| /* vi: set sw=4 ts=4: */ |
| /* |
| * Licensed under GPLv2 or later, see file LICENSE in this source tree. |
| */ |
| |
| /* |
| devfsd implementation for busybox |
| |
| Copyright (C) 2003 by Tito Ragusa <farmatito@tiscali.it> |
| |
| Busybox version is based on some previous work and ideas |
| Copyright (C) [2003] by [Matteo Croce] <3297627799@wind.it> |
| |
| devfsd.c |
| |
| Main file for devfsd (devfs daemon for Linux). |
| |
| Copyright (C) 1998-2002 Richard Gooch |
| |
| devfsd.h |
| |
| Header file for devfsd (devfs daemon for Linux). |
| |
| Copyright (C) 1998-2000 Richard Gooch |
| |
| compat_name.c |
| |
| Compatibility name file for devfsd (build compatibility names). |
| |
| Copyright (C) 1998-2002 Richard Gooch |
| |
| expression.c |
| |
| This code provides Borne Shell-like expression expansion. |
| |
| Copyright (C) 1997-1999 Richard Gooch |
| |
| 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; either version 2 of the License, or |
| (at your option) any later version. |
| |
| 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., 675 Mass Ave, Cambridge, MA 02139, USA. |
| |
| Richard Gooch may be reached by email at rgooch@atnf.csiro.au |
| The postal address is: |
| Richard Gooch, c/o ATNF, P. O. Box 76, Epping, N.S.W., 2121, Australia. |
| */ |
| //config:config DEVFSD |
| //config: bool "devfsd (obsolete)" |
| //config: default n |
| //config: select PLATFORM_LINUX |
| //config: select FEATURE_SYSLOG |
| //config: help |
| //config: This is deprecated and should NOT be used anymore. |
| //config: Use linux >= 2.6 (optionally with hotplug) and mdev instead! |
| //config: See docs/mdev.txt for detailed instructions on how to use mdev |
| //config: instead. |
| //config: |
| //config: Provides compatibility with old device names on a devfs systems. |
| //config: You should set it to true if you have devfs enabled. |
| //config: The following keywords in devsfd.conf are supported: |
| //config: "CLEAR_CONFIG", "INCLUDE", "OPTIONAL_INCLUDE", "RESTORE", |
| //config: "PERMISSIONS", "EXECUTE", "COPY", "IGNORE", |
| //config: "MKOLDCOMPAT", "MKNEWCOMPAT","RMOLDCOMPAT", "RMNEWCOMPAT". |
| //config: |
| //config: But only if they are written UPPERCASE!!!!!!!! |
| //config: |
| //config:config DEVFSD_MODLOAD |
| //config: bool "Adds support for MODLOAD keyword in devsfd.conf" |
| //config: default y |
| //config: depends on DEVFSD |
| //config: help |
| //config: This actually doesn't work with busybox modutils but needs |
| //config: the external modutils. |
| //config: |
| //config:config DEVFSD_FG_NP |
| //config: bool "Enable the -fg and -np options" |
| //config: default y |
| //config: depends on DEVFSD |
| //config: help |
| //config: -fg Run the daemon in the foreground. |
| //config: -np Exit after parsing config. Do not poll for events. |
| //config: |
| //config:config DEVFSD_VERBOSE |
| //config: bool "Increases logging (and size)" |
| //config: default y |
| //config: depends on DEVFSD |
| //config: help |
| //config: Increases logging to stderr or syslog. |
| //config: |
| //config:config FEATURE_DEVFS |
| //config: bool "Use devfs names for all devices (obsolete)" |
| //config: default n |
| //config: select PLATFORM_LINUX |
| //config: help |
| //config: This is obsolete and should NOT be used anymore. |
| //config: Use linux >= 2.6 (optionally with hotplug) and mdev instead! |
| //config: |
| //config: For legacy systems -- if there is no way around devfsd -- this |
| //config: tells busybox to look for names like /dev/loop/0 instead of |
| //config: /dev/loop0. If your /dev directory has normal names instead of |
| //config: devfs names, you don't want this. |
| |
| //applet:IF_DEVFSD(APPLET(devfsd, BB_DIR_SBIN, BB_SUID_DROP)) |
| |
| //kbuild:lib-$(CONFIG_DEVFSD) += devfsd.o |
| |
| //usage:#define devfsd_trivial_usage |
| //usage: "mntpnt [-v]" IF_DEVFSD_FG_NP("[-fg][-np]") |
| //usage:#define devfsd_full_usage "\n\n" |
| //usage: "Manage devfs permissions and old device name symlinks\n" |
| //usage: "\n mntpnt The mount point where devfs is mounted" |
| //usage: "\n -v Print the protocol version numbers for devfsd" |
| //usage: "\n and the kernel-side protocol version and exit" |
| //usage: IF_DEVFSD_FG_NP( |
| //usage: "\n -fg Run in foreground" |
| //usage: "\n -np Exit after parsing the configuration file" |
| //usage: "\n and processing synthetic REGISTER events," |
| //usage: "\n don't poll for events" |
| //usage: ) |
| |
| #include "libbb.h" |
| #include "xregex.h" |
| #include <syslog.h> |
| |
| #include <sys/un.h> |
| #include <sys/sysmacros.h> |
| |
| /* Various defines taken from linux/major.h */ |
| #define IDE0_MAJOR 3 |
| #define IDE1_MAJOR 22 |
| #define IDE2_MAJOR 33 |
| #define IDE3_MAJOR 34 |
| #define IDE4_MAJOR 56 |
| #define IDE5_MAJOR 57 |
| #define IDE6_MAJOR 88 |
| #define IDE7_MAJOR 89 |
| #define IDE8_MAJOR 90 |
| #define IDE9_MAJOR 91 |
| |
| |
| /* Various defines taken from linux/devfs_fs.h */ |
| #define DEVFSD_PROTOCOL_REVISION_KERNEL 5 |
| #define DEVFSD_IOCTL_BASE 'd' |
| /* These are the various ioctls */ |
| #define DEVFSDIOC_GET_PROTO_REV _IOR(DEVFSD_IOCTL_BASE, 0, int) |
| #define DEVFSDIOC_SET_EVENT_MASK _IOW(DEVFSD_IOCTL_BASE, 2, int) |
| #define DEVFSDIOC_RELEASE_EVENT_QUEUE _IOW(DEVFSD_IOCTL_BASE, 3, int) |
| #define DEVFSDIOC_SET_CONFIG_DEBUG_MASK _IOW(DEVFSD_IOCTL_BASE, 4, int) |
| #define DEVFSD_NOTIFY_REGISTERED 0 |
| #define DEVFSD_NOTIFY_UNREGISTERED 1 |
| #define DEVFSD_NOTIFY_ASYNC_OPEN 2 |
| #define DEVFSD_NOTIFY_CLOSE 3 |
| #define DEVFSD_NOTIFY_LOOKUP 4 |
| #define DEVFSD_NOTIFY_CHANGE 5 |
| #define DEVFSD_NOTIFY_CREATE 6 |
| #define DEVFSD_NOTIFY_DELETE 7 |
| #define DEVFS_PATHLEN 1024 |
| /* Never change this otherwise the binary interface will change */ |
| |
| struct devfsd_notify_struct { |
| /* Use native C types to ensure same types in kernel and user space */ |
| unsigned int type; /* DEVFSD_NOTIFY_* value */ |
| unsigned int mode; /* Mode of the inode or device entry */ |
| unsigned int major; /* Major number of device entry */ |
| unsigned int minor; /* Minor number of device entry */ |
| unsigned int uid; /* Uid of process, inode or device entry */ |
| unsigned int gid; /* Gid of process, inode or device entry */ |
| unsigned int overrun_count; /* Number of lost events */ |
| unsigned int namelen; /* Number of characters not including '\0' */ |
| /* The device name MUST come last */ |
| char devname[DEVFS_PATHLEN]; /* This will be '\0' terminated */ |
| }; |
| |
| #define BUFFER_SIZE 16384 |
| #define DEVFSD_VERSION "1.3.25" |
| #define CONFIG_FILE "/etc/devfsd.conf" |
| #define MODPROBE "/sbin/modprobe" |
| #define MODPROBE_SWITCH_1 "-k" |
| #define MODPROBE_SWITCH_2 "-C" |
| #define CONFIG_MODULES_DEVFS "/etc/modules.devfs" |
| #define MAX_ARGS (6 + 1) |
| #define MAX_SUBEXPR 10 |
| #define STRING_LENGTH 255 |
| |
| /* for get_uid_gid() */ |
| #define UID 0 |
| #define GID 1 |
| |
| /* fork_and_execute() */ |
| # define DIE 1 |
| # define NO_DIE 0 |
| |
| /* for dir_operation() */ |
| #define RESTORE 0 |
| #define SERVICE 1 |
| #define READ_CONFIG 2 |
| |
| /* Update only after changing code to reflect new protocol */ |
| #define DEVFSD_PROTOCOL_REVISION_DAEMON 5 |
| |
| /* Compile-time check */ |
| #if DEVFSD_PROTOCOL_REVISION_KERNEL != DEVFSD_PROTOCOL_REVISION_DAEMON |
| #error protocol version mismatch. Update your kernel headers |
| #endif |
| |
| #define AC_PERMISSIONS 0 |
| #define AC_MODLOAD 1 |
| #define AC_EXECUTE 2 |
| #define AC_MFUNCTION 3 /* not supported by busybox */ |
| #define AC_CFUNCTION 4 /* not supported by busybox */ |
