diff options
Diffstat (limited to 'toys/other/mdev.c')
-rw-r--r-- | toys/other/mdev.c | 346 |
1 files changed, 172 insertions, 174 deletions
diff --git a/toys/other/mdev.c b/toys/other/mdev.c index 6d030d14..b89ac2ca 100644 --- a/toys/other/mdev.c +++ b/toys/other/mdev.c @@ -1,6 +1,4 @@ -/* vi:set ts=4: - * - * mdev.c - Populate /dev directory and handle hotplug events +/* mdev.c - Populate /dev directory and handle hotplug events * * Copyright 2005, 2008 Rob Landley <rob@landley.net> * Copyright 2005 Frank Sorenson <frank@tuxrocks.com> @@ -8,27 +6,27 @@ USE_MDEV(NEWTOY(mdev, "s", TOYFLAG_USR|TOYFLAG_BIN|TOYFLAG_UMASK)) config MDEV - bool "mdev" - default n - help - usage: mdev [-s] + bool "mdev" + default n + help + usage: mdev [-s] - Create devices in /dev using information from /sys. + Create devices in /dev using information from /sys. - -s Scan all entries in /sys to populate /dev. + -s Scan all entries in /sys to populate /dev. config MDEV_CONF - bool "Configuration file for mdev" - default y - depends on MDEV - help - The mdev config file (/etc/mdev.conf) contains lines that look like: - hd[a-z][0-9]* 0:3 660 - - Each line must contain three whitespace separated fields. The first - field is a regular expression matching one or more device names, and - the second and third fields are uid:gid and file permissions for - matching devies. + bool "Configuration file for mdev" + default y + depends on MDEV + help + The mdev config file (/etc/mdev.conf) contains lines that look like: + hd[a-z][0-9]* 0:3 660 + + Each line must contain three whitespace separated fields. The first + field is a regular expression matching one or more device names, and + the second and third fields are uid:gid and file permissions for + matching devies. */ #include "toys.h" @@ -39,173 +37,173 @@ config MDEV_CONF // mknod in /dev based on a path like "/sys/block/hda/hda1" static void make_device(char *path) { - char *device_name, *s, *temp; - int major, minor, type, len, fd; - int mode = 0660; - uid_t uid = 0; - gid_t gid = 0; - - // Try to read major/minor string - - temp = strrchr(path, '/'); - fd = open(path, O_RDONLY); - *temp=0; - temp = toybuf; - len = read(fd, temp, 64); - close(fd); - if (len<1) return; - temp[len] = 0; - - // Determine device name, type, major and minor - - device_name = strrchr(path, '/') + 1; - type = path[5]=='c' ? S_IFCHR : S_IFBLK; - major = minor = 0; - sscanf(temp, "%u:%u", &major, &minor); - - // If we have a config file, look up permissions for this device - - if (CFG_MDEV_CONF) { - char *conf, *pos, *end; - - // mmap the config file - if (-1!=(fd = open("/etc/mdev.conf", O_RDONLY))) { - len = fdlength(fd); - conf = mmap(NULL, len, PROT_READ, MAP_PRIVATE, fd, 0); - if (conf) { - int line = 0; - - // Loop through lines in mmaped file - for (pos = conf; pos-conf<len;) { - int field; - char *end2; - - line++; - // find end of this line - for(end = pos; end-conf<len && *end!='\n'; end++); - - // Three fields: regex, uid:gid, mode - for (field = 3; field; field--) { - // Skip whitespace - while (pos<end && isspace(*pos)) pos++; - if (pos==end || *pos=='#') break; - for (end2 = pos; - end2<end && !isspace(*end2) && *end2!='#'; end2++); - switch(field) { - // Regex to match this device - case 3: - { - char *regex = strndup(pos, end2-pos); - regex_t match; - regmatch_t off; - int result; - - // Is this it? - xregcomp(&match, regex, REG_EXTENDED); - result=regexec(&match, device_name, 1, &off, 0); - regfree(&match); - free(regex); - - // If not this device, skip rest of line - if (result || off.rm_so - || off.rm_eo!=strlen(device_name)) - goto end_line; - - break; - } - // uid:gid - case 2: - { - char *s2; - - // Find : - for(s = pos; s<end2 && *s!=':'; s++); - if (s==end2) goto end_line; - - // Parse UID - uid = strtoul(pos,&s2,10); - if (s!=s2) { - struct passwd *pass; - char *str = strndup(pos, s-pos); - pass = getpwnam(str); - free(str); - if (!pass) goto end_line; - uid = pass->pw_uid; - } - s++; - // parse GID - gid = strtoul(s,&s2,10); - if (end2!=s2) { - struct group *grp; - char *str = strndup(s, end2-s); - grp = getgrnam(str); - free(str); - if (!grp) goto end_line; - gid = grp->gr_gid; - } - break; - } - // mode - case 1: - { - mode = strtoul(pos, &pos, 8); - if (pos!=end2) goto end_line; - goto found_device; - } - } - pos=end2; - } + char *device_name, *s, *temp; + int major, minor, type, len, fd; + int mode = 0660; + uid_t uid = 0; + gid_t gid = 0; + + // Try to read major/minor string + + temp = strrchr(path, '/'); + fd = open(path, O_RDONLY); + *temp=0; + temp = toybuf; + len = read(fd, temp, 64); + close(fd); + if (len<1) return; + temp[len] = 0; + + // Determine device name, type, major and minor + + device_name = strrchr(path, '/') + 1; + type = path[5]=='c' ? S_IFCHR : S_IFBLK; + major = minor = 0; + sscanf(temp, "%u:%u", &major, &minor); + + // If we have a config file, look up permissions for this device + + if (CFG_MDEV_CONF) { + char *conf, *pos, *end; + + // mmap the config file + if (-1!