#include <ccan/oserver/oserver.h>
+#include <ccan/oserver/oserver_types.h>
+#include <ccan/oserver/oserver_cdump.h>
#include <ccan/read_write_all/read_write_all.h>
#include <ccan/opt/opt.h>
#include <ccan/tevent/tevent.h>
#include <ccan/array_size/array_size.h>
+#include <ccan/grab_file/grab_file.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <string.h>
#include <errno.h>
#include <signal.h>
-
-enum state {
- SENDING_GREETING,
- RECEIVING_USER_QUESTION,
- SENDING_ANSWER_PREFIX,
- SENDING_ANSWER,
- FINISHED
-};
+#include <assert.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
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
};
-struct client {
- /* What are we doing today, brain? */
- enum state state;
- /* Our event info, and the file descriptor. */
- struct tevent_fd *fde;
- int fd;
- /* The question we read from client. */
- char *question;
- /* The answer to the client. */
- const char *answer;
- /* How many bytes of the reply we sent so far. */
- size_t bytes_sent;
- /* Our server. */
- struct oserver *oserver;
-};
-
-struct oserver {
- /* 5 clients should be enough for anybody! */
- struct client *clients[5];
- int fd;
- struct tevent_fd *fde;
- const char *last_answer;
-};
-
static ssize_t write_string(int fd, const char *str)
{
return write(fd, str, strlen(str));
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 == -1 && input_finished(c->question)) {
+ me->subclient = c->id;
+ c->oracle = me->id;
+ 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 == -1 && input_finished(c->question)) {
+ me->oracle = c->id;
+ c->subclient = me->id;
+ 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)
{
len = read_string(c->fd, &c->question);
if (len <= 0)
goto fail;
- if (input_finished(c->question)) {
- c->answer = talloc_steal(c, c->oserver->last_answer);
- c->oserver->last_answer
- = talloc_steal(c->oserver, c->question);
+ if (input_finished(c->question))
+ set_state(c, SENDING_OTHER_QUESTION_PREFIX);
+ break;
+ case SENDING_OTHER_QUESTION_PREFIX:
+ if (c->subclient == -1)
+ 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 == -1)
+ goto need_subclient;
+ if (!send_string(c,
+ c->oserver->clients[c->subclient]->question))
+ goto fail;
+ break;
+ case RECEIVING_OTHER_ANSWER:
+ if (c->subclient == -1)
+ goto need_subclient;
+ len = read_string(c->fd,
+ &c->oserver->clients[c->subclient]->answer);
+ if (len <= 0)
+ goto fail;
+ if (input_finished(c->oserver->clients[c->subclient]->answer)) {
set_state(c, SENDING_ANSWER_PREFIX);
+ wakeup(c->oserver->clients[c->subclient]);
}
break;
case SENDING_ANSWER_PREFIX:
- if (!send_string(c, "I believe a better question is "))
+ if (!input_finished(c->answer))
+ goto need_answer;
+ if (!send_string(c, "The Oracle spake thus:\n"))
goto fail;
break;
case SENDING_ANSWER:
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->oserver->clients[c->subclient]);
+ return;
+
+need_answer:
+ /* If we don't have an oracle and find one, that's OK. */
+ if (c->oracle == -1 && get_oracle(c)) {
+ /* In case they are waiting... */
+ wakeup(c->oserver->clients[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;
- for (i = 0; i < ARRAY_SIZE(client->oserver->clients); i++) {
- if (client->oserver->clients[i] == client) {
- client->oserver->clients[i] = NULL;
- tevent_fd_set_flags(client->oserver->fde,
- TEVENT_FD_READ);
- return 0;
- }
- }
- abort();
+ /* We were an oracle? */
+ if (client->subclient >= 0)
+ client->oserver->clients[client->subclient]->oracle = -1;
+
+ /* We had an oracle? */
+ if (client->oracle >= 0)
+ client->oserver->clients[client->oracle]->subclient = -1;
+
+ assert(client->oserver->clients[client->id] == client);
+ client->oserver->clients[client->id] = NULL;
+ return 0;
}
static void add_client(struct tevent_context *ev,
{
struct oserver *oserver = _oserver;
struct client *client;
