source: MondoRescue/branches/2.2.8.selinux/mindi-busybox/coreutils/dd.c@ 3654

Last change on this file since 3654 was 1765, checked in by Bruno Cornec, 18 years ago

Update to busybox 1.7.2
File size: 7.2 KB
Line 
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
17static 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
31struct 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
39static 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
48static 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
57static 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
76int dd_main(int argc, char **argv);
77int 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}
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