/* 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 source tree. */ //usage:#define dd_trivial_usage //usage: "[if=FILE] [of=FILE] " IF_FEATURE_DD_IBS_OBS("[ibs=N] [obs=N] ") "[bs=N] [count=N] [skip=N]\n" //usage: " [seek=N]" IF_FEATURE_DD_IBS_OBS(" [conv=notrunc|noerror|sync|fsync]") //usage:#define dd_full_usage "\n\n" //usage: "Copy a file with converting and formatting\n" //usage: "\n if=FILE Read from FILE instead of stdin" //usage: "\n of=FILE Write to FILE instead of stdout" //usage: "\n bs=N Read and write N bytes at a time" //usage: IF_FEATURE_DD_IBS_OBS( //usage: "\n ibs=N Read N bytes at a time" //usage: ) //usage: IF_FEATURE_DD_IBS_OBS( //usage: "\n obs=N Write N bytes at a time" //usage: ) //usage: "\n count=N Copy only N input blocks" //usage: "\n skip=N Skip N input blocks" //usage: "\n seek=N Skip N output blocks" //usage: IF_FEATURE_DD_IBS_OBS( //usage: "\n conv=notrunc Don't truncate output file" //usage: "\n conv=noerror Continue after read errors" //usage: "\n conv=sync Pad blocks with zeros" //usage: "\n conv=fsync Physically write data out before finishing" //usage: ) //usage: "\n" //usage: "\nNumbers may be suffixed by c (x1), w (x2), b (x512), kD (x1000), k (x1024)," //usage: "\nMD (x1000000), M (x1048576), GD (x1000000000) or G (x1073741824)" //usage: //usage:#define dd_example_usage //usage: "$ dd if=/dev/zero of=/dev/ram1 bs=1M count=4\n" //usage: "4+0 records in\n" //usage: "4+0 records out\n" #include "libbb.h" /* This is a NOEXEC applet. Be very careful! */ enum { ifd = STDIN_FILENO, ofd = STDOUT_FILENO, }; 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 }, { "", 0 } }; struct globals { off_t out_full, out_part, in_full, in_part; #if ENABLE_FEATURE_DD_THIRD_STATUS_LINE unsigned long long total_bytes; unsigned long long begin_time_us; #endif } FIX_ALIASING; #define G (*(struct globals*)&bb_common_bufsiz1) #define INIT_G() do { \ /* we have to zero it out because of NOEXEC */ \ memset(&G, 0, sizeof(G)); \ } while (0) static void dd_output_status(int UNUSED_PARAM cur_signal) { #if ENABLE_FEATURE_DD_THIRD_STATUS_LINE double seconds; unsigned long long bytes_sec; unsigned long long now_us = monotonic_us(); /* before fprintf */ #endif /* Deliberately using %u, not %d */ fprintf(stderr, "%"OFF_FMT"u+%"OFF_FMT"u records in\n" "%"OFF_FMT"u+%"OFF_FMT"u records out\n", G.in_full, G.in_part, G.out_full, G.out_part); #if ENABLE_FEATURE_DD_THIRD_STATUS_LINE fprintf(stderr, "%llu bytes (%sB) copied, ", G.total_bytes, /* show fractional digit, use suffixes */ make_human_readable_str(G.total_bytes, 1, 0) ); /* Corner cases: * ./busybox dd </dev/null >/dev/null * ./busybox dd bs=1M count=2000 </dev/zero >/dev/null * (echo DONE) | ./busybox dd >/dev/null * (sleep 1; echo DONE) | ./busybox dd >/dev/null */ seconds = (now_us - G.begin_time_us) / 1000000.0; bytes_sec = G.total_bytes / seconds; fprintf(stderr, "%f seconds, %sB/s\n", seconds, /* show fractional digit, use suffixes */ make_human_readable_str(bytes_sec, 1, 0) ); #endif } static ssize_t full_write_or_warn(const void *buf, size_t len, const char *const filename) { ssize_t n = full_write(ofd, buf, len); if (n < 0) bb_perror_msg("writing '%s'", filename); return n; } static bool write_and_stats(const void *buf, size_t len, size_t obs, const char *filename) { ssize_t n = full_write_or_warn(buf, len, filename); if (n < 0) return 1; if ((size_t)n == obs) G.out_full++; else if (n) /* > 0 */ G.out_part++; #if ENABLE_FEATURE_DD_THIRD_STATUS_LINE G.total_bytes += n; #endif return 0; } #if ENABLE_LFS # define XATOU_SFX xatoull_sfx #else # define XATOU_SFX xatoul_sfx #endif int dd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int dd_main(int argc UNUSED_PARAM, char **argv) { enum { /* Must be in the same order as OP_conv_XXX! */ /* (see "flags |= (1 << what)" below) */ FLAG_NOTRUNC = 1 << 0, FLAG_SYNC = 1 << 1, FLAG_NOERROR = 1 << 2, FLAG_FSYNC = 1 << 3, /* end of conv flags */ FLAG_TWOBUFS = 1 << 4, FLAG_COUNT = 1 << 5, }; static const char keywords[] ALIGN1 = "bs\0""count\0""seek\0""skip\0""if\0""of\0" #if ENABLE_FEATURE_DD_IBS_OBS "ibs\0""obs\0""conv\0" #endif ; #if ENABLE_FEATURE_DD_IBS_OBS static const char conv_words[] ALIGN1 = "notrunc\0""sync\0""noerror\0""fsync\0"; #endif enum { OP_bs = 0, OP_count, OP_seek, OP_skip, OP_if, OP_of, #if ENABLE_FEATURE_DD_IBS_OBS OP_ibs, OP_obs, OP_conv, /* Must be in the same order as FLAG_XXX! */ OP_conv_notrunc = 0, OP_conv_sync, OP_conv_noerror, OP_conv_fsync, /* Unimplemented conv=XXX: */ //nocreat do not create the output file //excl fail if the output file already exists //fdatasync physically write output file data before finishing //swab swap every pair of input bytes //lcase change upper case to lower case //ucase change lower case to upper case //block pad newline-terminated records with spaces to cbs-size //unblock replace trailing spaces in cbs-size records with newline //ascii from EBCDIC to ASCII //ebcdic from ASCII to EBCDIC //ibm from ASCII to alternate EBCDIC #endif }; int exitcode = EXIT_FAILURE; size_t ibs = 512, obs = 512; ssize_t n, w; char *ibuf, *obuf; /* And these are all zeroed at once! */ struct { int flags; size_t oc; off_t count; off_t seek, skip; const char *infile, *outfile; } Z; #define flags (Z.flags ) #define oc (Z.oc ) #define count (Z.count ) #define seek (Z.seek ) #define skip (Z.skip ) #define infile (Z.infile ) #define outfile (Z.outfile) memset(&Z, 0, sizeof(Z)); INIT_G(); //fflush_all(); - is this needed because of NOEXEC? for (n = 1; argv[n]; n++) { int what; char *val; char *arg = argv[n]; #if ENABLE_DESKTOP /* "dd --". NB: coreutils 6.9 will complain if they see * more than one of them. We wouldn't. */ if (arg[0] == '-' && arg[1] == '-' && arg[2] == '\0') continue; #endif val = strchr(arg, '='); if (val == NULL) bb_show_usage(); *val = '\0'; what = index_in_strings(keywords, arg); if (what < 0) bb_show_usage(); /* *val = '='; - to preserve ps listing? */ val++; #if ENABLE_FEATURE_DD_IBS_OBS if (what == OP_ibs) { /* Must fit into positive ssize_t */ ibs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, dd_suffixes); /*continue;*/ } if (what == OP_obs) { obs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, dd_suffixes); /*continue;*/ } if (what == OP_conv) { while (1) { /* find ',', replace them with NUL so