From 9488aa4c0452da1852a4f48bfad3c378d2b3e6cf Mon Sep 17 00:00:00 2001 From: David van Moolenbroek Date: Tue, 15 Sep 2015 20:42:11 +0000 Subject: [PATCH] Import NetBSD flock(1) Also fix the MINIX3 libc flock(3) implementation. Change-Id: Ia80280029968786d7f029940ec02e942057701bd --- distrib/sets/lists/minix/mi | 2 + minix/lib/libc/sys/flock.c | 13 +- usr.bin/Makefile | 2 +- usr.bin/flock/Makefile | 8 + usr.bin/flock/flock.1 | 100 +++++++++++ usr.bin/flock/flock.c | 324 ++++++++++++++++++++++++++++++++++++ 6 files changed, 442 insertions(+), 7 deletions(-) create mode 100644 usr.bin/flock/Makefile create mode 100644 usr.bin/flock/flock.1 create mode 100644 usr.bin/flock/flock.c diff --git a/distrib/sets/lists/minix/mi b/distrib/sets/lists/minix/mi index 7b4256f5e..691c27a27 100644 --- a/distrib/sets/lists/minix/mi +++ b/distrib/sets/lists/minix/mi @@ -331,6 +331,7 @@ ./usr/bin/fix minix-sys ./usr/bin/flex++ minix-sys ./usr/bin/flex minix-sys +./usr/bin/flock minix-sys ./usr/bin/fold minix-sys ./usr/bin/format minix-sys ./usr/bin/fpr minix-sys @@ -2405,6 +2406,7 @@ ./usr/man/man1/finger.1 minix-sys ./usr/man/man1/flex.1 minix-sys ./usr/man/man1/flexdoc.1 minix-sys +./usr/man/man1/flock.1 minix-sys ./usr/man/man1/fold.1 minix-sys ./usr/man/man1/for.1 minix-sys obsolete ./usr/man/man1/format.1 minix-sys diff --git a/minix/lib/libc/sys/flock.c b/minix/lib/libc/sys/flock.c index 9163598eb..e0249f5c6 100644 --- a/minix/lib/libc/sys/flock.c +++ b/minix/lib/libc/sys/flock.c @@ -21,14 +21,15 @@ int flock(int fd, int mode) { struct flock lck; - register int retcode; memset((void *) &lck, 0, sizeof(struct flock)); - lck.l_type = mode & ~LOCK_NB; - lck.l_pid = getpid(); - if ((retcode = fcntl(fd, mode & LOCK_NB ? F_SETLK : F_SETLKW, &lck)) < 0 && errno == EAGAIN) - errno = EWOULDBLOCK; - return retcode; + switch (mode & ~LOCK_NB) { + case LOCK_SH: lck.l_type = F_RDLCK; break; + case LOCK_EX: lck.l_type = F_WRLCK; break; + case LOCK_UN: lck.l_type = F_UNLCK; break; + default: errno = EINVAL; return -1; + } + return fcntl(fd, mode & LOCK_NB ? F_SETLK : F_SETLKW, &lck); } /** flock.c **/ diff --git a/usr.bin/Makefile b/usr.bin/Makefile index 04767a3f2..0be439f3f 100644 --- a/usr.bin/Makefile +++ b/usr.bin/Makefile @@ -10,7 +10,7 @@ SUBDIR= asa \ column comm csplit ctags cut \ deroff dirname du \ env expand \ - false find finger fold fpr from \ + false find finger flock fold fpr from \ fsplit ftp genassym getopt \ head hexdump id indent infocmp join jot \ lam last ldd leave \ diff --git a/usr.bin/flock/Makefile b/usr.bin/flock/Makefile new file mode 100644 index 000000000..ba91e5f79 --- /dev/null +++ b/usr.bin/flock/Makefile @@ -0,0 +1,8 @@ +# $NetBSD: Makefile,v 1.1 2012/11/01 23:30:19 christos Exp $ +# @(#)Makefile 8.1 (Berkeley) 6/6/93 + +PROG= flock +#LDADD+= -lutil +#DPADD+= ${LIBUTIL} + +.include diff --git a/usr.bin/flock/flock.1 b/usr.bin/flock/flock.1 new file mode 100644 index 000000000..395317231 --- /dev/null +++ b/usr.bin/flock/flock.1 @@ -0,0 +1,100 @@ +.\" $NetBSD: flock.1,v 1.9 2013/09/21 15:01:14 khorben Exp $ +.\" +.\" Copyright (c) 2012 The NetBSD Foundation, Inc. +.\" All rights reserved. +.\" +.\" This code is derived from software contributed to The NetBSD Foundation +.\" by Christos Zoulas. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS +.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED +.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR +.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS +.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR +.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF +.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS +.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN +.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) +.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE +.\" POSSIBILITY OF SUCH DAMAGE. +.\" +.