X-Git-Url: https://git.tokkee.org/?p=sysdb.git;a=blobdiff_plain;f=src%2Ffrontend%2Fconnection.c;h=f35f7b39c82a8278f47137e65810163094c33044;hp=75ac8c91c845af15dd89efd74fd5778b82821268;hb=ad77ec3d257ac66d74e91452d098882247abdc0a;hpb=c6c39d0721a53ee2a85bf1324a4092eea5ba04a3

diff --git a/src/frontend/connection.c b/src/frontend/connection.c
index 75ac8c9..f35f7b3 100644
--- a/src/frontend/connection.c
+++ b/src/frontend/connection.c
@@ -25,53 +25,387 @@
  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+#ifdef HAVE_CONFIG_H
+#	include "config.h"
+#endif
+
 #include "sysdb.h"
-#include "frontend/connection.h"
+#include "core/object.h"
+#include "core/plugin.h"
+#include "frontend/connection-private.h"
+#include "utils/error.h"
 #include "utils/strbuf.h"
+#include "utils/proto.h"
+#include "utils/os.h"
 
 #include <assert.h>
 #include <errno.h>
 
 #include <arpa/inet.h>
+#include <fcntl.h>
 
+#include <stdlib.h>
 #include <string.h>
 
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <sys/param.h>
+
+#ifdef HAVE_UCRED_H
+#	include <ucred.h>
+#endif
+#ifdef HAVE_SYS_UCRED_H
+#	include <sys/ucred.h>
+#endif
+
+#include <pwd.h>
+
+#include <pthread.h>
+
+/*
+ * private variables
+ */
+
+static pthread_key_t conn_ctx_key;
+static bool          conn_ctx_key_initialized = 0;
+
+/*
+ * private types
+ */
+
+/* name of connection objects */
+#define CONN_FD_PREFIX "conn#"
+#define CONN_FD_PLACEHOLDER "XXXXXXX"
+
+/* XXX: only supports UNIX sockets so far */
+static char *
+peer(int sockfd)
+{
+	uid_t uid;
+
+	struct passwd pw_entry;
+	struct passwd *result = NULL;
+	char buf[1024];
+
+#ifdef SO_PEERCRED
+	struct ucred cred;
+	socklen_t len = sizeof(cred);
+
+	if (getsockopt(sockfd, SOL_SOCKET, SO_PEERCRED, &cred, &len)
+			|| (len != sizeof(cred)))
+		return NULL;
+	uid = cred.uid;
+#else /* SO_PEERCRED */
+	errno = ENOSYS;
+	return NULL;
+#endif
+
+	memset(&pw_entry, 0, sizeof(pw_entry));
+	if (getpwuid_r(uid, &pw_entry, buf, sizeof(buf), &result)
+			|| (! result))
+		return NULL;
+	return strdup(result->pw_name);
+} /* peer */
+
+static ssize_t
+conn_read(sdb_conn_t *conn, size_t len)
+{
+	return sdb_strbuf_read(conn->buf, conn->fd, len);
+} /* conn_read */
+
+static ssize_t
+conn_write(sdb_conn_t *conn, const void *buf, size_t len)
+{
+	return sdb_write(conn->fd, len, buf);
+} /* conn_write */
+
+static int
+connection_init(sdb_object_t *obj, va_list ap)
+{
+	sdb_conn_t *conn;
+	int sock_fd;
+	int sock_fl;
+
+	assert(obj);
+	conn = CONN(obj);
+
+	sock_fd = va_arg(ap, int);
+
+	conn->buf = sdb_strbuf_create(/* size = */ 128);
+	if (! conn->buf) {
+		sdb_log(SDB_LOG_ERR, "frontend: Failed to allocate a read buffer "
+				"for a new connection");
+		return -1;
+	}
+	conn->errbuf = sdb_strbuf_create(0);
+	if (! conn->errbuf) {
+		sdb_log(SDB_LOG_ERR, "frontend: Failed to allocate an error buffer "
+				"for a new 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);
+
+	if (conn->fd < 0) {
+		char buf[1024];
+		sdb_log(SDB_LOG_ERR, "frontend: Failed to accept remote "
+				"connection: %s", sdb_strerror(errno,
+					buf, sizeof(buf)));
+		return -1;
+	}
+
+	/* defaults */
+	conn->read = conn_read;
+	conn->write = conn_write;
+	conn->finish = NULL;
+	conn->session = NULL;
+
