Cygwin: tcp: Support TCP_KEEPIDLE, TCP_KEEPCNT, TCP_KEEPINTVL

Use WSAIoctl(SIO_KEEPALIVE_VALS) on older systems.

Make sure that keep-alive timeout is equivalent to
TCP_KEEPIDLE + TCP_KEEPCNT * TCP_KEEPINTVL on older systems,
even with TCP_KEEPCNT being a fixed value on those systems.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
This commit is contained in:
Corinna Vinschen 2020-07-01 20:27:10 +02:00 committed by Ken Brown
parent 1acd185bea
commit 140029a099
5 changed files with 180 additions and 14 deletions

View File

@ -720,6 +720,11 @@ class fhandler_socket_inet: public fhandler_socket_wsock
private:
bool oobinline; /* True if option SO_OOBINLINE is set */
bool tcp_fastopen; /* True if TCP_FASTOPEN is set on older systems */
int tcp_keepidle; /* TCP_KEEPIDLE value in secs on older systems */
int tcp_keepcnt; /* TCP_KEEPCNT value on older systems */
int tcp_keepintvl; /* TCP_KEEPINTVL value in secs on older systems */
int set_keepalive (int keepidle, int keepcnt, int keepintvl);
protected:
int af_local_connect () { return 0; }

View File

@ -23,6 +23,7 @@
#endif
#include <w32api/ws2tcpip.h>
#include <w32api/mswsock.h>
#include <w32api/mstcpip.h>
#include <netinet/tcp.h>
#include <unistd.h>
#include <asm/byteorder.h>
@ -692,7 +693,10 @@ fhandler_socket_wsock::set_socket_handle (SOCKET sock, int af, int type,
fhandler_socket_inet::fhandler_socket_inet () :
fhandler_socket_wsock (),
oobinline (false),
tcp_fastopen (false)
tcp_fastopen (false),
tcp_keepidle (7200), /* WinSock default */
tcp_keepcnt (10), /* WinSock default */
tcp_keepintvl (1) /* WinSock default */
{
}
@ -1572,6 +1576,63 @@ fhandler_socket_wsock::writev (const struct iovec *const iov, const int iovcnt,
return send_internal (&wsamsg, 0);
}
#define MAX_TCP_KEEPIDLE 32767
#define MAX_TCP_KEEPCNT 255
#define MAX_TCP_KEEPINTVL 32767
#define FIXED_WSOCK_TCP_KEEPCNT 10
int
fhandler_socket_inet::set_keepalive (int keepidle, int keepcnt, int keepintvl)
{
struct tcp_keepalive tka;
int so_keepalive = 0;
int len = sizeof so_keepalive;
int ret;
DWORD dummy;
/* Per MSDN,
https://docs.microsoft.com/en-us/windows/win32/winsock/sio-keepalive-vals
the subsequent keep-alive settings in struct tcp_keepalive are only used
if the onoff member is != 0. Request the current state of SO_KEEPALIVE,
then set the keep-alive options with onoff set to 1. On success, if
SO_KEEPALIVE was 0, restore to the original SO_KEEPALIVE setting. Per
the above MSDN doc, the SIO_KEEPALIVE_VALS settings are persistent
across switching SO_KEEPALIVE. */
ret = ::getsockopt (get_socket (), SOL_SOCKET, SO_KEEPALIVE,
(char *) &so_keepalive, &len);
if (ret == SOCKET_ERROR)
debug_printf ("getsockopt (SO_KEEPALIVE) failed, %u\n", WSAGetLastError ());
tka.onoff = 1;
tka.keepalivetime = keepidle * MSPERSEC;
/* WinSock TCP_KEEPCNT is fixed. But we still want that the keep-alive
times out after TCP_KEEPIDLE + TCP_KEEPCNT * TCP_KEEPINTVL secs.
To that end, we set keepaliveinterval so that
keepaliveinterval * FIXED_WSOCK_TCP_KEEPCNT == TCP_KEEPINTVL * TCP_KEEPCNT
FIXME? Does that make sense?
Sidenote: Given the max values, the entire operation fits into an int. */
tka.keepaliveinterval = MSPERSEC / FIXED_WSOCK_TCP_KEEPCNT * keepcnt
* keepintvl;
if (WSAIoctl (get_socket (), SIO_KEEPALIVE_VALS, (LPVOID) &tka, sizeof tka,
