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-rw-r--r--libbb/untar.c200
1 files changed, 200 insertions, 0 deletions
diff --git a/libbb/untar.c b/libbb/untar.c
new file mode 100644
index 000000000..1542e390d
--- /dev/null
+++ b/libbb/untar.c
@@ -0,0 +1,200 @@
1/*
2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License as published by
4 * the Free Software Foundation; either version 2 of the License, or
5 * (at your option) any later version.
6 *
7 * This program is distributed in the hope that it will be useful,
8 * but WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10 * GNU Library General Public License for more details.
11 *
12 * You should have received a copy of the GNU General Public License
13 * along with this program; if not, write to the Free Software
14 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
15 *
16 * NOTE: This is used by deb_extract to avoid calling the whole tar applet.
17 * Its functionality should be merged with tar to avoid duplication
18 */
19
20#include <stdlib.h>
21#include <string.h>
22#include <unistd.h>
23#include "libbb.h"
24
25extern int untar(FILE *src_tar_file, int untar_function, char *base_path)
26{
27 typedef struct raw_tar_header {
28 char name[100]; /* 0-99 */
29 char mode[8]; /* 100-107 */
30 char uid[8]; /* 108-115 */
31 char gid[8]; /* 116-123 */
32 char size[12]; /* 124-135 */
33 char mtime[12]; /* 136-147 */
34 char chksum[8]; /* 148-155 */
35 char typeflag; /* 156-156 */
36 char linkname[100]; /* 157-256 */
37 char magic[6]; /* 257-262 */
38 char version[2]; /* 263-264 */
39 char uname[32]; /* 265-296 */
40 char gname[32]; /* 297-328 */
41 char devmajor[8]; /* 329-336 */
42 char devminor[8]; /* 337-344 */
43 char prefix[155]; /* 345-499 */
44 char padding[12]; /* 500-512 */
45 } raw_tar_header_t;
46
47// const int dpkg_deb_contents = 1;
48// const int dpkg_deb_control = 2;
49// const int dpkg_deb_info = 4;
50 const int untar_extract = 8;
51// const int dpkg_deb_verbose_extract = 16;
52// const int dpkg_deb_list = 32;
53
54 raw_tar_header_t raw_tar_header;
55 unsigned char *temp = (unsigned char *) &raw_tar_header;
56 long i;
57 long next_header_offset = 0;
58 long uncompressed_count = 0;
59 size_t size;
60 mode_t mode;
61
62// signal(SIGCHLD, child_died);
63
64 while (fread((char *) &raw_tar_header, 1, 512, src_tar_file)==512) {
65 long sum = 0;
66 char *dir;
67
68 uncompressed_count += 512;
69
70 /* Check header has valid magic */
71 if (strncmp(raw_tar_header.magic, "ustar", 5) != 0) {
72 /* Put this pack after TODO (check child still alive) is done */
73// error_msg("Invalid tar magic");
74 break;
75 }
76
77 /* Do checksum on headers */
78 for (i = 0; i < 148 ; i++) {
79 sum += temp[i];
80 }
81 sum += ' ' * 8;
82 for (i = 156; i < 512 ; i++) {
83 sum += temp[i];
84 }
85 if (sum != strtol(raw_tar_header.chksum, NULL, 8)) {
86 error_msg("Invalid tar header checksum");
87 break;
88 }
89
90 /* convert to type'ed variables */
91 size = strtol(raw_tar_header.size, NULL, 8);
92 parse_mode(raw_tar_header.mode, &mode);
93
94 /* start of next header is at */
95 next_header_offset = uncompressed_count + size;
96 if (size % 512 != 0) {
97 next_header_offset += (512 - size % 512);
98 }
99
100 /*
101 * seek to start of control file, return length
102 *
103 if (dpkg_untar_function & dpkg_untar_seek_control) {
104 if ((raw_tar_header.typeflag == '0') || (raw_tar_header.typeflag == '\0')) {
105 char *tar_filename;
106
107 tar_filename = strrchr(raw_tar_header.name, '/');
108 if (tar_filename == NULL) {
109 tar_filename = strdup(raw_tar_header.name);
110 } else {
111 tar_filename++;
112 }
113
114 if (strcmp(tar_filename, "control") == 0) {
115 return(size);
116 }
117 }
118
119 }
120*/
121 /* extract files */
122 dir = xmalloc(strlen(raw_tar_header.name) + strlen(base_path) + 2);
123
124 sprintf(dir, "%s/%s", base_path, raw_tar_header.name);
125 create_path(dir, 0777);
126 switch (raw_tar_header.typeflag ) {
127 case '0':
128 case '\0':
129 /* If the name ends in a '/' then assume it is
130 * supposed to be a directory, and fall through
131 */
132 if (raw_tar_header.name[strlen(raw_tar_header.name)-1] != '/') {
133 if (untar_function & untar_extract) {
134 int out_count=0;
135 FILE *dst_file;
136
137 dst_file = wfopen(dir, "w");
138 if (copy_file_chunk(src_tar_file, dst_file, size) == FALSE) {
139 error_msg_and_die("Couldnt extract file");
140 }
141 uncompressed_count += out_count;
142 fclose(dst_file);
143 break;
144 }
145 }
146 case '5':
147 if (untar_function & untar_extract) {
148 if (create_path(dir, mode) != TRUE) {
149 free(dir);
150 perror_msg("%s: Cannot mkdir", raw_tar_header.name);
151 return(EXIT_FAILURE);
152 }
153 }
154 break;
155 case '1':
156 if (untar_function & untar_extract) {
157 if (link(raw_tar_header.linkname, raw_tar_header.name) < 0) {
158 free(dir);
159 perror_msg("%s: Cannot create hard link to '%s'", raw_tar_header.name, raw_tar_header.linkname);
160 return(EXIT_FAILURE);
161 }
162 }
163 break;
164 case '2':
165 if (untar_function & untar_extract) {
166 if (symlink(raw_tar_header.linkname, raw_tar_header.name) < 0) {
167 free(dir);
168 perror_msg("%s: Cannot create symlink to '%s'", raw_tar_header.name, raw_tar_header.linkname);
169 return(EXIT_FAILURE);
170 }
171 }
172 break;
173 case '3':
174 case '4':
175 case '6':
176// if (tarExtractSpecial( &header, extractFlag, tostdoutFlag)==FALSE)
177// errorFlag=TRUE;
178// break;
179 default:
180 error_msg("Unknown file type '%c' in tar file", raw_tar_header.typeflag);
181 free(dir);
182 return(EXIT_FAILURE);
183 }
184 free(dir);
185 }
186 /* skip to start of next header */
187 while(uncompressed_count < next_header_offset) {
188 char ch[2];
189 if (fread(ch, 1, 1, src_tar_file) != 1) {
190 error_msg("read error\n");
191 getchar();
192 } else {
193 uncompressed_count++;
194 }
195 }
196 /*
197 * TODO: Check that gunzip child hasnt finished
198 */
199 return(EXIT_SUCCESS);
200}
generated by cgit v1.2.3-55-g6feb (git 2.39.1) at 2026-01-19 01:21:27 +0000