dccp.h

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#ifndef _LINUX_DCCP_H
#define _LINUX_DCCP_H


#include <linux/in.h>
#include <linux/interrupt.h>
#include <linux/ktime.h>
#include <linux/list.h>
#include <linux/uio.h>
#include <linux/workqueue.h>

#include <net/inet_connection_sock.h>
#include <net/inet_sock.h>
#include <net/inet_timewait_sock.h>
#include <net/tcp_states.h>
#include <uapi/linux/dccp.h>

enum dccp_state {
    DCCP_OPEN        = TCP_ESTABLISHED,
    DCCP_REQUESTING      = TCP_SYN_SENT,
    DCCP_LISTEN      = TCP_LISTEN,
    DCCP_RESPOND         = TCP_SYN_RECV,
    /*
     * States involved in closing a DCCP connection:
     * 1) ACTIVE_CLOSEREQ is entered by a server sending a CloseReq.
     *
     * 2) CLOSING can have three different meanings (RFC 4340, 8.3):
     *  a. Client has performed active-close, has sent a Close to the server
     *     from state OPEN or PARTOPEN, and is waiting for the final Reset
     *     (in this case, SOCK_DONE == 1).
     *  b. Client is asked to perform passive-close, by receiving a CloseReq
     *     in (PART)OPEN state. It sends a Close and waits for final Reset
     *     (in this case, SOCK_DONE == 0).
     *  c. Server performs an active-close as in (a), keeps TIMEWAIT state.
     *
     * 3) The following intermediate states are employed to give passively
     *    closing nodes a chance to process their unread data:
     *    - PASSIVE_CLOSE    (from OPEN => CLOSED) and
     *    - PASSIVE_CLOSEREQ (from (PART)OPEN to CLOSING; case (b) above).
     */
    DCCP_ACTIVE_CLOSEREQ = TCP_FIN_WAIT1,
    DCCP_PASSIVE_CLOSE   = TCP_CLOSE_WAIT,  /* any node receiving a Close */
    DCCP_CLOSING         = TCP_CLOSING,
    DCCP_TIME_WAIT       = TCP_TIME_WAIT,
    DCCP_CLOSED      = TCP_CLOSE,
    DCCP_PARTOPEN        = TCP_MAX_STATES,
    DCCP_PASSIVE_CLOSEREQ,          /* clients receiving CloseReq */
    DCCP_MAX_STATES
};

enum {
    DCCPF_OPEN        = TCPF_ESTABLISHED,
    DCCPF_REQUESTING      = TCPF_SYN_SENT,
    DCCPF_LISTEN          = TCPF_LISTEN,
    DCCPF_RESPOND         = TCPF_SYN_RECV,
    DCCPF_ACTIVE_CLOSEREQ = TCPF_FIN_WAIT1,
    DCCPF_CLOSING         = TCPF_CLOSING,
    DCCPF_TIME_WAIT       = TCPF_TIME_WAIT,
    DCCPF_CLOSED          = TCPF_CLOSE,
    DCCPF_PARTOPEN        = (1 << DCCP_PARTOPEN),
};

static inline struct dccp_hdr *dccp_hdr(const struct sk_buff *skb)
{
    return (struct dccp_hdr *)skb_transport_header(skb);
}

static inline struct dccp_hdr *dccp_zeroed_hdr(struct sk_buff *skb, int headlen)
{
    skb_push(skb, headlen);
    skb_reset_transport_header(skb);
    return memset(skb_transport_header(skb), 0, headlen);
}

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));
}

struct dccp_request_sock {
    struct inet_request_sock dreq_inet_rsk;
    __u64            dreq_iss;
    __u64            dreq_gss;
    __u64            dreq_isr;
    __u64            dreq_gsr;
    __be32           dreq_service;
    struct list_head     dreq_featneg;
    __u32            dreq_timestamp_echo;
    __u32            dreq_timestamp_time;
};

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;

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

struct dccp_options_received {
    u64 dccpor_ndp:48;
    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 {
    /* 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;
    __u32               dccps_mss_cache;
    struct dccp_service_list    *dccps_service_list;
    __u32               dccps_timestamp_echo;
    __u32               dccps_timestamp_time;
    __u16               dccps_l_ack_ratio;
    __u16               dccps_r_ack_ratio;
    __u64               dccps_l_seq_win:48;
    __u64               dccps_r_seq_win:48;
    __u8                dccps_pcslen:4;
    __u8                dccps_pcrlen:4;
    __u8                dccps_send_ndp_count:1;
    __u64               dccps_ndp_count:48;
    unsigned long           dccps_rate_last;
    struct list_head        dccps_featneg;
    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;
    __u8                dccps_qpolicy;
    __u32               dccps_tx_qlen;
    enum dccp_role          dccps_role:2;
    __u8                dccps_hc_rx_insert_options:1;
    __u8                dccps_hc_tx_insert_options:1;
    __u8                dccps_server_timewait:1;
    __u8                dccps_sync_scheduled:1;
    struct tasklet_struct       dccps_xmitlet;
    struct timer_list       dccps_xmit_timer;
};

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

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;
}

extern void dccp_syn_ack_timeout(struct sock *sk, struct request_sock *req);

#endif /* _LINUX_DCCP_H */