diff options
Diffstat (limited to 'src/servers/master.c')
| -rw-r--r-- | src/servers/master.c | 342 |
1 files changed, 342 insertions, 0 deletions
diff --git a/src/servers/master.c b/src/servers/master.c new file mode 100644 index 0000000..f655e37 --- /dev/null +++ b/src/servers/master.c @@ -0,0 +1,342 @@ +/** + * coopgammad -- Cooperative gamma server + * Copyright (C) 2016 Mattias Andrée (maandree@kth.se) + * + * 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 "master.h" +#include "crtc.h" +#include "gamma.h" +#include "coopgamma.h" +#include "../util.h" +#include "../communication.h" +#include "../state.h" + +#include <sys/select.h> +#include <sys/socket.h> +#include <errno.h> +#include <fcntl.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + + + +/** + * Extract headers from an inbound message and pass + * them on to appropriate message handling function + * + * @param conn The index of the connection + * @param msg The inbound message + * @return 1: The connection as closed + * 0: Successful + * -1: Failure + */ +static int dispatch_message(size_t conn, struct message* restrict msg) +{ + size_t i; + int r = 0; + const char* header; + const char* value; + const char* command = NULL; + const char* crtc = NULL; + const char* coalesce = NULL; + const char* high_priority = NULL; + const char* low_priority = NULL; + const char* priority = NULL; + const char* class = NULL; + const char* lifespan = NULL; + const char* message_id = NULL; + + for (i = 0; i < msg->header_count; i++) + { + value = strstr((header = msg->headers[i]), ": ") + 2; + if (strstr(header, "Command: ") == header) command = value; + else if (strstr(header, "CRTC: ") == header) crtc = value; + else if (strstr(header, "Coalesce: ") == header) coalesce = value; + else if (strstr(header, "High priority: ") == header) high_priority = value; + else if (strstr(header, "Low priority: ") == header) low_priority = value; + else if (strstr(header, "Priority: ") == header) priority = value; + else if (strstr(header, "Class: ") == header) class = value; + else if (strstr(header, "Lifespan: ") == header) lifespan = value; + else if (strstr(header, "Message ID: ") == header) message_id = value; + else + fprintf(stderr, "%s: ignoring unrecognised header: %s\n", argv0, header); + } + + if (command == NULL) + fprintf(stderr, "%s: ignoring message without Command header\n", argv0); + else if (message_id == NULL) + fprintf(stderr, "%s: ignoring message without Message ID header\n", argv0); + else if (!strcmp(command, "enumerate-crtcs")) + { + if (crtc || coalesce || high_priority || low_priority || priority || class || lifespan) + fprintf(stderr, "%s: ignoring superfluous headers in Command: enumerate-crtcs message\n", argv0); + r = handle_enumerate_crtcs(conn, message_id); + } + else if (!strcmp(command, "get-gamma-info")) + { + if (coalesce || high_priority || low_priority || priority || class || lifespan) + fprintf(stderr, "%s: ignoring superfluous headers in Command: get-gamma-info message\n", argv0); + r = handle_get_gamma_info(conn, message_id, crtc); + } + else if (!strcmp(command, "get-gamma")) + { + if (priority || class || lifespan) + fprintf(stderr, "%s: ignoring superfluous headers in Command: get-gamma message\n", argv0); + r = handle_get_gamma(conn, message_id, crtc, coalesce, high_priority, low_priority); + } + else if (!strcmp(command, "set-gamma")) + { + if (coalesce || high_priority || low_priority) + fprintf(stderr, "%s: ignoring superfluous headers in Command: set-gamma message\n", argv0); + r = handle_set_gamma(conn, message_id, crtc, priority, class, lifespan); + } + else + fprintf(stderr, "%s: ignoring unrecognised command: Command: %s\n", argv0, command); + + return r; +} + + +/** + * Sets the file descriptor set that includes + * the server socket and all connections + * + * @param fds The file descritor set + * @return The highest set file descritor plus 1 + */ +GCC_ONLY(__attribute__((nonnull))) +static int update_fdset(fd_set* restrict fds) +{ + int fdmax = socketfd; + size_t i; + FD_ZERO(fds); + FD_SET(socketfd, fds); + for (i = 0; i < connections_used; i++) + if (connections[i] >= 0) + { + FD_SET(connections[i], fds); + if (fdmax < connections[i]) + fdmax = connections[i]; + } + return fdmax + 1; +} + + +/** + * Handle event on the server socket + * + * @return 1: New connection accepted + * 0: Successful + * -1: Failure + */ +static int handle_server(void) +{ + int fd, flags, saved_errno; + + fd = accept(socketfd, NULL, NULL); + if (fd < 0) + switch (errno) + { + case EINTR: + return 0; + case ECONNABORTED: + case EINVAL: + terminate = 1; + return 0; + default: + return -1; + } + + flags = fcntl(fd, F_GETFL); + if (fcntl(fd, F_SETFL, flags | O_NONBLOCK) == -1) + goto fail; + + if (connections_ptr == connections_alloc) + { + void* new; + + new = realloc(connections, (connections_alloc + 10) * sizeof(*connections)); + if (new == NULL) + goto fail; + connections = new; + connections[connections_ptr] = fd; + + new = realloc(outbound, (connections_alloc + 10) * sizeof(*outbound)); + if (new == NULL) + goto fail; + outbound = new; + ring_initialise(outbound + connections_ptr); + + new = realloc(inbound, (connections_alloc + 10) * sizeof(*inbound)); + if (new == NULL) + goto fail; + inbound = new; + connections_alloc += 10; + if (message_initialise(inbound + connections_ptr)) + goto fail; + } + + connections_ptr++; + while (connections_ptr < connections_used) + if (connections[connections_ptr] >= 0) + connections_ptr++; + if (connections_used < connections_ptr) + connections_used = connections_ptr; + + return 1; + fail: + saved_errno = errno; + shutdown(fd, SHUT_RDWR); + close(fd); + errno = saved_errno; + return -1; +} + + +/** + * Handle event on a connection to a client + * + * @param conn The index of the connection + * @return 1: The connection as closed + * 0: Successful + * -1: Failure + */ +static int handle_connection(size_t conn) +{ + struct message* restrict msg = inbound + conn; + int r, fd = connections[conn]; + + again: + switch (message_read(msg, fd)) + { + default: + break; + case -1: + switch (errno) + { + case EINTR: + case EAGAIN: +#if EAGAIN != EWOULDBLOCK + case EWOULDBLOCK: +#endif + return 0; + default: + return -1; + case ECONNRESET:; + /* Fall throught to `case -2` in outer switch */ + } + case -2: + shutdown(fd, SHUT_RDWR); + close(fd); + connections[conn] = -1; + if (conn < connections_ptr) + connections_ptr = conn; + if (conn == connections_used) + connections_used -= 1; + message_destroy(msg); + if (connection_closed(fd) < 0) + return -1; + return 1; + } + + if ((r = dispatch_message(conn, msg))) + return r; + + goto again; +} + + + +/** + * Disconnect all clients + */ +void disconnect_all(void) +{ + size_t i; + for (i = 0; i < connections_used; i++) + if (connections[i] >= 0) + { + shutdown(connections[i], SHUT_RDWR); + close(connections[i]); + } +} + + +/** + * The program's main loop + * + * @return Zero on success, -1 on error + */ +int main_loop(void) +{ + fd_set fds_orig, fds_rd, fds_wr, fds_ex; + int i, r, update, fdn = update_fdset(&fds_orig); + size_t j; + + while (!reexec && !terminate) + { + if (connection) + { + if ((connection == 1 ? disconnect() : reconnect()) < 0) + return connection = 0, -1; + connection = 0; + } + + memcpy(&fds_rd, &fds_orig, sizeof(fd_set)); + memcpy(&fds_ex, &fds_orig, sizeof(fd_set)); + + FD_ZERO(&fds_wr); + for (j = 0; j < connections_used; j++) + if ((connections[j] >= 0) && ring_have_more(outbound + j)) + FD_SET(connections[j], &fds_wr); + + if (select(fdn, &fds_rd, &fds_wr, &fds_ex, NULL) < 0) + { + if (errno == EINTR) + continue; + return -1; + } + + update = 0; + for (i = 0; i < fdn; i++) + { + int do_read = FD_ISSET(i, &fds_rd) || FD_ISSET(i, &fds_ex); + int do_write = FD_ISSET(i, &fds_wr); + if (!do_read && !do_write) + continue; + + if (i == socketfd) + r = handle_server(); + else + { + for (j = 0; connections[j] != i; j++); + r = do_read ? handle_connection(j) : 0; + } + + if ((r >= 0) && do_write) + r |= continue_send(j); + if (r < 0) + return -1; + update |= (r > 0); + } + if (update) + update_fdset(&fds_orig); + } + + return 0; +} + |