/* It _is_ possible, that we have something out-of-order _after_ FIN.
* Probably, we should reset in this case. For now drop them.
*/
- __skb_queue_purge(&tp->out_of_order_queue);
+ skb_rbtree_purge(&tp->out_of_order_queue);
if (tcp_is_sack(tp))
tcp_sack_reset(&tp->rx_opt);
sk_mem_reclaim(sk);
int this_sack;
/* Empty ofo queue, hence, all the SACKs are eaten. Clear. */
- if (skb_queue_empty(&tp->out_of_order_queue)) {
+ if (RB_EMPTY_ROOT(&tp->out_of_order_queue)) {
tp->rx_opt.num_sacks = 0;
return;
}
{
struct tcp_sock *tp = tcp_sk(sk);
__u32 dsack_high = tp->rcv_nxt;
+ bool fin, fragstolen, eaten;
struct sk_buff *skb, *tail;
- bool fragstolen, eaten;
+ struct rb_node *p;
- while ((skb = skb_peek(&tp->out_of_order_queue)) != NULL) {
+ p = rb_first(&tp->out_of_order_queue);
+ while (p) {
+ skb = rb_entry(p, struct sk_buff, rbnode);
if (after(TCP_SKB_CB(skb)->seq, tp->rcv_nxt))
break;
dsack_high = TCP_SKB_CB(skb)->end_seq;
tcp_dsack_extend(sk, TCP_SKB_CB(skb)->seq, dsack);
}
+ p = rb_next(p);
+ rb_erase(&skb->rbnode, &tp->out_of_order_queue);
- __skb_unlink(skb, &tp->out_of_order_queue);
- if (!after(TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt)) {
+ if (unlikely(!after(TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt))) {
SOCK_DEBUG(sk, "ofo packet was already received\n");
tcp_drop(sk, skb);
continue;
tail = skb_peek_tail(&sk->sk_receive_queue);
eaten = tail && tcp_try_coalesce(sk, tail, skb, &fragstolen);
tcp_rcv_nxt_update(tp, TCP_SKB_CB(skb)->end_seq);
+ fin = TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN;
if (!eaten)
__skb_queue_tail(&sk->sk_receive_queue, skb);
- if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
- tcp_fin(sk);
- if (eaten)
+ else
kfree_skb_partial(skb, fragstolen);
+
+ if (unlikely(fin)) {
+ tcp_fin(sk);
+ /* tcp_fin() purges tp->out_of_order_queue,
+ * so we must end this loop right now.
+ */
+ break;
+ }
}
}
static void tcp_data_queue_ofo(struct sock *sk, struct sk_buff *skb)
{
struct tcp_sock *tp = tcp_sk(sk);
+ struct rb_node **p, *q, *parent;
struct sk_buff *skb1;
u32 seq, end_seq;
+ bool fragstolen;
tcp_ecn_check_ce(sk, skb);
inet_csk_schedule_ack(sk);
NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPOFOQUEUE);
+ seq = TCP_SKB_CB(skb)->seq;
+ end_seq = TCP_SKB_CB(skb)->end_seq;
SOCK_DEBUG(sk, "out of order segment: rcv_next %X seq %X - %X\n",
- tp->rcv_nxt, TCP_SKB_CB(skb)->seq, TCP_SKB_CB(skb)->end_seq);
+ tp->rcv_nxt, seq, end_seq);
- skb1 = skb_peek_tail(&tp->out_of_order_queue);
- if (!skb1) {
+ p = &tp->out_of_order_queue.rb_node;
+ if (RB_EMPTY_ROOT(&tp->out_of_order_queue)) {
/* Initial out of order segment, build 1 SACK. */
if (tcp_is_sack(tp)) {
tp->rx_opt.num_sacks = 1;
- tp->selective_acks[0].start_seq = TCP_SKB_CB(skb)->seq;
- tp->selective_acks[0].end_seq =
- TCP_SKB_CB(skb)->end_seq;
+ tp->selective_acks[0].start_seq = seq;
+ tp->selective_acks[0].end_seq = end_seq;
}
- __skb_queue_head(&tp->out_of_order_queue, skb);
- goto end;
- }
-
- seq = TCP_SKB_CB(skb)->seq;
- end_seq = TCP_SKB_CB(skb)->end_seq;
-
- if (seq == TCP_SKB_CB(skb1)->end_seq) {
- bool fragstolen;
-
- if (!tcp_try_coalesce(sk, skb1, skb, &fragstolen)) {
- __skb_queue_after(&tp->out_of_order_queue, skb1, skb);
- } else {
- tcp_grow_window(sk, skb);
- kfree_skb_partial(skb, fragstolen);
- skb = NULL;
- }
-
- if (!tp->rx_opt.num_sacks ||
- tp->selective_acks[0].end_seq != seq)
- goto add_sack;
-
- /* Common case: data arrive in order after hole. */
- tp->selective_acks[0].end_seq = end_seq;
+ rb_link_node(&skb->rbnode, NULL, p);
+ rb_insert_color(&skb->rbnode, &tp->out_of_order_queue);
+ tp->ooo_last_skb = skb;
goto end;
}
- /* Find place to insert this segment. */
- while (1) {
- if (!after(TCP_SKB_CB(skb1)->seq, seq))
- break;
- if (skb_queue_is_first(&tp->out_of_order_queue, skb1)) {
- skb1 = NULL;
- break;
+ /* In the typical case, we are adding an skb to the end of the list.
