private.h

/*
 * libwebsockets - small server side websockets and web server implementation
 *
 * Copyright (C) 2010 - 2018 Andy Green <andy@warmcat.com>
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation:
 *  version 2.1 of the License.
 *
 *  This library 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
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 *  MA  02110-1301  USA
 */

#include "lws_config.h"
#include "lws_config_private.h"

#if defined(LWS_WITH_CGI) && defined(LWS_HAVE_VFORK)
 #define  _GNU_SOURCE
#endif

#if defined(__COVERITY__) && !defined(LWS_COVERITY_WORKAROUND)
 #define LWS_COVERITY_WORKAROUND
 typedef float _Float32;
 typedef float _Float64;
 typedef float _Float128;
 typedef float _Float32x;
 typedef float _Float64x;
 typedef float _Float128x;
#endif

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <ctype.h>
#include <limits.h>
#include <stdarg.h>
#include <inttypes.h>
#include <assert.h>

#ifdef LWS_HAVE_SYS_TYPES_H
 #include <sys/types.h>
#endif
#ifdef LWS_HAVE_SYS_STAT_H
 #include <sys/stat.h>
#endif

#if LWS_MAX_SMP > 1
 #include <pthread.h>
#endif

#ifndef LWS_DEF_HEADER_LEN
#define LWS_DEF_HEADER_LEN 4096
#endif
#ifndef LWS_DEF_HEADER_POOL
#define LWS_DEF_HEADER_POOL 4
#endif
#ifndef LWS_MAX_PROTOCOLS
#define LWS_MAX_PROTOCOLS 5
#endif
#ifndef LWS_MAX_EXTENSIONS_ACTIVE
#define LWS_MAX_EXTENSIONS_ACTIVE 1
#endif
#ifndef LWS_MAX_EXT_OFFERS
#define LWS_MAX_EXT_OFFERS 8
#endif
#ifndef SPEC_LATEST_SUPPORTED
#define SPEC_LATEST_SUPPORTED 13
#endif
#ifndef AWAITING_TIMEOUT
#define AWAITING_TIMEOUT 20
#endif
#ifndef CIPHERS_LIST_STRING
#define CIPHERS_LIST_STRING "DEFAULT"
#endif
#ifndef LWS_SOMAXCONN
#define LWS_SOMAXCONN SOMAXCONN
#endif

#define MAX_WEBSOCKET_04_KEY_LEN 128

#ifndef SYSTEM_RANDOM_FILEPATH
#define SYSTEM_RANDOM_FILEPATH "/dev/urandom"
#endif

#define LWS_H2_RX_SCRATCH_SIZE 512

#define lws_socket_is_valid(x) (x != LWS_SOCK_INVALID)

#ifndef LWS_HAVE_STRERROR
 #define strerror(x) ""
#endif

 /*
  *
  *  ------ private platform defines ------
  *
  */

#if defined(LWS_WITH_ESP32)
 #include "plat/esp32/private.h"
#else
 #if defined(WIN32) || defined(_WIN32)
  #include "plat/windows/private.h"
 #else
  #if defined(LWS_PLAT_OPTEE)
   #include "plat/optee/private.h"
  #else
   #include "plat/unix/private.h"
  #endif
 #endif
#endif

#ifndef LWS_HAVE_BZERO
 #ifndef bzero
  #define bzero(b, len) (memset((b), '\0', (len)), (void) 0)
 #endif
#endif

 /*
  *
  *  ------ public api ------
  *
  */

#include "libwebsockets.h"


#include "tls/private.h"

#if defined(WIN32) || defined(_WIN32)
	 // Visual studio older than 2015 and WIN_CE has only _stricmp
	#if (defined(_MSC_VER) && _MSC_VER < 1900) || defined(_WIN32_WCE)
	#define strcasecmp _stricmp
	#elif !defined(__MINGW32__)
	#define strcasecmp stricmp
	#endif
	#define getdtablesize() 30000
#endif

#ifndef LWS_ARRAY_SIZE
#define LWS_ARRAY_SIZE(x) (sizeof(x) / sizeof(x[0]))
#endif

