mongoose.h

#ifdef __AVR__
#include "avrsupport.h"
#endif
/*
 * Copyright (c) 2014 Cesanta Software Limited
 * All rights reserved
 * This software is dual-licensed: 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. For the terms of this
 * license, see <http://www.gnu.org/licenses/>.
 *
 * You are free to use this software under the terms of the GNU General
 * Public License, 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.
 *
 * Alternatively, you can license this software under a commercial
 * license, as set out in <https://www.cesanta.com/license>.
 */

#define MG_FOSSA_VERSION "2.0.0"
/*
 * Copyright (c) 2015 Cesanta Software Limited
 * All rights reserved
 */

#ifndef OSDEP_HEADER_INCLUDED
#define OSDEP_HEADER_INCLUDED

#if !defined(MG_DISABLE_FILESYSTEM) && defined(AVR_NOFS)
#define MG_DISABLE_FILESYSTEM
#endif

#undef UNICODE                /* Use ANSI WinAPI functions */
#undef _UNICODE               /* Use multibyte encoding on Windows */
#define _MBCS                 /* Use multibyte encoding on Windows */
#define _INTEGRAL_MAX_BITS 64 /* Enable _stati64() on Windows */
#ifndef _CRT_SECURE_NO_WARNINGS
#define _CRT_SECURE_NO_WARNINGS /* Disable deprecation warning in VS2005+ */
#endif
#undef WIN32_LEAN_AND_MEAN /* Let windows.h always include winsock2.h */
#undef _XOPEN_SOURCE
#define _XOPEN_SOURCE 600    /* For flockfile() on Linux */
#define __STDC_FORMAT_MACROS /* <inttypes.h> wants this for C++ */
#define __STDC_LIMIT_MACROS  /* C++ wants that for INT64_MAX */
#ifndef _LARGEFILE_SOURCE
#define _LARGEFILE_SOURCE /* Enable fseeko() and ftello() functions */
#endif
#define _FILE_OFFSET_BITS 64 /* Enable 64-bit file offsets */

#if !(defined(AVR_LIBC) || defined(PICOTCP))
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <time.h>
#include <signal.h>
#endif

#ifndef BYTE_ORDER
#define LITTLE_ENDIAN 0x41424344
#define BIG_ENDIAN 0x44434241
#define PDP_ENDIAN 0x42414443
/* TODO(lsm): fix for big-endian machines. 'ABCD' is not portable */
/*#define BYTE_ORDER 'ABCD'*/
#define BYTE_ORDER LITTLE_ENDIAN
#endif

/*
 * MSVC++ 12.0 _MSC_VER == 1800 (Visual Studio 2013)
 * MSVC++ 11.0 _MSC_VER == 1700 (Visual Studio 2012)
 * MSVC++ 10.0 _MSC_VER == 1600 (Visual Studio 2010)
 * MSVC++ 9.0  _MSC_VER == 1500 (Visual Studio 2008)
 * MSVC++ 8.0  _MSC_VER == 1400 (Visual Studio 2005)
 * MSVC++ 7.1  _MSC_VER == 1310 (Visual Studio 2003)
 * MSVC++ 7.0  _MSC_VER == 1300
 * MSVC++ 6.0  _MSC_VER == 1200
 * MSVC++ 5.0  _MSC_VER == 1100
 */
#ifdef _MSC_VER
#pragma warning(disable : 4127) /* FD_SET() emits warning, disable it */
#pragma warning(disable : 4204) /* missing c99 support */
#endif

#ifdef PICOTCP
#define time(x) PICO_TIME()
#ifndef SOMAXCONN
#define SOMAXCONN (16)
#endif
#ifdef _POSIX_VERSION
#define signal(...)
#endif
#endif

#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <stdarg.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#ifndef va_copy
#ifdef __va_copy
#define va_copy __va_copy
#else
#define va_copy(x, y) (x) = (y)
#endif
#endif

