flag parameters: paccept
This patch is by far the most complex in the series. It adds a new syscall
paccept. This syscall differs from accept in that it adds (at the userlevel)
two additional parameters:
- a signal mask
- a flags value
The flags parameter can be used to set flag like SOCK_CLOEXEC. This is
imlpemented here as well. Some people argued that this is a property which
should be inherited from the file desriptor for the server but this is against
POSIX. Additionally, we really want the signal mask parameter as well
(similar to pselect, ppoll, etc). So an interface change in inevitable.
The flag value is the same as for socket and socketpair. I think diverging
here will only create confusion. Similar to the filesystem interfaces where
the use of the O_* constants differs, it is acceptable here.
The signal mask is handled as for pselect etc. The mask is temporarily
installed for the thread and removed before the call returns. I modeled the
code after pselect. If there is a problem it's likely also in pselect.
For architectures which use socketcall I maintained this interface instead of
adding a system call. The symmetry shouldn't be broken.
The following test must be adjusted for architectures other than x86 and
x86-64 and in case the syscall numbers changed.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#include <errno.h>
#include <fcntl.h>
#include <pthread.h>
#include <signal.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_CLOEXEC O_CLOEXEC
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);
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);
pthread_barrier_wait (&b);
sleep (2);
pthread_kill ((pthread_t) arg, SIGUSR1);
return NULL;
}
static void
handler (int s)
{
}
int
main (void)
{
pthread_barrier_init (&b, NULL, 2);
struct sockaddr_in sin;
pthread_t th;
if (pthread_create (&th, NULL, tf, (void *) pthread_self ()) != 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;
}
int coe = fcntl (s2, F_GETFD);
if (coe & FD_CLOEXEC)
{
puts ("paccept(0) set close-on-exec-flag");
return 1;
}
close (s2);
pthread_barrier_wait (&b);
s2 = paccept (s, NULL, 0, NULL, SOCK_CLOEXEC);
if (s2 < 0)
{
puts ("paccept(SOCK_CLOEXEC) failed");
return 1;
}
coe = fcntl (s2, F_GETFD);
if ((coe & FD_CLOEXEC) == 0)
{
puts ("paccept(SOCK_CLOEXEC) does not set close-on-exec flag");
return 1;
}
close (s2);
pthread_barrier_wait (&b);
struct sigaction sa;
sa.sa_handler = handler;
sa.sa_flags = 0;
sigemptyset (&sa.sa_mask);
sigaction (SIGUSR1, &sa, NULL);
sigset_t ss;
pthread_sigmask (SIG_SETMASK, NULL, &ss);
sigaddset (&ss, SIGUSR1);
pthread_sigmask (SIG_SETMASK, &ss, NULL);
sigdelset (&ss, SIGUSR1);
alarm (4);
pthread_barrier_wait (&b);
errno = 0 ;
s2 = paccept (s, NULL, 0, &ss, 0);
if (s2 != -1 || errno != EINTR)
{
puts ("paccept did not fail with EINTR");
return 1;
}
close (s);
puts ("OK");
return 0;
}
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
[akpm@linux-foundation.org: make it compile]
[akpm@linux-foundation.org: add sys_ni stub]
Signed-off-by: Ulrich Drepper <drepper@redhat.com>
Acked-by: Davide Libenzi <davidel@xmailserver.org>
Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
Cc: <linux-arch@vger.kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Roland McGrath <roland@redhat.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/asm-alpha/socket.h b/include/asm-alpha/socket.h
index 08c9793..a1057c2 100644
--- a/include/asm-alpha/socket.h
+++ b/include/asm-alpha/socket.h
@@ -62,4 +62,9 @@
#define SO_MARK 36
+/* O_NONBLOCK clashes with the bits used for socket types. Therefore we
+ * have to define SOCK_NONBLOCK to a different value here.
+ */
+#define SOCK_NONBLOCK 0x40000000
+
#endif /* _ASM_SOCKET_H */
diff --git a/include/asm-parisc/socket.h b/include/asm-parisc/socket.h
index 69a7a0d..fba402c 100644
--- a/include/asm-parisc/socket.h
+++ b/include/asm-parisc/socket.h
@@ -54,4 +54,9 @@
#define SO_MARK 0x401f
+/* O_NONBLOCK clashes with the bits used for socket types. Therefore we
+ * have to define SOCK_NONBLOCK to a different value here.
