diff options
| -rw-r--r-- | include/net/inet_frag.h | 6 | ||||
| -rw-r--r-- | net/ipv4/inet_fragment.c | 2 | ||||
| -rw-r--r-- | net/ipv4/ip_fragment.c | 183 |
3 files changed, 149 insertions, 42 deletions
diff --git a/include/net/inet_frag.h b/include/net/inet_frag.h index b86d14528188..1662cbc0b46b 100644 --- a/include/net/inet_frag.h +++ b/include/net/inet_frag.h @@ -57,7 +57,9 @@ struct frag_v6_compare_key { * @lock: spinlock protecting this frag * @refcnt: reference count of the queue * @fragments: received fragments head + * @rb_fragments: received fragments rb-tree root * @fragments_tail: received fragments tail + * @last_run_head: the head of the last "run". see ip_fragment.c * @stamp: timestamp of the last received fragment * @len: total length of the original datagram * @meat: length of received fragments so far @@ -78,6 +80,7 @@ struct inet_frag_queue { struct sk_buff *fragments; /* Used in IPv6. */ struct rb_root rb_fragments; /* Used in IPv4. */ struct sk_buff *fragments_tail; + struct sk_buff *last_run_head; ktime_t stamp; int len; int meat; @@ -113,6 +116,9 @@ void inet_frag_kill(struct inet_frag_queue *q); void inet_frag_destroy(struct inet_frag_queue *q); struct inet_frag_queue *inet_frag_find(struct netns_frags *nf, void *key); +/* Free all skbs in the queue; return the sum of their truesizes. */ +unsigned int inet_frag_rbtree_purge(struct rb_root *root); + static inline void inet_frag_put(struct inet_frag_queue *q) { if (refcount_dec_and_test(&q->refcnt)) diff --git a/net/ipv4/inet_fragment.c b/net/ipv4/inet_fragment.c index 6d258a5669e7..bcb11f3a27c0 100644 --- a/net/ipv4/inet_fragment.c +++ b/net/ipv4/inet_fragment.c @@ -146,7 +146,7 @@ void inet_frag_destroy(struct inet_frag_queue *q) fp = xp; } while (fp); } else { - sum_truesize = skb_rbtree_purge(&q->rb_fragments); + sum_truesize = inet_frag_rbtree_purge(&q->rb_fragments); } sum = sum_truesize + f->qsize; diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c index 7cb7ed761d8c..88281fbce88c 100644 --- a/net/ipv4/ip_fragment.c +++ b/net/ipv4/ip_fragment.c @@ -57,6 +57,57 @@ */ static const char ip_frag_cache_name[] = "ip4-frags"; +/* Use skb->cb to track consecutive/adjacent fragments coming at + * the end of the queue. Nodes in the rb-tree queue will + * contain "runs" of one or more adjacent fragments. + * + * Invariants: + * - next_frag is NULL at the tail of a "run"; + * - the head of a "run" has the sum of all fragment lengths in frag_run_len. + */ +struct ipfrag_skb_cb { + struct inet_skb_parm h; + struct sk_buff *next_frag; + int frag_run_len; +}; + +#define FRAG_CB(skb) ((struct ipfrag_skb_cb *)((skb)->cb)) + +static void ip4_frag_init_run(struct sk_buff *skb) +{ + BUILD_BUG_ON(sizeof(struct ipfrag_skb_cb) > sizeof(skb->cb)); + + FRAG_CB(skb)->next_frag = NULL; + FRAG_CB(skb)->frag_run_len = skb->len; +} + +/* Append skb to the last "run". */ +static void ip4_frag_append_to_last_run(struct inet_frag_queue *q, + struct sk_buff *skb) +{ + RB_CLEAR_NODE(&skb->rbnode); + FRAG_CB(skb)->next_frag = NULL; + + FRAG_CB(q->last_run_head)->frag_run_len += skb->len; + FRAG_CB(q->fragments_tail)->next_frag = skb; + q->fragments_tail = skb; +} + +/* Create a new "run" with the skb. */ +static void ip4_frag_create_run(struct inet_frag_queue *q, struct sk_buff *skb) +{ + if (q->last_run_head) + rb_link_node(&skb->rbnode, &q->last_run_head->rbnode, + &q->last_run_head->rbnode.rb_right); + else + rb_link_node(&skb->rbnode, NULL, &q->rb_fragments.rb_node); + rb_insert_color(&skb->rbnode, &q->rb_fragments); + + ip4_frag_init_run(skb); + q->fragments_tail = skb; + q->last_run_head = skb; +} + /* Describe an entry in the "incomplete datagrams" queue. */ struct ipq { struct