* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
-#include "nbd.h"
-#include "block.h"
+#include "block/nbd.h"
+#include "block/block.h"
-#include "qemu-coroutine.h"
+#include "block/coroutine.h"
#include <errno.h>
#include <string.h>
#include <linux/fs.h>
#endif
-#include "qemu_socket.h"
-#include "qemu-queue.h"
+#include "qemu/sockets.h"
+#include "qemu/queue.h"
+#include "qemu/main-loop.h"
//#define DEBUG_NBD
/* This is all part of the "official" NBD API */
+#define NBD_REQUEST_SIZE (4 + 4 + 8 + 8 + 4)
#define NBD_REPLY_SIZE (4 + 4 + 8)
#define NBD_REQUEST_MAGIC 0x25609513
#define NBD_REPLY_MAGIC 0x67446698
+#define NBD_OPTS_MAGIC 0x49484156454F5054LL
+#define NBD_CLIENT_MAGIC 0x0000420281861253LL
#define NBD_SET_SOCK _IO(0xab, 0)
#define NBD_SET_BLKSIZE _IO(0xab, 1)
#define NBD_OPT_EXPORT_NAME (1 << 0)
+/* Definitions for opaque data types */
+
+typedef struct NBDRequest NBDRequest;
+
+struct NBDRequest {
+ QSIMPLEQ_ENTRY(NBDRequest) entry;
+ NBDClient *client;
+ uint8_t *data;
+};
+
+struct NBDExport {
+ int refcount;
+ void (*close)(NBDExport *exp);
+
+ BlockDriverState *bs;
+ char *name;
+ off_t dev_offset;
+ off_t size;
+ uint32_t nbdflags;
+ QTAILQ_HEAD(, NBDClient) clients;
+ QTAILQ_ENTRY(NBDExport) next;
+};
+
+static QTAILQ_HEAD(, NBDExport) exports = QTAILQ_HEAD_INITIALIZER(exports);
+
+struct NBDClient {
+ int refcount;
+ void (*close)(NBDClient *client);
+
+ NBDExport *exp;
+ int sock;
+
+ Coroutine *recv_coroutine;
+
+ CoMutex send_lock;
+ Coroutine *send_coroutine;
+
+ QTAILQ_ENTRY(NBDClient) next;
+ int nb_requests;
+ bool closing;
+};
+
/* That's all folks */
ssize_t nbd_wr_sync(int fd, void *buffer, size_t size, bool do_read)
return ret;
}
-static void combine_addr(char *buf, size_t len, const char* address,
- uint16_t port)
-{
- /* If the address-part contains a colon, it's an IPv6 IP so needs [] */
- if (strstr(address, ":")) {
- snprintf(buf, len, "[%s]:%u", address, port);
- } else {
- snprintf(buf, len, "%s:%u", address, port);
- }
-}
-
-int tcp_socket_outgoing(const char *address, uint16_t port)
-{
- char address_and_port[128];
- combine_addr(address_and_port, 128, address, port);
- return tcp_socket_outgoing_spec(address_and_port);
-}
+/* Basic flow for negotiation
-int tcp_socket_outgoing_spec(const char *address_and_port)
-{
- return inet_connect(address_and_port, SOCK_STREAM);
-}
+ Server Client
+ Negotiate
-int tcp_socket_incoming(const char *address, uint16_t port)
-{
- char address_and_port[128];
- combine_addr(address_and_port, 128, address, port);
- return tcp_socket_incoming_spec(address_and_port);
-}
+ or
-int tcp_socket_incoming_spec(const char *address_and_port)
-{
- char *ostr = NULL;
- int olen = 0;
- return inet_listen(address_and_port, ostr, olen, SOCK_STREAM, 0);
-}
+ Server Client
+ Negotiate #1
+ Option
+ Negotiate #2
-int unix_socket_incoming(const char *path)
-{
- char *ostr = NULL;
- int olen = 0;
+ ----
- return unix_listen(path, ostr, olen);
-}
-
-int unix_socket_outgoing(const char *path)
-{
- return unix_connect(path);
-}
-
-/* Basic flow
+ followed by
Server Client
-
- Negotiate
Request
Response
Request
...
