diff options
Diffstat (limited to 'nbd/server.c')
| -rw-r--r-- | nbd/server.c | 304 |
1 files changed, 259 insertions, 45 deletions
diff --git a/nbd/server.c b/nbd/server.c index 9b0c588146..49ed57455c 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -1,5 +1,5 @@ /* - * Copyright (C) 2016 Red Hat, Inc. + * Copyright (C) 2016-2017 Red Hat, Inc. * Copyright (C) 2005 Anthony Liguori <anthony@codemonkey.ws> * * Network Block Device Server Side @@ -84,7 +84,6 @@ struct NBDClient { int refcount; void (*close_fn)(NBDClient *client, bool negotiated); - bool no_zeroes; NBDExport *exp; QCryptoTLSCreds *tlscreds; char *tlsaclname; @@ -139,8 +138,10 @@ static int nbd_negotiate_send_rep_len(QIOChannel *ioc, uint32_t type, { uint64_t magic; - trace_nbd_negotiate_send_rep_len(opt, type, len); + trace_nbd_negotiate_send_rep_len(opt, nbd_opt_lookup(opt), + type, nbd_rep_lookup(type), len); + assert(len < NBD_MAX_BUFFER_SIZE); magic = cpu_to_be64(NBD_REP_MAGIC); if (nbd_write(ioc, &magic, sizeof(magic), errp) < 0) { error_prepend(errp, "write failed (rep magic): "); @@ -275,10 +276,16 @@ static int nbd_negotiate_handle_list(NBDClient *client, uint32_t length, return nbd_negotiate_send_rep(client->ioc, NBD_REP_ACK, NBD_OPT_LIST, errp); } +/* Send a reply to NBD_OPT_EXPORT_NAME. + * Return -errno on error, 0 on success. */ static int nbd_negotiate_handle_export_name(NBDClient *client, uint32_t length, + uint16_t myflags, bool no_zeroes, Error **errp) { char name[NBD_MAX_NAME_SIZE + 1]; + char buf[8 + 4 + 124] = ""; + size_t len; + int ret; /* Client sends: [20 .. xx] export name (length bytes) @@ -302,12 +309,219 @@ static int nbd_negotiate_handle_export_name(NBDClient *client, uint32_t length, return -EINVAL; } + trace_nbd_negotiate_new_style_size_flags(client->exp->size, + client->exp->nbdflags | myflags); + stq_be_p(buf, client->exp->size); + stw_be_p(buf + 8, client->exp->nbdflags | myflags); + len = no_zeroes ? 10 : sizeof(buf); + ret = nbd_write(client->ioc, buf, len, errp); + if (ret < 0) { + error_prepend(errp, "write failed: "); + return ret; + } + QTAILQ_INSERT_TAIL(&client->exp->clients, client, next); nbd_export_get(client->exp); return 0; } +/* Send a single NBD_REP_INFO, with a buffer @buf of @length bytes. + * The buffer does NOT include the info type prefix. + * Return -errno on error, 0 if ready to send more. */ +static int nbd_negotiate_send_info(NBDClient *client, uint32_t opt, + uint16_t info, uint32_t length, void *buf, + Error **errp) +{ + int rc; + + trace_nbd_negotiate_send_info(info, nbd_info_lookup(info), length); + rc = nbd_negotiate_send_rep_len(client->ioc, NBD_REP_INFO, opt, + sizeof(info) + length, errp); + if (rc < 0) { + return rc; + } + cpu_to_be16s(&info); + if (nbd_write(client->ioc, &info, sizeof(info), errp) < 0) { + return -EIO; + } + if (nbd_write(client->ioc, buf, length, errp) < 0) { + return -EIO; + } + return 0; +} + +/* Handle NBD_OPT_INFO and NBD_OPT_GO. + * Return -errno on error, 0 if ready for next option, and 1 to move + * into transmission phase. */ +static int nbd_negotiate_handle_info(NBDClient *client, uint32_t length, + uint32_t opt, uint16_t myflags, + Error **errp) +{ + int rc; + char name[NBD_MAX_NAME_SIZE + 1]; + NBDExport *exp; + uint16_t requests; + uint16_t request; + uint32_t namelen; + bool sendname = false; + bool blocksize = false; + uint32_t sizes[3]; + char buf[sizeof(uint64_t) + sizeof(uint16_t)]; + const char *msg; + + /* Client