Football HTTP/Websocket functions. More...

#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#include <stdbool.h>
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <assert.h>
#include <ctype.h>
#include <sys/stat.h>
#include <time.h>
#include "fb_public.h"
#include "fb_service.h"
#include "sha1.h"

Include dependency graph for fb_http.c:

Classes
struct	media_dictionary_t

struct	language_rank

Macros
#define	_POSIX_C_SOURCE 200112L /* fileno() */

#define	_BSD_SOURCE /* strdup(), realpath() */

#define	_DARWIN_C_SOURCE /* strdup() on OS X */

#define	_DEFAULT_SOURCE

#define	countof(x) (sizeof (x) / sizeof (*x))

#define	WEBSOCKET_GUID "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"

#define	WEBSOCKET_VERSION "13"

#define	HTTP_VERSION "HTTP/1.1"

#define	get_hex_digit(c)

Typedefs
typedef enum ws_opcodes_t	OPCODE

typedef struct media_dictionary_t	MEDIA_DICTIONARY

typedef struct language_rank	LANGUAGE_RANK

Enumerations
enum	ws_opcodes_t { WSOC_CONTINUATION = 0x00 , WSOC_TEXT = 0x01 , WSOC_BINARY = 0x02 , WSOC_CLOSE = 0x08 , WSOC_PING = 0x09 , WSOC_PONG = 0x0a , WSOC_MASK = 0x0f }

Functions
static bool	fb_queue_http_noflush (FB_CONNECTION connection, char message, size_t length)

static bool	fb_queue_http (FB_CONNECTION connection, char message, size_t length)

static bool	fb_queue_http_alloc (FB_CONNECTION connection, const char message, size_t length)

static bool	write_message (FB_CONNECTION connection, const char message)

static bool	http_header (FB_CONNECTION connection, const char message, const char extra_header, const char detail)

static bool	http_response (FB_CONNECTION connection, const char message)

static bool	http_redirect (FB_CONNECTION connection, const char location)

static void	encodeblock (unsigned char in, unsigned char out, int len)

static void	perform_unmask (unsigned char message, const unsigned long length, const unsigned char mask)

static bool	fb_get_http_bytes (FB_CONNECTION *connection, size_t message_size)

void	reset_ping_interval (FB_CONNECTION *connection)
	Reset the next-ping interval. More...

FB_EVENT *	fb_read_websocket_input (FB_EVENT event, FB_CONNECTION connection)

bool	fb_websocket_ping (FB_CONNECTION *connection)

bool	fb_websocket_announce_close (FB_CONNECTION *connection)

bool	fb_websocket_encode (FB_CONNECTION *connection)

static bool	fb_greet_websocket (FB_CONNECTION *connection)

void	fb_destroy_httprequest (FB_HTTPREQUEST *request)

static bool	redirect_to_subdirectory (FB_CONNECTION *connection)

static bool	url_decode (char *request)

void	fb_collect_http_request (FB_EVENT event, FB_HTTPREQUEST request)

static bool	store (char *value, const char newvalue, FB_HTTPREQUEST *request)

void	fb_collect_http_parameter (char line, FB_HTTPREQUEST request)

bool	fb_http_command (const char *command)

static const char *	get_media_type (const char *filename)

static bool	http_serve_data (FB_CONNECTION connection, char name, FILE *file, bool sendbody)

static bool	malicious_request (FB_HTTPREQUEST request, const char filename)

static bool	request_malfunction (FB_CONNECTION connection, const char file_path)

static char *	next_language (char *languages)

static int	fb_language_compare (const void elem1, const void elem2)

static LANGUAGE_RANK *	parse_language_list (int socket, char languages, int count)

static FILE *	http_file_open (FB_CONNECTION connection, const char file_name, LANGUAGE_RANK languages, int language_count, char *file_path)

static bool	http_file_request (FB_CONNECTION *connection)

FB_EVENT *	fb_execute_http_request (FB_EVENT event, FB_CONNECTION connection)