| #define AC_COPY 5 |
| #define AC_IGNORE 6 |
| #define AC_MKOLDCOMPAT 7 |
| #define AC_MKNEWCOMPAT 8 |
| #define AC_RMOLDCOMPAT 9 |
| #define AC_RMNEWCOMPAT 10 |
| #define AC_RESTORE 11 |
| |
| struct permissions_type { |
| mode_t mode; |
| uid_t uid; |
| gid_t gid; |
| }; |
| |
| struct execute_type { |
| char *argv[MAX_ARGS + 1]; /* argv[0] must always be the programme */ |
| }; |
| |
| struct copy_type { |
| const char *source; |
| const char *destination; |
| }; |
| |
| struct action_type { |
| unsigned int what; |
| unsigned int when; |
| }; |
| |
| struct config_entry_struct { |
| struct action_type action; |
| regex_t preg; |
| union |
| { |
| struct permissions_type permissions; |
| struct execute_type execute; |
| struct copy_type copy; |
| } |
| u; |
| struct config_entry_struct *next; |
| }; |
| |
| struct get_variable_info { |
| const struct devfsd_notify_struct *info; |
| const char *devname; |
| char devpath[STRING_LENGTH]; |
| }; |
| |
| static void dir_operation(int , const char * , int, unsigned long*); |
| static void service(struct stat statbuf, char *path); |
| static int st_expr_expand(char *, unsigned, const char *, const char *(*)(const char *, void *), void *); |
| static const char *get_old_name(const char *, unsigned, char *, unsigned, unsigned); |
| static int mksymlink(const char *oldpath, const char *newpath); |
| static void read_config_file(char *path, int optional, unsigned long *event_mask); |
| static void process_config_line(const char *, unsigned long *); |
| static int do_servicing(int, unsigned long); |
| static void service_name(const struct devfsd_notify_struct *); |
| static void action_permissions(const struct devfsd_notify_struct *, const struct config_entry_struct *); |
| static void action_execute(const struct devfsd_notify_struct *, const struct config_entry_struct *, |
| const regmatch_t *, unsigned); |
| static void action_modload(const struct devfsd_notify_struct *info, const struct config_entry_struct *entry); |
| static void action_copy(const struct devfsd_notify_struct *, const struct config_entry_struct *, |
| const regmatch_t *, unsigned); |
| static void action_compat(const struct devfsd_notify_struct *, unsigned); |
| static void free_config(void); |
| static void restore(char *spath, struct stat source_stat, int rootlen); |
| static int copy_inode(const char *, const struct stat *, mode_t, const char *, const struct stat *); |
| static mode_t get_mode(const char *); |
| static void signal_handler(int); |
| static const char *get_variable(const char *, void *); |
| static int make_dir_tree(const char *); |
| static int expand_expression(char *, unsigned, const char *, const char *(*)(const char *, void *), void *, |
| const char *, const regmatch_t *, unsigned); |
| static void expand_regexp(char *, size_t, const char *, const char *, const regmatch_t *, unsigned); |
| static const char *expand_variable( char *, unsigned, unsigned *, const char *, |
| const char *(*)(const char *, void *), void *); |
| static const char *get_variable_v2(const char *, const char *(*)(const char *, void *), void *); |
| static char get_old_ide_name(unsigned, unsigned); |
| static char *write_old_sd_name(char *, unsigned, unsigned, const char *); |
| |
| /* busybox functions */ |
| static int get_uid_gid(int flag, const char *string); |
| static void safe_memcpy(char * dest, const char * src, int len); |
| static unsigned int scan_dev_name_common(const char *d, unsigned int n, int addendum, const char *ptr); |
| static unsigned int scan_dev_name(const char *d, unsigned int n, const char *ptr); |
| |
| /* Structs and vars */ |
| static struct config_entry_struct *first_config = NULL; |
| static struct config_entry_struct *last_config = NULL; |
| static char *mount_point = NULL; |
| static volatile int caught_signal = FALSE; |
| static volatile int caught_sighup = FALSE; |
| static struct initial_symlink_struct { |
| const char *dest; |
| const char *name; |
| } initial_symlinks[] = { |
| {"/proc/self/fd", "fd"}, |
| {"fd/0", "stdin"}, |
| {"fd/1", "stdout"}, |
| {"fd/2", "stderr"}, |
| {NULL, NULL}, |
| }; |
| |
| static struct event_type { |
| unsigned int type; /* The DEVFSD_NOTIFY_* value */ |
| const char *config_name; /* The name used in the config file */ |
| } event_types[] = { |
| {DEVFSD_NOTIFY_REGISTERED, "REGISTER"}, |
| {DEVFSD_NOTIFY_UNREGISTERED, "UNREGISTER"}, |
| {DEVFSD_NOTIFY_ASYNC_OPEN, "ASYNC_OPEN"}, |
| {DEVFSD_NOTIFY_CLOSE, "CLOSE"}, |
| {DEVFSD_NOTIFY_LOOKUP, "LOOKUP"}, |
| {DEVFSD_NOTIFY_CHANGE, "CHANGE"}, |
| {DEVFSD_NOTIFY_CREATE, "CREATE"}, |
| {DEVFSD_NOTIFY_DELETE, "DELETE"}, |
| {0xffffffff, NULL} |
| }; |
| |
| /* Busybox messages */ |
| |
| static const char bb_msg_proto_rev[] ALIGN1 = "protocol revision"; |
| static const char bb_msg_bad_config[] ALIGN1 = "bad %s config file: %s"; |
| static const char bb_msg_small_buffer[] ALIGN1 = "buffer too small"; |
| static const char bb_msg_variable_not_found[] ALIGN1 = "variable: %s not found"; |
| |
| /* Busybox stuff */ |
| #if ENABLE_DEVFSD_VERBOSE || ENABLE_DEBUG |
| #define info_logger(p, fmt, args...) bb_info_msg(fmt, ## args) |
| #define simple_info_logger(p, msg) bb_simple_info_msg(msg) |
| #define msg_logger(p, fmt, args...) bb_error_msg(fmt, ## args) |
| #define simple_msg_logger(p, msg) bb_simple_error_msg(msg) |
| #define msg_logger_and_die(p, fmt, args...) bb_error_msg_and_die(fmt, ## args) |
| #define simple_msg_logger_and_die(p, msg) bb_simple_error_msg_and_die(msg) |
| #define error_logger(p, fmt, args...) bb_perror_msg(fmt, ## args) |
| #define error_logger_and_die(p, fmt, args...) bb_perror_msg_and_die(fmt, ## args) |
| #else |
| #define info_logger(p, fmt, args...) |
| #define simple_info_logger(p, msg) |
| #define msg_logger(p, fmt, args...) |
| #define simple_msg_logger(p, msg) |
| #define msg_logger_and_die(p, fmt, args...) exit(EXIT_FAILURE) |
| #define simple_msg_logger_and_die(p, msg) exit(EXIT_FAILURE) |
| #define error_logger(p, fmt, args...) |
| #define error_logger_and_die(p, fmt, args...) exit(EXIT_FAILURE) |
| #endif |
| |
| static void safe_memcpy(char *dest, const char *src, int len) |
| { |
| memcpy(dest , src, len); |
| dest[len] = '\0'; |
| } |
| |
| static unsigned int scan_dev_name_common(const char *d, unsigned int n, int addendum, const char *ptr) |
| { |
| if (d[n - 4] == 'd' && d[n - 3] == 'i' && d[n - 2] == 's' && d[n - 1] == 'c') |
| return 2 + addendum; |
| if (d[n - 2] == 'c' && d[n - 1] == 'd') |
| return 3 + addendum; |
| if (ptr[0] == 'p' && ptr[1] == 'a' && ptr[2] == 'r' && ptr[3] == 't') |
| return 4 + addendum; |
| if (ptr[n - 2] == 'm' && ptr[n - 1] == 't') |
| return 5 + addendum; |
| return 0; |
| } |
| |
| static unsigned int scan_dev_name(const char *d, unsigned int n, const char *ptr) |
| { |
| if (d[0] == 's' && d[1] == 'c' && d[2] == 's' && d[3] == 'i' && d[4] == '/') { |
| if (d[n - 7] == 'g' && d[n - 6] == 'e' && d[n - 5] == 'n' |
| && d[n - 4] == 'e' && d[n - 3] == 'r' && d[n - 2] == 'i' && d[n - 1] == 'c' |
| ) |
| return 1; |
| return scan_dev_name_common(d, n, 0, ptr); |
| } |
| if (d[0] == 'i' && d[1] == 'd' && d[2] == 'e' && d[3] == '/' |
| && d[4] == 'h' && d[5] == 'o' && d[6] == 's' && d[7] == 't' |
| ) |
| return scan_dev_name_common(d, n, 4, ptr); |
| if (d[0] == 's' && d[1] == 'b' && d[2] == 'p' && d[3] == '/') |
| return 10; |
| if (d[0] == 'v' && d[1] == 'c' && d[2] == 'c' && d[3] == '/') |
| return 11; |
| if (d[0] == 'p' && d[1] == 't' && d[2] == 'y' && d[3] == '/') |
| return 12; |
| return 0; |
| } |
| |
| /* Public functions follow */ |
| |
