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NetBSD/bin/dd/dd.c

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/* $NetBSD: dd.c,v 1.38 2005/04/20 17:38:59 rillig Exp $ */
/*-
* Copyright (c) 1991, 1993, 1994
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Keith Muller of the University of California, San Diego and Lance
* Visser of Convex Computer Corporation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1991, 1993, 1994\n\
The Regents of the University of California. All rights reserved.\n");
#endif /* not lint */
#ifndef lint
#if 0
static char sccsid[] = "@(#)dd.c 8.5 (Berkeley) 4/2/94";
#else
__RCSID("$NetBSD: dd.c,v 1.38 2005/04/20 17:38:59 rillig Exp $");
#endif
#endif /* not lint */
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/mtio.h>
#include <sys/time.h>
#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "dd.h"
#include "extern.h"
static void dd_close(void);
static void dd_in(void);
static void getfdtype(IO *);
static int redup_clean_fd(int);
static void setup(void);
int main(int, char *[]);
IO in, out; /* input/output state */
STAT st; /* statistics */
void (*cfunc)(void); /* conversion function */
uint64_t cpy_cnt; /* # of blocks to copy */
static off_t pending = 0; /* pending seek if sparse */
u_int ddflags; /* conversion options */
uint64_t cbsz; /* conversion block size */
u_int files_cnt = 1; /* # of files to copy */
int progress = 0; /* display sign of life */
const u_char *ctab; /* conversion table */
sigset_t infoset; /* a set blocking SIGINFO */
int
main(int argc, char *argv[])
{
int ch;
while ((ch = getopt(argc, argv, "")) != -1) {
switch (ch) {
default:
errx(EXIT_FAILURE, "usage: dd [operand ...]");
/* NOTREACHED */
}
}
argc -= (optind - 1);
argv += (optind - 1);
jcl(argv);
setup();
(void)signal(SIGINFO, summaryx);
(void)signal(SIGINT, terminate);
(void)sigemptyset(&infoset);
(void)sigaddset(&infoset, SIGINFO);
(void)atexit(summary);
while (files_cnt--)
dd_in();
dd_close();
exit(0);
/* NOTREACHED */
}
static void
setup(void)
{
if (in.name == NULL) {
in.name = "stdin";
in.fd = STDIN_FILENO;
} else {
in.fd = open(in.name, O_RDONLY, 0);
if (in.fd < 0)
err(EXIT_FAILURE, "%s", in.name);
/* NOTREACHED */
/* Ensure in.fd is outside the stdio descriptor range */
in.fd = redup_clean_fd(in.fd);
}
getfdtype(&in);
if (files_cnt > 1 && !(in.flags & ISTAPE)) {
errx(EXIT_FAILURE, "files is not supported for non-tape devices");
/* NOTREACHED */
}
if (out.name == NULL) {
/* No way to check for read access here. */
out.fd = STDOUT_FILENO;
out.name = "stdout";
} else {
#define OFLAGS \
(O_CREAT | (ddflags & (C_SEEK | C_NOTRUNC) ? 0 : O_TRUNC))
out.fd = open(out.name, O_RDWR | OFLAGS, DEFFILEMODE);
/*
* May not have read access, so try again with write only.
* Without read we may have a problem if output also does
* not support seeks.
*/
if (out.fd < 0) {
out.fd = open(out.name, O_WRONLY | OFLAGS, DEFFILEMODE);
out.flags |= NOREAD;
}
if (out.fd < 0) {
err(EXIT_FAILURE, "%s", out.name);
/* NOTREACHED */
}
/* Ensure out.fd is outside the stdio descriptor range */
out.fd = redup_clean_fd(out.fd);
}
getfdtype(&out);
/*
* Allocate space for the input and output buffers. If not doing
* record oriented I/O, only need a single buffer.
*/
if (!(ddflags & (C_BLOCK|C_UNBLOCK))) {
if ((in.db = malloc(out.dbsz + in.dbsz - 1)) == NULL) {
err(EXIT_FAILURE, NULL);
/* NOTREACHED */
}
out.db = in.db;
} else if ((in.db =
malloc((u_int)(MAX(in.dbsz, cbsz) + cbsz))) == NULL ||
(out.db = malloc((u_int)(out.dbsz + cbsz))) == NULL) {
err(EXIT_FAILURE, NULL);
/* NOTREACHED */
}
in.dbp = in.db;
out.dbp = out.db;
/* Position the input/output streams. */
if (in.offset)
pos_in();
if (out.offset)
pos_out();
/*
* Truncate the output file; ignore errors because it fails on some
* kinds of output files, tapes, for example.
*/
if ((ddflags & (C_OF | C_SEEK | C_NOTRUNC)) == (C_OF | C_SEEK))
(void)ftruncate(out.fd, (off_t)out.offset * out.dbsz);
/*
* If converting case at the same time as another conversion, build a
* table that does both at once. If just converting case, use the
* built-in tables.
