Phonet: list subscribed resources via proc_fs

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

2 files changed, 98 insertions, 0 deletions

diff --git a/net/phonet/pn_dev.c b/net/phonet/pn_dev.c
index d0a429459370..947038ddd04c 100644
--- a/net/phonet/pn_dev.c
+++ b/net/phonet/pn_dev.c
@@ -373,6 +373,7 @@ int __init phonet_device_init(void)
         if (err)
                 return err;
 
+        proc_net_fops_create(&init_net, "pnresource", 0, &pn_res_seq_fops);
         register_netdevice_notifier(&phonet_device_notifier);
         err = phonet_netlink_register();
         if (err)
@@ -385,6 +386,7 @@ void phonet_device_exit(void)
         rtnl_unregister_all(PF_PHONET);
         unregister_netdevice_notifier(&phonet_device_notifier);
         unregister_pernet_device(&phonet_net_ops);
+        proc_net_remove(&init_net, "pnresource");
 }
 
 int phonet_route_add(struct net_device *dev, u8 daddr)
diff --git a/net/phonet/socket.c b/net/phonet/socket.c
index d4f41afc0583..6bf6e3c97d5c 100644
--- a/net/phonet/socket.c
+++ b/net/phonet/socket.c
@@ -654,3 +654,99 @@ void pn_sock_unbind_all_res(struct sock *sk)
                 match--;
         }
 }
+
+#ifdef CONFIG_PROC_FS
+static struct sock **pn_res_get_idx(struct seq_file *seq, loff_t pos)
+{
+        struct net *net = seq_file_net(seq);
+        unsigned i;
+
+        if (!net_eq(net, &init_net))
+                return NULL;
+
+        for (i = 0; i < 256; i++) {
+                if (pnres.sk[i] == NULL)
+                        continue;
+                if (!pos)
+                        return pnres.sk + i;
+                pos--;
+        }
+        return NULL;
+}
+
+static struct sock **pn_res_get_next(struct seq_file *seq, struct sock **sk)
+{
+        struct net *net = seq_file_net(seq);
+        unsigned i;
+
+        BUG_ON(!net_eq(net, &init_net));
+
+        for (i = (sk - pnres.sk) + 1; i < 256; i++)
+                if (pnres.sk[i])
+                        return pnres.sk + i;
+        return NULL;
+}
+
+static void *pn_res_seq_start(struct seq_file *seq, loff_t *pos)
+        __acquires(resource_mutex)
+{
+        mutex_lock(&resource_mutex);
+        return *pos ? pn_res_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
+}
+
+static void *pn_res_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+        struct sock **sk;
+
+        if (v == SEQ_START_TOKEN)
+                sk = pn_res_get_idx(seq, 0);
+        else
+                sk = pn_res_get_next(seq, v);
+        (*pos)++;
+        return sk;
+}
+
+static void pn_res_seq_stop(struct seq_file *seq, void *v)
+        __releases(resource_mutex)
+{
+        mutex_unlock(&resource_mutex);
+}
+
+static int pn_res_seq_show(struct seq_file *seq, void *v)
+{
+        int len;
+
+        if (v == SEQ_START_TOKEN)
+                seq_printf(seq, "%s%n", "rs   uid inode", &len);
+        else {
+                struct sock **psk = v;
+                struct sock *sk = *psk;
+
+                seq_printf(seq, "%02X %5d %lu%n",
+                        psk - pnres.sk, sock_i_uid(sk), sock_i_ino(sk), &len);
+        }
+        seq_printf(seq, "%*s\n", 63 - len, "");
+        return 0;
+}
+
+static const struct seq_operations pn_res_seq_ops = {
+        .start = pn_res_seq_start,
+        .next = pn_res_seq_next,
+        .stop = pn_res_seq_stop,
+        .show = pn_res_seq_show,
+};
+
+static int pn_res_open(struct inode *inode, struct file *file)
+{
+        return seq_open_net(inode, file, &pn_res_seq_ops,
+                                sizeof(struct seq_net_private));
+}
+
+const struct file_operations pn_res_seq_fops = {
+        .owner = THIS_MODULE,
+        .open = pn_res_open,
+        .read = seq_read,
+        .llseek = seq_lseek,
+        .release = seq_release_net,
+};
+#endif