1 | /* vi: set sw=4 ts=4: */
|
---|
2 | /*
|
---|
3 | * Mini dd implementation for busybox
|
---|
4 | *
|
---|
5 | *
|
---|
6 | * Copyright (C) 2000,2001 Matt Kraai
|
---|
7 | *
|
---|
8 | * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
|
---|
9 | */
|
---|
10 |
|
---|
11 | #include <signal.h> /* For FEATURE_DD_SIGNAL_HANDLING */
|
---|
12 | #include "libbb.h"
|
---|
13 |
|
---|
14 | /* This is a NOEXEC applet. Be very careful! */
|
---|
15 |
|
---|
16 |
|
---|
17 | static const struct suffix_mult dd_suffixes[] = {
|
---|
18 | { "c", 1 },
|
---|
19 | { "w", 2 },
|
---|
20 | { "b", 512 },
|
---|
21 | { "kD", 1000 },
|
---|
22 | { "k", 1024 },
|
---|
23 | { "K", 1024 }, /* compat with coreutils dd */
|
---|
24 | { "MD", 1000000 },
|
---|
25 | { "M", 1048576 },
|
---|
26 | { "GD", 1000000000 },
|
---|
27 | { "G", 1073741824 },
|
---|
28 | { }
|
---|
29 | };
|
---|
30 |
|
---|
31 | struct globals {
|
---|
32 | off_t out_full, out_part, in_full, in_part;
|
---|
33 | };
|
---|
34 | #define G (*(struct globals*)&bb_common_bufsiz1)
|
---|
35 | /* We have to zero it out because of NOEXEC */
|
---|
36 | #define INIT_G() memset(&G, 0, sizeof(G))
|
---|
37 |
|
---|
38 |
|
---|
39 | static void dd_output_status(int ATTRIBUTE_UNUSED cur_signal)
|
---|
40 | {
|
---|
41 | /* Deliberately using %u, not %d */
|
---|
42 | fprintf(stderr, "%"OFF_FMT"u+%"OFF_FMT"u records in\n"
|
---|
43 | "%"OFF_FMT"u+%"OFF_FMT"u records out\n",
|
---|
44 | G.in_full, G.in_part,
|
---|
45 | G.out_full, G.out_part);
|
---|
46 | }
|
---|
47 |
|
---|
48 | static ssize_t full_write_or_warn(int fd, const void *buf, size_t len,
|
---|
49 | const char *const filename)
|
---|
50 | {
|
---|
51 | ssize_t n = full_write(fd, buf, len);
|
---|
52 | if (n < 0)
|
---|
53 | bb_perror_msg("writing '%s'", filename);
|
---|
54 | return n;
|
---|
55 | }
|
---|
56 |
|
---|
57 | static bool write_and_stats(int fd, const void *buf, size_t len, size_t obs,
|
---|
58 | const char *filename)
|
---|
59 | {
|
---|
60 | ssize_t n = full_write_or_warn(fd, buf, len, filename);
|
---|
61 | if (n < 0)
|
---|
62 | return 1;
|
---|
63 | if (n == obs)
|
---|
64 | G.out_full++;
|
---|
65 | else if (n) /* > 0 */
|
---|
66 | G.out_part++;
|
---|
67 | return 0;
|
---|
68 | }
|
---|
69 |
|
---|
70 | #if ENABLE_LFS
|
---|
71 | #define XATOU_SFX xatoull_sfx
|
---|
72 | #else
|
---|
73 | #define XATOU_SFX xatoul_sfx
|
---|
74 | #endif
|
---|
75 |
|
---|
76 | int dd_main(int argc, char **argv);
|
---|
77 | int dd_main(int argc, char **argv)
|
---|
78 | {
|
---|
79 | enum {
|
---|
80 | FLAG_SYNC = 1 << 0,
|
---|
81 | FLAG_NOERROR = 1 << 1,
|
---|
82 | FLAG_NOTRUNC = 1 << 2,
|
---|
83 | FLAG_TWOBUFS = 1 << 3,
|
---|
84 | FLAG_COUNT = 1 << 4,
|
---|
85 | };
|
---|
86 | static const char keywords[] ALIGN1 =
|
---|
87 | "bs=\0""count=\0""seek=\0""skip=\0""if=\0""of=\0"
|
---|
88 | #if ENABLE_FEATURE_DD_IBS_OBS
|
---|
89 | "ibs=\0""obs=\0""conv=\0""notrunc\0""sync\0""noerror\0"
