diff options
Diffstat (limited to 'tools/flock')
| -rw-r--r-- | tools/flock/Makefile | 22 | ||||
| -rw-r--r-- | tools/flock/src/flock.c | 325 |
2 files changed, 347 insertions, 0 deletions
diff --git a/tools/flock/Makefile b/tools/flock/Makefile new file mode 100644 index 0000000000..64a8655b83 --- /dev/null +++ b/tools/flock/Makefile @@ -0,0 +1,22 @@ +# +# Copyright (C) 2006-2008 OpenWrt.org +# +# This is free software, licensed under the GNU General Public License v2. +# See /LICENSE for more information. +# +include $(TOPDIR)/rules.mk + +PKG_NAME := flock + +include $(INCLUDE_DIR)/host-build.mk + +define Host/Compile + mkdir -p $(HOST_BUILD_DIR) + $(HOSTCC) $(HOST_CFLAGS) -o $(HOST_BUILD_DIR)/flock src/flock.c +endef + +define Host/Install + $(INSTALL_BIN) $(HOST_BUILD_DIR)/flock $(STAGING_DIR_HOST)/bin/ +endef + +$(eval $(call HostBuild)) diff --git a/tools/flock/src/flock.c b/tools/flock/src/flock.c new file mode 100644 index 0000000000..13baec46ca --- /dev/null +++ b/tools/flock/src/flock.c @@ -0,0 +1,325 @@ +/* ----------------------------------------------------------------------- * + * + * Copyright 2003-2005 H. Peter Anvin - All Rights Reserved + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, + * copy, modify, merge, publish, distribute, sublicense, and/or + * sell copies of the Software, and to permit persons to whom + * the Software is furnished to do so, subject to the following + * conditions: + * + * The above copyright notice and this permission notice shall + * be included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES + * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT + * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, + * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR + * OTHER DEALINGS IN THE SOFTWARE. + * + * ----------------------------------------------------------------------- */ + +#include <errno.h> +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <getopt.h> +#include <signal.h> +#include <ctype.h> +#include <string.h> +#include <paths.h> +#include <sysexits.h> +#include <sys/types.h> +#include <sys/file.h> +#include <sys/time.h> +#include <sys/wait.h> + +#define PACKAGE_STRING "util-linux-ng 2.18" +#define _(x) (x) + +static const struct option long_options[] = { + { "shared", 0, NULL, 's' }, + { "exclusive", 0, NULL, 'x' }, + { "unlock", 0, NULL, 'u' }, + { "nonblocking", 0, NULL, 'n' }, + { "nb", 0, NULL, 'n' }, + { "timeout", 1, NULL, 'w' }, + { "wait", 1, NULL, 'w' }, + { "close", 0, NULL, 'o' }, + { "help", 0, NULL, 'h' }, + { "version", 0, NULL, 'V' }, + { 0, 0, 0, 0 } +}; + +const char *program; + +static void usage(int ex) +{ + fputs("flock (" PACKAGE_STRING ")\n", stderr); + fprintf(stderr, + _("Usage: %1$s [-sxun][-w #] fd#\n" + " %1$s [-sxon][-w #] file [-c] command...\n" + " %1$s [-sxon][-w #] directory [-c] command...\n" + " -s --shared Get a shared lock\n" + " -x --exclusive Get an exclusive lock\n" + " -u --unlock Remove a lock\n" + " -n --nonblock Fail rather than wait\n" + " -w --timeout Wait for a limited amount of time\n" + " -o --close Close file descriptor before running command\n" + " -c --command Run a single command string through the shell\n" + " -h --help Display this text\n" + " -V --version Display version\n"), + program); + exit(ex); +} + + +static sig_atomic_t timeout_expired = 0; + +static void timeout_handler(int sig) +{ + (void)sig; + + timeout_expired = 1; +} + + +static char * strtotimeval(const char *str, struct timeval *tv) +{ + char *s; + long fs; /* Fractional seconds */ + int i; + + tv->tv_sec = strtol(str, &s, 10); + fs = 0; + + if ( *s == '.' ) { + s++; + + for ( i = 0 ; i < 6 ; i++ ) { + if ( !isdigit(*s) ) + break; + + fs *= 10; + fs += *s++ - '0'; + } + + for ( ; i < 6; i++ ) + fs *= 10; + + while ( isdigit(*s) ) + s++; + } + + tv->tv_usec = fs; + return s; +} + +int main(int argc, char *argv[]) +{ + struct itimerval timeout, old_timer; + int have_timeout = 0; + int type = LOCK_EX; + int block = 0; + int fd = -1; + int opt, ix; + int do_close = 0; + int err; + int status; + char *eon; + char **cmd_argv = NULL, *sh_c_argv[4]; + const char *filename = NULL; + struct sigaction sa, old_sa; + + program = argv[0]; + + if ( argc < 2 ) + usage(EX_USAGE); + + memset(&timeout, 