Theodore Ts'o | 3839e65 | 1997-04-26 13:21:57 +0000 | [diff] [blame] | 1 | /* |
| 2 | * namei.c --- ext2fs directory lookup operations |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 3 | * |
Theodore Ts'o | 19c78dc | 1997-04-29 16:17:09 +0000 | [diff] [blame] | 4 | * Copyright (C) 1993, 1994, 1994, 1995 Theodore Ts'o. |
| 5 | * |
| 6 | * %Begin-Header% |
Theodore Ts'o | 543547a | 2010-05-17 21:31:56 -0400 | [diff] [blame] | 7 | * This file may be redistributed under the terms of the GNU Library |
| 8 | * General Public License, version 2. |
Theodore Ts'o | 19c78dc | 1997-04-29 16:17:09 +0000 | [diff] [blame] | 9 | * %End-Header% |
Theodore Ts'o | 3839e65 | 1997-04-26 13:21:57 +0000 | [diff] [blame] | 10 | */ |
| 11 | |
Theodore Ts'o | d1154eb | 2011-09-18 17:34:37 -0400 | [diff] [blame] | 12 | #include "config.h" |
Theodore Ts'o | 3839e65 | 1997-04-26 13:21:57 +0000 | [diff] [blame] | 13 | #include <stdio.h> |
| 14 | #include <string.h> |
Theodore Ts'o | 4cbe8af | 1997-08-10 23:07:40 +0000 | [diff] [blame] | 15 | #if HAVE_UNISTD_H |
Theodore Ts'o | 3839e65 | 1997-04-26 13:21:57 +0000 | [diff] [blame] | 16 | #include <unistd.h> |
Theodore Ts'o | 4cbe8af | 1997-08-10 23:07:40 +0000 | [diff] [blame] | 17 | #endif |
Theodore Ts'o | f3db356 | 1997-04-26 13:34:30 +0000 | [diff] [blame] | 18 | |
Theodore Ts'o | 1e3472c | 1997-04-29 14:53:37 +0000 | [diff] [blame] | 19 | /* #define NAMEI_DEBUG */ |
| 20 | |
Theodore Ts'o | b5abe6f | 1998-01-19 14:47:53 +0000 | [diff] [blame] | 21 | #include "ext2_fs.h" |
Theodore Ts'o | 3839e65 | 1997-04-26 13:21:57 +0000 | [diff] [blame] | 22 | #include "ext2fs.h" |
Niu Yawei | 08ae93a | 2011-11-19 23:08:03 -0500 | [diff] [blame] | 23 | #include "ext2fsP.h" |
Theodore Ts'o | 3839e65 | 1997-04-26 13:21:57 +0000 | [diff] [blame] | 24 | |
Theodore Ts'o | 31dbecd | 2001-01-11 04:54:39 +0000 | [diff] [blame] | 25 | static errcode_t open_namei(ext2_filsys fs, ext2_ino_t root, ext2_ino_t base, |
Theodore Ts'o | 3cb6c50 | 1997-08-11 20:29:22 +0000 | [diff] [blame] | 26 | const char *pathname, size_t pathlen, int follow, |
Theodore Ts'o | 31dbecd | 2001-01-11 04:54:39 +0000 | [diff] [blame] | 27 | int link_count, char *buf, ext2_ino_t *res_inode); |
Theodore Ts'o | 1e3472c | 1997-04-29 14:53:37 +0000 | [diff] [blame] | 28 | |
Theodore Ts'o | 31dbecd | 2001-01-11 04:54:39 +0000 | [diff] [blame] | 29 | static errcode_t follow_link(ext2_filsys fs, ext2_ino_t root, ext2_ino_t dir, |
| 30 | ext2_ino_t inode, int link_count, |
| 31 | char *buf, ext2_ino_t *res_inode) |
Theodore Ts'o | 1e3472c | 1997-04-29 14:53:37 +0000 | [diff] [blame] | 32 | { |
| 33 | char *pathname; |
| 34 | char *buffer = 0; |
| 35 | errcode_t retval; |
| 36 | struct ext2_inode ei; |
| 37 | |
| 38 | #ifdef NAMEI_DEBUG |
| 39 | printf("follow_link: root=%lu, dir=%lu, inode=%lu, lc=%d\n", |
| 40 | root, dir, inode, link_count); |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 41 | |
Theodore Ts'o | 1e3472c | 1997-04-29 14:53:37 +0000 | [diff] [blame] | 42 | #endif |
| 43 | retval = ext2fs_read_inode (fs, inode, &ei); |
| 44 | if (retval) return retval; |
| 45 | if (!LINUX_S_ISLNK (ei.i_mode)) { |