|
---|
90 | #endif
|
---|
91 | ;
|
---|
92 | enum {
|
---|
93 | OP_bs = 1,
|
---|
94 | OP_count,
|
---|
95 | OP_seek,
|
---|
96 | OP_skip,
|
---|
97 | OP_if,
|
---|
98 | OP_of,
|
---|
99 | #if ENABLE_FEATURE_DD_IBS_OBS
|
---|
100 | OP_ibs,
|
---|
101 | OP_obs,
|
---|
102 | OP_conv,
|
---|
103 | OP_conv_notrunc,
|
---|
104 | OP_conv_sync,
|
---|
105 | OP_conv_noerror,
|
---|
106 | #endif
|
---|
107 | };
|
---|
108 | size_t ibs = 512, obs = 512;
|
---|
109 | ssize_t n, w;
|
---|
110 | char *ibuf, *obuf;
|
---|
111 | /* And these are all zeroed at once! */
|
---|
112 | struct {
|
---|
113 | int flags;
|
---|
114 | int ifd, ofd;
|
---|
115 | size_t oc;
|
---|
116 | off_t count;
|
---|
117 | off_t seek, skip;
|
---|
118 | const char *infile, *outfile;
|
---|
119 | #if ENABLE_FEATURE_DD_SIGNAL_HANDLING
|
---|
120 | struct sigaction sigact;
|
---|
121 | #endif
|
---|
122 | } Z;
|
---|
123 | #define flags (Z.flags )
|
---|
124 | #define ifd (Z.ifd )
|
---|
125 | #define ofd (Z.ofd )
|
---|
126 | #define oc (Z.oc )
|
---|
127 | #define count (Z.count )
|
---|
128 | #define seek (Z.seek )
|
---|
129 | #define skip (Z.skip )
|
---|
130 | #define infile (Z.infile )
|
---|
131 | #define outfile (Z.outfile)
|
---|
132 | #define sigact (Z.sigact )
|
---|
133 |
|
---|
134 | memset(&Z, 0, sizeof(Z));
|
---|
135 | INIT_G();
|
---|
136 |
|
---|
137 | #if ENABLE_FEATURE_DD_SIGNAL_HANDLING
|
---|
138 | sigact.sa_handler = dd_output_status;
|
---|
139 | sigact.sa_flags = SA_RESTART;
|
---|
140 | sigemptyset(&sigact.sa_mask);
|
---|
141 | sigaction(SIGUSR1, &sigact, NULL);
|
---|
142 | #endif
|
---|
143 |
|
---|
144 | for (n = 1; n < argc; n++) {
|
---|
145 | smalluint key_len;
|
---|
146 | smalluint what;
|
---|
147 | char *key;
|
---|
148 | char *arg = argv[n];
|
---|
149 |
|
---|
150 | //XXX:FIXME: we reject plain "dd --" This would cost ~20 bytes, so..
|
---|
151 | //if (*arg == '-' && *++arg == '-' && !*++arg) continue;
|
---|
152 | key = strstr(arg, "=");
|
---|
153 | if (key == NULL)
|
---|
154 | bb_show_usage();
|
---|
155 | key_len = key - arg + 1;
|
---|
156 | key = xstrndup(arg, key_len);
|
---|
157 | what = index_in_strings(keywords, key) + 1;
|
---|
158 | if (ENABLE_FEATURE_CLEAN_UP)
|
---|
159 | free(key);
|
---|
160 | if (what == 0)
|
---|
161 | bb_show_usage();
|
---|
162 | arg += key_len;
|
---|
163 | /* Must fit into positive ssize_t */
|
---|
164 | #if ENABLE_FEATURE_DD_IBS_OBS
|
---|
165 | if (what == OP_ibs) {
|
---|
166 | ibs = xatoul_range_sfx(arg, 1, ((size_t)-1L)/2, dd_suffixes);
|
---|
167 | continue;
|
---|
168 | }
|
---|
169 | if (what == OP_obs) {
|
---|
170 | obs = xatoul_range_sfx(arg, 1, ((size_t)-1L)/2, dd_suffixes);
|
---|
171 | continue;
|
---|
172 | }
|
---|
173 | if (what == OP_conv) {
|
---|
174 | while (1) {
|
---|
175 | /* find ',', replace them with nil so we can use arg for
|
---|
176 | * index_in_strings() without copying.
