-/*\
+/*
* Copyright (C) 2005 Anthony Liguori <anthony@codemonkey.ws>
*
* Network Block Device
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
-\*/
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
-#include "nbd.h"
+#include "block/nbd.h"
+#include "block/block.h"
+
+#include "block/coroutine.h"
#include <errno.h>
#include <string.h>
+#ifndef _WIN32
#include <sys/ioctl.h>
+#endif
+#if defined(__sun__) || defined(__HAIKU__)
+#include <sys/ioccom.h>
+#endif
#include <ctype.h>
#include <inttypes.h>
-#include <sys/socket.h>
-#include <netinet/in.h>
-#include <netinet/tcp.h>
-#include <arpa/inet.h>
-#include <netdb.h>
-extern int verbose;
+#ifdef __linux__
+#include <linux/fs.h>
+#endif
+
+#include "qemu/sockets.h"
+#include "qemu/queue.h"
+
+//#define DEBUG_NBD
+
+#ifdef DEBUG_NBD
+#define TRACE(msg, ...) do { \
+ LOG(msg, ## __VA_ARGS__); \
+} while(0)
+#else
+#define TRACE(msg, ...) \
+ do { } while (0)
+#endif
#define LOG(msg, ...) do { \
fprintf(stderr, "%s:%s():L%d: " msg "\n", \
__FILE__, __FUNCTION__, __LINE__, ## __VA_ARGS__); \
} while(0)
-#define TRACE(msg, ...) do { \
- if (verbose) LOG(msg, ## __VA_ARGS__); \
-} while(0)
-
/* 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_DO_IT _IO(0xab, 3)
#define NBD_CLEAR_SOCK _IO(0xab, 4)
#define NBD_CLEAR_QUE _IO(0xab, 5)
-#define NBD_PRINT_DEBUG _IO(0xab, 6)
-#define NBD_SET_SIZE_BLOCKS _IO(0xab, 7)
+#define NBD_PRINT_DEBUG _IO(0xab, 6)
+#define NBD_SET_SIZE_BLOCKS _IO(0xab, 7)
#define NBD_DISCONNECT _IO(0xab, 8)
+#define NBD_SET_TIMEOUT _IO(0xab, 9)
+#define NBD_SET_FLAGS _IO(0xab, 10)
-/* That's all folks */
+#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);
-#define read_sync(fd, buffer, size) wr_sync(fd, buffer, size, true)
-#define write_sync(fd, buffer, size) wr_sync(fd, buffer, size, false)
+struct NBDClient {
+ int refcount;
+ void (*close)(NBDClient *client);
-static size_t wr_sync(int fd, void *buffer, size_t size, bool do_read)
+ 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)
{
size_t offset = 0;
+ int err;
+
+ if (qemu_in_coroutine()) {
+ if (do_read) {
+ return qemu_co_recv(fd, buffer, size);
+ } else {
+ return qemu_co_send(fd, buffer, size);
+ }
+ }
while (offset < size) {
ssize_t len;
if (do_read) {
- len = read(fd, buffer + offset, size - offset);
+ len = qemu_recv(fd, buffer + offset, size - offset, 0);
} else {
- len = write(fd, buffer + offset, size - offset);
+ len = send(fd, buffer + offset, size - offset, 0);
}
- /* recoverable error */
- if (len == -1 && errno == EAGAIN) {
- continue;
+ if (len < 0) {
+ err = socket_error();
+
+ /* recoverable error */
+ if (err == EINTR || (offset > 0 && err == EAGAIN)) {
+ continue;
+ }
+
+ /* unrecoverable error */
+ return -err;
}
/* eof */
break;
}
- /* unrecoverable error */
- if (len == -1) {
- return 0;
- }
-
offset += len;
}
return offset;
}
-static int tcp_socket_outgoing(const char *address, uint16_t port)
+static ssize_t read_sync(int fd, void *buffer, size_t size)
{
- int s;
- struct in_addr in;
- struct sockaddr_in addr;
- int serrno;
-
- s = socket(PF_INET, SOCK_STREAM, 0);
- if (s == -1) {
- return -1;
- }
-
- if (inet_aton(address, &in) == 0) {
- struct hostent *ent;
+ /* Sockets are kept in blocking mode in the negotiation phase. After
+ * that, a non-readable socket simply means that another thread stole
+ * our request/reply. Synchronization is done with recv_coroutine, so
+ * that this is coroutine-safe.
