dccp.h

linux 内核源代码

static inline struct dccp_hdr_ext *dccp_hdrx(const struct dccp_hdr *dh)
{
	return (struct dccp_hdr_ext *)((unsigned char *)dh + sizeof(*dh));
}

static inline unsigned int __dccp_basic_hdr_len(const struct dccp_hdr *dh)
{
	return sizeof(*dh) + (dh->dccph_x ? sizeof(struct dccp_hdr_ext) : 0);
}

static inline unsigned int dccp_basic_hdr_len(const struct sk_buff *skb)
{
	const struct dccp_hdr *dh = dccp_hdr(skb);
	return __dccp_basic_hdr_len(dh);
}

static inline __u64 dccp_hdr_seq(const struct dccp_hdr *dh)
{
	__u64 seq_nr =  ntohs(dh->dccph_seq);

	if (dh->dccph_x != 0)
		seq_nr = (seq_nr << 32) + ntohl(dccp_hdrx(dh)->dccph_seq_low);
	else
		seq_nr += (u32)dh->dccph_seq2 << 16;

	return seq_nr;
}

static inline struct dccp_hdr_request *dccp_hdr_request(struct sk_buff *skb)
{
	return (struct dccp_hdr_request *)(skb_transport_header(skb) +
					   dccp_basic_hdr_len(skb));
}

static inline struct dccp_hdr_ack_bits *dccp_hdr_ack_bits(const struct sk_buff *skb)
{
	return (struct dccp_hdr_ack_bits *)(skb_transport_header(skb) +
					    dccp_basic_hdr_len(skb));
}

static inline u64 dccp_hdr_ack_seq(const struct sk_buff *skb)
{
	const struct dccp_hdr_ack_bits *dhack = dccp_hdr_ack_bits(skb);
	return ((u64)ntohs(dhack->dccph_ack_nr_high) << 32) + ntohl(dhack->dccph_ack_nr_low);
}

static inline struct dccp_hdr_response *dccp_hdr_response(struct sk_buff *skb)
{
	return (struct dccp_hdr_response *)(skb_transport_header(skb) +
					    dccp_basic_hdr_len(skb));
}

static inline struct dccp_hdr_reset *dccp_hdr_reset(struct sk_buff *skb)
{
	return (struct dccp_hdr_reset *)(skb_transport_header(skb) +
					 dccp_basic_hdr_len(skb));
}

static inline unsigned int __dccp_hdr_len(const struct dccp_hdr *dh)
{
	return __dccp_basic_hdr_len(dh) +
	       dccp_packet_hdr_len(dh->dccph_type);
}

static inline unsigned int dccp_hdr_len(const struct sk_buff *skb)
{
	return __dccp_hdr_len(dccp_hdr(skb));
}


/* initial values for each feature */
#define DCCPF_INITIAL_SEQUENCE_WINDOW		100
#define DCCPF_INITIAL_ACK_RATIO			2
#define DCCPF_INITIAL_CCID			DCCPC_CCID2
#define DCCPF_INITIAL_SEND_ACK_VECTOR		1
/* FIXME: for now we're default to 1 but it should really be 0 */
#define DCCPF_INITIAL_SEND_NDP_COUNT		1

#define DCCP_NDP_LIMIT 0xFFFFFF

/**
  * struct dccp_minisock - Minimal DCCP connection representation
  *
  * Will be used to pass the state from dccp_request_sock to dccp_sock.
  *
  * @dccpms_sequence_window - Sequence Window Feature (section 7.5.2)
  * @dccpms_ccid - Congestion Control Id (CCID) (section 10)
  * @dccpms_send_ack_vector - Send Ack Vector Feature (section 11.5)
  * @dccpms_send_ndp_count - Send NDP Count Feature (7.7.2)
  * @dccpms_ack_ratio - Ack Ratio Feature (section 11.3)
  * @dccpms_pending - List of features being negotiated
  * @dccpms_conf -
  */
struct dccp_minisock {
	__u64			dccpms_sequence_window;
	__u8			dccpms_rx_ccid;
	__u8			dccpms_tx_ccid;
	__u8			dccpms_send_ack_vector;
	__u8			dccpms_send_ndp_count;
	__u8			dccpms_ack_ratio;
	struct list_head	dccpms_pending;
	struct list_head	dccpms_conf;
};

struct dccp_opt_conf {
	__u8			*dccpoc_val;
	__u8			dccpoc_len;
};

struct dccp_opt_pend {
	struct list_head	dccpop_node;
	__u8			dccpop_type;
	__u8			dccpop_feat;
	__u8		        *dccpop_val;
	__u8			dccpop_len;
	int			dccpop_conf;
	struct dccp_opt_conf    *dccpop_sc;
};

extern void dccp_minisock_init(struct dccp_minisock *dmsk);

extern int dccp_parse_options(struct sock *sk, struct sk_buff *skb);

struct dccp_request_sock {
	struct inet_request_sock dreq_inet_rsk;
	__u64			 dreq_iss;
	__u64			 dreq_isr;
	__be32			 dreq_service;
};

static inline struct dccp_request_sock *dccp_rsk(const struct request_sock *req)
{
	return (struct dccp_request_sock *)req;
}

extern struct inet_timewait_death_row dccp_death_row;

struct dccp_options_received {
	u32	dccpor_ndp; /* only 24 bits */
	u32	dccpor_timestamp;
	u32	dccpor_timestamp_echo;
	u32	dccpor_elapsed_time;
};

struct ccid;

enum dccp_role {
	DCCP_ROLE_UNDEFINED,
	DCCP_ROLE_LISTEN,
	DCCP_ROLE_CLIENT,
	DCCP_ROLE_SERVER,
};

struct dccp_service_list {
	__u32	dccpsl_nr;
	__be32	dccpsl_list[0];
};

