Author: Felipe Gasper <felipe@xxxxxxxxxxxxxxxx>
Date: Thu May 16 12:16:53 2019 -0500
Add UNIX_DIAG_UID to Netlink UNIX socket diagnostics.
This adds the ability for Netlink to report a socket’s UID along with the
other UNIX socket diagnostic information that is already available. This will
allow diagnostic tools greater insight into which users control which socket.
Signed-off-by: Felipe Gasper <felipe@xxxxxxxxxxxxxxxx>
diff --git a/include/uapi/linux/unix_diag.h b/include/uapi/linux/unix_diag.h
index 5c502fd..a198857 100644
--- a/include/uapi/linux/unix_diag.h
+++ b/include/uapi/linux/unix_diag.h
@@ -20,6 +20,7 @@ struct unix_diag_req {
#define UDIAG_SHOW_ICONS 0x00000008 /* show pending connections */
#define UDIAG_SHOW_RQLEN 0x00000010 /* show skb receive queue len */
#define UDIAG_SHOW_MEMINFO 0x00000020 /* show memory info of a socket */
+#define UDIAG_SHOW_UID 0x00000040 /* show socket's UID */
struct unix_diag_msg {
__u8 udiag_family;
@@ -40,6 +41,7 @@ enum {
UNIX_DIAG_RQLEN,
UNIX_DIAG_MEMINFO,
UNIX_DIAG_SHUTDOWN,
+ UNIX_DIAG_UID,
__UNIX_DIAG_MAX,
};
diff --git a/net/unix/diag.c b/net/unix/diag.c
index 3183d9b..011f56c 100644
--- a/net/unix/diag.c
+++ b/net/unix/diag.c
@@ -110,6 +110,11 @@ static int sk_diag_show_rqlen(struct sock *sk, struct sk_buff *nlskb)
return nla_put(nlskb, UNIX_DIAG_RQLEN, sizeof(rql), &rql);
}
+static int sk_diag_dump_uid(struct sock *sk, struct sk_buff *nlskb)
+{
+ return nla_put(nlskb, UNIX_DIAG_UID, sizeof(kuid_t), &(sk->sk_uid));
+}
+
static int sk_diag_fill(struct sock *sk, struct sk_buff *skb, struct unix_diag_req *req,
u32 portid, u32 seq, u32 flags, int sk_ino)
{
@@ -156,6 +161,10 @@ static int sk_diag_fill(struct sock *sk, struct sk_buff *skb, struct unix_diag_r
if (nla_put_u8(skb, UNIX_DIAG_SHUTDOWN, sk->sk_shutdown))
goto out_nlmsg_trim;
+ if ((req->udiag_show & UDIAG_SHOW_UID) &&
+ sk_diag_dump_uid(sk, skb))
+ goto out_nlmsg_trim;
+
nlmsg_end(skb, nlh);
return 0;