inet_frag_queue q; @@ -75,8 +126,8 @@ static u8 ip4_frag_ecn(u8 tos) static struct inet_frags ip4_frags; -static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev, - struct net_device *dev); +static int ip_frag_reasm(struct ipq *qp, struct sk_buff *skb, + struct sk_buff *prev_tail, struct net_device *dev); static void ip4_frag_init(struct inet_frag_queue *q, const void *a) @@ -168,7 +219,12 @@ static void ip_expire(struct timer_list *t) head = skb_rb_first(&qp->q.rb_fragments); if (!head) goto out; - rb_erase(&head->rbnode, &qp->q.rb_fragments); + if (FRAG_CB(head)->next_frag) + rb_replace_node(&head->rbnode, + &FRAG_CB(head)->next_frag->rbnode, + &qp->q.rb_fragments); + else + rb_erase(&head->rbnode, &qp->q.rb_fragments); memset(&head->rbnode, 0, sizeof(head->rbnode)); barrier(); } @@ -269,7 +325,7 @@ static int ip_frag_reinit(struct ipq *qp) return -ETIMEDOUT; } - sum_truesize = skb_rbtree_purge(&qp->q.rb_fragments); + sum_truesize = inet_frag_rbtree_purge(&qp->q.rb_fragments); sub_frag_mem_limit(qp->q.net, sum_truesize); qp->q.flags = 0; @@ -278,6 +334,7 @@ static int ip_frag_reinit(struct ipq *qp) qp->q.fragments = NULL; qp->q.rb_fragments = RB_ROOT; qp->q.fragments_tail = NULL; + qp->q.last_run_head = NULL; qp->iif = 0; qp->ecn = 0; @@ -289,7 +346,7 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb) { struct net *net = container_of(qp->q.net, struct net, ipv4.frags); struct rb_node **rbn, *parent; - struct sk_buff *skb1; + struct sk_buff *skb1, *prev_tail; struct net_device *dev; unsigned int fragsize; int flags, offset; @@ -367,38 +424,41 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb) */ /* Find out where to put this fragment. */ - skb1 = qp->q.fragments_tail; - if (!skb1) { - /* This is the first fragment we've received. */ - rb_link_node(&skb->rbnode, NULL, &qp->q.rb_fragments.rb_node); - qp->q.fragments_tail = skb; - } else if ((skb1->ip_defrag_offset + skb1->len) < end) { - /* This is the common/special case: skb goes to the end. */ + prev_tail = qp->q.fragments_tail; + if (!prev_tail) + ip4_frag_create_run(&qp->q, skb); /* First fragment. */ + else if (prev_tail->ip_defrag_offset + prev_tail->len < end) { + /* This is the common case: skb goes to the end. */ /* Detect and discard overlaps. */ - if (offset < (skb1->ip_defrag_offset + skb1->len)) + if (offset < prev_tail->ip_defrag_offset + prev_tail->len) goto discard_qp; - /* Insert after skb1. */ - rb_link_node(&skb->rbnode, &skb1->rbnode, &skb1->rbnode.rb_right); - qp->q.fragments_tail = skb; + if (offset == prev_tail->ip_defrag_offset + prev_tail->len) + ip4_frag_append_to_last_run(&qp->q, skb); + else + ip4_frag_create_run(&qp->q, skb); } else { - /* Binary search. Note that skb can become the first fragment, but - * not the last (covered above). */ + /* Binary search. Note that skb can become the first fragment, + * but not the last (covered above). + */ rbn = &qp->q.rb_fragments.rb_node; do { parent = *rbn; skb1 = rb_to_skb(parent); if (end <= skb1->ip_defrag_offset) rbn = &parent->rb_left; - else if (offset >= skb1->ip_defrag_offset + skb1->len) + else if (offset >= skb1->ip_defrag_offset + + FRAG_CB(skb1)->frag_run_len) rbn = &parent->rb_right; else /* Found an overlap with skb1. */ goto discard_qp; } while (*rbn); /* Here we have parent properly set, and rbn pointing to - * one of its NULL left/right children. Insert skb. */ + * one of its NULL left/right children. Insert skb. + */ + ip4_frag_init_run(skb); rb_link_node(&skb->rbnode, parent, rbn); + rb_insert_color(&skb->rbnode, &qp->q.rb_fragments); } - rb_insert_color(&skb->rbnode, &qp->q.rb_fragments); if (dev) qp->iif = dev->ifindex; @@ -425,7 +485,7 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb) unsigned