- unsigned int i;
client = talloc(oserver, struct client);
client->fd = accept(oserver->fd, NULL, 0);
client->bytes_sent = 0;
client->question = talloc_strdup(client, "");
client->oserver = oserver;
+ client->oracle = -1;
+ client->subclient = -1;
+ 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_auto_close(client->fde);
/* Find empty slot in array for this client. */
- for (i = 0; oserver->clients[i]; i++);
- oserver->clients[i] = client;
+ for (client->id = 0; oserver->clients[client->id]; client->id++);
+ oserver->clients[client->id] = client;
talloc_set_destructor(client, cleanup_client);
/* Full? Stop listening... */
- if (i == ARRAY_SIZE(oserver->clients)-1)
+ if (client->id == ARRAY_SIZE(oserver->clients)-1)
tevent_fd_set_flags(oserver->fde, 0);
}
return 0;
}
-struct oserver *oserver_setup(struct tevent_context *ev, unsigned short port)
+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;
+
+ /* Fork off a child for the report, so we aren't stopped. */
+ if (fork() == 0) {
+ f = fopen("/var/run/oserver/talloc.dump", "w");
+ if (f) {
+ talloc_report_full(oserver, f);
+ fclose(f);
+ }
+ _exit(0);
+ }
+}
+
+static void dump(struct tevent_context *ev,
+ struct tevent_signal *se,
+ int signum,
+ int count,
+ void *siginfo,
+ void *_oserver)
+{
+ struct oserver *oserver = _oserver;
+ char *str;
+ int fd;
+
+ str = cdump_bundle(ev, cdump_struct_oserver, oserver);
+ fd = open(oserver->dumpfile, O_CREAT|O_TRUNC|O_WRONLY, 0600);
+ write(fd, str, strlen(str));
+ close(fd);
+ talloc_free(str);
+}
+
+static bool load_file(struct oserver *oserver, const char *file)
+{
+ char *str;
+
+ if (!file)
+ return false;
+
+ str = grab_file(oserver, file, NULL);
+ if (!str)
+ return false;
+
+ if (!cdump_unbundle(oserver, cdump_struct_oserver, oserver, str)) {
+ talloc_free(str);
+ return false;
+ }
+ talloc_free(str);
+ return true;
+}
+
+static bool complete_server(struct tevent_context *ev,
+ struct oserver *oserver, const char *dumpfile)
+{
+ /* Re-set this even if restored from file, in case it changed. */
+ oserver->dumpfile = dumpfile;
+ if (oserver->dumpfile)
+ tevent_add_signal(ev, oserver, SIGHUP, SA_RESTART,
+ dump, oserver);
+
+ /* 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);
+
+ oserver->fde = tevent_add_fd(ev, oserver, oserver->fd,
+ TEVENT_FD_READ, add_client, oserver);
+ if (!oserver->fde)
+ return false;
+ return true;
+}
+
+struct oserver *oserver_restore(struct tevent_context *ev, const char *dumpfile)
+{
+ unsigned int i;
+ struct oserver *oserver = talloc(ev, struct oserver);
+ if (!load_file(oserver, dumpfile)) {
+ talloc_free(oserver);
+ return NULL;
+ }
+
+ /* Restore ignored fields in clients (fde and oserver). */
+ for (i = 0; i < ARRAY_SIZE(oserver->clients); i++) {
+ struct client *client = oserver->clients[i];
+ if (!client)
+ continue;
+ client->oserver = oserver;
+ client->fde = tevent_add_fd(ev, client, client->fd,
+ state_flag_map[client->state],
+ service_client, client);
+ tevent_fd_set_auto_close(client->fde);
+ }
+
+ if (!complete_server(ev, oserver, dumpfile)) {
+ talloc_free(oserver);
+ return NULL;
+ }
+ return oserver;
+}
+
+struct oserver *oserver_setup(struct tevent_context *ev, unsigned short port,
+ const char *dumpfile)
{
struct oserver *oserver;
int one = 1;
talloc_free(oserver);
return NULL;
}
- oserver->last_answer = talloc_strdup(oserver,
- "how many manly men mendaciously"
- " mention mending mansions?\n");
talloc_set_destructor(oserver, destroy_oserver);
return NULL;
}
- oserver->fde = tevent_add_fd(ev, oserver, oserver->fd,
- TEVENT_FD_READ, add_client, oserver);
- if (!oserver->fde) {
+ if (!complete_server(ev, oserver, dumpfile)) {
talloc_free(oserver);
return NULL;
}
- /* Don't kill us if client dies. */
- signal(SIGPIPE, SIG_IGN);
-
return oserver;
}
projects / ccan-lca-2011.git / blobdiff