diff options
| -rw-r--r-- | Makefile | 2 | ||||
| -rw-r--r-- | src/libmdsserver/mds-message.c | 19 | ||||
| -rw-r--r-- | src/libmdsserver/mds-message.h | 7 | ||||
| -rw-r--r-- | src/mds-server/mds-server.c | 468 | ||||
| -rw-r--r-- | src/mds-server/mds-server.h | 34 | ||||
| -rw-r--r-- | src/mds-server/reexec.c | 372 | ||||
| -rw-r--r-- | src/mds-server/reexec.h | 54 | ||||
| -rw-r--r-- | src/mds-server/slavery.c | 140 | ||||
| -rw-r--r-- | src/mds-server/slavery.h | 54 |
9 files changed, 682 insertions, 468 deletions
@@ -81,7 +81,7 @@ all: bin/mds bin/mds-server bin/libmdsserver.so MDS_SERVER_OBJ_ = mds-server interception_condition client multicast \ queued_interception globals signals interceptors \ - sending + sending slavery reexec MDS_SERVER_OBJ = $(foreach O,$(MDS_SERVER_OBJ_),mds-server/$(O)) bin/mds-server: $(foreach O,$(MDS_SERVER_OBJ),obj/$(O).o) bin/libmdsserver.so diff --git a/src/libmdsserver/mds-message.c b/src/libmdsserver/mds-message.c index bc71ca6..5051cb1 100644 --- a/src/libmdsserver/mds-message.c +++ b/src/libmdsserver/mds-message.c @@ -51,6 +51,25 @@ int mds_message_initialise(mds_message_t* restrict this) /** + * Zero initialise a message slot + * + * @param this Memory slot in which to store the new message + */ +void mds_message_zero_initialise(mds_message_t* restrict this) +{ + this->headers = NULL; + this->header_count = 0; + this->payload = NULL; + this->payload_size = 0; + this->payload_ptr = 0; + this->buffer = NULL; + this->buffer_size = 0; + this->buffer_ptr = 0; + this->stage = 0; +} + + +/** * Release all resources in a message, should * be done even if initialisation fails * diff --git a/src/libmdsserver/mds-message.h b/src/libmdsserver/mds-message.h index 6f0a61d..c6086c5 100644 --- a/src/libmdsserver/mds-message.h +++ b/src/libmdsserver/mds-message.h @@ -93,6 +93,13 @@ typedef struct mds_message int mds_message_initialise(mds_message_t* restrict this); /** + * Zero initialise a message slot + * + * @param this Memory slot in which to store the new message + */ +void mds_message_zero_initialise(mds_message_t* restrict this); + +/** * Release all resources in a message, should * be done even if initialisation fails * diff --git a/src/mds-server/mds-server.c b/src/mds-server/mds-server.c index 2f587a7..7da5f39 100644 --- a/src/mds-server/mds-server.c +++ b/src/mds-server/mds-server.c @@ -25,6 +25,8 @@ #include "signals.h" #include "interceptors.h" #include "sending.h" +#include "slavery.h" +#include "reexec.h" #include <libmdsserver/config.h> #include <libmdsserver/linked-list.h> @@ -44,10 +46,10 @@ #include <errno.h> #include <pthread.h> #include <sys/socket.h> -#include <sys/mman.h> #include <fcntl.h> #include <sys/stat.h> #include <sys/types.h> +#include <sys/mman.h> #include <dirent.h> #include <inttypes.h> #include <time.h> @@ -185,25 +187,7 @@ int main(int argc_, char** argv_) /* Unmarshal the state of the server. */ if (reexec) - { - pid_t pid = getpid(); - int reexec_fd, r; - char shm_path[NAME_MAX + 1]; - - /* Acquire access to marshalled data. */ - xsnprintf(shm_path, SHM_PATH_PATTERN, (unsigned long int)pid); - reexec_fd = shm_open(shm_path, O_RDONLY, S_IRWXU); - fail_if (reexec_fd < 0); /* Critical. */ - /* Unmarshal state. */ - r = unmarshal_server(reexec_fd); - close(reexec_fd); - shm_unlink(shm_path); - if (r < 0) - { - /* Close all files (hopefully sockets) we do not know what they are. */ - close_files((fd > 2) && (fd != socket_fd) && (fd_table_contains_key(&client_map, fd) == 0)); - } - } + complete_reexec(socket_fd); /* Accepting incoming connections. */ while (running && (terminating == 0)) @@ -229,7 +213,6 @@ int main(int argc_, char** argv_) } terminate: - if (reexecing) goto reexec; @@ -247,54 +230,9 @@ int main(int argc_, char** argv_) reexec: - { - pid_t pid = getpid(); - int reexec_fd; - char shm_path[NAME_MAX + 1]; - ssize_t node; - - /* Join with all slaves threads. */ - with_mutex (slave_mutex, - while (running_slaves > 0) - pthread_cond_wait(&slave_cond, &slave_mutex);); - - /* Release resources. */ - pthread_mutex_destroy(&slave_mutex); - pthread_cond_destroy(&slave_cond); - pthread_mutex_destroy(&modify_mutex); - pthread_cond_destroy(&modify_cond); - hash_table_destroy(&modify_map, NULL, NULL); - - /* Marshal the state of the server. */ - xsnprintf(shm_path, SHM_PATH_PATTERN, (unsigned