Contents of /tags/mkinitrd-6_1_4/busybox/procps/sysctl.c
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Wed Aug 5 16:25:39 2009 UTC (15 years, 1 month ago) by niro
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Wed Aug 5 16:25:39 2009 UTC (15 years, 1 month ago) by niro
File MIME type: text/plain
File size: 6436 byte(s)
tagged 'mkinitrd-6_1_4'
1 | /* vi: set sw=4 ts=4: */ |
2 | /* |
3 | * Sysctl 1.01 - A utility to read and manipulate the sysctl parameters |
4 | * |
5 | * Copyright 1999 George Staikos |
6 | * |
7 | * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. |
8 | * |
9 | * Changelog: |
10 | * v1.01: |
11 | * - added -p <preload> to preload values from a file |
12 | * v1.01.1 |
13 | * - busybox applet aware by <solar@gentoo.org> |
14 | * |
15 | */ |
16 | |
17 | #include "libbb.h" |
18 | |
19 | static int sysctl_read_setting(const char *setting); |
20 | static int sysctl_write_setting(const char *setting); |
21 | static int sysctl_display_all(const char *path); |
22 | static int sysctl_preload_file_and_exit(const char *filename); |
23 | static void sysctl_dots_to_slashes(char *name); |
24 | |
25 | static const char ETC_SYSCTL_CONF[] ALIGN1 = "/etc/sysctl.conf"; |
26 | static const char PROC_SYS[] ALIGN1 = "/proc/sys/"; |
27 | enum { strlen_PROC_SYS = sizeof(PROC_SYS) - 1 }; |
28 | |
29 | static const char msg_unknown_key[] ALIGN1 = |
30 | "error: '%s' is an unknown key"; |
31 | |
32 | static void dwrite_str(int fd, const char *buf) |
33 | { |
34 | write(fd, buf, strlen(buf)); |
35 | } |
36 | |
37 | enum { |
38 | FLAG_SHOW_KEYS = 1 << 0, |
39 | FLAG_SHOW_KEY_ERRORS = 1 << 1, |
40 | FLAG_TABLE_FORMAT = 1 << 2, /* not implemented */ |
41 | FLAG_SHOW_ALL = 1 << 3, |
42 | FLAG_PRELOAD_FILE = 1 << 4, |
43 | FLAG_WRITE = 1 << 5, |
44 | }; |
45 | |
46 | int sysctl_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
47 | int sysctl_main(int argc UNUSED_PARAM, char **argv) |
48 | { |
49 | int retval; |
50 | int opt; |
51 | |
52 | opt = getopt32(argv, "+neAapw"); /* '+' - stop on first non-option */ |
53 | argv += optind; |
54 | opt ^= (FLAG_SHOW_KEYS | FLAG_SHOW_KEY_ERRORS); |
55 | option_mask32 ^= (FLAG_SHOW_KEYS | FLAG_SHOW_KEY_ERRORS); |
56 | |
57 | if (opt & (FLAG_TABLE_FORMAT | FLAG_SHOW_ALL)) |
58 | return sysctl_display_all(PROC_SYS); |
59 | if (opt & FLAG_PRELOAD_FILE) |
60 | return sysctl_preload_file_and_exit(*argv ? *argv : ETC_SYSCTL_CONF); |
61 | |
62 | retval = 0; |
63 | while (*argv) { |
64 | if (opt & FLAG_WRITE) |
65 | retval |= sysctl_write_setting(*argv); |
66 | else |
67 | retval |= sysctl_read_setting(*argv); |
68 | argv++; |
69 | } |
70 | |
71 | return retval; |
72 | } /* end sysctl_main() */ |
73 | |
74 | /* Set sysctl's from a conf file. Format example: |
75 | * # Controls IP packet forwarding |
76 | * net.ipv4.ip_forward = 0 |
77 | */ |
78 | static int sysctl_preload_file_and_exit(const char *filename) |
79 | { |
80 | char *token[2]; |
81 | parser_t *parser; |
82 | |
83 | parser = config_open(filename); |
84 | // TODO: ';' is comment char too |
85 | while (config_read(parser, token, 2, 2, "# \t=", PARSE_NORMAL)) { |
86 | #if 0 |
87 | char *s = xasprintf("%s=%s", token[0], token[1]); |
88 | sysctl_write_setting(s); |
89 | free(s); |
90 | #else /* Save ~4 bytes by using parser internals */ |
91 | sprintf(parser->line, "%s=%s", token[0], token[1]); // must have room by definition |
92 | sysctl_write_setting(parser->line); |
93 | #endif |
94 | } |
95 | if (ENABLE_FEATURE_CLEAN_UP) |
96 | config_close(parser); |
97 | return 0; |
98 | } /* end sysctl_preload_file_and_exit() */ |
99 | |
100 | static int sysctl_write_setting(const char *setting) |
101 | { |
102 | int retval; |
103 | const char *name; |
104 | const char *value; |
105 | const char *equals; |
106 | char *tmpname, *outname, *cptr; |
107 | int fd; |
108 | |
109 | name = setting; |
110 | equals = strchr(setting, '='); |
111 | if (!equals) { |
112 | bb_error_msg("error: '%s' must be of the form name=value", setting); |
113 | return EXIT_FAILURE; |
114 | } |
115 | |
116 | value = equals + 1; /* point to the value in name=value */ |
117 | if (name == equals || !*value) { |
118 | bb_error_msg("error: malformed setting '%s'", setting); |
