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sysctl: fix file parsing, do not require -w for VAR=VAL

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function                                             old     new   delta
sysctl_act_on_setting                                  -     451    +451
sysctl_main                                          222     282     +60
packed_usage                                       31744   31793     +49
config_read                                          604     639     +35
sysctl_act_recursive                                 612     163    -449
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 3/1 up/down: 595/-449)          Total: 146 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko
2017-08-05 13:45:22 +02:00
parent feb79e8742
commit 9cf89cdf84
4 changed files with 77 additions and 32 deletions
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51
procps/sysctl.c
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@@ -21,17 +21,17 @@
//kbuild:lib-$(CONFIG_BB_SYSCTL) += sysctl.o
//usage:#define sysctl_trivial_usage
//usage: "[OPTIONS] [KEY[=VALUE]]..."
//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: "\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"
@@ -48,7 +48,7 @@ enum {
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: */
/* 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,
};
@@ -104,6 +104,7 @@ 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);
@@ -114,8 +115,10 @@ static int sysctl_act_on_setting(char *setting)
cptr++;
}
if (option_mask32 & FLAG_WRITE) {
cptr = strchr(setting, '=');
cptr = strchr(setting, '=');
if (cptr)
writing = 1;
if (writing) {
if (cptr == NULL) {
bb_error_msg("error: '%s' must be of the form name=value",
outname);
@@ -147,7 +150,7 @@ static int sysctl_act_on_setting(char *setting)
break;
default:
bb_perror_msg("error %sing key '%s'",
option_mask32 & FLAG_WRITE ?
writing ?
"sett" : "read",
outname);
break;
@@ -156,7 +159,7 @@ static int sysctl_act_on_setting(char *setting)
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);
@@ -238,22 +241,27 @@ static int sysctl_handle_preload_file(const char *filename)
{
char *token[2];
parser_t *parser;
int parse_flags;
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)) {
//TODO: <space><tab><space>#comment is also comment, not strictly 1st char only
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
while (config_read(parser, token, 2, 2, "#=", parse_flags)) {
char *tp;
trim(token[0]);
trim(token[1]);
sysctl_dots_to_slashes(token[0]);
tp = xasprintf("%s=%s", token[0], token[1]);
sysctl_act_recursive(tp);
sysctl_act_on_setting(tp);
free(tp);
}
if (ENABLE_FEATURE_CLEAN_UP)
@@ -273,12 +281,19 @@ int sysctl_main(int argc UNUSED_PARAM, char **argv)
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("/proc/sys") - if you are paranoid */
if (opt & (FLAG_TABLE_FORMAT | FLAG_SHOW_ALL)) {
return sysctl_act_recursive(".");
}