minix/lib/libc/ssp/ssp.3
Ben Gras 2fe8fb192f Full switch to clang/ELF. Drop ack. Simplify.
There is important information about booting non-ack images in
docs/UPDATING. ack/aout-format images can't be built any more, and
booting clang/ELF-format ones is a little different. Updating to the
new boot monitor is recommended.

Changes in this commit:

	. drop boot monitor -> allowing dropping ack support
	. facility to copy ELF boot files to /boot so that old boot monitor
	  can still boot fairly easily, see UPDATING
	. no more ack-format libraries -> single-case libraries
	. some cleanup of OBJECT_FMT, COMPILER_TYPE, etc cases
	. drop several ack toolchain commands, but not all support
	  commands (e.g. aal is gone but acksize is not yet).
	. a few libc files moved to netbsd libc dir
	. new /bin/date as minix date used code in libc/
	. test compile fix
	. harmonize includes
	. /usr/lib is no longer special: without ack, /usr/lib plays no
	  kind of special bootstrapping role any more and bootstrapping
	  is done exclusively through packages, so releases depend even
	  less on the state of the machine making them now.
	. rename nbsd_lib* to lib*
	. reduce mtree
2012-02-14 14:52:02 +01:00

122 lines
3.7 KiB
Groff

.\" $NetBSD: ssp.3,v 1.5 2010/12/19 08:28:40 jruoho Exp $
.\"
.\" Copyright (c) 2007 The NetBSD Foundation, Inc.
.\" All rights reserved.
.\"
.\" This code is derived from software contributed to The NetBSD Foundation
.\" by Christos Zoulas.
.\"
.\" 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.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
.\"
.\"
.Dd December 19, 2010
.Dt SSP 3
.Os
.Sh NAME
.Nm ssp
.Nd bounds checked libc functions
.Sh LIBRARY
.Lb libssp
.Sh SYNOPSIS
.In ssp/stdio.h
.Ft int
.Fn sprintf "char *str" "const char *fmt" "..."
.Ft int
.Fn vsprintf "char *str" "const char *fmt" "va_list ap"
.Ft int
.Fn snprintf "char *str" "size_t len" "const char *fmt" "..."
.Ft int
.Fn vsnprintf "char *str" "size_t len" "const char *fmt" "va_list ap"
.Ft char *
.Fn gets "char *str"
.Ft char *
.Fn fgets "char *str" "int len" "FILE *fp"
.In ssp/string.h
.Ft void *
.Fn memcpy "void *str" "const void *ptr" "size_t len"
.Ft void *
.Fn memmove "void *str" "const void *ptr" "size_t len"
.Ft void *
.Fn memset "void *str" "int val" "size_t len"
.Ft char *
.Fn strcpy "char *str" "const char *ptr" "size_t len"
.Ft char *
.Fn strcat "char *str" "const char *ptr" "size_t len"
.Ft char *
.Fn strncpy "char *str" "const char *ptr" "size_t len"
.Ft char *
.Fn strncat "char *str" "const char *ptr" "size_t len"
.In ssp/strings.h
.Ft void *
.Fn bcopy "const void *ptr" "void *str" "size_t len"
.Ft void *
.Fn bzero "void *str" "size_t len"
.In ssp/unistd.h
.Ft ssize_t
.Fn read "int fd" "void *str" "size_t len"
.Ft int
.Fn readlink "const char * restrict path" "char * restrict str" "size_t len"
.Ft int
.Fn getcwd "char *str" "size_t len"
.Sh DESCRIPTION
When
.Dv _FORTIFY_SOURCE
bounds checking is enabled as described below, the above functions get
overwritten to use the
.Xr __builtin_object_size 3
function to compute the size of
.Fa str ,
if known at compile time,
and perform bounds check on it in order
to avoid data buffer or stack buffer overflows.
If an overflow is detected, the routines will call
.Xr abort 3 .
.Pp
To enable these function overrides the following should be added to the
.Xr gcc 1
command line:
.Dq \-I/usr/include/ssp
to override the standard include files and
.Dq \-D_FORTIFY_SOURCE=1
or
.Dq \-D_FORTIFY_SOURCE=2 .
.Pp
If
.Dv _FORTIFY_SOURCE is set to
.Dv 1
the code will compute the maximum possible buffer size for
.Fa str ,
and if set to
.Dv 2
it will compute the minimum buffer size.
.Sh SEE ALSO
.Xr gcc 1 ,
.Xr __builtin_object_size 3 ,
.Xr stdio 3 ,
.Xr string 3 ,
.Xr security 8
.Sh HISTORY
The
.Nm ssp
library appeared
.Nx 4.0 .