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freebsd-dev/bin/sh/miscbltin.c
Kyle Evans b63d2d683d sh: fix read builtin on 32-bit systems 
Specifically, any system with a 32-bit size_t; -residue is calculated as a
32-bit *then* promoted to the 64-bit off_t and the result is ultimately
wrong. This resulted in what would appear to be truncated output, as only
the first line would be read.

Correct it by just making residue an off_t to begin with, since this is what
lseek will take anyways.

Reported by:	antoine, dim
Triaged by:	cem
Tested by:	kevans
X-MFC-With:	r358152
2020-02-22 03:14:05 +00:00

607 lines
13 KiB
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/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Kenneth Almquist.
*
* 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.
*/
#ifndef lint
#if 0
static char sccsid[] = "@(#)miscbltin.c 8.4 (Berkeley) 5/4/95";
#endif
#endif /* not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*
* Miscellaneous builtins.
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <unistd.h>
#include <errno.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include "shell.h"
#include "options.h"
#include "var.h"
#include "output.h"
#include "memalloc.h"
#include "error.h"
#include "mystring.h"
#include "syntax.h"
#include "trap.h"
#undef eflag
#define READ_BUFLEN 1024
struct fdctx {
int fd;
size_t off; /* offset in buf */
size_t buflen;
char *ep; /* tail pointer */
char buf[READ_BUFLEN];
};
static void fdctx_init(int, struct fdctx *);
static void fdctx_destroy(struct fdctx *);
static ssize_t fdgetc(struct fdctx *, char *);
int readcmd(int, char **);
int umaskcmd(int, char **);
int ulimitcmd(int, char **);
static void
fdctx_init(int fd, struct fdctx *fdc)
{
off_t cur;
/* Check if fd is seekable. */
cur = lseek(fd, 0, SEEK_CUR);
*fdc = (struct fdctx){
.fd = fd,
.buflen = (cur != -1) ? READ_BUFLEN : 1,
.ep = &fdc->buf[0], /* No data */
};
}
static ssize_t
fdgetc(struct fdctx *fdc, char *c)
{
ssize_t nread;
if (&fdc->buf[fdc->off] == fdc->ep) {
nread = read(fdc->fd, fdc->buf, fdc->buflen);
if (nread > 0) {
fdc->off = 0;
fdc->ep = fdc->buf + nread;
} else
return (nread);
}
*c = fdc->buf[fdc->off++];
return (1);
}
static void
fdctx_destroy(struct fdctx *fdc)
{
off_t residue;
if (fdc->buflen > 1) {
/*
* Reposition the file offset. Here is the layout of buf:
*
* | off
* v
* |*****************|-------|
* buf ep buf+buflen
* |<- residue ->|
*
* off: current character
* ep: offset just after read(2)
* residue: length for reposition
*/
residue = (fdc->ep - fdc->buf) - fdc->off;
if (residue > 0)
(void) lseek(fdc->fd, -residue, SEEK_CUR);
}
}
/*
* The read builtin. The -r option causes backslashes to be treated like
* ordinary characters.
*
* This uses unbuffered input, which may be avoidable in some cases.
*
* Note that if IFS=' :' then read x y should work so that:
* 'a b' x='a', y='b'
* ' a b ' x='a', y='b'
* ':b' x='', y='b'
* ':' x='', y=''
* '::' x='', y=''
* ': :' x='', y=''
* ':::' x='', y='::'
* ':b c:' x='', y='b c:'
*/
int
readcmd(int argc __unused, char **argv __unused)
{
char **ap;
int backslash;
char c;
int rflag;
char *prompt;
const char *ifs;
char *p;
int startword;
int status;
int i;
int is_ifs;
int saveall = 0;
ptrdiff_t lastnonifs, lastnonifsws;
struct timeval tv;
char *tvptr;
fd_set ifds;
ssize_t nread;
int sig;
struct fdctx fdctx;
rflag = 0;
prompt = NULL;
tv.tv_sec = -1;
tv.tv_usec = 0;
while ((i = nextopt("erp:t:")) != '\0') {
switch(i) {
case 'p':
prompt = shoptarg;
break;
case 'e':
break;
case 'r':
rflag = 1;
break;
case 't':
tv.tv_sec = strtol(shoptarg, &tvptr, 0);
if (tvptr == shoptarg)
error("timeout value");
switch(*tvptr) {
case 0:
case 's':
break;
case 'h':
tv.tv_sec *= 60;
/* FALLTHROUGH */
case 'm':
tv.tv_sec *= 60;
break;
default:
error("timeout unit");
}
break;
}
}
if (prompt && isatty(0)) {
out2str(prompt);
flushall();
}
if (*(ap = argptr) == NULL)
error("arg count");
if ((ifs = bltinlookup("IFS", 1)) == NULL)
ifs = " \t\n";
if (tv.tv_sec >= 0) {
/*
* Wait for something to become available.
*/
FD_ZERO(&ifds);
FD_SET(0, &ifds);
status = select(1, &ifds, NULL, NULL, &tv);
/*
* If there's nothing ready, return an error.
