diff options
Diffstat (limited to 'src/mds-registry.c')
| -rw-r--r-- | src/mds-registry.c | 890 |
1 files changed, 0 insertions, 890 deletions
diff --git a/src/mds-registry.c b/src/mds-registry.c deleted file mode 100644 index b0c6962..0000000 --- a/src/mds-registry.c +++ /dev/null @@ -1,890 +0,0 @@ -/** - * mds — A micro-display server - * Copyright © 2014 Mattias Andrée (maandree@member.fsf.org) - * - * This program is free software: you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation, either version 3 of the License, or - * (at your option) any later version. - * - * This program 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 General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program. If not, see <http://www.gnu.org/licenses/>. - */ -#include "mds-registry.h" - -#include <libmdsserver/macros.h> -#include <libmdsserver/util.h> -#include <libmdsserver/mds-message.h> -#include <libmdsserver/hash-table.h> -#include <libmdsserver/hash-help.h> -#include <libmdsserver/client-list.h> - -#include <errno.h> -#include <inttypes.h> -#include <string.h> -#include <stdio.h> -#include <stdlib.h> -#define reconnect_to_display() -1 /* TODO */ - - - -#define MDS_REGISTRY_VARS_VERSION 0 - - - -/** - * This variable should declared by the actual server implementation. - * It must be configured before `main` is invoked. - * - * This tells the server-base how to behave - */ -server_characteristics_t server_characteristics = - { - .require_privileges = 0, - .require_display = 1, - .require_respawn_info = 0, - .sanity_check_argc = 1 - }; - - - -/** - * Value of the ‘Message ID’ header for the next message - */ -static int32_t message_id = 2; - -/** - * Buffer for received messages - */ -static mds_message_t received; - -/** - * Whether the server is connected to the display - */ -static int connected = 1; - -/** - * Protocol registry table - */ -static hash_table_t reg_table; - -/** - * Reusable buffer for data to send - */ -static char* send_buffer = NULL; - -/** - * The size of `send_buffer` - */ -static size_t send_buffer_size = 0; - -/** - * General mutex - */ -static pthread_mutex_t reg_mutex; - -/** - * General condition - */ -static pthread_cond_t reg_cond; - -/** - * Used to temporarily store the old value when reallocating heap-allocations - */ -static char* old; - - - -/** - * This function will be invoked before `initialise_server` (if not re-exec:ing) - * or before `unmarshal_server` (if re-exec:ing) - * - * @return Non-zero on error - */ -int __attribute__((const)) preinitialise_server(void) -{ - if ((errno = pthread_mutex_init(®_mutex, NULL))) - { - perror(*argv); - return 1; - } - - if ((errno = pthread_cond_init(®_cond, NULL))) - { - perror(*argv); - pthread_mutex_destroy(®_mutex); - return 1; - } - - return 0; -} - - -/** - * This function should initialise the server, - * and it not invoked after a re-exec. - * - * @return Non-zero on error - */ -int initialise_server(void) -{ - const char* const message = - "Command: intercept\n" - "Message ID: 0\n" - "Length: 32\n" - "\n" - "Command: register\n" - "Client closed\n" - /* -- NEXT MESSAGE -- */ - "Command: reregister\n" - "Message ID: 1\n" - "\n"; - - /* We are asking all servers to reregister their - protocols for two reasons: - - 1) The server would otherwise not get registrations - from servers started before this server. - 2) If this server crashes we may miss registrations - that happen between the crash and the recovery. - */ - - if (full_send(message, strlen(message))) - return 1; - if (hash_table_create_tuned(®_table, 32)) - { - perror(*argv); - hash_table_destroy(®_table, NULL, NULL); - return 1; - } - reg_table.key_comparator = (compare_func*)string_comparator; - reg_table.hasher = (hash_func*)string_hash; - server_initialised(); - mds_message_initialise(&received); - return 0; -} - - -/** - * This function will be invoked after `initialise_server` (if not re-exec:ing) - * or after `unmarshal_server` (if re-exec:ing) - * - * @return Non-zero on error - */ -int postinitialise_server(void) -{ - if (connected) - return 0; - - if (reconnect_to_display()) - { - mds_message_destroy(&received); - return 1; - } - connected = 1; - return 0; -} - - -/** - * Calculate the number of bytes that will be stored by `marshal_server` - * - * On