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NetServices/lwip/core/ipv4/ip_frag.c@0:05ccbd4f84f1, 2013-12-02 (annotated)

Committer:
hendrikvincent
Date:
Mon Dec 02 09:01:23 2013 +0000
Revision:
0:05ccbd4f84f1
eerste programma;

Who changed what in which revision?

UserRevisionLine numberNew contents of line
hendrikvincent 0:05ccbd4f84f1 1 /**
hendrikvincent 0:05ccbd4f84f1 2 * @file
hendrikvincent 0:05ccbd4f84f1 3 * This is the IPv4 packet segmentation and reassembly implementation.
hendrikvincent 0:05ccbd4f84f1 4 *
hendrikvincent 0:05ccbd4f84f1 5 */
hendrikvincent 0:05ccbd4f84f1 6
hendrikvincent 0:05ccbd4f84f1 7 /*
hendrikvincent 0:05ccbd4f84f1 8 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
hendrikvincent 0:05ccbd4f84f1 9 * All rights reserved.
hendrikvincent 0:05ccbd4f84f1 10 *
hendrikvincent 0:05ccbd4f84f1 11 * Redistribution and use in source and binary forms, with or without modification,
hendrikvincent 0:05ccbd4f84f1 12 * are permitted provided that the following conditions are met:
hendrikvincent 0:05ccbd4f84f1 13 *
hendrikvincent 0:05ccbd4f84f1 14 * 1. Redistributions of source code must retain the above copyright notice,
hendrikvincent 0:05ccbd4f84f1 15 * this list of conditions and the following disclaimer.
hendrikvincent 0:05ccbd4f84f1 16 * 2. Redistributions in binary form must reproduce the above copyright notice,
hendrikvincent 0:05ccbd4f84f1 17 * this list of conditions and the following disclaimer in the documentation
hendrikvincent 0:05ccbd4f84f1 18 * and/or other materials provided with the distribution.
hendrikvincent 0:05ccbd4f84f1 19 * 3. The name of the author may not be used to endorse or promote products
hendrikvincent 0:05ccbd4f84f1 20 * derived from this software without specific prior written permission.
hendrikvincent 0:05ccbd4f84f1 21 *
hendrikvincent 0:05ccbd4f84f1 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
hendrikvincent 0:05ccbd4f84f1 23 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
hendrikvincent 0:05ccbd4f84f1 24 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
hendrikvincent 0:05ccbd4f84f1 25 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
hendrikvincent 0:05ccbd4f84f1 26 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
hendrikvincent 0:05ccbd4f84f1 27 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
hendrikvincent 0:05ccbd4f84f1 28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
hendrikvincent 0:05ccbd4f84f1 29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
hendrikvincent 0:05ccbd4f84f1 30 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
hendrikvincent 0:05ccbd4f84f1 31 * OF SUCH DAMAGE.
hendrikvincent 0:05ccbd4f84f1 32 *
hendrikvincent 0:05ccbd4f84f1 33 * This file is part of the lwIP TCP/IP stack.
hendrikvincent 0:05ccbd4f84f1 34 *
hendrikvincent 0:05ccbd4f84f1 35 * Author: Jani Monoses <jani@iv.ro>
hendrikvincent 0:05ccbd4f84f1 36 * Simon Goldschmidt
hendrikvincent 0:05ccbd4f84f1 37 * original reassembly code by Adam Dunkels <adam@sics.se>
hendrikvincent 0:05ccbd4f84f1 38 *
hendrikvincent 0:05ccbd4f84f1 39 */
hendrikvincent 0:05ccbd4f84f1 40
hendrikvincent 0:05ccbd4f84f1 41 #include "lwip/opt.h"
hendrikvincent 0:05ccbd4f84f1 42 #include "lwip/ip_frag.h"
hendrikvincent 0:05ccbd4f84f1 43 #include "lwip/def.h"
hendrikvincent 0:05ccbd4f84f1 44 #include "lwip/inet_chksum.h"
hendrikvincent 0:05ccbd4f84f1 45 #include "lwip/netif.h"
hendrikvincent 0:05ccbd4f84f1 46 #include "lwip/snmp.h"
hendrikvincent 0:05ccbd4f84f1 47 #include "lwip/stats.h"
hendrikvincent 0:05ccbd4f84f1 48 #include "lwip/icmp.h"
hendrikvincent 0:05ccbd4f84f1 49
hendrikvincent 0:05ccbd4f84f1 50 #include <string.h>
hendrikvincent 0:05ccbd4f84f1 51
hendrikvincent 0:05ccbd4f84f1 52 #if IP_REASSEMBLY
hendrikvincent 0:05ccbd4f84f1 53 /**
hendrikvincent 0:05ccbd4f84f1 54 * The IP reassembly code currently has the following limitations:
hendrikvincent 0:05ccbd4f84f1 55 * - IP header options are not supported
hendrikvincent 0:05ccbd4f84f1 56 * - fragments must not overlap (e.g. due to different routes),
hendrikvincent 0:05ccbd4f84f1 57 * currently, overlapping or duplicate fragments are thrown away
hendrikvincent 0:05ccbd4f84f1 58 * if IP_REASS_CHECK_OVERLAP=1 (the default)!
hendrikvincent 0:05ccbd4f84f1 59 *
hendrikvincent 0:05ccbd4f84f1 60 * @todo: work with IP header options
hendrikvincent 0:05ccbd4f84f1 61 */
hendrikvincent 0:05ccbd4f84f1 62
hendrikvincent 0:05ccbd4f84f1 63 /** Setting this to 0, you can turn off checking the fragments for overlapping
hendrikvincent 0:05ccbd4f84f1 64 * regions. The code gets a little smaller. Only use this if you know that
hendrikvincent 0:05ccbd4f84f1 65 * overlapping won't occur on your network! */
hendrikvincent 0:05ccbd4f84f1 66 #ifndef IP_REASS_CHECK_OVERLAP
hendrikvincent 0:05ccbd4f84f1 67 #define IP_REASS_CHECK_OVERLAP 1
hendrikvincent 0:05ccbd4f84f1 68 #endif /* IP_REASS_CHECK_OVERLAP */
hendrikvincent 0:05ccbd4f84f1 69
hendrikvincent 0:05ccbd4f84f1 70 /** Set to 0 to prevent freeing the oldest datagram when the reassembly buffer is
hendrikvincent 0:05ccbd4f84f1 71 * full (IP_REASS_MAX_PBUFS pbufs are enqueued). The code gets a little smaller.
hendrikvincent 0:05ccbd4f84f1 72 * Datagrams will be freed by timeout only. Especially useful when MEMP_NUM_REASSDATA
hendrikvincent 0:05ccbd4f84f1 73 * is set to 1, so one datagram can be reassembled at a time, only. */
hendrikvincent 0:05ccbd4f84f1 74 #ifndef IP_REASS_FREE_OLDEST
hendrikvincent 0:05ccbd4f84f1 75 #define IP_REASS_FREE_OLDEST 1
hendrikvincent 0:05ccbd4f84f1 76 #endif /* IP_REASS_FREE_OLDEST */
hendrikvincent 0:05ccbd4f84f1 77
hendrikvincent 0:05ccbd4f84f1 78 #define IP_REASS_FLAG_LASTFRAG 0x01
hendrikvincent 0:05ccbd4f84f1 79
hendrikvincent 0:05ccbd4f84f1 80 /** This is a helper struct which holds the starting
hendrikvincent 0:05ccbd4f84f1 81 * offset and the ending offset of this fragment to
hendrikvincent 0:05ccbd4f84f1 82 * easily chain the fragments.
hendrikvincent 0:05ccbd4f84f1 83 * It has the same packing requirements as the IP header, since it replaces
hendrikvincent 0:05ccbd4f84f1 84 * the IP header in memory in incoming fragments (after copying it) to keep
hendrikvincent 0:05ccbd4f84f1 85 * track of the various fragments. (-> If the IP header doesn't need packing,
hendrikvincent 0:05ccbd4f84f1 86 * this struct doesn't need packing, too.)
hendrikvincent 0:05ccbd4f84f1 87 */
hendrikvincent 0:05ccbd4f84f1 88 #ifdef PACK_STRUCT_USE_INCLUDES
hendrikvincent 0:05ccbd4f84f1 89 # include "arch/bpstruct.h"
hendrikvincent 0:05ccbd4f84f1 90 #endif
hendrikvincent 0:05ccbd4f84f1 91 PACK_STRUCT_BEGIN
hendrikvincent 0:05ccbd4f84f1 92 struct ip_reass_helper {
hendrikvincent 0:05ccbd4f84f1 93 PACK_STRUCT_FIELD(struct pbuf *next_pbuf);
hendrikvincent 0:05ccbd4f84f1 94 PACK_STRUCT_FIELD(u16_t start);
hendrikvincent 0:05ccbd4f84f1 95 PACK_STRUCT_FIELD(u16_t end);
hendrikvincent 0:05ccbd4f84f1 96 } PACK_STRUCT_STRUCT;
hendrikvincent 0:05ccbd4f84f1 97 PACK_STRUCT_END
hendrikvincent 0:05ccbd4f84f1 98 #ifdef PACK_STRUCT_USE_INCLUDES
hendrikvincent 0:05ccbd4f84f1 99 # include "arch/epstruct.h"
hendrikvincent 0:05ccbd4f84f1 100 #endif
hendrikvincent 0:05ccbd4f84f1 101
hendrikvincent 0:05ccbd4f84f1 102 #define IP_ADDRESSES_AND_ID_MATCH(iphdrA, iphdrB) \
hendrikvincent 0:05ccbd4f84f1 103 (ip_addr_cmp(&(iphdrA)->src, &(iphdrB)->src) && \
hendrikvincent 0:05ccbd4f84f1 104 ip_addr_cmp(&(iphdrA)->dest, &(iphdrB)->dest) && \
hendrikvincent 0:05ccbd4f84f1 105 IPH_ID(iphdrA) == IPH_ID(iphdrB)) ? 1 : 0
hendrikvincent 0:05ccbd4f84f1 106
hendrikvincent 0:05ccbd4f84f1 107 /* global variables */
hendrikvincent 0:05ccbd4f84f1 108 static struct ip_reassdata *reassdatagrams;
hendrikvincent 0:05ccbd4f84f1 109 static u16_t ip_reass_pbufcount;
hendrikvincent 0:05ccbd4f84f1 110
hendrikvincent 0:05ccbd4f84f1 111 /* function prototypes */
hendrikvincent 0:05ccbd4f84f1 112 static void ip_reass_dequeue_datagram(struct ip_reassdata *ipr, struct ip_reassdata *prev);
hendrikvincent 0:05ccbd4f84f1 113 static int ip_reass_free_complete_datagram(struct ip_reassdata *ipr, struct ip_reassdata *prev);
hendrikvincent 0:05ccbd4f84f1 114
hendrikvincent 0:05ccbd4f84f1 115 /**
hendrikvincent 0:05ccbd4f84f1 116 * Reassembly timer base function
hendrikvincent 0:05ccbd4f84f1 117 * for both NO_SYS == 0 and 1 (!).