*/
if (ddflags & (C_LCASE|C_UCASE)) {
#ifdef NO_CONV
/* Should not get here, but just in case... */
errx(EXIT_FAILURE, "case conv and -DNO_CONV");
/* NOTREACHED */
#else /* NO_CONV */
u_int cnt;
if (ddflags & C_ASCII || ddflags & C_EBCDIC) {
if (ddflags & C_LCASE) {
for (cnt = 0; cnt < 256; ++cnt)
casetab[cnt] = tolower(ctab[cnt]);
} else {
for (cnt = 0; cnt < 256; ++cnt)
casetab[cnt] = toupper(ctab[cnt]);
}
} else {
if (ddflags & C_LCASE) {
for (cnt = 0; cnt < 256; ++cnt)
casetab[cnt] = tolower(cnt);
} else {
for (cnt = 0; cnt < 256; ++cnt)
casetab[cnt] = toupper(cnt);
}
}
ctab = casetab;
#endif /* NO_CONV */
}
(void)gettimeofday(&st.start, NULL); /* Statistics timestamp. */
}
static void
getfdtype(IO *io)
{
struct mtget mt;
struct stat sb;
if (fstat(io->fd, &sb)) {
err(EXIT_FAILURE, "%s", io->name);
/* NOTREACHED */
}
if (S_ISCHR(sb.st_mode))
io->flags |= ioctl(io->fd, MTIOCGET, &mt) ? ISCHR : ISTAPE;
else if (lseek(io->fd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE)
io->flags |= ISPIPE; /* XXX fixed in 4.4BSD */
}
/*
* Move the parameter file descriptor to a descriptor that is outside the
* stdio descriptor range, if necessary. This is required to avoid
* accidentally outputting completion or error messages into the
* output file that were intended for the tty.
*/
static int
redup_clean_fd(int fd)
{
int newfd;
if (fd != STDIN_FILENO && fd != STDOUT_FILENO &&
fd != STDERR_FILENO)
/* File descriptor is ok, return immediately. */
return fd;
/*
* 3 is the first descriptor greater than STD*_FILENO. Any
* free descriptor valued 3 or above is acceptable...
*/
newfd = fcntl(fd, F_DUPFD, 3);
if (newfd < 0) {
err(EXIT_FAILURE, "dupfd IO");
/* NOTREACHED */
}
close(fd);
return newfd;
}
static void
dd_in(void)
{
int flags;
int64_t n;
for (flags = ddflags;;) {
if (cpy_cnt && (st.in_full + st.in_part) >= cpy_cnt)
return;
/*
* Clear the buffer first if doing "sync" on input.
* If doing block operations use spaces. This will
* affect not only the C_NOERROR case, but also the
* last partial input block which should be padded
* with zero and not garbage.
*/
if (flags & C_SYNC) {
if (flags & (C_BLOCK|C_UNBLOCK))
(void)memset(in.dbp, ' ', in.dbsz);
else
(void)memset(in.dbp, 0, in.dbsz);
}
n = read(in.fd, in.dbp, in.dbsz);
if (n == 0) {
in.dbrcnt = 0;
return;
}
/* Read error. */
if (n < 0) {
/*
* If noerror not specified, die. POSIX requires that
* the warning message be followed by an I/O display.
*/
if (!(flags & C_NOERROR)) {
err(EXIT_FAILURE, "%s", in.name);
/* NOTREACHED */
}
warn("%s", in.name);
summary();
/*
* If it's not a tape drive or a pipe, seek past the
* error. If your OS doesn't do the right thing for
* raw disks this section should be modified to re-read
* in sector size chunks.
*/
if (!(in.flags & (ISPIPE|ISTAPE)) &&
lseek(in.fd, (off_t)in.dbsz, SEEK_CUR))
warn("%s", in.name);
/* If sync not specified, omit block and continue. */
if (!(ddflags & C_SYNC))
continue;
/* Read errors count as full blocks. */
in.dbcnt += in.dbrcnt = in.dbsz;
++st.in_full;
/* Handle full input blocks. */
} else if (n == in.dbsz) {
in.dbcnt += in.dbrcnt = n;
++st.in_full;
/* Handle partial input blocks. */
} else {
/* If sync, use the entire block. */
if (ddflags & C_SYNC)
in.dbcnt += in.dbrcnt = in.dbsz;
else
in.dbcnt += in.dbrcnt = n;
++st.in_part;
}
/*
* POSIX states that if bs is set and no other conversions
* than noerror, notrunc or sync are specified, the block
* is output without buffering as it is read.
