diff options
| author | Eric Blake <eblake@redhat.com> | 2023-06-08 08:56:37 -0500 |
|---|---|---|
| committer | Eric Blake <eblake@redhat.com> | 2023-07-19 15:26:13 -0500 |
| commit | bfe04d0a7d5e8a4f4c9014ee7622af2056685974 (patch) | |
| tree | 3d3a227cacfa83af30af271e695d327953952954 /include/block/nbd.h | |
| parent | 70fa99f445a6fabe4b46f188cc665cd469cd8293 (diff) | |
nbd: Use enum for various negotiation modes
Deciphering the hard-coded list of integer return values from
nbd_start_negotiate() will only get more confusing when adding support
for 64-bit extended headers. Better is to name things in an enum.
Although the function in question is private to client.c, putting the
enum in a public header and including an enum-to-string conversion
will allow its use in more places in upcoming patches.
The enum is intentionally laid out so that operators like <= can be
used to group multiple modes with similar characteristics, and where
the least powerful mode has value 0, even though this patch does not
exploit that. No semantic change intended.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-ID: <20230608135653.2918540-9-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Diffstat (limited to 'include/block/nbd.h')
| -rw-r--r-- | include/block/nbd.h | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/include/block/nbd.h b/include/block/nbd.h index fb935d56e5..4428bcffbb 100644 --- a/include/block/nbd.h +++ b/include/block/nbd.h @@ -53,6 +53,16 @@ typedef struct NBDOptionReplyMetaContext { /* metadata context name follows */ } QEMU_PACKED NBDOptionReplyMetaContext; +/* Track results of negotiation */ +typedef enum NBDMode { + /* Keep this list in a continuum of increasing features. */ + NBD_MODE_OLDSTYLE, /* server lacks newstyle negotiation */ + NBD_MODE_EXPORT_NAME, /* newstyle but only OPT_EXPORT_NAME safe */ + NBD_MODE_SIMPLE, /* newstyle but only simple replies */ + NBD_MODE_STRUCTURED, /* newstyle, structured replies enabled */ + /* TODO add NBD_MODE_EXTENDED */ +} NBDMode; + /* Transmission phase structs * * Note: these are _NOT_ the same as the network representation of an NBD @@ -405,6 +415,7 @@ const char *nbd_rep_lookup(uint32_t rep); const char *nbd_info_lookup(uint16_t info); const char *nbd_cmd_lookup(uint16_t info); const char *nbd_err_lookup(int err); +const char *nbd_mode_lookup(NBDMode mode); /* nbd/client-connection.c */ void nbd_client_connection_enable_retry(NBDClientConnection *conn); |