Commit 67e1e2f4 authored by Guillaume Nault's avatar Guillaume Nault Committed by David S. Miller
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ipv4: Avoid using RTO_ONLINK with ip_route_connect().



Now that ip_rt_fix_tos() doesn't reset ->flowi4_scope unconditionally,
we don't have to rely on the RTO_ONLINK bit to properly set the scope
of a flowi4 structure. We can just set ->flowi4_scope explicitly and
avoid using RTO_ONLINK in ->flowi4_tos.

This patch converts callers of ip_route_connect(). Instead of setting
the tos parameter with RT_CONN_FLAGS(sk), as all callers do, we can:

  1- Drop the tos parameter from ip_route_connect(): its value was
     entirely based on sk, which is also passed as parameter.

  2- Set ->flowi4_scope depending on the SOCK_LOCALROUTE socket option
     instead of always initialising it with RT_SCOPE_UNIVERSE (let's
     define ip_sock_rt_scope() for this purpose).

  3- Avoid overloading ->flowi4_tos with RTO_ONLINK: since the scope is
     now properly initialised, we don't need to tell ip_rt_fix_tos() to
     adjust ->flowi4_scope for us. So let's define ip_sock_rt_tos(),
     which is the same as RT_CONN_FLAGS() but without the RTO_ONLINK
     bit overload.

Note:
  In the original ip_route_connect() code, __ip_route_output_key()
  might clear the RTO_ONLINK bit of fl4->flowi4_tos (because of
  ip_rt_fix_tos()). Therefore flowi4_update_output() had to reuse the
  original tos variable. Now that we don't set RTO_ONLINK any more,
  this is not a problem and we can use fl4->flowi4_tos in
  flowi4_update_output().

Signed-off-by: default avatarGuillaume Nault <gnault@redhat.com>
Reviewed-by: default avatarDavid Ahern <dsahern@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 16a28267
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+24 −12
Original line number Diff line number Diff line
@@ -43,6 +43,19 @@
#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))

static inline __u8 ip_sock_rt_scope(const struct sock *sk)
{
	if (sock_flag(sk, SOCK_LOCALROUTE))
		return RT_SCOPE_LINK;

	return RT_SCOPE_UNIVERSE;
}

static inline __u8 ip_sock_rt_tos(const struct sock *sk)
{
	return RT_TOS(inet_sk(sk)->tos);
}

struct ip_tunnel_info;
struct fib_nh;
struct fib_info;
@@ -289,39 +302,38 @@ static inline char rt_tos2priority(u8 tos)
 * ip_route_newports() calls.
 */

static inline void ip_route_connect_init(struct flowi4 *fl4, __be32 dst, __be32 src,
					 u32 tos, int oif, u8 protocol,
static inline void ip_route_connect_init(struct flowi4 *fl4, __be32 dst,
					 __be32 src, int oif, u8 protocol,
					 __be16 sport, __be16 dport,
					 struct sock *sk)
					 const struct sock *sk)
{
	__u8 flow_flags = 0;

	if (inet_sk(sk)->transparent)
		flow_flags |= FLOWI_FLAG_ANYSRC;

	flowi4_init_output(fl4, oif, sk->sk_mark, tos, RT_SCOPE_UNIVERSE,
			   protocol, flow_flags, dst, src, dport, sport,
			   sk->sk_uid);
	flowi4_init_output(fl4, oif, sk->sk_mark, ip_sock_rt_tos(sk),
			   ip_sock_rt_scope(sk), protocol, flow_flags, dst,
			   src, dport, sport, sk->sk_uid);
}

static inline struct rtable *ip_route_connect(struct flowi4 *fl4,
					      __be32 dst, __be32 src, u32 tos,
					      int oif, u8 protocol,
static inline struct rtable *ip_route_connect(struct flowi4 *fl4, __be32 dst,
					      __be32 src, int oif, u8 protocol,
					      __be16 sport, __be16 dport,
					      struct sock *sk)
{
	struct net *net = sock_net(sk);
	struct rtable *rt;

	ip_route_connect_init(fl4, dst, src, tos, oif, protocol,
			      sport, dport, sk);
	ip_route_connect_init(fl4, dst, src, oif, protocol, sport, dport, sk);

	if (!dst || !src) {
		rt = __ip_route_output_key(net, fl4);
		if (IS_ERR(rt))
			return rt;
		ip_rt_put(rt);
		flowi4_update_output(fl4, oif, tos, fl4->daddr, fl4->saddr);
		flowi4_update_output(fl4, oif, fl4->flowi4_tos, fl4->daddr,
				     fl4->saddr);
	}
	security_sk_classify_flow(sk, flowi4_to_flowi_common(fl4));
	return ip_route_output_flow(net, fl4, sk);
+2 −3
Original line number Diff line number Diff line
@@ -76,9 +76,8 @@ int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
	orig_dport = usin->sin_port;
	fl4 = &inet->cork.fl.u.ip4;
	rt = ip_route_connect(fl4, nexthop, inet->inet_saddr,
			      RT_CONN_FLAGS(sk), sk->sk_bound_dev_if,
			      IPPROTO_DCCP,
			      orig_sport, orig_dport, sk);
			      sk->sk_bound_dev_if, IPPROTO_DCCP, orig_sport,
			      orig_dport, sk);
	if (IS_ERR(rt))
		return PTR_ERR(rt);

+3 −3
Original line number Diff line number Diff line
@@ -1233,9 +1233,9 @@ static int inet_sk_reselect_saddr(struct sock *sk)

	/* Query new route. */
	fl4 = &inet->cork.fl.u.ip4;
	rt = ip_route_connect(fl4, daddr, 0, RT_CONN_FLAGS(sk),
			      sk->sk_bound_dev_if, sk->sk_protocol,
			      inet->inet_sport, inet->inet_dport, sk);
	rt = ip_route_connect(fl4, daddr, 0, sk->sk_bound_dev_if,
			      sk->sk_protocol, inet->inet_sport,
			      inet->inet_dport, sk);
	if (IS_ERR(rt))
		return PTR_ERR(rt);

+3 −4
Original line number Diff line number Diff line
@@ -44,10 +44,9 @@ int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len
			saddr = inet->mc_addr;
	}
	fl4 = &inet->cork.fl.u.ip4;
	rt = ip_route_connect(fl4, usin->sin_addr.s_addr, saddr,
			      RT_CONN_FLAGS(sk), oif,
			      sk->sk_protocol,
			      inet->inet_sport, usin->sin_port, sk);
	rt = ip_route_connect(fl4, usin->sin_addr.s_addr, saddr, oif,
			      sk->sk_protocol, inet->inet_sport,
			      usin->sin_port, sk);
	if (IS_ERR(rt)) {
		err = PTR_ERR(rt);
		if (err == -ENETUNREACH)
+2 −3
Original line number Diff line number Diff line
@@ -229,9 +229,8 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
	orig_dport = usin->sin_port;
	fl4 = &inet->cork.fl.u.ip4;
	rt = ip_route_connect(fl4, nexthop, inet->inet_saddr,
			      RT_CONN_FLAGS(sk), sk->sk_bound_dev_if,
			      IPPROTO_TCP,
			      orig_sport, orig_dport, sk);
			      sk->sk_bound_dev_if, IPPROTO_TCP, orig_sport,
			      orig_dport, sk);
	if (IS_ERR(rt)) {
		err = PTR_ERR(rt);
		if (err == -ENETUNREACH)