ar-internal.h

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/* AF_RXRPC internal definitions
 *
 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells ([email protected])
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#include <rxrpc/packet.h>

#if 0
#define CHECK_SLAB_OKAY(X)                   \
    BUG_ON(atomic_read((X)) >> (sizeof(atomic_t) - 2) == \
           (POISON_FREE << 8 | POISON_FREE))
#else
#define CHECK_SLAB_OKAY(X) do {} while(0)
#endif

#define FCRYPT_BSIZE 8
struct rxrpc_crypt {
    union {
        u8  x[FCRYPT_BSIZE];
        __be32  n[2];
    };
} __attribute__((aligned(8)));

#define rxrpc_queue_work(WS)    queue_work(rxrpc_workqueue, (WS))
#define rxrpc_queue_delayed_work(WS,D)  \
    queue_delayed_work(rxrpc_workqueue, (WS), (D))

#define rxrpc_queue_call(CALL)  rxrpc_queue_work(&(CALL)->processor)
#define rxrpc_queue_conn(CONN)  rxrpc_queue_work(&(CONN)->processor)

/*
 * sk_state for RxRPC sockets
 */
enum {
    RXRPC_UNCONNECTED = 0,
    RXRPC_CLIENT_BOUND,     /* client local address bound */
    RXRPC_CLIENT_CONNECTED,     /* client is connected */
    RXRPC_SERVER_BOUND,     /* server local address bound */
    RXRPC_SERVER_LISTENING,     /* server listening for connections */
    RXRPC_CLOSE,            /* socket is being closed */
};

/*
 * RxRPC socket definition
 */
struct rxrpc_sock {
    /* WARNING: sk has to be the first member */
    struct sock     sk;
    rxrpc_interceptor_t interceptor;    /* kernel service Rx interceptor function */
    struct rxrpc_local  *local;     /* local endpoint */
    struct rxrpc_transport  *trans;     /* transport handler */
    struct rxrpc_conn_bundle *bundle;   /* virtual connection bundle */
    struct rxrpc_connection *conn;      /* exclusive virtual connection */
    struct list_head    listen_link;    /* link in the local endpoint's listen list */
    struct list_head    secureq;    /* calls awaiting connection security clearance */
    struct list_head    acceptq;    /* calls awaiting acceptance */
    struct key      *key;       /* security for this socket */
    struct key      *securities;    /* list of server security descriptors */
    struct rb_root      calls;      /* outstanding calls on this socket */
    unsigned long       flags;
#define RXRPC_SOCK_EXCLUSIVE_CONN   1   /* exclusive connection for a client socket */
    rwlock_t        call_lock;  /* lock for calls */
    u32         min_sec_level;  /* minimum security level */
#define RXRPC_SECURITY_MAX  RXRPC_SECURITY_ENCRYPT
    struct sockaddr_rxrpc   srx;        /* local address */
    sa_family_t     proto;      /* protocol created with */
    __be16          service_id; /* service ID of local/remote service */
};

#define rxrpc_sk(__sk) container_of((__sk), struct rxrpc_sock, sk)

/*
 * RxRPC socket buffer private variables
 * - max 48 bytes (struct sk_buff::cb)
 */
struct rxrpc_skb_priv {
    struct rxrpc_call   *call;      /* call with which associated */
    unsigned long       resend_at;  /* time in jiffies at which to resend */
    union {
        unsigned int    offset;     /* offset into buffer of next read */
        int     remain;     /* amount of space remaining for next write */
        u32     error;      /* network error code */
        bool        need_resend;    /* T if needs resending */
    };

    struct rxrpc_header hdr;        /* RxRPC packet header from this packet */
};

#define rxrpc_skb(__skb) ((struct rxrpc_skb_priv *) &(__skb)->cb)

enum rxrpc_command {
    RXRPC_CMD_SEND_DATA,        /* send data message */
    RXRPC_CMD_SEND_ABORT,       /* request abort generation */
    RXRPC_CMD_ACCEPT,       /* [server] accept incoming call */
    RXRPC_CMD_REJECT_BUSY,      /* [server] reject a call as busy */
};

/*
 * RxRPC security module interface
 */
struct rxrpc_security {
    struct module       *owner;     /* providing module */
    struct list_head    link;       /* link in master list */
    const char      *name;      /* name of this service */
    u8          security_index; /* security type provided */

    /* initialise a connection's security */
    int (*init_connection_security)(struct rxrpc_connection *);

