Date: Mon, 21 Oct 1996 10:30:07 -0400 From: Garrett Wollman <wollman@lcs.mit.edu> To: Jean-Marc Zucconi <jmz@cabri.obs-besancon.fr> Cc: freebsd-current@freebsd.org Subject: socket (AF_UNIX) bug Message-ID: <9610211430.AA13042@halloran-eldar.lcs.mit.edu> In-Reply-To: <9610210218.AA09736@cabri.obs-besancon.fr> References: <9610210218.AA09736@cabri.obs-besancon.fr>
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<<On Mon, 21 Oct 96 03:18:14 +0100, Jean-Marc Zucconi <jmz@cabri.obs-besancon.fr> said:
> The following code creates a socket whose name is 1 char too
> short. A workaround is to add 1 to addrlen before calling bind, but I
> think that the code should work as is.
The code is wrong.
> strncpy (sockaddr.sun_path, path, sizeof(sockaddr.sun_path));
> addrlen = sizeof(sockaddr.sun_family) + strlen(path);
sizeof(sockaddr.sun_family) == 1
offsetof(struct sockaddr_un, sun_path) == 2
This would be clearer if the sockaddr were properly initialized; i.e.:
> strncpy (sockaddr.sun_path, path, sizeof(sockaddr.sun_path));
sockaddr.sun_len = offsetof(struct sockaddr_un, sun_path)
+ min(strlen(path), sizeof(sockaddr.sun_path));
> addrlen = sizeof(sockaddr.sun_family)
+ min(strlen(path), sizeof(sockaddr.sun_path));
/* alternatively, addrlen = sockaddr.sun_len */
-GAWollman
--
Garrett A. Wollman | O Siem / We are all family / O Siem / We're all the same
wollman@lcs.mit.edu | O Siem / The fires of freedom
Opinions not those of| Dance in the burning flame
MIT, LCS, ANA, or NSA| - Susan Aglukark and Chad Irschick
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