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/*
* 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 <preload> to preload values from a file
* v1.01.1
* - busybox applet aware by <solar@gentoo.org>
*
*/
#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 void sysctl_dots_to_slashes(char *name);
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 };
static const char msg_unknown_key[] ALIGN1 =
"error: '%s' is an unknown key";
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() */
/* Set sysctl's from a conf file. Format example:
* # Controls IP packet forwarding
* net.ipv4.ip_forward = 0
*/
static int sysctl_preload_file_and_exit(const char *filename)
{
char *token[2];
parser_t *parser;
parser = config_open(filename);
// TODO: ';' is comment char too
while (config_read(parser, token, 2, 2, "# \t=", PARSE_NORMAL)) {
#if 0
char *s = xasprintf("%s=%s", token[0], token[1]);
sysctl_write_setting(s);
free(s);
#else /* Save ~4 bytes by using parser internals */
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() */
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("error: '%s' must be of the form name=value", setting);
return EXIT_FAILURE;
}
value = equals + 1; /* point to the value in name=value */
if (name == equals || !*value) {
bb_error_msg("error: malformed setting '%s'", setting);
return EXIT_FAILURE;
}
tmpname = xasprintf("%s%.*s", PROC_SYS, (int)(equals - name), name);
outname = xstrdup(tmpname + strlen_PROC_SYS);
sysctl_dots_to_slashes(tmpname);
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(msg_unknown_key, outname);
break;
default:
bb_perror_msg("error setting key '%s'", 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() */
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(msg_unknown_key, name);
return -1;
}
tmpname = concat_path_file(PROC_SYS, name);
outname = xstrdup(tmpname + strlen_PROC_SYS);
sysctl_dots_to_slashes(tmpname);
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(msg_unknown_key, outname);
break;
default:
bb_perror_msg("error reading key '%s'", 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() */
static int sysctl_display_all(const char *path)
{
int retval = EXIT_SUCCESS;
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() */
static void sysctl_dots_to_slashes(char *name)
{
char *cptr = name;
/* Example from bug 3894:
* net.ipv4.conf.eth0.100.mc_forwarding ->
* net/ipv4/conf/eth0.100/mc_forwarding */
while (*cptr != '\0') {
if (*cptr == '.') {
*cptr = '\0';
if (access(name, F_OK) == 0)
*cptr = '/';
else
*cptr = '.';
}
cptr++;
}
} /* end sysctl_dots_to_slashes() */
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