This is added by handling the NBD_OPT_LIST and NBD_OPT_ABORT options. NBD_REP_ERR_UNSUP is also sent for unknown NBD option values.
Signed-off-by: Hani Benhabiles <h...@linux.com> --- include/block/nbd.h | 5 ++ nbd.c | 197 +++++++++++++++++++++++++++++++++++++++++----------- 2 files changed, 162 insertions(+), 40 deletions(-) diff --git a/include/block/nbd.h b/include/block/nbd.h index 95d52ab..fd7e057 100644 --- a/include/block/nbd.h +++ b/include/block/nbd.h @@ -51,6 +51,11 @@ struct nbd_reply { /* 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_CMD_MASK_COMMAND 0x0000ffff #define NBD_CMD_FLAG_FUA (1 << 16) diff --git a/nbd.c b/nbd.c index aa2e552..012e5da 100644 --- a/nbd.c +++ b/nbd.c @@ -64,6 +64,7 @@ #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 +78,9 @@ #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 */ @@ -215,54 +218,98 @@ 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; - - /* Client sends: - [ 0 .. 3] client flags - [ 4 .. 11] NBD_OPTS_MAGIC - [12 .. 15] NBD_OPT_EXPORT_NAME - [16 .. 19] length - [20 .. xx] export name (length bytes) - */ + uint32_t len; - 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 client flags"); - tmp = be32_to_cpu(tmp); - if (tmp != 0 && tmp != NBD_FLAG_C_FIXED_NEWSTYLE) { - LOG("Bad client flags 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 opts magic"); - 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; } - TRACE("Checking option"); - if (tmp != be32_to_cpu(NBD_OPT_EXPORT_NAME)) { - LOG("Bad option received"); - goto fail; + opt = cpu_to_be32(NBD_OPT_LIST); + if (write_sync(csock, &opt, sizeof(opt)) != sizeof(opt)) { + LOG("write failed (opt)"); + return -EINVAL; + } + 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; +} + +static int nbd_send_list(NBDClient *client) +{ + int csock; + NBDExport *exp; + + csock = client->sock; + /* 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) +{ + int rc = -EINVAL, csock = client->sock; + char name[256]; + uint32_t length; + /* Client sends: + [16 .. 19] length + [20 .. xx] export name (length bytes) + */ if (read_sync(csock, &length, sizeof(length)) != sizeof(length)) { LOG("read failed"); goto fail; @@ -287,8 +334,76 @@ static int nbd_receive_options(NBDClient *client) QTAILQ_INSERT_TAIL(&client->exp->clients, client, next); nbd_export_get(client->exp); + rc = 0; +fail: + return rc; +} + +static int nbd_receive_options(NBDClient *client) +{ + int rc = -EINVAL; - TRACE("Option negotiation succeeded."); + while (1) { + int csock = client->sock; + uint32_t tmp; + uint64_t magic; + + /* Client sends: + [ 0 .. 3] client flags + [ 4 .. 11] NBD_OPTS_MAGIC + [12 .. 15] NBD option + ... Rest of request + */ + + if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) { + LOG("read failed"); + goto fail; + } + TRACE("Checking client flags"); + tmp = be32_to_cpu(tmp); + if (tmp != 0 && tmp != NBD_FLAG_C_FIXED_NEWSTYLE) { + LOG("Bad client flags received"); + goto fail; + } + + if (read_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) { + LOG("read failed"); + goto fail; + } + TRACE("Checking opts magic"); + if (magic != be64_to_cpu(NBD_OPTS_MAGIC)) { + LOG("Bad magic received"); + goto fail; + } + + if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) { + LOG("read failed"); + goto fail; + } + + TRACE("Checking option"); + switch (be32_to_cpu(tmp)) { + case NBD_OPT_LIST: + if (nbd_send_list(client) < 0) { + return -EINVAL; + } + break; + + case NBD_OPT_ABORT: + return 1; + + case NBD_OPT_EXPORT_NAME: + return nbd_handle_export_name(client); + + default: + tmp = be32_to_cpu(tmp); + LOG("Unsupported option 0x%x", tmp); + if (nbd_send_rep(client->sock, NBD_REP_ERR_UNSUP, tmp)) { + return -EINVAL; + } + return 1; + } + } rc = 0; fail: return rc; @@ -351,6 +466,8 @@ static int nbd_send_negotiate(NBDClient *client) if (rc < 0) { LOG("option negotiation failed"); goto fail; + } else if (rc > 0) { + goto fail; } assert ((client->exp->nbdflags & ~65535) == 0); @@ -1175,7 +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; } -- 1.8.3.2