diff options
| -rw-r--r-- | blockdev-nbd.c | 5 | ||||
| -rw-r--r-- | include/block/nbd.h | 12 | ||||
| -rw-r--r-- | nbd.c | 217 | ||||
| -rw-r--r-- | qemu-nbd.c | 1 |
4 files changed, 186 insertions, 49 deletions
diff --git a/blockdev-nbd.c b/blockdev-nbd.c index b60b66d66c..b3a24740b2 100644 --- a/blockdev-nbd.c +++ b/blockdev-nbd.c @@ -28,6 +28,7 @@ static void nbd_accept(void *opaque) int fd = accept(server_fd, (struct sockaddr *)&addr, &addr_len); if (fd >= 0 && !nbd_client_new(NULL, fd, nbd_client_put)) { + shutdown(fd, 2); close(fd); } } @@ -91,6 +92,10 @@ void qmp_nbd_server_add(const char *device, bool has_writable, bool writable, error_set(errp, QERR_DEVICE_NOT_FOUND, device); return; } + if (!bdrv_is_inserted(bs)) { + error_set(errp, QERR_DEVICE_HAS_NO_MEDIUM, device); + return; + } if (!has_writable) { writable = false; diff --git a/include/block/nbd.h b/include/block/nbd.h index 79502a090b..9e835d2cbb 100644 --- a/include/block/nbd.h +++ b/include/block/nbd.h @@ -45,6 +45,18 @@ struct nbd_reply { #define NBD_FLAG_ROTATIONAL (1 << 4) /* Use elevator algorithm - rotational media */ #define NBD_FLAG_SEND_TRIM (1 << 5) /* Send TRIM (discard) */ +/* New-style global flags. */ +#define NBD_FLAG_FIXED_NEWSTYLE (1 << 0) /* Fixed newstyle protocol. */ + +/* New-style client flags. */ +#define NBD_FLAG_C_FIXED_NEWSTYLE (1 << 0) /* Fixed newstyle protocol. */ + +/* Reply types. */ +#define NBD_REP_ACK (1) /* Data sending finished. */ +#define NBD_REP_SERVER (2) /* Export description. */ +#define NBD_REP_ERR_UNSUP ((1 << 31) | 1) /* Unknown option. */ +#define NBD_REP_ERR_INVALID ((1 << 31) | 3) /* Invalid length. */ + #define NBD_CMD_MASK_COMMAND 0x0000ffff #define NBD_CMD_FLAG_FUA (1 << 16) diff --git a/nbd.c b/nbd.c index e0d032c252..e7d1ceec43 100644 --- a/nbd.c +++ b/nbd.c @@ -56,7 +56,11 @@ __FILE__, __FUNCTION__, __LINE__, ## __VA_ARGS__); \ } while(0) -/* This is all part of the "official" NBD API */ +/* This is all part of the "official" NBD API. + * + * The most up-to-date documentation is available at: + * https://github.com/yoe/nbd/blob/master/doc/proto.txt + */ #define NBD_REQUEST_SIZE (4 + 4 + 8 + 8 + 4) #define NBD_REPLY_SIZE (4 + 4 + 8) @@ -64,6 +68,7 @@ #define NBD_REPLY_MAGIC 0x67446698 #define NBD_OPTS_MAGIC 0x49484156454F5054LL #define NBD_CLIENT_MAGIC 0x0000420281861253LL +#define NBD_REP_MAGIC 0x3e889045565a9LL #define NBD_SET_SOCK _IO(0xab, 0) #define NBD_SET_BLKSIZE _IO(0xab, 1) @@ -77,7 +82,9 @@ #define NBD_SET_TIMEOUT _IO(0xab, 9) #define NBD_SET_FLAGS _IO(0xab, 10) -#define NBD_OPT_EXPORT_NAME (1 << 0) +#define NBD_OPT_EXPORT_NAME (1) +#define NBD_OPT_ABORT (2) +#define NBD_OPT_LIST (3) /* Definitions for opaque data types */ @@ -215,59 +222,101 @@ static ssize_t write_sync(int fd, void *buffer, size_t size) */ -static int nbd_receive_options(NBDClient *client) +static int nbd_send_rep(int csock, uint32_t type, uint32_t opt) { - int csock = client->sock; - char name[256]; - uint32_t tmp, length; uint64_t magic; - int rc; + uint32_t len; - /* Client sends: - [ 0 .. 3] reserved (0) - [ 4 .. 11] NBD_OPTS_MAGIC - [12 .. 15] NBD_OPT_EXPORT_NAME - [16 .. 