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
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
|
/* vi: set sw=4 ts=4: */
/*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
#include "libbb.h"
#include "bb_archive.h"
void FAST_FUNC init_transformer_aux_data(transformer_aux_data_t *aux)
{
memset(aux, 0, sizeof(*aux));
}
int FAST_FUNC check_signature16(transformer_aux_data_t *aux, int src_fd, unsigned magic16)
{
if (aux && aux->check_signature) {
uint16_t magic2;
if (full_read(src_fd, &magic2, 2) != 2 || magic2 != magic16) {
bb_error_msg("invalid magic");
#if 0 /* possible future extension */
if (aux->check_signature > 1)
xfunc_die();
#endif
return -1;
}
}
return 0;
}
void check_errors_in_children(int signo)
{
int status;
if (!signo) {
/* block waiting for any child */
if (wait(&status) < 0)
//FIXME: check EINTR?
return; /* probably there are no children */
goto check_status;
}
/* Wait for any child without blocking */
for (;;) {
if (wait_any_nohang(&status) < 0)
//FIXME: check EINTR?
/* wait failed?! I'm confused... */
return;
check_status:
/*if (WIFEXITED(status) && WEXITSTATUS(status) == 0)*/
/* On Linux, the above can be checked simply as: */
if (status == 0)
/* this child exited with 0 */
continue;
/* Cannot happen:
if (!WIFSIGNALED(status) && !WIFEXITED(status)) ???;
*/
bb_got_signal = 1;
}
}
/* transformer(), more than meets the eye */
#if BB_MMU
void FAST_FUNC open_transformer(int fd,
int check_signature,
IF_DESKTOP(long long) int FAST_FUNC (*transformer)(transformer_aux_data_t *aux, int src_fd, int dst_fd)
)
#else
void FAST_FUNC open_transformer(int fd, const char *transform_prog)
#endif
{
struct fd_pair fd_pipe;
int pid;
xpiped_pair(fd_pipe);
pid = BB_MMU ? xfork() : xvfork();
if (pid == 0) {
/* Child */
close(fd_pipe.rd); /* we don't want to read from the parent */
// FIXME: error check?
#if BB_MMU
{
IF_DESKTOP(long long) int r;
transformer_aux_data_t aux;
init_transformer_aux_data(&aux);
aux.check_signature = check_signature;
r = transformer(&aux, fd, fd_pipe.wr);
if (ENABLE_FEATURE_CLEAN_UP) {
close(fd_pipe.wr); /* send EOF */
close(fd);
}
/* must be _exit! bug was actually seen here */
_exit(/*error if:*/ r < 0);
}
#else
{
char *argv[4];
xmove_fd(fd, 0);
xmove_fd(fd_pipe.wr, 1);
argv[0] = (char*)transform_prog;
argv[1] = (char*)"-cf";
argv[2] = (char*)"-";
argv[3] = NULL;
BB_EXECVP(transform_prog, argv);
bb_perror_msg_and_die("can't execute '%s'", transform_prog);
}
#endif
/* notreached */
}
/* parent process */
close(fd_pipe.wr); /* don't want to write to the child */
xmove_fd(fd_pipe.rd, fd);
}
#if SEAMLESS_COMPRESSION
/* Used by e.g. rpm which gives us a fd without filename,
* thus we can't guess the format from filename's extension.
*/
int FAST_FUNC setup_unzip_on_fd(int fd, int fail_if_not_detected)
{
union {
uint8_t b[4];
uint16_t b16[2];
uint32_t b32[1];
} magic;
int offset = -2;
USE_FOR_MMU(IF_DESKTOP(long long) int FAST_FUNC (*xformer)(transformer_aux_data_t *aux, int src_fd, int dst_fd);)
USE_FOR_NOMMU(const char *xformer_prog;)
/* .gz and .bz2 both have 2-byte signature, and their
* unpack_XXX_stream wants this header skipped. */
xread(fd, magic.b16, sizeof(magic.b16[0]));
if (ENABLE_FEATURE_SEAMLESS_GZ
&& magic.b16[0] == GZIP_MAGIC
) {
USE_FOR_MMU(xformer = unpack_gz_stream;)
USE_FOR_NOMMU(xformer_prog = "gunzip";)
goto found_magic;
}
if (ENABLE_FEATURE_SEAMLESS_BZ2
&& magic.b16[0] == BZIP2_MAGIC
) {
USE_FOR_MMU(xformer = unpack_bz2_stream;)
USE_FOR_NOMMU(xformer_prog = "bunzip2";)
goto found_magic;
}
if (ENABLE_FEATURE_SEAMLESS_XZ
&& magic.b16[0] == XZ_MAGIC1
) {
offset = -6;
xread(fd, magic.b32, sizeof(magic.b32[0]));
if (magic.b32[0] == XZ_MAGIC2) {
USE_FOR_MMU(xformer = unpack_xz_stream;)
USE_FOR_NOMMU(xformer_prog = "unxz";)
goto found_magic;
}
}
/* No known magic seen */
if (fail_if_not_detected)
bb_error_msg_and_die("no gzip"
IF_FEATURE_SEAMLESS_BZ2("/bzip2")
IF_FEATURE_SEAMLESS_XZ("/xz")
" magic");
xlseek(fd, offset, SEEK_CUR);
return 1;
found_magic:
# if BB_MMU
open_transformer_with_no_sig(fd, xformer);
# else
/* NOMMU version of open_transformer execs
* an external unzipper that wants
* file position at the start of the file */
xlseek(fd, offset, SEEK_CUR);
open_transformer_with_sig(fd, xformer, xformer_prog);
# endif
return 0;
}
int FAST_FUNC open_zipped(const char *fname)
{
int fd;
fd = open(fname, O_RDONLY);
if (fd < 0)
return fd;
if (ENABLE_FEATURE_SEAMLESS_LZMA) {
/* .lzma has no header/signature, can only detect it by extension */
char *sfx = strrchr(fname, '.');
if (sfx && strcmp(sfx+1, "lzma") == 0) {
open_transformer_with_sig(fd, unpack_lzma_stream, "unlzma");
return fd;
}
}
if ((ENABLE_FEATURE_SEAMLESS_GZ)
|| (ENABLE_FEATURE_SEAMLESS_BZ2)
|| (ENABLE_FEATURE_SEAMLESS_XZ)
) {
/*
* Do we want to fail_if_not_detected?
* In most cases, no: think "insmod non_compressed_module".
* A case which would like to fail is "zcat uncompressed_file":
* otherwise, it happily outputs uncompressed_file as-is,
* which is, strictly speaking, not what is expected.
* If this ever becomes a problem, we can add
* fail_if_not_detected bool argument to open_zipped().
*/
setup_unzip_on_fd(fd, /*fail_if_not_detected:*/ 0);
}
return fd;
}
#endif /* SEAMLESS_COMPRESSION */
void* FAST_FUNC xmalloc_open_zipped_read_close(const char *fname, size_t *maxsz_p)
{
int fd;
char *image;
fd = open_zipped(fname);
if (fd < 0)
return NULL;
image = xmalloc_read(fd, maxsz_p);
if (!image)
bb_perror_msg("read error from '%s'", fname);
close(fd);
return image;
}
|
