X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;f=src%2Ffrontend%2Fsock.c;h=d7b2ee97324ddef9d32246f9be163ec30152f998;hb=23760ca65713cd9b8338f09bf45ec20ff4c3ef8d;hp=3662a2650cc41d313ea5c6e8613c59810825fd50;hpb=748bf089e36d56076583a8466052505fc786dba9;p=sysdb.git

diff --git a/src/frontend/sock.c b/src/frontend/sock.c
index 3662a26..d7b2ee9 100644
--- a/src/frontend/sock.c
+++ b/src/frontend/sock.c
@@ -32,17 +32,21 @@
 
 #include "utils/channel.h"
 #include "utils/llist.h"
+#include "utils/strbuf.h"
 
 #include <assert.h>
-
 #include <errno.h>
 
+#include <arpa/inet.h>
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
 #include <unistd.h>
 
+#include <fcntl.h>
+
 #include <sys/time.h>
 #include <sys/types.h>
 #include <sys/select.h>
@@ -60,14 +64,19 @@
  */
 
 typedef struct {
+	sdb_object_t super;
+
+	/* connection and client information */
 	int fd;
 	struct sockaddr_storage client_addr;
 	socklen_t client_addr_len;
-} connection_t;
 
-typedef struct {
-	sdb_object_t super;
-	connection_t conn;
+	/* read buffer */
+	sdb_strbuf_t *buf;
+
+	/* state information for the currently executed command */
+	uint32_t cmd;
+	uint32_t cmd_len;
 } connection_obj_t;
 #define CONN(obj) ((connection_obj_t *)(obj))
 
@@ -90,6 +99,10 @@ struct sdb_fe_socket {
 	size_t listeners_num;
 
 	sdb_llist_t *open_connections;
+
+	/* channel used for communication between main
+	 * and connection handler threads */
+	sdb_channel_t *chan;
 };
 
 /*
@@ -175,6 +188,7 @@ listener_destroy(listener_t *listener)
 
 	if (listener->sock_fd >= 0)
 		close(listener->sock_fd);
+	listener->sock_fd = -1;
 
 	if (listener->address)
 		free(listener->address);
@@ -226,6 +240,48 @@ listener_create(sdb_fe_socket_t *sock, const char *address)
 	return listener;
 } /* listener_create */
 
+static int
+listener_listen(listener_t *listener)
+{
+	assert(listener);
+
+	/* try to reopen */
+	if (listener->sock_fd < 0)
+		if (listener_impls[listener->type].opener(listener))
+			return -1;
+	assert(listener->sock_fd >= 0);
+
+	if (listen(listener->sock_fd, /* backlog = */ 32)) {
+		char buf[1024];
+		sdb_log(SDB_LOG_ERR, "frontend: Failed to listen on socket %s: %s",
+				listener->address, sdb_strerror(errno, buf, sizeof(buf)));
+		return -1;
+	}
+	return 0;
+} /* listener_listen */
+
+static void
+listener_close(listener_t *listener)
+{
+	assert(listener);
+
+	if (listener->sock_fd < 0)
+		return;
+
+	close(listener->sock_fd);
+	listener->sock_fd = -1;
+} /* listener_close */
+
+static void
+socket_close(sdb_fe_socket_t *sock)
+{
+	size_t i;
+
+	assert(sock);
+	for (i = 0; i < sock->listeners_num; ++i)
+		listener_close(sock->listeners + i);
+} /* socket_close */
+
 /*
  * private data types
  */
@@ -233,14 +289,22 @@ listener_create(sdb_fe_socket_t *sock, const char *address)
 static int
 connection_init(sdb_object_t *obj, va_list ap)
 {
-	connection_t *conn;
+	connection_obj_t *conn;
 	int sock_fd;
+	int sock_fl;
 
 	assert(obj);
-	conn = &CONN(obj)->conn;
+	conn = CONN(obj);
 
 	sock_fd = va_arg(ap, int);
 
+	CONN(obj)->buf = sdb_strbuf_create(/* size = */ 128);
+	if (! CONN(obj)->buf) {
+		sdb_log(SDB_LOG_ERR, "frontend: Failed to allocate a read buffer "
+				"for a new remote connection");
+		return -1;
+	}
+
 	conn->client_addr_len = sizeof(conn->client_addr);
 	conn->fd = accept(sock_fd, (struct sockaddr *)&conn->client_addr,
 			&conn->client_addr_len);
@@ -259,7 +323,16 @@ connection_init(sdb_object_t *obj, va_list ap)
 		return -1;
 	}
 
