+++ /dev/null
-/**
- * @file
- * This is the IPv4 packet segmentation and reassembly implementation.
- *
- */
-
-/*
- * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without modification,
- * are permitted provided that the following conditions are met:
- *
- * 1. Redistributions of source code must retain the above copyright notice,
- * this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright notice,
- * this list of conditions and the following disclaimer in the documentation
- * and/or other materials provided with the distribution.
- * 3. The name of the author may not be used to endorse or promote products
- * derived from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
- * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
- * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
- * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
- * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
- * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
- * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
- * OF SUCH DAMAGE.
- *
- * This file is part of the lwIP TCP/IP stack.
- *
- * Author: Jani Monoses <jani@iv.ro>
- * Simon Goldschmidt
- * original reassembly code by Adam Dunkels <adam@sics.se>
- *
- */
-
-#include "lwip/opt.h"
-#include "lwip/ip_frag.h"
-#include "lwip/def.h"
-#include "lwip/inet_chksum.h"
-#include "lwip/netif.h"
-#include "lwip/snmp.h"
-#include "lwip/stats.h"
-#include "lwip/icmp.h"
-
-#include <string.h>
-
-#if IP_REASSEMBLY
-/**
- * The IP reassembly code currently has the following limitations:
- * - IP header options are not supported
- * - fragments must not overlap (e.g. due to different routes),
- * currently, overlapping or duplicate fragments are thrown away
- * if IP_REASS_CHECK_OVERLAP=1 (the default)!
- *
- * @todo: work with IP header options
- */
-
-/** Setting this to 0, you can turn off checking the fragments for overlapping
- * regions. The code gets a little smaller. Only use this if you know that
- * overlapping won't occur on your network! */
-#ifndef IP_REASS_CHECK_OVERLAP
-#define IP_REASS_CHECK_OVERLAP 1
-#endif /* IP_REASS_CHECK_OVERLAP */
-
-/** Set to 0 to prevent freeing the oldest datagram when the reassembly buffer is
- * full (IP_REASS_MAX_PBUFS pbufs are enqueued). The code gets a little smaller.
- * Datagrams will be freed by timeout only. Especially useful when MEMP_NUM_REASSDATA
- * is set to 1, so one datagram can be reassembled at a time, only. */
-#ifndef IP_REASS_FREE_OLDEST
-#define IP_REASS_FREE_OLDEST 1
-#endif /* IP_REASS_FREE_OLDEST */
-
-#define IP_REASS_FLAG_LASTFRAG 0x01
-
-/** This is a helper struct which holds the starting
- * offset and the ending offset of this fragment to
- * easily chain the fragments.
- * It has the same packing requirements as the IP header, since it replaces
- * the IP header in memory in incoming fragments (after copying it) to keep
- * track of the various fragments. (-> If the IP header doesn't need packing,
- * this struct doesn't need packing, too.)
- */
-#ifdef PACK_STRUCT_USE_INCLUDES
-# include "arch/bpstruct.h"
-#endif
-PACK_STRUCT_BEGIN
-struct ip_reass_helper {
- PACK_STRUCT_FIELD(struct pbuf *next_pbuf);
- PACK_STRUCT_FIELD(u16_t start);
- PACK_STRUCT_FIELD(u16_t end);
-} PACK_STRUCT_STRUCT;
-PACK_STRUCT_END
-#ifdef PACK_STRUCT_USE_INCLUDES
-# include "arch/epstruct.h"
-#endif
-
-#define IP_ADDRESSES_AND_ID_MATCH(iphdrA, iphdrB) \
- (ip_addr_cmp(&(iphdrA)->src, &(iphdrB)->src) && \
- ip_addr_cmp(&(iphdrA)->dest, &(iphdrB)->dest) && \
- IPH_ID(iphdrA) == IPH_ID(iphdrB)) ? 1 : 0
-
-/* global variables */
-static struct ip_reassdata *reassdatagrams;
-static u16_t ip_reass_pbufcount;
-
-/* function prototypes */
-static void ip_reass_dequeue_datagram(struct ip_reassdata *ipr, struct ip_reassdata *prev);
-static int ip_reass_free_complete_datagram(struct ip_reassdata *ipr, struct ip_reassdata *prev);
-
-/**
- * Reassembly timer base function
- * for both NO_SYS == 0 and 1 (!).
- *
- * Should be called every 1000 msec (defined by IP_TMR_INTERVAL).
