinderen 0:8d87bc453349 658 * point PBUF_REFs into p (depending on IP_FRAG_USES_STATIC_BUF).
ninoderkinderen 0:8d87bc453349 659 *
ninoderkinderen 0:8d87bc453349 660 * @param p ip packet to send
ninoderkinderen 0:8d87bc453349 661 * @param netif the netif on which to send
ninoderkinderen 0:8d87bc453349 662 * @param dest destination ip address to which to send
ninoderkinderen 0:8d87bc453349 663 *
ninoderkinderen 0:8d87bc453349 664 * @return ERR_OK if sent successfully, err_t otherwise
ninoderkinderen 0:8d87bc453349 665 */
ninoderkinderen 0:8d87bc453349 666 err_t
ninoderkinderen 0:8d87bc453349 667 ip_frag(struct pbuf *p, struct netif *netif, ip_addr_t *dest)
ninoderkinderen 0:8d87bc453349 668 {
ninoderkinderen 0:8d87bc453349 669 struct pbuf *rambuf;
ninoderkinderen 0:8d87bc453349 670 #if IP_FRAG_USES_STATIC_BUF
ninoderkinderen 0:8d87bc453349 671 struct pbuf *header;
ninoderkinderen 0:8d87bc453349 672 #else
ninoderkinderen 0:8d87bc453349 673 #if !LWIP_NETIF_TX_SINGLE_PBUF
ninoderkinderen 0:8d87bc453349 674 struct pbuf *newpbuf;
ninoderkinderen 0:8d87bc453349 675 #endif
ninoderkinderen 0:8d87bc453349 676 struct ip_hdr *original_iphdr;
ninoderkinderen 0:8d87bc453349 677 #endif
ninoderkinderen 0:8d87bc453349 678 struct ip_hdr *iphdr;
ninoderkinderen 0:8d87bc453349 679 u16_t nfb;
ninoderkinderen 0:8d87bc453349 680 u16_t left, cop;
ninoderkinderen 0:8d87bc453349 681 u16_t mtu = netif->mtu;
ninoderkinderen 0:8d87bc453349 682 u16_t ofo, omf;
ninoderkinderen 0:8d87bc453349 683 u16_t last;
ninoderkinderen 0:8d87bc453349 684 u16_t poff = IP_HLEN;
ninoderkinderen 0:8d87bc453349 685 u16_t tmp;
ninoderkinderen 0:8d87bc453349 686 #if !IP_FRAG_USES_STATIC_BUF && !LWIP_NETIF_TX_SINGLE_PBUF
ninoderkinderen 0:8d87bc453349 687 u16_t newpbuflen = 0;
ninoderkinderen 0:8d87bc453349 688 u16_t left_to_copy;
ninoderkinderen 0:8d87bc453349 689 #endif
ninoderkinderen 0:8d87bc453349 690
ninoderkinderen 0:8d87bc453349 691 /* Get a RAM based MTU sized pbuf */
ninoderkinderen 0:8d87bc453349 692 #if IP_FRAG_USES_STATIC_BUF
ninoderkinderen 0:8d87bc453349 693 /* When using a static buffer, we use a PBUF_REF, which we will
ninoderkinderen 0:8d87bc453349 694 * use to reference the packet (without link header).
ninoderkinderen 0:8d87bc453349 695 * Layer and length is irrelevant.