| int devfsd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
| int devfsd_main(int argc, char **argv) |
| { |
| int print_version = FALSE; |
| int do_daemon = TRUE; |
| int no_polling = FALSE; |
| int do_scan; |
| int fd, proto_rev, count; |
| unsigned long event_mask = 0; |
| struct sigaction new_action; |
| struct initial_symlink_struct *curr; |
| |
| if (argc < 2) |
| bb_show_usage(); |
| |
| for (count = 2; count < argc; ++count) { |
| if (argv[count][0] == '-') { |
| if (argv[count][1] == 'v' && !argv[count][2]) /* -v */ |
| print_version = TRUE; |
| else if (ENABLE_DEVFSD_FG_NP && argv[count][1] == 'f' |
| && argv[count][2] == 'g' && !argv[count][3]) /* -fg */ |
| do_daemon = FALSE; |
| else if (ENABLE_DEVFSD_FG_NP && argv[count][1] == 'n' |
| && argv[count][2] == 'p' && !argv[count][3]) /* -np */ |
| no_polling = TRUE; |
| else |
| bb_show_usage(); |
| } |
| } |
| |
| mount_point = bb_simplify_path(argv[1]); |
| |
| xchdir(mount_point); |
| |
| fd = xopen(".devfsd", O_RDONLY); |
| close_on_exec_on(fd); |
| xioctl(fd, DEVFSDIOC_GET_PROTO_REV, &proto_rev); |
| |
| /*setup initial entries */ |
| for (curr = initial_symlinks; curr->dest != NULL; ++curr) |
| symlink(curr->dest, curr->name); |
| |
| /* NB: The check for CONFIG_FILE is done in read_config_file() */ |
| |
| if (print_version || (DEVFSD_PROTOCOL_REVISION_DAEMON != proto_rev)) { |
| printf("%s v%s\nDaemon %s:\t%d\nKernel-side %s:\t%d\n", |
| applet_name, DEVFSD_VERSION, bb_msg_proto_rev, |
| DEVFSD_PROTOCOL_REVISION_DAEMON, bb_msg_proto_rev, proto_rev); |
| if (DEVFSD_PROTOCOL_REVISION_DAEMON != proto_rev) |
| bb_error_msg_and_die("%s mismatch!", bb_msg_proto_rev); |
| exit(EXIT_SUCCESS); /* -v */ |
| } |
| /* Tell kernel we are special(i.e. we get to see hidden entries) */ |
| xioctl(fd, DEVFSDIOC_SET_EVENT_MASK, 0); |
| |
| /* Set up SIGHUP and SIGUSR1 handlers */ |
| sigemptyset(&new_action.sa_mask); |
| new_action.sa_flags = 0; |
| new_action.sa_handler = signal_handler; |
| sigaction_set(SIGHUP, &new_action); |
| sigaction_set(SIGUSR1, &new_action); |
| |
| printf("%s v%s started for %s\n", applet_name, DEVFSD_VERSION, mount_point); |
| |
| /* Set umask so that mknod(2), open(2) and mkdir(2) have complete control over permissions */ |
| umask(0); |
| read_config_file((char*)CONFIG_FILE, FALSE, &event_mask); |
| /* Do the scan before forking, so that boot scripts see the finished product */ |
| dir_operation(SERVICE, mount_point, 0, NULL); |
| |
| if (ENABLE_DEVFSD_FG_NP && no_polling) |
| exit(EXIT_SUCCESS); |
| |
| if (ENABLE_DEVFSD_VERBOSE || ENABLE_DEBUG) |
| logmode = LOGMODE_BOTH; |
| else if (do_daemon == TRUE) |
| logmode = LOGMODE_SYSLOG; |
| /* This is the default */ |
| /*else |
| logmode = LOGMODE_STDIO; */ |
| |
| if (do_daemon) { |
| /* Release so that the child can grab it */ |
| xioctl(fd, DEVFSDIOC_RELEASE_EVENT_QUEUE, 0); |
| bb_daemonize_or_rexec(0, argv); |
| } else if (ENABLE_DEVFSD_FG_NP) { |
| setpgid(0, 0); /* Become process group leader */ |
| } |
| |
| while (TRUE) { |
| do_scan = do_servicing(fd, event_mask); |
| |
| free_config(); |
| read_config_file((char*)CONFIG_FILE, FALSE, &event_mask); |
| if (do_scan) |
| dir_operation(SERVICE, mount_point, 0, NULL); |
| } |
| if (ENABLE_FEATURE_CLEAN_UP) free(mount_point); |
| } /* End Function main */ |
| |
| |
| /* Private functions follow */ |
| |
| static void read_config_file(char *path, int optional, unsigned long *event_mask) |
| /* [SUMMARY] Read a configuration database. |
| <path> The path to read the database from. If this is a directory, all |
| entries in that directory will be read(except hidden entries). |
| <optional> If TRUE, the routine will silently ignore a missing config file. |
| <event_mask> The event mask is written here. This is not initialised. |
| [RETURNS] Nothing. |
| */ |
| { |
| struct stat statbuf; |
| FILE *fp; |
| char buf[STRING_LENGTH]; |
| char *line = NULL; |
| char *p; |
| |
| if (stat(path, &statbuf) == 0) { |
| /* Don't read 0 length files: ignored */ |
| /*if (statbuf.st_size == 0) |
| return;*/ |
| if (S_ISDIR(statbuf.st_mode)) { |
| p = bb_simplify_path(path); |
| dir_operation(READ_CONFIG, p, 0, event_mask); |
| free(p); |
| return; |
| } |
| fp = fopen_for_read(path); |
| if (fp != NULL) { |
| while (fgets(buf, STRING_LENGTH, fp) != NULL) { |
| /* Skip whitespace */ |
| line = buf; |
| line = skip_whitespace(line); |
| if (line[0] == '\0' || line[0] == '#') |
| continue; |
| process_config_line(line, event_mask); |
| } |
| fclose(fp); |
| } else { |
| goto read_config_file_err; |
| } |
| } else { |
| read_config_file_err: |
| if (optional == 0 && errno == ENOENT) |
| error_logger_and_die(LOG_ERR, "read config file: %s", path); |
| } |
| } /* End Function read_config_file */ |
| |
| static void process_config_line(const char *line, unsigned long *event_mask) |
| /* [SUMMARY] Process a line from a configuration file. |
| <line> The configuration line. |
| <event_mask> The event mask is written here. This is not initialised. |
| [RETURNS] Nothing. |
| */ |
| { |
| int num_args, count; |
| struct config_entry_struct *new; |
| char p[MAX_ARGS][STRING_LENGTH]; |
| char when[STRING_LENGTH], what[STRING_LENGTH]; |
| char name[STRING_LENGTH]; |
| const char *msg = ""; |
| char *ptr; |
| int i; |
| |
| /* !!!! Only Uppercase Keywords in devsfd.conf */ |
| static const char options[] ALIGN1 = |
| "CLEAR_CONFIG\0""INCLUDE\0""OPTIONAL_INCLUDE\0" |
| "RESTORE\0""PERMISSIONS\0""MODLOAD\0""EXECUTE\0" |
| "COPY\0""IGNORE\0""MKOLDCOMPAT\0""MKNEWCOMPAT\0" |
| "RMOLDCOMPAT\0""RMNEWCOMPAT\0"; |
| |
| for (count = 0; count < MAX_ARGS; ++count) |
| p[count][0] = '\0'; |
| num_args = sscanf(line, "%s %s %s %s %s %s %s %s %s %s", |
| when, name, what, |
| p[0], p[1], p[2], p[3], p[4], p[5], p[6]); |
| |
| i = index_in_strings(options, when); |
| |
| /* "CLEAR_CONFIG" */ |
| if (i == 0) { |
| free_config(); |
| *event_mask = 0; |
| return; |
| } |
| |
| if (num_args < 2) |
| goto process_config_line_err; |
| |
| /* "INCLUDE" & "OPTIONAL_INCLUDE" */ |
| if (i == 1 || i == 2) { |
| st_expr_expand(name, STRING_LENGTH, name, get_variable, NULL); |
| info_logger(LOG_INFO, "%sinclude: %s", (toupper(when[0]) == 'I') ? "": "optional_", name); |
| read_config_file(name, (toupper(when[0]) == 'I') ? FALSE : TRUE, event_mask); |
| return; |
| } |
| /* "RESTORE" */ |
| if (i == 3) { |
| dir_operation(RESTORE, name, strlen(name),NULL); |
| return; |
| } |
| if (num_args < 3) |
| goto process_config_line_err; |
| |
| new = xzalloc(sizeof *new); |
| |
| for (count = 0; event_types[count].config_name != NULL; ++count) { |
| if (strcasecmp(when, event_types[count].config_name) != 0) |
| continue; |
| new->action.when = event_types[count].type; |
| break; |
| } |
| if (event_types[count].config_name == NULL) { |
| msg = "WHEN in"; |
| goto process_config_line_err; |
| } |
| |
| i = index_in_strings(options, what); |
| |
| switch (i) { |
| case 4: /* "PERMISSIONS" */ |
| new->action.what = AC_PERMISSIONS; |
| /* Get user and group */ |
| ptr = strchr(p[0], '.'); |
| if (ptr == NULL) { |
| msg = "UID.GID"; |
| goto process_config_line_err; /*"missing '.' in UID.GID"*/ |
| } |
| |
| *ptr++ = '\0'; |
| new->u.permissions.uid = get_uid_gid(UID, p[0]); |
| new->u.permissions.gid = get_uid_gid(GID, ptr); |
| /* Get mode */ |
| new->u.permissions.mode = get_mode(p[1]); |
| break; |
| case 5: /* MODLOAD */ |
| /*This action will pass "/dev/$devname"(i.e. "/dev/" prefixed to |
| the device name) to the module loading facility. In addition, |
| the /etc/modules.devfs configuration file is used.*/ |
| if (ENABLE_DEVFSD_MODLOAD) |
