| /* |
| * add-shell and remove-shell implementation for busybox |
| * |
| * Copyright (C) 2010 Nokia Corporation. All rights reserved. |
| * Written by Alexander Shishkin <virtuoso@slind.org> |
| * |
| * Licensed under GPLv2 or later, see the LICENSE file in this source tree |
| * for details. |
| */ |
| //config:config ADD_SHELL |
| //config: bool "add-shell" |
| //config: default y if DESKTOP |
| //config: help |
| //config: Add shells to /etc/shells. |
| //config: |
| //config:config REMOVE_SHELL |
| //config: bool "remove-shell" |
| //config: default y if DESKTOP |
| //config: help |
| //config: Remove shells from /etc/shells. |
| |
| // APPLET_ODDNAME:name main location suid_type help |
| //applet:IF_ADD_SHELL( APPLET_ODDNAME(add-shell , add_remove_shell, BB_DIR_USR_SBIN, BB_SUID_DROP, add_shell )) |
| //applet:IF_REMOVE_SHELL(APPLET_ODDNAME(remove-shell, add_remove_shell, BB_DIR_USR_SBIN, BB_SUID_DROP, remove_shell)) |
| |
| //kbuild:lib-$(CONFIG_ADD_SHELL) += add-remove-shell.o |
| //kbuild:lib-$(CONFIG_REMOVE_SHELL) += add-remove-shell.o |
| |
| //usage:#define add_shell_trivial_usage |
| //usage: "SHELL..." |
| //usage:#define add_shell_full_usage "\n\n" |
| //usage: "Add SHELLs to /etc/shells" |
| |
| //usage:#define remove_shell_trivial_usage |
| //usage: "SHELL..." |
| //usage:#define remove_shell_full_usage "\n\n" |
| //usage: "Remove SHELLs from /etc/shells" |
| |
| #include "libbb.h" |
| |
| #define SHELLS_FILE "/etc/shells" |
| |
| #define REMOVE_SHELL (ENABLE_REMOVE_SHELL && (!ENABLE_ADD_SHELL || applet_name[0] == 'r')) |
| #define ADD_SHELL (ENABLE_ADD_SHELL && (!ENABLE_REMOVE_SHELL || applet_name[0] == 'a')) |
| |
| #define dont_add ((char*)(uintptr_t)1) |
| |
| int add_remove_shell_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
| int add_remove_shell_main(int argc UNUSED_PARAM, char **argv) |
| { |
| FILE *orig_fp; |
| char *orig_fn; |
| char *new_fn; |
| struct stat sb; |
| |
| sb.st_mode = 0666; |
| |
| argv++; |
| |
| orig_fn = xmalloc_follow_symlinks(SHELLS_FILE); |
| if (!orig_fn) |
| return EXIT_FAILURE; |
| orig_fp = fopen_for_read(orig_fn); |
| if (orig_fp) |
| xfstat(fileno(orig_fp), &sb, orig_fn); |
| |
| new_fn = xasprintf("%s.tmp", orig_fn); |
| /* |
| * O_TRUNC or O_EXCL? At the first glance, O_EXCL looks better, |
| * since it prevents races. But: (1) it requires a retry loop, |
| * (2) if /etc/shells.tmp is *stale*, then retry loop |
| * with O_EXCL will never succeed - it should have a timeout, |
| * after which it should revert to O_TRUNC. |
| * For now, I settle for O_TRUNC instead. |
| */ |
| xmove_fd(xopen3(new_fn, O_WRONLY | O_CREAT | O_TRUNC, sb.st_mode), STDOUT_FILENO); |
| /* TODO? |
| xfchown(STDOUT_FILENO, sb.st_uid, sb.st_gid); |
| */ |
| |
| if (orig_fp) { |
| /* Copy old file, possibly skipping removed shell names */ |
| char *line; |
| while ((line = xmalloc_fgetline(orig_fp)) != NULL) { |
| char **cpp = argv; |
| while (*cpp) { |
| if (strcmp(*cpp, line) == 0) { |
| /* Old file has this shell name */ |
| if (REMOVE_SHELL) { |
| /* we are remove-shell */ |
| /* delete this name by not copying it */ |
| goto next_line; |
| } |
| /* we are add-shell */ |
| /* mark this name as "do not add" */ |
| *cpp = dont_add; |
| } |
| cpp++; |
| } |
| /* copy shell name from old to new file */ |
| puts(line); |
| next_line: |
| free(line); |
| } |
| if (ENABLE_FEATURE_CLEAN_UP) |
| fclose(orig_fp); |
| } |
| |
| if (ADD_SHELL) { |
| char **cpp = argv; |
| while (*cpp) { |
| if (*cpp != dont_add) |
| puts(*cpp); |
| cpp++; |
| } |
| } |
| |
| /* Ensure we wrote out everything */ |
| if (fclose(stdout) != 0) { |
| xunlink(new_fn); |
| bb_perror_msg_and_die("%s: write error", new_fn); |
| } |
| |
| /* Small hole: if rename fails, /etc/shells.tmp is not removed */ |
| xrename(new_fn, orig_fn); |
| |
| if (ENABLE_FEATURE_CLEAN_UP) { |
| free(orig_fn); |
| free(new_fn); |
| } |
| |
| return EXIT_SUCCESS; |
| } |