1 #include <ccan/oserver/oserver.h>
2 #include <ccan/oserver/oserver_types.h>
3 #include <ccan/read_write_all/read_write_all.h>
4 #include <ccan/opt/opt.h>
5 #include <ccan/tevent/tevent.h>
6 #include <ccan/array_size/array_size.h>
8 #include <sys/socket.h>
9 #include <netinet/in.h>
10 #include <netinet/tcp.h>
21 static uint16_t state_flag_map[] = {
22 [SENDING_GREETING] = TEVENT_FD_WRITE,
23 [RECEIVING_USER_QUESTION] = TEVENT_FD_READ,
24 [SENDING_OTHER_QUESTION_PREFIX] = TEVENT_FD_WRITE,
25 [SENDING_OTHER_QUESTION] = TEVENT_FD_WRITE,
26 [RECEIVING_OTHER_ANSWER] = TEVENT_FD_READ,
27 [SENDING_ANSWER_PREFIX] = TEVENT_FD_WRITE,
28 [SENDING_ANSWER] = TEVENT_FD_WRITE,
32 static ssize_t write_string(int fd, const char *str)
34 return write(fd, str, strlen(str));
37 static ssize_t read_string(int fd, char **buf)
39 ssize_t ret, len, maxlen;
42 maxlen = talloc_array_length(*buf);
44 if (maxlen < len + 100) {
46 *buf = talloc_realloc(NULL, *buf, char, maxlen);
49 ret = read(fd, *buf + len, maxlen - len - 1);
51 (*buf)[len + ret] = '\0';
55 static bool input_finished(const char *str)
57 return strchr(str, '\n');
60 /* Update state, and set our READ/WRITE flags appropriately. */
61 static void set_state(struct client *c, enum state state)
64 tevent_fd_set_flags(c->fde, state_flag_map[state]);
67 /* Returns false on error, increments state on finishing string. */
68 static bool send_string(struct client *c, const char *str)
70 ssize_t len = write_string(c->fd, str + c->bytes_sent);
74 if (c->bytes_sent == strlen(str)) {
76 set_state(c, c->state+1);
81 static bool get_subclient(struct client *me)
85 for (i = 0; i < ARRAY_SIZE(me->oserver->clients); i++) {
86 struct client *c = me->oserver->clients[i];
89 if (c->oracle == -1 && input_finished(c->question)) {
90 me->subclient = c->id;
98 static bool get_oracle(struct client *me)
102 for (i = 0; i < ARRAY_SIZE(me->oserver->clients); i++) {
103 struct client *c = me->oserver->clients[i];
106 if (c->subclient == -1 && input_finished(c->question)) {
108 c->subclient = me->id;
115 static void wakeup(struct client *c)
117 tevent_fd_set_flags(c->fde, state_flag_map[c->state]);
120 static void service_client(struct tevent_context *ev,
121 struct tevent_fd *fde, uint16_t flags, void *_c)
123 struct client *c = _c;
127 case SENDING_GREETING:
128 if (!send_string(c, "Welcome. Please ask your question.\n"))
131 case RECEIVING_USER_QUESTION:
132 len = read_string(c->fd, &c->question);
135 if (input_finished(c->question))
136 set_state(c, SENDING_OTHER_QUESTION_PREFIX);
138 case SENDING_OTHER_QUESTION_PREFIX:
139 if (c->subclient == -1)
141 if (!send_string(c, "While the Oracle ponders,"
142 " please answer the following question:\n"))
145 case SENDING_OTHER_QUESTION:
146 if (c->subclient == -1)
149 c->oserver->clients[c->subclient]->question))
152 case RECEIVING_OTHER_ANSWER:
153 if (c->subclient == -1)
155 len = read_string(c->fd,
156 &c->oserver->clients[c->subclient]->answer);
159 if (input_finished(c->oserver->clients[c->subclient]->answer)) {
160 set_state(c, SENDING_ANSWER_PREFIX);
161 wakeup(c->oserver->clients[c->subclient]);
164 case SENDING_ANSWER_PREFIX:
165 if (!input_finished(c->answer))
167 if (!send_string(c, "The Oracle spake thus:\n"))
171 if (!send_string(c, c->answer))
178 if (c->state != FINISHED)
185 if (!get_subclient(c)) {
186 /* We can't get one: go to sleep until someone find_oracle() */
