From: John Crispin Date: Fri, 8 Mar 2013 22:51:28 +0000 (+0100) Subject: add udevtrigger tool X-Git-Url: https://git.archive.openwrt.org/?p=project%2Fprocd.git;a=commitdiff_plain;h=1dc968d494c86e4a48335428b7c5cb99ca12e106 add udevtrigger tool --- diff --git a/udevtrigger.c b/udevtrigger.c new file mode 100644 index 0000000..be611c7 --- /dev/null +++ b/udevtrigger.c @@ -0,0 +1,352 @@ +/* + * Copyright (C) 2004-2006 Kay Sievers + * Copyright (C) 2006 Hannes Reinecke + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation version 2 of the License. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define PATH_SIZE 512 + +#ifndef strlcpy +#define strlcpy(d,s,l) (strncpy(d,s,l), (d)[(l)-1] = '\0') +#endif + +#ifndef strlcat +#define strlcat(d,s,l) strncat(d,s,(l)-strlen(d)-1) +#endif + +static int verbose; +static int dry_run; + +static void log_message(int priority, const char *format, ...) +{ + va_list args; + + va_start(args, format); + vsyslog(priority, format, args); + va_end(args); +} + +#undef err +#define err(format, arg...) \ + do { \ + log_message(LOG_ERR ,"%s: " format ,__FUNCTION__ ,## arg); \ + } while (0) + +#undef info +#define info(format, arg...) \ + do { \ + log_message(LOG_INFO ,"%s: " format ,__FUNCTION__ ,## arg); \ + } while (0) + +#ifdef DEBUG +#undef dbg +#define dbg(format, arg...) \ + do { \ + log_message(LOG_DEBUG ,"%s: " format ,__FUNCTION__ ,## arg); \ + } while (0) +#else +#define dbg(...) do {} while(0) +#endif + + +static void trigger_uevent(const char *devpath) +{ + char filename[PATH_SIZE]; + int fd; + + strlcpy(filename, "/sys", sizeof(filename)); + strlcat(filename, devpath, sizeof(filename)); + strlcat(filename, "/uevent", sizeof(filename)); + + if (verbose) + printf("%s\n", devpath); + + if (dry_run) + return; + + fd = open(filename, O_WRONLY); + if (fd < 0) { + dbg("error on opening %s: %s\n", filename, strerror(errno)); + return; + } + + if (write(fd, "add", 3) < 0) + info("error on triggering %s: %s\n", filename, strerror(errno)); + + close(fd); +} + +static int sysfs_resolve_link(char *devpath, size_t size) +{ + char link_path[PATH_SIZE]; + char link_target[PATH_SIZE]; + int len; + int i; + int back; + + strlcpy(link_path, "/sys", sizeof(link_path)); + strlcat(link_path, devpath, sizeof(link_path)); + len = readlink(link_path, link_target, sizeof(link_target)); + if (len <= 0) + return -1; + link_target[len] = '\0'; + dbg("path link '%s' points to '%s'", devpath, link_target); + + for (back = 0; strncmp(&link_target[back * 3], "../", 3) == 0; back++) + ; + dbg("base '%s', tail '%s', back %i", devpath, &link_target[back * 3], back); + for (i = 0; i <= back; i++) { + char *pos = strrchr(devpath, '/'); + + if (pos == NULL) + return -1; + pos[0] = '\0'; + } + dbg("after moving back '%s'", devpath); + strlcat(devpath, "/", size); + strlcat(devpath, &link_target[back * 3], size); + return 0; +} + + +static int device_list_insert(const char *path) +{ + char filename[PATH_SIZE]; + char devpath[PATH_SIZE]; + struct stat statbuf; + + dbg("add '%s'" , path); + + /* we only have a device, if we have an uevent file */ + strlcpy(filename, path, sizeof(filename)); + strlcat(filename, "/uevent", sizeof(filename)); + if (stat(filename, &statbuf) < 0) + return -1; + if (!