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

 /* Secure Shout Host Oriented Unified Talk
  * Copyright 2015-2023 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 "client.h"
 #include "misc.h"
 #include <sys/socket.h>
 #include <sys/un.h>
 #include <sys/stat.h>
 #include <unistd.h>
 #include <syslog.h>
 #include "syncrw.h"
 #include <string.h>
 #include <stdarg.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <errno.h>
 #include <fcntl.h>
 #ifndef NO_NLS
 #include <locale.h>
 #endif

 #define MAX(A,B) ((A)>(B)?(A):(B))
 #define REMOTE_MODE_CLI 1
 #define REMOTE_MODE_API 2
 #define REMOTE_MODE_LOG 3
 #define REMOTE_MODE_IRC 4

 static int send_login(int fd, const char *orig_user_name, const char *client_address
 #ifdef HAVE_ICONV
   , const char *text_encoding
 #endif
 ) {
 	int r = 0;
 	size_t user_name_len = strlen(orig_user_name);
 	//char user_name[USER_NAME_MAX_LENGTH];
 	if(user_name_len > USER_NAME_MAX_LENGTH - 1) user_name_len = USER_NAME_MAX_LENGTH - 1;
 	//memcpy(user_name, orig_user_name, user_name_len);
 	//memset(user_name + user_name_len, 0, USER_NAME_MAX_LENGTH - user_name_len);
 	const char *space = strchr(client_address, ' ');
 	size_t host_name_len = space ? space - client_address : strlen(client_address);
 	if(!host_name_len) {
 		errno = EINVAL;
 		return -1;
 	}
 	if(host_name_len > HOST_NAME_MAX_LENGTH - 1) host_name_len = HOST_NAME_MAX_LENGTH - 1;
 #ifdef HAVE_ICONV
 	size_t encoding_name_len = text_encoding ? strlen(text_encoding) : 0;
 	if(encoding_name_len > TEXT_ENCODING_NAME_MAX_LENGTH - 1) {
 		encoding_name_len = 0;
 		syslog(LOG_WARNING, "Text encoding name '%s' too long", text_encoding);
 	}
 #endif
 	size_t packet_len = sizeof(struct local_packet) + USER_NAME_MAX_LENGTH +
 #ifdef HAVE_ICONV
 		HOST_NAME_MAX_LENGTH + encoding_name_len + 1
 #else
 		host_name_len + 1
 #endif
 		;
 	struct local_packet *packet = malloc(packet_len);
 	if(!packet) return -1;
 	packet->length = packet_len - sizeof packet->length;
 	packet->type = SSHOUT_LOCAL_LOGIN;
 	memcpy(packet->data, orig_user_name, user_name_len);
 	memset(packet->data + user_name_len, 0, USER_NAME_MAX_LENGTH - user_name_len);
 	char *p = packet->data + USER_NAME_MAX_LENGTH;
 	memcpy(p, client_address, host_name_len);
 #ifdef HAVE_ICONV
 	memset(p + host_name_len, 0, HOST_NAME_MAX_LENGTH - host_name_len);
 	p += HOST_NAME_MAX_LENGTH;
 	if(encoding_name_len) memcpy(p, text_encoding, encoding_name_len);
 	p[encoding_name_len] = 0;
 #else
 	p[host_name_len] = 0;
 #endif
 	while(write(fd, packet, packet_len) < 0) {
 		if(errno == EINTR) continue;
 		r = -1;
 		break;
 	}
 	int e = errno;
 	free(packet);
 	errno = e;
 	return r;
 }

 int client_send_request_get_online_users(int fd) {
 	struct local_packet packet;
 	packet.length = sizeof packet - sizeof packet.length;
 	packet.type = SSHOUT_LOCAL_GET_ONLINE_USERS;
 	while(write(fd, &packet, sizeof packet) < 0) {
 		if(errno == EINTR) continue;
 		return -1;
 	}
 	return 0;
 }

 // field msg_from is not needed
 int client_post_message(int fd, const struct local_message *message) {
 	int r = 0;
 	size_t packet_len = sizeof(struct local_packet) + sizeof(struct local_message) + message->msg_length;
 	if(packet_len < message->msg_length) {
 #ifdef EOVERFLOW
 		errno = EOVERFLOW;
 #else
 		errno = EINVAL;
 #endif
 		return -1;
 	}
 	struct local_packet *packet = malloc(packet_len);
 	if(!packet) return -1;
 	packet->length = packet_len - sizeof packet->length;
 	packet->type = SSHOUT_LOCAL_POST_MESSAGE;
 	memcpy(packet->data, message, sizeof(struct local_message) + message->msg_length);
 	if(sync_write(fd, packet, packet_len) < 0) {
 		r = -1;
 	}
 	int e = errno;
 	free(packet);
 	errno = e;
 	return r;
 }

