summaryrefslogtreecommitdiff
path: root/net/ipv6/reassembly.c
diff options
context:
space:
mode:
Diffstat (limited to 'net/ipv6/reassembly.c')
-rw-r--r--net/ipv6/reassembly.c771
1 files changed, 771 insertions, 0 deletions
diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
new file mode 100644
index 00000000000..59e7c631787
--- /dev/null
+++ b/net/ipv6/reassembly.c
@@ -0,0 +1,771 @@
+/*
+ * IPv6 fragment reassembly
+ * Linux INET6 implementation
+ *
+ * Authors:
+ * Pedro Roque <roque@di.fc.ul.pt>
+ *
+ * $Id: reassembly.c,v 1.26 2001/03/07 22:00:57 davem Exp $
+ *
+ * Based on: net/ipv4/ip_fragment.c
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+/*
+ * Fixes:
+ * Andi Kleen Make it work with multiple hosts.
+ * More RFC compliance.
+ *
+ * Horst von Brand Add missing #include <linux/string.h>
+ * Alexey Kuznetsov SMP races, threading, cleanup.
+ * Patrick McHardy LRU queue of frag heads for evictor.
+ * Mitsuru KANDA @USAGI Register inet6_protocol{}.
+ * David Stevens and
+ * YOSHIFUJI,H. @USAGI Always remove fragment header to
+ * calculate ICV correctly.
+ */
+#include <linux/config.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/jiffies.h>
+#include <linux/net.h>
+#include <linux/list.h>
+#include <linux/netdevice.h>
+#include <linux/in6.h>
+#include <linux/ipv6.h>
+#include <linux/icmpv6.h>
+#include <linux/random.h>
+#include <linux/jhash.h>
+
+#include <net/sock.h>
+#include <net/snmp.h>
+
+#include <net/ipv6.h>
+#include <net/protocol.h>
+#include <net/transp_v6.h>
+#include <net/rawv6.h>
+#include <net/ndisc.h>
+#include <net/addrconf.h>
+
+int sysctl_ip6frag_high_thresh = 256*1024;
+int sysctl_ip6frag_low_thresh = 192*1024;
+
+int sysctl_ip6frag_time = IPV6_FRAG_TIMEOUT;
+
+struct ip6frag_skb_cb
+{
+ struct inet6_skb_parm h;
+ int offset;
+};
+
+#define FRAG6_CB(skb) ((struct ip6frag_skb_cb*)((skb)->cb))
+
+
+/*
+ * Equivalent of ipv4 struct ipq
+ */
+
+struct frag_queue
+{
+ struct frag_queue *next;
+ struct list_head lru_list; /* lru list member */
+
+ __u32 id; /* fragment id */
+ struct in6_addr saddr;
+ struct in6_addr daddr;
+
+ spinlock_t lock;
+ atomic_t refcnt;
+ struct timer_list timer; /* expire timer */
+ struct sk_buff *fragments;
+ int len;
+ int meat;
+ int iif;
+ struct timeval stamp;
+ unsigned int csum;
+ __u8 last_in; /* has first/last segment arrived? */
+#define COMPLETE 4
+#define FIRST_IN 2
+#define LAST_IN 1
+ __u16 nhoffset;
+ struct frag_queue **pprev;
+};
+
+/* Hash table. */
+
+#define IP6Q_HASHSZ 64
+
+static struct frag_queue *ip6_frag_hash[IP6Q_HASHSZ];
+static DEFINE_RWLOCK(ip6_frag_lock);
+static u32 ip6_frag_hash_rnd;
+static LIST_HEAD(ip6_frag_lru_list);
+int ip6_frag_nqueues = 0;
+
+static __inline__ void __fq_unlink(struct frag_queue *fq)
+{
+ if(fq->next)
+ fq->next->pprev = fq->pprev;
+ *fq->pprev = fq->next;
+ list_del(&fq->lru_list);
+ ip6_frag_nqueues--;
+}
+
+static __inline__ void fq_unlink(struct frag_queue *fq)
