#include <string.h>
#include <errno.h>
#include <signal.h>
+#include <assert.h>
enum state {
+ SENDING_GREETING,
RECEIVING_USER_QUESTION,
+ AWAITING_A_SUBCLIENT,
+ SENDING_OTHER_QUESTION_PREFIX,
+ SENDING_OTHER_QUESTION,
+ RECEIVING_OTHER_ANSWER,
+ AWAITING_OUR_ORACLE,
+ SENDING_ANSWER_PREFIX,
SENDING_ANSWER,
FINISHED
};
static uint16_t state_flag_map[] = {
+ [SENDING_GREETING] = TEVENT_FD_WRITE,
[RECEIVING_USER_QUESTION] = TEVENT_FD_READ,
+ [AWAITING_A_SUBCLIENT] = 0,
+ [SENDING_OTHER_QUESTION_PREFIX] = TEVENT_FD_WRITE,
+ [SENDING_OTHER_QUESTION] = TEVENT_FD_WRITE,
+ [RECEIVING_OTHER_ANSWER] = TEVENT_FD_READ,
+ [AWAITING_OUR_ORACLE] = 0,
+ [SENDING_ANSWER_PREFIX] = TEVENT_FD_WRITE,
[SENDING_ANSWER] = TEVENT_FD_WRITE,
[FINISHED] = 0
};
int fd;
/* The question we read from client. */
char *question;
+ /* The answer to the client. */
+ char *answer;
/* How many bytes of the reply we sent so far. */
size_t bytes_sent;
/* Our server. */
struct oserver *oserver;
+ /* Whose question this client is answering. */
+ struct client *subclient;
+ /* Who is answering our question. */
+ struct client *oracle;
};
struct oserver {
return true;
}
+static bool get_subclient(struct client *me)
+{
+ unsigned int i;
+
+ for (i = 0; i < ARRAY_SIZE(me->oserver->clients); i++) {
+ struct client *c = me->oserver->clients[i];
+ if (!c || c == me)
+ continue;
+ if (c->oracle == NULL && input_finished(c->question)) {
+ me->subclient = c;
+ c->oracle = me;
+ return true;
+ }
+ }
+ return false;
+}
+
+static bool get_oracle(struct client *me)
+{
+ unsigned int i;
+
+ for (i = 0; i < ARRAY_SIZE(me->oserver->clients); i++) {
+ struct client *c = me->oserver->clients[i];
+ if (!c || c == me)
+ continue;
+ if (c->subclient == NULL && input_finished(c->question)) {
+ me->oracle = c;
+ c->subclient = me;
+ return true;
+ }
+ }
+ return false;
+}
+
static void service_client(struct tevent_context *ev,
struct tevent_fd *fde, uint16_t flags, void *_c)
{
ssize_t len;
switch (c->state) {
+ case SENDING_GREETING:
+ if (!send_string(c, "Welcome. Please ask your question.\n"))
+ goto fail;
+ break;
case RECEIVING_USER_QUESTION:
len = read_string(c->fd, &c->question);
if (len <= 0)
goto fail;
if (input_finished(c->question)) {
- unsigned int i;
-
- for (i = 0; c->question[i]; i++)
- c->question[i] = toupper(c->question[i]);
- set_state(c, SENDING_ANSWER);
+ /* Look for someone to be oracle to. */
+ if (get_subclient(c)) {
+ set_state(c, SENDING_OTHER_QUESTION_PREFIX);
+ } else {
+ /* We sit here until someone find_oracles us */
+ set_state(c, AWAITING_A_SUBCLIENT);
+ }
+
+ /* Look for an oracle for ourselves. */
+ if (get_oracle(c)) {
+ assert(c->oracle->state
+ == AWAITING_A_SUBCLIENT);
+ set_state(c->oracle,
+ SENDING_OTHER_QUESTION_PREFIX);
+ }
+ }
+ break;
+ case SENDING_OTHER_QUESTION_PREFIX:
+ if (!send_string(c, "While the Oracle ponders,"
+ " please answer the following question:\n"))
+ goto fail;
+ break;
+ case SENDING_OTHER_QUESTION:
+ if (!send_string(c, c->subclient->question))
+ goto fail;
+ break;
+ case RECEIVING_OTHER_ANSWER:
+ len = read_string(c->fd, &c->subclient->answer);
+ if (len <= 0)
+ goto fail;
+ if (input_finished(c->subclient->answer)) {
+ /* Did our oracle answer for us already? */
+ if (input_finished(c->answer))
+ set_state(c, SENDING_ANSWER_PREFIX);
+ else
+ set_state(c, AWAITING_OUR_ORACLE);
+
+ /* If they were waiting for an answer, move them. */
+ if (c->subclient->state == AWAITING_OUR_ORACLE)
+ set_state(c->subclient, SENDING_ANSWER_PREFIX);
}
break;
+ case SENDING_ANSWER_PREFIX:
+ if (!send_string(c, "The Oracle spake thus:\n"))
+ goto fail;
+ break;
case SENDING_ANSWER:
- if (!send_string(c, c->question))
+ if (!send_string(c, c->answer))
goto fail;
break;
default:
if (client->fd < 0)
err(1, "Accepting client connection");
- client->state = RECEIVING_USER_QUESTION;
+ client->state = SENDING_GREETING;
client->bytes_sent = 0;
client->question = talloc_strdup(client, "");
client->oserver = oserver;
+ client->oracle = NULL;
+ client->subclient = NULL;
+ client->answer = talloc_strdup(client, "");
client->fde = tevent_add_fd(ev, client, client->fd,
state_flag_map[client->state],
service_client, client);
tevent_fd_set_flags(oserver->fde, 0);
}
+static void clear_clients(struct oserver *oserver)
+{
+ memset(oserver->clients, 0,
+ ARRAY_SIZE(oserver->clients) * sizeof(oserver->clients[0]));
+}
+
static int destroy_oserver(struct oserver *oserver)
{
close(oserver->fd);
} u;
oserver = talloc(ev, struct oserver);
-
+ clear_clients(oserver);
oserver->fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
if (oserver->fd < 0) {
talloc_free(oserver);
return NULL;
}
+
talloc_set_destructor(oserver, destroy_oserver);
if (setsockopt(oserver->fd, SOL_SOCKET, SO_REUSEADDR,