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43#include "libbb.h"
44
45enum {
46 FLAG_SHOW_KEYS = 1 << 0,
47 FLAG_SHOW_KEY_ERRORS = 1 << 1,
48 FLAG_TABLE_FORMAT = 1 << 2,
49 FLAG_SHOW_ALL = 1 << 3,
50 FLAG_PRELOAD_FILE = 1 << 4,
51
52 FLAG_WRITE = 1 << 5,
53 FLAG_QUIET = 1 << 6,
54};
55#define OPTION_STR "neAapwq"
56
57static void sysctl_dots_to_slashes(char *name)
58{
59 char *cptr, *last_good, *end, *slash;
60 char end_ch;
61
62 end = strchrnul(name, '=');
63
64 slash = strchrnul(name, '/');
65 if (slash < end
66 && strchrnul(name, '.') < slash
67 ) {
68
69
70
71
72
73
74
75
76 while (end != name) {
77 end--;
78 if (*end == '.') *end = '/';
79 else if (*end == '/') *end = '.';
80 }
81 return;
82 }
83
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100
101
102
103 end_ch = *end;
104 *end = '.';
105
106 last_good = name - 1;
107 again:
108 cptr = end;
109 while (cptr > last_good) {
110 if (*cptr == '.') {
111 *cptr = '\0';
112
113 if (access(name, F_OK) == 0) {
114 *cptr = '/';
115
116 last_good = cptr;
117 goto again;
118 }
119 *cptr = '.';
120 }
121 cptr--;
122 }
123 *end = end_ch;
124}
125
126static int sysctl_act_on_setting(char *setting)
127{
128 int fd, retval = EXIT_SUCCESS;
129 char *cptr, *outname;
130 char *value = value;
131 bool writing = (option_mask32 & FLAG_WRITE);
132
133 outname = xstrdup(setting);
134
135 cptr = outname;
136 while (*cptr) {
137 if (*cptr == '/')
138 *cptr = '.';
139 else if (*cptr == '.')
140 *cptr = '/';
141 cptr++;
142 }
143
144 cptr = strchr(setting, '=');
145 if (cptr)
146 writing = 1;
147 if (writing) {
148 if (!cptr) {
149 bb_error_msg("error: '%s' must be of the form name=value",
150 outname);
151 retval = EXIT_FAILURE;
152 goto end;
153 }
154 value = cptr + 1;
155 if (setting == cptr
156
157 ) {
158 bb_error_msg("error: malformed setting '%s'", outname);
159 retval = EXIT_FAILURE;
160 goto end;
161 }
162 *cptr = '\0';
163 outname[cptr - setting] = '\0';
164
165 fd = open(setting, O_WRONLY|O_CREAT|O_TRUNC, 0666);
166 } else {
167 fd = open(setting, O_RDONLY);
168 }
169
170 if (fd < 0) {
171 switch (errno) {
172 case ENOENT:
173 if (option_mask32 & FLAG_SHOW_KEY_ERRORS)
174 bb_error_msg("error: '%s' is an unknown key", outname);
175 break;
176 case EACCES:
177
178 if (!writing)
179 goto end;
180
181 default:
182 bb_perror_msg("error %sing key '%s'",
183 writing ?
