/*
This file is part of libmicrohttpd
Copyright (C) 2007-2017 Daniel Pittman and Christian Grothoff
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; either
version 2.1 of the License, or (at your option) any later version.
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
*/
/**
* @file microhttpd/internal.h
* @brief internal shared structures
* @author Daniel Pittman
* @author Christian Grothoff
*/
#ifndef INTERNAL_H
#define INTERNAL_H
#include "mhd_options.h"
#include "platform.h"
#include "microhttpd.h"
#include "mhd_assert.h"
#ifdef HTTPS_SUPPORT
#include <gnutls/gnutls.h>
#if GNUTLS_VERSION_MAJOR >= 3
#include <gnutls/abstract.h>
#endif
#endif /* HTTPS_SUPPORT */
#ifdef HAVE_STDBOOL_H
#include <stdbool.h>
#endif
#ifdef MHD_PANIC
/* Override any defined MHD_PANIC macro with proper one */
#undef MHD_PANIC
#endif /* MHD_PANIC */
#ifdef HAVE_MESSAGES
/**
* Trigger 'panic' action based on fatal errors.
*
* @param msg error message (const char *)
*/
#define MHD_PANIC(msg) do { mhd_panic (mhd_panic_cls, __FILE__, __LINE__, msg); BUILTIN_NOT_REACHED; } while (0)
#else
/**
* Trigger 'panic' action based on fatal errors.
*
* @param msg error message (const char *)
*/
#define MHD_PANIC(msg) do { mhd_panic (mhd_panic_cls, __FILE__, __LINE__, NULL); BUILTIN_NOT_REACHED; } while (0)
#endif
#include "mhd_threads.h"
#include "mhd_locks.h"
#include "mhd_sockets.h"
#include "mhd_itc_types.h"
/**
* Close FD and abort execution if error is detected.
* @param fd the FD to close
*/
#define MHD_fd_close_chk_(fd) do { \
if (0 == close ((fd)) && (EBADF == errno)) \
MHD_PANIC(_("Failed to close FD.\n")); \
} while(0)
/**
* Should we perform additional sanity checks at runtime (on our internal
* invariants)? This may lead to aborts, but can be useful for debugging.
*/
#define EXTRA_CHECKS MHD_NO
#define MHD_MAX(a,b) (((a)<(b)) ? (b) : (a))
#define MHD_MIN(a,b) (((a)<(b)) ? (a) : (b))
/**
* Minimum size by which MHD tries to increment read/write buffers.
* We usually begin with half the available pool space for the
* IO-buffer, but if absolutely needed we additively grow by the
* number of bytes given here (up to -- theoretically -- the full pool
* space).
*/
#define MHD_BUF_INC_SIZE 1024
/**
* Handler for fatal errors.
*/
extern MHD_PanicCallback mhd_panic;
/**
* Closure argument for "mhd_panic".
*/
extern void *mhd_panic_cls;
/* If we have Clang or gcc >= 4.5, use __buildin_unreachable() */
#if defined(__clang__) || (__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5)
#define BUILTIN_NOT_REACHED __builtin_unreachable()
#elif defined(_MSC_FULL_VER)
#define BUILTIN_NOT_REACHED __assume(0)
#else
#define BUILTIN_NOT_REACHED
#endif
#ifndef MHD_STATICSTR_LEN_
/**
* Determine length of static string / macro strings at compile time.
*/
#define MHD_STATICSTR_LEN_(macro) (sizeof(macro)/sizeof(char) - 1)
#endif /* ! MHD_STATICSTR_LEN_ */
/**
* State of the socket with respect to epoll (bitmask).
*/
enum MHD_EpollState
{
/**
* The socket is not involved with a defined state in epoll() right
* now.
*/
MHD_EPOLL_STATE_UNREADY = 0,
/**
* epoll() told us that data was ready for reading, and we did
* not consume all of it yet.
*/
MHD_EPOLL_STATE_READ_READY = 1,
/**
* epoll() told us that space was available for writing, and we did
* not consume all of it yet.
*/
MHD_EPOLL_STATE_WRITE_READY = 2,
/**
* Is this connection currently in the 'eready' EDLL?
*/
MHD_EPOLL_STATE_IN_EREADY_EDLL = 4,
/**
* Is this connection currently in the epoll() set?
*/
MHD_EPOLL_STATE_IN_EPOLL_SET = 8,
/**
* Is this connection currently suspended?
*/
MHD_EPOLL_STATE_SUSPENDED = 16,
/**
* Is this connection in some error state?
*/
MHD_EPOLL_STATE_ERROR = 128
};
/**
* What is this connection waiting for?
*/
enum MHD_ConnectionEventLoopInfo
{
/**
* We are waiting to be able to read.
*/
MHD_EVENT_LOOP_INFO_READ = 0,
/**
* We are waiting to be able to write.
*/
MHD_EVENT_LOOP_INFO_WRITE = 1,
/**
* We are waiting for the application to provide data.
*/
MHD_EVENT_LOOP_INFO_BLOCK = 2,
/**
* We are finished and are awaiting cleanup.
*/
MHD_EVENT_LOOP_INFO_CLEANUP = 3
};
/**
* Additional test value for enum MHD_FLAG to check only for MHD_ALLOW_SUSPEND_RESUME and
* NOT for MHD_USE_ITC.
*/
#define MHD_TEST_ALLOW_SUSPEND_RESUME 8192
/**
* Maximum length of a nonce in digest authentication. 32(MD5 Hex) +
* 8(Timestamp Hex) + 1(NULL); hence 41 should suffice, but Opera
* (already) takes more (see Mantis #1633), so we've increased the
* value to support something longer...
*/
#define MAX_NONCE_LENGTH 129
/**
* A structure representing the internal holder of the
* nonce-nc map.
*/
struct MHD_NonceNc
{
/**
* Nonce counter, a value that increases for each subsequent
* request for the same nonce.
*/
uint64_t nc;
/**
* Bitmask over the nc-64 previous nonce values. Used to
* allow out-of-order nonces.
*/
uint64_t nmask;
/**
* Nonce value:
*/
char nonce[MAX_NONCE_LENGTH];
};
#ifdef HAVE_MESSAGES
/**
* fprintf()-like helper function for logging debug
* messages.
