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nuttx/net/ipfrag/ipfrag.c
luojun1234 ff3733b5b5 Support fragmentation and reassembly 
Signed-off-by: luojun1 <luojun1@xiaomi.com>
2023-01-17 14:01:37 +08:00

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/****************************************************************************
* net/ipfrag/ipfrag.c
* Handling incoming IPv4 and IPv6 fragment input
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#if (defined(CONFIG_NET_IPv4) || defined(CONFIG_NET_IPv6)) && \
defined(CONFIG_NET_IPFRAG)
#include <sys/ioctl.h>
#include <stdint.h>
#include <stdlib.h>
#include <debug.h>
#include <string.h>
#include <errno.h>
#include <netinet/in.h>
#include <net/if.h>
#include <nuttx/nuttx.h>
#include <nuttx/wqueue.h>
#include <nuttx/kmalloc.h>
#include <nuttx/net/netconfig.h>
#include <nuttx/net/netdev.h>
#include <nuttx/net/netstats.h>
#include <nuttx/net/ip.h>
#include <nuttx/net/ipv6ext.h>
#include "netdev/netdev.h"
#include "inet/inet.h"
#include "icmp/icmp.h"
#include "icmpv6/icmpv6.h"
#include "ipfrag.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define GOTO_IF(expression, to) \
if (expression) \
{ \
goto to; \
}
#define UPDATE_IOB(iob, off, len) \
do \
{ \
(iob)->io_offset = (off); \
(iob)->io_len = (len); \
(iob)->io_pktlen = (len); \
} while (0);
/* Defined the minimal timeout interval to avoid triggering timeout timer
* too frequently, default: 0.5 seconds.
*/
#define REASSEMBLY_TIMEOUT_MINIMAL 5
#if CONFIG_NET_IPFRAG_REASS_MAXAGE < REASSEMBLY_TIMEOUT_MINIMAL
# define REASSEMBLY_TIMEOUT REASSEMBLY_TIMEOUT_MINIMAL
#else
# define REASSEMBLY_TIMEOUT CONFIG_NET_IPFRAG_REASS_MAXAGE
#endif
#define REASSEMBLY_TIMEOUT_MINIMALTICKS DSEC2TICK(REASSEMBLY_TIMEOUT_MINIMAL)
#define REASSEMBLY_TIMEOUT_TICKS DSEC2TICK(REASSEMBLY_TIMEOUT)
#define IPFRAGWORK LPWORK
/* Helper macro to count I/O buffer count for a given I/O buffer chain */
#define IOBUF_CNT(ptr) (((ptr)->io_pktlen + CONFIG_IOB_BUFSIZE - 1)/ \
CONFIG_IOB_BUFSIZE)
/* The maximum I/O buffer occupied by fragment reassembly cache */
#define REASSEMBLY_MAXOCCUPYIOB CONFIG_IOB_NBUFFERS / 5
/* Deciding whether to fragment outgoing packets which target is to ourself */
#define LOOPBACK_IPFRAME_NOFRAGMENT 0
/****************************************************************************
* Private Data
****************************************************************************/
/* A timeout timer used to start a worker which is used to check
* whether the assembly time of those fragments within one node is expired,
* if so, free all resources of this node.
*/
static struct wdog_s g_wdfragtimeout;
/* Reassembly timeout work */
static struct work_s g_wkfragtimeout;
/* Remember the number of I/O buffers currently in reassembly cache */
static uint8_t g_bufoccupy;
/* Queue header definition, it links all fragments of all NICs by ascending
* ipid.
*/
static sq_queue_t g_assemblyhead_ipid;
/* Queue header definition, which connects all fragments of all NICs in order
* of addition time.
*/
static sq_queue_t g_assemblyhead_time;
/****************************************************************************
* Public Data
****************************************************************************/
/* Only one thread can access g_assemblyhead_ipid and g_assemblyhead_time
* at a time.
*/
mutex_t g_ipfrag_lock = NXMUTEX_INITIALIZER;
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
static void ip_fragin_timerout_expiry(wdparm_t arg);
static void ip_fragin_timerwork(FAR void *arg);
static inline FAR struct ip_fraglink_s *
ip_fragin_freelink(FAR struct ip_fraglink_s *fraglink);
static void ip_fragin_check(FAR struct ip_fragsnode_s *fragsnode);
static void ip_fragin_cachemonitor(FAR struct ip_fragsnode_s *curnode);
static inline FAR struct iob_s *
ip_fragout_allocfragbuf(FAR struct iob_queue_s *fragq);
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: ip_fragin_timerout_expiry
*
* Description:
* Schedule the timeout checking and handling on the low priority work
* queue.
*
* Returned Value:
* None
*
****************************************************************************/
static void ip_fragin_timerout_expiry(wdparm_t arg)
{
assert(g_wkfragtimeout.worker == NULL);
work_queue(IPFRAGWORK, &g_wkfragtimeout, ip_fragin_timerwork, NULL, 0);
}
/****************************************************************************
* Name: ip_fragin_timerwork
*
* Description:
* The really work of fragment timeout checking and handling.
*
* Returned Value:
* None
*
****************************************************************************/
static void ip_fragin_timerwork(FAR void *arg)
{
clock_t curtick = clock_systime_ticks();
sclock_t interval;
FAR sq_entry_t *entry;
FAR sq_entry_t *entrynext;
FAR struct ip_fragsnode_s *node;
ninfo("Start reassembly work queue\n");
nxmutex_lock(&g_ipfrag_lock);
/* Walk through the list, check the timetout and calculate the next timer
* interval
*/
entry = sq_peek(&g_assemblyhead_time);
while (entry != NULL)
{
entrynext = sq_next(entry);
node = (FAR struct ip_fragsnode_s *)
container_of(entry, FAR struct ip_fragsnode_s, flinkat);
/* Check for timeout, be careful with the calculation formula,
* the tick counter may overflow
*/
interval = curtick - node->tick;
if (interval >= REASSEMBLY_TIMEOUT_TICKS)
{
/* If this timeout expires, the partially-reassembled datagram
* MUST be discarded and an ICMP Time Exceeded message sent to
* the source host (if fragment zero has been received).
*/
ninfo("Reassembly timeout occurs!");
#if defined(CONFIG_NET_ICMP) && !defined(CONFIG_NET_ICMP_NO_STACK)
if ((node->verifyflag & IP_FRAGVERIFY_RECVDZEROFRAG) != 0)
{
FAR struct net_driver_s *dev = node->dev;
net_lock();
netdev_iob_replace(dev, node->frags->frag);
node->frags->frag = NULL;
#ifdef CONFIG_NET_IPv4
if (node->frags->isipv4)
{
icmp_reply(dev, ICMP_TIME_EXCEEDED,
ICMP_EXC_FRAGTIME);
}
#endif
#ifdef CONFIG_NET_IPv6
if (!node->frags->isipv4)
{
icmpv6_reply(dev, ICMPv6_PACKET_TIME_EXCEEDED,
ICMPV6_EXC_FRAGTIME, 0);
}
#endif
if (iob_tryadd_queue(dev->d_iob, &dev->d_fragout) == 0)
{
netdev_iob_clear(dev);
/* Send ICMP Time Exceeded message via dev->d_fragout
* queue
*/
ninfo("Send Time Exceeded ICMP%s Message to source "
"host\n", node->frags->isipv4 ? "v4" : "v6");
netdev_txnotify_dev(dev);
}
net_unlock();
}
#endif
/* Remove fragments of this node */
if (node->frags != NULL)
{
FAR struct ip_fraglink_s *fraglink = node->frags;
while (fraglink)
{
fraglink = ip_fragin_freelink(fraglink);
}
}
/* Remove node from single-list and free node memory */
ip_frag_remnode(node);
kmm_free(node);
}
else
{
/* Because fragment nodes have been sorted to g_assemblyhead_time
* according to the added time, so enter here, we can get the
* 'interval' of the earliest time node that has not timed out.
* There is no need to continue the loop here, and use time
* REASSEMBLY_TIMEOUT_TICKS - 'interval' as the input for the next
* Timer starting.