+{
+ write_lock(&ip6_frag_lock);
+ __fq_unlink(fq);
+ write_unlock(&ip6_frag_lock);
+}
+
+static unsigned int ip6qhashfn(u32 id, struct in6_addr *saddr,
+ struct in6_addr *daddr)
+{
+ u32 a, b, c;
+
+ a = saddr->s6_addr32[0];
+ b = saddr->s6_addr32[1];
+ c = saddr->s6_addr32[2];
+
+ a += JHASH_GOLDEN_RATIO;
+ b += JHASH_GOLDEN_RATIO;
+ c += ip6_frag_hash_rnd;
+ __jhash_mix(a, b, c);
+
+ a += saddr->s6_addr32[3];
+ b += daddr->s6_addr32[0];
+ c += daddr->s6_addr32[1];
+ __jhash_mix(a, b, c);
+
+ a += daddr->s6_addr32[2];
+ b += daddr->s6_addr32[3];
+ c += id;
+ __jhash_mix(a, b, c);
+
+ return c & (IP6Q_HASHSZ - 1);
+}
+
+static struct timer_list ip6_frag_secret_timer;
+int sysctl_ip6frag_secret_interval = 10 * 60 * HZ;
+
+static void ip6_frag_secret_rebuild(unsigned long dummy)
+{
+ unsigned long now = jiffies;
+ int i;
+
+ write_lock(&ip6_frag_lock);
+ get_random_bytes(&ip6_frag_hash_rnd, sizeof(u32));
+ for (i = 0; i < IP6Q_HASHSZ; i++) {
+ struct frag_queue *q;
+
+ q = ip6_frag_hash[i];
+ while (q) {
+ struct frag_queue *next = q->next;
+ unsigned int hval = ip6qhashfn(q->id,
+ &q->saddr,
+ &q->daddr);
+
+ if (hval != i) {
+ /* Unlink. */
+ if (q->next)
+ q->next->pprev = q->pprev;
+ *q->pprev = q->next;
+
+ /* Relink to new hash chain. */
+ if ((q->next = ip6_frag_hash[hval]) != NULL)
+ q->next->pprev = &q->next;
+ ip6_frag_hash[hval] = q;
+ q->pprev = &ip6_frag_hash[hval];
+ }
+
+ q = next;
+ }
+ }
+ write_unlock(&ip6_frag_lock);
+
+ mod_timer(&ip6_frag_secret_timer, now + sysctl_ip6frag_secret_interval);
+}
+
+atomic_t ip6_frag_mem = ATOMIC_INIT(0);
+
+/* Memory Tracking Functions. */
+static inline void frag_kfree_skb(struct sk_buff *skb, int *work)
+{
+ if (work)
+ *work -= skb->truesize;
+ atomic_sub(skb->truesize, &ip6_frag_mem);
+ kfree_skb(skb);
+}
+
+static inline void frag_free_queue(struct frag_queue *fq, int *work)
+{
+ if (work)
+ *work -= sizeof(struct frag_queue);
+ atomic_sub(sizeof(struct frag_queue), &ip6_frag_mem);
+ kfree(fq);
+}
+
+static inline struct frag_queue *frag_alloc_queue(void)
+{
+ struct frag_queue *fq = kmalloc(sizeof(struct frag_queue), GFP_ATOMIC);
+
+ if(!fq)
+ return NULL;
+ atomic_add(sizeof(struct frag_queue), &ip6_frag_mem);
+ return fq;
+}
+
+/* Destruction primitives. */
+
+/* Complete destruction of fq. */
+static void ip6_frag_destroy(struct frag_queue *fq, int *work)
+{
+ struct sk_buff *fp;
+
+ BUG_TRAP(fq->last_in&COMPLETE);
+ BUG_TRAP(del_timer(&fq->timer) == 0);
+
+ /* Release all fragment data. */
+ fp = fq->fragments;
+ while (fp) {
+ struct sk_buff *xp = fp->next;
+
+ frag_kfree_skb(fp, work);
+ fp = xp;
+ }
+
+ frag_free_queue(fq, work);
+}
+
+static __inline__ void fq_put(struct frag_queue *fq, int *work)
+{
+ if (atomic_dec_and_test(&fq->refcnt))
+ ip6_frag_destroy(fq, work);
+}
+
+/* Kill fq entry. It is not destroyed immediately,
+ * because caller (and someone more) holds reference count.