*/
void
MHD_DLOG (const struct MHD_Daemon *daemon,
const char *format,
...);
#endif
/**
* Header or cookie in HTTP request or response.
*/
struct MHD_HTTP_Header
{
/**
* Headers are kept in a linked list.
*/
struct MHD_HTTP_Header *next;
/**
* The name of the header (key), without the colon.
*/
char *header;
/**
* The value of the header.
*/
char *value;
/**
* Type of the header (where in the HTTP protocol is this header
* from).
*/
enum MHD_ValueKind kind;
};
/**
* Representation of a response.
*/
struct MHD_Response
{
/**
* Headers to send for the response. Initially
* the linked list is created in inverse order;
* the order should be inverted before sending!
*/
struct MHD_HTTP_Header *first_header;
/**
* Buffer pointing to data that we are supposed
* to send as a response.
*/
char *data;
/**
* Closure to give to the content reader @e crc
* and content reader free callback @e crfc.
*/
void *crc_cls;
/**
* How do we get more data? NULL if we are
* given all of the data up front.
*/
MHD_ContentReaderCallback crc;
/**
* NULL if data must not be freed, otherwise
* either user-specified callback or "&free".
*/
MHD_ContentReaderFreeCallback crfc;
#ifdef UPGRADE_SUPPORT
/**
* Application function to call once we are done sending the headers
* of the response; NULL unless this is a response created with
* #MHD_create_response_for_upgrade().
*/
MHD_UpgradeHandler upgrade_handler;
/**
* Closure for @e uh.
*/
void *upgrade_handler_cls;
#endif /* UPGRADE_SUPPORT */
/**
* Mutex to synchronize access to @e data, @e size and
* @e reference_count.
*/
MHD_mutex_ mutex;
/**
* Set to #MHD_SIZE_UNKNOWN if size is not known.
*/
uint64_t total_size;
/**
* At what offset in the stream is the
* beginning of @e data located?
*/
uint64_t data_start;
/**
* Offset to start reading from when using @e fd.
*/
uint64_t fd_off;
/**
* Number of bytes ready in @e data (buffer may be larger
* than what is filled with payload).
*/
size_t data_size;
/**
* Size of the data buffer @e data.
*/
size_t data_buffer_size;
/**
* Reference count for this response. Free once the counter hits
* zero.
*/
unsigned int reference_count;
/**
* File-descriptor if this response is FD-backed.
*/
int fd;
/**
* Flags set for the MHD response.
*/
enum MHD_ResponseFlags flags;
};
/**
* States in a state machine for a connection.
*
* The main transitions are any-state to #MHD_CONNECTION_CLOSED, any
* state to state+1, #MHD_CONNECTION_FOOTERS_SENT to
* #MHD_CONNECTION_INIT. #MHD_CONNECTION_CLOSED is the terminal state
* and #MHD_CONNECTION_INIT the initial state.
*
* Note that transitions for *reading* happen only after the input has
* been processed; transitions for *writing* happen after the
* respective data has been put into the write buffer (the write does
* not have to be completed yet). A transition to
* #MHD_CONNECTION_CLOSED or #MHD_CONNECTION_INIT requires the write
* to be complete.
*/
enum MHD_CONNECTION_STATE
{
/**
* Connection just started (no headers received).
* Waiting for the line with the request type, URL and version.
*/
MHD_CONNECTION_INIT = 0,
/**
* 1: We got the URL (and request type and version). Wait for a header line.
*/
MHD_CONNECTION_URL_RECEIVED = MHD_CONNECTION_INIT + 1,
/**
* 2: We got part of a multi-line request header. Wait for the rest.
*/
MHD_CONNECTION_HEADER_PART_RECEIVED = MHD_CONNECTION_URL_RECEIVED + 1,
/**
* 3: We got the request headers. Process them.
*/
MHD_CONNECTION_HEADERS_RECEIVED = MHD_CONNECTION_HEADER_PART_RECEIVED + 1,
/**
* 4: We have processed the request headers. Send 100 continue.
*/
MHD_CONNECTION_HEADERS_PROCESSED = MHD_CONNECTION_HEADERS_RECEIVED + 1,
/**
* 5: We have processed the headers and need to send 100 CONTINUE.
*/
MHD_CONNECTION_CONTINUE_SENDING = MHD_CONNECTION_HEADERS_PROCESSED + 1,
/**
* 6: We have sent 100 CONTINUE (or do not need to). Read the message body.
*/
MHD_CONNECTION_CONTINUE_SENT = MHD_CONNECTION_CONTINUE_SENDING + 1,
/**
* 7: We got the request body. Wait for a line of the footer.
*/
MHD_CONNECTION_BODY_RECEIVED = MHD_CONNECTION_CONTINUE_SENT + 1,
/**
* 8: We got part of a line of the footer. Wait for the
* rest.
*/
MHD_CONNECTION_FOOTER_PART_RECEIVED = MHD_CONNECTION_BODY_RECEIVED + 1,
/**
* 9: We received the entire footer. Wait for a response to be queued
* and prepare the response headers.
*/
MHD_CONNECTION_FOOTERS_RECEIVED = MHD_CONNECTION_FOOTER_PART_RECEIVED + 1,
/**
* 10: We have prepared the response headers in the writ buffer.
* Send the response headers.
*/
MHD_CONNECTION_HEADERS_SENDING = MHD_CONNECTION_FOOTERS_RECEIVED + 1,
/**
* 11: We have sent the response headers. Get ready to send the body.
*/
MHD_CONNECTION_HEADERS_SENT = MHD_CONNECTION_HEADERS_SENDING + 1,
/**
* 12: We are ready to send a part of a non-chunked body. Send it.
*/
MHD_CONNECTION_NORMAL_BODY_READY = MHD_CONNECTION_HEADERS_SENT + 1,
/**
* 13: We are waiting for the client to provide more
* data of a non-chunked body.
*/
MHD_CONNECTION_NORMAL_BODY_UNREADY = MHD_CONNECTION_NORMAL_BODY_READY + 1,
/**
* 14: We are ready to send a chunk.