- */
-void
-ip_reass_tmr(void)
-{
- struct ip_reassdata *r, *prev = NULL;
-
- r = reassdatagrams;
- while (r != NULL) {
- /* Decrement the timer. Once it reaches 0,
- * clean up the incomplete fragment assembly */
- if (r->timer > 0) {
- r->timer--;
- LWIP_DEBUGF(IP_REASS_DEBUG, ("ip_reass_tmr: timer dec %"U16_F"\n",(u16_t)r->timer));
- prev = r;
- r = r->next;
- } else {
- /* reassembly timed out */
- struct ip_reassdata *tmp;
- LWIP_DEBUGF(IP_REASS_DEBUG, ("ip_reass_tmr: timer timed out\n"));
- tmp = r;
- /* get the next pointer before freeing */
- r = r->next;
- /* free the helper struct and all enqueued pbufs */
- ip_reass_free_complete_datagram(tmp, prev);
- }
- }
-}
-
-/**
- * Free a datagram (struct ip_reassdata) and all its pbufs.
- * Updates the total count of enqueued pbufs (ip_reass_pbufcount),
- * SNMP counters and sends an ICMP time exceeded packet.
- *
- * @param ipr datagram to free
- * @param prev the previous datagram in the linked list
- * @return the number of pbufs freed
- */
-static int
-ip_reass_free_complete_datagram(struct ip_reassdata *ipr, struct ip_reassdata *prev)
-{
- u16_t pbufs_freed = 0;
- u8_t clen;
- struct pbuf *p;
- struct ip_reass_helper *iprh;
-
- LWIP_ASSERT("prev != ipr", prev != ipr);
- if (prev != NULL) {
- LWIP_ASSERT("prev->next == ipr", prev->next == ipr);
- }
-
- snmp_inc_ipreasmfails();
-#if LWIP_ICMP
- iprh = (struct ip_reass_helper *)ipr->p->payload;
- if (iprh->start == 0) {
- /* The first fragment was received, send ICMP time exceeded. */
- /* First, de-queue the first pbuf from r->p. */
- p = ipr->p;
- ipr->p = iprh->next_pbuf;
- /* Then, copy the original header into it. */
- SMEMCPY(p->payload, &ipr->iphdr, IP_HLEN);
- icmp_time_exceeded(p, ICMP_TE_FRAG);
- clen = pbuf_clen(p);
- LWIP_ASSERT("pbufs_freed + clen <= 0xffff", pbufs_freed + clen <= 0xffff);
- pbufs_freed += clen;
- pbuf_free(p);
- }
-#endif /* LWIP_ICMP */
-
- /* First, free all received pbufs. The individual pbufs need to be released
- separately as they have not yet been chained */
- p = ipr->p;
- while (p != NULL) {
- struct pbuf *pcur;
- iprh = (struct ip_reass_helper *)p->payload;
- pcur = p;
- /* get the next pointer before freeing */
- p = iprh->next_pbuf;
- clen = pbuf_clen(pcur);
- LWIP_ASSERT("pbufs_freed + clen <= 0xffff", pbufs_freed + clen <= 0xffff);
- pbufs_freed += clen;
- pbuf_free(pcur);
- }
- /* Then, unchain the struct ip_reassdata from the list and free it. */
- ip_reass_dequeue_datagram(ipr, prev);
- LWIP_ASSERT("ip_reass_pbufcount >= clen", ip_reass_pbufcount >= pbufs_freed);
- ip_reass_pbufcount -= pbufs_freed;
-
- return pbufs_freed;
-}
-
-#if IP_REASS_FREE_OLDEST
-/**
- * Free the oldest datagram to make room for enqueueing new fragments.
- * The datagram 'fraghdr' belongs to is not freed!
- *
- * @param fraghdr IP header of the current fragment
- * @param pbufs_needed number of pbufs needed to enqueue
- * (used for freeing other datagrams if not enough space)
- * @return the number of pbufs freed
- */
-static int
-ip_reass_remove_oldest_datagram(struct ip_hdr *fraghdr, int pbufs_needed)
-{
- /* @todo Can't we simply remove the last datagram in the
- * linked list behind reassdatagrams?