long int)pid); - reexec_fd = shm_open(shm_path, O_RDWR | O_CREAT | O_EXCL, S_IRWXU); - fail_if (reexec_fd < 0); - if (marshal_server(reexec_fd) < 0) - goto reexec_fail; - close(reexec_fd); - reexec_fd = -1; - - /* Release resources. */ - foreach_linked_list_node (client_list, node) - { - client_t* client = (client_t*)(void*)(client_list.values[node]); - client_destroy(client); - } - fd_table_destroy(&client_map, NULL, NULL); - linked_list_destroy(&client_list); - - /* Re-exec the server. */ - reexec_server(argc, argv, reexec); - - reexec_fail: - perror(*argv); - if (reexec_fd >= 0) - close(reexec_fd); - shm_unlink(shm_path); - /* Returning non-zero is important, otherwise the server cannot - be respawn if the re-exec fails. */ - return 1; - } + perform_reexec(reexec); + /* Returning non-zero is important, otherwise the server cannot + be respawn if the re-exec fails. */ pfail: perror(*argv); @@ -311,47 +249,16 @@ int main(int argc_, char** argv_) void* slave_loop(void* data) { int socket_fd = (int)(intptr_t)data; - ssize_t entry = LINKED_LIST_UNUSED; size_t information_address = fd_table_get(&client_map, (size_t)socket_fd); client_t* information = (client_t*)(void*)information_address; char* msgbuf = NULL; size_t n; - size_t tmp; int r; + /* Intiailsie the client. */ if (information == NULL) - { - /* Create information table. */ - fail_if (xmalloc(information, 1, client_t)); - client_initialise(information); - - /* Add to list of clients. */ - pthread_mutex_lock(&slave_mutex); - entry = linked_list_insert_end(&client_list, (size_t)(void*)information); - if (entry == LINKED_LIST_UNUSED) - { - perror(*argv); - pthread_mutex_unlock(&slave_mutex); - goto fail; - } - - /* Add client to table. */ - tmp = fd_table_put(&client_map, socket_fd, (size_t)(void*)information); - if ((tmp == 0) && errno) - { - perror(*argv); - pthread_mutex_unlock(&slave_mutex); - goto fail; - } - pthread_mutex_unlock(&slave_mutex); - - /* Fill information table. */ - information->list_entry = entry; - information->socket_fd = socket_fd; - information->open = 1; - fail_if (mds_message_initialise(&(information->message))); - } + fail_if ((information = initialise_client(socket_fd)) == NULL); /* Store slave thread and create mutexes and conditions. */ fail_if (client_initialise_threading(information)); @@ -406,13 +313,15 @@ void* slave_loop(void* data) close(socket_fd); free(msgbuf); if (information != NULL) - client_destroy(information); + { + /* Unlist and free client. */ + with_mutex (slave_mutex, linked_list_remove(&client_list, information->list_entry);); + client_destroy(information); + } - /* Unlist client and decrease the slave count. */ + /* Unmap client and decrease the slave count. */ with_mutex (slave_mutex, fd_table_remove(&client_map, socket_fd); - if (entry != LINKED_LIST_UNUSED) - linked_list_remove(&client_list, entry); running_slaves--; pthread_cond_signal(&slave_cond);); return NULL; @@ -436,36 +345,6 @@ void* slave_loop(void* data) /** - * Receive a full message and update open status if the client closes - * - * @param client The client - * @return Zero on success, -2 on failure, otherwise -1 - */ -int fetch_message(client_t* client) -{ - int r = mds_message_read(&(client->message), client->socket_fd); - if (r == 0) - return 0; - - if (r == -2) - eprint("corrupt message received."); - else if (errno == ECONNRESET) - { - r = mds_message_read(&(client->message), client->socket_fd); - client->open = 0; - /* Connection closed. */ - } - else if (errno != EINTR) - { - r = -2; - perror(*argv); - } - - return r; -} - - -/** * Perform actions that should be taken when * a message has been received from a client * @@ -501,7 +380,7 @@ int message_received(client_t* client) /* Notify waiting client about a received message modification. */ - if (modifying != 0) + if (modifying) { /* pthread_cond_timedwait is required to handle re-exec and termination because pthread_cond_timedwait and pthread_cond_wait ignore interruptions via signals. */ @@ -526,35 +405,15 @@ int message_received(client_t* client) } address = hash_table_get(&modify_map, (size_t)modify_id); recipient = (client_t*)(void*)address; - if (xmalloc(multicast = recipient->modify_message, 1, mds_message_t)) - goto fail; - multicast->headers = NULL; - multicast->header_count = 0; - multicast->payload = NULL; - multicast->payload_size = 0; - multicast->payload_ptr = 0; - multicast->buffer = NULL; - multicast->buffer_size = 0; - multicast->buffer_ptr = 0; - multicast->stage = 0; - if (xmalloc(multicast->payload, message.payload_size, char)) - goto fail; + fail_if (xmalloc(multicast = recipient->modify_message, 1, mds_message_t)); + mds_message_zero_initialise(multicast); + fail_if (xmalloc(multicast->payload, message.payload_size, char)); memcpy(multicast->payload, message.payload, message.payload_size * sizeof(char)); - if (xmalloc(multicast->headers, message.header_count, char*)) - goto fail; + fail_if (xmalloc(multicast->headers, message.header_count, char*)); for (i = 0; i < message.header_count; i++, multicast->header_count++) { multicast->headers[i] = strdup(message.headers[i]); - if (multicast->headers[i] == NULL) - goto fail; - } - goto done; - fail: - if (multicast != NULL) - { - mds_message_destroy(multicast); - free(multicast); - recipient->modify_message = NULL; + fail_if (multicast->headers[i] == NULL); } done: pthread_mutex_unlock(&(modify_mutex)); @@ -562,6 +421,15 @@ int message_received(client_t* client) /* Do nothing more, not not even multicast this message. */ return 0; + pfail: + perror(*argv); + if (multicast != NULL) + { + mds_message_destroy(multicast); + free(multicast); + recipient->modify_message = NULL; + } + goto done; } @@ -707,15 +575,15 @@ int message_received(client_t* client) { /* Concatenate message to already pending messages. */ size_t new_len = client->send_pending_size + n; - char* msg_new = realloc(client->send_pending, new_len * sizeof(char)); - if (msg_new != NULL) + char* msg_new = client->send_pending; + if (xrealloc(msg_new, new_len, char)) + perror(*argv); + else { memcpy(msg_new + client->send_pending_size, msgbuf, n * sizeof(char)); client->send_pending = msg_new; client->send_pending_size = new_len; } - else - perror(*argv); free(msgbuf); } ); @@ -940,271 +808,3 @@ void run_initrc(char** args) eprintf("unable to run %s file, you might as well kill me.", INITRC_FILE); } - -/** - * Marshal the server's state into a file - * - * @param fd The file descriptor - * @return Negative on error - */ -int marshal_server(int fd) -{ - size_t list_size = linked_list_marshal_size(&client_list); - size_t map_size = fd_table_marshal_size(&client_map); - size_t list_elements = 0; - size_t state_n = 0; - char* state_buf = NULL; - char* state_buf_; - ssize_t node; - - - /* Calculate the grand size of all client information. */ - for (node = client_list.edge;; list_elements++) - { - if ((node = client_list.next[node]) == client_list.edge) - break; - state_n += client_marshal_size((client_t*)(void*)(client_list.values[node])); - } - - /* Add the size of the rest of the program's state. */ - state_n += sizeof(int) + sizeof(sig_atomic_t) + 2 * sizeof(uint64_t) + 2 * sizeof(size_t); - state_n += list_elements * sizeof(size_t) + list_size + map_size; - - /* Allocate a buffer for all data except the client list and the client map. */ - state_buf = state_buf_ = malloc(state_n); - if (state_buf == NULL) - goto fail; - - - /* Tell the new version of the program what version of the program it is marshalling. */ - buf_set_next(state_buf_, int, MDS_SERVER_VARS_VERSION); - - /* Marshal the miscellaneous state data. */ - buf_set_next(state_buf_, sig_atomic_t, running); - buf_set_next(state_buf_, uint64_t, next_client_id); - buf_set_next(state_buf_, uint64_t, next_modify_id); - - /* Tell the program how large the marshalled client list is and how any clients are marshalled. */ - buf_set_next(state_buf_, size_t, list_size); - buf_set_next(state_buf_, size_t, list_elements); - - /* Marshal the clients. */ - foreach_linked_list_node (client_list, node) - { - /* Get the memory address of the client. */ - size_t value_address = client_list.values[node]; - /* Get the client's information. */ - client_t* value = (client_t*)(void*)value_address; - - /* Marshal the address, it is used the the client list and the client map, that will be marshalled. */ - buf_set_next(state_buf_, size_t, value_address); - /* Marshal the client informationation. */ - state_buf_ += client_marshal(value, state_buf_) / sizeof(char); - } - - /* Marshal the client list. */ - linked_list_marshal(&client_list, state_buf_); - state_buf_ += list_size / sizeof(char); - /* Marshal