failure the program should `abort()` or exit by other means. - * However it should not be possible for this function to fail. - * - * @return The number of bytes that will be stored by `marshal_server` - */ -size_t marshal_server_size(void) -{ - size_t i, rc = 2 * sizeof(int) + sizeof(int32_t) + 3 * sizeof(size_t); - hash_entry_t* entry; - - rc += mds_message_marshal_size(&received); - - foreach_hash_table_entry (reg_table, i, entry) - { - char* command = (char*)(void*)(entry->key); - size_t len = strlen(command) + 1; - client_list_t* list = (client_list_t*)(void*)(entry->value); - - rc += len + sizeof(size_t) + client_list_marshal_size(list); - } - - return rc; -} - - -/** - * Marshal server implementation specific data into a buffer - * - * @param state_buf The buffer for the marshalled data - * @return Non-zero on error - */ -int marshal_server(char* state_buf) -{ - size_t i, n = mds_message_marshal_size(&received); - hash_entry_t* entry; - - buf_set_next(state_buf, int, MDS_REGISTRY_VARS_VERSION); - buf_set_next(state_buf, int, connected); - buf_set_next(state_buf, int32_t, message_id); - buf_set_next(state_buf, size_t, n); - mds_message_marshal(&received, state_buf); - state_buf += n / sizeof(char); - - buf_set_next(state_buf, size_t, reg_table.capacity); - buf_set_next(state_buf, size_t, reg_table.size); - foreach_hash_table_entry (reg_table, i, entry) - { - char* command = (char*)(void*)(entry->key); - size_t len = strlen(command) + 1; - client_list_t* list = (client_list_t*)(void*)(entry->value); - - memcpy(state_buf, command, len * sizeof(char)); - state_buf += len; - - n = client_list_marshal_size(list); - buf_set_next(state_buf, size_t, n); - client_list_marshal(list, state_buf); - state_buf += n / sizeof(char); - } - - hash_table_destroy(®_table, (free_func*)reg_table_free_key, (free_func*)reg_table_free_value); - mds_message_destroy(&received); - return 0; -} - - -/** - * Unmarshal server implementation specific data and update the servers state accordingly - * - * On critical failure the program should `abort()` or exit by other means. - * That is, do not let `reexec_failure_recover` run successfully, if it unrecoverable - * error has occurred or one severe enough that it is better to simply respawn. - * - * @param state_buf The marshalled data that as not been read already - * @return Non-zero on error - */ -int unmarshal_server(char* state_buf) -{ - char* command; - client_list_t* list; - size_t i, n, m; - int stage = 0; - - /* buf_get_next(state_buf, int, MDS_REGISTRY_VARS_VERSION); */ - buf_next(state_buf, int, 1); - buf_get_next(state_buf, int, connected); - buf_get_next(state_buf, int32_t, message_id); - buf_get_next(state_buf, size_t, n); - fail_if (mds_message_unmarshal(&received, state_buf)); - state_buf += n / sizeof(char); - stage = 1; - - buf_get_next(state_buf, size_t, n); - fail_if (hash_table_create_tuned(®_table, n)); - buf_get_next(state_buf, size_t, n); - for (i = 0; i < n; i++) - { - stage = 1; - fail_if ((command = strdup(state_buf)) == NULL); - state_buf += strlen(command) + 1; - - stage = 2; - fail_if ((list = malloc(sizeof(client_list_t))) == NULL); - buf_get_next(state_buf, size_t, m); - stage = 3; - fail_if (client_list_unmarshal(list, state_buf)); - state_buf += m / sizeof(char); - - hash_table_put(®_table, (size_t)(void*)command, (size_t)(void*)list); - fail_if (errno); - } - - reg_table.key_comparator = (compare_func*)string_comparator; - reg_table.hasher = (hash_func*)string_hash; - - return 0; - pfail: - perror(*argv); - mds_message_destroy(&received); - if (stage >= 1) - hash_table_destroy(®_table, (free_func*)reg_table_free_key, (free_func*)reg_table_free_value); - if (stage >= 2) - free(command); - if (stage >= 3) - { - client_list_destroy(list); - free(list); - } - abort(); - return -1; -} - - -/** - * Attempt to recover from a re-exec failure that has been - * detected after the server successfully updated it execution image - * - * @return Non-zero on error - */ -int __attribute__((const)) reexec_failure_recover(void) -{ - return -1; -} - - -/** - * Perform the server's mission - * - * @return Non-zero on error - */ -int master_loop(void) -{ - int rc = 1; - - while (!reexecing && !terminating) - { - int r = mds_message_read(&received, socket_fd); - if (r == 0) - { - r = handle_message(); - if (r == 0) - continue; - } - - if (r == -2) - { - eprint("corrupt message received, aborting."); - goto fail; - } - else if (errno == EINTR) - continue; - else if (errno != ECONNRESET) - goto pfail; - - eprint("lost connection to server."); - mds_message_destroy(&received); - mds_message_initialise(&received); - connected = 0; - if (reconnect_to_display()) - goto fail; - connected = 1; - } - - rc = 0; - goto fail; - pfail: - perror(*argv); - fail: - if (rc || !reexecing) - { - hash_table_destroy(®_table, (free_func*)reg_table_free_key, (free_func*)reg_table_free_value); - mds_message_destroy(&received); - } - pthread_mutex_destroy(®_mutex); - pthread_cond_destroy(®_cond); - free(send_buffer); - return rc; -} - - -/** - * Handle the received message containing ‘Command: register’-header–value - * - * @return Zero on success -1 on error or interruption, - * errno will be set accordingly - */ -static int handle_register_message(void) -{ - const char* recv_client_id = NULL; - const char* recv_message_id = NULL; - const char* recv_length = NULL; - const char* recv_action = NULL; - size_t i, length = 0; - -#define __get_header(storage, header) \ - (startswith(received.headers[i], header)) \ - storage = received.headers[i] + strlen(header) - - for (i = 0; i < received.header_count; i++) - { - if __get_header(recv_client_id, "Client ID: "); - else if __get_header(recv_message_id, "Message ID: "); - else if __get_header(recv_length, "Length: "); - else if __get_header(recv_action, "Action: "); - else - continue; - if (recv_client_id && recv_message_id && recv_length && recv_action) - break; - } - -#undef __get_header - - - if ((recv_client_id == NULL) || (strequals(recv_client_id, "0:0"))) - { - eprint("received message from anonymous sender, ignoring."); - return 0; - } - else if (strchr(recv_client_id, ':') == NULL) - { - eprint("received message from sender without a colon it its ID, ignoring, invalid ID."); - return 0; - } - else if ((recv_length == NULL) && ((recv_action == NULL) || !strequals(recv_action, "list"))) - { - eprint("received empty message without `Action: list`, ignoring, has no effect."); - return 0; - } - else if (recv_message_id == NULL) - { - eprint("received message with ID, ignoring, master server is misbehaving."); - return 0; - } - - - if (recv_length != NULL) - length = (size_t)atoll(recv_length); - if (recv_action != NULL) - recv_action = "add"; - -#define __registry_action(action) registry_action(length, action, recv_client_id, recv_message_id) - - if (strequals(recv_action, "add")) return __registry_action(1); - else if (strequals(recv_action, "remove")) return __registry_action(-1); - else if (strequals(recv_action, "wait")) return __registry_action(0); - else if (strequals(recv_action, "list")) return list_registry(recv_client_id, recv_message_id); - else - { - eprint("received invalid action, ignoring."); - return 0; - } - -#undef __registry_action -} - - -/** - * Handle the received message containing a ‘Client closed’-header - * - * @return Zero on success -1 on error or interruption, - * errno will be set accordingly - */ -static int handle_close_message(void) -{ - /* Servers do not close too often, there is no need to - optimise this with another hash table. */ - - size_t i, j, ptr = 0, size = 1; - size_t* keys = NULL; - size_t* old_keys; - - fail_if ((errno = pthread_mutex_lock(®_mutex))); - - for (i = 0; i < received.header_count; i++) - if (startswith(received.headers[i], "Client closed: ")) - { - uint64_t client = parse_client_id(received.headers[i] + strlen("Client closed: ")); - hash_entry_t* entry; - - foreach_hash_table_entry (reg_table, j, entry) - { - client_list_t* list = (client_list_t*)(void*)(entry->value); - client_list_remove(list, client); - if (list->size) - continue; - - fail_if ((keys == NULL) && xmalloc(keys, size, size_t)); - if (ptr == size ? growalloc(old_keys, keys, size, size_t) : 0) - goto fail; - keys[ptr++] = entry->key; - } - } - - for (i = 0; i < ptr; i++) - { - hash_entry_t* entry = hash_table_get_entry(®_table, keys[i]); - client_list_t* list = (client_list_t*)(void*)(entry->value); - char* command = (char*)(void*)(entry->key); - - hash_table_remove(®_table, entry->key); - - client_list_destroy(list); - free(list); - free(command); - } - - pthread_mutex_unlock(®_mutex); - - free(keys); - return 