- */
- struct ip_reassdata *r, *oldest, *prev;
- int pbufs_freed = 0, pbufs_freed_current;
- int other_datagrams;
-
- /* Free datagrams until being allowed to enqueue 'pbufs_needed' pbufs,
- * but don't free the datagram that 'fraghdr' belongs to! */
- do {
- oldest = NULL;
- prev = NULL;
- other_datagrams = 0;
- r = reassdatagrams;
- while (r != NULL) {
- if (!IP_ADDRESSES_AND_ID_MATCH(&r->iphdr, fraghdr)) {
- /* Not the same datagram as fraghdr */
- other_datagrams++;
- if (oldest == NULL) {
- oldest = r;
- } else if (r->timer <= oldest->timer) {
- /* older than the previous oldest */
- oldest = r;
- }
- }
- if (r->next != NULL) {
- prev = r;
- }
- r = r->next;
- }
- if (oldest != NULL) {
- pbufs_freed_current = ip_reass_free_complete_datagram(oldest, prev);
- pbufs_freed += pbufs_freed_current;
- }
- } while ((pbufs_freed < pbufs_needed) && (other_datagrams > 1));
- return pbufs_freed;
-}
-#endif /* IP_REASS_FREE_OLDEST */
-
-/**
- * Enqueues a new fragment into the fragment queue
- * @param fraghdr points to the new fragments IP hdr
- * @param clen number of pbufs needed to enqueue (used for freeing other datagrams if not enough space)
- * @return A pointer to the queue location into which the fragment was enqueued
- */
-static struct ip_reassdata*
-ip_reass_enqueue_new_datagram(struct ip_hdr *fraghdr, int clen)
-{
- struct ip_reassdata* ipr;
- /* No matching previous fragment found, allocate a new reassdata struct */
- ipr = (struct ip_reassdata *)memp_malloc(MEMP_REASSDATA);
- if (ipr == NULL) {
-#if IP_REASS_FREE_OLDEST
- if (ip_reass_remove_oldest_datagram(fraghdr, clen) >= clen) {
- ipr = (struct ip_reassdata *)memp_malloc(MEMP_REASSDATA);
- }
- if (ipr == NULL)
-#endif /* IP_REASS_FREE_OLDEST */
- {
- IPFRAG_STATS_INC(ip_frag.memerr);
- LWIP_DEBUGF(IP_REASS_DEBUG,("Failed to alloc reassdata struct\n"));
- return NULL;
- }
- }
- memset(ipr, 0, sizeof(struct ip_reassdata));
- ipr->timer = IP_REASS_MAXAGE;
-
- /* enqueue the new structure to the front of the list */
- ipr->next = reassdatagrams;
- reassdatagrams = ipr;
- /* copy the ip header for later tests and input */
- /* @todo: no ip options supported? */
- SMEMCPY(&(ipr->iphdr), fraghdr, IP_HLEN);
- return ipr;
-}
-
-/**
- * Dequeues a datagram from the datagram queue. Doesn't deallocate the pbufs.
- * @param ipr points to the queue entry to dequeue
- */
-static void
-ip_reass_dequeue_datagram(struct ip_reassdata *ipr, struct ip_reassdata *prev)
-{
-
- /* dequeue the reass struct */
- if (reassdatagrams == ipr) {
- /* it was the first in the list */
- reassdatagrams = ipr->next;
- } else {
- /* it wasn't the first, so it must have a valid 'prev' */
- LWIP_ASSERT("sanity check linked list", prev != NULL);
- prev->next = ipr->next;
- }
-
- /* now we can free the ip_reass struct */
- memp_free(MEMP_REASSDATA, ipr);
-}
-
-/**
- * Chain a new pbuf into the pbuf list that composes the datagram. The pbuf list
- * will grow over time as new pbufs are rx.
- * Also checks that the datagram passes basic continuity checks (if the last
- * fragment was received at least once).
- * @param root_p points to the 'root' pbuf for the current datagram being assembled.
