From 8488df894d05d6fa41c2bd298c335f944bb0e401 Mon Sep 17 00:00:00 2001 From: Wei Dong Date: Fri, 2 Mar 2007 12:37:26 -0800 Subject: [NET]: Fix bugs in "Whether sock accept queue is full" checking when I use linux TCP socket, and find there is a bug in function sk_acceptq_is_full(). When a new SYN comes, TCP module first checks its validation. If valid, send SYN,ACK to the client and add the sock to the syn hash table. Next time if received the valid ACK for SYN,ACK from the client. server will accept this connection and increase the sk->sk_ack_backlog -- which is done in function tcp_check_req().We check wether acceptq is full in function tcp_v4_syn_recv_sock(). Consider an example: After listen(sockfd, 1) system call, sk->sk_max_ack_backlog is set to 1. As we know, sk->sk_ack_backlog is initialized to 0. Assuming accept() system call is not invoked now. 1. 1st connection comes. invoke sk_acceptq_is_full(). sk- >sk_ack_backlog=0 sk->sk_max_ack_backlog=1, function return 0 accept this connection. Increase the sk->sk_ack_backlog 2. 2nd connection comes. invoke sk_acceptq_is_full(). sk- >sk_ack_backlog=1 sk->sk_max_ack_backlog=1, function return 0 accept this connection. Increase the sk->sk_ack_backlog 3. 3rd connection comes. invoke sk_acceptq_is_full(). sk- >sk_ack_backlog=2 sk->sk_max_ack_backlog=1, function return 1. Refuse this connection. I think it has bugs. after listen system call. sk->sk_max_ack_backlog=1 but now it can accept 2 connections. Signed-off-by: Wei Dong Signed-off-by: David S. Miller --- include/net/sock.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include') diff --git a/include/net/sock.h b/include/net/sock.h index 2c7d60ca354..849c7df2318 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -426,7 +426,7 @@ static inline void sk_acceptq_added(struct sock *sk) static inline int sk_acceptq_is_full(struct sock *sk) { - return sk->sk_ack_backlog > sk->sk_max_ack_backlog; + return sk->sk_ack_backlog >= sk->sk_max_ack_backlog; } /* -- cgit v1.2.3 From 5c15bdec5c38f4ccf73ef2585fc80a6164de9554 Mon Sep 17 00:00:00 2001 From: Dan Aloni Date: Fri, 2 Mar 2007 20:44:51 -0800 Subject: [VLAN]: Avoid a 4-order allocation. This patch splits the vlan_group struct into a multi-allocated struct. On x86_64, the size of the original struct is a little more than 32KB, causing a 4-order allocation, which is prune to problems caused by buddy-system external fragmentation conditions. I couldn't just use vmalloc() because vfree() cannot be called in the softirq context of the RCU callback. Signed-off-by: Dan Aloni Acked-by: Jeff Garzik Signed-off-by: David S. Miller --- include/linux/if_vlan.h | 25 ++++++++++++++++++++++--- 1 file changed, 22 insertions(+), 3 deletions(-) (limited to 'include') diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h index 35cb3857358..d103580c72d 100644 --- a/include/linux/if_vlan.h +++ b/include/linux/if_vlan.h @@ -70,15 +70,34 @@ extern void vlan_ioctl_set(int (*hook)(void __user *)); * depends on completely exhausting the VLAN identifier space. Thus * it gives constant time look-up, but in many cases it wastes memory. */ -#define VLAN_GROUP_ARRAY_LEN 4096 +#define VLAN_GROUP_ARRAY_LEN 4096 +#define VLAN_GROUP_ARRAY_SPLIT_PARTS 8 +#define VLAN_GROUP_ARRAY_PART_LEN (VLAN_GROUP_ARRAY_LEN/VLAN_GROUP_ARRAY_SPLIT_PARTS) struct vlan_group { int real_dev_ifindex; /* The ifindex of the ethernet(like) device the vlan is attached to. */ struct hlist_node hlist; /* linked list */ - struct net_device *vlan_devices[VLAN_GROUP_ARRAY_LEN]; + struct net_device **vlan_devices_arrays[VLAN_GROUP_ARRAY_SPLIT_PARTS]; struct rcu_head rcu; }; +static inline struct net_device *vlan_group_get_device(struct vlan_group *vg, int vlan_id) +{ + struct net_device **array; + array = vg->vlan_devices_arrays[vlan_id / VLAN_GROUP_ARRAY_PART_LEN]; + return array[vlan_id % VLAN_GROUP_ARRAY_PART_LEN]; +} + +static inline void vlan_group_set_device(struct vlan_group *vg, int vlan_id, + struct net_device *dev) +{ + struct net_device **array; + if (!vg) + return; + array = vg->vlan_devices_arrays[vlan_id / VLAN_GROUP_ARRAY_PART_LEN]; + array[vlan_id % VLAN_GROUP_ARRAY_PART_LEN] = dev; +} + struct vlan_priority_tci_mapping { unsigned long priority; unsigned short vlan_qos; /* This should be shifted when first set, so we only do it @@ -160,7 +179,7 @@ static inline int __vlan_hwaccel_rx(struct sk_buff *skb, return NET_RX_DROP; } - skb->dev = grp->vlan_devices[vlan_tag & VLAN_VID_MASK]; + skb->dev = vlan_group_get_device(grp, vlan_tag & VLAN_VID_MASK); if (skb->dev == NULL) { dev_kfree_skb_any(skb); -- cgit v1.2.3