147 lines
4 KiB
C
147 lines
4 KiB
C
/*
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* Handling communication with clients.
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*/
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#include "moxerver.h"
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/* Closes client connection. */
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int client_close(client_t *client) {
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char timestamp[TIMESTAMP_LEN];
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/* force closing in case of error */
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if (close(client->socket) == -1) {
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close(client->socket);
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}
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client->socket = -1;
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time2string(time(NULL), timestamp);
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fprintf(stderr,"[%s] socket closed for client %s @ %s\n", __func__, client->ip_string, timestamp);
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return 0;
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}
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/* Reads data from client into client data buffer. Returns number of read bytes. */
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int client_read(client_t *client) {
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int len;
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/* read client data */
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len = recv(client->socket, client->data, sizeof(client->data)-1, 0);
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if (len == -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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/* a disconnected client socket is ready for reading but read returns 0 */
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if (len == 0) {
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fprintf(stderr, "[%s:%d] no data available from client\n", __func__, __LINE__);
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return -ENODATA;
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}
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//TODO let's print received bytes during development phase...
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if (debug_messages) {
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int i;
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for(i = 0; i < len; i++) {
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fprintf(stderr, "client %s <- %u '%c'\n",
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client->ip_string,
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(unsigned char) client->data[i],
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(unsigned char) client->data[i]);
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}
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}
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/* handle special telnet characters coming from client */
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telnet_handle_client_read(client->data, &len);
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/* grab current time and store it as client last activity */
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client->last_active = time(NULL);
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return len;
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}
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/* Sends data from a buffer to client. Returns number of sent bytes. */
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int client_write(client_t *client, char *databuf, int datalen) {
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int len;
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/* handle special telnet characters to display them correctly on client */
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//telnet_handle_client_write(databuf, &datalen);
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//TODO let's print received bytes during development phase...
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if (debug_messages) {
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int i;
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for(i = 0; i < datalen; i++) {
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fprintf(stderr, "client %s -> %u '%c'\n",
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client->ip_string,
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(unsigned char) databuf[i],
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(unsigned char) databuf[i]);
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}
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}
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/* send data to client */
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len = send(client->socket, databuf, datalen, 0);
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if (len == -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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return len;
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}
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/* Waits for client input in "line mode". Blocks until input arrives. */
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int client_wait_line(client_t *client) {
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fd_set read_fds;
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struct timeval tv;
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client->data[0] = '\0';
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/* loop waiting for client input */
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while (client->data[0] == '\0') {
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/* setup select() parameters */
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tv.tv_sec = 15; /* 15 second timeout */
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tv.tv_usec = 0;
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FD_ZERO(&read_fds);
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FD_SET(client->socket, &read_fds);
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/* send prompt character to client */
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client_write(client, "> ", 2);
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/* block until input arrives */
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if (select((client->socket)+1, &read_fds, NULL, NULL, &tv) <= 0) return -1;
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if (FD_ISSET(client->socket, &read_fds)) {
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/* read client input */
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if (client_read(client) == -1) return -1;
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/* we don't want empty data so stop on \r or \n */
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if ( (client->data[0] == '\r') || (client->data[0] == '\n') ) {
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client->data[0] = '\0';
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}
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}
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}
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return 0;
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}
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/* Waits for client to provide a username. Blocks until a username is entered. */
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int client_ask_username(client_t *client) {
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int i;
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char msg[DATABUF_LEN];
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/* send username request to client */
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snprintf(msg, DATABUF_LEN,
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"\nPlease provide a username to identify yourself to other users (max %d characters):\n", USERNAME_LEN);
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client_write(client, msg, strlen(msg));
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/* wait for client input */
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if (client_wait_line(client) != 0) return -1;
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/* save received data as client username */
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for (i = 0; i < USERNAME_LEN; i++) {
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if ( (client->data[i] == '\r') || (client->data[i] == '\n') ) {
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/* don't include \r or \n in username */
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client->username[i] = '\0';
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break;
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}
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client->username[i] = client->data[i];
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}
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/* send welcome message to client */
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snprintf(msg, DATABUF_LEN,
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"\nWelcome %s!\n\n", client->username);
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client_write(client, msg, strlen(msg));
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return 0;
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}
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