| new->action.what = AC_MODLOAD; |
| break; |
| case 6: /* EXECUTE */ |
| new->action.what = AC_EXECUTE; |
| num_args -= 3; |
| |
| for (count = 0; count < num_args; ++count) |
| new->u.execute.argv[count] = xstrdup(p[count]); |
| |
| new->u.execute.argv[num_args] = NULL; |
| break; |
| case 7: /* COPY */ |
| new->action.what = AC_COPY; |
| num_args -= 3; |
| if (num_args != 2) |
| goto process_config_line_err; /* missing path and function in line */ |
| |
| new->u.copy.source = xstrdup(p[0]); |
| new->u.copy.destination = xstrdup(p[1]); |
| break; |
| case 8: /* IGNORE */ |
| /* FALLTROUGH */ |
| case 9: /* MKOLDCOMPAT */ |
| /* FALLTROUGH */ |
| case 10: /* MKNEWCOMPAT */ |
| /* FALLTROUGH */ |
| case 11:/* RMOLDCOMPAT */ |
| /* FALLTROUGH */ |
| case 12: /* RMNEWCOMPAT */ |
| /* AC_IGNORE 6 |
| AC_MKOLDCOMPAT 7 |
| AC_MKNEWCOMPAT 8 |
| AC_RMOLDCOMPAT 9 |
| AC_RMNEWCOMPAT 10*/ |
| new->action.what = i - 2; |
| break; |
| default: |
| msg = "WHAT in"; |
| goto process_config_line_err; |
| /*esac*/ |
| } /* switch (i) */ |
| |
| xregcomp(&new->preg, name, REG_EXTENDED); |
| |
| *event_mask |= 1 << new->action.when; |
| new->next = NULL; |
| if (first_config == NULL) |
| first_config = new; |
| else |
| last_config->next = new; |
| last_config = new; |
| return; |
| |
| process_config_line_err: |
| msg_logger_and_die(LOG_ERR, bb_msg_bad_config, msg, line); |
| } /* End Function process_config_line */ |
| |
| static int do_servicing(int fd, unsigned long event_mask) |
| /* [SUMMARY] Service devfs changes until a signal is received. |
| <fd> The open control file. |
| <event_mask> The event mask. |
| [RETURNS] TRUE if SIGHUP was caught, else FALSE. |
| */ |
| { |
| ssize_t bytes; |
| struct devfsd_notify_struct info; |
| |
| /* (void*) cast is only in order to match prototype */ |
| xioctl(fd, DEVFSDIOC_SET_EVENT_MASK, (void*)event_mask); |
| while (!caught_signal) { |
| errno = 0; |
| bytes = read(fd, (char *) &info, sizeof info); |
| if (caught_signal) |
| break; /* Must test for this first */ |
| if (errno == EINTR) |
| continue; /* Yes, the order is important */ |
| if (bytes < 1) |
| break; |
| service_name(&info); |
| } |
| if (caught_signal) { |
| int c_sighup = caught_sighup; |
| |
| caught_signal = FALSE; |
| caught_sighup = FALSE; |
| return c_sighup; |
| } |
| simple_msg_logger_and_die(LOG_ERR, "read error on control file"); |
| } /* End Function do_servicing */ |
| |
| static void service_name(const struct devfsd_notify_struct *info) |
| /* [SUMMARY] Service a single devfs change. |
| <info> The devfs change. |
| [RETURNS] Nothing. |
| */ |
| { |
| unsigned int n; |
| regmatch_t mbuf[MAX_SUBEXPR]; |
| struct config_entry_struct *entry; |
| |
| if (ENABLE_DEBUG && info->overrun_count > 0) |
| msg_logger(LOG_ERR, "lost %u events", info->overrun_count); |
| |
| /* Discard lookups on "/dev/log" and "/dev/initctl" */ |
| if (info->type == DEVFSD_NOTIFY_LOOKUP |
| && ((info->devname[0] == 'l' && info->devname[1] == 'o' |
| && info->devname[2] == 'g' && !info->devname[3]) |
| || (info->devname[0] == 'i' && info->devname[1] == 'n' |
| && info->devname[2] == 'i' && info->devname[3] == 't' |
| && info->devname[4] == 'c' && info->devname[5] == 't' |
| && info->devname[6] == 'l' && !info->devname[7])) |
| ) |
| return; |
| |
| for (entry = first_config; entry != NULL; entry = entry->next) { |
| /* First check if action matches the type, then check if name matches */ |
| if (info->type != entry->action.when |
| || regexec(&entry->preg, info->devname, MAX_SUBEXPR, mbuf, 0) != 0) |
| continue; |
| for (n = 0;(n < MAX_SUBEXPR) && (mbuf[n].rm_so != -1); ++n) |
| /* VOID */; |
| |
| switch (entry->action.what) { |
| case AC_PERMISSIONS: |
| action_permissions(info, entry); |
| break; |
| case AC_MODLOAD: |
| if (ENABLE_DEVFSD_MODLOAD) |
| action_modload(info, entry); |
| break; |
| case AC_EXECUTE: |
| action_execute(info, entry, mbuf, n); |
| break; |
| case AC_COPY: |
| action_copy(info, entry, mbuf, n); |
| break; |
| case AC_IGNORE: |
| return; |
| /*break;*/ |
| case AC_MKOLDCOMPAT: |
| case AC_MKNEWCOMPAT: |
| case AC_RMOLDCOMPAT: |
| case AC_RMNEWCOMPAT: |
| action_compat(info, entry->action.what); |
| break; |
| default: |
| simple_msg_logger_and_die(LOG_ERR, "Unknown action"); |
| } |
| } |
| } /* End Function service_name */ |
| |
| static void action_permissions(const struct devfsd_notify_struct *info, |
| const struct config_entry_struct *entry) |
| /* [SUMMARY] Update permissions for a device entry. |
| <info> The devfs change. |
| <entry> The config file entry. |
| [RETURNS] Nothing. |
| */ |
| { |
| struct stat statbuf; |
| |
| if (stat(info->devname, &statbuf) != 0 |
| || chmod(info->devname, (statbuf.st_mode & S_IFMT) | (entry->u.permissions.mode & ~S_IFMT)) != 0 |
| || chown(info->devname, entry->u.permissions.uid, entry->u.permissions.gid) != 0 |
| ) |
| error_logger(LOG_ERR, "Can't chmod or chown: %s", info->devname); |
| } /* End Function action_permissions */ |
| |
| static void action_modload(const struct devfsd_notify_struct *info, |
| const struct config_entry_struct *entry UNUSED_PARAM) |
| /* [SUMMARY] Load a module. |
| <info> The devfs change. |
| <entry> The config file entry. |
| [RETURNS] Nothing. |
| */ |
| { |
| char *argv[6]; |
| |
| argv[0] = (char*)MODPROBE; |
| argv[1] = (char*)MODPROBE_SWITCH_1; /* "-k" */ |
| argv[2] = (char*)MODPROBE_SWITCH_2; /* "-C" */ |
| argv[3] = (char*)CONFIG_MODULES_DEVFS; |
| argv[4] = concat_path_file("/dev", info->devname); /* device */ |
| argv[5] = NULL; |
| |
| spawn_and_wait(argv); |
| free(argv[4]); |
| } /* End Function action_modload */ |
| |
| static void action_execute(const struct devfsd_notify_struct *info, |
| const struct config_entry_struct *entry, |
| const regmatch_t *regexpr, unsigned int numexpr) |
| /* [SUMMARY] Execute a programme. |
| <info> The devfs change. |
| <entry> The config file entry. |
| <regexpr> The number of subexpression(start, end) offsets within the |
| device name. |
| <numexpr> The number of elements within <<regexpr>>. |
| [RETURNS] Nothing. |
| */ |
| { |
| unsigned int count; |
| struct get_variable_info gv_info; |
| char *argv[MAX_ARGS + 1]; |
| char largv[MAX_ARGS + 1][STRING_LENGTH]; |
| |
| gv_info.info = info; |
| gv_info.devname = info->devname; |
| snprintf(gv_info.devpath, sizeof(gv_info.devpath), "%s/%s", mount_point, info->devname); |
| for (count = 0; entry->u.execute.argv[count] != NULL; ++count) { |
| expand_expression(largv[count], STRING_LENGTH, |
| entry->u.execute.argv[count], |
| get_variable, &gv_info, |
| gv_info.devname, regexpr, numexpr); |
| argv[count] = largv[count]; |
| } |
| argv[count] = NULL; |
| spawn_and_wait(argv); |
| } /* End Function action_execute */ |
| |
| |
| static void action_copy(const struct devfsd_notify_struct *info, |
| const struct config_entry_struct *entry, |
| const regmatch_t *regexpr, unsigned int numexpr) |
| /* [SUMMARY] Copy permissions. |
| <info> The devfs change. |
| <entry> The config file entry. |
| <regexpr> This list of subexpression(start, end) offsets within the |
| device name. |
| <numexpr> The number of elements in <<regexpr>>. |
| [RETURNS] Nothing. |
| */ |
| { |
| mode_t new_mode; |
| struct get_variable_info gv_info; |
| struct stat source_stat, dest_stat; |
| char source[STRING_LENGTH], destination[STRING_LENGTH]; |
| int ret = 0; |
| |
| dest_stat.st_mode = 0; |
| |
| if ((info->type == DEVFSD_NOTIFY_CHANGE) && S_ISLNK(info->mode)) |
| return; |
| gv_info.info = info; |
| gv_info.devname = info->devname; |
| |
| snprintf(gv_info.devpath, sizeof(gv_info.devpath), "%s/%s", mount_point, info->devname); |
