c++/domain-socket-bridge/domain-socket-bridge.c
changeset 41 2383ed4da507
parent 40 ba40af6cf815
child 42 5bd10c0ae650
     1.1 --- a/c++/domain-socket-bridge/domain-socket-bridge.c	Sun Nov 20 20:39:08 2016 +0100
     1.2 +++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.3 @@ -1,224 +0,0 @@
     1.4 -#include <string.h>
     1.5 -#include <errno.h>
     1.6 -#include <stdio.h>
     1.7 -#include <signal.h>
     1.8 -#include <stdlib.h>
     1.9 -#include <string>
    1.10 -#include <regex>
    1.11 -
    1.12 -#include <event2/bufferevent.h>
    1.13 -#include <event2/buffer.h>
    1.14 -#include <event2/listener.h>
    1.15 -#include <event2/util.h>
    1.16 -#include <event2/event.h>
    1.17 -#include <sys/socket.h>
    1.18 -#include <sys/un.h>
    1.19 -#include <unistd.h>
    1.20 -
    1.21 -using namespace std;
    1.22 -
    1.23 -static const char MESSAGE[] = "Hello, World!\n";
    1.24 -
    1.25 -static const char PATH[] = "./roura";
    1.26 -
    1.27 -static const string COMMAND_EXIT("exit\n");
    1.28 -
    1.29 -static void listener_cb(evutil_socket_t, short, void *);
    1.30 -static void conn_read_cb(struct bufferevent *, void *);
    1.31 -static void conn_write_cb(struct bufferevent *, void *);
    1.32 -static void conn_event_cb(struct bufferevent *, short, void *);
    1.33 -static void signal_cb(evutil_socket_t, short, void *);
    1.34 -static void print_socket_info(int, int);
    1.35 -
    1.36 -int main(int argc, char **argv) {
    1.37 -	printf("%4s %8s\n", "*", "STARTED");
    1.38 -	struct event_base *base;
    1.39 -	evutil_socket_t listener;
    1.40 -	struct event *listener_event;
    1.41 -	struct event *signal_event;
    1.42 -
    1.43 -	struct sockaddr_un sun;
    1.44 -
    1.45 -	setvbuf(stdout, NULL, _IONBF, 0);
    1.46 -
    1.47 -	base = event_base_new();
    1.48 -	if (!base) {
    1.49 -		printf("%4s %8s %s\n", "*", "ERROR", "unable to initialize libevent");
    1.50 -		return 1;
    1.51 -	}
    1.52 -
    1.53 -	memset(&sun, 0, sizeof (sun));
    1.54 -	sun.sun_family = AF_UNIX;
    1.55 -	strcpy(sun.sun_path, PATH);
    1.56 -
    1.57 -	listener = socket(AF_UNIX, SOCK_STREAM, 0);
    1.58 -	evutil_make_socket_nonblocking(listener);
    1.59 -
    1.60 -	if (bind(listener, (struct sockaddr*) &sun, sizeof (sun)) < 0) {
    1.61 -		printf("%4s %8s %s: %s\n", "*", "ERROR", "unable to create domain socket:", PATH);
    1.62 -		return 1;
    1.63 -	}
    1.64 -
    1.65 -	if (listen(listener, 16) < 0) {
    1.66 -		printf("%4s %8s %s\n", "*", "ERROR", "unable to listen");
    1.67 -		return 1;
    1.68 -	}
    1.69 -
    1.70 -	// identifikátor serverového soketu (v současnosti číslo FD)
    1.71 -	printf("%4s %8s listening at: sun_path = %s → socketId = %d\n", "*", "SOCKET", sun.sun_path, listener);
    1.72 -
    1.73 -	listener_event = event_new(base, listener, EV_READ | EV_PERSIST, listener_cb, (void*) base);
    1.74 -
    1.75 -	if (!listener_event) {
    1.76 -		printf("%4s %8s %s\n", "*", "ERROR", "unable to do event_new()");
    1.77 -		return 1;
    1.78 -	}
    1.79 -
    1.80 -	event_add(listener_event, NULL);
    1.81 -
    1.82 -	signal_event = evsignal_new(base, SIGINT, signal_cb, (void *) base);
    1.83 -
    1.84 -	if (!signal_event || event_add(signal_event, NULL) < 0) {
    1.85 -		printf("%4s %8s %s\n", "*", "ERROR", "unable to create/add a signal event");
    1.86 -		return 1;
    1.87 -	}
    1.88 -
    1.89 -	event_base_dispatch(base);
    1.90 -
    1.91 -	event_free(listener_event);
    1.92 -	event_free(signal_event);
    1.93 -	event_base_free(base);
    1.94 -
    1.95 -	// smažeme soket na disku / soubor -- jinak by program příště spadl na bind()
    1.96 -	// TODO: co když soket někdo přesune a místo něj dá jiný soubor?