19] length - [20 .. xx] export name (length bytes) - */ - - rc = -EINVAL; - if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) { - LOG("read failed"); - goto fail; + magic = cpu_to_be64(NBD_REP_MAGIC); + if (write_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) { + LOG("write failed (rep magic)"); + return -EINVAL; } - TRACE("Checking reserved"); - if (tmp != 0) { - LOG("Bad reserved received"); - goto fail; + opt = cpu_to_be32(opt); + if (write_sync(csock, &opt, sizeof(opt)) != sizeof(opt)) { + LOG("write failed (rep opt)"); + return -EINVAL; } - - if (read_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) { - LOG("read failed"); - goto fail; + type = cpu_to_be32(type); + if (write_sync(csock, &type, sizeof(type)) != sizeof(type)) { + LOG("write failed (rep type)"); + return -EINVAL; } - TRACE("Checking reserved"); - if (magic != be64_to_cpu(NBD_OPTS_MAGIC)) { - LOG("Bad magic received"); - goto fail; + len = cpu_to_be32(0); + if (write_sync(csock, &len, sizeof(len)) != sizeof(len)) { + LOG("write failed (rep data length)"); + return -EINVAL; } + return 0; +} - if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) { - LOG("read failed"); - goto fail; +static int nbd_send_rep_list(int csock, NBDExport *exp) +{ + uint64_t magic, name_len; + uint32_t opt, type, len; + + name_len = strlen(exp->name); + magic = cpu_to_be64(NBD_REP_MAGIC); + if (write_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) { + LOG("write failed (magic)"); + return -EINVAL; + } + opt = cpu_to_be32(NBD_OPT_LIST); + if (write_sync(csock, &opt, sizeof(opt)) != sizeof(opt)) { + LOG("write failed (opt)"); + return -EINVAL; } - TRACE("Checking option"); - if (tmp != be32_to_cpu(NBD_OPT_EXPORT_NAME)) { - LOG("Bad option received"); - goto fail; + type = cpu_to_be32(NBD_REP_SERVER); + if (write_sync(csock, &type, sizeof(type)) != sizeof(type)) { + LOG("write failed (reply type)"); + return -EINVAL; } + len = cpu_to_be32(name_len + sizeof(len)); + if (write_sync(csock, &len, sizeof(len)) != sizeof(len)) { + LOG("write failed (length)"); + return -EINVAL; + } + len = cpu_to_be32(name_len); + if (write_sync(csock, &len, sizeof(len)) != sizeof(len)) { + LOG("write failed (length)"); + return -EINVAL; + } + if (write_sync(csock, exp->name, name_len) != name_len) { + LOG("write failed (buffer)"); + return -EINVAL; + } + return 0; +} - if (read_sync(csock, &length, sizeof(length)) != sizeof(length)) { - LOG("read failed"); - goto fail; +static int nbd_handle_list(NBDClient *client, uint32_t length) +{ + int csock; + NBDExport *exp; + + csock = client->sock; + if (length) { + return nbd_send_rep(csock, NBD_REP_ERR_INVALID, NBD_OPT_LIST); } + + /* For each export, send a NBD_REP_SERVER reply. */ + QTAILQ_FOREACH(exp, &exports, next) { + if (nbd_send_rep_list(csock, exp)) { + return -EINVAL; + } + } + /* Finish with a NBD_REP_ACK. */ + return nbd_send_rep(csock, NBD_REP_ACK, NBD_OPT_LIST); +} + +static int nbd_handle_export_name(NBDClient *client, uint32_t length) +{ + int rc = -EINVAL, csock = client->sock; + char name[256]; + + /* Client sends: + [20 .. xx] export name (length bytes) + */ TRACE("Checking length"); - length = be32_to_cpu(length); if (length > 255) { LOG("Bad length received"); goto fail; @@ -286,13 +335,81 @@ static int nbd_receive_options(NBDClient *client) QTAILQ_INSERT_TAIL(&client->exp->clients, client, next); nbd_export_get(client->exp); - - TRACE("Option negotiation succeeded."); rc = 0; fail: return rc; } +static int nbd_receive_options(NBDClient *client) +{ + while (1) { + int csock = client->sock; + uint32_t tmp, length; + uint64_t magic; + + /* Client sends: + [ 0 .. 