Patch "net-procfs: show net devices bound packet types" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    net-procfs: show net devices bound packet types

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     net-procfs-show-net-devices-bound-packet-types.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 691f0c86deb7be37ccea956a7e681cfdbc520907
Author: Jianguo Wu <wujianguo@xxxxxxxxxxxxxxx>
Date:   Fri Jan 21 17:15:31 2022 +0800

    net-procfs: show net devices bound packet types
    
    [ Upstream commit 1d10f8a1f40b965d449e8f2d5ed7b96a7c138b77 ]
    
    After commit:7866a621043f ("dev: add per net_device packet type chains"),
    we can not get packet types that are bound to a specified net device by
    /proc/net/ptype, this patch fix the regression.
    
    Run "tcpdump -i ens192 udp -nns0" Before and after apply this patch:
    
    Before:
      [root@localhost ~]# cat /proc/net/ptype
      Type Device      Function
      0800          ip_rcv
      0806          arp_rcv
      86dd          ipv6_rcv
    
    After:
      [root@localhost ~]# cat /proc/net/ptype
      Type Device      Function
      ALL  ens192   tpacket_rcv
      0800          ip_rcv
      0806          arp_rcv
      86dd          ipv6_rcv
    
    v1 -> v2:
      - fix the regression rather than adding new /proc API as
        suggested by Stephen Hemminger.
    
    Fixes: 7866a621043f ("dev: add per net_device packet type chains")
    Signed-off-by: Jianguo Wu <wujianguo@xxxxxxxxxxxxxxx>
    Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/net/core/net-procfs.c b/net/core/net-procfs.c
index 5b8016335acaf..88cc0ad7d386e 100644
--- a/net/core/net-procfs.c
+++ b/net/core/net-procfs.c
@@ -190,12 +190,23 @@ static const struct seq_operations softnet_seq_ops = {
 	.show  = softnet_seq_show,
 };
 
-static void *ptype_get_idx(loff_t pos)
+static void *ptype_get_idx(struct seq_file *seq, loff_t pos)
 {
+	struct list_head *ptype_list = NULL;
 	struct packet_type *pt = NULL;
+	struct net_device *dev;
 	loff_t i = 0;
 	int t;
 
+	for_each_netdev_rcu(seq_file_net(seq), dev) {
+		ptype_list = &dev->ptype_all;
+		list_for_each_entry_rcu(pt, ptype_list, list) {
+			if (i == pos)
+				return pt;
+			++i;
+		}
+	}
+
 	list_for_each_entry_rcu(pt, &ptype_all, list) {
 		if (i == pos)
 			return pt;
@@ -216,22 +227,40 @@ static void *ptype_seq_start(struct seq_file *seq, loff_t *pos)
 	__acquires(RCU)
 {
 	rcu_read_lock();
-	return *pos ? ptype_get_idx(*pos - 1) : SEQ_START_TOKEN;
+	return *pos ? ptype_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
 }
 
 static void *ptype_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 {
+	struct net_device *dev;
 	struct packet_type *pt;
 	struct list_head *nxt;
 	int hash;
 
 	++*pos;
 	if (v == SEQ_START_TOKEN)
-		return ptype_get_idx(0);
+		return ptype_get_idx(seq, 0);
 
 	pt = v;
 	nxt = pt->list.next;
+	if (pt->dev) {
+		if (nxt != &pt->dev->ptype_all)
+			goto found;
+
+		dev = pt->dev;
+		for_each_netdev_continue_rcu(seq_file_net(seq), dev) {
+			if (!list_empty(&dev->ptype_all)) {
+				nxt = dev->ptype_all.next;
+				goto found;
+			}
+		}
+
+		nxt = ptype_all.next;
+		goto ptype_all;
+	}
+
 	if (pt->type == htons(ETH_P_ALL)) {
+ptype_all:
 		if (nxt != &ptype_all)
 			goto found;
 		hash = 0;