+ * Use of ooo_last_skb avoids the O(Log(N)) rbtree lookup.
+ */
+ if (tcp_try_coalesce(sk, tp->ooo_last_skb, skb, &fragstolen)) {
+coalesce_done:
+ tcp_grow_window(sk, skb);
+ kfree_skb_partial(skb, fragstolen);
+ skb = NULL;
+ goto add_sack;
+ }
+
+ /* Find place to insert this segment. Handle overlaps on the way. */
+ parent = NULL;
+ while (*p) {
+ parent = *p;
+ skb1 = rb_entry(parent, struct sk_buff, rbnode);
+ if (before(seq, TCP_SKB_CB(skb1)->seq)) {
+ p = &parent->rb_left;
+ continue;
}
- skb1 = skb_queue_prev(&tp->out_of_order_queue, skb1);
- }
- /* Do skb overlap to previous one? */
- if (skb1 && before(seq, TCP_SKB_CB(skb1)->end_seq)) {
- if (!after(end_seq, TCP_SKB_CB(skb1)->end_seq)) {
- /* All the bits are present. Drop. */
- NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPOFOMERGE);
- tcp_drop(sk, skb);
- skb = NULL;
- tcp_dsack_set(sk, seq, end_seq);
- goto add_sack;
- }
- if (after(seq, TCP_SKB_CB(skb1)->seq)) {
- /* Partial overlap. */
- tcp_dsack_set(sk, seq,
- TCP_SKB_CB(skb1)->end_seq);
- } else {
- if (skb_queue_is_first(&tp->out_of_order_queue,
- skb1))
- skb1 = NULL;
- else
- skb1 = skb_queue_prev(
- &tp->out_of_order_queue,
- skb1);
+ if (before(seq, TCP_SKB_CB(skb1)->end_seq)) {
+ if (!after(end_seq, TCP_SKB_CB(skb1)->end_seq)) {
+ /* All the bits are present. Drop. */
+ NET_INC_STATS(sock_net(sk),
+ LINUX_MIB_TCPOFOMERGE);
+ __kfree_skb(skb);
+ skb = NULL;
+ tcp_dsack_set(sk, seq, end_seq);
+ goto add_sack;
+ }
+ if (after(seq, TCP_SKB_CB(skb1)->seq)) {
+ /* Partial overlap. */
+ tcp_dsack_set(sk, seq, TCP_SKB_CB(skb1)->end_seq);
+ } else {
+ /* skb's seq == skb1's seq and skb covers skb1.
+ * Replace skb1 with skb.
