// Copyright (c) 2004-2013 Sergey Lyubka // Copyright (c) 2013-2020 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 . // // 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 . #pragma once #define MG_VERSION "7.0" #define MG_ARCH_CUSTOM 0 #define MG_ARCH_UNIX 1 #define MG_ARCH_WIN32 2 #define MG_ARCH_ESP32 3 #define MG_ARCH_ESP8266 4 #define MG_ARCH_CC3100 5 #define MG_ARCH_CC3200 6 #define MG_ARCH_CC3220 7 #define MG_ARCH_MSP432 8 #define MG_ARCH_TM4C129 9 #define MG_ARCH_MBED 10 #define MG_ARCH_WINCE 11 #define MG_ARCH_NXP_LPC 12 #define MG_ARCH_NXP_KINETIS 13 #define MG_ARCH_NRF51 14 #define MG_ARCH_NRF52 15 #define MG_ARCH_PIC32 16 #define MG_ARCH_RS14100 17 #define MG_ARCH_STM32 18 #define MG_ARCH_FREERTOS 19 #if !defined(MG_ARCH) #if defined(TARGET_IS_MSP432P4XX) || defined(__MSP432P401R__) #define MG_ARCH MG_ARCH_MSP432 #elif defined(cc3200) || defined(TARGET_IS_CC3200) #define MG_ARCH MG_ARCH_CC3200 #elif defined(cc3220) || defined(TARGET_IS_CC3220) #define MG_ARCH MG_ARCH_CC3220 #elif defined(__unix__) || defined(__APPLE__) #define MG_ARCH MG_ARCH_UNIX #elif defined(WINCE) #define MG_ARCH MG_ARCH_WINCE #elif defined(_WIN32) #define MG_ARCH MG_ARCH_WIN32 #elif defined(__MBED__) #define MG_ARCH MG_ARCH_MBED #elif defined(__USE_LPCOPEN) #define MG_ARCH MG_ARCH_NXP_LPC #elif defined(FRDM_K64F) || defined(FREEDOM) #define MG_ARCH MG_ARCH_NXP_KINETIS #elif defined(PIC32) #define MG_ARCH MG_ARCH_PIC32 #elif defined(ESP_PLATFORM) #define MG_ARCH MG_ARCH_ESP32 #elif defined(ICACHE_FLASH) || defined(ICACHE_RAM_ATTR) #define MG_ARCH MG_ARCH_ESP8266 #elif defined(TARGET_IS_TM4C129_RA0) || defined(TARGET_IS_TM4C129_RA1) || \ defined(TARGET_IS_TM4C129_RA2) #define MG_ARCH MG_ARCH_TM4C129 #elif defined(RS14100) #define MG_ARCH MG_ARCH_RS14100 #elif defined(STM32) #define MG_ARCH MG_ARCH_STM32 #endif #if !defined(MG_ARCH) #error "MG_ARCH is not specified and we couldn't guess it." #endif #endif // !defined(MG_ARCH) #define WIN32_LEAN_AND_MEAN #define _CRT_SECURE_NO_WARNINGS #define _WINSOCK_DEPRECATED_NO_WARNINGS // Standard C headers #include #include #include #include #include #include #include #include #include #include #include #include #if MG_ARCH == MG_ARCH_CUSTOM #include #endif #if !defined(PRINTF_LIKE) #if defined(__GNUC__) || defined(__clang__) || defined(__TI_COMPILER_VERSION__) #define PRINTF_LIKE(f, a) __attribute__((format(printf, f, a))) #else #define PRINTF_LIKE(f, a) #endif #endif #if MG_ARCH == MG_ARCH_ESP32 #include #include #define MG_DIRSEP '/' #endif #if MG_ARCH == MG_ARCH_ESP8266 #include #include #include #include #define MG_DIRSEP '/' #ifndef PATH_MAX #define PATH_MAX 128 #endif #define MG_ENABLE_LWIP 1 #define LWIP_TIMEVAL_PRIVATE 0 // struct timeval is defined in sys/time.h #if LWIP_SOCKET #include #else #undef LWIP_SOCKET #define LWIP_SOCKET 1 #include // Source sockaddr_in anyway #undef LWIP_SOCKET #define LWIP_SOCKET 0 #endif #endif #if MG_ARCH == MG_ARCH_FREERTOS #include #include #include #include #include #define MG_DIRSEP '/' #define IPPROTO_TCP FREERTOS_IPPROTO_TCP #define IPPROTO_UDP FREERTOS_IPPROTO_UDP #define AF_INET FREERTOS_AF_INET #define SOCK_STREAM FREERTOS_SOCK_STREAM #define SOCK_DGRAM FREERTOS_SOCK_DGRAM #define SO_BROADCAST 0 #define SO_ERROR 0 #define SOL_SOCKET 0 #define SO_REUSEADDR 0 #define sockaddr_in freertos_sockaddr struct sockaddr { uint8_t sa_len, sa_family; }; #define accept(a, b, c) FreeRTOS_accept((a), (b), (c)) #define