projects / thirdparty / kernel / stable-queue.git / blame
| Commit | Line | Data |
|---|---|---|
| ff3875fa GKH |
1 | From foo@baz Sun Dec 31 11:12:48 CET 2017 |
| 2 | From: Shaohua Li <shli@fb.com> | |
| 3 | Date: Wed, 20 Dec 2017 12:10:21 -0800 | |
| 4 | Subject: net: reevalulate autoflowlabel setting after sysctl setting | |
| 5 | ||
| 6 | From: Shaohua Li <shli@fb.com> | |
| 7 | ||
| 8 | ||
| 9 | [ Upstream commit 513674b5a2c9c7a67501506419da5c3c77ac6f08 ] | |
| 10 | ||
| 11 | sysctl.ip6.auto_flowlabels is default 1. In our hosts, we set it to 2. | |
| 12 | If sockopt doesn't set autoflowlabel, outcome packets from the hosts are | |
| 13 | supposed to not include flowlabel. This is true for normal packet, but | |
| 14 | not for reset packet. | |
| 15 | ||
| 16 | The reason is ipv6_pinfo.autoflowlabel is set in sock creation. Later if | |
| 17 | we change sysctl.ip6.auto_flowlabels, the ipv6_pinfo.autoflowlabel isn't | |
| 18 | changed, so the sock will keep the old behavior in terms of auto | |
| 19 | flowlabel. Reset packet is suffering from this problem, because reset | |
| 20 | packet is sent from a special control socket, which is created at boot | |
| 21 | time. Since sysctl.ipv6.auto_flowlabels is 1 by default, the control | |
| 22 | socket will always have its ipv6_pinfo.autoflowlabel set, even after | |
| 23 | user set sysctl.ipv6.auto_flowlabels to 1, so reset packset will always | |
| 24 | have flowlabel. Normal sock created before sysctl setting suffers from | |
| 25 | the same issue. We can't even turn off autoflowlabel unless we kill all | |
| 26 | socks in the hosts. | |
| 27 | ||
| 28 | To fix this, if IPV6_AUTOFLOWLABEL sockopt is used, we use the | |
| 29 | autoflowlabel setting from user, otherwise we always call | |
| 30 | ip6_default_np_autolabel() which has the new settings of sysctl. | |
| 31 | ||
| 32 | Note, this changes behavior a little bit. Before commit 42240901f7c4 | |
| 33 | (ipv6: Implement different admin modes for automatic flow labels), the | |
| 34 | autoflowlabel behavior of a sock isn't sticky, eg, if sysctl changes, | |
| 35 | existing connection will change autoflowlabel behavior. After that | |
| 36 | commit, autoflowlabel behavior is sticky in the whole life of the sock. | |
| 37 | With this patch, the behavior isn't sticky again. | |
| 38 | ||
| 39 | Cc: Martin KaFai Lau <kafai@fb.com> | |
| 40 | Cc: Eric Dumazet <eric.dumazet@gmail.com> | |
| 41 | Cc: Tom Herbert <tom@quantonium.net> | |
| 42 | Signed-off-by: Shaohua Li <shli@fb.com> | |
| 43 | Signed-off-by: David S. Miller <davem@davemloft.net> | |
| 44 | Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> | |
| 45 | --- | |
| 46 | include/linux/ipv6.h | 3 ++- | |
| 47 | net/ipv6/af_inet6.c | 1 - | |
