server.c - net/sshout-daemon - Rivoreo Source Code Repositories

 /*
  * Copyright 2015-2018 Rivoreo
  *
  * 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.
  */

 #include "common.h"
 #include <sys/socket.h>
 #include <sys/un.h>
 #include <sys/stat.h>
 #include <unistd.h>
 #include <syslog.h>
 #include <string.h>
 #include <stdlib.h>
 #include <fcntl.h>
 #include <stdio.h>
 #include <errno.h>

 static struct local_online_user online_users[FD_SETSIZE];

 static void syslog_perror(const char *ident) {
 	int e = errno;
 	syslog(LOG_ERR, "%s: %s (%d)", ident, strerror(e), e);
 }

 static int user_online(int id, const char *user_name, const char *host_name, int *index) {
 	int i = 0;
 	while(online_users[i].id != -1) {
 		if(++i >= sizeof online_users / sizeof *online_users) {
 			syslog(LOG_WARNING, "cannot let user '%s' from %s login: too many users\n", user_name, host_name);
 			return -1;
 		}
 	}
 	struct local_online_user *p = online_users + i;
 	p->id = id;
 	strncpy(p->user_name, user_name, sizeof p->user_name);
 	strncpy(p->host_name, host_name, sizeof p->host_name);
 	return 0;
 }

 static void user_offline(int id) {
 	int i = 0;
 	while(online_users[i].id != id) {
 		if(++i >= sizeof online_users / sizeof *online_users) return;
 	}
 	online_users[i].id = -1;
 }

 static void send_online_users(int receiver_id, int receiver_fd) {
 	int i = 0, count = 0;
 	do {
 		if(online_users[i].id != -1) count++;
 	} while(++i < sizeof online_users / sizeof *online_users);
 	size_t packet_length = sizeof(struct local_packet) + sizeof(struct local_online_users_info) + sizeof(struct local_online_user) * count;
 	struct local_packet *packet = malloc(packet_length);
 	if(!packet) {
 		syslog(LOG_ERR, "send_online_users: out of memory");
 		return;
 	}
 	packet->length = packet_length - sizeof packet->length;
 	packet->type = SSHOUT_LOCAL_ONLINE_USERS_INFO;
 	struct local_online_users_info *info = (struct local_online_users_info *)packet->data;
 	info->your_id = receiver_id;
 	info->count = count;
 	i = 0;
 	for(i = 0; i < sizeof online_users / sizeof *online_users && count > 0; i++) {
 		if(online_users[i].id == -1) continue;
 		count--;
 		memcpy(info + count, online_users + i, sizeof(struct local_online_user));
 	}
 	while(write(receiver_fd, packet, packet_length) < 0) {
 		if(errno == EINTR) continue;
 		syslog_perror("send_online_users: write");
 		break;
 	}
 	free(packet);
 }

 int server_mode(const struct sockaddr_un *socket_addr) {
 	static const struct timeval timeout = { .tv_sec = 2 };

 	int fd = socket(AF_UNIX, SOCK_STREAM, 0);
 	if(fd == -1) {
 		perror("socket");
 		return 1;
 	}
 	//if(fcntl(fd, F_SETFL, O_NONBLOCK) < 0) syslog_perror("fcntl");
 	unlink(socket_addr->sun_path);
 	if(bind(fd, (struct sockaddr *)socket_addr, sizeof(struct sockaddr_un)) < 0) {
 		perror(socket_addr->sun_path);
 		close(fd);
 		return 1;
 	}
 	if(chmod(socket_addr->sun_path, 0600) < 0) {
 		perror(socket_addr->sun_path);
 		close(fd);
 		unlink(socket_addr->sun_path);
 		return 1;
 	}
 	if(listen(fd, 64) < 0) {
 		perror("listen");
 		close(fd);
 		unlink(socket_addr->sun_path);
 		return 1;
 	}

 	openlog("sshoutd", LOG_PID | LOG_PERROR, LOG_DAEMON);

 	fd_set fdset;
 	FD_ZERO(&fdset);
 	FD_SET(fd, &fdset);
 	int max_fd = fd;

 	int client_fds[FD_SETSIZE];
 	int online_users_indexes[FD_SETSIZE];
 	int i;
 	for(i=0; i<FD_SETSIZE; i++) {
 		client_fds[i] = -1;
 		online_users[i].id = -1;
 		online_users_indexes[i] = -1;
 	}

