Commit 32519f11 authored by Arnaldo Carvalho de Melo's avatar Arnaldo Carvalho de Melo Committed by David S. Miller
Browse files

[INET]: Introduce inet_sk_rebuild_header 



From tcp_v4_rebuild_header, that already was pretty generic, I only
needed to use sk->sk_protocol instead of the hardcoded IPPROTO_TCP and
establish the requirement that INET transport layer protocols that
want to use this function map TCP_SYN_SENT to its equivalent state.

Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 6cbb0df7

include/linux/ip.h

+2 −0
Original line number Diff line number Diff line
@@ -196,6 +196,8 @@ static inline void inet_sk_copy_descendant(struct sock *sk_to, 
#endif

#endif



extern int inet_sk_rebuild_header(struct sock *sk);



struct iphdr {

#if defined(__LITTLE_ENDIAN_BITFIELD)

	__u8	ihl:4,

include/net/tcp.h

+0 −2
Original line number Diff line number Diff line
@@ -799,8 +799,6 @@ extern void tcp_parse_options(struct sk_buff *skb, 
 *	TCP v4 functions exported for the inet6 API

 */



extern int		       	tcp_v4_rebuild_header(struct sock *sk);



extern int		       	tcp_v4_build_header(struct sock *sk, 

						    struct sk_buff *skb);

net/ipv4/af_inet.c

+113 −0
Original line number Diff line number Diff line
@@ -951,6 +951,119 @@ void inet_unregister_protosw(struct inet_protosw *p) 
	}

}



/*

 *      Shall we try to damage output packets if routing dev changes?

 */



int sysctl_ip_dynaddr;



static int inet_sk_reselect_saddr(struct sock *sk)

{

	struct inet_sock *inet = inet_sk(sk);

	int err;

	struct rtable *rt;

	__u32 old_saddr = inet->saddr;

	__u32 new_saddr;

	__u32 daddr = inet->daddr;



	if (inet->opt && inet->opt->srr)

		daddr = inet->opt->faddr;



	/* Query new route. */

	err = ip_route_connect(&rt, daddr, 0,

			       RT_CONN_FLAGS(sk),

			       sk->sk_bound_dev_if,

			       sk->sk_protocol,

			       inet->sport, inet->dport, sk);

	if (err)

		return err;



	sk_setup_caps(sk, &rt->u.dst);



	new_saddr = rt->rt_src;



	if (new_saddr == old_saddr)

		return 0;



	if (sysctl_ip_dynaddr > 1) {

		printk(KERN_INFO "%s(): shifting inet->"

				 "saddr from %d.%d.%d.%d to %d.%d.%d.%d\n",

		       __FUNCTION__,

		       NIPQUAD(old_saddr),

		       NIPQUAD(new_saddr));

	}



	inet->saddr = inet->rcv_saddr = new_saddr;



	/*

	 * XXX The only one ugly spot where we need to

	 * XXX really change the sockets identity after

	 * XXX it has entered the hashes. -DaveM

	 *

	 * Besides that, it does not check for connection

	 * uniqueness. Wait for troubles.

	 */

	__sk_prot_rehash(sk);

	return 0;

}



int inet_sk_rebuild_header(struct sock *sk)

{

	struct inet_sock *inet = inet_sk(sk);

	struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);

	u32 daddr;

	int err;



	/* Route is OK, nothing to do. */

	if (rt)

		return 0;



	/* Reroute. */

	daddr = inet->daddr;

	if (inet->opt && inet->opt->srr)

		daddr = inet->opt->faddr;

{

	struct flowi fl = {

		.oif = sk->sk_bound_dev_if,

		.nl_u = {

			.ip4_u = {

				.daddr	= daddr,

				.saddr	= inet->saddr,

				.tos	= RT_CONN_FLAGS(sk),

			},

		},

		.proto = sk->sk_protocol,

		.uli_u = {

			.ports = {

				.sport = inet->sport,

				.dport = inet->dport,

			},

		},

	};

						

	err = ip_route_output_flow(&rt, &fl, sk, 0);

}

	if (!err)

		sk_setup_caps(sk, &rt->u.dst);

	else {

		/* Routing failed... */

		sk->sk_route_caps = 0;

		/*

		 * Other protocols have to map its equivalent state to TCP_SYN_SENT.

		 * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme

		 */

		if (!sysctl_ip_dynaddr ||

		    sk->sk_state != TCP_SYN_SENT ||

		    (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||

		    (err = inet_sk_reselect_saddr(sk)) != 0)

			sk->sk_err_soft = -err;

	}



	return err;

}



EXPORT_SYMBOL(inet_sk_rebuild_header);



#ifdef CONFIG_IP_MULTICAST

static struct net_protocol igmp_protocol = {

	.handler =	igmp_rcv,

net/ipv4/ip_output.c

+0 −5
Original line number Diff line number Diff line
@@ -83,11 +83,6 @@ 
#include <linux/netlink.h>

#include <linux/tcp.h>



/*

 *      Shall we try to damage output packets if routing dev changes?