0; - pfail: - perror(*argv); - fail: - free(keys); - return -1; -} - - -/** - * Handle the received message - * - * @return Zero on success -1 on error or interruption, - * errno will be set accordingly - */ -int handle_message(void) -{ - size_t i; - for (i = 0; i < received.header_count; i++) - if (strequals(received.headers[i], "Command: register")) - return handle_register_message(); - return handle_close_message(); -} - - -/** - * Convert a client ID string into a client ID integer - * - * @param str The client ID string - * @return The client ID integer - */ -uint64_t parse_client_id(const char* str) -{ - char client_words[22]; - char* client_high; - char* client_low; - uint64_t client; - - strcpy(client_high = client_words, str); - client_low = rawmemchr(client_words, ':'); - *client_low++ = '\0'; - client = (uint64_t)atoll(client_high); - client <<= 32; - client |= (uint64_t)atoll(client_low); - - return client; -} - - -/** - * Add a protocol to the registry - * - * @param has_key Whether the command is already in the registry - * @param command The command - * @param command_key The address of `command` - * @param client The ID of the client that implements the server-side of the protocol - * @return Non-zero on error - */ -static int registry_action_add(int has_key, char* command, size_t command_key, uint64_t client) -{ - if (has_key) - { - size_t address = hash_table_get(®_table, command_key); - client_list_t* list = (client_list_t*)(void*)address; - if (client_list_add(list, client) < 0) - goto pfail; - } - else - { - client_list_t* list = malloc(sizeof(client_list_t)); - void* address = list; - if (list == NULL) - goto pfail; - if ((command = strdup(command)) == NULL) - { - free(list); - goto pfail; - } - command_key = (size_t)(void*)command; - if (client_list_create(list, 1) || - client_list_add(list, client) || - (hash_table_put(®_table, command_key, (size_t)address) == 0)) - { - client_list_destroy(list); - free(list); - free(command); - goto pfail; - } - } - - return 0; - pfail: - perror(*argv); - return -1; -} - - -/** - * Remove a protocol from the registry - * - * @param command_key The address of a string that contains the command - * @param client The ID of the client that implements the server-side of the protocol - * @return Non-zero on error - */ -static void registry_action_remove(size_t command_key, uint64_t client) -{ - hash_entry_t* entry = hash_table_get_entry(®_table, command_key); - size_t address = entry->value; - client_list_t* list = (client_list_t*)(void*)address; - client_list_remove(list, client); - if (list->size == 0) - { - client_list_destroy(list); - free(list); - hash_table_remove(®_table, command_key); - reg_table_free_key(entry->key); - } -} - - -/** - * Modify the protocol registry or list missing protocols - * - * @param command The command - * @param action -1 to remove command, +1 to add commands, 0 to - * wait until the message commnds are registered - * @param client The ID of the client that implements the server-side of the protocol - * @param wait_set Table to fill with missing protocols if `action == 0` - * @return Non-zero on error - */ -static int registry_action_act(char* command, int action, uint64_t client, hash_table_t* wait_set) -{ - size_t command_key = (size_t)(void*)command; - int has_key = hash_table_contains_key(®_table, command_key); - - if (action == 1) - { - if (registry_action_add(has_key, command, command_key, client)) - return -1; - } - else if ((action == -1) && has_key) - registry_action_remove(command_key, client); - else if ((action == 0) && !has_key) - { - if ((command = strdup(command)) == NULL) - goto pfail_wait; - command_key = (size_t)(void*)command; - if (hash_table_put(wait_set, command_key, 1) == 0) - if (errno) - { - free(command); - goto pfail_wait; - } - } - - return 0; - pfail_wait: - perror(*argv); - hash_table_destroy(wait_set, (free_func*)reg_table_free_key, NULL); - free(wait_set); - return -1; -} - - -/** - * Perform an action over the registry - * - * @param length The length of the received message - * @param action -1 to remove command, +1 to add commands, 0 to - * wait until the message commnds are registered - * @param