| 46 | *res_inode = inode; |
| 47 | return 0; |
| 48 | } |
Niu Yawei | 08ae93a | 2011-11-19 23:08:03 -0500 | [diff] [blame] | 49 | if (link_count++ >= EXT2FS_MAX_NESTED_LINKS) |
Theodore Ts'o | 1e3472c | 1997-04-29 14:53:37 +0000 | [diff] [blame] | 50 | return EXT2_ET_SYMLINK_LOOP; |
Niu Yawei | 08ae93a | 2011-11-19 23:08:03 -0500 | [diff] [blame] | 51 | |
Valerie Aurora Henson | 6d8b37f | 2010-06-13 11:00:00 -0400 | [diff] [blame] | 52 | /* FIXME-64: Actually, this is FIXME EXTENTS */ |
Theodore Ts'o | 795afc4 | 2004-02-21 20:54:31 -0500 | [diff] [blame] | 53 | if (ext2fs_inode_data_blocks(fs,&ei)) { |
Theodore Ts'o | c4e3d3f | 2003-08-01 09:41:07 -0400 | [diff] [blame] | 54 | retval = ext2fs_get_mem(fs->blocksize, &buffer); |
Theodore Ts'o | 7b4e453 | 1997-10-26 03:41:24 +0000 | [diff] [blame] | 55 | if (retval) |
| 56 | return retval; |
Theodore Ts'o | 1e3472c | 1997-04-29 14:53:37 +0000 | [diff] [blame] | 57 | retval = io_channel_read_blk(fs->io, ei.i_block[0], 1, buffer); |
| 58 | if (retval) { |
Theodore Ts'o | c4e3d3f | 2003-08-01 09:41:07 -0400 | [diff] [blame] | 59 | ext2fs_free_mem(&buffer); |
Theodore Ts'o | 1e3472c | 1997-04-29 14:53:37 +0000 | [diff] [blame] | 60 | return retval; |
| 61 | } |
| 62 | pathname = buffer; |
| 63 | } else |
| 64 | pathname = (char *)&(ei.i_block[0]); |
| 65 | retval = open_namei(fs, root, dir, pathname, ei.i_size, 1, |
| 66 | link_count, buf, res_inode); |
| 67 | if (buffer) |
Theodore Ts'o | c4e3d3f | 2003-08-01 09:41:07 -0400 | [diff] [blame] | 68 | ext2fs_free_mem(&buffer); |
Theodore Ts'o | 1e3472c | 1997-04-29 14:53:37 +0000 | [diff] [blame] | 69 | return retval; |
| 70 | } |
| 71 | |
| 72 | /* |
| 73 | * This routine interprets a pathname in the context of the current |
| 74 | * directory and the root directory, and returns the inode of the |
| 75 | * containing directory, and a pointer to the filename of the file |
| 76 | * (pointing into the pathname) and the length of the filename. |
| 77 | */ |
Theodore Ts'o | 31dbecd | 2001-01-11 04:54:39 +0000 | [diff] [blame] | 78 | static errcode_t dir_namei(ext2_filsys fs, ext2_ino_t root, ext2_ino_t dir, |
Theodore Ts'o | 1e3472c | 1997-04-29 14:53:37 +0000 | [diff] [blame] | 79 | const char *pathname, int pathlen, |
| 80 | int link_count, char *buf, |
Theodore Ts'o | 31dbecd | 2001-01-11 04:54:39 +0000 | [diff] [blame] | 81 | const char **name, int *namelen, |
| 82 | ext2_ino_t *res_inode) |
Theodore Ts'o | 1e3472c | 1997-04-29 14:53:37 +0000 | [diff] [blame] | 83 | { |
| 84 | char c; |
| 85 | const char *thisname; |
| 86 | int len; |
Theodore Ts'o | 31dbecd | 2001-01-11 04:54:39 +0000 | [diff] [blame] | 87 | ext2_ino_t inode; |
Theodore Ts'o | 1e3472c | 1997-04-29 14:53:37 +0000 | [diff] [blame] | 88 | errcode_t retval; |
| 89 | |
| 90 | if ((c = *pathname) == '/') { |
| 91 | dir = root; |
| 92 | pathname++; |
| 93 | pathlen--; |
| 94 | } |
| 95 | while (1) { |
| 96 | thisname = pathname; |
| 97 | for (len=0; --pathlen >= 0;len++) { |
| 98 | c = *(pathname++); |
| 99 | if (c == '/') |
| 100 | break; |
| 101 | } |
| 102 | if (pathlen < 0) |
| 103 | break; |