ninoderkinderen 0:8d87bc453349 696 */
ninoderkinderen 0:8d87bc453349 697 rambuf = pbuf_alloc(PBUF_LINK, 0, PBUF_REF);
ninoderkinderen 0:8d87bc453349 698 if (rambuf == NULL) {
ninoderkinderen 0:8d87bc453349 699 LWIP_DEBUGF(IP_REASS_DEBUG, ("ip_frag: pbuf_alloc(PBUF_LINK, 0, PBUF_REF) failed\n"));
ninoderkinderen 0:8d87bc453349 700 return ERR_MEM;
ninoderkinderen 0:8d87bc453349 701 }
ninoderkinderen 0:8d87bc453349 702 rambuf->tot_len = rambuf->len = mtu;
ninoderkinderen 0:8d87bc453349 703 rambuf->payload = LWIP_MEM_ALIGN((void *)buf);
ninoderkinderen 0:8d87bc453349 704
ninoderkinderen 0:8d87bc453349 705 /* Copy the IP header in it */
ninoderkinderen 0:8d87bc453349 706 iphdr = (struct ip_hdr *)rambuf->payload;
ninoderkinderen 0:8d87bc453349 707 SMEMCPY(iphdr, p->payload, IP_HLEN);
ninoderkinderen 0:8d87bc453349 708 #else /* IP_FRAG_USES_STATIC_BUF */
ninoderkinderen 0:8d87bc453349 709 original_iphdr = (struct ip_hdr *)p->payload;
ninoderkinderen 0:8d87bc453349 710 iphdr = original_iphdr;
ninoderkinderen 0:8d87bc453349 711 #endif /* IP_FRAG_USES_STATIC_BUF */
ninoderkinderen 0:8d87bc453349 712
ninoderkinderen 0:8d87bc453349 713 /* Save original offset */
ninoderkinderen 0:8d87bc453349 714 tmp = ntohs(IPH_OFFSET(iphdr));
ninoderkinderen 0:8d87bc453349 715 ofo = tmp & IP_OFFMASK;
ninoderkinderen 0:8d87bc453349 716 omf = tmp & IP_MF;
ninoderkinderen 0:8d87bc453349 717
ninoderkinderen 0:8d87bc453349 718 left = p->tot_len - IP_HLEN;
ninoderkinderen 0:8d87bc453349 719
ninoderkinderen 0:8d87bc453349 720 nfb = (mtu - IP_HLEN) / 8;
ninoderkinderen 0:8d87bc453349 721
ninoderkinderen 0:8d87bc453349 722 while (left) {
ninoderkinderen 0:8d87bc453349 723 last = (left <= mtu - IP_HLEN);
ninoderkinderen 0:8d87bc453349 724
ninoderkinderen 0:8d87bc453349 725 /* Set new offset and MF flag */
ninoderkinderen 0:8d87bc453349 726 tmp = omf | (IP_OFFMASK & (ofo));
ninoderkinderen 0:8d87bc453349 727 if (!last) {
ninoderkinderen 0:8d87bc453349 728 tmp = tmp | IP_MF;
ninoderkinderen 0:8d87bc453349 729 }
ninoderkinderen 0:8d87bc453349 730
ninoderkinderen 0:8d87bc453349 731 /* Fill this fragment */
ninoderkinderen 0:8d87bc453349 732 cop = last ? left : nfb * 8;
ninoderkinderen 0:8d87bc453349 733
ninoderkinderen 0:8d87bc453349 734 #if IP_FRAG_USES_STATIC_BUF
ninoderkinderen 0:8d87bc453349 735 poff += pbuf_copy_partial(p, (u8_t*)iphdr + IP_HLEN, cop, poff);
ninoderkinderen 0:8d87bc453349 736 #else /* IP_FRAG_USES_STATIC_BUF */
ninoderkinderen 0:8d87bc453349 737 #if LWIP_NETIF_TX_SINGLE_PBUF
ninoderkinderen 0:8d87bc453349 738 rambuf = pbuf_alloc(PBUF_IP, cop, PBUF_RAM);
ninoderkinderen 0:8d87bc453349 739 if (rambuf == NULL) {
ninoderkinderen 0:8d87bc453349 740 return ERR_MEM;
ninoderkinderen 0:8d87bc453349 741 }
ninoderkinderen 0:8d87bc453349 742 LWIP_ASSERT("this needs a pbuf in one piece!",
ninoderkinderen 0:8d87bc453349 743 (rambuf->len == rambuf->tot_len) && (rambuf->next == NULL));
ninoderkinderen 0:8d87bc453349 744 poff += pbuf_copy_partial(p, rambuf->payload, cop, poff);
ninoderkinderen 0:8d87bc453349 745 /* make room for the IP header */
ninoderkinderen 0:8d87bc453349 746 if(pbuf_header(rambuf, IP_HLEN)) {
ninoderkinderen 0:8d87bc453349 747 pbuf_free(rambuf);
ninoderkinderen 0:8d87bc453349 748 return ERR_MEM;
ninoderkinderen 0:8d87bc453349 749 }
ninoderkinderen 0:8d87bc453349 750 /* fill in the IP header */
ninoderkinderen 0:8d87bc453349 751 SMEMCPY(rambuf->payload, original_iphdr, IP_HLEN);
ninoderkinderen 0:8d87bc453349 752 iphdr = rambuf->payload;
ninoderkinderen 0:8d87bc453349 753 #else /* LWIP_NETIF_TX_SINGLE_PBUF */
ninoderkinderen 0:8d87bc453349 754 /* When not using a static buffer, create a chain of pbufs.
ninoderkinderen 0:8d87bc453349 755 * The first will be a PBUF_RAM holding the link and IP header.
ninoderkinderen 0:8d87bc453349 756 * The rest will be PBUF_REFs mirroring the pbuf chain to be fragged,
ninoderkinderen 0:8d87bc453349 757 * but limited to the size of an mtu.
