[PATCH v3] net: inet: diag: expose sockets cgroup classid

From: Levin, Alexander (Sasha Levin)
Date: Wed Aug 16 2017 - 20:35:42 EST


From: "Levin, Alexander (Sasha Levin)" <alexander.levin@xxxxxxxxxxxxxxx>

This is useful for directly looking up a task based on class id rather than
having to scan through all open file descriptors.

Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
---
include/uapi/linux/inet_diag.h | 1 +
net/ipv4/inet_diag.c | 11 +++++++++++
2 files changed, 12 insertions(+)

diff --git a/include/uapi/linux/inet_diag.h b/include/uapi/linux/inet_diag.h
index bbe201047df6..678496897a68 100644
--- a/include/uapi/linux/inet_diag.h
+++ b/include/uapi/linux/inet_diag.h
@@ -142,6 +142,7 @@ enum {
INET_DIAG_PAD,
INET_DIAG_MARK,
INET_DIAG_BBRINFO,
+ INET_DIAG_CLASS_ID,
__INET_DIAG_MAX,
};

diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
index 3828b3a805cd..67325d5832d7 100644
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -274,6 +274,17 @@ int inet_sk_diag_fill(struct sock *sk, struct inet_connection_sock *icsk,
goto errout;
}

+ if (ext & (1 << (INET_DIAG_CLASS_ID - 1))) {
+ u32 classid = 0;
+
+#ifdef CONFIG_SOCK_CGROUP_DATA
+ classid = sock_cgroup_classid(&sk->sk_cgrp_data);
+#endif
+
+ if (nla_put_u32(skb, INET_DIAG_CLASS_ID, classid))
+ goto errout;
+ }
+
out:
nlmsg_end(skb, nlh);
return 0;
--
2.11.0