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- /* vi: set sw=4 ts=4: */
- /*
- * Mini dd implementation for busybox
- *
- *
- * Copyright (C) 2000,2001 Matt Kraai
- *
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
- */
- #include <signal.h> /* For FEATURE_DD_SIGNAL_HANDLING */
- #include "libbb.h"
- /* This is a NOEXEC applet. Be very careful! */
- static const struct suffix_mult dd_suffixes[] = {
- { "c", 1 },
- { "w", 2 },
- { "b", 512 },
- { "kD", 1000 },
- { "k", 1024 },
- { "K", 1024 }, /* compat with coreutils dd */
- { "MD", 1000000 },
- { "M", 1048576 },
- { "GD", 1000000000 },
- { "G", 1073741824 },
- { NULL, 0 }
- };
- struct globals {
- off_t out_full, out_part, in_full, in_part;
- };
- #define G (*(struct globals*)&bb_common_bufsiz1)
- static void dd_output_status(int ATTRIBUTE_UNUSED cur_signal)
- {
- fprintf(stderr, "%"OFF_FMT"d+%"OFF_FMT"d records in\n"
- "%"OFF_FMT"d+%"OFF_FMT"d records out\n",
- G.in_full, G.in_part,
- G.out_full, G.out_part);
- }
- static ssize_t full_write_or_warn(int fd, const void *buf, size_t len,
- const char * const filename)
- {
- ssize_t n = full_write(fd, buf, len);
- if (n < 0)
- bb_perror_msg("writing '%s'", filename);
- return n;
- }
- static bool write_and_stats(int fd, const void *buf, size_t len, size_t obs,
- const char * const filename)
- {
- ssize_t n = full_write_or_warn(fd, buf, len, filename);
- if (n < 0)
- return 1;
- if (n == obs)
- G.out_full++;
- else if (n) /* > 0 */
- G.out_part++;
- return 0;
- }
- #if ENABLE_LFS
- #define XATOU_SFX xatoull_sfx
- #else
- #define XATOU_SFX xatoul_sfx
- #endif
- int dd_main(int argc, char **argv);
- int dd_main(int argc, char **argv)
- {
- enum {
- SYNC_FLAG = 1 << 0,
- NOERROR = 1 << 1,
- TRUNC_FLAG = 1 << 2,
- TWOBUFS_FLAG = 1 << 3,
- };
- static const char * const keywords[] = {
- "bs=", "count=", "seek=", "skip=", "if=", "of=",
- #if ENABLE_FEATURE_DD_IBS_OBS
- "ibs=", "obs=", "conv=", "notrunc", "sync", "noerror",
- #endif
- NULL
- };
- enum {
- OP_bs = 1,
- OP_count,
- OP_seek,
- OP_skip,
- OP_if,
- OP_of,
- #if ENABLE_FEATURE_DD_IBS_OBS
- OP_ibs,
- OP_obs,
- OP_conv,
- OP_conv_notrunc,
- OP_conv_sync,
- OP_conv_noerror,
- #endif
- };
- int flags = TRUNC_FLAG;
- size_t oc = 0, ibs = 512, obs = 512;
- ssize_t n, w;
- off_t seek = 0, skip = 0, count = OFF_T_MAX;
- int ifd, ofd;
- const char *infile = NULL, *outfile = NULL;
- char *ibuf, *obuf;
- memset(&G, 0, sizeof(G)); /* because of NOEXEC */
- if (ENABLE_FEATURE_DD_SIGNAL_HANDLING) {
- struct sigaction sa;
- memset(&sa, 0, sizeof(sa));
- sa.sa_handler = dd_output_status;
- sa.sa_flags = SA_RESTART;
- sigemptyset(&sa.sa_mask);
- sigaction(SIGUSR1, &sa, 0);
- }
- for (n = 1; n < argc; n++) {
- smalluint key_len;
- smalluint what;
- char *key;
- char *arg = argv[n];
- //XXX:FIXME: we reject plain "dd --" This would cost ~20 bytes, so..
- //if (*arg == '-' && *++arg == '-' && !*++arg) continue;
- key = strstr(arg, "=");
- if (key == NULL)
- bb_show_usage();
- key_len = key - arg + 1;
- key = xstrndup(arg, key_len);
- what = index_in_str_array(keywords, key) + 1;
- if (ENABLE_FEATURE_CLEAN_UP)
- free(key);
- if (what == 0)
- bb_show_usage();
- arg += key_len;
- /* Must fit into positive ssize_t */
- #if ENABLE_FEATURE_DD_IBS_OBS
- if (what == OP_ibs) {
- ibs = xatoul_range_sfx(arg, 1, ((size_t)-1L)/2, dd_suffixes);
- continue;
- }
- if (what == OP_obs) {
- obs = xatoul_range_sfx(arg, 1, ((size_t)-1L)/2, dd_suffixes);
- continue;
- }
- if (what == OP_conv) {
- while (1) {
- /* find ',', replace them with nil so we can use arg for
- * index_in_str_array without copying.