connect(a, b, c) FreeRTOS_connect((a), (b), (c)) #define bind(a, b, c) FreeRTOS_bind((a), (b), (c)) #define listen(a, b) FreeRTOS_listen((a), (b)) #define socket(a, b, c) FreeRTOS_socket((a), (b), (c)) #define send(a, b, c, d) FreeRTOS_send((a), (b), (c), (d)) #define recv(a, b, c, d) FreeRTOS_recv((a), (b), (c), (d)) #define setsockopt(a, b, c, d, e) FreeRTOS_setsockopt((a), (b), (c), (d), (e)) #define sendto(a, b, c, d, e, f) FreeRTOS_sendto((a), (b), (c), (d), (e), (f)) #define recvfrom(a, b, c, d, e, f) \ FreeRTOS_recvfrom((a), (b), (c), (d), (e), (f)) #define closesocket(x) FreeRTOS_closesocket(x) #define gethostbyname(x) FreeRTOS_gethostbyname(x) #include #undef FILE #define FILE FF_FILE //#define SEEK_SET FF_SEEK_SET //#define SEEK_END FF_SEEK_END #define stat(a, b) ff_stat((a), (b)) #define fopen(a, b) ff_fopen((a), (b)) #define fclose(a) ff_fclose(a) #define fread(a, b, c, d) ff_fread((a), (b), (c), (d)) #define fwrite(a, b, c, d) ff_fwrite((a), (b), (c), (d)) #define vfprintf ff_vfprintf #define fprintf ff_fprintf #define remove(a) ff_remove(a) #define rename(a, b) ff_rename((a), (b), 1) static inline int ff_vfprintf(FF_FILE *fp, const char *fmt, va_list ap) { char *buf = NULL; int n = mg_vasprintf(&buf, 0, fmt, ap); if (buf != NULL) ff_fwrite(buf, 1, n, fp), free(buf); return n; } #endif #if MG_ARCH == MG_ARCH_UNIX #define _DARWIN_UNLIMITED_SELECT 1 #include #include #include #include #include #include #include #include #include #include #include #define MG_DIRSEP '/' #define MG_ENABLE_POSIX 1 #endif #if MG_ARCH == MG_ARCH_WIN32 #if defined(_MSC_VER) && _MSC_VER < 1700 #define __func__ "" typedef __int64 int64_t; typedef unsigned __int64 uint64_t; typedef unsigned char uint8_t; typedef unsigned short uint16_t; typedef unsigned int uint32_t; typedef int bool; enum { false = 0, true = 1 }; #else #include #include #endif #include #define snprintf _snprintf #define vsnprintf _vsnprintf #define strdup(x) _strdup(x) #define sleep(x) Sleep((x) *1000) typedef int socklen_t; #define PATH_MAX MAX_PATH #define MG_DIRSEP '\\' #define inline __inline #ifndef EINPROGRESS #define EINPROGRESS WSAEINPROGRESS #endif #ifndef EWOULDBLOCK #define EWOULDBLOCK WSAEWOULDBLOCK #endif #define realpath(a, b) _fullpath((b), (a), 512) #ifndef va_copy #ifdef __va_copy #define va_copy __va_copy #else #define va_copy(x, y) (x) = (y) #endif #endif #ifndef S_ISDIR #define S_ISDIR(x) (((x) &_S_IFMT) == _S_IFDIR) #endif #endif #ifndef MG_ENABLE_LWIP #define MG_ENABLE_LWIP 0 #endif #if MG_ENABLE_LWIP #define MG_ENABLE_SOCKET 0 #else #define MG_ENABLE_SOCKET 1 #endif #ifndef MG_ENABLE_MBEDTLS #define MG_ENABLE_MBEDTLS 0 #endif #ifndef MG_ENABLE_OPENSSL #define MG_ENABLE_OPENSSL 0 #endif #ifndef MG_ENABLE_FS #define MG_ENABLE_FS 1 #endif #ifndef MG_ENABLE_IPV6 #define MG_ENABLE_IPV6 0 #endif #ifndef MG_ENABLE_LOG #define MG_ENABLE_LOG 1 #endif #ifndef MG_ENABLE_MGOS #define MG_ENABLE_MGOS 0 #endif #ifndef MG_ENABLE_MD5 #define MG_ENABLE_MD5 0 #endif #ifndef MG_ENABLE_DIRECTORY_LISTING #define MG_ENABLE_DIRECTORY_LISTING 0 #endif #ifndef MG_ENABLE_HTTP_DEBUG_ENDPOINT #define MG_ENABLE_HTTP_DEBUG_ENDPOINT 0 #endif #ifndef MG_ENABLE_SOCKETPAIR #define MG_ENABLE_SOCKETPAIR 0 #endif // Granularity of the send/recv IO buffer growth #ifndef MG_IO_SIZE #define MG_IO_SIZE 512 #endif // Maximum size of the recv IO buffer #ifndef MG_MAX_RECV_BUF_SIZE #define MG_MAX_RECV_BUF_SIZE (3 * 1024 * 