    /* prime a connection's packet security */
    void (*prime_packet_security)(struct rxrpc_connection *);

    /* impose security on a packet */
    int (*secure_packet)(const struct rxrpc_call *,
                 struct sk_buff *,
                 size_t,
                 void *);

    /* verify the security on a received packet */
    int (*verify_packet)(const struct rxrpc_call *, struct sk_buff *,
                 u32 *);

    /* issue a challenge */
    int (*issue_challenge)(struct rxrpc_connection *);

    /* respond to a challenge */
    int (*respond_to_challenge)(struct rxrpc_connection *,
                    struct sk_buff *,
                    u32 *);

    /* verify a response */
    int (*verify_response)(struct rxrpc_connection *,
                   struct sk_buff *,
                   u32 *);

    /* clear connection security */
    void (*clear)(struct rxrpc_connection *);
};

/*
 * RxRPC local transport endpoint definition
 * - matched by local port, address and protocol type
 */
struct rxrpc_local {
    struct socket       *socket;    /* my UDP socket */
    struct work_struct  destroyer;  /* endpoint destroyer */
    struct work_struct  acceptor;   /* incoming call processor */
    struct work_struct  rejecter;   /* packet reject writer */
    struct list_head    services;   /* services listening on this endpoint */
    struct list_head    link;       /* link in endpoint list */
    struct rw_semaphore defrag_sem; /* control re-enablement of IP DF bit */
    struct sk_buff_head accept_queue;   /* incoming calls awaiting acceptance */
    struct sk_buff_head reject_queue;   /* packets awaiting rejection */
    spinlock_t      lock;       /* access lock */
    rwlock_t        services_lock;  /* lock for services list */
    atomic_t        usage;
    int         debug_id;   /* debug ID for printks */
    volatile char       error_rcvd; /* T if received ICMP error outstanding */
    struct sockaddr_rxrpc   srx;        /* local address */
};

/*
 * RxRPC remote transport endpoint definition
 * - matched by remote port, address and protocol type
 * - holds the connection ID counter for connections between the two endpoints
 */
struct rxrpc_peer {
    struct work_struct  destroyer;  /* peer destroyer */
    struct list_head    link;       /* link in master peer list */
    struct list_head    error_targets;  /* targets for net error distribution */
    spinlock_t      lock;       /* access lock */
    atomic_t        usage;
    unsigned int        if_mtu;     /* interface MTU for this peer */
    unsigned int        mtu;        /* network MTU for this peer */
    unsigned int        maxdata;    /* data size (MTU - hdrsize) */
    unsigned short      hdrsize;    /* header size (IP + UDP + RxRPC) */
    int         debug_id;   /* debug ID for printks */
    int         net_error;  /* network error distributed */
    struct sockaddr_rxrpc   srx;        /* remote address */

    /* calculated RTT cache */
#define RXRPC_RTT_CACHE_SIZE 32
    suseconds_t     rtt;        /* current RTT estimate (in uS) */
    unsigned int        rtt_point;  /* next entry at which to insert */
    unsigned int        rtt_usage;  /* amount of cache actually used */
    suseconds_t     rtt_cache[RXRPC_RTT_CACHE_SIZE]; /* calculated RTT cache */
};

/*
 * RxRPC point-to-point transport / connection manager definition
 * - handles a bundle of connections between two endpoints
 * - matched by { local, peer }
 */
struct rxrpc_transport {
    struct rxrpc_local  *local;     /* local transport endpoint */
    struct rxrpc_peer   *peer;      /* remote transport endpoint */
    struct work_struct  error_handler;  /* network error distributor */
    struct rb_root      bundles;    /* client connection bundles on this transport */
    struct rb_root      client_conns;   /* client connections on this transport */
    struct rb_root      server_conns;   /* server connections on this transport */
    struct list_head    link;       /* link in master session list */
    struct sk_buff_head error_queue;    /* error packets awaiting processing */
    time_t          put_time;   /* time at which to reap */
    spinlock_t      client_lock;    /* client connection allocation lock */
    rwlock_t        conn_lock;  /* lock for active/dead connections */
    atomic_t        usage;
    int         debug_id;   /* debug ID for printks */
    unsigned int        conn_idcounter; /* connection ID counter (client) */
};

