*
* Copyright 1999 George Staikos
*
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
*
* Changelog:
- * v1.01:
- * - added -p <preload> to preload values from a file
- * v1.01.1
- * - busybox applet aware by <solar@gentoo.org>
- *
+ * v1.01 - added -p <preload> to preload values from a file
+ * v1.01.1 - busybox applet aware by <solar@gentoo.org>
*/
+//config:config BB_SYSCTL
+//config: bool "sysctl (7.4 kb)"
+//config: default y
+//config: help
+//config: Configure kernel parameters at runtime.
+
+//applet:IF_BB_SYSCTL(APPLET_NOEXEC(sysctl, sysctl, BB_DIR_SBIN, BB_SUID_DROP, sysctl))
+
+//kbuild:lib-$(CONFIG_BB_SYSCTL) += sysctl.o
+
+//usage:#define sysctl_trivial_usage
+//usage: "-p [-enq] [FILE...] / [-enqaw] [KEY[=VALUE]]..."
+//usage:#define sysctl_full_usage "\n\n"
+//usage: "Show/set kernel parameters\n"
+//usage: "\n -p Set values from FILEs (default /etc/sysctl.conf)"
+//usage: "\n -e Don't warn about unknown keys"
+//usage: "\n -n Don't show key names"
+//usage: "\n -q Quiet"
+//usage: "\n -a Show all values"
+/* Same as -a, no need to show it */
+/* //usage: "\n -A Show all values in table form" */
+//usage: "\n -w Set values"
+//usage:
+//usage:#define sysctl_example_usage
+//usage: "sysctl [-n] [-e] variable...\n"
+//usage: "sysctl [-n] [-e] [-q] -w variable=value...\n"
+//usage: "sysctl [-n] [-e] -a\n"
+//usage: "sysctl [-n] [-e] [-q] -p file (default /etc/sysctl.conf)\n"
+//usage: "sysctl [-n] [-e] -A\n"
#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,
+ /* NB: procps 3.2.8 does not require -w for KEY=VAL to work, it only rejects non-KEY=VAL form */
FLAG_WRITE = 1 << 5,
+ FLAG_QUIET = 1 << 6,
};
+#define OPTION_STR "neAapwq"
-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)
- */
-#define PRELOAD_BUF 256
-
-static int sysctl_preload_file_and_exit(const char *filename)
+static void sysctl_dots_to_slashes(char *name)
{
- int lineno;
- char oneline[PRELOAD_BUF];
- char buffer[PRELOAD_BUF];
- char *name, *value;
- FILE *fp;
-
- fp = xfopen(filename, "r");
-
- lineno = 0;
- while (fgets(oneline, sizeof(oneline) - 1, fp)) {
- lineno++;
- trim(oneline);
- if (oneline[0] == '#' || oneline[0] == ';')
- continue;
- if (!oneline[0] || !oneline[1])
- continue;
-
- name = strtok(oneline, "=");
- if (!name) {
- bb_error_msg(WARN_BAD_LINE, filename, lineno);
- continue;
- }
- trim(name);
- if (!*name) {
- bb_error_msg(WARN_BAD_LINE, filename, lineno);
- continue;
+ char *cptr, *last_good, *end, *slash;
+ char end_ch;
+
+ end = strchrnul(name, '=');
+
+ slash = strchrnul(name, '/');
+ if (slash < end
+ && strchrnul(name, '.') < slash
+ ) {
+ /* There are both dots and slashes, and 1st dot is
+ * before 1st slash.
+ * (IOW: not raw, unmangled a/b/c.d format)
+ *
+ * procps supports this syntax for names with dots:
+ * net.ipv4.conf.eth0/100.mc_forwarding
+ * (dots and slashes are simply swapped)
+ */
+ while (end != name) {
+ end--;
+ if (*end == '.') *end = '/';
+ else if (*end == '/') *end = '.';
}
-
- value = strtok(NULL, "\n\r");
- if (!value) {
- bb_error_msg(WARN_BAD_LINE, filename, lineno);
- continue;
- }
- while (*value == ' ' || *value == '\t')
- value++;
- if (!*value) {
- bb_error_msg(WARN_BAD_LINE, filename, lineno);
- continue;
+ return;
+ }
+ /* else: use our old behavior: */
+
+ /* Convert minimum number of '.' to '/' so that
+ * we end up with existing file's name.
+ *
+ * Example from bug 3894:
+ * net.ipv4.conf.eth0.100.mc_forwarding ->
+ * net/ipv4/conf/eth0.100/mc_forwarding
+ * NB: net/ipv4/conf/eth0/mc_forwarding *also exists*,
+ * therefore we must start from the end, and if
+ * we replaced even one . -> /, start over again,
+ * but never replace dots before the position
+ * where last replacement occurred.