1024) #endif #ifndef MG_MAX_HTTP_HEADERS #define MG_MAX_HTTP_HEADERS 40 #endif #include #include struct mg_str { const char *ptr; size_t len; }; #define MG_NULL_STR \ { NULL, 0 } struct mg_str mg_str(const char *s); struct mg_str mg_str_n(const char *s, size_t n); int mg_lower(const char *s); int mg_ncasecmp(const char *s1, const char *s2, size_t len); int mg_casecmp(const char *s1, const char *s2); int mg_vcmp(const struct mg_str *s1, const char *s2); int mg_vcasecmp(const struct mg_str *str1, const char *str2); int mg_strcmp(const struct mg_str str1, const struct mg_str str2); struct mg_str mg_strstrip(struct mg_str s); struct mg_str mg_strdup(const struct mg_str s); const char *mg_strstr(const struct mg_str haystack, const struct mg_str needle); #if MG_ENABLE_MGOS #include #else #if MG_ENABLE_LOG #define LOG(level, args) \ do { \ if (mg_log_prefix((level), __FILE__, __LINE__, __func__)) mg_log args; \ } while (0) enum { LL_NONE, LL_ERROR, LL_INFO, LL_DEBUG, LL_VERBOSE_DEBUG }; bool mg_log_prefix(int ll, const char *file, int line, const char *fname); void mg_log(const char *fmt, ...) PRINTF_LIKE(1, 2); void mg_log_set(const char *spec); void mg_log_set_callback(void (*fn)(const void *, int, void *), void *param); #else #define LOG(level, args) #endif #endif struct mg_timer { int period_ms; // Timer period in milliseconds int flags; // Possible flags values below #define MG_TIMER_REPEAT 1 // Call function periodically, otherwise run once #define MG_TIMER_RUN_NOW 2 // Call immediately when timer is set void (*fn)(void *); // Function to call void *arg; // Function agrument unsigned long expire; // Expiration timestamp in milliseconds struct mg_timer *next; // Linkage in g_timers list }; extern struct mg_timer *g_timers; // Global list of timers void mg_timer_init(struct mg_timer *, int ms, int, void (*fn)(void *), void *); void mg_timer_free(struct mg_timer *); void mg_timer_poll(unsigned long uptime_ms); char *mg_file_read(const char *path); size_t mg_file_size(const char *path); int mg_file_write(const char *path, const char *fmt, ...); void mg_random(void *buf, size_t len); bool mg_globmatch(const char *pattern, int plen, const char *s, int n); bool mg_next_comma_entry(struct mg_str *s, struct mg_str *k, struct mg_str *v); uint16_t mg_ntohs(uint16_t net); uint32_t mg_ntohl(uint32_t net); char *mg_hexdump(const void *buf, int len); char *mg_hex(const void *buf, int len, char *dst); void mg_unhex(const char *buf, int len, unsigned char *to); unsigned long mg_unhexn(const char *s, int len); int mg_asprintf(char **buf, size_t size, const char *fmt, ...); int mg_vasprintf(char **buf, size_t size, const char *fmt, va_list ap); int64_t mg_to64(const char *s); bool mg_aton(const char *s, uint32_t *ipaddr); char *mg_ntoa(uint32_t ipaddr, char *buf, size_t len); double mg_time(void); unsigned long mg_millis(void); void mg_usleep(unsigned long usecs); #define mg_htons(x) mg_ntohs(x) #define mg_htonl(x) mg_ntohl(x) #define MG_SWAP16(x) ((((x) >> 8) & 255) | ((x & 255) << 8)) #define MG_SWAP32(x) \ (((x) >> 24) | (((x) &0xff0000) >> 8) | (((x) &0xff00) << 8) | ((x) << 24)) #if !defined(WEAK) #if (defined(__GNUC__) || defined(__clang__) || \ defined(__TI_COMPILER_VERSION__)) && \ !defined(_WIN32) #define WEAK __attribute__((weak)) #else #define WEAK #endif #endif // Expands to a string representation of its argument: e.g. // MG_STRINGIFY_LITERAL(5) expands to "5" #if !defined(_MSC_VER) || _MSC_VER >= 1900 #define MG_STRINGIFY_LITERAL(...) #__VA_ARGS__ #else #define MG_STRINGIFY_LITERAL(x) #x #endif #define LIST_ADD_HEAD(type_, head_, elem_) \ do { \ (elem_)->next = (*head_); \ *(head_) = (elem_); \ } while (0) #define LIST_ADD_TAIL(type_, head_, elem_) \ do { \ type_ **h = head_; \ while (*h != NULL) h = &(*h)->next; \ *h = (elem_); \ } while (0) #define LIST_DELETE(type_, head_, elem_) \ do { \ type_ **h = head_; \ while (*h != (elem_)) h = &(*h)->next; \ *h = (elem_)->next; \ } while (0) // Expands to a string representation of its argument, which can be a macro: // #define FOO 123 // MG_STRINGIFY_MACRO(FOO) // Expands to 123 #define MG_STRINGIFY_MACRO(x) MG_STRINGIFY_LITERAL(x) unsigned short mg_url_port(const char *url); int mg_url_is_ssl(const char *url); struct mg_str mg_url_host(const char *url); struct mg_str mg_url_user(const char *url); struct mg_str mg_url_pass(const char *url); const char *mg_url_uri(const char *url); #include struct mg_iobuf { unsigned char *buf; size_t size, len; }; void mg_iobuf_init(struct mg_iobuf *, size_t); void mg_iobuf_resize(struct mg_iobuf *, size_t); void mg_iobuf_free(struct mg_iobuf *); size_t mg_iobuf_append(struct mg_iobuf *, const void *, size_t, size_t); size_t mg_iobuf_delete(struct mg_iobuf *, size_t); int mg_base64_update(unsigned char p, char *to, int len); int mg_base64_final(char *to, int len); int mg_base64_encode(const unsigned char *p, int n, char *to); int mg_base64_decode(const char *src, int n, char *dst); typedef struct { uint32_t buf[4]; uint32_t bits[2]; unsigned char in[64]; } mg_md5_ctx; void mg_md5_init(mg_md5_ctx *c); void mg_md5_update(mg_md5_ctx *c, const unsigned char *data, size_t len); void mg_md5_final(mg_md5_ctx *c, unsigned char[16]); typedef struct { uint32_t state[5]; uint32_t count[2]; unsigned char buffer[64]; } mg_sha1_ctx; void mg_sha1_init(mg_sha1_ctx *); void mg_sha1_update(mg_sha1_ctx *, const unsigned char *data, size_t len); void mg_sha1_final(unsigned char digest[20], mg_sha1_ctx *); void mg_hmac_sha1(const unsigned char *key, size_t key_len, const unsigned char *text, size_t text_len, unsigned char out[20]); struct mg_connection; typedef void (*mg_event_handler_t)(struct mg_connection *, int ev, void *ev_data, void *fn_data); #if 0 struct mg_fn { struct mg_fn *next; mg_event_handler_t fn; void *fn_data; }; void mg_fn_add(struct mg_connection *c, mg_event_handler_t fn, void *fn_data); void mg_fn_del(struct mg_connection *c, mg_event_handler_t fn); #endif void mg_call(struct mg_connection *c, int ev, void *ev_data); void mg_error(struct mg_connection *c, const char *fmt, ...); enum { MG_EV_ERROR, // Error char *error_message MG_EV_POLL, // mg_mgr_poll iteration unsigned long *millis MG_EV_RESOLVE, // Host name is resolved NULL MG_EV_CONNECT, // Connection established NULL MG_EV_ACCEPT, // Connection accepted NULL MG_EV_READ, // Data received from socket struct mg_str * MG_EV_WRITE, // Data written to socket int *num_bytes_written MG_EV_CLOSE, // Connection closed NULL MG_EV_HTTP_MSG, // HTTP request/response struct mg_http_message * MG_EV_WS_OPEN, // Websocket handshake done NULL MG_EV_WS_MSG, // Websocket message received struct mg_ws_message * MG_EV_MQTT_MSG, // MQTT message struct mg_mqtt_message * MG_EV_MQTT_OPEN, // MQTT CONNACK received int *connack_status_code MG_EV_SNTP_TIME, // SNTP time received struct timeval * MG_EV_USER, // Starting ID for user events }; struct mg_mgr { struct mg_connection *conns; // List of active connections struct mg_connection *dnsc; // DNS resolver connection const char *dnsserver; // DNS server URL int dnstimeout; // DNS resolve timeout in milliseconds #if MG_ARCH == MG_ARCH_FREERTOS SocketSet_t ss; // NOTE(lsm): referenced from socket struct #endif }; struct mg_addr { uint16_t port; // TCP or UDP port in network byte order uint32_t ip; // IP address in network byte order }; struct mg_connection { struct mg_connection *next; // Linkage in struct mg_mgr :: connections struct mg_mgr *mgr; // Our container struct mg_addr peer; // Remote peer address void *fd; // Connected socket, or LWIP data struct mg_iobuf recv; // Incoming data struct mg_iobuf send; // Outgoing data mg_event_handler_t fn; // User-specified event handler function void *fn_data; // User-speficied function parameter mg_event_handler_t pfn; // Protocol-specific handler function void *pfn_data; // Protocol-specific function parameter char label[32]; // Arbitrary label void *tls; // TLS specific data unsigned is_listening : 1; // Listening connection unsigned is_client : 1; // Outbound (client) connection unsigned is_accepted : 1; // Accepted (server) connection unsigned is_resolving : 1; // Non-blocking DNS resolv is in progress unsigned is_connecting : 1; // Non-blocking connect is in progress unsigned is_tls : 1; // TLS-enabled connection unsigned is_tls_hs : 1; // TLS handshake is in progress unsigned is_udp : 1; // UDP connection unsigned is_websocket : 1; // WebSocket connection unsigned is_hexdumping : 1; // Hexdump in/out traffic unsigned is_draining : 1; // Send remaining data, then close and free unsigned is_closing : 1; // Close and free the connection immediately unsigned is_readable : 1; // Connection is ready to read unsigned is_writable : 1; // Connection is ready to write }; void mg_mgr_poll(struct mg_mgr *, int ms); void mg_mgr_init(struct mg_mgr *); void mg_mgr_free(struct mg_mgr *); struct mg_connection *mg_listen(struct mg_mgr *, const char *url, mg_event_handler_t fn, void *fn_data); struct mg_connection *mg_connect(struct mg_mgr *, const char *url, mg_event_handler_t fn, void *fn_data); int mg_send(struct mg_connection *, const void *, size_t); int mg_printf(struct mg_connection *, const char *fmt, ...); int mg_vprintf(struct mg_connection *, const char *fmt, va_list ap); char *mg_straddr(struct mg_connection *, char *, size_t); bool mg_socketpair(int *s1, int *s2); struct mg_http_header { struct mg_str name; struct mg_str value; }; struct mg_http_message { // GET /foo/bar/baz?aa=b&cc=ddd HTTP/1.1 // method |-| |----uri---| |--query--| |proto-| struct mg_str method, uri, query, proto; // Request/response line struct mg_http_header headers[MG_MAX_HTTP_HEADERS]; // Headers struct mg_str body; // Body struct mg_str message; // Request line + headers + body }; int mg_http_parse(const char *s, size_t len, struct mg_http_message *); int mg_http_get_request_len(const unsigned char *buf, size_t buf_len); void mg_http_write_head(struct mg_connection *, int code, const char *fmt, ...); void mg_http_printf_chunk(struct mg_connection *cnn, const char *fmt, ...); void mg_http_write_chunk(struct mg_connection *c, const char *buf, size_t len); struct mg_connection *mg_http_listen(struct mg_mgr *, const char *url, mg_event_handler_t fn, void *fn_data); struct mg_connection *mg_http_connect(struct mg_mgr *, const char *url, mg_event_handler_t fn, void *fn_data); void mg_http_serve_dir(struct mg_connection *, struct mg_http_message *hm, const char *path); void mg_http_serve_file(struct mg_connection *, struct mg_http_message *, const char *, const char *mime); void mg_http_reply(struct mg_connection *c, int code, const char *fmt, ...); struct mg_str *mg_http_get_header(struct mg_http_message *, const char *name); void mg_http_event_handler(struct mg_connection *c, int ev); int mg_http_get_var(const struct mg_str *, const char *name, char *, int); int mg_url_decode(const char *s, size_t n, char *to, size_t to_len, int form); void mg_http_creds(struct mg_http_message *, char *user, int, char *pass, int); bool mg_http_match_uri(const struct mg_http_message *, const char *glob); int mg_http_upload(struct mg_connection *, struct mg_http_message *hm, const char *dir); void mg_http_bauth(struct mg_connection *, const char *user, const char *pass); struct mg_tls_opts { const char *ca; // CA certificate file. For both listeners and clients const char *cert; // Certificate const char *certkey; // Certificate key const char *ciphers; // Cipher list const char *srvname; // If not NULL, enables server name verification }; int mg_tls_init(struct mg_connection *, struct mg_tls_opts *); int mg_tls_free(struct mg_connection *); int mg_tls_send(struct mg_connection *, const void *buf, size_t len, int *fail); int mg_tls_recv(struct mg_connection *, void *buf, size_t len, int *fail); int mg_tls_handshake(struct mg_connection *); #define WEBSOCKET_OP_CONTINUE 0 #define WEBSOCKET_OP_TEXT 1 #define WEBSOCKET_OP_BINARY 2 #define WEBSOCKET_OP_CLOSE 8 #define WEBSOCKET_OP_PING 9 #define WEBSOCKET_OP_PONG 10 #define WEBSOCKET_FLAGS_MASK_FIN 128 #define WEBSOCKET_FLAGS_MASK_OP 15 struct mg_ws_message { struct mg_str data; uint8_t flags; // Websocket message flags }; struct mg_connection *mg_ws_connect(struct mg_mgr *, const char *url, mg_event_handler_t fn, void *fn_data, const char *fmt, ...); void mg_ws_upgrade(struct mg_connection *, struct mg_http_message *); size_t mg_ws_send(struct mg_connection *, const char *buf, size_t len, int op); struct mg_connection *mg_sntp_connect(struct mg_mgr *mgr, const char *url, mg_event_handler_t fn, void *fn_data); void mg_sntp_send(struct mg_connection *c, unsigned long utc); int mg_sntp_parse(const unsigned char *buf, size_t len, struct timeval *tv); struct mg_mqtt_opts { struct mg_str client_id; struct mg_str will_topic; struct mg_str will_message; uint8_t qos; // Quality of service bool will_retain; // Retain last will bool clean; // Use clean session, 0 or 1 uint16_t keepalive; // Keep-alive timer in seconds }; struct mg_mqtt_message { struct mg_str topic; struct mg_str data; }; struct mg_connection *mg_mqtt_connect(struct mg_mgr *, const char *url, struct mg_mqtt_opts *opts, mg_event_handler_t fn, void *fn_data); void mg_mqtt_pub(struct mg_connection *, struct mg_str *topic, struct mg_str *data); void mg_mqtt_sub(struct mg_connection *, struct mg_str *topic); int mg_mqtt_parse(const unsigned char *buf, int len, struct mg_mqtt_message *m); struct mg_dns_message { uint16_t txnid; // Transaction ID uint32_t ipaddr; // Resolved IPv4 address char name[256]; // Host name }; void mg_resolve(struct mg_mgr *, struct mg_connection *, struct mg_str *, int); void mg_resolve_cancel(struct mg_mgr *, struct mg_connection *); int mg_dns_parse(const uint8_t *buf, size_t len, struct mg_dns_message *);