GUACAMOLE-422: Remove duplicate code and migrate handshake to user handlers.

This commit is contained in:
Nick Couchman 2019-04-02 21:38:28 -04:00
parent 2b68925ec9
commit 2f57564f5d
5 changed files with 245 additions and 282 deletions

View File

@ -505,79 +505,6 @@ struct guac_user {
};
/**
* Handler for Guacamole protocol opcode specific to the handshake that
* happens between client and server at the beginning of the connection. The
* handler will be invoked when the matching opcode is received during the
* handshake process.
*
* @param user
* The user that initiated the handshake.
*
* @param parser
* The parser allocated for parsing the data provided by the client.
*
* @param timeout
* The timeout, in microseconds, for parsing the value.
*
* @return
* Zero if the handshake instruction is successfully parsed; otherwise
* false.
*/
typedef int __guac_handshake_handler(guac_user* user, int argc, char** argv);
/**
* Structure that maps opcodes received during the handshake phase of the
* connection to callback functions used when those opcodes are received.
*/
typedef struct __guac_handshake_mapping {
/**
* The instruction opcode which maps to the handler.
*/
char* opcode;
/**
* The handler function used when specified opcode is received.
*/
__guac_handshake_handler* handler;
} __guac_handshake_mapping;
/**
* Internal handler function that is called when the size instruction is
* received during the handshake process.
*/
__guac_handshake_handler __guac_handshake_size_handler;
/**
* Internal handler function that is called when the audio instruction is
* received during the handshake process, specifying the audio mimetypes
* available to the client.
*/
__guac_handshake_handler __guac_handshake_audio_handler;
/**
* Internal handler function that is called when the video instruction is
* received during the handshake process, specifying the video mimetypes
* available to the client.
*/
__guac_handshake_handler __guac_handshake_video_handler;
/**
* Internal handler function that is called when the image instruction is
* received during the handshake process, specifying the image mimetypes
* available to the client.
*/
__guac_handshake_handler __guac_handshake_image_handler;
/**
* Internal handler function that is called when the timezone instruction is
* received during the handshake process, specifying the timezone of the
* client.
*/
__guac_handshake_handler __guac_handshake_timezone_handler;
/**
* Allocates a new, blank user, not associated with any specific client or
* socket.
@ -617,32 +544,6 @@ void guac_user_free(guac_user* user);
*/
int guac_user_handle_connection(guac_user* user, int usec_timeout);
/**
* Call the appropriate handler defined by the given user for the given
* instruction. A comparison is made between the instruction opcode and the
* initial handler lookup table defined in user-handlers.c. The intial handlers
* will in turn call the user's handler (if defined).
*
* @param user
* The user whose handlers should be called.
*
* @param opcode
* The opcode of the instruction to pass to the user via the appropriate
* handler.
*
* @param argc
* The number of arguments which are part of the instruction.
*
* @param argv
* An array of all arguments which are part of the instruction.
*
* @return
* Non-negative if the instruction was handled successfully, or negative
* if an error occurred.
*/
int guac_user_handle_instruction(guac_user* user, const char* opcode,
int argc, char** argv);
/**
* Allocates a new stream. An arbitrary index is automatically assigned
* if no previously-allocated stream is available for use.

