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Commit ee1a1592 authored by Gerrit Renker's avatar Gerrit Renker Committed by David S. Miller
Browse files

[DCCP]: Remove duplicate code for Reset from connected socket 



In this patch, duplicated code is removed for the case when a Reset packet is
sent from a connected socket. This code duplication is between dccp_make_reset
and dccp_transmit_skb, which already contained an (up to now entirely unused)
switch statement to fill in the reset code from the DCCP_SKB_CB.

The only thing that has been removed is the call to dst_clone(dst), since
the queue_xmit functions use sk_dst_cache anyway.

I wasn't sure which purpose inet_sk_rebuild_header served, so I left it in.

Signed-off-by: default avatarGerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@ghostprotocols.net>
parent 0430ee34

net/dccp/output.c

+19 −59
Original line number Diff line number Diff line
@@ -61,6 +61,7 @@ static int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb) 
			set_ack = 0;

			/* fall through */

		case DCCP_PKT_DATAACK:

		case DCCP_PKT_RESET:

			break;



		case DCCP_PKT_REQUEST:
@@ -73,8 +74,10 @@ static int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb) 
			/* fall through */

		default:

			/*

			 * Only data packets should come through with skb->sk

			 * set.

			 * Set owner/destructor: some skbs are allocated via

			 * alloc_skb (e.g. when retransmission may happen).

			 * Only Data, DataAck, and Reset packets should come

			 * through here with skb->sk set.

			 */

			WARN_ON(skb->sk);

			skb_set_owner_w(skb, sk);
@@ -324,72 +327,29 @@ struct sk_buff *dccp_make_response(struct sock *sk, struct dst_entry *dst, 


EXPORT_SYMBOL_GPL(dccp_make_response);



static struct sk_buff *dccp_make_reset(struct sock *sk, struct dst_entry *dst,

				       const enum dccp_reset_codes code)

{

	struct dccp_hdr *dh;

	struct dccp_sock *dp = dccp_sk(sk);

	const u32 dccp_header_size = sizeof(struct dccp_hdr) +

				     sizeof(struct dccp_hdr_ext) +

				     sizeof(struct dccp_hdr_reset);

	struct sk_buff *skb = sock_wmalloc(sk, sk->sk_prot->max_header, 1,

					   GFP_ATOMIC);

	if (skb == NULL)

		return NULL;



	/* Reserve space for headers. */

	skb_reserve(skb, sk->sk_prot->max_header);



	skb->dst = dst_clone(dst);



	dccp_inc_seqno(&dp->dccps_gss);



	DCCP_SKB_CB(skb)->dccpd_reset_code = code;

	DCCP_SKB_CB(skb)->dccpd_type	   = DCCP_PKT_RESET;

	DCCP_SKB_CB(skb)->dccpd_seq	   = dp->dccps_gss;



	if (dccp_insert_options(sk, skb)) {

		kfree_skb(skb);

		return NULL;

	}



	dh = dccp_zeroed_hdr(skb, dccp_header_size);



	dh->dccph_sport	= inet_sk(sk)->sport;

	dh->dccph_dport	= inet_sk(sk)->dport;

	dh->dccph_doff	= (dccp_header_size +

			   DCCP_SKB_CB(skb)->dccpd_opt_len) / 4;

	dh->dccph_type	= DCCP_PKT_RESET;

	dh->dccph_x	= 1;

	dccp_hdr_set_seq(dh, dp->dccps_gss);

	dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dp->dccps_gsr);



	dccp_hdr_reset(skb)->dccph_reset_code = code;

	inet_csk(sk)->icsk_af_ops->send_check(sk, 0, skb);



	DCCP_INC_STATS(DCCP_MIB_OUTSEGS);

	return skb;

}



/* send Reset on established socket, to close or abort the connection */

int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code)

{

	struct sk_buff *skb;

	/*

	 * FIXME: what if rebuild_header fails?

	 * Should we be doing a rebuild_header here?

	 */

	int err = inet_sk_rebuild_header(sk);



	if (err == 0) {

		struct sk_buff *skb = dccp_make_reset(sk, sk->sk_dst_cache,

						      code);

		if (skb != NULL) {

			memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));

			err = inet_csk(sk)->icsk_af_ops->queue_xmit(skb, 0);

			return net_xmit_eval(err);

		}

	}



	if (err != 0)

		return err;



	skb = sock_wmalloc(sk, sk->sk_prot->max_header, 1, GFP_ATOMIC);

	if (skb == NULL)

		return -ENOBUFS;



	/* Reserve space for headers and prepare control bits. */

	skb_reserve(skb, sk->sk_prot->max_header);

	DCCP_SKB_CB(skb)->dccpd_type	   = DCCP_PKT_RESET;

	DCCP_SKB_CB(skb)->dccpd_reset_code = code;



	return dccp_transmit_skb(sk, skb);

}



/*