Variables
static const unsigned int	WS_OPCODE = 0

static const unsigned int	WS_PAYLOAD = 1

static const unsigned int	WS_HEADER_MAXIMUM = 32

static const unsigned char	WS_FIN = 0x80

static const unsigned char	WS_MASK = 0x80

static const unsigned char	WS_PAYLOAD_MASK = 0x7f

static const unsigned int	WS_PAYLOAD_MAX_8BIT = 125

static const unsigned int	WS_PAYLOAD_MAGIC_16BIT = 126

static const unsigned int	WS_PAYLOAD_MAGIC_64BIT = 127

static const unsigned int	WS_PAYLOAD_MAX_16BIT = 0xffff

static const char	cb64 [] ="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"

Detailed Description

Football HTTP/Websocket functions.

Football socket abstraction layer
Author
Perette Barella

Date
2014-04-08

Copyright
Copyright 2014-2021 Devious Fish. All rights reserved.

Macro Definition Documentation

◆ _BSD_SOURCE

#define _BSD_SOURCE /* strdup(), realpath() */

◆ _DARWIN_C_SOURCE

#define _DARWIN_C_SOURCE /* strdup() on OS X */

◆ _DEFAULT_SOURCE

#define _DEFAULT_SOURCE

◆ _POSIX_C_SOURCE

#define _POSIX_C_SOURCE 200112L /* fileno() */

◆ countof

#define countof ( x ) (sizeof (x) / sizeof (*x))

◆ get_hex_digit

#define get_hex_digit ( c )

Value:

                          (((c) >= '0' && (c) <= '9') ? (c) - '0' : \
                          ((c) >= 'a' && (c) <= 'f') ? (c) - '0' + 10 : \
                          (c) - 'A' + 10)

◆ HTTP_VERSION

#define HTTP_VERSION "HTTP/1.1"

◆ WEBSOCKET_GUID

#define WEBSOCKET_GUID "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"

◆ WEBSOCKET_VERSION

#define WEBSOCKET_VERSION "13"

Typedef Documentation

◆ LANGUAGE_RANK

typedef struct language_rank LANGUAGE_RANK

Private structure for language rankings

◆ MEDIA_DICTIONARY

typedef struct media_dictionary_t MEDIA_DICTIONARY

Map file extensions to MIME types reported by HTTP server.

◆ OPCODE

typedef enum ws_opcodes_t OPCODE

Enumeration Type Documentation

◆ ws_opcodes_t

enum ws_opcodes_t

Enumerator
WSOC_CONTINUATION
WSOC_TEXT
WSOC_BINARY
WSOC_CLOSE
WSOC_PING
WSOC_PONG
WSOC_MASK

Function Documentation

◆ encodeblock()

static void encodeblock	(	unsigned char *	in,
		unsigned char *	out,
		int	len
	)

static

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◆ fb_collect_http_parameter()

void fb_collect_http_parameter	(	char *	line,
		FB_HTTPREQUEST *	request
	)

Collect HTTP method parameters that are relevant.

Parameters

line	the HTTP header line received.
request	the request structure into which details will be stored.

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◆ fb_collect_http_request()

void fb_collect_http_request	(	FB_EVENT *	event,
		FB_HTTPREQUEST *	request
	)

Collect the relevant bits of 'get', 'head' or other HTTP method.

Parameters

event	an event, complete with argv structure.
request	HTTP request structure into which details will be placed.

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◆ fb_destroy_httprequest()

void fb_destroy_httprequest ( FB_HTTPREQUEST * request )

Reset a request structure. Frees dynamically allocated elements and clears structure.

Parameters

request The request structure to reset.

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◆ fb_execute_http_request()

FB_EVENT* fb_execute_http_request	(	FB_EVENT *	event,
		FB_CONNECTION *	connection
	)

Interpret the collected HTTP request. Return an HTTP error if the request is invalid. If it is a WebSocket request, initiate a WebSocket session. Otherwise serve the request and reset the connection.

Parameters

event	a partially filled event applicable to this connection.
connection	the connection being served.

Returns: An FB_EVENT_CONNECT event if a WebSocket session is initiated, NULL otherwise.

