From 3ff2c948beaad303e376e1ad778d1cd8693a3099 Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Fri, 25 Jul 2008 05:30:10 +0000 Subject: * sysdeps/unix/sysv/linux/kernel-features.h: Define __ASSUME_PACCEPT, __ASSUME_IN_NONBLOCK, and __ASSUME_PACCEPT if appropriate. * nscd/connections.c: Avoid fcntl calls to set close-on-exec flag and non-blocking mode by using socket, paccept, and inotify_init1. --- ChangeLog | 6 ++ nscd/connections.c | 99 ++++++++++++++++++++++++------- sysdeps/unix/sysv/linux/kernel-features.h | 9 +++ 3 files changed, 92 insertions(+), 22 deletions(-) diff --git a/ChangeLog b/ChangeLog index 67fc9d3d1d..c46770a8ff 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,11 @@ 2008-07-24 Ulrich Drepper + * sysdeps/unix/sysv/linux/kernel-features.h: Define + __ASSUME_PACCEPT, __ASSUME_IN_NONBLOCK, and __ASSUME_PACCEPT if + appropriate. + * nscd/connections.c: Avoid fcntl calls to set close-on-exec flag and + non-blocking mode by using socket, paccept, and inotify_init1. + * Versions.def (glibc): Add GLIBC_2.9. * io/Makefile (routines): Add dup3 and pipe2. * io/Versions [glibc] (GLIBC_2.9): Add dup3 and pipe2. diff --git a/nscd/connections.c b/nscd/connections.c index e4d32b27de..9b003cb2b0 100644 --- a/nscd/connections.c +++ b/nscd/connections.c @@ -234,6 +234,14 @@ static int inotify_fd = -1; static int resolv_conf_descr = -1; #endif +#ifndef __ASSUME_SOCK_CLOEXEC +/* Negative if SOCK_CLOEXEC is not supported, positive if it is, zero + before be know the result. */ +static int have_sock_cloexec; +/* The paccept syscall was introduced at the same time as SOCK_CLOEXEC. */ +# define have_paccept have_sock_cloexec +#endif + /* Number of times clients had to wait. */ unsigned long int client_queued; @@ -517,9 +525,15 @@ nscd_init (void) #ifdef HAVE_INOTIFY /* Use inotify to recognize changed files. */ - inotify_fd = inotify_init (); - if (inotify_fd != -1) - fcntl (inotify_fd, F_SETFL, O_NONBLOCK); + inotify_fd = inotify_init1 (IN_NONBLOCK); +# ifndef __ASSUME_IN_NONBLOCK + if (inotify_fd == -1 && errno == ENOSYS) + { + inotify_fd = inotify_init (); + if (inotify_fd != -1) + fcntl (inotify_fd, F_SETFL, O_NONBLOCK); + } +# endif #endif for (size_t cnt = 0; cnt < lastdb; ++cnt) @@ -860,7 +874,21 @@ cannot set socket to close on exec: %s; disabling paranoia mode"), } /* Create the socket. */ - sock = socket (AF_UNIX, SOCK_STREAM, 0); +#ifndef __ASSUME_SOCK_CLOEXEC + sock = -1; + if (have_sock_cloexec >= 0) +#endif + { + sock = socket (AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 0); +#ifdef __ASSUME_SOCK_CLOEXEC + if (have_sock_cloexec == 0) + have_sock_cloexec = sock != -1 || errno != EINVAL ? 1 : -1; +#endif + } +#ifndef __ASSUME_SOCK_CLOEXEC + if (have_sock_cloexec < 0) + sock = socket (AF_UNIX, SOCK_STREAM, 0); +#endif if (sock < 0) { dbg_log (_("cannot open socket: %s"), strerror (errno)); @@ -876,22 +904,27 @@ cannot set socket to close on exec: %s; disabling paranoia mode"), exit (errno == EACCES ? 