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libtirpc/libtirpc-rpc_broadcast_misformed_replies.patch

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commit 17619288497d76ade1671f0adbda682548d026d5
Author: Olaf Kirch <okir@suse.de>
Date: Thu Nov 13 10:24:39 2008 +0100
rpc_broadcast: handle misformed rpcbind replies
Some rpcbind implementations seem to return IPv6 uaddrs
in response to an IPv4 broadcast (which is probably due
to their using a single v6 socket to handle both v6 and
v4 requests).
We can either discard these replies, or fix them up silently.
Here's a patch that implements the latter.
Signed-off-by: Olaf Kirch <okir@suse.de>
diff --git a/src/clnt_bcast.c b/src/clnt_bcast.c
index 899eb76..55efc9d 100644
--- a/src/clnt_bcast.c
+++ b/src/clnt_bcast.c
@@ -227,6 +227,39 @@ __rpc_broadenable(int af, int s, struct broadif *bip)
return 0;
}
+/*
+ * Some rpcbind implementations use an IPv6 socket to serve both
+ * IPv4 and IPv6 messages, but neglect to check for the caller's
+ * address family when sending broadcast replies. These rpcbind
+ * implementations return an IPv6 address in reply to an IPv4
+ * broadcast. We can either ignore them, or try to patch them up.
+ */
+static struct netbuf *
+__ipv6v4_fixup(struct sockaddr_storage *ss, const char *uaddr)
+{
+ struct sockaddr_in sin;
+ struct netbuf *np;
+
+ /* ss is the remote rpcbind server's address */
+ if (ss->ss_family != AF_INET)
+ return NULL;
+ memcpy(&sin, ss, sizeof(sin));
+
+ np = __rpc_uaddr2taddr_af(AF_INET6, uaddr);
+ if (np == NULL)
+ return NULL;
+
+ /* Overwrite the port with that of the service we
+ * wanted to talk to. */
+ sin.sin_port = ((struct sockaddr_in6 *) np)->sin6_port;
+
+ /* We know netbuf holds a sockaddr_in6, so it can easily
+ * hold a sockaddr_in as well. */
+ memcpy(np->buf, &sin, sizeof(sin));
+ np->len = sizeof(sin);
+
+ return np;
+}
enum clnt_stat
rpc_broadcast_exp(prog, vers, proc, xargs, argsp, xresults, resultsp,
@@ -607,6 +640,13 @@ rpc_broadcast_exp(prog, vers, proc, xargs, argsp, xresults, resultsp,
#endif
np = uaddr2taddr(
fdlist[i].nconf, uaddrp);
+ /* Some misguided rpcbind implemenations
+ * seem to return an IPv6 uaddr in IPv4
+ * responses. */
+ if (np == NULL)
+ np = __ipv6v4_fixup(
+ &fdlist[i].raddr,
+ uaddrp);
if (np != NULL) {
done = (*eachresult)(resultsp,
np, fdlist[i].nconf);