/*
 * RxRPC client connection bundle
 * - matched by { transport, service_id, key }
 */
struct rxrpc_conn_bundle {
    struct rb_node      node;       /* node in transport's lookup tree */
    struct list_head    unused_conns;   /* unused connections in this bundle */
    struct list_head    avail_conns;    /* available connections in this bundle */
    struct list_head    busy_conns; /* busy connections in this bundle */
    struct key      *key;       /* security for this bundle */
    wait_queue_head_t   chanwait;   /* wait for channel to become available */
    atomic_t        usage;
    int         debug_id;   /* debug ID for printks */
    unsigned short      num_conns;  /* number of connections in this bundle */
    __be16          service_id; /* service ID */
    u8          security_ix;    /* security type */
};

/*
 * RxRPC connection definition
 * - matched by { transport, service_id, conn_id, direction, key }
 * - each connection can only handle four simultaneous calls
 */
struct rxrpc_connection {
    struct rxrpc_transport  *trans;     /* transport session */
    struct rxrpc_conn_bundle *bundle;   /* connection bundle (client) */
    struct work_struct  processor;  /* connection event processor */
    struct rb_node      node;       /* node in transport's lookup tree */
    struct list_head    link;       /* link in master connection list */
    struct list_head    bundle_link;    /* link in bundle */
    struct rb_root      calls;      /* calls on this connection */
    struct sk_buff_head rx_queue;   /* received conn-level packets */
    struct rxrpc_call   *channels[RXRPC_MAXCALLS]; /* channels (active calls) */
    struct rxrpc_security   *security;  /* applied security module */
    struct key      *key;       /* security for this connection (client) */
    struct key      *server_key;    /* security for this service */
    struct crypto_blkcipher *cipher;    /* encryption handle */
    struct rxrpc_crypt  csum_iv;    /* packet checksum base */
    unsigned long       events;
#define RXRPC_CONN_CHALLENGE    0       /* send challenge packet */
    time_t          put_time;   /* time at which to reap */
    rwlock_t        lock;       /* access lock */
    spinlock_t      state_lock; /* state-change lock */
    atomic_t        usage;
    u32         real_conn_id;   /* connection ID (host-endian) */
    enum {                  /* current state of connection */
        RXRPC_CONN_UNUSED,      /* - connection not yet attempted */
        RXRPC_CONN_CLIENT,      /* - client connection */
        RXRPC_CONN_SERVER_UNSECURED,    /* - server unsecured connection */
        RXRPC_CONN_SERVER_CHALLENGING,  /* - server challenging for security */
        RXRPC_CONN_SERVER,      /* - server secured connection */
        RXRPC_CONN_REMOTELY_ABORTED,    /* - conn aborted by peer */
        RXRPC_CONN_LOCALLY_ABORTED, /* - conn aborted locally */
        RXRPC_CONN_NETWORK_ERROR,   /* - conn terminated by network error */
    } state;
    int         error;      /* error code for local abort */
    int         debug_id;   /* debug ID for printks */
    unsigned int        call_counter;   /* call ID counter */
    atomic_t        serial;     /* packet serial number counter */
    atomic_t        hi_serial;  /* highest serial number received */
    u8          avail_calls;    /* number of calls available */
    u8          size_align; /* data size alignment (for security) */
    u8          header_size;    /* rxrpc + security header size */
    u8          security_size;  /* security header size */
    u32         security_level; /* security level negotiated */
    u32         security_nonce; /* response re-use preventer */

    /* the following are all in net order */
    __be32          epoch;      /* epoch of this connection */
    __be32          cid;        /* connection ID */
    __be16          service_id; /* service ID */
    u8          security_ix;    /* security type */
    u8          in_clientflag;  /* RXRPC_CLIENT_INITIATED if we are server */
    u8          out_clientflag; /* RXRPC_CLIENT_INITIATED if we are client */
};