 int client_post_plain_text_message(int fd, const char *receiver, const char *text) {
 	size_t receiver_len = strlen(receiver);
 	size_t text_len = strlen(text);
 	struct local_message *message = malloc(sizeof(struct local_message) + text_len);
 	if(!message) return -1;
 	if(receiver_len > USER_NAME_MAX_LENGTH - 1) receiver_len = USER_NAME_MAX_LENGTH - 1;
 	memcpy(message->msg_to, receiver, receiver_len);
 	message->msg_to[receiver_len] = 0;
 	message->msg_type = SSHOUT_MSG_PLAIN;
 	message->msg_length = text_len;
 	memcpy(message->msg, text, text_len);
 	int r = client_post_message(fd, message);
 	free(message);
 	return r;
 }

 static int local_socket = -1;

 int client_get_local_socket_fd() {
 	return local_socket;
 }

 int client_mode(const struct sockaddr_un *socket_addr, const char *user_name) {
 	pid_t ppid = getppid();
 	int remote_mode = REMOTE_MODE_CLI;

 	const char *client_address = getenv("SSH_CLIENT");
 	if(!client_address) {
 		fputs("client mode can only be used in a SSH session\n", stderr);
 		return 1;
 	}

 #ifndef NO_NLS
 	setlocale(LC_ALL, "");
 	textdomain("sshout");
 #endif

 	if(!is_valid_user_name(user_name)) {
 		fprintf(stderr, _("Invalid user name '%s'\n"), user_name);
 		return 1;
 	}
 	const char *command = getenv("SSH_ORIGINAL_COMMAND");
 	if(command) {
 		if(strcmp(command, "cli") == 0) remote_mode = REMOTE_MODE_CLI;
 		else if(strcmp(command, "api") == 0) remote_mode = REMOTE_MODE_API;
 		else if(strcmp(command, "log") == 0) remote_mode = REMOTE_MODE_LOG;
 #ifdef ENABLE_IRC_FRONTEND
 		else if(strcmp(command, "irc") == 0) remote_mode = REMOTE_MODE_IRC;
 #endif
 		else {
 			fprintf(stderr, _("Command '%s' is not recognized\n"), command);
 			return 1;
 		}
 	}

 	size_t len = 8 + USER_NAME_MAX_LENGTH + 4 + 1;
 	char *syslog_ident = malloc(len);
 	if(!syslog_ident) {
 		perror("malloc");
 		exit(1);
 	}
 	snprintf(syslog_ident, len, "sshoutd:%s:%s", user_name, command ? : "cli");
 	openlog(syslog_ident, LOG_PID, LOG_DAEMON);

 	char *tz = getenv("TZ");
 	if(tz) {
 		if((tz[0] == ':' && tz[1] == '/') || tz[0] == '/') {
 			*tz = 0;
 			fputs(_("Ignoring absolute path name in TZ\n"), stderr);
 			syslog(LOG_WARNING, "TZ contains absolute path name '%s', ignored", tz);
 		} else if(strstr(tz, "../")) {
 			*tz = 0;
 			fputs(_("Ignoring TZ\n"), stderr);
 			syslog(LOG_WARNING, "TZ='%s', ignored", tz);
 		}
 	}

 	const char *tty_path = ttyname(STDOUT_FILENO);
 	if(tty_path && strcmp(tty_path, "/dev/tty")) {
 		struct stat st;
 		if(fstat(STDOUT_FILENO, &st) < 0) {
 			syslog(LOG_ERR, "Failed to get status of stdout (%s): %s", tty_path, strerror(errno));
 			return 1;
 		}
 		if(st.st_uid != getuid()) {
 			syslog(LOG_ERR, "stdout terminal %s isn't owned by me", tty_path);
 			return 1;
 		}
 		if(fchmod(STDOUT_FILENO, 0600) < 0) {
 			syslog(LOG_WARNING, "Failed to change mode for stdout (%s): %s", tty_path, strerror(errno));
 		}
 	}

 	int fd = socket(AF_UNIX, SOCK_STREAM, 0);
 	if(fd == -1) {
 		perror("socket");
 		return 1;
 	}
 	while(connect(fd, (struct sockaddr *)socket_addr, sizeof(struct sockaddr_un)) < 0) {
 		if(errno == EINTR) continue;
 		perror("connect");
 		return 1;
 	}