    1.97 -	unlink(PATH);
    1.98 -
    1.99 -	printf("%4s %8s\n", "*", "FINISHED");
   1.100 -	return 0;
   1.101 -}
   1.102 -
   1.103 -static void listener_cb(evutil_socket_t listener, short event, void *user_data) {
   1.104 -	struct event_base *base = (event_base *) user_data;
   1.105 -	struct bufferevent *bev;
   1.106 -
   1.107 -	struct sockaddr_storage ss;
   1.108 -	socklen_t slen = sizeof (ss);
   1.109 -	int fd = accept(listener, (struct sockaddr*) &ss, &slen);
   1.110 -
   1.111 -	// identifikátor navázaného spojení (v současnosti číslo FD)
   1.112 -	int * connectionId = (int*) malloc(sizeof (fd));
   1.113 -	*connectionId = fd;
   1.114 -
   1.115 -	if (fd < 0) {
   1.116 -		printf("%4d %8s %s\n", *connectionId, "ERROR", "unable to accept()");
   1.117 -		return;
   1.118 -	} else if (fd > FD_SETSIZE) {
   1.119 -		// FD_SETSIZE = 1024 -- Proč? Co když bude spojení víc?
   1.120 -		printf("%4d %8s fd (%d) > FD_SETSIZE (%d)\n", *connectionId, "ERROR", fd, FD_SETSIZE);
   1.121 -		close(fd);
   1.122 -		return;
   1.123 -	}
   1.124 -
   1.125 -	evutil_make_socket_nonblocking(fd);
   1.126 -
   1.127 -
   1.128 -	bev = bufferevent_socket_new(base, fd, BEV_OPT_CLOSE_ON_FREE);
   1.129 -	if (!bev) {
   1.130 -		printf("%4d %8s %s\n", *connectionId, "ERROR", "constructing bufferevent");
   1.131 -		event_base_loopbreak(base);
   1.132 -		return;
   1.133 -	}
   1.134 -
   1.135 -
   1.136 -
   1.137 -
   1.138 -	bufferevent_setcb(bev, conn_read_cb, conn_write_cb, conn_event_cb, (void*) connectionId);
   1.139 -	bufferevent_enable(bev, EV_READ | EV_WRITE);
   1.140 -
   1.141 -	printf("%4d %8s somebody has connected: socketId = %d → connectionId = %d\n", *connectionId, "CONN", listener, *connectionId);
   1.142 -	print_socket_info(*connectionId, fd);
   1.143 -
   1.144 -	bufferevent_write(bev, MESSAGE, strlen(MESSAGE));
   1.145 -}
   1.146 -
   1.147 -static void conn_read_cb(struct bufferevent *bev, void *user_data) {
   1.148 -	int connectionId = *((int*) user_data);
   1.149 -
   1.150 -	/* This callback is invoked when there is data to read on bev. */
   1.151 -	struct evbuffer *input = bufferevent_get_input(bev);
   1.152 -	struct evbuffer *output = bufferevent_get_output(bev);
   1.153 -	struct event_base *base = bufferevent_get_base(bev);
   1.154 -
   1.155 -	size_t len = evbuffer_get_length(input);
   1.156 -	char *data = (char*) malloc(len);
   1.157 -	evbuffer_copyout(input, data, len);
   1.158 -
   1.159 -
   1.160 -	string dataFormated(data);
   1.161 -	dataFormated = regex_replace(dataFormated, regex("\\n"), "\\n");
   1.162 -	printf("%4d %8s '%s'\n", connectionId, "IN", dataFormated.c_str());
   1.163 -
   1.164 -	if (COMMAND_EXIT.compare(data) == 0) {