 */



int sysctl_ip_dynaddr;

int sysctl_ip_default_ttl = IPDEFTTL;



/* Generate a checksum for an outgoing IP datagram. */

net/ipv4/tcp_ipv4.c

+1 −97
Original line number Diff line number Diff line
@@ -1832,101 +1832,6 @@ do_time_wait: 
	goto discard_it;

}



static int tcp_v4_reselect_saddr(struct sock *sk)

{

	struct inet_sock *inet = inet_sk(sk);

	int err;

	struct rtable *rt;

	__u32 old_saddr = inet->saddr;

	__u32 new_saddr;

	__u32 daddr = inet->daddr;



	if (inet->opt && inet->opt->srr)

		daddr = inet->opt->faddr;



	/* Query new route. */

	err = ip_route_connect(&rt, daddr, 0,

			       RT_CONN_FLAGS(sk),

			       sk->sk_bound_dev_if,

			       IPPROTO_TCP,

			       inet->sport, inet->dport, sk);

	if (err)

		return err;



	sk_setup_caps(sk, &rt->u.dst);



	new_saddr = rt->rt_src;



	if (new_saddr == old_saddr)

		return 0;



	if (sysctl_ip_dynaddr > 1) {

		printk(KERN_INFO "tcp_v4_rebuild_header(): shifting inet->"

				 "saddr from %d.%d.%d.%d to %d.%d.%d.%d\n",

		       NIPQUAD(old_saddr),

		       NIPQUAD(new_saddr));

	}



	inet->saddr = new_saddr;

	inet->rcv_saddr = new_saddr;



	/* XXX The only one ugly spot where we need to

	 * XXX really change the sockets identity after

	 * XXX it has entered the hashes. -DaveM

	 *

	 * Besides that, it does not check for connection

	 * uniqueness. Wait for troubles.

	 */

	__sk_prot_rehash(sk);

	return 0;

}



int tcp_v4_rebuild_header(struct sock *sk)

{

	struct inet_sock *inet = inet_sk(sk);

	struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);

	u32 daddr;

	int err;



	/* Route is OK, nothing to do. */

	if (rt)

		return 0;



	/* Reroute. */

	daddr = inet->daddr;

	if (inet->opt && inet->opt->srr)

		daddr = inet->opt->faddr;



	{

		struct flowi fl = { .oif = sk->sk_bound_dev_if,

				    .nl_u = { .ip4_u =

					      { .daddr = daddr,

						.saddr = inet->saddr,

						.tos = RT_CONN_FLAGS(sk) } },

				    .proto = IPPROTO_TCP,

				    .uli_u = { .ports =

					       { .sport = inet->sport,

						 .dport = inet->dport } } };

						

		err = ip_route_output_flow(&rt, &fl, sk, 0);

	}

	if (!err) {

		sk_setup_caps(sk, &rt->u.dst);

		return 0;

	}



	/* Routing failed... */

	sk->sk_route_caps = 0;



	if (!sysctl_ip_dynaddr ||

	    sk->sk_state != TCP_SYN_SENT ||

	    (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||

	    (err = tcp_v4_reselect_saddr(sk)) != 0)

		sk->sk_err_soft = -err;



	return err;

}



static void v4_addr2sockaddr(struct sock *sk, struct sockaddr * uaddr)

{

	struct sockaddr_in *sin = (struct sockaddr_in *) uaddr;
@@ -1998,7 +1903,7 @@ int tcp_v4_tw_remember_stamp(struct tcp_tw_bucket *tw) 
struct tcp_func ipv4_specific = {

	.queue_xmit	=	ip_queue_xmit,

	.send_check	=	tcp_v4_send_check,

	.rebuild_header	=	tcp_v4_rebuild_header,

	.rebuild_header	=	inet_sk_rebuild_header,

	.conn_request	=	tcp_v4_conn_request,

	.syn_recv_sock	=	tcp_v4_syn_recv_sock,

	.remember_stamp	=	tcp_v4_remember_stamp,
@@ -2630,7 +2535,6 @@ EXPORT_SYMBOL(tcp_unhash); 
EXPORT_SYMBOL(tcp_v4_conn_request);

EXPORT_SYMBOL(tcp_v4_connect);

EXPORT_SYMBOL(tcp_v4_do_rcv);

EXPORT_SYMBOL(tcp_v4_rebuild_header);

EXPORT_SYMBOL(tcp_v4_remember_stamp);

EXPORT_SYMBOL(tcp_v4_send_check);

EXPORT_SYMBOL(tcp_v4_syn_recv_sock);

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