 /*
 	char *buffer = malloc(LOCAL_PACKET_BUFFER_SIZE);
 	if(!buffer) {
 		perror("malloc");
 		return 1;
 	}
 */

 	while(1) {
 		int have_client_fd_closed = 0;
 		fd_set rfdset = fdset;
 		int n = select(max_fd + 1, &rfdset, NULL, NULL, NULL);
 		if(n < 0) {
 			if(errno == EINTR) continue;
 			syslog_perror("select");
 		}
 		if(FD_ISSET(fd, &rfdset)) {
 			struct sockaddr_un client_addr;
 			socklen_t addr_len = sizeof client_addr;
 			int cfd;
 			do {
 				cfd = accept(fd, (struct sockaddr *)&client_addr, &addr_len);
 			} while(cfd == -1 && errno == EINTR);
 			if(cfd == -1) {
 				syslog_perror("accept");
 				//if(errno == EMFILE) continue;
 				//return 1;
 				//continue;
 				if(errno == EMFILE && n < 2) sleep(1);
 			} else {
 				syslog(LOG_INFO, "client fd %d\n", cfd);
 			        if(setsockopt(cfd, SOL_SOCKET, SO_SNDTIMEO, &timeout, sizeof timeout) < 0) syslog_perror("setsockopt");
 			        if(setsockopt(cfd, SOL_SOCKET, SO_RCVTIMEO, &timeout, sizeof timeout) < 0) syslog_perror("setsockopt");
 				i = 0;
 				while(1) {
 					if(i >= FD_SETSIZE) {
 						syslog(LOG_WARNING, "cannot add fd %d to set, too many clients\n", cfd);
 						close(cfd);
 						break;
 					}
 					if(client_fds[i] == -1) {
 						client_fds[i] = cfd;
 						FD_SET(cfd, &fdset);
 						if(cfd > max_fd) max_fd = cfd;
 						syslog(LOG_INFO, "client %d fd %d\n", i, cfd);
 						break;
 					}
 					i++;
 				}
 			}
 			n--;
 		}
 		for(i=0; n && i<FD_SETSIZE; i++) {
 			int cfd = client_fds[i];
 			if(cfd == -1) continue;
 			if(FD_ISSET(cfd, &rfdset)) {
 				n--;
 				struct local_packet *packet;
 				switch(get_local_packet(cfd, &packet)) {
 					case GET_PACKET_EOF:
 						syslog(LOG_INFO, "client %d fd %d EOF\n", i, cfd);
 						goto end_of_connection;
 					case GET_PACKET_ERROR:
 						syslog_perror("read");
 						goto end_of_connection;
 					case GET_PACKET_SHORT_READ:
 						syslog(LOG_INFO, "client %d fd %d short read\n", i, cfd);
 						goto end_of_connection;
 					case GET_PACKET_TOO_LARGE:
 						syslog(LOG_WARNING, "client %d fd %d packet too large (%u bytes)\n",
 							i, cfd, *(unsigned int *)packet);
 						goto end_of_connection;
 					case GET_PACKET_OUT_OF_MEMORY:
 						syslog(LOG_WARNING, "client %d fd %d out of memory (allocating %u bytes)\n",
 							i, cfd, *(unsigned int *)packet);
 						goto end_of_connection;
 					case 0:
 						break;
 					default:
 						syslog(LOG_INFO, "client %d fd %d unknown error\n", i, cfd);
 						//abort();
 						goto end_of_connection;
 				}
 				switch(packet->type) {
 					case SSHOUT_LOCAL_LOGIN:
 						user_online(i, packet->data, packet->data + USER_NAME_MAX_LENGTH, online_users_indexes + i);
 						break;
 					case SSHOUT_LOCAL_POST_MESSAGE:
 						if(online_users_indexes[i] == -1) {
 							syslog(LOG_INFO, "client %d fd %d posting message without login", i, cfd);
 							break;
 						}
 						// TODO
 						break;
 					case SSHOUT_LOCAL_GET_ONLINE_USERS:
 						send_online_users(i, cfd);
 						break;
 					default:
 						syslog(LOG_NOTICE, "client %d fd %d unknown packet type %d",
 							i, cfd, packet->type);
 						break;
 				}
 				free(packet);
 				continue;
 end_of_connection:
 				close(cfd);
 				FD_CLR(cfd, &fdset);
 				have_client_fd_closed = 1;
 				user_offline(i);
 				online_users_indexes[i] = -1;
 			}
 		}
 		if(have_client_fd_closed) {
 			max_fd = fd;
 			for(i=0; n && i<FD_SETSIZE; i++) if(client_fds[i] > max_fd) max_fd = client_fds[i];
 		}
 	}
 }
	/*
	* Copyright 2015-2018 Rivoreo
	*
	* 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.
	*/

