linux_dsm_epyc7002/net
Ulrich Drepper 77d2720059 flag parameters: NONBLOCK in socket and socketpair
This patch introduces support for the SOCK_NONBLOCK flag in socket,
socketpair, and  paccept.  To do this the internal function sock_attach_fd
gets an additional parameter which it uses to set the appropriate flag for
the file descriptor.

Given that in modern, scalable programs almost all socket connections are
non-blocking and the minimal additional cost for the new functionality
I see no reason not to add this code.

The following test must be adjusted for architectures other than x86 and
x86-64 and in case the syscall numbers changed.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#include <fcntl.h>
#include <pthread.h>
#include <stdio.h>
#include <unistd.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <sys/syscall.h>

#ifndef __NR_paccept
# ifdef __x86_64__
#  define __NR_paccept 288
# elif defined __i386__
#  define SYS_PACCEPT 18
#  define USE_SOCKETCALL 1
# else
#  error "need __NR_paccept"
# endif
#endif

#ifdef USE_SOCKETCALL
# define paccept(fd, addr, addrlen, mask, flags) \
  ({ long args[6] = { \
       (long) fd, (long) addr, (long) addrlen, (long) mask, 8, (long) flags }; \
     syscall (__NR_socketcall, SYS_PACCEPT, args); })
#else
# define paccept(fd, addr, addrlen, mask, flags) \
  syscall (__NR_paccept, fd, addr, addrlen, mask, 8, flags)
#endif

#define PORT 57392

#define SOCK_NONBLOCK O_NONBLOCK

static pthread_barrier_t b;

static void *
tf (void *arg)
{
  pthread_barrier_wait (&b);
  int s = socket (AF_INET, SOCK_STREAM, 0);
  struct sockaddr_in sin;
  sin.sin_family = AF_INET;
  sin.sin_addr.s_addr = htonl (INADDR_LOOPBACK);
  sin.sin_port = htons (PORT);
  connect (s, (const struct sockaddr *) &sin, sizeof (sin));
  close (s);
  pthread_barrier_wait (&b);

  pthread_barrier_wait (&b);
  s = socket (AF_INET, SOCK_STREAM, 0);
  sin.sin_port = htons (PORT);
  connect (s, (const struct sockaddr *) &sin, sizeof (sin));
  close (s);
  pthread_barrier_wait (&b);

  return NULL;
}

int
main (void)
{
  int fd;
  fd = socket (PF_INET, SOCK_STREAM, 0);
  if (fd == -1)
    {
      puts ("socket(0) failed");
      return 1;
    }
  int fl = fcntl (fd, F_GETFL);
  if (fl == -1)
    {
      puts ("fcntl failed");
      return 1;
    }
  if (fl & O_NONBLOCK)
    {
      puts ("socket(0) set non-blocking mode");
      return 1;
    }
  close (fd);

  fd = socket (PF_INET, SOCK_STREAM|SOCK_NONBLOCK, 0);
  if (fd == -1)
    {
      puts ("socket(SOCK_NONBLOCK) failed");
      return 1;
    }
  fl = fcntl (fd, F_GETFL);
  if (fl == -1)
    {
      puts ("fcntl failed");
      return 1;
    }
  if ((fl & O_NONBLOCK) == 0)
    {
      puts ("socket(SOCK_NONBLOCK) does not set non-blocking mode");
      return 1;
    }
  close (fd);

  int fds[2];
  if (socketpair (PF_UNIX, SOCK_STREAM, 0, fds) == -1)
    {
      puts ("socketpair(0) failed");
      return 1;
    }
  for (int i = 0; i < 2; ++i)
    {
      fl = fcntl (fds[i], F_GETFL);
      if (fl == -1)
        {
          puts ("fcntl failed");
          return 1;
        }
      if (fl & O_NONBLOCK)
        {
          printf ("socketpair(0) set non-blocking mode for fds[%d]\n", i);
          return 1;
        }
      close (fds[i]);
    }

