diff options
| -rw-r--r-- | nbd/server.c | 122 |
1 files changed, 62 insertions, 60 deletions
diff --git a/nbd/server.c b/nbd/server.c index 04da1c2f1e..78b08f5891 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -229,6 +229,40 @@ nbd_negotiate_send_rep_err(NBDClient *client, uint32_t type, return ret; } +/* Drop remainder of the current option, and send a reply with the + * given error type and message. Return -errno on read or write + * failure; or 0 if connection is still live. */ +static int GCC_FMT_ATTR(4, 5) +nbd_opt_drop(NBDClient *client, uint32_t type, Error **errp, + const char *fmt, ...) +{ + int ret = nbd_drop(client->ioc, client->optlen, errp); + va_list va; + + client->optlen = 0; + if (!ret) { + va_start(va, fmt); + ret = nbd_negotiate_send_rep_verr(client, type, errp, fmt, va); + va_end(va); + } + return ret; +} + +/* Read size bytes from the unparsed payload of the current option. + * Return -errno on I/O error, 0 if option was completely handled by + * sending a reply about inconsistent lengths, or 1 on success. */ +static int nbd_opt_read(NBDClient *client, void *buffer, size_t size, + Error **errp) +{ + if (size > client->optlen) { + return nbd_opt_drop(client, NBD_REP_ERR_INVALID, errp, + "Inconsistent lengths in option %s", + nbd_opt_lookup(client->opt)); + } + client->optlen -= size; + return qio_channel_read_all(client->ioc, buffer, size, errp) < 0 ? -EIO : 1; +} + /* Send a single NBD_REP_SERVER reply to NBD_OPT_LIST, including payload. * Return -errno on error, 0 on success. */ static int nbd_negotiate_send_rep_list(NBDClient *client, NBDExport *exp, @@ -378,14 +412,11 @@ static int nbd_reject_length(NBDClient *client, bool fatal, Error **errp) int ret; assert(client->optlen); - if (nbd_drop(client->ioc, client->optlen, errp) < 0) { - return -EIO; - } - ret = nbd_negotiate_send_rep_err(client, NBD_REP_ERR_INVALID, errp, - "option '%s' should have zero length", - nbd_opt_lookup(client->opt)); + ret = nbd_opt_drop(client, NBD_REP_ERR_INVALID, errp, + "option '%s' has unexpected length", + nbd_opt_lookup(client->opt)); if (fatal && !ret) { - error_setg(errp, "option '%s' should have zero length", + error_setg(errp, "option '%s' has unexpected length", nbd_opt_lookup(client->opt)); return -EINVAL; } @@ -408,7 +439,6 @@ static int nbd_negotiate_handle_info(NBDClient *client, uint16_t myflags, 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) @@ -416,48 +446,34 @@ static int nbd_negotiate_handle_info(NBDClient *client, uint16_t myflags, 2 bytes: N, number of requests (can be 0) N * 2 bytes: N requests */ - if (client->optlen < sizeof(namelen) + sizeof(requests)) { - msg = "overall request too short"; - goto invalid; - } - if (nbd_read(client->ioc, &namelen, sizeof(namelen), errp) < 0) { - return -EIO; + rc = nbd_opt_read(client, &namelen, sizeof(namelen), errp); + if (rc <= 0) { + return rc; } be32_to_cpus(&namelen); - client->optlen -= sizeof(namelen); - if (namelen > client->optlen - sizeof(requests) || - (client->optlen - namelen) % 2) - { - msg = "name length is incorrect"; - goto invalid; - } if (namelen >= sizeof(name)) { - msg = "name too long for qemu"; - goto invalid; + return nbd_opt_drop(client, NBD_REP_ERR_INVALID, errp, + "name too long for qemu"); } - if (nbd_read(client->ioc, name, namelen, errp) < 0) { - return -EIO; + rc = nbd_opt_read(client, name, namelen, errp); + if (rc <= 0) { + return rc; } name[namelen] = '\0'; - client->optlen -= namelen; trace_nbd_negotiate_handle_export_name_request(name); - if (nbd_read(client->ioc, &requests, sizeof(requests), errp) < 0) { - return -EIO; + rc = nbd_opt_read(client, &requests, sizeof(requests), errp); + if (rc <= 0) { + return rc; } be16_to_cpus(&requests); - client->optlen -= sizeof(requests); trace_nbd_negotiate_handle_info_requests(requests); - if (requests != client->optlen / 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; + rc = nbd_opt_read(client, &request, sizeof(request), errp); + if (rc <= 0) { + return rc; } be16_to_cpus(&request); - client->optlen -= sizeof(request); trace_nbd_negotiate_handle_info_request(request, nbd_info_lookup(request)); /* We care about NBD_INFO_NAME and NBD_INFO_BLOCK_SIZE; @@ -472,7 +488,9 @@ static int nbd_negotiate_handle_info(NBDClient *client, uint16_t myflags, break; } } - assert(client->optlen == 0); + if (client->optlen) { + return nbd_reject_length(client, false, errp); + } exp = nbd_export_find(name); if (!exp) { @@ -560,13 +578,6 @@ static int nbd_negotiate_handle_info(NBDClient *client, uint16_t myflags, rc = 1; } return rc; - - invalid: - if (nbd_drop(client->ioc, client->optlen, errp) < 0) { - return -EIO; - } - return nbd_negotiate_send_rep_err(client, NBD_REP_ERR_INVALID, - errp, "%s", msg); } @@ -696,6 +707,7 @@ static int nbd_negotiate_options(NBDClient *client, uint16_t myflags, return -EINVAL; } length = be32_to_cpu(length); + assert(!client->optlen); client->optlen = length; if (length > NBD_MAX_BUFFER_SIZE) { @@ -736,14 +748,9 @@ static int nbd_negotiate_options(NBDClient *client, uint16_t myflags, return -EINVAL; default: - if (nbd_drop(client->ioc, length, errp) < 0) { - return -EIO; - } - ret = nbd_negotiate_send_rep_err(client, - NBD_REP_ERR_TLS_REQD, errp, - "Option 0x%" PRIx32 - "not permitted before TLS", - option); + ret = nbd_opt_drop(client, NBD_REP_ERR_TLS_REQD, errp, + "Option 0x%" PRIx32 + "not permitted before TLS", option); /* 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. */ @@ -812,14 +819,9 @@ static int nbd_negotiate_options(NBDClient *client, uint16_t myflags, break; default: - if (nbd_drop(client->ioc, length, errp) < 0) { - return -EIO; - } - ret = nbd_negotiate_send_rep_err(client, - NBD_REP_ERR_UNSUP, errp, - "Unsupported option 0x%" - PRIx32 " (%s)", option, - nbd_opt_lookup(option)); + ret = nbd_opt_drop(client, NBD_REP_ERR_UNSUP, errp, + "Unsupported option 0x%" PRIx32 " (%s)", + option, nbd_opt_lookup(option)); break; } } else { |