blob: badd4a841656e4c1fd0b02c7b1b1d872f74493e6
1 | /* vi: set sw=4 ts=4: */ |
2 | /* Copyright 2002 Laurence Anderson |
3 | * |
4 | * Licensed under GPLv2 or later, see file LICENSE in this source tree. |
5 | */ |
6 | |
7 | #include "libbb.h" |
8 | #include "bb_archive.h" |
9 | |
10 | typedef struct hardlinks_t { |
11 | struct hardlinks_t *next; |
12 | int inode; /* TODO: must match maj/min too! */ |
13 | int mode ; |
14 | int mtime; /* These three are useful only in corner case */ |
15 | int uid ; /* of hardlinks with zero size body */ |
16 | int gid ; |
17 | char name[1]; |
18 | } hardlinks_t; |
19 | |
20 | char FAST_FUNC get_header_cpio(archive_handle_t *archive_handle) |
21 | { |
22 | file_header_t *file_header = archive_handle->file_header; |
23 | char cpio_header[110]; |
24 | int namesize; |
25 | int major, minor, nlink, mode, inode; |
26 | unsigned size, uid, gid, mtime; |
27 | |
28 | /* There can be padding before archive header */ |
29 | data_align(archive_handle, 4); |
30 | |
31 | size = full_read(archive_handle->src_fd, cpio_header, 110); |
32 | if (size == 0) { |
33 | goto create_hardlinks; |
34 | } |
35 | if (size != 110) { |
36 | bb_error_msg_and_die("short read"); |
37 | } |
38 | archive_handle->offset += 110; |
39 | |
40 | if (!is_prefixed_with(&cpio_header[0], "07070") |
41 | || (cpio_header[5] != '1' && cpio_header[5] != '2') |
42 | ) { |
43 | bb_error_msg_and_die("unsupported cpio format, use newc or crc"); |
44 | } |
45 | |
46 | if (sscanf(cpio_header + 6, |
47 | "%8x" "%8x" "%8x" "%8x" |
48 | "%8x" "%8x" "%8x" /*maj,min:*/ "%*16c" |
49 | /*rmaj,rmin:*/"%8x" "%8x" "%8x" /*chksum: "%*8c"*/, |
50 | &inode, &mode, &uid, &gid, |
51 | &nlink, &mtime, &size, |
52 | &major, &minor, &namesize) != 10) |
53 | bb_error_msg_and_die("damaged cpio file"); |
54 | file_header->mode = mode; |
55 | /* "cpio -R USER:GRP" support: */ |
56 | if (archive_handle->cpio__owner.uid != (uid_t)-1L) |
57 | uid = archive_handle->cpio__owner.uid; |
58 | if (archive_handle->cpio__owner.gid != (gid_t)-1L) |
59 | gid = archive_handle->cpio__owner.gid; |
60 | file_header->uid = uid; |
61 | file_header->gid = gid; |
62 | file_header->mtime = mtime; |
63 | file_header->size = size; |
64 | |
65 | namesize &= 0x1fff; /* paranoia: limit names to 8k chars */ |
66 | file_header->name = xzalloc(namesize + 1); |
67 | /* Read in filename */ |
68 | xread(archive_handle->src_fd, file_header->name, namesize); |
69 | if (file_header->name[0] == '/') { |
70 | /* Testcase: echo /etc/hosts | cpio -pvd /tmp |
71 | * Without this code, it tries to unpack /etc/hosts |
72 | * into "/etc/hosts", not "etc/hosts". |
73 | */ |
74 | char *p = file_header->name; |
75 | do p++; while (*p == '/'); |
76 | overlapping_strcpy(file_header->name, p); |
77 | } |
78 | archive_handle->offset += namesize; |
79 | |
80 | /* Update offset amount and skip padding before file contents */ |
81 | data_align(archive_handle, 4); |
82 | |
83 | if (strcmp(file_header->name, cpio_TRAILER) == 0) { |
84 | /* Always round up. ">> 9" divides by 512 */ |
85 | archive_handle->cpio__blocks = (uoff_t)(archive_handle->offset + 511) >> 9; |
86 | goto create_hardlinks; |
87 | } |
88 | |
89 | file_header->link_target = NULL; |
90 | if (S_ISLNK(file_header->mode)) { |
91 | file_header->size &= 0x1fff; /* paranoia: limit names to 8k chars */ |
92 | file_header->link_target = xzalloc(file_header->size + 1); |
93 | xread(archive_handle->src_fd, file_header->link_target, file_header->size); |
94 | archive_handle->offset += file_header->size; |
95 | file_header->size = 0; /* Stop possible seeks in future */ |
96 | } |
97 | |
98 | // TODO: data_extract_all can't deal with hardlinks to non-files... |
