From 3fbc290540a1ed1a8a076ed8f53bee7a38a9f408 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Thu, 24 May 2012 17:21:27 -0600 Subject: [PATCH] netlink: Make the sending netlink socket availabe in NETLINK_CB The sending socket of an skb is already available by it's port id in the NETLINK_CB. If you want to know more like to examine the credentials on the sending socket you have to look up the sending socket by it's port id and all of the needed functions and data structures are static inside of af_netlink.c. So do the simple thing and pass the sending socket to the receivers in the NETLINK_CB. I intend to use this to get the user namespace of the sending socket in inet_diag so that I can report uids in the context of the process who opened the socket, the same way I report uids in the contect of the process who opens files. Acked-by: David S. Miller Acked-by: Serge Hallyn Signed-off-by: Eric W. Biederman --- include/linux/netlink.h | 1 + net/netlink/af_netlink.c | 6 ++++-- 2 files changed, 5 insertions(+), 2 deletions(-) diff --git a/include/linux/netlink.h b/include/linux/netlink.h index f74dd133788f..c9fdde2bc73f 100644 --- a/include/linux/netlink.h +++ b/include/linux/netlink.h @@ -165,6 +165,7 @@ struct netlink_skb_parms { struct ucred creds; /* Skb credentials */ __u32 pid; __u32 dst_group; + struct sock *ssk; }; #define NETLINK_CB(skb) (*(struct netlink_skb_parms*)&((skb)->cb)) diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index 5463969da45b..7cb7867cc369 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -912,7 +912,8 @@ static void netlink_rcv_wake(struct sock *sk) wake_up_interruptible(&nlk->wait); } -static int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb) +static int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb, + struct sock *ssk) { int ret; struct netlink_sock *nlk = nlk_sk(sk); @@ -921,6 +922,7 @@ static int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb) if (nlk->netlink_rcv != NULL) { ret = skb->len; skb_set_owner_r(skb, sk); + NETLINK_CB(skb).ssk = ssk; nlk->netlink_rcv(skb); consume_skb(skb); } else { @@ -947,7 +949,7 @@ retry: return PTR_ERR(sk); } if (netlink_is_kernel(sk)) - return netlink_unicast_kernel(sk, skb); + return netlink_unicast_kernel(sk, skb, ssk); if (sk_filter(sk, skb)) { err = skb->len; -- 2.20.1