*/
break;
}
entry = entrynext;
}
/* Be sure to start the timer, if there are nodes in the linked list */
if (sq_peek(&g_assemblyhead_time) != NULL)
{
clock_t delay = REASSEMBLY_TIMEOUT_MINIMALTICKS;
/* The interval for the next timer is REASSEMBLY_TIMEOUT_TICKS -
* interval, if it is less than the minimum timeout interval,
* fix it to REASSEMBLY_TIMEOUT_MINIMALTICKS
*/
if (delay < REASSEMBLY_TIMEOUT_TICKS - interval)
{
delay = REASSEMBLY_TIMEOUT_TICKS - interval;
}
ninfo("Reschedule reassembly work queue\n");
wd_start(&g_wdfragtimeout, delay, ip_fragin_timerout_expiry,
(wdparm_t)NULL);
}
else
{
ninfo("Stop reassembly work queue\n");
}
nxmutex_unlock(&g_ipfrag_lock);
}
/****************************************************************************
* Name: ip_fragin_freelink
*
* Description:
* Free the I/O buffer and ip_fraglink_s buffer at the head of a
* ip_fraglink_s chain.
*
* Input Parameters:
* fraglink - node of the lower-level linked list, it maintains
* information of one fragment
*
* Returned Value:
* The link to the next ip_fraglink_s buffer in the chain.
*
****************************************************************************/
static inline FAR struct ip_fraglink_s *
ip_fragin_freelink(FAR struct ip_fraglink_s *fraglink)
{
FAR struct ip_fraglink_s *next = fraglink->flink;
if (fraglink->frag != NULL)
{
iob_free_chain(fraglink->frag);
}
kmm_free(fraglink);
return next;
}
/****************************************************************************
* Name: ip_fragin_check
*
* Description:
* Check whether the zero fragment has been received or all fragments have
* been received.
*
* Input Parameters:
* fragsnode - node of the upper-level linked list, it maintains
* information bout all fragments belonging to an IP datagram
*
* Returned Value:
* None
*
****************************************************************************/
static void ip_fragin_check(FAR struct ip_fragsnode_s *fragsnode)
{
uint16_t formerlen = 0;
FAR struct ip_fraglink_s *entry;
if (fragsnode->verifyflag & IP_FRAGVERIFY_RECVDTAILFRAG)
{
entry = fragsnode->frags;
while (entry != NULL)
{
if (entry->morefrags)
{
formerlen += entry->fraglen;
}
else
{
/* Only the last entry has a 0 morefrags flag */
if (entry->fragoff == formerlen)
{
fragsnode->verifyflag |= IP_FRAGVERIFY_RECVDALLFRAGS;
}
}
entry = entry->flink;
}
}
}
/****************************************************************************
* Name: ip_fragin_cachemonitor
*
* Description:
* Check the reassembly cache buffer size, if it exceeds the configured
* threshold, some I/O buffers need to be freed
*
* Input Parameters:
* curnode - node of the upper-level linked list, it maintains information
* about all fragments belonging to an IP datagram
*
* Returned Value:
* none
*
****************************************************************************/
static void ip_fragin_cachemonitor(FAR struct ip_fragsnode_s *curnode)
{
uint32_t cleancnt = 0;
uint32_t bufcnt;
FAR sq_entry_t *entry;
FAR sq_entry_t *entrynext;
FAR struct ip_fragsnode_s *node;
/* Start cache cleaning if g_bufoccupy exceeds the cache threshold */
if (g_bufoccupy > REASSEMBLY_MAXOCCUPYIOB)
{
cleancnt = g_bufoccupy - REASSEMBLY_MAXOCCUPYIOB;
entry = sq_peek(&g_assemblyhead_time);
while (entry != NULL && cleancnt > 0)
{
entrynext = sq_next(entry);
node = (FAR struct ip_fragsnode_s *)
container_of(entry, FAR struct ip_fragsnode_s, flinkat);
/* Skip specified node */
if (node != curnode)
{
/* Remove fragments of this node */
if (node->frags != NULL)
{
FAR struct ip_fraglink_s *fraglink = node->frags;
while (fraglink != NULL)
{
fraglink = ip_fragin_freelink(fraglink);
}
}
/* Remove node from single-list and free node memory */
bufcnt = ip_frag_remnode(node);
kmm_free(node);