- * We rely on arg being non-null, else strchr would fault.
- */
- key = strchr(arg, ',');
- if (key)
- *key = '\0';
- what = index_in_str_array(keywords, arg) + 1;
- if (what < OP_conv_notrunc)
- bb_error_msg_and_die(bb_msg_invalid_arg, arg, "conv");
- if (what == OP_conv_notrunc)
- flags &= ~TRUNC_FLAG;
- if (what == OP_conv_sync)
- flags |= SYNC_FLAG;
- if (what == OP_conv_noerror)
- flags |= NOERROR;
- if (!key) /* no ',' left, so this was the last specifier */
- break;
- arg = key + 1; /* skip this keyword and ',' */
- }
- continue;
- }
- #endif
- if (what == OP_bs) {
- ibs = obs = xatoul_range_sfx(arg, 1, ((size_t)-1L)/2, dd_suffixes);
- continue;
- }
- /* These can be large: */
- if (what == OP_count) {
- count = XATOU_SFX(arg, dd_suffixes);
- continue;
- }
- if (what == OP_seek) {
- seek = XATOU_SFX(arg, dd_suffixes);
- continue;
- }
- if (what == OP_skip) {
- skip = XATOU_SFX(arg, dd_suffixes);
- continue;
- }
- if (what == OP_if) {
- infile = arg;
- continue;
- }
- if (what == OP_of)
- outfile = arg;
- }
- //XXX:FIXME for huge ibs or obs, malloc'ing them isn't the brightest idea ever
- ibuf = obuf = xmalloc(ibs);
- if (ibs != obs) {
- flags |= TWOBUFS_FLAG;
- obuf = xmalloc(obs);
- }
- if (infile != NULL)
- ifd = xopen(infile, O_RDONLY);
- else {
- ifd = STDIN_FILENO;
- infile = bb_msg_standard_input;
- }
- if (outfile != NULL) {
- int oflag = O_WRONLY | O_CREAT;
- if (!seek && (flags & TRUNC_FLAG))
- oflag |= O_TRUNC;
- ofd = xopen(outfile, oflag);
- if (seek && (flags & TRUNC_FLAG)) {
- if (ftruncate(ofd, seek * obs) < 0) {
- struct stat st;
- if (fstat(ofd, &st) < 0 || S_ISREG(st.st_mode) ||
- S_ISDIR(st.st_mode))
- goto die_outfile;
- }
- }
- } else {
- ofd = STDOUT_FILENO;
- outfile = bb_msg_standard_output;
- }
- if (skip) {
- if (lseek(ifd, skip * ibs, SEEK_CUR) < 0) {
- while (skip-- > 0) {
- n = safe_read(ifd, ibuf, ibs);
- if (n < 0)
- goto die_infile;
- if (n == 0)
- break;
- }
- }
- }
- if (seek) {
- if (lseek(ofd, seek * obs, SEEK_CUR) < 0)
- goto die_outfile;
- }
- while (G.in_full + G.in_part != count) {
- if (flags & NOERROR) /* Pre-zero the buffer when for NOERROR */
- memset(ibuf, '\0', ibs);
- n = safe_read(ifd, ibuf, ibs);
- if (n == 0)
- break;
- if (n < 0) {
- if (flags & NOERROR) {
- n = ibs;
- bb_perror_msg("%s", infile);
- } else
- goto die_infile;
- }
- if ((size_t)n == ibs)
- G.in_full++;
- else {
- G.in_part++;
- if (flags & SYNC_FLAG) {
- memset(ibuf + n, '\0', ibs - n);
- n = ibs;
- }
- }
- if (flags & TWOBUFS_FLAG) {
- char *tmp = ibuf;
- while (n) {
- size_t d = obs - oc;
- if (d > n)
- d = n;
- memcpy(obuf + oc, tmp, d);
- n -= d;
- tmp += d;
- oc += d;
- if (oc == obs) {
- if (write_and_stats(ofd, obuf, obs, obs, outfile))
- goto out_status;
- oc = 0;
- }
- }
- } else if (write_and_stats(ofd, ibuf, n, obs, outfile))
- goto out_status;
- }
- if (ENABLE_FEATURE_DD_IBS_OBS && oc) {
- w = full_write_or_warn(ofd, obuf, oc, outfile);
- if (w < 0) goto out_status;
- if (w > 0)
- G.out_part++;
- }
- if (close(ifd) < 0) {
- die_infile:
- bb_perror_msg_and_die("%s", infile);
- }
- if (close(ofd) < 0) {
- die_outfile:
- bb_perror_msg_and_die("%s", outfile);
- }
- out_status:
- dd_output_status(0);
- return EXIT_SUCCESS;
- }
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