diff options
Diffstat (limited to 'util-linux')
| -rw-r--r-- | util-linux/Config.in | 27 | ||||
| -rw-r--r-- | util-linux/mdev.c | 186 |
2 files changed, 116 insertions, 97 deletions
diff --git a/util-linux/Config.in b/util-linux/Config.in index a493fbf..501ed6b 100644 --- a/util-linux/Config.in +++ b/util-linux/Config.in @@ -265,16 +265,31 @@ config CONFIG_FEATURE_MDEV_CONF That's device name (with regex match), uid:gid, and permissions. - Optionally, that can be followed (on the same line) by an asterisk - and a command line to run after creating the corresponding device(s), - ala: - - hdc root:cdrom 660 *ln -s hdc cdrom - Config file parsing stops on the first matching line. If no config entry is matched, devices are created with default 0:0 660. (Make the last line match .* to override this.) +config CONFIG_FEATURE_MDEV_EXEC + bool "Support command execution at device addition/removal" + default n + depends on CONFIG_FEATURE_MDEV_CONF + help + This adds support for an optional field to /etc/mdev.conf, consisting + of a special character and a command line to run after creating the + corresponding device(s) and before removing, ala: + + hdc root:cdrom 660 *ln -s $MDEV cdrom + + The $MDEV environment variable is set to the name of the device. + + The special characters and their meanings are: + @ Run after creating the device. + $ Run before removing the device. + * Run both after creating and before removing the device. + + Commands are executed via system() so you need /bin/sh, meaning you + probably want to select a default shell in the Shells menu. + config CONFIG_MKSWAP bool "mkswap" default n diff --git a/util-linux/mdev.c b/util-linux/mdev.c index 73a8231..3c7cf7b 100644 --- a/util-linux/mdev.c +++ b/util-linux/mdev.c @@ -8,25 +8,14 @@ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. */ +#include "busybox.h" #include <ctype.h> -#include <dirent.h> #include <errno.h> -#include <fcntl.h> -#include <stdio.h> -#include <string.h> #include <sys/mman.h> -#include <sys/stat.h> #include <sys/sysmacros.h> -#include <sys/types.h> -#include <unistd.h> -#include <stdlib.h> -#include "busybox.h" #include "xregex.h" #define DEV_PATH "/dev" -#define MDEV_CONF "/etc/mdev.conf" - -#include <busybox.h> struct mdev_globals { @@ -36,14 +25,15 @@ struct mdev_globals #define bbg mdev_globals /* mknod in /dev based on a path like "/sys/block/hda/hda1" */ -static void make_device(char *path) +static void make_device(char *path, int delete) { - char *device_name, *s; + char *device_name; int major, minor, type, len, fd; int mode = 0660; uid_t uid = 0; gid_t gid = 0; char *temp = path + strlen(path); + char *command = NULL; /* Try to read major/minor string. Note that the kernel puts \n after * the data, so we don't need to worry about null terminating the string @@ -69,7 +59,7 @@ static void make_device(char *path) char *conf, *pos, *end; /* mmap the config file */ - if (-1 != (fd=open(MDEV_CONF,O_RDONLY))) { + if (-1 != (fd=open("/etc/mdev.conf",O_RDONLY))) { len = lseek(fd, 0, SEEK_END); conf = mmap(NULL, len, PROT_READ, MAP_PRIVATE, fd, 0); if (conf) { @@ -86,88 +76,89 @@ static void make_device(char *path) ; /* Three fields: regex, uid:gid, mode */ - for (field=3; field; field--) { + for (field=0; field < (3 + ENABLE_FEATURE_MDEV_EXEC); + field++) + { /* Skip whitespace */ - while (pos<end && isspace(*pos)) - pos++; - if (pos==end || *pos=='#') - break; - for (end2=pos; end2<end && !isspace(*end2) && *end2!='#'; end2++) + while (pos<end && isspace(*pos)) pos++; + if (pos==end || *pos=='#') break; + for (end2=pos; + end2<end && !isspace(*end2) && *end2!