hendrikvincent 0:05ccbd4f84f1 118 *
hendrikvincent 0:05ccbd4f84f1 119 * Should be called every 1000 msec (defined by IP_TMR_INTERVAL).
hendrikvincent 0:05ccbd4f84f1 120 */
hendrikvincent 0:05ccbd4f84f1 121 void
hendrikvincent 0:05ccbd4f84f1 122 ip_reass_tmr(void)
hendrikvincent 0:05ccbd4f84f1 123 {
hendrikvincent 0:05ccbd4f84f1 124 struct ip_reassdata *r, *prev = NULL;
hendrikvincent 0:05ccbd4f84f1 125
hendrikvincent 0:05ccbd4f84f1 126 r = reassdatagrams;
hendrikvincent 0:05ccbd4f84f1 127 while (r != NULL) {
hendrikvincent 0:05ccbd4f84f1 128 /* Decrement the timer. Once it reaches 0,
hendrikvincent 0:05ccbd4f84f1 129 * clean up the incomplete fragment assembly */
hendrikvincent 0:05ccbd4f84f1 130 if (r->timer > 0) {
hendrikvincent 0:05ccbd4f84f1 131 r->timer--;
hendrikvincent 0:05ccbd4f84f1 132 LWIP_DEBUGF(IP_REASS_DEBUG, ("ip_reass_tmr: timer dec %"U16_F"\n",(u16_t)r->timer));
hendrikvincent 0:05ccbd4f84f1 133 prev = r;
hendrikvincent 0:05ccbd4f84f1 134 r = r->next;
hendrikvincent 0:05ccbd4f84f1 135 } else {
hendrikvincent 0:05ccbd4f84f1 136 /* reassembly timed out */
hendrikvincent 0:05ccbd4f84f1 137 struct ip_reassdata *tmp;
hendrikvincent 0:05ccbd4f84f1 138 LWIP_DEBUGF(IP_REASS_DEBUG, ("ip_reass_tmr: timer timed out\n"));
hendrikvincent 0:05ccbd4f84f1 139 tmp = r;
hendrikvincent 0:05ccbd4f84f1 140 /* get the next pointer before freeing */
hendrikvincent 0:05ccbd4f84f1 141 r = r->next;
hendrikvincent 0:05ccbd4f84f1 142 /* free the helper struct and all enqueued pbufs */
hendrikvincent 0:05ccbd4f84f1 143 ip_reass_free_complete_datagram(tmp, prev);
hendrikvincent 0:05ccbd4f84f1 144 }
hendrikvincent 0:05ccbd4f84f1 145 }
hendrikvincent 0:05ccbd4f84f1 146 }
hendrikvincent 0:05ccbd4f84f1 147
hendrikvincent 0:05ccbd4f84f1 148 /**
hendrikvincent 0:05ccbd4f84f1 149 * Free a datagram (struct ip_reassdata) and all its pbufs.
hendrikvincent 0:05ccbd4f84f1 150 * Updates the total count of enqueued pbufs (ip_reass_pbufcount),
hendrikvincent 0:05ccbd4f84f1 151 * SNMP counters and sends an ICMP time exceeded packet.
hendrikvincent 0:05ccbd4f84f1 152 *
hendrikvincent 0:05ccbd4f84f1 153 * @param ipr datagram to free
hendrikvincent 0:05ccbd4f84f1 154 * @param prev the previous datagram in the linked list
hendrikvincent 0:05ccbd4f84f1 155 * @return the number of pbufs freed
hendrikvincent 0:05ccbd4f84f1 156 */
hendrikvincent 0:05ccbd4f84f1 157 static int
hendrikvincent 0:05ccbd4f84f1 158 ip_reass_free_complete_datagram(struct ip_reassdata *ipr, struct ip_reassdata *prev)
hendrikvincent 0:05ccbd4f84f1 159 {
hendrikvincent 0:05ccbd4f84f1 160 u16_t pbufs_freed = 0;
hendrikvincent 0:05ccbd4f84f1 161 u8_t clen;
hendrikvincent 0:05ccbd4f84f1 162 struct pbuf *p;
hendrikvincent 0:05ccbd4f84f1 163 struct ip_reass_helper *iprh;
hendrikvincent 0:05ccbd4f84f1 164
hendrikvincent 0:05ccbd4f84f1 165 LWIP_ASSERT("prev != ipr", prev != ipr);
hendrikvincent 0:05ccbd4f84f1 166 if (prev != NULL) {
hendrikvincent 0:05ccbd4f84f1 167 LWIP_ASSERT("prev->next == ipr", prev->next == ipr);
hendrikvincent 0:05ccbd4f84f1 168 }
hendrikvincent 0:05ccbd4f84f1 169
hendrikvincent 0:05ccbd4f84f1 170 snmp_inc_ipreasmfails();
hendrikvincent 0:05ccbd4f84f1 171 #if LWIP_ICMP
hendrikvincent 0:05ccbd4f84f1 172 iprh = (struct ip_reass_helper *)ipr->p->payload;
hendrikvincent 0:05ccbd4f84f1 173 if (iprh->start == 0) {
hendrikvincent 0:05ccbd4f84f1 174 /* The first fragment was received, send ICMP time exceeded. */
hendrikvincent 0:05ccbd4f84f1 175 /* First, de-queue the first pbuf from r->p. */
hendrikvincent 0:05ccbd4f84f1 176 p = ipr->p;
hendrikvincent 0:05ccbd4f84f1 177 ipr->p = iprh->next_pbuf;
hendrikvincent 0:05ccbd4f84f1 178 /* Then, copy the original header into it. */
hendrikvincent 0:05ccbd4f84f1 179 SMEMCPY(p->payload, &ipr->iphdr, IP_HLEN);
hendrikvincent 0:05ccbd4f84f1 180 icmp_time_exceeded(p, ICMP_TE_FRAG);
hendrikvincent 0:05ccbd4f84f1 181 clen = pbuf_clen(p);
hendrikvincent 0:05ccbd4f84f1 182 LWIP_ASSERT("pbufs_freed + clen <= 0xffff", pbufs_freed + clen <= 0xffff);
hendrikvincent 0:05ccbd4f84f1 183 pbufs_freed += clen;
hendrikvincent 0:05ccbd4f84f1 184 pbuf_free(p);
hendrikvincent 0:05ccbd4f84f1 185 }
hendrikvincent 0:05ccbd4f84f1 186 #endif /* LWIP_ICMP */
hendrikvincent 0:05ccbd4f84f1 187
hendrikvincent 0:05ccbd4f84f1 188 /* First, free all received pbufs. The individual pbufs need to be released
hendrikvincent 0:05ccbd4f84f1 189 separately as they have not yet been chained */
hendrikvincent 0:05ccbd4f84f1 190 p = ipr->p;
hendrikvincent 0:05ccbd4f84f1 191 while (p != NULL) {
hendrikvincent 0:05ccbd4f84f1 192 struct pbuf *pcur;
hendrikvincent 0:05ccbd4f84f1 193 iprh = (struct ip_reass_helper *)p->payload;
hendrikvincent 0:05ccbd4f84f1 194 pcur = p;
hendrikvincent 0:05ccbd4f84f1 195 /* get the next pointer before freeing */
hendrikvincent 0:05ccbd4f84f1 196 p = iprh->next_pbuf;
hendrikvincent 0:05ccbd4f84f1 197 clen = pbuf_clen(pcur);
hendrikvincent 0:05ccbd4f84f1 198 LWIP_ASSERT("pbufs_freed + clen <= 0xffff", pbufs_freed + clen <= 0xffff);
hendrikvincent 0:05ccbd4f84f1 199 pbufs_freed += clen;
hendrikvincent 0:05ccbd4f84f1 200 pbuf_free(pcur);
hendrikvincent 0:05ccbd4f84f1 201 }
hendrikvincent 0:05ccbd4f84f1 202 /* Then, unchain the struct ip_reassdata from the list and free it. */
hendrikvincent 0:05ccbd4f84f1 203 ip_reass_dequeue_datagram(ipr, prev);
hendrikvincent 0:05ccbd4f84f1 204 LWIP_ASSERT("ip_reass_pbufcount >= clen", ip_reass_pbufcount >= pbufs_freed);
hendrikvincent 0:05ccbd4f84f1 205 ip_reass_pbufcount -= pbufs_freed;
hendrikvincent 0:05ccbd4f84f1 206
hendrikvincent 0:05ccbd4f84f1 207 return pbufs_freed;
hendrikvincent 0:05ccbd4f84f1 208 }
hendrikvincent 0:05ccbd4f84f1 209
hendrikvincent 0:05ccbd4f84f1 210 #if IP_REASS_FREE_OLDEST
hendrikvincent 0:05ccbd4f84f1 211 /**
hendrikvincent 0:05ccbd4f84f1 212 * Free the oldest datagram to make room for enqueueing new fragments.
hendrikvincent 0:05ccbd4f84f1 213 * The datagram 'fraghdr' belongs to is not freed!
hendrikvincent 0:05ccbd4f84f1 214 *
hendrikvincent 0:05ccbd4f84f1 215 * @param fraghdr IP header of the current fragment
hendrikvincent 0:05ccbd4f84f1 216 * @param pbufs_needed number of pbufs needed to enqueue
hendrikvincent 0:05ccbd4f84f1 217 * (used for freeing other datagrams if not enough space)
hendrikvincent 0:05ccbd4f84f1 218 * @return the number of pbufs freed
hendrikvincent 0:05ccbd4f84f1 219 */
hendrikvincent 0:05ccbd4f84f1 220 static int
hendrikvincent 0:05ccbd4f84f1 221 ip_reass_remove_oldest_datagram(struct ip_hdr *fraghdr, int pbufs_needed)
hendrikvincent 0:05ccbd4f84f1 222 {
hendrikvincent 0:05ccbd4f84f1 223 /* @todo Can't we simply remove the last datagram in the
hendrikvincent 0:05ccbd4f84f1 224 * linked list behind reassdatagrams?