|
---|
177 | * We rely on arg being non-null, else strchr would fault.
|
---|
178 | */
|
---|
179 | key = strchr(arg, ',');
|
---|
180 | if (key)
|
---|
181 | *key = '\0';
|
---|
182 | what = index_in_strings(keywords, arg) + 1;
|
---|
183 | if (what < OP_conv_notrunc)
|
---|
184 | bb_error_msg_and_die(bb_msg_invalid_arg, arg, "conv");
|
---|
185 | if (what == OP_conv_notrunc)
|
---|
186 | flags |= FLAG_NOTRUNC;
|
---|
187 | if (what == OP_conv_sync)
|
---|
188 | flags |= FLAG_SYNC;
|
---|
189 | if (what == OP_conv_noerror)
|
---|
190 | flags |= FLAG_NOERROR;
|
---|
191 | if (!key) /* no ',' left, so this was the last specifier */
|
---|
192 | break;
|
---|
193 | arg = key + 1; /* skip this keyword and ',' */
|
---|
194 | }
|
---|
195 | continue;
|
---|
196 | }
|
---|
197 | #endif
|
---|
198 | if (what == OP_bs) {
|
---|
199 | ibs = obs = xatoul_range_sfx(arg, 1, ((size_t)-1L)/2, dd_suffixes);
|
---|
200 | continue;
|
---|
201 | }
|
---|
202 | /* These can be large: */
|
---|
203 | if (what == OP_count) {
|
---|
204 | flags |= FLAG_COUNT;
|
---|
205 | count = XATOU_SFX(arg, dd_suffixes);
|
---|
206 | continue;
|
---|
207 | }
|
---|
208 | if (what == OP_seek) {
|
---|
209 | seek = XATOU_SFX(arg, dd_suffixes);
|
---|
210 | continue;
|
---|
211 | }
|
---|
212 | if (what == OP_skip) {
|
---|
213 | skip = XATOU_SFX(arg, dd_suffixes);
|
---|
214 | continue;
|
---|
215 | }
|
---|
216 | if (what == OP_if) {
|
---|
217 | infile = arg;
|
---|
218 | continue;
|
---|
219 | }
|
---|
220 | if (what == OP_of)
|
---|
221 | outfile = arg;
|
---|
222 | }
|
---|
223 | //XXX:FIXME for huge ibs or obs, malloc'ing them isn't the brightest idea ever
|
---|
224 | ibuf = obuf = xmalloc(ibs);
|
---|
225 | if (ibs != obs) {
|
---|
226 | flags |= FLAG_TWOBUFS;
|
---|
227 | obuf = xmalloc(obs);
|
---|
228 | }
|
---|
229 | if (infile != NULL)
|
---|
230 | ifd = xopen(infile, O_RDONLY);
|
---|
231 | else {
|
---|
232 | /* ifd = STDIN_FILENO; - it's zero and it's already there */
|
---|
233 | infile = bb_msg_standard_input;
|
---|
234 | }
|
---|
235 | if (outfile != NULL) {
|
---|
236 | int oflag = O_WRONLY | O_CREAT;
|
---|
237 |
|
---|
238 | if (!seek && !(flags & FLAG_NOTRUNC))
|
---|
239 | oflag |= O_TRUNC;
|
---|
240 |
|
---|
241 | ofd = xopen(outfile, oflag);
|
---|
242 |
|
---|
243 | if (seek && !(flags & FLAG_NOTRUNC)) {
|
---|
244 | if (ftruncate(ofd, seek * obs) < 0) {
|
---|
245 | struct stat st;
|
---|
246 |
|
---|
247 | if (fstat(ofd, &st) < 0 || S_ISREG(st.st_mode) ||
|
---|
248 | S_ISDIR(st.st_mode))
|
---|