+ *
+ * Another bug we later had is that
+ * net.ipv4.conf.eth0.100
+ * (without .mc_forwarding) was mishandled.
+ *
+ * To set up testing: modprobe 8021q; vconfig add eth0 100
+ */
+ end_ch = *end;
+ *end = '.'; /* trick the loop into trying full name too */
+
+ last_good = name - 1;
+ again:
+ cptr = end;
+ while (cptr > last_good) {
+ if (*cptr == '.') {
+ *cptr = '\0';
+ //bb_error_msg("trying:'%s'", name);
+ if (access(name, F_OK) == 0) {
+ *cptr = '/';
+ //bb_error_msg("replaced:'%s'", name);
+ last_good = cptr;
+ goto again;
+ }
+ *cptr = '.';
}
-
- /* safe because sizeof(oneline) == sizeof(buffer) */
- sprintf(buffer, "%s=%s", name, value);
- sysctl_write_setting(buffer);
+ cptr--;
}
- if (ENABLE_FEATURE_CLEAN_UP)
- fclose(fp);
- return 0;
-} /* end sysctl_preload_file_and_exit() */
+ *end = end_ch;
+}
-/*
- * Write a single sysctl setting
- */
-static int sysctl_write_setting(const char *setting)
+static int sysctl_act_on_setting(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;
+ int fd, retval = EXIT_SUCCESS;
+ char *cptr, *outname;
+ char *value = value; /* for compiler */
+ bool writing = (option_mask32 & FLAG_WRITE);
+
+ outname = xstrdup(setting);
+
+ cptr = outname;
+ while (*cptr) {
+ if (*cptr == '/')
+ *cptr = '.';
+ else if (*cptr == '.')
+ *cptr = '/';
+ cptr++;
}
- value = equals + 1; /* point to the value in name=value */
- if (name == equals || !*value) {
- bb_error_msg(ERR_MALFORMED_SETTING, setting);
- return EXIT_FAILURE;
+ cptr = strchr(setting, '=');
+ if (cptr)
+ writing = 1;
+ if (writing) {
+ if (!cptr) {
+ bb_error_msg("error: '%s' must be of the form name=value",
+ outname);
+ retval = EXIT_FAILURE;
+ goto end;
+ }
+ value = cptr + 1; /* point to the value in name=value */
+ if (setting == cptr /* "name" can't be empty */
+ /* || !*value - WRONG: "sysctl net.ipv4.ip_local_reserved_ports=" is a valid syntax (clears the value) */
+ ) {
+ bb_error_msg("error: malformed setting '%s'", outname);
+ retval = EXIT_FAILURE;
+ goto end;
+ }
+ *cptr = '\0';
+ outname[cptr - setting] = '\0';
+ /* procps 3.2.7 actually uses these flags */
+ fd = open(setting, O_WRONLY|O_CREAT|O_TRUNC, 0666);
+ } else {
+ fd = open(setting, O_RDONLY);
}
- 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 EACCES:
+ /* Happens for write-only settings, e.g. net.ipv6.route.flush */
+ goto end;
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);
+ bb_error_msg("error: '%s' is an unknown key", outname);
break;
default:
- bb_perror_msg(ERR_UNKNOWN_WRITING, outname);
+ bb_perror_msg("error %sing key '%s'",
+ writing ?
+ "sett" : "read",
+ outname);
break;
}
retval = EXIT_FAILURE;
+ goto end;
+ }
+
+ if (writing) {
+//TODO: procps 3.2.7 writes "value\n", note trailing "\n"
+ xwrite_str(fd, value);
+ close(fd);
+ if (!(option_mask32 & FLAG_QUIET)) {
+ if (option_mask32 & FLAG_SHOW_KEYS)
+ printf("%s = ", outname);
+ puts(value);
+ }
} else {
- dwrite_str(fd, value);
+ char c;
+
+ value = cptr = xmalloc_read(fd, NULL);
close(fd);
- if (option_mask32 & FLAG_SHOW_KEYS) {
- printf("%s = ", outname);
+ if (value == NULL) {
+ bb_perror_msg("error reading key '%s'", outname);
+ retval = EXIT_FAILURE;
+ goto end;
}
- puts(value);
- retval = EXIT_SUCCESS;
- }
- free(tmpname);
+ /* dev.cdrom.info and sunrpc.transports, for example,
+ * are multi-line. Try "sysctl sunrpc.transports"
+ */
+ while ((c = *cptr) != '\0') {
+ if (option_mask32 & FLAG_SHOW_KEYS)
+ printf("%s = ", outname);
+ while (1) {
+ fputc(c, stdout);
+ cptr++;
+ if (c == '\n')
+ break;
+ c = *cptr;
+ if (c == '\0')
+ break;
+ }
+ }
+ free(value);
+ }
+ end:
free(outname);
return retval;
-} /* end sysctl_write_setting() */
+}
-/*
- * Read a sysctl setting
- */
-static int sysctl_read_setting(const char *name)
+static int sysctl_act_recursive(const char *path)
{
- 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 = '.';
+ struct stat buf;
+ int retval = 0;
- fp = fopen(tmpname, "r");
- 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;
+ if (!(option_mask32 & FLAG_WRITE)
+ && stat(path, &buf) == 0
+ && S_ISDIR(buf.st_mode)
+ ) {
+ struct dirent *entry;
+ DIR *dirp;
+
+ dirp = opendir(path);
+ if (dirp == NULL)
+ return -1;
+ while ((entry = readdir(dirp)) != NULL) {
+ char *next = concat_subpath_file(path, entry->d_name);
+ if (next == NULL)
+ continue; /* d_name is "." or ".." */
+ /* if path was ".", drop "./" prefix: */
+ retval |= sysctl_act_recursive((next[0] == '.' && next[1] == '/') ?