+ */
+static __inline__ void fq_kill(struct frag_queue *fq)
+{
+ if (del_timer(&fq->timer))
+ atomic_dec(&fq->refcnt);
+
+ if (!(fq->last_in & COMPLETE)) {
+ fq_unlink(fq);
+ atomic_dec(&fq->refcnt);
+ fq->last_in |= COMPLETE;
+ }
+}
+
+static void ip6_evictor(void)
+{
+ struct frag_queue *fq;
+ struct list_head *tmp;
+ int work;
+
+ work = atomic_read(&ip6_frag_mem) - sysctl_ip6frag_low_thresh;
+ if (work <= 0)
+ return;
+
+ while(work > 0) {
+ read_lock(&ip6_frag_lock);
+ if (list_empty(&ip6_frag_lru_list)) {
+ read_unlock(&ip6_frag_lock);
+ return;
+ }
+ tmp = ip6_frag_lru_list.next;
+ fq = list_entry(tmp, struct frag_queue, lru_list);
+ atomic_inc(&fq->refcnt);
+ read_unlock(&ip6_frag_lock);
+
+ spin_lock(&fq->lock);
+ if (!(fq->last_in&COMPLETE))
+ fq_kill(fq);
+ spin_unlock(&fq->lock);
+
+ fq_put(fq, &work);
+ IP6_INC_STATS_BH(IPSTATS_MIB_REASMFAILS);
+ }
+}
+
+static void ip6_frag_expire(unsigned long data)
+{
+ struct frag_queue *fq = (struct frag_queue *) data;
+
+ spin_lock(&fq->lock);
+
+ if (fq->last_in & COMPLETE)
+ goto out;
+
+ fq_kill(fq);
+
+ IP6_INC_STATS_BH(IPSTATS_MIB_REASMTIMEOUT);
+ IP6_INC_STATS_BH(IPSTATS_MIB_REASMFAILS);
+
+ /* Send error only if the first segment arrived. */
+ if (fq->last_in&FIRST_IN && fq->fragments) {
+ struct net_device *dev = dev_get_by_index(fq->iif);
+
+ /*
+ But use as source device on which LAST ARRIVED
+ segment was received. And do not use fq->dev
+ pointer directly, device might already disappeared.
