/* -*- mode:c; c-file-style:"k&r"; c-basic-offset: 4; tab-width:4; indent-tabs-mode:nil; mode:auto-fill; fill-column:78; -*- */
/* vim: set ts=4 sw=4 et tw=78 fo=cqt wm=0: */

/* Copyright (C) 2014 OSCAR lab, Stony Brook University
   This file is part of Graphene Library OS.

   Graphene Library OS 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 3 of the
   License, or (at your option) any later version.

   Graphene Library OS is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

/*
 * shim_ipc.h
 *
 * Definitions of types and functions for IPC bookkeeping.
 */

#ifndef _SHIM_IPC_H_
#define _SHIM_IPC_H_

#include <shim_types.h>
#include <shim_defs.h>
#include <shim_handle.h>
#include <shim_thread.h>
#include <shim_sysv.h>

#include <pal.h>
#include <linux_list.h>

struct shim_ipc_info {
    IDTYPE                  vmid;
    struct shim_ipc_port *  port;
    PAL_HANDLE              pal_handle;
    struct shim_qstr        uri;
    struct hlist_node       hlist;
    REFTYPE                 ref_count;
};

enum { PID_NS, SYSV_NS, TOTAL_NS };

struct shim_process {
    IDTYPE              vmid;
    LOCKTYPE            lock;
    int                 exit_code;
    struct shim_ipc_info * self, * parent;
    struct shim_ipc_info * ns[TOTAL_NS];
};

extern struct shim_process cur_process;

#define IPC_MSG_MINIMAL_SIZE        48
#define IPC_MSG_READAHEAD           96

struct shim_ipc_msg {
    unsigned char       code;
    unsigned int        size;
    IDTYPE              src, dst;
    unsigned long       seq;
#ifdef PROFILE
    unsigned long       time;
#endif
    char                msg[];
} __attribute__((packed));

struct shim_ipc_port;
struct shim_thread;

struct shim_ipc_msg_obj {
    struct shim_thread *    thread;
    struct list_head        list;
    int                     retval;
    void *                  private;
    struct shim_ipc_msg     msg;
};

typedef void (*port_fini) (struct shim_ipc_port *, IDTYPE vmid,
                           unsigned int exitcode);

#define MAX_IPC_PORT_FINI_CB        3

struct shim_ipc_port {
    PAL_HANDLE          pal_handle;

    REFTYPE             ref_count;
    struct hlist_node   hlist;
    struct list_head    list;
    struct list_head    msgs;
    LOCKTYPE            msgs_lock;

    port_fini           fini[MAX_IPC_PORT_FINI_CB];

    bool                update, recent;
    struct {
        unsigned int    type;
        IDTYPE          vmid;
    }                   info, private;
};

#define IPC_CALLBACK_ARGS   \
    struct shim_ipc_msg * msg, struct shim_ipc_port * port

/* if callback return RESPONSE_CALLBACK, send a response even if the callback
   succeed. */
#define RESPONSE_CALLBACK   1

typedef int (*ipc_callback) (IPC_CALLBACK_ARGS);

/* Messagge code to response the connection */
enum {
    IPC_RESP = 0,
    IPC_FINDURI,
    IPC_TELLURI,
    IPC_CHECKPOINT,
    IPC_BASE_BOUND,
};

/* IPC_RESP: response for incoming messages */
struct shim_ipc_resp {
    int retval;
} __attribute__((packed));

/* IPC_FINDURI: request a URI from a connect process */
int ipc_finduri_send (struct shim_ipc_port * port, IDTYPE dest,
                      struct shim_ipc_info ** info);
int ipc_finduri_callback (IPC_CALLBACK_ARGS);

/* IPC_TELLURI: replying with a connectable URI */
struct shim_ipc_telluri {
    char uri[1];
} __attribute__((packed));

int ipc_telluri_send (struct shim_ipc_port * port, IDTYPE dest,
                      struct shim_ipc_info * info);
int ipc_telluri_callback (IPC_CALLBACK_ARGS);

/* PID_CHECKPOINT: broadcast checkpointing */
struct shim_ipc_checkpoint {
    IDTYPE cpsession;
    char cpdir[1];
} __attribute__((packed));

int ipc_checkpoint_send (const char * cpdir, IDTYPE cpsession);
int ipc_checkpoint_callback (IPC_CALLBACK_ARGS);