| 104 | retval = ext2fs_lookup (fs, dir, thisname, len, buf, &inode); |
| 105 | if (retval) return retval; |
| 106 | retval = follow_link (fs, root, dir, inode, |
| 107 | link_count, buf, &dir); |
| 108 | if (retval) return retval; |
| 109 | } |
| 110 | *name = thisname; |
| 111 | *namelen = len; |
| 112 | *res_inode = dir; |
| 113 | return 0; |
| 114 | } |
| 115 | |
Theodore Ts'o | 31dbecd | 2001-01-11 04:54:39 +0000 | [diff] [blame] | 116 | static errcode_t open_namei(ext2_filsys fs, ext2_ino_t root, ext2_ino_t base, |
Theodore Ts'o | 3cb6c50 | 1997-08-11 20:29:22 +0000 | [diff] [blame] | 117 | const char *pathname, size_t pathlen, int follow, |
Theodore Ts'o | 31dbecd | 2001-01-11 04:54:39 +0000 | [diff] [blame] | 118 | int link_count, char *buf, ext2_ino_t *res_inode) |
Theodore Ts'o | 1e3472c | 1997-04-29 14:53:37 +0000 | [diff] [blame] | 119 | { |
Theodore Ts'o | dec5cd1 | 2006-11-14 23:14:12 -0500 | [diff] [blame] | 120 | const char *base_name; |
Theodore Ts'o | 1e3472c | 1997-04-29 14:53:37 +0000 | [diff] [blame] | 121 | int namelen; |
Theodore Ts'o | 31dbecd | 2001-01-11 04:54:39 +0000 | [diff] [blame] | 122 | ext2_ino_t dir, inode; |
Theodore Ts'o | 1e3472c | 1997-04-29 14:53:37 +0000 | [diff] [blame] | 123 | errcode_t retval; |
| 124 | |
| 125 | #ifdef NAMEI_DEBUG |
| 126 | printf("open_namei: root=%lu, dir=%lu, path=%*s, lc=%d\n", |
| 127 | root, base, pathlen, pathname, link_count); |
| 128 | #endif |
| 129 | retval = dir_namei(fs, root, base, pathname, pathlen, |
Theodore Ts'o | dec5cd1 | 2006-11-14 23:14:12 -0500 | [diff] [blame] | 130 | link_count, buf, &base_name, &namelen, &dir); |
Theodore Ts'o | 1e3472c | 1997-04-29 14:53:37 +0000 | [diff] [blame] | 131 | if (retval) return retval; |
| 132 | if (!namelen) { /* special case: '/usr/' etc */ |
| 133 | *res_inode=dir; |
| 134 | return 0; |
| 135 | } |
Theodore Ts'o | dec5cd1 | 2006-11-14 23:14:12 -0500 | [diff] [blame] | 136 | retval = ext2fs_lookup (fs, dir, base_name, namelen, buf, &inode); |
Theodore Ts'o | 1e3472c | 1997-04-29 14:53:37 +0000 | [diff] [blame] | 137 | if (retval) |
| 138 | return retval; |
| 139 | if (follow) { |
| 140 | retval = follow_link(fs, root, dir, inode, link_count, |
| 141 | buf, &inode); |
| 142 | if (retval) |
| 143 | return retval; |
| 144 | } |
| 145 | #ifdef NAMEI_DEBUG |
| 146 | printf("open_namei: (link_count=%d) returns %lu\n", |
| 147 | link_count, inode); |
| 148 | #endif |
| 149 | *res_inode = inode; |
| 150 | return 0; |
| 151 | } |
| 152 | |
Theodore Ts'o | 31dbecd | 2001-01-11 04:54:39 +0000 | [diff] [blame] | 153 | errcode_t ext2fs_namei(ext2_filsys fs, ext2_ino_t root, ext2_ino_t cwd, |
| 154 | const char *name, ext2_ino_t *inode) |
Theodore Ts'o | 1e3472c | 1997-04-29 14:53:37 +0000 | [diff] [blame] | 155 | { |
| 156 | char *buf; |
| 157 | errcode_t retval; |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 158 | |
Theodore Ts'o | f3db356 | 1997-04-26 13:34:30 +0000 | [diff] [blame] | 159 | EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); |
| 160 | |
Theodore Ts'o | c4e3d3f | 2003-08-01 09:41:07 -0400 | [diff] [blame] | 161 | retval = ext2fs_get_mem(fs->blocksize, &buf); |
