nbd: Expose and debug more NBD constants (3736cc5b) · Commits · SUMMER2020 / students / proj-2021291

include/block/nbd.h

+28 −9

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2016 Red Hat, Inc.
		* Copyright (C) 2016-2017 Red Hat, Inc.
		* Copyright (C) 2005 Anthony Liguori <anthony@codemonkey.ws>
		*
		* Network Block Device
		@@ -83,18 +83,37 @@ typedef struct NBDReply NBDReply;
		#define NBD_FLAG_C_FIXED_NEWSTYLE (1 << 0) /* Fixed newstyle protocol. */
		#define NBD_FLAG_C_NO_ZEROES (1 << 1) /* End handshake without zeroes. */

		/* Reply types. */
		/* Option requests. */
		#define NBD_OPT_EXPORT_NAME (1)
		#define NBD_OPT_ABORT (2)
		#define NBD_OPT_LIST (3)
		/* #define NBD_OPT_PEEK_EXPORT (4) not in use */
		#define NBD_OPT_STARTTLS (5)
		#define NBD_OPT_INFO (6)
		#define NBD_OPT_GO (7)
		#define NBD_OPT_STRUCTURED_REPLY (8)

		/* Option reply types. */
		#define NBD_REP_ERR(value) ((UINT32_C(1) << 31) \| (value))

		#define NBD_REP_ACK (1) /* Data sending finished. */
		#define NBD_REP_SERVER (2) /* Export description. */
		#define NBD_REP_INFO (3) /* NBD_OPT_INFO/GO. */

		#define NBD_REP_ERR_UNSUP NBD_REP_ERR(1) /* Unknown option */
		#define NBD_REP_ERR_POLICY NBD_REP_ERR(2) /* Server denied */
		#define NBD_REP_ERR_INVALID NBD_REP_ERR(3) /* Invalid length */
		#define NBD_REP_ERR_PLATFORM NBD_REP_ERR(4) /* Not compiled in */
		#define NBD_REP_ERR_TLS_REQD NBD_REP_ERR(5) /* TLS required */
		#define NBD_REP_ERR_UNKNOWN NBD_REP_ERR(6) /* Export unknown */
		#define NBD_REP_ERR_SHUTDOWN NBD_REP_ERR(7) /* Server shutting down */
		#define NBD_REP_ERR_BLOCK_SIZE_REQD NBD_REP_ERR(8) /* Need INFO_BLOCK_SIZE */

		/* Info types, used during NBD_REP_INFO */
		#define NBD_INFO_EXPORT 0
		#define NBD_INFO_NAME 1
		#define NBD_INFO_DESCRIPTION 2
		#define NBD_INFO_BLOCK_SIZE 3

		/* Request flags, sent from client to server during transmission phase */
		#define NBD_CMD_FLAG_FUA (1 << 0) /* 'force unit access' during write */

nbd/client.c

+34 −18

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2016 Red Hat, Inc.
		* Copyright (C) 2016-2017 Red Hat, Inc.
		* Copyright (C) 2005 Anthony Liguori <anthony@codemonkey.ws>
		*
		* Network Block Device Client Side
		@@ -104,7 +104,7 @@ static int nbd_send_option_request(QIOChannel *ioc, uint32_t opt,
		if (len == -1) {
		req.length = len = strlen(data);
		}
		trace_nbd_send_option_request(opt, len);
		trace_nbd_send_option_request(opt, nbd_opt_lookup(opt), len);

		stq_be_p(&req.magic, NBD_OPTS_MAGIC);
		stl_be_p(&req.option, opt);
		@@ -154,7 +154,9 @@ static int nbd_receive_option_reply(QIOChannel *ioc, uint32_t opt,
		be32_to_cpus(&reply->type);
		be32_to_cpus(&reply->length);

		trace_nbd_receive_option_reply(reply->option, reply->type, reply->length);
		trace_nbd_receive_option_reply(reply->option, nbd_opt_lookup(reply->option),
		reply->type, nbd_rep_lookup(reply->type),
		reply->length);

		if (reply->magic != NBD_REP_MAGIC) {
		error_setg(errp, "Unexpected option reply magic");
		@@ -188,12 +190,16 @@ static int nbd_handle_reply_err(QIOChannel ioc, nbd_opt_reply reply,