hendrikvincent 0:05ccbd4f84f1 225 */
hendrikvincent 0:05ccbd4f84f1 226 struct ip_reassdata *r, *oldest, *prev;
hendrikvincent 0:05ccbd4f84f1 227 int pbufs_freed = 0, pbufs_freed_current;
hendrikvincent 0:05ccbd4f84f1 228 int other_datagrams;
hendrikvincent 0:05ccbd4f84f1 229
hendrikvincent 0:05ccbd4f84f1 230 /* Free datagrams until being allowed to enqueue 'pbufs_needed' pbufs,
hendrikvincent 0:05ccbd4f84f1 231 * but don't free the datagram that 'fraghdr' belongs to! */
hendrikvincent 0:05ccbd4f84f1 232 do {
hendrikvincent 0:05ccbd4f84f1 233 oldest = NULL;
hendrikvincent 0:05ccbd4f84f1 234 prev = NULL;
hendrikvincent 0:05ccbd4f84f1 235 other_datagrams = 0;
hendrikvincent 0:05ccbd4f84f1 236 r = reassdatagrams;
hendrikvincent 0:05ccbd4f84f1 237 while (r != NULL) {
hendrikvincent 0:05ccbd4f84f1 238 if (!IP_ADDRESSES_AND_ID_MATCH(&r->iphdr, fraghdr)) {
hendrikvincent 0:05ccbd4f84f1 239 /* Not the same datagram as fraghdr */
hendrikvincent 0:05ccbd4f84f1 240 other_datagrams++;
hendrikvincent 0:05ccbd4f84f1 241 if (oldest == NULL) {
hendrikvincent 0:05ccbd4f84f1 242 oldest = r;
hendrikvincent 0:05ccbd4f84f1 243 } else if (r->timer <= oldest->timer) {
hendrikvincent 0:05ccbd4f84f1 244 /* older than the previous oldest */
hendrikvincent 0:05ccbd4f84f1 245 oldest = r;
hendrikvincent 0:05ccbd4f84f1 246 }
hendrikvincent 0:05ccbd4f84f1 247 }
hendrikvincent 0:05ccbd4f84f1 248 if (r->next != NULL) {
hendrikvincent 0:05ccbd4f84f1 249 prev = r;
hendrikvincent 0:05ccbd4f84f1 250 }
hendrikvincent 0:05ccbd4f84f1 251 r = r->next;
hendrikvincent 0:05ccbd4f84f1 252 }
hendrikvincent 0:05ccbd4f84f1 253 if (oldest != NULL) {
hendrikvincent 0:05ccbd4f84f1 254 pbufs_freed_current = ip_reass_free_complete_datagram(oldest, prev);
hendrikvincent 0:05ccbd4f84f1 255 pbufs_freed += pbufs_freed_current;
hendrikvincent 0:05ccbd4f84f1 256 }
hendrikvincent 0:05ccbd4f84f1 257 } while ((pbufs_freed < pbufs_needed) && (other_datagrams > 1));
hendrikvincent 0:05ccbd4f84f1 258 return pbufs_freed;
hendrikvincent 0:05ccbd4f84f1 259 }
hendrikvincent 0:05ccbd4f84f1 260 #endif /* IP_REASS_FREE_OLDEST */
hendrikvincent 0:05ccbd4f84f1 261
hendrikvincent 0:05ccbd4f84f1 262 /**
hendrikvincent 0:05ccbd4f84f1 263 * Enqueues a new fragment into the fragment queue
hendrikvincent 0:05ccbd4f84f1 264 * @param fraghdr points to the new fragments IP hdr
hendrikvincent 0:05ccbd4f84f1 265 * @param clen number of pbufs needed to enqueue (used for freeing other datagrams if not enough space)
hendrikvincent 0:05ccbd4f84f1 266 * @return A pointer to the queue location into which the fragment was enqueued
hendrikvincent 0:05ccbd4f84f1 267 */
hendrikvincent 0:05ccbd4f84f1 268 static struct ip_reassdata*
hendrikvincent 0:05ccbd4f84f1 269 ip_reass_enqueue_new_datagram(struct ip_hdr *fraghdr, int clen)
hendrikvincent 0:05ccbd4f84f1 270 {
hendrikvincent 0:05ccbd4f84f1 271 struct ip_reassdata* ipr;
hendrikvincent 0:05ccbd4f84f1 272 /* No matching previous fragment found, allocate a new reassdata struct */
hendrikvincent 0:05ccbd4f84f1 273 ipr = (struct ip_reassdata *)memp_malloc(MEMP_REASSDATA);
hendrikvincent 0:05ccbd4f84f1 274 if (ipr == NULL) {
hendrikvincent 0:05ccbd4f84f1 275 #if IP_REASS_FREE_OLDEST
hendrikvincent 0:05ccbd4f84f1 276 if (ip_reass_remove_oldest_datagram(fraghdr, clen) >= clen) {
hendrikvincent 0:05ccbd4f84f1 277 ipr = (struct ip_reassdata *)memp_malloc(MEMP_REASSDATA);
hendrikvincent 0:05ccbd4f84f1 278 }
hendrikvincent 0:05ccbd4f84f1 279 if (ipr == NULL)
hendrikvincent 0:05ccbd4f84f1 280 #endif /* IP_REASS_FREE_OLDEST */
hendrikvincent 0:05ccbd4f84f1 281 {
hendrikvincent 0:05ccbd4f84f1 282 IPFRAG_STATS_INC(ip_frag.memerr);
hendrikvincent 0:05ccbd4f84f1 283 LWIP_DEBUGF(IP_REASS_DEBUG,("Failed to alloc reassdata struct\n"));
hendrikvincent 0:05ccbd4f84f1 284 return NULL;
hendrikvincent 0:05ccbd4f84f1 285 }
hendrikvincent 0:05ccbd4f84f1 286 }
hendrikvincent 0:05ccbd4f84f1 287 memset(ipr, 0, sizeof(struct ip_reassdata));
hendrikvincent 0:05ccbd4f84f1 288 ipr->timer = IP_REASS_MAXAGE;
hendrikvincent 0:05ccbd4f84f1 289
hendrikvincent 0:05ccbd4f84f1 290 /* enqueue the new structure to the front of the list */
hendrikvincent 0:05ccbd4f84f1 291 ipr->next = reassdatagrams;
hendrikvincent 0:05ccbd4f84f1 292 reassdatagrams = ipr;
hendrikvincent 0:05ccbd4f84f1 293 /* copy the ip header for later tests and input */
hendrikvincent 0:05ccbd4f84f1 294 /* @todo: no ip options supported? */
hendrikvincent 0:05ccbd4f84f1 295 SMEMCPY(&(ipr->iphdr), fraghdr, IP_HLEN);
hendrikvincent 0:05ccbd4f84f1 296 return ipr;
hendrikvincent 0:05ccbd4f84f1 297 }
hendrikvincent 0:05ccbd4f84f1 298
hendrikvincent 0:05ccbd4f84f1 299 /**
hendrikvincent 0:05ccbd4f84f1 300 * Dequeues a datagram from the datagram queue. Doesn't deallocate the pbufs.
hendrikvincent 0:05ccbd4f84f1 301 * @param ipr points to the queue entry to dequeue
hendrikvincent 0:05ccbd4f84f1 302 */
hendrikvincent 0:05ccbd4f84f1 303 static void
hendrikvincent 0:05ccbd4f84f1 304 ip_reass_dequeue_datagram(struct ip_reassdata *ipr, struct ip_reassdata *prev)
hendrikvincent 0:05ccbd4f84f1 305 {
hendrikvincent 0:05ccbd4f84f1 306
hendrikvincent 0:05ccbd4f84f1 307 /* dequeue the reass struct */
hendrikvincent 0:05ccbd4f84f1 308 if (reassdatagrams == ipr) {
hendrikvincent 0:05ccbd4f84f1 309 /* it was the first in the list */
hendrikvincent 0:05ccbd4f84f1 310 reassdatagrams = ipr->next;
hendrikvincent 0:05ccbd4f84f1 311 } else {
hendrikvincent 0:05ccbd4f84f1 312 /* it wasn't the first, so it must have a valid 'prev' */
hendrikvincent 0:05ccbd4f84f1 313 LWIP_ASSERT("sanity check linked list", prev != NULL);
hendrikvincent 0:05ccbd4f84f1 314 prev->next = ipr->next;
hendrikvincent 0:05ccbd4f84f1 315 }
hendrikvincent 0:05ccbd4f84f1 316
hendrikvincent 0:05ccbd4f84f1 317 /* now we can free the ip_reass struct */
hendrikvincent 0:05ccbd4f84f1 318 memp_free(MEMP_REASSDATA, ipr);
hendrikvincent 0:05ccbd4f84f1 319 }
hendrikvincent 0:05ccbd4f84f1 320
hendrikvincent 0:05ccbd4f84f1 321 /**
hendrikvincent 0:05ccbd4f84f1 322 * Chain a new pbuf into the pbuf list that composes the datagram. The pbuf list
hendrikvincent 0:05ccbd4f84f1 323 * will grow over time as new pbufs are rx.
hendrikvincent 0:05ccbd4f84f1 324 * Also checks that the datagram passes basic continuity checks (if the last
hendrikvincent 0:05ccbd4f84f1 325 * fragment was received at least once).
hendrikvincent 0:05ccbd4f84f1 326 * @param root_p points to the 'root' pbuf for the current datagram being assembled.