99 | // when fixed, change S_ISREG to !S_ISDIR here |
100 | |
101 | if (nlink > 1 && S_ISREG(file_header->mode)) { |
102 | hardlinks_t *new = xmalloc(sizeof(*new) + namesize); |
103 | new->inode = inode; |
104 | new->mode = mode ; |
105 | new->mtime = mtime; |
106 | new->uid = uid ; |
107 | new->gid = gid ; |
108 | strcpy(new->name, file_header->name); |
109 | /* Put file on a linked list for later */ |
110 | if (size == 0) { |
111 | new->next = archive_handle->cpio__hardlinks_to_create; |
112 | archive_handle->cpio__hardlinks_to_create = new; |
113 | return EXIT_SUCCESS; /* Skip this one */ |
114 | /* TODO: this breaks cpio -t (it does not show hardlinks) */ |
115 | } |
116 | new->next = archive_handle->cpio__created_hardlinks; |
117 | archive_handle->cpio__created_hardlinks = new; |
118 | } |
119 | file_header->device = makedev(major, minor); |
120 | |
121 | if (archive_handle->filter(archive_handle) == EXIT_SUCCESS) { |
122 | archive_handle->action_data(archive_handle); |
123 | //TODO: run "echo /etc/hosts | cpio -pv /tmp" twice. On 2nd run: |
124 | //cpio: etc/hosts not created: newer or same age file exists |
125 | //etc/hosts <-- should NOT show it |
126 | //2 blocks <-- should say "0 blocks" |
127 | archive_handle->action_header(file_header); |
128 | } else { |
129 | data_skip(archive_handle); |
130 | } |
131 | |
132 | archive_handle->offset += file_header->size; |
133 | |
134 | free(file_header->link_target); |
135 | free(file_header->name); |
136 | file_header->link_target = NULL; |
137 | file_header->name = NULL; |
138 | |
139 | return EXIT_SUCCESS; |
140 | |
141 | create_hardlinks: |
142 | free(file_header->link_target); |
143 | free(file_header->name); |
144 | |
145 | while (archive_handle->cpio__hardlinks_to_create) { |
146 | hardlinks_t *cur; |
147 | hardlinks_t *make_me = archive_handle->cpio__hardlinks_to_create; |
148 | |
149 | archive_handle->cpio__hardlinks_to_create = make_me->next; |
150 | |
151 | memset(file_header, 0, sizeof(*file_header)); |
152 | file_header->mtime = make_me->mtime; |
153 | file_header->name = make_me->name; |
154 | file_header->mode = make_me->mode; |
155 | file_header->uid = make_me->uid; |
156 | file_header->gid = make_me->gid; |
157 | /*file_header->size = 0;*/ |
158 | /*file_header->link_target = NULL;*/ |
159 | |
160 | /* Try to find a file we are hardlinked to */ |
161 | cur = archive_handle->cpio__created_hardlinks; |
162 | while (cur) { |
163 | /* TODO: must match maj/min too! */ |
164 | if (cur->inode == make_me->inode) { |
165 | file_header->link_target = cur->name; |
166 | /* link_target != NULL, size = 0: "I am a hardlink" */ |
167 | if (archive_handle->filter(archive_handle) == EXIT_SUCCESS) |
168 | archive_handle->action_data(archive_handle); |
169 | free(make_me); |
170 | goto next_link; |
171 | } |
172 | cur = cur->next; |
173 | } |
174 | /* Oops... no file with such inode was created... do it now |
175 | * (happens when hardlinked files are empty (zero length)) */ |
176 | if (archive_handle->filter(archive_handle) == EXIT_SUCCESS) |
177 | archive_handle->action_data(archive_handle); |
178 | /* Move to the list of created hardlinked files */ |
179 | make_me->next = archive_handle->cpio__created_hardlinks; |
180 | archive_handle->cpio__created_hardlinks = make_me; |
181 | next_link: ; |
182 | } |
183 | |
184 | while (archive_handle->cpio__created_hardlinks) { |
185 | hardlinks_t *p = archive_handle->cpio__created_hardlinks; |
186 | archive_handle->cpio__created_hardlinks = p->next; |
187 | free(p); |
188 | } |
189 | |
190 | return EXIT_FAILURE; /* "No more files to process" */ |
191 | } |
192 |