-	sdb_log(SDB_LOG_DEBUG, "frontend: Accepted connection on fd=%i\n",
+	sock_fl = fcntl(conn->fd, F_GETFL);
+	if (fcntl(conn->fd, F_SETFL, sock_fl | O_NONBLOCK)) {
+		char buf[1024];
+		sdb_log(SDB_LOG_ERR, "frontend: Failed to switch connection conn#%i "
+				"to non-blocking mode: %s", conn->fd,
+				sdb_strerror(errno, buf, sizeof(buf)));
+		return -1;
+	}
+
+	sdb_log(SDB_LOG_DEBUG, "frontend: Accepted connection on fd=%i",
 			conn->fd);
 
 	/* update the object name */
@@ -271,13 +344,22 @@ connection_init(sdb_object_t *obj, va_list ap)
 static void
 connection_destroy(sdb_object_t *obj)
 {
-	connection_t *conn;
+	connection_obj_t *conn;
+	size_t len;
 
 	assert(obj);
-	conn = &CONN(obj)->conn;
+	conn = CONN(obj);
 
+	len = sdb_strbuf_len(conn->buf);
+	if (len)
+		sdb_log(SDB_LOG_INFO, "frontend: Discarding incomplete command "
+				"(%zu bytes left in buffer)", len);
+
+	sdb_log(SDB_LOG_DEBUG, "frontend: Closing connection on fd=%i", conn->fd);
 	close(conn->fd);
 	conn->fd = -1;
+
+	sdb_strbuf_destroy(CONN(obj)->buf);
 } /* connection_destroy */
 
 static sdb_type_t connection_type = {
@@ -290,12 +372,72 @@ static sdb_type_t connection_type = {
  * connection handler functions
  */
 
+static uint32_t
+connection_get_int32(connection_obj_t *conn, size_t offset)
+{
+	const char *data;
+	uint32_t n;
+
+	assert(conn && (sdb_strbuf_len(conn->buf) >= offset + sizeof(uint32_t)));
+
+	data = sdb_strbuf_string(conn->buf);
+	memcpy(&n, data + offset, sizeof(n));
+	n = ntohl(n);
+	return n;
+} /* connection_get_int32 */
+
+static int
+command_handle(connection_obj_t *conn)
+{
+	assert(conn && conn->cmd && conn->cmd_len);
+	/* XXX */
+	sdb_strbuf_skip(conn->buf, conn->cmd_len);
+	return 0;
+} /* command_handle */
+
+/* initialize the connection state information */
+static int
+command_init(connection_obj_t *conn)
+{
+	assert(conn && (! conn->cmd) && (! conn->cmd_len));
+
+	conn->cmd = connection_get_int32(conn, 0);
+	conn->cmd_len = connection_get_int32(conn, sizeof(uint32_t));
+	sdb_strbuf_skip(conn->buf, 2 * sizeof(uint32_t));
+	return 0;
+} /* command_init */
+
+/* returns negative value on error, 0 on EOF, number of octets else */
+static ssize_t
+connection_read(connection_obj_t *conn)
+{
+	ssize_t n = 0;
+
+	while (42) {
+		ssize_t status;
+
+		errno = 0;
+		status = sdb_strbuf_read(conn->buf, conn->fd, 1024);
+		if (status < 0) {
+			if ((errno == EAGAIN) || (errno == EWOULDBLOCK))
+				return n;
+			return (int)status;
+		}
+		else if (! status) /* EOF */
+			return n;
+
+		n += status;
+	}
+
+	return n;
+} /* connection_read */
+
 static void *
 connection_handler(void *data)
 {
-	sdb_channel_t *chan = data;
+	sdb_fe_socket_t *sock = data;
 
-	assert(chan);
+	assert(sock);
 
 	while (42) {
 		struct timespec timeout = { 0, 500000000 }; /* .5 seconds */
@@ -303,7 +445,8 @@ connection_handler(void *data)
 		int status;
 
 		errno = 0;
-		status = sdb_channel_select(chan, NULL, &conn, NULL, NULL, &timeout);
+		status = sdb_channel_select(sock->chan, /* read */ NULL, &conn,
+				/* write */ NULL, NULL, &timeout);
 		if (status) {
 			char buf[1024];
 
