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Merge branch 'SO_PRIORITY'
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Eric Dumazet says:

====================
tcp: provide correct skb->priority

SO_PRIORITY socket option requests TCP egress packets
to contain a user provided value.

TCP manages to send most packets with the requested values,
notably for TCP_ESTABLISHED state, but fails to do so for
few packets.

These packets are control packets sent on behalf
of SYN_RECV or TIME_WAIT states.

Note that to test this with packetdrill, it is a bit
of a hassle, since packetdrill can not verify priority
of egress packets, other than indirect observations,
using for example sch_prio on its tunnel device.

The bad skb priorities cause problems for GCP,
as this field is one of the keys used in routing.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
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David S. Miller committed Sep 27, 2019
2 parents 2b6fd3e + f6c0f5d commit 4e1e83b
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Showing 10 changed files with 29 additions and 17 deletions.
1 change: 1 addition & 0 deletions include/net/inet_timewait_sock.h
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Original file line number Diff line number Diff line change
Expand Up @@ -71,6 +71,7 @@ struct inet_timewait_sock {
tw_pad : 2, /* 2 bits hole */
tw_tos : 8;
u32 tw_txhash;
u32 tw_priority;
struct timer_list tw_timer;
struct inet_bind_bucket *tw_tb;
};
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2 changes: 1 addition & 1 deletion include/net/ipv6.h
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Original file line number Diff line number Diff line change
Expand Up @@ -981,7 +981,7 @@ int ip6_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb);
* upper-layer output functions
*/
int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
__u32 mark, struct ipv6_txoptions *opt, int tclass);
__u32 mark, struct ipv6_txoptions *opt, int tclass, u32 priority);

int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr);

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5 changes: 3 additions & 2 deletions net/dccp/ipv6.c
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Original file line number Diff line number Diff line change
Expand Up @@ -230,7 +230,8 @@ static int dccp_v6_send_response(const struct sock *sk, struct request_sock *req
opt = ireq->ipv6_opt;
if (!opt)
opt = rcu_dereference(np->opt);
err = ip6_xmit(sk, skb, &fl6, sk->sk_mark, opt, np->tclass);
err = ip6_xmit(sk, skb, &fl6, sk->sk_mark, opt, np->tclass,
sk->sk_priority);
rcu_read_unlock();
err = net_xmit_eval(err);
}
Expand Down Expand Up @@ -284,7 +285,7 @@ static void dccp_v6_ctl_send_reset(const struct sock *sk, struct sk_buff *rxskb)
dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL);
if (!IS_ERR(dst)) {
skb_dst_set(skb, dst);
ip6_xmit(ctl_sk, skb, &fl6, 0, NULL, 0);
ip6_xmit(ctl_sk, skb, &fl6, 0, NULL, 0, 0);
DCCP_INC_STATS(DCCP_MIB_OUTSEGS);
DCCP_INC_STATS(DCCP_MIB_OUTRSTS);
return;
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1 change: 0 additions & 1 deletion net/ipv4/ip_output.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1694,7 +1694,6 @@ void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb,

inet_sk(sk)->tos = arg->tos;

sk->sk_priority = skb->priority;
sk->sk_protocol = ip_hdr(skb)->protocol;
sk->sk_bound_dev_if = arg->bound_dev_if;
sk->sk_sndbuf = sysctl_wmem_default;
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4 changes: 4 additions & 0 deletions net/ipv4/tcp_ipv4.c
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Original file line number Diff line number Diff line change
Expand Up @@ -771,6 +771,8 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb)
if (sk) {
ctl_sk->sk_mark = (sk->sk_state == TCP_TIME_WAIT) ?
inet_twsk(sk)->tw_mark : sk->sk_mark;
ctl_sk->sk_priority = (sk->sk_state == TCP_TIME_WAIT) ?
inet_twsk(sk)->tw_priority : sk->sk_priority;
transmit_time = tcp_transmit_time(sk);
}
ip_send_unicast_reply(ctl_sk,
Expand Down Expand Up @@ -866,6 +868,8 @@ static void tcp_v4_send_ack(const struct sock *sk,
ctl_sk = this_cpu_read(*net->ipv4.tcp_sk);
ctl_sk->sk_mark = (sk->sk_state == TCP_TIME_WAIT) ?
inet_twsk(sk)->tw_mark : sk->sk_mark;
ctl_sk->sk_priority = (sk->sk_state == TCP_TIME_WAIT) ?
inet_twsk(sk)->tw_priority : sk->sk_priority;
transmit_time = tcp_transmit_time(sk);
ip_send_unicast_reply(ctl_sk,
skb, &TCP_SKB_CB(skb)->header.h4.opt,
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1 change: 1 addition & 0 deletions net/ipv4/tcp_minisocks.c
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Original file line number Diff line number Diff line change
Expand Up @@ -266,6 +266,7 @@ void tcp_time_wait(struct sock *sk, int state, int timeo)

tw->tw_transparent = inet->transparent;
tw->tw_mark = sk->sk_mark;
tw->tw_priority = sk->sk_priority;
tw->tw_rcv_wscale = tp->rx_opt.rcv_wscale;
tcptw->tw_rcv_nxt = tp->rcv_nxt;
tcptw->tw_snd_nxt = tp->snd_nxt;
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2 changes: 1 addition & 1 deletion net/ipv6/inet6_connection_sock.c
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Original file line number Diff line number Diff line change
Expand Up @@ -133,7 +133,7 @@ int inet6_csk_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl_unused
fl6.daddr = sk->sk_v6_daddr;

