Commit e187013a authored by Akhmat Karakotov's avatar Akhmat Karakotov Committed by David S. Miller
Browse files

txhash: Make rethinking txhash behavior configurable via sysctl 



Add a per ns sysctl that controls the txhash rethink behavior:
net.core.txrehash. When enabled, the same behavior is retained,
when disabled, rethink is not performed. Sysctl is enabled by default.

Signed-off-by: default avatarAkhmat Karakotov <hmukos@yandex-team.ru>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 678dfd52

include/net/netns/core.h

+1 −0
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ struct netns_core { 
	struct ctl_table_header	*sysctl_hdr;



	int	sysctl_somaxconn;

	u8	sysctl_txrehash;



#ifdef CONFIG_PROC_FS

	struct prot_inuse __percpu *prot_inuse;

include/net/sock.h

+21 −13
Original line number Diff line number Diff line
@@ -587,6 +587,18 @@ static inline bool sk_user_data_is_nocopy(const struct sock *sk) 
			   __tmp | SK_USER_DATA_NOCOPY);		\

})



static inline

struct net *sock_net(const struct sock *sk)

{

	return read_pnet(&sk->sk_net);

}



static inline

void sock_net_set(struct sock *sk, struct net *net)

{

	write_pnet(&sk->sk_net, net);

}



/*

 * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK

 * or not whether his port will be reused by someone else. SK_FORCE_REUSE
@@ -2054,10 +2066,18 @@ static inline void sk_set_txhash(struct sock *sk) 


static inline bool sk_rethink_txhash(struct sock *sk)

{

	if (sk->sk_txhash) {

	u8 rehash;



	if (!sk->sk_txhash)

		return false;



	rehash = READ_ONCE(sock_net(sk)->core.sysctl_txrehash);



	if (rehash) {

		sk_set_txhash(sk);

		return true;

	}



	return false;

}
@@ -2704,18 +2724,6 @@ static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb) 
	__kfree_skb(skb);

}



static inline

struct net *sock_net(const struct sock *sk)

{

	return read_pnet(&sk->sk_net);

}



static inline

void sock_net_set(struct sock *sk, struct net *net)

{

	write_pnet(&sk->sk_net, net);

}



static inline bool

skb_sk_is_prefetched(struct sk_buff *skb)

{

include/uapi/linux/socket.h

+3 −0
Original line number Diff line number Diff line
@@ -31,4 +31,7 @@ struct __kernel_sockaddr_storage { 


#define SOCK_BUF_LOCK_MASK (SOCK_SNDBUF_LOCK | SOCK_RCVBUF_LOCK)



#define SOCK_TXREHASH_DISABLED	0

#define SOCK_TXREHASH_ENABLED	1



#endif /* _UAPI_LINUX_SOCKET_H */

net/core/net_namespace.c

+2 −0
Original line number Diff line number Diff line
@@ -364,6 +364,8 @@ static __net_init int setup_net(struct net *net, struct user_namespace *user_ns) 
static int __net_init net_defaults_init_net(struct net *net)

{

	net->core.sysctl_somaxconn = SOMAXCONN;

	net->core.sysctl_txrehash = SOCK_TXREHASH_ENABLED;



	return 0;

}

net/core/sysctl_net_core.c

+12 −2
Original line number Diff line number Diff line
@@ -593,6 +593,15 @@ static struct ctl_table netns_core_table[] = { 
		.extra1		= SYSCTL_ZERO,

		.proc_handler	= proc_dointvec_minmax

	},

	{

		.procname	= "txrehash",

		.data		= &init_net.core.sysctl_txrehash,

		.maxlen		= sizeof(u8),

		.mode		= 0644,

		.extra1		= SYSCTL_ZERO,

		.extra2		= SYSCTL_ONE,

		.proc_handler	= proc_dou8vec_minmax,

	},

	{ }

};
@@ -611,7 +620,7 @@ __setup("fb_tunnels=", fb_tunnels_only_for_init_net_sysctl_setup); 


static __net_init int sysctl_core_net_init(struct net *net)

{

	struct ctl_table *tbl;

	struct ctl_table *tbl, *tmp;



	tbl = netns_core_table;

	if (!net_eq(net, &init_net)) {
@@ -619,7 +628,8 @@ static __net_init int sysctl_core_net_init(struct net *net) 
		if (tbl == NULL)

			goto err_dup;



		tbl[0].data = &net->core.sysctl_somaxconn;

		for (tmp = tbl; tmp->procname; tmp++)

			tmp->data += (char *)net - (char *)&init_net;



		/* Don't export any sysctls to unprivileged users */

		if (net->user_ns != &init_user_ns) {