ninoderkinderen 0:8d87bc453349 758 */
ninoderkinderen 0:8d87bc453349 759 rambuf = pbuf_alloc(PBUF_LINK, IP_HLEN, PBUF_RAM);
ninoderkinderen 0:8d87bc453349 760 if (rambuf == NULL) {
ninoderkinderen 0:8d87bc453349 761 return ERR_MEM;
ninoderkinderen 0:8d87bc453349 762 }
ninoderkinderen 0:8d87bc453349 763 LWIP_ASSERT("this needs a pbuf in one piece!",
ninoderkinderen 0:8d87bc453349 764 (p->len >= (IP_HLEN)));
ninoderkinderen 0:8d87bc453349 765 SMEMCPY(rambuf->payload, original_iphdr, IP_HLEN);
ninoderkinderen 0:8d87bc453349 766 iphdr = (struct ip_hdr *)rambuf->payload;
ninoderkinderen 0:8d87bc453349 767
ninoderkinderen 0:8d87bc453349 768 /* Can just adjust p directly for needed offset. */
ninoderkinderen 0:8d87bc453349 769 p->payload = (u8_t *)p->payload + poff;
ninoderkinderen 0:8d87bc453349 770 p->len -= poff;
ninoderkinderen 0:8d87bc453349 771
ninoderkinderen 0:8d87bc453349 772 left_to_copy = cop;
ninoderkinderen 0:8d87bc453349 773 while (left_to_copy) {
ninoderkinderen 0:8d87bc453349 774 struct pbuf_custom_ref *pcr;
ninoderkinderen 0:8d87bc453349 775 newpbuflen = (left_to_copy < p->len) ? left_to_copy : p->len;
ninoderkinderen 0:8d87bc453349 776 /* Is this pbuf already empty? */
ninoderkinderen 0:8d87bc453349 777 if (!newpbuflen) {
ninoderkinderen 0:8d87bc453349 778 p = p->next;
ninoderkinderen 0:8d87bc453349 779 continue;
ninoderkinderen 0:8d87bc453349 780 }
ninoderkinderen 0:8d87bc453349 781 pcr = ip_frag_alloc_pbuf_custom_ref();
ninoderkinderen 0:8d87bc453349 782 if (pcr == NULL) {
ninoderkinderen 0:8d87bc453349 783 pbuf_free(rambuf);
ninoderkinderen 0:8d87bc453349 784 return ERR_MEM;
ninoderkinderen 0:8d87bc453349 785 }
ninoderkinderen 0:8d87bc453349 786 /* Mirror this pbuf, although we might not need all of it. */
ninoderkinderen 0:8d87bc453349 787 newpbuf = pbuf_alloced_custom(PBUF_RAW, newpbuflen, PBUF_REF, &pcr->pc, p->payload, newpbuflen);
ninoderkinderen 0:8d87bc453349 788 if (newpbuf == NULL) {
ninoderkinderen 0:8d87bc453349 789 ip_frag_free_pbuf_custom_ref(pcr);
ninoderkinderen 0:8d87bc453349 790 pbuf_free(rambuf);
ninoderkinderen 0:8d87bc453349 791 return ERR_MEM;
ninoderkinderen 0:8d87bc453349 792 }
ninoderkinderen 0:8d87bc453349 793 pbuf_ref(p);
ninoderkinderen 0:8d87bc453349 794 pcr->original = p;
ninoderkinderen 0:8d87bc453349 795 pcr->pc.custom_free_function = ipfrag_free_pbuf_custom;
ninoderkinderen 0:8d87bc453349 796
ninoderkinderen 0:8d87bc453349 797 /* Add it to end of rambuf's chain, but using pbuf_cat, not pbuf_chain
ninoderkinderen 0:8d87bc453349 798 * so that it is removed when pbuf_dechain is later called on rambuf.
