/* vi: set sw=4 ts=4: */ /* * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. */ /* devfsd implementation for busybox Copyright (C) 2003 by Tito Ragusa 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. */ //#include //#include //#include #include #include #include #include #include "libbb.h" #include "xregex.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 msg_logger(p, fmt, args...) bb_error_msg(fmt, ## args) #define msg_logger_and_die(p, fmt, args...) bb_error_msg_and_die(fmt, ## args) #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 msg_logger(p, fmt, args...) #define msg_logger_and_die(p, fmt, args...) exit(1) #define error_logger(p, fmt, args...) #define error_logger_and_die(p, fmt, args...) exit(1) #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); 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); if (fcntl(fd, F_SETFD, FD_CLOEXEC) != 0) bb_perror_msg_and_die("FD_CLOEXEC"); 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); sigemptyset(&new_action.sa_mask); new_action.sa_flags = 0; /* Set up SIGHUP and SIGUSR1 handlers */ new_action.sa_handler = signal_handler; if (sigaction(SIGHUP, &new_action, NULL) != 0 || sigaction(SIGUSR1, &new_action, NULL) != 0) bb_error_msg_and_die("sigaction"); 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(0); 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. The path to read the database from. If this is a directory, all entries in that directory will be read(except hidden entries). If TRUE, the routine will silently ignore a missing config file. 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; } if ((fp = fopen(path, "r")) != 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. The configuration line. 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 */ if ((ptr = strchr(p[0], '.')) == 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. The open control file. 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; } 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. 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: 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. The devfs change. 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 ATTRIBUTE_UNUSED) /* [SUMMARY] Load a module. The devfs change. 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; wait4pid(xspawn(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. The devfs change. The config file entry. The number of subexpression(start, end) offsets within the device name. The number of elements within <>. [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; wait4pid(spawn(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. The devfs change. The config file entry. This list of subexpression(start, end) offsets within the device name. The number of elements in <>. [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. The devfs change. 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. The destination path. An existing inode may be deleted. The destination stat(2) information. The desired new mode for the destination. The source path. 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)) { if ((source_len = readlink(sourcepath, source_link, STRING_LENGTH - 1)) < 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: if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) < 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: if ((val = readlink(sourcepath, symlink_val, STRING_LENGTH - 1)) < 0) break; symlink_val[val] = '\0'; if (symlink(symlink_val, destpath) == 0) return TRUE; break; case S_IFREG: if ((fd = open(destpath, O_RDONLY | O_CREAT, new_mode & ~S_IFMT)) < 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. "UID" or "GID". The string. [RETURNS] The UID or GID value. */ { struct passwd *pw_ent; struct group *grp_ent; static const char *msg; if (ENABLE_DEVFSD_VERBOSE) msg = "user"; 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 (flag == GID && (grp_ent = getgrnam(string)) != NULL) return grp_ent->gr_gid; else 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. 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 sbuf[sizeof(int)*3 + 2]; /* sign and NUL */ char hostname[STRING_LENGTH]; struct get_variable_info *gv_info = info; const char *field_names[] = { "hostname", "mntpt", "devpath", "devname", "uid", "gid", "mode", hostname, mount_point, gv_info->devpath, gv_info->devname, NULL }; int i; if (gethostname(hostname, STRING_LENGTH - 1) != 0) /* Here on error we should do exit(RV_SYS_ERROR), instead we do exit(EXIT_FAILURE) */ error_logger_and_die(LOG_ERR, "gethostname"); hostname[STRING_LENGTH - 1] = '\0'; /* 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) sprintf(sbuf, "%u", gv_info->info->uid); else if (i == 5) sprintf(sbuf, "%u", gv_info->info->gid); else if (i == 6) sprintf(sbuf, "%o", gv_info->info->mode); return sbuf; } /* 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. To choose which function to perform The directory pointer. This is closed upon completion. The name of the directory. string length parameter. [RETURNS] Nothing. */ { struct stat statbuf; DIR *dp; struct dirent *de; char *path; if ((dp = warn_opendir(dir_name)) == 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. The string contained in the symlink. 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. 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. The output expanded expression is written here. The size of the output buffer. The input expression. This may equal <>. 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. An arbitrary pointer passed to <>. Device name; specifically, this is the string that contains all of the regular subexpressions. Array of start / end offsets into info->devname for each subexpression Number of regular subexpressions found in <>. [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. The output expanded expression is written here. The size of the output buffer. The input expression. This may NOT equal <>, 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. Device name; specifically, this is the string that contains all of the regular subexpressions. An array of start and end offsets into <>, one for each subexpression Number of subexpressions in the offset-array <>. [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. The device name provided by the kernel. The length of the name. A buffer that may be used. This should be at least 128 bytes long. The major number for the device. 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; size_t len; /* 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) { len = strlen(trans->match); if (strncmp(devname, trans->match, len) == 0) { if (trans->format == NULL) return devname + len; sprintf(buffer, trans->format, devname + len); 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. The major number for the device. 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. The buffer to write to. The major number for the device. The minor number for the device. 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. The output expanded expression is written here. The size of the output buffer. The input expression. This may equal <>. 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. An arbitrary pointer passed to <>. [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 */ if ((env = getenv("HOME")) == 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; if ((pwent = getpwnam(tmp)) == 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: 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. The buffer to write to. The length of the output buffer. The current output position. This is updated. A pointer to the input character pointer. 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. An arbitrary pointer passed to <>. 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; if ((env = get_variable_v2(tmp, func, info)) == 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 "${var}" */ len = ptr - input; if ((size_t)len >= sizeof tmp) goto expand_variable_out; safe_memcpy(tmp, input, len); ptr = expand_variable(buffer, length, out_pos, tmp, func, info); if (ptr == NULL) return NULL; return input + len; } if (ch != ':' || ptr[1] != '-') { info_logger(LOG_INFO, "illegal char in var name"); return NULL; } /* It's that handy "${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 "${var:-word}" */ if ((env = get_variable_v2(tmp, func, info)) != NULL) { /* Found environment variable, so skip the input to the closing brace and return the variable */ input = ptr; len = strlen(env); if (len + *out_pos >= length) goto expand_variable_out; memcpy(buffer + *out_pos, env, len + 1); *out_pos += len; return input; } /* Environment variable was not found, so process word. Advance input pointer to start of word in "${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: 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 . The variable name. 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 */