packet: Report socket mclist info via diag module

The info is reported as an array of packet_diag_mclist structures. Each
includes not only the directly configured values (index, type, etc), but
also the "count".

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 39 insertions, 0 deletions

diff --git a/net/packet/diag.c b/net/packet/diag.c
index d5bd0372d004..3dda4ecb9a46 100644
--- a/net/packet/diag.c
+++ b/net/packet/diag.c
@@ -1,6 +1,7 @@
 #include <linux/module.h>
 #include <linux/sock_diag.h>
 #include <linux/net.h>
+#include <linux/netdevice.h>
 #include <linux/packet_diag.h>
 #include <net/net_namespace.h>
 #include <net/sock.h>
@@ -32,6 +33,40 @@ static int pdiag_put_info(const struct packet_sock *po, struct sk_buff *nlskb)
         return nla_put(nlskb, PACKET_DIAG_INFO, sizeof(pinfo), &pinfo);
 }
 
+static int pdiag_put_mclist(const struct packet_sock *po, struct sk_buff *nlskb)
+{
+        struct nlattr *mca;
+        struct packet_mclist *ml;
+
+        mca = nla_nest_start(nlskb, PACKET_DIAG_MCLIST);
+        if (!mca)
+                return -EMSGSIZE;
+
+        rtnl_lock();
+        for (ml = po->mclist; ml; ml = ml->next) {
+                struct packet_diag_mclist *dml;
+
+                dml = nla_reserve_nohdr(nlskb, sizeof(*dml));
+                if (!dml) {
+                        rtnl_unlock();
+                        nla_nest_cancel(nlskb, mca);
+                        return -EMSGSIZE;
+                }
+
+                dml->pdmc_index = ml->ifindex;
+                dml->pdmc_type = ml->type;
+                dml->pdmc_alen = ml->alen;
+                dml->pdmc_count = ml->count;
+                BUILD_BUG_ON(sizeof(dml->pdmc_addr) != sizeof(ml->addr));
+                memcpy(dml->pdmc_addr, ml->addr, sizeof(ml->addr));
+        }
+
+        rtnl_unlock();
+        nla_nest_end(nlskb, mca);
+
+        return 0;
+}
+
 static int sk_diag_fill(struct sock *sk, struct sk_buff *skb, struct packet_diag_req *req,
                 u32 pid, u32 seq, u32 flags, int sk_ino)
 {
@@ -54,6 +89,10 @@ static int sk_diag_fill(struct sock *sk, struct sk_buff *skb, struct packet_diag
                         pdiag_put_info(po, skb))
                 goto out_nlmsg_trim;
 
+        if ((req->pdiag_show & PACKET_SHOW_MCLIST) &&
+                        pdiag_put_mclist(po, skb))
+                goto out_nlmsg_trim;
+
         return nlmsg_end(skb, nlh);
 
 out_nlmsg_trim: