[PATCH] net: split sk_reuse into sk_reuse and sk_force_reuse
From: Andrei Vagin <hidden>
Date: 2018-06-14 00:56:15
The commit f396922d862a added a check to not allow changing
SO_REUSEADDR/SO_REUSEPORT on bound sockets. First, it doesn't
take into account that TCP_REPAIR changes SO_REUSEADDR. Second, now it
is impossible to restore a socket state and set SO_REUSEADDR,
because the kernel always sets SO_REUSEADDR into zero after disabling
the repair mode.
Currently, sk_reuse can have three values: SK_NO_REUSE, SK_CAN_REUSE,
SK_FORCE_REUSE. SK_CAN_REUSE is set by SOL_REUSEADDR. SK_FORCE_REUSE is
used to ignore bind conflicts for sockets in the repair mode.
This patch makes sk->sk_reuse back into a boolean and adds
sk->sk_force_reuse to track SK_FORCE_REUSE separatly.
In this case, the tcp_repair mode doesn't affect sk_reuse and
it's value can be set before switching a socketn into the repair mode.
Fixes: f396922d862a ("net: do not allow changing SO_REUSEADDR/SO_REUSEPORT on bound sockets")
Cc: Maciej Żenczykowski <redacted>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Andrei Vagin <redacted>
---
include/net/sock.h | 13 ++++---------
net/ipv4/inet_connection_sock.c | 2 +-
net/ipv4/tcp.c | 4 ++--
3 files changed, 7 insertions(+), 12 deletions(-)
diff --git a/include/net/sock.h b/include/net/sock.h
index b3b75419eafe..8ad19286ab9e 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h@@ -130,6 +130,7 @@ typedef __u64 __bitwise __addrpair; * @skc_family: network address family * @skc_state: Connection state * @skc_reuse: %SO_REUSEADDR setting + * @skc_force_reuse: ignore bind conflicts * @skc_reuseport: %SO_REUSEPORT setting * @skc_bound_dev_if: bound device index if != 0 * @skc_bind_node: bind hash linkage for various protocol lookup tables
@@ -174,7 +175,8 @@ struct sock_common { unsigned short skc_family; volatile unsigned char skc_state; - unsigned char skc_reuse:4; + unsigned char skc_reuse:1; + unsigned char skc_force_reuse:1; unsigned char skc_reuseport:1; unsigned char skc_ipv6only:1; unsigned char skc_net_refcnt:1;
@@ -339,6 +341,7 @@ struct sock { #define sk_family __sk_common.skc_family #define sk_state __sk_common.skc_state #define sk_reuse __sk_common.skc_reuse +#define sk_force_reuse __sk_common.skc_force_reuse #define sk_reuseport __sk_common.skc_reuseport #define sk_ipv6only __sk_common.skc_ipv6only #define sk_net_refcnt __sk_common.skc_net_refcnt
@@ -502,16 +505,8 @@ enum sk_pacing { #define rcu_dereference_sk_user_data(sk) rcu_dereference(__sk_user_data((sk))) #define rcu_assign_sk_user_data(sk, ptr) rcu_assign_pointer(__sk_user_data((sk)), ptr) -/* - * 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 - * on a socket means that the socket will reuse everybody else's port - * without looking at the other's sk_reuse value. - */ - #define SK_NO_REUSE 0 #define SK_CAN_REUSE 1 -#define SK_FORCE_REUSE 2 int sk_set_peek_off(struct sock *sk, int val);
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index 33a88e045efd..2ac1c591b60c 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c@@ -306,7 +306,7 @@ int inet_csk_get_port(struct sock *sk, unsigned short snum) goto fail_unlock; tb_found: if (!hlist_empty(&tb->owners)) { - if (sk->sk_reuse == SK_FORCE_REUSE) + if (sk->sk_force_reuse) goto success; if ((tb->fastreuse > 0 && reuse) ||
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 2741953adaba..70bfdd5a2fc4 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c@@ -2810,11 +2810,11 @@ static int do_tcp_setsockopt(struct sock *sk, int level, err = -EPERM; else if (val == 1) { tp->repair = 1; - sk->sk_reuse = SK_FORCE_REUSE; + sk->sk_force_reuse = 1; tp->repair_queue = TCP_NO_QUEUE; } else if (val == 0) { tp->repair = 0; - sk->sk_reuse = SK_NO_REUSE; + sk->sk_force_reuse = 0; tcp_send_window_probe(sk); } else err = -EINVAL;
--
2.17.0