Subject: Re: [PATCH v3] Phonet: set the pipe handle using setsockopt

From: Rémi Denis-Courmont <[email-masked]>
Date: Fri, 11 Nov 2011 12:47:23 +0200

Le Vendredi 11 Novembre 2011 15:58:22 ext Hemant Vilas RAMDASI a écrit :
> From: Dinesh Kumar Sharma <[email-masked]>
> 
> This provides flexibility to set the pipe handle
> using setsockopt and enable the same.
> 
> Signed-off-by: Hemant Ramdasi <[email-masked]>
> Signed-off-by: Dinesh Kumar Sharma <[email-masked]>
> ---
>  include/linux/phonet.h |    2 +
>  net/phonet/pep.c       |  111
> +++++++++++++++++++++++++++++++++++++++++++---- 2 files changed, 103
> insertions(+), 10 deletions(-)
> 
> diff --git a/include/linux/phonet.h b/include/linux/phonet.h
> index 6fb1384..491caec 100644
> --- a/include/linux/phonet.h
> +++ b/include/linux/phonet.h
> @@ -37,6 +37,8 @@
>  #define PNPIPE_ENCAP		1
>  #define PNPIPE_IFINDEX		2
>  #define PNPIPE_HANDLE		3
> +#define PNPIPE_ENABLE		4
> +#define PNPIPE_INITSTATE	5
> 
>  #define PNADDR_ANY		0
>  #define PNADDR_BROADCAST	0xFC
> diff --git a/net/phonet/pep.c b/net/phonet/pep.c
> index f17fd84..33230c5 100644
> --- a/net/phonet/pep.c
> +++ b/net/phonet/pep.c
> @@ -167,6 +167,12 @@ static int pipe_handler_send_created_ind(struct sock
> *sk) data, 4, GFP_ATOMIC);
>  }
> 
> +static int pipe_handler_send_enabled_ind(struct sock *sk)
> +{
> +	return pep_indicate(sk, PNS_PIPE_ENABLED_IND, 0 /* sub-blocks */,
> +				NULL, 0, GFP_ATOMIC);
> +}

This really could be inlined.

> +
>  static int pep_accept_conn(struct sock *sk, struct sk_buff *skb)
>  {
>  	static const u8 data[20] = {
> @@ -533,6 +539,27 @@ static int pep_connresp_rcv(struct sock *sk, struct
> sk_buff *skb) return pipe_handler_send_created_ind(sk);
>  }
> 
> +static int pep_enableresp_rcv(struct sock *sk, struct sk_buff *skb)
> +{
> +	struct pnpipehdr *hdr = pnp_hdr(skb);
> +
> +	if (hdr->error_code != PN_PIPE_NO_ERROR)
> +		return -ECONNREFUSED;
> +
> +	return pipe_handler_send_enabled_ind(sk);
> +}
> +
> +static void pipe_start_flow_control(struct sock *sk)
> +{
> +	struct pep_sock *pn = pep_sk(sk);
> +
> +	if (!pn_flow_safe(pn->tx_fc)) {
> +		atomic_set(&pn->tx_credits, 1);
> +		sk->sk_write_space(sk);
> +	}
> +	pipe_grant_credits(sk, GFP_ATOMIC);
> +}
> +
>  /* Queue an skb to an actively connected sock.
>   * Socket lock must be held. */
>  static int pipe_handler_do_rcv(struct sock *sk, struct sk_buff *skb)
> @@ -578,13 +605,25 @@ static int pipe_handler_do_rcv(struct sock *sk, struct
> sk_buff *skb) sk->sk_state = TCP_CLOSE_WAIT;
>  			break;
>  		}
> +		if (pn->init_enable == PN_PIPE_DISABLE)
> +			sk->sk_state = TCP_SYN_RECV;
> +		else {
> +			sk->sk_state = TCP_ESTABLISHED;
> +			pipe_start_flow_control(sk);
> +		}
> +		break;
> 
> -		sk->sk_state = TCP_ESTABLISHED;
> -		if (!pn_flow_safe(pn->tx_fc)) {
> -			atomic_set(&pn->tx_credits, 1);
> -			sk->sk_write_space(sk);
> +	case PNS_PEP_ENABLE_RESP:
> +		if (sk->sk_state != TCP_SYN_SENT)
> +			break;
> +
> +		if (pep_enableresp_rcv(sk, skb)) {
> +			sk->sk_state = TCP_CLOSE_WAIT;
> +			break;
>  		}
> -		pipe_grant_credits(sk, GFP_ATOMIC);
> +
> +		sk->sk_state = TCP_ESTABLISHED;
> +		pipe_start_flow_control(sk);
>  		break;
> 
>  	case PNS_PEP_DISCONNECT_RESP:
> @@ -863,14 +902,31 @@ static int pep_sock_connect(struct sock *sk, struct
> sockaddr *addr, int len) int err;
>  	u8 data[4] = { 0 /* sub-blocks */, PAD, PAD, PAD };
> 
> -	pn->pipe_handle = 1; /* anything but INVALID_HANDLE */
> +	if (pn->pipe_handle == PN_PIPE_INVALID_HANDLE)
> +		pn->pipe_handle = 1; /* anything but INVALID_HANDLE */
> +
>  	err = pipe_handler_request(sk, PNS_PEP_CONNECT_REQ,
> -					PN_PIPE_ENABLE, data, 4);
> -	if (err) {
> -		pn->pipe_handle = PN_PIPE_INVALID_HANDLE;
> +				pn->init_enable, data, 4);
> +	if (err)
>  		return err;
> -	}
> +
>  	sk->sk_state = TCP_SYN_SENT;
> +
> +	return 0;
> +}
> +
> +static int pep_sock_enable(struct sock *sk, struct sockaddr *addr, int len)
> +{
> +	int err;
> +
> +	err = pipe_handler_request(sk, PNS_PEP_ENABLE_REQ, PAD,
> +				NULL, 0);
> +
> +	if (err)
> +		return err;
> +
> +	sk->sk_state = TCP_SYN_SENT;
> +
>  	return 0;
>  }
> 
> @@ -959,6 +1015,30 @@ static int pep_setsockopt(struct sock *sk, int level,
> int optname, }
>  		goto out_norel;
> 
> +	case PNPIPE_HANDLE:
> +		if ((sk->sk_state == TCP_CLOSE) &&
> +			(val >= 0) && (val < PN_PIPE_INVALID_HANDLE))
> +			pn->pipe_handle = val;
> +		else
> +			err = -EINVAL;
> +		break;
> +
> +	case PNPIPE_ENABLE:
> +		if (sk->sk_state == TCP_SYN_SENT)
> +			err = -EBUSY;
> +		else if (sk->sk_state == TCP_ESTABLISHED)
> +			err = -EISCONN;
> +		else
> +			err = pep_sock_enable(sk, NULL, 0);
> +		break;

For the umpteenth time, this does not obey set/get conventions.

> +
> +	case PNPIPE_INITSTATE:
> +		if ((val == 0) || (val == 1))
> +			pn->init_enable = val;
> +		else
> +			err = -EINVAL;

I think kernel style is more akin to:

pn->init_enable = !!val;