...
Request (type == 2)
+
*/
-static int nbd_send_negotiate(int csock, off_t size, uint32_t flags)
+static int nbd_receive_options(NBDClient *client)
{
+ int csock = client->sock;
+ char name[256];
+ uint32_t tmp, length;
+ uint64_t magic;
+ int rc;
+
+ /* 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;
+ }
+ TRACE("Checking reserved");
+ if (tmp != 0) {
+ LOG("Bad reserved received");
+ goto fail;
+ }
+
+ if (read_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) {
+ LOG("read failed");
+ goto fail;
+ }
+ TRACE("Checking reserved");
+ 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");
+ if (tmp != be32_to_cpu(NBD_OPT_EXPORT_NAME)) {
+ LOG("Bad option received");
+ goto fail;
+ }
+
+ if (read_sync(csock, &length, sizeof(length)) != sizeof(length)) {
+ LOG("read failed");
+ goto fail;
+ }
+ TRACE("Checking length");
+ length = be32_to_cpu(length);
+ if (length > 255) {
+ LOG("Bad length received");
+ goto fail;
+ }
+ if (read_sync(csock, name, length) != length) {
+ LOG("read failed");
+ goto fail;
+ }
+ name[length] = '\0';
+
+ client->exp = nbd_export_find(name);
+ if (!client->exp) {
+ LOG("export not found");
+ goto fail;
+ }
+
+ 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_send_negotiate(NBDClient *client)
+{
+ int csock = client->sock;
char buf[8 + 8 + 8 + 128];
int rc;
+ const int myflags = (NBD_FLAG_HAS_FLAGS | NBD_FLAG_SEND_TRIM |
+ NBD_FLAG_SEND_FLUSH | NBD_FLAG_SEND_FUA);
- /* Negotiate
- [ 0 .. 7] passwd ("NBDMAGIC")
- [ 8 .. 15] magic (0x00420281861253)
+ /* Negotiation header without options:
+ [ 0 .. 7] passwd ("NBDMAGIC")
+ [ 8 .. 15] magic (NBD_CLIENT_MAGIC)
[16 .. 23] size
- [24 .. 27] flags
- [28 .. 151] reserved (0)
+ [24 .. 25] server flags (0)
+ [26 .. 27] export flags
+ [28 .. 151] reserved (0)
+
+ Negotiation header with options, part 1:
+ [ 0 .. 7] passwd ("NBDMAGIC")
+ [ 8 .. 15] magic (NBD_OPTS_MAGIC)
+ [16 .. 17] server flags (0)
+
+ part 2 (after options are sent):
+ [18 .. 25] size
+ [26 .. 27] export flags
+ [28 .. 151] reserved (0)
*/
- socket_set_block(csock);
+ qemu_set_block(csock);
rc = -EINVAL;
TRACE("Beginning negotiation.");
+ memset(buf, 0, sizeof(buf));
memcpy(buf, "NBDMAGIC", 8);
- cpu_to_be64w((uint64_t*)(buf + 8), 0x00420281861253LL);
- cpu_to_be64w((uint64_t*)(buf + 16), size);
- cpu_to_be32w((uint32_t*)(buf + 24),
- flags | NBD_FLAG_HAS_FLAGS | NBD_FLAG_SEND_TRIM |
- NBD_FLAG_SEND_FLUSH | NBD_FLAG_SEND_FUA);
- memset(buf + 28, 0, 124);
-
- if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
- LOG("write failed");
- goto fail;
+ if (client->exp) {
+ assert ((client->exp->nbdflags & ~65535) == 0);
+ cpu_to_be64w((uint64_t*)(buf + 8), NBD_CLIENT_MAGIC);
+ cpu_to_be64w((uint64_t*)(buf + 16), client->exp->size);
+ cpu_to_be16w((uint16_t*)(buf + 26), client->exp->nbdflags | myflags);
+ } else {
+ cpu_to_be64w((uint64_t*)(buf + 8), NBD_OPTS_MAGIC);
+ }
+
+ if (client->exp) {
+ if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
+ LOG("write failed");
+ goto fail;
+ }
+ } else {
+ if (write_sync(csock, buf, 18) != 18) {
+ LOG("write failed");
+ goto fail;
+ }
+ rc = nbd_receive_options(client);
+ if (rc < 0) {