 #ifdef HAVE_ICONV
 	char *locale = getenv("LC_CTYPE");
 	if(!locale) locale = getenv("LANG");
 	char *encoding = locale ? strchr(locale, '.') : NULL;
 	if(encoding) encoding++;
 	if(send_login(fd, user_name, client_address, encoding) < 0) {
 #else
 	if(send_login(fd, user_name, client_address) < 0) {
 #endif
 		perror("send_login");
 		return 1;
 	}

 	struct timeval timeout = { .tv_sec = 60 };
 	fd_set fdset;
 	FD_ZERO(&fdset);
 	FD_SET(fd, &fdset);
 	int max_fd;
 	if(remote_mode == REMOTE_MODE_LOG) {
 		max_fd = fd;
 		close(STDIN_FILENO);
 		if(open("/dev/null", O_RDONLY) != 0) {
 			fputs(_("Cannot open /dev/null for read as fd 0\n"), stderr);
 			syslog(LOG_WARNING, "Cannot open /dev/null for read as fd 0");
 			return 1;
 		}
 	} else {
 		FD_SET(STDIN_FILENO, &fdset);
 		max_fd = MAX(fd, STDIN_FILENO);
 	}

 	struct client_frontend_actions actions;
 	switch(remote_mode) {
 		case REMOTE_MODE_CLI:
 			client_cli_get_actions(&actions, 0);
 			break;
 		case REMOTE_MODE_API:
 			client_api_get_actions(&actions);
 			break;
 		case REMOTE_MODE_LOG:
 			client_cli_get_actions(&actions, 1);
 			break;
 #ifdef ENABLE_IRC_FRONTEND
 		case REMOTE_MODE_IRC:
 			client_irc_get_actions(&actions);
 			break;
 #endif
 	}
 	actions.init_io(user_name);
 	local_socket = fd;

 	while(getppid() == ppid) {
 		fd_set rfdset = fdset;
 		struct timeval current_timeout = timeout;
 		int n = select(max_fd + 1, &rfdset, NULL, NULL, &current_timeout);
 		if(n < 0) {
 			if(errno == EINTR) {
 				if(actions.do_after_signal) actions.do_after_signal();
 				continue;
 			}
 			perror("select");
 			return 1;
 		}
 		if(actions.do_tick) actions.do_tick();
 		if(n) {
 			if(FD_ISSET(fd, &rfdset)) actions.do_local_packet(fd);
 			if(FD_ISSET(STDIN_FILENO, &rfdset)) actions.do_stdin(fd);
 		}
 	}

 	//fputs(_("Parent process changed, exiting\n"), stderr);
 	return 0;
 }
	/* Secure Shout Host Oriented Unified Talk
	* Copyright 2015-2023 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 "client.h"
	#include "misc.h"
	#include <sys/socket.h>
	#include <sys/un.h>
	#include <sys/stat.h>
	#include <unistd.h>
	#include <syslog.h>
	#include "syncrw.h"
	#include <string.h>
	#include <stdarg.h>
	#include <stdlib.h>
	#include <stdio.h>
	#include <errno.h>
	#include <fcntl.h>
	#ifndef NO_NLS
	#include <locale.h>
	#endif

	#define MAX(A,B) ((A)>(B)?(A):(B))
	#define REMOTE_MODE_CLI 1
	#define REMOTE_MODE_API 2
	#define REMOTE_MODE_LOG 3
	#define REMOTE_MODE_IRC 4

