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/* See LICENSE file for copyright and license details. */
#include <fcntl.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "text.h"
#include "util.h"
static void
replacestr(char *s, int a, int b)
{
for (; *s; s++)
if (*s == a)
*s = b;
}
static int
getsysctl(char *variable, char **value)
{
char path[PATH_MAX];
char *p;
char *buf, *tmp, c;
int fd;
ssize_t n;
size_t sz, i;
replacestr(variable, '.', '/');
strlcpy(path, "/proc/sys/", sizeof(path));
if (strlcat(path, variable, sizeof(path)) >= sizeof(path)) {
replacestr(variable, '/', '.');
return -1;
}
replacestr(variable, '/', '.');
fd = open(path, O_RDONLY);
if (fd < 0)
return -1;
i = 0;
sz = 1;
buf = NULL;
while (1) {
n = read(fd, &c, 1);
if (n < 0) {
close(fd);
free(buf);
return -1;
}
if (n == 0)
break;
if (i == sz - 1) {
sz *= 2;
tmp = realloc(buf, sz);
if (!tmp) {
close(fd);
free(buf);
return -1;
}
buf = tmp;
}
buf[i++] = c;
}
buf[i] = '\0';
p = strrchr(buf, '\n');
if (p)
*p = '\0';
*value = buf;
close(fd);
return 0;
}
static int
setsysctl(char *variable, char *value)
{
char path[PATH_MAX];
int fd;
ssize_t n;
replacestr(variable, '.', '/');
strlcpy(path, "/proc/sys/", sizeof(path));
if (strlcat(path, variable, sizeof(path)) >= sizeof(path)) {
replacestr(variable, '/', '.');
return -1;
}
replacestr(variable, '/', '.');
fd = open(path, O_WRONLY);
if (fd < 0)
return -1;
n = write(fd, value, strlen(value));
if ((size_t)n != strlen(value)) {
close(fd);
return -1;
}
close(fd);
return 0;
}
static int
parsepair(char *pair)
{
char *p;
char *variable;
char *value;
for (p = pair; *p; p++) {
if (p[0] == '.' && p[1] == '.') {
weprintf("malformed input: %s\n", pair);
return -1;
}
}
p = strchr(pair, '=');
if (p) {
if (p[1] == '\0') {
weprintf("malformed input: %s\n", pair);
return -1;
}
*p = '\0';
value = &p[1];
} else {
value = NULL;
}
variable = pair;
if (value) {
if (setsysctl(variable, value) < 0) {
weprintf("failed to set sysctl for %s\n", variable);
return -1;
}
} else {
if (getsysctl(variable, &value) < 0) {
weprintf("failed to get sysctl for %s\n", variable);
return -1;
}
printf("%s = %s\n", variable, value);
free(value);
}
return 0;
}
static void
usage(void)
{
eprintf("usage: %s [-p file] variable[=value]...\n", argv0);
}
int
main(int argc, char *argv[])
{
FILE *fp;
char *buf = NULL, *p;
char *file = NULL;
size_t size = 0;
int i;
int r = 0;
ARGBEGIN {
case 'p':
file = EARGF(usage());
break;
default:
usage();
} ARGEND;
if (!file && argc < 1)
usage();
if (!file) {
for (i = 0; i < argc; i++)
if (parsepair(argv[i]) < 0)
r = 1;
} else {
fp = fopen(file, "r");
if (!fp)
eprintf("fopen %s:", file);
while (agetline(&buf, &size, fp) != -1) {
p = buf;
for (p = buf; *p == ' ' || *p == '\t'; p++)
;
if (*p == '#' || *p == '\n')
continue;
for (p = buf; *p; p++) {
if (*p == '\n') {
*p = '\0';
break;
}
}
p = buf;
if (parsepair(p) < 0)
r = 1;
}
if (ferror(fp))
eprintf("%s: read error:", file);
free(buf);
fclose(fp);
}
return r;
}