*/
MHD_CONNECTION_CHUNKED_BODY_READY = MHD_CONNECTION_NORMAL_BODY_UNREADY + 1,
/**
* 15: We are waiting for the client to provide a chunk of the body.
*/
MHD_CONNECTION_CHUNKED_BODY_UNREADY = MHD_CONNECTION_CHUNKED_BODY_READY + 1,
/**
* 16: We have sent the response body. Prepare the footers.
*/
MHD_CONNECTION_BODY_SENT = MHD_CONNECTION_CHUNKED_BODY_UNREADY + 1,
/**
* 17: We have prepared the response footer. Send it.
*/
MHD_CONNECTION_FOOTERS_SENDING = MHD_CONNECTION_BODY_SENT + 1,
/**
* 18: We have sent the response footer. Shutdown or restart.
*/
MHD_CONNECTION_FOOTERS_SENT = MHD_CONNECTION_FOOTERS_SENDING + 1,
/**
* 19: This connection is to be closed.
*/
MHD_CONNECTION_CLOSED = MHD_CONNECTION_FOOTERS_SENT + 1,
/**
* 20: This connection is finished (only to be freed)
*/
MHD_CONNECTION_IN_CLEANUP = MHD_CONNECTION_CLOSED + 1,
#ifdef UPGRADE_SUPPORT
/**
* Connection was "upgraded" and socket is now under the
* control of the application.
*/
MHD_CONNECTION_UPGRADE
#endif /* UPGRADE_SUPPORT */
};
/**
* States of TLS transport layer.
*/
enum MHD_TLS_CONN_STATE
{
MHD_TLS_CONN_NO_TLS = 0, /**< Not a TLS connection (plain socket). */
MHD_TLS_CONN_INIT, /**< TLS connection is not established yet. */
MHD_TLS_CONN_HANDSHAKING, /**< TLS is in handshake process. */
MHD_TLS_CONN_CONNECTED, /**< TLS is established. */
MHD_TLS_CONN_WR_CLOSING, /**< Closing WR side of TLS layer. */
MHD_TLS_CONN_WR_CLOSED, /**< WR side of TLS layer is closed. */
MHD_TLS_CONN_TLS_CLOSING, /**< TLS session is terminating. */
MHD_TLS_CONN_TLS_CLOSED, /**< TLS session is terminated. */
MHD_TLS_CONN_TLS_FAILED, /**< TLS session failed. */
MHD_TLS_CONN_INVALID_STATE/**< Sentinel. Not a valid value. */
};
/**
* Should all state transitions be printed to stderr?
*/
#define DEBUG_STATES MHD_NO
#ifdef HAVE_MESSAGES
#if DEBUG_STATES
const char *
MHD_state_to_string (enum MHD_CONNECTION_STATE state);
#endif
#endif
/**
* Function to receive plaintext data.
*
* @param conn the connection struct
* @param write_to where to write received data
* @param max_bytes maximum number of bytes to receive
* @return number of bytes written to @a write_to
*/
typedef ssize_t
(*ReceiveCallback) (struct MHD_Connection *conn,
void *write_to,
size_t max_bytes);
/**
* Function to transmit plaintext data.
*
* @param conn the connection struct
* @param read_from where to read data to transmit
* @param max_bytes maximum number of bytes to transmit
* @return number of bytes transmitted
*/
typedef ssize_t
(*TransmitCallback) (struct MHD_Connection *conn,
const void *read_from,
size_t max_bytes);
/**
* Ability to use same connection for next request
*/
enum MHD_ConnKeepAlive
{
/**
* Connection must be closed after sending response.
*/
MHD_CONN_MUST_CLOSE = -1,
/**
* KeelAlive state is not yet determined
*/
MHD_CONN_KEEPALIVE_UNKOWN = 0,
/**
* Connection can be used for serving next request
*/
MHD_CONN_USE_KEEPALIVE = 1
};
/**
* State kept for each HTTP request.
*/
struct MHD_Connection
{
#ifdef EPOLL_SUPPORT
/**
* Next pointer for the EDLL listing connections that are epoll-ready.
*/
struct MHD_Connection *nextE;
/**
* Previous pointer for the EDLL listing connections that are epoll-ready.
*/
struct MHD_Connection *prevE;
#endif
/**
* Next pointer for the DLL describing our IO state.
*/
struct MHD_Connection *next;
/**
* Previous pointer for the DLL describing our IO state.
*/
struct MHD_Connection *prev;
/**
* Next pointer for the XDLL organizing connections by timeout.
* This DLL can be either the
* 'manual_timeout_head/manual_timeout_tail' or the
* 'normal_timeout_head/normal_timeout_tail', depending on whether a
* custom timeout is set for the connection.
*/
struct MHD_Connection *nextX;
/**
* Previous pointer for the XDLL organizing connections by timeout.
*/
struct MHD_Connection *prevX;
/**
* Reference to the MHD_Daemon struct.
*/
struct MHD_Daemon *daemon;
/**
* Linked list of parsed headers.
*/
struct MHD_HTTP_Header *headers_received;
/**
* Tail of linked list of parsed headers.
*/
struct MHD_HTTP_Header *headers_received_tail;
/**
* Response to transmit (initially NULL).
*/
struct MHD_Response *response;
/**
* The memory pool is created whenever we first read from the TCP
* stream and destroyed at the end of each request (and re-created
* for the next request). In the meantime, this pointer is NULL.
* The pool is used for all connection-related data except for the
* response (which maybe shared between connections) and the IP
* address (which persists across individual requests).
*/
struct MemoryPool *pool;
/**
* We allow the main application to associate some pointer with the
* HTTP request, which is passed to each #MHD_AccessHandlerCallback
* and some other API calls. Here is where we store it. (MHD does
* not know or care what it is).
*/
void *client_context;
/**
* We allow the main application to associate some pointer with the
* TCP connection (which may span multiple HTTP requests). Here is
* where we store it. (MHD does not know or care what it is).
* The location is given to the #MHD_NotifyConnectionCallback and
* also accessible via #MHD_CONNECTION_INFO_SOCKET_CONTEXT.
*/
void *socket_context;
/**
* Request method. Should be GET/POST/etc. Allocated in pool.
*/
char *method;
/**
* Requested URL (everything after "GET" only). Allocated
* in pool.