sends: + 4 bytes: L, name length (can be 0) + L bytes: export name + 2 bytes: N, number of requests (can be 0) + N * 2 bytes: N requests + */ + if (length < sizeof(namelen) + sizeof(requests)) { + msg = "overall request too short"; + goto invalid; + } + if (nbd_read(client->ioc, &namelen, sizeof(namelen), errp) < 0) { + return -EIO; + } + be32_to_cpus(&namelen); + length -= sizeof(namelen); + if (namelen > length - sizeof(requests) || (length - namelen) % 2) { + msg = "name length is incorrect"; + goto invalid; + } + if (nbd_read(client->ioc, name, namelen, errp) < 0) { + return -EIO; + } + name[namelen] = '\0'; + length -= namelen; + trace_nbd_negotiate_handle_export_name_request(name); + + if (nbd_read(client->ioc, &requests, sizeof(requests), errp) < 0) { + return -EIO; + } + be16_to_cpus(&requests); + length -= sizeof(requests); + trace_nbd_negotiate_handle_info_requests(requests); + if (requests != length / sizeof(request)) { + msg = "incorrect number of requests for overall length"; + goto invalid; + } + while (requests--) { + if (nbd_read(client->ioc, &request, sizeof(request), errp) < 0) { + return -EIO; + } + be16_to_cpus(&request); + length -= sizeof(request); + trace_nbd_negotiate_handle_info_request(request, + nbd_info_lookup(request)); + /* We care about NBD_INFO_NAME and NBD_INFO_BLOCK_SIZE; + * everything else is either a request we don't know or + * something we send regardless of request */ + switch (request) { + case NBD_INFO_NAME: + sendname = true; + break; + case NBD_INFO_BLOCK_SIZE: + blocksize = true; + break; + } + } + + exp = nbd_export_find(name); + if (!exp) { + return nbd_negotiate_send_rep_err(client->ioc, NBD_REP_ERR_UNKNOWN, + opt, errp, "export '%s' not present", + name); + } + + /* Don't bother sending NBD_INFO_NAME unless client requested it */ + if (sendname) { + rc = nbd_negotiate_send_info(client, opt, NBD_INFO_NAME, length, name, + errp); + if (rc < 0) { + return rc; + } + } + + /* Send NBD_INFO_DESCRIPTION only if available, regardless of + * client request */ + if (exp->description) { + size_t len = strlen(exp->description); + + rc = nbd_negotiate_send_info(client, opt, NBD_INFO_DESCRIPTION, + len, exp->description, errp); + if (rc < 0) { + return rc; + } + } + + /* Send NBD_INFO_BLOCK_SIZE always, but tweak the minimum size + * according to whether the client requested it, and according to + * whether this is OPT_INFO or OPT_GO. */ + /* minimum - 1 for back-compat, or 512 if client is new enough. + * TODO: consult blk_bs(blk)->bl.request_alignment? */ + sizes[0] = (opt == NBD_OPT_INFO || blocksize) ? BDRV_SECTOR_SIZE : 1; + /* preferred - Hard-code to 4096 for now. + * TODO: is blk_bs(blk)->bl.opt_transfer appropriate? */ + sizes[1] = 4096; + /* maximum - At most 32M, but smaller as appropriate. */ + sizes[2] = MIN(blk_get_max_transfer(exp->blk), NBD_MAX_BUFFER_SIZE); + trace_nbd_negotiate_handle_info_block_size(sizes[0], sizes[1], sizes[2]); + cpu_to_be32s(&sizes[0]); + cpu_to_be32s(&sizes[1]); + cpu_to_be32s(&sizes[2]); + rc = nbd_negotiate_send_info(client, opt, NBD_INFO_BLOCK_SIZE, + sizeof(sizes), sizes, errp); + if (rc < 0) { + return rc; + } + + /* Send NBD_INFO_EXPORT always */ + trace_nbd_negotiate_new_style_size_flags(exp->size, + exp->nbdflags | myflags); + stq_be_p(buf, exp->size); + stw_be_p(buf + 8, exp->nbdflags | myflags); + rc = nbd_negotiate_send_info(client, opt, NBD_INFO_EXPORT, + sizeof(buf), buf, errp); + if (rc < 