119 | return EXIT_FAILURE; |
120 | } |
121 | |
122 | tmpname = xasprintf("%s%.*s", PROC_SYS, (int)(equals - name), name); |
123 | outname = xstrdup(tmpname + strlen_PROC_SYS); |
124 | |
125 | sysctl_dots_to_slashes(tmpname); |
126 | |
127 | while ((cptr = strchr(outname, '/')) != NULL) |
128 | *cptr = '.'; |
129 | |
130 | fd = open(tmpname, O_WRONLY | O_CREAT | O_TRUNC, 0666); |
131 | if (fd < 0) { |
132 | switch (errno) { |
133 | case ENOENT: |
134 | if (option_mask32 & FLAG_SHOW_KEY_ERRORS) |
135 | bb_error_msg(msg_unknown_key, outname); |
136 | break; |
137 | default: |
138 | bb_perror_msg("error setting key '%s'", outname); |
139 | break; |
140 | } |
141 | retval = EXIT_FAILURE; |
142 | } else { |
143 | dwrite_str(fd, value); |
144 | close(fd); |
145 | if (option_mask32 & FLAG_SHOW_KEYS) { |
146 | printf("%s = ", outname); |
147 | } |
148 | puts(value); |
149 | retval = EXIT_SUCCESS; |
150 | } |
151 | |
152 | free(tmpname); |
153 | free(outname); |
154 | return retval; |
155 | } /* end sysctl_write_setting() */ |
156 | |
157 | static int sysctl_read_setting(const char *name) |
158 | { |
159 | int retval; |
160 | char *tmpname, *outname, *cptr; |
161 | char inbuf[1025]; |
162 | FILE *fp; |
163 | |
164 | if (!*name) { |
165 | if (option_mask32 & FLAG_SHOW_KEY_ERRORS) |
166 | bb_error_msg(msg_unknown_key, name); |
167 | return -1; |
168 | } |
169 | |
170 | tmpname = concat_path_file(PROC_SYS, name); |
171 | outname = xstrdup(tmpname + strlen_PROC_SYS); |
172 | |
173 | sysctl_dots_to_slashes(tmpname); |
174 | |
175 | while ((cptr = strchr(outname, '/')) != NULL) |
176 | *cptr = '.'; |
177 | |
178 | fp = fopen_for_read(tmpname); |
179 | if (fp == NULL) { |
180 | switch (errno) { |
181 | case ENOENT: |
182 | if (option_mask32 & FLAG_SHOW_KEY_ERRORS) |
183 | bb_error_msg(msg_unknown_key, outname); |
184 | break; |
185 | default: |
186 | bb_perror_msg("error reading key '%s'", outname); |
187 | break; |
188 | } |
189 | retval = EXIT_FAILURE; |
190 | } else { |
191 | while (fgets(inbuf, sizeof(inbuf) - 1, fp)) { |
192 | if (option_mask32 & FLAG_SHOW_KEYS) { |
193 | printf("%s = ", outname); |
194 | } |
195 | fputs(inbuf, stdout); |
196 | } |
197 | fclose(fp); |
198 | retval = EXIT_SUCCESS; |
199 | } |
200 | |
201 | free(tmpname); |
202 | free(outname); |
203 | return retval; |
204 | } /* end sysctl_read_setting() */ |
205 | |
206 | static int sysctl_display_all(const char *path) |
207 | { |
208 | int retval = EXIT_SUCCESS; |
209 | DIR *dp; |
210 | struct dirent *de; |
211 | char *tmpdir; |
212 | struct stat ts; |
213 | |
214 | dp = opendir(path); |
215 | if (!dp) { |
216 | return EXIT_FAILURE; |
217 | } |
218 | while ((de = readdir(dp)) != NULL) { |
219 | tmpdir = concat_subpath_file(path, de->d_name); |
220 | if (tmpdir == NULL) |
221 | continue; /* . or .. */ |
222 | if (stat(tmpdir, &ts) != 0) { |
223 | bb_perror_msg(tmpdir); |
224 | } else if (S_ISDIR(ts.st_mode)) { |
225 | retval |= sysctl_display_all(tmpdir); |
226 | } else { |
227 | retval |= sysctl_read_setting(tmpdir + strlen_PROC_SYS); |
228 | } |
229 | free(tmpdir); |
230 | } /* end while */ |
231 | closedir(dp); |
232 | |
233 | return retval; |
234 | } /* end sysctl_display_all() */ |
235 | |
236 | static void sysctl_dots_to_slashes(char *name) |
237 | { |
238 | char *cptr, *last_good, *end; |
239 | |
240 | /* It can be good as-is! */ |
241 | if (access(name, F_OK) == 0) |
242 | return; |
243 | |
244 | /* Example from bug 3894: |
245 | * net.ipv4.conf.eth0.100.mc_forwarding -> |
246 | * net/ipv4/conf/eth0.100/mc_forwarding. NB: |
247 | * net/ipv4/conf/eth0/mc_forwarding *also exists*, |
248 | * therefore we must start from the end, and if |
249 | * we replaced even one . -> /, start over again, |
250 | * but never replace dots before the position |
251 | * where replacement occurred. */ |
252 | end = name + strlen(name) - 1; |
253 | last_good = name - 1; |
254 | again: |
255 | cptr = end; |
256 | while (cptr > last_good) { |
257 | if (*cptr == '.') { |
258 | *cptr = '\0'; |
259 | if (access(name, F_OK) == 0) { |
260 | *cptr = '/'; |
261 | last_good = cptr; |
262 | goto again; |
263 | } |
264 | *cptr = '.'; |
265 | } |
266 | cptr--; |
267 | } |
268 | } /* end sysctl_dots_to_slashes() */ |