From 1ec17dbd90f8b638f41ee650558609c1af63dfa0 Mon Sep 17 00:00:00 2001 From: Konstantin Khlebnikov Date: Sat, 9 Feb 2019 13:35:52 +0300 Subject: inet_diag: fix reporting cgroup classid and fallback to priority Field idiag_ext in struct inet_diag_req_v2 used as bitmap of requested extensions has only 8 bits. Thus extensions starting from DCTCPINFO cannot be requested directly. Some of them included into response unconditionally or hook into some of lower 8 bits. Extension INET_DIAG_CLASS_ID has not way to request from the beginning. This patch bundle it with INET_DIAG_TCLASS (ipv6 tos), fixes space reservation, and documents behavior for other extensions. Also this patch adds fallback to reporting socket priority. This filed is more widely used for traffic classification because ipv4 sockets automatically maps TOS to priority and default qdisc pfifo_fast knows about that. But priority could be changed via setsockopt SO_PRIORITY so INET_DIAG_TOS isn't enough for predicting class. Also cgroup2 obsoletes net_cls classid (it always zero), but we cannot reuse this field for reporting cgroup2 id because it is 64-bit (ino+gen). So, after this patch INET_DIAG_CLASS_ID will report socket priority for most common setup when net_cls isn't set and/or cgroup2 in use. Fixes: 0888e372c37f ("net: inet: diag: expose sockets cgroup classid") Signed-off-by: Konstantin Khlebnikov Signed-off-by: David S. Miller --- net/ipv4/inet_diag.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'net/ipv4/inet_diag.c') diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c index 1a4e9ff02762..5731670c560b 100644 --- a/net/ipv4/inet_diag.c +++ b/net/ipv4/inet_diag.c @@ -108,6 +108,7 @@ static size_t inet_sk_attr_size(struct sock *sk, + nla_total_size(1) /* INET_DIAG_TOS */ + nla_total_size(1) /* INET_DIAG_TCLASS */ + nla_total_size(4) /* INET_DIAG_MARK */ + + nla_total_size(4) /* INET_DIAG_CLASS_ID */ + nla_total_size(sizeof(struct inet_diag_meminfo)) + nla_total_size(sizeof(struct inet_diag_msg)) + nla_total_size(SK_MEMINFO_VARS * sizeof(u32)) @@ -287,12 +288,19 @@ int inet_sk_diag_fill(struct sock *sk, struct inet_connection_sock *icsk, goto errout; } - if (ext & (1 << (INET_DIAG_CLASS_ID - 1))) { + if (ext & (1 << (INET_DIAG_CLASS_ID - 1)) || + ext & (1 << (INET_DIAG_TCLASS - 1))) { u32 classid = 0; #ifdef CONFIG_SOCK_CGROUP_DATA classid = sock_cgroup_classid(&sk->sk_cgrp_data); #endif + /* Fallback to socket priority if class id isn't set. + * Classful qdiscs use it as direct reference to class. + * For cgroup2 classid is always zero. + */ + if (!classid) + classid = sk->sk_priority; if (nla_put_u32(skb, INET_DIAG_CLASS_ID, classid)) goto errout; -- cgit v1.2.3-59-g8ed1b