184 "sett" : "read",
185 outname);
186 break;
187 }
188 retval = EXIT_FAILURE;
189 goto end;
190 }
191
192 if (writing) {
193
194 xwrite_str(fd, value);
195 close(fd);
196 if (!(option_mask32 & FLAG_QUIET)) {
197 if (option_mask32 & FLAG_SHOW_KEYS)
198 printf("%s = ", outname);
199 puts(value);
200 }
201 } else {
202 char c;
203
204 value = cptr = xmalloc_read(fd, NULL);
205 close(fd);
206 if (value == NULL) {
207 bb_perror_msg("error reading key '%s'", outname);
208 retval = EXIT_FAILURE;
209 goto end;
210 }
211
212
213
214
215 while ((c = *cptr) != '\0') {
216 if (option_mask32 & FLAG_SHOW_KEYS)
217 printf("%s = ", outname);
218 while (1) {
219 fputc(c, stdout);
220 cptr++;
221 if (c == '\n')
222 break;
223 c = *cptr;
224 if (c == '\0')
225 break;
226 }
227 }
228 free(value);
229 }
230 end:
231 free(outname);
232 return retval;
233}
234
235static int sysctl_act_recursive(const char *path)
236{
237 struct stat buf;
238 int retval = 0;
239
240 if (!(option_mask32 & FLAG_WRITE)
241 && !strchr(path, '=')
242 && stat(path, &buf) == 0
243 && S_ISDIR(buf.st_mode)
244 ) {
245 struct dirent *entry;
246 DIR *dirp;
247
248 dirp = opendir(path);
249 if (dirp == NULL)
250 return -1;
251 while ((entry = readdir(dirp)) != NULL) {
252 char *next = concat_subpath_file(path, entry->d_name);
253 if (next == NULL)
254 continue;
255
256 retval |= sysctl_act_recursive((next[0] == '.' && next[1] == '/') ?
257 next + 2 : next);
258 free(next);
259 }
260 closedir(dirp);
261 } else {
262 char *name = xstrdup(path);
263 retval |= sysctl_act_on_setting(name);
264 free(name);
265 }
266
267 return retval;
268}
269
270
271
272
273
274static int sysctl_handle_preload_file(const char *filename)
275{
276 char *token[2];
277 parser_t *parser;
278 int parse_flags;
279
280 parser = config_open(filename);
281
282 xchdir("/proc/sys");
283
284 parse_flags = 0;
285 parse_flags &= ~PARSE_COLLAPSE;
286 parse_flags &= ~PARSE_TRIM;
287 parse_flags |= PARSE_GREEDY;
288 parse_flags &= ~PARSE_MIN_DIE;
289 parse_flags &= ~PARSE_EOL_COMMENTS;
290 parse_flags |= PARSE_ALT_COMMENTS;
291
292 parse_flags |= PARSE_WS_COMMENTS;
293 while (config_read(parser, token, 2, 2, ";#=", parse_flags)) {
294 char *tp;
295
296 trim(token[1]);
297 tp = trim(token[0]);
298 sysctl_dots_to_slashes(token[0]);
299
300
301 *tp++ = '=';
302 overlapping_strcpy(tp, token[1]);
303
304 sysctl_act_on_setting(token[0]);
305 }
306 if (ENABLE_FEATURE_CLEAN_UP)
307 config_close(parser);
308 return 0;
309}
310
311int sysctl_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
312int sysctl_main(int argc UNUSED_PARAM, char **argv)
313{
314 int retval;
315 int opt;
316
317 opt = getopt32(argv, "+" OPTION_STR);
318 argv += optind;
319 opt ^= (FLAG_SHOW_KEYS | FLAG_SHOW_KEY_ERRORS);
320 option_mask32 = opt;
321
322 if (opt & FLAG_PRELOAD_FILE) {
323 int cur_dir_fd;
324 option_mask32 |= FLAG_WRITE;
325 if (!*argv)
326 *--argv = (char*)"/etc/sysctl.conf";
327 cur_dir_fd = xopen(".", O_RDONLY | O_DIRECTORY);
328 do {
329
330 sysctl_handle_preload_file(*argv);
331 xfchdir(cur_dir_fd);
332 } while (*++argv);
333 return 0;
334 }
335 xchdir("/proc/sys");
336 if (opt & (FLAG_TABLE_FORMAT | FLAG_SHOW_ALL)) {
337 return sysctl_act_recursive(".");
338 }
339
340
341
342 retval = 0;
343 while (*argv) {
344 sysctl_dots_to_slashes(*argv);
345 retval |= sysctl_act_recursive(*argv);
346 argv++;
347 }
348
349 return retval;
350}
351