Refactor nbd_negotiate_simple_meta_context() to pull out the code that can be reused to send a LIST request for 0 or 1 query. No semantic change. The old comment about 'sizeof(uint32_t)' being equivalent to '/* number of queries */' is no longer needed, now that we are computing 'sizeof(queries)' instead.
Signed-off-by: Eric Blake <ebl...@redhat.com> Message-Id: <20181215135324.152629-14-ebl...@redhat.com> Reviewed-by: Richard W.M. Jones <rjo...@redhat.com> --- v3: Improve commit message [Rich], formatting tweak [checkpatch], rebase to dropped patch --- nbd/client.c | 67 +++++++++++++++++++++++++++++++++--------------- nbd/trace-events | 2 +- 2 files changed, 48 insertions(+), 21 deletions(-) diff --git a/nbd/client.c b/nbd/client.c index 77993890f04..3c716be2719 100644 --- a/nbd/client.c +++ b/nbd/client.c @@ -629,6 +629,49 @@ static QIOChannel *nbd_receive_starttls(QIOChannel *ioc, return QIO_CHANNEL(tioc); } +/* + * nbd_send_one_meta_context: + * Send 0 or 1 set/list meta context queries. + * Return 0 on success, -1 with errp set for any error + */ +static int nbd_send_one_meta_context(QIOChannel *ioc, + uint32_t opt, + const char *export, + const char *query, + Error **errp) +{ + int ret; + uint32_t export_len = strlen(export); + uint32_t queries = !!query; + uint32_t context_len = 0; + uint32_t data_len; + char *data; + char *p; + + data_len = sizeof(export_len) + export_len + sizeof(queries); + if (query) { + context_len = strlen(query); + data_len += sizeof(context_len) + context_len; + } else { + assert(opt == NBD_OPT_LIST_META_CONTEXT); + } + data = g_malloc(data_len); + p = data; + + trace_nbd_opt_meta_request(nbd_opt_lookup(opt), query ?: "(all)", export); + stl_be_p(p, export_len); + memcpy(p += sizeof(export_len), export, export_len); + stl_be_p(p += export_len, queries); + if (query) { + stl_be_p(p += sizeof(uint32_t), context_len); + memcpy(p += sizeof(context_len), query, context_len); + } + + ret = nbd_send_option_request(ioc, opt, data_len, data, errp); + g_free(data); + return ret; +} + /* nbd_negotiate_simple_meta_context: * Request the server to set the meta context for export @info->name * using @info->x_dirty_bitmap with a fallback to "base:allocation", @@ -653,26 +696,10 @@ static int nbd_negotiate_simple_meta_context(QIOChannel *ioc, NBDOptionReply reply; const char *context = info->x_dirty_bitmap ?: "base:allocation"; bool received = false; - uint32_t export_len = strlen(info->name); - uint32_t context_len = strlen(context); - uint32_t data_len = sizeof(export_len) + export_len + - sizeof(uint32_t) + /* number of queries */ - sizeof(context_len) + context_len; - char *data = g_malloc(data_len); - char *p = data; - trace_nbd_opt_meta_request(context, info->name); - stl_be_p(p, export_len); - memcpy(p += sizeof(export_len), info->name, export_len); - stl_be_p(p += export_len, 1); - stl_be_p(p += sizeof(uint32_t), context_len); - memcpy(p += sizeof(context_len), context, context_len); - - ret = nbd_send_option_request(ioc, NBD_OPT_SET_META_CONTEXT, data_len, data, - errp); - g_free(data); - if (ret < 0) { - return ret; + if (nbd_send_one_meta_context(ioc, NBD_OPT_SET_META_CONTEXT, + info->name, context, errp) < 0) { + return -1; } if (nbd_receive_option_reply(ioc, NBD_OPT_SET_META_CONTEXT, &reply, @@ -689,7 +716,7 @@ static int nbd_negotiate_simple_meta_context(QIOChannel *ioc, if (reply.type == NBD_REP_META_CONTEXT) { char *name; - if (reply.length != sizeof(info->context_id) + context_len) { + if (reply.length != sizeof(info->context_id) + strlen(context)) { error_setg(errp, "Failed to negotiate meta context '%s', server " "answered with unexpected length %" PRIu32, context, reply.length); diff --git a/nbd/trace-events b/nbd/trace-events index c3966d2b653..59521e47a3d 100644 --- a/nbd/trace-events +++ b/nbd/trace-events @@ -12,7 +12,7 @@ nbd_receive_query_exports_start(const char *wantname) "Querying export list for nbd_receive_query_exports_success(const char *wantname) "Found desired export name '%s'" nbd_receive_starttls_new_client(void) "Setting up TLS" nbd_receive_starttls_tls_handshake(void) "Starting TLS handshake" -nbd_opt_meta_request(const char *context, const char *export) "Requesting to set meta context %s for export %s" +nbd_opt_meta_request(const char *optname, const char *context, const char *export) "Requesting %s %s for export %s" nbd_opt_meta_reply(const char *context, uint32_t id) "Received mapping of context %s to id %" PRIu32 nbd_receive_negotiate(void *tlscreds, const char *hostname) "Receiving negotiation tlscreds=%p hostname=%s" nbd_receive_negotiate_magic(uint64_t magic) "Magic is 0x%" PRIx64 -- 2.20.1