1 #include <ccan/oserver/oserver.h>
2 #include <ccan/read_write_all/read_write_all.h>
3 #include <ccan/opt/opt.h>
4 #include <ccan/tevent/tevent.h>
5 #include <ccan/array_size/array_size.h>
7 #include <sys/socket.h>
8 #include <netinet/in.h>
9 #include <netinet/tcp.h>
21 RECEIVING_USER_QUESTION,
22 SENDING_ANSWER_PREFIX,
27 static uint16_t state_flag_map[] = {
28 [SENDING_GREETING] = TEVENT_FD_WRITE,
29 [RECEIVING_USER_QUESTION] = TEVENT_FD_READ,
30 [SENDING_ANSWER_PREFIX] = TEVENT_FD_WRITE,
31 [SENDING_ANSWER] = TEVENT_FD_WRITE,
36 /* What are we doing today, brain? */
38 /* Our event info, and the file descriptor. */
39 struct tevent_fd *fde;
41 /* The question we read from client. */
43 /* The answer to the client. */
45 /* How many bytes of the reply we sent so far. */
48 struct oserver *oserver;
52 /* 5 clients should be enough for anybody! */
53 struct client *clients[5];
55 struct tevent_fd *fde;
56 const char *last_answer;
59 static ssize_t write_string(int fd, const char *str)
61 return write(fd, str, strlen(str));
64 static ssize_t read_string(int fd, char **buf)
66 ssize_t ret, len, maxlen;
69 maxlen = talloc_array_length(*buf);
71 if (maxlen < len + 100) {
73 *buf = talloc_realloc(NULL, *buf, char, maxlen);
76 ret = read(fd, *buf + len, maxlen - len - 1);
78 (*buf)[len + ret] = '\0';
82 static bool input_finished(const char *str)
84 return strchr(str, '\n');
87 /* Update state, and set our READ/WRITE flags appropriately. */
88 static void set_state(struct client *c, enum state state)
91 tevent_fd_set_flags(c->fde, state_flag_map[state]);
94 /* Returns false on error, increments state on finishing string. */
95 static bool send_string(struct client *c, const char *str)
97 ssize_t len = write_string(c->fd, str + c->bytes_sent);
100 c->bytes_sent += len;
101 if (c->bytes_sent == strlen(str)) {
103 set_state(c, c->state+1);
108 static void service_client(struct tevent_context *ev,
109 struct tevent_fd *fde, uint16_t flags, void *_c)
111 struct client *c = _c;
115 case SENDING_GREETING:
116 if (!send_string(c, "Welcome. Please ask your question.\n"))
119 case RECEIVING_USER_QUESTION:
120 len = read_string(c->fd, &c->question);
123 if (input_finished(c->question)) {
124 c->answer = talloc_steal(c, c->oserver->last_answer);
125 c->oserver->last_answer
126 = talloc_steal(c->oserver, c->question);
127 set_state(c, SENDING_ANSWER_PREFIX);
130 case SENDING_ANSWER_PREFIX:
131 if (!send_string(c, "I believe a better question is "))
135 if (!send_string(c, c->answer))
142 if (c->state != FINISHED)
149 static int cleanup_client(struct client *client)
153 for (i = 0; i < ARRAY_SIZE(client->oserver->clients); i++) {
154 if (client->oserver->clients[i] == client) {
155 client->oserver->clients[i] = NULL;
156 tevent_fd_set_flags(client->oserver->fde,
164 static void add_client(struct tevent_context *ev,
165 struct tevent_fd *fde, uint16_t flags, void *_oserver)
167 struct oserver *oserver = _oserver;
168 struct client *client;
171 client = talloc(oserver, struct client);
172 client->fd = accept(oserver->fd, NULL, 0);
174 err(1, "Accepting client connection");
176 client->state = SENDING_GREETING;
177 client->bytes_sent = 0;
178 client->question = talloc_strdup(client, "");
179 client->oserver = oserver;
180 client->fde = tevent_add_fd(ev, client, client->fd,
181 state_flag_map[client->state],
182 service_client, client);
183 tevent_fd_set_auto_close(client->fde);
185 /* Find empty slot in array for this client. */
186 for (i = 0; oserver->clients[i]; i++);
187 oserver->clients[i] = client;
188 talloc_set_destructor(client, cleanup_client);
190 /* Full? Stop listening... */
191 if (i == ARRAY_SIZE(oserver->clients)-1)
192 tevent_fd_set_flags(oserver->fde, 0);
195 static void clear_clients(struct oserver *oserver)
197 memset(oserver->clients, 0,
198 ARRAY_SIZE(oserver->clients) * sizeof(oserver->clients[0]));
201 static int destroy_oserver(struct oserver *oserver)
207 struct oserver *oserver_setup(struct tevent_context *ev, unsigned short port)
209 struct oserver *oserver;
212 struct sockaddr addr;
213 struct sockaddr_in in;
216 oserver = talloc(ev, struct oserver);
217 clear_clients(oserver);
218 oserver->fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
219 if (oserver->fd < 0) {
220 talloc_free(oserver);
223 oserver->last_answer = talloc_strdup(oserver,
224 "how many manly men mendaciously"
225 " mention mending mansions?\n");
227 talloc_set_destructor(oserver, destroy_oserver);
229 if (setsockopt(oserver->fd, SOL_SOCKET, SO_REUSEADDR,
231 warn("Setting socket reuse");
233 u.in.sin_family = AF_INET;
234 u.in.sin_port = htons(port);
235 u.in.sin_addr.s_addr = INADDR_ANY;
236 if (bind(oserver->fd, &u.addr, sizeof(u.in)) == -1) {
237 talloc_free(oserver);
241 if (listen(oserver->fd, 0) != 0) {
242 talloc_free(oserver);
246 oserver->fde = tevent_add_fd(ev, oserver, oserver->fd,
247 TEVENT_FD_READ, add_client, oserver);
249 talloc_free(oserver);
253 /* Don't kill us if client dies. */
254 signal(SIGPIPE, SIG_IGN);