diff options
| -rw-r--r-- | include/block/nbd.h | 15 | ||||
| -rw-r--r-- | nbd/client.c | 132 |
2 files changed, 143 insertions, 4 deletions
diff --git a/include/block/nbd.h b/include/block/nbd.h index be19aac2fc..19332b4671 100644 --- a/include/block/nbd.h +++ b/include/block/nbd.h @@ -1,5 +1,5 @@ /* - * Copyright (C) 2016-2017 Red Hat, Inc. + * Copyright (C) 2016-2019 Red Hat, Inc. * Copyright (C) 2005 Anthony Liguori <anthony@codemonkey.ws> * * Network Block Device @@ -262,6 +262,9 @@ struct NBDExportInfo { /* Set by client before nbd_receive_negotiate() */ bool request_sizes; char *x_dirty_bitmap; + + /* Set by client before nbd_receive_negotiate(), or by server results + * during nbd_receive_export_list() */ char *name; /* must be non-NULL */ /* In-out fields, set by client before nbd_receive_negotiate() and @@ -269,7 +272,8 @@ struct NBDExportInfo { bool structured_reply; bool base_allocation; /* base:allocation context for NBD_CMD_BLOCK_STATUS */ - /* Set by server results during nbd_receive_negotiate() */ + /* Set by server results during nbd_receive_negotiate() and + * nbd_receive_export_list() */ uint64_t size; uint16_t flags; uint32_t min_block; @@ -277,12 +281,19 @@ struct NBDExportInfo { uint32_t max_block; uint32_t context_id; + + /* Set by server results during nbd_receive_export_list() */ + char *description; }; typedef struct NBDExportInfo NBDExportInfo; int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, const char *hostname, QIOChannel **outioc, NBDExportInfo *info, Error **errp); +void nbd_free_export_list(NBDExportInfo *info, int count); +int nbd_receive_export_list(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, + const char *hostname, NBDExportInfo **info, + Error **errp); int nbd_init(int fd, QIOChannelSocket *sioc, NBDExportInfo *info, Error **errp); int nbd_send_request(QIOChannel *ioc, NBDRequest *request); diff --git a/nbd/client.c b/nbd/client.c index fa1657a1cb..8a32169970 100644 --- a/nbd/client.c +++ b/nbd/client.c @@ -836,7 +836,9 @@ static int nbd_start_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, trace_nbd_start_negotiate(tlscreds, hostname ? hostname : "<null>"); - *zeroes = true; + if (zeroes) { + *zeroes = true; + } if (outioc) { *outioc = NULL; } @@ -880,7 +882,9 @@ static int nbd_start_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, clientflags |= NBD_FLAG_C_FIXED_NEWSTYLE; } if (globalflags & NBD_FLAG_NO_ZEROES) { - *zeroes = false; + if (zeroes) { + *zeroes = false; + } clientflags |= NBD_FLAG_C_NO_ZEROES; } /* client requested flags */ @@ -1059,6 +1063,130 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, return 0; } +/* Clean up result of nbd_receive_export_list */ +void nbd_free_export_list(NBDExportInfo *info, int count) +{ + int i; + + if (!info) { + return; + } + + for (i = 0; i < count; i++) { + g_free(info[i].name); + g_free(info[i].description); + } + g_free(info); +} + +/* + * nbd_receive_export_list: + * Query details about a server's exports, then disconnect without + * going into transmission phase. Return a count of the exports listed + * in @info by the server, or -1 on error. Caller must free @info using + * nbd_free_export_list(). + */ +int nbd_receive_export_list(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, + const char *hostname, NBDExportInfo **info, + Error **errp) +{ + int result; + int count = 0; + int i; + int rc; + int ret = -1; + NBDExportInfo *array = NULL; + QIOChannel *sioc = NULL; + + *info = NULL; + result = nbd_start_negotiate(ioc, tlscreds, hostname, &sioc, true, NULL, + errp); + if (tlscreds && sioc) { + ioc = sioc; + } + + switch (result) { + case 2: + case 3: + /* newstyle - use NBD_OPT_LIST to populate array, then try + * NBD_OPT_INFO on each array member. If structured replies + * are enabled, also try NBD_OPT_LIST_META_CONTEXT. */ + if (nbd_send_option_request(ioc, NBD_OPT_LIST, 0, NULL, errp) < 0) { + goto out; + } + while (1) { + char *name; + char *desc; + + rc = nbd_receive_list(ioc, &name, &desc, errp); + if (rc < 0) { + goto out; + } else if (rc == 0) { + break; + } + array = g_renew(NBDExportInfo, array, ++count); + memset(&array[count - 1], 0, sizeof(*array)); + array[count - 1].name = name; + array[count - 1].description = desc; + array[count - 1].structured_reply = result == 3; + } + + for (i = 0; i < count; i++) { + array[i].request_sizes = true; + rc = nbd_opt_info_or_go(ioc, NBD_OPT_INFO, &array[i], errp); + if (rc < 0) { + goto out; + } else if (rc == 0) { + /* + * Pointless to try rest of loop. If OPT_INFO doesn't work, + * it's unlikely that meta contexts work either + */ + break; + } + + /* TODO: Grab meta contexts */ + } + + /* Send NBD_OPT_ABORT as a courtesy before hanging up */ + nbd_send_opt_abort(ioc); + break; + case 1: /* newstyle, but limited to EXPORT_NAME */ + error_setg(errp, "Server does not support export lists"); + /* We can't even send NBD_OPT_ABORT, so merely hang up */ + goto out; + case 0: /* oldstyle, parse length and flags */ + array = g_new0(NBDExportInfo, 1); + array->name = g_strdup(""); + count = 1; + + if (nbd_negotiate_finish_oldstyle(ioc, array, errp) < 0) { + goto out; + } + + /* Send NBD_CMD_DISC as a courtesy to the server, but ignore all + * errors now that we have the information we wanted. */ + if (nbd_drop(ioc, 124, NULL) == 0) { + NBDRequest request = { .type = NBD_CMD_DISC }; + + nbd_send_request(ioc, &request); + } + break; + default: + goto out; + } + + *info = array; + array = NULL; + ret = count; + + out: + qio_channel_shutdown(ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL); + qio_channel_close(ioc, NULL); + object_unref(OBJECT(sioc)); + nbd_free_export_list(array, count); + return ret; +} + #ifdef __linux__ int nbd_init(int fd, QIOChannelSocket *sioc, NBDExportInfo *info, Error **errp) |