@@ -317,20 +460,38 @@ connection_handler(void *data)
 			continue;
 		}
 
-		/* XXX */
-		sdb_log(SDB_LOG_INFO, "frontend: Data available on connection fd=%i\n",
-				conn->conn.fd);
+		status = (int)connection_read(conn);
+		if (status <= 0) {
+			/* error or EOF -> close connection */
+			sdb_object_deref(SDB_OBJ(conn));
+			continue;
+		}
+
+		if (conn->cmd_len && (sdb_strbuf_len(conn->buf) >= conn->cmd_len))
+			command_handle(conn);
+		else if (sdb_strbuf_len(conn->buf) >= 2 * sizeof(int32_t))
+			command_init(conn);
+
+		/* return the connection to the main loop */
+		if (sdb_llist_append(sock->open_connections, SDB_OBJ(conn))) {
+			sdb_log(SDB_LOG_ERR, "frontend: Failed to re-append "
+					"connection %s to list of open connections",
+					SDB_OBJ(conn)->name);
+		}
+
+		/* pass ownership back to list; or destroy in case of an error */
+		sdb_object_deref(SDB_OBJ(conn));
 	}
 	return NULL;
 } /* connection_handler */
 
 static int
-accept_connection(sdb_fe_socket_t *sock, listener_t *listener)
+connection_accept(sdb_fe_socket_t *sock, listener_t *listener)
 {
 	sdb_object_t *obj;
 
-	/* the X's will be replaced with the accepted file descriptor
-	 * when initializing the object */
+	/* the placeholder will be replaced with the accepted file
+	 * descriptor when initializing the object */
 	obj = sdb_object_create(CONN_FD_PREFIX CONN_FD_PLACEHOLDER,
 			connection_type, listener->sock_fd);
 	if (! obj)
@@ -347,7 +508,44 @@ accept_connection(sdb_fe_socket_t *sock, listener_t *listener)
 	/* hand ownership over to the list */
 	sdb_object_deref(obj);
 	return 0;
-} /* accept_connection */
+} /* connection_accept */
+
+static int
+socket_handle_incoming(sdb_fe_socket_t *sock,
+		fd_set *ready, fd_set *exceptions)
+{
+	sdb_llist_iter_t *iter;
+	size_t i;
+
+	for (i = 0; i < sock->listeners_num; ++i) {
+		listener_t *listener = sock->listeners + i;
+		if (FD_ISSET(listener->sock_fd, ready))
+			if (connection_accept(sock, listener))
+				continue;
+	}
+
+	iter = sdb_llist_get_iter(sock->open_connections);
+	if (! iter) {
+		sdb_log(SDB_LOG_ERR, "frontend: Failed to acquire iterator "
+				"for open connections");
+		return -1;
+	}
+
+	while (sdb_llist_iter_has_next(iter)) {
+		sdb_object_t *obj = sdb_llist_iter_get_next(iter);
+
+		if (FD_ISSET(CONN(obj)->fd, exceptions))
+			sdb_log(SDB_LOG_INFO, "Exception on fd %d",
+					CONN(obj)->fd);
+
+		if (FD_ISSET(CONN(obj)->fd, ready)) {
+			sdb_llist_iter_remove_current(iter);
+			sdb_channel_write(sock->chan, &obj);
+		}
+	}
+	sdb_llist_iter_destroy(iter);
+	return 0;
+} /* socket_handle_incoming */
 
 /*
  * public API
@@ -407,7 +605,6 @@ sdb_fe_sock_add_listener(sdb_fe_socket_t *sock, const char *address)
 int
 sdb_fe_sock_listen_and_serve(sdb_fe_socket_t *sock, sdb_fe_loop_t *loop)
 {
-	sdb_channel_t *chan;
 	fd_set sockets;
 	int max_listen_fd = 0;
 	size_t i;
@@ -415,18 +612,15 @@ sdb_fe_sock_listen_and_serve(sdb_fe_socket_t *sock, sdb_fe_loop_t *loop)
 	/* XXX: make the number of threads configurable */
 	pthread_t handler_threads[5];
 
-	if ((! sock) || (! sock->listeners_num) || (! loop))
+	if ((! sock) || (! sock->listeners_num) || (! loop) || sock->chan)
 		return -1;
 
 	FD_ZERO(&sockets);
-
 	for (i = 0; i < sock->listeners_num; ++i) {
 		listener_t *listener = sock->listeners + i;
 
-		if (listen(listener->sock_fd, /* backlog = */ 32)) {
-			char buf[1024];
-			sdb_log(SDB_LOG_ERR, "frontend: Failed to listen on socket %s: %s",
-					listener->address, sdb_strerror(errno, buf, sizeof(buf)));
+		if (listener_listen(listener)) {
+			socket_close(sock);
 			return -1;
 		}
 
@@ -435,46 +629,46 @@ sdb_fe_sock_listen_and_serve(sdb_fe_socket_t *sock, sdb_fe_loop_t *loop)
 			max_listen_fd = listener->sock_fd;
 	}
 
