1 /* makedevs.c - Make ranges of device files.
2  *
3  * Copyright 2014 Bilal Qureshi <bilal.jmi@gmail.com>
4  * Copyright 2014 Kyungwan Han <asura321@gmail.com>
5  *
6  * No Standard
7 
8 USE_MAKEDEVS(NEWTOY(makedevs, "<1>1d:", TOYFLAG_USR|TOYFLAG_BIN))
9 
10 config MAKEDEVS
11   bool "makedevs"
12   default y
13   help
14     usage: makedevs [-d device_table] rootdir
15 
16     Create a range of special files as specified in a device table.
17 
18     -d	file containing device table (default reads from stdin)
19 
20     Each line of of the device table has the fields:
21     <name> <type> <mode> <uid> <gid> <major> <minor> <start> <increment> <count>
22     Where name is the file name, and type is one of the following:
23 
24     b	Block device
25     c	Character device
26     d	Directory
27     f	Regular file
28     p	Named pipe (fifo)
29 
30     Other fields specify permissions, user and group id owning the file,
31     and additional fields for device special files. Use '-' for blank entries,
32     unspecified fields are treated as '-'.
33 */
34 
35 #define FOR_makedevs
36 #include "toys.h"
37 
GLOBALS(char * fname;)38 GLOBALS(
39   char *fname;
40 )
41 
42 void makedevs_main()
43 {
44   int fd = 0, line_no, i;
45   char *line = NULL;
46 
47   // Open file and chdir, verbosely
48   xprintf("rootdir = %s\n", *toys.optargs);
49   if (toys.optflags & FLAG_d && strcmp(TT.fname, "-")) {
50     fd = xopen(TT.fname, O_RDONLY);
51     xprintf("table = %s\n", TT.fname);
52   } else xprintf("table = <stdin>\n");
53   xchdir(*toys.optargs);
54 
55   for (line_no = 0; (line = get_line(fd)); free(line)) {
56     char type=0, user[64], group[64], *node, *ptr = line;
57     unsigned int mode = 0755, major = 0, minor = 0, cnt = 0, incr = 0,
58                  st_val = 0;
59     uid_t uid;
60     gid_t gid;
61     struct stat st;
62 
63     line_no++;
64     while (isspace(*ptr)) ptr++;
65     if (!*ptr || *ptr == '#') continue;
66     node = ptr;
67 
68     while (*ptr && !isspace(*ptr)) ptr++;
69     if (*ptr) *(ptr++) = 0;
70     *user = *group = 0;
71     sscanf(ptr, "%c %o %63s %63s %u %u %u %u %u", &type, &mode,
72            user, group, &major, &minor, &st_val, &incr, &cnt);
73 
74     // type order here needs to line up with actions[] order.
75     i = stridx("pcbdf", type);
76     if (i == -1) {
77       error_msg("line %d: bad type %c", line_no, type);
78       continue;
79     } else mode |= (mode_t[]){S_IFIFO, S_IFCHR, S_IFBLK, 0, 0}[i];
80 
81     uid = *user ? xgetpwnamid(user)->pw_uid : getuid();
82     gid = *group ? xgetgrnamid(group)->gr_gid : getgid();
83 
84     while (*node == '/') node++; // using relative path
85 
86     for (i = 0; (!cnt && !i) || i < cnt; i++) {
87       if (cnt>1) {
88         snprintf(toybuf, sizeof(toybuf), "%.999s%u", node, st_val + i);
89         ptr = toybuf;
90       } else ptr = node;
91 
92       if (type == 'd') {
93         if (mkpathat(AT_FDCWD, ptr, mode, 3))  {
94           perror_msg("can't create directory '%s'", ptr);
95           continue;
96         }
97       } else if (type == 'f') {
98         if (stat(ptr, &st) || !S_ISREG(st.st_mode)) {
99           perror_msg("line %d: file '%s' does not exist", line_no, ptr);
100           continue;
101         }
102       } else if (mknod(ptr, mode, makedev(major, minor + i*incr))) {
103         perror_msg("line %d: can't create node '%s'", line_no, ptr);
104         continue;
105       }
106 
107       if (chown(ptr, uid, gid) || chmod(ptr, mode))
108         perror_msg("line %d: can't chown/chmod '%s'", line_no, ptr);
109     }
110   }
111   xclose(fd);
112 }
113