kernel: ipv6: ip6_fragment: fix headroom tests and skb leak
[openwrt/svn-archive/archive.git] / target / linux / generic / patches-3.18 / 667-ipv6-Fixed-source-specific-default-route-handling.patch
1 From e16e888b525503be05b3aea64190e8b3bdef44d0 Mon Sep 17 00:00:00 2001
2 From: Markus Stenberg <markus.stenberg@iki.fi>
3 Date: Tue, 5 May 2015 13:36:59 +0300
4 Subject: [PATCH] ipv6: Fixed source specific default route handling.
5
6 If there are only IPv6 source specific default routes present, the
7 host gets -ENETUNREACH on e.g. connect() because ip6_dst_lookup_tail
8 calls ip6_route_output first, and given source address any, it fails,
9 and ip6_route_get_saddr is never called.
10
11 The change is to use the ip6_route_get_saddr, even if the initial
12 ip6_route_output fails, and then doing ip6_route_output _again_ after
13 we have appropriate source address available.
14
15 Note that this is '99% fix' to the problem; a correct fix would be to
16 do route lookups only within addrconf.c when picking a source address,
17 and never call ip6_route_output before source address has been
18 populated.
19
20 Signed-off-by: Markus Stenberg <markus.stenberg@iki.fi>
21 Signed-off-by: David S. Miller <davem@davemloft.net>
22 ---
23 net/ipv6/ip6_output.c | 39 +++++++++++++++++++++++++++++++--------
24 net/ipv6/route.c | 5 +++--
25 2 files changed, 34 insertions(+), 10 deletions(-)
26
27 --- a/net/ipv6/ip6_output.c
28 +++ b/net/ipv6/ip6_output.c
29 @@ -900,21 +900,45 @@ static int ip6_dst_lookup_tail(struct so
30 #endif
31 int err;
32
33 - if (*dst == NULL)
34 - *dst = ip6_route_output(net, sk, fl6);
35 -
36 - if ((err = (*dst)->error))
37 - goto out_err_release;
38 + /* The correct way to handle this would be to do
39 + * ip6_route_get_saddr, and then ip6_route_output; however,
40 + * the route-specific preferred source forces the
41 + * ip6_route_output call _before_ ip6_route_get_saddr.
42 + *
43 + * In source specific routing (no src=any default route),
44 + * ip6_route_output will fail given src=any saddr, though, so
45 + * that's why we try it again later.
46 + */
47 + if (ipv6_addr_any(&fl6->saddr) && (!*dst || !(*dst)->error)) {
48 + struct rt6_info *rt;
49 + bool had_dst = *dst != NULL;
50
51 - if (ipv6_addr_any(&fl6->saddr)) {
52 - struct rt6_info *rt = (struct rt6_info *) *dst;
53 + if (!had_dst)
54 + *dst = ip6_route_output(net, sk, fl6);
55 + rt = (*dst)->error ? NULL : (struct rt6_info *)*dst;
56 err = ip6_route_get_saddr(net, rt, &fl6->daddr,
57 sk ? inet6_sk(sk)->srcprefs : 0,
58 &fl6->saddr);
59 if (err)
60 goto out_err_release;
61 +
62 + /* If we had an erroneous initial result, pretend it
63 + * never existed and let the SA-enabled version take
64 + * over.
65 + */
66 + if (!had_dst && (*dst)->error) {
67 + dst_release(*dst);
68 + *dst = NULL;
69 + }
70 }
71
72 + if (!*dst)
73 + *dst = ip6_route_output(net, sk, fl6);
74 +
75 + err = (*dst)->error;
76 + if (err)
77 + goto out_err_release;
78 +
79 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
80 /*
81 * Here if the dst entry we've looked up
82 --- a/net/ipv6/route.c
83 +++ b/net/ipv6/route.c
84 @@ -2182,9 +2182,10 @@ int ip6_route_get_saddr(struct net *net,
85 unsigned int prefs,
86 struct in6_addr *saddr)
87 {
88 - struct inet6_dev *idev = ip6_dst_idev((struct dst_entry *)rt);
89 + struct inet6_dev *idev =
90 + rt ? ip6_dst_idev((struct dst_entry *)rt) : NULL;
91 int err = 0;
92 - if (rt->rt6i_prefsrc.plen)
93 + if (rt && rt->rt6i_prefsrc.plen)
94 *saddr = rt->rt6i_prefsrc.addr;
95 else
96 err = ipv6_dev_get_saddr(net, idev ? idev->dev : NULL,