#ifdef _WIN32
#define random() rand()
#ifdef _MSC_VER
#pragma comment(lib, "ws2_32.lib") /* Linking with winsock library */
#endif
#include <windows.h>
#include <process.h>
#ifndef EINPROGRESS
#define EINPROGRESS WSAEINPROGRESS
#endif
#ifndef EWOULDBLOCK
#define EWOULDBLOCK WSAEWOULDBLOCK
#endif
#ifndef __func__
#define STRX(x) #x
#define STR(x) STRX(x)
#define __func__ __FILE__ ":" STR(__LINE__)
#endif
#define snprintf _snprintf
#define vsnprintf _vsnprintf
#define sleep(x) Sleep((x) *1000)
#define to64(x) _atoi64(x)
#define popen(x, y) _popen((x), (y))
#define pclose(x) _pclose(x)
#if defined(_MSC_VER) && _MSC_VER >= 1400
#define fseeko(x, y, z) _fseeki64((x), (y), (z))
#else
#define fseeko(x, y, z) fseek((x), (y), (z))
#endif
#define random() rand()
typedef int socklen_t;
typedef char int8_t;
typedef unsigned char uint8_t;
typedef int int32_t;
typedef unsigned int uint32_t;
typedef short int16_t;
typedef unsigned short uint16_t;
typedef __int64 int64_t;
typedef unsigned __int64 uint64_t;
typedef SOCKET sock_t;
typedef uint32_t in_addr_t;
#ifndef UINT16_MAX
#define UINT16_MAX 65535
#endif
#ifndef UINT32_MAX
#define UINT32_MAX 4294967295
#endif
#ifndef pid_t
#define pid_t HANDLE
#endif
#define INT64_FMT "I64d"
#define SIZE_T_FMT "Iu"
#ifdef __MINGW32__
typedef struct stat cs_stat_t;
#else
typedef struct _stati64 cs_stat_t;
#endif
#ifndef S_ISDIR
#define S_ISDIR(x) ((x) &_S_IFDIR)
#endif
#define DIRSEP '\\'

/* POSIX opendir/closedir/readdir API for Windows. */
struct dirent {
  char d_name[MAX_PATH];
};

typedef struct DIR {
  HANDLE handle;
  WIN32_FIND_DATAW info;
  struct dirent result;
} DIR;

DIR *opendir(const char *name);
int closedir(DIR *dir);
struct dirent *readdir(DIR *dir);

#elif /* not _WIN32 */ defined(MG_CC3200)

#include <fcntl.h>
#include <unistd.h>
#include <cc3200_libc.h>
#include <cc3200_socket.h>

#elif /* not CC3200 */ defined(MG_ESP8266) && defined(RTOS_SDK)

#include <lwip/sockets.h>
#include <lwip/netdb.h>
#include <lwip/dns.h>
#include <esp_libc.h>
#define random() os_random()
/* TODO(alashkin): check if zero is OK */
#define SOMAXCONN 0
#include <stdlib.h>

#elif /* not ESP8266 RTOS */ !defined(NO_LIBC) && !defined(NO_BSD_SOCKETS)

#include <dirent.h>
#include <fcntl.h>
#include <netdb.h>
#include <pthread.h>
#include <unistd.h>
#include <arpa/inet.h> /* For inet_pton() when MG_ENABLE_IPV6 is defined */
#include <netinet/in.h>
#include <sys/socket.h>
#include <sys/select.h>
#endif

#ifndef _WIN32
#include <errno.h>
#include <inttypes.h>
#include <stdarg.h>

#ifndef AVR_LIBC
#ifndef MG_ESP8266
#define closesocket(x) close(x)
#endif
#ifndef __cdecl
#define __cdecl
#endif

#define INVALID_SOCKET (-1)
#define INT64_FMT PRId64
#define SIZE_T_FMT "zu"
#define to64(x) strtoll(x, NULL, 10)
typedef int sock_t;
typedef struct stat cs_stat_t;
#define DIRSEP '/'
#endif /* !AVR_LIBC */

#ifdef __APPLE__
int64_t strtoll(const char *str, char **endptr, int base);
#endif
#endif /* !_WIN32 */

#define __DBG(x)                \
  do {                          \
    printf("%-20s ", __func__); \
    printf x;                   \
    putchar('\n');              \
    fflush(stdout);             \
  } while (0)

#ifdef MG_ENABLE_DEBUG
#define DBG __DBG
#else
#define DBG(x)
#endif

#ifndef ARRAY_SIZE
#define ARRAY_SIZE(array) (sizeof(array) / sizeof(array[0]))
#endif

