Phonet: sockets list through proc_fs

This provides a list of sockets with their Phonet bind addresses and
some socket debug informations through /proc/net/phonet.

Signed-off-by: Rémi Denis-Courmont <remi.denis-courmont@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 103 insertions, 0 deletions

diff --git a/net/phonet/pn_dev.c b/net/phonet/pn_dev.c
index b0d6ddd82a9d..5107b7949c9c 100644
--- a/net/phonet/pn_dev.c
+++ b/net/phonet/pn_dev.c
@@ -218,6 +218,11 @@ static int phonet_init_net(struct net *net)
         if (!pnn)
                 return -ENOMEM;
 
+        if (!proc_net_fops_create(net, "phonet", 0, &pn_sock_seq_fops)) {
+                kfree(pnn);
+                return -ENOMEM;
+        }
+
         INIT_LIST_HEAD(&pnn->pndevs.list);
         spin_lock_init(&pnn->pndevs.lock);
         net_assign_generic(net, phonet_net_id, pnn);
@@ -233,6 +238,8 @@ static void phonet_exit_net(struct net *net)
         for_each_netdev(net, dev)
                 phonet_device_destroy(dev);
         rtnl_unlock();
+
+        proc_net_remove(net, "phonet");
         kfree(pnn);
 }
 
diff --git a/net/phonet/socket.c b/net/phonet/socket.c
index ada2a35bf7a2..aa1617a7f265 100644
--- a/net/phonet/socket.c
+++ b/net/phonet/socket.c
@@ -412,3 +412,99 @@ found:
         return 0;
 }
 EXPORT_SYMBOL(pn_sock_get_port);
+
+static struct sock *pn_sock_get_idx(struct seq_file *seq, loff_t pos)
+{
+        struct net *net = seq_file_net(seq);
+        struct hlist_node *node;
+        struct sock *sknode;
+
+        sk_for_each(sknode, node, &pnsocks.hlist) {
+                if (!net_eq(net, sock_net(sknode)))
+                        continue;
+                if (!pos)
+                        return sknode;
+                pos--;
+        }
+        return NULL;
+}
+
+static struct sock *pn_sock_get_next(struct seq_file *seq, struct sock *sk)
+{
+        struct net *net = seq_file_net(seq);
+
+        do
+                sk = sk_next(sk);
+        while (sk && !net_eq(net, sock_net(sk)));
+
+        return sk;
+}
+
+static void *pn_sock_seq_start(struct seq_file *seq, loff_t *pos)
+        __acquires(pnsocks.lock)
+{
+        spin_lock_bh(&pnsocks.lock);
+        return *pos ? pn_sock_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
+}
+
+static void *pn_sock_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+        struct sock *sk;
+
+        if (v == SEQ_START_TOKEN)
+                sk = pn_sock_get_idx(seq, 0);
+        else
+                sk = pn_sock_get_next(seq, v);
+        (*pos)++;
+        return sk;
+}
+
+static void pn_sock_seq_stop(struct seq_file *seq, void *v)
+        __releases(pnsocks.lock)
+{
+        spin_unlock_bh(&pnsocks.lock);
+}
+
+static int pn_sock_seq_show(struct seq_file *seq, void *v)
+{
+        int len;
+
+        if (v == SEQ_START_TOKEN)
+                seq_printf(seq, "%s%n", "pt  loc  rem rs st tx_queue rx_queue "
+                        "  uid inode ref pointer drops", &len);
+        else {
+                struct sock *sk = v;
+                struct pn_sock *pn = pn_sk(sk);
+
+                seq_printf(seq, "%2d %04X:%04X:%02X %02X %08X:%08X %5d %lu "
+                        "%d %p %d%n",
+                        sk->sk_protocol, pn->sobject, 0, pn->resource,
+                        sk->sk_state,
+                        sk_wmem_alloc_get(sk), sk_rmem_alloc_get(sk),
+                        sock_i_uid(sk), sock_i_ino(sk),
+                        atomic_read(&sk->sk_refcnt), sk,
+                        atomic_read(&sk->sk_drops), &len);
+        }
+        seq_printf(seq, "%*s\n", 127 - len, "");
+        return 0;
+}
+
+static const struct seq_operations pn_sock_seq_ops = {
+        .start = pn_sock_seq_start,
+        .next = pn_sock_seq_next,
+        .stop = pn_sock_seq_stop,
+        .show = pn_sock_seq_show,
+};
+
+static int pn_sock_open(struct inode *inode, struct file *file)
+{
+        return seq_open(file, &pn_sock_seq_ops);
+}
+
+const struct file_operations pn_sock_seq_fops = {
+        .owner = THIS_MODULE,
+        .open = pn_sock_open,
+        .read = seq_read,
+        .llseek = seq_lseek,
+        .release = seq_release,
+};