Theodore Ts'o | 7b4e453 | 1997-10-26 03:41:24 +0000 | [diff] [blame] | 162 | if (retval) |
| 163 | return retval; |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 164 | |
Theodore Ts'o | 1e3472c | 1997-04-29 14:53:37 +0000 | [diff] [blame] | 165 | retval = open_namei(fs, root, cwd, name, strlen(name), 0, 0, |
| 166 | buf, inode); |
| 167 | |
Theodore Ts'o | c4e3d3f | 2003-08-01 09:41:07 -0400 | [diff] [blame] | 168 | ext2fs_free_mem(&buf); |
Theodore Ts'o | 1e3472c | 1997-04-29 14:53:37 +0000 | [diff] [blame] | 169 | return retval; |
Theodore Ts'o | 3839e65 | 1997-04-26 13:21:57 +0000 | [diff] [blame] | 170 | } |
Theodore Ts'o | 1e3472c | 1997-04-29 14:53:37 +0000 | [diff] [blame] | 171 | |
Theodore Ts'o | 31dbecd | 2001-01-11 04:54:39 +0000 | [diff] [blame] | 172 | errcode_t ext2fs_namei_follow(ext2_filsys fs, ext2_ino_t root, ext2_ino_t cwd, |
| 173 | const char *name, ext2_ino_t *inode) |
Theodore Ts'o | 1e3472c | 1997-04-29 14:53:37 +0000 | [diff] [blame] | 174 | { |
| 175 | char *buf; |
| 176 | errcode_t retval; |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 177 | |
Theodore Ts'o | 1e3472c | 1997-04-29 14:53:37 +0000 | [diff] [blame] | 178 | EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); |
| 179 | |
Theodore Ts'o | c4e3d3f | 2003-08-01 09:41:07 -0400 | [diff] [blame] | 180 | retval = ext2fs_get_mem(fs->blocksize, &buf); |
Theodore Ts'o | 7b4e453 | 1997-10-26 03:41:24 +0000 | [diff] [blame] | 181 | if (retval) |
| 182 | return retval; |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 183 | |
Theodore Ts'o | 1e3472c | 1997-04-29 14:53:37 +0000 | [diff] [blame] | 184 | retval = open_namei(fs, root, cwd, name, strlen(name), 1, 0, |
| 185 | buf, inode); |
| 186 | |
Theodore Ts'o | c4e3d3f | 2003-08-01 09:41:07 -0400 | [diff] [blame] | 187 | ext2fs_free_mem(&buf); |
Theodore Ts'o | 1e3472c | 1997-04-29 14:53:37 +0000 | [diff] [blame] | 188 | return retval; |
| 189 | } |
| 190 | |
Theodore Ts'o | 31dbecd | 2001-01-11 04:54:39 +0000 | [diff] [blame] | 191 | errcode_t ext2fs_follow_link(ext2_filsys fs, ext2_ino_t root, ext2_ino_t cwd, |
| 192 | ext2_ino_t inode, ext2_ino_t *res_inode) |
Theodore Ts'o | 1e3472c | 1997-04-29 14:53:37 +0000 | [diff] [blame] | 193 | { |
| 194 | char *buf; |
| 195 | errcode_t retval; |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 196 | |
Theodore Ts'o | 1e3472c | 1997-04-29 14:53:37 +0000 | [diff] [blame] | 197 | EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); |
| 198 | |
Theodore Ts'o | c4e3d3f | 2003-08-01 09:41:07 -0400 | [diff] [blame] | 199 | retval = ext2fs_get_mem(fs->blocksize, &buf); |
Theodore Ts'o | 7b4e453 | 1997-10-26 03:41:24 +0000 | [diff] [blame] | 200 | if (retval) |
| 201 | return retval; |
| 202 | |
Theodore Ts'o | 1e3472c | 1997-04-29 14:53:37 +0000 | [diff] [blame] | 203 | retval = follow_link(fs, root, cwd, inode, 0, buf, res_inode); |
| 204 | |
Theodore Ts'o | c4e3d3f | 2003-08-01 09:41:07 -0400 | [diff] [blame] | 205 | ext2fs_free_mem(&buf); |
Theodore Ts'o | 1e3472c | 1997-04-29 14:53:37 +0000 | [diff] [blame] | 206 | return retval; |
| 207 | } |
| 208 | |