Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 | /* 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 source tree.
*
* Changelog:
* 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"
//config: default y
//config: help
//config: Configure kernel parameters at runtime.
//applet:IF_BB_SYSCTL(APPLET(sysctl, BB_DIR_SBIN, BB_SUID_DROP))
//kbuild:lib-$(CONFIG_BB_SYSCTL) += sysctl.o
//usage:#define sysctl_trivial_usage
//usage: "[OPTIONS] [KEY[=VALUE]]..."
//usage:#define sysctl_full_usage "\n\n"
//usage: "Show/set kernel parameters\n"
//usage: "\n -e Don't warn about unknown keys"
//usage: "\n -n Don't show key names"
//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: "\n -p FILE Set values from FILE (default /etc/sysctl.conf)"
//usage: "\n -q Set values silently"
//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"
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,
/* TODO: procps 3.2.8 seems to not require -w for KEY=VAL to work: */
FLAG_WRITE = 1 << 5,
FLAG_QUIET = 1 << 6,
};
#define OPTION_STR "neAapwq"
static void sysctl_dots_to_slashes(char *name)
{
char *cptr, *last_good, *end;
/* 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 = name + strlen(name);
last_good = name - 1;
*end = '.'; /* trick the loop into trying full name too */
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 = '.';
}
cptr--;
}
*end = '\0';
}
static int sysctl_act_on_setting(char *setting)
{
int fd, retval = EXIT_SUCCESS;
char *cptr, *outname;
char *value = value; /* for compiler */
outname = xstrdup(setting);
cptr = outname;
while (*cptr) {
if (*cptr == '/')
*cptr = '.';
cptr++;
}
if (option_mask32 & FLAG_WRITE) {
cptr = strchr(setting, '=');
if (cptr == NULL) {
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 || !*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);
}
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("error: '%s' is an unknown key", outname);
break;
default:
bb_perror_msg("error %sing key '%s'",
option_mask32 & FLAG_WRITE ?
"sett" : "read",
outname);
break;
}
retval = EXIT_FAILURE;
goto end;
}
if (option_mask32 & FLAG_WRITE) {
//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 {
char c;
value = cptr = xmalloc_read(fd, NULL);
close(fd);
if (value == NULL) {
bb_perror_msg("error reading key '%s'", outname);
goto end;
}
/* 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;
}
static int sysctl_act_recursive(const char *path)
{
DIR *dirp;
struct stat buf;
struct dirent *entry;
char *next;
int retval = 0;
stat(path, &buf);
if (S_ISDIR(buf.st_mode) && !(option_mask32 & FLAG_WRITE)) {
dirp = opendir(path);
if (dirp == NULL)
return -1;
while ((entry = readdir(dirp)) != NULL) {
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);
}
closedir(dirp);
} else {
char *name = xstrdup(path);
retval |= sysctl_act_on_setting(name);
free(name);
}
return retval;
}
/* Set sysctl's from a conf file. Format example:
* # Controls IP packet forwarding
* net.ipv4.ip_forward = 0
*/
static int sysctl_handle_preload_file(const char *filename)
{
char *token[2];
parser_t *parser;
parser = config_open(filename);
/* Must do it _after_ config_open(): */
xchdir("/proc/sys");
/* xchroot("/proc/sys") - if you are paranoid */
//TODO: ';' is comment char too
//TODO: comment may be only at line start. "var=1 #abc" - "1 #abc" is the value
// (but _whitespace_ from ends should be trimmed first (and we do it right))
//TODO: "var==1" is mishandled (must use "=1" as a value, but uses "1")
// can it be fixed by removing PARSE_COLLAPSE bit?
while (config_read(parser, token, 2, 2, "# \t=", PARSE_NORMAL)) {
char *tp;
sysctl_dots_to_slashes(token[0]);
tp = xasprintf("%s=%s", token[0], token[1]);
sysctl_act_recursive(tp);
free(tp);
}
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) {
option_mask32 |= FLAG_WRITE;
/* xchdir("/proc/sys") is inside */
return sysctl_handle_preload_file(*argv ? *argv : "/etc/sysctl.conf");
}
xchdir("/proc/sys");
/* xchroot("/proc/sys") - if you are paranoid */
if (opt & (FLAG_TABLE_FORMAT | FLAG_SHOW_ALL)) {
return sysctl_act_recursive(".");
}
retval = 0;
while (*argv) {
sysctl_dots_to_slashes(*argv);
retval |= sysctl_act_recursive(*argv);
argv++;
}
return retval;
}
|