*/
const char *url;
/**
* HTTP version string (i.e. http/1.1). Allocated
* in pool.
*/
char *version;
/**
* Close connection after sending response?
* Functions may change value from "Unknown" or "KeepAlive" to "Must close",
* but no functions reset value "Must Close" to any other value.
*/
enum MHD_ConnKeepAlive keepalive;
/**
* Buffer for reading requests. Allocated in pool. Actually one
* byte larger than @e read_buffer_size (if non-NULL) to allow for
* 0-termination.
*/
char *read_buffer;
/**
* Buffer for writing response (headers only). Allocated
* in pool.
*/
char *write_buffer;
/**
* Last incomplete header line during parsing of headers.
* Allocated in pool. Only valid if state is
* either #MHD_CONNECTION_HEADER_PART_RECEIVED or
* #MHD_CONNECTION_FOOTER_PART_RECEIVED.
*/
char *last;
/**
* Position after the colon on the last incomplete header
* line during parsing of headers.
* Allocated in pool. Only valid if state is
* either #MHD_CONNECTION_HEADER_PART_RECEIVED or
* #MHD_CONNECTION_FOOTER_PART_RECEIVED.
*/
char *colon;
/**
* Foreign address (of length @e addr_len). MALLOCED (not
* in pool!).
*/
struct sockaddr *addr;
/**
* Thread handle for this connection (if we are using
* one thread per connection).
*/
MHD_thread_handle_ID_ pid;
/**
* Size of @e read_buffer (in bytes). This value indicates
* how many bytes we're willing to read into the buffer;
* the real buffer is one byte longer to allow for
* adding zero-termination (when needed).
*/
size_t read_buffer_size;
/**
* Position where we currently append data in
* @e read_buffer (last valid position).
*/
size_t read_buffer_offset;
/**
* Size of @e write_buffer (in bytes).
*/
size_t write_buffer_size;
/**
* Offset where we are with sending from @e write_buffer.
*/
size_t write_buffer_send_offset;
/**
* Last valid location in write_buffer (where do we
* append and up to where is it safe to send?)
*/
size_t write_buffer_append_offset;
/**
* Number of bytes we had in the HTTP header, set once we
* pass #MHD_CONNECTION_HEADERS_RECEIVED.
*/
size_t header_size;
/**
* How many more bytes of the body do we expect
* to read? #MHD_SIZE_UNKNOWN for unknown.
*/
uint64_t remaining_upload_size;
/**
* Current write position in the actual response
* (excluding headers, content only; should be 0
* while sending headers).
*/
uint64_t response_write_position;
#if defined(_MHD_HAVE_SENDFILE)
enum MHD_resp_sender_
{
MHD_resp_sender_std = 0,
MHD_resp_sender_sendfile
} resp_sender;
#endif /* _MHD_HAVE_SENDFILE */
/**
* Position in the 100 CONTINUE message that
* we need to send when receiving http 1.1 requests.
*/
size_t continue_message_write_offset;
/**
* Length of the foreign address.
*/
socklen_t addr_len;
/**
* Last time this connection had any activity
* (reading or writing).
*/
time_t last_activity;
/**
* After how many seconds of inactivity should
* this connection time out? Zero for no timeout.
*/
time_t connection_timeout;
/**
* Special member to be returned by #MHD_get_connection_info()
*/
unsigned int connection_timeout_dummy;
/**
* Did we ever call the "default_handler" on this connection? (this
* flag will determine if we call the #MHD_OPTION_NOTIFY_COMPLETED
* handler when the connection closes down).
*/
bool client_aware;
/**
* Socket for this connection. Set to #MHD_INVALID_SOCKET if
* this connection has died (daemon should clean
* up in that case).
*/
MHD_socket socket_fd;
/**
* true if #socket_fd is non-blocking, false otherwise.
*/
bool sk_nonblck;
/**
* Has this socket been closed for reading (i.e. other side closed
* the connection)? If so, we must completely close the connection
* once we are done sending our response (and stop trying to read
* from this socket).
*/
bool read_closed;
/**
* Set to `true` if the thread has been joined.
*/
bool thread_joined;
/**
* Are we currently inside the "idle" handler (to avoid recursively
* invoking it).
*/
bool in_idle;
/**
* Are we currently inside the "idle" handler (to avoid recursively
* invoking it).
*/
bool in_cleanup;
#ifdef EPOLL_SUPPORT
/**
* What is the state of this socket in relation to epoll?
*/
enum MHD_EpollState epoll_state;
#endif
/**
* State in the FSM for this connection.
*/
enum MHD_CONNECTION_STATE state;
/**
* What is this connection waiting for?
*/
enum MHD_ConnectionEventLoopInfo event_loop_info;
/**
* HTTP response code. Only valid if response object
* is already set.
*/
unsigned int responseCode;
/**
* Are we receiving with chunked encoding? This will be set to
* #MHD_YES after we parse the headers and are processing the body
* with chunks. After we are done with the body and we are
* processing the footers; once the footers are also done, this will
* be set to #MHD_NO again (before the final call to the handler).
*/
bool have_chunked_upload;
/**
* If we are receiving with chunked encoding, where are we right
* now? Set to 0 if we are waiting to receive the chunk size;
* otherwise, this is the size of the current chunk. A value of
* zero is also used when we're at the end of the chunks.
*/
uint64_t current_chunk_size;
/**
* If we are receiving with chunked encoding, where are we currently
* with respect to the current chunk (at what offset / position)?
*/
uint64_t current_chunk_offset;
/**
* Function used for reading HTTP request stream.
*/
ReceiveCallback recv_cls;
/**
* Function used for writing HTTP response stream.
*/
TransmitCallback send_cls;
#ifdef UPGRADE_SUPPORT
/**
* If this connection was upgraded, this points to
* the upgrade response details such that the
* #thread_main_connection_upgrade()-logic can perform the
* bi-directional forwarding.
*/
struct MHD_UpgradeResponseHandle *urh;
#endif /* UPGRADE_SUPPORT */
#ifdef HTTPS_SUPPORT
/**
* State required for HTTPS/SSL/TLS support.
*/
gnutls_session_t tls_session;
/**
* Memory location to return for protocol session info.