+ */
+#define SOCK_NONBLOCK 0x40000000
+
#endif /* _ASM_SOCKET_H */
diff --git a/include/asm-x86/unistd_64.h b/include/asm-x86/unistd_64.h
index 9c1a4a3..e323994 100644
--- a/include/asm-x86/unistd_64.h
+++ b/include/asm-x86/unistd_64.h
@@ -639,6 +639,8 @@
__SYSCALL(__NR_timerfd_settime, sys_timerfd_settime)
#define __NR_timerfd_gettime 287
__SYSCALL(__NR_timerfd_gettime, sys_timerfd_gettime)
+#define __NR_paccept 288
+__SYSCALL(__NR_paccept, sys_paccept)
#ifndef __NO_STUBS
diff --git a/include/linux/net.h b/include/linux/net.h
index 8b5383c..3a9b06d 100644
--- a/include/linux/net.h
+++ b/include/linux/net.h
@@ -47,6 +47,7 @@
#define SYS_GETSOCKOPT 15 /* sys_getsockopt(2) */
#define SYS_SENDMSG 16 /* sys_sendmsg(2) */
#define SYS_RECVMSG 17 /* sys_recvmsg(2) */
+#define SYS_PACCEPT 18 /* sys_paccept(2) */
typedef enum {
SS_FREE = 0, /* not allocated */
@@ -219,6 +220,8 @@
extern struct socket *sockfd_lookup(int fd, int *err);
#define sockfd_put(sock) fput(sock->file)
extern int net_ratelimit(void);
+extern long do_accept(int fd, struct sockaddr __user *upeer_sockaddr,
+ int __user *upeer_addrlen, int flags);
#define net_random() random32()
#define net_srandom(seed) srandom32((__force u32)seed)
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 4394dad..2a2a40a 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -409,6 +409,8 @@
asmlinkage long sys_bind(int, struct sockaddr __user *, int);
asmlinkage long sys_connect(int, struct sockaddr __user *, int);
asmlinkage long sys_accept(int, struct sockaddr __user *, int __user *);
+asmlinkage long sys_paccept(int, struct sockaddr __user *, int __user *,
+ const sigset_t *, size_t, int);
asmlinkage long sys_getsockname(int, struct sockaddr __user *, int __user *);
asmlinkage long sys_getpeername(int, struct sockaddr __user *, int __user *);
asmlinkage long sys_send(int, void __user *, size_t, unsigned);
diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
index 0fea0ee..2f0b8a2 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -31,6 +31,7 @@
cond_syscall(sys_bind);
cond_syscall(sys_listen);
cond_syscall(sys_accept);
+cond_syscall(sys_paccept);
cond_syscall(sys_connect);
cond_syscall(sys_getsockname);
cond_syscall(sys_getpeername);
diff --git a/net/compat.c b/net/compat.c
index 6e1b03b..67fb6a3 100644
--- a/net/compat.c
+++ b/net/compat.c
@@ -722,9 +722,10 @@
/* Argument list sizes for compat_sys_socketcall */
#define AL(x) ((x) * sizeof(u32))
-static unsigned char nas[18]={AL(0),AL(3),AL(3),AL(3),AL(2),AL(3),
+static unsigned char nas[19]={AL(0),AL(3),AL(3),AL(3),AL(2),AL(3),
AL(3),AL(3),AL(4),AL(4),AL(4),AL(6),
- AL(6),AL(2),AL(5),AL(5),AL(3),AL(3)};
+ AL(6),AL(2),AL(5),AL(5),AL(3),AL(3),
+ AL(6)};
#undef AL
asmlinkage long compat_sys_sendmsg(int fd, struct compat_msghdr __user *msg, unsigned flags)
@@ -737,13 +738,52 @@
return sys_recvmsg(fd, (struct msghdr __user *)msg, flags | MSG_CMSG_COMPAT);
}
+asmlinkage long compat_sys_paccept(int fd, struct sockaddr __user *upeer_sockaddr,
+ int __user *upeer_addrlen,
+ const compat_sigset_t __user *sigmask,
+ compat_size_t sigsetsize, int flags)
+{
+ compat_sigset_t ss32;
+ sigset_t ksigmask, sigsaved;
+ int ret;
+
+ if (sigmask) {
+ if (sigsetsize != sizeof(compat_sigset_t))
+ return -EINVAL;
+ if (copy_from_user(&ss32, sigmask, sizeof(ss32)))
+ return -EFAULT;
+ sigset_from_compat(&ksigmask, &ss32);
+
+ sigdelsetmask(&ksigmask, sigmask(SIGKILL)|sigmask(SIGSTOP));
+ sigprocmask(SIG_SETMASK, &ksigmask, &sigsaved);
+ }
+
+ ret = do_accept(fd, upeer_sockaddr, upeer_addrlen, flags);
+
+ if (ret == -ERESTARTNOHAND) {
+ /*
+ * Don't restore the signal mask yet. Let do_signal() deliver
+ * the signal on the way back to userspace, before the signal
+ * mask is restored.