/*
 * RxRPC call definition
 * - matched by { connection, call_id }
 */
struct rxrpc_call {
    struct rxrpc_connection *conn;      /* connection carrying call */
    struct rxrpc_sock   *socket;    /* socket responsible */
    struct timer_list   lifetimer;  /* lifetime remaining on call */
    struct timer_list   deadspan;   /* reap timer for re-ACK'ing, etc  */
    struct timer_list   ack_timer;  /* ACK generation timer */
    struct timer_list   resend_timer;   /* Tx resend timer */
    struct work_struct  destroyer;  /* call destroyer */
    struct work_struct  processor;  /* packet processor and ACK generator */
    struct list_head    link;       /* link in master call list */
    struct list_head    error_link; /* link in error distribution list */
    struct list_head    accept_link;    /* calls awaiting acceptance */
    struct rb_node      sock_node;  /* node in socket call tree */
    struct rb_node      conn_node;  /* node in connection call tree */
    struct sk_buff_head rx_queue;   /* received packets */
    struct sk_buff_head rx_oos_queue;   /* packets received out of sequence */
    struct sk_buff      *tx_pending;    /* Tx socket buffer being filled */
    wait_queue_head_t   tx_waitq;   /* wait for Tx window space to become available */
    unsigned long       user_call_ID;   /* user-defined call ID */
    unsigned long       creation_jif;   /* time of call creation */
    unsigned long       flags;
#define RXRPC_CALL_RELEASED 0   /* call has been released - no more message to userspace */
#define RXRPC_CALL_TERMINAL_MSG 1   /* call has given the socket its final message */
#define RXRPC_CALL_RCVD_LAST    2   /* all packets received */
#define RXRPC_CALL_RUN_RTIMER   3   /* Tx resend timer started */
#define RXRPC_CALL_TX_SOFT_ACK  4   /* sent some soft ACKs */
#define RXRPC_CALL_PROC_BUSY    5   /* the processor is busy */
#define RXRPC_CALL_INIT_ACCEPT  6   /* acceptance was initiated */
#define RXRPC_CALL_HAS_USERID   7   /* has a user ID attached */
#define RXRPC_CALL_EXPECT_OOS   8   /* expect out of sequence packets */
    unsigned long       events;
#define RXRPC_CALL_RCVD_ACKALL  0   /* ACKALL or reply received */
#define RXRPC_CALL_RCVD_BUSY    1   /* busy packet received */
#define RXRPC_CALL_RCVD_ABORT   2   /* abort packet received */
#define RXRPC_CALL_RCVD_ERROR   3   /* network error received */
#define RXRPC_CALL_ACK_FINAL    4   /* need to generate final ACK (and release call) */
#define RXRPC_CALL_ACK      5   /* need to generate ACK */
#define RXRPC_CALL_REJECT_BUSY  6   /* need to generate busy message */
#define RXRPC_CALL_ABORT    7   /* need to generate abort */
#define RXRPC_CALL_CONN_ABORT   8   /* local connection abort generated */
#define RXRPC_CALL_RESEND_TIMER 9   /* Tx resend timer expired */
#define RXRPC_CALL_RESEND   10  /* Tx resend required */
#define RXRPC_CALL_DRAIN_RX_OOS 11  /* drain the Rx out of sequence queue */
#define RXRPC_CALL_LIFE_TIMER   12  /* call's lifetimer ran out */
#define RXRPC_CALL_ACCEPTED 13  /* incoming call accepted by userspace app */
#define RXRPC_CALL_SECURED  14  /* incoming call's connection is now secure */
#define RXRPC_CALL_POST_ACCEPT  15  /* need to post an "accept?" message to the app */
#define RXRPC_CALL_RELEASE  16  /* need to release the call's resources */

    spinlock_t      lock;
    rwlock_t        state_lock; /* lock for state transition */
    atomic_t        usage;
    atomic_t        sequence;   /* Tx data packet sequence counter */
    u32         abort_code; /* local/remote abort code */
    enum {                  /* current state of call */
        RXRPC_CALL_CLIENT_SEND_REQUEST, /* - client sending request phase */
        RXRPC_CALL_CLIENT_AWAIT_REPLY,  /* - client awaiting reply */
        RXRPC_CALL_CLIENT_RECV_REPLY,   /* - client receiving reply phase */
        RXRPC_CALL_CLIENT_FINAL_ACK,    /* - client sending final ACK phase */
        RXRPC_CALL_SERVER_SECURING, /* - server securing request connection */
        RXRPC_CALL_SERVER_ACCEPTING,    /* - server accepting request */
        RXRPC_CALL_SERVER_RECV_REQUEST, /* - server receiving request */
        RXRPC_CALL_SERVER_ACK_REQUEST,  /* - server pending ACK of request */
        RXRPC_CALL_SERVER_SEND_REPLY,   /* - server sending reply */
        RXRPC_CALL_SERVER_AWAIT_ACK,    /* - server awaiting final ACK */
        RXRPC_CALL_COMPLETE,        /* - call completed */
        RXRPC_CALL_SERVER_BUSY,     /* - call rejected by busy server */
        RXRPC_CALL_REMOTELY_ABORTED,    /* - call aborted by peer */
        RXRPC_CALL_LOCALLY_ABORTED, /* - call aborted locally on error or close */
        RXRPC_CALL_NETWORK_ERROR,   /* - call terminated by network error */
        RXRPC_CALL_DEAD,        /* - call is dead */
    } state;
    int         debug_id;   /* debug ID for printks */
    u8          channel;    /* connection channel occupied by this call */

