X-Git-Url: https://git.ozlabs.org/?a=blobdiff_plain;f=ccan%2Foserver%2Foserver.c;h=50b49bd5f94746c8259fb3c609c285c5d68684c9;hb=ce689e269acaabd77dcb82166340441a4a00f9a1;hp=5a40ff98cce90c8c96908da83ff497d1bed921d1;hpb=75020f977fecd26610845171aaba4f9accc75c6e;p=ccan-lca-2011.git

diff --git a/ccan/oserver/oserver.c b/ccan/oserver/oserver.c
index 5a40ff9..50b49bd 100644
--- a/ccan/oserver/oserver.c
+++ b/ccan/oserver/oserver.c
@@ -1,5 +1,11 @@
 #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>
@@ -10,52 +16,408 @@
 #include <ctype.h>
 #include <stdlib.h>
 #include <string.h>
+#include <errno.h>
+#include <signal.h>
+#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
+};
 
-void oserver_serve(int fd)
+static ssize_t write_string(int fd, const char *str)
+{
+	return write(fd, str, strlen(str));
+}
+
+static ssize_t read_string(int fd, char **buf)
+{
+	ssize_t ret, len, maxlen;
+
+	len = strlen(*buf);
+	maxlen = talloc_array_length(*buf);
+
+	if (maxlen < len + 100) {
+		maxlen += 100;
+		*buf = talloc_realloc(NULL, *buf, char, maxlen);
+	}
+
+	ret = read(fd, *buf + len, maxlen - len - 1);
+	if (ret >= 0)
+		(*buf)[len + ret] = '\0';
+	return ret;
+}
+
+static bool input_finished(const char *str)
+{
+	return strchr(str, '\n');
+}
+
+/* Update state, and set our READ/WRITE flags appropriately. */
+static void set_state(struct client *c, enum state state)
+{
+	c->state = state;
+	tevent_fd_set_flags(c->fde, state_flag_map[state]);
+}
+
+/* Returns false on error, increments state on finishing string. */
+static bool send_string(struct client *c, const char *str)
+{
+	ssize_t len = write_string(c->fd, str + c->bytes_sent);
+	if (len < 0)
+		return false;
+	c->bytes_sent += len;
+	if (c->bytes_sent == strlen(str)) {
+		c->bytes_sent = 0;
+		set_state(c, c->state+1);
+	}
+	return true;
+}
+
+static bool get_subclient(struct client *me)
 {
-	char buf[1024];
 	unsigned int i;
 
-	for (i = 0; i < sizeof(buf)-1; i++) {
-		if (read(fd, &buf[i], 1) != 1)
-			errx(1, "Client disconnected");
-		if (buf[i] == '\n' || buf[i] == '\r')
-			break;
-		buf[i] = toupper(buf[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;
+		}
 	}
-	buf[i] = '\0';
+	return false;
+}
 
-	if (!write_all(fd, "Louder, like this: '",
-		       strlen("Louder, like this: '"))
-	    || !write_all(fd, buf, i)
-	    || !write_all(fd, "'\r\n", strlen("'\r\n")))
-		err(1, "Write failed");
-	exit(0);
+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)
+{
+	struct client *c = _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))
+			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 (!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->answer))
+			goto fail;
+		break;
+	default:
+		goto fail;
+	}
+
+	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)
+{
+
+	/* 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;
 }
 
-int oserver_setup(void)
+static void add_client(struct tevent_context *ev,
+		       struct tevent_fd *fde, uint16_t flags, void *_oserver)
 {
-	int sockfd;
+	struct oserver *oserver = _oserver;
+	struct client *client;
+
+	client = talloc(oserver, struct client);
+	client->fd = accept(oserver->fd, NULL, 0);
+	if (client->fd < 0)
+		err(1, "Accepting client connection");
+
+	client->state = SENDING_GREETING;
+	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 (client->id = 0; oserver->clients[client->id]; client->id++);
+	oserver->clients[client->id] = client;
+	talloc_set_destructor(client, cleanup_client);
+
+	/* Full?  Stop listening... */
+	if (client->id == ARRAY_SIZE(oserver->clients)-1)
+		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;
+
+	/* 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;
 	union {
 		struct sockaddr addr;
 		struct sockaddr_in in;
 	} u;
 
-	sockfd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
-	if (sockfd < 0)
-		err(1, "Creating TCP socket");
+	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(sockfd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)))
+	if (setsockopt(oserver->fd, SOL_SOCKET, SO_REUSEADDR,
+		       &one, sizeof(one)))
 		warn("Setting socket reuse");
 
 	u.in.sin_family = AF_INET;
-	u.in.sin_port = htons(OSERVER_PORT);
+	u.in.sin_port = htons(port);
 	u.in.sin_addr.s_addr = INADDR_ANY;
-	if (bind(sockfd, &u.addr, sizeof(u.in)) == -1)
-		err(1, "Binding TCP socket");
+	if (bind(oserver->fd, &u.addr, sizeof(u.in)) == -1) {
+		talloc_free(oserver);
+		return NULL;
+	}
+
+	if (listen(oserver->fd, 0) != 0) {
+		talloc_free(oserver);
+		return NULL;
+	}
+
+	if (!complete_server(ev, oserver, dumpfile)) {
+		talloc_free(oserver);
+		return NULL;
+	}
 
-	if (listen(sockfd, 0) != 0)
-		err(1, "Listening on TCP socket");
-	return sockfd;
+	return oserver;
 }