* 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"
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 "neAapw"
+#define OPTION_STR "neAapwq"
static void sysctl_dots_to_slashes(char *name)
{
- char *cptr, *last_good, *end;
+ 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 = '.';
+ }
+ return;
+ }
+ /* else: use our old behavior: */
/* Convert minimum number of '.' to '/' so that
* we end up with existing file's name.
*
* To set up testing: modprobe 8021q; vconfig add eth0 100
*/
- end = name + strlen(name);
- last_good = name - 1;
+ end_ch = *end;
*end = '.'; /* trick the loop into trying full name too */
+ last_good = name - 1;
again:
cptr = end;
while (cptr > last_good) {
}
cptr--;
}
- *end = '\0';
+ *end = end_ch;
}
static int sysctl_act_on_setting(char *setting)
int fd, retval = EXIT_SUCCESS;
char *cptr, *outname;
char *value = value; /* for compiler */
+ bool writing = (option_mask32 & FLAG_WRITE);
outname = xstrdup(setting);
while (*cptr) {
if (*cptr == '/')
*cptr = '.';
+ else if (*cptr == '.')
+ *cptr = '/';
cptr++;
}
- if (option_mask32 & FLAG_WRITE) {
- cptr = strchr(setting, '=');
- if (cptr == NULL) {
+ 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 || !*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;
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 ?
+ writing ?
"sett" : "read",
outname);
break;
goto end;
}
- if (option_mask32 & FLAG_WRITE) {
+ if (writing) {
//TODO: procps 3.2.7 writes "value\n", note trailing "\n"
xwrite_str(fd, value);
close(fd);
- if (option_mask32 & FLAG_SHOW_KEYS)
- printf("%s = ", outname);
- puts(value);
+ if (!(option_mask32 & FLAG_QUIET)) {
+ if (option_mask32 & FLAG_SHOW_KEYS)
+ printf("%s = ", outname);
+ puts(value);
+ }
} else {
char c;
close(fd);
if (value == NULL) {
bb_perror_msg("error reading key '%s'", outname);
+ retval = EXIT_FAILURE;
goto end;
}
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)) {
+ 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) {
- next = concat_subpath_file(path, entry->d_name);
+ 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);
+ next + 2 : next);
free(next);
}
closedir(dirp);
{
char *token[2];
parser_t *parser;
+ int parse_flags;
parser = config_open(filename);
/* Must do it _after_ config_open(): */
xchdir("/proc/sys");
- /* xchroot(".") - 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)) {
+
+ 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]);
- tp = xasprintf("%s=%s", token[0], token[1]);
- sysctl_act_recursive(tp);
- free(tp);
+ /* ^^^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);
option_mask32 = opt;
if (opt & FLAG_PRELOAD_FILE) {
+ int cur_dir_fd;
option_mask32 |= FLAG_WRITE;
- /* xchdir("/proc/sys") is inside */
- return sysctl_handle_preload_file(*argv ? *argv : "/etc/sysctl.conf");
+ 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");
- /* xchroot(".") - if you are paranoid */
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);
projects / oweals / busybox.git / blobdiff