/* Message code from child to parent */
#define IPC_CLD_BASE       IPC_BASE_BOUND
enum {
    IPC_CLD_EXIT = IPC_CLD_BASE,
    IPC_CLD_JOIN,
#ifdef PROFILE
    IPC_CLD_PROFILE,
#endif
    IPC_CLD_BOUND,
};

/* CLD_EXIT: thread exit */
struct shim_ipc_cld_exit {
    IDTYPE ppid, tid;
    unsigned int exitcode;
    unsigned int term_signal;
#ifdef PROFILE
    unsigned long time;
#endif
} __attribute__((packed));

int ipc_cld_exit_send (IDTYPE ppid, IDTYPE tid, unsigned int exitcode, unsigned int term_signal);
int ipc_cld_exit_callback (IPC_CALLBACK_ARGS);

/* CLD_JOIN: child join the parent group */
int ipc_cld_join_send (IDTYPE dest);
int ipc_cld_join_callback (IPC_CALLBACK_ARGS);

#ifdef PROFILE
# include <shim_profile.h>

struct shim_ipc_cld_profile {
    unsigned long time;
    int nprofile;
    struct profile_val profile[];
} __attribute__((packed));

int ipc_cld_profile_send (void);
int ipc_cld_profile_callback (IPC_CALLBACK_ARGS);
#endif

/* Message code to namespace manager */
#define IPC_PID_BASE       IPC_CLD_BOUND

#define NS     pid
#define NS_CAP PID

#include "shim_ipc_ns.h"

enum {
    IPC_PID_KILL = IPC_PID_TEMPLATE_BOUND,
    IPC_PID_GETSTATUS,
    IPC_PID_RETSTATUS,
    IPC_PID_GETMETA,
    IPC_PID_RETMETA,
    IPC_PID_NOP,
    IPC_PID_SENDRPC,
    IPC_PID_BOUND,
};

enum kill_type { KILL_THREAD, KILL_PROCESS, KILL_PGROUP, KILL_ALL };

/* PID_KILL: send signal to certain pid */
struct shim_ipc_pid_kill {
    IDTYPE sender;
    enum kill_type type;
    IDTYPE id;
    int signum;
} __attribute__((packed));

int ipc_pid_kill_send (IDTYPE sender, IDTYPE id, enum kill_type type,
                       int signum);
int ipc_pid_kill_callback (IPC_CALLBACK_ARGS);

struct pid_status {
    IDTYPE pid, tgid, pgid;
} __attribute__((packed));

/* PID_GETSTATUS: check if certain pid(s) exists */
struct shim_ipc_pid_getstatus {
    int npids;
    IDTYPE pids[];
} __attribute__((packed));

int ipc_pid_getstatus_send (struct shim_ipc_port * port, IDTYPE dest,
                            int npids, IDTYPE * pids,
                            struct pid_status ** status);
int ipc_pid_getstatus_callback (IPC_CALLBACK_ARGS);

/* PID_RETSTATUS: return status of pid(s) */
struct shim_ipc_pid_retstatus {
    int nstatus;
    struct pid_status status[];
} __attribute__((packed));

int ipc_pid_retstatus_send (struct shim_ipc_port * port, IDTYPE dest,
                            int nstatus, struct pid_status * status,
                            unsigned long seq);
int ipc_pid_retstatus_callback (IPC_CALLBACK_ARGS);

/* PID_GETMETA: get metadata of certain pid */
enum pid_meta_code {
    PID_META_CRED,
    PID_META_EXEC,
    PID_META_CWD,
    PID_META_ROOT,
};

struct shim_ipc_pid_getmeta {
    IDTYPE pid;
    enum pid_meta_code code;
} __attribute__((packed));

int ipc_pid_getmeta_send (IDTYPE pid, enum pid_meta_code code,
                          void ** data);
int ipc_pid_getmeta_callback (IPC_CALLBACK_ARGS);

/* PID_RETMETA: return metadata of certain pid */
struct shim_ipc_pid_retmeta {
    IDTYPE pid;
    enum pid_meta_code code;
    int datasize;
    char data[];
} __attribute__((packed));

int ipc_pid_retmeta_send (struct shim_ipc_port * port, IDTYPE dest,
                          IDTYPE pid, enum pid_meta_code code,
                          const void * data, int datasize,
                          unsigned long seq);
int ipc_pid_retmeta_callback (IPC_CALLBACK_ARGS);