+ */
+ rb_replace_node(&skb1->rbnode, &skb->rbnode,
+ &tp->out_of_order_queue);
+ tcp_dsack_extend(sk,
+ TCP_SKB_CB(skb1)->seq,
+ TCP_SKB_CB(skb1)->end_seq);
+ NET_INC_STATS(sock_net(sk),
+ LINUX_MIB_TCPOFOMERGE);
+ __kfree_skb(skb1);
+ goto add_sack;
+ }
+ } else if (tcp_try_coalesce(sk, skb1, skb, &fragstolen)) {
+ goto coalesce_done;
}
+ p = &parent->rb_right;
}
- if (!skb1)
- __skb_queue_head(&tp->out_of_order_queue, skb);
- else
- __skb_queue_after(&tp->out_of_order_queue, skb1, skb);
- /* And clean segments covered by new one as whole. */
- while (!skb_queue_is_last(&tp->out_of_order_queue, skb)) {
- skb1 = skb_queue_next(&tp->out_of_order_queue, skb);
+ /* Insert segment into RB tree. */
+ rb_link_node(&skb->rbnode, parent, p);
+ rb_insert_color(&skb->rbnode, &tp->out_of_order_queue);
+ /* Remove other segments covered by skb. */
+ while ((q = rb_next(&skb->rbnode)) != NULL) {
+ skb1 = rb_entry(q, struct sk_buff, rbnode);
if (!after(end_seq, TCP_SKB_CB(skb1)->seq))
break;
if (before(end_seq, TCP_SKB_CB(skb1)->end_seq)) {
end_seq);
break;
}
- __skb_unlink(skb1, &tp->out_of_order_queue);
+ rb_erase(&skb1->rbnode, &tp->out_of_order_queue);
tcp_dsack_extend(sk, TCP_SKB_CB(skb1)->seq,
TCP_SKB_CB(skb1)->end_seq);
NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPOFOMERGE);
tcp_drop(sk, skb1);
}
+ /* If there is no skb after us, we are the last_skb ! */
+ if (!q)
+ tp->ooo_last_skb = skb;
add_sack:
if (tcp_is_sack(tp))
if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
tcp_fin(sk);
- if (!skb_queue_empty(&tp->out_of_order_queue)) {
+ if (!RB_EMPTY_ROOT(&tp->out_of_order_queue)) {
tcp_ofo_queue(sk);
/* RFC2581. 4.2. SHOULD send immediate ACK, when
* gap in queue is filled.
*/
- if (skb_queue_empty(&tp->out_of_order_queue))
+ if (RB_EMPTY_ROOT(&tp->out_of_order_queue))
inet_csk(sk)->icsk_ack.pingpong = 0;
}
tcp_data_queue_ofo(sk, skb);
}
+static struct sk_buff *tcp_skb_next(struct sk_buff *skb, struct sk_buff_head *list)
+{
+ if (list)
+ return !skb_queue_is_last(list, skb) ? skb->next : NULL;
+
+ return rb_entry_safe(rb_next(&skb->rbnode), struct sk_buff, rbnode);
+}
+
static struct sk_buff *tcp_collapse_one(struct sock *sk, struct sk_buff *skb,
- struct sk_buff_head *list)
+ struct sk_buff_head *list,
+ struct rb_root *root)
{
- struct sk_buff *next = NULL;
+ struct sk_buff *next = tcp_skb_next(skb, list);
- if (!skb_queue_is_last(list, skb))
- next = skb_queue_next(list, skb);
+ if (list)
+ __skb_unlink(skb, list);
+ else
+ rb_erase(&skb->rbnode, root);
- __skb_unlink(skb, list);
__kfree_skb(skb);
NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPRCVCOLLAPSED);
return next;
}
+/* Insert skb into rb tree, ordered by TCP_SKB_CB(skb)->seq */
+static void tcp_rbtree_insert(struct rb_root *root, struct sk_buff *skb)
+{
+ struct rb_node **p = &root->rb_node;
+ struct rb_node *parent = NULL;
+ struct sk_buff *skb1;
+
+ while (*p) {
+ parent = *p;
+ skb1 = rb_entry(parent, struct sk_buff, rbnode);
+ if (before(TCP_SKB_CB(skb)->seq, TCP_SKB_CB(skb1)->seq))
+ p = &parent->rb_left;
+ else
+ p = &parent->rb_right;
+ }
+ rb_link_node(&skb->rbnode, parent, p);
+ rb_insert_color(&skb->rbnode, root);
+}
+
/* Collapse contiguous sequence of skbs head..tail with
* sequence numbers start..end.
*
- * If tail is NULL, this means until the end of the list.
+ * If tail is NULL, this means until the end of the queue.
