Add helper to read name in format:
uint32 len (<= NBD_MAX_NAME_SIZE)
len bytes string (not 0-terminated)
The helper would be reused in following patch.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
---
v2: splitted and changed a lot helper from larger patch of v1
nbd/server.c | 55 ++++++++++++++++++++++++++++++++++++++++++-------------
1 file changed, 42 insertions(+), 13 deletions(-)
diff --git a/nbd/server.c b/nbd/server.c
index d163964cf9..085e14afbf 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -273,6 +273,47 @@ static int nbd_opt_read(NBDClient *client, void *buffer,
size_t size,
return qio_channel_read_all(client->ioc, buffer, size, errp) < 0 ? -EIO :
1;
}
+/* nbd_opt_read_name
+ *
+ * Read string in format:
+ * uint32_t len (<= NBD_MAX_NAME_SIZE)
+ * len bytes string (not 0-terminated)
+ *
+ * @name should be enough to store NBD_MAX_NAME_SIZE+1.
+ * if @length is non-zero, it would be set to read string length.
+ *
+ * Return -errno on I/O error, 0 if option was completely handled by
+ * sending a reply about inconsistent lengths, or 1 on success. */
+static int nbd_opt_read_name(NBDClient *client, char *name, uint32_t *length,
+ Error **errp)
+{
+ int ret;
+ uint32_t len;
+
+ ret = nbd_opt_read(client, &len, sizeof(len), errp);
+ if (ret <= 0) {
+ return ret;
+ }
+ cpu_to_be32s(&len);
+
+ if (len > NBD_MAX_NAME_SIZE) {
+ return nbd_opt_invalid(client, errp,
+ "Invalid name length: %" PRIu32, len);
+ }
+
+ ret = nbd_opt_read(client, name, len, errp);
+ if (ret <= 0) {
+ return ret;
+ }
+ name[len] = '\0';
+
+ if (length) {
+ *length = len;
+ }
+
+ return 1;
+}
+
/* Send a single NBD_REP_SERVER reply to NBD_OPT_LIST, including payload.
* Return -errno on error, 0 on success. */
static int nbd_negotiate_send_rep_list(NBDClient *client, NBDExport *exp,
@@ -455,19 +496,7 @@ static int nbd_negotiate_handle_info(NBDClient *client,
uint16_t myflags,
2 bytes: N, number of requests (can be 0)
N * 2 bytes: N requests
*/
- rc = nbd_opt_read(client, &namelen, sizeof(namelen), errp);
- if (rc <= 0) {
- return rc;
- }
- be32_to_cpus(&namelen);
- if (namelen >= sizeof(name)) {
- return nbd_opt_invalid(client, errp, "name too long for qemu");
- }
- rc = nbd_opt_read(client, name, namelen, errp);
- if (rc <= 0) {
- return rc;
- }
- name[namelen] = '\0';
+ rc = nbd_opt_read_name(client, name, &namelen, errp);
trace_nbd_negotiate_handle_export_name_request(name);
rc = nbd_opt_read(client, &requests, sizeof(requests), errp);
--
2.11.1