recv_client_id The ID of the client - * @param recv_message_id The ID of the received message - * @return Zero on success -1 on error or interruption, - * errno will be set accordingly - */ -int registry_action(size_t length, int action, const char* recv_client_id, const char* recv_message_id) -{ - char* payload = received.payload; - uint64_t client = action ? parse_client_id(recv_client_id) : 0; - hash_table_t* wait_set = NULL; - size_t begin; - - if (action == 0) - { - wait_set = malloc(sizeof(hash_table_t)); - if (hash_table_create(wait_set)) - { - hash_table_destroy(wait_set, NULL, NULL); - free(wait_set); - goto pfail; - } - wait_set->key_comparator = (compare_func*)string_comparator; - wait_set->hasher = (hash_func*)string_hash; - } - - if (received.payload_size == length) - { - if (growalloc(old, received.payload, received.payload_size, char)) - { - if (wait_set != NULL) - hash_table_destroy(wait_set, NULL, NULL), free(wait_set); - return -1; - } - else - payload = received.payload; - } - - payload[length] = '\n'; - - fail_if ((errno = pthread_mutex_lock(®_mutex))); - - for (begin = 0; begin < length;) - { - char* end = rawmemchr(payload + begin, '\n'); - size_t len = (size_t)(end - payload) - begin - 1; - char* command = payload + begin; - - command[len] = '\0'; - begin += len + 1; - - if (registry_action_act(command, action, client, wait_set)) - goto fail_in_mutex; - } - - pthread_mutex_unlock(®_mutex); - - if (action == 0) - { - /* FIXME */ - } - - return 0; - - - pfail: - perror(*argv); - return -1; - fail_in_mutex: - pthread_mutex_unlock(®_mutex); - return -1; -} - - -/** - * Send a list of all registered commands to a client - * - * @param recv_client_id The ID of the client - * @param recv_message_id The ID of the received message - * @return Zero on success -1 on error or interruption, - * errno will be set accordingly - */ -int list_registry(const char* recv_client_id, const char* recv_message_id) -{ - size_t ptr = 0, i; - hash_entry_t* entry; - - if (send_buffer_size == 0) - { - fail_if (xmalloc(send_buffer, 256, char)); - send_buffer_size = 256; - } - - fail_if ((errno = pthread_mutex_lock(®_mutex))); - - foreach_hash_table_entry (reg_table, i, entry) - { - size_t key = entry->key; - char* command = (char*)(void*)key; - size_t len = strlen(command); - - while (ptr + len + 1 >= send_buffer_size) - if (growalloc(old, send_buffer, send_buffer_size, char)) - goto fail_in_mutex; - - memcpy(send_buffer + ptr, command, len * sizeof(char)); - ptr += len; - send_buffer[ptr++] = '\n'; - } - - i = strlen(recv_message_id) + strlen(recv_client_id) + 10 + 19; - i += strlen("To: %s\nIn response to: %s\nMessage ID: %" PRIi32 "\nLength: %" PRIu64 "\n\n"); - - while (ptr + i >= send_buffer_size) - { - if (growalloc(old, send_buffer, send_buffer_size, char)) - goto fail_in_mutex; - } - - sprintf(send_buffer + ptr, "To: %s\nIn response to: %s\nMessage ID: %" PRIi32 "\nLength: %" PRIu64 "\n\n", - recv_message_id, recv_client_id, message_id, ptr); - - message_id = message_id == INT32_MAX ? 0 : (message_id + 1); - - pthread_mutex_unlock(®_mutex); - - if (full_send(send_buffer + ptr, strlen(send_buffer + ptr))) - return 1; - return full_send(send_buffer, ptr); - - - fail_in_mutex: - pthread_mutex_unlock(®_mutex); - return -1; - - pfail: - perror(*argv); - return -1; -} - - -/** - * Free a key from a table - * - * @param obj The key - */ -void reg_table_free_key(size_t obj) -{ - char* command = (char*)(void*)obj; - free(command); -} - - -/** - * Free a value from a table - * - * @param obj The value - */ -void reg_table_free_value(size_t obj) -{ - client_list_t* list = (client_list_t*)(void*)obj; - client_list_destroy(list); - free(list); -} - - -/** - * Send a full message even if interrupted - * - * @param message The message to send - * @param length The length of the message - * @return Non-zero on success - */ -int full_send(const char* message, size_t length) -{ - size_t sent; - - while (length > 0) - { - sent = send_message(socket_fd, message, length); - if (sent > length) - { - eprint("Sent more of a message than exists in the message, aborting."); - return -1; - } - else if ((sent < length) && (errno != EINTR)) - { - perror(*argv); - return -1; - } - message += sent; - length -= sent; - } - return 0; -} - |