From 916f95cb58604038695347ee41a430d8ca1f0556 Mon Sep 17 00:00:00 2001 From: John Crispin Date: Thu, 14 Nov 2013 13:41:13 +0100 Subject: debloat and reorganize code split app into procd and init binaries remove log support, this is an external service now Signed-off-by: John Crispin --- plug/udevtrigger.c | 264 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 264 insertions(+) create mode 100644 plug/udevtrigger.c (limited to 'plug/udevtrigger.c') diff --git a/plug/udevtrigger.c b/plug/udevtrigger.c new file mode 100644 index 0000000..5013189 --- /dev/null +++ b/plug/udevtrigger.c @@ -0,0 +1,264 @@ +/* + * 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 +#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 bool device_has_attribute(const char *path, const char *attr, + mode_t mode) +{ + char filename[PATH_SIZE]; + struct stat statbuf; + + strlcpy(filename, path, sizeof(filename)); + strlcat(filename, attr, sizeof(filename)); + + if (stat(filename, &statbuf) < 0) + return false; + + if (!(statbuf.st_mode & mode)) + return false; + + return true; +} + +static int device_list_insert(const char *path) +{ + char devpath[PATH_SIZE]; + struct stat statbuf; + + dbg("add '%s'" , path); + + /* we only have a device, if we have a dev and an uevent file */ + if (!device_has_attribute(path, "/dev", S_IRUSR) || + !device_has_attribute(path, "/uevent", 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_subdir(const char *base, const char *subdir, + bool insert, int depth) +{ + DIR *dir; + struct dirent *dent; + + dir = opendir(base); + if (dir == NULL) + return; + + for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) { + char dirname[PATH_SIZE]; + + if (dent->d_name[0] == '.') + continue; + + strlcpy(dirname, base, sizeof(dirname)); + strlcat(dirname, "/", sizeof(dirname)); + strlcat(dirname, dent->d_name, sizeof(dirname)); + + if (insert) { + int err; + + err = device_list_insert(dirname); + if (err) + continue; + } + + if (subdir) + strlcat(dirname, subdir, sizeof(base)); + + if (depth) + scan_subdir(dirname, NULL, true, depth - 1); + } + + closedir(dir); +} + +int main(int argc, char *argv[], char *envp[]) +{ + 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_subdir("/sys/bus", "/devices", false, 1); + scan_subdir("/sys/class", NULL, false, 1); + + /* scan "block" if it isn't a "class" */ + if (stat("/sys/class/block", &statbuf) != 0) + scan_subdir("/sys/block", NULL, true, 1); + +exit: + + closelog(); + return 0; +} -- cgit v1.2.3