long orefdst = skb->_skb_refdst; skb->_skb_refdst = 0UL; - err = ip_frag_reasm(qp, skb, dev); + err = ip_frag_reasm(qp, skb, prev_tail, dev); skb->_skb_refdst = orefdst; return err; } @@ -444,7 +504,7 @@ err: /* Build a new IP datagram from all its fragments. */ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *skb, - struct net_device *dev) + struct sk_buff *prev_tail, struct net_device *dev) { struct net *net = container_of(qp->q.net, struct net, ipv4.frags); struct iphdr *iph; @@ -468,10 +528,16 @@ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *skb, fp = skb_clone(skb, GFP_ATOMIC); if (!fp) goto out_nomem; - rb_replace_node(&skb->rbnode, &fp->rbnode, &qp->q.rb_fragments); + FRAG_CB(fp)->next_frag = FRAG_CB(skb)->next_frag; + if (RB_EMPTY_NODE(&skb->rbnode)) + FRAG_CB(prev_tail)->next_frag = fp; + else + rb_replace_node(&skb->rbnode, &fp->rbnode, + &qp->q.rb_fragments); if (qp->q.fragments_tail == skb) qp->q.fragments_tail = fp; skb_morph(skb, head); + FRAG_CB(skb)->next_frag = FRAG_CB(head)->next_frag; rb_replace_node(&head->rbnode, &skb->rbnode, &qp->q.rb_fragments); consume_skb(head); @@ -507,7 +573,7 @@ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *skb, for (i = 0; i < skb_shinfo(head)->nr_frags; i++) plen += skb_frag_size(&skb_shinfo(head)->frags[i]); clone->len = clone->data_len = head->data_len - plen; - skb->truesize += clone->truesize; + head->truesize += clone->truesize; clone->csum = 0; clone->ip_summed = head->ip_summed; add_frag_mem_limit(qp->q.net, clone->truesize); @@ -520,24 +586,36 @@ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *skb, skb_push(head, head->data - skb_network_header(head)); /* Traverse the tree in order, to build frag_list. */ + fp = FRAG_CB(head)->next_frag; rbn = rb_next(&head->rbnode); rb_erase(&head->rbnode, &qp->q.rb_fragments); - while (rbn) { - struct rb_node *rbnext = rb_next(rbn); - fp = rb_to_skb(rbn); - rb_erase(rbn, &qp->q.rb_fragments); - rbn = rbnext; - *nextp = fp; - nextp = &fp->next; - fp->prev = NULL; - memset(&fp->rbnode, 0, sizeof(fp->rbnode)); - 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_COMPLETE) - head->csum = csum_add(head->csum, fp->csum); - head->truesize += fp->truesize; + while (rbn || fp) { + /* fp points to the next sk_buff in the current run; + * rbn points to the next run. + */ + /* Go through the current run. */ + while (fp) { + *nextp = fp; + nextp = &fp->next; + fp->prev = NULL; + memset(&fp->rbnode, 0, sizeof(fp->rbnode)); + 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_COMPLETE) + head->csum = csum_add(head->csum, fp->csum); + head->truesize += fp->truesize; + fp = FRAG_CB(fp)->next_frag; + } + /* Move to the next run. */ + if (rbn) { + struct rb_node *rbnext = rb_next(rbn); + + fp = rb_to_skb(rbn); + rb_erase(rbn, &qp->q.rb_fragments); + rbn = rbnext; + } } sub_frag_mem_limit(qp->q.net, head->truesize); @@ -573,6 +651,7 @@ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *skb, qp->q.fragments = NULL; qp->q.rb_fragments = RB_ROOT; qp->q.fragments_tail = NULL; + qp->q.last_run_head = NULL; return 0; out_nomem: @@ -654,6 +733,28 @@ struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user) } EXPORT_SYMBOL(ip_check_defrag); +unsigned int inet_frag_rbtree_purge(struct rb_root *root) +{ + struct rb_node *p = rb_first(root); + unsigned int sum = 0; + + while (p) { + struct sk_buff *skb = rb_entry(p, struct sk_buff, rbnode); + + p = rb_next(p); + rb_erase(&skb->rbnode, root); + while (skb) { + struct sk_buff *next = FRAG_CB(skb)->next_frag; + + sum += skb->truesize; + kfree_skb(skb); + skb = next; + } + } + return sum; +} +EXPORT_SYMBOL(inet_frag_rbtree_purge); + #ifdef CONFIG_SYSCTL static int dist_min; |