hendrikvincent 0:05ccbd4f84f1 327 * @param new_p points to the pbuf for the current fragment
hendrikvincent 0:05ccbd4f84f1 328 * @return 0 if invalid, >0 otherwise
hendrikvincent 0:05ccbd4f84f1 329 */
hendrikvincent 0:05ccbd4f84f1 330 static int
hendrikvincent 0:05ccbd4f84f1 331 ip_reass_chain_frag_into_datagram_and_validate(struct ip_reassdata *ipr, struct pbuf *new_p)
hendrikvincent 0:05ccbd4f84f1 332 {
hendrikvincent 0:05ccbd4f84f1 333 struct ip_reass_helper *iprh, *iprh_tmp, *iprh_prev=NULL;
hendrikvincent 0:05ccbd4f84f1 334 struct pbuf *q;
hendrikvincent 0:05ccbd4f84f1 335 u16_t offset,len;
hendrikvincent 0:05ccbd4f84f1 336 struct ip_hdr *fraghdr;
hendrikvincent 0:05ccbd4f84f1 337 int valid = 1;
hendrikvincent 0:05ccbd4f84f1 338
hendrikvincent 0:05ccbd4f84f1 339 /* Extract length and fragment offset from current fragment */
hendrikvincent 0:05ccbd4f84f1 340 fraghdr = (struct ip_hdr*)new_p->payload;
hendrikvincent 0:05ccbd4f84f1 341 len = ntohs(IPH_LEN(fraghdr)) - IPH_HL(fraghdr) * 4;
hendrikvincent 0:05ccbd4f84f1 342 offset = (ntohs(IPH_OFFSET(fraghdr)) & IP_OFFMASK) * 8;
hendrikvincent 0:05ccbd4f84f1 343
hendrikvincent 0:05ccbd4f84f1 344 /* overwrite the fragment's ip header from the pbuf with our helper struct,
hendrikvincent 0:05ccbd4f84f1 345 * and setup the embedded helper structure. */
hendrikvincent 0:05ccbd4f84f1 346 /* make sure the struct ip_reass_helper fits into the IP header */
hendrikvincent 0:05ccbd4f84f1 347 LWIP_ASSERT("sizeof(struct ip_reass_helper) <= IP_HLEN",
hendrikvincent 0:05ccbd4f84f1 348 sizeof(struct ip_reass_helper) <= IP_HLEN);
hendrikvincent 0:05ccbd4f84f1 349 iprh = (struct ip_reass_helper*)new_p->payload;
hendrikvincent 0:05ccbd4f84f1 350 iprh->next_pbuf = NULL;
hendrikvincent 0:05ccbd4f84f1 351 iprh->start = offset;
hendrikvincent 0:05ccbd4f84f1 352 iprh->end = offset + len;
hendrikvincent 0:05ccbd4f84f1 353
hendrikvincent 0:05ccbd4f84f1 354 /* Iterate through until we either get to the end of the list (append),
hendrikvincent 0:05ccbd4f84f1 355 * or we find on with a larger offset (insert). */
hendrikvincent 0:05ccbd4f84f1 356 for (q = ipr->p; q != NULL;) {
hendrikvincent 0:05ccbd4f84f1 357 iprh_tmp = (struct ip_reass_helper*)q->payload;
hendrikvincent 0:05ccbd4f84f1 358 if (iprh->start < iprh_tmp->start) {
hendrikvincent 0:05ccbd4f84f1 359 /* the new pbuf should be inserted before this */
hendrikvincent 0:05ccbd4f84f1 360 iprh->next_pbuf = q;
hendrikvincent 0:05ccbd4f84f1 361 if (iprh_prev != NULL) {
hendrikvincent 0:05ccbd4f84f1 362 /* not the fragment with the lowest offset */
hendrikvincent 0:05ccbd4f84f1 363 #if IP_REASS_CHECK_OVERLAP
hendrikvincent 0:05ccbd4f84f1 364 if ((iprh->start < iprh_prev->end) || (iprh->end > iprh_tmp->start)) {
hendrikvincent 0:05ccbd4f84f1 365 /* fragment overlaps with previous or following, throw away */
hendrikvincent 0:05ccbd4f84f1 366 goto freepbuf;
hendrikvincent 0:05ccbd4f84f1 367 }
hendrikvincent 0:05ccbd4f84f1 368 #endif /* IP_REASS_CHECK_OVERLAP */
hendrikvincent 0:05ccbd4f84f1 369 iprh_prev->next_pbuf = new_p;
hendrikvincent 0:05ccbd4f84f1 370 } else {
hendrikvincent 0:05ccbd4f84f1 371 /* fragment with the lowest offset */
hendrikvincent 0:05ccbd4f84f1 372 ipr->p = new_p;
hendrikvincent 0:05ccbd4f84f1 373 }
hendrikvincent 0:05ccbd4f84f1 374 break;
hendrikvincent 0:05ccbd4f84f1 375 } else if(iprh->start == iprh_tmp->start) {
hendrikvincent 0:05ccbd4f84f1 376 /* received the same datagram twice: no need to keep the datagram */
hendrikvincent 0:05ccbd4f84f1 377 goto freepbuf;
hendrikvincent 0:05ccbd4f84f1 378 #if IP_REASS_CHECK_OVERLAP
hendrikvincent 0:05ccbd4f84f1 379 } else if(iprh->start < iprh_tmp->end) {
hendrikvincent 0:05ccbd4f84f1 380 /* overlap: no need to keep the new datagram */
hendrikvincent 0:05ccbd4f84f1 381 goto freepbuf;
hendrikvincent 0:05ccbd4f84f1 382 #endif /* IP_REASS_CHECK_OVERLAP */
hendrikvincent 0:05ccbd4f84f1 383 } else {
hendrikvincent 0:05ccbd4f84f1 384 /* Check if the fragments received so far have no wholes. */
hendrikvincent 0:05ccbd4f84f1 385 if (iprh_prev != NULL) {
hendrikvincent 0:05ccbd4f84f1 386 if (iprh_prev->end != iprh_tmp->start) {
hendrikvincent 0:05ccbd4f84f1 387 /* There is a fragment missing between the current
hendrikvincent 0:05ccbd4f84f1 388 * and the previous fragment */
hendrikvincent 0:05ccbd4f84f1 389 valid = 0;
hendrikvincent 0:05ccbd4f84f1 390 }
hendrikvincent 0:05ccbd4f84f1 391 }
hendrikvincent 0:05ccbd4f84f1 392 }
hendrikvincent 0:05ccbd4f84f1 393 q = iprh_tmp->next_pbuf;
hendrikvincent 0:05ccbd4f84f1 394 iprh_prev = iprh_tmp;
hendrikvincent 0:05ccbd4f84f1 395 }
hendrikvincent 0:05ccbd4f84f1 396
hendrikvincent 0:05ccbd4f84f1 397 /* If q is NULL, then we made it to the end of the list. Determine what to do now */
hendrikvincent 0:05ccbd4f84f1 398 if (q == NULL) {
hendrikvincent 0:05ccbd4f84f1 399 if (iprh_prev != NULL) {
hendrikvincent 0:05ccbd4f84f1 400 /* this is (for now), the fragment with the highest offset:
hendrikvincent 0:05ccbd4f84f1 401 * chain it to the last fragment */
hendrikvincent 0:05ccbd4f84f1 402 #if IP_REASS_CHECK_OVERLAP
hendrikvincent 0:05ccbd4f84f1 403 LWIP_ASSERT("check fragments don't overlap", iprh_prev->end <= iprh->start);
hendrikvincent 0:05ccbd4f84f1 404 #endif /* IP_REASS_CHECK_OVERLAP */
hendrikvincent 0:05ccbd4f84f1 405 iprh_prev->next_pbuf = new_p;
hendrikvincent 0:05ccbd4f84f1 406 if (iprh_prev->end != iprh->start) {
hendrikvincent 0:05ccbd4f84f1 407 valid = 0;
hendrikvincent 0:05ccbd4f84f1 408 }
hendrikvincent 0:05ccbd4f84f1 409 } else {
hendrikvincent 0:05ccbd4f84f1 410 #if IP_REASS_CHECK_OVERLAP
hendrikvincent 0:05ccbd4f84f1 411 LWIP_ASSERT("no previous fragment, this must be the first fragment!",
hendrikvincent 0:05ccbd4f84f1 412 ipr->p == NULL);
hendrikvincent 0:05ccbd4f84f1 413 #endif /* IP_REASS_CHECK_OVERLAP */
hendrikvincent 0:05ccbd4f84f1 414 /* this is the first fragment we ever received for this ip datagram */
hendrikvincent 0:05ccbd4f84f1 415 ipr->p = new_p;
hendrikvincent 0:05ccbd4f84f1 416 }
hendrikvincent 0:05ccbd4f84f1 417 }
hendrikvincent 0:05ccbd4f84f1 418
hendrikvincent 0:05ccbd4f84f1 419 /* At this point, the validation part begins: */
hendrikvincent 0:05ccbd4f84f1 420 /* If we already received the last fragment */
hendrikvincent 0:05ccbd4f84f1 421 if ((ipr->flags & IP_REASS_FLAG_LASTFRAG) != 0) {
hendrikvincent 0:05ccbd4f84f1 422 /* and had no wholes so far */
hendrikvincent 0:05ccbd4f84f1 423 if (valid) {
hendrikvincent 0:05ccbd4f84f1 424 /* then check if the rest of the fragments is here */
hendrikvincent 0:05ccbd4f84f1 425 /* Check if the queue starts with the first datagram */
hendrikvincent 0:05ccbd4f84f1 426 if (((struct ip_reass_helper*)ipr->p->payload)->start != 0) {
hendrikvincent 0:05ccbd4f84f1 427 valid = 0;
hendrikvincent 0:05ccbd4f84f1 428 } else {
hendrikvincent 0:05ccbd4f84f1 429 /* and check that there are no wholes after this datagram */
hendrikvincent 0:05ccbd4f84f1 430 iprh_prev = iprh;
hendrikvincent 0:05ccbd4f84f1 431 q = iprh->next_pbuf;
hendrikvincent 0:05ccbd4f84f1 432 while (q != NULL) {
hendrikvincent 0:05ccbd4f84f1 433 iprh = (struct ip_reass_helper*)q->payload;
hendrikvincent 0:05ccbd4f84f1 434 if (iprh_prev->end != iprh->start) {
hendrikvincent 0:05ccbd4f84f1 435 valid = 0;
hendrikvincent 0:05ccbd4f84f1 436 break;
hendrikvincent 0:05ccbd4f84f1 437 }
hendrikvincent 0:05ccbd4f84f1 438 iprh_prev = iprh;
hendrikvincent 0:05ccbd4f84f1 439 q = iprh->next_pbuf;
hendrikvincent 0:05ccbd4f84f1 440 }
hendrikvincent 0:05ccbd4f84f1 441 /* if still valid, all fragments are received
hendrikvincent 0:05ccbd4f84f1 442 * (because to the MF==0 already arrived */
hendrikvincent 0:05ccbd4f84f1 443 if (valid) {
hendrikvincent 0:05ccbd4f84f1 444 LWIP_ASSERT("sanity check", ipr->p != NULL);
hendrikvincent 0:05ccbd4f84f1 445 LWIP_ASSERT("sanity check",
hendrikvincent 0:05ccbd4f84f1 446 ((struct ip_reass_helper*)ipr->p->payload) != iprh);
hendrikvincent 0:05ccbd4f84f1 447 LWIP_ASSERT("validate_datagram:next_pbuf!=NULL",
hendrikvincent 0:05ccbd4f84f1 448 iprh->next_pbuf == NULL);
hendrikvincent 0:05ccbd4f84f1 449 LWIP_ASSERT("validate_datagram:datagram end!=datagram len",
hendrikvincent 0:05ccbd4f84f1 450 iprh->end == ipr->datagram_len);
hendrikvincent 0:05ccbd4f84f1 451 }
hendrikvincent 0:05ccbd4f84f1 452 }
hendrikvincent 0:05ccbd4f84f1 453 }
hendrikvincent 0:05ccbd4f84f1 454 /* If valid is 0 here, there are some fragments missing in the middle
hendrikvincent 0:05ccbd4f84f1 455 * (since MF == 0 has already arrived). Such datagrams simply time out if
hendrikvincent 0:05ccbd4f84f1 456 * no more fragments are received... */
hendrikvincent 0:05ccbd4f84f1 457 return valid;
hendrikvincent 0:05ccbd4f84f1 458 }
hendrikvincent 0:05ccbd4f84f1 459 /* If we come here, not all fragments were received, yet! */
hendrikvincent 0:05ccbd4f84f1 460 return 0; /* not yet valid! */
hendrikvincent 0:05ccbd4f84f1 461 #if IP_REASS_CHECK_OVERLAP
hendrikvincent 0:05ccbd4f84f1 462 freepbuf:
hendrikvincent 0:05ccbd4f84f1 463 ip_reass_pbufcount -= pbuf_clen(new_p);
hendrikvincent 0:05ccbd4f84f1 464 pbuf_free(new_p);
hendrikvincent 0:05ccbd4f84f1 465 return 0;
hendrikvincent 0:05ccbd4f84f1 466 #endif /* IP_REASS_CHECK_OVERLAP */
hendrikvincent 0:05ccbd4f84f1 467 }
hendrikvincent 0:05ccbd4f84f1 468
hendrikvincent 0:05ccbd4f84f1 469 /**
hendrikvincent 0:05ccbd4f84f1 470 * Reassembles incoming IP fragments into an IP datagram.
