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freebsd-skq/lib/libc/gen/gethostname.c

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BSD 4.4 Lite Lib Sources
1994-05-27 05:00:24 +00:00
/*
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 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.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)gethostname.c 8.1 (Berkeley) 6/4/93";
#endif /* LIBC_SCCS and not lint */
Fix the style of the SCM ID's. I believe have made all of libc .c's as consistent as possible.
2002-03-22 21:53:29 +00:00
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
BSD 4.4 Lite Lib Sources
1994-05-27 05:00:24 +00:00
#include <sys/param.h>
#include <sys/sysctl.h>
Change gethostname() to set errno to ENAMETOOLONG instead of ENOMEM when the buffer is not long enough to hold the current host name. POSIX does not standardize error returns for gethostname(), so it doesn't matter which one we use, but ENAMETOOLONG is at least a little more intuitive, and mi suggests the existence of prior art. I've been running with this change for a while on my home machine with no effect. At the same time, I've updated the prototype for gethostname() to use the correct standard type (size_t) for the namelen argument. All of the in-tree callers fall into one of the following categories: 1) Call perror() or equivalent when gethostname() fails. 2) Ignore gethostname()'s return value entirely, potentially resulting in data corruption if the buffer is too small. 3) Fall back to a (possibly sensible) default value if gethostname() fails. Many of the callers I examined shows signs of confusion about the correct sizing of the host name buffer. gethostname(3) now has more information about this, as well as updated standards information. PR: 48114 Submitted by: mi (in part)
2003-08-19 20:38:44 +00:00
#include <errno.h>
gethostname() returns int, not long. Answered my own question by RTFM'ing. Either both the header files and the man pages are wrong or this code is, and I'll take the majority decision. :-)
1996-12-05 18:14:56 +00:00
int
BSD 4.4 Lite Lib Sources
1994-05-27 05:00:24 +00:00
gethostname(name, namelen)
char *name;
Change gethostname() to set errno to ENAMETOOLONG instead of ENOMEM when the buffer is not long enough to hold the current host name. POSIX does not standardize error returns for gethostname(), so it doesn't matter which one we use, but ENAMETOOLONG is at least a little more intuitive, and mi suggests the existence of prior art. I've been running with this change for a while on my home machine with no effect. At the same time, I've updated the prototype for gethostname() to use the correct standard type (size_t) for the namelen argument. All of the in-tree callers fall into one of the following categories: 1) Call perror() or equivalent when gethostname() fails. 2) Ignore gethostname()'s return value entirely, potentially resulting in data corruption if the buffer is too small. 3) Fall back to a (possibly sensible) default value if gethostname() fails. Many of the callers I examined shows signs of confusion about the correct sizing of the host name buffer. gethostname(3) now has more information about this, as well as updated standards information. PR: 48114 Submitted by: mi (in part)
2003-08-19 20:38:44 +00:00
size_t namelen;
BSD 4.4 Lite Lib Sources
1994-05-27 05:00:24 +00:00
{
int mib[2];
Add a kluge suggested by Marcel to paper over the difference between gethostname()'s old and new signatures without requiring a library bump. Note that programs which called gethostname() with a negative argument were already broken, since the same type conversion was done by the old implementation. Add a note in the Makefile so that whoever next bumps the libc revision will delete the kluge at the same time (as it will no longer be necessary). This is only operative on 64-bit platforms. Submitted by: marcel
2003-08-19 23:01:46 +00:00
/* Kluge to avoid ABI breakage. */
namelen = (int)namelen;
BSD 4.4 Lite Lib Sources
1994-05-27 05:00:24 +00:00
mib[0] = CTL_KERN;
mib[1] = KERN_HOSTNAME;
Change gethostname() to set errno to ENAMETOOLONG instead of ENOMEM when the buffer is not long enough to hold the current host name. POSIX does not standardize error returns for gethostname(), so it doesn't matter which one we use, but ENAMETOOLONG is at least a little more intuitive, and mi suggests the existence of prior art. I've been running with this change for a while on my home machine with no effect. At the same time, I've updated the prototype for gethostname() to use the correct standard type (size_t) for the namelen argument. All of the in-tree callers fall into one of the following categories: 1) Call perror() or equivalent when gethostname() fails. 2) Ignore gethostname()'s return value entirely, potentially resulting in data corruption if the buffer is too small. 3) Fall back to a (possibly sensible) default value if gethostname() fails. Many of the callers I examined shows signs of confusion about the correct sizing of the host name buffer. gethostname(3) now has more information about this, as well as updated standards information. PR: 48114 Submitted by: mi (in part)
2003-08-19 20:38:44 +00:00
if (sysctl(mib, 2, name, &namelen, NULL, 0) == -1) {
if (errno == ENOMEM)
errno = ENAMETOOLONG;
BSD 4.4 Lite Lib Sources
1994-05-27 05:00:24 +00:00
return (-1);
Change gethostname() to set errno to ENAMETOOLONG instead of ENOMEM when the buffer is not long enough to hold the current host name. POSIX does not standardize error returns for gethostname(), so it doesn't matter which one we use, but ENAMETOOLONG is at least a little more intuitive, and mi suggests the existence of prior art. I've been running with this change for a while on my home machine with no effect. At the same time, I've updated the prototype for gethostname() to use the correct standard type (size_t) for the namelen argument. All of the in-tree callers fall into one of the following categories: 1) Call perror() or equivalent when gethostname() fails. 2) Ignore gethostname()'s return value entirely, potentially resulting in data corruption if the buffer is too small. 3) Fall back to a (possibly sensible) default value if gethostname() fails. Many of the callers I examined shows signs of confusion about the correct sizing of the host name buffer. gethostname(3) now has more information about this, as well as updated standards information. PR: 48114 Submitted by: mi (in part)
2003-08-19 20:38:44 +00:00
}
BSD 4.4 Lite Lib Sources
1994-05-27 05:00:24 +00:00
return (0);
}
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