+ LOG("option negotiation failed");
+ goto fail;
+ }
+
+ assert ((client->exp->nbdflags & ~65535) == 0);
+ cpu_to_be64w((uint64_t*)(buf + 18), client->exp->size);
+ cpu_to_be16w((uint16_t*)(buf + 26), client->exp->nbdflags | myflags);
+ if (write_sync(csock, buf + 18, sizeof(buf) - 18) != sizeof(buf) - 18) {
+ LOG("write failed");
+ goto fail;
+ }
}
TRACE("Negotiation succeeded.");
rc = 0;
fail:
- socket_set_nonblock(csock);
+ qemu_set_nonblock(csock);
return rc;
}
TRACE("Receiving negotiation.");
- socket_set_block(csock);
rc = -EINVAL;
if (read_sync(csock, buf, 8) != 8) {
uint32_t namesize;
TRACE("Checking magic (opts_magic)");
- if (magic != 0x49484156454F5054LL) {
+ if (magic != NBD_OPTS_MAGIC) {
LOG("Bad magic received");
goto fail;
}
} else {
TRACE("Checking magic (cli_magic)");
- if (magic != 0x00420281861253LL) {
+ if (magic != NBD_CLIENT_MAGIC) {
LOG("Bad magic received");
goto fail;
}
rc = 0;
fail:
- socket_set_nonblock(csock);
return rc;
}
return -serrno;
}
- if (flags & NBD_FLAG_READ_ONLY) {
- int read_only = 1;
- TRACE("Setting readonly attribute");
+ if (ioctl(fd, NBD_SET_FLAGS, flags) < 0) {
+ if (errno == ENOTTY) {
+ int read_only = (flags & NBD_FLAG_READ_ONLY) != 0;
+ TRACE("Setting readonly attribute");
- if (ioctl(fd, BLKROSET, (unsigned long) &read_only) < 0) {
+ if (ioctl(fd, BLKROSET, (unsigned long) &read_only) < 0) {
+ int serrno = errno;
+ LOG("Failed setting read-only attribute");
+ return -serrno;
+ }
+ } else {
int serrno = errno;
- LOG("Failed setting read-only attribute");
+ LOG("Failed setting flags");
return -serrno;
}
}
- if (ioctl(fd, NBD_SET_FLAGS, flags) < 0
- && errno != ENOTTY) {
- int serrno = errno;
- LOG("Failed setting flags");
- return -serrno;
- }
-
TRACE("Negotiation ended");
return 0;
ssize_t nbd_send_request(int csock, struct nbd_request *request)
{
- uint8_t buf[4 + 4 + 8 + 8 + 4];
+ uint8_t buf[NBD_REQUEST_SIZE];
ssize_t ret;
cpu_to_be32w((uint32_t*)buf, NBD_REQUEST_MAGIC);
static ssize_t nbd_receive_request(int csock, struct nbd_request *request)
{
- uint8_t buf[4 + 4 + 8 + 8 + 4];
+ uint8_t buf[NBD_REQUEST_SIZE];
uint32_t magic;
ssize_t ret;
static ssize_t nbd_send_reply(int csock, struct nbd_reply *reply)
{
- uint8_t buf[4 + 4 + 8];
+ uint8_t buf[NBD_REPLY_SIZE];
ssize_t ret;
/* Reply
#define MAX_NBD_REQUESTS 16
-typedef struct NBDRequest NBDRequest;
-
-struct NBDRequest {
- QSIMPLEQ_ENTRY(NBDRequest) entry;
- NBDClient *client;
- uint8_t *data;
-};
-
-struct NBDExport {
- BlockDriverState *bs;
- off_t dev_offset;
- off_t size;
- uint32_t nbdflags;
- QSIMPLEQ_HEAD(, NBDRequest) requests;
-};
-
-struct NBDClient {
- int refcount;
- void (*close)(NBDClient *client);
-
- NBDExport *exp;
- int sock;
-
- Coroutine *recv_coroutine;
-
- CoMutex send_lock;
- Coroutine *send_coroutine;
-
- int nb_requests;
-};
-
-static void nbd_client_get(NBDClient *client)
+void nbd_client_get(NBDClient *client)
{
client->refcount++;
}
-static void nbd_client_put(NBDClient *client)
+void nbd_client_put(NBDClient *client)
{
if (--client->refcount == 0) {
+ /* The last reference should be dropped by client->close,
+ * which is called by nbd_client_close.