hendrikvincent 0:05ccbd4f84f1 471 *
hendrikvincent 0:05ccbd4f84f1 472 * @param p points to a pbuf chain of the fragment
hendrikvincent 0:05ccbd4f84f1 473 * @return NULL if reassembly is incomplete, ? otherwise
hendrikvincent 0:05ccbd4f84f1 474 */
hendrikvincent 0:05ccbd4f84f1 475 struct pbuf *
hendrikvincent 0:05ccbd4f84f1 476 ip_reass(struct pbuf *p)
hendrikvincent 0:05ccbd4f84f1 477 {
hendrikvincent 0:05ccbd4f84f1 478 struct pbuf *r;
hendrikvincent 0:05ccbd4f84f1 479 struct ip_hdr *fraghdr;
hendrikvincent 0:05ccbd4f84f1 480 struct ip_reassdata *ipr;
hendrikvincent 0:05ccbd4f84f1 481 struct ip_reass_helper *iprh;
hendrikvincent 0:05ccbd4f84f1 482 u16_t offset, len;
hendrikvincent 0:05ccbd4f84f1 483 u8_t clen;
hendrikvincent 0:05ccbd4f84f1 484 struct ip_reassdata *ipr_prev = NULL;
hendrikvincent 0:05ccbd4f84f1 485
hendrikvincent 0:05ccbd4f84f1 486 IPFRAG_STATS_INC(ip_frag.recv);
hendrikvincent 0:05ccbd4f84f1 487 snmp_inc_ipreasmreqds();
hendrikvincent 0:05ccbd4f84f1 488
hendrikvincent 0:05ccbd4f84f1 489 fraghdr = (struct ip_hdr*)p->payload;
hendrikvincent 0:05ccbd4f84f1 490
hendrikvincent 0:05ccbd4f84f1 491 if ((IPH_HL(fraghdr) * 4) != IP_HLEN) {
hendrikvincent 0:05ccbd4f84f1 492 LWIP_DEBUGF(IP_REASS_DEBUG,("ip_reass: IP options currently not supported!\n"));
hendrikvincent 0:05ccbd4f84f1 493 IPFRAG_STATS_INC(ip_frag.err);
hendrikvincent 0:05ccbd4f84f1 494 goto nullreturn;
hendrikvincent 0:05ccbd4f84f1 495 }
hendrikvincent 0:05ccbd4f84f1 496
hendrikvincent 0:05ccbd4f84f1 497 offset = (ntohs(IPH_OFFSET(fraghdr)) & IP_OFFMASK) * 8;
hendrikvincent 0:05ccbd4f84f1 498 len = ntohs(IPH_LEN(fraghdr)) - IPH_HL(fraghdr) * 4;
hendrikvincent 0:05ccbd4f84f1 499
hendrikvincent 0:05ccbd4f84f1 500 /* Check if we are allowed to enqueue more datagrams. */
hendrikvincent 0:05ccbd4f84f1 501 clen = pbuf_clen(p);
hendrikvincent 0:05ccbd4f84f1 502 if ((ip_reass_pbufcount + clen) > IP_REASS_MAX_PBUFS) {
hendrikvincent 0:05ccbd4f84f1 503 #if IP_REASS_FREE_OLDEST
hendrikvincent 0:05ccbd4f84f1 504 if (!ip_reass_remove_oldest_datagram(fraghdr, clen) ||
hendrikvincent 0:05ccbd4f84f1 505 ((ip_reass_pbufcount + clen) > IP_REASS_MAX_PBUFS))
hendrikvincent 0:05ccbd4f84f1 506 #endif /* IP_REASS_FREE_OLDEST */
hendrikvincent 0:05ccbd4f84f1 507 {
hendrikvincent 0:05ccbd4f84f1 508 /* No datagram could be freed and still too many pbufs enqueued */
hendrikvincent 0:05ccbd4f84f1 509 LWIP_DEBUGF(IP_REASS_DEBUG,("ip_reass: Overflow condition: pbufct=%d, clen=%d, MAX=%d\n",
hendrikvincent 0:05ccbd4f84f1 510 ip_reass_pbufcount, clen, IP_REASS_MAX_PBUFS));
hendrikvincent 0:05ccbd4f84f1 511 IPFRAG_STATS_INC(ip_frag.memerr);
hendrikvincent 0:05ccbd4f84f1 512 /* @todo: send ICMP time exceeded here? */
hendrikvincent 0:05ccbd4f84f1 513 /* drop this pbuf */
hendrikvincent 0:05ccbd4f84f1 514 goto nullreturn;
hendrikvincent 0:05ccbd4f84f1 515 }
hendrikvincent 0:05ccbd4f84f1 516 }
hendrikvincent 0:05ccbd4f84f1 517
hendrikvincent 0:05ccbd4f84f1 518 /* Look for the datagram the fragment belongs to in the current datagram queue,
hendrikvincent 0:05ccbd4f84f1 519 * remembering the previous in the queue for later dequeueing. */
hendrikvincent 0:05ccbd4f84f1 520 for (ipr = reassdatagrams; ipr != NULL; ipr = ipr->next) {
hendrikvincent 0:05ccbd4f84f1 521 /* Check if the incoming fragment matches the one currently present
hendrikvincent 0:05ccbd4f84f1 522 in the reassembly buffer. If so, we proceed with copying the
hendrikvincent 0:05ccbd4f84f1 523 fragment into the buffer. */
hendrikvincent 0:05ccbd4f84f1 524 if (IP_ADDRESSES_AND_ID_MATCH(&ipr->iphdr, fraghdr)) {
hendrikvincent 0:05ccbd4f84f1 525 LWIP_DEBUGF(IP_REASS_DEBUG, ("ip_reass: matching previous fragment ID=%"X16_F"\n",
hendrikvincent 0:05ccbd4f84f1 526 ntohs(IPH_ID(fraghdr))));
hendrikvincent 0:05ccbd4f84f1 527 IPFRAG_STATS_INC(ip_frag.cachehit);
hendrikvincent 0:05ccbd4f84f1 528 break;
hendrikvincent 0:05ccbd4f84f1 529 }
hendrikvincent 0:05ccbd4f84f1 530 ipr_prev = ipr;
hendrikvincent 0:05ccbd4f84f1 531 }
hendrikvincent 0:05ccbd4f84f1 532
hendrikvincent 0:05ccbd4f84f1 533 if (ipr == NULL) {
hendrikvincent 0:05ccbd4f84f1 534 /* Enqueue a new datagram into the datagram queue */
hendrikvincent 0:05ccbd4f84f1 535 ipr = ip_reass_enqueue_new_datagram(fraghdr, clen);
hendrikvincent 0:05ccbd4f84f1 536 /* Bail if unable to enqueue */
hendrikvincent 0:05ccbd4f84f1 537 if(ipr == NULL) {
hendrikvincent 0:05ccbd4f84f1 538 goto nullreturn;
hendrikvincent 0:05ccbd4f84f1 539 }
hendrikvincent 0:05ccbd4f84f1 540 } else {
hendrikvincent 0:05ccbd4f84f1 541 if (((ntohs(IPH_OFFSET(fraghdr)) & IP_OFFMASK) == 0) &&
hendrikvincent 0:05ccbd4f84f1 542 ((ntohs(IPH_OFFSET(&ipr->iphdr)) & IP_OFFMASK) != 0)) {
hendrikvincent 0:05ccbd4f84f1 543 /* ipr->iphdr is not the header from the first fragment, but fraghdr is
hendrikvincent 0:05ccbd4f84f1 544 * -> copy fraghdr into ipr->iphdr since we want to have the header
hendrikvincent 0:05ccbd4f84f1 545 * of the first fragment (for ICMP time exceeded and later, for copying
hendrikvincent 0:05ccbd4f84f1 546 * all options, if supported)*/
hendrikvincent 0:05ccbd4f84f1 547 SMEMCPY(&ipr->iphdr, fraghdr, IP_HLEN);
hendrikvincent 0:05ccbd4f84f1 548 }
hendrikvincent 0:05ccbd4f84f1 549 }
hendrikvincent 0:05ccbd4f84f1 550 /* Track the current number of pbufs current 'in-flight', in order to limit
hendrikvincent 0:05ccbd4f84f1 551 the number of fragments that may be enqueued at any one time */
hendrikvincent 0:05ccbd4f84f1 552 ip_reass_pbufcount += clen;
hendrikvincent 0:05ccbd4f84f1 553
hendrikvincent 0:05ccbd4f84f1 554 /* At this point, we have either created a new entry or pointing
hendrikvincent 0:05ccbd4f84f1 555 * to an existing one */
hendrikvincent 0:05ccbd4f84f1 556
hendrikvincent 0:05ccbd4f84f1 557 /* check for 'no more fragments', and update queue entry*/
hendrikvincent 0:05ccbd4f84f1 558 if ((IPH_OFFSET(fraghdr) & PP_NTOHS(IP_MF)) == 0) {
hendrikvincent 0:05ccbd4f84f1 559 ipr->flags |= IP_REASS_FLAG_LASTFRAG;
hendrikvincent 0:05ccbd4f84f1 560 ipr->datagram_len = offset + len;