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@ -31,6 +31,7 @@
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
/* Guacamole instruction handler map */
@ -53,6 +54,17 @@ __guac_instruction_handler_mapping __guac_instruction_handler_map[] = {
{NULL, NULL}
};
/* Guacamole handshake handler map */
__guac_instruction_handler_mapping __guac_handshake_handler_map[] = {
{"size", __guac_handshake_size_handler},
{"audio", __guac_handshake_audio_handler},
{"video", __guac_handshake_video_handler},
{"image", __guac_handshake_image_handler},
{"timezone", __guac_handshake_timezone_handler},
{NULL, NULL}
};
/**
* Parses a 64-bit integer from the given string. It is assumed that the string
* will contain only decimal digits, with an optional leading minus sign.
@ -581,3 +593,122 @@ int __guac_handle_disconnect(guac_user* user, int argc, char** argv) {
return 0;
}
/* Guacamole handshake handler functions. */
int __guac_handshake_size_handler(guac_user* user, int argc, char** argv) {
/* Validate size of instruction. */
if (argc < 2) {
guac_user_log(user, GUAC_LOG_ERROR, "Received \"size\" "
"instruction lacked required arguments.");
return 1;
}
/* Parse optimal screen dimensions from size instruction */
user->info.optimal_width = atoi(argv[0]);
user->info.optimal_height = atoi(argv[1]);
/* If DPI given, set the user resolution */
if (argc >= 3)
user->info.optimal_resolution = atoi(argv[2]);
/* Otherwise, use a safe default for rough backwards compatibility */
else
user->info.optimal_resolution = 96;
return 0;
}
int __guac_handshake_audio_handler(guac_user* user, int argc, char** argv) {
/* Store audio mimetypes */
user->info.audio_mimetypes = (const char**) guac_copy_mimetypes(argv, argc);
return 0;
}
int __guac_handshake_video_handler(guac_user* user, int argc, char** argv) {
/* Store video mimetypes */
user->info.video_mimetypes = (const char**) guac_copy_mimetypes(argv, argc);
return 0;
}
int __guac_handshake_image_handler(guac_user* user, int argc, char** argv) {
/* Store image mimetypes */
user->info.image_mimetypes = (const char**) guac_copy_mimetypes(argv, argc);
return 0;
}
int __guac_handshake_timezone_handler(guac_user* user, int argc, char** argv) {
/* Free any past value */
free((char *) user->info.timezone);
/* Store timezone, if present */
if (argc > 0 && strcmp(argv[0], ""))
user->info.timezone = (const char*) strdup(argv[0]);
return 0;
}
char** guac_copy_mimetypes(char** mimetypes, int count) {
int i;
/* Allocate sufficient space for NULL-terminated array of mimetypes */
char** mimetypes_copy = malloc(sizeof(char*) * (count+1));
/* Copy each provided mimetype */
for (i = 0; i < count; i++)
mimetypes_copy[i] = strdup(mimetypes[i]);
/* Terminate with NULL */
mimetypes_copy[count] = NULL;
return mimetypes_copy;
}
void guac_free_mimetypes(char** mimetypes) {
char** current_mimetype = mimetypes;
/* Free all strings within NULL-terminated mimetype array */
while (*current_mimetype != NULL) {
free(*current_mimetype);
current_mimetype++;
}
/* Free the array itself, now that its contents have been freed */
free(mimetypes);
}
int guac_user_handle_instruction(__guac_instruction_handler_mapping* map,
guac_user* user, const char* opcode, int argc, char** argv) {
/* For each defined instruction */
__guac_instruction_handler_mapping* current = map;
while (current->opcode != NULL) {
/* If recognized, call handler */
if (strcmp(opcode, current->opcode) == 0)
return current->handler(user, argc, argv);
current++;
}
/* If unrecognized, ignore */
return 0;
}