(statbuf.st_mode & S_IWUSR)) + return -1; + + strlcpy(devpath, &path[4], sizeof(devpath)); + + /* resolve possible link to real target */ + if (lstat(path, &statbuf) < 0) + return -1; + if (S_ISLNK(statbuf.st_mode)) + if (sysfs_resolve_link(devpath, sizeof(devpath)) != 0) + return -1; + + trigger_uevent(devpath); + return 0; +} + + +static void scan_subsystem(const char *subsys) +{ + char base[PATH_SIZE]; + DIR *dir; + struct dirent *dent; + + strlcpy(base, "/sys/", sizeof(base)); + strlcat(base, subsys, sizeof(base)); + + dir = opendir(base); + if (dir != NULL) { + for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) { + char dirname[PATH_SIZE]; + DIR *dir2; + struct dirent *dent2; + + if (dent->d_name[0] == '.') + continue; + + strlcpy(dirname, base, sizeof(dirname)); + strlcat(dirname, "/", sizeof(dirname)); + strlcat(dirname, dent->d_name, sizeof(dirname)); + strlcat(dirname, "/devices", sizeof(dirname)); + + /* look for devices */ + dir2 = opendir(dirname); + if (dir2 != NULL) { + for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) { + char dirname2[PATH_SIZE]; + + if (dent2->d_name[0] == '.') + continue; + + strlcpy(dirname2, dirname, sizeof(dirname2)); + strlcat(dirname2, "/", sizeof(dirname2)); + strlcat(dirname2, dent2->d_name, sizeof(dirname2)); + device_list_insert(dirname2); + } + closedir(dir2); + } + } + closedir(dir); + } +} + +static void scan_block(void) +{ + char base[PATH_SIZE]; + DIR *dir; + struct dirent *dent; + + strlcpy(base, "/sys/block", sizeof(base)); + + dir = opendir(base); + if (dir != NULL) { + for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) { + char dirname[PATH_SIZE]; + DIR *dir2; + struct dirent *dent2; + + if (dent->d_name[0] == '.') + continue; + + strlcpy(dirname, base, sizeof(dirname)); + strlcat(dirname, "/", sizeof(dirname)); + strlcat(dirname, dent->d_name, sizeof(dirname)); + if (device_list_insert(dirname) != 0) + continue; + + /* look for partitions */ + dir2 = opendir(dirname); + if (dir2 != NULL) { + for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) { + char dirname2[PATH_SIZE]; + + if (dent2->d_name[0] == '.') + continue; + + if (!strcmp(dent2->d_name,"device")) + continue; + + strlcpy(dirname2, dirname, sizeof(dirname2)); + strlcat(dirname2, "/", sizeof(dirname2)); + strlcat(dirname2, dent2->d_name, sizeof(dirname2)); + device_list_insert(dirname2); + } + closedir(dir2); + } + } + closedir(dir); + } +} + +static void scan_class(void) +{ + char base[PATH_SIZE]; + DIR *dir; + struct dirent *dent; + + strlcpy(base, "/sys/class", sizeof(base)); + + dir = opendir(base); + if (dir != NULL) { + for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) { + char dirname[PATH_SIZE]; + DIR *dir2; + struct dirent *dent2; + + if (dent->d_name[0] == '.') + continue; + + strlcpy(dirname, base, sizeof(dirname)); + strlcat(dirname, "/", sizeof(dirname)); + strlcat(dirname, dent->d_name, sizeof(dirname)); + dir2 = opendir(dirname); + if (dir2 != NULL) { + for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) { + char dirname2[PATH_SIZE]; + + if (dent2->d_name[0] == '.') + continue; + + if (!strcmp(dent2->d_name, "device")) + continue; + + strlcpy(dirname2, dirname, sizeof(dirname2)); + strlcat(dirname2, "/", sizeof(dirname2)); + strlcat(dirname2, dent2->d_name, sizeof(dirname2)); + device_list_insert(dirname2); + } + closedir(dir2); + } + } + closedir(dir); + } +} + +int main(int argc, char *argv[], char *envp[]) +{ + char base[PATH_SIZE]; + struct stat statbuf; + int option; + + openlog("udevtrigger", LOG_PID | LOG_CONS, LOG_DAEMON); + + while (1) { + option = getopt(argc, argv, "vnh"); + if (option == -1) + break; + + switch (option) { + case 'v': + verbose = 1; + break; + case 'n': + dry_run = 1; + break; + case 'h': + printf("Usage: udevtrigger OPTIONS\n" + " -v print the list of devices while running\n" + " -n do not actually trigger the events\n" + " -h print this text\n" + "\n"); + goto exit; + default: + goto exit; + } + } + + + /* if we have /sys/subsystem, forget all the old stuff */ + scan_subsystem("bus"); + scan_class(); + + /* scan "block" if it isn't a "class" */ + strlcpy(base, "/sys/class/block", sizeof(base)); + if (stat(base, &statbuf) != 0) + scan_block(); + +exit: + + closelog(); + return 0; +}