NULL, 0, &dummy, NULL, NULL) == SOCKET_ERROR)
{
set_winsock_errno ();
return -1;
}
if (!so_keepalive)
{
ret = ::setsockopt (get_socket (), SOL_SOCKET, SO_KEEPALIVE,
(const char *) &so_keepalive, sizeof so_keepalive);
if (ret == SOCKET_ERROR)
debug_printf ("setsockopt (SO_KEEPALIVE) failed, %u\n",
WSAGetLastError ());
}
return 0;
}
int
fhandler_socket_inet::setsockopt (int level, int optname, const void *optval,
socklen_t optlen)
@ -1686,6 +1747,14 @@ fhandler_socket_inet::setsockopt (int level, int optname, const void *optval,
break;
case IPPROTO_TCP:
/* Check for stream socket early on, so we don't have to do this for
every option. Also, WinSock returns EINVAL. */
if (type != SOCK_STREAM)
{
set_errno (EOPNOTSUPP);
return -1;
}
switch (optname)
{
case TCP_MAXSEG:
@ -1698,16 +1767,59 @@ fhandler_socket_inet::setsockopt (int level, int optname, const void *optval,
/* Fake FastOpen on older systems. */
if (!wincap.has_tcp_fastopen ())
{
if (type != SOCK_STREAM)
{
set_errno (EOPNOTSUPP);
return -1;
}
ignore = true;
tcp_fastopen = *(int *) optval ? true : false;
}
break;
case TCP_KEEPIDLE:
/* Handle TCP_KEEPIDLE on older systems. */
if (!wincap.has_linux_tcp_keepalive_sockopts ())
{
if (*(int *) optval < 1 || *(int *) optval > MAX_TCP_KEEPIDLE)
{
set_errno (EINVAL);
return -1;
}
if (set_keepalive (*(int *) optval, tcp_keepcnt, tcp_keepintvl))
return -1;
ignore = true;
tcp_keepidle = *(int *) optval;
}
break;
case TCP_KEEPCNT:
/* Fake TCP_KEEPCNT on older systems. */
if (!wincap.has_linux_tcp_keepalive_sockopts ())
{
if (*(int *) optval < 1 || *(int *) optval > MAX_TCP_KEEPCNT)
{
set_errno (EINVAL);
return -1;
}
if (set_keepalive (tcp_keepidle, *(int *) optval, tcp_keepintvl))
return -1;
ignore = true;
tcp_keepcnt = *(int *) optval;
}
break;
case TCP_KEEPINTVL:
/* Handle TCP_KEEPINTVL on older systems. */
if (!wincap.has_linux_tcp_keepalive_sockopts ())
{
if (*(int *) optval < 1 || *(int *) optval > MAX_TCP_KEEPINTVL)
{
set_errno (EINVAL);
return -1;
}
if (set_keepalive (tcp_keepidle, tcp_keepcnt, *(int *) optval))
return -1;
ignore = true;
tcp_keepintvl = *(int *) optval;
}
break;
default:
break;
}
@ -1841,23 +1953,56 @@ fhandler_socket_inet::getsockopt (int level, int optname, const void *optval,
break;
case IPPROTO_TCP:
/* Check for stream socket early on, so we don't have to do this for
every option. Also, WinSock returns EINVAL. */
if (type != SOCK_STREAM)
{
set_errno (EOPNOTSUPP);
return -1;
}
switch (optname)
{
case TCP_FASTOPEN:
/* Fake FastOpen on older systems */
if (!wincap.has_tcp_fastopen ())
{
if (type != SOCK_STREAM)
{
set_errno (EOPNOTSUPP);
return -1;
}
*(int *) optval = tcp_fastopen ? 1 : 0;
*optlen = sizeof (int);
return 0;
}
break;
case TCP_KEEPIDLE:
/* Use stored value on older systems */
if (!wincap.has_linux_tcp_keepalive_sockopts ())
{
*(int *) optval = tcp_keepidle;
*optlen = sizeof (int);
return 0;
}
break;
case TCP_KEEPCNT:
/* Use stored value on older systems */
if (!wincap.has_linux_tcp_keepalive_sockopts ())
{
*(int *) optval = tcp_keepcnt;
*optlen = sizeof (int);
return 0;
}
break;
case TCP_KEEPINTVL:
/* Use stored value on older systems */
if (!wincap.has_linux_tcp_keepalive_sockopts ())
{
*(int *) optval = tcp_keepintvl;
*optlen = sizeof (int);
return 0;
}
break;
default:
break;
}