+ */
+ assert(client->closing);
+
+ qemu_set_fd_handler2(client->sock, NULL, NULL, NULL, NULL);
+ close(client->sock);
+ client->sock = -1;
+ if (client->exp) {
+ QTAILQ_REMOVE(&client->exp->clients, client, next);
+ nbd_export_put(client->exp);
+ }
g_free(client);
}
}
-static void nbd_client_close(NBDClient *client)
+void nbd_client_close(NBDClient *client)
{
- qemu_set_fd_handler2(client->sock, NULL, NULL, NULL, NULL);
- close(client->sock);
- client->sock = -1;
+ if (client->closing) {
+ return;
+ }
+
+ client->closing = true;
+
+ /* Force requests to finish. They will drop their own references,
+ * then we'll close the socket and free the NBDClient.
+ */
+ shutdown(client->sock, 2);
+
+ /* Also tell the client, so that they release their reference. */
if (client->close) {
client->close(client);
}
- nbd_client_put(client);
}
static NBDRequest *nbd_request_get(NBDClient *client)
{
NBDRequest *req;
- NBDExport *exp = client->exp;
assert(client->nb_requests <= MAX_NBD_REQUESTS - 1);
client->nb_requests++;
- if (QSIMPLEQ_EMPTY(&exp->requests)) {
- req = g_malloc0(sizeof(NBDRequest));
- req->data = qemu_blockalign(exp->bs, NBD_BUFFER_SIZE);
- } else {
- req = QSIMPLEQ_FIRST(&exp->requests);
- QSIMPLEQ_REMOVE_HEAD(&exp->requests, entry);
- }
+ req = g_slice_new0(NBDRequest);
nbd_client_get(client);
req->client = client;
return req;
static void nbd_request_put(NBDRequest *req)
{
NBDClient *client = req->client;
- QSIMPLEQ_INSERT_HEAD(&client->exp->requests, req, entry);
+
+ if (req->data) {
+ qemu_vfree(req->data);
+ }
+ g_slice_free(NBDRequest, req);
+
if (client->nb_requests-- == MAX_NBD_REQUESTS) {
qemu_notify_event();
}
}
NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset,
- off_t size, uint32_t nbdflags)
+ off_t size, uint32_t nbdflags,
+ void (*close)(NBDExport *))
{
NBDExport *exp = g_malloc0(sizeof(NBDExport));
- QSIMPLEQ_INIT(&exp->requests);
+ exp->refcount = 1;
+ QTAILQ_INIT(&exp->clients);
exp->bs = bs;
exp->dev_offset = dev_offset;
exp->nbdflags = nbdflags;
exp->size = size == -1 ? bdrv_getlength(bs) : size;
+ exp->close = close;
+ bdrv_ref(bs);
return exp;
}
+NBDExport *nbd_export_find(const char *name)
+{
+ NBDExport *exp;
+ QTAILQ_FOREACH(exp, &exports, next) {
+ if (strcmp(name, exp->name) == 0) {
+ return exp;
+ }
+ }
+
+ return NULL;
+}
+
+void nbd_export_set_name(NBDExport *exp, const char *name)
+{
+ if (exp->name == name) {
+ return;
+ }
+
+ nbd_export_get(exp);
+ if (exp->name != NULL) {
+ g_free(exp->name);
+ exp->name = NULL;
+ QTAILQ_REMOVE(&exports, exp, next);
+ nbd_export_put(exp);
+ }
+ if (name != NULL) {
+ nbd_export_get(exp);
+ exp->name = g_strdup(name);
+ QTAILQ_INSERT_TAIL(&exports, exp, next);
+ }
+ nbd_export_put(exp);
+}
+
void nbd_export_close(NBDExport *exp)
{
- while (!QSIMPLEQ_EMPTY(&exp->requests)) {