='#'; end2++) ; - switch (field) { + if (!field) { /* Regex to match this device */ - case 3: - { - char *regex = strndupa(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); - - /* If not this device, skip rest of line */ - if (result || off.rm_so || off.rm_eo!=strlen(device_name)) - goto end_line; + char *regex = strndupa(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); + + /* If not this device, skip rest of line */ + if (result || off.rm_so + || off.rm_eo != strlen(device_name)) break; - } + + } else if (field == 1) { /* 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; - pass = getpwnam(strndupa(pos,s-pos)); - if (!pass) - goto end_line; - uid = pass->pw_uid; - } - s++; - /* parse GID */ - gid = strtoul(s,&s2,10); - if (end2 != s2) { - struct group *grp; - grp = getgrnam(strndupa(s,end2-s)); - if (!grp) - goto end_line; - gid = grp->gr_gid; - } - break; + + char *s, *s2; + + /* Find : */ + for(s=pos; s<end2 && *s!=':'; s++) + ; + if (s == end2) break; + + /* Parse UID */ + uid = strtoul(pos,&s2,10); + if (s != s2) { + struct passwd *pass; + pass = getpwnam(strndupa(pos, s-pos)); + if (!pass) break; + uid = pass->pw_uid; + } + s++; + /* parse GID */ + gid = strtoul(s, &s2, 10); + if (end2 != s2) { + struct group *grp; + grp = getgrnam(strndupa(s, end2-s)); + if (!grp) break; + gid = grp->gr_gid; } + } else if (field == 2) { /* mode */ - case 1: - { - mode = strtoul(pos,&pos,8); - if (pos != end2) - goto end_line; - else - goto found_device; + + mode = strtoul(pos, &pos, 8); + if (pos != end2) break; + } else if (ENABLE_FEATURE_MDEV_EXEC && field == 3) { + // Command to run + char *s = "@$*", *s2; + if (!(s2 = strchr(s, *pos++))) { + // Force error + field = 1; + break; } + if ((s2-s+1) & (1<<delete)) + command = bb_xstrndup(pos, end-pos); } + pos = end2; } -end_line: + /* Did everything parse happily? */ - if (field && field!=3) - bb_error_msg_and_die("Bad line %d",line); + + if (field > 2) break; + if (field) bb_error_msg_and_die("Bad line %d",line); /* Next line */ pos = ++end; } -found_device: munmap(conf, len); } close(fd); @@ -175,13 +166,29 @@ found_device: } umask(0); - if (mknod(device_name, mode | type, makedev(major, minor)) && errno != EEXIST) - bb_perror_msg_and_die("mknod %s failed", device_name); + if (!delete) { + if (mknod(device_name, mode | type, makedev(major, minor)) && errno != EEXIST) + bb_perror_msg_and_die("mknod %s failed", device_name); - if (major==bbg.root_major && minor==bbg.root_minor) - symlink(device_name, "root"); + if (major == bbg.root_major && minor == bbg.root_minor) + symlink(device_name, "root"); - if (ENABLE_FEATURE_MDEV_CONF) chown(device_name, uid, gid); + if (ENABLE_FEATURE_MDEV_CONF) chown(device_name, uid, gid); + } + if (command) { + int rc; + char *s; + + s=bb_xasprintf("MDEV=%s",device_name); + putenv(s); + rc = system(command); + s[4]=0; + putenv(s); + free(s); + free(command); + if (rc == -1) bb_perror_msg_and_die("Couldn't run %s", command); + } + if (delete) unlink(device_name); } /* Recursive search of /sys/block or /sys/class. path must be a writeable @@ -212,7 +219,7 @@ static void find_dev(char *path) /* If there's a dev entry, mknod it */ - if (!strcmp(entry->d_name, "dev")) make_device(path); + if (!strcmp(entry->d_name, "dev")) make_device(path, 0); } closedir(dir); @@ -247,12 +254,9 @@ int mdev_main(int argc, char *argv[]) if (!action || !env_path) bb_show_usage(); - if (!strcmp(action, "add")) { - sprintf(temp, "/sys%s", env_path); - make_device(temp); - } else if (!strcmp(action, "remove")) { - unlink(strrchr(env_path, '/') + 1); - } + sprintf(temp, "/sys%s", env_path); + if (!strcmp(action, "add")) make_device(temp,0); + else if (!strcmp(action, "remove")) make_device(temp,1); } if (ENABLE_FEATURE_CLEAN_UP) RELEASE_CONFIG_BUFFER(temp); |