\" +.Dd November 2, 2012 +.Dt FLOCK 1 +.Os +.Sh NAME +.Nm flock +.Nd Provide locking API for shell scripts +.Sh SYNOPSIS +.Nm +.Op Fl dnosvx +.Op Fl w Ar timeout +.Ar lockfile|lockdir +.Op Fl c Ar command +| +.Op Ar command ... +.Nm +.Op Fl dnsuvx +.Op Fl w Ar timeout +.Ar lockfd +.Sh DESCRIPTION +The +.Nm +utility provides +.Xr flock 2 +access to the command line or scripts. +The first form locks a file or directory while the command provided is executed. +If the file or directory does not exist, then a file is created. +.Pp +The second form can use an arbitrary file descriptor that is provided from a +shell script for example: +.Bd -literal +( + flock -s 100 + # commands to be executed under the lock +) 100> /path/to/lockfile +.Ed +.Pp +The following options are available: +.Bl -tag -width "XXXXXXXXXXXXXXXXX" +.It Fl c Ar command +Pass a command to a the shell. +.It Fl d , Fl Fl debug +Provide debugging output. +.It Fl n , Fl Fl nb , Fl Fl nonblock +Don't block and fail immediately if the lock could not be obtained. +.It Fl o , Fl Fl close +Close the file before executing the command. +This is useful if the child forks and should not be holding the lock. +.It Fl s , Fl Fl shared +Obtain a shared lock. +.It Fl u , Fl Fl unlock +Unlock an existing lock. +This is available only for a file descriptor. +.It Fl v , Fl Fl verbose +On error print an explanation of the failure. +.It Fl w , Fl Fl wait , Fl Fl timeout Ar seconds +Fail if the lock could not be obtained after +.Ar seconds . +.It Fl x , Fl Fl exclusive +Obtain an exclusive lock. +.El +.Sh EXIT STATUS +.Ex -std +.Sh SEE ALSO +.Xr shlock 1 , +.Xr flock 2 +.Sh HISTORY +An +.Nm +utility appeared in +.Nx 6.1 . diff --git a/usr.bin/flock/flock.c b/usr.bin/flock/flock.c new file mode 100644 index 000000000..d087fd36f --- /dev/null +++ b/usr.bin/flock/flock.c @@ -0,0 +1,324 @@ +/* $NetBSD: flock.c,v 1.8 2013/10/29 16:02:15 christos Exp $ */ + +/*- + * Copyright (c) 2012 The NetBSD Foundation, Inc. + * All rights reserved. + * + * This code is derived from software contributed to The NetBSD Foundation + * by Christos Zoulas. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS + * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED + * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR + * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS + * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#include +__RCSID("$NetBSD: flock.c,v 1.8 2013/10/29 16:02:15 christos Exp $"); + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static struct option flock_longopts[] = { + { "debug", no_argument, 0, 'd' }, + { "help", no_argument, 0, 'h' }, + { "nonblock", no_argument, 0, 'n' }, + { "nb", no_argument, 0, 'n' }, + { "close", no_argument, 0, 'o' }, + { "shared", no_argument, 0, 's' }, + { "exclusive", no_argument, 0, 'x' }, + { "unlock", no_argument, 0, 'u' }, + { "verbose", no_argument, 0, 'v' }, + { "command", required_argument, 0, 'c' }, + { "wait", required_argument, 0, 'w' }, + { "timeout", required_argument, 0, 'w' }, + { NULL, 0, 0, 0 }, +}; + +static sig_atomic_t timeout_expired; + +static __dead void +usage(const char *fmt, ...) +{ + if (fmt) { + va_list ap; + va_start(ap, fmt); + fprintf(stderr, "%s: ", getprogname()); + vfprintf(stderr, fmt, ap); + fputc('\n', stderr); + va_end(ap); + } + + fprintf(stderr, "Usage: %s [-dnosvx] [-w timeout] lockfile|lockdir " + "[-c command]|command ...\n\t%s [-dnsuvx] [-w timeout] lockfd\n", + getprogname(), getprogname()); + exit(EXIT_FAILURE); +} + +static void +sigalrm(int sig) +{ + timeout_expired++; +} + +static const char * +lock2name(int l) +{ + static char buf[1024]; + int nb = l & LOCK_NB; + + l &= ~LOCK_NB; + if (nb) + strlcpy(buf, "LOCK_NB|", sizeof(buf)); + else + buf[0] = '\0'; + + switch (l) { + case LOCK_SH: + strlcat(buf, "LOCK_SH", sizeof(buf)); + return buf; + case LOCK_EX: + strlcat(buf, "LOCK_EX", sizeof(buf)); + return buf; + case LOCK_UN: + strlcat(buf, "LOCK_UN", sizeof(buf)); + return buf; + default: + snprintf(buf, sizeof(buf), "*%d*", l | nb); + return buf; + } +} + +static char +lockchar(int l) +{ + switch (l & ~LOCK_NB) { + case LOCK_SH: + return 's'; + case LOCK_EX: + return 'x'; + case LOCK_UN: + return 'u'; + default: + return '*'; + } +} + +static char * +cmdline(char **av) +{ + char *v = NULL; + while (*av) + if (v) { + if (asprintf(&v, "%s %s", v, *av++) < 0) + err(EXIT_FAILURE, "malloc"); + } else { + if ((v = strdup(*av++)) == NULL) + err(EXIT_FAILURE, "strdup"); + } + return v; +} + +int +main(int argc, char *argv[]) +{ + int c; + int lock = 0; + double timeout = 0; + int cls = 0; + int fd = -1; + int debug = 0; + int verbose = 0; + char *mcargv[] = { + __UNCONST(_PATH_BSHELL), __UNCONST("-c"), NULL, NULL + }; + char **cmdargv = NULL, *v; +#ifndef __minix + timer_t tm; +#else /* __minix */ + struct itimerval it; +#endif /* __minix */ + + setprogname(argv[0]); + + while ((c = getopt_long(argc, argv, "+dnosuvw:x", flock_longopts, NULL)) + != -1) + switch (c) { + case 'd': + debug++; + break; + case 'x': +#define T(l) (lock & ~LOCK_NB) != (l) && (lock & ~LOCK_NB) != 0 + if (T(LOCK_EX)) + goto badlock; + lock |= LOCK_EX; + break; + case 'n': + lock |= LOCK_NB; + break; + case 's': + if (T(LOCK_SH)) + goto badlock; + lock |= LOCK_SH; + break; + case 'u': + if (T(LOCK_UN)) + goto badlock; + lock |= LOCK_UN; + break; + case 'w': + timeout = strtod(optarg, NULL); + break; + case 'v': + verbose = 1; + break; + case 'o': + cls = 1; + break; + default: + usage("Invalid option '%c'", c); + badlock: + usage("-%c can't be used with -%c", c, lockchar(lock)); + } + + argc -= optind; + argv += optind; + + if ((lock & ~LOCK_NB) == 0) + usage("Missing lock type flag"); + + switch (argc) { + case 0: + usage("Missing lock file argument"); + case 1: + if (cls) + usage("Close is valid only for descriptors"); + fd = strtol(argv[0], NULL, 0); // XXX: error checking + if (debug) { + fprintf(stderr, "descriptor %s lock %s\n", + argv[0], lock2name(lock)); + } + break; + + default: + if ((lock & LOCK_NB) == LOCK_UN) + usage("Unlock is only valid for descriptors"); + if (strcmp(argv[1], "-c") == 0 || + strcmp(argv[1], "--command") == 0) { + if (argc == 2) + usage("Missing argument to %s", strcmp(argv[1], + "-c") == 0 ? "-c" : "--command"); + mcargv[2] = argv[2]; + cmdargv = mcargv; + } else + cmdargv = argv + 1; + + if ((fd = open(argv[0], O_RDONLY)) == -1) { + if (errno != ENOENT || + (fd = open(argv[0], O_RDWR|O_CREAT, 0600)) == -1) + err(EXIT_FAILURE, "Cannot open `%s'", argv[0]); + } + if (debug) { + fprintf(stderr, "file %s lock %s command %s ...\n", + argv[0], lock2name(lock), v = cmdline(cmdargv)); + free(v); + } + break; + } + + if (timeout) { +#ifndef __minix + struct sigevent ev; + struct itimerspec it; +#endif /* !__minix */ + struct sigaction sa; + +#ifndef __minix + timespecclear(&it.it_interval); + it.it_value.tv_sec = timeout; + it.it_value.tv_nsec = (timeout - it.it_value.tv_sec) * + 1000000000; + + memset(&ev, 0, sizeof(ev)); + ev.sigev_notify = SIGEV_SIGNAL; + ev.sigev_signo = SIGALRM; + + if (timer_create(CLOCK_REALTIME, &ev, &tm) == -1) + err(EXIT_FAILURE, "timer_create"); + + if (timer_settime(tm, TIMER_RELTIME, &it, NULL) == -1) + err(EXIT_FAILURE, "timer_settime"); +#else /* __minix */ + memset(&it.it_interval, 0, sizeof(it.it_interval)); + it.it_value.tv_sec = timeout; + it.it_value.tv_usec = (timeout - it.it_value.tv_sec) * 1000000; + + if (setitimer(ITIMER_REAL, &it, NULL) == -1) + err(EXIT_FAILURE, "setitimer"); + + memset(&it, 0, sizeof(it)); /* for the reset later */ +#endif /* __minix */ + + memset(&sa, 0, sizeof(sa)); + sa.sa_handler = sigalrm; + sigemptyset(&sa.sa_mask); + sa.sa_flags = 0; + if (sigaction(SIGALRM, &sa, NULL) == -1) + err(EXIT_FAILURE, "sigaction"); + + if (debug) + fprintf(stderr, "alarm %g\n", timeout); + } + + while (flock(fd, lock) == -1) { + if (errno == EINTR && timeout_expired == 0) + continue; + if (verbose) + err(EXIT_FAILURE, "flock(%d, %s)", fd, lock2name(lock)); + else + return EXIT_FAILURE; + } + + if (timeout) +#ifndef __minix + timer_delete(tm); +#else /* __minix */ + setitimer(ITIMER_REAL, &it, NULL); +#endif /* __minix */ + + if (cls) + (void)close(fd); + + if (cmdargv != NULL) { + execvp(cmdargv[0], cmdargv); + err(EXIT_FAILURE, "execvp '%s'", v = cmdline(cmdargv)); + free(v); + } + return 0; +}