    /* transmission-phase ACK management */
    u8          acks_head;  /* offset into window of first entry */
    u8          acks_tail;  /* offset into window of last entry */
    u8          acks_winsz; /* size of un-ACK'd window */
    u8          acks_unacked;   /* lowest unacked packet in last ACK received */
    int         acks_latest;    /* serial number of latest ACK received */
    rxrpc_seq_t     acks_hard;  /* highest definitively ACK'd msg seq */
    unsigned long       *acks_window;   /* sent packet window
                         * - elements are pointers with LSB set if ACK'd
                         */

    /* receive-phase ACK management */
    rxrpc_seq_t     rx_data_expect; /* next data seq ID expected to be received */
    rxrpc_seq_t     rx_data_post;   /* next data seq ID expected to be posted */
    rxrpc_seq_t     rx_data_recv;   /* last data seq ID encountered by recvmsg */
    rxrpc_seq_t     rx_data_eaten;  /* last data seq ID consumed by recvmsg */
    rxrpc_seq_t     rx_first_oos;   /* first packet in rx_oos_queue (or 0) */
    rxrpc_seq_t     ackr_win_top;   /* top of ACK window (rx_data_eaten is bottom) */
    rxrpc_seq_net_t     ackr_prev_seq;  /* previous sequence number received */
    u8          ackr_reason;    /* reason to ACK */
    __be32          ackr_serial;    /* serial of packet being ACK'd */
    atomic_t        ackr_not_idle;  /* number of packets in Rx queue */

    /* received packet records, 1 bit per record */
#define RXRPC_ACKR_WINDOW_ASZ DIV_ROUND_UP(RXRPC_MAXACKS, BITS_PER_LONG)
    unsigned long       ackr_window[RXRPC_ACKR_WINDOW_ASZ + 1];

    /* the following should all be in net order */
    __be32          cid;        /* connection ID + channel index  */
    __be32          call_id;    /* call ID on connection  */
};

/*
 * locally abort an RxRPC call
 */
static inline void rxrpc_abort_call(struct rxrpc_call *call, u32 abort_code)
{
    write_lock_bh(&call->state_lock);
    if (call->state < RXRPC_CALL_COMPLETE) {
        call->abort_code = abort_code;
        call->state = RXRPC_CALL_LOCALLY_ABORTED;
        set_bit(RXRPC_CALL_ABORT, &call->events);
    }
    write_unlock_bh(&call->state_lock);
}

/*
 * af_rxrpc.c
 */
extern atomic_t rxrpc_n_skbs;
extern __be32 rxrpc_epoch;
extern atomic_t rxrpc_debug_id;
extern struct workqueue_struct *rxrpc_workqueue;

/*
 * ar-accept.c
 */
extern void rxrpc_accept_incoming_calls(struct work_struct *);
extern struct rxrpc_call *rxrpc_accept_call(struct rxrpc_sock *,
                        unsigned long);
extern int rxrpc_reject_call(struct rxrpc_sock *);

/*
 * ar-ack.c
 */
extern void __rxrpc_propose_ACK(struct rxrpc_call *, u8, __be32, bool);
extern void rxrpc_propose_ACK(struct rxrpc_call *, u8, __be32, bool);
extern void rxrpc_process_call(struct work_struct *);

/*
 * ar-call.c
 */
extern struct kmem_cache *rxrpc_call_jar;
extern struct list_head rxrpc_calls;
extern rwlock_t rxrpc_call_lock;

extern struct rxrpc_call *rxrpc_get_client_call(struct rxrpc_sock *,
                        struct rxrpc_transport *,
                        struct rxrpc_conn_bundle *,
                        unsigned long, int, gfp_t);
extern struct rxrpc_call *rxrpc_incoming_call(struct rxrpc_sock *,
                          struct rxrpc_connection *,
                          struct rxrpc_header *, gfp_t);
extern struct rxrpc_call *rxrpc_find_server_call(struct rxrpc_sock *,
                         unsigned long);
extern void rxrpc_release_call(struct rxrpc_call *);
extern void rxrpc_release_calls_on_socket(struct rxrpc_sock *);
extern void __rxrpc_put_call(struct rxrpc_call *);
extern void __exit rxrpc_destroy_all_calls(void);