  if (socketpair (PF_UNIX, SOCK_STREAM|SOCK_NONBLOCK, 0, fds) == -1)
    {
      puts ("socketpair(SOCK_NONBLOCK) failed");
      return 1;
    }
  for (int i = 0; i < 2; ++i)
    {
      fl = fcntl (fds[i], F_GETFL);
      if (fl == -1)
        {
          puts ("fcntl failed");
          return 1;
        }
      if ((fl & O_NONBLOCK) == 0)
        {
          printf ("socketpair(SOCK_NONBLOCK) does not set non-blocking mode for fds[%d]\n", i);
          return 1;
        }
      close (fds[i]);
    }

  pthread_barrier_init (&b, NULL, 2);

  struct sockaddr_in sin;
  pthread_t th;
  if (pthread_create (&th, NULL, tf, NULL) != 0)
    {
      puts ("pthread_create failed");
      return 1;
    }

  int s = socket (AF_INET, SOCK_STREAM, 0);
  int reuse = 1;
  setsockopt (s, SOL_SOCKET, SO_REUSEADDR, &reuse, sizeof (reuse));
  sin.sin_family = AF_INET;
  sin.sin_addr.s_addr = htonl (INADDR_LOOPBACK);
  sin.sin_port = htons (PORT);
  bind (s, (struct sockaddr *) &sin, sizeof (sin));
  listen (s, SOMAXCONN);

  pthread_barrier_wait (&b);

  int s2 = paccept (s, NULL, 0, NULL, 0);
  if (s2 < 0)
    {
      puts ("paccept(0) failed");
      return 1;
    }

  fl = fcntl (s2, F_GETFL);
  if (fl & O_NONBLOCK)
    {
      puts ("paccept(0) set non-blocking mode");
      return 1;
    }
  close (s2);
  close (s);

  pthread_barrier_wait (&b);

  s = socket (AF_INET, SOCK_STREAM, 0);
  sin.sin_port = htons (PORT);
  setsockopt (s, SOL_SOCKET, SO_REUSEADDR, &reuse, sizeof (reuse));
  bind (s, (struct sockaddr *) &sin, sizeof (sin));
  listen (s, SOMAXCONN);

  pthread_barrier_wait (&b);

  s2 = paccept (s, NULL, 0, NULL, SOCK_NONBLOCK);
  if (s2 < 0)
    {
      puts ("paccept(SOCK_NONBLOCK) failed");
      return 1;
    }

  fl = fcntl (s2, F_GETFL);
  if ((fl & O_NONBLOCK) == 0)
    {
      puts ("paccept(SOCK_NONBLOCK) does not set non-blocking mode");
      return 1;
    }
  close (s2);
  close (s);

  pthread_barrier_wait (&b);
  puts ("OK");

