1 files changed, 558 insertions, 0 deletions

diff --git a/src/doveadm/client-connection-tcp.c b/src/doveadm/client-connection-tcp.c
new file mode 100644
index 0000000..b80d674
--- /dev/null
+++ b/src/doveadm/client-connection-tcp.c
@@ -0,0 +1,558 @@
+/* Copyright (c) 2010-2018 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+#include "lib-signals.h"
+#include "str.h"
+#include "base64.h"
+#include "ioloop.h"
+#include "istream.h"
+#include "ostream.h"
+#include "strescape.h"
+#include "iostream-ssl.h"
+#include "ostream-multiplex.h"
+#include "master-service.h"
+#include "master-service-ssl.h"
+#include "mail-storage-service.h"
+#include "doveadm-util.h"
+#include "doveadm-mail.h"
+#include "doveadm-print.h"
+#include "doveadm-server.h"
+#include "client-connection-private.h"
+
+#include <unistd.h>
+
+#define MAX_INBUF_SIZE (1024*1024)
+
+struct client_connection_tcp {
+	struct client_connection conn;
+
+	int fd;
+	struct io *io;
+	struct istream *input;
+	struct ostream *output;
+	struct ostream *log_out;
+	struct ssl_iostream *ssl_iostream;
+	struct ioloop *ioloop;
+
+	bool handshaked:1;
+	bool preauthenticated:1;
+	bool authenticated:1;
+	bool io_setup:1;
+	bool use_multiplex:1;
+};
+
+static void
+client_connection_tcp_input(struct client_connection_tcp *conn);
+static void
+client_connection_tcp_send_auth_handshake(struct client_connection_tcp *conn);
+static void
+client_connection_tcp_destroy(struct client_connection_tcp **_conn);
+static int
+client_connection_tcp_init_ssl(struct client_connection_tcp *conn);
+
+static failure_callback_t *orig_error_callback, *orig_fatal_callback;
+static failure_callback_t *orig_info_callback, *orig_debug_callback = NULL;
+
+static bool log_recursing = FALSE;
+
+static void ATTR_FORMAT(2, 0)
+doveadm_server_log_handler(const struct failure_context *ctx,
+			   const char *format, va_list args)
+{
+	struct client_connection_tcp *conn = NULL;
+
+	if (doveadm_client != NULL &&
+		doveadm_client->type == DOVEADM_CONNECTION_TYPE_TCP)
+		conn = (struct client_connection_tcp *)doveadm_client;
+
+	if (!log_recursing && conn != NULL &&
+	    conn->log_out != NULL) T_BEGIN {
+		struct ioloop *prev_ioloop = current_ioloop;
+		struct ostream *log_out = conn->log_out;
+		char c;
+		const char *ptr;
+		bool corked;
+		va_list va;
+
+		/* prevent re-entering this code if
+		   any of the following code causes logging */
+		log_recursing = TRUE;
+
+		/* since we can get here from just about anywhere, make sure
+		   the log ostream uses the connection's ioloop. */
+		if (conn->ioloop != NULL)
+			io_loop_set_current(conn->ioloop);
+
+		const char *log_prefix =
+			ctx->log_prefix != NULL ? ctx->log_prefix :
+			i_get_failure_prefix();
+		size_t log_prefix_len = strlen(log_prefix);
+		c = doveadm_log_type_to_char(ctx->type);
+		corked = o_stream_is_corked(log_out);
+
+		va_copy(va, args);
+		const char *str = t_strdup_vprintf(format, va);
+		va_end(va);
+
+		if (!corked)
+			o_stream_cork(log_out);
+		for (;;) {
+			ptr = strchr(str, '\n');
+			size_t len = ptr == NULL ? strlen(str) :
+				(size_t)(ptr - str);
+
+			o_stream_nsend(log_out, &c, 1);
+			o_stream_nsend(log_out, log_prefix, log_prefix_len);
+			o_stream_nsend(log_out, str, len);
+			o_stream_nsend(log_out, "\n", 1);