| expand_expression(source, STRING_LENGTH, entry->u.copy.source, |
| get_variable, &gv_info, gv_info.devname, |
| regexpr, numexpr); |
| |
| expand_expression(destination, STRING_LENGTH, entry->u.copy.destination, |
| get_variable, &gv_info, gv_info.devname, |
| regexpr, numexpr); |
| |
| if (!make_dir_tree(destination) || lstat(source, &source_stat) != 0) |
| return; |
| lstat(destination, &dest_stat); |
| new_mode = source_stat.st_mode & ~S_ISVTX; |
| if (info->type == DEVFSD_NOTIFY_CREATE) |
| new_mode |= S_ISVTX; |
| else if ((info->type == DEVFSD_NOTIFY_CHANGE) &&(dest_stat.st_mode & S_ISVTX)) |
| new_mode |= S_ISVTX; |
| ret = copy_inode(destination, &dest_stat, new_mode, source, &source_stat); |
| if (ENABLE_DEBUG && ret && (errno != EEXIST)) |
| error_logger(LOG_ERR, "copy_inode: %s to %s", source, destination); |
| } /* End Function action_copy */ |
| |
| static void action_compat(const struct devfsd_notify_struct *info, unsigned int action) |
| /* [SUMMARY] Process a compatibility request. |
| <info> The devfs change. |
| <action> The action to take. |
| [RETURNS] Nothing. |
| */ |
| { |
| int ret; |
| const char *compat_name = NULL; |
| const char *dest_name = info->devname; |
| const char *ptr; |
| char compat_buf[STRING_LENGTH], dest_buf[STRING_LENGTH]; |
| int mode, host, bus, target, lun; |
| unsigned int i; |
| char rewind_; |
| /* 1 to 5 "scsi/" , 6 to 9 "ide/host" */ |
| static const char *const fmt[] = { |
| NULL , |
| "sg/c%db%dt%du%d", /* scsi/generic */ |
| "sd/c%db%dt%du%d", /* scsi/disc */ |
| "sr/c%db%dt%du%d", /* scsi/cd */ |
| "sd/c%db%dt%du%dp%d", /* scsi/part */ |
| "st/c%db%dt%du%dm%d%c", /* scsi/mt */ |
| "ide/hd/c%db%dt%du%d", /* ide/host/disc */ |
| "ide/cd/c%db%dt%du%d", /* ide/host/cd */ |
| "ide/hd/c%db%dt%du%dp%d", /* ide/host/part */ |
| "ide/mt/c%db%dt%du%d%s", /* ide/host/mt */ |
| NULL |
| }; |
| |
| /* First construct compatibility name */ |
| switch (action) { |
| case AC_MKOLDCOMPAT: |
| case AC_RMOLDCOMPAT: |
| compat_name = get_old_name(info->devname, info->namelen, compat_buf, info->major, info->minor); |
| break; |
| case AC_MKNEWCOMPAT: |
| case AC_RMNEWCOMPAT: |
| ptr = bb_basename(info->devname); |
| i = scan_dev_name(info->devname, info->namelen, ptr); |
| |
| /* nothing found */ |
| if (i == 0 || i > 9) |
| return; |
| |
| sscanf(info->devname + ((i < 6) ? 5 : 4), "host%d/bus%d/target%d/lun%d/", &host, &bus, &target, &lun); |
| snprintf(dest_buf, sizeof(dest_buf), "../%s", info->devname + (( i > 5) ? 4 : 0)); |
| dest_name = dest_buf; |
| compat_name = compat_buf; |
| |
| |
| /* 1 == scsi/generic 2 == scsi/disc 3 == scsi/cd 6 == ide/host/disc 7 == ide/host/cd */ |
| if (i == 1 || i == 2 || i == 3 || i == 6 || i ==7) |
| sprintf(compat_buf, fmt[i], host, bus, target, lun); |
| |
| /* 4 == scsi/part 8 == ide/host/part */ |
| if (i == 4 || i == 8) |
| sprintf(compat_buf, fmt[i], host, bus, target, lun, atoi(ptr + 4)); |
| |
| /* 5 == scsi/mt */ |
| if (i == 5) { |
| rewind_ = info->devname[info->namelen - 1]; |
| if (rewind_ != 'n') |
| rewind_ = '\0'; |
| mode=0; |
| if (ptr[2] == 'l' /*108*/ || ptr[2] == 'm'/*109*/) |
| mode = ptr[2] - 107; /* 1 or 2 */ |
| if (ptr[2] == 'a') |
| mode = 3; |
| sprintf(compat_buf, fmt[i], host, bus, target, lun, mode, rewind_); |
| } |
| |
| /* 9 == ide/host/mt */ |
| if (i == 9) |
| snprintf(compat_buf, sizeof(compat_buf), fmt[i], host, bus, target, lun, ptr + 2); |
| /* esac */ |
| } /* switch (action) */ |
| |
| if (compat_name == NULL) |
| return; |
| |
| /* Now decide what to do with it */ |
| switch (action) { |
| case AC_MKOLDCOMPAT: |
| case AC_MKNEWCOMPAT: |
| mksymlink(dest_name, compat_name); |
| break; |
| case AC_RMOLDCOMPAT: |
| case AC_RMNEWCOMPAT: |
| ret = unlink(compat_name); |
| if (ENABLE_DEBUG && ret) |
| error_logger(LOG_ERR, "unlink: %s", compat_name); |
| break; |
| /*esac*/ |
| } /* switch (action) */ |
| } /* End Function action_compat */ |
| |
| static void restore(char *spath, struct stat source_stat, int rootlen) |
| { |
| char *dpath; |
| struct stat dest_stat; |
| |
| dest_stat.st_mode = 0; |
| dpath = concat_path_file(mount_point, spath + rootlen); |
| lstat(dpath, &dest_stat); |
| free(dpath); |
| if (S_ISLNK(source_stat.st_mode) || (source_stat.st_mode & S_ISVTX)) |
| copy_inode(dpath, &dest_stat, (source_stat.st_mode & ~S_ISVTX), spath, &source_stat); |
| |
| if (S_ISDIR(source_stat.st_mode)) |
| dir_operation(RESTORE, spath, rootlen, NULL); |
| } |
| |
| |
| static int copy_inode(const char *destpath, const struct stat *dest_stat, |
| mode_t new_mode, |
| const char *sourcepath, const struct stat *source_stat) |
| /* [SUMMARY] Copy an inode. |
| <destpath> The destination path. An existing inode may be deleted. |
| <dest_stat> The destination stat(2) information. |
| <new_mode> The desired new mode for the destination. |
| <sourcepath> The source path. |
| <source_stat> The source stat(2) information. |
| [RETURNS] TRUE on success, else FALSE. |
| */ |
| { |
| int source_len, dest_len; |
| char source_link[STRING_LENGTH], dest_link[STRING_LENGTH]; |
| int fd, val; |
| struct sockaddr_un un_addr; |
| char symlink_val[STRING_LENGTH]; |
| |
| if ((source_stat->st_mode & S_IFMT) ==(dest_stat->st_mode & S_IFMT)) { |
| /* Same type */ |
| if (S_ISLNK(source_stat->st_mode)) { |
| source_len = readlink(sourcepath, source_link, STRING_LENGTH - 1); |
| if ((source_len < 0) |
| || (dest_len = readlink(destpath, dest_link, STRING_LENGTH - 1)) < 0 |
| ) |
| return FALSE; |
| source_link[source_len] = '\0'; |
| dest_link[dest_len] = '\0'; |
| if ((source_len != dest_len) || (strcmp(source_link, dest_link) != 0)) { |
| unlink(destpath); |
| symlink(source_link, destpath); |
| } |
| return TRUE; |
| } /* Else not a symlink */ |
| chmod(destpath, new_mode & ~S_IFMT); |
| chown(destpath, source_stat->st_uid, source_stat->st_gid); |
| return TRUE; |
| } |
| /* Different types: unlink and create */ |
| unlink(destpath); |
| switch (source_stat->st_mode & S_IFMT) { |
| case S_IFSOCK: |
| fd = socket(AF_UNIX, SOCK_STREAM, 0); |
| if (fd < 0) |
| break; |
| un_addr.sun_family = AF_UNIX; |
| snprintf(un_addr.sun_path, sizeof(un_addr.sun_path), "%s", destpath); |
| val = bind(fd, (struct sockaddr *) &un_addr, (int) sizeof un_addr); |
| close(fd); |
| if (val != 0 || chmod(destpath, new_mode & ~S_IFMT) != 0) |
| break; |
| goto do_chown; |
| case S_IFLNK: |
| val = readlink(sourcepath, symlink_val, STRING_LENGTH - 1); |
| if (val < 0) |
| break; |
| symlink_val[val] = '\0'; |
| if (symlink(symlink_val, destpath) == 0) |
| return TRUE; |
| break; |
| case S_IFREG: |
| fd = open(destpath, O_RDONLY | O_CREAT, new_mode & ~S_IFMT); |
| if (fd < 0) |
| break; |
| close(fd); |
| if (chmod(destpath, new_mode & ~S_IFMT) != 0) |
| break; |
| goto do_chown; |
| case S_IFBLK: |
| case S_IFCHR: |
| case S_IFIFO: |
| if (mknod(destpath, new_mode, source_stat->st_rdev) != 0) |
| break; |
| goto do_chown; |
| case S_IFDIR: |
| if (mkdir(destpath, new_mode & ~S_IFMT) != 0) |
| break; |
| do_chown: |
| if (chown(destpath, source_stat->st_uid, source_stat->st_gid) == 0) |
| return TRUE; |
| /*break;*/ |
| } |
| return FALSE; |
| } /* End Function copy_inode */ |
| |
| static void free_config(void) |
| /* [SUMMARY] Free the configuration information. |
| [RETURNS] Nothing. |
| */ |
| { |
| struct config_entry_struct *c_entry; |
| void *next; |
| |
| for (c_entry = first_config; c_entry != NULL; c_entry = next) { |
| unsigned int count; |
| |
| next = c_entry->next; |
| regfree(&c_entry->preg); |
| if (c_entry->action.what == AC_EXECUTE) { |