res = ip6_xmit(sk, skb, &fl6, sk->sk_mark, rcu_dereference(np->opt),
np->tclass);
np->tclass, sk->sk_priority);
rcu_read_unlock();
return res;
}
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4 changes: 2 additions & 2 deletions net/ipv6/ip6_output.c
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Original file line number Diff line number Diff line change
Expand Up @@ -193,7 +193,7 @@ bool ip6_autoflowlabel(struct net *net, const struct ipv6_pinfo *np)
* which are using proper atomic operations or spinlocks.
*/
int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
__u32 mark, struct ipv6_txoptions *opt, int tclass)
__u32 mark, struct ipv6_txoptions *opt, int tclass, u32 priority)
{
struct net *net = sock_net(sk);
const struct ipv6_pinfo *np = inet6_sk(sk);
Expand Down Expand Up @@ -258,7 +258,7 @@ int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
hdr->daddr = *first_hop;

skb->protocol = htons(ETH_P_IPV6);
skb->priority = sk->sk_priority;
skb->priority = priority;
skb->mark = mark;

mtu = dst_mtu(dst);
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24 changes: 15 additions & 9 deletions net/ipv6/tcp_ipv6.c
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Original file line number Diff line number Diff line change
Expand Up @@ -512,7 +512,8 @@ static int tcp_v6_send_synack(const struct sock *sk, struct dst_entry *dst,
opt = ireq->ipv6_opt;
if (!opt)
opt = rcu_dereference(np->opt);
err = ip6_xmit(sk, skb, fl6, sk->sk_mark, opt, np->tclass);
err = ip6_xmit(sk, skb, fl6, sk->sk_mark, opt, np->tclass,
sk->sk_priority);
rcu_read_unlock();
err = net_xmit_eval(err);
}
Expand Down Expand Up @@ -803,7 +804,7 @@ static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 seq,
u32 ack, u32 win, u32 tsval, u32 tsecr,
int oif, struct tcp_md5sig_key *key, int rst,
u8 tclass, __be32 label)
u8 tclass, __be32 label, u32 priority)
{
const struct tcphdr *th = tcp_hdr(skb);
struct tcphdr *t1;
Expand Down Expand Up @@ -907,7 +908,8 @@ static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32
dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL);
if (!IS_ERR(dst)) {
skb_dst_set(buff, dst);
ip6_xmit(ctl_sk, buff, &fl6, fl6.flowi6_mark, NULL, tclass);
ip6_xmit(ctl_sk, buff, &fl6, fl6.flowi6_mark, NULL, tclass,
priority);
TCP_INC_STATS(net, TCP_MIB_OUTSEGS);
if (rst)
TCP_INC_STATS(net, TCP_MIB_OUTRSTS);
Expand All @@ -930,6 +932,7 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
struct sock *sk1 = NULL;
#endif
__be32 label = 0;
u32 priority = 0;
struct net *net;
int oif = 0;

Expand Down Expand Up @@ -990,16 +993,19 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
trace_tcp_send_reset(sk, skb);
if (np->repflow)
label = ip6_flowlabel(ipv6h);
priority = sk->sk_priority;
}
if (sk->sk_state == TCP_TIME_WAIT)
if (sk->sk_state == TCP_TIME_WAIT) {
label = cpu_to_be32(inet_twsk(sk)->tw_flowlabel);
priority = inet_twsk(sk)->tw_priority;
}
} else {
if (net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_TCP_RESET)
label = ip6_flowlabel(ipv6h);
}

tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1, 0,
label);
label, priority);

#ifdef CONFIG_TCP_MD5SIG
out:
Expand All @@ -1010,10 +1016,10 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
static void tcp_v6_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq,
u32 ack, u32 win, u32 tsval, u32 tsecr, int oif,
struct tcp_md5sig_key *key, u8 tclass,
__be32 label)
__be32 label, u32 priority)
{
tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, key, 0,
tclass, label);
tclass, label, priority);
}

static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
Expand All @@ -1025,7 +1031,7 @@ static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
tcp_time_stamp_raw() + tcptw->tw_ts_offset,
tcptw->tw_ts_recent, tw->tw_bound_dev_if, tcp_twsk_md5_key(tcptw),
tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel));
tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel), tw->tw_priority);

inet_twsk_put(tw);
}
Expand All @@ -1048,7 +1054,7 @@ static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
tcp_time_stamp_raw() + tcp_rsk(req)->ts_off,
req->ts_recent, sk->sk_bound_dev_if,
tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->saddr),
0, 0);
0, 0, sk->sk_priority);
}


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2 changes: 1 addition & 1 deletion net/sctp/ipv6.c
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Original file line number Diff line number Diff line change
Expand Up @@ -215,7 +215,7 @@ static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport)

rcu_read_lock();
res = ip6_xmit(sk, skb, fl6, sk->sk_mark, rcu_dereference(np->opt),
tclass);
tclass, sk->sk_priority);
rcu_read_unlock();
return res;
}
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