*/
if (status <= 0) {
sig = pendingsig;
return (128 + (sig != 0 ? sig : SIGALRM));
}
}
status = 0;
startword = 2;
backslash = 0;
STARTSTACKSTR(p);
lastnonifs = lastnonifsws = -1;
fdctx_init(STDIN_FILENO, &fdctx);
for (;;) {
nread = fdgetc(&fdctx, &c);
if (nread == -1) {
if (errno == EINTR) {
sig = pendingsig;
if (sig == 0)
continue;
status = 128 + sig;
break;
}
warning("read error: %s", strerror(errno));
status = 2;
break;
} else if (nread != 1) {
status = 1;
break;
}
if (c == '\0')
continue;
CHECKSTRSPACE(1, p);
if (backslash) {
backslash = 0;
if (c != '\n') {
startword = 0;
lastnonifs = lastnonifsws = p - stackblock();
USTPUTC(c, p);
}
continue;
}
if (!rflag && c == '\\') {
backslash++;
continue;
}
if (c == '\n')
break;
if (strchr(ifs, c))
is_ifs = strchr(" \t\n", c) ? 1 : 2;
else
is_ifs = 0;
if (startword != 0) {
if (is_ifs == 1) {
/* Ignore leading IFS whitespace */
if (saveall)
USTPUTC(c, p);
continue;
}
if (is_ifs == 2 && startword == 1) {
/* Only one non-whitespace IFS per word */
startword = 2;
if (saveall) {
lastnonifsws = p - stackblock();
USTPUTC(c, p);
}
continue;
}
}
if (is_ifs == 0) {
/* append this character to the current variable */
startword = 0;
if (saveall)
/* Not just a spare terminator */
saveall++;
lastnonifs = lastnonifsws = p - stackblock();
USTPUTC(c, p);
continue;
}
/* end of variable... */
startword = is_ifs;
if (ap[1] == NULL) {
/* Last variable needs all IFS chars */
saveall++;
if (is_ifs == 2)
lastnonifsws = p - stackblock();
USTPUTC(c, p);
continue;
}
STACKSTRNUL(p);
setvar(*ap, stackblock(), 0);
ap++;
STARTSTACKSTR(p);
lastnonifs = lastnonifsws = -1;
}
fdctx_destroy(&fdctx);
STACKSTRNUL(p);
/*
* Remove trailing IFS chars: always remove whitespace, don't remove
* non-whitespace unless it was naked
*/
if (saveall <= 1)
lastnonifsws = lastnonifs;
stackblock()[lastnonifsws + 1] = '\0';
setvar(*ap, stackblock(), 0);
/* Set any remaining args to "" */
while (*++ap != NULL)
setvar(*ap, "", 0);
return status;
}
int
umaskcmd(int argc __unused, char **argv __unused)
{
char *ap;
int mask;
int i;
int symbolic_mode = 0;
while ((i = nextopt("S")) != '\0') {
symbolic_mode = 1;
}
INTOFF;
mask = umask(0);
umask(mask);
INTON;
if ((ap = *argptr) == NULL) {
if (symbolic_mode) {
char u[4], g[4], o[4];
i = 0;
if ((mask & S_IRUSR) == 0)
u[i++] = 'r';
if ((mask & S_IWUSR) == 0)
u[i++] = 'w';
if ((mask & S_IXUSR) == 0)
u[i++] = 'x';
u[i] = '\0';
i = 0;
if ((mask & S_IRGRP) == 0)
g[i++] = 'r';
if ((mask & S_IWGRP) == 0)
g[i++] = 'w';
if ((mask & S_IXGRP) == 0)
g[i++] = 'x';
g[i] = '\0';
i = 0;
if ((mask & S_IROTH) == 0)
o[i++] = 'r';
if ((mask & S_IWOTH) == 0)
o[i++] = 'w';
if ((mask & S_IXOTH) == 0)
o[i++] = 'x';
o[i] = '\0';
out1fmt("u=%s,g=%s,o=%s\n", u, g, o);
} else {
out1fmt("%.4o\n", mask);
}
} else {
if (is_digit(*ap)) {
mask = 0;
do {
if (*ap >= '8' || *ap < '0')
error("Illegal number: %s", *argptr);
mask = (mask << 3) + (*ap - '0');
} while (*++ap != '\0');
umask(mask);
} else {
void *set;
INTOFF;
if ((set = setmode (ap)) == NULL)
error("Illegal number: %s", ap);
mask = getmode (set, ~mask & 0777);
umask(~mask & 0777);
free(set);
INTON;
}
}
return 0;
}
/*
* ulimit builtin
*
* This code, originally by Doug Gwyn, Doug Kingston, Eric Gisin, and
* Michael Rendell was ripped from pdksh 5.0.8 and hacked for use with
* ash by J.T. Conklin.
*
* Public domain.