hendrikvincent 0:05ccbd4f84f1 561 LWIP_DEBUGF(IP_REASS_DEBUG,
hendrikvincent 0:05ccbd4f84f1 562 ("ip_reass: last fragment seen, total len %"S16_F"\n",
hendrikvincent 0:05ccbd4f84f1 563 ipr->datagram_len));
hendrikvincent 0:05ccbd4f84f1 564 }
hendrikvincent 0:05ccbd4f84f1 565 /* find the right place to insert this pbuf */
hendrikvincent 0:05ccbd4f84f1 566 /* @todo: trim pbufs if fragments are overlapping */
hendrikvincent 0:05ccbd4f84f1 567 if (ip_reass_chain_frag_into_datagram_and_validate(ipr, p)) {
hendrikvincent 0:05ccbd4f84f1 568 /* the totally last fragment (flag more fragments = 0) was received at least
hendrikvincent 0:05ccbd4f84f1 569 * once AND all fragments are received */
hendrikvincent 0:05ccbd4f84f1 570 ipr->datagram_len += IP_HLEN;
hendrikvincent 0:05ccbd4f84f1 571
hendrikvincent 0:05ccbd4f84f1 572 /* save the second pbuf before copying the header over the pointer */
hendrikvincent 0:05ccbd4f84f1 573 r = ((struct ip_reass_helper*)ipr->p->payload)->next_pbuf;
hendrikvincent 0:05ccbd4f84f1 574
hendrikvincent 0:05ccbd4f84f1 575 /* copy the original ip header back to the first pbuf */
hendrikvincent 0:05ccbd4f84f1 576 fraghdr = (struct ip_hdr*)(ipr->p->payload);
hendrikvincent 0:05ccbd4f84f1 577 SMEMCPY(fraghdr, &ipr->iphdr, IP_HLEN);
hendrikvincent 0:05ccbd4f84f1 578 IPH_LEN_SET(fraghdr, htons(ipr->datagram_len));
hendrikvincent 0:05ccbd4f84f1 579 IPH_OFFSET_SET(fraghdr, 0);
hendrikvincent 0:05ccbd4f84f1 580 IPH_CHKSUM_SET(fraghdr, 0);
hendrikvincent 0:05ccbd4f84f1 581 /* @todo: do we need to set calculate the correct checksum? */
hendrikvincent 0:05ccbd4f84f1 582 IPH_CHKSUM_SET(fraghdr, inet_chksum(fraghdr, IP_HLEN));
hendrikvincent 0:05ccbd4f84f1 583
hendrikvincent 0:05ccbd4f84f1 584 p = ipr->p;
hendrikvincent 0:05ccbd4f84f1 585
hendrikvincent 0:05ccbd4f84f1 586 /* chain together the pbufs contained within the reass_data list. */
hendrikvincent 0:05ccbd4f84f1 587 while(r != NULL) {
hendrikvincent 0:05ccbd4f84f1 588 iprh = (struct ip_reass_helper*)r->payload;
hendrikvincent 0:05ccbd4f84f1 589
hendrikvincent 0:05ccbd4f84f1 590 /* hide the ip header for every succeding fragment */
hendrikvincent 0:05ccbd4f84f1 591 pbuf_header(r, -IP_HLEN);
hendrikvincent 0:05ccbd4f84f1 592 pbuf_cat(p, r);
hendrikvincent 0:05ccbd4f84f1 593 r = iprh->next_pbuf;
hendrikvincent 0:05ccbd4f84f1 594 }
hendrikvincent 0:05ccbd4f84f1 595 /* release the sources allocate for the fragment queue entry */
hendrikvincent 0:05ccbd4f84f1 596 ip_reass_dequeue_datagram(ipr, ipr_prev);
hendrikvincent 0:05ccbd4f84f1 597
hendrikvincent 0:05ccbd4f84f1 598 /* and adjust the number of pbufs currently queued for reassembly. */
hendrikvincent 0:05ccbd4f84f1 599 ip_reass_pbufcount -= pbuf_clen(p);
hendrikvincent 0:05ccbd4f84f1 600
hendrikvincent 0:05ccbd4f84f1 601 /* Return the pbuf chain */
hendrikvincent 0:05ccbd4f84f1 602 return p;
hendrikvincent 0:05ccbd4f84f1 603 }
hendrikvincent 0:05ccbd4f84f1 604 /* the datagram is not (yet?) reassembled completely */
hendrikvincent 0:05ccbd4f84f1 605 LWIP_DEBUGF(IP_REASS_DEBUG,("ip_reass_pbufcount: %d out\n", ip_reass_pbufcount));
hendrikvincent 0:05ccbd4f84f1 606 return NULL;
hendrikvincent 0:05ccbd4f84f1 607
hendrikvincent 0:05ccbd4f84f1 608 nullreturn:
hendrikvincent 0:05ccbd4f84f1 609 LWIP_DEBUGF(IP_REASS_DEBUG,("ip_reass: nullreturn\n"));
hendrikvincent 0:05ccbd4f84f1 610 IPFRAG_STATS_INC(ip_frag.drop);
hendrikvincent 0:05ccbd4f84f1 611 pbuf_free(p);
hendrikvincent 0:05ccbd4f84f1 612 return NULL;
hendrikvincent 0:05ccbd4f84f1 613 }
hendrikvincent 0:05ccbd4f84f1 614 #endif /* IP_REASSEMBLY */
hendrikvincent 0:05ccbd4f84f1 615
hendrikvincent 0:05ccbd4f84f1 616 #if IP_FRAG
hendrikvincent 0:05ccbd4f84f1 617 #if IP_FRAG_USES_STATIC_BUF
hendrikvincent 0:05ccbd4f84f1 618 static u8_t buf[LWIP_MEM_ALIGN_SIZE(IP_FRAG_MAX_MTU + MEM_ALIGNMENT - 1)];
hendrikvincent 0:05ccbd4f84f1 619 #else /* IP_FRAG_USES_STATIC_BUF */
hendrikvincent 0:05ccbd4f84f1 620
hendrikvincent 0:05ccbd4f84f1 621 #if !LWIP_NETIF_TX_SINGLE_PBUF
hendrikvincent 0:05ccbd4f84f1 622 /** Allocate a new struct pbuf_custom_ref */
hendrikvincent 0:05ccbd4f84f1 623 static struct pbuf_custom_ref*
hendrikvincent 0:05ccbd4f84f1 624 ip_frag_alloc_pbuf_custom_ref(void)
hendrikvincent 0:05ccbd4f84f1 625 {
hendrikvincent 0:05ccbd4f84f1 626 return (struct pbuf_custom_ref*)memp_malloc(MEMP_FRAG_PBUF);
hendrikvincent 0:05ccbd4f84f1 627 }
hendrikvincent 0:05ccbd4f84f1 628
hendrikvincent 0:05ccbd4f84f1 629 /** Free a struct pbuf_custom_ref */
hendrikvincent 0:05ccbd4f84f1 630 static void
hendrikvincent 0:05ccbd4f84f1 631 ip_frag_free_pbuf_custom_ref(struct pbuf_custom_ref* p)
hendrikvincent 0:05ccbd4f84f1 632 {
hendrikvincent 0:05ccbd4f84f1 633 LWIP_ASSERT("p != NULL", p != NULL);
hendrikvincent 0:05ccbd4f84f1 634 memp_free(MEMP_FRAG_PBUF, p);
hendrikvincent 0:05ccbd4f84f1 635 }
hendrikvincent 0:05ccbd4f84f1 636
hendrikvincent 0:05ccbd4f84f1 637 /** Free-callback function to free a 'struct pbuf_custom_ref', called by
hendrikvincent 0:05ccbd4f84f1 638 * pbuf_free. */
hendrikvincent 0:05ccbd4f84f1 639 static void
hendrikvincent 0:05ccbd4f84f1 640 ipfrag_free_pbuf_custom(struct pbuf *p)
hendrikvincent 0:05ccbd4f84f1 641 {
hendrikvincent 0:05ccbd4f84f1 642 struct pbuf_custom_ref *pcr = (struct pbuf_custom_ref*)p;
hendrikvincent 0:05ccbd4f84f1 643 LWIP_ASSERT("pcr != NULL", pcr != NULL);
hendrikvincent 0:05ccbd4f84f1 644 LWIP_ASSERT("pcr == p", (void*)pcr == (void*)p);
hendrikvincent 0:05ccbd4f84f1 645 if (pcr->original != NULL) {
hendrikvincent 0:05ccbd4f84f1 646 pbuf_free(pcr->original);
hendrikvincent 0:05ccbd4f84f1 647 }
hendrikvincent 0:05ccbd4f84f1 648 ip_frag_free_pbuf_custom_ref(pcr);
hendrikvincent 0:05ccbd4f84f1 649 }
hendrikvincent 0:05ccbd4f84f1 650 #endif /* !LWIP_NETIF_TX_SINGLE_PBUF */
hendrikvincent 0:05ccbd4f84f1 651 #endif /* IP_FRAG_USES_STATIC_BUF */
hendrikvincent 0:05ccbd4f84f1 652
hendrikvincent 0:05ccbd4f84f1 653 /**
hendrikvincent 0:05ccbd4f84f1 654 * Fragment an IP datagram if too large for the netif.