		if (reply->length) {
		if (reply->length > NBD_MAX_BUFFER_SIZE) {
		error_setg(errp, "server's error message is too long");
		error_setg(errp, "server error 0x%" PRIx32
		" (%s) message is too long",
		reply->type, nbd_rep_lookup(reply->type));
		goto cleanup;
		}
		msg = g_malloc(reply->length + 1);
		if (nbd_read(ioc, msg, reply->length, errp) < 0) {
		error_prepend(errp, "failed to read option error message");
		error_prepend(errp, "failed to read option error 0x%" PRIx32
		" (%s) message",
		reply->type, nbd_rep_lookup(reply->type));
		goto cleanup;
		}
		msg[reply->length] = '\0';
		@@ -201,38 +207,48 @@ static int nbd_handle_reply_err(QIOChannel ioc, nbd_opt_reply reply,

		switch (reply->type) {
		case NBD_REP_ERR_UNSUP:
		trace_nbd_reply_err_unsup(reply->option);
		trace_nbd_reply_err_unsup(reply->option, nbd_opt_lookup(reply->option));
		result = 0;
		goto cleanup;

		case NBD_REP_ERR_POLICY:
		error_setg(errp, "Denied by server for option %" PRIx32,
		reply->option);
		error_setg(errp, "Denied by server for option %" PRIx32 " (%s)",
		reply->option, nbd_opt_lookup(reply->option));
		break;

		case NBD_REP_ERR_INVALID:
		error_setg(errp, "Invalid data length for option %" PRIx32,
		reply->option);
		error_setg(errp, "Invalid data length for option %" PRIx32 " (%s)",
		reply->option, nbd_opt_lookup(reply->option));
		break;

		case NBD_REP_ERR_PLATFORM:
		error_setg(errp, "Server lacks support for option %" PRIx32,
		reply->option);
		error_setg(errp, "Server lacks support for option %" PRIx32 " (%s)",
		reply->option, nbd_opt_lookup(reply->option));
		break;

		case NBD_REP_ERR_TLS_REQD:
		error_setg(errp, "TLS negotiation required before option %" PRIx32,
		reply->option);
		error_setg(errp, "TLS negotiation required before option %" PRIx32
		" (%s)", reply->option, nbd_opt_lookup(reply->option));
		break;

		case NBD_REP_ERR_UNKNOWN:
		error_setg(errp, "Requested export not available for option %" PRIx32
		" (%s)", reply->option, nbd_opt_lookup(reply->option));
		break;

		case NBD_REP_ERR_SHUTDOWN:
		error_setg(errp, "Server shutting down before option %" PRIx32,
		reply->option);
		error_setg(errp, "Server shutting down before option %" PRIx32 " (%s)",
		reply->option, nbd_opt_lookup(reply->option));
		break;

		case NBD_REP_ERR_BLOCK_SIZE_REQD:
		error_setg(errp, "Server requires INFO_BLOCK_SIZE for option %" PRIx32
		" (%s)", reply->option, nbd_opt_lookup(reply->option));
		break;

		default:
		error_setg(errp, "Unknown error code when asking for option %" PRIx32,
		reply->option);
		error_setg(errp, "Unknown error code when asking for option %" PRIx32
		" (%s)", reply->option, nbd_opt_lookup(reply->option));
		break;
		}

nbd/common.c

+92 −0

Original line number	Diff line number	Diff line
		@@ -101,3 +101,95 @@ void nbd_tls_handshake(QIOTask *task,
		data->complete = true;
		g_main_loop_quit(data->loop);
		}


		const char *nbd_opt_lookup(uint32_t opt)
		{
		switch (opt) {
		case NBD_OPT_EXPORT_NAME:
		return "export name";
		case NBD_OPT_ABORT:
		return "abort";
		case NBD_OPT_LIST:
		return "list";
		case NBD_OPT_STARTTLS:
		return "starttls";
		case NBD_OPT_INFO:
		return "info";
		case NBD_OPT_GO:
		return "go";
		case NBD_OPT_STRUCTURED_REPLY:
		return "structured reply";
		default:
		return "<unknown>";
		}
		}


		const char *nbd_rep_lookup(uint32_t rep)
		{
		switch (rep) {
		case NBD_REP_ACK:
		return "ack";
		case NBD_REP_SERVER:
		return "server";
		case NBD_REP_INFO:
		return "info";
		case NBD_REP_ERR_UNSUP:
		return "unsupported";
		case NBD_REP_ERR_POLICY:
		return "denied by policy";
		case NBD_REP_ERR_INVALID:
		return "invalid";
		case NBD_REP_ERR_PLATFORM:
		return "platform lacks support";
		case NBD_REP_ERR_TLS_REQD:
		return "TLS required";
		case NBD_REP_ERR_UNKNOWN:
		return "export unknown";
		case NBD_REP_ERR_SHUTDOWN:
		return "server shutting down";
		case NBD_REP_ERR_BLOCK_SIZE_REQD:
		return "block size required";
		default:
		return "<unknown>";
		}
		}


		const char *nbd_info_lookup(uint16_t info)
		{
		switch (info) {
		case NBD_INFO_EXPORT:
		return "export";
		case NBD_INFO_NAME:
		return "name";
		case NBD_INFO_DESCRIPTION:
		return "description";
		case NBD_INFO_BLOCK_SIZE:
		return "block size";
		default:
		return "<unknown>";
		}
		}


		const char *nbd_cmd_lookup(uint16_t cmd)
		{
		switch (cmd) {
		case NBD_CMD_READ:
		return "read";
		case NBD_CMD_WRITE:
		return "write";
		case NBD_CMD_DISC:
		return "discard";
		case NBD_CMD_FLUSH:
		return "flush";
		case NBD_CMD_TRIM:
		return "trim";
		case NBD_CMD_WRITE_ZEROES:
		return "write zeroes";
		default:
		return "<unknown>";
		}
		}

nbd/nbd-internal.h

+4 −6

Original line number	Diff line number	Diff line
		@@ -57,12 +57,6 @@
		#define NBD_SET_TIMEOUT _IO(0xab, 9)
		#define NBD_SET_FLAGS _IO(0xab, 10)

		#define NBD_OPT_EXPORT_NAME (1)
		#define NBD_OPT_ABORT (2)
		#define NBD_OPT_LIST (3)
		#define NBD_OPT_PEEK_EXPORT (4)
		#define NBD_OPT_STARTTLS (5)

		/* NBD errors are based on errno numbers, so there is a 1:1 mapping,
		* but only a limited set of errno values is specified in the protocol.
		* Everything else is squashed to EINVAL.
		@@ -133,6 +127,10 @@ struct NBDTLSHandshakeData {

		void nbd_tls_handshake(QIOTask *task,
		void *opaque);
		const char *nbd_opt_lookup(uint32_t opt);
		const char *nbd_rep_lookup(uint32_t rep);
		const char *nbd_info_lookup(uint16_t info);
		const char *nbd_cmd_lookup(uint16_t info);

		int nbd_drop(QIOChannel ioc, size_t size, Error *errp);

nbd/server.c

+11 −7

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2016 Red Hat, Inc.
		* Copyright (C) 2016-2017 Red Hat, Inc.
		* Copyright (C) 2005 Anthony Liguori <anthony@codemonkey.ws>
		*
		* Network Block Device Server Side
		@@ -139,7 +139,8 @@ static int nbd_negotiate_send_rep_len(QIOChannel *ioc, uint32_t type,
		{
		uint64_t magic;

		trace_nbd_negotiate_send_rep_len(opt, type, len);
		trace_nbd_negotiate_send_rep_len(opt, nbd_opt_lookup(opt),
		type, nbd_rep_lookup(type), len);

		magic = cpu_to_be64(NBD_REP_MAGIC);
		if (nbd_write(ioc, &magic, sizeof(magic), errp) < 0) {
		@@ -441,7 +442,8 @@ static int nbd_negotiate_options(NBDClient client, Error *errp)
		}
		length = be32_to_cpu(length);

		trace_nbd_negotiate_options_check_option(option);
		trace_nbd_negotiate_options_check_option(option,
		nbd_opt_lookup(option));
		if (client->tlscreds &&
		client->ioc == (QIOChannel *)client->sioc) {
		QIOChannel *tioc;
		@@ -532,8 +534,8 @@ static int nbd_negotiate_options(NBDClient client, Error *errp)
		NBD_REP_ERR_UNSUP,
		option, errp,
		"Unsupported option 0x%"
		PRIx32,
		option);
		PRIx32 " (%s)", option,
		nbd_opt_lookup(option));
		if (ret < 0) {
		return ret;
		}
		@@ -549,7 +551,8 @@ static int nbd_negotiate_options(NBDClient client, Error *errp)
		return nbd_negotiate_handle_export_name(client, length, errp);

		default:
		error_setg(errp, "Unsupported option 0x%" PRIx32, option);
		error_setg(errp, "Unsupported option 0x%" PRIx32 " (%s)",
		option, nbd_opt_lookup(option));
		return -EINVAL;
		}
		}
		@@ -1033,7 +1036,8 @@ static int nbd_co_receive_request(NBDRequestData req, NBDRequest request,
		return -EIO;
		}

		trace_nbd_co_receive_request_decode_type(request->handle, request->type);
		trace_nbd_co_receive_request_decode_type(request->handle, request->type,
		nbd_cmd_lookup(request->type));

		if (request->type != NBD_CMD_WRITE) {
		/* No payload, we are ready to read the next request. */