- * @param new_p points to the pbuf for the current fragment
- * @return 0 if invalid, >0 otherwise
- */
-static int
-ip_reass_chain_frag_into_datagram_and_validate(struct ip_reassdata *ipr, struct pbuf *new_p)
-{
- struct ip_reass_helper *iprh, *iprh_tmp, *iprh_prev=NULL;
- struct pbuf *q;
- u16_t offset,len;
- struct ip_hdr *fraghdr;
- int valid = 1;
-
- /* Extract length and fragment offset from current fragment */
- fraghdr = (struct ip_hdr*)new_p->payload;
- len = ntohs(IPH_LEN(fraghdr)) - IPH_HL(fraghdr) * 4;
- offset = (ntohs(IPH_OFFSET(fraghdr)) & IP_OFFMASK) * 8;
-
- /* overwrite the fragment's ip header from the pbuf with our helper struct,
- * and setup the embedded helper structure. */
- /* make sure the struct ip_reass_helper fits into the IP header */
- LWIP_ASSERT("sizeof(struct ip_reass_helper) <= IP_HLEN",
- sizeof(struct ip_reass_helper) <= IP_HLEN);
- iprh = (struct ip_reass_helper*)new_p->payload;
- iprh->next_pbuf = NULL;
- iprh->start = offset;
- iprh->end = offset + len;
-
- /* Iterate through until we either get to the end of the list (append),
- * or we find on with a larger offset (insert). */
- for (q = ipr->p; q != NULL;) {
- iprh_tmp = (struct ip_reass_helper*)q->payload;
- if (iprh->start < iprh_tmp->start) {
- /* the new pbuf should be inserted before this */
- iprh->next_pbuf = q;
- if (iprh_prev != NULL) {
- /* not the fragment with the lowest offset */
-#if IP_REASS_CHECK_OVERLAP
- if ((iprh->start < iprh_prev->end) || (iprh->end > iprh_tmp->start)) {
- /* fragment overlaps with previous or following, throw away */
- goto freepbuf;
- }
-#endif /* IP_REASS_CHECK_OVERLAP */
- iprh_prev->next_pbuf = new_p;
- } else {
- /* fragment with the lowest offset */
- ipr->p = new_p;
- }
- break;
- } else if(iprh->start == iprh_tmp->start) {
- /* received the same datagram twice: no need to keep the datagram */
- goto freepbuf;
-#if IP_REASS_CHECK_OVERLAP
- } else if(iprh->start < iprh_tmp->end) {
- /* overlap: no need to keep the new datagram */
- goto freepbuf;
-#endif /* IP_REASS_CHECK_OVERLAP */
- } else {
- /* Check if the fragments received so far have no wholes. */
- if (iprh_prev != NULL) {
- if (iprh_prev->end != iprh_tmp->start) {
- /* There is a fragment missing between the current
- * and the previous fragment */
- valid = 0;
- }
- }
- }
- q = iprh_tmp->next_pbuf;
- iprh_prev = iprh_tmp;
- }
-
- /* If q is NULL, then we made it to the end of the list. Determine what to do now */
- if (q == NULL) {
- if (iprh_prev != NULL) {
- /* this is (for now), the fragment with the highest offset:
- * chain it to the last fragment */
-#if IP_REASS_CHECK_OVERLAP
- LWIP_ASSERT("check fragments don't overlap", iprh_prev->end <= iprh->start);
-#endif /* IP_REASS_CHECK_OVERLAP */
- iprh_prev->next_pbuf = new_p;
- if (iprh_prev->end != iprh->start) {
- valid = 0;
- }
- } else {
-#if IP_REASS_CHECK_OVERLAP
- LWIP_ASSERT("no previous fragment, this must be the first fragment!",
- ipr->p == NULL);
-#endif /* IP_REASS_CHECK_OVERLAP */
- /* this is the first fragment we ever received for this ip datagram */
- ipr->p = new_p;
- }
- }
-
- /* At this point, the validation part begins: */
- /* If we already received the last fragment */
- if ((ipr->flags & IP_REASS_FLAG_LASTFRAG) != 0) {
- /* and had no wholes so far */
- if (valid) {
- /* then check if the rest of the fragments is here */
- /* Check if the queue starts with the first datagram */
- if (((struct ip_reass_helper*)ipr->p->payload)->start != 0) {
- valid = 0;
- } else {
- /* and check that there are no wholes after this datagram */
- iprh_prev = iprh;
- q = iprh->next_pbuf;
- while (q != NULL) {
- iprh = (struct ip_reass_helper*)q->payload;
- if (iprh_prev->end != iprh->start) {
- valid = 0;
- break;
- }
- iprh_prev = iprh;
- q = iprh->next_pbuf;
- }
- /* if still valid, all fragments are received
- * (because to the MF==0 already arrived */
- if (valid) {
- LWIP_ASSERT("sanity check", ipr->p != NULL);
- LWIP_ASSERT("sanity check",
- ((struct ip_reass_helper*)ipr->p->payload) != iprh);
- LWIP_ASSERT("validate_datagram:next_pbuf!=NULL",
- iprh->next_pbuf == NULL);
- LWIP_ASSERT("validate_datagram:datagram end!=datagram len",
- iprh->end == ipr->datagram_len);
- }
- }
- }
- /* If valid is 0 here, there are some fragments missing in the middle
- * (since MF == 0 has already arrived). Such datagrams simply time out if
- * no more fragments are received... */
- return valid;
- }
- /* If we come here, not all fragments were received, yet! */
- return 0; /* not yet valid! */
-#if IP_REASS_CHECK_OVERLAP
-freepbuf:
- ip_reass_pbufcount -= pbuf_clen(new_p);
- pbuf_free(new_p);
- return 0;
-#endif /* IP_REASS_CHECK_OVERLAP */
-}
-
-/**
- * Reassembles incoming IP fragments into an IP datagram.
