diff options
| -rw-r--r-- | nbd/client.c | 49 |
1 files changed, 32 insertions, 17 deletions
diff --git a/nbd/client.c b/nbd/client.c index 77cc12356f..6829c684fe 100644 --- a/nbd/client.c +++ b/nbd/client.c @@ -814,7 +814,7 @@ static int nbd_negotiate_simple_meta_context(QIOChannel *ioc, * Start the handshake to the server. After a positive return, the server * is ready to accept additional NBD_OPT requests. * Returns: negative errno: failure talking to server - * 0: server is oldstyle, client must still parse export size + * 0: server is oldstyle, must call nbd_negotiate_finish_oldstyle * 1: server is newstyle, but can only accept EXPORT_NAME * 2: server is newstyle, but lacks structured replies * 3: server is newstyle and set up for structured replies @@ -921,6 +921,36 @@ static int nbd_start_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, } /* + * nbd_negotiate_finish_oldstyle: + * Populate @info with the size and export flags from an oldstyle server, + * but does not consume 124 bytes of reserved zero padding. + * Returns 0 on success, -1 with @errp set on failure + */ +static int nbd_negotiate_finish_oldstyle(QIOChannel *ioc, NBDExportInfo *info, + Error **errp) +{ + uint32_t oldflags; + + if (nbd_read(ioc, &info->size, sizeof(info->size), errp) < 0) { + error_prepend(errp, "Failed to read export length: "); + return -EINVAL; + } + info->size = be64_to_cpu(info->size); + + if (nbd_read(ioc, &oldflags, sizeof(oldflags), errp) < 0) { + error_prepend(errp, "Failed to read export flags: "); + return -EINVAL; + } + oldflags = be32_to_cpu(oldflags); + if (oldflags & ~0xffff) { + error_setg(errp, "Unexpected export flags %0x" PRIx32, oldflags); + return -EINVAL; + } + info->flags = oldflags; + return 0; +} + +/* * nbd_receive_negotiate: * Connect to server, complete negotiation, and move into transmission phase. * Returns: negative errno: failure talking to server @@ -933,7 +963,6 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, int result; bool zeroes; bool base_allocation = info->base_allocation; - uint32_t oldflags; assert(info->name); trace_nbd_receive_negotiate_name(info->name); @@ -1006,23 +1035,9 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, error_setg(errp, "Server does not support non-empty export names"); return -EINVAL; } - - if (nbd_read(ioc, &info->size, sizeof(info->size), errp) < 0) { - error_prepend(errp, "Failed to read export length: "); - return -EINVAL; - } - info->size = be64_to_cpu(info->size); - - if (nbd_read(ioc, &oldflags, sizeof(oldflags), errp) < 0) { - error_prepend(errp, "Failed to read export flags: "); - return -EINVAL; - } - oldflags = be32_to_cpu(oldflags); - if (oldflags & ~0xffff) { - error_setg(errp, "Unexpected export flags %0x" PRIx32, oldflags); + if (nbd_negotiate_finish_oldstyle(ioc, info, errp) < 0) { return -EINVAL; } - info->flags = oldflags; break; default: return result; |