/* AF_RXRPC internal definitions
 *
 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * 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        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                if_mtu;         /* interface MTU for this peer */
        unsigned                mtu;            /* network MTU for this peer */
        unsigned                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                rtt_point;      /* next entry at which to insert */
        unsigned                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                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 rxrpc_debug;

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

/* make sure we maintain the format strings, even when debugging is disabled */
static inline __attribute__((format(printf,1,2)))
void _dbprintk(const char *fmt, ...)
{
}

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