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◆ fb_get_http_bytes()

static bool fb_get_http_bytes	(	FB_CONNECTION *	connection,
		size_t	message_size
	)

static

Ensure that input buffer contains required number of bytes. Read more input if necessary.

Parameters

connection	the connection read from.
message_size	The amount of data we need to collect.

Returns: true when the buffering requirements are met.

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◆ fb_greet_websocket()

static bool fb_greet_websocket ( FB_CONNECTION * connection )

static

Respond to the HTTP WebSocket request with the connection upgrade response. This requires crafting a custom SHA1 key to confirm we're really speaking WebSocket.

Parameters

connection The connection to greet.

Returns: true on success, false on failure.

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◆ fb_http_command()

bool fb_http_command ( const char * command )

Determine if a request is an HTTP one.

Parameters

command the HTTP request (GET, HEAD, etc.)

Returns: true if command is an HTTP request, false otherwise.

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◆ fb_language_compare()

static int fb_language_compare	(	const void *	elem1,
		const void *	elem2
	)

static

A qsort() etc compliant callback that compares languages for sorting.

Parameters

elem1	the first language rank for comparison.
elem2	the other language rank for comparison.

Returns: Negative, 0, or positive value in the usual manner.

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◆ fb_queue_http()

static bool fb_queue_http	(	FB_CONNECTION *	connection,
		char *	message,
		size_t	length
	)

inlinestatic

Add a message to the output queue. The message must be dynamically allocated by caller and is added to the connections queue. On failure. it is freed by this function.

Parameters

connection	the destination of the message
message	the message body, dynamically allocated by the caller.
length	the length of message.

Returns: true on success, false on failure.

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◆ fb_queue_http_alloc()

static bool fb_queue_http_alloc	(	FB_CONNECTION *	connection,
		const char *	message,
		size_t	length
	)

static

Add a message to the output queue, dynamically allocating the message.

Parameters

connection	Where to send the message.
message	The message to send.
length	The length of message.

Returns: true on success, false on failure.

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◆ fb_queue_http_noflush()

static bool fb_queue_http_noflush	(	FB_CONNECTION *	connection,
		char *	message,
		size_t	length
	)

static

Same as fb_queue_http, but does not flush output after queueing.

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◆ fb_read_websocket_input()

FB_EVENT* fb_read_websocket_input	(	FB_EVENT *	event,
		FB_CONNECTION *	connection
	)

Read data from WebSocket connection. Reads a WebSocket packet and decodes it, and returns an event for the payload.

Parameters

event	a partially filled event applicable to the connection.
connection	the connection to read from.

Returns: an FB_EVENT_INPUT for the message received, or NULL if the packet is incomplete.

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◆ fb_websocket_announce_close()

bool fb_websocket_announce_close ( FB_CONNECTION * connection )

Send a WebSocket close packet. This should be called as last thing prior to closing the connection.

Parameters

connection The connection to write the close to.

Returns: true on success, false on failure.

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◆ fb_websocket_encode()

bool fb_websocket_encode ( FB_CONNECTION * connection )

Build WebSocket packets from output. Checks if there's a complete packet (line) in the assembly queue. When there is, assemble a WebSocket packet and put it in the output queue.

Parameters

connection The connection to check.

Returns: true on success, false on failure.

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◆ fb_websocket_ping()

bool fb_websocket_ping ( FB_CONNECTION * connection )

Send a WebSocket ping packet. Some browsers have timeouts, so we need to send pings as keep-alives.

Parameters

connection The connection to check.

Returns: true on success, false on failure.

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◆ get_media_type()

static const char* get_media_type ( const char * filename )

static

Guess the media type from a file's extension.

Parameters

filename the name of a file.

Returns: a media type string corresponding to the file's extension, or the default "text/plain".

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◆ http_file_open()

static FILE* http_file_open	(	FB_CONNECTION *	connection,
		const char *	file_name,
		LANGUAGE_RANK *	languages,
		int	language_count,
		char **	file_path
	)

static

Handle opening a file, accounting for preferred language.