+	if (conn->client_addr.ss_family != AF_UNIX) {
+		sdb_log(SDB_LOG_ERR, "frontend: Accepted connection using "
+				"unexpected family type %d", conn->client_addr.ss_family);
+		return -1;
+	}
+
+	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;
+	}
+
+	conn->username = peer(conn->fd);
+	if (! conn->username) {
+		char buf[1024];
+		sdb_log(SDB_LOG_ERR, "frontend: Failed to retrieve peer for "
+				"connection conn#%i: %s", conn->fd,
+				sdb_strerror(errno, buf, sizeof(buf)));
+		return -1;
+	}
+	conn->ready = 0;
+
+	sdb_log(SDB_LOG_DEBUG, "frontend: Accepted connection on fd=%i",
+			conn->fd);
+
+	conn->cmd = SDB_CONNECTION_IDLE;
+	conn->cmd_len = 0;
+	conn->skip_len = 0;
+
+	/* update the object name */
+	snprintf(obj->name + strlen(CONN_FD_PREFIX),
+			strlen(CONN_FD_PLACEHOLDER), "%i", conn->fd);
+	return 0;
+} /* connection_init */
+
+static void
+connection_destroy(sdb_object_t *obj)
+{
+	sdb_conn_t *conn;
+	size_t len;
+
+	assert(obj);
+	conn = CONN(obj);
+
+	conn->ready = 0;
+
+	if (conn->finish)
+		conn->finish(conn);
+	conn->finish = NULL;
+
+	if (conn->buf) {
+		len = sdb_strbuf_len(conn->buf);
+		if (len)
+			sdb_log(SDB_LOG_INFO, "frontend: Discarding incomplete command "
+					"(%zu byte%s left in buffer)", len, len == 1 ? "" : "s");
+	}
+
+	sdb_log(SDB_LOG_DEBUG, "frontend: Closing connection %s", obj->name);
+	sdb_connection_close(conn);
+
+	if (conn->username)
+		free(conn->username);
+	conn->username = NULL;
+
+	sdb_strbuf_destroy(conn->buf);
+	conn->buf = NULL;
+	sdb_strbuf_destroy(conn->errbuf);
+	conn->errbuf = NULL;
+} /* connection_destroy */
+
+static sdb_type_t connection_type = {
+	/* size = */ sizeof(sdb_conn_t),
+	/* init = */ connection_init,
+	/* destroy = */ connection_destroy,
+};
+
+/*
+ * private helper functions
+ */
+
+static void
+sdb_conn_ctx_destructor(void *c)
+{
+	sdb_object_t *conn = c;
+
+	if (! conn)
+		return;
+	sdb_object_deref(conn);
+} /* sdb_conn_ctx_destructor */
+
+static void
+sdb_conn_ctx_init(void)
+{
+	if (conn_ctx_key_initialized)
+		return;
+
+	pthread_key_create(&conn_ctx_key, sdb_conn_ctx_destructor);
+	conn_ctx_key_initialized = 1;
+} /* sdb_conn_ctx_init */
+
+static void
+sdb_conn_set_ctx(sdb_conn_t *conn)
+{
+	sdb_conn_t *old;
+
+	sdb_conn_ctx_init();
+
+	old = pthread_getspecific(conn_ctx_key);
+	if (old)
+		sdb_object_deref(SDB_OBJ(old));
+	if (conn)
+		sdb_object_ref(SDB_OBJ(conn));
+	pthread_setspecific(conn_ctx_key, conn);
+} /* sdb_conn_set_ctx */
+
+static sdb_conn_t *
+sdb_conn_get_ctx(void)
+{
+	if (! conn_ctx_key_initialized)
+		return NULL;
+	return pthread_getspecific(conn_ctx_key);
+} /* sdb_conn_get_ctx */
+
 /*
  * connection handler functions
  */
 
-static uint32_t
-connection_get_int32(sdb_conn_t *conn, size_t offset)
+/*
+ * connection_log:
+ * Send a log message originating from the current thread to the client.
+ */
+static int
+connection_log(int prio, const char *msg,
+		sdb_object_t __attribute__((unused)) *user_data)
 {
-	const char *data;
-	uint32_t n;
+	uint32_t len = (uint32_t)sizeof(uint32_t) + (uint32_t)strlen(msg);
+	uint32_t p = htonl((uint32_t)prio);
+	char tmp[len + 1];
 
-	assert(conn && (sdb_strbuf_len(conn->buf) >= offset + sizeof(uint32_t)));
+	sdb_conn_t *conn;
 