#endif /* OSDEP_HEADER_INCLUDED */
/*
 * Copyright (c) 2015 Cesanta Software Limited
 * All rights reserved
 */

/*
 * === Memory Buffers
 *
 * Mbufs are mutable/growing memory buffers, like C++ strings.
 * Mbuf can append data to the end of a buffer, or insert data into arbitrary
 * position in the middle of a buffer. The buffer grows automatically when
 * needed.
 */

#ifndef MBUF_H_INCLUDED
#define MBUF_H_INCLUDED

#if defined(__cplusplus)
extern "C" {
#endif

#include <stdlib.h>

#ifndef MBUF_SIZE_MULTIPLIER
#define MBUF_SIZE_MULTIPLIER 1.5
#endif

/* Memory buffer descriptor */
struct mbuf {
  char *buf;   /* Buffer pointer */
  size_t len;  /* Data length. Data is located between offset 0 and len. */
  size_t size; /* Buffer size allocated by realloc(1). Must be >= len */
};

/*
 * Initialize an Mbuf.
 * `initial_capacity` specifies the initial capacity of the mbuf.
 */
void mbuf_init(struct mbuf *, size_t initial_capacity);

/* Free the space allocated for the mbuffer and resets the mbuf structure. */
void mbuf_free(struct mbuf *);

/*
 * Appends data to the Mbuf.
 *
 * Return the number of bytes appended, or 0 if out of memory.
 */
size_t mbuf_append(struct mbuf *, const void *data, size_t data_size);

/*
 * Insert data at a specified offset in the Mbuf.
 *
 * Existing data will be shifted forwards and the buffer will
 * be grown if necessary.
 * Return the number of bytes inserted.
 */
size_t mbuf_insert(struct mbuf *, size_t, const void *, size_t);

/* Remove `data_size` bytes from the beginning of the buffer. */
void mbuf_remove(struct mbuf *, size_t data_size);

/*
 * Resize an Mbuf.
 *
 * If `new_size` is smaller than buffer's `len`, the
 * resize is not performed.
 */
void mbuf_resize(struct mbuf *, size_t new_size);

/* Shrink an Mbuf by resizing its `size` to `len`. */
void mbuf_trim(struct mbuf *);

#if defined(__cplusplus)
}
#endif /* __cplusplus */

#endif /* MBUF_H_INCLUDED */
/*
 * Copyright (c) 2014 Cesanta Software Limited
 * All rights reserved
 */

#if !defined(MG_SHA1_HEADER_INCLUDED) && !defined(DISABLE_SHA1)
#define MG_SHA1_HEADER_INCLUDED


#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */

typedef struct {
  uint32_t state[5];
  uint32_t count[2];
  unsigned char buffer[64];
} cs_sha1_ctx;

void cs_sha1_init(cs_sha1_ctx *);
void cs_sha1_update(cs_sha1_ctx *, const unsigned char *data, uint32_t len);
void cs_sha1_final(unsigned char digest[20], cs_sha1_ctx *);
void cs_hmac_sha1(const unsigned char *key, size_t key_len,
                  const unsigned char *text, size_t text_len,
                  unsigned char out[20]);
#ifdef __cplusplus
}
#endif /* __cplusplus */
#endif /* MG_SHA1_HEADER_INCLUDED */
/*
 * Copyright (c) 2014 Cesanta Software Limited
 * All rights reserved
 */

#ifndef MD5_HEADER_DEFINED
#define MD5_HEADER_DEFINED


#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */

typedef struct MD5Context {
  uint32_t buf[4];
  uint32_t bits[2];
  unsigned char in[64];
} MD5_CTX;

void MD5_Init(MD5_CTX *c);
void MD5_Update(MD5_CTX *c, const unsigned char *data, size_t len);
void MD5_Final(unsigned char *md, MD5_CTX *c);

#ifdef __cplusplus
}
#endif /* __cplusplus */

#endif
/*
 * Copyright (c) 2014 Cesanta Software Limited
 * All rights reserved
 */

#if !defined(BASE64_H_INCLUDED) && !defined(DISABLE_BASE64)
#define BASE64_H_INCLUDED

