freebsd-dev/bin/dd/args.c
Conrad Meyer b156d221c9 dd(1): Enable access to SIZE_T_MAX character devices
On machines where SIZE_T_MAX exceeds OFF_MAX (signed 64-bit), permit seeking
character devices to negative off_t values.  This enables dd(1) to interact
with kernel KVA in /dev/kmem on amd64, for example.

Sponsored by:	EMC / Isilon Storage Division
2016-07-09 17:11:54 +00:00

509 lines
12 KiB
C

/*-
* 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.
* 4. 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.
*/
#ifndef lint
#if 0
static char sccsid[] = "@(#)args.c 8.3 (Berkeley) 4/2/94";
#endif
#endif /* not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <err.h>
#include <errno.h>
#include <inttypes.h>
#include <limits.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include "dd.h"
#include "extern.h"
static int c_arg(const void *, const void *);
static int c_conv(const void *, const void *);
static void f_bs(char *);
static void f_cbs(char *);
static void f_conv(char *);
static void f_count(char *);
static void f_files(char *);
static void f_fillchar(char *);
static void f_ibs(char *);
static void f_if(char *);
static void f_obs(char *);
static void f_of(char *);
static void f_seek(char *);
static void f_skip(char *);
static void f_speed(char *);
static void f_status(char *);
static uintmax_t get_num(const char *);
static off_t get_off_t(const char *);
static const struct arg {
const char *name;
void (*f)(char *);
u_int set, noset;
} args[] = {
{ "bs", f_bs, C_BS, C_BS|C_IBS|C_OBS|C_OSYNC },
{ "cbs", f_cbs, C_CBS, C_CBS },
{ "conv", f_conv, 0, 0 },
{ "count", f_count, C_COUNT, C_COUNT },
{ "files", f_files, C_FILES, C_FILES },
{ "fillchar", f_fillchar, C_FILL, C_FILL },
{ "ibs", f_ibs, C_IBS, C_BS|C_IBS },
{ "if", f_if, C_IF, C_IF },
{ "iseek", f_skip, C_SKIP, C_SKIP },
{ "obs", f_obs, C_OBS, C_BS|C_OBS },
{ "of", f_of, C_OF, C_OF },
{ "oseek", f_seek, C_SEEK, C_SEEK },
{ "seek", f_seek, C_SEEK, C_SEEK },
{ "skip", f_skip, C_SKIP, C_SKIP },
{ "speed", f_speed, 0, 0 },
{ "status", f_status, C_STATUS,C_STATUS },
};
static char *oper;
/*
* args -- parse JCL syntax of dd.
*/
void
jcl(char **argv)
{
struct arg *ap, tmp;
char *arg;
in.dbsz = out.dbsz = 512;
while ((oper = *++argv) != NULL) {
if ((oper = strdup(oper)) == NULL)
errx(1, "unable to allocate space for the argument \"%s\"", *argv);
if ((arg = strchr(oper, '=')) == NULL)
errx(1, "unknown operand %s", oper);
*arg++ = '\0';
if (!*arg)
errx(1, "no value specified for %s", oper);
tmp.name = oper;
if (!(ap = (struct arg *)bsearch(&tmp, args,
sizeof(args)/sizeof(struct arg), sizeof(struct arg),
c_arg)))
errx(1, "unknown operand %s", tmp.name);
if (ddflags & ap->noset)
errx(1, "%s: illegal argument combination or already set",
tmp.name);
ddflags |= ap->set;
ap->f(arg);
}
/* Final sanity checks. */
if (ddflags & C_BS) {
/*
* Bs is turned off by any conversion -- we assume the user
* just wanted to set both the input and output block sizes
* and didn't want the bs semantics, so we don't warn.
*/
if (ddflags & (C_BLOCK | C_LCASE | C_SWAB | C_UCASE |
C_UNBLOCK))
ddflags &= ~C_BS;
/* Bs supersedes ibs and obs. */
if (ddflags & C_BS && ddflags & (C_IBS | C_OBS))
warnx("bs supersedes ibs and obs");
}
/*
* Ascii/ebcdic and cbs implies block/unblock.
* Block/unblock requires cbs and vice-versa.
