2.2.14: recvfrom() bug or feature?

From: Frank van Maarseveen (F.vanMaarseveen@inter.NL.net)
Date: Wed Mar 01 2000 - 17:46:18 EST

I'm tracking down a possible bug in RH6.1 routed daemon. It does a

        recvfrom(fd, &inbuf, sizeof (inbuf), 0, &from, &fromlen)

and it appears that even when `from' is cleared in advance the from->sa_data
contains not only a 2 byte port number + source IP but also some trailing
garbage afterwards as it seems to me. Is this a bug or a feature?

Example data:

(gdb) p fromlen
$4 = 16
(gdb) p from
$5 = {sa_family = 2, sa_data = "\002\bÁ°\231@\000 üÁ %pÂ"}
This roughly translates to:

        \002\b = 520 (source port: route service)
        Á°\231@ = 193.176.153.64 (source IP: ppp1 peer)

and the remaining 8 bytes are a mistery and seem to block proper operation of
routed (expects zeroes instead when matching it with interface addresses):

hex 00 20 fc c1 7c 25 70 c2
dec 0 32 252 193 124 37 112 194 

-- 
Frank

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