*/
int protocol;
/**
* Memory location to return for protocol session info.
*/
int cipher;
/**
* State of connection's TLS layer
*/
enum MHD_TLS_CONN_STATE tls_state;
/**
* Could it be that we are ready to read due to TLS buffers
* even though the socket is not?
*/
bool tls_read_ready;
#endif /* HTTPS_SUPPORT */
/**
* Is the connection suspended?
*/
bool suspended;
/**
* Special member to be returned by #MHD_get_connection_info()
*/
int suspended_dummy;
/**
* Is the connection wanting to resume?
*/
bool resuming;
};
#ifdef UPGRADE_SUPPORT
/**
* Buffer we use for upgrade response handling in the unlikely
* case where the memory pool was so small it had no buffer
* capacity left. Note that we don't expect to _ever_ use this
* buffer, so it's mostly wasted memory (except that it allows
* us to handle a tricky error condition nicely). So no need to
* make this one big. Applications that want to perform well
* should just pick an adequate size for the memory pools.
*/
#define RESERVE_EBUF_SIZE 8
/**
* Context we pass to epoll() for each of the two sockets
* of a `struct MHD_UpgradeResponseHandle`. We need to do
* this so we can distinguish the two sockets when epoll()
* gives us event notifications.
*/
struct UpgradeEpollHandle
{
/**
* Reference to the overall response handle this struct is
* included within.
*/
struct MHD_UpgradeResponseHandle *urh;
/**
* The socket this event is kind-of about. Note that this is NOT
* necessarily the socket we are polling on, as for when we read
* from TLS, we epoll() on the connection's socket
* (`urh->connection->socket_fd`), while this then the application's
* socket (where the application will read from). Nevertheless, for
* the application to read, we need to first read from TLS, hence
* the two are related.
*
* Similarly, for writing to TLS, this epoll() will be on the
* connection's `socket_fd`, and this will merely be the FD which
* the applicatio would write to. Hence this struct must always be
* interpreted based on which field in `struct
* MHD_UpgradeResponseHandle` it is (`app` or `mhd`).
*/
MHD_socket socket;
/**
* IO-state of the @e socket (or the connection's `socket_fd`).
*/
enum MHD_EpollState celi;
};
/**
* Handle given to the application to manage special
* actions relating to MHD responses that "upgrade"
* the HTTP protocol (i.e. to WebSockets).
*/
struct MHD_UpgradeResponseHandle
{
/**
* The connection for which this is an upgrade handle. Note that
* because a response may be shared over many connections, this may
* not be the only upgrade handle for the response of this connection.
*/
struct MHD_Connection *connection;
#ifdef HTTPS_SUPPORT
/**
* Kept in a DLL per daemon.
*/
struct MHD_UpgradeResponseHandle *next;
/**
* Kept in a DLL per daemon.
*/
struct MHD_UpgradeResponseHandle *prev;
#ifdef EPOLL_SUPPORT
/**
* Next pointer for the EDLL listing urhs that are epoll-ready.
*/
struct MHD_UpgradeResponseHandle *nextE;
/**
* Previous pointer for the EDLL listing urhs that are epoll-ready.
*/
struct MHD_UpgradeResponseHandle *prevE;
/**
* Specifies whether urh already in EDLL list of ready connections.
*/
bool in_eready_list;
#endif
/**
* The buffer for receiving data from TLS to
* be passed to the application. Contains @e in_buffer_size
* bytes (unless @e in_buffer_size is zero). Do not free!
*/
char *in_buffer;
/**
* The buffer for receiving data from the application to
* be passed to TLS. Contains @e out_buffer_size
* bytes (unless @e out_buffer_size is zero). Do not free!
*/
char *out_buffer;
/**
* Size of the @e in_buffer.
* Set to 0 if the TLS connection went down for reading or socketpair
* went down for writing.
*/
size_t in_buffer_size;
/**
* Size of the @e out_buffer.
* Set to 0 if the TLS connection went down for writing or socketpair
* went down for reading.
*/
size_t out_buffer_size;
/**
* Number of bytes actually in use in the @e in_buffer. Can be larger
* than @e in_buffer_size if and only if @a in_buffer_size is zero and
* we still have bytes that can be forwarded.
* Reset to zero if all data was forwarded to socketpair or
* if socketpair went down for writing.
*/
size_t in_buffer_used;
/**
* Number of bytes actually in use in the @e out_buffer. Can be larger
* than @e out_buffer_size if and only if @a out_buffer_size is zero and
* we still have bytes that can be forwarded.
* Reset to zero if all data was forwarded to TLS connection or
* if TLS connection went down for writing.
*/
size_t out_buffer_used;
/**
* The socket we gave to the application (r/w).
*/
struct UpgradeEpollHandle app;
/**
* If @a app_sock was a socketpair, our end of it, otherwise
* #MHD_INVALID_SOCKET; (r/w).
*/
struct UpgradeEpollHandle mhd;
/**
* Emergency IO buffer we use in case the memory pool has literally
* nothing left.
*/
char e_buf[RESERVE_EBUF_SIZE];
#endif /* HTTPS_SUPPORT */
/**
* Set to true after the application finished with the socket
* by #MHD_UPGRADE_ACTION_CLOSE.
*
* When BOTH @e was_closed (changed by command from application)
* AND @e clean_ready (changed internally by MHD) are set to
* #MHD_YES, function #MHD_resume_connection() will move this
* connection to cleanup list.
* @remark This flag could be changed from any thread.
*/
volatile bool was_closed;
/**
* Set to true if connection is ready for cleanup.
*
* In TLS mode functions #MHD_connection_finish_forward_() must
* be called before setting this flag to true.
*
* In thread-per-connection mode, true in this flag means
* that connection's thread exited or about to exit and will
* not use MHD_Connection::urh data anymore.
*
* In any mode true in this flag also means that
* MHD_Connection::urh data will not be used for socketpair
* forwarding and forwarding itself is finished.
*
* When BOTH @e was_closed (changed by command from application)
* AND @e clean_ready (changed internally by MHD) are set to
* true, function #MHD_resume_connection() will move this
* connection to cleanup list.
* @remark This flag could be changed from thread that process
* connection's recv(), send() and response.