#include <stdio.h>

#ifdef __cplusplus
extern "C" {
#endif

typedef void (*cs_base64_putc_t)(char, void *);

struct cs_base64_ctx {
  /* cannot call it putc because it's a macro on some environments */
  cs_base64_putc_t b64_putc;
  unsigned char chunk[3];
  int chunk_size;
  void *user_data;
};

void cs_base64_init(struct cs_base64_ctx *ctx, cs_base64_putc_t putc,
                    void *user_data);
void cs_base64_update(struct cs_base64_ctx *ctx, const char *str, size_t len);
void cs_base64_finish(struct cs_base64_ctx *ctx);

void cs_base64_encode(const unsigned char *src, int src_len, char *dst);
void cs_fprint_base64(FILE *f, const unsigned char *src, int src_len);
int cs_base64_decode(const unsigned char *s, int len, char *dst);

#ifdef __cplusplus
}
#endif
#endif
/*
 * Copyright (c) 2015 Cesanta Software Limited
 * All rights reserved
 */

#ifndef STR_UTIL_H
#define STR_UTIL_H

#include <stdarg.h>
#include <stdlib.h>

#ifdef __cplusplus
extern "C" {
#endif

int c_snprintf(char *buf, size_t buf_size, const char *format, ...);
int c_vsnprintf(char *buf, size_t buf_size, const char *format, va_list ap);

#if !(_XOPEN_SOURCE >= 700 || _POSIX_C_SOURCE >= 200809L) &&    \
        !(__DARWIN_C_LEVEL >= 200809L) && !defined(RTOS_SDK) || \
    defined(_WIN32)
int strnlen(const char *s, size_t maxlen);
#endif

#ifdef __cplusplus
}
#endif
#endif
/*
 * Copyright (c) 2004-2013 Sergey Lyubka <valenok@gmail.com>
 * Copyright (c) 2013 Cesanta Software Limited
 * All rights reserved
 *
 * This library is dual-licensed: 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. For the terms of this
 * license, see <http: *www.gnu.org/licenses/>.
 *
 * You are free to use this library under the terms of the GNU General
 * Public License, 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.
 *
 * Alternatively, you can license this library under a commercial
 * license, as set out in <https://www.cesanta.com/license>.
 */

#ifndef FROZEN_HEADER_INCLUDED
#define FROZEN_HEADER_INCLUDED

#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */

#include <stdarg.h>

enum json_type {
  JSON_TYPE_EOF     = 0,      /* End of parsed tokens marker */
  JSON_TYPE_STRING  = 1,
  JSON_TYPE_NUMBER  = 2,
  JSON_TYPE_OBJECT  = 3,
  JSON_TYPE_TRUE    = 4,
  JSON_TYPE_FALSE   = 5,
  JSON_TYPE_NULL    = 6,
  JSON_TYPE_ARRAY   = 7
};

struct json_token {
  const char *ptr;      /* Points to the beginning of the token */
  int len;              /* Token length */
  int num_desc;         /* For arrays and object, total number of descendants */
  enum json_type type;  /* Type of the token, possible values above */
};

/* Error codes */
#define JSON_STRING_INVALID           -1
#define JSON_STRING_INCOMPLETE        -2
#define JSON_TOKEN_ARRAY_TOO_SMALL    -3

int parse_json(const char *json_string, int json_string_length,
               struct json_token *tokens_array, int size_of_tokens_array);
struct json_token *parse_json2(const char *json_string, int string_length);
struct json_token *find_json_token(struct json_token *toks, const char *path);

int json_emit_long(char *buf, int buf_len, long value);
int json_emit_double(char *buf, int buf_len, double value);
int json_emit_quoted_str(char *buf, int buf_len, const char *str, int len);
int json_emit_unquoted_str(char *buf, int buf_len, const char *str, int len);
int json_emit(char *buf, int buf_len, const char *fmt, ...);
int json_emit_va(char *buf, int buf_len, const char *fmt, va_list);

#ifdef __cplusplus
}
#endif /* __cplusplus */

#endif /* FROZEN_HEADER_INCLUDED */
/*
 * Copyright (c) 2014 Cesanta Software Limited
 * All rights reserved
 * This software is dual-licensed: 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. For the terms of this
 * license, see <http://www.gnu.org/licenses/>.
 *
 * You are free to use this software under the terms of the GNU General
 * Public License, 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.
 *
 * Alternatively, you can license this software under a commercial
 * license, as set out in <https://www.cesanta.com/license>.
 */