*/
if (ddflags & C_BS) {
out.dbcnt = in.dbcnt;
dd_out(1);
in.dbcnt = 0;
continue;
}
if (ddflags & C_SWAB) {
if ((n = in.dbrcnt) & 1) {
++st.swab;
--n;
}
swab(in.dbp, in.dbp, n);
}
in.dbp += in.dbrcnt;
(*cfunc)();
}
}
/*
* Cleanup any remaining I/O and flush output. If necesssary, output file
* is truncated.
*/
static void
dd_close(void)
{
if (cfunc == def)
def_close();
else if (cfunc == block)
block_close();
else if (cfunc == unblock)
unblock_close();
if (ddflags & C_OSYNC && out.dbcnt < out.dbsz) {
(void)memset(out.dbp, 0, out.dbsz - out.dbcnt);
out.dbcnt = out.dbsz;
}
/* If there are pending sparse blocks, make sure
* to write out the final block un-sparse
*/
if ((out.dbcnt == 0) && pending) {
memset(out.db, 0, out.dbsz);
out.dbcnt = out.dbsz;
out.dbp = out.db + out.dbcnt;
pending -= out.dbsz;
}
if (out.dbcnt)
dd_out(1);
/*
* Reporting nfs write error may be defered until next
* write(2) or close(2) system call. So, we need to do an
* extra check. If an output is stdout, the file structure
* may be shared among with other processes and close(2) just
* decreases the reference count.
*/
if (out.fd == STDOUT_FILENO && fsync(out.fd) == -1 && errno != EINVAL) {
err(EXIT_FAILURE, "fsync stdout");
/* NOTREACHED */
}
if (close(out.fd) == -1) {
err(EXIT_FAILURE, "close");
/* NOTREACHED */
}
}
void
dd_out(int force)
{
static int warned;
int64_t cnt, n, nw;
u_char *outp;
/*
* Write one or more blocks out. The common case is writing a full
* output block in a single write; increment the full block stats.
* Otherwise, we're into partial block writes. If a partial write,
* and it's a character device, just warn. If a tape device, quit.
*
* The partial writes represent two cases. 1: Where the input block
* was less than expected so the output block was less than expected.
* 2: Where the input block was the right size but we were forced to
* write the block in multiple chunks. The original versions of dd(1)
* never wrote a block in more than a single write, so the latter case
* never happened.
*
* One special case is if we're forced to do the write -- in that case
* we play games with the buffer size, and it's usually a partial write.
*/
outp = out.db;
for (n = force ? out.dbcnt : out.dbsz;; n = out.dbsz) {
for (cnt = n;; cnt -= nw) {
if (!force && ddflags & C_SPARSE) {
int sparse, i;
sparse = 1; /* Is buffer sparse? */
for (i = 0; i < cnt; i++)
if (outp[i] != 0) {
sparse = 0;
break;
}
if (sparse) {
pending += cnt;
outp += cnt;
nw = 0;
break;
}
}
if (pending != 0) {
if (lseek(out.fd, pending, SEEK_CUR) ==
-1)
err(EXIT_FAILURE, "%s: seek error creating sparse file",
out.name);
}
nw = bwrite(out.fd, outp, cnt);
if (nw <= 0) {
if (nw == 0)
errx(EXIT_FAILURE,
"%s: end of device", out.name);
/* NOTREACHED */
if (errno != EINTR)
err(EXIT_FAILURE, "%s", out.name);
/* NOTREACHED */
nw = 0;
}
if (pending) {
st.bytes += pending;
st.sparse += pending/out.dbsz;
st.out_full += pending/out.dbsz;
pending = 0;
}
outp += nw;
st.bytes += nw;
if (nw == n) {
if (n != out.dbsz)
++st.out_part;
else
++st.out_full;
break;
}
++st.out_part;
if (nw == cnt)
break;
if (out.flags & ISCHR && !warned) {
warned = 1;
warnx("%s: short write on character device", out.name);
}
if (out.flags & ISTAPE)
errx(EXIT_FAILURE,
"%s: short write on tape device", out.name);
/* NOTREACHED */
}
if ((out.dbcnt -= n) < out.dbsz)
break;
}
/* Reassemble the output block. */
if (out.dbcnt)
(void)memmove(out.db, out.dbp - out.dbcnt, out.dbcnt);
out.dbp = out.db + out.dbcnt;
if (progress)
(void)write(STDERR_FILENO, ".", 1);
}
/*
* A protected against SIGINFO write
*/
ssize_t
bwrite(int fd, const void *buf, size_t len)
{
sigset_t oset;
ssize_t rv;
int oerrno;
(void)sigprocmask(SIG_BLOCK, &infoset, &oset);
rv = write(fd, buf, len);
oerrno = errno;
(void)sigprocmask(SIG_SETMASK, &oset, NULL);
errno = oerrno;
return (rv);
}
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