*/
bool clean_ready;
};
#endif /* UPGRADE_SUPPORT */
/**
* Signature of function called to log URI accesses.
*
* @param cls closure
* @param uri uri being accessed
* @param con connection handle
* @return new closure
*/
typedef void *
(*LogCallback)(void *cls,
const char *uri,
struct MHD_Connection *con);
/**
* Signature of function called to unescape URIs. See also
* #MHD_http_unescape().
*
* @param cls closure
* @param conn connection handle
* @param uri 0-terminated string to unescape (should be updated)
* @return length of the resulting string
*/
typedef size_t
(*UnescapeCallback)(void *cls,
struct MHD_Connection *conn,
char *uri);
/**
* State kept for each MHD daemon. All connections are kept in two
* doubly-linked lists. The first one reflects the state of the
* connection in terms of what operations we are waiting for (read,
* write, locally blocked, cleanup) whereas the second is about its
* timeout state (default or custom).
*/
struct MHD_Daemon
{
/**
* Callback function for all requests.
*/
MHD_AccessHandlerCallback default_handler;
/**
* Closure argument to default_handler.
*/
void *default_handler_cls;
/**
* Head of doubly-linked list of our current, active connections.
*/
struct MHD_Connection *connections_head;
/**
* Tail of doubly-linked list of our current, active connections.
*/
struct MHD_Connection *connections_tail;
/**
* Head of doubly-linked list of our current but suspended connections.
*/
struct MHD_Connection *suspended_connections_head;
/**
* Tail of doubly-linked list of our current but suspended connections.
*/
struct MHD_Connection *suspended_connections_tail;
/**
* Head of doubly-linked list of connections to clean up.
*/
struct MHD_Connection *cleanup_head;
/**
* Tail of doubly-linked list of connections to clean up.
*/
struct MHD_Connection *cleanup_tail;
#ifdef EPOLL_SUPPORT
/**
* Head of EDLL of connections ready for processing (in epoll mode).
*/
struct MHD_Connection *eready_head;
/**
* Tail of EDLL of connections ready for processing (in epoll mode)
*/
struct MHD_Connection *eready_tail;
#ifdef UPGRADE_SUPPORT
/**
* Head of EDLL of upgraded connections ready for processing (in epoll mode).
*/
struct MHD_UpgradeResponseHandle *eready_urh_head;
/**
* Tail of EDLL of upgraded connections ready for processing (in epoll mode)
*/
struct MHD_UpgradeResponseHandle *eready_urh_tail;
#endif /* UPGRADE_SUPPORT */
#endif /* EPOLL_SUPPORT */
/**
* Head of the XDLL of ALL connections with a default ('normal')
* timeout, sorted by timeout (earliest at the tail, most recently
* used connection at the head). MHD can just look at the tail of
* this list to determine the timeout for all of its elements;
* whenever there is an event of a connection, the connection is
* moved back to the tail of the list.
*
* All connections by default start in this list; if a custom
* timeout that does not match @e connection_timeout is set, they
* are moved to the @e manual_timeout_head-XDLL.
* Not used in MHD_USE_THREAD_PER_CONNECTION mode as each thread
* needs only one connection-specific timeout.
*/
struct MHD_Connection *normal_timeout_head;
/**
* Tail of the XDLL of ALL connections with a default timeout,
* sorted by timeout (earliest timeout at the tail).
* Not used in MHD_USE_THREAD_PER_CONNECTION mode.
*/
struct MHD_Connection *normal_timeout_tail;
/**
* Head of the XDLL of ALL connections with a non-default/custom
* timeout, unsorted. MHD will do a O(n) scan over this list to
* determine the current timeout.
* Not used in MHD_USE_THREAD_PER_CONNECTION mode.
*/
struct MHD_Connection *manual_timeout_head;
/**
* Tail of the XDLL of ALL connections with a non-default/custom
* timeout, unsorted.
* Not used in MHD_USE_THREAD_PER_CONNECTION mode.
*/
struct MHD_Connection *manual_timeout_tail;
/**
* Function to call to check if we should accept or reject an
* incoming request. May be NULL.
*/
MHD_AcceptPolicyCallback apc;
/**
* Closure argument to apc.
*/
void *apc_cls;
/**
* Function to call when we are done processing
* a particular request. May be NULL.
*/
MHD_RequestCompletedCallback notify_completed;
/**
* Closure argument to @e notify_completed.
*/
void *notify_completed_cls;
/**
* Function to call when we are starting/stopping
* a connection. May be NULL.
*/
MHD_NotifyConnectionCallback notify_connection;
/**
* Closure argument to @e notify_connection.
*/
void *notify_connection_cls;
/**
* Function to call with the full URI at the
* beginning of request processing. May be NULL.
* <p>
* Returns the initial pointer to internal state
* kept by the client for the request.
*/
LogCallback uri_log_callback;
/**
* Closure argument to @e uri_log_callback.
*/
void *uri_log_callback_cls;
/**
* Function to call when we unescape escape sequences.
*/
UnescapeCallback unescape_callback;
/**
* Closure for @e unescape_callback.
*/
void *unescape_callback_cls;
#ifdef HAVE_MESSAGES
/**
* Function for logging error messages (if we
* support error reporting).
*/
void (*custom_error_log) (void *cls, const char *fmt, va_list va);
/**
* Closure argument to @e custom_error_log.
*/
void *custom_error_log_cls;
#endif
/**
* Pointer to master daemon (NULL if this is the master)
*/
struct MHD_Daemon *master;
/**
* Worker daemons (one per thread)
*/
struct MHD_Daemon *worker_pool;
/**
* Table storing number of connections per IP
*/
void *per_ip_connection_count;
/**
* Size of the per-connection memory pools.
*/
size_t pool_size;
/**
* Increment for growth of the per-connection memory pools.
*/
size_t pool_increment;
/**
* Size of threads created by MHD.
*/
size_t thread_stack_size;
/**
* Number of worker daemons
*/
unsigned int worker_pool_size;
/**
* The select thread handle (if we have internal select)
*/
MHD_thread_handle_ID_ pid;
/**
* Mutex for per-IP connection counts.