| for (count = 0; count < MAX_ARGS; ++count) { |
| if (c_entry->u.execute.argv[count] == NULL) |
| break; |
| free(c_entry->u.execute.argv[count]); |
| } |
| } |
| free(c_entry); |
| } |
| first_config = NULL; |
| last_config = NULL; |
| } /* End Function free_config */ |
| |
| static int get_uid_gid(int flag, const char *string) |
| /* [SUMMARY] Convert a string to a UID or GID value. |
| <flag> "UID" or "GID". |
| <string> The string. |
| [RETURNS] The UID or GID value. |
| */ |
| { |
| struct passwd *pw_ent; |
| struct group *grp_ent; |
| const char *msg; |
| |
| if (isdigit(string[0]) || ((string[0] == '-') && isdigit(string[1]))) |
| return atoi(string); |
| |
| if (flag == UID && (pw_ent = getpwnam(string)) != NULL) |
| return pw_ent->pw_uid; |
| |
| if (ENABLE_DEVFSD_VERBOSE) |
| msg = "user"; |
| |
| if (flag == GID) { |
| if ((grp_ent = getgrnam(string)) != NULL) |
| return grp_ent->gr_gid; |
| if (ENABLE_DEVFSD_VERBOSE) |
| msg = "group"; |
| } |
| |
| if (ENABLE_DEVFSD_VERBOSE) |
| msg_logger(LOG_ERR, "unknown %s: %s, defaulting to %cid=0", msg, string, msg[0]); |
| return 0; |
| }/* End Function get_uid_gid */ |
| |
| static mode_t get_mode(const char *string) |
| /* [SUMMARY] Convert a string to a mode value. |
| <string> The string. |
| [RETURNS] The mode value. |
| */ |
| { |
| mode_t mode; |
| int i; |
| |
| if (isdigit(string[0])) |
| return strtoul(string, NULL, 8); |
| if (strlen(string) != 9) |
| msg_logger_and_die(LOG_ERR, "bad mode: %s", string); |
| |
| mode = 0; |
| i = S_IRUSR; |
| while (i > 0) { |
| if (string[0] == 'r' || string[0] == 'w' || string[0] == 'x') |
| mode += i; |
| i = i / 2; |
| string++; |
| } |
| return mode; |
| } /* End Function get_mode */ |
| |
| static void signal_handler(int sig) |
| { |
| caught_signal = TRUE; |
| if (sig == SIGHUP) |
| caught_sighup = TRUE; |
| |
| info_logger(LOG_INFO, "Caught signal %d", sig); |
| } /* End Function signal_handler */ |
| |
| static const char *get_variable(const char *variable, void *info) |
| { |
| static char *hostname; |
| |
| struct get_variable_info *gv_info = info; |
| const char *field_names[] = { |
| "hostname", "mntpt", "devpath", "devname", "uid", "gid", "mode", |
| NULL, mount_point, gv_info->devpath, gv_info->devname, NULL |
| }; |
| int i; |
| |
| if (!hostname) |
| hostname = safe_gethostname(); |
| field_names[7] = hostname; |
| |
| /* index_in_str_array returns i>=0 */ |
| i = index_in_str_array(field_names, variable); |
| |
| if (i > 6 || i < 0 || (i > 1 && gv_info == NULL)) |
| return NULL; |
| if (i >= 0 && i <= 3) |
| return field_names[i + 7]; |
| |
| if (i == 4) |
| return auto_string(xasprintf("%u", gv_info->info->uid)); |
| if (i == 5) |
| return auto_string(xasprintf("%u", gv_info->info->gid)); |
| /* i == 6 */ |
| return auto_string(xasprintf("%o", gv_info->info->mode)); |
| } /* End Function get_variable */ |
| |
| static void service(struct stat statbuf, char *path) |
| { |
| struct devfsd_notify_struct info; |
| |
| memset(&info, 0, sizeof info); |
| info.type = DEVFSD_NOTIFY_REGISTERED; |
| info.mode = statbuf.st_mode; |
| info.major = major(statbuf.st_rdev); |
| info.minor = minor(statbuf.st_rdev); |
| info.uid = statbuf.st_uid; |
| info.gid = statbuf.st_gid; |
| snprintf(info.devname, sizeof(info.devname), "%s", path + strlen(mount_point) + 1); |
| info.namelen = strlen(info.devname); |
| service_name(&info); |
| if (S_ISDIR(statbuf.st_mode)) |
| dir_operation(SERVICE, path, 0, NULL); |
| } |
| |
| static void dir_operation(int type, const char * dir_name, int var, unsigned long *event_mask) |
| /* [SUMMARY] Scan a directory tree and generate register events on leaf nodes. |
| <flag> To choose which function to perform |
| <dp> The directory pointer. This is closed upon completion. |
| <dir_name> The name of the directory. |
| <rootlen> string length parameter. |
| [RETURNS] Nothing. |
| */ |
| { |
| struct stat statbuf; |
| DIR *dp; |
| struct dirent *de; |
| char *path; |
| |
| dp = warn_opendir(dir_name); |
| if (dp == NULL) |
| return; |
| |
| while ((de = readdir(dp)) != NULL) { |
| |
| if (de->d_name && DOT_OR_DOTDOT(de->d_name)) |
| continue; |
| path = concat_path_file(dir_name, de->d_name); |
| if (lstat(path, &statbuf) == 0) { |
| switch (type) { |
| case SERVICE: |
| service(statbuf, path); |
| break; |
| case RESTORE: |
| restore(path, statbuf, var); |
| break; |
| case READ_CONFIG: |
| read_config_file(path, var, event_mask); |
| break; |
| } |
| } |
| free(path); |
| } |
| closedir(dp); |
| } /* End Function do_scan_and_service */ |
| |
| static int mksymlink(const char *oldpath, const char *newpath) |
| /* [SUMMARY] Create a symlink, creating intervening directories as required. |
| <oldpath> The string contained in the symlink. |
| <newpath> The name of the new symlink. |
| [RETURNS] 0 on success, else -1. |
| */ |
| { |
| if (!make_dir_tree(newpath)) |
| return -1; |
| |
| if (symlink(oldpath, newpath) != 0) { |
| if (errno != EEXIST) |
| return -1; |
| } |
| return 0; |
| } /* End Function mksymlink */ |
| |
| |
| static int make_dir_tree(const char *path) |
| /* [SUMMARY] Creating intervening directories for a path as required. |
| <path> The full pathname(including the leaf node). |
| [RETURNS] TRUE on success, else FALSE. |
| */ |
| { |
| if (bb_make_directory(dirname((char *)path), -1, FILEUTILS_RECUR) == -1) |
| return FALSE; |
| return TRUE; |
| } /* End Function make_dir_tree */ |
| |
| static int expand_expression(char *output, unsigned int outsize, |
| const char *input, |
| const char *(*get_variable_func)(const char *variable, void *info), |
| void *info, |
| const char *devname, |
| const regmatch_t *ex, unsigned int numexp) |
| /* [SUMMARY] Expand environment variables and regular subexpressions in string. |
| <output> The output expanded expression is written here. |
| <length> The size of the output buffer. |
| <input> The input expression. This may equal <<output>>. |
| <get_variable> A function which will be used to get variable values. If |
| this returns NULL, the environment is searched instead. If this is NULL, |
| only the environment is searched. |
| <info> An arbitrary pointer passed to <<get_variable>>. |
| <devname> Device name; specifically, this is the string that contains all |
| of the regular subexpressions. |
| <ex> Array of start / end offsets into info->devname for each subexpression |
| <numexp> Number of regular subexpressions found in <<devname>>. |
| [RETURNS] TRUE on success, else FALSE. |
| */ |
| { |
| char temp[STRING_LENGTH]; |
| |
| if (!st_expr_expand(temp, STRING_LENGTH, input, get_variable_func, info)) |
| return FALSE; |
| expand_regexp(output, outsize, temp, devname, ex, numexp); |
| return TRUE; |
| } /* End Function expand_expression */ |
| |
| static void expand_regexp(char *output, size_t outsize, const char *input, |
| const char *devname, |
| const regmatch_t *ex, unsigned int numex) |
| /* [SUMMARY] Expand all occurrences of the regular subexpressions \0 to \9. |
| <output> The output expanded expression is written here. |
| <outsize> The size of the output buffer. |
| <input> The input expression. This may NOT equal <<output>>, because |
| supporting that would require yet another string-copy. However, it's not |
| hard to write a simple wrapper function to add this functionality for those |
| few cases that need it. |
| <devname> Device name; specifically, this is the string that contains all |
| of the regular subexpressions. |
| <ex> An array of start and end offsets into <<devname>>, one for each |
| subexpression |
| <numex> Number of subexpressions in the offset-array <<ex>>. |