cleancnt = cleancnt > bufcnt ? cleancnt - bufcnt : 0;
}
entry = entrynext;
}
}
}
/****************************************************************************
* Name: ip_fragout_allocfragbuf
*
* Description:
* Prepare one I/O buffer and enqueue it to a specified queue
*
* Input Parameters:
* fragq - the queue head
*
* Returned Value:
* The pointer to I/O buffer
*
****************************************************************************/
static inline FAR struct iob_s *
ip_fragout_allocfragbuf(FAR struct iob_queue_s *fragq)
{
FAR struct iob_s *iob;
iob = iob_tryalloc(false);
if (iob != NULL)
{
if (iob_tryadd_queue(iob, fragq) < 0)
{
iob_free(iob);
iob = NULL;
}
}
return iob;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: ip_frag_remnode
*
* Description:
* free ip_fragsnode_s
*
* Input Parameters:
* node - node of the upper-level linked list, it maintains
* information about all fragments belonging to an IP datagram
*
* Returned Value:
* I/O buffer count of this node
*
****************************************************************************/
uint32_t ip_frag_remnode(FAR struct ip_fragsnode_s *node)
{
g_bufoccupy -= node->bufcnt;
assert(g_bufoccupy < CONFIG_IOB_NBUFFERS);
sq_rem((FAR sq_entry_t *)node, &g_assemblyhead_ipid);
sq_rem((FAR sq_entry_t *)&node->flinkat, &g_assemblyhead_time);
return node->bufcnt;
}
/****************************************************************************
* Name: ip_fragin_enqueue
*
* Description:
* Enqueue one fragment.
* All fragments belonging to one IP frame are organized in a linked list
* form, that is a ip_fragsnode_s node. All ip_fragsnode_s nodes are also
* organized in an upper-level linked list.
*
* Input Parameters:
* dev - NIC Device instance
* curfraglink - node of the lower-level linked list, it maintains
* information of one fragment
*
* Returned Value:
* Whether queue is empty before enqueue the new node
*
****************************************************************************/
bool ip_fragin_enqueue(FAR struct net_driver_s *dev,
FAR struct ip_fraglink_s *curfraglink)
{
FAR struct ip_fragsnode_s *node;
FAR sq_entry_t *entry;
FAR sq_entry_t *entrylast = NULL;
bool empty;
/* The linked list is ordered by IP ID value, walk through it and try to
* find a node that has the same IP ID value, otherwise need to create a
* new node and insert it into the linked list.
*/
entry = sq_peek(&g_assemblyhead_ipid);
empty = (entry == NULL) ? true : false;
while (entry != NULL)
{
node = (struct ip_fragsnode_s *)entry;
if (dev == node->dev && curfraglink->ipid <= node->ipid)
{
break;
}
entrylast = entry;
entry = sq_next(entry);
}
node = (FAR struct ip_fragsnode_s *)entry;
if (node != NULL && curfraglink->ipid == node->ipid)
{
FAR struct ip_fraglink_s *fraglink;
FAR struct ip_fraglink_s *lastlink = NULL;
/* Found a previously created ip_fragsnode_s, insert this new
* ip_fraglink_s to the subchain of this node.
*/
fraglink = node->frags;
/* An ip_fragsnode_s must have an ip_fraglink_s because we allocate a
* new ip_fraglink_s when caching a new ip_fraglink_s with a new IP ID
*/
while (fraglink != NULL)
{
/* The fragment list is ordered by fragment offset value */
if (curfraglink->fragoff <= fraglink->fragoff)
{
break;
}
lastlink = fraglink;
fraglink = fraglink->flink;
}
if (fraglink == NULL)
{
/* This fragment offset is greater than the previous fragments,
* added to the last position
*/
lastlink->flink = curfraglink;
/* Remember I/O buffer count */
node->bufcnt += IOBUF_CNT(curfraglink->frag);
g_bufoccupy += IOBUF_CNT(curfraglink->frag);
}
else if (curfraglink->fragoff == fraglink->fragoff)
{
/* Fragments with same offset value contain the same data, use the
* more recently arrived copy. Refer to RFC791, Section3.2, Page29.