0, sizeof timeout); + + optopt = 0; + while ( (opt = getopt_long(argc, argv, "+sexnouw:hV?", long_options, &ix)) != EOF ) { + switch(opt) { + case 's': + type = LOCK_SH; + break; + case 'e': + case 'x': + type = LOCK_EX; + break; + case 'u': + type = LOCK_UN; + break; + case 'o': + do_close = 1; + break; + case 'n': + block = LOCK_NB; + break; + case 'w': + have_timeout = 1; + eon = strtotimeval(optarg, &timeout.it_value); + if ( *eon ) + usage(EX_USAGE); + break; + case 'V': + printf("flock (%s)\n", PACKAGE_STRING); + exit(0); + default: + /* optopt will be set if this was an unrecognized option, i.e. *not* 'h' or '?' */ + usage(optopt ? EX_USAGE : 0); + break; + } + } + + if ( argc > optind+1 ) { + /* Run command */ + + if ( !strcmp(argv[optind+1], "-c") || + !strcmp(argv[optind+1], "--command") ) { + + if ( argc != optind+3 ) { + fprintf(stderr, _("%s: %s requires exactly one command argument\n"), + program, argv[optind+1]); + exit(EX_USAGE); + } + + cmd_argv = sh_c_argv; + + cmd_argv[0] = getenv("SHELL"); + if ( !cmd_argv[0] || !*cmd_argv[0] ) + cmd_argv[0] = _PATH_BSHELL; + + cmd_argv[1] = "-c"; + cmd_argv[2] = argv[optind+2]; + cmd_argv[3] = 0; + } else { + cmd_argv = &argv[optind+1]; + } + + filename = argv[optind]; + fd = open(filename, O_RDONLY|O_NOCTTY|O_CREAT, 0666); + /* Linux doesn't like O_CREAT on a directory, even though it should be a + no-op */ + if (fd < 0 && errno == EISDIR) + fd = open(filename, O_RDONLY|O_NOCTTY); + + if ( fd < 0 ) { + err = errno; + fprintf(stderr, _("%s: cannot open lock file %s: %s\n"), + program, argv[optind], strerror(err)); + exit((err == ENOMEM||err == EMFILE||err == ENFILE) ? EX_OSERR : + (err == EROFS||err == ENOSPC) ? EX_CANTCREAT : + EX_NOINPUT); + } + + } else if (optind < argc) { + /* Use provided file descriptor */ + + fd = (int)strtol(argv[optind], &eon, 10); + if ( *eon || !argv[optind] ) { + fprintf(stderr, _("%s: bad number: %s\n"), program, argv[optind]); + exit(EX_USAGE); + } + + } else { + /* Bad options */ + + fprintf(stderr, _("%s: requires file descriptor, file or directory\n"), + program); + exit(EX_USAGE); + } + + + if ( have_timeout ) { + if ( timeout.it_value.tv_sec == 0 && + timeout.it_value.tv_usec == 0 ) { + /* -w 0 is equivalent to -n; this has to be special-cased + because setting an itimer to zero means disabled! */ + + have_timeout = 0; + block = LOCK_NB; + } else { + memset(&sa, 0, sizeof sa); + + sa.sa_handler = timeout_handler; + sa.sa_flags = SA_RESETHAND; + sigaction(SIGALRM, &sa, &old_sa); + + setitimer(ITIMER_REAL, &timeout, &old_timer); + } + } + + while ( flock(fd, type|block) ) { + switch( (err = errno) ) { + case EWOULDBLOCK: /* -n option set and failed to lock */ + exit(1); + case EINTR: /* Signal received */ + if ( timeout_expired ) + exit(1); /* -w option set and failed to lock */ + continue; /* otherwise try again */ + default: /* Other errors */ + if ( filename ) + fprintf(stderr, "%s: %s: %s\n", program, filename, strerror(err)); + else + fprintf(stderr, "%s: %d: %s\n", program, fd, strerror(err)); + exit((err == ENOLCK||err == ENOMEM) ? EX_OSERR : EX_DATAERR); + } + } + + if ( have_timeout ) { + setitimer(ITIMER_REAL, &old_timer, NULL); /* Cancel itimer */ + sigaction(SIGALRM, &old_sa, NULL); /* Cancel signal handler */ + } + + status = 0; + + if ( cmd_argv ) { + pid_t w, f; + + /* Clear any inherited settings */ + signal(SIGCHLD, SIG_DFL); + f = fork(); + + if ( f < 0 ) { + err = errno; + fprintf(stderr, _("%s: fork failed: %s\n"), program, strerror(err)); + exit(EX_OSERR); + } else if ( f == 0 ) { + if ( do_close ) + close(fd); + err = errno; + execvp(cmd_argv[0], cmd_argv); + /* execvp() failed */ + fprintf(stderr, "%s: %s: %s\n", program, cmd_argv[0], strerror(err)); + _exit((err == ENOMEM) ? EX_OSERR: EX_UNAVAILABLE); + } else { + do { + w = waitpid(f, &status, 0); + if (w == -1 && errno != EINTR) + break; + } while ( w != f ); + + if (w == -1) { + err = errno; + status = EXIT_FAILURE; + fprintf(stderr, "%s: waitpid failed: %s\n", program, strerror(err)); + } else if ( WIFEXITED(status) ) + status = WEXITSTATUS(status); + else if ( WIFSIGNALED(status) ) + status = WTERMSIG(status) + 128; + else + status = EX_OSERR; /* WTF? */ + } + } + + return status; +} + |