0) { + return rc; + } + + /* If the client is just asking for NBD_OPT_INFO, but forgot to + * request block sizes, return an error. + * TODO: consult blk_bs(blk)->request_align, and only error if it + * is not 1? */ + if (opt == NBD_OPT_INFO && !blocksize) { + return nbd_negotiate_send_rep_err(client->ioc, + NBD_REP_ERR_BLOCK_SIZE_REQD, opt, + errp, + "request NBD_INFO_BLOCK_SIZE to " + "use this export"); + } + + /* Final reply */ + rc = nbd_negotiate_send_rep(client->ioc, NBD_REP_ACK, opt, errp); + if (rc < 0) { + return rc; + } + + if (opt == NBD_OPT_GO) { + client->exp = exp; + QTAILQ_INSERT_TAIL(&client->exp->clients, client, next); + nbd_export_get(client->exp); + rc = 1; + } + return rc; + + invalid: + if (nbd_drop(client->ioc, length, errp) < 0) { + return -EIO; + } + return nbd_negotiate_send_rep_err(client->ioc, NBD_REP_ERR_INVALID, opt, + errp, "%s", msg); +} + + /* Handle NBD_OPT_STARTTLS. Return NULL to drop connection, or else the * new channel for all further (now-encrypted) communication. */ static QIOChannel *nbd_negotiate_handle_starttls(NBDClient *client, @@ -365,22 +579,25 @@ static QIOChannel *nbd_negotiate_handle_starttls(NBDClient *client, } /* nbd_negotiate_options - * Process all NBD_OPT_* client option commands. + * Process all NBD_OPT_* client option commands, during fixed newstyle + * negotiation. * Return: * -errno on error, errp is set * 0 on successful negotiation, errp is not set * 1 if client sent NBD_OPT_ABORT, i.e. on valid disconnect, * errp is not set */ -static int nbd_negotiate_options(NBDClient *client, Error **errp) +static int nbd_negotiate_options(NBDClient *client, uint16_t myflags, + Error **errp) { uint32_t flags; bool fixedNewstyle = false; - Error *local_err = NULL; + bool no_zeroes = false; /* Client sends: [ 0 .. 3] client flags + Then we loop until NBD_OPT_EXPORT_NAME or NBD_OPT_GO: [ 0 .. 7] NBD_OPTS_MAGIC [ 8 .. 11] NBD option [12 .. 15] Data length @@ -396,21 +613,19 @@ static int nbd_negotiate_options(NBDClient *client, Error **errp) error_prepend(errp, "read failed: "); return -EIO; } - trace_nbd_negotiate_options_flags(); be32_to_cpus(&flags); + trace_nbd_negotiate_options_flags(flags); if (flags & NBD_FLAG_C_FIXED_NEWSTYLE) { - trace_nbd_negotiate_options_newstyle(); fixedNewstyle = true; flags &= ~NBD_FLAG_C_FIXED_NEWSTYLE; } if (flags & NBD_FLAG_C_NO_ZEROES) { - trace_nbd_negotiate_options_no_zeroes(); - client->no_zeroes = true; + no_zeroes = true; flags &= ~NBD_FLAG_C_NO_ZEROES; } if (flags != 0) { error_setg(errp, "Unknown client flags 0x%" PRIx32 " received", flags); - return -EIO; + return -EINVAL; } while (1) { @@ -442,7 +657,8 @@ static int nbd_negotiate_options(NBDClient *client, Error **errp) } length = be32_to_cpu(length); - trace_nbd_negotiate_options_check_option(option); + trace_nbd_negotiate_options_check_option(option, + nbd_opt_lookup(option)); if (client->tlscreds && client->ioc == (QIOChannel *)client->sioc) { QIOChannel *tioc; @@ -479,7 +695,9 @@ static int nbd_negotiate_options(NBDClient *client, Error **errp) if (ret < 0) { return ret; } - /* Let the client keep trying, unless they asked to quit */ + /* Let the client keep trying, unless they asked to + * quit. In this mode, we've already sent an error, so + * we can't ack the abort. */ if (option == NBD_OPT_ABORT) { return 1; } @@ -498,19 +716,26 @@ static int nbd_negotiate_options(NBDClient *client, Error **errp) /* NBD spec says we must try to