+ */
+ if (dev) {
+ fq->fragments->dev = dev;
+ icmpv6_send(fq->fragments, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0,
+ dev);
+ dev_put(dev);
+ }
+ }
+out:
+ spin_unlock(&fq->lock);
+ fq_put(fq, NULL);
+}
+
+/* Creation primitives. */
+
+
+static struct frag_queue *ip6_frag_intern(unsigned int hash,
+ struct frag_queue *fq_in)
+{
+ struct frag_queue *fq;
+
+ write_lock(&ip6_frag_lock);
+#ifdef CONFIG_SMP
+ for (fq = ip6_frag_hash[hash]; fq; fq = fq->next) {
+ if (fq->id == fq_in->id &&
+ ipv6_addr_equal(&fq_in->saddr, &fq->saddr) &&
+ ipv6_addr_equal(&fq_in->daddr, &fq->daddr)) {
+ atomic_inc(&fq->refcnt);
+ write_unlock(&ip6_frag_lock);
+ fq_in->last_in |= COMPLETE;
+ fq_put(fq_in, NULL);
+ return fq;
+ }
+ }
+#endif
+ fq = fq_in;
+
+ if (!mod_timer(&fq->timer, jiffies + sysctl_ip6frag_time))
+ atomic_inc(&fq->refcnt);
+
+ atomic_inc(&fq->refcnt);
+ if((fq->next = ip6_frag_hash[hash]) != NULL)
+ fq->next->pprev = &fq->next;
+ ip6_frag_hash[hash] = fq;
+ fq->pprev = &ip6_frag_hash[hash];
+ INIT_LIST_HEAD(&fq->lru_list);
+ list_add_tail(&fq->lru_list, &ip6_frag_lru_list);
+ ip6_frag_nqueues++;
+ write_unlock(&ip6_frag_lock);
+ return fq;
+}
+
+
+static struct frag_queue *
+ip6_frag_create(unsigned int hash, u32 id, struct in6_addr *src, struct in6_addr *dst)
+{
+ struct frag_queue *fq;
+
+ if ((fq = frag_alloc_queue()) == NULL)
+ goto oom;
+
+ memset(fq, 0, sizeof(struct frag_queue));
+
+ fq->id = id;
+ ipv6_addr_copy(&fq->saddr, src);
+ ipv6_addr_copy(&fq->daddr, dst);
+
+ init_timer(&fq->timer);
+ fq->timer.function = ip6_frag_expire;
+ fq->timer.data = (long) fq;
+ spin_lock_init(&fq->lock);
+ atomic_set(&fq->refcnt, 1);
+
+ return ip6_frag_intern(hash, fq);
+
+oom:
+ IP6_INC_STATS_BH(IPSTATS_MIB_REASMFAILS);
+ return NULL;
+}
+
+static __inline__ struct frag_queue *
+fq_find(u32 id, struct in6_addr *src, struct in6_addr *dst)
+{
+ struct frag_queue *fq;
+ unsigned int hash = ip6qhashfn(id, src, dst);
+
+ read_lock(&ip6_frag_lock);
+ for(fq = ip6_frag_hash[hash]; fq; fq = fq->next) {
+ if (fq->id == id &&
+ ipv6_addr_equal(src, &fq->saddr) &&
+ ipv6_addr_equal(dst, &fq->daddr)) {
+ atomic_inc(&fq->refcnt);
+ read_unlock(&ip6_frag_lock);
+ return fq;
+ }
+ }
+ read_unlock(&ip6_frag_lock);
+
+ return ip6_frag_create(hash, id, src, dst);
+}
+
+
+static void ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb,
+ struct frag_hdr *fhdr, int nhoff)
+{
+ struct sk_buff *prev, *next;
+ int offset, end;
+
+ if (fq->last_in & COMPLETE)
+ goto err;
+
+ offset = ntohs(fhdr->frag_off) & ~0x7;
+ end = offset + (ntohs(skb->nh.ipv6h->payload_len) -
+ ((u8 *) (fhdr + 1) - (u8 *) (skb->nh.ipv6h + 1)));
+
+ if ((unsigned int)end > IPV6_MAXPLEN) {
+ IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
+ icmpv6_param_prob(skb,ICMPV6_HDR_FIELD, (u8*)&fhdr->frag_off - skb->nh.raw);
+ return;
+ }
+
+ if (skb->ip_summed == CHECKSUM_HW)
+ skb->csum = csum_sub(skb->csum,
+ csum_partial(skb->nh.raw, (u8*)(fhdr+1)-skb->nh.raw, 0));
+
+ /* Is this the final fragment? */
+ if (!(fhdr->frag_off & htons(IP6_MF))) {
+ /* If we already have some bits beyond end
+ * or have different end, the segment is corrupted.
+ */
+ if (end < fq->len ||
+ ((fq->last_in & LAST_IN) && end != fq->len))
+ goto err;
+ fq->last_in |= LAST_IN;
+ fq->len = end;
+ } else {
+ /* Check if the fragment is rounded to 8 bytes.