+ */
+ if (sigmask) {
+ memcpy(¤t->saved_sigmask, &sigsaved,
+ sizeof(sigsaved));
+ set_restore_sigmask();
+ }
+ } else if (sigmask)
+ sigprocmask(SIG_SETMASK, &sigsaved, NULL);
+
+ return ret;
+}
+
asmlinkage long compat_sys_socketcall(int call, u32 __user *args)
{
int ret;
u32 a[6];
u32 a0, a1;
- if (call < SYS_SOCKET || call > SYS_RECVMSG)
+ if (call < SYS_SOCKET || call > SYS_PACCEPT)
return -EINVAL;
if (copy_from_user(a, args, nas[call]))
return -EFAULT;
@@ -764,7 +804,7 @@
ret = sys_listen(a0, a1);
break;
case SYS_ACCEPT:
- ret = sys_accept(a0, compat_ptr(a1), compat_ptr(a[2]));
+ ret = do_accept(a0, compat_ptr(a1), compat_ptr(a[2]), 0);
break;
case SYS_GETSOCKNAME:
ret = sys_getsockname(a0, compat_ptr(a1), compat_ptr(a[2]));
@@ -804,6 +844,10 @@
case SYS_RECVMSG:
ret = compat_sys_recvmsg(a0, compat_ptr(a1), a[2]);
break;
+ case SYS_PACCEPT:
+ ret = compat_sys_paccept(a0, compat_ptr(a1), compat_ptr(a[2]),
+ compat_ptr(a[3]), a[4], a[5]);
+ break;
default:
ret = -EINVAL;
break;
diff --git a/net/socket.c b/net/socket.c
index 64601f9..a0ce8ad 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -63,6 +63,7 @@
#include <linux/file.h>
#include <linux/net.h>
#include <linux/interrupt.h>
+#include <linux/thread_info.h>
#include <linux/rcupdate.h>
#include <linux/netdevice.h>
#include <linux/proc_fs.h>
@@ -1225,6 +1226,9 @@
return -EINVAL;
type &= SOCK_TYPE_MASK;
+ if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK))
+ flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
+
retval = sock_create(family, type, protocol, &sock);
if (retval < 0)
goto out;
@@ -1259,6 +1263,9 @@
return -EINVAL;
type &= SOCK_TYPE_MASK;
+ if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK))
+ flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
+
/*
* Obtain the first socket and check if the underlying protocol
* supports the socketpair call.
@@ -1413,14 +1420,20 @@
* clean when we restucture accept also.