- NBDRequest *first = QSIMPLEQ_FIRST(&exp->requests);
- QSIMPLEQ_REMOVE_HEAD(&exp->requests, entry);
- qemu_vfree(first->data);
- g_free(first);
+ NBDClient *client, *next;
+
+ nbd_export_get(exp);
+ QTAILQ_FOREACH_SAFE(client, &exp->clients, next, next) {
+ nbd_client_close(client);
+ }
+ nbd_export_set_name(exp, NULL);
+ nbd_export_put(exp);
+ if (exp->bs) {
+ bdrv_unref(exp->bs);
+ exp->bs = NULL;
}
+}
- bdrv_close(exp->bs);
- g_free(exp);
+void nbd_export_get(NBDExport *exp)
+{
+ assert(exp->refcount > 0);
+ exp->refcount++;
+}
+
+void nbd_export_put(NBDExport *exp)
+{
+ assert(exp->refcount > 0);
+ if (exp->refcount == 1) {
+ nbd_export_close(exp);
+ }
+
+ if (--exp->refcount == 0) {
+ assert(exp->name == NULL);
+
+ if (exp->close) {
+ exp->close(exp);
+ }
+
+ g_free(exp);
+ }
+}
+
+BlockDriverState *nbd_export_get_blockdev(NBDExport *exp)
+{
+ return exp->bs;
+}
+
+void nbd_export_close_all(void)
+{
+ NBDExport *exp, *next;
+
+ QTAILQ_FOREACH_SAFE(exp, &exports, next, next) {
+ nbd_export_close(exp);
+ }
}
static int nbd_can_read(void *opaque);
{
NBDClient *client = req->client;
int csock = client->sock;
+ uint32_t command;
ssize_t rc;
client->recv_coroutine = qemu_coroutine_self();
goto out;
}
- if (request->len > NBD_BUFFER_SIZE) {
+ if (request->len > NBD_MAX_BUFFER_SIZE) {
LOG("len (%u) is larger than max len (%u)",
- request->len, NBD_BUFFER_SIZE);
+ request->len, NBD_MAX_BUFFER_SIZE);
rc = -EINVAL;
goto out;
}
TRACE("Decoding type");
- if ((request->type & NBD_CMD_MASK_COMMAND) == NBD_CMD_WRITE) {
+ command = request->type & NBD_CMD_MASK_COMMAND;
+ if (command == NBD_CMD_READ || command == NBD_CMD_WRITE) {
+ req->data = qemu_blockalign(client->exp->bs, request->len);
+ }
+ if (command == NBD_CMD_WRITE) {
TRACE("Reading %u byte(s)", request->len);
if (qemu_co_recv(csock, req->data, request->len) != request->len) {
static void nbd_trip(void *opaque)
{
NBDClient *client = opaque;
- NBDRequest *req = nbd_request_get(client);
NBDExport *exp = client->exp;
+ NBDRequest *req;
struct nbd_request request;
struct nbd_reply reply;
ssize_t ret;
TRACE("Reading request.");
+ if (client->closing) {
+ return;
+ }
+ req = nbd_request_get(client);
ret = nbd_co_receive_request(req, &request);
if (ret == -EAGAIN) {
goto done;
void (*close)(NBDClient *))
{
NBDClient *client;
- if (nbd_send_negotiate(csock, exp->size, exp->nbdflags) < 0) {
- return NULL;
- }
client = g_malloc0(sizeof(NBDClient));
client->refcount = 1;
client->exp = exp;
client->sock = csock;
+ if (nbd_send_negotiate(client) < 0) {
+ g_free(client);
+ return NULL;
+ }
client->close = close;
qemu_co_mutex_init(&client->send_lock);
qemu_set_fd_handler2(csock, nbd_can_read, nbd_read, NULL, client);
+
+ if (exp) {
+ QTAILQ_INSERT_TAIL(&exp->clients, client, next);
+ nbd_export_get(exp);
+ }
return client;
}
projects / qemu.git / blobdiff