/*
 * ar-connection.c
 */
extern struct list_head rxrpc_connections;
extern rwlock_t rxrpc_connection_lock;

extern struct rxrpc_conn_bundle *rxrpc_get_bundle(struct rxrpc_sock *,
                          struct rxrpc_transport *,
                          struct key *,
                          __be16, gfp_t);
extern void rxrpc_put_bundle(struct rxrpc_transport *,
                 struct rxrpc_conn_bundle *);
extern int rxrpc_connect_call(struct rxrpc_sock *, struct rxrpc_transport *,
                  struct rxrpc_conn_bundle *, struct rxrpc_call *,
                  gfp_t);
extern void rxrpc_put_connection(struct rxrpc_connection *);
extern void __exit rxrpc_destroy_all_connections(void);
extern struct rxrpc_connection *rxrpc_find_connection(struct rxrpc_transport *,
                              struct rxrpc_header *);
extern struct rxrpc_connection *
rxrpc_incoming_connection(struct rxrpc_transport *, struct rxrpc_header *,
              gfp_t);

/*
 * ar-connevent.c
 */
extern void rxrpc_process_connection(struct work_struct *);
extern void rxrpc_reject_packet(struct rxrpc_local *, struct sk_buff *);
extern void rxrpc_reject_packets(struct work_struct *);

/*
 * ar-error.c
 */
extern void rxrpc_UDP_error_report(struct sock *);
extern void rxrpc_UDP_error_handler(struct work_struct *);

/*
 * ar-input.c
 */
extern unsigned long rxrpc_ack_timeout;
extern const char *rxrpc_pkts[];

extern void rxrpc_data_ready(struct sock *, int);
extern int rxrpc_queue_rcv_skb(struct rxrpc_call *, struct sk_buff *, bool,
                   bool);
extern void rxrpc_fast_process_packet(struct rxrpc_call *, struct sk_buff *);

/*
 * ar-local.c
 */
extern rwlock_t rxrpc_local_lock;
extern struct rxrpc_local *rxrpc_lookup_local(struct sockaddr_rxrpc *);
extern void rxrpc_put_local(struct rxrpc_local *);
extern void __exit rxrpc_destroy_all_locals(void);

/*
 * ar-key.c
 */
extern struct key_type key_type_rxrpc;
extern struct key_type key_type_rxrpc_s;

extern int rxrpc_request_key(struct rxrpc_sock *, char __user *, int);
extern int rxrpc_server_keyring(struct rxrpc_sock *, char __user *, int);
extern int rxrpc_get_server_data_key(struct rxrpc_connection *, const void *,
                     time_t, u32);

/*
 * ar-output.c
 */
extern int rxrpc_resend_timeout;

extern int rxrpc_send_packet(struct rxrpc_transport *, struct sk_buff *);
extern int rxrpc_client_sendmsg(struct kiocb *, struct rxrpc_sock *,
                struct rxrpc_transport *, struct msghdr *,
                size_t);
extern int rxrpc_server_sendmsg(struct kiocb *, struct rxrpc_sock *,
                struct msghdr *, size_t);

/*
 * ar-peer.c
 */
extern struct rxrpc_peer *rxrpc_get_peer(struct sockaddr_rxrpc *, gfp_t);
extern void rxrpc_put_peer(struct rxrpc_peer *);
extern struct rxrpc_peer *rxrpc_find_peer(struct rxrpc_local *,
                      __be32, __be16);
extern void __exit rxrpc_destroy_all_peers(void);

/*
 * ar-proc.c
 */
extern const char *const rxrpc_call_states[];
extern const struct file_operations rxrpc_call_seq_fops;
extern const struct file_operations rxrpc_connection_seq_fops;

/*
 * ar-recvmsg.c
 */
extern void rxrpc_remove_user_ID(struct rxrpc_sock *, struct rxrpc_call *);
extern int rxrpc_recvmsg(struct kiocb *, struct socket *, struct msghdr *,
             size_t, int);