| [RETURNS] Nothing. |
| */ |
| { |
| const char last_exp = '0' - 1 + numex; |
| int c = -1; |
| |
| /* Guarantee NULL termination by writing an explicit '\0' character into |
| the very last byte */ |
| if (outsize) |
| output[--outsize] = '\0'; |
| /* Copy the input string into the output buffer, replacing '\\' with '\' |
| and '\0' .. '\9' with subexpressions 0 .. 9, if they exist. Other \x |
| codes are deleted */ |
| while ((c != '\0') && (outsize != 0)) { |
| c = *input; |
| ++input; |
| if (c == '\\') { |
| c = *input; |
| ++input; |
| if (c != '\\') { |
| if ((c >= '0') && (c <= last_exp)) { |
| const regmatch_t *subexp = ex + (c - '0'); |
| unsigned int sublen = subexp->rm_eo - subexp->rm_so; |
| |
| /* Range checking */ |
| if (sublen > outsize) |
| sublen = outsize; |
| strncpy(output, devname + subexp->rm_so, sublen); |
| output += sublen; |
| outsize -= sublen; |
| } |
| continue; |
| } |
| } |
| *output = c; |
| ++output; |
| --outsize; |
| } /* while */ |
| } /* End Function expand_regexp */ |
| |
| |
| /* from compat_name.c */ |
| |
| struct translate_struct { |
| const char *match; /* The string to match to(up to length) */ |
| const char *format; /* Format of output, "%s" takes data past match string, |
| NULL is effectively "%s"(just more efficient) */ |
| }; |
| |
| static struct translate_struct translate_table[] = |
| { |
| {"sound/", NULL}, |
| {"printers/", "lp%s"}, |
| {"v4l/", NULL}, |
| {"parports/", "parport%s"}, |
| {"fb/", "fb%s"}, |
| {"netlink/", NULL}, |
| {"loop/", "loop%s"}, |
| {"floppy/", "fd%s"}, |
| {"rd/", "ram%s"}, |
| {"md/", "md%s"}, /* Meta-devices */ |
| {"vc/", "tty%s"}, |
| {"misc/", NULL}, |
| {"isdn/", NULL}, |
| {"pg/", "pg%s"}, /* Parallel port generic ATAPI interface*/ |
| {"i2c/", "i2c-%s"}, |
| {"staliomem/", "staliomem%s"}, /* Stallion serial driver control */ |
| {"tts/E", "ttyE%s"}, /* Stallion serial driver */ |
| {"cua/E", "cue%s"}, /* Stallion serial driver callout */ |
| {"tts/R", "ttyR%s"}, /* Rocketport serial driver */ |
| {"cua/R", "cur%s"}, /* Rocketport serial driver callout */ |
| {"ip2/", "ip2%s"}, /* Computone serial driver control */ |
| {"tts/F", "ttyF%s"}, /* Computone serial driver */ |
| {"cua/F", "cuf%s"}, /* Computone serial driver callout */ |
| {"tts/C", "ttyC%s"}, /* Cyclades serial driver */ |
| {"cua/C", "cub%s"}, /* Cyclades serial driver callout */ |
| {"tts/", "ttyS%s"}, /* Generic serial: must be after others */ |
| {"cua/", "cua%s"}, /* Generic serial: must be after others */ |
| {"input/js", "js%s"}, /* Joystick driver */ |
| {NULL, NULL} |
| }; |
| |
| const char *get_old_name(const char *devname, unsigned int namelen, |
| char *buffer, unsigned int major, unsigned int minor) |
| /* [SUMMARY] Translate a kernel-supplied name into an old name. |
| <devname> The device name provided by the kernel. |
| <namelen> The length of the name. |
| <buffer> A buffer that may be used. This should be at least 128 bytes long. |
| <major> The major number for the device. |
| <minor> The minor number for the device. |
| [RETURNS] A pointer to the old name if known, else NULL. |
| */ |
| { |
| const char *compat_name = NULL; |
| const char *ptr; |
| struct translate_struct *trans; |
| unsigned int i; |
| char mode; |
| int indexx; |
| const char *pty1; |
| const char *pty2; |
| /* 1 to 5 "scsi/" , 6 to 9 "ide/host", 10 sbp/, 11 vcc/, 12 pty/ */ |
| static const char *const fmt[] = { |
| NULL , |
| "sg%u", /* scsi/generic */ |
| NULL, /* scsi/disc */ |
| "sr%u", /* scsi/cd */ |
| NULL, /* scsi/part */ |
| "nst%u%c", /* scsi/mt */ |
| "hd%c" , /* ide/host/disc */ |
| "hd%c" , /* ide/host/cd */ |
| "hd%c%s", /* ide/host/part */ |
| "%sht%d", /* ide/host/mt */ |
| "sbpcd%u", /* sbp/ */ |
| "vcs%s", /* vcc/ */ |
| "%cty%c%c", /* pty/ */ |
| NULL |
| }; |
| |
| for (trans = translate_table; trans->match != NULL; ++trans) { |
| char *after_match = is_prefixed_with(devname, trans->match); |
| if (after_match) { |
| if (trans->format == NULL) |
| return after_match; |
| sprintf(buffer, trans->format, after_match); |
| return buffer; |
| } |
| } |
| |
| ptr = bb_basename(devname); |
| i = scan_dev_name(devname, namelen, ptr); |
| |
| if (i > 0 && i < 13) |
| compat_name = buffer; |
| else |
| return NULL; |
| |
| /* 1 == scsi/generic, 3 == scsi/cd, 10 == sbp/ */ |
| if (i == 1 || i == 3 || i == 10) |
| sprintf(buffer, fmt[i], minor); |
| |
| /* 2 ==scsi/disc, 4 == scsi/part */ |
| if (i == 2 || i == 4) |
| compat_name = write_old_sd_name(buffer, major, minor, ((i == 2) ? "" : (ptr + 4))); |
| |
| /* 5 == scsi/mt */ |
| if (i == 5) { |
| mode = ptr[2]; |
| if (mode == 'n') |
| mode = '\0'; |
| sprintf(buffer, fmt[i], minor & 0x1f, mode); |
| if (devname[namelen - 1] != 'n') |
| ++compat_name; |
| } |
| /* 6 == ide/host/disc, 7 == ide/host/cd, 8 == ide/host/part */ |
| if (i == 6 || i == 7 || i == 8) |
| /* last arg should be ignored for i == 6 or i== 7 */ |
| sprintf(buffer, fmt[i] , get_old_ide_name(major, minor), ptr + 4); |
| |
| /* 9 == ide/host/mt */ |
| if (i == 9) |
| sprintf(buffer, fmt[i], ptr + 2, minor & 0x7f); |
| |
| /* 11 == vcc/ */ |
| if (i == 11) { |
| sprintf(buffer, fmt[i], devname + 4); |
| if (buffer[3] == '0') |
| buffer[3] = '\0'; |
| } |
| /* 12 == pty/ */ |
| if (i == 12) { |
| pty1 = "pqrstuvwxyzabcde"; |
| pty2 = "0123456789abcdef"; |
| indexx = atoi(devname + 5); |
| sprintf(buffer, fmt[i], (devname[4] == 'm') ? 'p' : 't', pty1[indexx >> 4], pty2[indexx & 0x0f]); |
| } |
| return compat_name; |
| } /* End Function get_old_name */ |
| |
| static char get_old_ide_name(unsigned int major, unsigned int minor) |
| /* [SUMMARY] Get the old IDE name for a device. |
| <major> The major number for the device. |
| <minor> The minor number for the device. |
| [RETURNS] The drive letter. |
| */ |
| { |
| char letter = 'y'; /* 121 */ |
| char c = 'a'; /* 97 */ |
| int i = IDE0_MAJOR; |
| |
| /* I hope it works like the previous code as it saves a few bytes. Tito ;P */ |
| do { |
| if (i == IDE0_MAJOR || i == IDE1_MAJOR || i == IDE2_MAJOR |
| || i == IDE3_MAJOR || i == IDE4_MAJOR || i == IDE5_MAJOR |
| || i == IDE6_MAJOR || i == IDE7_MAJOR || i == IDE8_MAJOR |
| || i == IDE9_MAJOR |
| ) { |
| if ((unsigned int)i == major) { |
| letter = c; |
| break; |
| } |
| c += 2; |
| } |
| i++; |
| } while (i <= IDE9_MAJOR); |
| |
| if (minor > 63) |
| ++letter; |
| return letter; |
| } /* End Function get_old_ide_name */ |
| |
| static char *write_old_sd_name(char *buffer, |
| unsigned int major, unsigned int minor, |
| const char *part) |
| /* [SUMMARY] Write the old SCSI disc name to a buffer. |
| <buffer> The buffer to write to. |
| <major> The major number for the device. |
| <minor> The minor number for the device. |
| <part> The partition string. Must be "" for a whole-disc entry. |
| [RETURNS] A pointer to the buffer on success, else NULL. |
| */ |
| { |
| unsigned int disc_index; |
| |
| if (major == 8) { |
| sprintf(buffer, "sd%c%s", 'a' + (minor >> 4), part); |
| return buffer; |
| } |
| if ((major > 64) && (major < 72)) { |
| disc_index = ((major - 64) << 4) +(minor >> 4); |
| if (disc_index < 26) |
| sprintf(buffer, "sd%c%s", 'a' + disc_index, part); |
| else |
| sprintf(buffer, "sd%c%c%s", 'a' +(disc_index / 26) - 1, 'a' + disc_index % 26, part); |
| return buffer; |
| } |
| return NULL; |
| } /* End Function write_old_sd_name */ |
| |
| |
| /* expression.c */ |
| |
| /*EXPERIMENTAL_FUNCTION*/ |
| |
| int st_expr_expand(char *output, unsigned int length, const char *input, |
| const char *(*get_variable_func)(const char *variable, |
| void *info), |
| void *info) |