187 tevent_fd_set_flags(c->fde, 0);
189 /* In case they are waiting... */
190 wakeup(c->oserver->clients[c->subclient]);
194 /* If we don't have an oracle and find one, that's OK. */
195 if (c->oracle == -1 && get_oracle(c)) {
196 /* In case they are waiting... */
197 wakeup(c->oserver->clients[c->oracle]);
201 /* Either our oracle is not finished, or we don't have one: sleep. */
202 tevent_fd_set_flags(c->fde, 0);
205 static int cleanup_client(struct client *client)
208 /* We were an oracle? */
209 if (client->subclient >= 0)
210 client->oserver->clients[client->subclient]->oracle = -1;
212 /* We had an oracle? */
213 if (client->oracle >= 0)
214 client->oserver->clients[client->oracle]->subclient = -1;
216 assert(client->oserver->clients[client->id] == client);
217 client->oserver->clients[client->id] = NULL;
221 static void add_client(struct tevent_context *ev,
222 struct tevent_fd *fde, uint16_t flags, void *_oserver)
224 struct oserver *oserver = _oserver;
225 struct client *client;
227 client = talloc(oserver, struct client);
228 client->fd = accept(oserver->fd, NULL, 0);
230 err(1, "Accepting client connection");
232 client->state = SENDING_GREETING;
233 client->bytes_sent = 0;
234 client->question = talloc_strdup(client, "");
235 client->oserver = oserver;
237 client->subclient = -1;
238 client->answer = talloc_strdup(client, "");
239 client->fde = tevent_add_fd(ev, client, client->fd,
240 state_flag_map[client->state],
241 service_client, client);
242 tevent_fd_set_auto_close(client->fde);
244 /* Find empty slot in array for this client. */
245 for (client->id = 0; oserver->clients[client->id]; client->id++);
246 oserver->clients[client->id] = client;
247 talloc_set_destructor(client, cleanup_client);
249 /* Full? Stop listening... */
250 if (client->id == ARRAY_SIZE(oserver->clients)-1)
251 tevent_fd_set_flags(oserver->fde, 0);
254 static void clear_clients(struct oserver *oserver)
256 memset(oserver->clients, 0,
257 ARRAY_SIZE(oserver->clients) * sizeof(oserver->clients[0]));
260 static int destroy_oserver(struct oserver *oserver)
266 static void talloc_dump(struct tevent_context *ev,
267 struct tevent_signal *se,
273 struct oserver *oserver = _oserver;
276 /* Fork off a child for the report, so we aren't stopped. */
278 f = fopen("/var/run/oserver/talloc.dump", "w");
280 talloc_report_full(oserver, f);
287 struct oserver *oserver_setup(struct tevent_context *ev, unsigned short port)
289 struct oserver *oserver;
292 struct sockaddr addr;
293 struct sockaddr_in in;
296 oserver = talloc(ev, struct oserver);
297 clear_clients(oserver);
298 oserver->fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
299 if (oserver->fd < 0) {
300 talloc_free(oserver);
304 talloc_set_destructor(oserver, destroy_oserver);
306 if (setsockopt(oserver->fd, SOL_SOCKET, SO_REUSEADDR,
308 warn("Setting socket reuse");
310 u.in.sin_family = AF_INET;
311 u.in.sin_port = htons(port);
312 u.in.sin_addr.s_addr = INADDR_ANY;
313 if (bind(oserver->fd, &u.addr, sizeof(u.in)) == -1) {
314 talloc_free(oserver);
318 if (listen(oserver->fd, 0) != 0) {
319 talloc_free(oserver);
323 oserver->fde = tevent_add_fd(ev, oserver, oserver->fd,
324 TEVENT_FD_READ, add_client, oserver);
326 talloc_free(oserver);
330 /* Don't kill us if client dies. */
331 signal(SIGPIPE, SIG_IGN);
333 /* Show talloc tree on SIGUSR1. */
334 tevent_add_signal(ev, oserver, SIGUSR1, SA_RESTART,
335 talloc_dump, oserver);