| /* 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! */ |
| |
| |
| 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 }, |
| { } |
| }; |
| |
| struct globals { |
| off_t out_full, out_part, in_full, in_part; |
| }; |
| #define G (*(struct globals*)&bb_common_bufsiz1) |
| /* We have to zero it out because of NOEXEC */ |
| #define INIT_G() memset(&G, 0, sizeof(G)) |
| |
| |
| static void dd_output_status(int ATTRIBUTE_UNUSED cur_signal) |
| { |
| /* 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); |
| } |
| |
| 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++; |
| 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 ATTRIBUTE_UNUSED, 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(NULL); - is this needed because of NOEXEC? |
| |
| #if ENABLE_FEATURE_DD_SIGNAL_HANDLING |
| signal_SA_RESTART_empty_mask(SIGUSR1, dd_output_status); |
| #endif |
| |
| 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 (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)) { |
| if (flags & FLAG_NOERROR) /* Pre-zero the buffer if conv=noerror */ |
| memset(ibuf, 0, ibs); |
| n = safe_read(ifd, ibuf, ibs); |
| if (n == 0) |
| break; |
| if (n < 0) { |
| if (!(flags & FLAG_NOERROR)) |
| goto die_infile; |
| n = ibs; |
| bb_simple_perror_msg(infile); |
| } |
| 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); |
| |
| return exitcode; |
| } |