the client map. */ - fd_table_marshal(&client_map, state_buf_); - - /* Send the marshalled data into the file. */ - if (full_write(fd, state_buf, state_n) < 0) - goto fail; - free(state_buf); - - return 0; - - fail: - perror(*argv); - free(state_buf); - return -1; -} - - -/** - * Address translation table used by `unmarshal_server` and `remapper` - */ -static hash_table_t unmarshal_remap_map; - -/** - * Address translator for `unmarshal_server` - * - * @param old The old address - * @return The new address - */ -static size_t unmarshal_remapper(size_t old) -{ - return hash_table_get(&unmarshal_remap_map, old); -} - -/** - * Unmarshal the server's state from a file - * - * @param fd The file descriptor - * @return Negative on error - */ -int unmarshal_server(int fd) -{ - int with_error = 0; - char* state_buf; - char* state_buf_; - size_t list_size; - size_t list_elements; - size_t i; - ssize_t node; - pthread_t slave_thread; - - - /* Read the file. */ - if ((state_buf = state_buf_ = full_read(fd)) == NULL) - { - perror(*argv); - return -1; - } - - /* Create memory address remapping table. */ - if (hash_table_create(&unmarshal_remap_map)) - { - perror(*argv); - free(state_buf); - hash_table_destroy(&unmarshal_remap_map, NULL, NULL); - return -1; - } - - - /* Get the marshal protocal version. Not needed, there is only the one version right now. */ - /* buf_get(state_buf_, int, 0, MDS_SERVER_VARS_VERSION); */ - buf_next(state_buf_, int, 1); - - /* Unmarshal the miscellaneous state data. */ - buf_get_next(state_buf_, sig_atomic_t, running); - buf_get_next(state_buf_, uint64_t, next_client_id); - buf_get_next(state_buf_, uint64_t, next_modify_id); - - /* Get the marshalled size of the client list and how any clients that are marshalled. */ - buf_get_next(state_buf_, size_t, list_size); - buf_get_next(state_buf_, size_t, list_elements); - - /* Unmarshal the clients. */ - for (i = 0; i < list_elements; i++) - { - size_t n; - size_t value_address; - client_t* value; - - /* Allocate the client's information. */ - if (xmalloc(value, 1, client_t)) - goto clients_fail; - - /* Unmarshal the address, it is used the the client list and the client map, that are also marshalled. */ - buf_get_next(state_buf_, size_t, value_address); - /* Unmarshal the client information. */ - n = client_unmarshal(value, state_buf_); - if (n == 0) - goto clients_fail; - - /* Populate the remapping table. */ - if (hash_table_put(&unmarshal_remap_map, value_address, (size_t)(void*)value) == 0) - if (errno) - goto clients_fail; - - /* Delayed seeking. */ - state_buf_ += n / sizeof(char); - - - /* On error, seek past all clients. */ - continue; - clients_fail: - perror(*argv); - with_error = 1; - if (value != NULL) - { - buf_prev(state_buf_, size_t, 1); - free(value); - } - for (; i < list_elements; i++) - /* There is not need to close the sockets, it is done by - the caller because there are conditions where we cannot - get here anyway. */ - state_buf_ += client_unmarshal_skip(state_buf_) / sizeof(char); - break; - } - - /* Unmarshal the client list. */ - if (linked_list_unmarshal(&client_list, state_buf_)) - goto critical_fail; - state_buf_ += list_size / sizeof(char); - - /* Unmarshal the client map. */ - if (fd_table_unmarshal(&client_map, state_buf_, unmarshal_remapper)) - goto critical_fail; - - /* Release the raw data. */ - free(state_buf); - - /* Remove non-found elements from the fd table. */ -#define __bit(I, _OP_) client_map.used[I / 64] _OP_ ((uint64_t)1 << (I % 64)) - if (with_error) - for (i = 0; i < client_map.capacity; i++) - if ((__bit(i, &)) && (client_map.values[i] == 0)) - /* Lets not presume that fd-table actually initialise its allocations. */ - __bit(i, &= ~); -#undef __bit - - /* Remap the linked list and remove non-found elements, and start the clients. */ - foreach_linked_list_node (client_list, node) - { - /* Remap the linked list and remove non-found elements. */ - size_t new_address = unmarshal_remapper(client_list.values[node]); - client_list.values[node] = new_address; - if (new_address == 0) /* Returned if missing (or if the address is the invalid NULL.) */ - linked_list_remove(&client_list, node); - else - { - /* Start the clients. (Errors do not need to be reported.) */ - client_t* client = (client_t*)(void*)new_address; - int socket_fd = client->socket_fd; - - /* Increase number of running slaves. */ - with_mutex (slave_mutex, running_slaves++;); - - /* Start slave thread. */ - create_slave(&slave_thread, socket_fd); - } - } - - /* Release the remapping table's resources. */ - hash_table_destroy(&unmarshal_remap_map, NULL, NULL); - - return -with_error; - - critical_fail: - perror(*argv); - abort(); -} - - -/** - * Create, start and detache a slave thread - * - * @param thread The address at where to store the thread - * @param socket_fd The file descriptor of the slave's socket - * @return Zero on success, -1 on error, error message will have been printed - */ -int create_slave(pthread_t* thread_slot, int socket_fd) -{ - if ((errno = pthread_create(thread_slot, NULL, slave_loop, (void*)(intptr_t)socket_fd))) - { - perror(*argv); - with_mutex (slave_mutex, running_slaves--;); - return -1; - } - if ((errno = pthread_detach(*thread_slot))) - { - perror(*argv); - return -1; - } - return 0; -} - diff --git a/src/mds-server/mds-server.h b/src/mds-server/mds-server.h index a6ed9d4..c4d166f 100644 --- a/src/mds-server/mds-server.h +++ b/src/mds-server/mds-server.h @@ -18,6 +18,7 @@ #ifndef MDS_MDS_SERVER_H #define MDS_MDS_SERVER_H + #include "client.h" #include "multicast.h" @@ -51,45 +52,12 @@ int message_received(client_t* client); void queue_message_multicast(char* message, size_t length, client_t* sender); /** - * Receive a full message and update open status if the client closes - * - * @param client The client - * @return Zero on success, -2 on failure, otherwise -1 - */ -int fetch_message(client_t* client); - -/** * Exec into the mdsinitrc script * * @param args The arguments to the child process */ void run_initrc(char** args); -/** - * Marshal the server's state into a file - * - * @param fd The file descriptor - * @return Negative on error - */ -int marshal_server(int fd); - -/** - * Unmarshal the server's state from a file - * - * @param fd The file descriptor - * @return Negative on error - */ -int unmarshal_server(int fd); - -/** - * Create, start and detache a slave thread - * - * @param thread The address at where to store the thread - * @param socket_fd The file descriptor of the slave's socket - * @return Zero on success, -1 on error, error message will have been printed - */ -int create_slave(pthread_t* thread_slot, int socket_fd); - #endif diff --git a/src/mds-server/reexec.c b/src/mds-server/reexec.c new file mode 100644 index 0000000..0262288 --- /dev/null +++ b/src/mds-server/reexec.c @@ -0,0 +1,372 @@ +/** + * 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 "reexec.h" + +#include "globals.h" +#include "client.h" +#include "slavery.h" + +#include <libmdsserver/linked-list.h> +#include <libmdsserver/hash-table.h> +#include <libmdsserver/fd-table.h> +#include <libmdsserver/macros.h> +#include <libmdsserver/util.h> + +#include <stddef.h> +#include <stdlib.h> +#include <stdio.h> +#include <pthread.h> +#include <errno.h> +#include <signal.h> +#include <limits.h> +#include <fcntl.h> +#include <sys/mman.h> +#include <unistd.h> +#include <dirent.h> +#include <string.h> + + +/** + * Marshal the server's state into a file + * + * @param fd The file descriptor + * @return Negative on error + */ +int marshal_server(int fd) +{ + size_t list_size = linked_list_marshal_size(&client_list); + size_t map_size = fd_table_marshal_size(&client_map); + size_t list_elements = 0; + size_t state_n = 0; + char* state_buf = NULL; + char* state_buf_; + ssize_t node; + + + /* Calculate the grand size of all client information. */ + for (node = client_list.edge;; list_elements++) + { + if ((node = client_list.next[node]) == client_list.edge) + break; + state_n += client_marshal_size((client_t*)(void*)(client_list.values[node])); + } + + /* Add the size of the rest of the program's state. */ + state_n += sizeof(int) + sizeof(sig_atomic_t) + 2 * sizeof(uint64_t) + 2 * sizeof(size_t); + state_n += list_elements * sizeof(size_t) + list_size + map_size; + + /* Allocate a buffer for all data except the client list and the client map. */ + state_buf = state_buf_ = malloc(state_n); + if (state_buf == NULL) + goto fail; + + + /* Tell the new version of the program what version of the program it is marshalling. */ + buf_set_next(state_buf_, int, MDS_SERVER_VARS_VERSION); + + /* Marshal the miscellaneous