* Replace and removed the old packet from the fragment list
*/
curfraglink->flink = fraglink->flink;
if (lastlink == NULL)
{
node->frags = curfraglink;
}
else
{
lastlink->flink = curfraglink;
}
iob_free_chain(fraglink->frag);
kmm_free(fraglink);
}
else
{
/* Insert into the fragment list */
if (lastlink == NULL)
{
/* Insert before the first node */
curfraglink->flink = node->frags;
node->frags = curfraglink;
}
else
{
/* Insert this node after lastlink */
curfraglink->flink = lastlink->flink;
lastlink->flink = curfraglink;
}
/* Remember I/O buffer count */
node->bufcnt += IOBUF_CNT(curfraglink->frag);
g_bufoccupy += IOBUF_CNT(curfraglink->frag);
}
}
else
{
/* It's a new IP ID fragment, malloc a new node and insert it into the
* linked list
*/
node = kmm_malloc(sizeof(struct ip_fragsnode_s));
if (node == NULL)
{
nerr("ERROR: Failed to allocate buffer.\n");
return -ENOMEM;
}
node->flink = NULL;
node->flinkat = NULL;
node->dev = dev;
node->ipid = curfraglink->ipid;
node->frags = curfraglink;
node->tick = clock_systime_ticks();
node->bufcnt = IOBUF_CNT(curfraglink->frag);
g_bufoccupy += IOBUF_CNT(curfraglink->frag);
node->verifyflag = 0;
node->outgoframe = NULL;
/* Insert this new node into linked list identified by
* g_assemblyhead_ipid with correct position
*/
if (sq_peek(&g_assemblyhead_ipid) == NULL || entrylast == NULL)
{
sq_addfirst((FAR sq_entry_t *)node, &g_assemblyhead_ipid);
}
else
{
sq_addafter(entrylast, (FAR sq_entry_t *)node,
&g_assemblyhead_ipid);
}
/* Add this new node to the tail of linked list identified by
* g_assemblyhead_time
*/
sq_addlast((FAR sq_entry_t *)&node->flinkat, &g_assemblyhead_time);
}
if (curfraglink->fragoff == 0)
{
/* Have received the zero fragment */
node->verifyflag |= IP_FRAGVERIFY_RECVDZEROFRAG;
}
else if (!curfraglink->morefrags)
{
/* Have received the tail fragment */
node->verifyflag |= IP_FRAGVERIFY_RECVDTAILFRAG;
}
/* For indexing convenience */
curfraglink->fragsnode = node;
/* Check receiving status */
ip_fragin_check(node);
/* Buffer is take away, clear original pointers in NIC */
netdev_iob_clear(dev);
/* Perform cache cleaning when reassembly cache size exceeds the configured
* threshold
*/
ip_fragin_cachemonitor(node);
return empty;
}
/****************************************************************************
* Name: ip_fragout_slice
*
* Description:
* According to the MTU of a given NIC, split the original data into
* multiple data pieces, and the space for filling the L3 header is
* reserved at the forefront of each piece. Each piece is stored in
* independent I/O buffer(s) and eventually forms an I/O buffer queue.
* Note:
* 1.About the 'piece' above
* 1).If MTU < CONFIG_IOB_BUFSIZE, a piece consists of an I/O buffer;
* 2).If MTU >= CONFIG_IOB_BUFSIZE, a piece consists of multiple I/O
* buffers.
* 2.This function split and gathers the incoming data into outgoing
* I/O buffers according to the MTU, but is not responsible for
* building the L3 header related to the fragmentation.
