diff options
Diffstat (limited to 'src/mds-server/mds-server.c')
| -rw-r--r-- | src/mds-server/mds-server.c | 201 |
1 files changed, 98 insertions, 103 deletions
diff --git a/src/mds-server/mds-server.c b/src/mds-server/mds-server.c index 3179ee7..b1008cd 100644 --- a/src/mds-server/mds-server.c +++ b/src/mds-server/mds-server.c @@ -22,11 +22,9 @@ #include "client.h" #include "queued_interception.h" #include "multicast.h" -#include "signals.h" #include "interceptors.h" #include "sending.h" #include "slavery.h" -#include "reexec.h" #include "receiving.h" #include <libmdsserver/config.h> @@ -47,19 +45,41 @@ #include <inttypes.h> +/** + * 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 = 0 /* We will service one ourself. */ + }; + + + +#define __free(I) \ + if (I > 0) pthread_mutex_destroy(&slave_mutex); \ + if (I > 1) pthread_cond_destroy(&slave_cond); \ + if (I > 2) pthread_mutex_destroy(&modify_mutex); \ + if (I > 3) pthread_cond_destroy(&modify_cond); \ + if (I >= 4) hash_table_destroy(&modify_map, NULL, NULL); \ + if (I >= 5) fd_table_destroy(&client_map, NULL, NULL); \ + if (I >= 6) linked_list_destroy(&client_list) + +#define error_if(I, CONDITION) \ + if (CONDITION) { perror(*argv); __free(I); return 1; } + /** - * Entry point of the server + * This function will be invoked before `initialise_server` (if not re-exec:ing) + * or before `unmarshal_server` (if re-exec:ing) * - * @param argc_ Number of elements in `argv_` - * @param argv_ Command line arguments - * @return Non-zero on error + * @return Non-zero on error */ -int main(int argc_, char** argv_) +int preinitialise_server(void) { - int is_respawn = -1; - int socket_fd = -1; - int reexec = 0; int unparsed_args_ptr = 1; char* unparsed_args[ARGC_LIMIT + LIBEXEC_ARGC_EXTRA_LIMIT + 1]; int i; @@ -69,58 +89,27 @@ int main(int argc_, char** argv_) #endif - argc = argc_; - argv = argv_; - - - /* Drop privileges like it's hot. */ - fail_if (drop_privileges()); - - /* Sanity check the number of command line arguments. */ - exit_if (argc > ARGC_LIMIT + LIBEXEC_ARGC_EXTRA_LIMIT, - eprint("that number of arguments is ridiculous, I will not allow it.");); - - /* Parse command line arguments. */ for (i = 1; i < argc; i++) { char* arg = argv[i]; - int v; - if ((v = strequals(arg, "--initial-spawn")) || /* Initial spawn? */ - strequals(arg, "--respawn")) /* Respawning after crash? */ - { - exit_if (is_respawn == v, - eprintf("conflicting arguments %s and %s cannot be combined.", - "--initial-spawn", "--respawn");); - is_respawn = !v; - } - else if (startswith(arg, "--socket-fd=")) /* Socket file descriptor. */ + if (startswith(arg, "--socket-fd=")) /* Socket file descriptor. */ { exit_if (socket_fd != -1, eprintf("duplicate declaration of %s.", "--socket-fd");); exit_if (strict_atoi(arg += strlen("--socket-fd="), &socket_fd, 0, INT_MAX) < 0, eprintf("invalid value for %s: %s.", "--socket-fd", arg);); } - else if (strequals(arg, "--re-exec")) /* Re-exec state-marshal. */ - reexec = 1; else if (startswith(arg, "--alarm=")) /* Schedule an alarm signal for forced abort. */ alarm((unsigned)min(atoi(arg + strlen("--alarm=")), 60)); /* At most 1 minute. */ else - /* Not recognised, it is probably for another server. */ - unparsed_args[unparsed_args_ptr++] = arg; + if (!strequals(arg, "--initial-spawn") && !strequals(arg, "--respawn")) + /* Not recognised, it is probably for another server. */ + unparsed_args[unparsed_args_ptr++] = arg; } unparsed_args[unparsed_args_ptr] = NULL; - if (reexec) - { - is_respawn = 1; - eprint("re-exec performed."); - } - /* Check that manditory arguments have been specified. */ - exit_if (is_respawn < 0, - eprintf("missing state argument, require either %s or %s.", - "--initial-spawn", "--respawn");); exit_if (socket_fd < 0, eprint("missing socket file descriptor argument.");); @@ -142,85 +131,91 @@ int main(int argc_, char** argv_) } } -#define __free(I) \ - if (I >= 0) fd_table_destroy(&client_map, NULL, NULL); \ - if (I >= 1) linked_list_destroy(&client_list); \ - if (I >= 2) pthread_mutex_destroy(&slave_mutex); \ - if (I >= 3) pthread_cond_destroy(&slave_cond); \ - if (I >= 4) pthread_mutex_destroy(&modify_mutex); \ - if (I >= 5) pthread_cond_destroy(&modify_cond); \ - if (I >= 6) hash_table_destroy(&modify_map, NULL, NULL) - -#define error_if(I, CONDITION) if (CONDITION) { perror(*argv); __free(I); return 1; } - - /* Create list and table of clients. */ - if (reexec == 0) - { - error_if (0, fd_table_create(&client_map)); - error_if (1, linked_list_create(&client_list, 32)); - } - - /* Store the current thread so it can be killed from elsewhere. */ - master_thread = pthread_self(); - - /* Set up traps for especially handled signals. */ - error_if (1, trap_signals() < 0); /* Create mutex and condition for slave counter. */ - error_if (1, (errno = pthread_mutex_init(&slave_mutex, NULL))); - error_if (2, (errno = pthread_cond_init(&slave_cond, NULL))); + error_if (0, (errno = pthread_mutex_init(&slave_mutex, NULL))); + error_if (1, (errno = pthread_cond_init(&slave_cond, NULL))); /* Create mutex, condition and map for message modification. */ - error_if (3, (errno = pthread_mutex_init(&modify_mutex, NULL))); - error_if (4, (errno = pthread_cond_init(&modify_cond, NULL))); - error_if (5, hash_table_create(&modify_map)); + error_if (2, (errno = pthread_mutex_init(&modify_mutex, NULL))); + error_if (3, (errno = pthread_cond_init(&modify_cond, NULL))); + error_if (4, hash_table_create(&modify_map)); -#undef error_if + return 0; - /* Unmarshal the state of the server. */ - if (reexec) - complete_reexec(socket_fd); + pfail: + perror(*argv); + return 1; +} + + +/** + * This function should initialise the server, + * and it not invoked after a re-exec. + * + * @return Non-zero on error + */ +int initialise_server(void) +{ + /* Create list and table of clients. */ + error_if (5, fd_table_create(&client_map)); + error_if (6, linked_list_create(&client_list, 32)); + return 0; +} + + +/** + * This function will be invoked asgter `initialise_server` (if not re-exec:ing) + * or after `unmarshal_server` (if re-exec:ing) + * + * @return Non-zero on error + */ +int __attribute__((const)) postinitialise_server(void) +{ + /* We do not need to initialise anything else. */ + return 0; +} + + +/** + * Perform the server's mission + * + * @return Non-zero on error + */ +int master_loop(void) +{ /* Accepting incoming connections. */ while (running && (terminating == 0)) - if (accept_connection(socket_fd) == 1) + if (accept_connection() == 1) break; - if (reexecing) - goto reexec; - /* Join with all slaves threads. */ with_mutex (slave_mutex, while (running_slaves > 0) pthread_cond_wait(&slave_cond, &slave_mutex);); - /* Release resources. */ - __free(9999); + if (reexecing == 0) + { + /* Release resources. */ + __free(9999); + } return 0; - -#undef __free - - - reexec: - perform_reexec(reexec); - /* Returning non-zero is important, otherwise the server cannot - be respawn if the re-exec fails. */ - - pfail: - perror(*argv); - return 1; } +#undef error_if +#undef __free + + /** * Accept an incoming and start a slave thread for it * - * @param socket_fd The file descriptor of the server socket - * @return Zero normally, 1 if terminating + * @return Zero normally, 1 if terminating */ -int accept_connection(int socket_fd) +int accept_connection(void) { pthread_t slave_thread; int client_fd; @@ -255,8 +250,8 @@ int accept_connection(int socket_fd) */ void* slave_loop(void* data) { - int socket_fd = (int)(intptr_t)data; - size_t information_address = fd_table_get(&client_map, (size_t)socket_fd); + int slave_fd = (int)(intptr_t)data; + size_t information_address = fd_table_get(&client_map, (size_t)slave_fd); client_t* information = (client_t*)(void*)information_address; char* msgbuf = NULL; char buf[] = "To: all"; @@ -267,7 +262,7 @@ void* slave_loop(void* data) if (information == NULL) /* Did not re-exec. */ { /* Initialise the client. */ - fail_if ((information = initialise_client(socket_fd)) == NULL); + fail_if ((information = initialise_client(slave_fd)) == NULL); /* Register client to receive broadcasts. */ add_intercept_condition(information, buf, 0, 0, 0); @@ -324,7 +319,7 @@ void* slave_loop(void* data) fail: /* This done on success as well. */ /* Close socket and free resources. */ - close(socket_fd); + close(slave_fd); free(msgbuf); if (information != NULL) { @@ -335,7 +330,7 @@ void* slave_loop(void* data) /* Unmap client and decrease the slave count. */ with_mutex (slave_mutex, - fd_table_remove(&client_map, socket_fd); + fd_table_remove(&client_map, slave_fd); running_slaves--; pthread_cond_signal(&slave_cond);); return NULL; |