| 48 | net/ipv6/ip6_output.c | 12 ++++++++++-- | |
| 49 | net/ipv6/ipv6_sockglue.c | 1 + | |
| 50 | 4 files changed, 13 insertions(+), 4 deletions(-) | |
| 51 | ||
| 52 | --- a/include/linux/ipv6.h | |
| 53 | +++ b/include/linux/ipv6.h | |
| 54 | @@ -272,7 +272,8 @@ struct ipv6_pinfo { | |
| 55 | * 100: prefer care-of address | |
| 56 | */ | |
| 57 | dontfrag:1, | |
| 58 | - autoflowlabel:1; | |
| 59 | + autoflowlabel:1, | |
| 60 | + autoflowlabel_set:1; | |
| 61 | __u8 min_hopcount; | |
| 62 | __u8 tclass; | |
| 63 | __be32 rcv_flowinfo; | |
| 64 | --- a/net/ipv6/af_inet6.c | |
| 65 | +++ b/net/ipv6/af_inet6.c | |
| 66 | @@ -210,7 +210,6 @@ lookup_protocol: | |
| 67 | np->mcast_hops = IPV6_DEFAULT_MCASTHOPS; | |
| 68 | np->mc_loop = 1; | |
| 69 | np->pmtudisc = IPV6_PMTUDISC_WANT; | |
| 70 | - np->autoflowlabel = ip6_default_np_autolabel(net); | |
| 71 | np->repflow = net->ipv6.sysctl.flowlabel_reflect; | |
| 72 | sk->sk_ipv6only = net->ipv6.sysctl.bindv6only; | |
| 73 | ||
| 74 | --- a/net/ipv6/ip6_output.c | |
| 75 | +++ b/net/ipv6/ip6_output.c | |
| 76 | @@ -166,6 +166,14 @@ int ip6_output(struct net *net, struct s | |
| 77 | !(IP6CB(skb)->flags & IP6SKB_REROUTED)); | |
| 78 | } | |
| 79 | ||
| 80 | +static bool ip6_autoflowlabel(struct net *net, const struct ipv6_pinfo *np) | |
| 81 | +{ | |
| 82 | + if (!np->autoflowlabel_set) | |
| 83 | + return ip6_default_np_autolabel(net); | |
| 84 | + else | |
| 85 | + return np->autoflowlabel; | |
| 86 | +} | |
| 87 | + | |
| 88 | /* | |
| 89 | * xmit an sk_buff (used by TCP, SCTP and DCCP) | |
| 90 | * Note : socket lock is not held for SYNACK packets, but might be modified | |
| 91 | @@ -230,7 +238,7 @@ int ip6_xmit(const struct sock *sk, stru | |
| 92 | hlimit = ip6_dst_hoplimit(dst); | |
| 93 | ||
| 94 | ip6_flow_hdr(hdr, tclass, ip6_make_flowlabel(net, skb, fl6->flowlabel, | |
| 95 | - np->autoflowlabel, fl6)); | |
| 96 | + ip6_autoflowlabel(net, np), fl6)); | |
| 97 | ||
| 98 | hdr->payload_len = htons(seg_len); | |
| 99 | hdr->nexthdr = proto; | |
| 100 | @@ -1626,7 +1634,7 @@ struct sk_buff *__ip6_make_skb(struct so | |
| 101 | ||
| 102 | ip6_flow_hdr(hdr, v6_cork->tclass, | |
| 103 | ip6_make_flowlabel(net, skb, fl6->flowlabel, | |
| 104 | - np->autoflowlabel, fl6)); | |
| 105 | + ip6_autoflowlabel(net, np), fl6)); | |
| 106 | hdr->hop_limit = v6_cork->hop_limit; | |
| 107 | hdr->nexthdr = proto; | |
| 108 | hdr->saddr = fl6->saddr; | |
| 109 | --- a/net/ipv6/ipv6_sockglue.c | |
| 110 | +++ b/net/ipv6/ipv6_sockglue.c | |
| 111 | @@ -878,6 +878,7 @@ pref_skip_coa: | |
| 112 | break; | |
| 113 | case IPV6_AUTOFLOWLABEL: | |
| 114 | np->autoflowlabel = valbool; | |
| 115 | + np->autoflowlabel_set = 1; | |
| 116 | retv = 0; | |
| 117 | break; | |
| 118 | case IPV6_RECVFRAGSIZE: |