	#include "common.h"
	#include <sys/socket.h>
	#include <sys/un.h>
	#include <sys/stat.h>
	#include <unistd.h>
	#include <syslog.h>
	#include <string.h>
	#include <stdlib.h>
	#include <fcntl.h>
	#include <stdio.h>
	#include <errno.h>

	static struct local_online_user online_users[FD_SETSIZE];

	static void syslog_perror(const char *ident) {
	int e = errno;
	syslog(LOG_ERR, "%s: %s (%d)", ident, strerror(e), e);
	}

	static int user_online(int id, const char user_name, const char host_name, int *index) {
	int i = 0;
	while(online_users[i].id != -1) {
	if(++i >= sizeof online_users / sizeof *online_users) {
	syslog(LOG_WARNING, "cannot let user '%s' from %s login: too many users\n", user_name, host_name);
	return -1;
	}
	}
	struct local_online_user *p = online_users + i;
	p->id = id;
	strncpy(p->user_name, user_name, sizeof p->user_name);
	strncpy(p->host_name, host_name, sizeof p->host_name);
	return 0;
	}

	static void user_offline(int id) {
	int i = 0;
	while(online_users[i].id != id) {
	if(++i >= sizeof online_users / sizeof *online_users) return;
	}
	online_users[i].id = -1;
	}

	static void send_online_users(int receiver_id, int receiver_fd) {
	int i = 0, count = 0;
	do {
	if(online_users[i].id != -1) count++;
	} while(++i < sizeof online_users / sizeof *online_users);
	size_t packet_length = sizeof(struct local_packet) + sizeof(struct local_online_users_info) + sizeof(struct local_online_user) * count;
	struct local_packet *packet = malloc(packet_length);
	if(!packet) {
	syslog(LOG_ERR, "send_online_users: out of memory");
	return;
	}
	packet->length = packet_length - sizeof packet->length;
	packet->type = SSHOUT_LOCAL_ONLINE_USERS_INFO;
	struct local_online_users_info info = (struct local_online_users_info )packet->data;
	info->your_id = receiver_id;
	info->count = count;
	i = 0;
	for(i = 0; i < sizeof online_users / sizeof *online_users && count > 0; i++) {
	if(online_users[i].id == -1) continue;
	count--;
	memcpy(info + count, online_users + i, sizeof(struct local_online_user));
	}
	while(write(receiver_fd, packet, packet_length) < 0) {
	if(errno == EINTR) continue;
	syslog_perror("send_online_users: write");
	break;
	}
	free(packet);
	}

	int server_mode(const struct sockaddr_un *socket_addr) {
	static const struct timeval timeout = { .tv_sec = 2 };

	int fd = socket(AF_UNIX, SOCK_STREAM, 0);
	if(fd == -1) {
	perror("socket");
	return 1;
	}
	//if(fcntl(fd, F_SETFL, O_NONBLOCK) < 0) syslog_perror("fcntl");
	unlink(socket_addr->sun_path);
	if(bind(fd, (struct sockaddr *)socket_addr, sizeof(struct sockaddr_un)) < 0) {
	perror(socket_addr->sun_path);
	close(fd);
	return 1;
	}
	if(chmod(socket_addr->sun_path, 0600) < 0) {
	perror(socket_addr->sun_path);
	close(fd);
	unlink(socket_addr->sun_path);
	return 1;
	}
	if(listen(fd, 64) < 0) {
	perror("listen");
	close(fd);
	unlink(socket_addr->sun_path);
	return 1;
	}

	openlog("sshoutd", LOG_PID \| LOG_PERROR, LOG_DAEMON);

	fd_set fdset;
	FD_ZERO(&fdset);
	FD_SET(fd, &fdset);
	int max_fd = fd;

	int client_fds[FD_SETSIZE];
	int online_users_indexes[FD_SETSIZE];
	int i;
	for(i=0; i<FD_SETSIZE; i++) {
	client_fds[i] = -1;
	online_users[i].id = -1;
	online_users_indexes[i] = -1;
	}