/*
 * ar-security.c
 */
extern int rxrpc_register_security(struct rxrpc_security *);
extern void rxrpc_unregister_security(struct rxrpc_security *);
extern int rxrpc_init_client_conn_security(struct rxrpc_connection *);
extern int rxrpc_init_server_conn_security(struct rxrpc_connection *);
extern int rxrpc_secure_packet(const struct rxrpc_call *, struct sk_buff *,
                   size_t, void *);
extern int rxrpc_verify_packet(const struct rxrpc_call *, struct sk_buff *,
                   u32 *);
extern void rxrpc_clear_conn_security(struct rxrpc_connection *);

/*
 * ar-skbuff.c
 */
extern void rxrpc_packet_destructor(struct sk_buff *);

/*
 * ar-transport.c
 */
extern struct rxrpc_transport *rxrpc_get_transport(struct rxrpc_local *,
                           struct rxrpc_peer *,
                           gfp_t);
extern void rxrpc_put_transport(struct rxrpc_transport *);
extern void __exit rxrpc_destroy_all_transports(void);
extern struct rxrpc_transport *rxrpc_find_transport(struct rxrpc_local *,
                            struct rxrpc_peer *);

/*
 * debug tracing
 */
extern unsigned int rxrpc_debug;

#define dbgprintk(FMT,...) \
    printk("[%-6.6s] "FMT"\n", current->comm ,##__VA_ARGS__)

#define kenter(FMT,...) dbgprintk("==> %s("FMT")",__func__ ,##__VA_ARGS__)
#define kleave(FMT,...) dbgprintk("<== %s()"FMT"",__func__ ,##__VA_ARGS__)
#define kdebug(FMT,...) dbgprintk("    "FMT ,##__VA_ARGS__)
#define kproto(FMT,...) dbgprintk("### "FMT ,##__VA_ARGS__)
#define knet(FMT,...)   dbgprintk("@@@ "FMT ,##__VA_ARGS__)


#if defined(__KDEBUG)
#define _enter(FMT,...) kenter(FMT,##__VA_ARGS__)
#define _leave(FMT,...) kleave(FMT,##__VA_ARGS__)
#define _debug(FMT,...) kdebug(FMT,##__VA_ARGS__)
#define _proto(FMT,...) kproto(FMT,##__VA_ARGS__)
#define _net(FMT,...)   knet(FMT,##__VA_ARGS__)

#elif defined(CONFIG_AF_RXRPC_DEBUG)
#define RXRPC_DEBUG_KENTER  0x01
#define RXRPC_DEBUG_KLEAVE  0x02
#define RXRPC_DEBUG_KDEBUG  0x04
#define RXRPC_DEBUG_KPROTO  0x08
#define RXRPC_DEBUG_KNET    0x10

#define _enter(FMT,...)                 \
do {                            \
    if (unlikely(rxrpc_debug & RXRPC_DEBUG_KENTER)) \
        kenter(FMT,##__VA_ARGS__);      \
} while (0)

#define _leave(FMT,...)                 \
do {                            \
    if (unlikely(rxrpc_debug & RXRPC_DEBUG_KLEAVE)) \
        kleave(FMT,##__VA_ARGS__);      \
} while (0)

#define _debug(FMT,...)                 \
do {                            \
    if (unlikely(rxrpc_debug & RXRPC_DEBUG_KDEBUG)) \
        kdebug(FMT,##__VA_ARGS__);      \
} while (0)

#define _proto(FMT,...)                 \
do {                            \
    if (unlikely(rxrpc_debug & RXRPC_DEBUG_KPROTO)) \
        kproto(FMT,##__VA_ARGS__);      \
} while (0)

#define _net(FMT,...)                   \
do {                            \
    if (unlikely(rxrpc_debug & RXRPC_DEBUG_KNET))   \
        knet(FMT,##__VA_ARGS__);        \
} while (0)

#else
#define _enter(FMT,...) no_printk("==> %s("FMT")",__func__ ,##__VA_ARGS__)
#define _leave(FMT,...) no_printk("<== %s()"FMT"",__func__ ,##__VA_ARGS__)
#define _debug(FMT,...) no_printk("    "FMT ,##__VA_ARGS__)
#define _proto(FMT,...) no_printk("### "FMT ,##__VA_ARGS__)
#define _net(FMT,...)   no_printk("@@@ "FMT ,##__VA_ARGS__)
#endif

