97 lines
3.1 KiB
Diff
97 lines
3.1 KiB
Diff
From e16e888b525503be05b3aea64190e8b3bdef44d0 Mon Sep 17 00:00:00 2001
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From: Markus Stenberg <markus.stenberg@iki.fi>
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Date: Tue, 5 May 2015 13:36:59 +0300
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Subject: [PATCH] ipv6: Fixed source specific default route handling.
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If there are only IPv6 source specific default routes present, the
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host gets -ENETUNREACH on e.g. connect() because ip6_dst_lookup_tail
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calls ip6_route_output first, and given source address any, it fails,
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and ip6_route_get_saddr is never called.
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The change is to use the ip6_route_get_saddr, even if the initial
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ip6_route_output fails, and then doing ip6_route_output _again_ after
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we have appropriate source address available.
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Note that this is '99% fix' to the problem; a correct fix would be to
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do route lookups only within addrconf.c when picking a source address,
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and never call ip6_route_output before source address has been
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populated.
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Signed-off-by: Markus Stenberg <markus.stenberg@iki.fi>
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Signed-off-by: David S. Miller <davem@davemloft.net>
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---
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net/ipv6/ip6_output.c | 39 +++++++++++++++++++++++++++++++--------
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net/ipv6/route.c | 5 +++--
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2 files changed, 34 insertions(+), 10 deletions(-)
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--- a/net/ipv6/ip6_output.c
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+++ b/net/ipv6/ip6_output.c
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@@ -903,21 +903,45 @@ static int ip6_dst_lookup_tail(struct so
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#endif
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int err;
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- if (*dst == NULL)
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- *dst = ip6_route_output(net, sk, fl6);
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-
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- if ((err = (*dst)->error))
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- goto out_err_release;
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+ /* The correct way to handle this would be to do
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+ * ip6_route_get_saddr, and then ip6_route_output; however,
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+ * the route-specific preferred source forces the
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+ * ip6_route_output call _before_ ip6_route_get_saddr.
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+ *
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+ * In source specific routing (no src=any default route),
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+ * ip6_route_output will fail given src=any saddr, though, so
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+ * that's why we try it again later.
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+ */
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+ if (ipv6_addr_any(&fl6->saddr) && (!*dst || !(*dst)->error)) {
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+ struct rt6_info *rt;
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+ bool had_dst = *dst != NULL;
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- if (ipv6_addr_any(&fl6->saddr)) {
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- struct rt6_info *rt = (struct rt6_info *) *dst;
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+ if (!had_dst)
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+ *dst = ip6_route_output(net, sk, fl6);
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+ rt = (*dst)->error ? NULL : (struct rt6_info *)*dst;
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err = ip6_route_get_saddr(net, rt, &fl6->daddr,
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sk ? inet6_sk(sk)->srcprefs : 0,
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&fl6->saddr);
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if (err)
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goto out_err_release;
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+
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+ /* If we had an erroneous initial result, pretend it
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+ * never existed and let the SA-enabled version take
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+ * over.
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+ */
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+ if (!had_dst && (*dst)->error) {
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+ dst_release(*dst);
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+ *dst = NULL;
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+ }
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}
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+ if (!*dst)
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+ *dst = ip6_route_output(net, sk, fl6);
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+
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+ err = (*dst)->error;
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+ if (err)
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+ goto out_err_release;
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+
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#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
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/*
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* Here if the dst entry we've looked up
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--- a/net/ipv6/route.c
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+++ b/net/ipv6/route.c
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@@ -2182,9 +2182,10 @@ int ip6_route_get_saddr(struct net *net,
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unsigned int prefs,
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struct in6_addr *saddr)
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{
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- struct inet6_dev *idev = ip6_dst_idev((struct dst_entry *)rt);
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+ struct inet6_dev *idev =
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+ rt ? ip6_dst_idev((struct dst_entry *)rt) : NULL;
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int err = 0;
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- if (rt->rt6i_prefsrc.plen)
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+ if (rt && rt->rt6i_prefsrc.plen)
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*saddr = rt->rt6i_prefsrc.addr;
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else
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err = ipv6_dev_get_saddr(net, idev ? idev->dev : NULL,
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