| 1 | --- a/include/applets.src.h |
| 2 | +++ b/include/applets.src.h |
| 3 | @@ -218,6 +218,7 @@ IF_LN(APPLET_NOEXEC(ln, ln, BB_DIR_BIN, |
| 4 | IF_LOAD_POLICY(APPLET(load_policy, BB_DIR_USR_SBIN, BB_SUID_DROP)) |
| 5 | IF_LOADFONT(APPLET(loadfont, BB_DIR_USR_SBIN, BB_SUID_DROP)) |
| 6 | IF_LOADKMAP(APPLET(loadkmap, BB_DIR_SBIN, BB_SUID_DROP)) |
| 7 | +IF_LOCK(APPLET(lock, BB_DIR_BIN, BB_SUID_DROP)) |
| 8 | IF_LOGGER(APPLET(logger, BB_DIR_USR_BIN, BB_SUID_DROP)) |
| 9 | /* Needs to be run by root or be suid root - needs to change uid and gid: */ |
| 10 | IF_LOGIN(APPLET(login, BB_DIR_BIN, BB_SUID_REQUIRE)) |
| 11 | --- a/miscutils/Config.src |
| 12 | +++ b/miscutils/Config.src |
| 13 | @@ -419,6 +419,11 @@ config FEATURE_HDPARM_HDIO_GETSET_DMA |
| 14 | help |
| 15 | Enables the 'hdparm -d' option to get/set using_dma flag. |
| 16 | |
| 17 | +config LOCK |
| 18 | + bool "lock" |
| 19 | + help |
| 20 | + Small utility for using locks in scripts |
| 21 | + |
| 22 | config MAKEDEVS |
| 23 | bool "makedevs" |
| 24 | default y |
| 25 | --- a/miscutils/Kbuild.src |
| 26 | +++ b/miscutils/Kbuild.src |
| 27 | @@ -29,6 +29,7 @@ lib-$(CONFIG_INOTIFYD) += inotifyd.o |
| 28 | lib-$(CONFIG_FEATURE_LAST_SMALL)+= last.o |
| 29 | lib-$(CONFIG_FEATURE_LAST_FANCY)+= last_fancy.o |
| 30 | lib-$(CONFIG_LESS) += less.o |
| 31 | +lib-$(CONFIG_LOCK) += lock.o |
| 32 | lib-$(CONFIG_MAKEDEVS) += makedevs.o |
| 33 | lib-$(CONFIG_MAN) += man.o |
| 34 | lib-$(CONFIG_MICROCOM) += microcom.o |
| 35 | --- /dev/null |
| 36 | +++ b/miscutils/lock.c |
| 37 | @@ -0,0 +1,135 @@ |
| 38 | +/* |
| 39 | + * Copyright (C) 2006 Felix Fietkau <nbd@openwrt.org> |
| 40 | + * |
| 41 | + * This is free software, licensed under the GNU General Public License v2. |
| 42 | + */ |
| 43 | +#include <sys/types.h> |
| 44 | +#include <sys/file.h> |
| 45 | +#include <sys/stat.h> |
| 46 | +#include <signal.h> |
| 47 | +#include <fcntl.h> |
| 48 | +#include <unistd.h> |
| 49 | +#include <stdio.h> |
| 50 | +#include "busybox.h" |
| 51 | + |
| 52 | +//usage:#define lock_trivial_usage NOUSAGE_STR |
| 53 | +//usage:#define lock_full_usage "" |
| 54 | + |
| 55 | +static int unlock = 0; |
| 56 | +static int shared = 0; |
| 57 | +static int waitonly = 0; |
| 58 | +static int fd; |
| 59 | +static char *file; |
| 60 | + |
| 61 | +static void usage(char *name) |
| 62 | +{ |
| 63 | + fprintf(stderr, "Usage: %s [-suw] <filename>\n" |
| 64 | + " -s Use shared locking\n" |
| 65 | + " -u Unlock\n" |
| 66 | + " -w Wait for the lock to become free, don't acquire lock\n" |
| 67 | + "\n", name); |
| 68 | + exit(1); |
