Mercurial > hg > toybox

comparison toys/pending/mdev.c @ 820:c4284bb4016c

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Move mdev into the pending directory, since it's not done yet.
author Rob Landley <rob@landley.net>
date Sat, 16 Mar 2013 10:54:38 -0500
parents toys/other/mdev.c@786841fdb1e0
children 63db77909fc8
comparison
equal deleted inserted replaced
819:547f6c1d6972 820:c4284bb4016c
1 /* mdev.c - Populate /dev directory and handle hotplug events
2 *
3 * Copyright 2005, 2008 Rob Landley <rob@landley.net>
4 * Copyright 2005 Frank Sorenson <frank@tuxrocks.com>
5
6 USE_MDEV(NEWTOY(mdev, "s", TOYFLAG_USR|TOYFLAG_BIN|TOYFLAG_UMASK))
7
8 config MDEV
9 bool "mdev"
10 default n
11 help
12 usage: mdev [-s]
13
14 Create devices in /dev using information from /sys.
15
16 -s Scan all entries in /sys to populate /dev.
17
18 config MDEV_CONF
19 bool "Configuration file for mdev"
20 default y
21 depends on MDEV
22 help
23 The mdev config file (/etc/mdev.conf) contains lines that look like:
24 hd[a-z][0-9]* 0:3 660
25
26 Each line must contain three whitespace separated fields. The first
27 field is a regular expression matching one or more device names, and
28 the second and third fields are uid:gid and file permissions for
29 matching devies.
30 */
31
32 #include "toys.h"
33 #include "lib/xregcomp.h"
34
35 // todo, open() block devices to trigger partition scanning.
36
37 // mknod in /dev based on a path like "/sys/block/hda/hda1"
38 static void make_device(char *path)
39 {
40 char *device_name, *s, *temp;
41 int major, minor, type, len, fd;
42 int mode = 0660;
43 uid_t uid = 0;
44 gid_t gid = 0;
45
46 // Try to read major/minor string
47
48 temp = strrchr(path, '/');
49 fd = open(path, O_RDONLY);
50 *temp=0;
51 temp = toybuf;
52 len = read(fd, temp, 64);
53 close(fd);
54 if (len<1) return;
55 temp[len] = 0;
56
57 // Determine device name, type, major and minor
58
59 device_name = strrchr(path, '/') + 1;
60 type = path[5]=='c' ? S_IFCHR : S_IFBLK;
61 major = minor = 0;
62 sscanf(temp, "%u:%u", &major, &minor);
63
64 // If we have a config file, look up permissions for this device
65
66 if (CFG_MDEV_CONF) {
67 char *conf, *pos, *end;
68
69 // mmap the config file
70 if (-1!=(fd = open("/etc/mdev.conf", O_RDONLY))) {
71 len = fdlength(fd);
72 conf = mmap(NULL, len, PROT_READ, MAP_PRIVATE, fd, 0);
73 if (conf) {
74 int line = 0;
75
76 // Loop through lines in mmaped file
77 for (pos = conf; pos-conf<len;) {
78 int field;
79 char *end2;
80
81 line++;
82 // find end of this line
83 for(end = pos; end-conf<len && *end!='\n'; end++);
84
85 // Three fields: regex, uid:gid, mode
86 for (field = 3; field; field--) {
87 // Skip whitespace
88 while (pos<end && isspace(*pos)) pos++;
89 if (pos==end || *pos=='#') break;
90 for (end2 = pos;
91 end2<end && !isspace(*end2) && *end2!='#'; end2++);
92 switch(field) {
93 // Regex to match this device
94 case 3:
95 {
96 char *regex = strndup(pos, end2-pos);
97 regex_t match;
98 regmatch_t off;
99 int result;
100
101 // Is this it?
102 xregcomp(&match, regex, REG_EXTENDED);
103 result=regexec(&match, device_name, 1, &off, 0);
104 regfree(&match);
105 free(regex);
106
107 // If not this device, skip rest of line
108 if (result || off.rm_so
109 || off.rm_eo!=strlen(device_name))
110 goto end_line;
111
112 break;
113 }
114 // uid:gid
115 case 2:
116 {
117 char *s2;
118
119 // Find :
120 for(s = pos; s<end2 && *s!=':'; s++);
121 if (s==end2) goto end_line;
122
123 // Parse UID
124 uid = strtoul(pos,&s2,10);
125 if (s!=s2) {
126 struct passwd *pass;
127 char *str = strndup(pos, s-pos);
128 pass = getpwnam(str);
129 free(str);
130 if (!pass) goto end_line;
131 uid = pass->pw_uid;
132 }
133 s++;
134 // parse GID
135 gid = strtoul(s,&s2,10);
136 if (end2!=s2) {
137 struct group *grp;
138 char *str = strndup(s, end2-s);
139 grp = getgrnam(str);
140 free(str);
141 if (!grp) goto end_line;
142 gid = grp->gr_gid;
143 }
144 break;
145 }
146 // mode
147 case 1:
148 {
149 mode = strtoul(pos, &pos, 8);
150 if (pos!=end2) goto end_line;
151 goto found_device;
152 }
153 }
154 pos=end2;
155 }
156 end_line:
157 // Did everything parse happily?
158 if (field && field!=3) error_exit("Bad line %d", line);
159
160 // Next line
161 pos = ++end;
162 }
163 found_device:
164 munmap(conf, len);
165 }
166 close(fd);
167 }
168 }
169
170 sprintf(temp, "/dev/%s", device_name);
171 if (mknod(temp, mode | type, makedev(major, minor)) && errno != EEXIST)
172 perror_exit("mknod %s failed", temp);
173
174 if (CFG_MDEV_CONF) mode=chown(temp, uid, gid);
175 }
176
177 static int callback(struct dirtree *node)
178 {
179 // Entries in /sys/class/block aren't char devices, so skip 'em. (We'll
180 // get block devices out of /sys/block.)
181 if(!strcmp(node->name, "block")) return 0;
182
183 // Does this directory have a "dev" entry in it?
184 // This is path based because the hotplug callbacks are
185 if (S_ISDIR(node->st.st_mode) || S_ISLNK(node->st.st_mode)) {
186 int len=4;
187 char *dev = dirtree_path(node, &len);
188 strcpy(dev+len, "/dev");
189 if (!access(dev, R_OK)) make_device(dev);
190 free(dev);
191 }
192
193 // Circa 2.6.25 the entries more than 2 deep are all either redundant
194 // (mouse#, event#) or unnamed (every usb_* entry is called "device").
195
196 return (node->parent && node->parent->parent) ? 0 : DIRTREE_RECURSE;
197 }
198
199 void mdev_main(void)
200 {
201 // Handle -s
202
203 if (toys.optflags) {
204 dirtree_read("/sys/class", callback);
205 dirtree_read("/sys/block", callback);
206 }
207
208 // hotplug support goes here
209 }