/* PID_NOP: send junk message (for benchmarking) */
struct shim_ipc_pid_nop {
    int count;
    char payload[];
} __attribute__((packed));

int ipc_pid_nop_send (struct shim_ipc_port * port, IDTYPE dest, int count,
                      const void * buf, int len);
int ipc_pid_nop_callback(IPC_CALLBACK_ARGS);

/* PID_SENDRPC: send arbitary message (for benchmarking) */
struct shim_ipc_pid_sendrpc {
    IDTYPE sender;
    int len;
    char payload[];
} __attribute__((packed));

int ipc_pid_sendrpc_send (IDTYPE pid, IDTYPE sender, const void * buf,
                          int len);
int ipc_pid_sendrpc_callback (IPC_CALLBACK_ARGS);

#define IPC_SYSV_BASE      IPC_PID_BOUND

struct sysv_key {
    unsigned long   key;
    enum sysv_type  type;
};

#define NS     sysv
#define NS_CAP SYSV
#define NS_KEY struct sysv_key

#include "shim_ipc_ns.h"

enum {
    IPC_SYSV_DELRES = IPC_SYSV_TEMPLATE_BOUND,
    IPC_SYSV_MOVRES,
    IPC_SYSV_MSGSND,
    IPC_SYSV_MSGRCV,
    IPC_SYSV_MSGMOV,
    IPC_SYSV_SEMOP,
    IPC_SYSV_SEMCTL,
    IPC_SYSV_SEMRET,
    IPC_SYSV_SEMMOV,
#ifdef USE_SHARED_SEMAPHORE
    IPC_SYSV_SEMQUERY,
    IPC_SYSV_SEMREPLY,
#endif
    IPC_SYSV_BOUND,
};

/* SYSV_DELRES */
struct shim_ipc_sysv_delres {
    IDTYPE resid;
    enum sysv_type type;
} __attribute__((packed));

int ipc_sysv_delres_send (struct shim_ipc_port * port, IDTYPE dest,
                          IDTYPE resid, enum sysv_type type);
int ipc_sysv_delres_callback (IPC_CALLBACK_ARGS);

/* SYSV_MOVRES */
struct shim_ipc_sysv_movres {
    IDTYPE resid;
    enum sysv_type type;
    IDTYPE owner;
    LEASETYPE lease;
    char uri[1];
} __attribute__((packed));

int ipc_sysv_movres_send (struct sysv_client * client, IDTYPE owner,
                          const char * uri, LEASETYPE lease, IDTYPE resid,
                          enum sysv_type type);
int ipc_sysv_movres_callback (IPC_CALLBACK_ARGS);

/* SYSV_MSGSND */
struct shim_ipc_sysv_msgsnd {
    IDTYPE msgid;
    long msgtype;
    char msg[];
} __attribute__((packed));

int ipc_sysv_msgsnd_send (struct shim_ipc_port * port, IDTYPE dest,
                          IDTYPE msgid, long msgtype,
                          const void * buf, size_t size, unsigned long seq);
int ipc_sysv_msgsnd_callback (IPC_CALLBACK_ARGS);

/* SYSV_MSGRCV */
struct shim_ipc_sysv_msgrcv {
    IDTYPE msgid;
    long msgtype;
    int size;
    int flags;
} __attribute__((packed));

int ipc_sysv_msgrcv_send (IDTYPE msgid, long msgtype, int flags, void * buf,
                          size_t size);
int ipc_sysv_msgrcv_callback (IPC_CALLBACK_ARGS);

/* SYSV_MSGMOV */
struct shim_ipc_sysv_msgmov {
    IDTYPE msgid;
    LEASETYPE lease;
    unsigned short nscores;
    struct sysv_score scores[];
} __attribute__((packed));

int ipc_sysv_msgmov_send (struct shim_ipc_port * port, IDTYPE dest,
                          IDTYPE msgid, LEASETYPE lease,
                          struct sysv_score * scores, int nscores);
int ipc_sysv_msgmov_callback (IPC_CALLBACK_ARGS);

/* SYSV_SEMOP */
struct shim_ipc_sysv_semop {
    IDTYPE semid;
    unsigned long timeout;
    int nsops;
    struct sembuf sops[];
} __attribute__((packed));

#define IPC_SEM_NOTIMEOUT ((unsigned long) -1)

int ipc_sysv_semop_send (IDTYPE semid, struct sembuf * sops, int nsops,
                         unsigned long timeout, unsigned long * seq);
int ipc_sysv_semop_callback (IPC_CALLBACK_ARGS);