-	chan = sdb_channel_create(1024, sizeof(connection_obj_t *));
-	if (! chan)
+	sock->chan = sdb_channel_create(1024, sizeof(connection_obj_t *));
+	if (! sock->chan) {
+		socket_close(sock);
 		return -1;
+	}
 
 	memset(&handler_threads, 0, sizeof(handler_threads));
 	/* XXX: error handling */
 	for (i = 0; i < SDB_STATIC_ARRAY_LEN(handler_threads); ++i)
 		pthread_create(&handler_threads[i], /* attr = */ NULL,
-				connection_handler, /* arg = */ chan);
+				connection_handler, /* arg = */ sock);
 
 	while (loop->do_loop) {
+		struct timeval timeout = { 1, 0 }; /* one second */
+		sdb_llist_iter_t *iter;
+
+		int max_fd = max_listen_fd;
 		fd_set ready;
 		fd_set exceptions;
-		int max_fd;
 		int n;
 
-		struct timeval timeout = { 1, 0 }; /* one second */
-		sdb_llist_iter_t *iter;
-
 		FD_ZERO(&ready);
 		FD_ZERO(&exceptions);
 
 		ready = sockets;
 
-		max_fd = max_listen_fd;
-
 		iter = sdb_llist_get_iter(sock->open_connections);
 		if (! iter) {
 			sdb_log(SDB_LOG_ERR, "frontend: Failed to acquire iterator "
 					"for open connections");
-			return -1;
+			break;
 		}
 
 		while (sdb_llist_iter_has_next(iter)) {
 			sdb_object_t *obj = sdb_llist_iter_get_next(iter);
-			FD_SET(CONN(obj)->conn.fd, &ready);
-			FD_SET(CONN(obj)->conn.fd, &exceptions);
+			FD_SET(CONN(obj)->fd, &ready);
+			FD_SET(CONN(obj)->fd, &exceptions);
 
-			if (CONN(obj)->conn.fd > max_fd)
-				max_fd = CONN(obj)->conn.fd;
+			if (CONN(obj)->fd > max_fd)
+				max_fd = CONN(obj)->fd;
 		}
 		sdb_llist_iter_destroy(iter);
 
@@ -488,48 +682,27 @@ sdb_fe_sock_listen_and_serve(sdb_fe_socket_t *sock, sdb_fe_loop_t *loop)
 
 			sdb_log(SDB_LOG_ERR, "frontend: Failed to monitor sockets: %s",
 					sdb_strerror(errno, buf, sizeof(buf)));
-			return -1;
+			break;
 		}
-
-		if (! n)
+		else if (! n)
 			continue;
 
-		for (i = 0; i < sock->listeners_num; ++i) {
-			listener_t *listener = sock->listeners + i;
-			if (FD_ISSET(listener->sock_fd, &ready))
-				if (accept_connection(sock, listener))
-					continue;
-		}
-
-		iter = sdb_llist_get_iter(sock->open_connections);
-		if (! iter) {
-			sdb_log(SDB_LOG_ERR, "frontend: Failed to acquire iterator "
-					"for open connections");
-			return -1;
-		}
-
-		while (sdb_llist_iter_has_next(iter)) {
-			sdb_object_t *obj = sdb_llist_iter_get_next(iter);
-
-			if (FD_ISSET(CONN(obj)->conn.fd, &exceptions))
-				sdb_log(SDB_LOG_INFO, "Exception on fd %d",
-						CONN(obj)->conn.fd);
-
-			if (FD_ISSET(CONN(obj)->conn.fd, &ready)) {
-				sdb_log(SDB_LOG_INFO, "Data on fd %d", CONN(obj)->conn.fd);
-				sdb_llist_iter_remove_current(iter);
-				sdb_channel_write(chan, &obj);
-			}
-		}
-		sdb_llist_iter_destroy(iter);
+		/* handle new and open connections */
+		if (socket_handle_incoming(sock, &ready, &exceptions))
+			break;
 	}
 
+	socket_close(sock);
+
 	sdb_log(SDB_LOG_INFO, "frontend: Waiting for connection handler threads "
 			"to terminate");
-	if (! sdb_channel_shutdown(chan))
+	if (! sdb_channel_shutdown(sock->chan))
 		for (i = 0; i < SDB_STATIC_ARRAY_LEN(handler_threads); ++i)
 			pthread_join(handler_threads[i], NULL);
 	/* else: we tried our best; let the operating system clean up */
+
+	sdb_channel_destroy(sock->chan);
+	sock->chan = NULL;
 	return 0;
 } /* sdb_fe_sock_listen_and_server */