diff options
Diffstat (limited to 'busybox/libbb/loop.c')
-rw-r--r-- | busybox/libbb/loop.c | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/busybox/libbb/loop.c b/busybox/libbb/loop.c new file mode 100644 index 000000000..e2287b5ba --- /dev/null +++ b/busybox/libbb/loop.c | |||
@@ -0,0 +1,157 @@ | |||
1 | /* vi: set sw=4 ts=4: */ | ||
2 | /* | ||
3 | * Utility routines. | ||
4 | * | ||
5 | * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org> | ||
6 | * | ||
7 | * This program is free software; you can redistribute it and/or modify | ||
8 | * it under the terms of the GNU General Public License as published by | ||
9 | * the Free Software Foundation; either version 2 of the License, or | ||
10 | * (at your option) any later version. | ||
11 | * | ||
12 | * This program is distributed in the hope that it will be useful, | ||
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | ||
15 | * General Public License for more details. | ||
16 | * | ||
17 | * You should have received a copy of the GNU General Public License | ||
18 | * along with this program; if not, write to the Free Software | ||
19 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | ||
20 | */ | ||
21 | |||
22 | #include <stdio.h> | ||
23 | #include <errno.h> | ||
24 | #include <fcntl.h> | ||
25 | #include <string.h> | ||
26 | #include <unistd.h> | ||
27 | #include <sys/ioctl.h> | ||
28 | #include "libbb.h" | ||
29 | |||
30 | /* Grumble... The 2.6.x kernel breaks asm/posix_types.h | ||
31 | * so we get to try and cope as best we can... */ | ||
32 | #include <linux/version.h> | ||
33 | #include <asm/posix_types.h> | ||
34 | |||
35 | #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0) | ||
36 | #define __bb_kernel_dev_t __kernel_old_dev_t | ||
37 | #elif LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0) | ||
38 | #define __bb_kernel_dev_t __kernel_dev_t | ||
39 | #else | ||
40 | #define __bb_kernel_dev_t unsigned short | ||
41 | #endif | ||
42 | |||
43 | /* Stuff stolen from linux/loop.h */ | ||
44 | #define LO_NAME_SIZE 64 | ||
45 | #define LO_KEY_SIZE 32 | ||
46 | #define LOOP_SET_FD 0x4C00 | ||
47 | #define LOOP_CLR_FD 0x4C01 | ||
48 | #define LOOP_SET_STATUS 0x4C02 | ||
49 | #define LOOP_GET_STATUS 0x4C03 | ||
50 | struct loop_info { | ||
51 | int lo_number; | ||
52 | __bb_kernel_dev_t lo_device; | ||
53 | unsigned long lo_inode; | ||
54 | __bb_kernel_dev_t lo_rdevice; | ||
55 | int lo_offset; | ||
56 | int lo_encrypt_type; | ||
57 | int lo_encrypt_key_size; | ||
58 | int lo_flags; | ||
59 | char lo_name[LO_NAME_SIZE]; | ||
60 | unsigned char lo_encrypt_key[LO_KEY_SIZE]; | ||
61 | unsigned long lo_init[2]; | ||
62 | char reserved[4]; | ||
63 | }; | ||
64 | |||
65 | extern int del_loop(const char *device) | ||
66 | { | ||
67 | int fd; | ||
68 | |||
69 | if ((fd = open(device, O_RDONLY)) < 0) { | ||
70 | bb_perror_msg("%s", device); | ||
71 | return (FALSE); | ||
72 | } | ||
73 | if (ioctl(fd, LOOP_CLR_FD, 0) < 0) { | ||
74 | close(fd); | ||
75 | bb_perror_msg("ioctl: LOOP_CLR_FD"); | ||
76 | return (FALSE); | ||
77 | } | ||
78 | close(fd); | ||
79 | return (TRUE); | ||
80 | } | ||
81 | |||
82 | extern int set_loop(const char *device, const char *file, int offset, | ||
83 | int *loopro) | ||
84 | { | ||
85 | struct loop_info loopinfo; | ||
86 | int fd, ffd, mode; | ||
87 | |||
88 | mode = *loopro ? O_RDONLY : O_RDWR; | ||
89 | if ((ffd = open(file, mode)) < 0 && !*loopro | ||
90 | && (errno != EROFS || (ffd = open(file, mode = O_RDONLY)) < 0)) { | ||
91 | bb_perror_msg("%s", file); | ||
92 | return 1; | ||
93 | } | ||
94 | if ((fd = open(device, mode)) < 0) { | ||
95 | close(ffd); | ||
96 | bb_perror_msg("%s", device); | ||
97 | return 1; | ||
98 | } | ||
99 | *loopro = (mode == O_RDONLY); | ||
100 | |||
101 | memset(&loopinfo, 0, sizeof(loopinfo)); | ||
102 | safe_strncpy(loopinfo.lo_name, file, LO_NAME_SIZE); | ||
103 | |||
104 | loopinfo.lo_offset = offset; | ||
105 | |||
106 | loopinfo.lo_encrypt_key_size = 0; | ||
107 | if (ioctl(fd, LOOP_SET_FD, ffd) < 0) { | ||
108 | bb_perror_msg("ioctl: LOOP_SET_FD"); | ||
109 | close(fd); | ||
110 | close(ffd); | ||
111 | return 1; | ||
112 | } | ||
113 | if (ioctl(fd, LOOP_SET_STATUS, &loopinfo) < 0) { | ||
114 | (void) ioctl(fd, LOOP_CLR_FD, 0); | ||
115 | bb_perror_msg("ioctl: LOOP_SET_STATUS"); | ||
116 | close(fd); | ||
117 | close(ffd); | ||
118 | return 1; | ||
119 | } | ||
120 | close(fd); | ||
121 | close(ffd); | ||
122 | return 0; | ||
123 | } | ||
124 | |||
125 | extern char *find_unused_loop_device(void) | ||
126 | { | ||
127 | char dev[20]; | ||
128 | int i, fd; | ||
129 | struct stat statbuf; | ||
130 | struct loop_info loopinfo; | ||
131 | |||
132 | for (i = 0; i <= 7; i++) { | ||
133 | sprintf(dev, LOOP_FORMAT, i); | ||
134 | if (stat(dev, &statbuf) == 0 && S_ISBLK(statbuf.st_mode)) { | ||
135 | if ((fd = open(dev, O_RDONLY)) >= 0) { | ||
136 | if (ioctl(fd, LOOP_GET_STATUS, &loopinfo) != 0) { | ||
137 | if (errno == ENXIO) { /* probably free */ | ||
138 | close(fd); | ||
139 | return strdup(dev); | ||
140 | } | ||
141 | } | ||
142 | close(fd); | ||
143 | } | ||
144 | } | ||
145 | } | ||
146 | return NULL; | ||
147 | } | ||
148 | |||
149 | |||
150 | /* END CODE */ | ||
151 | /* | ||
152 | Local Variables: | ||
153 | c-file-style: "linux" | ||
154 | c-basic-offset: 4 | ||
155 | tab-width: 4 | ||
156 | End: | ||
157 | */ | ||