	/*
	char *buffer = malloc(LOCAL_PACKET_BUFFER_SIZE);
	if(!buffer) {
	perror("malloc");
	return 1;
	}
	*/

	while(1) {
	int have_client_fd_closed = 0;
	fd_set rfdset = fdset;
	int n = select(max_fd + 1, &rfdset, NULL, NULL, NULL);
	if(n < 0) {
	if(errno == EINTR) continue;
	syslog_perror("select");
	}
	if(FD_ISSET(fd, &rfdset)) {
	struct sockaddr_un client_addr;
	socklen_t addr_len = sizeof client_addr;
	int cfd;
	do {
	cfd = accept(fd, (struct sockaddr *)&client_addr, &addr_len);
	} while(cfd == -1 && errno == EINTR);
	if(cfd == -1) {
	syslog_perror("accept");
	//if(errno == EMFILE) continue;
	//return 1;
	//continue;
	if(errno == EMFILE && n < 2) sleep(1);
	} else {
	syslog(LOG_INFO, "client fd %d\n", cfd);
	if(setsockopt(cfd, SOL_SOCKET, SO_SNDTIMEO, &timeout, sizeof timeout) < 0) syslog_perror("setsockopt");
	if(setsockopt(cfd, SOL_SOCKET, SO_RCVTIMEO, &timeout, sizeof timeout) < 0) syslog_perror("setsockopt");
	i = 0;
	while(1) {
	if(i >= FD_SETSIZE) {
	syslog(LOG_WARNING, "cannot add fd %d to set, too many clients\n", cfd);
	close(cfd);
	break;
	}
	if(client_fds[i] == -1) {
	client_fds[i] = cfd;
	FD_SET(cfd, &fdset);
	if(cfd > max_fd) max_fd = cfd;
	syslog(LOG_INFO, "client %d fd %d\n", i, cfd);
	break;
	}
	i++;
	}
	}
	n--;
	}
	for(i=0; n && i<FD_SETSIZE; i++) {
	int cfd = client_fds[i];
	if(cfd == -1) continue;
	if(FD_ISSET(cfd, &rfdset)) {
	n--;
	struct local_packet *packet;
	switch(get_local_packet(cfd, &packet)) {
	case GET_PACKET_EOF:
	syslog(LOG_INFO, "client %d fd %d EOF\n", i, cfd);
	goto end_of_connection;
	case GET_PACKET_ERROR:
	syslog_perror("read");
	goto end_of_connection;
	case GET_PACKET_SHORT_READ:
	syslog(LOG_INFO, "client %d fd %d short read\n", i, cfd);
	goto end_of_connection;
	case GET_PACKET_TOO_LARGE:
	syslog(LOG_WARNING, "client %d fd %d packet too large (%u bytes)\n",
	i, cfd, (unsigned int )packet);
	goto end_of_connection;
	case GET_PACKET_OUT_OF_MEMORY:
	syslog(LOG_WARNING, "client %d fd %d out of memory (allocating %u bytes)\n",
	i, cfd, (unsigned int )packet);
	goto end_of_connection;
	case 0:
	break;
	default:
	syslog(LOG_INFO, "client %d fd %d unknown error\n", i, cfd);
	//abort();
	goto end_of_connection;
	}
	switch(packet->type) {
	case SSHOUT_LOCAL_LOGIN:
	user_online(i, packet->data, packet->data + USER_NAME_MAX_LENGTH, online_users_indexes + i);
	break;
	case SSHOUT_LOCAL_POST_MESSAGE:
	if(online_users_indexes[i] == -1) {
	syslog(LOG_INFO, "client %d fd %d posting message without login", i, cfd);
	break;
	}
	// TODO
	break;
	case SSHOUT_LOCAL_GET_ONLINE_USERS:
	send_online_users(i, cfd);
	break;
	default:
	syslog(LOG_NOTICE, "client %d fd %d unknown packet type %d",
	i, cfd, packet->type);
	break;
	}
	free(packet);
	continue;
	end_of_connection:
	close(cfd);
	FD_CLR(cfd, &fdset);
	have_client_fd_closed = 1;
	user_offline(i);
	online_users_indexes[i] = -1;
	}
	}
	if(have_client_fd_closed) {
	max_fd = fd;
	for(i=0; n && i<FD_SETSIZE; i++) if(client_fds[i] > max_fd) max_fd = client_fds[i];
	}
	}
	}