From 67e1e2f4854bb2c0dd2b8440cf090016a0e1a091 Mon Sep 17 00:00:00 2001 From: Guillaume Nault Date: Thu, 21 Apr 2022 01:21:33 +0200 Subject: [PATCH] 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: Guillaume Nault Reviewed-by: David Ahern Signed-off-by: David S. Miller --- include/net/route.h | 36 ++++++++++++++++++++++++------------ net/dccp/ipv4.c | 5 ++--- net/ipv4/af_inet.c | 6 +++--- net/ipv4/datagram.c | 7 +++---- net/ipv4/tcp_ipv4.c | 5 ++--- 5 files changed, 34 insertions(+), 25 deletions(-) diff --git a/include/net/route.h b/include/net/route.h index 25404fc2b483..991a3985712d 100644 --- a/include/net/route.h +++ b/include/net/route.h @@ -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); diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c index ae662567a6cb..82696ab86f74 100644 --- a/net/dccp/ipv4.c +++ b/net/dccp/ipv4.c @@ -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); diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index 195ecfa2f000..93da9f783bec 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -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); diff --git a/net/ipv4/datagram.c b/net/ipv4/datagram.c index 48f337ccf949..ffd57523331f 100644 --- a/net/ipv4/datagram.c +++ b/net/ipv4/datagram.c @@ -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) diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 157265aecbed..2c2d42142555 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -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)