	static int send_login(int fd, const char orig_user_name, const char client_address
	#ifdef HAVE_ICONV
	, const char *text_encoding
	#endif
	) {
	int r = 0;
	size_t user_name_len = strlen(orig_user_name);
	//char user_name[USER_NAME_MAX_LENGTH];
	if(user_name_len > USER_NAME_MAX_LENGTH - 1) user_name_len = USER_NAME_MAX_LENGTH - 1;
	//memcpy(user_name, orig_user_name, user_name_len);
	//memset(user_name + user_name_len, 0, USER_NAME_MAX_LENGTH - user_name_len);
	const char *space = strchr(client_address, ' ');
	size_t host_name_len = space ? space - client_address : strlen(client_address);
	if(!host_name_len) {
	errno = EINVAL;
	return -1;
	}
	if(host_name_len > HOST_NAME_MAX_LENGTH - 1) host_name_len = HOST_NAME_MAX_LENGTH - 1;
	#ifdef HAVE_ICONV
	size_t encoding_name_len = text_encoding ? strlen(text_encoding) : 0;
	if(encoding_name_len > TEXT_ENCODING_NAME_MAX_LENGTH - 1) {
	encoding_name_len = 0;
	syslog(LOG_WARNING, "Text encoding name '%s' too long", text_encoding);
	}
	#endif
	size_t packet_len = sizeof(struct local_packet) + USER_NAME_MAX_LENGTH +
	#ifdef HAVE_ICONV
	HOST_NAME_MAX_LENGTH + encoding_name_len + 1
	#else
	host_name_len + 1
	#endif
	;
	struct local_packet *packet = malloc(packet_len);
	if(!packet) return -1;
	packet->length = packet_len - sizeof packet->length;
	packet->type = SSHOUT_LOCAL_LOGIN;
	memcpy(packet->data, orig_user_name, user_name_len);
	memset(packet->data + user_name_len, 0, USER_NAME_MAX_LENGTH - user_name_len);
	char *p = packet->data + USER_NAME_MAX_LENGTH;
	memcpy(p, client_address, host_name_len);
	#ifdef HAVE_ICONV
	memset(p + host_name_len, 0, HOST_NAME_MAX_LENGTH - host_name_len);
	p += HOST_NAME_MAX_LENGTH;
	if(encoding_name_len) memcpy(p, text_encoding, encoding_name_len);
	p[encoding_name_len] = 0;
	#else
	p[host_name_len] = 0;
	#endif
	while(write(fd, packet, packet_len) < 0) {
	if(errno == EINTR) continue;
	r = -1;
	break;
	}
	int e = errno;
	free(packet);
	errno = e;
	return r;
	}

	int client_send_request_get_online_users(int fd) {
	struct local_packet packet;
	packet.length = sizeof packet - sizeof packet.length;
	packet.type = SSHOUT_LOCAL_GET_ONLINE_USERS;
	while(write(fd, &packet, sizeof packet) < 0) {
	if(errno == EINTR) continue;
	return -1;
	}
	return 0;
	}

	// field msg_from is not needed
	int client_post_message(int fd, const struct local_message *message) {
	int r = 0;
	size_t packet_len = sizeof(struct local_packet) + sizeof(struct local_message) + message->msg_length;
	if(packet_len < message->msg_length) {
	#ifdef EOVERFLOW
	errno = EOVERFLOW;
	#else
	errno = EINVAL;
	#endif
	return -1;
	}
	struct local_packet *packet = malloc(packet_len);
	if(!packet) return -1;
	packet->length = packet_len - sizeof packet->length;
	packet->type = SSHOUT_LOCAL_POST_MESSAGE;
	memcpy(packet->data, message, sizeof(struct local_message) + message->msg_length);
	if(sync_write(fd, packet, packet_len) < 0) {
	r = -1;
	}
	int e = errno;
	free(packet);
	errno = e;
	return r;
	}

	int client_post_plain_text_message(int fd, const char receiver, const char text) {
	size_t receiver_len = strlen(receiver);
	size_t text_len = strlen(text);
	struct local_message *message = malloc(sizeof(struct local_message) + text_len);
	if(!message) return -1;
	if(receiver_len > USER_NAME_MAX_LENGTH - 1) receiver_len = USER_NAME_MAX_LENGTH - 1;
	memcpy(message->msg_to, receiver, receiver_len);
	message->msg_to[receiver_len] = 0;
	message->msg_type = SSHOUT_MSG_PLAIN;
	message->msg_length = text_len;
	memcpy(message->msg, text, text_len);
	int r = client_post_message(fd, message);
	free(message);
	return r;
	}

	static int local_socket = -1;

	int client_get_local_socket_fd() {
	return local_socket;
	}

	int client_mode(const struct sockaddr_un socket_addr, const char user_name) {
	pid_t ppid = getppid();
	int remote_mode = REMOTE_MODE_CLI;

	const char *client_address = getenv("SSH_CLIENT");
	if(!client_address) {
	fputs("client mode can only be used in a SSH session\n", stderr);
	return 1;
	}

	#ifndef NO_NLS
	setlocale(LC_ALL, "");
	textdomain("sshout");
	#endif

	if(!is_valid_user_name(user_name)) {
	fprintf(stderr, _("Invalid user name '%s'\n"), user_name);
	return 1;
	}
	const char *command = getenv("SSH_ORIGINAL_COMMAND");
	if(command) {
	if(strcmp(command, "cli") == 0) remote_mode = REMOTE_MODE_CLI;
	else if(strcmp(command, "api") == 0) remote_mode = REMOTE_MODE_API;
	else if(strcmp(command, "log") == 0) remote_mode = REMOTE_MODE_LOG;
	#ifdef ENABLE_IRC_FRONTEND
	else if(strcmp(command, "irc") == 0) remote_mode = REMOTE_MODE_IRC;
	#endif
	else {
	fprintf(stderr, _("Command '%s' is not recognized\n"), command);
	return 1;
	}
	}