*
* Segments with FIN/SYN are not collapsed (only because this
* simplifies code)
*/
static void
-tcp_collapse(struct sock *sk, struct sk_buff_head *list,
- struct sk_buff *head, struct sk_buff *tail,
- u32 start, u32 end)
+tcp_collapse(struct sock *sk, struct sk_buff_head *list, struct rb_root *root,
+ struct sk_buff *head, struct sk_buff *tail, u32 start, u32 end)
{
- struct sk_buff *skb, *n;
+ struct sk_buff *skb = head, *n;
+ struct sk_buff_head tmp;
bool end_of_skbs;
/* First, check that queue is collapsible and find
- * the point where collapsing can be useful. */
- skb = head;
+ * the point where collapsing can be useful.
+ */
restart:
- end_of_skbs = true;
- skb_queue_walk_from_safe(list, skb, n) {
- if (skb == tail)
- break;
+ for (end_of_skbs = true; skb != NULL && skb != tail; skb = n) {
+ n = tcp_skb_next(skb, list);
+
/* No new bits? It is possible on ofo queue. */
if (!before(start, TCP_SKB_CB(skb)->end_seq)) {
- skb = tcp_collapse_one(sk, skb, list);
+ skb = tcp_collapse_one(sk, skb, list, root);
if (!skb)
break;
goto restart;
break;
}
- if (!skb_queue_is_last(list, skb)) {
- struct sk_buff *next = skb_queue_next(list, skb);
- if (next != tail &&
- TCP_SKB_CB(skb)->end_seq != TCP_SKB_CB(next)->seq) {
- end_of_skbs = false;
- break;
- }
+ if (n && n != tail &&
+ TCP_SKB_CB(skb)->end_seq != TCP_SKB_CB(n)->seq) {
+ end_of_skbs = false;
+ break;
}
/* Decided to skip this, advance start seq. */
(TCP_SKB_CB(skb)->tcp_flags & (TCPHDR_SYN | TCPHDR_FIN)))
return;
+ __skb_queue_head_init(&tmp);
+
while (before(start, end)) {
int copy = min_t(int, SKB_MAX_ORDER(0, 0), end - start);
struct sk_buff *nskb;
nskb = alloc_skb(copy, GFP_ATOMIC);
if (!nskb)
- return;
+ break;
memcpy(nskb->cb, skb->cb, sizeof(skb->cb));
TCP_SKB_CB(nskb)->seq = TCP_SKB_CB(nskb)->end_seq = start;
- __skb_queue_before(list, skb, nskb);
+ if (list)
+ __skb_queue_before(list, skb, nskb);
+ else
+ __skb_queue_tail(&tmp, nskb); /* defer rbtree insertion */
skb_set_owner_r(nskb, sk);
/* Copy data, releasing collapsed skbs. */
start += size;
}
if (!before(start, TCP_SKB_CB(skb)->end_seq)) {
- skb = tcp_collapse_one(sk, skb, list);
+ skb = tcp_collapse_one(sk, skb, list, root);
if (!skb ||
skb == tail ||
(TCP_SKB_CB(skb)->tcp_flags & (TCPHDR_SYN | TCPHDR_FIN)))
- return;
+ goto end;
}
}
}
+end:
+ skb_queue_walk_safe(&tmp, skb, n)
+ tcp_rbtree_insert(root, skb);
}
/* Collapse ofo queue. Algorithm: select contiguous sequence of skbs
{
struct tcp_sock *tp = tcp_sk(sk);
u32 range_truesize, sum_tiny = 0;
- struct sk_buff *skb = skb_peek(&tp->out_of_order_queue);
- struct sk_buff *head;
+ struct sk_buff *skb, *head;
+ struct rb_node *p;
u32 start, end;
- if (!skb)
+ p = rb_first(&tp->out_of_order_queue);
+ skb = rb_entry_safe(p, struct sk_buff, rbnode);
+new_range:
+ if (!skb) {
+ p = rb_last(&tp->out_of_order_queue);
+ /* Note: This is possible p is NULL here. We do not
+ * use rb_entry_safe(), as ooo_last_skb is valid only
+ * if rbtree is not empty.