*
* Input Parameters:
* iob - The data comes from
* domain - PF_INET or PF_INET6
* mtu - MTU of current NIC
* unfraglen - The starting position to fragmentation processing
* fragq - Those output slices
*
* Returned Value:
* Number of fragments
*
* Assumptions:
* Data length(iob->io_pktlen) is grater than the MTU of current NIC
*
****************************************************************************/
int32_t ip_fragout_slice(FAR struct iob_s *iob, uint8_t domain, uint16_t mtu,
uint16_t unfraglen, FAR struct iob_queue_s *fragq)
{
FAR uint8_t *leftstart;
uint16_t leftlen = 0;
uint16_t ncopy;
uint16_t navail;
uint32_t nfrags = 0;
bool expand = false;
FAR struct iob_s *orig = NULL;
FAR struct iob_s *reorg = NULL;
FAR struct iob_s *head = NULL;
if (iob == NULL || fragq == NULL)
{
nerr("ERROR: Invalid parameters! iob: %p, fragq: %p\n", iob, fragq);
return 0;
}
assert(iob->io_pktlen > mtu);
#ifdef CONFIG_NET_IPv4
if (domain == PF_INET)
{
uint16_t nreside;
/* Fragmentation requires that the data length after the IP header
* must be a multiple of 8
*/
mtu = ((mtu - IPv4_HDRLEN) & ~0x7) + IPv4_HDRLEN;
/* Remember the number of resident bytes */
nreside = mtu;
/* For IPv4, fragmented frames and non-fragmented frames have the
* same length L3 header. So process it as follows:
* the zero fragment use the original I/O buffer and reorganize
* the non-zero fragments (copy to new I/O buffers), space for the
* L3 IP header must be reserved for all fragments
*/
head = iob;
while (iob != NULL && nreside > iob->io_len)
{
nreside -= iob->io_len;
iob = iob->io_flink;
}
leftstart = iob->io_data + iob->io_offset + nreside;
leftlen = iob->io_len - nreside;
orig = iob->io_flink;
if (orig != NULL)
{
orig->io_pktlen = head->io_pktlen - (mtu + leftlen);
iob->io_flink = NULL;
}
head->io_pktlen = mtu;
iob->io_len = nreside;
if (iob_tryadd_queue(head, fragq) < 0)
{
goto allocfail;
}
head = NULL;
nfrags++;
if (leftlen == 0 && orig != NULL)
{
reorg = ip_fragout_allocfragbuf(fragq);
GOTO_IF(reorg == NULL, allocfail);
nfrags++;
/* This is a new fragment buffer, reserve L2&L3 header space
* in the front of this buffer
*/
UPDATE_IOB(reorg, CONFIG_NET_LL_GUARDSIZE, unfraglen);
}
else
{
/* If the MTU is relatively small, the remaining data of the first
* I/O buffer may need to be fragmented multiple times.
* For IPv4, the first I/O Buffer is reused, which have reserved
* the L4 header space, the following fragmentation flow is only
* for non-zero fragments, so following flow does not need to
* consider the L4 header
*/
while (leftlen > 0)
{
reorg = ip_fragout_allocfragbuf(fragq);
GOTO_IF(reorg == NULL, allocfail);
nfrags++;
if (leftlen + unfraglen > mtu)
{
ncopy = mtu - unfraglen;
}
else
{
ncopy = leftlen;
}
/* This is a new fragment buffer, reserve L2&L3 header space
* in the front of this buffer
*/
UPDATE_IOB(reorg, CONFIG_NET_LL_GUARDSIZE, unfraglen);
/* Then copy L4 data */
GOTO_IF(iob_trycopyin(reorg, leftstart, ncopy,
reorg->io_pktlen, false) < 0, allocfail);
leftstart += ncopy;
leftlen -= ncopy;
}
}
}
#ifdef CONFIG_NET_IPv6
else
#endif
#endif
#ifdef CONFIG_NET_IPv6
if (domain == PF_INET6)
{
unfraglen += EXTHDR_FRAG_LEN;
/* Fragmentation requires the length field to be a multiples of 8,
* and the length of the IPv6 basic header and all extended headers
* is a multiples of 8, so here directly fix the MTU to 8-byte
* alignment.
