Commit bdf13d20 authored by Andrea Bittau's avatar Andrea Bittau Committed by David S. Miller
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[DCCP] ackvec: infrastructure for sending more than one ackvec per packet 



Commiter note:

This was split from Andrea's original patch, in the process I changed the type
of the ackvec index fields to u16 instead of to int and haven't folded
dccp_ackvec_parse with dccp_ackvec_check_rcv_ackno.

Next patch will actually do the insertion of more than one ackvec per packet,
using, initially, up to a max of 2 ackvecs as per Andrea's original patch, then
I'll work on support for larger ackvecs, be it using a sysctl or using
setsockopt.

Signed-off-by: default avatarAndrea Bittau <a.bittau@cs.ucl.ac.uk>
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@mandriva.com>
parent 0bd4ff1b

net/dccp/ackvec.c

+11 −12
Original line number Diff line number Diff line
@@ -169,13 +169,13 @@ void dccp_ackvec_free(struct dccp_ackvec *av) 
}



static inline u8 dccp_ackvec_state(const struct dccp_ackvec *av,

				   const u8 index)

				   const u32 index)

{

	return av->dccpav_buf[index] & DCCP_ACKVEC_STATE_MASK;

}



static inline u8 dccp_ackvec_len(const struct dccp_ackvec *av,

				 const u8 index)

				 const u32 index)

{

	return av->dccpav_buf[index] & DCCP_ACKVEC_LEN_MASK;

}
@@ -275,7 +275,7 @@ int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk, 
		 *	could reduce the complexity of this scan.)

		 */

		u64 delta = dccp_delta_seqno(ackno, av->dccpav_buf_ackno);

		u8 index = av->dccpav_buf_head;

		u32 index = av->dccpav_buf_head;



		while (1) {

			const u8 len = dccp_ackvec_len(av, index);
@@ -385,7 +385,7 @@ void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av, struct sock *sk, 
}



static void dccp_ackvec_check_rcv_ackvector(struct dccp_ackvec *av,

					    struct sock *sk, u64 ackno,

					    struct sock *sk, u64 *ackno,

					    const unsigned char len,

					    const unsigned char *vector)

{
@@ -408,7 +408,7 @@ static void dccp_ackvec_check_rcv_ackvector(struct dccp_ackvec *av, 
		const u8 rl = *vector & DCCP_ACKVEC_LEN_MASK;

		u64 ackno_end_rl;



		dccp_set_seqno(&ackno_end_rl, ackno - rl);

		dccp_set_seqno(&ackno_end_rl, *ackno - rl);



		/*

		 * If our AVR sequence number is greater than the ack, go
@@ -416,13 +416,13 @@ static void dccp_ackvec_check_rcv_ackvector(struct dccp_ackvec *av, 
		 */

		list_for_each_entry_from(avr, &av->dccpav_records,

					 dccpavr_node) {

			if (!after48(avr->dccpavr_ack_seqno, ackno))

			if (!after48(avr->dccpavr_ack_seqno, *ackno))

				goto found;

		}

		/* End of the dccpav_records list, not found, exit */

		break;

found:

		if (between48(avr->dccpavr_ack_seqno, ackno_end_rl, ackno)) {

		if (between48(avr->dccpavr_ack_seqno, ackno_end_rl, *ackno)) {

			const u8 state = *vector & DCCP_ACKVEC_STATE_MASK;

			if (state != DCCP_ACKVEC_STATE_NOT_RECEIVED) {

				dccp_pr_debug("%s ACK vector 0, len=%d, "
@@ -442,21 +442,20 @@ found: 
			 */

		}



		dccp_set_seqno(&ackno, ackno_end_rl - 1);

		dccp_set_seqno(ackno, ackno_end_rl - 1);

		++vector;

	}

}



int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb,

		      const u8 opt, const u8 *value, const u8 len)

		      u64 *ackno, const u8 opt, const u8 *value, const u8 len)