- *
- * @param p points to a pbuf chain of the fragment
- * @return NULL if reassembly is incomplete, ? otherwise
- */
-struct pbuf *
-ip_reass(struct pbuf *p)
-{
- struct pbuf *r;
- struct ip_hdr *fraghdr;
- struct ip_reassdata *ipr;
- struct ip_reass_helper *iprh;
- u16_t offset, len;
- u8_t clen;
- struct ip_reassdata *ipr_prev = NULL;
-
- IPFRAG_STATS_INC(ip_frag.recv);
- snmp_inc_ipreasmreqds();
-
- fraghdr = (struct ip_hdr*)p->payload;
-
- if ((IPH_HL(fraghdr) * 4) != IP_HLEN) {
- LWIP_DEBUGF(IP_REASS_DEBUG,("ip_reass: IP options currently not supported!\n"));
- IPFRAG_STATS_INC(ip_frag.err);
- goto nullreturn;
- }
-
- offset = (ntohs(IPH_OFFSET(fraghdr)) & IP_OFFMASK) * 8;
- len = ntohs(IPH_LEN(fraghdr)) - IPH_HL(fraghdr) * 4;
-
- /* Check if we are allowed to enqueue more datagrams. */
- clen = pbuf_clen(p);
- if ((ip_reass_pbufcount + clen) > IP_REASS_MAX_PBUFS) {
-#if IP_REASS_FREE_OLDEST
- if (!ip_reass_remove_oldest_datagram(fraghdr, clen) ||
- ((ip_reass_pbufcount + clen) > IP_REASS_MAX_PBUFS))
-#endif /* IP_REASS_FREE_OLDEST */
- {
- /* No datagram could be freed and still too many pbufs enqueued */
- LWIP_DEBUGF(IP_REASS_DEBUG,("ip_reass: Overflow condition: pbufct=%d, clen=%d, MAX=%d\n",
- ip_reass_pbufcount, clen, IP_REASS_MAX_PBUFS));
- IPFRAG_STATS_INC(ip_frag.memerr);
- /* @todo: send ICMP time exceeded here? */
- /* drop this pbuf */
- goto nullreturn;
- }
- }
-
- /* Look for the datagram the fragment belongs to in the current datagram queue,
- * remembering the previous in the queue for later dequeueing. */
- for (ipr = reassdatagrams; ipr != NULL; ipr = ipr->next) {
- /* Check if the incoming fragment matches the one currently present
- in the reassembly buffer. If so, we proceed with copying the
- fragment into the buffer. */
- if (IP_ADDRESSES_AND_ID_MATCH(&ipr->iphdr, fraghdr)) {
- LWIP_DEBUGF(IP_REASS_DEBUG, ("ip_reass: matching previous fragment ID=%"X16_F"\n",
- ntohs(IPH_ID(fraghdr))));
- IPFRAG_STATS_INC(ip_frag.cachehit);
- break;
- }
- ipr_prev = ipr;
- }
-
- if (ipr == NULL) {
- /* Enqueue a new datagram into the datagram queue */
- ipr = ip_reass_enqueue_new_datagram(fraghdr, clen);
- /* Bail if unable to enqueue */
- if(ipr == NULL) {
- goto nullreturn;
- }
- } else {
- if (((ntohs(IPH_OFFSET(fraghdr)) & IP_OFFMASK) == 0) &&
- ((ntohs(IPH_OFFSET(&ipr->iphdr)) & IP_OFFMASK) != 0)) {
- /* ipr->iphdr is not the header from the first fragment, but fraghdr is
- * -> copy fraghdr into ipr->iphdr since we want to have the header
- * of the first fragment (for ICMP time exceeded and later, for copying
- * all options, if supported)*/
- SMEMCPY(&ipr->iphdr, fraghdr, IP_HLEN);
- }
- }
- /* Track the current number of pbufs current 'in-flight', in order to limit
- the number of fragments that may be enqueued at any one time */
- ip_reass_pbufcount += clen;
-
- /* At this point, we have either created a new entry or pointing
- * to an existing one */
-
- /* check for 'no more fragments', and update queue entry*/
- if ((IPH_OFFSET(fraghdr) & PP_NTOHS(IP_MF)) == 0) {
