source: branches/3.2/mindi-busybox/archival/libarchive/open_transformer.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: 5.1 KB
Line 
1/* vi: set sw=4 ts=4: */
2/*
3 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
4 */
5
6#include "libbb.h"
7#include "bb_archive.h"
8
9void FAST_FUNC init_transformer_aux_data(transformer_aux_data_t *aux)
10{
11    memset(aux, 0, sizeof(*aux));
12}
13
14int FAST_FUNC check_signature16(transformer_aux_data_t *aux, int src_fd, unsigned magic16)
15{
16    if (aux && aux->check_signature) {
17        uint16_t magic2;
18        if (full_read(src_fd, &magic2, 2) != 2 || magic2 != magic16) {
19            bb_error_msg("invalid magic");
20#if 0 /* possible future extension */
21            if (aux->check_signature > 1)
22                xfunc_die();
23#endif
24            return -1;
25        }
26    }
27    return 0;
28}
29
30void check_errors_in_children(int signo)
31{
32    int status;
33
34    if (!signo) {
35        /* block waiting for any child */
36        if (wait(&status) < 0)
37            return; /* probably there are no children */
38        goto check_status;
39    }
40
41    /* Wait for any child without blocking */
42    for (;;) {
43        if (wait_any_nohang(&status) < 0)
44            /* wait failed?! I'm confused... */
45            return;
46 check_status:
47        if (WIFEXITED(status) && WEXITSTATUS(status) == 0)
48            /* this child exited with 0 */
49            continue;
50        /* Cannot happen?
51        if (!WIFSIGNALED(status) && !WIFEXITED(status)) ???; */
52        bb_got_signal = 1;
53    }
54}
55
56/* transformer(), more than meets the eye */
57#if BB_MMU
58void FAST_FUNC open_transformer(int fd,
59    int check_signature,
60    IF_DESKTOP(long long) int FAST_FUNC (*transformer)(transformer_aux_data_t *aux, int src_fd, int dst_fd)
61)
62#else
63void FAST_FUNC open_transformer(int fd, const char *transform_prog)
64#endif
65{
66    struct fd_pair fd_pipe;
67    int pid;
68
69    xpiped_pair(fd_pipe);
70    pid = BB_MMU ? xfork() : xvfork();
71    if (pid == 0) {
72        /* Child */
73        close(fd_pipe.rd); /* we don't want to read from the parent */
74        // FIXME: error check?
75#if BB_MMU
76        {
77            transformer_aux_data_t aux;
78            init_transformer_aux_data(&aux);
79            aux.check_signature = check_signature;
80            transformer(&aux, fd, fd_pipe.wr);
81            if (ENABLE_FEATURE_CLEAN_UP) {
82                close(fd_pipe.wr); /* send EOF */
83                close(fd);
84            }
85            /* must be _exit! bug was actually seen here */
86            _exit(EXIT_SUCCESS);
87        }
88#else
89        {
90            char *argv[4];
91            xmove_fd(fd, 0);
92            xmove_fd(fd_pipe.wr, 1);
93            argv[0] = (char*)transform_prog;
94            argv[1] = (char*)"-cf";
95            argv[2] = (char*)"-";
96            argv[3] = NULL;
97            BB_EXECVP(transform_prog, argv);
98            bb_perror_msg_and_die("can't execute '%s'", transform_prog);
99        }
100#endif
101        /* notreached */
102    }
103
104    /* parent process */
105    close(fd_pipe.wr); /* don't want to write to the child */
106    xmove_fd(fd_pipe.rd, fd);
107}
108
109
110#if SEAMLESS_COMPRESSION
111
112/* Used by e.g. rpm which gives us a fd without filename,
113 * thus we can't guess the format from filename's extension.