*/
-asmlinkage long sys_accept(int fd, struct sockaddr __user *upeer_sockaddr,
- int __user *upeer_addrlen)
+long do_accept(int fd, struct sockaddr __user *upeer_sockaddr,
+ int __user *upeer_addrlen, int flags)
{
struct socket *sock, *newsock;
struct file *newfile;
int err, len, newfd, fput_needed;
struct sockaddr_storage address;
+ if (flags & ~SOCK_CLOEXEC)
+ return -EINVAL;
+
+ if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK))
+ flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
+
sock = sockfd_lookup_light(fd, &err, &fput_needed);
if (!sock)
goto out;
@@ -1438,7 +1451,7 @@
*/
__module_get(newsock->ops->owner);
- newfd = sock_alloc_fd(&newfile, 0);
+ newfd = sock_alloc_fd(&newfile, flags & O_CLOEXEC);
if (unlikely(newfd < 0)) {
err = newfd;
sock_release(newsock);
@@ -1491,6 +1504,50 @@
goto out_put;
}
+asmlinkage long sys_paccept(int fd, struct sockaddr __user *upeer_sockaddr,
+ int __user *upeer_addrlen,
+ const sigset_t __user *sigmask,
+ size_t sigsetsize, int flags)
+{
+ sigset_t ksigmask, sigsaved;
+ int ret;
+
+ if (sigmask) {
+ /* XXX: Don't preclude handling different sized sigset_t's. */
+ if (sigsetsize != sizeof(sigset_t))
+ return -EINVAL;
+ if (copy_from_user(&ksigmask, sigmask, sizeof(ksigmask)))
+ return -EFAULT;
+
+ sigdelsetmask(&ksigmask, sigmask(SIGKILL)|sigmask(SIGSTOP));
+ sigprocmask(SIG_SETMASK, &ksigmask, &sigsaved);
+ }
+
+ ret = do_accept(fd, upeer_sockaddr, upeer_addrlen, flags);
+
+ if (ret < 0 && signal_pending(current)) {
+ /*
+ * Don't restore the signal mask yet. Let do_signal() deliver
+ * the signal on the way back to userspace, before the signal
+ * mask is restored.
+ */
+ if (sigmask) {
+ memcpy(¤t->saved_sigmask, &sigsaved,
+ sizeof(sigsaved));
+ set_restore_sigmask();
+ }
+ } else if (sigmask)
+ sigprocmask(SIG_SETMASK, &sigsaved, NULL);
+
+ return ret;
+}
+
+asmlinkage long sys_accept(int fd, struct sockaddr __user *upeer_sockaddr,
+ int __user *upeer_addrlen)
+{
+ return do_accept(fd, upeer_sockaddr, upeer_addrlen, 0);
+}
+
/*
* Attempt to connect to a socket with the server address. The address
* is in user space so we verify it is OK and move it to kernel space.
@@ -2011,10 +2068,11 @@
/* Argument list sizes for sys_socketcall */
#define AL(x) ((x) * sizeof(unsigned long))
-static const unsigned char nargs[18]={
+static const unsigned char nargs[19]={
AL(0),AL(3),AL(3),AL(3),AL(2),AL(3),
AL(3),AL(3),AL(4),AL(4),AL(4),AL(6),
- AL(6),AL(2),AL(5),AL(5),AL(3),AL(3)
+ AL(6),AL(2),AL(5),AL(5),AL(3),AL(3),
+ AL(6)
};
#undef AL
@@ -2033,7 +2091,7 @@
unsigned long a0, a1;
int err;
- if (call < 1 || call > SYS_RECVMSG)
+ if (call < 1 || call > SYS_PACCEPT)
return -EINVAL;
/* copy_from_user should be SMP safe. */
@@ -2062,8 +2120,8 @@
break;
case SYS_ACCEPT:
err =
- sys_accept(a0, (struct sockaddr __user *)a1,
- (int __user *)a[2]);
+ do_accept(a0, (struct sockaddr __user *)a1,
+ (int __user *)a[2], 0);
break;
case SYS_GETSOCKNAME:
err =
@@ -2110,6 +2168,13 @@
case SYS_RECVMSG:
err = sys_recvmsg(a0, (struct msghdr __user *)a1, a[2]);
break;
+ case SYS_PACCEPT:
+ err =
+ sys_paccept(a0, (struct sockaddr __user *)a1,
+ (int __user *)a[2],
+ (const sigset_t __user *) a[3],
+ a[4], a[5]);
+ break;
default:
err = -EINVAL;
break;
