/*
- * Copyright (C) 2016 Red Hat, Inc.
+ * Copyright (C) 2016-2017 Red Hat, Inc.
*
* Network Block Device Client Side
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);
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");
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';
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");
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;
}
if (msg) {
- error_append_hint(errp, "%s\n", msg);
+ error_append_hint(errp, "server reported: %s\n", msg);
}
cleanup:
}
+/* Returns -1 if NBD_OPT_GO proves the export @wantname cannot be
+ * used, 0 if NBD_OPT_GO is unsupported (fall back to NBD_OPT_LIST and
+ * NBD_OPT_EXPORT_NAME in that case), and > 0 if the export is good to
+ * go (with @info populated). */
+static int nbd_opt_go(QIOChannel *ioc, const char *wantname,
+ NBDExportInfo *info, Error **errp)
+{
+ nbd_opt_reply reply;
+ uint32_t len = strlen(wantname);
+ uint16_t type;
+ int error;
+ char *buf;
+
+ /* The protocol requires that the server send NBD_INFO_EXPORT with
+ * a non-zero flags (at least NBD_FLAG_HAS_FLAGS must be set); so
+ * flags still 0 is a witness of a broken server. */
+ info->flags = 0;
+
+ trace_nbd_opt_go_start(wantname);
+ buf = g_malloc(4 + len + 2 + 2 * info->request_sizes + 1);
+ stl_be_p(buf, len);
+ memcpy(buf + 4, wantname, len);
+ /* At most one request, everything else up to server */
+ stw_be_p(buf + 4 + len, info->request_sizes);
+ if (info->request_sizes) {
+ stw_be_p(buf + 4 + len + 2, NBD_INFO_BLOCK_SIZE);
+ }
+ error = nbd_send_option_request(ioc, NBD_OPT_GO,
+ 4 + len + 2 + 2 * info->request_sizes,
+ buf, errp);
+ g_free(buf);
+ if (error < 0) {
+ return -1;
+ }
+
+ while (1) {
+ if (nbd_receive_option_reply(ioc, NBD_OPT_GO, &reply, errp) < 0) {
+ return -1;
+ }
+ error = nbd_handle_reply_err(ioc, &reply, errp);
+ if (error <= 0) {
+ return error;
+ }
+ len = reply.length;
+
+ if (reply.type == NBD_REP_ACK) {
+ /* Server is done sending info and moved into transmission
+ phase, but make sure it sent flags */
+ if (len) {
+ error_setg(errp, "server sent invalid NBD_REP_ACK");
+ return -1;
+ }
+ if (!info->flags) {
+ error_setg(errp, "broken server omitted NBD_INFO_EXPORT");
+ return -1;
+ }
+ trace_nbd_opt_go_success();
+ return 1;
+ }
+ if (reply.type != NBD_REP_INFO) {
+ error_setg(errp, "unexpected reply type %" PRIx32
+ " (%s), expected %x",
+ reply.type, nbd_rep_lookup(reply.type), NBD_REP_INFO);
+ nbd_send_opt_abort(ioc);
+ return -1;
+ }
+ if (len < sizeof(type)) {
+ error_setg(errp, "NBD_REP_INFO length %" PRIu32 " is too short",
+ len);
+ nbd_send_opt_abort(ioc);
+ return -1;
+ }
+ if (nbd_read(ioc, &type, sizeof(type), errp) < 0) {
+ error_prepend(errp, "failed to read info type");
+ nbd_send_opt_abort(ioc);
+ return -1;
+ }
+ len -= sizeof(type);
+ be16_to_cpus(&type);
+ switch (type) {
+ case NBD_INFO_EXPORT:
+ if (len != sizeof(info->size) + sizeof(info->flags)) {
+ error_setg(errp, "remaining export info len %" PRIu32
+ " is unexpected size", len);
+ nbd_send_opt_abort(ioc);
+ return -1;
+ }
+ if (nbd_read(ioc, &info->size, sizeof(info->size), errp) < 0) {
+ error_prepend(errp, "failed to read info size");
+ nbd_send_opt_abort(ioc);
+ return -1;
+ }
+ be64_to_cpus(&info->size);
+ if (nbd_read(ioc, &info->flags, sizeof(info->flags), errp) < 0) {
+ error_prepend(errp, "failed to read info flags");
+ nbd_send_opt_abort(ioc);
+ return -1;
+ }
+ be16_to_cpus(&info->flags);
+ trace_nbd_receive_negotiate_size_flags(info->size, info->flags);
+ break;
+
+ case NBD_INFO_BLOCK_SIZE:
+ if (len != sizeof(info->min_block) * 3) {
+ error_setg(errp, "remaining export info len %" PRIu32
+ " is unexpected size", len);
+ nbd_send_opt_abort(ioc);
+ return -1;
+ }
+ if (nbd_read(ioc, &info->min_block, sizeof(info->min_block),
+ errp) < 0) {
+ error_prepend(errp, "failed to read info minimum block size");
+ nbd_send_opt_abort(ioc);
+ return -1;
+ }
+ be32_to_cpus(&info->min_block);
+ if (!is_power_of_2(info->min_block)) {
+ error_setg(errp, "server minimum block size %" PRId32
+ "is not a power of two", info->min_block);
+ nbd_send_opt_abort(ioc);
+ return -1;
+ }
+ if (nbd_read(ioc, &info->opt_block, sizeof(info->opt_block),
+ errp) < 0) {
+ error_prepend(errp, "failed to read info preferred block size");
+ nbd_send_opt_abort(ioc);
+ return -1;
+ }
+ be32_to_cpus(&info->opt_block);
+ if (!is_power_of_2(info->opt_block) ||
+ info->opt_block < info->min_block) {
+ error_setg(errp, "server preferred block size %" PRId32
+ "is not valid", info->opt_block);
+ nbd_send_opt_abort(ioc);
+ return -1;
+ }
+ if (nbd_read(ioc, &info->max_block, sizeof(info->max_block),
+ errp) < 0) {
+ error_prepend(errp, "failed to read info maximum block size");
+ nbd_send_opt_abort(ioc);
+ return -1;
+ }
+ be32_to_cpus(&info->max_block);
+ trace_nbd_opt_go_info_block_size(info->min_block, info->opt_block,
+ info->max_block);
+ break;
+
+ default:
+ trace_nbd_opt_go_info_unknown(type, nbd_info_lookup(type));
+ if (nbd_drop(ioc, len, errp) < 0) {
+ error_prepend(errp, "Failed to read info payload");
+ nbd_send_opt_abort(ioc);
+ return -1;
+ }
+ break;
+ }
+ }
+}
+
/* Return -1 on failure, 0 if wantname is an available export. */
static int nbd_receive_query_exports(QIOChannel *ioc,
const char *wantname,
}
-int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags,
+int nbd_receive_negotiate(QIOChannel *ioc, const char *name,
QCryptoTLSCreds *tlscreds, const char *hostname,
- QIOChannel **outioc,
- off_t *size, Error **errp)
+ QIOChannel **outioc, NBDExportInfo *info,
+ Error **errp)
{
char buf[256];
- uint64_t magic, s;
+ uint64_t magic;
int rc;
bool zeroes = true;
name = "";
}
if (fixedNewStyle) {
+ int result;
+
+ /* Try NBD_OPT_GO first - if it works, we are done (it
+ * also gives us a good message if the server requires
+ * TLS). If it is not available, fall back to
+ * NBD_OPT_LIST for nicer error messages about a missing
+ * export, then use NBD_OPT_EXPORT_NAME. */
+ result = nbd_opt_go(ioc, name, info, errp);
+ if (result < 0) {
+ goto fail;
+ }
+ if (result > 0) {
+ return 0;
+ }
/* Check our desired export is present in the
* server export list. Since NBD_OPT_EXPORT_NAME
* cannot return an error message, running this
- * query gives us good error reporting if the
- * server required TLS
+ * query gives us better error reporting if the
+ * export name is not available.
*/
if (nbd_receive_query_exports(ioc, name, errp) < 0) {
goto fail;
}
/* Read the response */
- if (nbd_read(ioc, &s, sizeof(s), errp) < 0) {
+ if (nbd_read(ioc, &info->size, sizeof(info->size), errp) < 0) {
error_prepend(errp, "Failed to read export length");
goto fail;
}
- *size = be64_to_cpu(s);
+ be64_to_cpus(&info->size);
- if (nbd_read(ioc, flags, sizeof(*flags), errp) < 0) {
+ if (nbd_read(ioc, &info->flags, sizeof(info->flags), errp) < 0) {
error_prepend(errp, "Failed to read export flags");
goto fail;
}
- be16_to_cpus(flags);
+ be16_to_cpus(&info->flags);
} else if (magic == NBD_CLIENT_MAGIC) {
uint32_t oldflags;
goto fail;
}
- if (nbd_read(ioc, &s, sizeof(s), errp) < 0) {
+ if (nbd_read(ioc, &info->size, sizeof(info->size), errp) < 0) {
error_prepend(errp, "Failed to read export length");
goto fail;
}
- *size = be64_to_cpu(s);
+ be64_to_cpus(&info->size);
if (nbd_read(ioc, &oldflags, sizeof(oldflags), errp) < 0) {
error_prepend(errp, "Failed to read export flags");
error_setg(errp, "Unexpected export flags %0x" PRIx32, oldflags);
goto fail;
}
- *flags = oldflags;
+ info->flags = oldflags;
} else {
error_setg(errp, "Bad magic received");
goto fail;
}
- trace_nbd_receive_negotiate_size_flags(*size, *flags);
+ trace_nbd_receive_negotiate_size_flags(info->size, info->flags);
if (zeroes && nbd_drop(ioc, 124, errp) < 0) {
error_prepend(errp, "Failed to read reserved block");
goto fail;
}
#ifdef __linux__
-int nbd_init(int fd, QIOChannelSocket *sioc, uint16_t flags, off_t size,
+int nbd_init(int fd, QIOChannelSocket *sioc, NBDExportInfo *info,
Error **errp)
{
- unsigned long sectors = size / BDRV_SECTOR_SIZE;
- if (size / BDRV_SECTOR_SIZE != sectors) {
- error_setg(errp, "Export size %lld too large for 32-bit kernel",
- (long long) size);
+ unsigned long sector_size = MAX(BDRV_SECTOR_SIZE, info->min_block);
+ unsigned long sectors = info->size / sector_size;
+
+ /* FIXME: Once the kernel module is patched to honor block sizes,
+ * and to advertise that fact to user space, we should update the
+ * hand-off to the kernel to use any block sizes we learned. */
+ assert(!info->request_sizes);
+ if (info->size / sector_size != sectors) {
+ error_setg(errp, "Export size %" PRIu64 " too large for 32-bit kernel",
+ info->size);
return -E2BIG;
}
return -serrno;
}
- trace_nbd_init_set_block_size(BDRV_SECTOR_SIZE);
+ trace_nbd_init_set_block_size(sector_size);
- if (ioctl(fd, NBD_SET_BLKSIZE, (unsigned long)BDRV_SECTOR_SIZE) < 0) {
+ if (ioctl(fd, NBD_SET_BLKSIZE, sector_size) < 0) {
int serrno = errno;
error_setg(errp, "Failed setting NBD block size");
return -serrno;
}
trace_nbd_init_set_size(sectors);
- if (size % BDRV_SECTOR_SIZE) {
- trace_nbd_init_trailing_bytes(size % BDRV_SECTOR_SIZE);
+ if (info->size % sector_size) {
+ trace_nbd_init_trailing_bytes(info->size % sector_size);
}
if (ioctl(fd, NBD_SET_SIZE_BLOCKS, sectors) < 0) {
return -serrno;
}
- if (ioctl(fd, NBD_SET_FLAGS, (unsigned long) flags) < 0) {
+ if (ioctl(fd, NBD_SET_FLAGS, (unsigned long) info->flags) < 0) {
if (errno == ENOTTY) {
- int read_only = (flags & NBD_FLAG_READ_ONLY) != 0;
+ int read_only = (info->flags & NBD_FLAG_READ_ONLY) != 0;
trace_nbd_init_set_readonly();
if (ioctl(fd, BLKROSET, (unsigned long) &read_only) < 0) {
}
#else
-int nbd_init(int fd, QIOChannelSocket *ioc, uint16_t flags, off_t size,
+int nbd_init(int fd, QIOChannelSocket *ioc, NBDExportInfo *info,
Error **errp)
{
error_setg(errp, "nbd_init is only supported on Linux");
}
#endif
-ssize_t nbd_send_request(QIOChannel *ioc, NBDRequest *request)
+int nbd_send_request(QIOChannel *ioc, NBDRequest *request)
{
uint8_t buf[NBD_REQUEST_SIZE];
trace_nbd_send_request(request->from, request->len, request->handle,
- request->flags, request->type);
+ request->flags, request->type,
+ nbd_cmd_lookup(request->type));
stl_be_p(buf, NBD_REQUEST_MAGIC);
stw_be_p(buf + 4, request->flags);
return nbd_write(ioc, buf, sizeof(buf), NULL);
}
-ssize_t nbd_receive_reply(QIOChannel *ioc, NBDReply *reply, Error **errp)
+/* nbd_receive_reply
+ * Returns 1 on success
+ * 0 on eof, when no data was read (errp is not set)
+ * negative errno on failure (errp is set)
+ */
+int nbd_receive_reply(QIOChannel *ioc, NBDReply *reply, Error **errp)
{
uint8_t buf[NBD_REPLY_SIZE];
uint32_t magic;
- ssize_t ret;
+ int ret;
ret = nbd_read_eof(ioc, buf, sizeof(buf), errp);
if (ret <= 0) {
return ret;
}
- if (ret != sizeof(buf)) {
- error_setg(errp, "read failed");
- return -EINVAL;
- }
-
/* Reply
[ 0 .. 3] magic (NBD_REPLY_MAGIC)
[ 4 .. 7] error (0 == no error)
error_setg(errp, "invalid magic (got 0x%" PRIx32 ")", magic);
return -EINVAL;
}
- return sizeof(buf);
+
+ return 1;
}
projects / qemu.git / blobdiff