diff --git a/include/block/nbd.h b/include/block/nbd.h index 80610ff31b..fd58390d5d 100644 --- a/include/block/nbd.h +++ b/include/block/nbd.h @@ -115,6 +115,7 @@ BlockBackend *nbd_export_get_blockdev(NBDExport *exp); NBDExport *nbd_export_find(const char *name); void nbd_export_set_name(NBDExport *exp, const char *name); +void nbd_export_set_description(NBDExport *exp, const char *description); void nbd_export_close_all(void); void nbd_client_new(NBDExport *exp, diff --git a/nbd/nbd-internal.h b/nbd/nbd-internal.h index 93a6ca8549..7e78064021 100644 --- a/nbd/nbd-internal.h +++ b/nbd/nbd-internal.h @@ -104,9 +104,10 @@ static inline ssize_t read_sync(QIOChannel *ioc, void *buffer, size_t size) return nbd_wr_syncv(ioc, &iov, 1, size, true); } -static inline ssize_t write_sync(QIOChannel *ioc, void *buffer, size_t size) +static inline ssize_t write_sync(QIOChannel *ioc, const void *buffer, + size_t size) { - struct iovec iov = { .iov_base = buffer, .iov_len = size }; + struct iovec iov = { .iov_base = (void *) buffer, .iov_len = size }; return nbd_wr_syncv(ioc, &iov, 1, size, false); } diff --git a/nbd/server.c b/nbd/server.c index 36bcafcd50..ac42391b45 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -61,6 +61,7 @@ struct NBDExport { BlockBackend *blk; char *name; + char *description; off_t dev_offset; off_t size; uint16_t nbdflags; @@ -129,7 +130,8 @@ static ssize_t nbd_negotiate_read(QIOChannel *ioc, void *buffer, size_t size) } -static ssize_t nbd_negotiate_write(QIOChannel *ioc, void *buffer, size_t size) +static ssize_t nbd_negotiate_write(QIOChannel *ioc, const void *buffer, + size_t size) { ssize_t ret; guint watch; @@ -225,11 +227,15 @@ static int nbd_negotiate_send_rep(QIOChannel *ioc, uint32_t type, uint32_t opt) static int nbd_negotiate_send_rep_list(QIOChannel *ioc, NBDExport *exp) { - uint64_t magic, name_len; + uint64_t magic; + size_t name_len, desc_len; uint32_t opt, type, len; + const char *name = exp->name ? exp->name : ""; + const char *desc = exp->description ? exp->description : ""; - TRACE("Advertising export name '%s'", exp->name ? exp->name : ""); - name_len = strlen(exp->name); + TRACE("Advertising export name '%s' description '%s'", name, desc); + name_len = strlen(name); + desc_len = strlen(desc); magic = cpu_to_be64(NBD_REP_MAGIC); if (nbd_negotiate_write(ioc, &magic, sizeof(magic)) != sizeof(magic)) { LOG("write failed (magic)"); @@ -245,18 +251,22 @@ static int nbd_negotiate_send_rep_list(QIOChannel *ioc, NBDExport *exp) LOG("write failed (reply type)"); return -EINVAL; } - len = cpu_to_be32(name_len + sizeof(len)); + len = cpu_to_be32(name_len + desc_len + sizeof(len)); if (nbd_negotiate_write(ioc, &len, sizeof(len)) != sizeof(len)) { LOG("write failed (length)"); return -EINVAL; } len = cpu_to_be32(name_len); if (nbd_negotiate_write(ioc, &len, sizeof(len)) != sizeof(len)) { - LOG("write failed (length)"); + LOG("write failed (name length)"); return -EINVAL; } - if (nbd_negotiate_write(ioc, exp->name, name_len) != name_len) { - LOG("write failed (buffer)"); + if (nbd_negotiate_write(ioc, name, name_len) != name_len) { + LOG("write failed (name buffer)"); + return -EINVAL; + } + if (nbd_negotiate_write(ioc, desc, desc_len) != desc_len) { + LOG("write failed (description buffer)"); return -EINVAL; } return 0; @@ -894,6 +904,12 @@ void nbd_export_set_name(NBDExport *exp, const char *name) nbd_export_put(exp); } +void nbd_export_set_description(NBDExport *exp, const char *description) +{ + g_free(exp->description); + exp->description = g_strdup(description); +} + void nbd_export_close(NBDExport *exp) { NBDClient *client, *next; @@ -903,6 +919,7 @@ void nbd_export_close(NBDExport *exp) client_close(client); } nbd_export_set_name(exp, NULL); + nbd_export_set_description(exp, NULL); nbd_export_put(exp); } @@ -921,6 +938,7 @@ void nbd_export_put(NBDExport *exp) if (--exp->refcount == 0) { assert(exp->name == NULL); + assert(exp->description == NULL); if (exp->close) { exp->close(exp); diff --git a/qemu-nbd.c b/qemu-nbd.c index b757dc7621..c734f627b4 100644 --- a/qemu-nbd.c +++ b/qemu-nbd.c @@ -83,6 +83,7 @@ static void usage(const char *name) " -t, --persistent don't exit on the last connection\n" " -v, --verbose display extra debugging information\n" " -x, --export-name=NAME expose export by name\n" +" -D, --description=TEXT with -x, also export a human-readable description\n" "\n" "Exposing part of the image:\n" " -o, --offset=OFFSET offset into the image\n" @@ -477,7 +478,7 @@ int main(int argc, char **argv) off_t fd_size; QemuOpts *sn_opts = NULL; const char *sn_id_or_name = NULL; - const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:x:T:"; + const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:x:T:D:"; struct option lopt[] = { { "help", no_argument, NULL, 'h' }, { "version", no_argument, NULL, 'V' }, @@ -503,6 +504,7 @@ int main(int argc, char **argv) { "verbose", no_argument, NULL, 'v' }, { "object", required_argument, NULL, QEMU_NBD_OPT_OBJECT }, { "export-name", required_argument, NULL, 'x' }, + { "description", required_argument, NULL, 'D' }, { "tls-creds", required_argument, NULL, QEMU_NBD_OPT_TLSCREDS }, { "image-opts", no_argument, NULL, QEMU_NBD_OPT_IMAGE_OPTS }, { "trace", required_argument, NULL, 'T' }, @@ -524,6 +526,7 @@ int main(int argc, char **argv) BlockdevDetectZeroesOptions detect_zeroes = BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF; QDict *options = NULL; const char *export_name = NULL; + const char *export_description = NULL; const char *tlscredsid = NULL; bool imageOpts = false; bool writethrough = true; @@ -689,6 +692,9 @@ int main(int argc, char **argv) case 'x': export_name = optarg; break; + case 'D': + export_description = optarg; + break; case 'v': verbose = 1; break; @@ -937,7 +943,11 @@ int main(int argc, char **argv) } if (export_name) { nbd_export_set_name(exp, export_name); + nbd_export_set_description(exp, export_description); newproto = true; + } else if (export_description) { + error_report("Export description requires an export name"); + exit(EXIT_FAILURE); } server_ioc = qio_channel_socket_new(); diff --git a/qemu-nbd.texi b/qemu-nbd.texi index b7a9c6d02f..9a84e81eed 100644 --- a/qemu-nbd.texi +++ b/qemu-nbd.texi @@ -79,9 +79,12 @@ Disconnect the device @var{dev} Allow up to @var{num} clients to share the device (default @samp{1}) @item -t, --persistent Don't exit on the last connection -@item -x NAME, --export-name=NAME +@item -x, --export-name=@var{name} Set the NBD volume export name. This switches the server to use the new style NBD protocol negotiation +@item -D, --description=@var{description} +Set the NBD volume export description, as a human-readable +string. Requires the use of @option{-x} @item --tls-creds=ID Enable mandatory TLS encryption for the server by setting the ID of the TLS credentials object previously created with the --object