+
+			if (ptr == NULL)
+				break;
+			str = ptr+1;
+		}
+		o_stream_uncork(log_out);
+		if (corked)
+			o_stream_cork(log_out);
+		io_loop_set_current(prev_ioloop);
+
+		log_recursing = FALSE;
+	} T_END;
+
+	switch(ctx->type) {
+	case LOG_TYPE_DEBUG:
+		orig_debug_callback(ctx, format, args);
+		break;
+	case LOG_TYPE_INFO:
+		orig_info_callback(ctx, format, args);
+		break;
+	case LOG_TYPE_WARNING:
+	case LOG_TYPE_ERROR:
+		orig_error_callback(ctx, format, args);
+		break;
+	default:
+		i_unreached();
+	}
+}
+
+static void doveadm_server_capture_logs(void)
+{
+	i_assert(orig_debug_callback == NULL);
+	i_get_failure_handlers(&orig_fatal_callback, &orig_error_callback,
+			       &orig_info_callback, &orig_debug_callback);
+	i_set_error_handler(doveadm_server_log_handler);
+	i_set_info_handler(doveadm_server_log_handler);
+	i_set_debug_handler(doveadm_server_log_handler);
+}
+
+static void doveadm_server_restore_logs(void)
+{
+	i_assert(orig_debug_callback != NULL);
+	i_set_error_handler(orig_error_callback);
+	i_set_info_handler(orig_info_callback);
+	i_set_debug_handler(orig_debug_callback);
+	orig_fatal_callback = NULL;
+	orig_error_callback = NULL;
+	orig_info_callback = NULL;
+	orig_debug_callback = NULL;
+}
+
+static void
+doveadm_cmd_server_post(struct client_connection_tcp *conn, const char *cmd_name)
+{
+	const char *str = NULL;
+
+	if (doveadm_exit_code == 0) {
+		o_stream_nsend(conn->output, "\n+\n", 3);
+		return;
+	}
+
+	str = doveadm_exit_code_to_str(doveadm_exit_code);
+
+	if (str != NULL) {
+		o_stream_nsend_str(conn->output,
+				   t_strdup_printf("\n-%s\n", str));
+	} else {
+		o_stream_nsend_str(conn->output, "\n-\n");
+		i_error("BUG: Command '%s' returned unknown error code %d",
+			cmd_name, doveadm_exit_code);
+	}
+}
+
+static void
+doveadm_cmd_server_run_ver2(struct client_connection_tcp *conn,
+			    int argc, const char *const argv[],
+			    struct doveadm_cmd_context *cctx)
+{
+	i_getopt_reset();
+	if (doveadm_cmd_run_ver2(argc, argv, cctx) < 0)
+		doveadm_exit_code = EX_USAGE;
+	doveadm_cmd_server_post(conn, cctx->cmd->name);
+}
+
+static int doveadm_cmd_handle(struct client_connection_tcp *conn,
+			      const char *cmd_name,
+			      int argc, const char *const argv[],
+			      struct doveadm_cmd_context *cctx)
+{
+	struct ioloop *prev_ioloop = current_ioloop;
+	const struct doveadm_cmd_ver2 *cmd_ver2;
+
+	if ((cmd_ver2 = doveadm_cmd_find_with_args_ver2(cmd_name, &argc, &argv)) == NULL) {
+		i_error("doveadm: Client sent unknown command: %s", cmd_name);
+		return -1;
+	}
+	cctx->cmd = cmd_ver2;
+
+	/* some commands will want to call io_loop_run(), but we're already
+	   running one and we can't call the original one recursively, so
+	   create a new ioloop. */
+	conn->ioloop = io_loop_create();
+	o_stream_switch_ioloop(conn->output);
+	if (conn->log_out != NULL)
+		o_stream_switch_ioloop(conn->log_out);
+
+	doveadm_cmd_server_run_ver2(conn, argc, argv, cctx);
+
+	o_stream_switch_ioloop_to(conn->output, prev_ioloop);
+	if (conn->log_out != NULL)
+		o_stream_switch_ioloop_to(conn->log_out, prev_ioloop);
+	io_loop_destroy(&conn->ioloop);
+
+	/* clear all headers */
+	doveadm_print_deinit();
+	doveadm_print_init(DOVEADM_PRINT_TYPE_SERVER);
+
