net-procfs: show net devices bound packet types

BugLink: https://bugs.launchpad.net/bugs/1959879
commit 1d10f8a1f40b965d449e8f2d5ed7b96a7c138b77 upstream.

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@chinatelecom.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>

diff --git a/net/core/net-procfs.c b/net/core/net-procfs.c
index 5b8016335acaf0cae143cdd15cb16b4e970f5e46..88cc0ad7d386e825fefb6961db195e9370bfc84d 100644 (file)
--- 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;