*/
mtu = mtu & ~0x7;
/* For IPv6 fragment, a fragment header needs to be inserted before
* the l4 header, so all data must be reorganized, a space for IPv6
* header and fragment external header is reserved before l4 header
* for all fragments
*/
reorg = ip_fragout_allocfragbuf(fragq);
GOTO_IF(reorg == NULL, allocfail);
nfrags++;
/* Reserve L3 header space */
UPDATE_IOB(reorg, CONFIG_NET_LL_GUARDSIZE, unfraglen);
/* Copy L3 header(include unfragmentable extention header if present)
* from original I/O buffer
*/
orig = iob;
memcpy(reorg->io_data + reorg->io_offset,
orig->io_data + orig->io_offset, unfraglen - EXTHDR_FRAG_LEN);
iob_trimhead(orig, unfraglen - EXTHDR_FRAG_LEN);
}
#endif
/* Copy data from original I/O buffer chain 'orig' to new reorganized
* I/O buffer chain 'reorg'
*/
while (orig != NULL)
{
leftstart = orig->io_data + orig->io_offset;
leftlen = orig->io_len;
/* For each I/O buffer data of the 'orig' chain */
while (leftlen > 0)
{
/* Calculate target area size */
navail = mtu - reorg->io_pktlen;
if (navail > 0)
{
if (leftlen > navail)
{
/* Target area is too small, need expand the destination
* chain
*/
expand = true;
ncopy = navail;
}
else
{
ncopy = leftlen;
}
if (iob_trycopyin(reorg, leftstart, ncopy,
reorg->io_pktlen, false) < 0)
{
goto allocfail;
}
leftlen -= ncopy;
leftstart += ncopy;
}
else
{
expand = true;
}
if (expand)
{
reorg = ip_fragout_allocfragbuf(fragq);
GOTO_IF(reorg == NULL, allocfail);
nfrags++;
/* This is a new fragment buffer, reserve L2&L3 header space
* in the front of this buffer
*/
UPDATE_IOB(reorg, CONFIG_NET_LL_GUARDSIZE, unfraglen);
expand = false;
}
}
orig = iob_free(orig);
}
return nfrags;
allocfail:
nerr("ERROR: Fragout fail! No I/O buffer available!");
iob_free_chain(head);
iob_free_chain(orig);
iob_free_chain(reorg);
iob_free_queue(fragq);
return 0;
}
/****************************************************************************
* Name: ip_frag_startwdog
*
* Description:
* Start the reassembly timeout timer
*
* Returned Value:
* None
*
****************************************************************************/
void ip_frag_startwdog(void)
{
if (g_wdfragtimeout.func == NULL)
{
wd_start(&g_wdfragtimeout, REASSEMBLY_TIMEOUT_TICKS,
ip_fragin_timerout_expiry, (wdparm_t)NULL);
}
}
/****************************************************************************
* Name: ip_frag_uninit
*
* Description:
* Uninitialize the fragment processing module.
*
* Returned Value:
* None
*
****************************************************************************/
int32_t ip_frag_uninit(void)
{
FAR struct net_driver_s *dev;
ninfo("Uninitialize frag proccessing module\n");
/* Stop work queue */
if (!work_available(&g_wkfragtimeout))
{
ninfo("Cancel reassembly work queue\n");
work_cancel(IPFRAGWORK, &g_wkfragtimeout);
}
/* Release frag processing resources of each NIC */
net_lock();
for (dev = g_netdevices; dev; dev = dev->flink)
{
/* Is the interface in the "up" state? */
if ((dev->d_flags & IFF_UP) != 0)
{
ip_frag_stop(dev);
}
}
net_unlock();
return OK;
}
/****************************************************************************
* Name: ip_frag_stop
*
* Description:
* Stop the fragment process function for the specified NIC.
