diff options
author | Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> | 2018-03-12 18:21:20 +0300 |
---|---|---|
committer | Eric Blake <eblake@redhat.com> | 2018-03-13 15:38:55 -0500 |
commit | 12296459f4319e5d0a0f720ffc3d52113cde026e (patch) | |
tree | b83e985cd7c984a6ebedbf0b8a2c4d979529d664 | |
parent | 2e425fd56849d36485131b3363ab596d39e0e13b (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.c | 53 |
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); |