/*
 *  OpenVPN -- An application to securely tunnel IP networks
 *             over a single TCP/UDP port, with support for SSL/TLS-based
 *             session authentication and key exchange,
 *             packet encryption, packet authentication, and
 *             packet compression.
 *
 *  Copyright (C) 2002-2026 OpenVPN Inc <sales@openvpn.net>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2
 *  as published by the Free Software Foundation.
 *
 *  This program 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 <https://www.gnu.org/licenses/>.
 */

#ifndef ERROR_H
#define ERROR_H

#include "basic.h"
#include "syshead.h"

#include <assert.h>

/* #define ABORT_ON_ERROR */

#if defined(ENABLE_PKCS11) || defined(ENABLE_MANAGEMENT)
#define ERR_BUF_SIZE 10240
#else
#define ERR_BUF_SIZE 1280
#endif

struct gc_arena;

/*
 * Where should messages be printed before syslog is opened?
 * Not used if OPENVPN_DEBUG_COMMAND_LINE is defined.
 */
#define OPENVPN_MSG_FP   stdout
#define OPENVPN_ERROR_FP stderr

/*
 * Exit status codes
 */

#define OPENVPN_EXIT_STATUS_GOOD                   0
#define OPENVPN_EXIT_STATUS_ERROR                  1
#define OPENVPN_EXIT_STATUS_USAGE                  1
#define OPENVPN_EXIT_STATUS_CANNOT_OPEN_DEBUG_FILE 1

/*
 * Special command line debugging mode.
 * If OPENVPN_DEBUG_COMMAND_LINE
 * is defined, contents of argc/argv will
 * be dumped to OPENVPN_DEBUG_FILE as well
 * as all other OpenVPN messages.
 */

/* #define OPENVPN_DEBUG_COMMAND_LINE */
#define OPENVPN_DEBUG_FILE PACKAGE ".log"

/* String and Error functions */

#ifdef _WIN32
#define openvpn_errno() GetLastError()
const char *strerror_win32(DWORD errnum, struct gc_arena *gc);
#else
#define openvpn_errno() errno
#endif

typedef unsigned int msglvl_t;

/*
 * These globals should not be accessed directly,
 * but rather through macros or inline functions defined below.
 */
extern msglvl_t x_debug_level;
extern int x_msg_line_num;

/* msg() flags */

#define M_DEBUG_LEVEL (0x0Fu) /* debug level mask */

#define M_FATAL    (1u << 4)  /* exit program */
#define M_NONFATAL (1u << 5)  /* non-fatal error */
#define M_WARN     (1u << 6)  /* call syslog with LOG_WARNING */
#define M_DEBUG    (1u << 7)

#define M_ERRNO (1u << 8)         /* show errno description */

#define M_NOMUTE       (1u << 11) /* don't do mute processing */
#define M_NOPREFIX     (1u << 12) /* don't show date/time prefix */
#define M_USAGE_SMALL  (1u << 13) /* fatal options error, call usage_small */
#define M_MSG_VIRT_OUT (1u << 14) /* output message through msg_status_output callback */
#define M_OPTERR       (1u << 15) /* print "Options error:" prefix */
#define M_NOLF         (1u << 16) /* don't print new line */
#define M_NOIPREFIX    (1u << 17) /* don't print instance prefix */

/* flag combinations which are frequently used */
#define M_ERR    (M_FATAL | M_ERRNO)
#define M_USAGE  (M_USAGE_SMALL | M_NOPREFIX | M_OPTERR)
#define M_CLIENT (M_MSG_VIRT_OUT | M_NOMUTE | M_NOIPREFIX)

/*
 * Mute levels are designed to avoid large numbers of
 * mostly similar messages clogging the log file.
 *
 * A mute level of 0 is always printed.
 */
#define MUTE_LEVEL_SHIFT 24
#define MUTE_LEVEL_MASK  0xFFu

#define ENCODE_MUTE_LEVEL(mute_level) (((mute_level) & MUTE_LEVEL_MASK) << MUTE_LEVEL_SHIFT)
#define DECODE_MUTE_LEVEL(flags)      (((flags) >> MUTE_LEVEL_SHIFT) & MUTE_LEVEL_MASK)

/*
 * log_level:  verbosity level n (--verb n) must be >= log_level to print.
 * mute_level: don't print more than n (--mute n) consecutive messages at
 *             a given mute level, or if 0 disable muting and print everything.
 *
 * Mask map:
 * Bits 0-3:   log level
 * Bits 4-23:  M_x flags
 * Bits 24-31: mute level
 */
#define LOGLEV(log_level, mute_level, other) ((log_level) | ENCODE_MUTE_LEVEL(mute_level) | other)

/*
 * If compiler supports variable arguments in macros, define
 * msg() as a macro for optimization win.
 */

/** Check muting filter */
bool dont_mute(msglvl_t flags);

/* Macro to ensure (and teach static analysis tools) we exit on fatal errors */
#define EXIT_FATAL(flags)      \
    do                         \
    {                          \
        if ((flags) & M_FATAL) \
        {                      \
            _exit(1);          \
        }                      \
    } while (false)

#define msg(flags, ...)                  \
    do                                   \
    {                                    \
        if (msg_test(flags))             \
        {                                \
            x_msg((flags), __VA_ARGS__); \
        }                                \
        EXIT_FATAL(flags);               \
    } while (false)
#ifdef ENABLE_DEBUG
#define dmsg(flags, ...)                 \
    do                                   \
    {                                    \
        if (msg_test(flags))             \
        {                                \
            x_msg((flags), __VA_ARGS__); \
        }                                \
        EXIT_FATAL(flags);               \
    } while (false)
#else
#define dmsg(flags, ...)
#endif

void x_msg(const msglvl_t flags, const char *format, ...)
#ifdef __GNUC__
#if __USE_MINGW_ANSI_STDIO
    __attribute__((format(gnu_printf, 2, 3)))
#else
    __attribute__((format(__printf__, 2, 3)))
#endif
#endif
    ; /* should be called via msg above */

void x_msg_va(const msglvl_t flags, const char *format, va_list arglist);

