freebsd-skq/libexec/rtld-elf/rtld_printf.c
Jonathan Anderson 02d3b38e0a Add the LD_LIBRARY_PATH_FDS environmental variable.
This variable allows the loading of shared libraries via directory descriptors
rather than via library paths.  If LD_LIBRARY_PATH_FDS=3:4:12, the directories
represented by file descriptors 3, 4 and 12 will searched for shared libraries
before the normal path-based mechanisms are used.  This allows us to execute
unprivileged binaries from within a Capsicum sandbox even if they require
shared libraries.

Approved by:	rwatson (mentor)
Reviewed by:	kib
MFC after:	3 weeks
Sponsored by:	DARPA/AFRL
2014-06-20 17:08:32 +00:00

502 lines
10 KiB
C

/*-
* Copyright (c) 1986, 1988, 1991, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
* Copyright (c) 2011 Konstantin Belousov <kib@FreeBSD.org>
*
* 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.
*
* $FreeBSD$
*/
#include <sys/param.h>
#include <inttypes.h>
#include <stdarg.h>
#include <stddef.h>
#include <string.h>
#include <unistd.h>
#include "rtld_printf.h"
#define MAXNBUF (sizeof(intmax_t) * NBBY + 1)
#define PRINT_METHOD_SNPRINTF 1
#define PRINT_METHOD_WRITE 2
struct snprintf_arg {
int method;
char *str;
char *buf;
size_t remain;
size_t buf_total;
int fd;
};
static void
printf_out(struct snprintf_arg *info)
{
if (info->remain == info->buf_total)
return;
write(info->fd, info->buf, info->buf_total - info->remain);
info->str = info->buf;
info->remain = info->buf_total;
}
static void
snprintf_func(int ch, struct snprintf_arg *const info)
{
switch (info->method) {
case PRINT_METHOD_SNPRINTF:
if (info->remain >= 2) {
*info->str++ = ch;
info->remain--;
}
break;
case PRINT_METHOD_WRITE:
if (info->remain > 0) {
*info->str++ = ch;
info->remain--;
} else
printf_out(info);
break;
}
}
static char const hex2ascii_lower[] = "0123456789abcdefghijklmnopqrstuvwxyz";
static char const hex2ascii_upper[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
#define hex2ascii(hex) (hex2ascii_lower[hex])
#define hex2ascii_upper(hex) (hex2ascii_upper[hex])
static __inline int
imax(int a, int b)
{
return (a > b ? a : b);
}
static char *
ksprintn(char *nbuf, uintmax_t num, int base, int *lenp, int upper)
{
char *p, c;
p = nbuf;
*p = '\0';
do {
c = upper ? hex2ascii_upper(num % base) :
hex2ascii(num % base);
*++p = c;
} while (num /= base);
if (lenp)
*lenp = p - nbuf;
return (p);
}
static int
kvprintf(char const *fmt, struct snprintf_arg *arg, int radix, va_list ap)
{
#define PCHAR(c) snprintf_func((c), arg)
char nbuf[MAXNBUF];
const char *p, *percent, *q;
u_char *up;
int ch, n;
uintmax_t num;
int base, lflag, qflag, tmp, width, ladjust, sharpflag, neg, sign, dot;
int cflag, hflag, jflag, tflag, zflag;
int dwidth, upper;
char padc;
int stop = 0, retval = 0;
num = 0;
if (fmt == NULL)
fmt = "(fmt null)\n";
if (radix < 2 || radix > 36)
radix = 10;
for (;;) {
padc = ' ';
width = 0;
while ((ch = (u_char)*fmt++) != '%' || stop) {
if (ch == '\0')
return (retval);
PCHAR(ch);
}
percent = fmt - 1;
qflag = 0; lflag = 0; ladjust = 0; sharpflag = 0; neg = 0;
sign = 0; dot = 0; dwidth = 0; upper = 0;
cflag = 0; hflag = 0; jflag = 0; tflag = 0; zflag = 0;
reswitch: switch (ch = (u_char)*fmt++) {
case '.':
dot = 1;
goto reswitch;
case '#':
sharpflag = 1;
goto reswitch;
case '+':
sign = 1;
goto reswitch;
case '-':
ladjust = 1;
goto reswitch;
case '%':
PCHAR(ch);
break;
case '*':
if (!dot) {
width = va_arg(ap, int);
if (width < 0) {
ladjust = !ladjust;
width = -width;
}
} else {
dwidth = va_arg(ap, int);
}
goto reswitch;
case '0':
if (!dot) {
padc = '0';
goto reswitch;
}
case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
for (n = 0;; ++fmt) {
n = n * 10 + ch - '0';
ch = *fmt;
if (ch < '0' || ch > '9')
break;
}
if (dot)
dwidth = n;
else
width = n;
goto reswitch;
case 'b':
num = (u_int)va_arg(ap, int);
p = va_arg(ap, char *);
for (q = ksprintn(nbuf, num, *p++, NULL, 0); *q;)
PCHAR(*q--);
if (num == 0)
break;
for (tmp = 0; *p;) {
n = *p++;
if (num & (1 << (n - 1))) {
PCHAR(tmp ? ',' : '<');
for (; (n = *p) > ' '; ++p)
PCHAR(n);
tmp = 1;
} else
for (; *p > ' '; ++p)
continue;
}
if (tmp)
PCHAR('>');
break;
case 'c':
PCHAR(va_arg(ap, int));
break;
case 'D':
up = va_arg(ap, u_char *);
p = va_arg(ap, char *);
if (!width)
width = 16;