View File

@ -123,8 +123,11 @@ struct tcphdr {
/*
* User-settable options (used with setsockopt).
*/
#define TCP_NODELAY 0x01 /* don't delay send to coalesce packets */
#define TCP_MAXSEG 0x04 /* get maximum segment size (r/o on windows) */
#define TCP_FASTOPEN 0x0f /* enable FastOpen on listeners */
#define TCP_NODELAY 0x01 /* don't delay send to coalesce packets */
#define TCP_KEEPIDLE 0x03 /* start keepalives after this period */
#define TCP_MAXSEG 0x04 /* get maximum segment size (r/o on windows) */
#define TCP_FASTOPEN 0x0f /* enable FastOpen on listeners */
#define TCP_KEEPCNT 0x10 /* number of keepalives before death */
#define TCP_KEEPINTVL 0x11 /* interval between keepalives */
#endif

View File

@ -47,6 +47,7 @@ wincaps wincap_vista __attribute__((section (".cygwin_dll_common"), shared)) = {
has_con_esc_rep:false,
has_extended_mem_api:false,
has_tcp_fastopen:false,
has_linux_tcp_keepalive_sockopts:false,
},
};
@ -79,6 +80,7 @@ wincaps wincap_7 __attribute__((section (".cygwin_dll_common"), shared)) = {
has_con_esc_rep:false,
has_extended_mem_api:false,
has_tcp_fastopen:false,
has_linux_tcp_keepalive_sockopts:false,
},
};
@ -111,6 +113,7 @@ wincaps wincap_8 __attribute__((section (".cygwin_dll_common"), shared)) = {
has_con_esc_rep:false,
has_extended_mem_api:false,
has_tcp_fastopen:false,
has_linux_tcp_keepalive_sockopts:false,
},
};
@ -143,6 +146,7 @@ wincaps wincap_8_1 __attribute__((section (".cygwin_dll_common"), shared)) = {
has_con_esc_rep:false,
has_extended_mem_api:false,
has_tcp_fastopen:false,
has_linux_tcp_keepalive_sockopts:false,
},
};
@ -175,6 +179,7 @@ wincaps wincap_10_1507 __attribute__((section (".cygwin_dll_common"), shared))
has_con_esc_rep:false,
has_extended_mem_api:false,
has_tcp_fastopen:false,
has_linux_tcp_keepalive_sockopts:false,
},
};
@ -207,6 +212,7 @@ wincaps wincap_10_1607 __attribute__((section (".cygwin_dll_common"), shared))
has_con_esc_rep:false,
has_extended_mem_api:false,
has_tcp_fastopen:true,
has_linux_tcp_keepalive_sockopts:false,
},
};
@ -239,6 +245,7 @@ wincaps wincap_10_1703 __attribute__((section (".cygwin_dll_common"), shared)) =
has_con_esc_rep:false,
has_extended_mem_api:false,
has_tcp_fastopen:true,
has_linux_tcp_keepalive_sockopts:false,
},
};
@ -271,6 +278,7 @@ wincaps wincap_10_1709 __attribute__((section (".cygwin_dll_common"), shared)) =
has_con_esc_rep:false,
has_extended_mem_api:false,
has_tcp_fastopen:true,
has_linux_tcp_keepalive_sockopts:true,
},
};
@ -303,6 +311,7 @@ wincaps wincap_10_1803 __attribute__((section (".cygwin_dll_common"), shared)) =
has_con_esc_rep:false,
has_extended_mem_api:true,
has_tcp_fastopen:true,
has_linux_tcp_keepalive_sockopts:true,
},
};
@ -335,6 +344,7 @@ wincaps wincap_10_1809 __attribute__((section (".cygwin_dll_common"), shared)) =
has_con_esc_rep:false,
has_extended_mem_api:true,
has_tcp_fastopen:true,
has_linux_tcp_keepalive_sockopts:true,
},
};
@ -367,6 +377,7 @@ wincaps wincap_10_1903 __attribute__((section (".cygwin_dll_common"), shared)) =
has_con_esc_rep:true,
has_extended_mem_api:true,
has_tcp_fastopen:true,
has_linux_tcp_keepalive_sockopts:true,
},
};

View File

@ -41,6 +41,7 @@ struct wincaps
unsigned has_con_esc_rep : 1;
unsigned has_extended_mem_api : 1;
unsigned has_tcp_fastopen : 1;
unsigned has_linux_tcp_keepalive_sockopts : 1;
};
};
@ -105,6 +106,7 @@ public:
bool IMPLEMENT (has_con_esc_rep)
bool IMPLEMENT (has_extended_mem_api)
bool IMPLEMENT (has_tcp_fastopen)
bool IMPLEMENT (has_linux_tcp_keepalive_sockopts)
void disable_case_sensitive_dirs ()
{