View File

@ -177,6 +177,40 @@ __guac_instruction_handler __guac_handle_size;
*/
__guac_instruction_handler __guac_handle_disconnect;
/**
* Internal handler function that is called when the size instruction is
* received during the handshake process.
*/
__guac_instruction_handler __guac_handshake_size_handler;
/**
* Internal handler function that is called when the audio instruction is
* received during the handshake process, specifying the audio mimetypes
* available to the client.
*/
__guac_instruction_handler __guac_handshake_audio_handler;
/**
* Internal handler function that is called when the video instruction is
* received during the handshake process, specifying the video mimetypes
* available to the client.
*/
__guac_instruction_handler __guac_handshake_video_handler;
/**
* Internal handler function that is called when the image instruction is
* received during the handshake process, specifying the image mimetypes
* available to the client.
*/
__guac_instruction_handler __guac_handshake_image_handler;
/**
* Internal handler function that is called when the timezone instruction is
* received during the handshake process, specifying the timezone of the
* client.
*/
__guac_instruction_handler __guac_handshake_timezone_handler;
/**
* Instruction handler mapping table. This is a NULL-terminated array of
* __guac_instruction_handler_mapping structures, each mapping an opcode
@ -186,4 +220,71 @@ __guac_instruction_handler __guac_handle_disconnect;
*/
extern __guac_instruction_handler_mapping __guac_instruction_handler_map[];
/**
* Handler mapping table for instructions (opcodes) specifically for the
* handshake portion of the connection. Each
* __guac_instruction_handler_mapping structure within this NULL-terminated
* array maps an opcode to a __guac_instruction_handler. The end of the array
* must be marked with a mapping with the opcode set to NULL.
*/
extern __guac_instruction_handler_mapping __guac_handshake_handler_map[];
/**
* Frees the given array of mimetypes, including the space allocated to each
* mimetype string within the array. The provided array of mimetypes MUST have
* been allocated with guac_copy_mimetypes().
*
* @param mimetypes
* The NULL-terminated array of mimetypes to free. This array MUST have
* been previously allocated with guac_copy_mimetypes().
*/
void guac_free_mimetypes(char** mimetypes);
/**
* Copies the given array of mimetypes (strings) into a newly-allocated NULL-
* terminated array of strings. Both the array and the strings within the array
* are newly-allocated and must be later freed via guac_free_mimetypes().
*
* @param mimetypes
* The array of mimetypes to copy.
*
* @param count
* The number of mimetypes in the given array.
*
* @return
* A newly-allocated, NULL-terminated array containing newly-allocated
* copies of each of the mimetypes provided in the original mimetypes
* array.
*/
char** guac_copy_mimetypes(char** mimetypes, int count);
/**
* Call the appropriate handler defined by the given user for the given
* instruction. A comparison is made between the instruction opcode and the
* initial handler lookup table defined in user-handlers.c. The intial handlers
* will in turn call the user's handler (if defined).
*
* @param map
* The array that holds the opcode to handler mappings.
*
* @param user
* The user whose handlers should be called.
*
* @param opcode
* The opcode of the instruction to pass to the user via the appropriate
* handler.
*
* @param argc
* The number of arguments which are part of the instruction.
*
* @param argv
* An array of all arguments which are part of the instruction.
*
* @return
* Non-negative if the instruction was handled successfully, or negative
* if an error occurred.
*/
int guac_user_handle_instruction(__guac_instruction_handler_mapping* map,
guac_user* user, const char* opcode, int argc, char** argv);
#endif

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@ -113,141 +113,6 @@ static void guac_user_log_handshake_failure(guac_user* user) {
}
/**
* Copies the given array of mimetypes (strings) into a newly-allocated NULL-
* terminated array of strings. Both the array and the strings within the array
* are newly-allocated and must be later freed via guac_free_mimetypes().
*
* @param mimetypes
* The array of mimetypes to copy.
*
* @param count
* The number of mimetypes in the given array.
*
* @return
* A newly-allocated, NULL-terminated array containing newly-allocated
* copies of each of the mimetypes provided in the original mimetypes
* array.
*/
static char** guac_copy_mimetypes(char** mimetypes, int count) {
int i;
/* Allocate sufficient space for NULL-terminated array of mimetypes */
char** mimetypes_copy = malloc(sizeof(char*) * (count+1));
/* Copy each provided mimetype */
for (i = 0; i < count; i++)
mimetypes_copy[i] = strdup(mimetypes[i]);
/* Terminate with NULL */
mimetypes_copy[count] = NULL;
return mimetypes_copy;
}
/**
* Frees the given array of mimetypes, including the space allocated to each
* mimetype string within the array. The provided array of mimetypes MUST have
* been allocated with guac_copy_mimetypes().
*
* @param mimetypes
* The NULL-terminated array of mimetypes to free. This array MUST have
* been previously allocated with guac_copy_mimetypes().
*/
static void guac_free_mimetypes(char** mimetypes) {
char** current_mimetype = mimetypes;
/* Free all strings within NULL-terminated mimetype array */
while (*current_mimetype != NULL) {
free(*current_mimetype);
current_mimetype++;
}
/* Free the array itself, now that its contents have been freed */
free(mimetypes);
}
/* Guacamole handshake handler functions. */
int __guac_handshake_size_handler(guac_user* user, int argc, char** argv) {
/* Validate size of instruction. */
if (argc < 2) {
guac_user_log(user, GUAC_LOG_ERROR, "Received \"size\" "
"instruction lacked required arguments.");
return 1;
}
/* Parse optimal screen dimensions from size instruction */
user->info.optimal_width = atoi(argv[0]);
user->info.optimal_height = atoi(argv[1]);
/* If DPI given, set the user resolution */
if (argc >= 3)
user->info.optimal_resolution = atoi(argv[2]);
/* Otherwise, use a safe default for rough backwards compatibility */
else
user->info.optimal_resolution = 96;
return 0;
}
int __guac_handshake_audio_handler(guac_user* user, int argc, char** argv) {
/* Store audio mimetypes */
user->info.audio_mimetypes = (const char**) guac_copy_mimetypes(argv, argc);
return 0;
}
int __guac_handshake_video_handler(guac_user* user, int argc, char** argv) {
/* Store video mimetypes */
user->info.video_mimetypes = (const char**) guac_copy_mimetypes(argv, argc);
return 0;
}
int __guac_handshake_image_handler(guac_user* user, int argc, char** argv) {
/* Store image mimetypes */
user->info.image_mimetypes = (const char**) guac_copy_mimetypes(argv, argc);
return 0;
}
int __guac_handshake_timezone_handler(guac_user* user, int argc, char** argv) {
/* Free any past value */
free((char *) user->info.timezone);
/* Store timezone, if present */
if (argc > 0 && strcmp(argv[0], ""))
user->info.timezone = (const char*) strdup(argv[0]);
return 0;
}
/* Guacamole handshake handler mappings. */
__guac_handshake_mapping __guac_handshake_map[] = {
{"size", __guac_handshake_size_handler},
{"audio", __guac_handshake_audio_handler},
{"video", __guac_handshake_video_handler},
{"image", __guac_handshake_image_handler},
{"timezone", __guac_handshake_timezone_handler},
{NULL, NULL}
};
/**
* The thread which handles all user input, calling event handlers for received
* instructions.
@ -296,7 +161,8 @@ static void* guac_user_input_thread(void* data) {
guac_error_message = NULL;
/* Call handler, stop on error */
if (guac_user_handle_instruction(user, parser->opcode, parser->argc, parser->argv) < 0) {
if (guac_user_handle_instruction(__guac_instruction_handler_map,
user, parser->opcode, parser->argc, parser->argv) < 0) {
/* Log error */
guac_user_log_guac_error(user, GUAC_LOG_WARNING,
@ -399,39 +265,21 @@ int guac_user_handle_connection(guac_user* user, int usec_timeout) {
guac_user_log(user, GUAC_LOG_DEBUG, "Processing instruction: %s",
parser->opcode);
/* Loop available opcodes and run handler if/when match found. */
__guac_handshake_mapping* current = __guac_handshake_map;
while (current->opcode != NULL) {
/* Run instruction handler for opcode with arguments. */
if (guac_user_handle_instruction(__guac_handshake_handler_map, user,
parser->opcode, parser->argc, parser->argv)) {
/* Check if loop opcode matches parsed opcode. */
if (strcmp(parser->opcode, current->opcode) == 0) {
/* If calling the handler fails, log it and return. */
if (current->handler(user, parser->argc, parser->argv)) {
guac_user_log_handshake_failure(user);
guac_user_log_guac_error(user, GUAC_LOG_DEBUG,
"Error handling handling opcode during handshake.");
guac_user_log(user, GUAC_LOG_DEBUG, "Failed opcode: %s",
current->opcode);
guac_user_log_handshake_failure(user);
guac_user_log_guac_error(user, GUAC_LOG_DEBUG,
"Error handling handling opcode during handshake.");
guac_user_log(user, GUAC_LOG_DEBUG, "Failed opcode: %s",
parser->opcode);
guac_parser_free(parser);
return 1;
}
/* If calling the handler has succeeded, log it and break. */
else {
guac_user_log(user, GUAC_LOG_DEBUG,
"Successfully processed instruction: \"%s\"",
current->opcode);
break;
}
}
guac_parser_free(parser);
return 1;
/* Move to next opcode. */
current++;
}
}
/* Acknowledge connection availability */

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@ -167,24 +167,6 @@ void guac_user_free_object(guac_user* user, guac_object* object) {
}
int guac_user_handle_instruction(guac_user* user, const char* opcode, int argc, char** argv) {
/* For each defined instruction */
__guac_instruction_handler_mapping* current = __guac_instruction_handler_map;
while (current->opcode != NULL) {
/* If recognized, call handler */
if (strcmp(opcode, current->opcode) == 0)
return current->handler(user, argc, argv);
current++;
}
/* If unrecognized, ignore */
return 0;
}
void guac_user_stop(guac_user* user) {
user->active = 0;
}