-	data = sdb_strbuf_string(conn->buf);
-	memcpy(&n, data + offset, sizeof(n));
-	n = ntohl(n);
-	return n;
-} /* connection_get_int32 */
+	conn = sdb_conn_get_ctx();
+	/* no connection associated to this thread
+	 * or startup not done yet => don't leak any information */
+	if ((! conn) || (! conn->ready))
+		return 0;
+
+	/* XXX: make the log-level configurable by the client at runtime */
+	if (prio >= SDB_LOG_DEBUG)
+		return 0;
+
+	memcpy(tmp, &p, sizeof(p));
+	strcpy(tmp + sizeof(p), msg);
+
+	if (sdb_connection_send(conn, SDB_CONNECTION_LOG, len, tmp) < 0)
+		return -1;
+	return 0;
+} /* connection_log */
 
 static int
 command_handle(sdb_conn_t *conn)
 {
-	assert(conn && conn->cmd && conn->cmd_len);
-	/* XXX */
-	sdb_strbuf_skip(conn->buf, conn->cmd_len);
-	return 0;
+	int status = -1;
+
+	assert(conn && (conn->cmd != SDB_CONNECTION_IDLE));
+	assert(! conn->skip_len);
+
+	sdb_log(SDB_LOG_DEBUG, "frontend: Handling command %u (len: %u)",
+			conn->cmd, conn->cmd_len);
+
+	if (conn->cmd == SDB_CONNECTION_PING)
+		status = sdb_connection_ping(conn);
+	else if (conn->cmd == SDB_CONNECTION_STARTUP)
+		status = sdb_fe_session_start(conn);
+	else if (conn->cmd == SDB_CONNECTION_QUERY)
+		status = sdb_fe_query(conn);
+	else if (conn->cmd == SDB_CONNECTION_FETCH)
+		status = sdb_fe_fetch(conn);
+	else if (conn->cmd == SDB_CONNECTION_LIST)
+		status = sdb_fe_list(conn);
+	else if (conn->cmd == SDB_CONNECTION_LOOKUP)
+		status = sdb_fe_lookup(conn);
+	else if (conn->cmd == SDB_CONNECTION_STORE)
+		status = sdb_fe_store(conn);
+	else {
+		sdb_log(SDB_LOG_WARNING, "frontend: Ignoring invalid command %#x",
+				conn->cmd);
+		sdb_strbuf_sprintf(conn->errbuf, "Invalid command %#x", conn->cmd);
+		status = -1;
+	}
+
+	if (status) {
+		if (! sdb_strbuf_len(conn->errbuf))
+			sdb_strbuf_sprintf(conn->errbuf, "Failed to execute command");
+		sdb_connection_send(conn, SDB_CONNECTION_ERROR,
+				(uint32_t)sdb_strbuf_len(conn->errbuf),
+				sdb_strbuf_string(conn->errbuf));
+	}
+	return status;
 } /* command_handle */
 
 /* initialize the connection state information */
 static int
 command_init(sdb_conn_t *conn)
 {
-	assert(conn && (! conn->cmd) && (! conn->cmd_len));
+	const char *errmsg = NULL;
 
-	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));
+	assert(conn && (conn->cmd == SDB_CONNECTION_IDLE) && (! conn->cmd_len));
+
+	if (conn->skip_len)
+		return -1;
+
+	/* reset */
+	sdb_strbuf_clear(conn->errbuf);
+
+	if (sdb_proto_unmarshal_header(SDB_STRBUF_STR(conn->buf),
+				&conn->cmd, &conn->cmd_len) < 0)
+		return -1;
+	sdb_strbuf_skip(conn->buf, 0, 2 * sizeof(uint32_t));
+
+	if ((! conn->ready) && (conn->cmd != SDB_CONNECTION_STARTUP))
+		errmsg = "Authentication required";
+	else if (conn->cmd == SDB_CONNECTION_IDLE)
+		errmsg = "Invalid command 0";
+
+	if (errmsg) {
+		size_t len = sdb_strbuf_len(conn->buf);
+
+		sdb_strbuf_sprintf(conn->errbuf, "%s", errmsg);
+		sdb_connection_send(conn, SDB_CONNECTION_ERROR,
+				(uint32_t)strlen(errmsg), errmsg);
+		conn->skip_len += conn->cmd_len;
+		conn->cmd = SDB_CONNECTION_IDLE;
+		conn->cmd_len = 0;
+
+		if (len > conn->skip_len)
+			len = conn->skip_len;
+		sdb_strbuf_skip(conn->buf, 0, len);
+		conn->skip_len -= len;
+		/* connection_read will handle anything else */
+	}
 	return 0;
 } /* command_init */
 
@@ -81,20 +415,37 @@ connection_read(sdb_conn_t *conn)
 {
 	ssize_t n = 0;
 
