From 04190bf8944deb7e3ac165a1a494db23aa0160a9 Mon Sep 17 00:00:00 2001 From: Pavel Tikhomirov Date: Wed, 4 Aug 2021 10:55:56 +0300 Subject: [PATCH] sock: allow reading and changing sk_userlocks with setsockopt SOCK_SNDBUF_LOCK and SOCK_RCVBUF_LOCK flags disable automatic socket buffers adjustment done by kernel (see tcp_fixup_rcvbuf() and tcp_sndbuf_expand()). If we've just created a new socket this adjustment is enabled on it, but if one changes the socket buffer size by setsockopt(SO_{SND,RCV}BUF*) it becomes disabled. CRIU needs to call setsockopt(SO_{SND,RCV}BUF*) on each socket on restore as it first needs to increase buffer sizes for packet queues restore and second it needs to restore back original buffer sizes. So after CRIU restore all sockets become non-auto-adjustable, which can decrease network performance of restored applications significantly. CRIU need to be able to restore sockets with enabled/disabled adjustment to the same state it was before dump, so let's add special setsockopt for it. Let's also export SOCK_SNDBUF_LOCK and SOCK_RCVBUF_LOCK flags to uAPI so that using these interface one can reenable automatic socket buffer adjustment on their sockets. Signed-off-by: Pavel Tikhomirov Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller --- arch/alpha/include/uapi/asm/socket.h | 2 ++ arch/mips/include/uapi/asm/socket.h | 2 ++ arch/parisc/include/uapi/asm/socket.h | 2 ++ arch/sparc/include/uapi/asm/socket.h | 2 ++ include/net/sock.h | 3 +-- include/uapi/asm-generic/socket.h | 2 ++ include/uapi/linux/socket.h | 5 +++++ net/core/sock.c | 13 +++++++++++++ 8 files changed, 29 insertions(+), 2 deletions(-) diff --git a/arch/alpha/include/uapi/asm/socket.h b/arch/alpha/include/uapi/asm/socket.h index 6b3daba60987e..1dd9baf4a6c21 100644 --- a/arch/alpha/include/uapi/asm/socket.h +++ b/arch/alpha/include/uapi/asm/socket.h @@ -129,6 +129,8 @@ #define SO_NETNS_COOKIE 71 +#define SO_BUF_LOCK 72 + #if !defined(__KERNEL__) #if __BITS_PER_LONG == 64 diff --git a/arch/mips/include/uapi/asm/socket.h b/arch/mips/include/uapi/asm/socket.h index cdf404a831b25..1eaf6a1ca5610 100644 --- a/arch/mips/include/uapi/asm/socket.h +++ b/arch/mips/include/uapi/asm/socket.h @@ -140,6 +140,8 @@ #define SO_NETNS_COOKIE 71 +#define SO_BUF_LOCK 72 + #if !defined(__KERNEL__) #if __BITS_PER_LONG == 64 diff --git a/arch/parisc/include/uapi/asm/socket.h b/arch/parisc/include/uapi/asm/socket.h index 5b5351cdcb338..8baaad52d7996 100644 --- a/arch/parisc/include/uapi/asm/socket.h +++ b/arch/parisc/include/uapi/asm/socket.h @@ -121,6 +121,8 @@ #define SO_NETNS_COOKIE 0x4045 +#define SO_BUF_LOCK 0x4046 + #if !defined(__KERNEL__) #if __BITS_PER_LONG == 64 diff --git a/arch/sparc/include/uapi/asm/socket.h b/arch/sparc/include/uapi/asm/socket.h index 92675dc380fa2..e80ee8641ac3e 100644 --- a/arch/sparc/include/uapi/asm/socket.h +++ b/arch/sparc/include/uapi/asm/socket.h @@ -122,6 +122,8 @@ #define SO_NETNS_COOKIE 0x0050 +#define SO_BUF_LOCK 0x0051 + #if !defined(__KERNEL__) diff --git a/include/net/sock.h b/include/net/sock.h index ff1be7e7e90bd..6e761451c9278 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -68,6 +68,7 @@ #include #include #include +#include /* * This structure really needs to be cleaned up. @@ -1438,8 +1439,6 @@ static inline int __sk_prot_rehash(struct sock *sk) #define RCV_SHUTDOWN 1 #define SEND_SHUTDOWN 2 -#define SOCK_SNDBUF_LOCK 1 -#define SOCK_RCVBUF_LOCK 2 #define SOCK_BINDADDR_LOCK 4 #define SOCK_BINDPORT_LOCK 8 diff --git a/include/uapi/asm-generic/socket.h b/include/uapi/asm-generic/socket.h index d588c244ec2fa..1f0a2b4864e44 100644 --- a/include/uapi/asm-generic/socket.h +++ b/include/uapi/asm-generic/socket.h @@ -124,6 +124,8 @@ #define SO_NETNS_COOKIE 71 +#define SO_BUF_LOCK 72 + #if !defined(__KERNEL__) #if __BITS_PER_LONG == 64 || (defined(__x86_64__) && defined(__ILP32__)) diff --git a/include/uapi/linux/socket.h b/include/uapi/linux/socket.h index c3409c8ec0ddd..eb0a9a5b6e71f 100644 --- a/include/uapi/linux/socket.h +++ b/include/uapi/linux/socket.h @@ -26,4 +26,9 @@ struct __kernel_sockaddr_storage { }; }; +#define SOCK_SNDBUF_LOCK 1 +#define SOCK_RCVBUF_LOCK 2 + +#define SOCK_BUF_LOCK_MASK (SOCK_SNDBUF_LOCK | SOCK_RCVBUF_LOCK) + #endif /* _UAPI_LINUX_SOCKET_H */ diff --git a/net/core/sock.c b/net/core/sock.c index 9671c32e6ef56..aada649e07e8d 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1358,6 +1358,15 @@ int sock_setsockopt(struct socket *sock, int level, int optname, ret = sock_bindtoindex_locked(sk, val); break; + case SO_BUF_LOCK: + if (val & ~SOCK_BUF_LOCK_MASK) { + ret = -EINVAL; + break; + } + sk->sk_userlocks = val | (sk->sk_userlocks & + ~SOCK_BUF_LOCK_MASK); + break; + default: ret = -ENOPROTOOPT; break; @@ -1720,6 +1729,10 @@ int sock_getsockopt(struct socket *sock, int level, int optname, v.val64 = sock_net(sk)->net_cookie; break; + case SO_BUF_LOCK: + v.val = sk->sk_userlocks & SOCK_BUF_LOCK_MASK; + break; + default: /* We implement the SO_SNDLOWAT etc to not be settable * (1003.1g 7).