reply before * disconnecting, but that we must also tolerate * guests that don't wait for our reply. */ - nbd_negotiate_send_rep(client->ioc, NBD_REP_ACK, option, - &local_err); - - if (local_err != NULL) { - const char *error = error_get_pretty(local_err); - trace_nbd_opt_abort_reply_failed(error); - error_free(local_err); - } - + nbd_negotiate_send_rep(client->ioc, NBD_REP_ACK, option, NULL); return 1; case NBD_OPT_EXPORT_NAME: - return nbd_negotiate_handle_export_name(client, length, errp); + return nbd_negotiate_handle_export_name(client, length, + myflags, no_zeroes, + errp); + + case NBD_OPT_INFO: + case NBD_OPT_GO: + ret = nbd_negotiate_handle_info(client, length, option, + myflags, errp); + if (ret == 1) { + assert(option == NBD_OPT_GO); + return 0; + } + if (ret) { + return ret; + } + break; case NBD_OPT_STARTTLS: if (nbd_drop(client->ioc, length, errp) < 0) { @@ -539,8 +764,8 @@ static int nbd_negotiate_options(NBDClient *client, Error **errp) NBD_REP_ERR_UNSUP, option, errp, "Unsupported option 0x%" - PRIx32, - option); + PRIx32 " (%s)", option, + nbd_opt_lookup(option)); if (ret < 0) { return ret; } @@ -553,10 +778,13 @@ static int nbd_negotiate_options(NBDClient *client, Error **errp) */ switch (option) { case NBD_OPT_EXPORT_NAME: - return nbd_negotiate_handle_export_name(client, length, errp); + return nbd_negotiate_handle_export_name(client, length, + myflags, no_zeroes, + errp); default: - error_setg(errp, "Unsupported option 0x%" PRIx32, option); + error_setg(errp, "Unsupported option 0x%" PRIx32 " (%s)", + option, nbd_opt_lookup(option)); return -EINVAL; } } @@ -578,7 +806,6 @@ static coroutine_fn int nbd_negotiate(NBDClient *client, Error **errp) NBD_FLAG_SEND_FLUSH | NBD_FLAG_SEND_FUA | NBD_FLAG_SEND_WRITE_ZEROES); bool oldStyle; - size_t len; /* Old style negotiation header without options [ 0 .. 7] passwd ("NBDMAGIC") @@ -592,10 +819,7 @@ static coroutine_fn int nbd_negotiate(NBDClient *client, Error **errp) [ 0 .. 7] passwd ("NBDMAGIC") [ 8 .. 15] magic (NBD_OPTS_MAGIC) [16 .. 17] server flags (0) - ....options sent.... - [18 .. 25] size - [26 .. 27] export flags - [28 .. 151] reserved (0, omit if no_zeroes) + ....options sent, ending in NBD_OPT_EXPORT_NAME or NBD_OPT_GO.... */ qio_channel_set_blocking(client->ioc, false, NULL); @@ -624,24 +848,13 @@ static coroutine_fn int nbd_negotiate(NBDClient *client, Error **errp) error_prepend(errp, "write failed: "); return -EINVAL; } - ret = nbd_negotiate_options(client, errp); + ret = nbd_negotiate_options(client, myflags, errp); if (ret != 0) { if (ret < 0) { error_prepend(errp, "option negotiation failed: "); } return ret; } - - trace_nbd_negotiate_new_style_size_flags( - client->exp->size, client->exp->nbdflags | myflags); - stq_be_p(buf + 18, client->exp->size); - stw_be_p(buf + 26, client->exp->nbdflags | myflags); - len = client->no_zeroes ? 10 : sizeof(buf) - 18; - ret = nbd_write(client->ioc, buf + 18, len, errp); - if (ret < 0) { - error_prepend(errp, "write failed: "); - return ret; - } } trace_nbd_negotiate_success(); @@ -1040,7 +1253,8 @@ static int nbd_co_receive_request(NBDRequestData *req, NBDRequest *request, return -EIO; } - trace_nbd_co_receive_request_decode_type(request->handle, request->type); + trace_nbd_co_receive_request_decode_type(request->handle, request->type, + nbd_cmd_lookup(request->type)); if (request->type != NBD_CMD_WRITE) { /* No payload, we are ready to read the next request. */ |