/*
 * debug assertion checking
 */
#if 1 // defined(__KDEBUGALL)

#define ASSERT(X)                       \
do {                                \
    if (unlikely(!(X))) {                   \
        printk(KERN_ERR "\n");              \
        printk(KERN_ERR "RxRPC: Assertion failed\n");   \
        BUG();                      \
    }                           \
} while(0)

#define ASSERTCMP(X, OP, Y)                     \
do {                                    \
    if (unlikely(!((X) OP (Y)))) {                  \
        printk(KERN_ERR "\n");                  \
        printk(KERN_ERR "RxRPC: Assertion failed\n");       \
        printk(KERN_ERR "%lu " #OP " %lu is false\n",       \
               (unsigned long)(X), (unsigned long)(Y));     \
        printk(KERN_ERR "0x%lx " #OP " 0x%lx is false\n",   \
               (unsigned long)(X), (unsigned long)(Y));     \
        BUG();                          \
    }                               \
} while(0)

#define ASSERTIF(C, X)                      \
do {                                \
    if (unlikely((C) && !(X))) {                \
        printk(KERN_ERR "\n");              \
        printk(KERN_ERR "RxRPC: Assertion failed\n");   \
        BUG();                      \
    }                           \
} while(0)

#define ASSERTIFCMP(C, X, OP, Y)                    \
do {                                    \
    if (unlikely((C) && !((X) OP (Y)))) {               \
        printk(KERN_ERR "\n");                  \
        printk(KERN_ERR "RxRPC: Assertion failed\n");       \
        printk(KERN_ERR "%lu " #OP " %lu is false\n",       \
               (unsigned long)(X), (unsigned long)(Y));     \
        printk(KERN_ERR "0x%lx " #OP " 0x%lx is false\n",   \
               (unsigned long)(X), (unsigned long)(Y));     \
        BUG();                          \
    }                               \
} while(0)

#else

#define ASSERT(X)               \
do {                        \
} while(0)

#define ASSERTCMP(X, OP, Y)         \
do {                        \
} while(0)

#define ASSERTIF(C, X)              \
do {                        \
} while(0)

#define ASSERTIFCMP(C, X, OP, Y)        \
do {                        \
} while(0)

#endif /* __KDEBUGALL */

/*
 * socket buffer accounting / leak finding
 */
static inline void __rxrpc_new_skb(struct sk_buff *skb, const char *fn)
{
    //_net("new skb %p %s [%d]", skb, fn, atomic_read(&rxrpc_n_skbs));
    //atomic_inc(&rxrpc_n_skbs);
}

#define rxrpc_new_skb(skb) __rxrpc_new_skb((skb), __func__)

static inline void __rxrpc_kill_skb(struct sk_buff *skb, const char *fn)
{
    //_net("kill skb %p %s [%d]", skb, fn, atomic_read(&rxrpc_n_skbs));
    //atomic_dec(&rxrpc_n_skbs);
}

#define rxrpc_kill_skb(skb) __rxrpc_kill_skb((skb), __func__)

static inline void __rxrpc_free_skb(struct sk_buff *skb, const char *fn)
{
    if (skb) {
        CHECK_SLAB_OKAY(&skb->users);
        //_net("free skb %p %s [%d]",
        //     skb, fn, atomic_read(&rxrpc_n_skbs));
        //atomic_dec(&rxrpc_n_skbs);
        kfree_skb(skb);
    }
}

#define rxrpc_free_skb(skb) __rxrpc_free_skb((skb), __func__)

static inline void rxrpc_purge_queue(struct sk_buff_head *list)
{
    struct sk_buff *skb;
    while ((skb = skb_dequeue((list))) != NULL)
        rxrpc_free_skb(skb);
}

static inline void __rxrpc_get_local(struct rxrpc_local *local, const char *f)
{
    CHECK_SLAB_OKAY(&local->usage);
    if (atomic_inc_return(&local->usage) == 1)
        printk("resurrected (%s)\n", f);
}

#define rxrpc_get_local(LOCAL) __rxrpc_get_local((LOCAL), __func__)

#define rxrpc_get_call(CALL)                \
do {                            \
    CHECK_SLAB_OKAY(&(CALL)->usage);        \
    if (atomic_inc_return(&(CALL)->usage) == 1) \
        BUG();                  \
} while(0)

#define rxrpc_put_call(CALL)                \
do {                            \
    __rxrpc_put_call(CALL);             \
} while(0)