/*
 * Function prototypes
 */

void error_reset(void);

/* route errors to stderr that would normally go to stdout */
void errors_to_stderr(void);

void set_suppress_timestamps(bool suppressed);

void set_machine_readable_output(bool parsable);


#define SDL_CONSTRAIN (1 << 0)
bool set_debug_level(const int level, const unsigned int flags);

bool set_mute_cutoff(const int cutoff);

msglvl_t get_debug_level(void);

int get_mute_cutoff(void);

const char *msg_flags_string(const msglvl_t flags, struct gc_arena *gc);

/*
 * File to print messages to before syslog is opened.
 */
FILE *msg_fp(const msglvl_t flags);

/* Fatal logic errors */
#ifndef ENABLE_SMALL
#define ASSERT(x)                                  \
    do                                             \
    {                                              \
        if (!(x))                                  \
        {                                          \
            assert_failed(__FILE__, __LINE__, #x); \
        }                                          \
    } while (false)
#else
#define ASSERT(x)                                    \
    do                                               \
    {                                                \
        if (!(x))                                    \
        {                                            \
            assert_failed(__FILE__, __LINE__, NULL); \
        }                                            \
    } while (false)
#endif

#ifdef _MSC_VER
__declspec(noreturn)
#endif
void
assert_failed(const char *filename, int line, const char *condition)
#ifndef _MSC_VER
    __attribute__((__noreturn__))
#endif
    ;

/* Inline functions */

static inline bool
check_debug_level(msglvl_t level)
{
    return (level & M_DEBUG_LEVEL) <= x_debug_level;
}

/** Return true if flags represent an enabled, not muted log level */
static inline bool
msg_test(msglvl_t flags)
{
    return check_debug_level(flags) && dont_mute(flags);
}

/* Call if we forked */
void msg_forked(void);

/* syslog output */

void open_syslog(const char *pgmname, bool stdio_to_null);

void close_syslog(void);

/* log file output */
void redirect_stdout_stderr(const char *file, bool append);

#ifdef _WIN32
/* get original stderr fd, even if redirected by --log/--log-append */
int get_orig_stderr(void);

#endif

/* exit program */
void openvpn_exit(const int status);

/* exit program on out of memory error */
void out_of_memory(void);

/*
 * Check the return status of read/write routines.
 */

struct link_socket;
struct tuntap;

extern unsigned int x_cs_info_level;
extern unsigned int x_cs_verbose_level;
extern unsigned int x_cs_err_delay_ms;

void reset_check_status(void);

void set_check_status(unsigned int info_level, unsigned int verbose_level);

void x_check_status(ssize_t status, const char *description, struct link_socket *sock,
                    struct tuntap *tt);

static inline void
check_status(ssize_t status, const char *description, struct link_socket *sock, struct tuntap *tt)
{
    if (status < 0 || check_debug_level(x_cs_verbose_level))
    {
        x_check_status(status, description, sock, tt);
    }
}

static inline void
set_check_status_error_delay(unsigned int milliseconds)
{
    x_cs_err_delay_ms = milliseconds;
}

/*
 * In multiclient mode, put a client-specific prefix
 * before each message.
 *
 * TODO: x_msg_prefix should be thread-local
 */

extern const char *x_msg_prefix;

static inline void
msg_set_prefix(const char *prefix)
{
    x_msg_prefix = prefix;
}

static inline const char *
msg_get_prefix(void)
{
    return x_msg_prefix;
}

/*
 * Allow MSG to be redirected through a virtual_output object
 */

struct virtual_output;

extern const struct virtual_output *x_msg_virtual_output;

static inline void
msg_set_virtual_output(const struct virtual_output *vo)
{
    x_msg_virtual_output = vo;
}

static inline const struct virtual_output *
msg_get_virtual_output(void)
{
    return x_msg_virtual_output;
}

/*
 * Return true if this is a system error
 * which can be safely ignored.
 */
static inline bool
ignore_sys_error(const int err, bool crt_error)
{
#ifdef _WIN32
    if (!crt_error && ((err == WSAEWOULDBLOCK || err == WSAEINVAL)))
    {
        return true;
    }
#else
    crt_error = true;
#endif

    /* I/O operation pending */
    if (crt_error && (err == EAGAIN))
    {
        return true;
    }

#if 0 /* if enabled, suppress ENOBUFS errors */
#ifdef ENOBUFS
    /* No buffer space available */
    if (err == ENOBUFS)
    {
        return true;
    }
#endif
#endif

    return false;
}

/** Convert fatal errors to nonfatal, don't touch other errors */
static inline msglvl_t
nonfatal(const msglvl_t err)
{
    return err & M_FATAL ? (err ^ M_FATAL) | M_NONFATAL : err;
}

static inline int
openvpn_errno_maybe_crt(bool *crt_error)
{
    int err = 0;
    *crt_error = false;
#ifdef _WIN32
    err = GetLastError();
    if (err == ERROR_SUCCESS)
    {
        /* error is likely C runtime */
        *crt_error = true;
        err = errno;
    }
#else /* ifdef _WIN32 */
    *crt_error = true;
    err = errno;
#endif
    return err;
}

#include "errlevel.h"

#endif /* ifndef ERROR_H */