  return 0;
}
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Ulrich Drepper <drepper@redhat.com>
Acked-by: Davide Libenzi <davidel@xmailserver.org>
Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:29 -07:00
..
9p flag parameters: socket and socketpair 2008-07-24 10:47:27 -07:00
802 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6 2008-07-18 02:39:39 -07:00
8021q netdev: Handle ->addr_list_lock just like ->_xmit_lock for lockdep. 2008-07-22 14:16:42 -07:00
appletalk netns: Use net_eq() to compare net-namespaces for optimization. 2008-07-19 22:34:43 -07:00
atm netns: Use net_eq() to compare net-namespaces for optimization. 2008-07-19 22:34:43 -07:00
ax25 netns: Use net_eq() to compare net-namespaces for optimization. 2008-07-19 22:34:43 -07:00
bluetooth bluetooth: remove improper bluetooth class symlinks. 2008-07-21 21:54:51 -07:00
bridge netns: Use net_eq() to compare net-namespaces for optimization. 2008-07-19 22:34:43 -07:00
can netns: Use net_eq() to compare net-namespaces for optimization. 2008-07-19 22:34:43 -07:00
core Merge branch 'cpus4096-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2008-07-23 18:37:44 -07:00
dccp mib: add net to NET_INC_STATS_BH 2008-07-16 20:31:16 -07:00
decnet netns: Use net_eq() to compare net-namespaces for optimization. 2008-07-19 22:34:43 -07:00
econet netns: Use net_eq() to compare net-namespaces for optimization. 2008-07-19 22:34:43 -07:00
ethernet [NET]: Return more appropriate error from eth_validate_addr(). 2008-04-13 22:45:40 -07:00
ieee80211 wext: Emit event stream entries correctly when compat. 2008-06-16 18:50:49 -07:00
ipv4 tcp: Fix bitmask test in tcp_syn_options() 2008-07-21 18:45:34 -07:00
ipv6 ipv6: icmp6_dst_gc return change 2008-07-22 14:35:50 -07:00
ipx netns: Use net_eq() to compare net-namespaces for optimization. 2008-07-19 22:34:43 -07:00
irda Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6 2008-07-20 17:43:29 -07:00
iucv Merge branch 'linus' into cpus4096-for-linus 2008-07-21 17:19:50 +02:00
key Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2008-06-13 20:52:39 -07:00
lapb [LAPB] net/lapb/lapb_iface.c: use LIST_HEAD instead of LIST_HEAD_INIT 2008-01-28 14:56:52 -08:00
llc netns: Use net_eq() to compare net-namespaces for optimization. 2008-07-19 22:34:43 -07:00
mac80211 net_sched: Add qdisc_enqueue wrapper 2008-07-20 00:08:04 -07:00
netfilter netfilter: nf_conntrack_sctp: fix sparse warnings 2008-07-21 10:11:02 -07:00
netlabel netns: Use net_eq() to compare net-namespaces for optimization. 2008-07-19 22:34:43 -07:00
netlink Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2008-07-05 23:08:07 -07:00
netrom netdev: Handle ->addr_list_lock just like ->_xmit_lock for lockdep. 2008-07-22 14:16:42 -07:00
packet netns: Use net_eq() to compare net-namespaces for optimization. 2008-07-19 22:34:43 -07:00
rfkill rfkill: ignore errors from rfkill_toggle_radio in rfkill_add_switch 2008-07-08 14:16:03 -04:00
rose netdev: Handle ->addr_list_lock just like ->_xmit_lock for lockdep. 2008-07-22 14:16:42 -07:00
rxrpc MIB: add struct net to UDP_INC_STATS_BH 2008-07-05 21:18:48 -07:00
sched pkt_sched: make qdisc_class_hash_alloc() static 2008-07-22 14:20:11 -07:00
sctp flag parameters: socket and socketpair 2008-07-24 10:47:27 -07:00
sunrpc Merge branch 'linus' into cpus4096-for-linus 2008-07-21 17:19:50 +02:00
tipc netns: Use net_eq() to compare net-namespaces for optimization. 2008-07-19 22:34:43 -07:00
unix Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2008-06-28 01:19:40 -07:00
wanrouter net: Remove references to wan-router.txt in Kconfigs 2008-07-14 22:22:29 -07:00
wireless netns: Use net_eq() to compare net-namespaces for optimization. 2008-07-19 22:34:43 -07:00
x25 netns: Use net_eq() to compare net-namespaces for optimization. 2008-07-19 22:34:43 -07:00
xfrm netns: Use net_eq() to compare net-namespaces for optimization. 2008-07-19 22:34:43 -07:00
compat.c flag parameters: paccept 2008-07-24 10:47:27 -07:00
Kconfig net: Add STP demux layer 2008-07-05 21:25:39 -07:00
Makefile vlan: uninline __vlan_hwaccel_rx 2008-07-08 03:23:36 -07:00
nonet.c
socket.c flag parameters: NONBLOCK in socket and socketpair 2008-07-24 10:47:29 -07:00
sysctl_net.c net: remove CVS keywords 2008-06-11 21:00:38 -07:00
TUNABLE