summaryrefslogtreecommitdiff
path: root/archival/libunarchive/data_extract_all.c
blob: cc4894229b5e7ba6ec24d91aebf7cc9f9c4f9515 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
/* vi: set sw=4 ts=4: */
/*
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 */

#include "libbb.h"
#include "unarchive.h"

void FAST_FUNC data_extract_all(archive_handle_t *archive_handle)
{
	file_header_t *file_header = archive_handle->file_header;
	int dst_fd;
	int res;

#if ENABLE_FEATURE_TAR_SELINUX
	char *sctx = archive_handle->tar__next_file_sctx;
	if (!sctx)
		sctx = archive_handle->tar__global_sctx;
	if (sctx) { /* setfscreatecon is 4 syscalls, avoid if possible */
		setfscreatecon(sctx);
		free(archive_handle->tar__next_file_sctx);
		archive_handle->tar__next_file_sctx = NULL;
	}
#endif

	if (archive_handle->ah_flags & ARCHIVE_CREATE_LEADING_DIRS) {
		char *slash = strrchr(file_header->name, '/');
		if (slash) {
			*slash = '\0';
			bb_make_directory(file_header->name, -1, FILEUTILS_RECUR);
			*slash = '/';
		}
	}

	if (archive_handle->ah_flags & ARCHIVE_UNLINK_OLD) {
		/* Remove the entry if it exists */
		if ((!S_ISDIR(file_header->mode))
		 && (unlink(file_header->name) == -1)
		 && (errno != ENOENT)
		) {
			bb_perror_msg_and_die("can't remove old file %s",
					file_header->name);
		}
	}
	else if (archive_handle->ah_flags & ARCHIVE_EXTRACT_NEWER) {
		/* Remove the existing entry if its older than the extracted entry */
		struct stat existing_sb;
		if (lstat(file_header->name, &existing_sb) == -1) {
			if (errno != ENOENT) {
				bb_perror_msg_and_die("can't stat old file");
			}
		}
		else if (existing_sb.st_mtime >= file_header->mtime) {
			if (!(archive_handle->ah_flags & ARCHIVE_EXTRACT_QUIET)) {
				bb_error_msg("%s not created: newer or "
					"same age file exists", file_header->name);
			}
			data_skip(archive_handle);
			goto ret;
		}
		else if ((unlink(file_header->name) == -1) && (errno != EISDIR)) {
			bb_perror_msg_and_die("can't remove old file %s",
					file_header->name);
		}
	}

	/* Handle hard links separately
	 * We identified hard links as regular files of size 0 with a symlink */
	if (S_ISREG(file_header->mode)
	 && file_header->link_target
	 && file_header->size == 0
	) {
		/* hard link */
		res = link(file_header->link_target, file_header->name);
		if ((res == -1) && !(archive_handle->ah_flags & ARCHIVE_EXTRACT_QUIET)) {
			bb_perror_msg("can't create %slink "
					"from %s to %s", "hard",
					file_header->name,
					file_header->link_target);
		}
	} else {
		/* Create the filesystem entry */
		switch (file_header->mode & S_IFMT) {
		case S_IFREG: {
			/* Regular file */
			int flags = O_WRONLY | O_CREAT | O_EXCL;
			if (archive_handle->ah_flags & ARCHIVE_O_TRUNC)
				flags = O_WRONLY | O_CREAT | O_TRUNC;
			dst_fd = xopen3(file_header->name,
				flags,
				file_header->mode
				);
			bb_copyfd_exact_size(archive_handle->src_fd, dst_fd, file_header->size);
			close(dst_fd);
			break;
		}
		case S_IFDIR:
			res = mkdir(file_header->name, file_header->mode);
			if ((res == -1)
			 && (errno != EISDIR) /* btw, Linux doesn't return this */
			 && (errno != EEXIST)
			 && !(archive_handle->ah_flags & ARCHIVE_EXTRACT_QUIET)
			) {
				bb_perror_msg("can't make dir %s", file_header->name);
			}
			break;
		case S_IFLNK:
			/* Symlink */
			res = symlink(file_header->link_target, file_header->name);
			if ((res == -1)
			 && !(archive_handle->ah_flags & ARCHIVE_EXTRACT_QUIET)
			) {
				bb_perror_msg("can't create %slink "
					"from %s to %s", "sym",
					file_header->name,
					file_header->link_target);
			}
			break;
		case S_IFSOCK:
		case S_IFBLK:
		case S_IFCHR:
		case S_IFIFO:
			res = mknod(file_header->name, file_header->mode, file_header->device);
			if ((res == -1)
			 && !(archive_handle->ah_flags & ARCHIVE_EXTRACT_QUIET)
			) {
				bb_perror_msg("can't create node %s", file_header->name);
			}
			break;
		default:
			bb_error_msg_and_die("unrecognized file type");
		}
	}

	if (!(archive_handle->ah_flags & ARCHIVE_DONT_RESTORE_OWNER)) {
#if ENABLE_FEATURE_TAR_UNAME_GNAME
		if (!(archive_handle->ah_flags & ARCHIVE_NUMERIC_OWNER)) {
			uid_t uid = file_header->uid;
			gid_t gid = file_header->gid;

			if (file_header->tar__uname) {
//TODO: cache last name/id pair?
				struct passwd *pwd = getpwnam(file_header->tar__uname);
				if (pwd) uid = pwd->pw_uid;
			}
			if (file_header->tar__gname) {
				struct group *grp = getgrnam(file_header->tar__gname);
				if (grp) gid = grp->gr_gid;
			}
			/* GNU tar 1.15.1 uses chown, not lchown */
			chown(file_header->name, uid, gid);
		} else
#endif
			chown(file_header->name, file_header->uid, file_header->gid);
	}
	if (!S_ISLNK(file_header->mode)) {
		/* uclibc has no lchmod, glibc is even stranger -
		 * it has lchmod which seems to do nothing!
		 * so we use chmod... */
		if (!(archive_handle->ah_flags & ARCHIVE_DONT_RESTORE_PERM)) {
			chmod(file_header->name, file_header->mode);
		}
		/* same for utime */
		if (archive_handle->ah_flags & ARCHIVE_RESTORE_DATE) {
			struct timeval t[2];

			t[1].tv_sec = t[0].tv_sec = file_header->mtime;
			t[1].tv_usec = t[0].tv_usec = 0;
			utimes(file_header->name, t);
		}
	}

 ret: ;
#if ENABLE_FEATURE_TAR_SELINUX
	if (sctx) {
		/* reset the context after creating an entry */
		setfscreatecon(NULL);
	}
#endif
}