116 lines
4.1 KiB
C
116 lines
4.1 KiB
C
/*
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* Handling server operation.
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*/
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#include "moxerver.h"
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/* Sets up the server on specific port, binds to a socket and listens for client connections. */
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int server_setup(struct server_t *server, unsigned int port) {
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int opt;
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/* set up server address information */
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server->address.sin_family = AF_INET; /* use IPv4 address family */
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server->address.sin_port = htons(port); /* set up port number, htons is for using network byte order */
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server->address.sin_addr.s_addr = INADDR_ANY; /* use local address */
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/* create stream socket using TCP */
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server->socket = socket(AF_INET, SOCK_STREAM, 0);
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if (server->socket == -1) {
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fprintf(stderr, "[%s:%d] error %d: %s\n", __func__, __LINE__, errno, strerror(errno));
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return -errno;
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}
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fprintf(stderr,"[%s] socket created\n", __func__);
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/* try to avoid "Address already in use" error */
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opt = 1; /* true value for setsockopt option */
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if (setsockopt(server->socket, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(int)) == -1) {
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fprintf(stderr, "[%s:%d] error %d: %s\n", __func__, __LINE__, errno, strerror(errno));
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return -errno;
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}
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/* turn off Nagle algorithm */
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opt = 1; /* true value for setsockopt option */
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if (setsockopt(server->socket, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof(int)) == -1) {
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fprintf(stderr, "[%s:%d] error %d: %s\n", __func__, __LINE__, errno, strerror(errno));
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return -errno;
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}
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/* bind server address to a socket */
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if (bind(server->socket, (struct sockaddr *) &server->address, sizeof(server->address)) == -1) {
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fprintf(stderr, "[%s:%d] error %d: %s\n", __func__, __LINE__, errno, strerror(errno));
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return -errno;
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}
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fprintf(stderr,"[%s] bind successful\n", __func__);
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/* save server port number */
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server->port = port;
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fprintf(stderr,"[%s] assigned port %u\n", __func__, server->port); //ntohs(server->address.sin_port)
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/* listen for a client connection, allow 2 connections in queue */
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if (listen(server->socket, 2) == -1) {
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fprintf(stderr, "[%s:%d] error %d: %s\n", __func__, __LINE__, errno, strerror(errno));
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return -errno;
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}
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fprintf(stderr,"[%s] server is up, listening for client connection\n", __func__);
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return 0;
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}
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/* Closes the server socket. */
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int server_close(struct server_t *server) {
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/* force closing in case of error */
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if (close(server->socket) == -1) {
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close(server->socket);
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}
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fprintf(stderr,"[%s] socket closed, server is down\n", __func__);
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return 0;
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}
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/* Accepts incoming client connection. */
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int server_accept(struct server_t *server, struct client_t *accepted_client) {
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int namelen;
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/* accept connection request */
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namelen = sizeof(accepted_client->address);
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accepted_client->socket = accept(server->socket, (struct sockaddr *) &accepted_client->address, (socklen_t *) &namelen);
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if (accepted_client->socket == -1) {
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fprintf(stderr, "[%s:%d] error %d: %s\n", __func__, __LINE__, errno, strerror(errno));
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return -errno;
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}
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/* make client socket non-blocking */
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if (fcntl(accepted_client->socket, F_SETFL, O_NONBLOCK) == -1) {
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fprintf(stderr, "[%s:%d] error %d: %s\n", __func__, __LINE__, errno, strerror(errno));
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return -errno;
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}
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/* get client IP address as human readable string */
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inet_ntop(accepted_client->address.sin_family, &accepted_client->address.sin_addr.s_addr,
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accepted_client->ip_string, INET_ADDRSTRLEN);
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/* print client information */
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//TODO also print timestamp
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fprintf(stderr, "[%s] accepted client %s on port %u\n", __func__,
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accepted_client->ip_string, server->port);
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return 0;
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}
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/* Rejects incoming client connection. Errors with rejected client are ignored. */
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int server_reject(struct server_t *server) {
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int namelen;
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struct client_t rclient;
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char reject_msg[128];
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/* accept connection request */
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namelen = sizeof(rclient.address);
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rclient.socket = accept(server->socket, (struct sockaddr *) &rclient.address, (socklen_t *) &namelen);
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/* send reject message */
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sprintf(reject_msg, "[%s] port %u is already being used\n", __func__, server->port);
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send(rclient.socket, reject_msg, strlen(reject_msg), 0);
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/* close connection */
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close(rclient.socket);
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fprintf(stderr, "[%s] rejected new client request, there is alredy a client connected\n", __func__);
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return 0;
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}
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