+ */
+ tp->ooo_last_skb = rb_entry(p, struct sk_buff, rbnode);
return;
-
+ }
start = TCP_SKB_CB(skb)->seq;
end = TCP_SKB_CB(skb)->end_seq;
range_truesize = skb->truesize;
- head = skb;
-
- for (;;) {
- struct sk_buff *next = NULL;
- if (!skb_queue_is_last(&tp->out_of_order_queue, skb))
- next = skb_queue_next(&tp->out_of_order_queue, skb);
- skb = next;
+ for (head = skb;;) {
+ skb = tcp_skb_next(skb, NULL);
- /* Segment is terminated when we see gap or when
- * we are at the end of all the queue. */
+ /* Range is terminated when we see a gap or when
+ * we are at the queue end.
+ */
if (!skb ||
after(TCP_SKB_CB(skb)->seq, end) ||
before(TCP_SKB_CB(skb)->end_seq, start)) {
/* Do not attempt collapsing tiny skbs */
if (range_truesize != head->truesize ||
end - start >= SKB_WITH_OVERHEAD(SK_MEM_QUANTUM)) {
- tcp_collapse(sk, &tp->out_of_order_queue,
+ tcp_collapse(sk, NULL, &tp->out_of_order_queue,
head, skb, start, end);
} else {
sum_tiny += range_truesize;
return;
}
- head = skb;
- if (!skb)
- break;
- /* Start new segment */
+ goto new_range;
+ }
+
+ range_truesize += skb->truesize;
+ if (unlikely(before(TCP_SKB_CB(skb)->seq, start)))
start = TCP_SKB_CB(skb)->seq;
+ if (after(TCP_SKB_CB(skb)->end_seq, end))
end = TCP_SKB_CB(skb)->end_seq;
- range_truesize = skb->truesize;
- } else {
- range_truesize += skb->truesize;
- if (before(TCP_SKB_CB(skb)->seq, start))
- start = TCP_SKB_CB(skb)->seq;
- if (after(TCP_SKB_CB(skb)->end_seq, end))
- end = TCP_SKB_CB(skb)->end_seq;
- }
}
}
static bool tcp_prune_ofo_queue(struct sock *sk)
{
struct tcp_sock *tp = tcp_sk(sk);
- bool res = false;
+ struct rb_node *node, *prev;
- if (!skb_queue_empty(&tp->out_of_order_queue)) {
- NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_OFOPRUNED);
- __skb_queue_purge(&tp->out_of_order_queue);
+ if (RB_EMPTY_ROOT(&tp->out_of_order_queue))
+ return false;
- /* Reset SACK state. A conforming SACK implementation will
- * do the same at a timeout based retransmit. When a connection
- * is in a sad state like this, we care only about integrity
- * of the connection not performance.
- */
- if (tp->rx_opt.sack_ok)
- tcp_sack_reset(&tp->rx_opt);
+ NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_OFOPRUNED);
+
+ node = &tp->ooo_last_skb->rbnode;
+ do {
+ prev = rb_prev(node);
+ rb_erase(node, &tp->out_of_order_queue);
+ __kfree_skb(rb_to_skb(node));
sk_mem_reclaim(sk);
- res = true;
- }
- return res;
+ if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf &&
+ !tcp_under_memory_pressure(sk))
+ break;
+
+ node = prev;
+ } while (node);
+ tp->ooo_last_skb = rb_entry(prev, struct sk_buff, rbnode);
+
+ /* Reset SACK state. A conforming SACK implementation will
+ * do the same at a timeout based retransmit. When a connection
+ * is in a sad state like this, we care only about integrity
+ * of the connection not performance.
+ */
+ if (tp->rx_opt.sack_ok)
+ tcp_sack_reset(&tp->rx_opt);
+
+ return true;
}
/* Reduce allocated memory if we can, trying to get
tcp_collapse_ofo_queue(sk);
if (!skb_queue_empty(&sk->sk_receive_queue))
- tcp_collapse(sk, &sk->sk_receive_queue,
+ tcp_collapse(sk, &sk->sk_receive_queue, NULL,
skb_peek(&sk->sk_receive_queue),
NULL,
tp->copied_seq, tp->rcv_nxt);
/* We ACK each frame or... */
tcp_in_quickack_mode(sk) ||
/* We have out of order data. */
- (ofo_possible && skb_peek(&tp->out_of_order_queue))) {
+ (ofo_possible && !RB_EMPTY_ROOT(&tp->out_of_order_queue))) {
/* Then ack it now */
tcp_send_ack(sk);
} else {
projects / linux / commitdiff