*/
if (ddflags & (C_BLOCK | C_UNBLOCK)) {
if (!(ddflags & C_CBS))
errx(1, "record operations require cbs");
if (cbsz == 0)
errx(1, "cbs cannot be zero");
cfunc = ddflags & C_BLOCK ? block : unblock;
} else if (ddflags & C_CBS) {
if (ddflags & (C_ASCII | C_EBCDIC)) {
if (ddflags & C_ASCII) {
ddflags |= C_UNBLOCK;
cfunc = unblock;
} else {
ddflags |= C_BLOCK;
cfunc = block;
}
} else
errx(1, "cbs meaningless if not doing record operations");
} else
cfunc = def;
}
static int
c_arg(const void *a, const void *b)
{
return (strcmp(((const struct arg *)a)->name,
((const struct arg *)b)->name));
}
static void
f_bs(char *arg)
{
uintmax_t res;
res = get_num(arg);
if (res < 1 || res > SSIZE_MAX)
errx(1, "bs must be between 1 and %jd", (intmax_t)SSIZE_MAX);
in.dbsz = out.dbsz = (size_t)res;
}
static void
f_cbs(char *arg)
{
uintmax_t res;
res = get_num(arg);
if (res < 1 || res > SSIZE_MAX)
errx(1, "cbs must be between 1 and %jd", (intmax_t)SSIZE_MAX);
cbsz = (size_t)res;
}
static void
f_count(char *arg)
{
intmax_t res;
res = (intmax_t)get_num(arg);
if (res < 0)
errx(1, "count cannot be negative");
if (res == 0)
cpy_cnt = (uintmax_t)-1;
else
cpy_cnt = (uintmax_t)res;
}
static void
f_files(char *arg)
{
files_cnt = get_num(arg);
if (files_cnt < 1)
errx(1, "files must be between 1 and %jd", (uintmax_t)-1);
}
static void
f_fillchar(char *arg)
{
if (strlen(arg) != 1)
errx(1, "need exactly one fill char");
fill_char = arg[0];
}
static void
f_ibs(char *arg)
{
uintmax_t res;
if (!(ddflags & C_BS)) {
res = get_num(arg);
if (res < 1 || res > SSIZE_MAX)
errx(1, "ibs must be between 1 and %jd",
(intmax_t)SSIZE_MAX);
in.dbsz = (size_t)res;
}
}
static void
f_if(char *arg)
{
in.name = arg;
}
static void
f_obs(char *arg)
{
uintmax_t res;
if (!(ddflags & C_BS)) {
res = get_num(arg);
if (res < 1 || res > SSIZE_MAX)
errx(1, "obs must be between 1 and %jd",
(intmax_t)SSIZE_MAX);
out.dbsz = (size_t)res;
}
}
static void
f_of(char *arg)
{
out.name = arg;
}
static void
f_seek(char *arg)
{
out.offset = get_off_t(arg);
}
static void
f_skip(char *arg)
{
in.offset = get_off_t(arg);
}
static void
f_speed(char *arg)
{
speed = get_num(arg);
}
static void
f_status(char *arg)
{
if (strcmp(arg, "none") == 0)
ddflags |= C_NOINFO;
else if (strcmp(arg, "noxfer") == 0)
ddflags |= C_NOXFER;
else
errx(1, "unknown status %s", arg);
}
static const struct conv {
const char *name;
u_int set, noset;
const u_char *ctab;
} clist[] = {
{ "ascii", C_ASCII, C_EBCDIC, e2a_POSIX },
{ "block", C_BLOCK, C_UNBLOCK, NULL },
{ "ebcdic", C_EBCDIC, C_ASCII, a2e_POSIX },
{ "ibm", C_EBCDIC, C_ASCII, a2ibm_POSIX },
{ "lcase", C_LCASE, C_UCASE, NULL },
{ "noerror", C_NOERROR, 0, NULL },
{ "notrunc", C_NOTRUNC, 0, NULL },
{ "oldascii", C_ASCII, C_EBCDIC, e2a_32V },
{ "oldebcdic", C_EBCDIC, C_ASCII, a2e_32V },
{ "oldibm", C_EBCDIC, C_ASCII, a2ibm_32V },
{ "osync", C_OSYNC, C_BS, NULL },
{ "pareven", C_PAREVEN, C_PARODD|C_PARSET|C_PARNONE, NULL},
{ "parnone", C_PARNONE, C_PARODD|C_PARSET|C_PAREVEN, NULL},
{ "parodd", C_PARODD, C_PAREVEN|C_PARSET|C_PARNONE, NULL},
{ "parset", C_PARSET, C_PARODD|C_PAREVEN|C_PARNONE, NULL},
{ "sparse", C_SPARSE, 0, NULL },
{ "swab", C_SWAB, 0, NULL },
{ "sync", C_SYNC, 0, NULL },
{ "ucase", C_UCASE, C_LCASE, NULL },
{ "unblock", C_UNBLOCK, C_BLOCK, NULL },
};
static void
f_conv(char *arg)
{
struct conv *cp, tmp;
while (arg != NULL) {
tmp.name = strsep(&arg, ",");
