Date: Sat, 14 Nov 2020 14:50:34 +0000 (UTC) From: "Jonathan T. Looney" <jtl@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r367680 - head/sys/netinet6 Message-ID: <202011141450.0AEEoYWL079087@repo.freebsd.org>
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Author: jtl Date: Sat Nov 14 14:50:34 2020 New Revision: 367680 URL: https://svnweb.freebsd.org/changeset/base/367680 Log: Fix implicit automatic local port selection for IPv6 during connect calls. When a user creates a TCP socket and tries to connect to the socket without explicitly binding the socket to a local address, the connect call implicitly chooses an appropriate local port. When evaluating candidate local ports, the algorithm checks for conflicts with existing ports by doing a lookup in the connection hash table. In this circumstance, both the IPv4 and IPv6 code look for exact matches in the hash table. However, the IPv4 code goes a step further and checks whether the proposed 4-tuple will match wildcard (e.g. TCP "listen") entries. The IPv6 code has no such check. The missing wildcard check can cause problems when connecting to a local server. It is possible that the algorithm will choose the same value for the local port as the foreign port uses. This results in a connection with identical source and destination addresses and ports. Changing the IPv6 code to align with the IPv4 code's behavior fixes this problem. Reviewed by: tuexen Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D27164 Modified: head/sys/netinet6/in6_pcb.c Modified: head/sys/netinet6/in6_pcb.c ============================================================================== --- head/sys/netinet6/in6_pcb.c Sat Nov 14 14:15:49 2020 (r367679) +++ head/sys/netinet6/in6_pcb.c Sat Nov 14 14:50:34 2020 (r367680) @@ -464,7 +464,8 @@ in6_pcbconnect_mbuf(struct inpcb *inp, struct sockaddr rehash = false; error = in_pcb_lport_dest(inp, (struct sockaddr *) &laddr6, &inp->inp_lport, - (struct sockaddr *) sin6, sin6->sin6_port, cred, 0); + (struct sockaddr *) sin6, sin6->sin6_port, cred, + INPLOOKUP_WILDCARD); if (error) return (error); }
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