hendrikvincent 0:05ccbd4f84f1 655 *
hendrikvincent 0:05ccbd4f84f1 656 * Chop the datagram in MTU sized chunks and send them in order
hendrikvincent 0:05ccbd4f84f1 657 * by using a fixed size static memory buffer (PBUF_REF) or
hendrikvincent 0:05ccbd4f84f1 658 * point PBUF_REFs into p (depending on IP_FRAG_USES_STATIC_BUF).
hendrikvincent 0:05ccbd4f84f1 659 *
hendrikvincent 0:05ccbd4f84f1 660 * @param p ip packet to send
hendrikvincent 0:05ccbd4f84f1 661 * @param netif the netif on which to send
hendrikvincent 0:05ccbd4f84f1 662 * @param dest destination ip address to which to send
hendrikvincent 0:05ccbd4f84f1 663 *
hendrikvincent 0:05ccbd4f84f1 664 * @return ERR_OK if sent successfully, err_t otherwise
hendrikvincent 0:05ccbd4f84f1 665 */
hendrikvincent 0:05ccbd4f84f1 666 err_t
hendrikvincent 0:05ccbd4f84f1 667 ip_frag(struct pbuf *p, struct netif *netif, ip_addr_t *dest)
hendrikvincent 0:05ccbd4f84f1 668 {
hendrikvincent 0:05ccbd4f84f1 669 struct pbuf *rambuf;
hendrikvincent 0:05ccbd4f84f1 670 #if IP_FRAG_USES_STATIC_BUF
hendrikvincent 0:05ccbd4f84f1 671 struct pbuf *header;
hendrikvincent 0:05ccbd4f84f1 672 #else
hendrikvincent 0:05ccbd4f84f1 673 #if !LWIP_NETIF_TX_SINGLE_PBUF
hendrikvincent 0:05ccbd4f84f1 674 struct pbuf *newpbuf;
hendrikvincent 0:05ccbd4f84f1 675 #endif
hendrikvincent 0:05ccbd4f84f1 676 struct ip_hdr *original_iphdr;
hendrikvincent 0:05ccbd4f84f1 677 #endif
hendrikvincent 0:05ccbd4f84f1 678 struct ip_hdr *iphdr;
hendrikvincent 0:05ccbd4f84f1 679 u16_t nfb;
hendrikvincent 0:05ccbd4f84f1 680 u16_t left, cop;
hendrikvincent 0:05ccbd4f84f1 681 u16_t mtu = netif->mtu;
hendrikvincent 0:05ccbd4f84f1 682 u16_t ofo, omf;
hendrikvincent 0:05ccbd4f84f1 683 u16_t last;
hendrikvincent 0:05ccbd4f84f1 684 u16_t poff = IP_HLEN;
hendrikvincent 0:05ccbd4f84f1 685 u16_t tmp;
hendrikvincent 0:05ccbd4f84f1 686 #if !IP_FRAG_USES_STATIC_BUF && !LWIP_NETIF_TX_SINGLE_PBUF
hendrikvincent 0:05ccbd4f84f1 687 u16_t newpbuflen = 0;
hendrikvincent 0:05ccbd4f84f1 688 u16_t left_to_copy;
hendrikvincent 0:05ccbd4f84f1 689 #endif
hendrikvincent 0:05ccbd4f84f1 690
hendrikvincent 0:05ccbd4f84f1 691 /* Get a RAM based MTU sized pbuf */
hendrikvincent 0:05ccbd4f84f1 692 #if IP_FRAG_USES_STATIC_BUF
hendrikvincent 0:05ccbd4f84f1 693 /* When using a static buffer, we use a PBUF_REF, which we will
hendrikvincent 0:05ccbd4f84f1 694 * use to reference the packet (without link header).
hendrikvincent 0:05ccbd4f84f1 695 * Layer and length is irrelevant.
hendrikvincent 0:05ccbd4f84f1 696 */
hendrikvincent 0:05ccbd4f84f1 697 rambuf = pbuf_alloc(PBUF_LINK, 0, PBUF_REF);
hendrikvincent 0:05ccbd4f84f1 698 if (rambuf == NULL) {
hendrikvincent 0:05ccbd4f84f1 699 LWIP_DEBUGF(IP_REASS_DEBUG, ("ip_frag: pbuf_alloc(PBUF_LINK, 0, PBUF_REF) failed\n"));
hendrikvincent 0:05ccbd4f84f1 700 return ERR_MEM;
hendrikvincent 0:05ccbd4f84f1 701 }
hendrikvincent 0:05ccbd4f84f1 702 rambuf->tot_len = rambuf->len = mtu;
hendrikvincent 0:05ccbd4f84f1 703 rambuf->payload = LWIP_MEM_ALIGN((void *)buf);
hendrikvincent 0:05ccbd4f84f1 704
hendrikvincent 0:05ccbd4f84f1 705 /* Copy the IP header in it */
hendrikvincent 0:05ccbd4f84f1 706 iphdr = (struct ip_hdr *)rambuf->payload;
hendrikvincent 0:05ccbd4f84f1 707 SMEMCPY(iphdr, p->payload, IP_HLEN);
hendrikvincent 0:05ccbd4f84f1 708 #else /* IP_FRAG_USES_STATIC_BUF */
hendrikvincent 0:05ccbd4f84f1 709 original_iphdr = (struct ip_hdr *)p->payload;
hendrikvincent 0:05ccbd4f84f1 710 iphdr = original_iphdr;
hendrikvincent 0:05ccbd4f84f1 711 #endif /* IP_FRAG_USES_STATIC_BUF */
hendrikvincent 0:05ccbd4f84f1 712
hendrikvincent 0:05ccbd4f84f1 713 /* Save original offset */
hendrikvincent 0:05ccbd4f84f1 714 tmp = ntohs(IPH_OFFSET(iphdr));
hendrikvincent 0:05ccbd4f84f1 715 ofo = tmp & IP_OFFMASK;
hendrikvincent 0:05ccbd4f84f1 716 omf = tmp & IP_MF;
hendrikvincent 0:05ccbd4f84f1 717
hendrikvincent 0:05ccbd4f84f1 718 left = p->tot_len - IP_HLEN;
hendrikvincent 0:05ccbd4f84f1 719
hendrikvincent 0:05ccbd4f84f1 720 nfb = (mtu - IP_HLEN) / 8;
hendrikvincent 0:05ccbd4f84f1 721
hendrikvincent 0:05ccbd4f84f1 722 while (left) {
hendrikvincent 0:05ccbd4f84f1 723 last = (left <= mtu - IP_HLEN);
hendrikvincent 0:05ccbd4f84f1 724
hendrikvincent 0:05ccbd4f84f1 725 /* Set new offset and MF flag */
hendrikvincent 0:05ccbd4f84f1 726 tmp = omf | (IP_OFFMASK & (ofo));
hendrikvincent 0:05ccbd4f84f1 727 if (!last) {
hendrikvincent 0:05ccbd4f84f1 728 tmp = tmp | IP_MF;
hendrikvincent 0:05ccbd4f84f1 729 }
hendrikvincent 0:05ccbd4f84f1 730
hendrikvincent 0:05ccbd4f84f1 731 /* Fill this fragment */
hendrikvincent 0:05ccbd4f84f1 732 cop = last ? left : nfb * 8;
hendrikvincent 0:05ccbd4f84f1 733
hendrikvincent 0:05ccbd4f84f1 734 #if IP_FRAG_USES_STATIC_BUF
hendrikvincent 0:05ccbd4f84f1 735 poff += pbuf_copy_partial(p, (u8_t*)iphdr + IP_HLEN, cop, poff);
hendrikvincent 0:05ccbd4f84f1 736 #else /* IP_FRAG_USES_STATIC_BUF */
hendrikvincent 0:05ccbd4f84f1 737 #if LWIP_NETIF_TX_SINGLE_PBUF
hendrikvincent 0:05ccbd4f84f1 738 rambuf = pbuf_alloc(PBUF_IP, cop, PBUF_RAM);
hendrikvincent 0:05ccbd4f84f1 739 if (rambuf == NULL) {
hendrikvincent 0:05ccbd4f84f1 740 return ERR_MEM;
hendrikvincent 0:05ccbd4f84f1 741 }
hendrikvincent 0:05ccbd4f84f1 742 LWIP_ASSERT("this needs a pbuf in one piece!",
hendrikvincent 0:05ccbd4f84f1 743 (rambuf->len == rambuf->tot_len) && (rambuf->next == NULL));
hendrikvincent 0:05ccbd4f84f1 744 poff += pbuf_copy_partial(p, rambuf->payload, cop, poff);
hendrikvincent 0:05ccbd4f84f1 745 /* make room for the IP header */
hendrikvincent 0:05ccbd4f84f1 746 if(pbuf_header(rambuf, IP_HLEN)) {
hendrikvincent 0:05ccbd4f84f1 747 pbuf_free(rambuf);
hendrikvincent 0:05ccbd4f84f1 748 return ERR_MEM;
hendrikvincent 0:05ccbd4f84f1 749 }
hendrikvincent 0:05ccbd4f84f1 750 /* fill in the IP header */
hendrikvincent 0:05ccbd4f84f1 751 SMEMCPY(rambuf->payload, original_iphdr, IP_HLEN);
hendrikvincent 0:05ccbd4f84f1 752 iphdr = rambuf->payload;
hendrikvincent 0:05ccbd4f84f1 753 #else /* LWIP_NETIF_TX_SINGLE_PBUF */
hendrikvincent 0:05ccbd4f84f1 754 /* When not using a static buffer, create a chain of pbufs.