cp = bsearch(&tmp, clist, sizeof(clist) / sizeof(struct conv),
sizeof(struct conv), c_conv);
if (cp == NULL)
errx(1, "unknown conversion %s", tmp.name);
if (ddflags & cp->noset)
errx(1, "%s: illegal conversion combination", tmp.name);
ddflags |= cp->set;
if (cp->ctab)
ctab = cp->ctab;
}
}
static int
c_conv(const void *a, const void *b)
{
return (strcmp(((const struct conv *)a)->name,
((const struct conv *)b)->name));
}
static intmax_t
postfix_to_mult(const char expr)
{
intmax_t mult;
mult = 0;
switch (expr) {
case 'B':
case 'b':
mult = 512;
break;
case 'K':
case 'k':
mult = 1 << 10;
break;
case 'M':
case 'm':
mult = 1 << 20;
break;
case 'G':
case 'g':
mult = 1 << 30;
break;
case 'T':
case 't':
mult = (uintmax_t)1 << 40;
break;
case 'P':
case 'p':
mult = (uintmax_t)1 << 50;
break;
case 'W':
case 'w':
mult = sizeof(int);
break;
}
return (mult);
}
/*
* Convert an expression of the following forms to a uintmax_t.
* 1) A positive decimal number.
* 2) A positive decimal number followed by a 'b' or 'B' (mult by 512).
* 3) A positive decimal number followed by a 'k' or 'K' (mult by 1 << 10).
* 4) A positive decimal number followed by a 'm' or 'M' (mult by 1 << 20).
* 5) A positive decimal number followed by a 'g' or 'G' (mult by 1 << 30).
* 6) A positive decimal number followed by a 't' or 'T' (mult by 1 << 40).
* 7) A positive decimal number followed by a 'p' or 'P' (mult by 1 << 50).
* 8) A positive decimal number followed by a 'w' or 'W' (mult by sizeof int).
* 9) Two or more positive decimal numbers (with/without [BbKkMmGgWw])
* separated by 'x' or 'X' (also '*' for backwards compatibility),
* specifying the product of the indicated values.
*/
static uintmax_t
get_num(const char *val)
{
uintmax_t num, mult, prevnum;
char *expr;
errno = 0;
num = strtoumax(val, &expr, 0);
if (expr == val) /* No valid digits. */
errx(1, "%s: invalid numeric value", oper);
if (errno != 0)
err(1, "%s", oper);
mult = postfix_to_mult(*expr);
if (mult != 0) {
prevnum = num;
num *= mult;
/* Check for overflow. */
if (num / mult != prevnum)
goto erange;
expr++;
}
switch (*expr) {
case '\0':
break;
case '*': /* Backward compatible. */
case 'X':
case 'x':
mult = get_num(expr + 1);
prevnum = num;
num *= mult;
if (num / mult == prevnum)
break;
erange:
errx(1, "%s: %s", oper, strerror(ERANGE));
default:
errx(1, "%s: illegal numeric value", oper);
}
return (num);
}
/*
* Convert an expression of the following forms to an off_t. This is the
* same as get_num(), but it uses signed numbers.
*
* The major problem here is that an off_t may not necessarily be a intmax_t.
*/
static off_t
get_off_t(const char *val)
{
intmax_t num, mult, prevnum;
char *expr;
errno = 0;
num = strtoimax(val, &expr, 0);
if (expr == val) /* No valid digits. */
errx(1, "%s: invalid numeric value", oper);
if (errno != 0)
err(1, "%s", oper);
mult = postfix_to_mult(*expr);
if (mult != 0) {
prevnum = num;
num *= mult;
/* Check for overflow. */
if ((prevnum > 0) != (num > 0) || num / mult != prevnum)
goto erange;
expr++;
}
switch (*expr) {
case '\0':
break;
case '*': /* Backward compatible. */
case 'X':
case 'x':
mult = (intmax_t)get_off_t(expr + 1);
prevnum = num;
num *= mult;
if ((prevnum > 0) == (num > 0) && num / mult == prevnum)
break;
erange:
errx(1, "%s: %s", oper, strerror(ERANGE));
default:
errx(1, "%s: illegal numeric value", oper);
}
return (num);
}