Commit aa661581 authored by Francesco Fusco's avatar Francesco Fusco Committed by David S. Miller
Browse files

ipv4: processing ancillary IP_TOS or IP_TTL 



If IP_TOS or IP_TTL are specified as ancillary data, then sendmsg() sends out
packets with the specified TTL or TOS overriding the socket values specified
with the traditional setsockopt().

The struct inet_cork stores the values of TOS, TTL and priority that are
passed through the struct ipcm_cookie. If there are user-specified TOS
(tos != -1) or TTL (ttl != 0) in the struct ipcm_cookie, these values are
used to override the per-socket values. In case of TOS also the priority
is changed accordingly.

Two helper functions get_rttos and get_rtconn_flags are defined to take
into account the presence of a user specified TOS value when computing
RT_TOS and RT_CONN_FLAGS.

Signed-off-by: default avatarFrancesco Fusco <ffusco@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent f02db315

include/net/inet_sock.h

+3 −0
Original line number Diff line number Diff line
@@ -103,6 +103,9 @@ struct inet_cork { 
	int			length; /* Total length of all frames */

	struct dst_entry	*dst;

	u8			tx_flags;

	__u8			ttl;

	__s16			tos;

	char			priority;

};



struct inet_cork_full {

include/net/ip.h

+11 −0
Original line number Diff line number Diff line
@@ -28,6 +28,7 @@ 
#include <linux/skbuff.h>



#include <net/inet_sock.h>

#include <net/route.h>

#include <net/snmp.h>

#include <net/flow.h>
@@ -140,6 +141,16 @@ static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4) 
	return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base);

}



static inline __u8 get_rttos(struct ipcm_cookie* ipc, struct inet_sock *inet)

{

	return (ipc->tos != -1) ? RT_TOS(ipc->tos) : RT_TOS(inet->tos);

}



static inline __u8 get_rtconn_flags(struct ipcm_cookie* ipc, struct sock* sk)

{

	return (ipc->tos != -1) ? RT_CONN_FLAGS_TOS(sk, ipc->tos) : RT_CONN_FLAGS(sk);

}



/* datagram.c */

int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);

include/net/route.h

+1 −0
Original line number Diff line number Diff line
@@ -39,6 +39,7 @@ 
#define RTO_ONLINK	0x01



#define RT_CONN_FLAGS(sk)   (RT_TOS(inet_sk(sk)->tos) | sock_flag(sk, SOCK_LOCALROUTE))

#define RT_CONN_FLAGS_TOS(sk,tos)   (RT_TOS(tos) | sock_flag(sk, SOCK_LOCALROUTE))



struct fib_nh;

struct fib_info;

net/ipv4/icmp.c

+5 −0
Original line number Diff line number Diff line
@@ -353,6 +353,9 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb) 
	saddr = fib_compute_spec_dst(skb);

	ipc.opt = NULL;

	ipc.tx_flags = 0;

	ipc.ttl = 0;

	ipc.tos = -1;



	if (icmp_param->replyopts.opt.opt.optlen) {

		ipc.opt = &icmp_param->replyopts.opt;

		if (ipc.opt->opt.srr)
@@ -608,6 +611,8 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info) 
	ipc.addr = iph->saddr;

	ipc.opt = &icmp_param->replyopts.opt;

	ipc.tx_flags = 0;

	ipc.ttl = 0;

	ipc.tos = -1;



	rt = icmp_route_lookup(net, &fl4, skb_in, iph, saddr, tos,

			       type, code, icmp_param);

net/ipv4/ip_output.c

+10 −3
Original line number Diff line number Diff line
@@ -1060,6 +1060,9 @@ static int ip_setup_cork(struct sock *sk, struct inet_cork *cork, 
			 rt->dst.dev->mtu : dst_mtu(&rt->dst);

	cork->dst = &rt->dst;

	cork->length = 0;

	cork->ttl = ipc->ttl;

	cork->tos = ipc->tos;

	cork->priority = ipc->priority;

	cork->tx_flags = ipc->tx_flags;



	return 0;
@@ -1311,7 +1314,9 @@ struct sk_buff *__ip_make_skb(struct sock *sk, 
	if (cork->flags & IPCORK_OPT)

		opt = cork->opt;



	if (rt->rt_type == RTN_MULTICAST)

	if (cork->ttl != 0)

		ttl = cork->ttl;

	else if (rt->rt_type == RTN_MULTICAST)

		ttl = inet->mc_ttl;

	else

		ttl = ip_select_ttl(inet, &rt->dst);
@@ -1319,7 +1324,7 @@ struct sk_buff *__ip_make_skb(struct sock *sk, 
	iph = ip_hdr(skb);

	iph->version = 4;

	iph->ihl = 5;

	iph->tos = inet->tos;

	iph->tos = (cork->tos != -1) ? cork->tos : inet->tos;

	iph->frag_off = df;

	iph->ttl = ttl;

	iph->protocol = sk->sk_protocol;
@@ -1331,7 +1336,7 @@ struct sk_buff *__ip_make_skb(struct sock *sk, 
		ip_options_build(skb, opt, cork->addr, rt, 0);

	}



	skb->priority = sk->sk_priority;

	skb->priority = (cork->tos != -1) ? cork->priority: sk->sk_priority;

	skb->mark = sk->sk_mark;

	/*

	 * Steal rt from cork.dst to avoid a pair of atomic_inc/atomic_dec
@@ -1481,6 +1486,8 @@ void ip_send_unicast_reply(struct net *net, struct sk_buff *skb, __be32 daddr, 
	ipc.addr = daddr;

	ipc.opt = NULL;

	ipc.tx_flags = 0;

	ipc.ttl = 0;

	ipc.tos = -1;



	if (replyopts.opt.opt.optlen) {

		ipc.opt = &replyopts.opt;

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