/* SYSV_SEMCTL */
struct shim_ipc_sysv_semctl {
    IDTYPE semid;
    int semnum;
    int cmd;
    int valsize;
    unsigned char vals[];
} __attribute__((packed));

int ipc_sysv_semctl_send (IDTYPE semid, int semnum, int cmd, void * vals,
                          int valsize);
int ipc_sysv_semctl_callback (IPC_CALLBACK_ARGS);

/* SYSV_SEMRET */
struct shim_ipc_sysv_semret {
    int valsize;
    unsigned char vals[];
} __attribute__((packed));

int ipc_sysv_semret_send (struct shim_ipc_port * port, IDTYPE dest,
                          void * vals, int valsize, unsigned long seq);
int ipc_sysv_semret_callback (IPC_CALLBACK_ARGS);

/* SYSV_SEMMOV */
struct shim_ipc_sysv_semmov {
    IDTYPE semid;
    LEASETYPE lease;
    unsigned short nsems, nsrcs, nscores;
    struct sem_backup sems[];
} __attribute__((packed));

int ipc_sysv_semmov_send (struct shim_ipc_port * port, IDTYPE dest,
                          IDTYPE semid, LEASETYPE lease,
                          struct sem_backup * sems, int nsems,
                          struct sem_client_backup * srcs, int nsrcs,
                          struct sysv_score * scores, int nscores);
int ipc_sysv_semmov_callback (IPC_CALLBACK_ARGS);

#ifdef USE_SHARED_SEMAPHORE
/* SYSV_SEMQUERY */
struct shim_ipc_sysv_semquery {
    IDTYPE semid;
} __attribute__((packed));

int ipc_sysv_semquery_send (IDTYPE semid, int * nsems, PAL_NUM ** host_sem_ids);
int ipc_sysv_semquery_callback (IPC_CALLBACK_ARGS);

/* SYSV_SEMREPLY */
struct shim_ipc_sysv_semreply {
    IDTYPE semid;
    int nsems;
    PAL_NUM host_sem_ids[];
} __attribute__((packed));

int ipc_sysv_semreply_send (struct shim_ipc_port * port, IDTYPE dest,
                            IDTYPE semid, int nsems, PAL_NUM * host_sem_ids,
                            unsigned long seq);
int ipc_sysv_semreply_callback (IPC_CALLBACK_ARGS);
#endif

#define IPC_CODE_NUM     IPC_SYSV_BOUND

/* functions and routines */
int init_ipc (void);
int init_ipc_helper (void);

struct shim_process * create_new_process (bool inherit_parent);
void destroy_process (struct shim_process * proc);

struct shim_ipc_info * create_ipc_port (IDTYPE vmid, bool listen);
int create_ipc_location (struct shim_ipc_info ** pinfo);

enum {
    LISTEN,     /* listening */
    SERVER,     /* connect as a server */
    KEEPALIVE,  /* keep the connetion alive */
    DIRCLD,     /* direct child */
    DIRPRT,     /* direct parent */
    NS_PORT_CONSTS(PID)
    NS_PORT_CONSTS(SYSV)
};

enum {
    IPC_PORT_LISTEN = 1<<LISTEN,
    IPC_PORT_SERVER = 1<<SERVER,
    IPC_PORT_KEEPALIVE = 1<<KEEPALIVE,
    IPC_PORT_DIRCLD = 1<<DIRCLD,
    IPC_PORT_DIRPRT = 1<<DIRPRT,
    NS_PORT_TYPES(PID)
    NS_PORT_TYPES(SYSV)
};

#define IPC_PORT_IFPOLL    (IPC_PORT_SERVER|IPC_PORT_LISTEN)

/* general-purpose routines */
void add_ipc_port_by_id (IDTYPE vmid, PAL_HANDLE hdl, int type,
                         port_fini fini,
                         struct shim_ipc_port ** portptr);
void add_ipc_port (struct shim_ipc_port * port, IDTYPE vmid, int type,
                   port_fini fini);
void del_ipc_port_by_id (IDTYPE vm_pid, int type);
void del_ipc_port (struct shim_ipc_port * port, int type);
void del_ipc_port_fini (struct shim_ipc_port * port, unsigned int exitcode);
struct shim_ipc_port * lookup_ipc_port (IDTYPE vmid, int type);
void get_ipc_port (struct shim_ipc_port * port);
void put_ipc_port (struct shim_ipc_port * port);
void del_all_ipc_ports (int type);

struct shim_ipc_info * get_new_ipc_info (IDTYPE vmid, const char * uri,
                                         size_t len);
void get_ipc_info(struct shim_ipc_info * port);
void put_ipc_info(struct shim_ipc_info * port);

struct shim_ipc_info * lookup_and_alloc_client (IDTYPE vmid, const char * uri);
void put_client (struct shim_ipc_info * info);
struct shim_ipc_info * discover_client (struct shim_ipc_port * port,
                                        IDTYPE vmid);