   1.165 -		struct timeval delay = {2, 123};
   1.166 -		printf("%4d %8s client asks us to terminate; finishing in %ld sesonds and %ld microseconds\n", connectionId, "EXIT", delay.tv_sec, delay.tv_usec);
   1.167 -		event_base_loopexit(base, &delay);
   1.168 -	}
   1.169 -
   1.170 -	evbuffer_add(output, "echo: ", 6);
   1.171 -	/* Copy all the data from the input buffer to the output buffer. */
   1.172 -	evbuffer_add_buffer(output, input);
   1.173 -	free(data);
   1.174 -}
   1.175 -
   1.176 -static void conn_write_cb(struct bufferevent *bev, void *user_data) {
   1.177 -	int connectionId = *((int*) user_data);
   1.178 -
   1.179 -	struct evbuffer *output = bufferevent_get_output(bev);
   1.180 -	if (evbuffer_get_length(output) == 0) {
   1.181 -		printf("%4d %8s\n", connectionId, "FLUSH");
   1.182 -		/* nebudeme ukončovat spojení
   1.183 -		bufferevent_free(bev);
   1.184 -		 */
   1.185 -	} else {
   1.186 -		// FIXME: sem to nikdy nepřijde
   1.187 -		size_t len = evbuffer_get_length(output);
   1.188 -		char *data = (char*) malloc(len);
   1.189 -		evbuffer_copyout(output, data, len);
   1.190 -		printf("%4d %8s '%s'\n", connectionId, "OUT", data);
   1.191 -		free(data);
   1.192 -	}
   1.193 -}
   1.194 -
   1.195 -static void conn_event_cb(struct bufferevent *bev, short events, void *user_data) {
   1.196 -	int connectionId = *((int*) user_data);
   1.197 -
   1.198 -	if (events & BEV_EVENT_EOF) {
   1.199 -		printf("%4d %8s\n", connectionId, "CLOSE");
   1.200 -	} else if (events & BEV_EVENT_ERROR) {
   1.201 -		printf("%4d %8s %s\n", connectionId, "ERROR", strerror(errno));
   1.202 -	} else {
   1.203 -		printf("%4d %8s\n", connectionId, "OTHER");
   1.204 -		// None of the other events can happen here, since we haven't enabled timeouts
   1.205 -	}
   1.206 -
   1.207 -	bufferevent_free(bev);
   1.208 -	free(user_data);
   1.209 -}
   1.210 -
   1.211 -static void signal_cb(evutil_socket_t sig, short events, void *user_data) {
   1.212 -	struct event_base *base = (event_base *) user_data;
   1.213 -	struct timeval delay = {2, 123};
   1.214 -
   1.215 -	printf("\n%4s %8s got SIGINT (Ctrl+C); finishing in %ld sesonds and %ld microseconds\n", "*", "SIGNAL", delay.tv_sec, delay.tv_usec);
   1.216 -
   1.217 -	event_base_loopexit(base, &delay);
   1.218 -}
   1.219 -
   1.220 -static void print_socket_info(int connectionId, int fd) {
   1.221 -	struct ucred cr;
   1.222 -	unsigned int cl = sizeof (cr);
   1.223 -
   1.224 -	if (getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &cr, &cl) == 0) {
   1.225 -		printf("%4d %8s client identification: pid=%d, uid=%d, gid=%d\n", connectionId, "CONN", cr.pid, cr.uid, cr.gid);
   1.226 -	}
   1.227 -}
   1.228 \ No newline at end of file