249 | goto die_outfile;
|
---|
250 | }
|
---|
251 | }
|
---|
252 | } else {
|
---|
253 | ofd = STDOUT_FILENO;
|
---|
254 | outfile = bb_msg_standard_output;
|
---|
255 | }
|
---|
256 | if (skip) {
|
---|
257 | if (lseek(ifd, skip * ibs, SEEK_CUR) < 0) {
|
---|
258 | while (skip-- > 0) {
|
---|
259 | n = safe_read(ifd, ibuf, ibs);
|
---|
260 | if (n < 0)
|
---|
261 | goto die_infile;
|
---|
262 | if (n == 0)
|
---|
263 | break;
|
---|
264 | }
|
---|
265 | }
|
---|
266 | }
|
---|
267 | if (seek) {
|
---|
268 | if (lseek(ofd, seek * obs, SEEK_CUR) < 0)
|
---|
269 | goto die_outfile;
|
---|
270 | }
|
---|
271 |
|
---|
272 | while (!(flags & FLAG_COUNT) || (G.in_full + G.in_part != count)) {
|
---|
273 | if (flags & FLAG_NOERROR) /* Pre-zero the buffer if conv=noerror */
|
---|
274 | memset(ibuf, 0, ibs);
|
---|
275 | n = safe_read(ifd, ibuf, ibs);
|
---|
276 | if (n == 0)
|
---|
277 | break;
|
---|
278 | if (n < 0) {
|
---|
279 | if (flags & FLAG_NOERROR) {
|
---|
280 | n = ibs;
|
---|
281 | bb_perror_msg("%s", infile);
|
---|
282 | } else
|
---|
283 | goto die_infile;
|
---|
284 | }
|
---|
285 | if ((size_t)n == ibs)
|
---|
286 | G.in_full++;
|
---|
287 | else {
|
---|
288 | G.in_part++;
|
---|
289 | if (flags & FLAG_SYNC) {
|
---|
290 | memset(ibuf + n, '\0', ibs - n);
|
---|
291 | n = ibs;
|
---|
292 | }
|
---|
293 | }
|
---|
294 | if (flags & FLAG_TWOBUFS) {
|
---|
295 | char *tmp = ibuf;
|
---|
296 | while (n) {
|
---|
297 | size_t d = obs - oc;
|
---|
298 |
|
---|
299 | if (d > n)
|
---|
300 | d = n;
|
---|
301 | memcpy(obuf + oc, tmp, d);
|
---|
302 | n -= d;
|
---|
303 | tmp += d;
|
---|
304 | oc += d;
|
---|
305 | if (oc == obs) {
|
---|
306 | if (write_and_stats(ofd, obuf, obs, obs, outfile))
|
---|
307 | goto out_status;
|
---|
308 | oc = 0;
|
---|
309 | }
|
---|
310 | }
|
---|
311 | } else if (write_and_stats(ofd, ibuf, n, obs, outfile))
|
---|
312 | goto out_status;
|
---|
313 | }
|
---|
314 |
|
---|
315 | if (ENABLE_FEATURE_DD_IBS_OBS && oc) {
|
---|
316 | w = full_write_or_warn(ofd, obuf, oc, outfile);
|
---|
317 | if (w < 0) goto out_status;
|
---|
318 | if (w > 0)
|
---|
319 | G.out_part++;
|
---|
320 | }
|
---|
321 | if (close(ifd) < 0) {
|
---|
322 | die_infile:
|
---|
323 | bb_perror_msg_and_die("%s", infile);
|
---|
324 | }
|
---|
325 |
|
---|
326 | if (close(ofd) < 0) {
|
---|
327 | die_outfile:
|
---|
328 | bb_perror_msg_and_die("%s", outfile);
|
---|
329 | }
|
---|
330 | out_status:
|
---|
331 | dd_output_status(0);
|
---|
332 |
|
---|
333 | return EXIT_SUCCESS;
|
---|
334 | }
|
---|