+	/* We already sent the success/failure reply to the client. Return 0
+	   so caller never adds another failure reply. */
+	return 0;
+}
+
+static bool client_handle_command(struct client_connection_tcp *conn,
+				  const char *const *args)
+{
+	struct doveadm_cmd_context cctx;
+	const char *flags, *cmd_name;
+	unsigned int argc = str_array_length(args);
+
+	if (argc < 3) {
+		i_error("doveadm client: No command given");
+		return FALSE;
+	}
+	i_zero(&cctx);
+	cctx.conn_type = conn->conn.type;
+	cctx.input = conn->input;
+	cctx.output = conn->output;
+	cctx.local_ip = conn->conn.local_ip;
+	cctx.remote_ip = conn->conn.remote_ip;
+	cctx.local_port = conn->conn.local_port;
+	cctx.remote_port = conn->conn.remote_port;
+	doveadm_exit_code = 0;
+
+	flags = args[0];
+	cctx.username = args[1];
+	cmd_name = args[2];
+
+	doveadm_debug = FALSE;
+	doveadm_verbose = FALSE;
+
+	for (; *flags != '\0'; flags++) {
+		switch (*flags) {
+		case 'D':
+			doveadm_debug = TRUE;
+			doveadm_verbose = TRUE;
+			break;
+		case 'v':
+			doveadm_verbose = TRUE;
+			break;
+		default:
+			i_error("doveadm client: Unknown flag: %c", *flags);
+			return FALSE;
+		}
+	}
+
+	if (!doveadm_client_is_allowed_command(conn->conn.set, cmd_name)) {
+		i_error("doveadm client isn't allowed to use command: %s",
+			cmd_name);
+		return FALSE;
+	}
+
+	client_connection_set_proctitle(&conn->conn, cmd_name);
+	o_stream_cork(conn->output);
+	/* Disable IO while running a command. This is required for commands
+	   that do IO themselves (e.g. dsync-server). */
+	io_remove(&conn->io);
+	if (doveadm_cmd_handle(conn, cmd_name, argc-2, args+2, &cctx) < 0)
+		o_stream_nsend(conn->output, "\n-\n", 3);
+	o_stream_uncork(conn->output);
+	conn->io = io_add_istream(conn->input, client_connection_tcp_input, conn);
+	client_connection_set_proctitle(&conn->conn, "");
+
+	/* Try to flush the output. It might finish later. */
+	(void)o_stream_flush(conn->output);
+	return TRUE;
+}
+
+static int
+client_connection_tcp_authenticate(struct client_connection_tcp *conn)
+{
+	const struct doveadm_settings *set = conn->conn.set;
+	const char *line, *pass;
+	buffer_t *plain;
+	const unsigned char *data;
+	size_t size;
+
+	if ((line = i_stream_read_next_line(conn->input)) == NULL) {
+		if (conn->input->eof)
+			return -1;
+		return 0;
+	}
+
+	if (*set->doveadm_password == '\0') {
+		i_error("doveadm_password not set, "
+			"remote authentication disabled");
+		return -1;
+	}
+
+	if (strcmp(line, "STARTTLS") == 0) {
+		io_remove(&conn->io);
+		if (client_connection_tcp_init_ssl(conn) < 0)
+			return -1;
+		conn->io = io_add_istream(conn->input, client_connection_tcp_input, conn);
+		return 0;
+	}
+
+	/* FIXME: some day we should probably let auth process do this and
+	   support all kinds of authentication */
+	if (!str_begins(line, "PLAIN\t")) {
+		i_error("doveadm client attempted non-PLAIN authentication: %s", line);
+		return -1;
+	}
+
+	plain = t_buffer_create(128);
+	if (base64_decode(line + 6, strlen(line + 6), NULL, plain) < 0) {
+		i_error("doveadm client sent invalid base64 auth PLAIN data");
+		return -1;
+	}
+	data = plain->data;
+	size = plain->used;
+
+	if (size < 10 || data[0] != '\0' ||
+	    memcmp(data+1, "doveadm", 7) != 0 || data[8] != '\0') {
