diff options
Diffstat (limited to 'ctrl/facemgr/examples/updownsrv/updownsrv.c')
| -rw-r--r-- | ctrl/facemgr/examples/updownsrv/updownsrv.c | 231 |
1 files changed, 231 insertions, 0 deletions
diff --git a/ctrl/facemgr/examples/updownsrv/updownsrv.c b/ctrl/facemgr/examples/updownsrv/updownsrv.c new file mode 100644 index 000000000..e10247860 --- /dev/null +++ b/ctrl/facemgr/examples/updownsrv/updownsrv.c @@ -0,0 +1,231 @@ +/* + * Dummy server sending alternating bytes to all clients. + * + * This is used by the face manager to illustrate the creation of interfaces + * using unix domains that sets a face up and down. + */ + +#include <arpa/inet.h> // inet_ntop +#include <errno.h> // EINTR,. .. +#include <netinet/in.h> // INET_ADDRSTRLEN, INET6_ADDRSTRLEN +#include <stdio.h> +#include <inttypes.h> + +#include <stdlib.h> +#include <sys/socket.h> +#include <sys/timerfd.h> +#include <sys/un.h> // sockaddr_un +#include <unistd.h> // fcntl +#include <fcntl.h> // fcntl + + +/** + * \brief Default unix socket path (the leading \0 means using the abstract + * namespace instead of the filesystem). + */ +#define UNIX_PATH "\0updownsrv" + +/** + * \brief Default interval (in seconds) between timer events */ +#define DEFAULT_INTERVAL 100000 + +/** + * \brief Maximum allowed number of connected clients + */ +#define MAX_CLIENTS 5 + +/** + * \brief Maximum backlog of listening unix socket + */ +#define LISTEN_BACKLOG MAX_CLIENTS + + +/** + * \brief Creates a unix server socket + * \param [in] path - string representing the path on which to listen for + * connections + * \return int - fd associated to the socket + */ +int +create_unix_server(char * path) +{ + struct sockaddr_un addr; + int fd; + + fd = socket(AF_UNIX, SOCK_STREAM, 0); + if (fd == -1) { + perror("socket error"); + return -1; + } + + if (fcntl(fd, F_SETFL, O_NONBLOCK) < 0) { + perror("fcntl"); + return -1; + } + + memset(&addr, 0, sizeof(addr)); + addr.sun_family = AF_UNIX; + if (*path == '\0') { + *addr.sun_path = '\0'; + strncpy(addr.sun_path+1, path+1, sizeof(addr.sun_path)-2); + } else { + strncpy(addr.sun_path, path, sizeof(addr.sun_path)-1); + unlink(path); + } + + if (bind(fd, (struct sockaddr*)&addr, sizeof(addr)) == -1) { + perror("bind error"); + return -1; + } + + if (listen(fd, LISTEN_BACKLOG) == -1) { + perror("listen error"); + return -1; + } + + return fd; +} + + +/** + * \brief Main function + */ +int main() { + int fd, tfd; + int rc; + + /* Alternating state of the server : 0 / 1 */ + unsigned state = 0; + + /* + * This server has to send a signal to all connected clients at periodic + * intervals. Since we don't expect a large number of connected clients for + * such a simple program, we simply use a statically allocated array. + */ + int clients[MAX_CLIENTS]; + size_t num_clients = 0; + + fd_set active_fd_set, read_fd_set; + FD_ZERO (&active_fd_set); + + /* Create listening unix socket */ + fd = create_unix_server(UNIX_PATH); + if (fd < 0) + exit(EXIT_FAILURE); + FD_SET (fd, &active_fd_set); + + /* Create timer */ + tfd = timerfd_create(CLOCK_MONOTONIC, 0); + if (tfd == -1) { + perror("timer error"); + exit(EXIT_FAILURE); + } + + if (fcntl(fd, F_SETFL, O_NONBLOCK) < 0) { + perror("fcntl"); + exit(EXIT_FAILURE); + } + + FD_SET (tfd, &active_fd_set); + + struct itimerspec ts = { + .it_interval = { + .tv_sec = DEFAULT_INTERVAL, + .tv_nsec = 0, + }, + .it_value = { + .tv_sec = DEFAULT_INTERVAL, + .tv_nsec = 0, + } + }; + rc = timerfd_settime(tfd, 0, &ts, NULL); + if (rc == -1) { + perror("timerfd_settime"); + exit(EXIT_FAILURE); + } + + printf("Waiting for clients...\n"); + + for(;;) { + /* Block until input arrives on one or more active sockets. */ + read_fd_set = active_fd_set; + rc = select (FD_SETSIZE, &read_fd_set, NULL, NULL, NULL); + if (rc < 0) { + if (rc == EINTR) + break; + perror("select"); + exit (EXIT_FAILURE); + } + + /* Service all the sockets with input pending. */ + for (int i = 0; i < FD_SETSIZE; ++i) { + if (!FD_ISSET (i, &read_fd_set)) + continue; + if (i == fd) { + /* Connection request on original socket. */ + int client_fd = accept(fd, NULL, NULL); + if (client_fd < 0) { + perror("accept"); + continue; + } + + fprintf(stderr, "Server: connect from new client\n"); + clients[num_clients++] = client_fd; + FD_SET(client_fd, &active_fd_set); + } else if (i == tfd) { + /* Timer event */ + uint64_t res; + + read(tfd, &res, sizeof(res)); +// while (read(fd, &missed, sizeof(missed)) > 0) +// ; + for (unsigned j = 0; j < num_clients; j++) { + write(clients[j], state ? "\1" : "\0", 1); + } + printf("STATE=%d\n", state); + state = 1 - state; + } else { + char buf[1024]; + rc = read(i, buf, sizeof(buf)); + /* Client event : we close the connection on any event... */ + for (unsigned j = 0; j < num_clients; j++) { + if (i == clients[j]) { + clients[j] = clients[num_clients--]; + break; + } + } + close(i); + FD_CLR(i, &active_fd_set); + } + } + + } + + int ret = EXIT_SUCCESS; + + /* Close all active client connections */ + for (unsigned i = 0; i < num_clients; i++) { + rc = close(clients[i]); + if (rc == -1) { + perror("close"); + ret = EXIT_FAILURE; + } + } + + /* Close server */ + rc = close(fd); + if (rc == -1) { + perror("close"); + ret = EXIT_FAILURE; + } + + /* Terminate timer */ + ts.it_value.tv_sec = 0; + rc = timerfd_settime(tfd, 0, &ts, NULL); + if (rc == -1) { + perror("timerfd_settime"); + exit(EXIT_FAILURE); + } + + exit(ret); +} |