packet: Add helpers to register/unregister ->prot_hook (ce06b03e) · Commits · e / devices / android_kernel_xiaomi_markw

net/packet/af_packet.c

+59 −44

Original line number	Diff line number	Diff line
		@@ -222,6 +222,55 @@ struct packet_skb_cb {

		#define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb))

		static inline struct packet_sock pkt_sk(struct sock sk)
		{
		return (struct packet_sock *)sk;
		}

		/* register_prot_hook must be invoked with the po->bind_lock held,
		* or from a context in which asynchronous accesses to the packet
		* socket is not possible (packet_create()).
		*/
		static void register_prot_hook(struct sock *sk)
		{
		struct packet_sock *po = pkt_sk(sk);
		if (!po->running) {
		dev_add_pack(&po->prot_hook);
		sock_hold(sk);
		po->running = 1;
		}
		}

		/* {,__}unregister_prot_hook() must be invoked with the po->bind_lock
		* held. If the sync parameter is true, we will temporarily drop
		* the po->bind_lock and do a synchronize_net to make sure no
		* asynchronous packet processing paths still refer to the elements
		* of po->prot_hook. If the sync parameter is false, it is the
		* callers responsibility to take care of this.
		*/
		static void __unregister_prot_hook(struct sock *sk, bool sync)
		{
		struct packet_sock *po = pkt_sk(sk);

		po->running = 0;
		__dev_remove_pack(&po->prot_hook);
		__sock_put(sk);

		if (sync) {
		spin_unlock(&po->bind_lock);
		synchronize_net();
		spin_lock(&po->bind_lock);
		}
		}

		static void unregister_prot_hook(struct sock *sk, bool sync)
		{
		struct packet_sock *po = pkt_sk(sk);

		if (po->running)
		__unregister_prot_hook(sk, sync);
		}

		static inline __pure struct page pgv_to_page(void addr)
		{
		if (is_vmalloc_addr(addr))
		@@ -324,11 +373,6 @@ static inline void packet_increment_head(struct packet_ring_buffer *buff)
		buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
		}

		static inline struct packet_sock pkt_sk(struct sock sk)
		{
		return (struct packet_sock *)sk;
		}

		static void packet_sock_destruct(struct sock *sk)
		{
		skb_queue_purge(&sk->sk_error_queue);
		@@ -1337,15 +1381,7 @@ static int packet_release(struct socket *sock)
		spin_unlock_bh(&net->packet.sklist_lock);

		spin_lock(&po->bind_lock);
		if (po->running) {
		/*
		* Remove from protocol table
		*/
		po->running = 0;
		po->num = 0;
		__dev_remove_pack(&po->prot_hook);
		__sock_put(sk);
		}
		unregister_prot_hook(sk, false);
		if (po->prot_hook.dev) {
		dev_put(po->prot_hook.dev);
		po->prot_hook.dev = NULL;
		@@ -1392,15 +1428,7 @@ static int packet_do_bind(struct sock sk, struct net_device dev, __be16 protoc
		lock_sock(sk);

		spin_lock(&po->bind_lock);
		if (po->running) {
		__sock_put(sk);
		po->running = 0;
		po->num = 0;
		spin_unlock(&po->bind_lock);
		dev_remove_pack(&po->prot_hook);
		spin_lock(&po->bind_lock);
		}

		unregister_prot_hook(sk, true);
		po->num = protocol;
		po->prot_hook.type = protocol;
		if (po->prot_hook.dev)
		@@ -1413,9 +1441,7 @@ static int packet_do_bind(struct sock sk, struct net_device dev, __be16 protoc
		goto out_unlock;

		if (!dev \|\| (dev->flags & IFF_UP)) {
		dev_add_pack(&po->prot_hook);
		sock_hold(sk);
		po->running = 1;
		register_prot_hook(sk);
		} else {
		sk->sk_err = ENETDOWN;
		if (!sock_flag(sk, SOCK_DEAD))
		@@ -1542,9 +1568,7 @@ static int packet_create(struct net net, struct socket sock, int protocol,

		if (proto) {
		po->prot_hook.type = proto;
		dev_add_pack(&po->prot_hook);
		sock_hold(sk);
		po->running = 1;
		register_prot_hook(sk);
		}

		spin_lock_bh(&net->packet.sklist_lock);
		@@ -2240,9 +2264,7 @@ static int packet_notifier(struct notifier_block *this, unsigned long msg, void
		if (dev->ifindex == po->ifindex) {
		spin_lock(&po->bind_lock);
		if (po->running) {
		__dev_remove_pack(&po->prot_hook);
		__sock_put(sk);
		po->running = 0;
		__unregister_prot_hook(sk, false);
		sk->sk_err = ENETDOWN;
		if (!sock_flag(sk, SOCK_DEAD))
		sk->sk_error_report(sk);
		@@ -2259,11 +2281,8 @@ static int packet_notifier(struct notifier_block *this, unsigned long msg, void
		case NETDEV_UP:
		if (dev->ifindex == po->ifindex) {
		spin_lock(&po->bind_lock);
		if (po->num && !po->running) {
		dev_add_pack(&po->prot_hook);
		sock_hold(sk);
		po->running = 1;
		}
		if (po->num)
		register_prot_hook(sk);
		spin_unlock(&po->bind_lock);
		}
		break;
		@@ -2530,10 +2549,8 @@ static int packet_set_ring(struct sock sk, struct tpacket_req req,
		was_running = po->running;
		num = po->num;
		if (was_running) {
		__dev_remove_pack(&po->prot_hook);
		po->num = 0;
		po->running = 0;
		__sock_put(sk);
		__unregister_prot_hook(sk, false);
		}
		spin_unlock(&po->bind_lock);

		@@ -2564,11 +2581,9 @@ static int packet_set_ring(struct sock sk, struct tpacket_req req,
		mutex_unlock(&po->pg_vec_lock);

		spin_lock(&po->bind_lock);
		if (was_running && !po->running) {
		sock_hold(sk);
		po->running = 1;
		if (was_running) {
		po->num = num;
		dev_add_pack(&po->prot_hook);
		register_prot_hook(sk);
		}
		spin_unlock(&po->bind_lock);