- ipr->flags |= IP_REASS_FLAG_LASTFRAG;
- ipr->datagram_len = offset + len;
- LWIP_DEBUGF(IP_REASS_DEBUG,
- ("ip_reass: last fragment seen, total len %"S16_F"\n",
- ipr->datagram_len));
- }
- /* find the right place to insert this pbuf */
- /* @todo: trim pbufs if fragments are overlapping */
- if (ip_reass_chain_frag_into_datagram_and_validate(ipr, p)) {
- /* the totally last fragment (flag more fragments = 0) was received at least
- * once AND all fragments are received */
- ipr->datagram_len += IP_HLEN;
-
- /* save the second pbuf before copying the header over the pointer */
- r = ((struct ip_reass_helper*)ipr->p->payload)->next_pbuf;
-
- /* copy the original ip header back to the first pbuf */
- fraghdr = (struct ip_hdr*)(ipr->p->payload);
- SMEMCPY(fraghdr, &ipr->iphdr, IP_HLEN);
- IPH_LEN_SET(fraghdr, htons(ipr->datagram_len));
- IPH_OFFSET_SET(fraghdr, 0);
- IPH_CHKSUM_SET(fraghdr, 0);
- /* @todo: do we need to set calculate the correct checksum? */
- IPH_CHKSUM_SET(fraghdr, inet_chksum(fraghdr, IP_HLEN));
-
- p = ipr->p;
-
- /* chain together the pbufs contained within the reass_data list. */
- while(r != NULL) {
- iprh = (struct ip_reass_helper*)r->payload;
-
- /* hide the ip header for every succeding fragment */
- pbuf_header(r, -IP_HLEN);
- pbuf_cat(p, r);
- r = iprh->next_pbuf;
- }
- /* release the sources allocate for the fragment queue entry */
- ip_reass_dequeue_datagram(ipr, ipr_prev);
-
- /* and adjust the number of pbufs currently queued for reassembly. */
- ip_reass_pbufcount -= pbuf_clen(p);
-
- /* Return the pbuf chain */
- return p;
- }
- /* the datagram is not (yet?) reassembled completely */
- LWIP_DEBUGF(IP_REASS_DEBUG,("ip_reass_pbufcount: %d out\n", ip_reass_pbufcount));
- return NULL;
-
-nullreturn:
- LWIP_DEBUGF(IP_REASS_DEBUG,("ip_reass: nullreturn\n"));
- IPFRAG_STATS_INC(ip_frag.drop);
- pbuf_free(p);
- return NULL;
-}
-#endif /* IP_REASSEMBLY */
-
-#if IP_FRAG
-#if IP_FRAG_USES_STATIC_BUF
-static u8_t buf[LWIP_MEM_ALIGN_SIZE(IP_FRAG_MAX_MTU + MEM_ALIGNMENT - 1)];
-#else /* IP_FRAG_USES_STATIC_BUF */
-
-#if !LWIP_NETIF_TX_SINGLE_PBUF
-/** Allocate a new struct pbuf_custom_ref */
-static struct pbuf_custom_ref*
-ip_frag_alloc_pbuf_custom_ref(void)
-{
- return (struct pbuf_custom_ref*)memp_malloc(MEMP_FRAG_PBUF);
-}
-
-/** Free a struct pbuf_custom_ref */
-static void
-ip_frag_free_pbuf_custom_ref(struct pbuf_custom_ref* p)
-{
- LWIP_ASSERT("p != NULL", p != NULL);
- memp_free(MEMP_FRAG_PBUF, p);
-}
-
-/** Free-callback function to free a 'struct pbuf_custom_ref', called by
- * pbuf_free. */
-static void
-ipfrag_free_pbuf_custom(struct pbuf *p)
-{
- struct pbuf_custom_ref *pcr = (struct pbuf_custom_ref*)p;
- LWIP_ASSERT("pcr != NULL", pcr != NULL);
- LWIP_ASSERT("pcr == p", (void*)pcr == (void*)p);
- if (pcr->original != NULL) {
- pbuf_free(pcr->original);
- }
- ip_frag_free_pbuf_custom_ref(pcr);
-}
-#endif /* !LWIP_NETIF_TX_SINGLE_PBUF */
-#endif /* IP_FRAG_USES_STATIC_BUF */
-
-/**
- * Fragment an IP datagram if too large for the netif.
