source: branches/3.2/mindi-busybox/archival/libarchive/get_header_cpio.c @ 3232

Last change on this file since 3232 was 3232, checked in by bruno, 5 years ago
  • Update mindi-busybox to 1.21.1
  • Property svn:eol-style set to native
File size: 5.8 KB
Line 
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
10typedef 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
20char 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 (strncmp(&cpio_header[0], "07070", 5) != 0
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    file_header->uid = uid;
56    file_header->gid = gid;
57    file_header->mtime = mtime;
58    file_header->size = size;
59
60    namesize &= 0x1fff; /* paranoia: limit names to 8k chars */
61    file_header->name = xzalloc(namesize + 1);
62    /* Read in filename */
63    xread(archive_handle->src_fd, file_header->name, namesize);
64    if (file_header->name[0] == '/') {
65        /* Testcase: echo /etc/hosts | cpio -pvd /tmp
66         * Without this code, it tries to unpack /etc/hosts
67         * into "/etc/hosts", not "etc/hosts".
68         */
69        char *p = file_header->name;
70        do p++; while (*p == '/');
71        overlapping_strcpy(file_header->name, p);
72    }
73    archive_handle->offset += namesize;
74
75    /* Update offset amount and skip padding before file contents */
76    data_align(archive_handle, 4);
77
78    if (strcmp(file_header->name, "TRAILER!!!") == 0) {
79        /* Always round up. ">> 9" divides by 512 */
80        archive_handle->cpio__blocks = (uoff_t)(archive_handle->offset + 511) >> 9;
81        goto create_hardlinks;
82    }
83
84    file_header->link_target = NULL;
85    if (S_ISLNK(file_header->mode)) {
86        file_header->size &= 0x1fff; /* paranoia: limit names to 8k chars */
87        file_header->link_target = xzalloc(file_header->size + 1);
88        xread(archive_handle->src_fd, file_header->link_target, file_header->size);
89        archive_handle->offset += file_header->size;
90        file_header->size = 0; /* Stop possible seeks in future */
91    }
92
93// TODO: data_extract_all can't deal with hardlinks to non-files...
94// when fixed, change S_ISREG to !S_ISDIR here
95
96    if (nlink > 1 && S_ISREG(file_header->mode)) {
97        hardlinks_t *new = xmalloc(sizeof(*new) + namesize);
98        new->inode = inode;
99        new->mode  = mode ;
100        new->mtime = mtime;
101        new->uid   = uid  ;
102        new->gid   = gid  ;
103        strcpy(new->name, file_header->name);
104        /* Put file on a linked list for later */
105        if (size == 0) {
106            new->next = archive_handle->cpio__hardlinks_to_create;
107            archive_handle->cpio__hardlinks_to_create = new;
108            return EXIT_SUCCESS; /* Skip this one */
109            /* TODO: this breaks cpio -t (it does not show hardlinks) */
110        }
111        new->next = archive_handle->cpio__created_hardlinks;
112        archive_handle->cpio__created_hardlinks = new;
113    }
114    file_header->device = makedev(major, minor);
115
116    if (archive_handle->filter(archive_handle) == EXIT_SUCCESS) {
117        archive_handle->action_data(archive_handle);
118//TODO: run "echo /etc/hosts | cpio -pv /tmp" twice. On 2nd run:
119//cpio: etc/hosts not created: newer or same age file exists
120//etc/hosts  <-- should NOT show it
121//2 blocks <-- should say "0 blocks"
122        archive_handle->action_header(file_header);
123    } else {
124        data_skip(archive_handle);
125    }
126
127    archive_handle->offset += file_header->size;
128
129    free(file_header->link_target);
130    free(file_header->name);
131    file_header->link_target = NULL;
132    file_header->name = NULL;
133
134    return EXIT_SUCCESS;
135
136 create_hardlinks:
137    free(file_header->link_target);
138    free(file_header->name);
139
140    while (archive_handle->cpio__hardlinks_to_create) {
141        hardlinks_t *cur;
142        hardlinks_t *make_me = archive_handle->cpio__hardlinks_to_create;
143
144        archive_handle->cpio__hardlinks_to_create = make_me->next;
145
146        memset(file_header, 0, sizeof(*file_header));
147        file_header->mtime = make_me->mtime;
148        file_header->name = make_me->name;
149        file_header->mode = make_me->mode;
150        file_header->uid = make_me->uid;
151        file_header->gid = make_me->gid;
152        /*file_header->size = 0;*/
153        /*file_header->link_target = NULL;*/
154
155        /* Try to find a file we are hardlinked to */
156        cur = archive_handle->cpio__created_hardlinks;
157        while (cur) {
158            /* TODO: must match maj/min too! */
159            if (cur->inode == make_me->inode) {
160                file_header->link_target = cur->name;
161                 /* link_target != NULL, size = 0: "I am a hardlink" */
162                if (archive_handle->filter(archive_handle) == EXIT_SUCCESS)
163                    archive_handle->action_data(archive_handle);
164                free(make_me);
165                goto next_link;
166            }
167            cur = cur->next;
168        }
169        /* Oops... no file with such inode was created... do it now
170         * (happens when hardlinked files are empty (zero length)) */
171        if (archive_handle->filter(archive_handle) == EXIT_SUCCESS)
172            archive_handle->action_data(archive_handle);
173        /* Move to the list of created hardlinked files */
174        make_me->next = archive_handle->cpio__created_hardlinks;
175        archive_handle->cpio__created_hardlinks = make_me;
176 next_link: ;
177    }
178
179    while (archive_handle->cpio__created_hardlinks) {
180        hardlinks_t *p = archive_handle->cpio__created_hardlinks;
181        archive_handle->cpio__created_hardlinks = p->next;
182        free(p);
183    }
184
185    return EXIT_FAILURE; /* "No more files to process" */
186}
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