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From: nigel@9fs.org
To: 9fans@cse.psu.edu
Subject: [9fans] APE socket bug fix
Date: Tue, 31 Oct 2000 11:32:22 +0000	[thread overview]
Message-ID: <E13qZeR-000Afr-0U@anchor-post-30.mail.demon.net> (raw)

gethostbyaddr() has a sign extension bug which causes it to mess up
the building of the 32 bit address to put in in_addr.  Additionally,
htonl() is required to convert to network byte order.  So

	struct hostent*
	gethostbyaddr(char *addr, int len, int type)
	{
		struct in_addr x;

		if(type != AF_INET){
			h_errno = NO_RECOVERY;
			return 0;
		}

		x.s_addr = (addr[0]<<24)|(addr[1]<<16)|(addr[2]<<8)|addr[3];

		return gethostbyname(inet_ntoa(x));
	}

probably ought to be

	struct hostent*
	gethostbyaddr(char *addr, int len, int type)
	{
		struct in_addr x;
		unsigned char *uaddr = (unsigned char *)addr;

		if(type != AF_INET){
			h_errno = NO_RECOVERY;
			return 0;
		}

		x.s_addr = htonl((uaddr[0]<<24)|(uaddr[1]<<16)|(uaddr[2]<<8)|uaddr[3]);

		return gethostbyname(inet_ntoa(x));
	}

or words to that effect.



             reply	other threads:[~2000-10-31 11:32 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2000-10-31 11:32 nigel [this message]
2000-10-31 16:57 ` Scott Schwartz
2000-10-31 17:03   ` Scott Schwartz

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