// SPDX-License-Identifier: AGPL-3.0-or-later
/*
    Copyright (C) 2018 - 2021 Proxmox Server Solutions GmbH

    Author: Dominik Csapak <d.csapak@proxmox.com>
    Author: Stefan Reiter <s.reiter@proxmox.com>
*/

#include <sys/syscall.h>

#ifndef __NR_pidfd_open
#define __NR_pidfd_open 434
#endif
#ifndef __NR_pidfd_send_signal
#define __NR_pidfd_send_signal 424
#endif

#define VERBOSE_PRINT(...) do { if (verbose) { printf(__VA_ARGS__); fflush(stdout); } } while (0)

static inline void log_neg(int errval, const char *msg)
{
    if (errval < 0) {
	perror(msg);
    }
}

static inline void bail_neg(int errval, const char *msg)
{
    if (errval < 0) {
	perror(msg);
	exit(EXIT_FAILURE);
    }
}

static inline int
pidfd_open(pid_t pid, unsigned int flags)
{
    return syscall(__NR_pidfd_open, pid, flags);
}

static inline int
pidfd_send_signal(int pidfd, int sig, siginfo_t *info, unsigned int flags)
{
    return syscall(__NR_pidfd_send_signal, pidfd, sig, info, flags);
}

typedef enum {
    CLIENT_NONE,
    CLIENT_QEMU,
    CLIENT_VZDUMP
} ClientType;

typedef enum {
    STATE_HANDSHAKE,
    STATE_IDLE,
    STATE_EXPECT_STATUS_RESP,
    STATE_TERMINATING
} ClientState;

struct Client {
    char buf[4096];
    unsigned int buflen;

    int fd;
    pid_t pid;

    ClientType type;
    ClientState state;

    // only relevant for type=CLIENT_QEMU
    struct {
        char vmid[16];
        unsigned short graceful;
        unsigned short guest;
        bool term_check_queued;
        bool backup;
    } qemu;

    // only relevant for type=CLIENT_VZDUMP
    struct {
        // vmid of referenced backup
        char vmid[16];
    } vzdump;
};

struct CleanupData {
    pid_t pid;
    int pidfd;
};

void handle_qmp_handshake(struct Client *client);
void handle_qmp_event(struct Client *client, struct json_object *obj);
void handle_qmp_return(struct Client *client, struct json_object *data, bool error);
void handle_vzdump_handshake(struct Client *client, struct json_object *data);
void handle_client(struct Client *client);
void add_new_client(int client_fd);
void cleanup_client(struct Client *client);
void terminate_client(struct Client *client);
void terminate_check(struct Client *client);