| /* [SUMMARY] Expand an expression using Borne Shell-like unquoted rules. |
| <output> The output expanded expression is written here. |
| <length> The size of the output buffer. |
| <input> The input expression. This may equal <<output>>. |
| <get_variable> A function which will be used to get variable values. If |
| this returns NULL, the environment is searched instead. If this is NULL, |
| only the environment is searched. |
| <info> An arbitrary pointer passed to <<get_variable>>. |
| [RETURNS] TRUE on success, else FALSE. |
| */ |
| { |
| char ch; |
| unsigned int len; |
| unsigned int out_pos = 0; |
| const char *env; |
| const char *ptr; |
| struct passwd *pwent; |
| char buffer[BUFFER_SIZE], tmp[STRING_LENGTH]; |
| |
| if (length > BUFFER_SIZE) |
| length = BUFFER_SIZE; |
| for (; TRUE; ++input) { |
| switch (ch = *input) { |
| case '$': |
| /* Variable expansion */ |
| input = expand_variable(buffer, length, &out_pos, ++input, get_variable_func, info); |
| if (input == NULL) |
| return FALSE; |
| break; |
| case '~': |
| /* Home directory expansion */ |
| ch = input[1]; |
| if (isspace(ch) ||(ch == '/') ||(ch == '\0')) { |
| /* User's own home directory: leave separator for next time */ |
| env = getenv("HOME"); |
| if (env == NULL) { |
| info_logger(LOG_INFO, bb_msg_variable_not_found, "HOME"); |
| return FALSE; |
| } |
| len = strlen(env); |
| if (len + out_pos >= length) |
| goto st_expr_expand_out; |
| memcpy(buffer + out_pos, env, len + 1); |
| out_pos += len; |
| continue; |
| } |
| /* Someone else's home directory */ |
| for (ptr = ++input; !isspace(ch) && (ch != '/') && (ch != '\0'); ch = *++ptr) |
| /* VOID */; |
| len = ptr - input; |
| if (len >= sizeof tmp) |
| goto st_expr_expand_out; |
| safe_memcpy(tmp, input, len); |
| input = ptr - 1; |
| pwent = getpwnam(tmp); |
| if (pwent == NULL) { |
| info_logger(LOG_INFO, "no pwent for: %s", tmp); |
| return FALSE; |
| } |
| len = strlen(pwent->pw_dir); |
| if (len + out_pos >= length) |
| goto st_expr_expand_out; |
| memcpy(buffer + out_pos, pwent->pw_dir, len + 1); |
| out_pos += len; |
| break; |
| case '\0': |
| /* Falltrough */ |
| default: |
| if (out_pos >= length) |
| goto st_expr_expand_out; |
| buffer[out_pos++] = ch; |
| if (ch == '\0') { |
| memcpy(output, buffer, out_pos); |
| return TRUE; |
| } |
| break; |
| /* esac */ |
| } |
| } |
| return FALSE; |
| st_expr_expand_out: |
| simple_info_logger(LOG_INFO, bb_msg_small_buffer); |
| return FALSE; |
| } /* End Function st_expr_expand */ |
| |
| |
| /* Private functions follow */ |
| |
| static const char *expand_variable(char *buffer, unsigned int length, |
| unsigned int *out_pos, const char *input, |
| const char *(*func)(const char *variable, |
| void *info), |
| void *info) |
| /* [SUMMARY] Expand a variable. |
| <buffer> The buffer to write to. |
| <length> The length of the output buffer. |
| <out_pos> The current output position. This is updated. |
| <input> A pointer to the input character pointer. |
| <func> A function which will be used to get variable values. If this |
| returns NULL, the environment is searched instead. If this is NULL, only |
| the environment is searched. |
| <info> An arbitrary pointer passed to <<func>>. |
| <errfp> Diagnostic messages are written here. |
| [RETURNS] A pointer to the end of this subexpression on success, else NULL. |
| */ |
| { |
| char ch; |
| int len; |
| unsigned int open_braces; |
| const char *env, *ptr; |
| char tmp[STRING_LENGTH]; |
| |
| ch = input[0]; |
| if (ch == '$') { |
| /* Special case for "$$": PID */ |
| sprintf(tmp, "%d", (int) getpid()); |
| len = strlen(tmp); |
| if (len + *out_pos >= length) |
| goto expand_variable_out; |
| |
| memcpy(buffer + *out_pos, tmp, len + 1); |
| out_pos += len; |
| return input; |
| } |
| /* Ordinary variable expansion, possibly in braces */ |
| if (ch != '{') { |
| /* Simple variable expansion */ |
| for (ptr = input; isalnum(ch) || (ch == '_') || (ch == ':'); ch = *++ptr) |
| /* VOID */; |
| len = ptr - input; |
| if ((size_t)len >= sizeof tmp) |
| goto expand_variable_out; |
| |
| safe_memcpy(tmp, input, len); |
| input = ptr - 1; |
| env = get_variable_v2(tmp, func, info); |
| if (env == NULL) { |
| info_logger(LOG_INFO, bb_msg_variable_not_found, tmp); |
| return NULL; |
| } |
| len = strlen(env); |
| if (len + *out_pos >= length) |
| goto expand_variable_out; |
| |
| memcpy(buffer + *out_pos, env, len + 1); |
| *out_pos += len; |
| return input; |
| } |
| /* Variable in braces: check for ':' tricks */ |
| ch = *++input; |
| for (ptr = input; isalnum(ch) || (ch == '_'); ch = *++ptr) |
| /* VOID */; |
| if (ch == '}') { |
| /* Must be simple variable expansion with "${var}" */ |
| len = ptr - input; |
| if ((size_t)len >= sizeof tmp) |
| goto expand_variable_out; |
| |
| safe_memcpy(tmp, input, len); |
| ptr = expand_variable(buffer, length, out_pos, tmp, func, info); |
| if (ptr == NULL) |
| return NULL; |
| return input + len; |
| } |
| if (ch != ':' || ptr[1] != '-') { |
| simple_info_logger(LOG_INFO, "illegal char in var name"); |
| return NULL; |
| } |
| /* It's that handy "${var:-word}" expression. Check if var is defined */ |
| len = ptr - input; |
| if ((size_t)len >= sizeof tmp) |
| goto expand_variable_out; |
| |
| safe_memcpy(tmp, input, len); |
| /* Move input pointer to ':' */ |
| input = ptr; |
| /* First skip to closing brace, taking note of nested expressions */ |
| ptr += 2; |
| ch = ptr[0]; |
| for (open_braces = 1; open_braces > 0; ch = *++ptr) { |
| switch (ch) { |
| case '{': |
| ++open_braces; |
| break; |
| case '}': |
| --open_braces; |
| break; |
| case '\0': |
| info_logger(LOG_INFO, "\"}\" not found in: %s", input); |
| return NULL; |
| default: |
| break; |
| } |
| } |
| --ptr; |
| /* At this point ptr should point to closing brace of "${var:-word}" */ |
| env = get_variable_v2(tmp, func, info); |
| if (env != NULL) { |
| /* Found environment variable, so skip the input to the closing brace |
| and return the variable */ |
| input = ptr; |
| len = strlen(env); |
| if (len + *out_pos >= length) |
| goto expand_variable_out; |
| |
| memcpy(buffer + *out_pos, env, len + 1); |
| *out_pos += len; |
| return input; |
| } |
| /* Environment variable was not found, so process word. Advance input |
| pointer to start of word in "${var:-word}" */ |
| input += 2; |
| len = ptr - input; |
| if ((size_t)len >= sizeof tmp) |
| goto expand_variable_out; |
| |
| safe_memcpy(tmp, input, len); |
| input = ptr; |
| if (!st_expr_expand(tmp, STRING_LENGTH, tmp, func, info)) |
| return NULL; |
| len = strlen(tmp); |
| if (len + *out_pos >= length) |
| goto expand_variable_out; |
| |
| memcpy(buffer + *out_pos, tmp, len + 1); |
| *out_pos += len; |
| return input; |
| expand_variable_out: |
| simple_info_logger(LOG_INFO, bb_msg_small_buffer); |
| return NULL; |
| } /* End Function expand_variable */ |
| |
| |
| static const char *get_variable_v2(const char *variable, |
| const char *(*func)(const char *variable, void *info), |
| void *info) |
| /* [SUMMARY] Get a variable from the environment or . |
| <variable> The variable name. |
| <func> A function which will be used to get the variable. If this returns |
| NULL, the environment is searched instead. If this is NULL, only the |
| environment is searched. |
| [RETURNS] The value of the variable on success, else NULL. |
| */ |
| { |
| const char *value; |
| |
| if (func != NULL) { |
| value = (*func)(variable, info); |
| if (value != NULL) |
| return value; |
| } |
| return getenv(variable); |
| } /* End Function get_variable */ |
| |
| /* END OF CODE */ |