+		i_error("doveadm client didn't authenticate as 'doveadm'");
+		return -1;
+	}
+	pass = t_strndup(data + 9, size - 9);
+	if (strlen(pass) != strlen(set->doveadm_password) ||
+	    !mem_equals_timing_safe(pass, set->doveadm_password,
+				    strlen(pass))) {
+		i_error("doveadm client authenticated with wrong password");
+		return -1;
+	}
+	return 1;
+}
+
+static void client_log_disconnect_error(struct client_connection_tcp *conn)
+{
+	const char *error;
+
+	error = conn->ssl_iostream == NULL ? NULL :
+		ssl_iostream_get_last_error(conn->ssl_iostream);
+	if (error == NULL) {
+		error = conn->input->stream_errno == 0 ? "EOF" :
+			strerror(conn->input->stream_errno);
+	}
+	i_error("doveadm client disconnected before handshake: %s", error);
+}
+
+static void
+client_connection_tcp_input(struct client_connection_tcp *conn)
+{
+	const char *line;
+	bool ok = TRUE;
+	int ret;
+	unsigned int minor;
+
+	if (!conn->handshaked) {
+		if ((line = i_stream_read_next_line(conn->input)) == NULL) {
+			if (conn->input->eof || conn->input->stream_errno != 0) {
+				client_log_disconnect_error(conn);
+				client_connection_tcp_destroy(&conn);
+			}
+			return;
+		}
+		if (!version_string_verify_full(line, "doveadm-server",
+				DOVEADM_SERVER_PROTOCOL_VERSION_MAJOR, &minor)) {
+			i_error("doveadm client not compatible with this server "
+				"(mixed old and new binaries?)");
+			client_connection_tcp_destroy(&conn);
+			return;
+		}
+		if (minor > 0) {
+			/* send version reply */
+			o_stream_nsend_str(conn->output,
+					   DOVEADM_CLIENT_PROTOCOL_VERSION_LINE"\n");
+			conn->use_multiplex = TRUE;
+		}
+		client_connection_tcp_send_auth_handshake(conn);
+		conn->handshaked = TRUE;
+	}
+	if (!conn->authenticated) {
+		if ((ret = client_connection_tcp_authenticate(conn)) <= 0) {
+			if (ret < 0) {
+				o_stream_nsend(conn->output, "-\n", 2);
+				client_connection_tcp_destroy(&conn);
+			}
+			return;
+		}
+		o_stream_nsend(conn->output, "+\n", 2);
+		conn->authenticated = TRUE;
+	}
+
+	if (!conn->io_setup) {
+		conn->io_setup = TRUE;
+                if (conn->use_multiplex) {
+                        struct ostream *os = conn->output;
+                        conn->output = o_stream_create_multiplex(os, SIZE_MAX);
+                        o_stream_set_name(conn->output, o_stream_get_name(os));
+                        o_stream_set_no_error_handling(conn->output, TRUE);
+                        o_stream_unref(&os);
+                        conn->log_out =
+                                o_stream_multiplex_add_channel(conn->output,
+                                                               DOVEADM_LOG_CHANNEL_ID);
+                        o_stream_set_no_error_handling(conn->log_out, TRUE);
+                        o_stream_set_name(conn->log_out, t_strdup_printf("%s (log)",
+                                          o_stream_get_name(conn->output)));
+                        doveadm_server_capture_logs();
+                }
+		doveadm_print_ostream = conn->output;
+	}
+
+	while (ok && !conn->input->closed &&
+	       (line = i_stream_read_next_line(conn->input)) != NULL) {
+		T_BEGIN {
+			const char *const *args;
+
+			args = t_strsplit_tabescaped(line);
+			ok = client_handle_command(conn, args);
+		} T_END;
+	}