while(width--) {
PCHAR(hex2ascii(*up >> 4));
PCHAR(hex2ascii(*up & 0x0f));
up++;
if (width)
for (q=p;*q;q++)
PCHAR(*q);
}
break;
case 'd':
case 'i':
base = 10;
sign = 1;
goto handle_sign;
case 'h':
if (hflag) {
hflag = 0;
cflag = 1;
} else
hflag = 1;
goto reswitch;
case 'j':
jflag = 1;
goto reswitch;
case 'l':
if (lflag) {
lflag = 0;
qflag = 1;
} else
lflag = 1;
goto reswitch;
case 'n':
if (jflag)
*(va_arg(ap, intmax_t *)) = retval;
else if (qflag)
*(va_arg(ap, quad_t *)) = retval;
else if (lflag)
*(va_arg(ap, long *)) = retval;
else if (zflag)
*(va_arg(ap, size_t *)) = retval;
else if (hflag)
*(va_arg(ap, short *)) = retval;
else if (cflag)
*(va_arg(ap, char *)) = retval;
else
*(va_arg(ap, int *)) = retval;
break;
case 'o':
base = 8;
goto handle_nosign;
case 'p':
base = 16;
sharpflag = (width == 0);
sign = 0;
num = (uintptr_t)va_arg(ap, void *);
goto number;
case 'q':
qflag = 1;
goto reswitch;
case 'r':
base = radix;
if (sign)
goto handle_sign;
goto handle_nosign;
case 's':
p = va_arg(ap, char *);
if (p == NULL)
p = "(null)";
if (!dot)
n = strlen (p);
else
for (n = 0; n < dwidth && p[n]; n++)
continue;
width -= n;
if (!ladjust && width > 0)
while (width--)
PCHAR(padc);
while (n--)
PCHAR(*p++);
if (ladjust && width > 0)
while (width--)
PCHAR(padc);
break;
case 't':
tflag = 1;
goto reswitch;
case 'u':
base = 10;
goto handle_nosign;
case 'X':
upper = 1;
case 'x':
base = 16;
goto handle_nosign;
case 'y':
base = 16;
sign = 1;
goto handle_sign;
case 'z':
zflag = 1;
goto reswitch;
handle_nosign:
sign = 0;
if (jflag)
num = va_arg(ap, uintmax_t);
else if (qflag)
num = va_arg(ap, u_quad_t);
else if (tflag)
num = va_arg(ap, ptrdiff_t);
else if (lflag)
num = va_arg(ap, u_long);
else if (zflag)
num = va_arg(ap, size_t);
else if (hflag)
num = (u_short)va_arg(ap, int);
else if (cflag)
num = (u_char)va_arg(ap, int);
else
num = va_arg(ap, u_int);
goto number;
handle_sign:
if (jflag)
num = va_arg(ap, intmax_t);
else if (qflag)
num = va_arg(ap, quad_t);
else if (tflag)
num = va_arg(ap, ptrdiff_t);
else if (lflag)
num = va_arg(ap, long);
else if (zflag)
num = va_arg(ap, ssize_t);
else if (hflag)
num = (short)va_arg(ap, int);
else if (cflag)
num = (char)va_arg(ap, int);
else
num = va_arg(ap, int);
number:
if (sign && (intmax_t)num < 0) {
neg = 1;
num = -(intmax_t)num;
}
p = ksprintn(nbuf, num, base, &n, upper);
tmp = 0;
if (sharpflag && num != 0) {
if (base == 8)
tmp++;
else if (base == 16)
tmp += 2;
}
if (neg)
tmp++;
if (!ladjust && padc == '0')
dwidth = width - tmp;
width -= tmp + imax(dwidth, n);
dwidth -= n;
if (!ladjust)
while (width-- > 0)
PCHAR(' ');
if (neg)
PCHAR('-');
if (sharpflag && num != 0) {
if (base == 8) {
PCHAR('0');
} else if (base == 16) {
PCHAR('0');
PCHAR('x');
}
}
while (dwidth-- > 0)
PCHAR('0');
while (*p)
PCHAR(*p--);
if (ladjust)
while (width-- > 0)
PCHAR(' ');
break;
default:
while (percent < fmt)
PCHAR(*percent++);
/*
* Since we ignore an formatting argument it is no
* longer safe to obey the remaining formatting
* arguments as the arguments will no longer match
* the format specs.
*/
stop = 1;
break;
}
}
#undef PCHAR
}
int
rtld_snprintf(char *buf, size_t bufsize, const char *fmt, ...)
{
va_list ap;
int retval;
va_start(ap, fmt);
retval = rtld_vsnprintf(buf, bufsize, fmt, ap);
va_end(ap);
return (retval);
}
int
rtld_vsnprintf(char *buf, size_t bufsize, const char *fmt, va_list ap)
{
struct snprintf_arg info;
int retval;
info.method = PRINT_METHOD_SNPRINTF;
info.buf = info.str = buf;
info.buf_total = info.remain = bufsize;
info.fd = -1;
retval = kvprintf(fmt, &info, 10, ap);
if (info.remain >= 1)
*info.str++ = '\0';
return (retval);
}
int
rtld_vfdprintf(int fd, const char *fmt, va_list ap)
{
char buf[512];
struct snprintf_arg info;
int retval;
info.method = PRINT_METHOD_WRITE;
info.buf = info.str = buf;
info.buf_total = info.remain = sizeof(buf);
info.fd = fd;
retval = kvprintf(fmt, &info, 10, ap);
printf_out(&info);
return (retval);
}
int
rtld_fdprintf(int fd, const char *fmt, ...)
{
va_list ap;
int retval;
va_start(ap, fmt);
retval = rtld_vfdprintf(fd, fmt, ap);
va_end(ap);
return (retval);
}
void
rtld_fdputstr(int fd, const char *str)
{
write(fd, str, strlen(str));
}
void
rtld_fdputchar(int fd, int c)
{
char c1;
c1 = c;
write(fd, &c1, 1);
}