state data. */ + buf_set_next(state_buf_, sig_atomic_t, running); + buf_set_next(state_buf_, uint64_t, next_client_id); + buf_set_next(state_buf_, uint64_t, next_modify_id); + + /* Tell the program how large the marshalled client list is and how any clients are marshalled. */ + buf_set_next(state_buf_, size_t, list_size); + buf_set_next(state_buf_, size_t, list_elements); + + /* Marshal the clients. */ + foreach_linked_list_node (client_list, node) + { + /* Get the memory address of the client. */ + size_t value_address = client_list.values[node]; + /* Get the client's information. */ + client_t* value = (client_t*)(void*)value_address; + + /* Marshal the address, it is used the the client list and the client map, that will be marshalled. */ + buf_set_next(state_buf_, size_t, value_address); + /* Marshal the client informationation. */ + state_buf_ += client_marshal(value, state_buf_) / sizeof(char); + } + + /* Marshal the client list. */ + linked_list_marshal(&client_list, state_buf_); + state_buf_ += list_size / sizeof(char); + /* Marshal the client map. */ + fd_table_marshal(&client_map, state_buf_); + + /* Send the marshalled data into the file. */ + if (full_write(fd, state_buf, state_n) < 0) + goto fail; + free(state_buf); + + return 0; + + fail: + perror(*argv); + free(state_buf); + return -1; +} + + +/** + * Address translation table used by `unmarshal_server` and `remapper` + */ +static hash_table_t unmarshal_remap_map; + +/** + * Address translator for `unmarshal_server` + * + * @param old The old address + * @return The new address + */ +static size_t unmarshal_remapper(size_t old) +{ + return hash_table_get(&unmarshal_remap_map, old); +} + +/** + * Unmarshal the server's state from a file + * + * @param fd The file descriptor + * @return Negative on error + */ +int unmarshal_server(int fd) +{ + int with_error = 0; + char* state_buf; + char* state_buf_; + size_t list_size; + size_t list_elements; + size_t i; + ssize_t node; + pthread_t slave_thread; + + + /* Read the file. */ + if ((state_buf = state_buf_ = full_read(fd)) == NULL) + { + perror(*argv); + return -1; + } + + /* Create memory address remapping table. */ + if (hash_table_create(&unmarshal_remap_map)) + { + perror(*argv); + free(state_buf); + hash_table_destroy(&unmarshal_remap_map, NULL, NULL); + return -1; + } + + + /* Get the marshal protocal version. Not needed, there is only the one version right now. */ + /* buf_get(state_buf_, int, 0, MDS_SERVER_VARS_VERSION); */ + buf_next(state_buf_, int, 1); + + /* Unmarshal the miscellaneous state data. */ + buf_get_next(state_buf_, sig_atomic_t, running); + buf_get_next(state_buf_, uint64_t, next_client_id); + buf_get_next(state_buf_, uint64_t, next_modify_id); + + /* Get the marshalled size of the client list and how any clients that are marshalled. */ + buf_get_next(state_buf_, size_t, list_size); + buf_get_next(state_buf_, size_t, list_elements); + + /* Unmarshal the clients. */ + for (i = 0; i < list_elements; i++) + { + size_t n; + size_t value_address; + client_t* value; + + /* Allocate the client's information. */ + if (xmalloc(value, 1, client_t)) + goto clients_fail; + + /* Unmarshal the address, it is used the the client list and the client map, that are also marshalled. */ + buf_get_next(state_buf_, size_t, value_address); + /* Unmarshal the client information. */ + n = client_unmarshal(value, state_buf_); + if (n == 0) + goto clients_fail; + + /* Populate the remapping table. */ + if (hash_table_put(&unmarshal_remap_map, value_address, (size_t)(void*)value) == 0) + if (errno) + goto clients_fail; + + /* Delayed seeking. */ + state_buf_ += n / sizeof(char); + + + /* On error, seek past all clients. */ + continue; + clients_fail: + perror(*argv); + with_error = 1; + if (value != NULL) + { + buf_prev(state_buf_, size_t, 1); + free(value); + } + for (; i < list_elements; i++) + /* There is not need to close the sockets, it is done by + the caller because there are conditions where we cannot + get here anyway. */ + state_buf_ += client_unmarshal_skip(state_buf_) / sizeof(char); + break; + } + + /* Unmarshal the client list. */ + if (linked_list_unmarshal(&client_list, state_buf_)) + goto critical_fail; + state_buf_ += list_size / sizeof(char); + + /* Unmarshal the client map. */ + if (fd_table_unmarshal(&client_map, state_buf_, unmarshal_remapper)) + goto critical_fail; + + /* Release the raw data. */ + free(state_buf); + + /* Remove non-found elements from the fd table. */ +#define __bit(I, _OP_) client_map.used[I / 64] _OP_ ((uint64_t)1 << (I % 64)) + if (with_error) + for (i = 0; i < client_map.capacity; i++) + if ((__bit(i, &)) && (client_map.values[i] == 0)) + /* Lets not presume that fd-table actually initialise its allocations. */ + __bit(i, &= ~); +#undef __bit + + /* Remap the linked list and remove non-found elements, and start the clients. */ + foreach_linked_list_node (client_list, node) + { + /* Remap the linked list and remove non-found elements. */ + size_t new_address = unmarshal_remapper(client_list.values[node]); + client_list.values[node] = new_address; + if (new_address == 0) /* Returned if missing (or if the address is the invalid NULL.) */ + linked_list_remove(&client_list, node); + else + { + /* Start the clients. (Errors do not need to be reported.) */ + client_t* client = (client_t*)(void*)new_address; + int socket_fd = client->socket_fd; + + /* Increase number of running slaves. */ + with_mutex (slave_mutex, running_slaves++;); + + /* Start slave thread. */ + create_slave(&slave_thread, socket_fd); + } + } + + /* Release the remapping table's resources. */ + hash_table_destroy(&unmarshal_remap_map, NULL, NULL); + + return -with_error; + + critical_fail: + perror(*argv); + abort(); +} + + +/** + * Marshal and re-execute the server + * + * @param reexec Whether the server was previously re-executed + */ +void perform_reexec(int reexec) +{ + pid_t pid = getpid(); + int reexec_fd; + char shm_path[NAME_MAX + 1]; + ssize_t node; + + /* Join with all slaves threads. */ + with_mutex (slave_mutex, + while (running_slaves > 0) + pthread_cond_wait(&slave_cond, &slave_mutex);); + + /* Release resources. */ + pthread_mutex_destroy(&slave_mutex); + pthread_cond_destroy(&slave_cond); + pthread_mutex_destroy(&modify_mutex); + pthread_cond_destroy(&modify_cond); + hash_table_destroy(&modify_map, NULL, NULL); + + /* Marshal the state of the server. */ + xsnprintf(shm_path, SHM_PATH_PATTERN, (unsigned long int)pid); + reexec_fd = shm_open(shm_path, O_RDWR | O_CREAT | O_EXCL, S_IRWXU); + fail_if (reexec_fd < 0); + fail_if (marshal_server(reexec_fd) < 0); + close(reexec_fd); + reexec_fd = -1; + + /* Release resources. */ + foreach_linked_list_node (client_list, node) + { + client_t* client = (client_t*)(void*)(client_list.values[node]); + client_destroy(client); + } + fd_table_destroy(&client_map, NULL, NULL); + linked_list_destroy(&client_list); + + /* Re-exec the server. */ + reexec_server(argc, argv, reexec); + + pfail: + perror(*argv); + if (reexec_fd >= 0) + { + close(reexec_fd); + shm_unlink(shm_path); + } +} + + +/** + * Attempt to reload the server after a re-execution + * + * @param socket_fd The file descriptor of the server socket + */ +void complete_reexec(int socket_fd) +{ + pid_t pid = getpid(); + int reexec_fd, r; + char shm_path[NAME_MAX + 1]; + + /* Acquire access to marshalled data. */ + xsnprintf(shm_path, SHM_PATH_PATTERN, (unsigned long int)pid); + reexec_fd = shm_open(shm_path, O_RDONLY, S_IRWXU); + fail_if (reexec_fd < 0); /* Critical. */ + /* Unmarshal state. */ + r = unmarshal_server(reexec_fd); + close(reexec_fd); + shm_unlink(shm_path); + if (r < 0) + { + /* Close all files (hopefully sockets) we do not know what they are. */ + close_files((fd > 2) && (fd != socket_fd) && (fd_table_contains_key(&client_map, fd) == 0)); + } + + return; + pfail: + perror(*argv); + abort(); +} + diff --git a/src/mds-server/reexec.h b/src/mds-server/reexec.h new file mode 100644 index 0000000..266fdfd --- /dev/null +++ b/src/mds-server/reexec.h @@ -0,0 +1,54 @@ +/** + * 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/>. + */ +#ifndef MDS_MDS_SERVER_REEXEC_H +#define MDS_MDS_SERVER_REEXEC_H + + +/** + * Marshal the server's state into a file + * + * @param fd The file descriptor + * @return Negative on error + */ +int marshal_server(int fd); + +/** + * Unmarshal the server's state from a file + * + * @param fd The file descriptor + * @return Negative on error + */ +int unmarshal_server(int fd); + +/** + * Marshal and re-execute the server + * + * @param reexec Whether the server was previously re-executed + */ +void perform_reexec(int reexec); + +/** + * Attempt to reload the server after a re-execution + * + * @param socket_fd The file descriptor of the server socket + */ +void complete_reexec(int socket_fd); + + +#endif + diff --git a/src/mds-server/slavery.c b/src/mds-server/slavery.c new file mode 100644 index 0000000..1a5555e --- /dev/null +++ b/src/mds-server/slavery.c @@ -0,0 +1,140 @@ +/** + * 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 "slavery.h" + +#include "globals.h" +#include "client.h" + +#include <libmdsserver/macros.h> +#include <libmdsserver/linked-list.h> + +#include <pthread.h> +#include <stdint.h> +#include <errno.h> +#include <stdio.h> + + +void* slave_loop(void*); + + +/** + * Receive a full message and update open status if the client closes + * + * @param client The client + * @return Zero on success, -2 on failure, otherwise -1 + */ +int fetch_message(client_t* client) +{ + int r = mds_message_read(&(client->message), client->socket_fd); + if (r == 0) + return 0; + + if (r == -2) + eprint("corrupt message received."); + else if (errno == ECONNRESET) + { + r = mds_message_read(&(client->message), client->socket_fd); + client->open = 0; + /* Connection closed. */ + } + else if (errno != EINTR) + { + r = -2; + perror(*argv); + } + + return r; +} + + +/** + * Create, start and detache a slave thread + * + * @param thread The address at where to store the thread + * @param socket_fd The file descriptor of the slave's socket + * @return Zero on success, -1 on error, error message will have been printed + */ +int create_slave(pthread_t* thread_slot, int socket_fd) +{ + if ((errno = pthread_create(thread_slot, NULL, slave_loop, (void*)(intptr_t)socket_fd))) + { + perror(*argv); + with_mutex (slave_mutex, running_slaves--;); + return -1; + } + if ((errno = pthread_detach(*thread_slot))) + { + perror(*argv); + return -1; + } + return 0; +} + + +/** + * Initialise a client, except for threading + * + * @param socket_fd The file descriptor of the client's socket + * @return The client information, NULL on error + */ +client_t* initialise_client(int socket_fd) +{ + ssize_t entry = LINKED_LIST_UNUSED; + int locked = 0; + client_t* information; + int errno_; + size_t tmp; + + /* Create information table. */ + fail_if (xmalloc(information, 1, client_t)); + client_initialise(information); + + /* Add to list of clients. */ + fail_if ((errno = pthread_mutex_lock(&slave_mutex))); + locked = 1; + entry = linked_list_insert_end(&client_list, (size_t)(void*)information); + fail_if (entry == LINKED_LIST_UNUSED); + + /* Add client to table. */ + tmp = fd_table_put(&client_map, socket_fd, (size_t)(void*)information); + fail_if ((tmp == 0) && errno); + pthread_mutex_unlock(&slave_mutex); + locked = 0; + + /* Fill information table. */ + information->list_entry = entry; + information->socket_fd = socket_fd; + information->open = 1; + fail_if (mds_message_initialise(&(information->message))); + + return information; + + + pfail: + errno_ = errno; + if (locked) + pthread_mutex_unlock(&slave_mutex); + free(information); + if (entry != LINKED_LIST_UNUSED) + { + with_mutex (slave_mutex, linked_list_remove(&client_list, entry);); + } + errno = errno_; + return NULL; +} + diff --git a/src/mds-server/slavery.h b/src/mds-server/slavery.h new file mode 100644 index 0000000..0b94e7d --- /dev/null +++ b/src/mds-server/slavery.h @@ -0,0 +1,54 @@ +/** + * 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/>. + */ +#ifndef MDS_MDS_SERVER_SLAVERY_H +#define MDS_MDS_SERVER_SLAVERY_H + + +#include "client.h" + +#include <pthread.h> + + +/** + * Receive a full message and update open status if the client closes + * + * @param client The client + * @return Zero on success, -2 on failure, otherwise -1 + */ +int fetch_message(client_t* client); + +/** + * Create, start and detache a slave thread + * + * @param thread The address at where to store the thread + * @param socket_fd The file descriptor of the slave's socket + * @return Zero on success, -1 on error, error message will have been printed + */ +int create_slave(pthread_t* thread_slot, int socket_fd); + +/** + * Initialise a client, except for threading + * + * @param socket_fd The file descriptor of the client's socket + * @return The client information, NULL on error + */ +client_t* initialise_client(int socket_fd); + + +#endif + |