*/
MHD_mutex_ per_ip_connection_mutex;
/**
* Mutex for (modifying) access to the "cleanup", "normal_timeout" and
* "manual_timeout" DLLs.
*/
MHD_mutex_ cleanup_connection_mutex;
/**
* Listen socket.
*/
MHD_socket listen_fd;
/**
* Whether to allow/disallow/ignore reuse of listening address.
* The semantics is the following:
* 0: ignore (user did not ask for neither allow/disallow, use SO_REUSEADDR
* except W32)
* >0: allow (use SO_REUSEPORT on most platforms, SO_REUSEADDR on Windows)
* <0: disallow (mostly no action, SO_EXCLUSIVEADDRUSE on Windows or SO_EXCLBIND
* on Solaris)
*/
int listening_address_reuse;
#ifdef EPOLL_SUPPORT
/**
* File descriptor associated with our epoll loop.
*/
int epoll_fd;
/**
* true if the listen socket is in the 'epoll' set,
* false if not.
*/
bool listen_socket_in_epoll;
#if defined(HTTPS_SUPPORT) && defined(UPGRADE_SUPPORT)
/**
* File descriptor associated with the #run_epoll_for_upgrade() loop.
* Only available if #MHD_USE_HTTPS_EPOLL_UPGRADE is set.
*/
int epoll_upgrade_fd;
/**
* true if @e epoll_upgrade_fd is in the 'epoll' set,
* false if not.
*/
bool upgrade_fd_in_epoll;
#endif /* HTTPS_SUPPORT && UPGRADE_SUPPORT */
#endif
/**
* Inter-thread communication channel.
*/
struct MHD_itc_ itc;
/**
* Are we shutting down?
*/
volatile bool shutdown;
/**
* Has this deamon been quiesced via #MHD_quiesce_daemon()?
* If so, we should no longer use the @e listen_fd (including
* removing it from the @e epoll_fd when possible).
*/
volatile bool was_quiesced;
/**
* Did we hit some system or process-wide resource limit while
* trying to accept() the last time? If so, we don't accept new
* connections until we close an existing one. This effectively
* temporarily lowers the "connection_limit" to the current
* number of connections.
*/
bool at_limit;
/*
* Do we need to process resuming connections?
*/
bool resuming;
/**
* 'True' if some data is already waiting to be processed.
* If set to 'true' - zero timeout for select()/poll*()
* is used.
* Should be reset each time before processing connections
* and raised by any connection which require additional
* immediately processing (application does not provide
* data for response, data waiting in TLS buffers etc.)
*/
bool data_already_pending;
/**
* Number of active parallel connections.
*/
unsigned int connections;
/**
* Limit on the number of parallel connections.
*/
unsigned int connection_limit;
/**
* After how many seconds of inactivity should
* connections time out? Zero for no timeout.
*/
time_t connection_timeout;
/**
* Maximum number of connections per IP, or 0 for
* unlimited.
*/
unsigned int per_ip_connection_limit;
/**
* Daemon's flags (bitfield).
*/
enum MHD_FLAG options;
/**
* Listen port.
*/
uint16_t port;
/**
* Be neutral (zero), strict (1) or permissive (-1) to client.
*/
int strict_for_client;
#ifdef HTTPS_SUPPORT
#ifdef UPGRADE_SUPPORT
/**
* Head of DLL of upgrade response handles we are processing.
* Used for upgraded TLS connections when thread-per-connection
* is not used.
*/
struct MHD_UpgradeResponseHandle *urh_head;
/**
* Tail of DLL of upgrade response handles we are processing.
* Used for upgraded TLS connections when thread-per-connection
* is not used.
*/
struct MHD_UpgradeResponseHandle *urh_tail;
#endif /* UPGRADE_SUPPORT */
/**
* Desired cipher algorithms.
*/
gnutls_priority_t priority_cache;
/**
* What kind of credentials are we offering
* for SSL/TLS?
*/
gnutls_credentials_type_t cred_type;
/**
* Server x509 credentials
*/
gnutls_certificate_credentials_t x509_cred;
/**
* Diffie-Hellman parameters
*/
gnutls_dh_params_t dh_params;
#if GNUTLS_VERSION_MAJOR >= 3
/**
* Function that can be used to obtain the certificate. Needed
* for SNI support. See #MHD_OPTION_HTTPS_CERT_CALLBACK.
*/
gnutls_certificate_retrieve_function2 *cert_callback;
#endif
/**
* Pointer to our SSL/TLS key (in ASCII) in memory.
*/
const char *https_mem_key;
/**
* Pointer to our SSL/TLS certificate (in ASCII) in memory.
*/
const char *https_mem_cert;
/**
* Pointer to 0-terminated HTTPS passphrase in memory.
*/
const char *https_key_password;
/**
* Pointer to our SSL/TLS certificate authority (in ASCII) in memory.
*/
const char *https_mem_trust;
/**
* Our Diffie-Hellman parameters in memory.
*/
gnutls_dh_params_t https_mem_dhparams;
/**
* true if we have initialized @e https_mem_dhparams.
*/
bool have_dhparams;
#endif /* HTTPS_SUPPORT */
#ifdef DAUTH_SUPPORT
/**
* Character array of random values.
*/
const char *digest_auth_random;
/**
* An array that contains the map nonce-nc.
*/
struct MHD_NonceNc *nnc;
/**
* A rw-lock for synchronizing access to @e nnc.
*/
MHD_mutex_ nnc_lock;
/**
* Size of `digest_auth_random.
*/
size_t digest_auth_rand_size;
/**
* Size of the nonce-nc array.
*/
unsigned int nonce_nc_size;
#endif
#ifdef TCP_FASTOPEN
/**
* The queue size for incoming SYN + DATA packets.
*/
unsigned int fastopen_queue_size;
#endif
/**
* The size of queue for listen socket.
*/
unsigned int listen_backlog_size;
};
/**
* Insert an element at the head of a DLL. Assumes that head, tail and
* element are structs with prev and next fields.
