Date: Mon, 15 Mar 2004 01:58:25 -0800 (PST) From: Lee Brotherston <lee@nerds.org.uk> To: freebsd-gnats-submit@FreeBSD.org Subject: docs/64291: inet_ntoa static buffer - man page ammendment Message-ID: <200403150958.i2F9wPdP094019@www.freebsd.org> Resent-Message-ID: <200403151000.i2FA0Zah093637@freefall.freebsd.org>
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>Number: 64291
>Category: docs
>Synopsis: inet_ntoa static buffer - man page ammendment
>Confidential: no
>Severity: non-critical
>Priority: low
>Responsible: freebsd-doc
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: doc-bug
>Submitter-Id: current-users
>Arrival-Date: Mon Mar 15 02:00:35 PST 2004
>Closed-Date:
>Last-Modified:
>Originator: Lee Brotherston
>Release: FreeBSD 5.2.1-RELEASE
>Organization:
>Environment:
FreeBSD 5.2.1-RELEASE FreeBSD 5.2.1-RELEASE #2: Mon Mar 8 03:32:49 GMT 2004 lee@:/usr/obj/usr/src/sys/MYKERN i386
>Description:
The man page for inet_ntoa does not mention that is uses a static buffer. It is perhaps worth mentioning this as further calls to inet_ntoa will overwrite the previous response.
Perhaps this should be obvious, however I just fell foul of this and thought clarification on the man page might be useful.
>How-To-Repeat:
The following section of code (where ip_hdr is a struct *ip) will log both addresses to be the same when they are not. Presumably because both inet_ntoa's are evaluated before the log function is run. As a result the first result has been lost.
log(LOG_INFO, "%s -> %s", inet_ntoa(ip_hdr->ip_src), inet_ntoa(ip_hdr->ip_dst));
>Fix:
Ammendment to the man page. If it helps I found this version on a linux machines manpage:
The inet_ntoa() function converts the Internet host address in given in network byte order to a string in standard numbers-and-dots notation. The string is returned in a statically allocated buffer, which subsequent calls will overwrite.
>Release-Note:
>Audit-Trail:
>Unformatted:
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