- *
- * Chop the datagram in MTU sized chunks and send them in order
- * by using a fixed size static memory buffer (PBUF_REF) or
- * point PBUF_REFs into p (depending on IP_FRAG_USES_STATIC_BUF).
- *
- * @param p ip packet to send
- * @param netif the netif on which to send
- * @param dest destination ip address to which to send
- *
- * @return ERR_OK if sent successfully, err_t otherwise
- */
-err_t
-ip_frag(struct pbuf *p, struct netif *netif, ip_addr_t *dest)
-{
- struct pbuf *rambuf;
-#if IP_FRAG_USES_STATIC_BUF
- struct pbuf *header;
-#else
-#if !LWIP_NETIF_TX_SINGLE_PBUF
- struct pbuf *newpbuf;
-#endif
- struct ip_hdr *original_iphdr;
-#endif
- struct ip_hdr *iphdr;
- u16_t nfb;
- u16_t left, cop;
- u16_t mtu = netif->mtu;
- u16_t ofo, omf;
- u16_t last;
- u16_t poff = IP_HLEN;
- u16_t tmp;
-#if !IP_FRAG_USES_STATIC_BUF && !LWIP_NETIF_TX_SINGLE_PBUF
- u16_t newpbuflen = 0;
- u16_t left_to_copy;
-#endif
-
- /* Get a RAM based MTU sized pbuf */
-#if IP_FRAG_USES_STATIC_BUF
- /* When using a static buffer, we use a PBUF_REF, which we will
- * use to reference the packet (without link header).
- * Layer and length is irrelevant.
- */
- rambuf = pbuf_alloc(PBUF_LINK, 0, PBUF_REF);
- if (rambuf == NULL) {
- LWIP_DEBUGF(IP_REASS_DEBUG, ("ip_frag: pbuf_alloc(PBUF_LINK, 0, PBUF_REF) failed\n"));
- return ERR_MEM;
- }
- rambuf->tot_len = rambuf->len = mtu;
- rambuf->payload = LWIP_MEM_ALIGN((void *)buf);
-
- /* Copy the IP header in it */
- iphdr = (struct ip_hdr *)rambuf->payload;
- SMEMCPY(iphdr, p->payload, IP_HLEN);
-#else /* IP_FRAG_USES_STATIC_BUF */
- original_iphdr = (struct ip_hdr *)p->payload;
- iphdr = original_iphdr;
-#endif /* IP_FRAG_USES_STATIC_BUF */
-
- /* Save original offset */
- tmp = ntohs(IPH_OFFSET(iphdr));
- ofo = tmp & IP_OFFMASK;
- omf = tmp & IP_MF;
-
- left = p->tot_len - IP_HLEN;
-
- nfb = (mtu - IP_HLEN) / 8;
-
- while (left) {
- last = (left <= mtu - IP_HLEN);
-
- /* Set new offset and MF flag */
- tmp = omf | (IP_OFFMASK & (ofo));
- if (!last) {
- tmp = tmp | IP_MF;
- }
-
- /* Fill this fragment */
- cop = last ? left : nfb * 8;
-
-#if IP_FRAG_USES_STATIC_BUF
- poff += pbuf_copy_partial(p, (u8_t*)iphdr + IP_HLEN, cop, poff);
-#else /* IP_FRAG_USES_STATIC_BUF */
-#if LWIP_NETIF_TX_SINGLE_PBUF
- rambuf = pbuf_alloc(PBUF_IP, cop, PBUF_RAM);
- if (rambuf == NULL) {
- return ERR_MEM;
- }
- LWIP_ASSERT("this needs a pbuf in one piece!",
- (rambuf->len == rambuf->tot_len) && (rambuf->next == NULL));
- poff += pbuf_copy_partial(p, rambuf->payload, cop, poff);
- /* make room for the IP header */
- if(pbuf_header(rambuf, IP_HLEN)) {
- pbuf_free(rambuf);
- return ERR_MEM;
- }
- /* fill in the IP header */
- SMEMCPY(rambuf->payload, original_iphdr, IP_HLEN);
- iphdr = rambuf->payload;
-#else /* LWIP_NETIF_TX_SINGLE_PBUF */
- /* When not using a static buffer, create a chain of pbufs.
- * The first will be a PBUF_RAM holding the link and IP header.
- * The rest will be PBUF_REFs mirroring the pbuf chain to be fragged,
- * but limited to the size of an mtu.
- */
- rambuf = pbuf_alloc(PBUF_LINK, IP_HLEN, PBUF_RAM);
- if (rambuf == NULL) {
- return ERR_MEM;
- }
- LWIP_ASSERT("this needs a pbuf in one piece!",
- (p->len >= (IP_HLEN)));
- SMEMCPY(rambuf->payload, original_iphdr, IP_HLEN);
- iphdr = (struct ip_hdr *)rambuf->payload;
-
- /* Can just adjust p directly for needed offset. */
- p->payload = (u8_t *)p->payload + poff;
- p->len -= poff;
-
- left_to_copy = cop;
- while (left_to_copy) {
- struct pbuf_custom_ref *pcr;
- newpbuflen = (left_to_copy < p->len) ? left_to_copy : p->len;
- /* Is this pbuf already empty? */
- if (!newpbuflen) {
- p = p->next;
- continue;
- }
- pcr = ip_frag_alloc_pbuf_custom_ref();
- if (pcr == NULL) {
- pbuf_free(rambuf);
- return ERR_MEM;
- }
- /* Mirror this pbuf, although we might not need all of it. */
- newpbuf = pbuf_alloced_custom(PBUF_RAW, newpbuflen, PBUF_REF, &pcr->pc, p->payload, newpbuflen);
- if (newpbuf == NULL) {
- ip_frag_free_pbuf_custom_ref(pcr);
- pbuf_free(rambuf);
- return ERR_MEM;
- }
- pbuf_ref(p);
- pcr->original = p;
- pcr->pc.custom_free_function = ipfrag_free_pbuf_custom;
-
- /* Add it to end of rambuf's chain, but using pbuf_cat, not pbuf_chain
- * so that it is removed when pbuf_dechain is later called on rambuf.
- */
- pbuf_cat(rambuf, newpbuf);
- left_to_copy -= newpbuflen;
- if (left_to_copy) {
- p = p->next;
- }
- }
- poff = newpbuflen;
-#endif /* LWIP_NETIF_TX_SINGLE_PBUF */
-#endif /* IP_FRAG_USES_STATIC_BUF */
-
- /* Correct header */
- IPH_OFFSET_SET(iphdr, htons(tmp));
- IPH_LEN_SET(iphdr, htons(cop + IP_HLEN));
- IPH_CHKSUM_SET(iphdr, 0);
- IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, IP_HLEN));
-
-#if IP_FRAG_USES_STATIC_BUF
- if (last) {
- pbuf_realloc(rambuf, left + IP_HLEN);
- }
-
- /* This part is ugly: we alloc a RAM based pbuf for
- * the link level header for each chunk and then
- * free it.A PBUF_ROM style pbuf for which pbuf_header
- * worked would make things simpler.
- */
- header = pbuf_alloc(PBUF_LINK, 0, PBUF_RAM);
- if (header != NULL) {
- pbuf_chain(header, rambuf);
- netif->output(netif, header, dest);
- IPFRAG_STATS_INC(ip_frag.xmit);
- snmp_inc_ipfragcreates();
- pbuf_free(header);
- } else {
- LWIP_DEBUGF(IP_REASS_DEBUG, ("ip_frag: pbuf_alloc() for header failed\n"));
- pbuf_free(rambuf);
- return ERR_MEM;
- }
-#else /* IP_FRAG_USES_STATIC_BUF */
- /* No need for separate header pbuf - we allowed room for it in rambuf
- * when allocated.
- */
- netif->output(netif, rambuf, dest);
- IPFRAG_STATS_INC(ip_frag.xmit);
-
- /* Unfortunately we can't reuse rambuf - the hardware may still be
- * using the buffer. Instead we free it (and the ensuing chain) and
- * recreate it next time round the loop. If we're lucky the hardware
- * will have already sent the packet, the free will really free, and
- * there will be zero memory penalty.
- */
-
- pbuf_free(rambuf);
-#endif /* IP_FRAG_USES_STATIC_BUF */
- left -= cop;
- ofo += nfb;
- }
-#if IP_FRAG_USES_STATIC_BUF
- pbuf_free(rambuf);
-#endif /* IP_FRAG_USES_STATIC_BUF */
- snmp_inc_ipfragoks();
- return ERR_OK;
-}
-#endif /* IP_FRAG */
projects / reactos.git / blobdiff