+ * Required by the RFC.
+ */
+ if (end & 0x7) {
+ /* RFC2460 says always send parameter problem in
+ * this case. -DaveM
+ */
+ IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
+ icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
+ offsetof(struct ipv6hdr, payload_len));
+ return;
+ }
+ if (end > fq->len) {
+ /* Some bits beyond end -> corruption. */
+ if (fq->last_in & LAST_IN)
+ goto err;
+ fq->len = end;
+ }
+ }
+
+ if (end == offset)
+ goto err;
+
+ /* Point into the IP datagram 'data' part. */
+ if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data))
+ goto err;
+ if (end-offset < skb->len) {
+ if (pskb_trim(skb, end - offset))
+ goto err;
+ if (skb->ip_summed != CHECKSUM_UNNECESSARY)
+ skb->ip_summed = CHECKSUM_NONE;
+ }
+
+ /* Find out which fragments are in front and at the back of us
+ * in the chain of fragments so far. We must know where to put
+ * this fragment, right?
+ */
+ prev = NULL;
+ for(next = fq->fragments; next != NULL; next = next->next) {
+ if (FRAG6_CB(next)->offset >= offset)
+ break; /* bingo! */
+ prev = next;
+ }
+
+ /* We found where to put this one. Check for overlap with
+ * preceding fragment, and, if needed, align things so that
+ * any overlaps are eliminated.
+ */
+ if (prev) {
+ int i = (FRAG6_CB(prev)->offset + prev->len) - offset;
+
+ if (i > 0) {
+ offset += i;
+ if (end <= offset)
+ goto err;
+ if (!pskb_pull(skb, i))
+ goto err;
+ if (skb->ip_summed != CHECKSUM_UNNECESSARY)
+ skb->ip_summed = CHECKSUM_NONE;
+ }
+ }
+
+ /* Look for overlap with succeeding segments.
+ * If we can merge fragments, do it.
+ */
+ while (next && FRAG6_CB(next)->offset < end) {
+ int i = end - FRAG6_CB(next)->offset; /* overlap is 'i' bytes */
+
+ if (i < next->len) {
+ /* Eat head of the next overlapped fragment
+ * and leave the loop. The next ones cannot overlap.
+ */
+ if (!pskb_pull(next, i))
+ goto err;
+ FRAG6_CB(next)->offset += i; /* next fragment */
+ fq->meat -= i;
+ if (next->ip_summed != CHECKSUM_UNNECESSARY)
+ next->ip_summed = CHECKSUM_NONE;
+ break;
+ } else {
+ struct sk_buff *free_it = next;
+
+ /* Old fragment is completely overridden with
+ * new one drop it.
+ */
+ next = next->next;
+
+ if (prev)
+ prev->next = next;
+ else
+ fq->fragments = next;
+
+ fq->meat -= free_it->len;
+ frag_kfree_skb(free_it, NULL);
+ }
+ }
+
+ FRAG6_CB(skb)->offset = offset;
+
+ /* Insert this fragment in the chain of fragments. */
+ skb->next = next;
+ if (prev)
+ prev->next = skb;
+ else
+ fq->fragments = skb;
+
+ if (skb->dev)
+ fq->iif = skb->dev->ifindex;
+ skb->dev = NULL;
+ fq->stamp = skb->stamp;
+ fq->meat += skb->len;
+ atomic_add(skb->truesize, &ip6_frag_mem);
+
+ /* The first fragment.
+ * nhoffset is obtained from the first fragment, of course.
+ */
+ if (offset == 0) {
+ fq->nhoffset = nhoff;
+ fq->last_in |= FIRST_IN;
+ }
+ write_lock(&ip6_frag_lock);
+ list_move_tail(&fq->lru_list, &ip6_frag_lru_list);
+ write_unlock(&ip6_frag_lock);
+ return;
+
+err:
+ IP6_INC_STATS(IPSTATS_MIB_REASMFAILS);
+ kfree_skb(skb);
+}
+
+/*
+ * Check if this packet is complete.
