diff options
| -rw-r--r-- | nbd/client.c | 145 | ||||
| -rw-r--r-- | nbd/trace-events | 2 |
2 files changed, 96 insertions, 51 deletions
diff --git a/nbd/client.c b/nbd/client.c index 9028fd0939..77cc12356f 100644 --- a/nbd/client.c +++ b/nbd/client.c @@ -809,22 +809,26 @@ static int nbd_negotiate_simple_meta_context(QIOChannel *ioc, return received; } -int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, - const char *hostname, QIOChannel **outioc, - NBDExportInfo *info, Error **errp) +/* + * nbd_start_negotiate: + * 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 + * 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 + */ +static int nbd_start_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, + const char *hostname, QIOChannel **outioc, + bool structured_reply, bool *zeroes, + Error **errp) { uint64_t magic; - bool zeroes = true; - bool structured_reply = info->structured_reply; - bool base_allocation = info->base_allocation; - trace_nbd_receive_negotiate(tlscreds, hostname ? hostname : "<null>"); - - assert(info->name); - trace_nbd_receive_negotiate_name(info->name); - info->structured_reply = false; - info->base_allocation = false; + trace_nbd_start_negotiate(tlscreds, hostname ? hostname : "<null>"); + *zeroes = true; if (outioc) { *outioc = NULL; } @@ -868,7 +872,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, clientflags |= NBD_FLAG_C_FIXED_NEWSTYLE; } if (globalflags & NBD_FLAG_NO_ZEROES) { - zeroes = false; + *zeroes = false; clientflags |= NBD_FLAG_C_NO_ZEROES; } /* client requested flags */ @@ -890,7 +894,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, } } if (fixedNewStyle) { - int result; + int result = 0; if (structured_reply) { result = nbd_request_simple_option(ioc, @@ -899,39 +903,85 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, if (result < 0) { return -EINVAL; } - info->structured_reply = result == 1; } + return 2 + result; + } else { + return 1; + } + } else if (magic == NBD_CLIENT_MAGIC) { + if (tlscreds) { + error_setg(errp, "Server does not support STARTTLS"); + return -EINVAL; + } + return 0; + } else { + error_setg(errp, "Bad server magic received: 0x%" PRIx64, magic); + return -EINVAL; + } +} - if (info->structured_reply && base_allocation) { - result = nbd_negotiate_simple_meta_context(ioc, info, errp); - if (result < 0) { - return -EINVAL; - } - info->base_allocation = result == 1; - } +/* + * nbd_receive_negotiate: + * Connect to server, complete negotiation, and move into transmission phase. + * Returns: negative errno: failure talking to server + * 0: server is connected + */ +int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, + const char *hostname, QIOChannel **outioc, + NBDExportInfo *info, Error **errp) +{ + int result; + bool zeroes; + bool base_allocation = info->base_allocation; + uint32_t oldflags; - /* Try NBD_OPT_GO first - if it works, we are done (it - * also gives us a good message if the server requires - * TLS). If it is not available, fall back to - * NBD_OPT_LIST for nicer error messages about a missing - * export, then use NBD_OPT_EXPORT_NAME. */ - result = nbd_opt_go(ioc, info, errp); + assert(info->name); + trace_nbd_receive_negotiate_name(info->name); + + result = nbd_start_negotiate(ioc, tlscreds, hostname, outioc, + info->structured_reply, &zeroes, errp); + + info->structured_reply = false; + info->base_allocation = false; + if (tlscreds && *outioc) { + ioc = *outioc; + } + + switch (result) { + case 3: /* newstyle, with structured replies */ + info->structured_reply = true; + if (base_allocation) { + result = nbd_negotiate_simple_meta_context(ioc, info, errp); if (result < 0) { return -EINVAL; } - if (result > 0) { - return 0; - } - /* Check our desired export is present in the - * server export list. Since NBD_OPT_EXPORT_NAME - * cannot return an error message, running this - * query gives us better error reporting if the - * export name is not available. - */ - if (nbd_receive_query_exports(ioc, info->name, errp) < 0) { - return -EINVAL; - } + info->base_allocation = result == 1; + } + /* fall through */ + case 2: /* newstyle, try OPT_GO */ + /* Try NBD_OPT_GO first - if it works, we are done (it + * also gives us a good message if the server requires + * TLS). If it is not available, fall back to + * NBD_OPT_LIST for nicer error messages about a missing + * export, then use NBD_OPT_EXPORT_NAME. */ + result = nbd_opt_go(ioc, info, errp); + if (result < 0) { + return -EINVAL; } + if (result > 0) { + return 0; + } + /* Check our desired export is present in the + * server export list. Since NBD_OPT_EXPORT_NAME + * cannot return an error message, running this + * query gives us better error reporting if the + * export name is not available. + */ + if (nbd_receive_query_exports(ioc, info->name, errp) < 0) { + return -EINVAL; + } + /* fall through */ + case 1: /* newstyle, but limited to EXPORT_NAME */ /* write the export name request */ if (nbd_send_option_request(ioc, NBD_OPT_EXPORT_NAME, -1, info->name, errp) < 0) { @@ -950,17 +1000,12 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, return -EINVAL; } info->flags = be16_to_cpu(info->flags); - } else if (magic == NBD_CLIENT_MAGIC) { - uint32_t oldflags; - + break; + case 0: /* oldstyle, parse length and flags */ if (*info->name) { error_setg(errp, "Server does not support non-empty export names"); return -EINVAL; } - if (tlscreds) { - error_setg(errp, "Server does not support STARTTLS"); - return -EINVAL; - } if (nbd_read(ioc, &info->size, sizeof(info->size), errp) < 0) { error_prepend(errp, "Failed to read export length: "); @@ -978,9 +1023,9 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, return -EINVAL; } info->flags = oldflags; - } else { - error_setg(errp, "Bad server magic received: 0x%" PRIx64, magic); - return -EINVAL; + break; + default: + return result; } trace_nbd_receive_negotiate_size_flags(info->size, info->flags); diff --git a/nbd/trace-events b/nbd/trace-events index b4802c1570..663d11687a 100644 --- a/nbd/trace-events +++ b/nbd/trace-events @@ -14,7 +14,7 @@ nbd_receive_starttls_new_client(void) "Setting up TLS" nbd_receive_starttls_tls_handshake(void) "Starting TLS handshake" 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 *optname, const char *context, uint32_t id) "Received %s mapping of %s to id %" PRIu32 -nbd_receive_negotiate(void *tlscreds, const char *hostname) "Receiving negotiation tlscreds=%p hostname=%s" +nbd_start_negotiate(void *tlscreds, const char *hostname) "Receiving negotiation tlscreds=%p hostname=%s" nbd_receive_negotiate_magic(uint64_t magic) "Magic is 0x%" PRIx64 nbd_receive_negotiate_server_flags(uint32_t globalflags) "Global flags are 0x%" PRIx32 nbd_receive_negotiate_name(const char *name) "Requesting NBD export name '%s'" |