ninoderkinderen 0:8d87bc453349 799 */
ninoderkinderen 0:8d87bc453349 800 pbuf_cat(rambuf, newpbuf);
ninoderkinderen 0:8d87bc453349 801 left_to_copy -= newpbuflen;
ninoderkinderen 0:8d87bc453349 802 if (left_to_copy) {
ninoderkinderen 0:8d87bc453349 803 p = p->next;
ninoderkinderen 0:8d87bc453349 804 }
ninoderkinderen 0:8d87bc453349 805 }
ninoderkinderen 0:8d87bc453349 806 poff = newpbuflen;
ninoderkinderen 0:8d87bc453349 807 #endif /* LWIP_NETIF_TX_SINGLE_PBUF */
ninoderkinderen 0:8d87bc453349 808 #endif /* IP_FRAG_USES_STATIC_BUF */
ninoderkinderen 0:8d87bc453349 809
ninoderkinderen 0:8d87bc453349 810 /* Correct header */
ninoderkinderen 0:8d87bc453349 811 IPH_OFFSET_SET(iphdr, htons(tmp));
ninoderkinderen 0:8d87bc453349 812 IPH_LEN_SET(iphdr, htons(cop + IP_HLEN));
ninoderkinderen 0:8d87bc453349 813 IPH_CHKSUM_SET(iphdr, 0);
ninoderkinderen 0:8d87bc453349 814 IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, IP_HLEN));
ninoderkinderen 0:8d87bc453349 815
ninoderkinderen 0:8d87bc453349 816 #if IP_FRAG_USES_STATIC_BUF
ninoderkinderen 0:8d87bc453349 817 if (last) {
ninoderkinderen 0:8d87bc453349 818 pbuf_realloc(rambuf, left + IP_HLEN);
ninoderkinderen 0:8d87bc453349 819 }
ninoderkinderen 0:8d87bc453349 820
ninoderkinderen 0:8d87bc453349 821 /* This part is ugly: we alloc a RAM based pbuf for
ninoderkinderen 0:8d87bc453349 822 * the link level header for each chunk and then
ninoderkinderen 0:8d87bc453349 823 * free it.A PBUF_ROM style pbuf for which pbuf_header
ninoderkinderen 0:8d87bc453349 824 * worked would make things simpler.
ninoderkinderen 0:8d87bc453349 825 */
ninoderkinderen 0:8d87bc453349 826 header = pbuf_alloc(PBUF_LINK, 0, PBUF_RAM);
ninoderkinderen 0:8d87bc453349 827 if (header != NULL) {
ninoderkinderen 0:8d87bc453349 828 pbuf_chain(header, rambuf);
ninoderkinderen 0:8d87bc453349 829 netif->output(netif, header, dest);
ninoderkinderen 0:8d87bc453349 830 IPFRAG_STATS_INC(ip_frag.xmit);
ninoderkinderen 0:8d87bc453349 831 snmp_inc_ipfragcreates();
ninoderkinderen 0:8d87bc453349 832 pbuf_free(header);
ninoderkinderen 0:8d87bc453349 833 } else {
ninoderkinderen 0:8d87bc453349 834 LWIP_DEBUGF(IP_REASS_DEBUG, ("ip_frag: pbuf_alloc() for header failed\n"));
ninoderkinderen 0:8d87bc453349 835 pbuf_free(rambuf);
ninoderkinderen 0:8d87bc453349 836 return ERR_MEM;
ninoderkinderen 0:8d87bc453349 837 }
ninoderkinderen 0:8d87bc453349 838 #else /* IP_FRAG_USES_STATIC_BUF */
ninoderkinderen 0:8d87bc453349 839 /* No need for separate header pbuf - we allowed room for it in rambuf
ninoderkinderen 0:8d87bc453349 840 * when allocated.
ninoderkinderen 0:8d87bc453349 841 */
ninoderkinderen 0:8d87bc453349 842 netif->output(netif, rambuf, dest);
ninoderkinderen 0:8d87bc453349 843 IPFRAG_STATS_INC(ip_frag.xmit);
ninoderkinderen 0:8d87bc453349 844
ninoderkinderen 0:8d87bc453349 845 /* Unfortunately we can't reuse rambuf - the hardware may still be
ninoderkinderen 0:8d87bc453349 846 * using the buffer. Instead we free it (and the ensuing chain) and
ninoderkinderen 0:8d87bc453349 847 * recreate it next time round the loop. If we're lucky the hardware
ninoderkinderen 0:8d87bc453349 848 * will have already sent the packet, the free will really free, and
ninoderkinderen 0:8d87bc453349 849 * there will be zero memory penalty.
ninoderkinderen 0:8d87bc453349 850 */
ninoderkinderen 0:8d87bc453349 851
ninoderkinderen 0:8d87bc453349 852 pbuf_free(rambuf);
ninoderkinderen 0:8d87bc453349 853 #endif /* IP_FRAG_USES_STATIC_BUF */
ninoderkinderen 0:8d87bc453349 854 left -= cop;
ninoderkinderen 0:8d87bc453349 855 ofo += nfb;
ninoderkinderen 0:8d87bc453349 856 }
ninoderkinderen 0:8d87bc453349 857 #if IP_FRAG_USES_STATIC_BUF
ninoderkinderen 0:8d87bc453349 858 pbuf_free(rambuf);
ninoderkinderen 0:8d87bc453349 859 #endif /* IP_FRAG_USES_STATIC_BUF */
ninoderkinderen 0:8d87bc453349 860 snmp_inc_ipfragoks();
ninoderkinderen 0:8d87bc453349 861 return ERR_OK;
ninoderkinderen 0:8d87bc453349 862 }
ninoderkinderen 0:8d87bc453349 863 #endif /* IP_FRAG */