+ * Returns NULL on failure by any reason, and pointer
+ * to current nexthdr field in reassembled frame.
+ *
+ * It is called with locked fq, and caller must check that
+ * queue is eligible for reassembly i.e. it is not COMPLETE,
+ * the last and the first frames arrived and all the bits are here.
+ */
+static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff **skb_in,
+ unsigned int *nhoffp,
+ struct net_device *dev)
+{
+ struct sk_buff *fp, *head = fq->fragments;
+ int payload_len;
+ unsigned int nhoff;
+
+ fq_kill(fq);
+
+ BUG_TRAP(head != NULL);
+ BUG_TRAP(FRAG6_CB(head)->offset == 0);
+
+ /* Unfragmented part is taken from the first segment. */
+ payload_len = (head->data - head->nh.raw) - sizeof(struct ipv6hdr) + fq->len - sizeof(struct frag_hdr);
+ if (payload_len > IPV6_MAXPLEN)
+ goto out_oversize;
+
+ /* Head of list must not be cloned. */
+ if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC))
+ goto out_oom;
+
+ /* If the first fragment is fragmented itself, we split
+ * it to two chunks: the first with data and paged part
+ * and the second, holding only fragments. */
+ if (skb_shinfo(head)->frag_list) {
+ struct sk_buff *clone;
+ int i, plen = 0;
+
+ if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL)
+ goto out_oom;
+ clone->next = head->next;
+ head->next = clone;
+ skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
+ skb_shinfo(head)->frag_list = NULL;
+ for (i=0; i<skb_shinfo(head)->nr_frags; i++)
+ plen += skb_shinfo(head)->frags[i].size;
+ clone->len = clone->data_len = head->data_len - plen;
+ head->data_len -= clone->len;
+ head->len -= clone->len;
+ clone->csum = 0;
+ clone->ip_summed = head->ip_summed;
+ atomic_add(clone->truesize, &ip6_frag_mem);
+ }
+
+ /* We have to remove fragment header from datagram and to relocate
+ * header in order to calculate ICV correctly. */
+ nhoff = fq->nhoffset;
+ head->nh.raw[nhoff] = head->h.raw[0];
+ memmove(head->head + sizeof(struct frag_hdr), head->head,
+ (head->data - head->head) - sizeof(struct frag_hdr));
+ head->mac.raw += sizeof(struct frag_hdr);
+ head->nh.raw += sizeof(struct frag_hdr);
+
+ skb_shinfo(head)->frag_list = head->next;
+ head->h.raw = head->data;
+ skb_push(head, head->data - head->nh.raw);
+ atomic_sub(head->truesize, &ip6_frag_mem);
+
+ for (fp=head->next; fp; fp = fp->next) {
+ head->data_len += fp->len;
+ head->len += fp->len;
+ if (head->ip_summed != fp->ip_summed)
+ head->ip_summed = CHECKSUM_NONE;
+ else if (head->ip_summed == CHECKSUM_HW)
+ head->csum = csum_add(head->csum, fp->csum);
+ head->truesize += fp->truesize;
+ atomic_sub(fp->truesize, &ip6_frag_mem);
+ }
+
+ head->next = NULL;
+ head->dev = dev;
+ head->stamp = fq->stamp;
+ head->nh.ipv6h->payload_len = htons(payload_len);
+
+ *skb_in = head;