4 : 1); } - /* We don't want to get stuck on accept. */ - int fl = fcntl (sock, F_GETFL); - if (fl == -1 || fcntl (sock, F_SETFL, fl | O_NONBLOCK) == -1) +#ifndef __ASSUME_SOCK_CLOEXEC + if (have_sock_cloexec < 0) { - dbg_log (_("cannot change socket to nonblocking mode: %s"), - strerror (errno)); - exit (1); - } + /* We don't want to get stuck on accept. */ + int fl = fcntl (sock, F_GETFL); + if (fl == -1 || fcntl (sock, F_SETFL, fl | O_NONBLOCK) == -1) + { + dbg_log (_("cannot change socket to nonblocking mode: %s"), + strerror (errno)); + exit (1); + } - /* The descriptor needs to be closed on exec. */ - if (paranoia && fcntl (sock, F_SETFD, FD_CLOEXEC) == -1) - { - dbg_log (_("cannot set socket to close on exec: %s"), - strerror (errno)); - exit (1); + /* The descriptor needs to be closed on exec. */ + if (paranoia && fcntl (sock, F_SETFD, FD_CLOEXEC) == -1) + { + dbg_log (_("cannot set socket to close on exec: %s"), + strerror (errno)); + exit (1); + } } +#endif /* Set permissions for the socket. */ chmod (_PATH_NSCDSOCKET, DEFFILEMODE); @@ -1576,10 +1609,15 @@ nscd_run_worker (void *p) /* We are done with the list. */ pthread_mutex_unlock (&readylist_lock); - /* We do not want to block on a short read or so. */ - int fl = fcntl (fd, F_GETFL); - if (fl == -1 || fcntl (fd, F_SETFL, fl | O_NONBLOCK) == -1) - goto close_and_out; +#ifndef __ASSUME_SOCK_CLOEXEC + if (have_sock_cloexec < 0) + { + /* We do not want to block on a short read or so. */ + int fl = fcntl (fd, F_GETFL); + if (fl == -1 || fcntl (fd, F_SETFL, fl | O_NONBLOCK) == -1) + goto close_and_out; + } +#endif /* Now read the request. */ request_header req; @@ -1779,7 +1817,24 @@ main_loop_poll (void) if (conns[0].revents != 0) { /* We have a new incoming connection. Accept the connection. */ - int fd = TEMP_FAILURE_RETRY (accept (sock, NULL, NULL)); + int fd; + +#ifndef __ASSUME_PACCEPT + fd = -1; + if (have_paccept >= 0) +#endif + { + fd = TEMP_FAILURE_RETRY (paccept (sock, NULL, NULL, NULL, + SOCK_NONBLOCK)); +#ifndef __ASSUME_PACCEPT + if (have_paccept == 0) + have_paccept = fd != -1 || errno != ENOSYS ? 1 : -1; +#endif + } +#ifndef __ASSUME_PACCEPT + if (have_paccept < 0) + fd = TEMP_FAILURE_RETRY (accept (sock, NULL, NULL)); +#endif /* Use the descriptor if we have not reached the limit. */ if (fd >= 0) diff --git a/sysdeps/unix/sysv/linux/kernel-features.h b/sysdeps/unix/sysv/linux/kernel-features.h index 5b41429f16..d5951317e4 100644 --- a/sysdeps/unix/sysv/linux/kernel-features.h +++ b/sysdeps/unix/sysv/linux/kernel-features.h @@ -497,3 +497,12 @@ #if __LINUX_KERNEL_VERSION >= 0x02061b # define __ASSUME_AT_EXECFN 1 #endif + +/* Support for various CLOEXEC and NONBLOCK flags was added for x86 and + x86-64 in 2.6.27. */ +#if __LINUX_KERNEL_VERSION >= 0x02061b \ + && (defined __i386__ || defined __x86_64__) +# define __ASSUME_SOCK_CLOEXEC 1 +# define __ASSUME_IN_NONBLOCK 1 +# define __ASSUME_PACCEPT 1 +#endif -- cgit v1.2.3