/*
 * === Core: TCP/UDP/SSL
 *
 * NOTE: Mongoose manager is single threaded. It does not protect
 * its data structures by mutexes, therefore all functions that are dealing
 * with particular event manager should be called from the same thread,
 * with exception of `mg_broadcast()` function. It is fine to have different
 * event managers handled by different threads.
 */

#ifndef MG_NET_HEADER_INCLUDED
#define MG_NET_HEADER_INCLUDED


#ifdef MG_ENABLE_SSL
#ifdef __APPLE__
#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
#endif
#include <openssl/ssl.h>
#else
typedef void *SSL;
typedef void *SSL_CTX;
#endif

#ifdef MG_USE_READ_WRITE
#define MG_EV_RECV_FUNC(s, b, l, f) read(s, b, l)
#define MG_EV_SEND_FUNC(s, b, l, f) write(s, b, l)
#else
#define MG_EV_RECV_FUNC(s, b, l, f) recv(s, b, l, f)
#define MG_EV_SEND_FUNC(s, b, l, f) send(s, b, l, f)
#endif

#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */

union socket_address {
  struct sockaddr sa;
  struct sockaddr_in sin;
#ifdef MG_ENABLE_IPV6
  struct sockaddr_in6 sin6;
#else
  struct sockaddr sin6;
#endif
};

/* Describes chunk of memory */
struct mg_str {
  const char *p; /* Memory chunk pointer */
  size_t len;    /* Memory chunk length */
};

#define MG_STR(str_literal) \
  { str_literal, sizeof(str_literal) - 1 }

/*
 * Callback function (event handler) prototype, must be defined by user.
 * Mongoose calls event handler, passing events defined below.
 */
struct mg_connection;
typedef void (*mg_event_handler_t)(struct mg_connection *, int ev, void *);

/* Events. Meaning of event parameter (evp) is given in the comment. */
#define MG_EV_POLL 0    /* Sent to each connection on each mg_mgr_poll() call */
#define MG_EV_ACCEPT 1  /* New connection accepted. union socket_address * */
#define MG_EV_CONNECT 2 /* connect() succeeded or failed. int *  */
#define MG_EV_RECV 3    /* Data has benn received. int *num_bytes */
#define MG_EV_SEND 4    /* Data has been written to a socket. int *num_bytes */
#define MG_EV_CLOSE 5   /* Connection is closed. NULL */

/*
 * Mongoose event manager.
 */
struct mg_mgr {
  struct mg_connection *active_connections;
  const char *hexdump_file; /* Debug hexdump file path */
  sock_t ctl[2];            /* Socketpair for mg_wakeup() */
  void *user_data;          /* User data */
  void *mgr_data;           /* Implementation-specific event manager's data. */
};

/*
 * Mongoose connection.
 */
struct mg_connection {
  struct mg_connection *next, *prev; /* mg_mgr::active_connections linkage */
  struct mg_connection *listener;    /* Set only for accept()-ed connections */
  struct mg_mgr *mgr;                /* Pointer to containing manager */

  sock_t sock;             /* Socket to the remote peer */
  union socket_address sa; /* Remote peer address */
  size_t recv_mbuf_limit;  /* Max size of recv buffer */
  struct mbuf recv_mbuf;   /* Received data */
  struct mbuf send_mbuf;   /* Data scheduled for sending */
  SSL *ssl;
  SSL_CTX *ssl_ctx;
  time_t last_io_time;              /* Timestamp of the last socket IO */
  mg_event_handler_t proto_handler; /* Protocol-specific event handler */
  void *proto_data;                 /* Protocol-specific data */
  mg_event_handler_t handler;       /* Event handler function */
  void *user_data;                  /* User-specific data */
  void *priv_1;                     /* Used by mg_enable_multithreading() */
  void *priv_2;                     /* Used by mg_enable_multithreading() */
  void *mgr_data; /* Implementation-specific event manager's data. */

  unsigned long flags;
/* Flags set by Mongoose */
#define MG_F_LISTENING (1 << 0)          /* This connection is listening */
#define MG_F_UDP (1 << 1)                /* This connection is UDP */
#define MG_F_RESOLVING (1 << 2)          /* Waiting for async resolver */
#define MG_F_CONNECTING (1 << 3)         /* connect() call in progress */
#define MG_F_SSL_HANDSHAKE_DONE (1 << 4) /* SSL specific */
#define MG_F_WANT_READ (1 << 5)          /* SSL specific */
#define MG_F_WANT_WRITE (1 << 6)         /* SSL specific */
#define MG_F_IS_WEBSOCKET (1 << 7)       /* Websocket specific */

