Re: [PATCH v4 1/8] bluetooth: /proc/net/ entries for bluetooth protocols

[Gustavo Padovan <gustavo@padovan.org>]

Hi Masatake,

* Masatake YAMATO <yamato@redhat.com> [2012-07-16 22:20:18 +0900]:

> (I resend this mail becasue I got some troubles in mail sending.
>  Andrei, [PATCH v4 [2-8]/8] are the same as [PATCH v3 [2-8]/8]. So
>  I send [PATCH v4 1/8] only here. If I should the rest of v4 patches,
>  please, let me know that.)

Please keep this kind of information after the --- line, so git am
automatically skip this when applying, otherwise I have to edit the commit
message by hand.

> 
> lsof command can tell the type of socket processes are using.
> Internal lsof uses inode numbers on socket fs to resolve the type of
> sockets. Files under /proc/net/, such as tcp, udp, unix, etc provides
> such inode information.
> 
> Unfortunately bluetooth related protocols don't provide such inode
> information. This patch series introduces /proc/net files for the protocols.
> 
> This patch against af_bluetooth.c provides facility to the implementation
> of protocols. This patch extends bt_sock_list and introduces two exported
> function bt_procfs_init, bt_procfs_cleanup.
> 
> The type bt_sock_list is already used in some of implementation of
> protocols. bt_procfs_init prepare seq_operations which converts
> protocol own bt_sock_list data to protocol own proc entry when the
> entry is accessed.
> 
> What I, lsof user, need is just inode number of bluetooth
> socket. However, people may want more information. The bt_procfs_init
> takes a function pointer for customizing the show handler of
> seq_operations.
> 
> In v4 patch, __acquires and __releases attributes are added to suppress
> sparse warning. Suggested by Andrei Emeltchenko.
> 
> Signed-off-by: Masatake YAMATO <yamato@redhat.com>
> ---
>  include/net/bluetooth/bluetooth.h |   10 +++
>  net/bluetooth/af_bluetooth.c      |  138 +++++++++++++++++++++++++++++++++++++
>  2 files changed, 148 insertions(+)

Patch has been applied to bluetooth-next, however I had to fix a minor
issue...