hendrikvincent 0:05ccbd4f84f1 755 * The first will be a PBUF_RAM holding the link and IP header.
hendrikvincent 0:05ccbd4f84f1 756 * The rest will be PBUF_REFs mirroring the pbuf chain to be fragged,
hendrikvincent 0:05ccbd4f84f1 757 * but limited to the size of an mtu.
hendrikvincent 0:05ccbd4f84f1 758 */
hendrikvincent 0:05ccbd4f84f1 759 rambuf = pbuf_alloc(PBUF_LINK, IP_HLEN, PBUF_RAM);
hendrikvincent 0:05ccbd4f84f1 760 if (rambuf == NULL) {
hendrikvincent 0:05ccbd4f84f1 761 return ERR_MEM;
hendrikvincent 0:05ccbd4f84f1 762 }
hendrikvincent 0:05ccbd4f84f1 763 LWIP_ASSERT("this needs a pbuf in one piece!",
hendrikvincent 0:05ccbd4f84f1 764 (p->len >= (IP_HLEN)));
hendrikvincent 0:05ccbd4f84f1 765 SMEMCPY(rambuf->payload, original_iphdr, IP_HLEN);
hendrikvincent 0:05ccbd4f84f1 766 iphdr = (struct ip_hdr *)rambuf->payload;
hendrikvincent 0:05ccbd4f84f1 767
hendrikvincent 0:05ccbd4f84f1 768 /* Can just adjust p directly for needed offset. */
hendrikvincent 0:05ccbd4f84f1 769 p->payload = (u8_t *)p->payload + poff;
hendrikvincent 0:05ccbd4f84f1 770 p->len -= poff;
hendrikvincent 0:05ccbd4f84f1 771
hendrikvincent 0:05ccbd4f84f1 772 left_to_copy = cop;
hendrikvincent 0:05ccbd4f84f1 773 while (left_to_copy) {
hendrikvincent 0:05ccbd4f84f1 774 struct pbuf_custom_ref *pcr;
hendrikvincent 0:05ccbd4f84f1 775 newpbuflen = (left_to_copy < p->len) ? left_to_copy : p->len;
hendrikvincent 0:05ccbd4f84f1 776 /* Is this pbuf already empty? */
hendrikvincent 0:05ccbd4f84f1 777 if (!newpbuflen) {
hendrikvincent 0:05ccbd4f84f1 778 p = p->next;
hendrikvincent 0:05ccbd4f84f1 779 continue;
hendrikvincent 0:05ccbd4f84f1 780 }
hendrikvincent 0:05ccbd4f84f1 781 pcr = ip_frag_alloc_pbuf_custom_ref();
hendrikvincent 0:05ccbd4f84f1 782 if (pcr == NULL) {
hendrikvincent 0:05ccbd4f84f1 783 pbuf_free(rambuf);
hendrikvincent 0:05ccbd4f84f1 784 return ERR_MEM;
hendrikvincent 0:05ccbd4f84f1 785 }
hendrikvincent 0:05ccbd4f84f1 786 /* Mirror this pbuf, although we might not need all of it. */
hendrikvincent 0:05ccbd4f84f1 787 newpbuf = pbuf_alloced_custom(PBUF_RAW, newpbuflen, PBUF_REF, &pcr->pc, p->payload, newpbuflen);
hendrikvincent 0:05ccbd4f84f1 788 if (newpbuf == NULL) {
hendrikvincent 0:05ccbd4f84f1 789 ip_frag_free_pbuf_custom_ref(pcr);
hendrikvincent 0:05ccbd4f84f1 790 pbuf_free(rambuf);
hendrikvincent 0:05ccbd4f84f1 791 return ERR_MEM;
hendrikvincent 0:05ccbd4f84f1 792 }
hendrikvincent 0:05ccbd4f84f1 793 pbuf_ref(p);
hendrikvincent 0:05ccbd4f84f1 794 pcr->original = p;
hendrikvincent 0:05ccbd4f84f1 795 pcr->pc.custom_free_function = ipfrag_free_pbuf_custom;
hendrikvincent 0:05ccbd4f84f1 796
hendrikvincent 0:05ccbd4f84f1 797 /* Add it to end of rambuf's chain, but using pbuf_cat, not pbuf_chain
hendrikvincent 0:05ccbd4f84f1 798 * so that it is removed when pbuf_dechain is later called on rambuf.
hendrikvincent 0:05ccbd4f84f1 799 */
hendrikvincent 0:05ccbd4f84f1 800 pbuf_cat(rambuf, newpbuf);
hendrikvincent 0:05ccbd4f84f1 801 left_to_copy -= newpbuflen;
hendrikvincent 0:05ccbd4f84f1 802 if (left_to_copy) {
hendrikvincent 0:05ccbd4f84f1 803 p = p->next;
hendrikvincent 0:05ccbd4f84f1 804 }
hendrikvincent 0:05ccbd4f84f1 805 }
hendrikvincent 0:05ccbd4f84f1 806 poff = newpbuflen;
hendrikvincent 0:05ccbd4f84f1 807 #endif /* LWIP_NETIF_TX_SINGLE_PBUF */
hendrikvincent 0:05ccbd4f84f1 808 #endif /* IP_FRAG_USES_STATIC_BUF */
hendrikvincent 0:05ccbd4f84f1 809
hendrikvincent 0:05ccbd4f84f1 810 /* Correct header */
hendrikvincent 0:05ccbd4f84f1 811 IPH_OFFSET_SET(iphdr, htons(tmp));
hendrikvincent 0:05ccbd4f84f1 812 IPH_LEN_SET(iphdr, htons(cop + IP_HLEN));
hendrikvincent 0:05ccbd4f84f1 813 IPH_CHKSUM_SET(iphdr, 0);
hendrikvincent 0:05ccbd4f84f1 814 IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, IP_HLEN));
hendrikvincent 0:05ccbd4f84f1 815
hendrikvincent 0:05ccbd4f84f1 816 #if IP_FRAG_USES_STATIC_BUF
hendrikvincent 0:05ccbd4f84f1 817 if (last) {
hendrikvincent 0:05ccbd4f84f1 818 pbuf_realloc(rambuf, left + IP_HLEN);
hendrikvincent 0:05ccbd4f84f1 819 }
hendrikvincent 0:05ccbd4f84f1 820
hendrikvincent 0:05ccbd4f84f1 821 /* This part is ugly: we alloc a RAM based pbuf for
hendrikvincent 0:05ccbd4f84f1 822 * the link level header for each chunk and then
hendrikvincent 0:05ccbd4f84f1 823 * free it.A PBUF_ROM style pbuf for which pbuf_header
hendrikvincent 0:05ccbd4f84f1 824 * worked would make things simpler.
hendrikvincent 0:05ccbd4f84f1 825 */
hendrikvincent 0:05ccbd4f84f1 826 header = pbuf_alloc(PBUF_LINK, 0, PBUF_RAM);
hendrikvincent 0:05ccbd4f84f1 827 if (header != NULL) {
hendrikvincent 0:05ccbd4f84f1 828 pbuf_chain(header, rambuf);
hendrikvincent 0:05ccbd4f84f1 829 netif->output(netif, header, dest);
hendrikvincent 0:05ccbd4f84f1 830 IPFRAG_STATS_INC(ip_frag.xmit);
hendrikvincent 0:05ccbd4f84f1 831 snmp_inc_ipfragcreates();
hendrikvincent 0:05ccbd4f84f1 832 pbuf_free(header);
hendrikvincent 0:05ccbd4f84f1 833 } else {
hendrikvincent 0:05ccbd4f84f1 834 LWIP_DEBUGF(IP_REASS_DEBUG, ("ip_frag: pbuf_alloc() for header failed\n"));
hendrikvincent 0:05ccbd4f84f1 835 pbuf_free(rambuf);
hendrikvincent 0:05ccbd4f84f1 836 return ERR_MEM;
hendrikvincent 0:05ccbd4f84f1 837 }
hendrikvincent 0:05ccbd4f84f1 838 #else /* IP_FRAG_USES_STATIC_BUF */
hendrikvincent 0:05ccbd4f84f1 839 /* No need for separate header pbuf - we allowed room for it in rambuf
hendrikvincent 0:05ccbd4f84f1 840 * when allocated.
hendrikvincent 0:05ccbd4f84f1 841 */
hendrikvincent 0:05ccbd4f84f1 842 netif->output(netif, rambuf, dest);
hendrikvincent 0:05ccbd4f84f1 843 IPFRAG_STATS_INC(ip_frag.xmit);
hendrikvincent 0:05ccbd4f84f1 844
hendrikvincent 0:05ccbd4f84f1 845 /* Unfortunately we can't reuse rambuf - the hardware may still be
hendrikvincent 0:05ccbd4f84f1 846 * using the buffer. Instead we free it (and the ensuing chain) and
hendrikvincent 0:05ccbd4f84f1 847 * recreate it next time round the loop. If we're lucky the hardware
hendrikvincent 0:05ccbd4f84f1 848 * will have already sent the packet, the free will really free, and
hendrikvincent 0:05ccbd4f84f1 849 * there will be zero memory penalty.
hendrikvincent 0:05ccbd4f84f1 850 */
hendrikvincent 0:05ccbd4f84f1 851
hendrikvincent 0:05ccbd4f84f1 852 pbuf_free(rambuf);
hendrikvincent 0:05ccbd4f84f1 853 #endif /* IP_FRAG_USES_STATIC_BUF */
hendrikvincent 0:05ccbd4f84f1 854 left -= cop;
hendrikvincent 0:05ccbd4f84f1 855 ofo += nfb;
hendrikvincent 0:05ccbd4f84f1 856 }
hendrikvincent 0:05ccbd4f84f1 857 #if IP_FRAG_USES_STATIC_BUF
hendrikvincent 0:05ccbd4f84f1 858 pbuf_free(rambuf);
hendrikvincent 0:05ccbd4f84f1 859 #endif /* IP_FRAG_USES_STATIC_BUF */
hendrikvincent 0:05ccbd4f84f1 860 snmp_inc_ipfragoks();
hendrikvincent 0:05ccbd4f84f1 861 return ERR_OK;
hendrikvincent 0:05ccbd4f84f1 862 }
hendrikvincent 0:05ccbd4f84f1 863 #endif /* IP_FRAG */