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authorUlrich Drepper <drepper@redhat.com>2008-07-24 00:29:20 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2008-07-24 13:47:27 -0400
commitaaca0bdca573f3f51ea03139f9c7289541e7bca3 (patch)
treed25b0baa73b5301d91a5c848a896bad0fb719acc /net/compat.c
parenta677a039be7243357d93502bff2b40850c942e2d (diff)
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>
Diffstat (limited to 'net/compat.c')
-rw-r--r--net/compat.c52
1 files changed, 48 insertions, 4 deletions
diff --git a/net/compat.c b/net/compat.c
index 6e1b03b51933..67fb6a3834a3 100644
--- a/net/compat.c
+++ b/net/compat.c
@@ -722,9 +722,10 @@ EXPORT_SYMBOL(compat_mc_getsockopt);
722 722
723/* Argument list sizes for compat_sys_socketcall */ 723/* Argument list sizes for compat_sys_socketcall */
724#define AL(x) ((x) * sizeof(u32)) 724#define AL(x) ((x) * sizeof(u32))
725static unsigned char nas[18]={AL(0),AL(3),AL(3),AL(3),AL(2),AL(3), 725static unsigned char nas[19]={AL(0),AL(3),AL(3),AL(3),AL(2),AL(3),
726 AL(3),AL(3),AL(4),AL(4),AL(4),AL(6), 726 AL(3),AL(3),AL(4),AL(4),AL(4),AL(6),
727 AL(6),AL(2),AL(5),AL(5),AL(3),AL(3)}; 727 AL(6),AL(2),AL(5),AL(5),AL(3),AL(3),
728 AL(6)};
728#undef AL 729#undef AL
729 730
730asmlinkage long compat_sys_sendmsg(int fd, struct compat_msghdr __user *msg, unsigned flags) 731asmlinkage long compat_sys_sendmsg(int fd, struct compat_msghdr __user *msg, unsigned flags)
@@ -737,13 +738,52 @@ asmlinkage long compat_sys_recvmsg(int fd, struct compat_msghdr __user *msg, uns
737 return sys_recvmsg(fd, (struct msghdr __user *)msg, flags | MSG_CMSG_COMPAT); 738 return sys_recvmsg(fd, (struct msghdr __user *)msg, flags | MSG_CMSG_COMPAT);
738} 739}
739 740
741asmlinkage long compat_sys_paccept(int fd, struct sockaddr __user *upeer_sockaddr,
742 int __user *upeer_addrlen,
743 const compat_sigset_t __user *sigmask,
744 compat_size_t sigsetsize, int flags)
745{
746 compat_sigset_t ss32;
747 sigset_t ksigmask, sigsaved;
748 int ret;
749
750 if (sigmask) {
751 if (sigsetsize != sizeof(compat_sigset_t))
752 return -EINVAL;
753 if (copy_from_user(&ss32, sigmask, sizeof(ss32)))
754 return -EFAULT;
755 sigset_from_compat(&ksigmask, &ss32);
756
757 sigdelsetmask(&ksigmask, sigmask(SIGKILL)|sigmask(SIGSTOP));
758 sigprocmask(SIG_SETMASK, &ksigmask, &sigsaved);
759 }
760
761 ret = do_accept(fd, upeer_sockaddr, upeer_addrlen, flags);
762
763 if (ret == -ERESTARTNOHAND) {
764 /*
765 * Don't restore the signal mask yet. Let do_signal() deliver
766 * the signal on the way back to userspace, before the signal
767 * mask is restored.
768 */
769 if (sigmask) {
770 memcpy(&current->saved_sigmask, &sigsaved,
771 sizeof(sigsaved));
772 set_restore_sigmask();
773 }
774 } else if (sigmask)
775 sigprocmask(SIG_SETMASK, &sigsaved, NULL);
776
777 return ret;
778}
779
740asmlinkage long compat_sys_socketcall(int call, u32 __user *args) 780asmlinkage long compat_sys_socketcall(int call, u32 __user *args)
741{ 781{
742 int ret; 782 int ret;
743 u32 a[6]; 783 u32 a[6];
744 u32 a0, a1; 784 u32 a0, a1;
745 785
746 if (call < SYS_SOCKET || call > SYS_RECVMSG) 786 if (call < SYS_SOCKET || call > SYS_PACCEPT)
747 return -EINVAL; 787 return -EINVAL;
748 if (copy_from_user(a, args, nas[call])) 788 if (copy_from_user(a, args, nas[call]))
749 return -EFAULT; 789 return -EFAULT;
@@ -764,7 +804,7 @@ asmlinkage long compat_sys_socketcall(int call, u32 __user *args)
764 ret = sys_listen(a0, a1); 804 ret = sys_listen(a0, a1);
765 break; 805 break;
766 case SYS_ACCEPT: 806 case SYS_ACCEPT:
767 ret = sys_accept(a0, compat_ptr(a1), compat_ptr(a[2])); 807 ret = do_accept(a0, compat_ptr(a1), compat_ptr(a[2]), 0);
768 break; 808 break;
769 case SYS_GETSOCKNAME: 809 case SYS_GETSOCKNAME:
770 ret = sys_getsockname(a0, compat_ptr(a1), compat_ptr(a[2])); 810 ret = sys_getsockname(a0, compat_ptr(a1), compat_ptr(a[2]));
@@ -804,6 +844,10 @@ asmlinkage long compat_sys_socketcall(int call, u32 __user *args)
804 case SYS_RECVMSG: 844 case SYS_RECVMSG:
805 ret = compat_sys_recvmsg(a0, compat_ptr(a1), a[2]); 845 ret = compat_sys_recvmsg(a0, compat_ptr(a1), a[2]);
806 break; 846 break;
847 case SYS_PACCEPT:
848 ret = compat_sys_paccept(a0, compat_ptr(a1), compat_ptr(a[2]),
849 compat_ptr(a[3]), a[4], a[5]);
850 break;
807 default: 851 default:
808 ret = -EINVAL; 852 ret = -EINVAL;
809 break; 853 break;