1 /*
2 * kmod-static-nodes - manage modules.devname
3 *
4 * Copyright (C) 2004-2012 Kay Sievers <kay@vrfy.org>
5 * Copyright (C) 2011-2013 ProFUSION embedded systems
6 * Copyright (C) 2013 Tom Gundersen <teg@jklm.no>
7 *
8 * This program is free software: you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation, either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program. If not, see <http://www.gnu.org/licenses/>.
20 */
21
22 #include <errno.h>
23 #include <getopt.h>
24 #include <limits.h>
25 #include <stddef.h>
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <string.h>
29 #include <unistd.h>
30 #include <sys/stat.h>
31 #include <sys/types.h>
32 #include <sys/utsname.h>
33
34 #include <shared/util.h>
35
36 #include "kmod.h"
37
38 struct static_nodes_format {
39 const char *name;
40 int (*write)(FILE *, char[], char[], char, unsigned int, unsigned int);
41 const char *description;
42 };
43
44 static const struct static_nodes_format static_nodes_format_human;
45 static const struct static_nodes_format static_nodes_format_tmpfiles;
46 static const struct static_nodes_format static_nodes_format_devname;
47
48 static const struct static_nodes_format *static_nodes_formats[] = {
49 &static_nodes_format_human,
50 &static_nodes_format_tmpfiles,
51 &static_nodes_format_devname,
52 };
53
54 static const char cmdopts_s[] = "o:f:h";
55 static const struct option cmdopts[] = {
56 { "output", required_argument, 0, 'o'},
57 { "format", required_argument, 0, 'f'},
58 { "help", no_argument, 0, 'h'},
59 { },
60 };
61
write_human(FILE * out,char modname[],char devname[],char type,unsigned int maj,unsigned int min)62 static int write_human(FILE *out, char modname[], char devname[], char type, unsigned int maj, unsigned int min)
63 {
64 int ret;
65
66 ret = fprintf(out,
67 "Module: %s\n"
68 "\tDevice node: /dev/%s\n"
69 "\t\tType: %s device\n"
70 "\t\tMajor: %u\n"
71 "\t\tMinor: %u\n",
72 modname, devname,
73 (type == 'c') ? "character" : "block", maj, min);
74 if (ret >= 0)
75 return EXIT_SUCCESS;
76 else
77 return EXIT_FAILURE;
78 }
79
80 static const struct static_nodes_format static_nodes_format_human = {
81 .name = "human",
82 .write = write_human,
83 .description = "(default) a human readable format. Do not parse.",
84 };
85
write_tmpfiles(FILE * out,char modname[],char devname[],char type,unsigned int maj,unsigned int min)86 static int write_tmpfiles(FILE *out, char modname[], char devname[], char type, unsigned int maj, unsigned int min)
87 {
88 const char *dir;
89 int ret;
90
91 dir = strrchr(devname, '/');
92 if (dir) {
93 ret = fprintf(out, "d /dev/%.*s 0755 - - -\n",
94 (int)(dir - devname), devname);
95 if (ret < 0)
96 return EXIT_FAILURE;
97 }
98
99 ret = fprintf(out, "%c! /dev/%s 0600 - - - %u:%u\n",
100 type, devname, maj, min);
101 if (ret < 0)
102 return EXIT_FAILURE;
103
104 return EXIT_SUCCESS;
105 }
106
107 static const struct static_nodes_format static_nodes_format_tmpfiles = {
108 .name = "tmpfiles",
109 .write = write_tmpfiles,
110 .description = "the tmpfiles.d(5) format used by systemd-tmpfiles.",
111 };
112
write_devname(FILE * out,char modname[],char devname[],char type,unsigned int maj,unsigned int min)113 static int write_devname(FILE *out, char modname[], char devname[], char type, unsigned int maj, unsigned int min)
114 {
115 int ret;
116
117 ret = fprintf(out, "%s %s %c%u:%u\n", modname, devname, type, maj, min);
118 if (ret >= 0)
119 return EXIT_SUCCESS;
120 else
121 return EXIT_FAILURE;
122 }
123
124 static const struct static_nodes_format static_nodes_format_devname = {
125 .name = "devname",
126 .write = write_devname,
127 .description = "the modules.devname format.",
128 };
129
help(void)130 static void help(void)
131 {
132 size_t i;
133
134 printf("Usage:\n"
135 "\t%s static-nodes [options]\n"
136 "\n"
137 "kmod static-nodes outputs the static-node information of the currently running kernel.\n"
138 "\n"
139 "Options:\n"
140 "\t-f, --format=FORMAT choose format to use: see \"Formats\"\n"
141 "\t-o, --output=FILE write output to file\n"
142 "\t-h, --help show this help\n"
143 "\n"
144 "Formats:\n",
145 program_invocation_short_name);
146
147 for (i = 0; i < ARRAY_SIZE(static_nodes_formats); i++) {
148 if (static_nodes_formats[i]->description != NULL) {
149 printf("\t%-12s %s\n", static_nodes_formats[i]->name,
150 static_nodes_formats[i]->description);
151 }
152 }
153 }
154
do_static_nodes(int argc,char * argv[])155 static int do_static_nodes(int argc, char *argv[])
156 {
157 struct utsname kernel;
158 char modules[PATH_MAX], buf[4096];
159 const char *output = "/dev/stdout";
160 FILE *in = NULL, *out = NULL;
161 const struct static_nodes_format *format = &static_nodes_format_human;
162 int r, ret = EXIT_SUCCESS;
163
164 for (;;) {
165 int c, idx = 0, valid;
166 size_t i;
167
168 c = getopt_long(argc, argv, cmdopts_s, cmdopts, &idx);
169 if (c == -1) {
170 break;
171 }
172 switch (c) {
173 case 'o':
174 output = optarg;
175 break;
176 case 'f':
177 valid = 0;
178
179 for (i = 0; i < ARRAY_SIZE(static_nodes_formats); i++) {
180 if (streq(static_nodes_formats[i]->name, optarg)) {
181 format = static_nodes_formats[i];
182 valid = 1;
183 }
184 }
185
186 if (!valid) {
187 fprintf(stderr, "Unknown format: '%s'.\n",
188 optarg);
189 help();
190 ret = EXIT_FAILURE;
191 goto finish;
192 }
193 break;
194 case 'h':
195 help();
196 goto finish;
197 case '?':
198 ret = EXIT_FAILURE;
199 goto finish;
200 default:
201 fprintf(stderr, "Unexpected commandline option '%c'.\n",
202 c);
203 help();
204 ret = EXIT_FAILURE;
205 goto finish;
206 }
207 }
208
209 if (uname(&kernel) < 0) {
210 fputs("Error: uname failed!\n", stderr);
211 ret = EXIT_FAILURE;
212 goto finish;
213 }
214
215 snprintf(modules, sizeof(modules), "/lib/modules/%s/modules.devname", kernel.release);
216 in = fopen(modules, "re");
217 if (in == NULL) {
218 if (errno == ENOENT) {
219 fprintf(stderr, "Warning: /lib/modules/%s/modules.devname not found - ignoring\n",
220 kernel.release);
221 ret = EXIT_SUCCESS;
222 } else {
223 fprintf(stderr, "Error: could not open /lib/modules/%s/modules.devname - %m\n",
224 kernel.release);
225 ret = EXIT_FAILURE;
226 }
227 goto finish;
228 }
229
230 r = mkdir_parents(output, 0755);
231 if (r < 0) {
232 fprintf(stderr, "Error: could not create parent directory for %s - %m.\n", output);
233 ret = EXIT_FAILURE;
234 goto finish;
235 }
236
237 out = fopen(output, "we");
238 if (out == NULL) {
239 fprintf(stderr, "Error: could not create %s - %m\n", output);
240 ret = EXIT_FAILURE;
241 goto finish;
242 }
243
244 while (fgets(buf, sizeof(buf), in) != NULL) {
245 char modname[PATH_MAX];
246 char devname[PATH_MAX];
247 char type;
248 unsigned int maj, min;
249 int matches;
250
251 if (buf[0] == '#')
252 continue;
253
254 matches = sscanf(buf, "%s %s %c%u:%u", modname, devname,
255 &type, &maj, &min);
256 if (matches != 5 || (type != 'c' && type != 'b')) {
257 fprintf(stderr, "Error: invalid devname entry: %s", buf);
258 ret = EXIT_FAILURE;
259 continue;
260 }
261
262 format->write(out, modname, devname, type, maj, min);
263 }
264
265 finish:
266 if (in)
267 fclose(in);
268 if (out)
269 fclose(out);
270 return ret;
271 }
272
273 const struct kmod_cmd kmod_cmd_static_nodes = {
274 .name = "static-nodes",
275 .cmd = do_static_nodes,
276 .help = "outputs the static-node information installed with the currently running kernel",
277 };
278