*/
struct limits {
const char *name;
const char *units;
int cmd;
short factor; /* multiply by to get rlim_{cur,max} values */
char option;
};
static const struct limits limits[] = {
#ifdef RLIMIT_CPU
{ "cpu time", "seconds", RLIMIT_CPU, 1, 't' },
#endif
#ifdef RLIMIT_FSIZE
{ "file size", "512-blocks", RLIMIT_FSIZE, 512, 'f' },
#endif
#ifdef RLIMIT_DATA
{ "data seg size", "kbytes", RLIMIT_DATA, 1024, 'd' },
#endif
#ifdef RLIMIT_STACK
{ "stack size", "kbytes", RLIMIT_STACK, 1024, 's' },
#endif
#ifdef RLIMIT_CORE
{ "core file size", "512-blocks", RLIMIT_CORE, 512, 'c' },
#endif
#ifdef RLIMIT_RSS
{ "max memory size", "kbytes", RLIMIT_RSS, 1024, 'm' },
#endif
#ifdef RLIMIT_MEMLOCK
{ "locked memory", "kbytes", RLIMIT_MEMLOCK, 1024, 'l' },
#endif
#ifdef RLIMIT_NPROC
{ "max user processes", (char *)0, RLIMIT_NPROC, 1, 'u' },
#endif
#ifdef RLIMIT_NOFILE
{ "open files", (char *)0, RLIMIT_NOFILE, 1, 'n' },
#endif
#ifdef RLIMIT_VMEM
{ "virtual mem size", "kbytes", RLIMIT_VMEM, 1024, 'v' },
#endif
#ifdef RLIMIT_SWAP
{ "swap limit", "kbytes", RLIMIT_SWAP, 1024, 'w' },
#endif
#ifdef RLIMIT_SBSIZE
{ "socket buffer size", "bytes", RLIMIT_SBSIZE, 1, 'b' },
#endif
#ifdef RLIMIT_NPTS
{ "pseudo-terminals", (char *)0, RLIMIT_NPTS, 1, 'p' },
#endif
#ifdef RLIMIT_KQUEUES
{ "kqueues", (char *)0, RLIMIT_KQUEUES, 1, 'k' },
#endif
#ifdef RLIMIT_UMTXP
{ "umtx shared locks", (char *)0, RLIMIT_UMTXP, 1, 'o' },
#endif
{ (char *) 0, (char *)0, 0, 0, '\0' }
};
enum limithow { SOFT = 0x1, HARD = 0x2 };
static void
printlimit(enum limithow how, const struct rlimit *limit,
const struct limits *l)
{
rlim_t val = 0;
if (how & SOFT)
val = limit->rlim_cur;
else if (how & HARD)
val = limit->rlim_max;
if (val == RLIM_INFINITY)
out1str("unlimited\n");
else
{
val /= l->factor;
out1fmt("%jd\n", (intmax_t)val);
}
}
int
ulimitcmd(int argc __unused, char **argv __unused)
{
rlim_t val = 0;
enum limithow how = SOFT | HARD;
const struct limits *l;
int set, all = 0;
int optc, what;
struct rlimit limit;
what = 'f';
while ((optc = nextopt("HSatfdsmcnuvlbpwko")) != '\0')
switch (optc) {
case 'H':
how = HARD;
break;
case 'S':
how = SOFT;
break;
case 'a':
all = 1;
break;
default:
what = optc;
}
for (l = limits; l->name && l->option != what; l++)
;
if (!l->name)
error("internal error (%c)", what);
set = *argptr ? 1 : 0;
if (set) {
char *p = *argptr;
if (all || argptr[1])
error("too many arguments");
if (strcmp(p, "unlimited") == 0)
val = RLIM_INFINITY;
else {
char *end;
uintmax_t uval;
if (*p < '0' || *p > '9')
error("bad number");
errno = 0;
uval = strtoumax(p, &end, 10);
if (errno != 0 || *end != '\0')
error("bad number");
if (uval > UINTMAX_MAX / l->factor)
error("bad number");
uval *= l->factor;
val = (rlim_t)uval;
if (val < 0 || (uintmax_t)val != uval ||
val == RLIM_INFINITY)
error("bad number");
}
}
if (all) {
for (l = limits; l->name; l++) {
char optbuf[40];
if (getrlimit(l->cmd, &limit) < 0)
error("can't get limit: %s", strerror(errno));
if (l->units)
snprintf(optbuf, sizeof(optbuf),
"(%s, -%c) ", l->units, l->option);
else
snprintf(optbuf, sizeof(optbuf),
"(-%c) ", l->option);
out1fmt("%-18s %18s ", l->name, optbuf);
printlimit(how, &limit, l);
}
return 0;
}
if (getrlimit(l->cmd, &limit) < 0)
error("can't get limit: %s", strerror(errno));
if (set) {
if (how & SOFT)
limit.rlim_cur = val;
if (how & HARD)
limit.rlim_max = val;
if (setrlimit(l->cmd, &limit) < 0)
error("bad limit: %s", strerror(errno));
} else
printlimit(how, &limit, l);
return 0;
}
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