+	if (conn->input->eof || conn->input->stream_errno != 0 || !ok)
+		client_connection_tcp_destroy(&conn);
+}
+
+static int
+client_connection_tcp_init_ssl(struct client_connection_tcp *conn)
+{
+	const char *error;
+
+	if (master_service_ssl_init(master_service,
+				    &conn->input, &conn->output,
+				    &conn->ssl_iostream, &error) < 0) {
+		i_error("SSL init failed: %s", error);
+		return -1;
+	}
+	if (ssl_iostream_handshake(conn->ssl_iostream) < 0) {
+		i_error("SSL handshake failed: %s",
+			ssl_iostream_get_last_error(conn->ssl_iostream));
+		return -1;
+	}
+	return 0;
+}
+
+static bool
+client_connection_is_preauthenticated(int listen_fd)
+{
+	const char *listen_path;
+	struct stat st;
+
+	/* we'll have to do this with stat(), because at least in Linux
+	   fstat() always returns mode as 0777 */
+	return net_getunixname(listen_fd, &listen_path) == 0 &&
+		stat(listen_path, &st) == 0 && S_ISSOCK(st.st_mode) &&
+		(st.st_mode & 0777) == 0600;
+}
+
+static void
+client_connection_tcp_send_auth_handshake(struct client_connection_tcp *conn)
+{
+	if (conn->preauthenticated) {
+		/* no need for client to authenticate */
+		conn->authenticated = TRUE;
+		o_stream_nsend(conn->output, "+\n", 2);
+	} else {
+		o_stream_nsend(conn->output, "-\n", 2);
+	}
+}
+
+static void
+client_connection_tcp_free(struct client_connection *_conn)
+{
+	struct client_connection_tcp *conn =
+		(struct client_connection_tcp *)_conn;
+
+	i_assert(_conn->type == DOVEADM_CONNECTION_TYPE_TCP);
+
+	doveadm_print_deinit();
+	doveadm_print_ostream = NULL;
+
+	if (conn->log_out != NULL) {
+		doveadm_server_restore_logs();
+		o_stream_unref(&conn->log_out);
+	}
+	ssl_iostream_destroy(&conn->ssl_iostream);
+
+	io_remove(&conn->io);
+	o_stream_destroy(&conn->output);
+	i_stream_destroy(&conn->input);
+	i_close_fd(&conn->fd);
+}
+
+struct client_connection *
+client_connection_tcp_create(int fd, int listen_fd, bool ssl)
+{
+	struct client_connection_tcp *conn;
+	pool_t pool;
+
+	pool = pool_alloconly_create("doveadm client", 1024*16);
+	conn = p_new(pool, struct client_connection_tcp, 1);
+	conn->fd = fd;
+
+	if (client_connection_init(&conn->conn,
+		DOVEADM_CONNECTION_TYPE_TCP, pool, fd) < 0) {
+		client_connection_tcp_destroy(&conn);
+		return NULL;
+	}
+	conn->conn.free = client_connection_tcp_free;
+
+	doveadm_print_init(DOVEADM_PRINT_TYPE_SERVER);
+
+	conn->input = i_stream_create_fd(fd, MAX_INBUF_SIZE);
+	conn->output = o_stream_create_fd(fd, SIZE_MAX);
+	i_stream_set_name(conn->input, conn->conn.name);
+	o_stream_set_name(conn->output, conn->conn.name);
+	o_stream_set_no_error_handling(conn->output, TRUE);
+
+	if (ssl) {
+		if (client_connection_tcp_init_ssl(conn) < 0) {
+			client_connection_tcp_destroy(&conn);
+			return NULL;
+		}
+	}
+	/* add IO after SSL istream is created */
+	conn->io = io_add_istream(conn->input, client_connection_tcp_input, conn);
+	conn->preauthenticated =
+		client_connection_is_preauthenticated(listen_fd);
+	client_connection_set_proctitle(&conn->conn, "");
+
+	return &conn->conn;
+}
+
+static void
+client_connection_tcp_destroy(struct client_connection_tcp **_conn)
+{
+	struct client_connection_tcp *conn = *_conn;
+	struct client_connection *bconn = &conn->conn;
+
+	*_conn = NULL;
+	client_connection_destroy(&bconn);
+}