#ifdef __cplusplus
extern "C" {
#endif

/*
 * All lws_tls...() functions must return this type, converting the
 * native backend result and doing the extra work to determine which one
 * as needed.
 *
 * Native TLS backend return codes are NOT ALLOWED outside the backend.
 *
 * Non-SSL mode also uses these types.
 */
enum lws_ssl_capable_status {
	LWS_SSL_CAPABLE_ERROR			= -1, /* it failed */
	LWS_SSL_CAPABLE_DONE			= 0,  /* it succeeded */
	LWS_SSL_CAPABLE_MORE_SERVICE_READ	= -2, /* retry WANT_READ */
	LWS_SSL_CAPABLE_MORE_SERVICE_WRITE	= -3, /* retry WANT_WRITE */
	LWS_SSL_CAPABLE_MORE_SERVICE		= -4, /* general retry */
};

#if defined(__clang__)
#define lws_memory_barrier() __sync_synchronize()
#elif defined(__GNUC__)
#define lws_memory_barrier() __sync_synchronize()
#else
#define lws_memory_barrier()
#endif

/*
 *
 *  ------ roles ------
 *
 */

#include "roles/private.h"

/* null-terminated array of pointers to roles lws built with */
extern const struct lws_role_ops *available_roles[];

#define LWS_FOR_EVERY_AVAILABLE_ROLE_START(xx) { \
		const struct lws_role_ops **ppxx = available_roles; \
		while (*ppxx) { \
			const struct lws_role_ops *xx = *ppxx++;

#define LWS_FOR_EVERY_AVAILABLE_ROLE_END }}

/*
 *
 *  ------ event_loop ops ------
 *
 */

#include "event-libs/private.h"

/* enums of socks version */
enum socks_version {
	SOCKS_VERSION_4 = 4,
	SOCKS_VERSION_5 = 5
};

/* enums of subnegotiation version */
enum socks_subnegotiation_version {
	SOCKS_SUBNEGOTIATION_VERSION_1 = 1,
};

/* enums of socks commands */
enum socks_command {
	SOCKS_COMMAND_CONNECT = 1,
	SOCKS_COMMAND_BIND = 2,
	SOCKS_COMMAND_UDP_ASSOCIATE = 3
};

/* enums of socks address type */
enum socks_atyp {
	SOCKS_ATYP_IPV4 = 1,
	SOCKS_ATYP_DOMAINNAME = 3,
	SOCKS_ATYP_IPV6 = 4
};

/* enums of socks authentication methods */
enum socks_auth_method {
	SOCKS_AUTH_NO_AUTH = 0,
	SOCKS_AUTH_GSSAPI = 1,
	SOCKS_AUTH_USERNAME_PASSWORD = 2
};

/* enums of subnegotiation status */
enum socks_subnegotiation_status {
	SOCKS_SUBNEGOTIATION_STATUS_SUCCESS = 0,
};

/* enums of socks request reply */
enum socks_request_reply {
	SOCKS_REQUEST_REPLY_SUCCESS = 0,
	SOCKS_REQUEST_REPLY_FAILURE_GENERAL = 1,
	SOCKS_REQUEST_REPLY_CONNECTION_NOT_ALLOWED = 2,
	SOCKS_REQUEST_REPLY_NETWORK_UNREACHABLE = 3,
	SOCKS_REQUEST_REPLY_HOST_UNREACHABLE = 4,
	SOCKS_REQUEST_REPLY_CONNECTION_REFUSED = 5,
	SOCKS_REQUEST_REPLY_TTL_EXPIRED = 6,
	SOCKS_REQUEST_REPLY_COMMAND_NOT_SUPPORTED = 7,
	SOCKS_REQUEST_REPLY_ATYP_NOT_SUPPORTED = 8
};

/* enums used to generate socks messages */
enum socks_msg_type {
	/* greeting */
	SOCKS_MSG_GREETING,
	/* credential, user name and password */
	SOCKS_MSG_USERNAME_PASSWORD,
	/* connect command */
	SOCKS_MSG_CONNECT
};

enum {
	LWS_RXFLOW_ALLOW = (1 << 0),
	LWS_RXFLOW_PENDING_CHANGE = (1 << 1),
};

struct lws_ring {
	void *buf;
	void (*destroy_element)(void *element);
	uint32_t buflen;
	uint32_t element_len;
	uint32_t head;
	uint32_t oldest_tail;
};

struct lws_protocols;
struct lws;

struct lws_io_watcher {
#ifdef LWS_WITH_LIBEV
	struct lws_io_watcher_libev ev;
#endif
#ifdef LWS_WITH_LIBUV
	struct lws_io_watcher_libuv uv;
#endif
#ifdef LWS_WITH_LIBEVENT
	struct lws_io_watcher_libevent event;
#endif
	struct lws_context *context;

