#include <string.h>
#include <errno.h>
#include <signal.h>
+#include <assert.h>
enum state {
+ SENDING_GREETING,
RECEIVING_USER_QUESTION,
+ SENDING_OTHER_QUESTION_PREFIX,
+ SENDING_OTHER_QUESTION,
+ RECEIVING_OTHER_ANSWER,
+ SENDING_ANSWER_PREFIX,
SENDING_ANSWER,
FINISHED
};
static uint16_t state_flag_map[] = {
+ [SENDING_GREETING] = TEVENT_FD_WRITE,
[RECEIVING_USER_QUESTION] = TEVENT_FD_READ,
+ [SENDING_OTHER_QUESTION_PREFIX] = TEVENT_FD_WRITE,
+ [SENDING_OTHER_QUESTION] = TEVENT_FD_WRITE,
+ [RECEIVING_OTHER_ANSWER] = TEVENT_FD_READ,
+ [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 wakeup(struct client *c)
+{
+ tevent_fd_set_flags(c->fde, state_flag_map[c->state]);
+}
+
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);
+ if (input_finished(c->question))
+ set_state(c, SENDING_OTHER_QUESTION_PREFIX);
+ break;
+ case SENDING_OTHER_QUESTION_PREFIX:
+ if (!c->subclient)
+ goto need_subclient;
+ if (!send_string(c, "While the Oracle ponders,"
+ " please answer the following question:\n"))
+ goto fail;
+ break;
+ case SENDING_OTHER_QUESTION:
+ if (!c->subclient)
+ goto need_subclient;
+ if (!send_string(c, c->subclient->question))
+ goto fail;
+ break;
+ case RECEIVING_OTHER_ANSWER:
+ if (!c->subclient)
+ goto need_subclient;
+ len = read_string(c->fd, &c->subclient->answer);
+ if (len <= 0)
+ goto fail;
+ if (input_finished(c->subclient->answer)) {
+ set_state(c, SENDING_ANSWER_PREFIX);
+ wakeup(c->subclient);
}
break;
+ case SENDING_ANSWER_PREFIX:
+ if (!input_finished(c->answer))
+ goto need_answer;
+ 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 (c->state != FINISHED)
return;
-
fail:
talloc_free(c);
+ return;
+
+need_subclient:
+ if (!get_subclient(c)) {
+ /* We can't get one: go to sleep until someone find_oracle() */
+ tevent_fd_set_flags(c->fde, 0);
+ } else
+ /* In case they are waiting... */
+ wakeup(c->subclient);
+ return;
+
+need_answer:
+ /* If we don't have an oracle and find one, that's OK. */
+ if (!c->oracle && get_oracle(c)) {
+ /* In case they are waiting... */
+ wakeup(c->oracle);
+ return;
+ }
+
+ /* Either our oracle is not finished, or we don't have one: sleep. */
+ tevent_fd_set_flags(c->fde, 0);
}
static int cleanup_client(struct client *client)
{
unsigned int i;
+ /* We were an oracle? */
+ if (client->subclient)
+ client->subclient->oracle = NULL;
+
+ /* We had an oracle? */
+ if (client->oracle)
+ client->oracle->subclient = NULL;
+
for (i = 0; i < ARRAY_SIZE(client->oserver->clients); i++) {
if (client->oserver->clients[i] == client) {
client->oserver->clients[i] = NULL;
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);
return 0;
}
+static void talloc_dump(struct tevent_context *ev,
+ struct tevent_signal *se,
+ int signum,
+ int count,
+ void *siginfo,
+ void *_oserver)
+{
+ struct oserver *oserver = _oserver;
+ FILE *f = fopen("/var/run/oserver/talloc.dump", "w");
+ if (f) {
+ talloc_report_full(oserver, f);
+ fclose(f);
+ }
+}
+
struct oserver *oserver_setup(struct tevent_context *ev, unsigned short port)
{
struct oserver *oserver;
} 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,
/* Don't kill us if client dies. */
signal(SIGPIPE, SIG_IGN);
+ /* Show talloc tree on SIGUSR1. */
+ tevent_add_signal(ev, oserver, SIGUSR1, SA_RESTART,
+ talloc_dump, oserver);
+
return oserver;
}
projects / ccan-lca-2011.git / blobdiff