	size_t len = 8 + USER_NAME_MAX_LENGTH + 4 + 1;
	char *syslog_ident = malloc(len);
	if(!syslog_ident) {
	perror("malloc");
	exit(1);
	}
	snprintf(syslog_ident, len, "sshoutd:%s:%s", user_name, command ? : "cli");
	openlog(syslog_ident, LOG_PID, LOG_DAEMON);

	char *tz = getenv("TZ");
	if(tz) {
	if((tz[0] == ':' && tz[1] == '/') \|\| tz[0] == '/') {
	*tz = 0;
	fputs(_("Ignoring absolute path name in TZ\n"), stderr);
	syslog(LOG_WARNING, "TZ contains absolute path name '%s', ignored", tz);
	} else if(strstr(tz, "../")) {
	*tz = 0;
	fputs(_("Ignoring TZ\n"), stderr);
	syslog(LOG_WARNING, "TZ='%s', ignored", tz);
	}
	}

	const char *tty_path = ttyname(STDOUT_FILENO);
	if(tty_path && strcmp(tty_path, "/dev/tty")) {
	struct stat st;
	if(fstat(STDOUT_FILENO, &st) < 0) {
	syslog(LOG_ERR, "Failed to get status of stdout (%s): %s", tty_path, strerror(errno));
	return 1;
	}
	if(st.st_uid != getuid()) {
	syslog(LOG_ERR, "stdout terminal %s isn't owned by me", tty_path);
	return 1;
	}
	if(fchmod(STDOUT_FILENO, 0600) < 0) {
	syslog(LOG_WARNING, "Failed to change mode for stdout (%s): %s", tty_path, strerror(errno));
	}
	}

	int fd = socket(AF_UNIX, SOCK_STREAM, 0);
	if(fd == -1) {
	perror("socket");
	return 1;
	}
	while(connect(fd, (struct sockaddr *)socket_addr, sizeof(struct sockaddr_un)) < 0) {
	if(errno == EINTR) continue;
	perror("connect");
	return 1;
	}

	#ifdef HAVE_ICONV
	char *locale = getenv("LC_CTYPE");
	if(!locale) locale = getenv("LANG");
	char *encoding = locale ? strchr(locale, '.') : NULL;
	if(encoding) encoding++;
	if(send_login(fd, user_name, client_address, encoding) < 0) {
	#else
	if(send_login(fd, user_name, client_address) < 0) {
	#endif
	perror("send_login");
	return 1;
	}

	struct timeval timeout = { .tv_sec = 60 };
	fd_set fdset;
	FD_ZERO(&fdset);
	FD_SET(fd, &fdset);
	int max_fd;
	if(remote_mode == REMOTE_MODE_LOG) {
	max_fd = fd;
	close(STDIN_FILENO);
	if(open("/dev/null", O_RDONLY) != 0) {
	fputs(_("Cannot open /dev/null for read as fd 0\n"), stderr);
	syslog(LOG_WARNING, "Cannot open /dev/null for read as fd 0");
	return 1;
	}
	} else {
	FD_SET(STDIN_FILENO, &fdset);
	max_fd = MAX(fd, STDIN_FILENO);
	}

	struct client_frontend_actions actions;
	switch(remote_mode) {
	case REMOTE_MODE_CLI:
	client_cli_get_actions(&actions, 0);
	break;
	case REMOTE_MODE_API:
	client_api_get_actions(&actions);
	break;
	case REMOTE_MODE_LOG:
	client_cli_get_actions(&actions, 1);
	break;
	#ifdef ENABLE_IRC_FRONTEND
	case REMOTE_MODE_IRC:
	client_irc_get_actions(&actions);
	break;
	#endif
	}
	actions.init_io(user_name);
	local_socket = fd;

	while(getppid() == ppid) {
	fd_set rfdset = fdset;
	struct timeval current_timeout = timeout;
	int n = select(max_fd + 1, &rfdset, NULL, NULL, &current_timeout);
	if(n < 0) {
	if(errno == EINTR) {
	if(actions.do_after_signal) actions.do_after_signal();
	continue;
	}
	perror("select");
	return 1;
	}
	if(actions.do_tick) actions.do_tick();
	if(n) {
	if(FD_ISSET(fd, &rfdset)) actions.do_local_packet(fd);
	if(FD_ISSET(STDIN_FILENO, &rfdset)) actions.do_stdin(fd);
	}
	}

	//fputs(_("Parent process changed, exiting\n"), stderr);
	return 0;
	}