| 69 | +} |
| 70 | + |
| 71 | +static void exit_unlock(int sig) |
| 72 | +{ |
| 73 | + flock(fd, LOCK_UN); |
| 74 | + exit(0); |
| 75 | +} |
| 76 | + |
| 77 | +static int do_unlock(void) |
| 78 | +{ |
| 79 | + FILE *f; |
| 80 | + int i; |
| 81 | + |
| 82 | + if ((f = fopen(file, "r")) == NULL) |
| 83 | + return 0; |
| 84 | + |
| 85 | + fscanf(f, "%d", &i); |
| 86 | + if (i > 0) |
| 87 | + kill(i, SIGTERM); |
| 88 | + |
| 89 | + fclose(f); |
| 90 | + |
| 91 | + return 0; |
| 92 | +} |
| 93 | + |
| 94 | +static int do_lock(void) |
| 95 | +{ |
| 96 | + int pid; |
| 97 | + char pidstr[8]; |
| 98 | + |
| 99 | + if ((fd = open(file, O_RDWR | O_CREAT | O_EXCL, 0700)) < 0) { |
| 100 | + if ((fd = open(file, O_RDWR)) < 0) { |
| 101 | + fprintf(stderr, "Can't open %s\n", file); |
| 102 | + return 1; |
| 103 | + } |
| 104 | + } |
| 105 | + |
| 106 | + if (flock(fd, (shared ? LOCK_SH : LOCK_EX)) < 0) { |
| 107 | + fprintf(stderr, "Can't lock %s\n", file); |
| 108 | + return 1; |
| 109 | + } |
| 110 | + |
| 111 | + pid = fork(); |
| 112 | + |
| 113 | + if (pid < 0) |
| 114 | + return -1; |
| 115 | + |
| 116 | + if (pid == 0) { |
| 117 | + signal(SIGKILL, exit_unlock); |
| 118 | + signal(SIGTERM, exit_unlock); |
| 119 | + signal(SIGINT, exit_unlock); |
| 120 | + if (waitonly) |
| 121 | + exit_unlock(0); |
| 122 | + else |
| 123 | + while (1) |
| 124 | + sleep(1); |
| 125 | + } else { |
| 126 | + if (!waitonly) { |
| 127 | + lseek(fd, 0, SEEK_SET); |
| 128 | + ftruncate(fd, 0); |
| 129 | + sprintf(pidstr, "%d\n", pid); |
| 130 | + write(fd, pidstr, strlen(pidstr)); |
| 131 | + close(fd); |
| 132 | + } |
| 133 | + |
| 134 | + return 0; |
| 135 | + } |
| 136 | + return 0; |
| 137 | +} |
| 138 | + |
| 139 | +int lock_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
| 140 | +int lock_main(int argc, char **argv) |
| 141 | +{ |
| 142 | + char **args = &argv[1]; |
| 143 | + int c = argc - 1; |
| 144 | + |
| 145 | + while ((*args != NULL) && (*args)[0] == '-') { |
| 146 | + char *ch = *args; |
| 147 | + while (*(++ch) > 0) { |
| 148 | + switch(*ch) { |
| 149 | + case 'w': |
| 150 | + waitonly = 1; |
| 151 | + break; |
| 152 | + case 's': |
| 153 | + shared = 1; |
| 154 | + break; |
| 155 | + case 'u': |
| 156 | + unlock = 1; |
| 157 | + break; |
| 158 | + } |
| 159 | + } |
| 160 | + c--; |
| 161 | + args++; |
| 162 | + } |
| 163 | + |
| 164 | + if (c != 1) |
| 165 | + usage(argv[0]); |
| 166 | + |
| 167 | + file = *args; |
| 168 | + if (unlock) |
| 169 | + return do_unlock(); |
| 170 | + else |
| 171 | + return do_lock(); |
| 172 | +} |
| 173 | |