we can use val for * index_in_strings() without copying. * We rely on val being non-null, else strchr would fault. */ arg = strchr(val, ','); if (arg) *arg = '\0'; what = index_in_strings(conv_words, val); if (what < 0) bb_error_msg_and_die(bb_msg_invalid_arg, val, "conv"); flags |= (1 << what); if (!arg) /* no ',' left, so this was the last specifier */ break; /* *arg = ','; - to preserve ps listing? */ val = arg + 1; /* skip this keyword and ',' */ } continue; /* we trashed 'what', can't fall through */ } #endif if (what == OP_bs) { ibs = obs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, dd_suffixes); /*continue;*/ } /* These can be large: */ if (what == OP_count) { flags |= FLAG_COUNT; count = XATOU_SFX(val, dd_suffixes); /*continue;*/ } if (what == OP_seek) { seek = XATOU_SFX(val, dd_suffixes); /*continue;*/ } if (what == OP_skip) { skip = XATOU_SFX(val, dd_suffixes); /*continue;*/ } if (what == OP_if) { infile = val; /*continue;*/ } if (what == OP_of) { outfile = val; /*continue;*/ } } /* end of "for (argv[n])" */ //XXX:FIXME for huge ibs or obs, malloc'ing them isn't the brightest idea ever ibuf = obuf = xmalloc(ibs); if (ibs != obs) { flags |= FLAG_TWOBUFS; obuf = xmalloc(obs); } #if ENABLE_FEATURE_DD_SIGNAL_HANDLING signal_SA_RESTART_empty_mask(SIGUSR1, dd_output_status); #endif #if ENABLE_FEATURE_DD_THIRD_STATUS_LINE G.begin_time_us = monotonic_us(); #endif if (infile != NULL) xmove_fd(xopen(infile, O_RDONLY), ifd); else { infile = bb_msg_standard_input; } if (outfile != NULL) { int oflag = O_WRONLY | O_CREAT; if (!seek && !(flags & FLAG_NOTRUNC)) oflag |= O_TRUNC; xmove_fd(xopen(outfile, oflag), ofd); if (seek && !(flags & FLAG_NOTRUNC)) { 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 { 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 (!(flags & FLAG_COUNT) || (G.in_full + G.in_part != count)) { n = safe_read(ifd, ibuf, ibs); if (n == 0) break; if (n < 0) { /* "Bad block" */ if (!(flags & FLAG_NOERROR)) goto die_infile; bb_simple_perror_msg(infile); /* GNU dd with conv=noerror skips over bad blocks */ xlseek(ifd, ibs, SEEK_CUR); /* conv=noerror,sync writes NULs, * conv=noerror just ignores input bad blocks */ n = 0; } if ((size_t)n == ibs) G.in_full++; else { G.in_part++; if (flags & FLAG_SYNC) { memset(ibuf + n, 0, ibs - n); n = ibs; } } if (flags & FLAG_TWOBUFS) { char *tmp = ibuf; while (n) { size_t d = obs - oc; if (d > (size_t)n) d = n; memcpy(obuf + oc, tmp, d); n -= d; tmp += d; oc += d; if (oc == obs) { if (write_and_stats(obuf, obs, obs, outfile)) goto out_status; oc = 0; } } } else if (write_and_stats(ibuf, n, obs, outfile)) goto out_status; if (flags & FLAG_FSYNC) { if (fsync(ofd) < 0) goto die_outfile; } } if (ENABLE_FEATURE_DD_IBS_OBS && oc) { w = full_write_or_warn(obuf, oc, outfile); if (w < 0) goto out_status; if (w > 0) G.out_part++; } if (close(ifd) < 0) { die_infile: bb_simple_perror_msg_and_die(infile); } if (close(ofd) < 0) { die_outfile: bb_simple_perror_msg_and_die(outfile); } exitcode = EXIT_SUCCESS; out_status: dd_output_status(0); if (ENABLE_FEATURE_CLEAN_UP) { free(obuf); if (flags & FLAG_TWOBUFS) free(ibuf); } return exitcode; }