/* Flags that are settable by user */
#define MG_F_SEND_AND_CLOSE (1 << 10)      /* Push remaining data and close  */
#define MG_F_DONT_SEND (1 << 11)           /* Do not send data to peer */
#define MG_F_CLOSE_IMMEDIATELY (1 << 12)   /* Disconnect */
#define MG_F_WEBSOCKET_NO_DEFRAG (1 << 13) /* Websocket specific */
#define MG_F_DELETE_CHUNK (1 << 14)        /* HTTP specific */

#define MG_F_USER_1 (1 << 20) /* Flags left for application */
#define MG_F_USER_2 (1 << 21)
#define MG_F_USER_3 (1 << 22)
#define MG_F_USER_4 (1 << 23)
#define MG_F_USER_5 (1 << 24)
#define MG_F_USER_6 (1 << 25)
};

/*
 * Initialize Mongoose manager. Side effect: ignores SIGPIPE signal.
 * `mgr->user_data` field will be initialized with `user_data` parameter.
 * That is an arbitrary pointer, where user code can associate some data
 * with the particular Mongoose manager. For example, a C++ wrapper class
 * could be written, in which case `user_data` can hold a pointer to the
 * class instance.
 */
void mg_mgr_init(struct mg_mgr *mgr, void *user_data);

/*
 * De-initializes Mongoose manager.
 *
 * Close and deallocate all active connections.
 */
void mg_mgr_free(struct mg_mgr *);

/*
 * This function performs the actual IO, and must be called in a loop
 * (an event loop). Returns the current timestamp.
 * `milli` is the maximum number of milliseconds to sleep.
 * `mg_mgr_poll()` checks all connection for IO readiness. If at least one
 * of the connections is IO-ready, `mg_mgr_poll()` triggers respective
 * event handlers and returns.
 */
time_t mg_mgr_poll(struct mg_mgr *, int milli);

/*
 * Pass a message of a given length to all connections.
 *
 * Must be called from a thread that does NOT call `mg_mgr_poll()`.
 * Note that `mg_broadcast()` is the only function
 * that can be, and must be, called from a different (non-IO) thread.
 *
 * `func` callback function will be called by the IO thread for each
 * connection. When called, event would be `MG_EV_POLL`, and message will
 * be passed as `ev_data` pointer. Maximum message size is capped
 * by `MG_CTL_MSG_MESSAGE_SIZE` which is set to 8192 bytes.
 */
void mg_broadcast(struct mg_mgr *, mg_event_handler_t func, void *, size_t);

/*
 * Iterate over all active connections.
 *
 * Returns next connection from the list
 * of active connections, or `NULL` if there is no more connections. Below
 * is the iteration idiom:
 *
 * [source,c]
 * ----
 * for (c = mg_next(srv, NULL); c != NULL; c = mg_next(srv, c)) {
 *   // Do something with connection `c`
 * }
 * ----
 */
struct mg_connection *mg_next(struct mg_mgr *, struct mg_connection *);

/*
 * Optional parameters to mg_add_sock_opt()
 * `flags` is an initial `struct mg_connection::flags` bitmask to set,
 * see `MG_F_*` flags definitions.
 */
struct mg_add_sock_opts {
  void *user_data;           /* Initial value for connection's user_data */
  unsigned int flags;        /* Initial connection flags */
  const char **error_string; /* Placeholder for the error string */
};

/*
 * Create a connection, associate it with the given socket and event handler,
 * and add it to the manager.
 *
 * For more options see the `mg_add_sock_opt` variant.
 */
struct mg_connection *mg_add_sock(struct mg_mgr *, sock_t, mg_event_handler_t);

/*
 * Create a connection, associate it with the given socket and event handler,
 * and add to the manager.
 *
 * See the `mg_add_sock_opts` structure for a description of the options.
 */
struct mg_connection *mg_add_sock_opt(struct mg_mgr *, sock_t,
                                      mg_event_handler_t,
                                      struct mg_add_sock_opts);