#define IPC_MSG_SIZE(extra)                                             \
    ({  int _size = (extra) + sizeof(struct shim_ipc_msg);              \
        _size > IPC_MSG_MINIMAL_SIZE ? _size : IPC_MSG_MINIMAL_SIZE; })
#define IPC_MSGOBJ_SIZE(extra)                                          \
    ({  int _size = (extra) + sizeof(struct shim_ipc_msg);              \
        (_size > IPC_MSG_MINIMAL_SIZE ? _size : IPC_MSG_MINIMAL_SIZE) + \
        (sizeof(struct shim_ipc_msg_obj) - sizeof(struct shim_ipc_msg)); })

int __init_ipc_msg (struct shim_ipc_msg * msg, int code, int size, IDTYPE dest);
struct shim_ipc_msg * create_ipc_msg (int code, int size, IDTYPE dest);

static_inline
struct shim_ipc_msg * create_ipc_msg_on_stack (int code, int size, IDTYPE dest)
{
    struct shim_ipc_msg * msg = __alloca(IPC_MSG_SIZE(size));

    return (!__init_ipc_msg(msg, code, size, dest)) ? msg : NULL;
}

int __init_ipc_msg_duplex (struct shim_ipc_msg_obj * msg, int code, int size,
                           IDTYPE dest);
struct shim_ipc_msg_obj *
create_ipc_msg_duplex (int code, int size, IDTYPE dest);

static_inline
struct shim_ipc_msg_obj *
create_ipc_msg_duplex_on_stack (int code, int size, IDTYPE dest)
{
    struct shim_ipc_msg_obj * msg = __alloca(IPC_MSGOBJ_SIZE(size));

    return (!__init_ipc_msg_duplex(msg, code, size, dest)) ?
           msg : NULL;
}

int __init_ipc_resp_msg (struct shim_ipc_msg * resp, int ret,
                         unsigned long seq);
struct shim_ipc_msg *
create_ipc_resp_msg (int ret, IDTYPE dest, unsigned long seq);

static_inline
struct shim_ipc_msg *
create_ipc_resp_msg_on_stack (int ret, IDTYPE dest, unsigned long seq)
{
    struct shim_ipc_msg * resp = create_ipc_msg_on_stack(IPC_RESP,
                                        sizeof(struct shim_ipc_resp), dest);

    return (resp && !__init_ipc_resp_msg(resp, ret, seq)) ? resp : NULL;
}

int send_ipc_message (struct shim_ipc_msg * msg, struct shim_ipc_port * port);
int send_ipc_message_duplex (struct shim_ipc_msg_obj * msg,
                             struct shim_ipc_port * port, bool save,
                             void * private_data);
int close_ipc_message_duplex (struct shim_ipc_msg_obj * msg,
                              struct shim_ipc_port * port);
int broadcast_ipc (struct shim_ipc_msg * msg, struct shim_ipc_port ** exclude,
                   int exsize, int target_type);
struct shim_ipc_msg_obj * find_ipc_msg_duplex (struct shim_ipc_port * port,
                                               unsigned long seq);
int receive_ipc_message (struct shim_ipc_port * port, unsigned long seq,
                         struct shim_ipc_msg ** msg);

/* for convenience */
int __response_ipc_message (struct shim_ipc_port * port, IDTYPE dest,
                            int ret, unsigned long seq);

int do_ipc_duplex (struct shim_ipc_msg_obj * msg,
                   struct shim_ipc_port * port, unsigned long * seq,
                   void * private_data);

void ipc_parent_exit  (struct shim_ipc_port * port, IDTYPE vmid,
                       unsigned int exitcode, unsigned int term_signal);
void ipc_child_exit   (struct shim_ipc_port * port, IDTYPE vmid,
                       unsigned int exitcode, unsigned int term_signal);

int create_ipc_helper (void);
int exit_with_ipc_helper (bool handover);

#define IPC_FORCE_RECONNECT     ((void *) -1)

int prepare_ns_leaders (void);

#endif /* _SHIM_IPC_H_ */