#define DCCP_SERVICE_INVALID_VALUE htonl((__u32)-1)
#define DCCP_SERVICE_CODE_IS_ABSENT		0

static inline int dccp_list_has_service(const struct dccp_service_list *sl,
					const __be32 service)
{
	if (likely(sl != NULL)) {
		u32 i = sl->dccpsl_nr;
		while (i--)
			if (sl->dccpsl_list[i] == service)
				return 1;
	}
	return 0;
}

struct dccp_ackvec;

/**
 * struct dccp_sock - DCCP socket state
 *
 * @dccps_swl - sequence number window low
 * @dccps_swh - sequence number window high
 * @dccps_awl - acknowledgement number window low
 * @dccps_awh - acknowledgement number window high
 * @dccps_iss - initial sequence number sent
 * @dccps_isr - initial sequence number received
 * @dccps_osr - first OPEN sequence number received
 * @dccps_gss - greatest sequence number sent
 * @dccps_gsr - greatest valid sequence number received
 * @dccps_gar - greatest valid ack number received on a non-Sync; initialized to %dccps_iss
 * @dccps_service - first (passive sock) or unique (active sock) service code
 * @dccps_service_list - second .. last service code on passive socket
 * @dccps_timestamp_time - time of latest TIMESTAMP option
 * @dccps_timestamp_echo - latest timestamp received on a TIMESTAMP option
 * @dccps_l_ack_ratio - feature-local Ack Ratio
 * @dccps_r_ack_ratio - feature-remote Ack Ratio
 * @dccps_pcslen - sender   partial checksum coverage (via sockopt)
 * @dccps_pcrlen - receiver partial checksum coverage (via sockopt)
 * @dccps_ndp_count - number of Non Data Packets since last data packet
 * @dccps_mss_cache - current value of MSS (path MTU minus header sizes)
 * @dccps_rate_last - timestamp for rate-limiting DCCP-Sync (RFC 4340, 7.5.4)
 * @dccps_minisock - associated minisock (accessed via dccp_msk)
 * @dccps_hc_rx_ackvec - rx half connection ack vector
 * @dccps_hc_rx_ccid - CCID used for the receiver (or receiving half-connection)
 * @dccps_hc_tx_ccid - CCID used for the sender (or sending half-connection)
 * @dccps_options_received - parsed set of retrieved options
 * @dccps_role - role of this sock, one of %dccp_role
 * @dccps_hc_rx_insert_options - receiver wants to add options when acking
 * @dccps_hc_tx_insert_options - sender wants to add options when sending
 * @dccps_xmit_timer - timer for when CCID is not ready to send
 * @dccps_syn_rtt - RTT sample from Request/Response exchange (in usecs)
 */
struct dccp_sock {
	/* inet_connection_sock has to be the first member of dccp_sock */
	struct inet_connection_sock	dccps_inet_connection;
#define dccps_syn_rtt			dccps_inet_connection.icsk_ack.lrcvtime
	__u64				dccps_swl;
	__u64				dccps_swh;
	__u64				dccps_awl;
	__u64				dccps_awh;
	__u64				dccps_iss;
	__u64				dccps_isr;
	__u64				dccps_osr;
	__u64				dccps_gss;
	__u64				dccps_gsr;
	__u64				dccps_gar;
	__be32				dccps_service;
	struct dccp_service_list	*dccps_service_list;
	ktime_t				dccps_timestamp_time;
	__u32				dccps_timestamp_echo;
	__u16				dccps_l_ack_ratio;
	__u16				dccps_r_ack_ratio;
	__u16				dccps_pcslen;
	__u16				dccps_pcrlen;
	unsigned long			dccps_ndp_count;
	__u32				dccps_mss_cache;
	unsigned long			dccps_rate_last;
	struct dccp_minisock		dccps_minisock;
	struct dccp_ackvec		*dccps_hc_rx_ackvec;
	struct ccid			*dccps_hc_rx_ccid;
	struct ccid			*dccps_hc_tx_ccid;
	struct dccp_options_received	dccps_options_received;
	enum dccp_role			dccps_role:2;
	__u8				dccps_hc_rx_insert_options:1;
	__u8				dccps_hc_tx_insert_options:1;
	struct timer_list		dccps_xmit_timer;
};

static inline struct dccp_sock *dccp_sk(const struct sock *sk)
{
	return (struct dccp_sock *)sk;
}

static inline struct dccp_minisock *dccp_msk(const struct sock *sk)
{
	return (struct dccp_minisock *)&dccp_sk(sk)->dccps_minisock;
}

static inline const char *dccp_role(const struct sock *sk)
{
	switch (dccp_sk(sk)->dccps_role) {
	case DCCP_ROLE_UNDEFINED: return "undefined";
	case DCCP_ROLE_LISTEN:	  return "listen";
	case DCCP_ROLE_SERVER:	  return "server";
	case DCCP_ROLE_CLIENT:	  return "client";
	}
	return NULL;
}

#endif /* __KERNEL__ */

#endif /* _LINUX_DCCP_H */