*
* @param head pointer to the head of the DLL
* @param tail pointer to the tail of the DLL
* @param element element to insert
*/
#define DLL_insert(head,tail,element) do { \
mhd_assert (NULL == (element)->next); \
mhd_assert (NULL == (element)->prev); \
(element)->next = (head); \
(element)->prev = NULL; \
if ((tail) == NULL) \
(tail) = element; \
else \
(head)->prev = element; \
(head) = (element); } while (0)
/**
* Remove an element from a DLL. Assumes
* that head, tail and element are structs
* with prev and next fields.
*
* @param head pointer to the head of the DLL
* @param tail pointer to the tail of the DLL
* @param element element to remove
*/
#define DLL_remove(head,tail,element) do { \
mhd_assert ( (NULL != (element)->next) || ((element) == (tail))); \
mhd_assert ( (NULL != (element)->prev) || ((element) == (head))); \
if ((element)->prev == NULL) \
(head) = (element)->next; \
else \
(element)->prev->next = (element)->next; \
if ((element)->next == NULL) \
(tail) = (element)->prev; \
else \
(element)->next->prev = (element)->prev; \
(element)->next = NULL; \
(element)->prev = NULL; } while (0)
/**
* Insert an element at the head of a XDLL. Assumes that head, tail and
* element are structs with prevX and nextX fields.
*
* @param head pointer to the head of the XDLL
* @param tail pointer to the tail of the XDLL
* @param element element to insert
*/
#define XDLL_insert(head,tail,element) do { \
mhd_assert (NULL == (element)->nextX); \
mhd_assert (NULL == (element)->prevX); \
(element)->nextX = (head); \
(element)->prevX = NULL; \
if (NULL == (tail)) \
(tail) = element; \
else \
(head)->prevX = element; \
(head) = (element); } while (0)
/**
* Remove an element from a XDLL. Assumes
* that head, tail and element are structs
* with prevX and nextX fields.
*
* @param head pointer to the head of the XDLL
* @param tail pointer to the tail of the XDLL
* @param element element to remove
*/
#define XDLL_remove(head,tail,element) do { \
mhd_assert ( (NULL != (element)->nextX) || ((element) == (tail))); \
mhd_assert ( (NULL != (element)->prevX) || ((element) == (head))); \
if (NULL == (element)->prevX) \
(head) = (element)->nextX; \
else \
(element)->prevX->nextX = (element)->nextX; \
if (NULL == (element)->nextX) \
(tail) = (element)->prevX; \
else \
(element)->nextX->prevX = (element)->prevX; \
(element)->nextX = NULL; \
(element)->prevX = NULL; } while (0)
/**
* Insert an element at the head of a EDLL. Assumes that head, tail and
* element are structs with prevE and nextE fields.
*
* @param head pointer to the head of the EDLL
* @param tail pointer to the tail of the EDLL
* @param element element to insert
*/
#define EDLL_insert(head,tail,element) do { \
(element)->nextE = (head); \
(element)->prevE = NULL; \
if ((tail) == NULL) \
(tail) = element; \
else \
(head)->prevE = element; \
(head) = (element); } while (0)
/**
* Remove an element from a EDLL. Assumes
* that head, tail and element are structs
* with prevE and nextE fields.
*
* @param head pointer to the head of the EDLL
* @param tail pointer to the tail of the EDLL
* @param element element to remove
*/
#define EDLL_remove(head,tail,element) do { \
if ((element)->prevE == NULL) \
(head) = (element)->nextE; \
else \
(element)->prevE->nextE = (element)->nextE; \
if ((element)->nextE == NULL) \
(tail) = (element)->prevE; \
else \
(element)->nextE->prevE = (element)->prevE; \
(element)->nextE = NULL; \
(element)->prevE = NULL; } while (0)
/**
* Convert all occurrences of '+' to ' '.
*
* @param arg string that is modified (in place), must be 0-terminated
*/
void
MHD_unescape_plus (char *arg);
/**
* Callback invoked when iterating over @a key / @a value
* argument pairs during parsing.
*
* @param connection context of the iteration
* @param key 0-terminated key string, never NULL
* @param value 0-terminated value string, may be NULL
* @param kind origin of the key-value pair
* @return #MHD_YES on success (continue to iterate)
* #MHD_NO to signal failure (and abort iteration)
*/
typedef int
(*MHD_ArgumentIterator_)(struct MHD_Connection *connection,
const char *key,
const char *value,
enum MHD_ValueKind kind);
/**
* Parse and unescape the arguments given by the client
* as part of the HTTP request URI.
*
* @param kind header kind to pass to @a cb
* @param connection connection to add headers to
* @param[in,out] args argument URI string (after "?" in URI),
* clobbered in the process!
* @param cb function to call on each key-value pair found
* @param[out] num_headers set to the number of headers found
* @return #MHD_NO on failure (@a cb returned #MHD_NO),
* #MHD_YES for success (parsing succeeded, @a cb always
* returned #MHD_YES)
*/
int
MHD_parse_arguments_ (struct MHD_Connection *connection,
enum MHD_ValueKind kind,
char *args,
MHD_ArgumentIterator_ cb,
unsigned int *num_headers);
/**
* Check whether response header contains particular @a token.
*
* Token could be surrounded by spaces and tabs and delimited by comma.
* Case-insensitive match used for header names and tokens.
* @param response the response to query
* @param key header name
* @param token the token to find
* @param token_len the length of token, not including optional
* terminating null-character.
* @return true if token is found in specified header,
* false otherwise
*/
bool
MHD_check_response_header_token_ci (const struct MHD_Response *response,
const char *key,
const char *token,
size_t token_len);
/**
* Check whether response header contains particular static @a tkn.
*
* Token could be surrounded by spaces and tabs and delimited by comma.
* Case-insensitive match used for header names and tokens.
* @param r the response to query
* @param k header name
* @param tkn the static string of token to find
* @return true if token is found in specified header,
* false otherwise
*/
#define MHD_check_response_header_s_token_ci(r,k,tkn) \
MHD_check_response_header_token_ci((r),(k),(tkn),MHD_STATICSTR_LEN_(tkn))
/**
* Internal version of #MHD_suspend_connection().
*
* @remark In thread-per-connection mode: can be called from any thread,
* in any other mode: to be called only from thread that process
* daemon's select()/poll()/etc.
*
* @param connection the connection to suspend
*/
void
internal_suspend_connection_ (struct MHD_Connection *connection);
#endif