+	if ((! conn) || (conn->fd < 0))
+		return -1;
+
 	while (42) {
 		ssize_t status;
 
 		errno = 0;
-		status = sdb_strbuf_read(conn->buf, conn->fd, 1024);
+		status = conn->read(conn, 1024);
 		if (status < 0) {
 			if ((errno == EAGAIN) || (errno == EWOULDBLOCK))
 				break;
+
+			sdb_connection_close(conn);
 			return (int)status;
 		}
 		else if (! status) /* EOF */
 			break;
 
+		if (conn->skip_len) {
+			size_t len = (size_t)status < conn->skip_len
+				? (size_t)status : conn->skip_len;
+			sdb_strbuf_skip(conn->buf, 0, len);
+			conn->skip_len -= len;
+		}
+
 		n += status;
+
+		/* give the main loop a chance to execute commands (and free up buffer
+		 * space) on large amounts of incoming traffic */
+		if (n > 1024 * 1024)
+			break;
 	}
 
 	return n;
@@ -104,27 +455,113 @@ connection_read(sdb_conn_t *conn)
  * public API
  */
 
+int
+sdb_connection_enable_logging(void)
+{
+	return sdb_plugin_register_log("connection-logger", connection_log,
+			/* user_data = */ NULL);
+} /* sdb_connection_enable_logging */
+
+sdb_conn_t *
+sdb_connection_accept(int fd)
+{
+	if (fd < 0)
+		return NULL;
+
+	/* the placeholder will be replaced with the accepted file
+	 * descriptor when initializing the object */
+	return CONN(sdb_object_create(CONN_FD_PREFIX CONN_FD_PLACEHOLDER,
+				connection_type, fd));
+} /* sdb_connection_create */
+
+void
+sdb_connection_close(sdb_conn_t *conn)
+{
+	if (! conn)
+		return;
+
+	if (conn->finish)
+		conn->finish(conn);
+	conn->finish = NULL;
+
+	/* close the connection even if someone else still references it */
+	if (conn->fd >= 0)
+		close(conn->fd);
+	conn->fd = -1;
+} /* sdb_connection_close */
+
 ssize_t
-sdb_connection_read(sdb_conn_t *conn)
+sdb_connection_handle(sdb_conn_t *conn)
 {
 	ssize_t n = 0;
 
+	sdb_conn_set_ctx(conn);
+
 	while (42) {
 		ssize_t status = connection_read(conn);
 
-		if ((! conn->cmd) && (! conn->cmd_len)
+		if ((conn->cmd == SDB_CONNECTION_IDLE) && (! conn->cmd_len)
 				&& (sdb_strbuf_len(conn->buf) >= 2 * sizeof(int32_t)))
 			command_init(conn);
-		if (conn->cmd_len && (sdb_strbuf_len(conn->buf) >= conn->cmd_len))
+		if ((conn->cmd != SDB_CONNECTION_IDLE)
+				&& (sdb_strbuf_len(conn->buf) >= conn->cmd_len)) {
 			command_handle(conn);
 
+			/* remove the command from the buffer */
+			if (conn->cmd_len)
+				sdb_strbuf_skip(conn->buf, 0, conn->cmd_len);
+			conn->cmd = SDB_CONNECTION_IDLE;
+			conn->cmd_len = 0;
+		}
+
 		if (status <= 0)
 			break;
 
 		n += status;
 	}
+
+	sdb_conn_set_ctx(NULL);
 	return n;
-} /* sdb_connection_read */
+} /* sdb_connection_handle */
+
+ssize_t
+sdb_connection_send(sdb_conn_t *conn, uint32_t code,
+		uint32_t msg_len, const char *msg)
+{
+	char buf[2 * sizeof(uint32_t) + msg_len];
+	ssize_t status;
+
+	if ((! conn) || (conn->fd < 0))
+		return -1;
+	if (sdb_proto_marshal(buf, sizeof(buf), code, msg_len, msg) < 0)
+		return -1;
+
+	status = conn->write(conn, buf, sizeof(buf));
+	if (status < 0) {
+		char errbuf[1024];
+
+		/* tell other code that there was a problem and, more importantly,
+		 * make sure we don't try to send further logs to the connection */
+		sdb_connection_close(conn);
+		conn->ready = 0;
+
+		sdb_log(SDB_LOG_ERR, "frontend: Failed to send msg "
+				"(code: %u, len: %u) to client: %s", code, msg_len,
+				sdb_strerror(errno, errbuf, sizeof(errbuf)));
+	}
+	return status;
+} /* sdb_connection_send */
+
+int
+sdb_connection_ping(sdb_conn_t *conn)
+{
+	if ((! conn) || (conn->cmd != SDB_CONNECTION_PING))
+		return -1;
+
+	/* we're alive */
+	sdb_connection_send(conn, SDB_CONNECTION_OK, 0, NULL);
+	return 0;
+} /* sdb_connection_ping */
 
 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */