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Diffstat (limited to 'nbd/client.c')
-rw-r--r--nbd/client.c195
1 files changed, 192 insertions, 3 deletions
diff --git a/nbd/client.c b/nbd/client.c
index 88f2ada..be5f08d 100644
--- a/nbd/client.c
+++ b/nbd/client.c
@@ -71,6 +71,177 @@ static QTAILQ_HEAD(, NBDExport) exports = QTAILQ_HEAD_INITIALIZER(exports);
*/
+
+static int nbd_handle_reply_err(uint32_t opt, uint32_t type, Error **errp)
+{
+ if (!(type & (1 << 31))) {
+ return 0;
+ }
+
+ switch (type) {
+ case NBD_REP_ERR_UNSUP:
+ error_setg(errp, "Unsupported option type %x", opt);
+ break;
+
+ case NBD_REP_ERR_INVALID:
+ error_setg(errp, "Invalid data length for option %x", opt);
+ break;
+
+ default:
+ error_setg(errp, "Unknown error code when asking for option %x", opt);
+ break;
+ }
+
+ return -1;
+}
+
+static int nbd_receive_list(QIOChannel *ioc, char **name, Error **errp)
+{
+ uint64_t magic;
+ uint32_t opt;
+ uint32_t type;
+ uint32_t len;
+ uint32_t namelen;
+
+ *name = NULL;
+ if (read_sync(ioc, &magic, sizeof(magic)) != sizeof(magic)) {
+ error_setg(errp, "failed to read list option magic");
+ return -1;
+ }
+ magic = be64_to_cpu(magic);
+ if (magic != NBD_REP_MAGIC) {
+ error_setg(errp, "Unexpected option list magic");
+ return -1;
+ }
+ if (read_sync(ioc, &opt, sizeof(opt)) != sizeof(opt)) {
+ error_setg(errp, "failed to read list option");
+ return -1;
+ }
+ opt = be32_to_cpu(opt);
+ if (opt != NBD_OPT_LIST) {
+ error_setg(errp, "Unexpected option type %x expected %x",
+ opt, NBD_OPT_LIST);
+ return -1;
+ }
+
+ if (read_sync(ioc, &type, sizeof(type)) != sizeof(type)) {
+ error_setg(errp, "failed to read list option type");
+ return -1;
+ }
+ type = be32_to_cpu(type);
+ if (type == NBD_REP_ERR_UNSUP) {
+ return 0;
+ }
+ if (nbd_handle_reply_err(opt, type, errp) < 0) {
+ return -1;
+ }
+
+ if (read_sync(ioc, &len, sizeof(len)) != sizeof(len)) {
+ error_setg(errp, "failed to read option length");
+ return -1;
+ }
+ len = be32_to_cpu(len);
+
+ if (type == NBD_REP_ACK) {
+ if (len != 0) {
+ error_setg(errp, "length too long for option end");
+ return -1;
+ }
+ } else if (type == NBD_REP_SERVER) {
+ if (read_sync(ioc, &namelen, sizeof(namelen)) != sizeof(namelen)) {
+ error_setg(errp, "failed to read option name length");
+ return -1;
+ }
+ namelen = be32_to_cpu(namelen);
+ if (len != (namelen + sizeof(namelen))) {
+ error_setg(errp, "incorrect option mame length");
+ return -1;
+ }
+ if (namelen > 255) {
+ error_setg(errp, "export name length too long %d", namelen);
+ return -1;
+ }
+
+ *name = g_new0(char, namelen + 1);
+ if (read_sync(ioc, *name, namelen) != namelen) {
+ error_setg(errp, "failed to read export name");
+ g_free(*name);
+ *name = NULL;
+ return -1;
+ }
+ (*name)[namelen] = '\0';
+ } else {
+ error_setg(errp, "Unexpected reply type %x expected %x",
+ type, NBD_REP_SERVER);
+ return -1;
+ }
+ return 1;
+}
+
+
+static int nbd_receive_query_exports(QIOChannel *ioc,
+ const char *wantname,
+ Error **errp)
+{
+ uint64_t magic = cpu_to_be64(NBD_OPTS_MAGIC);
+ uint32_t opt = cpu_to_be32(NBD_OPT_LIST);
+ uint32_t length = 0;
+ bool foundExport = false;
+
+ TRACE("Querying export list");
+ if (write_sync(ioc, &magic, sizeof(magic)) != sizeof(magic)) {
+ error_setg(errp, "Failed to send list option magic");
+ return -1;
+ }
+
+ if (write_sync(ioc, &opt, sizeof(opt)) != sizeof(opt)) {
+ error_setg(errp, "Failed to send list option number");
+ return -1;
+ }
+
+ if (write_sync(ioc, &length, sizeof(length)) != sizeof(length)) {
+ error_setg(errp, "Failed to send list option length");
+ return -1;
+ }
+
+ TRACE("Reading available export names");
+ while (1) {
+ char *name = NULL;
+ int ret = nbd_receive_list(ioc, &name, errp);
+
+ if (ret < 0) {
+ g_free(name);
+ name = NULL;
+ return -1;
+ }
+ if (ret == 0) {
+ /* Server doesn't support export listing, so
+ * we will just assume an export with our
+ * wanted name exists */
+ foundExport = true;
+ break;
+ }
+ if (name == NULL) {
+ TRACE("End of export name list");
+ break;
+ }
+ if (g_str_equal(name, wantname)) {
+ foundExport = true;
+ TRACE("Found desired export name '%s'", name);
+ } else {
+ TRACE("Ignored export name '%s'", name);
+ }
+ g_free(name);
+ }
+
+ if (!foundExport) {
+ error_setg(errp, "No export with name '%s' available", wantname);
+ return -1;
+ }
+
+ return 0;
+}
+
int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint32_t *flags,
off_t *size, Error **errp)
{
@@ -121,28 +292,44 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint32_t *flags,
uint32_t namesize;
uint16_t globalflags;
uint16_t exportflags;
+ bool fixedNewStyle = false;
if (read_sync(ioc, &globalflags, sizeof(globalflags)) !=
sizeof(globalflags)) {
error_setg(errp, "Failed to read server flags");
goto fail;
}
- *flags = be16_to_cpu(globalflags) << 16;
+ globalflags = be16_to_cpu(globalflags);
+ *flags = globalflags << 16;
+ TRACE("Global flags are %x", globalflags);
if (globalflags & NBD_FLAG_FIXED_NEWSTYLE) {
+ fixedNewStyle = true;
TRACE("Server supports fixed new style");
clientflags |= NBD_FLAG_C_FIXED_NEWSTYLE;
}
/* client requested flags */
+ clientflags = cpu_to_be32(clientflags);
if (write_sync(ioc, &clientflags, sizeof(clientflags)) !=
sizeof(clientflags)) {
error_setg(errp, "Failed to send clientflags field");
goto fail;
}
- /* write the export name */
if (!name) {
error_setg(errp, "Server requires an export name");
goto fail;
}
+ if (fixedNewStyle) {
+ /* 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
+ */
+ if (nbd_receive_query_exports(ioc, name, errp) < 0) {
+ goto fail;
+ }
+ }
+ /* write the export name */
magic = cpu_to_be64(magic);
if (write_sync(ioc, &magic, sizeof(magic)) != sizeof(magic)) {
error_setg(errp, "Failed to send export name magic");
@@ -176,7 +363,9 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint32_t *flags,
error_setg(errp, "Failed to read export flags");
goto fail;
}
- *flags |= be16_to_cpu(exportflags);
+ exportflags = be16_to_cpu(exportflags);
+ *flags |= exportflags;
+ TRACE("Export flags are %x", exportflags);
} else if (magic == NBD_CLIENT_MAGIC) {
if (name) {
error_setg(errp, "Server does not support export names");