	uint8_t actual_events;
};

struct lws_signal_watcher {
#ifdef LWS_WITH_LIBEV
	struct lws_signal_watcher_libev ev;
#endif
#ifdef LWS_WITH_LIBUV
	struct lws_signal_watcher_libuv uv;
#endif
#ifdef LWS_WITH_LIBEVENT
	struct lws_signal_watcher_libevent event;
#endif
	struct lws_context *context;
};

struct lws_foreign_thread_pollfd {
	struct lws_foreign_thread_pollfd *next;
	int fd_index;
	int _and;
	int _or;
};

#if LWS_MAX_SMP > 1

struct lws_mutex_refcount {
	pthread_mutex_t lock;
	pthread_t lock_owner;
	const char *last_lock_reason;
	char lock_depth;
	char metadata;
};

void
lws_mutex_refcount_init(struct lws_mutex_refcount *mr);

void
lws_mutex_refcount_destroy(struct lws_mutex_refcount *mr);

void
lws_mutex_refcount_lock(struct lws_mutex_refcount *mr, const char *reason);

void
lws_mutex_refcount_unlock(struct lws_mutex_refcount *mr);
#endif

#define LWS_HRTIMER_NOWAIT (0x7fffffffffffffffll)

/*
 * so we can have n connections being serviced simultaneously,
 * these things need to be isolated per-thread.
 */

struct lws_context_per_thread {
#if LWS_MAX_SMP > 1
	pthread_mutex_t lock_stats;
	struct lws_mutex_refcount mr;
	pthread_t self;
#endif

	struct lws_context *context;

	/*
	 * usable by anything in the service code, but only if the scope
	 * does not last longer than the service action (since next service
	 * of any socket can likewise use it and overwrite)
	 */
	unsigned char *serv_buf;

	struct lws_dll_lws dll_head_timeout;
	struct lws_dll_lws dll_head_hrtimer;
	struct lws_dll_lws dll_head_buflist; /* guys with pending rxflow */

#if defined(LWS_WITH_TLS)
	struct lws_pt_tls tls;
#endif

	struct lws_pollfd *fds;
	volatile struct lws_foreign_thread_pollfd * volatile foreign_pfd_list;
#ifdef _WIN32
	WSAEVENT events;
#endif
	lws_sockfd_type dummy_pipe_fds[2];
	struct lws *pipe_wsi;

	/* --- role based members --- */

#if defined(LWS_ROLE_WS) && !defined(LWS_WITHOUT_EXTENSIONS)
	struct lws_pt_role_ws ws;
#endif
#if defined(LWS_ROLE_H1) || defined(LWS_ROLE_H2)
	struct lws_pt_role_http http;
#endif
#if defined(LWS_ROLE_DBUS)
	struct lws_pt_role_dbus dbus;
#endif

	/* --- event library based members --- */

#if defined(LWS_WITH_LIBEV)
	struct lws_pt_eventlibs_libev ev;
#endif
#if defined(LWS_WITH_LIBUV)
	struct lws_pt_eventlibs_libuv uv;
#endif
#if defined(LWS_WITH_LIBEVENT)
	struct lws_pt_eventlibs_libevent event;
#endif

#if defined(LWS_WITH_LIBEV) || defined(LWS_WITH_LIBUV) || \
    defined(LWS_WITH_LIBEVENT)
	struct lws_signal_watcher w_sigint;
#endif

	/* --- */

	unsigned long count_conns;
	unsigned int fds_count;

	/*
	 * set to the Thread ID that's doing the service loop just before entry
	 * to poll indicates service thread likely idling in poll()
	 * volatile because other threads may check it as part of processing
	 * for pollfd event change.
	 */
	volatile int service_tid;
	int service_tid_detected;

	volatile unsigned char inside_poll;
	volatile unsigned char foreign_spinlock;

	unsigned char tid;

	unsigned char inside_service:1;
	unsigned char event_loop_foreign:1;
	unsigned char event_loop_destroy_processing_done:1;
};

struct lws_conn_stats {
	unsigned long long rx, tx;
	unsigned long h1_conn, h1_trans, h2_trans, ws_upg, h2_alpn, h2_subs,
		      h2_upg, rejected;
};

void
lws_sum_stats(const struct lws_context *ctx, struct lws_conn_stats *cs);

struct lws_timed_vh_protocol {
	struct lws_timed_vh_protocol *next;
	const struct lws_protocols *protocol;
	struct lws_vhost *vhost; /* only used for pending processing */
	time_t time;
	int reason;
	int tsi_req;
};

/*
 * virtual host -related context information
 *   vhostwide SSL context
 *   vhostwide proxy
 *
 * hierarchy:
 *
 * context -> vhost -> wsi
 *
 * incoming connection non-SSL vhost binding:
 *
 *    listen socket -> wsi -> select vhost after first headers
 *
 * incoming connection SSL vhost binding:
 *
 *    SSL SNI -> wsi -> bind after SSL negotiation
 */


struct lws_vhost {
#if !defined(LWS_WITHOUT_CLIENT)
	char proxy_basic_auth_token[128];
#endif
#if LWS_MAX_SMP > 1
	pthread_mutex_t lock;
	char close_flow_vs_tsi[LWS_MAX_SMP];
#endif

#if defined(LWS_ROLE_H2)
	struct lws_vhost_role_h2 h2;
#endif
#if defined(LWS_ROLE_H1) || defined(LWS_ROLE_H2)
	struct lws_vhost_role_http http;
#endif
#if defined(LWS_ROLE_WS) && !defined(LWS_WITHOUT_EXTENSIONS)
	struct lws_vhost_role_ws ws;
#endif

#if defined(LWS_WITH_SOCKS5)
	char socks_proxy_address[128];
	char socks_user[96];
	char socks_password[96];
#endif
#if defined(LWS_WITH_LIBEV)
	struct lws_io_watcher w_accept;
#endif
	struct lws_conn_stats conn_stats;
	struct lws_context *context;
	struct lws_vhost *vhost_next;

	struct lws *lserv_wsi;
	const char *name;
	const char *iface;

	void (*finalize)(struct lws_vhost *vh, void *arg);
	void *finalize_arg;

#if !defined(LWS_WITH_ESP32) && !defined(OPTEE_TA) && !defined(WIN32)
	int bind_iface;
#endif
	const struct lws_protocols *protocols;
	void **protocol_vh_privs;
	const struct lws_protocol_vhost_options *pvo;
	const struct lws_protocol_vhost_options *headers;
	struct lws_dll_lws *same_vh_protocol_heads;
	struct lws_vhost *no_listener_vhost_list;
#if !defined(LWS_NO_CLIENT)
	struct lws_dll_lws dll_active_client_conns;
#endif

#if defined(LWS_WITH_TLS)
	struct lws_vhost_tls tls;
#endif

	struct lws_timed_vh_protocol *timed_vh_protocol_list;
	void *user;

	int listen_port;

#if defined(LWS_WITH_SOCKS5)
	unsigned int socks_proxy_port;
#endif
	unsigned int options;
	int count_protocols;
	int ka_time;
	int ka_probes;
	int ka_interval;
	int keepalive_timeout;
	int timeout_secs_ah_idle;

	int count_bound_wsi;

#ifdef LWS_WITH_ACCESS_LOG
	int log_fd;
#endif

	unsigned int created_vhost_protocols:1;
	unsigned int being_destroyed:1;

	unsigned char default_protocol_index;
	unsigned char raw_protocol_index;
};

void
lws_vhost_bind_wsi(struct lws_vhost *vh, struct lws *wsi);
void
lws_vhost_unbind_wsi(struct lws *wsi);
void
__lws_vhost_destroy2(struct lws_vhost *vh);

struct lws_deferred_free
{
	struct lws_deferred_free *next;
	time_t deadline;
	void *payload;
};

typedef union {
#ifdef LWS_WITH_IPV6
	struct sockaddr_in6 sa6;
#endif
	struct sockaddr_in sa4;
} sockaddr46;


#if defined(LWS_WITH_PEER_LIMITS)
struct lws_peer {
	struct lws_peer *next;
	struct lws_peer *peer_wait_list;

	time_t time_created;
	time_t time_closed_all;

	uint8_t addr[32];
	uint32_t hash;
	uint32_t count_wsi;
	uint32_t total_wsi;

#if defined(LWS_ROLE_H1) || defined(LWS_ROLE_H2)
	struct lws_peer_role_http http;
#endif

	uint8_t af;
};
#endif

/*
 * the rest is managed per-context, that includes
 *
 *  - processwide single fd -> wsi lookup
 *  - contextwide headers pool
 */

struct lws_context {
	time_t last_timeout_check_s;
	time_t last_ws_ping_pong_check_s;
	time_t time_up;
	time_t time_discontiguity;
	time_t time_fixup;
	const struct lws_plat_file_ops *fops;
	struct lws_plat_file_ops fops_platform;
	struct lws_context **pcontext_finalize;

	const struct lws_tls_ops *tls_ops;

#if defined(LWS_WITH_HTTP2)
	struct http2_settings set;
#endif
#if defined(LWS_WITH_ZIP_FOPS)
	struct lws_plat_file_ops fops_zip;
#endif
	struct lws_context_per_thread pt[LWS_MAX_SMP];
	struct lws_conn_stats conn_stats;
#if LWS_MAX_SMP > 1
	struct lws_mutex_refcount mr;
#endif
#ifdef _WIN32
/* different implementation between unix and windows */
	struct lws_fd_hashtable fd_hashtable[FD_HASHTABLE_MODULUS];
#else
	struct lws **lws_lookup;  /* fd to wsi */
#endif
	struct lws_vhost *vhost_list;
	struct lws_vhost *no_listener_vhost_list;
	struct lws_vhost *vhost_pending_destruction_list;
	struct lws_plugin *plugin_list;
	struct lws_deferred_free *deferred_free_list;

#if defined(LWS_WITH_THREADPOOL)
	struct lws_threadpool *tp_list_head;
#endif

#if defined(LWS_WITH_PEER_LIMITS)
	struct lws_peer **pl_hash_table;
	struct lws_peer *peer_wait_list;
	time_t next_cull;
#endif

	void *external_baggage_free_on_destroy;
	const struct lws_token_limits *token_limits;
	void *user_space;
	const struct lws_protocol_vhost_options *reject_service_keywords;
	lws_reload_func deprecation_cb;
	void (*eventlib_signal_cb)(void *event_lib_handle, int signum);

#if defined(LWS_HAVE_SYS_CAPABILITY_H) && defined(LWS_HAVE_LIBCAP)
	cap_value_t caps[4];
	char count_caps;
#endif

#if defined(LWS_WITH_LIBEV)
	struct lws_context_eventlibs_libev ev;
#endif
#if defined(LWS_WITH_LIBUV)
	struct lws_context_eventlibs_libuv uv;
#endif
#if defined(LWS_WITH_LIBEVENT)
	struct lws_context_eventlibs_libevent event;
#endif
	struct lws_event_loop_ops *event_loop_ops;


#if defined(LWS_WITH_TLS)
	struct lws_context_tls tls;
#endif

	char canonical_hostname[128];
	const char *server_string;

#ifdef LWS_LATENCY
	unsigned long worst_latency;
	char worst_latency_info[256];
#endif

#if defined(LWS_WITH_STATS)
	uint64_t lws_stats[LWSSTATS_SIZE];
	uint64_t last_dump;
	int updated;
#endif
#if defined(LWS_WITH_ESP32)
	unsigned long time_last_state_dump;
	uint32_t last_free_heap;
#endif

	int max_fds;
	int count_event_loop_static_asset_handles;
	int started_with_parent;
	int uid, gid;

	int fd_random;

	int count_wsi_allocated;
	int count_cgi_spawned;
	unsigned int options;
	unsigned int fd_limit_per_thread;
	unsigned int timeout_secs;
	unsigned int pt_serv_buf_size;
	int max_http_header_data;
	int max_http_header_pool;
	int simultaneous_ssl_restriction;
	int simultaneous_ssl;
#if defined(LWS_WITH_PEER_LIMITS)
	uint32_t pl_hash_elements;	/* protected by context->lock */
	uint32_t count_peers;		/* protected by context->lock */
	unsigned short ip_limit_ah;
	unsigned short ip_limit_wsi;
#endif
	unsigned int deprecated:1;
	unsigned int being_destroyed:1;
	unsigned int being_destroyed1:1;
	unsigned int being_destroyed2:1;
	unsigned int requested_kill:1;
	unsigned int protocol_init_done:1;
	unsigned int doing_protocol_init:1;
	unsigned int done_protocol_destroy_cb:1;
	unsigned int finalize_destroy_after_internal_loops_stopped:1;

	short count_threads;
	short plugin_protocol_count;
	short plugin_extension_count;
	short server_string_len;
	unsigned short ws_ping_pong_interval;
	unsigned short deprecation_pending_listen_close_count;

	uint8_t max_fi;
};

int
lws_check_deferred_free(struct lws_context *context, int tsi, int force);

#define lws_get_context_protocol(ctx, x) ctx->vhost_list->protocols[x]
#define lws_get_vh_protocol(vh, x) vh->protocols[x]

LWS_EXTERN void
__lws_close_free_wsi_final(struct lws *wsi);
LWS_EXTERN void
lws_libuv_closehandle(struct lws *wsi);
LWS_EXTERN int
lws_libuv_check_watcher_active(struct lws *wsi);

LWS_VISIBLE LWS_EXTERN int
lws_plat_plugins_init(struct lws_context * context, const char * const *d);

LWS_VISIBLE LWS_EXTERN int
lws_plat_plugins_destroy(struct lws_context * context);

LWS_EXTERN void
lws_restart_ws_ping_pong_timer(struct lws *wsi);

struct lws *
lws_adopt_socket_vhost(struct lws_vhost *vh, lws_sockfd_type accept_fd);

int
lws_jws_base64_enc(const char *in, size_t in_len, char *out, size_t out_max);

void
lws_vhost_destroy1(struct lws_vhost *vh);

enum {
	LWS_EV_READ = (1 << 0),
	LWS_EV_WRITE = (1 << 1),
	LWS_EV_START = (1 << 2),
	LWS_EV_STOP = (1 << 3),

	LWS_EV_PREPARE_DELETION = (1u << 31),
};


#if defined(LWS_WITH_ESP32)
LWS_EXTERN int
lws_find_string_in_file(const char *filename, const char *str, int stringlen);
#endif

#ifdef LWS_WITH_IPV6
#define LWS_IPV6_ENABLED(vh) \
	(!lws_check_opt(vh->context->options, LWS_SERVER_OPTION_DISABLE_IPV6) && \
	 !lws_check_opt(vh->options, LWS_SERVER_OPTION_DISABLE_IPV6))
#else
#define LWS_IPV6_ENABLED(context) (0)
#endif

#ifdef LWS_WITH_UNIX_SOCK
#define LWS_UNIX_SOCK_ENABLED(vhost) \
	(vhost->options & LWS_SERVER_OPTION_UNIX_SOCK)
#else
#define LWS_UNIX_SOCK_ENABLED(vhost) (0)
#endif

enum uri_path_states {
	URIPS_IDLE,
	URIPS_SEEN_SLASH,
	URIPS_SEEN_SLASH_DOT,
	URIPS_SEEN_SLASH_DOT_DOT,
};

enum uri_esc_states {
	URIES_IDLE,
	URIES_SEEN_PERCENT,
	URIES_SEEN_PERCENT_H1,
};


#ifndef LWS_NO_CLIENT
struct client_info_stash {
	char *address;
	char *path;
	char *host;
	char *origin;
	char *protocol;
	char *method;
	char *iface;
	char *alpn;
};
#endif


signed char char_to_hex(const char c);


struct lws_buflist {
	struct lws_buflist *next;

	size_t len;
	size_t pos;

	uint8_t buf[1]; /* true length of this is set by the oversize malloc */
};

#define lws_wsi_is_udp(___wsi) (!!___wsi->udp)

#define LWS_H2_FRAME_HEADER_LENGTH 9


struct lws {
	/* structs */

#if defined(LWS_ROLE_H1) || defined(LWS_ROLE_H2)
	struct _lws_http_mode_related http;
#endif
#if defined(LWS_ROLE_H2)
	struct _lws_h2_related h2;
#endif
#if defined(LWS_ROLE_WS)
	struct _lws_websocket_related *ws; /* allocated if we upgrade to ws */
#endif
#if defined(LWS_ROLE_DBUS)
	struct _lws_dbus_mode_related dbus;
#endif

	const struct lws_role_ops *role_ops;
	lws_wsi_state_t	wsistate;
	lws_wsi_state_t wsistate_pre_close;

	/* lifetime members */

#if defined(LWS_WITH_LIBEV) || defined(LWS_WITH_LIBUV) || \
    defined(LWS_WITH_LIBEVENT)
	struct lws_io_watcher w_read;
#endif
#if defined(LWS_WITH_LIBEV) || defined(LWS_WITH_LIBEVENT)
	struct lws_io_watcher w_write;
#endif

	/* pointers */

	struct lws_context *context;
	struct lws_vhost *vhost;
	struct lws *parent; /* points to parent, if any */
	struct lws *child_list; /* points to first child */
	struct lws *sibling_list; /* subsequent children at same level */

	const struct lws_protocols *protocol;
	struct lws_dll_lws same_vh_protocol;

	struct lws_dll_lws dll_timeout;
	struct lws_dll_lws dll_hrtimer;
	struct lws_dll_lws dll_buflist; /* guys with pending rxflow */

#if defined(LWS_WITH_THREADPOOL)
	struct lws_threadpool_task *tp_task;
#endif

#if defined(LWS_WITH_PEER_LIMITS)
	struct lws_peer *peer;
#endif

	struct lws_udp *udp;
#ifndef LWS_NO_CLIENT
	struct client_info_stash *stash;
	char *client_hostname_copy;
	struct lws_dll_lws dll_active_client_conns;
	struct lws_dll_lws dll_client_transaction_queue_head;
	struct lws_dll_lws dll_client_transaction_queue;
#endif
	void *user_space;
	void *opaque_parent_data;

	struct lws_buflist *buflist;		/* input-side buflist */
	struct lws_buflist *buflist_out;	/* output-side buflist */

#if defined(LWS_WITH_TLS)
	struct lws_lws_tls tls;
#endif

	lws_sock_file_fd_type desc; /* .filefd / .sockfd */
#if defined(LWS_WITH_STATS)
	uint64_t active_writable_req_us;
#if defined(LWS_WITH_TLS)
	uint64_t accept_start_us;
#endif
#endif

	lws_usec_t pending_timer; /* hrtimer fires */
	time_t pending_timeout_set; /* second-resolution timeout start */

#ifdef LWS_LATENCY
	unsigned long action_start;
	unsigned long latency_start;
#endif

	/* ints */
#define LWS_NO_FDS_POS (-1)
	int position_in_fds_table;

#ifndef LWS_NO_CLIENT
	int chunk_remaining;
#endif
	unsigned int cache_secs;

	unsigned int hdr_parsing_completed:1;
	unsigned int http2_substream:1;
	unsigned int upgraded_to_http2:1;
	unsigned int h2_stream_carries_ws:1;
	unsigned int seen_nonpseudoheader:1;
	unsigned int listener:1;
	unsigned int user_space_externally_allocated:1;
	unsigned int socket_is_permanently_unusable:1;
	unsigned int rxflow_change_to:2;
	unsigned int conn_stat_done:1;
	unsigned int cache_reuse:1;
	unsigned int cache_revalidate:1;
	unsigned int cache_intermediaries:1;
	unsigned int favoured_pollin:1;
	unsigned int sending_chunked:1;
	unsigned int interpreting:1;
	unsigned int already_did_cce:1;
	unsigned int told_user_closed:1;
	unsigned int told_event_loop_closed:1;
	unsigned int waiting_to_send_close_frame:1;
	unsigned int close_needs_ack:1;
	unsigned int ipv6:1;
	unsigned int parent_pending_cb_on_writable:1;
	unsigned int cgi_stdout_zero_length:1;
	unsigned int seen_zero_length_recv:1;
	unsigned int rxflow_will_be_applied:1;
	unsigned int event_pipe:1;
	unsigned int handling_404:1;
	unsigned int protocol_bind_balance:1;
	unsigned int unix_skt:1;

	unsigned int could_have_pending:1; /* detect back-to-back writes */
	unsigned int outer_will_close:1;
	unsigned int shadow:1; /* we do not control fd lifecycle at all */

#ifdef LWS_WITH_ACCESS_LOG
	unsigned int access_log_pending:1;
#endif
#ifndef LWS_NO_CLIENT
	unsigned int do_ws:1; /* whether we are doing http or ws flow */
	unsigned int chunked:1; /* if the clientside connection is chunked */
	unsigned int client_rx_avail:1;
	unsigned int client_http_body_pending:1;
	unsigned int transaction_from_pipeline_queue:1;
	unsigned int keepalive_active:1;
	unsigned int keepalive_rejected:1;
	unsigned int client_pipeline:1;
	unsigned int client_h2_alpn:1;
	unsigned int client_h2_substream:1;
#endif

#ifdef _WIN32
	unsigned int sock_send_blocking:1;
#endif

#ifndef LWS_NO_CLIENT
	unsigned short c_port;
#endif
	unsigned short pending_timeout_limit;