Parameters

connection	The connection and request for which file is being opened.
file_name	The name of the file to open, before language mangling.
languages	The list of languages from Accept-Language header.
language_count	The number of languages in the list.
file_path	The name of the file that was opened. It is the caller's responsibility to free this, regardless of whether http_file_open succeeded.

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◆ http_file_request()

static bool http_file_request ( FB_CONNECTION * connection )

static

Handle a GET or HEAD request. Generate appropriate HTTP error messages if the file is inaccessible or does not exist.

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◆ http_header()

static bool http_header	(	FB_CONNECTION *	connection,
		const char *	message,
		const char *	extra_header,
		const char *	detail
	)

static

Send an HTTP response header to a client. Closes the connection if anything goes wrong.

Parameters

connection	Where to send the header.
message	The HTTP response code/text.
extra_header	Extra line(s) to include with the header, or NULL.
detail	Text to provide to the user, or NULL to go with the default.

Returns: true on success, false on failure.

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◆ http_redirect()

static bool http_redirect	(	FB_CONNECTION *	connection,
		const char *	location
	)

static

Create a properly formatted HTTP redirect response.

Parameters

connection	Where to send the response.
location	The URL to redirect to.

Returns: True on success, false on failure.

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◆ http_response()

static bool http_response	(	FB_CONNECTION *	connection,
		const char *	message
	)

static

Create a properly formatted HTTP response header.

Parameters

connection	Where to send the response.
message	The HTTP response code/text.

Returns: True on success, false on failure.

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◆ http_serve_data()

static bool http_serve_data	(	FB_CONNECTION *	connection,
		char *	name,
		FILE *	file,
		bool	sendbody
	)

static

Handle a complete and valid GET or HEAD request.

Parameters

connection	the connection issuing the request.
name	the name of the file being served.
file	an open file handle for the file being served.
sendbody	true if the file should be served (GET request), false if not (HEAD)

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◆ malicious_request()

static bool malicious_request	(	FB_HTTPREQUEST *	request,
		const char *	filename
	)

static

Determine request maliciousness. Requests for a language with a '.' or '/' characters are malicious. Assess the filename of a GET/HEAD request to see if it looks maliciously crafted. Currently, disallow hidden files or parent directories.

Parameters

request	the request details
filename	the requested pathname.

Returns: true if the request appears malicious.

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◆ next_language()

static char* next_language ( char * languages )

static

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◆ parse_language_list()

static LANGUAGE_RANK* parse_language_list	(	int	socket,
		char *	languages,
		int *	count
	)

static

Parse an Accept-Language header into a list of languages.

Parameters

socket	The connection's socket, to which error messages are sent.
languages	The Accept-Language header value. Modified by this function.
count	Set to the number of languages found on return.

Returns: Pointer to array of LANGUAGE_RANKs, or NULL on error.

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◆ perform_unmask()

static void perform_unmask	(	unsigned char *	message,
		const unsigned long	length,
		const unsigned char *	mask
	)

static

Mask or umask a websocket packet.

Parameters

message	the message to be masked/unmasked.
length	the length of the message.
mask	Pointer to a 4 bytes containing mask .

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◆ redirect_to_subdirectory()

static bool redirect_to_subdirectory ( FB_CONNECTION * connection )

static

Redirect to a subdirectory. Given a request pointing to a directory (without trailing slash), request the contents (with slash).

Parameters

connection The client to redirect.

Returns: True on success, false on failure.

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◆ request_malfunction()

static bool request_malfunction	(	FB_CONNECTION *	connection,
		const char *	file_path
	)

static

Determine if request path is valid on the server side.

Ensure that the served file is within the served area. We check earlier for malicious requests; this is for erroneous or abusive configuration where a symlink redirects outsite the serve directory.
Parameters

connection the connection issuing the request

file_path the requested pathname.

Returns
true if the request is invalid for some reason.

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◆ reset_ping_interval()

void reset_ping_interval ( FB_CONNECTION * connection )

Reset the next-ping interval.

