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authorVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>2018-03-12 18:21:20 +0300
committerEric Blake <eblake@redhat.com>2018-03-13 15:38:55 -0500
commit12296459f4319e5d0a0f720ffc3d52113cde026e (patch)
treeb83e985cd7c984a6ebedbf0b8a2c4d979529d664
parent2e425fd56849d36485131b3363ab596d39e0e13b (diff)
nbd/server: add nbd_read_opt_name helper
Add helper to read name in format: uint32 len (<= NBD_MAX_NAME_SIZE) len bytes string (not 0-terminated) The helper will be reused in following patch. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20180312152126.286890-3-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> [eblake: grammar fixes, actually check error] Signed-off-by: Eric Blake <eblake@redhat.com>
-rw-r--r--nbd/server.c53
1 files changed, 43 insertions, 10 deletions
diff --git a/nbd/server.c b/nbd/server.c
index 01ea97afe9..280bdbb104 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -273,6 +273,48 @@ 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 a string with the 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-null, it will be set to the actual 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 +497,10 @@ 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);
+ rc = nbd_opt_read_name(client, name, &namelen, errp);
if (rc <= 0) {
return rc;
}
- name[namelen] = '\0';
trace_nbd_negotiate_handle_export_name_request(name);
rc = nbd_opt_read(client, &requests, sizeof(requests), errp);