=(fd = open("/etc/mdev.conf", O_RDONLY))) { + len = fdlength(fd); + conf = mmap(NULL, len, PROT_READ, MAP_PRIVATE, fd, 0); + if (conf) { + int line = 0; + + // Loop through lines in mmaped file + for (pos = conf; pos-conf<len;) { + int field; + char *end2; + + line++; + // find end of this line + for(end = pos; end-conf<len && *end!='\n'; end++); + + // Three fields: regex, uid:gid, mode + for (field = 3; field; field--) { + // Skip whitespace + while (pos<end && isspace(*pos)) pos++; + if (pos==end || *pos=='#') break; + for (end2 = pos; + end2<end && !isspace(*end2) && *end2!='#'; end2++); + switch(field) { + // Regex to match this device + case 3: + { + char *regex = strndup(pos, end2-pos); + regex_t match; + regmatch_t off; + int result; + + // Is this it? + xregcomp(&match, regex, REG_EXTENDED); + result=regexec(&match, device_name, 1, &off, 0); + regfree(&match); + free(regex); + + // If not this device, skip rest of line + if (result || off.rm_so + || off.rm_eo!=strlen(device_name)) + goto end_line; + + break; + } + // uid:gid + case 2: + { + char *s2; + + // Find : + for(s = pos; s<end2 && *s!=':'; s++); + if (s==end2) goto end_line; + + // Parse UID + uid = strtoul(pos,&s2,10); + if (s!=s2) { + struct passwd *pass; + char *str = strndup(pos, s-pos); + pass = getpwnam(str); + free(str); + if (!pass) goto end_line; + uid = pass->pw_uid; + } + s++; + // parse GID + gid = strtoul(s,&s2,10); + if (end2!=s2) { + struct group *grp; + char *str = strndup(s, end2-s); + grp = getgrnam(str); + free(str); + if (!grp) goto end_line; + gid = grp->gr_gid; + } + break; + } + // mode + case 1: + { + mode = strtoul(pos, &pos, 8); + if (pos!=end2) goto end_line; + goto found_device; + } + } + pos=end2; + } end_line: - // Did everything parse happily? - if (field && field!=3) error_exit("Bad line %d", line); + // Did everything parse happily? + if (field && field!=3) error_exit("Bad line %d", line); - // Next line - pos = ++end; - } + // Next line + pos = ++end; + } found_device: - munmap(conf, len); - } - close(fd); - } - } + munmap(conf, len); + } + close(fd); + } + } - sprintf(temp, "/dev/%s", device_name); - if (mknod(temp, mode | type, makedev(major, minor)) && errno != EEXIST) - perror_exit("mknod %s failed", temp); + sprintf(temp, "/dev/%s", device_name); + if (mknod(temp, mode | type, makedev(major, minor)) && errno != EEXIST) + perror_exit("mknod %s failed", temp); - if (CFG_MDEV_CONF) mode=chown(temp, uid, gid); + if (CFG_MDEV_CONF) mode=chown(temp, uid, gid); } static int callback(struct dirtree *node) { - // Entries in /sys/class/block aren't char devices, so skip 'em. (We'll - // get block devices out of /sys/block.) - if(!strcmp(node->name, "block")) return 0; - - // Does this directory have a "dev" entry in it? - // This is path based because the hotplug callbacks are - if (S_ISDIR(node->st.st_mode) || S_ISLNK(node->st.st_mode)) { - int len=4; - char *dev = dirtree_path(node, &len); - strcpy(dev+len, "/dev"); - if (!access(dev, R_OK)) make_device(dev); - free(dev); - } - - // Circa 2.6.25 the entries more than 2 deep are all either redundant - // (mouse#, event#) or unnamed (every usb_* entry is called "device"). - - return (node->parent && node->parent->parent) ? 0 : DIRTREE_RECURSE; + // Entries in /sys/class/block aren't char devices, so skip 'em. (We'll + // get block devices out of /sys/block.) + if(!strcmp(node->name, "block")) return 0; + + // Does this directory have a "dev" entry in it? + // This is path based because the hotplug callbacks are + if (S_ISDIR(node->st.st_mode) || S_ISLNK(node->st.st_mode)) { + int len=4; + char *dev = dirtree_path(node, &len); + strcpy(dev+len, "/dev"); + if (!access(dev, R_OK)) make_device(dev); + free(dev); + } + + // Circa 2.6.25 the entries more than 2 deep are all either redundant + // (mouse#, event#) or unnamed (every usb_* entry is called "device"). + + return (node->parent && node->parent->parent) ? 0 : DIRTREE_RECURSE; } void mdev_main(void) { - // Handle -s + // Handle -s - if (toys.optflags) { - dirtree_read("/sys/class", callback); - dirtree_read("/sys/block", callback); - } + if (toys.optflags) { + dirtree_read("/sys/class", callback); + dirtree_read("/sys/block", callback); + } - // hotplug support goes here + // hotplug support goes here } |