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◆ store()

static bool store	(	char **	value,
		const char *	newvalue,
		FB_HTTPREQUEST *	request
	)

static

Store a value in the request structure, or consider it an error if it's duplicate.

Parameters

value	The destination of the value.
newvalue	The value store.
request	The request structure.

Returns: True on success, false on failure.

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◆ url_decode()

static bool url_decode ( char * request )

static

Decode URL encoding.

Parameters

request the URL to decode. Contents are overwritten with decoded URL.

Returns: true if the URL decodes okay, false if it is encoded incorrectly.

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◆ write_message()

static bool write_message	(	FB_CONNECTION *	connection,
		const char *	message
	)

static

Send some raw text to a connection.

Parameters

connection	Where to send the message.
message	The message to send.

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Variable Documentation

◆ cb64

const char cb64[] ="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"

static

◆ WS_FIN

const unsigned char WS_FIN = 0x80

static

◆ WS_HEADER_MAXIMUM

const unsigned int WS_HEADER_MAXIMUM = 32

static

◆ WS_MASK

const unsigned char WS_MASK = 0x80

static

◆ WS_OPCODE

const unsigned int WS_OPCODE = 0

static

◆ WS_PAYLOAD

const unsigned int WS_PAYLOAD = 1

static

◆ WS_PAYLOAD_MAGIC_16BIT

const unsigned int WS_PAYLOAD_MAGIC_16BIT = 126

static

◆ WS_PAYLOAD_MAGIC_64BIT

const unsigned int WS_PAYLOAD_MAGIC_64BIT = 127

static

◆ WS_PAYLOAD_MASK

const unsigned char WS_PAYLOAD_MASK = 0x7f

static

◆ WS_PAYLOAD_MAX_16BIT

const unsigned int WS_PAYLOAD_MAX_16BIT = 0xffff

static

◆ WS_PAYLOAD_MAX_8BIT

const unsigned int WS_PAYLOAD_MAX_8BIT = 125

static

connection	the connection issuing the request
file_path	the requested pathname.

Classes

Macros

Typedefs

Enumerations

Functions

Variables

Detailed Description

Macro Definition Documentation

◆ _BSD_SOURCE

◆ _DARWIN_C_SOURCE

◆ _DEFAULT_SOURCE

◆ _POSIX_C_SOURCE

◆ countof

◆ get_hex_digit

◆ HTTP_VERSION

◆ WEBSOCKET_GUID

◆ WEBSOCKET_VERSION

Typedef Documentation

◆ LANGUAGE_RANK

◆ MEDIA_DICTIONARY

◆ OPCODE

Enumeration Type Documentation

◆ ws_opcodes_t

Function Documentation

◆ encodeblock()

◆ fb_collect_http_parameter()

◆ fb_collect_http_request()

◆ fb_destroy_httprequest()

◆ fb_execute_http_request()

◆ fb_get_http_bytes()

◆ fb_greet_websocket()

◆ fb_http_command()

◆ fb_language_compare()

◆ fb_queue_http()

◆ fb_queue_http_alloc()

◆ fb_queue_http_noflush()

◆ fb_read_websocket_input()

◆ fb_websocket_announce_close()

◆ fb_websocket_encode()

◆ fb_websocket_ping()

◆ get_media_type()

◆ http_file_open()

◆ http_file_request()

◆ http_header()

◆ http_redirect()

◆ http_response()

◆ http_serve_data()

◆ malicious_request()

◆ next_language()

◆ parse_language_list()

◆ perform_unmask()

◆ redirect_to_subdirectory()

◆ request_malfunction()

◆ reset_ping_interval()

◆ store()

◆ url_decode()

◆ write_message()

Variable Documentation

◆ cb64

◆ WS_FIN

◆ WS_HEADER_MAXIMUM

◆ WS_MASK

◆ WS_OPCODE

◆ WS_PAYLOAD

◆ WS_PAYLOAD_MAGIC_16BIT

◆ WS_PAYLOAD_MAGIC_64BIT

◆ WS_PAYLOAD_MASK

◆ WS_PAYLOAD_MAX_16BIT

◆ WS_PAYLOAD_MAX_8BIT