diff options
| -rw-r--r-- | net/ipv4/ip_fragment.c | 76 |
1 files changed, 55 insertions, 21 deletions
diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c index fabb86db763b..d7fa2bf3a0c1 100644 --- a/net/ipv4/ip_fragment.c +++ b/net/ipv4/ip_fragment.c @@ -109,6 +109,9 @@ static u32 ipfrag_hash_rnd; static LIST_HEAD(ipq_lru_list); int ip_frag_nqueues = 0; +static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev, + struct net_device *dev); + static __inline__ void __ipq_unlink(struct ipq *qp) { hlist_del(&qp->list); @@ -464,17 +467,20 @@ static int ip_frag_reinit(struct ipq *qp) } /* Add new segment to existing queue. */ -static void ip_frag_queue(struct ipq *qp, struct sk_buff *skb) +static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb) { struct sk_buff *prev, *next; + struct net_device *dev; int flags, offset; int ihl, end; + int err = -ENOENT; if (qp->last_in & COMPLETE) goto err; if (!(IPCB(skb)->flags & IPSKB_FRAG_COMPLETE) && - unlikely(ip_frag_too_far(qp)) && unlikely(ip_frag_reinit(qp))) { + unlikely(ip_frag_too_far(qp)) && + unlikely(err = ip_frag_reinit(qp))) { ipq_kill(qp); goto err; } @@ -487,6 +493,7 @@ static void ip_frag_queue(struct ipq *qp, struct sk_buff *skb) /* Determine the position of this fragment. */ end = offset + skb->len - ihl; + err = -EINVAL; /* Is this the final fragment? */ if ((flags & IP_MF) == 0) { @@ -514,9 +521,12 @@ static void ip_frag_queue(struct ipq *qp, struct sk_buff *skb) if (end == offset) goto err; + err = -ENOMEM; if (pskb_pull(skb, ihl) == NULL) goto err; - if (pskb_trim_rcsum(skb, end-offset)) + + err = pskb_trim_rcsum(skb, end - offset); + if (err) goto err; /* Find out which fragments are in front and at the back of us @@ -539,8 +549,10 @@ static void ip_frag_queue(struct ipq *qp, struct sk_buff *skb) if (i > 0) { offset += i; + err = -EINVAL; if (end <= offset) goto err; + err = -ENOMEM; if (!pskb_pull(skb, i)) goto err; if (skb->ip_summed != CHECKSUM_UNNECESSARY) @@ -548,6 +560,8 @@ static void ip_frag_queue(struct ipq *qp, struct sk_buff *skb) } } + err = -ENOMEM; + while (next && FRAG_CB(next)->offset < end) { int i = end - FRAG_CB(next)->offset; /* overlap is 'i' bytes */ @@ -589,37 +603,62 @@ static void ip_frag_queue(struct ipq *qp, struct sk_buff *skb) else qp->fragments = skb; - if (skb->dev) - qp->iif = skb->dev->ifindex; - skb->dev = NULL; + dev = skb->dev; + if (dev) { + qp->iif = dev->ifindex; + skb->dev = NULL; + } qp->stamp = skb->tstamp; qp->meat += skb->len; atomic_add(skb->truesize, &ip_frag_mem); if (offset == 0) qp->last_in |= FIRST_IN; + if (qp->last_in == (FIRST_IN | LAST_IN) && qp->meat == qp->len) + return ip_frag_reasm(qp, prev, dev); + write_lock(&ipfrag_lock); list_move_tail(&qp->lru_list, &ipq_lru_list); write_unlock(&ipfrag_lock); - - return; + return -EINPROGRESS; err: kfree_skb(skb); + return err; } /* Build a new IP datagram from all its fragments. */ -static struct sk_buff *ip_frag_reasm(struct ipq *qp, struct net_device *dev) +static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev, + struct net_device *dev) { struct iphdr *iph; struct sk_buff *fp, *head = qp->fragments; int len; int ihlen; + int err; ipq_kill(qp); + /* Make the one we just received the head. */ + if (prev) { + head = prev->next; + fp = skb_clone(head, GFP_ATOMIC); + + if (!fp) + goto out_nomem; + + fp->next = head->next; + prev->next = fp; + + skb_morph(head, qp->fragments); + head->next = qp->fragments->next; + + kfree_skb(qp->fragments); + qp->fragments = head; + } + BUG_TRAP(head != NULL); BUG_TRAP(FRAG_CB(head)->offset == 0); @@ -627,10 +666,12 @@ static struct sk_buff *ip_frag_reasm(struct ipq *qp, struct net_device *dev) ihlen = ip_hdrlen(head); len = ihlen + qp->len; + err = -E2BIG; if (len > 65535) goto out_oversize; /* Head of list must not be cloned. */ + err = -ENOMEM; if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC)) goto out_nomem; @@ -681,7 +722,7 @@ static struct sk_buff *ip_frag_reasm(struct ipq *qp, struct net_device *dev) iph->tot_len = htons(len); IP_INC_STATS_BH(IPSTATS_MIB_REASMOKS); qp->fragments = NULL; - return head; + return 0; out_nomem: LIMIT_NETDEBUG(KERN_ERR "IP: queue_glue: no memory for gluing " @@ -694,14 +735,13 @@ out_oversize: NIPQUAD(qp->saddr)); out_fail: IP_INC_STATS_BH(IPSTATS_MIB_REASMFAILS); - return NULL; + return err; } /* Process an incoming IP datagram fragment. */ struct sk_buff *ip_defrag(struct sk_buff *skb, u32 user) { struct ipq *qp; - struct net_device *dev; IP_INC_STATS_BH(IPSTATS_MIB_REASMREQDS); @@ -709,23 +749,17 @@ struct sk_buff *ip_defrag(struct sk_buff *skb, u32 user) if (atomic_read(&ip_frag_mem) > sysctl_ipfrag_high_thresh) ip_evictor(); - dev = skb->dev; - /* Lookup (or create) queue header */ if ((qp = ip_find(ip_hdr(skb), user)) != NULL) { - struct sk_buff *ret = NULL; + int ret; spin_lock(&qp->lock); - ip_frag_queue(qp, skb); - - if (qp->last_in == (FIRST_IN|LAST_IN) && - qp->meat == qp->len) - ret = ip_frag_reasm(qp, dev); + ret = ip_frag_queue(qp, skb); spin_unlock(&qp->lock); ipq_put(qp, NULL); - return ret; + return ret ? NULL : skb; } IP_INC_STATS_BH(IPSTATS_MIB_REASMFAILS); |