{

	if (len > DCCP_MAX_ACKVEC_LEN)

	if (len > DCCP_MAX_ACKVEC_OPT_LEN)

		return -1;



	/* dccp_ackvector_print(DCCP_SKB_CB(skb)->dccpd_ack_seq, value, len); */

	dccp_ackvec_check_rcv_ackvector(dccp_sk(sk)->dccps_hc_rx_ackvec, sk,

					DCCP_SKB_CB(skb)->dccpd_ack_seq,

				        len, value);

					ackno, len, value);

	return 0;

}

net/dccp/ackvec.h

+11 −7
Original line number Diff line number Diff line
@@ -17,7 +17,9 @@ 
#include <linux/types.h>



/* Read about the ECN nonce to see why it is 253 */

#define DCCP_MAX_ACKVEC_LEN 253

#define DCCP_MAX_ACKVEC_OPT_LEN 253

/* We can spread an ack vector across multiple options */

#define DCCP_MAX_ACKVEC_LEN (DCCP_MAX_ACKVEC_OPT_LEN * 2)



#define DCCP_ACKVEC_STATE_RECEIVED	0

#define DCCP_ACKVEC_STATE_ECN_MARKED	(1 << 6)
@@ -51,8 +53,8 @@ struct dccp_ackvec { 
	u64		dccpav_buf_ackno;

	struct list_head dccpav_records;

	struct timeval	dccpav_time;

	u8		dccpav_buf_head;

	u8		dccpav_vec_len;

	u16		dccpav_buf_head;

	u16		dccpav_vec_len;

	u8		dccpav_buf_nonce;

	u8		dccpav_ack_nonce;

	u8		dccpav_buf[DCCP_MAX_ACKVEC_LEN];
@@ -75,9 +77,9 @@ struct dccp_ackvec_record { 
	struct list_head dccpavr_node;

	u64		 dccpavr_ack_seqno;

	u64		 dccpavr_ack_ackno;

	u8		 dccpavr_ack_ptr;

	u16		 dccpavr_ack_ptr;

	u16		 dccpavr_sent_len;

	u8		 dccpavr_ack_nonce;

	u8		 dccpavr_sent_len;

};



struct sock;
@@ -96,7 +98,8 @@ extern int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk, 
extern void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av,

					struct sock *sk, const u64 ackno);

extern int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb,

			     const u8 opt, const u8 *value, const u8 len);

			     u64 *ackno, const u8 opt,

			     const u8 *value, const u8 len);



extern int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb);
@@ -135,7 +138,8 @@ static inline void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av, 
}



static inline int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb,

				    const u8 opt, const u8 *value, const u8 len)

				    const u64 *ackno, const u8 opt,

				    const u8 *value, const u8 len)

{

	return -1;

}

net/dccp/options.c

+2 −1
Original line number Diff line number Diff line
@@ -62,6 +62,7 @@ int dccp_parse_options(struct sock *sk, struct sk_buff *skb) 
	struct dccp_sock *dp = dccp_sk(sk);

	const struct dccp_hdr *dh = dccp_hdr(skb);

	const u8 pkt_type = DCCP_SKB_CB(skb)->dccpd_type;

	u64 ackno = DCCP_SKB_CB(skb)->dccpd_ack_seq;

	unsigned char *options = (unsigned char *)dh + dccp_hdr_len(skb);

	unsigned char *opt_ptr = options;

	const unsigned char *opt_end = (unsigned char *)dh +
@@ -149,7 +150,7 @@ int dccp_parse_options(struct sock *sk, struct sk_buff *skb) 
				break;



			if (dccp_msk(sk)->dccpms_send_ack_vector &&

			    dccp_ackvec_parse(sk, skb, opt, value, len))

			    dccp_ackvec_parse(sk, skb, &ackno, opt, value, len))

				goto out_invalid_option;

			break;

		case DCCPO_TIMESTAMP:

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