> 
> diff --git a/include/net/bluetooth/bluetooth.h b/include/net/bluetooth/bluetooth.h
> index 565d4be..ede0369 100644
> --- a/include/net/bluetooth/bluetooth.h
> +++ b/include/net/bluetooth/bluetooth.h
> @@ -27,6 +27,7 @@
>  
>  #include <linux/poll.h>
>  #include <net/sock.h>
> +#include <linux/seq_file.h>
>  
>  #ifndef AF_BLUETOOTH
>  #define AF_BLUETOOTH	31
> @@ -202,6 +203,10 @@ enum {
>  struct bt_sock_list {
>  	struct hlist_head head;
>  	rwlock_t          lock;
> +#ifdef CONFIG_PROC_FS
> +        struct file_operations   fops;
> +        int (* custom_seq_show)(struct seq_file *, void *);
> +#endif
>  };
>  
>  int  bt_sock_register(int proto, const struct net_proto_family *ops);
> @@ -292,6 +297,11 @@ extern void hci_sock_cleanup(void);
>  extern int bt_sysfs_init(void);
>  extern void bt_sysfs_cleanup(void);
>  
> +extern int  bt_procfs_init(struct module* module, struct net *net, const char *name,
> +			   struct bt_sock_list* sk_list,
> +			   int (* seq_show)(struct seq_file *, void *));
> +extern void bt_procfs_cleanup(struct net *net, const char *name);
> +
>  extern struct dentry *bt_debugfs;
>  
>  int l2cap_init(void);
> diff --git a/net/bluetooth/af_bluetooth.c b/net/bluetooth/af_bluetooth.c
> index f7db579..f76cf2f 100644
> --- a/net/bluetooth/af_bluetooth.c
> +++ b/net/bluetooth/af_bluetooth.c
> @@ -532,6 +532,144 @@ int bt_sock_wait_state(struct sock *sk, int state, unsigned long timeo)
>  }
>  EXPORT_SYMBOL(bt_sock_wait_state);
>  
> +#ifdef CONFIG_PROC_FS
> +struct bt_seq_state {
> +	struct bt_sock_list *l;
> +};
> +
> +static void *bt_seq_start(struct seq_file *seq, loff_t *pos)
> +	__acquires(seq->private->l->lock)
> +{
> +	struct bt_seq_state *s = seq->private;
> +	struct bt_sock_list *l = s->l;
> +
> +	read_lock(&l->lock);
> +	return seq_hlist_start_head(&l->head, *pos);
> +}
> +
> +static void *bt_seq_next(struct seq_file *seq, void *v, loff_t *pos)
> +{
> +	struct bt_seq_state *s = seq->private;
> +	struct bt_sock_list *l = s->l;
> +
> +	return seq_hlist_next(v, &l->head, pos);
> +}
> +
> +static void bt_seq_stop(struct seq_file *seq, void *v)
> +	__releases(seq->private->l->lock)
> +{
> +	struct bt_seq_state *s = seq->private;
> +	struct bt_sock_list *l = s->l;
> +
> +	read_unlock(&l->lock);
> +}
> +
> +static int bt_seq_show(struct seq_file *seq, void *v)
> +{
> +	struct sock *sk;
> +	struct bt_sock *bt;
> +	struct bt_seq_state *s = seq->private;
> +	struct bt_sock_list *l = s->l;
> +	bdaddr_t src_baswapped, dst_baswapped;
> +
> +	if (v == SEQ_START_TOKEN) {
> +		seq_puts(seq ,"sk               RefCnt Rmem   Wmem   User   Inode  Src Dst Parent");
> +
> +		if (l->custom_seq_show) {
> +			seq_putc(seq, ' ');
> +			l->custom_seq_show(seq, v);
> +		}
> +
> +		seq_putc(seq, '\n');
> +	} else {
> +		sk = sk_entry(v);
> +		bt = bt_sk(sk);
> +		baswap(&src_baswapped, &bt->src);
> +		baswap(&dst_baswapped, &bt->dst);
> +
> +		seq_printf(seq, "%pK %-6d %-6u %-6u %-6u %-6lu %pM %pM %-6lu",
> +			   sk,
> +			   atomic_read(&sk->sk_refcnt),
> +			   sk_rmem_alloc_get(sk),
> +			   sk_wmem_alloc_get(sk),
> +			   sock_i_uid(sk),
> +			   sock_i_ino(sk),
> +			   &src_baswapped,
> +			   &dst_baswapped,
> +			   bt->parent? sock_i_ino(bt->parent): 0LU);
> +
> +		if (l->custom_seq_show) {
> +			seq_putc(seq, ' ');
> +			l->custom_seq_show(seq, v);
> +		}
> +
> +		seq_putc(seq, '\n');
> +	}
> +	return 0;
> +}
> +
> +static struct seq_operations bt_seq_ops = {
> +	.start = bt_seq_start,
> +	.next  = bt_seq_next,
> +	.stop  = bt_seq_stop,
> +	.show  = bt_seq_show,
> +};
> +
> +static int bt_seq_open(struct inode *inode, struct file *file)
> +{
> +	struct bt_sock_list *sk_list;
> +	struct bt_seq_state *s;
> +
> +	sk_list = PDE(inode)->data;
> +	s = __seq_open_private(file, &bt_seq_ops,
> +			       sizeof(struct bt_seq_state));
> +	if (s == NULL)
> +		return -ENOMEM;
> +
> +	s->l = sk_list;
> +	return 0;
> +}
> +
> +int bt_procfs_init(struct module* module, struct net *net, const char *name, struct bt_sock_list* sk_list,
> +		   int (* seq_show)(struct seq_file *, void *))

... the identation here is a bit wrong, I fixed it. Thanks for doing this
work.

	Gustavo