1 /* $NetBSD: hello-world.c,v 1.1.1.1 2013/04/11 16:43:31 christos Exp $ */
2 /*
3 This exmple program provides a trivial server program that listens for TCP
4 connections on port 9995. When they arrive, it writes a short message to
5 each client connection, and closes each connection once it is flushed.
6
7 Where possible, it exits cleanly in response to a SIGINT (ctrl-c).
8 */
9
10
11 #include <string.h>
12 #include <errno.h>
13 #include <stdio.h>
14 #include <signal.h>
15 #ifndef WIN32
16 #include <netinet/in.h>
17 # ifdef _XOPEN_SOURCE_EXTENDED
18 # include <arpa/inet.h>
19 # endif
20 #include <sys/socket.h>
21 #endif
22
23 #include <event2/bufferevent.h>
24 #include <event2/buffer.h>
25 #include <event2/listener.h>
26 #include <event2/util.h>
27 #include <event2/event.h>
28
29 static const char MESSAGE[] = "Hello, World!\n";
30
31 static const int PORT = 9995;
32
33 static void listener_cb(struct evconnlistener *, evutil_socket_t,
34 struct sockaddr *, int socklen, void *);
35 static void conn_writecb(struct bufferevent *, void *);
36 static void conn_eventcb(struct bufferevent *, short, void *);
37 static void signal_cb(evutil_socket_t, short, void *);
38
39 int
main(int argc,char ** argv)40 main(int argc, char **argv)
41 {
42 struct event_base *base;
43 struct evconnlistener *listener;
44 struct event *signal_event;
45
46 struct sockaddr_in sin;
47 #ifdef WIN32
48 WSADATA wsa_data;
49 WSAStartup(0x0201, &wsa_data);
50 #endif
51
52 base = event_base_new();
53 if (!base) {
54 fprintf(stderr, "Could not initialize libevent!\n");
55 return 1;
56 }
57
58 memset(&sin, 0, sizeof(sin));
59 sin.sin_family = AF_INET;
60 sin.sin_port = htons(PORT);
61
62 listener = evconnlistener_new_bind(base, listener_cb, (void *)base,
63 LEV_OPT_REUSEABLE|LEV_OPT_CLOSE_ON_FREE, -1,
64 (struct sockaddr*)&sin,
65 sizeof(sin));
66
67 if (!listener) {
68 fprintf(stderr, "Could not create a listener!\n");
69 return 1;
70 }
71
72 signal_event = evsignal_new(base, SIGINT, signal_cb, (void *)base);
73
74 if (!signal_event || event_add(signal_event, NULL)<0) {
75 fprintf(stderr, "Could not create/add a signal event!\n");
76 return 1;
77 }
78
79 event_base_dispatch(base);
80
81 evconnlistener_free(listener);
82 event_free(signal_event);
83 event_base_free(base);
84
85 printf("done\n");
86 return 0;
87 }
88
89 static void
listener_cb(struct evconnlistener * listener,evutil_socket_t fd,struct sockaddr * sa,int socklen,void * user_data)90 listener_cb(struct evconnlistener *listener, evutil_socket_t fd,
91 struct sockaddr *sa, int socklen, void *user_data)
92 {
93 struct event_base *base = user_data;
94 struct bufferevent *bev;
95
96 bev = bufferevent_socket_new(base, fd, BEV_OPT_CLOSE_ON_FREE);
97 if (!bev) {
98 fprintf(stderr, "Error constructing bufferevent!");
99 event_base_loopbreak(base);
100 return;
101 }
102 bufferevent_setcb(bev, NULL, conn_writecb, conn_eventcb, NULL);
103 bufferevent_enable(bev, EV_WRITE);
104 bufferevent_disable(bev, EV_READ);
105
106 bufferevent_write(bev, MESSAGE, strlen(MESSAGE));
107 }
108
109 static void
conn_writecb(struct bufferevent * bev,void * user_data)110 conn_writecb(struct bufferevent *bev, void *user_data)
111 {
112 struct evbuffer *output = bufferevent_get_output(bev);
113 if (evbuffer_get_length(output) == 0) {
114 printf("flushed answer\n");
115 bufferevent_free(bev);
116 }
117 }
118
119 static void
conn_eventcb(struct bufferevent * bev,short events,void * user_data)120 conn_eventcb(struct bufferevent *bev, short events, void *user_data)
121 {
122 if (events & BEV_EVENT_EOF) {
123 printf("Connection closed.\n");
124 } else if (events & BEV_EVENT_ERROR) {
125 printf("Got an error on the connection: %s\n",
126 strerror(errno));/*XXX win32*/
127 }
128 /* None of the other events can happen here, since we haven't enabled
129 * timeouts */
130 bufferevent_free(bev);
131 }
132
133 static void
signal_cb(evutil_socket_t sig,short events,void * user_data)134 signal_cb(evutil_socket_t sig, short events, void *user_data)
135 {
136 struct event_base *base = user_data;
137 struct timeval delay = { 2, 0 };
138
139 printf("Caught an interrupt signal; exiting cleanly in two seconds.\n");
140
141 event_base_loopexit(base, &delay);
142 }
143