3] client flags + [ 4 .. 11] NBD_OPTS_MAGIC + [12 .. 15] NBD option + [16 .. 19] length + ... Rest of request + */ + + if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) { + LOG("read failed"); + return -EINVAL; + } + TRACE("Checking client flags"); + tmp = be32_to_cpu(tmp); + if (tmp != 0 && tmp != NBD_FLAG_C_FIXED_NEWSTYLE) { + LOG("Bad client flags received"); + return -EINVAL; + } + + if (read_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) { + LOG("read failed"); + return -EINVAL; + } + TRACE("Checking opts magic"); + if (magic != be64_to_cpu(NBD_OPTS_MAGIC)) { + LOG("Bad magic received"); + return -EINVAL; + } + + if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) { + LOG("read failed"); + return -EINVAL; + } + + if (read_sync(csock, &length, sizeof(length)) != sizeof(length)) { + LOG("read failed"); + return -EINVAL; + } + length = be32_to_cpu(length); + + TRACE("Checking option"); + switch (be32_to_cpu(tmp)) { + case NBD_OPT_LIST: + if (nbd_handle_list(client, length) < 0) { + return 1; + } + break; + + case NBD_OPT_ABORT: + return -EINVAL; + + case NBD_OPT_EXPORT_NAME: + return nbd_handle_export_name(client, length); + + default: + tmp = be32_to_cpu(tmp); + LOG("Unsupported option 0x%x", tmp); + nbd_send_rep(client->sock, NBD_REP_ERR_UNSUP, tmp); + return -EINVAL; + } + } +} + static int nbd_send_negotiate(NBDClient *client) { int csock = client->sock; @@ -333,6 +450,7 @@ static int nbd_send_negotiate(NBDClient *client) cpu_to_be16w((uint16_t*)(buf + 26), client->exp->nbdflags | myflags); } else { cpu_to_be64w((uint64_t*)(buf + 8), NBD_OPTS_MAGIC); + cpu_to_be16w((uint16_t *)(buf + 16), NBD_FLAG_FIXED_NEWSTYLE); } if (client->exp) { @@ -346,7 +464,7 @@ static int nbd_send_negotiate(NBDClient *client) goto fail; } rc = nbd_receive_options(client); - if (rc < 0) { + if (rc != 0) { LOG("option negotiation failed"); goto fail; } @@ -1001,6 +1119,7 @@ static void nbd_trip(void *opaque) struct nbd_request request; struct nbd_reply reply; ssize_t ret; + uint32_t command; TRACE("Reading request."); if (client->closing) { @@ -1023,8 +1142,8 @@ static void nbd_trip(void *opaque) reply.error = -ret; goto error_reply; } - - if ((request.from + request.len) > exp->size) { + command = request.type & NBD_CMD_MASK_COMMAND; + if (command != NBD_CMD_DISC && (request.from + request.len) > exp->size) { LOG("From: %" PRIu64 ", Len: %u, Size: %" PRIu64 ", Offset: %" PRIu64 "\n", request.from, request.len, @@ -1033,7 +1152,7 @@ static void nbd_trip(void *opaque) goto invalid_request; } - switch (request.type & NBD_CMD_MASK_COMMAND) { + switch (command) { case NBD_CMD_READ: TRACE("Request type is READ"); @@ -1173,7 +1292,7 @@ NBDClient *nbd_client_new(NBDExport *exp, int csock, client->refcount = 1; client->exp = exp; client->sock = csock; - if (nbd_send_negotiate(client) < 0) { + if (nbd_send_negotiate(client)) { g_free(client); return NULL; } diff --git a/qemu-nbd.c b/qemu-nbd.c index ba6043680a..626e5844f9 100644 --- a/qemu-nbd.c +++ b/qemu-nbd.c @@ -372,6 +372,7 @@ static void nbd_accept(void *opaque) if (nbd_client_new(exp, fd, nbd_client_closed)) { nb_fds++; } else { + shutdown(fd, 2); close(fd); } } |