*
* Input Parameters:
* dev - NIC Device instance which will be bring down
*
* Returned Value:
* None
*
****************************************************************************/
void ip_frag_stop(FAR struct net_driver_s *dev)
{
FAR sq_entry_t *entry = NULL;
FAR sq_entry_t *entrynext;
ninfo("Stop frag processing for NIC:%p\n", dev);
nxmutex_lock(&g_ipfrag_lock);
entry = sq_peek(&g_assemblyhead_ipid);
/* Drop those unassembled incoming fragments belonging to this NIC */
while (entry != NULL)
{
FAR struct ip_fragsnode_s *node = (FAR struct ip_fragsnode_s *)entry;
entrynext = sq_next(entry);
if (dev == node->dev)
{
if (node->frags != NULL)
{
FAR struct ip_fraglink_s *fraglink = node->frags;
while (fraglink != NULL)
{
fraglink = ip_fragin_freelink(fraglink);
}
}
ip_frag_remnode(node);
kmm_free(entry);
}
entry = entrynext;
}
nxmutex_unlock(&g_ipfrag_lock);
/* Drop those unsent outgoing fragments belonging to this NIC */
iob_free_queue(&dev->d_fragout);
}
/****************************************************************************
* Name: ip_frag_remallfrags
*
* Description:
* Release all I/O Buffers used by fragment processing module when
* I/O Buffer resources are exhausted.
*
* Returned Value:
* None
*
****************************************************************************/
void ip_frag_remallfrags(void)
{
FAR sq_entry_t *entry = NULL;
FAR sq_entry_t *entrynext;
FAR struct net_driver_s *dev;
nxmutex_lock(&g_ipfrag_lock);
entry = sq_peek(&g_assemblyhead_ipid);
/* Drop all unassembled incoming fragments */
while (entry != NULL)
{
FAR struct ip_fragsnode_s *node = (FAR struct ip_fragsnode_s *)entry;
entrynext = sq_next(entry);
if (node->frags != NULL)
{
FAR struct ip_fraglink_s *fraglink = node->frags;
while (fraglink != NULL)
{
fraglink = ip_fragin_freelink(fraglink);
}
}
/* Because nodes managed by the two queues are the same,
* and g_assemblyhead_ipid will be cleared after this loop ends,
* so only reset g_assemblyhead_time is needed after this loop ends
*/
sq_rem(entry, &g_assemblyhead_ipid);
kmm_free(entry);
entry = entrynext;
}
sq_init(&g_assemblyhead_time);
g_bufoccupy = 0;
nxmutex_unlock(&g_ipfrag_lock);
/* Drop all unsent outgoing fragments */
net_lock();
for (dev = g_netdevices; dev; dev = dev->flink)
{
/* Is the interface in the "up" state? */
if ((dev->d_flags & IFF_UP) != 0)
{
iob_free_queue(&dev->d_fragout);
}
}
net_unlock();
}
/****************************************************************************
* Name: ip_fragout
*
* Description:
* Fragout processing
*
* Input Parameters:
* dev - The NIC device
*
* Returned Value:
* A non-negative value is returned on success; negative value on failure.
*
****************************************************************************/
int32_t ip_fragout(FAR struct net_driver_s *dev)
{
uint16_t mtu = dev->d_pktsize - dev->d_llhdrlen;
if (dev->d_iob == NULL || dev->d_len == 0)
{
return -EINVAL;
}
if (dev->d_iob->io_pktlen <= mtu)
{
return OK;
}
#ifdef CONFIG_NET_6LOWPAN
if (dev->d_lltype == NET_LL_IEEE802154 ||
dev->d_lltype == NET_LL_PKTRADIO)
{
return -EINVAL;
}
#endif
if (devif_is_loopback(dev))
{
return OK;
}
ninfo("pkt size: %d, MTU: %d\n", dev->d_iob->io_pktlen, mtu);
#ifdef CONFIG_NET_IPv4
if (IFF_IS_IPv4(dev->d_flags))
{
return ipv4_fragout(dev, mtu);
}
#endif
#ifdef CONFIG_NET_IPv6
if (IFF_IS_IPv6(dev->d_flags))
{
return ipv6_fragout(dev, mtu);
}
#endif
return -EINVAL;
}
#endif /* (CONFIG_NET_IPv4 || CONFIG_NET_IPv6) && CONFIG_NET_IPFRAG */
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