+
+ /* Yes, and fold redundant checksum back. 8) */
+ if (head->ip_summed == CHECKSUM_HW)
+ head->csum = csum_partial(head->nh.raw, head->h.raw-head->nh.raw, head->csum);
+
+ IP6_INC_STATS_BH(IPSTATS_MIB_REASMOKS);
+ fq->fragments = NULL;
+ *nhoffp = nhoff;
+ return 1;
+
+out_oversize:
+ if (net_ratelimit())
+ printk(KERN_DEBUG "ip6_frag_reasm: payload len = %d\n", payload_len);
+ goto out_fail;
+out_oom:
+ if (net_ratelimit())
+ printk(KERN_DEBUG "ip6_frag_reasm: no memory for reassembly\n");
+out_fail:
+ IP6_INC_STATS_BH(IPSTATS_MIB_REASMFAILS);
+ return -1;
+}
+
+static int ipv6_frag_rcv(struct sk_buff **skbp, unsigned int *nhoffp)
+{
+ struct sk_buff *skb = *skbp;
+ struct net_device *dev = skb->dev;
+ struct frag_hdr *fhdr;
+ struct frag_queue *fq;
+ struct ipv6hdr *hdr;
+
+ hdr = skb->nh.ipv6h;
+
+ IP6_INC_STATS_BH(IPSTATS_MIB_REASMREQDS);
+
+ /* Jumbo payload inhibits frag. header */
+ if (hdr->payload_len==0) {
+ IP6_INC_STATS(IPSTATS_MIB_INHDRERRORS);
+ icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, skb->h.raw-skb->nh.raw);
+ return -1;
+ }
+ if (!pskb_may_pull(skb, (skb->h.raw-skb->data)+sizeof(struct frag_hdr))) {
+ IP6_INC_STATS(IPSTATS_MIB_INHDRERRORS);
+ icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, skb->h.raw-skb->nh.raw);
+ return -1;
+ }
+
+ hdr = skb->nh.ipv6h;
+ fhdr = (struct frag_hdr *)skb->h.raw;
+
+ if (!(fhdr->frag_off & htons(0xFFF9))) {
+ /* It is not a fragmented frame */
+ skb->h.raw += sizeof(struct frag_hdr);
+ IP6_INC_STATS_BH(IPSTATS_MIB_REASMOKS);
+
+ *nhoffp = (u8*)fhdr - skb->nh.raw;
+ return 1;
+ }
+
+ if (atomic_read(&ip6_frag_mem) > sysctl_ip6frag_high_thresh)
+ ip6_evictor();
+
+ if ((fq = fq_find(fhdr->identification, &hdr->saddr, &hdr->daddr)) != NULL) {
+ int ret = -1;
+
+ spin_lock(&fq->lock);
+
+ ip6_frag_queue(fq, skb, fhdr, *nhoffp);
+
+ if (fq->last_in == (FIRST_IN|LAST_IN) &&
+ fq->meat == fq->len)
+ ret = ip6_frag_reasm(fq, skbp, nhoffp, dev);
+
+ spin_unlock(&fq->lock);
+ fq_put(fq, NULL);
+ return ret;
+ }
+
+ IP6_INC_STATS_BH(IPSTATS_MIB_REASMFAILS);
+ kfree_skb(skb);
+ return -1;
+}
+
+static struct inet6_protocol frag_protocol =
+{
+ .handler = ipv6_frag_rcv,
+ .flags = INET6_PROTO_NOPOLICY,
+};
+
+void __init ipv6_frag_init(void)
+{
+ if (inet6_add_protocol(&frag_protocol, IPPROTO_FRAGMENT) < 0)
+ printk(KERN_ERR "ipv6_frag_init: Could not register protocol\n");
+
+ ip6_frag_hash_rnd = (u32) ((num_physpages ^ (num_physpages>>7)) ^
+ (jiffies ^ (jiffies >> 6)));
+
+ init_timer(&ip6_frag_secret_timer);
+ ip6_frag_secret_timer.function = ip6_frag_secret_rebuild;
+ ip6_frag_secret_timer.expires = jiffies + sysctl_ip6frag_secret_interval;
+ add_timer(&ip6_frag_secret_timer);
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-04-19 21:12:49 +0000