/* vi: set sw=4 ts=4: */ /* * Sysctl 1.01 - A utility to read and manipulate the sysctl parameters * * Copyright 1999 George Staikos * * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. * * Changelog: * v1.01: * - added -p to preload values from a file * v1.01.1 * - busybox applet aware by * */ #include "libbb.h" static int sysctl_read_setting(const char *setting); static int sysctl_write_setting(const char *setting); static int sysctl_display_all(const char *path); static int sysctl_preload_file_and_exit(const char *filename); static const char ETC_SYSCTL_CONF[] ALIGN1 = "/etc/sysctl.conf"; static const char PROC_SYS[] ALIGN1 = "/proc/sys/"; enum { strlen_PROC_SYS = sizeof(PROC_SYS) - 1 }; /* error messages */ static const char ERR_MALFORMED_SETTING[] ALIGN1 = "error: malformed setting '%s'"; static const char ERR_NO_EQUALS[] ALIGN1 = "error: '%s' must be of the form name=value"; static const char ERR_INVALID_KEY[] ALIGN1 = "error: '%s' is an unknown key"; static const char ERR_UNKNOWN_WRITING[] ALIGN1 = "error setting key '%s'"; static const char ERR_UNKNOWN_READING[] ALIGN1 = "error reading key '%s'"; static const char ERR_PERMISSION_DENIED[] ALIGN1 = "error: permission denied on key '%s'"; static const char WARN_BAD_LINE[] ALIGN1 = "warning: %s(%d): invalid syntax, continuing"; static void dwrite_str(int fd, const char *buf) { write(fd, buf, strlen(buf)); } enum { FLAG_SHOW_KEYS = 1 << 0, FLAG_SHOW_KEY_ERRORS = 1 << 1, FLAG_TABLE_FORMAT = 1 << 2, /* not implemented */ FLAG_SHOW_ALL = 1 << 3, FLAG_PRELOAD_FILE = 1 << 4, FLAG_WRITE = 1 << 5, }; int sysctl_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int sysctl_main(int argc UNUSED_PARAM, char **argv) { int retval; int opt; opt = getopt32(argv, "+neAapw"); /* '+' - stop on first non-option */ argv += optind; opt ^= (FLAG_SHOW_KEYS | FLAG_SHOW_KEY_ERRORS); option_mask32 ^= (FLAG_SHOW_KEYS | FLAG_SHOW_KEY_ERRORS); if (opt & (FLAG_TABLE_FORMAT | FLAG_SHOW_ALL)) return sysctl_display_all(PROC_SYS); if (opt & FLAG_PRELOAD_FILE) return sysctl_preload_file_and_exit(*argv ? *argv : ETC_SYSCTL_CONF); retval = 0; while (*argv) { if (opt & FLAG_WRITE) retval |= sysctl_write_setting(*argv); else retval |= sysctl_read_setting(*argv); argv++; } return retval; } /* end sysctl_main() */ /* * preload the sysctl's from a conf file * - we parse the file and then reform it (strip out whitespace) */ static int sysctl_preload_file_and_exit(const char *filename) { char *token[2]; parser_t *parser; parser = config_open(filename); while (config_read(parser, token, 2, 2, "# \t=", PARSE_NORMAL)) { // TODO: ';' is comment char too // if (!token[1]) { // bb_error_msg(WARN_BAD_LINE, filename, parser->lineno); // } else { { #if 0 char *s = xasprintf("%s=%s", token[0], token[1]); sysctl_write_setting(s); free(s); #else // PLAY_WITH_FIRE for -4 bytes? sprintf(parser->line, "%s=%s", token[0], token[1]); // must have room by definition sysctl_write_setting(parser->line); #endif } } if (ENABLE_FEATURE_CLEAN_UP) config_close(parser); return 0; } /* end sysctl_preload_file_and_exit() */ /* * Write a single sysctl setting */ static int sysctl_write_setting(const char *setting) { int retval; const char *name; const char *value; const char *equals; char *tmpname, *outname, *cptr; int fd; name = setting; equals = strchr(setting, '='); if (!equals) { bb_error_msg(ERR_NO_EQUALS, setting); return EXIT_FAILURE; } value = equals + 1; /* point to the value in name=value */ if (name == equals || !*value) { bb_error_msg(ERR_MALFORMED_SETTING, setting); return EXIT_FAILURE; } tmpname = xasprintf("%s%.*s", PROC_SYS, (int)(equals - name), name); outname = xstrdup(tmpname + strlen_PROC_SYS); while ((cptr = strchr(tmpname, '.')) != NULL) *cptr = '/'; while ((cptr = strchr(outname, '/')) != NULL) *cptr = '.'; fd = open(tmpname, O_WRONLY | O_CREAT | O_TRUNC, 0666); if (fd < 0) { switch (errno) { case ENOENT: if (option_mask32 & FLAG_SHOW_KEY_ERRORS) bb_error_msg(ERR_INVALID_KEY, outname); break; case EACCES: bb_perror_msg(ERR_PERMISSION_DENIED, outname); break; default: bb_perror_msg(ERR_UNKNOWN_WRITING, outname); break; } retval = EXIT_FAILURE; } else { dwrite_str(fd, value); close(fd); if (option_mask32 & FLAG_SHOW_KEYS) { printf("%s = ", outname); } puts(value); retval = EXIT_SUCCESS; } free(tmpname); free(outname); return retval; } /* end sysctl_write_setting() */ /* * Read a sysctl setting */ static int sysctl_read_setting(const char *name) { int retval; char *tmpname, *outname, *cptr; char inbuf[1025]; FILE *fp; if (!*name) { if (option_mask32 & FLAG_SHOW_KEY_ERRORS) bb_error_msg(ERR_INVALID_KEY, name); return -1; } tmpname = concat_path_file(PROC_SYS, name); outname = xstrdup(tmpname + strlen_PROC_SYS); while ((cptr = strchr(tmpname, '.')) != NULL) *cptr = '/'; while ((cptr = strchr(outname, '/')) != NULL) *cptr = '.'; fp = fopen_for_read(tmpname); if (fp == NULL) { switch (errno) { case ENOENT: if (option_mask32 & FLAG_SHOW_KEY_ERRORS) bb_error_msg(ERR_INVALID_KEY, outname); break; case EACCES: bb_error_msg(ERR_PERMISSION_DENIED, outname); break; default: bb_perror_msg(ERR_UNKNOWN_READING, outname); break; } retval = EXIT_FAILURE; } else { while (fgets(inbuf, sizeof(inbuf) - 1, fp)) { if (option_mask32 & FLAG_SHOW_KEYS) { printf("%s = ", outname); } fputs(inbuf, stdout); } fclose(fp); retval = EXIT_SUCCESS; } free(tmpname); free(outname); return retval; } /* end sysctl_read_setting() */ /* * Display all the sysctl settings */ static int sysctl_display_all(const char *path) { int retval = 0; DIR *dp; struct dirent *de; char *tmpdir; struct stat ts; dp = opendir(path); if (!dp) { return EXIT_FAILURE; } while ((de = readdir(dp)) != NULL) { tmpdir = concat_subpath_file(path, de->d_name); if (tmpdir == NULL) continue; /* . or .. */ if (stat(tmpdir, &ts) != 0) { bb_perror_msg(tmpdir); } else if (S_ISDIR(ts.st_mode)) { retval |= sysctl_display_all(tmpdir); } else { retval |= sysctl_read_setting(tmpdir + strlen_PROC_SYS); } free(tmpdir); } /* end while */ closedir(dp); return retval; } /* end sysctl_display_all() */