Contents of /tags/mkinitrd-6_5_1/busybox/procps/sysctl.c
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Wed Sep 7 17:51:16 2011 UTC (13 years ago) by niro
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Wed Sep 7 17:51:16 2011 UTC (13 years ago) by niro
File MIME type: text/plain
File size: 6208 byte(s)
tagged 'mkinitrd-6_5_1'
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 - added -p <preload> to preload values from a file |
11 | * v1.01.1 - busybox applet aware by <solar@gentoo.org> |
12 | */ |
13 | |
14 | #include "libbb.h" |
15 | |
16 | enum { |
17 | FLAG_SHOW_KEYS = 1 << 0, |
18 | FLAG_SHOW_KEY_ERRORS = 1 << 1, |
19 | FLAG_TABLE_FORMAT = 1 << 2, /* not implemented */ |
20 | FLAG_SHOW_ALL = 1 << 3, |
21 | FLAG_PRELOAD_FILE = 1 << 4, |
22 | FLAG_WRITE = 1 << 5, |
23 | }; |
24 | #define OPTION_STR "neAapw" |
25 | |
26 | static void sysctl_dots_to_slashes(char *name) |
27 | { |
28 | char *cptr, *last_good, *end; |
29 | |
30 | /* Convert minimum number of '.' to '/' so that |
31 | * we end up with existing file's name. |
32 | * |
33 | * Example from bug 3894: |
34 | * net.ipv4.conf.eth0.100.mc_forwarding -> |
35 | * net/ipv4/conf/eth0.100/mc_forwarding |
36 | * NB: net/ipv4/conf/eth0/mc_forwarding *also exists*, |
37 | * therefore we must start from the end, and if |
38 | * we replaced even one . -> /, start over again, |
39 | * but never replace dots before the position |
40 | * where last replacement occurred. |
41 | * |
42 | * Another bug we later had is that |
43 | * net.ipv4.conf.eth0.100 |
44 | * (without .mc_forwarding) was mishandled. |
45 | * |
46 | * To set up testing: modprobe 8021q; vconfig add eth0 100 |
47 | */ |
48 | end = name + strlen(name); |
49 | last_good = name - 1; |
50 | *end = '.'; /* trick the loop into trying full name too */ |
51 | |
52 | again: |
53 | cptr = end; |
54 | while (cptr > last_good) { |
55 | if (*cptr == '.') { |
56 | *cptr = '\0'; |
57 | //bb_error_msg("trying:'%s'", name); |
58 | if (access(name, F_OK) == 0) { |
59 | *cptr = '/'; |
60 | //bb_error_msg("replaced:'%s'", name); |
61 | last_good = cptr; |
62 | goto again; |
63 | } |
64 | *cptr = '.'; |
65 | } |
66 | cptr--; |
67 | } |
68 | *end = '\0'; |
69 | } |
70 | |
71 | static int sysctl_act_on_setting(char *setting) |
72 | { |
73 | int fd, retval = EXIT_SUCCESS; |
74 | char *cptr, *outname; |
75 | char *value = value; /* for compiler */ |
76 | |
77 | outname = xstrdup(setting); |
78 | |
79 | cptr = outname; |
80 | while (*cptr) { |
81 | if (*cptr == '/') |
82 | *cptr = '.'; |
83 | cptr++; |
84 | } |
85 | |
86 | if (option_mask32 & FLAG_WRITE) { |
87 | cptr = strchr(setting, '='); |
88 | if (cptr == NULL) { |
89 | bb_error_msg("error: '%s' must be of the form name=value", |
90 | outname); |
91 | retval = EXIT_FAILURE; |
92 | goto end; |
93 | } |
94 | value = cptr + 1; /* point to the value in name=value */ |
95 | if (setting == cptr || !*value) { |
96 | bb_error_msg("error: malformed setting '%s'", outname); |
97 | retval = EXIT_FAILURE; |
98 | goto end; |
99 | } |
100 | *cptr = '\0'; |
101 | outname[cptr - setting] = '\0'; |
102 | /* procps 3.2.7 actually uses these flags */ |
103 | fd = open(setting, O_WRONLY|O_CREAT|O_TRUNC, 0666); |
104 | } else { |
105 | fd = open(setting, O_RDONLY); |
106 | } |
107 | |
108 | if (fd < 0) { |
109 | switch (errno) { |
110 | case ENOENT: |
111 | if (option_mask32 & FLAG_SHOW_KEY_ERRORS) |
112 | bb_error_msg("error: '%s' is an unknown key", outname); |
113 | break; |
114 | default: |
115 | bb_perror_msg("error %sing key '%s'", |
116 | option_mask32 & FLAG_WRITE ? |
117 | "sett" : "read", |
118 | outname); |
119 | break; |
120 | } |
121 | retval = EXIT_FAILURE; |
122 | goto end; |
123 | } |
124 | |
125 | if (option_mask32 & FLAG_WRITE) { |
126 | //TODO: procps 3.2.7 writes "value\n", note trailing "\n" |
127 | xwrite_str(fd, value); |
128 | close(fd); |
129 | if (option_mask32 & FLAG_SHOW_KEYS) |
