1 /* vi: set sw=4 ts=4: */
3 * Sysctl 1.01 - A utility to read and manipulate the sysctl parameters
5 * Copyright 1999 George Staikos
7 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
11 * - added -p <preload> to preload values from a file
13 * - busybox applet aware by <solar@gentoo.org>
22 static int sysctl_read_setting(const char *setting, int output);
23 static int sysctl_write_setting(const char *setting, int output);
24 static int sysctl_preload_file(const char *filename, int output);
25 static int sysctl_display_all(const char *path, int output, int show_table);
30 static const char PROC_PATH[] = "/proc/sys/";
31 static const char DEFAULT_PRELOAD[] = "/etc/sysctl.conf";
34 static const char ERR_UNKNOWN_PARAMETER[] = "error: Unknown parameter '%s'\n";
35 static const char ERR_MALFORMED_SETTING[] = "error: Malformed setting '%s'\n";
36 static const char ERR_NO_EQUALS[] =
37 "error: '%s' must be of the form name=value\n";
38 static const char ERR_INVALID_KEY[] = "error: '%s' is an unknown key\n";
39 static const char ERR_UNKNOWN_WRITING[] =
40 "error: unknown error %d setting key '%s'\n";
41 static const char ERR_UNKNOWN_READING[] =
42 "error: unknown error %d reading key '%s'\n";
43 static const char ERR_PERMISSION_DENIED[] =
44 "error: permission denied on key '%s'\n";
45 static const char ERR_PRELOAD_FILE[] =
46 "error: cannot open preload file '%s'\n";
47 static const char WARN_BAD_LINE[] =
48 "warning: %s(%d): invalid syntax, continuing...\n";
51 static void dwrite_str(int fd, const char *buf)
53 write(fd, buf, strlen(buf));
59 int sysctl_main(int argc, char **argv);
60 int sysctl_main(int argc, char **argv)
65 int switches_allowed = 1;
72 for (; argv && *argv && **argv; argv++) {
73 if (switches_allowed && **argv == '-') { /* we have a switch */
85 sysctl_preload_file(((argv && *argv
87 DEFAULT_PRELOAD), output);
91 return sysctl_display_all(PROC_PATH, output,
92 ((*argv)[1] == 'a') ? 0 : 1);
97 bb_error_msg(ERR_UNKNOWN_PARAMETER, *argv);
101 switches_allowed = 0;
103 retval = sysctl_write_setting(*argv, output);
105 sysctl_read_setting(*argv, output);
109 } /* end sysctl_main() */
114 * sysctl_preload_file
115 * preload the sysctl's from a conf file
116 * - we parse the file and then reform it (strip out whitespace)
118 #define PRELOAD_BUF 256
120 int sysctl_preload_file(const char *filename, int output)
123 char oneline[PRELOAD_BUF];
124 char buffer[PRELOAD_BUF];
125 char *name, *value, *ptr;
128 if (!filename || ((fp = fopen(filename, "r")) == NULL)) {
129 bb_error_msg_and_die(ERR_PRELOAD_FILE, filename);
132 while (fgets(oneline, sizeof(oneline) - 1, fp)) {
133 oneline[sizeof(oneline) - 1] = '\0';
136 ptr = (char *) oneline;
138 if (*ptr == '#' || *ptr == ';')
144 name = strtok(ptr, "=");
145 if (!name || !*name) {
146 bb_error_msg(WARN_BAD_LINE, filename, lineno);
152 value = strtok(NULL, "\n\r");
153 if (!value || !*value) {
154 bb_error_msg(WARN_BAD_LINE, filename, lineno);
158 while ((*value == ' ' || *value == '\t') && *value != 0)
160 /* safe because sizeof(oneline) == sizeof(buffer) */
161 sprintf(buffer, "%s=%s", name, value);
162 sysctl_write_setting(buffer, output);
166 } /* end sysctl_preload_file() */
170 * Write a single sysctl setting
172 int sysctl_write_setting(const char *setting, int output)
175 const char *name = setting;
178 char *tmpname, *outname, *cptr;
181 if (!name) /* probably dont' want to display this err */
184 if (!(equals = strchr(setting, '='))) {
185 bb_error_msg(ERR_NO_EQUALS, setting);
189 value = equals + sizeof(char); /* point to the value in name=value */
191 if (!*name || !*value || name == equals) {
192 bb_error_msg(ERR_MALFORMED_SETTING, setting);
196 tmpname = xasprintf("%s%.*s", PROC_PATH, (int)(equals - name), name);
197 outname = xstrdup(tmpname + strlen(PROC_PATH));
199 while ((cptr = strchr(tmpname, '.')) != NULL)
202 while ((cptr = strchr(outname, '/')) != NULL)
205 if ((fd = open(tmpname, O_WRONLY | O_CREAT | O_TRUNC, 0666)) < 0) {
208 bb_error_msg(ERR_INVALID_KEY, outname);
211 bb_perror_msg(ERR_PERMISSION_DENIED, outname);
214 bb_error_msg(ERR_UNKNOWN_WRITING, errno, outname);
219 dwrite_str(fd, value);
222 dwrite_str(STDOUT_FILENO, outname);
223 dwrite_str(STDOUT_FILENO, " = ");
225 dwrite_str(STDOUT_FILENO, value);
226 dwrite_str(STDOUT_FILENO, "\n");
233 } /* end sysctl_write_setting() */
237 * Read a sysctl setting
240 int sysctl_read_setting(const char *setting, int output)
243 char *tmpname, *outname, *cptr;
245 const char *name = setting;
248 if (!setting || !*setting)
249 bb_error_msg(ERR_INVALID_KEY, setting);
251 tmpname = concat_path_file(PROC_PATH, name);
252 outname = xstrdup(tmpname + strlen(PROC_PATH));
254 while ((cptr = strchr(tmpname, '.')) != NULL)
256 while ((cptr = strchr(outname, '/')) != NULL)
259 if ((fp = fopen(tmpname, "r")) == NULL) {
262 bb_error_msg(ERR_INVALID_KEY, outname);
265 bb_error_msg(ERR_PERMISSION_DENIED, outname);
268 bb_error_msg(ERR_UNKNOWN_READING, errno, outname);
273 while (fgets(inbuf, sizeof(inbuf) - 1, fp)) {
275 dwrite_str(STDOUT_FILENO, outname);
276 dwrite_str(STDOUT_FILENO, " = ");
278 dwrite_str(STDOUT_FILENO, inbuf);
286 } /* end sysctl_read_setting() */
291 * Display all the sysctl settings
294 int sysctl_display_all(const char *path, int output, int show_table)
303 if (!(dp = opendir(path))) {
306 while ((de = readdir(dp)) != NULL) {
307 tmpdir = concat_subpath_file(path, de->d_name);
310 if ((retval2 = stat(tmpdir, &ts)) != 0)
311 bb_perror_msg(tmpdir);
313 if (S_ISDIR(ts.st_mode)) {
314 sysctl_display_all(tmpdir, output, show_table);
317 sysctl_read_setting(tmpdir + strlen(PROC_PATH),
327 } /* end sysctl_display_all() */