114 */
115int FAST_FUNC setup_unzip_on_fd(int fd, int fail_if_not_detected)
116{
117    union {
118        uint8_t b[4];
119        uint16_t b16[2];
120        uint32_t b32[1];
121    } magic;
122    int offset = -2;
123    USE_FOR_MMU(IF_DESKTOP(long long) int FAST_FUNC (*xformer)(transformer_aux_data_t *aux, int src_fd, int dst_fd);)
124    USE_FOR_NOMMU(const char *xformer_prog;)
125
126    /* .gz and .bz2 both have 2-byte signature, and their
127     * unpack_XXX_stream wants this header skipped. */
128    xread(fd, magic.b16, sizeof(magic.b16[0]));
129    if (ENABLE_FEATURE_SEAMLESS_GZ
130     && magic.b16[0] == GZIP_MAGIC
131    ) {
132        USE_FOR_MMU(xformer = unpack_gz_stream;)
133        USE_FOR_NOMMU(xformer_prog = "gunzip";)
134        goto found_magic;
135    }
136    if (ENABLE_FEATURE_SEAMLESS_BZ2
137     && magic.b16[0] == BZIP2_MAGIC
138    ) {
139        USE_FOR_MMU(xformer = unpack_bz2_stream;)
140        USE_FOR_NOMMU(xformer_prog = "bunzip2";)
141        goto found_magic;
142    }
143    if (ENABLE_FEATURE_SEAMLESS_XZ
144     && magic.b16[0] == XZ_MAGIC1
145    ) {
146        offset = -6;
147        xread(fd, magic.b32, sizeof(magic.b32[0]));
148        if (magic.b32[0] == XZ_MAGIC2) {
149            USE_FOR_MMU(xformer = unpack_xz_stream;)
150            USE_FOR_NOMMU(xformer_prog = "unxz";)
151            goto found_magic;
152        }
153    }
154
155    /* No known magic seen */
156    if (fail_if_not_detected)
157        bb_error_msg_and_die("no gzip"
158            IF_FEATURE_SEAMLESS_BZ2("/bzip2")
159            IF_FEATURE_SEAMLESS_XZ("/xz")
160            " magic");
161    xlseek(fd, offset, SEEK_CUR);
162    return 1;
163
164 found_magic:
165# if BB_MMU
166    open_transformer_with_no_sig(fd, xformer);
167# else
168    /* NOMMU version of open_transformer execs
169     * an external unzipper that wants
170     * file position at the start of the file */
171    xlseek(fd, offset, SEEK_CUR);
172    open_transformer_with_sig(fd, xformer, xformer_prog);
173# endif
174    return 0;
175}
176
177int FAST_FUNC open_zipped(const char *fname)
178{
179    char *sfx;
180    int fd;
181
182    fd = open(fname, O_RDONLY);
183    if (fd < 0)
184        return fd;
185
186    sfx = strrchr(fname, '.');
187    if (sfx) {
188        sfx++;
189        if (ENABLE_FEATURE_SEAMLESS_LZMA && strcmp(sfx, "lzma") == 0)
190            /* .lzma has no header/signature, just trust it */
191            open_transformer_with_sig(fd, unpack_lzma_stream, "unlzma");
192        else
193        if ((ENABLE_FEATURE_SEAMLESS_GZ && strcmp(sfx, "gz") == 0)
194         || (ENABLE_FEATURE_SEAMLESS_BZ2 && strcmp(sfx, "bz2") == 0)
195         || (ENABLE_FEATURE_SEAMLESS_XZ && strcmp(sfx, "xz") == 0)
196        ) {
197            setup_unzip_on_fd(fd, /*fail_if_not_detected:*/ 1);
198        }
199    }
200
201    return fd;
202}
203
204#endif /* SEAMLESS_COMPRESSION */
205
206void* FAST_FUNC xmalloc_open_zipped_read_close(const char *fname, size_t *maxsz_p)
207{
208    int fd;
209    char *image;
210
211    fd = open_zipped(fname);
212    if (fd < 0)
213        return NULL;
214
215    image = xmalloc_read(fd, maxsz_p);
216    if (!image)
217        bb_perror_msg("read error from '%s'", fname);
218    close(fd);
219
220    return image;
221}
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