+ next + 2 : next);
+ free(next);
}
- retval = EXIT_FAILURE;
+ closedir(dirp);
} 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;
+ char *name = xstrdup(path);
+ retval |= sysctl_act_on_setting(name);
+ free(name);
}
- free(tmpname);
- free(outname);
return retval;
-} /* end sysctl_read_setting() */
+}
-/*
- * Display all the sysctl settings
+/* Set sysctl's from a conf file. Format example:
+ * # Controls IP packet forwarding
+ * net.ipv4.ip_forward = 0
*/
-static int sysctl_display_all(const char *path)
+static int sysctl_handle_preload_file(const char *filename)
{
- int retval = 0;
- DIR *dp;
- struct dirent *de;
- char *tmpdir;
- struct stat ts;
-
- dp = opendir(path);
- if (!dp) {
- return EXIT_FAILURE;
+ char *token[2];
+ parser_t *parser;
+ int parse_flags;
+
+ parser = config_open(filename);
+ /* Must do it _after_ config_open(): */
+ xchdir("/proc/sys");
+
+ parse_flags = 0;
+ parse_flags &= ~PARSE_COLLAPSE; // NO (var==val is not var=val) - treat consecutive delimiters as one
+ parse_flags &= ~PARSE_TRIM; // NO - trim leading and trailing delimiters
+ parse_flags |= PARSE_GREEDY; // YES - last token takes entire remainder of the line
+ parse_flags &= ~PARSE_MIN_DIE; // NO - die if < min tokens found
+ parse_flags &= ~PARSE_EOL_COMMENTS; // NO (only first char) - comments are recognized even if not first char
+ parse_flags |= PARSE_ALT_COMMENTS;// YES - two comment chars: ';' and '#'
+ /* <space><tab><space>#comment is also comment, not strictly 1st char only */
+ parse_flags |= PARSE_WS_COMMENTS; // YES - comments are recognized even if there is whitespace before
+ while (config_read(parser, token, 2, 2, ";#=", parse_flags)) {
+ char *tp;
+
+ trim(token[1]);
+ tp = trim(token[0]);
+ sysctl_dots_to_slashes(token[0]);
+ /* ^^^converted in-place. tp still points to NUL */
+ /* now, add "=TOKEN1" */
+ *tp++ = '=';
+ overlapping_strcpy(tp, token[1]);
+
+ sysctl_act_on_setting(token[0]);
+ }
+ if (ENABLE_FEATURE_CLEAN_UP)
+ config_close(parser);
+ return 0;
+}
+
+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, "+" OPTION_STR); /* '+' - stop on first non-option */
+ argv += optind;
+ opt ^= (FLAG_SHOW_KEYS | FLAG_SHOW_KEY_ERRORS);
+ option_mask32 = opt;
+
+ if (opt & FLAG_PRELOAD_FILE) {
+ int cur_dir_fd;
+ option_mask32 |= FLAG_WRITE;
+ if (!*argv)
+ *--argv = (char*)"/etc/sysctl.conf";
+ cur_dir_fd = xopen(".", O_RDONLY | O_DIRECTORY);
+ do {
+ /* xchdir("/proc/sys") is inside */
+ sysctl_handle_preload_file(*argv);
+ xfchdir(cur_dir_fd); /* files can be relative, must restore cwd */
+ } while (*++argv);
+ return 0; /* procps-ng 3.3.10 does not flag parse errors */
+ }
+ xchdir("/proc/sys");
+ if (opt & (FLAG_TABLE_FORMAT | FLAG_SHOW_ALL)) {
+ return sysctl_act_recursive(".");
+ }
+
+//TODO: if(!argv[0]) bb_show_usage() ?
+
+ retval = 0;
+ while (*argv) {
+ sysctl_dots_to_slashes(*argv);
+ retval |= sysctl_act_recursive(*argv);
+ argv++;
}
- 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() */
+}
projects / oweals / busybox.git / blobdiff