130 | printf("%s = ", outname); |
131 | puts(value); |
132 | } else { |
133 | char c; |
134 | |
135 | value = cptr = xmalloc_read(fd, NULL); |
136 | close(fd); |
137 | if (value == NULL) { |
138 | bb_perror_msg("error reading key '%s'", outname); |
139 | goto end; |
140 | } |
141 | |
142 | /* dev.cdrom.info and sunrpc.transports, for example, |
143 | * are multi-line. Try "sysctl sunrpc.transports" |
144 | */ |
145 | while ((c = *cptr) != '\0') { |
146 | if (option_mask32 & FLAG_SHOW_KEYS) |
147 | printf("%s = ", outname); |
148 | while (1) { |
149 | fputc(c, stdout); |
150 | cptr++; |
151 | if (c == '\n') |
152 | break; |
153 | c = *cptr; |
154 | if (c == '\0') |
155 | break; |
156 | } |
157 | } |
158 | free(value); |
159 | } |
160 | end: |
161 | free(outname); |
162 | return retval; |
163 | } |
164 | |
165 | static int sysctl_act_recursive(const char *path) |
166 | { |
167 | DIR *dirp; |
168 | struct stat buf; |
169 | struct dirent *entry; |
170 | char *next; |
171 | int retval = 0; |
172 | |
173 | stat(path, &buf); |
174 | if (S_ISDIR(buf.st_mode) && !(option_mask32 & FLAG_WRITE)) { |
175 | dirp = opendir(path); |
176 | if (dirp == NULL) |
177 | return -1; |
178 | while ((entry = readdir(dirp)) != NULL) { |
179 | next = concat_subpath_file(path, entry->d_name); |
180 | if (next == NULL) |
181 | continue; /* d_name is "." or ".." */ |
182 | /* if path was ".", drop "./" prefix: */ |
183 | retval |= sysctl_act_recursive((next[0] == '.' && next[1] == '/') ? |
184 | next + 2 : next); |
185 | free(next); |
186 | } |
187 | closedir(dirp); |
188 | } else { |
189 | char *name = xstrdup(path); |
190 | retval |= sysctl_act_on_setting(name); |
191 | free(name); |
192 | } |
193 | |
194 | return retval; |
195 | } |
196 | |
197 | /* Set sysctl's from a conf file. Format example: |
198 | * # Controls IP packet forwarding |
199 | * net.ipv4.ip_forward = 0 |
200 | */ |
201 | static int sysctl_handle_preload_file(const char *filename) |
202 | { |
203 | char *token[2]; |
204 | parser_t *parser; |
205 | |
206 | parser = config_open(filename); |
207 | /* Must do it _after_ config_open(): */ |
208 | xchdir("/proc/sys"); |
209 | /* xchroot(".") - if you are paranoid */ |
210 | |
211 | //TODO: ';' is comment char too |
212 | //TODO: comment may be only at line start. "var=1 #abc" - "1 #abc" is the value |
213 | // (but _whitespace_ from ends should be trimmed first (and we do it right)) |
214 | //TODO: "var==1" is mishandled (must use "=1" as a value, but uses "1") |
215 | // can it be fixed by removing PARSE_COLLAPSE bit? |
216 | while (config_read(parser, token, 2, 2, "# \t=", PARSE_NORMAL)) { |
217 | char *tp; |
218 | sysctl_dots_to_slashes(token[0]); |
219 | tp = xasprintf("%s=%s", token[0], token[1]); |
220 | sysctl_act_recursive(tp); |
221 | free(tp); |
222 | } |
223 | if (ENABLE_FEATURE_CLEAN_UP) |
224 | config_close(parser); |
225 | return 0; |
226 | } |
227 | |
228 | int sysctl_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
229 | int sysctl_main(int argc UNUSED_PARAM, char **argv) |
230 | { |
231 | int retval; |
232 | int opt; |
233 | |
234 | opt = getopt32(argv, "+" OPTION_STR); /* '+' - stop on first non-option */ |
235 | argv += optind; |
236 | opt ^= (FLAG_SHOW_KEYS | FLAG_SHOW_KEY_ERRORS); |
237 | option_mask32 = opt; |
238 | |
239 | if (opt & FLAG_PRELOAD_FILE) { |
240 | option_mask32 |= FLAG_WRITE; |
241 | /* xchdir("/proc/sys") is inside */ |
242 | return sysctl_handle_preload_file(*argv ? *argv : "/etc/sysctl.conf"); |
243 | } |
244 | xchdir("/proc/sys"); |
245 | /* xchroot(".") - if you are paranoid */ |
246 | if (opt & (FLAG_TABLE_FORMAT | FLAG_SHOW_ALL)) { |
247 | return sysctl_act_recursive("."); |
248 | } |
249 | |
250 | retval = 0; |
251 | while (*argv) { |
252 | sysctl_dots_to_slashes(*argv); |
253 | retval |= sysctl_act_recursive(*argv); |
254 | argv++; |
255 | } |
256 | |
257 | return retval; |
258 | } |