/*
 * Optional parameters to mg_bind_opt()
 * `flags` is an initial `struct mg_connection::flags` bitmask to set,
 * see `MG_F_*` flags definitions.
 */
struct mg_bind_opts {
  void *user_data;           /* Initial value for connection's user_data */
  unsigned int flags;        /* Extra connection flags */
  const char **error_string; /* Placeholder for the error string */
};

/*
 * Create listening connection.
 *
 * See `mg_bind_opt` for full documentation.
 */
struct mg_connection *mg_bind(struct mg_mgr *, const char *,
                              mg_event_handler_t);
/*
 * Create listening connection.
 *
 * `address` parameter tells which address to bind to. It's format is the same
 * as for the `mg_connect()` call, where `HOST` part is optional. `address`
 * can be just a port number, e.g. `:8000`. To bind to a specific interface,
 * an IP address can be specified, e.g. `1.2.3.4:8000`. By default, a TCP
 * connection is created. To create UDP connection, prepend `udp://` prefix,
 * e.g. `udp://:8000`. To summarize, `address` paramer has following format:
 * `[PROTO://][IP_ADDRESS]:PORT`, where `PROTO` could be `tcp` or `udp`.
 *
 * See the `mg_bind_opts` structure for a description of the optional
 * parameters.
 *
 * Return a new listening connection, or `NULL` on error.
 * NOTE: Connection remains owned by the manager, do not free().
 */
struct mg_connection *mg_bind_opt(struct mg_mgr *, const char *,
                                  mg_event_handler_t, struct mg_bind_opts);

/* Optional parameters to mg_connect_opt() */
struct mg_connect_opts {
  void *user_data;           /* Initial value for connection's user_data */
  unsigned int flags;        /* Extra connection flags */
  const char **error_string; /* Placeholder for the error string */
};

/*
 * Connect to a remote host.
 *
 * See `mg_connect_opt()` for full documentation.
 */
struct mg_connection *mg_connect(struct mg_mgr *, const char *,
                                 mg_event_handler_t);

/*
 * Connect to a remote host.
 *
 * `address` format is `[PROTO://]HOST:PORT`. `PROTO` could be `tcp` or `udp`.
 * `HOST` could be an IP address,
 * IPv6 address (if Mongoose is compiled with `-DMG_ENABLE_IPV6`), or a host
 * name. If `HOST` is a name, Mongoose will resolve it asynchronously. Examples
 * of valid addresses: `google.com:80`, `udp://1.2.3.4:53`, `10.0.0.1:443`,
 * `[::1]:80`
 *
 * See the `mg_connect_opts` structure for a description of the optional
 * parameters.
 *
 * Returns a new outbound connection, or `NULL` on error.
 *
 * NOTE: Connection remains owned by the manager, do not free().
 *
 * NOTE: To enable IPv6 addresses, `-DMG_ENABLE_IPV6` should be specified
 * in the compilation flags.
 *
 * NOTE: New connection will receive `MG_EV_CONNECT` as it's first event
 * which will report connect success status.
 * If asynchronous resolution fail, or `connect()` syscall fail for whatever
 * reason (e.g. with `ECONNREFUSED` or `ENETUNREACH`), then `MG_EV_CONNECT`
 * event report failure. Code example below:
 *
 * [source,c]
 * ----
 * static void ev_handler(struct mg_connection *nc, int ev, void *ev_data) {
 *   int connect_status;
 *
 *   switch (ev) {
 *     case MG_EV_CONNECT:
 *       connect_status = * (int *) ev_data;
 *       if (connect_status == 0) {
 *         // Success
 *       } else  {
 *         // Error
 *         printf("connect() error: %s\n", strerror(connect_status));
 *       }
 *       break;
 *     ...
 *   }
 * }
 *
 *   ...
 *   mg_connect(mgr, "my_site.com:80", ev_handler);
 * ----
 */
struct mg_connection *mg_connect_opt(struct mg_mgr *, const char *,
                                     mg_event_handler_t,
                                     struct mg_connect_opts);

/*
 * Enable SSL for a given connection.
 * `cert` is a server certificate file name for a listening connection,
 * or a client certificate file name for an outgoing connection.
 * Certificate files must be in PEM format. Server certificate file
 * must contain a certificate, concatenated with a private key, optionally
 * concatenated with parameters.
 * `ca_cert` is a CA certificate, or NULL if peer verification is not
 * required.
 * Return: NULL on success, or error message on error.
 */
const char *mg_set_ssl(struct mg_connection *nc, const char *cert,
                       const char *ca_cert);

/*
 * Send data to the connection.
 *
 * Return number of written bytes. Note that sending
 * functions do not actually push data to the socket. They just append data
 * to the output buffer. The exception is UDP connections. For UDP, data is
 * sent immediately, and returned value indicates an actual number of bytes
 * sent to the socket.
 */
int mg_send(struct mg_connection *, const void *buf, int len);

/*
 * Send `printf`-style formatted data to the connection.
 *
 * See `mg_send` for more details on send semantics.
 */
int mg_printf(struct mg_connection *, const char *fmt, ...);

/* Same as `mg_printf()`, but takes `va_list ap` as an argument. */
int mg_vprintf(struct mg_connection *, const char *fmt, va_list ap);

/*
 * Create a socket pair.
 * `sock_type` can be either `SOCK_STREAM` or `SOCK_DGRAM`.
 * Return 0 on failure, 1 on success.
 */
int mg_socketpair(sock_t[2], int sock_type);

/*
 * Convert domain name into IP address.
 *
 * This is a utility function. If compilation flags have
 * `-DMG_ENABLE_GETADDRINFO`, then `getaddrinfo()` call is used for name
 * resolution. Otherwise, `gethostbyname()` is used.
 *
 * CAUTION: this function can block.
 * Return 1 on success, 0 on failure.
 */
int mg_resolve(const char *domain_name, char *ip_addr_buf, size_t buf_len);

/*
 * Verify given IP address against the ACL.
 *
 * `remote_ip` - an IPv4 address to check, in host byte order
 * `acl` - a comma separated list of IP subnets: `x.x.x.x/x` or `x.x.x.x`.
 * Each subnet is
 * prepended by either a - or a + sign. A plus sign means allow, where a
 * minus sign means deny. If a subnet mask is omitted, such as `-1.2.3.4`,
 * this means to deny only that single IP address.
 * Subnet masks may vary from 0 to 32, inclusive. The default setting
 * is to allow all accesses. On each request the full list is traversed,
 * and the last match wins. Example:
 *
 * `-0.0.0.0/0,+192.168/16` - deny all acccesses, only allow 192.168/16 subnet
 *
 * To learn more about subnet masks, see the
 * link:https://en.wikipedia.org/wiki/Subnetwork[Wikipedia page on Subnetwork]
 *
 * Return -1 if ACL is malformed, 0 if address is disallowed, 1 if allowed.
 */
int mg_check_ip_acl(const char *acl, uint32_t remote_ip);

/*
 * Enable multi-threaded handling for the given listening connection `nc`.
 * For each accepted connection, Mongoose will create a separate thread
 * and run event handler in that thread. Thus, if an event hanler is doing
 * a blocking call or some long computation, that will not slow down
 * other connections.
 */
void mg_enable_multithreading(struct mg_connection *nc);

#ifdef __cplusplus
}
#endif /* __cplusplus */

#endif /* MG_NET_HEADER_INCLUDED */
/*
 * Copyright (c) 2014 Cesanta Software Limited
 * All rights reserved
 */

/*
 * === Utilities
 */

#ifndef MG_UTIL_HEADER_DEFINED
#define MG_UTIL_HEADER_DEFINED

#include <stdio.h>


#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */

#ifndef MAX_PATH_SIZE
#define MAX_PATH_SIZE 500
#endif

/*
 * Fetch substring from input string `s`, `end` into `v`.
 * Skips initial delimiter characters. Records first non-delimiter character
 * as the beginning of substring `v`. Then scans the rest of the string
 * until a delimiter character or end-of-string is found.
 * `delimiters` is a 0-terminated string containing delimiter characters.
 * Either one of `delimiters` or `end_string` terminates the search.
 * Return an `s` pointer, advanced forward where parsing stopped.
 */
const char *mg_skip(const char *s, const char *end_string,
                    const char *delimiters, struct mg_str *v);

/*
 * Cross-platform version of `strncasecmp()`.
 */