+ */
+ return nbd_wr_sync(fd, buffer, size, true);
+}
- ent = gethostbyname(address);
- if (ent == NULL) {
- goto error;
- }
+static ssize_t write_sync(int fd, void *buffer, size_t size)
+{
+ int ret;
+ do {
+ /* For writes, we do expect the socket to be writable. */
+ ret = nbd_wr_sync(fd, buffer, size, false);
+ } while (ret == -EAGAIN);
+ return ret;
+}
- memcpy(&in, ent->h_addr, sizeof(in));
+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);
}
+}
- addr.sin_family = AF_INET;
- addr.sin_port = htons(port);
- memcpy(&addr.sin_addr.s_addr, &in, sizeof(in));
-
- if (connect(s, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
- goto error;
+int tcp_socket_outgoing_opts(QemuOpts *opts)
+{
+ Error *local_err = NULL;
+ int fd = inet_connect_opts(opts, &local_err, NULL, NULL);
+ if (local_err != NULL) {
+ qerror_report_err(local_err);
+ error_free(local_err);
}
- return s;
-error:
- serrno = errno;
- close(s);
- errno = serrno;
- return -1;
+ return fd;
}
int tcp_socket_incoming(const char *address, uint16_t port)
{
- int s;
- struct in_addr in;
- struct sockaddr_in addr;
- int serrno;
- int opt;
-
- s = socket(PF_INET, SOCK_STREAM, 0);
- if (s == -1) {
- return -1;
- }
-
- if (inet_aton(address, &in) == 0) {
- struct hostent *ent;
+ char address_and_port[128];
+ combine_addr(address_and_port, 128, address, port);
+ return tcp_socket_incoming_spec(address_and_port);
+}
- ent = gethostbyname(address);
- if (ent == NULL) {
- goto error;
- }
+int tcp_socket_incoming_spec(const char *address_and_port)
+{
+ Error *local_err = NULL;
+ int fd = inet_listen(address_and_port, NULL, 0, SOCK_STREAM, 0, &local_err);
- memcpy(&in, ent->h_addr, sizeof(in));
+ if (local_err != NULL) {
+ qerror_report_err(local_err);
+ error_free(local_err);
}
+ return fd;
+}
- addr.sin_family = AF_INET;
- addr.sin_port = htons(port);
- memcpy(&addr.sin_addr.s_addr, &in, sizeof(in));
+int unix_socket_incoming(const char *path)
+{
+ Error *local_err = NULL;
+ int fd = unix_listen(path, NULL, 0, &local_err);
- opt = 1;
- if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) == -1) {
- goto error;
+ if (local_err != NULL) {
+ qerror_report_err(local_err);
+ error_free(local_err);
}
+ return fd;
+}
- if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
- goto error;
- }
+int unix_socket_outgoing(const char *path)
+{
+ Error *local_err = NULL;
+ int fd = unix_connect(path, &local_err);
- if (listen(s, 128) == -1) {
- goto error;
+ if (local_err != NULL) {
+ qerror_report_err(local_err);
+ error_free(local_err);
}
-
- return s;
-error:
- serrno = errno;
- close(s);
- errno = serrno;
- return -1;
+ return fd;
}
-/* Basic flow
+/* Basic flow for negotiation
Server Client
-
Negotiate
+
+ or
+
+ Server Client
+ Negotiate #1
+ Option
+ Negotiate #2
+
+ ----
+
+ followed by
+
+ Server Client
Request
Response
Request
...
...
Request (type == 2)
+
*/
-int nbd_negotiate(BlockDriverState *bs, int csock, off_t size)
-{
- char buf[8 + 8 + 8 + 128];
-
- /* Negotiate
- [ 0 .. 7] passwd ("NBDMAGIC")
- [ 8 .. 15] magic (0x00420281861253)
- [16 .. 23] size
- [24 .. 151] reserved (0)
- */
-
- TRACE("Beginning negotiation.");
- memcpy(buf, "NBDMAGIC", 8);
- cpu_to_be64w((uint64_t*)(buf + 8), 0x00420281861253LL);
- cpu_to_be64w((uint64_t*)(buf + 16), size);
- memset(buf + 24, 0, 128);
+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 (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
- LOG("write failed");
- errno = EINVAL;
- return -1;
- }
+ 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;
+ }
- TRACE("Negotation succeeded.");
+ 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;
+ }
- return 0;
+ 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);
+
+ /* Negotiation header without options:
+ [ 0 .. 7] passwd ("NBDMAGIC")
+ [ 8 .. 15] magic (NBD_CLIENT_MAGIC)
+ [16 .. 23] size
+ [24 .. 25] server flags (0)
+ [24 .. 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)
+ */
+
+ qemu_set_block(csock);
+ rc = -EINVAL;
+
+ TRACE("Beginning negotiation.");
+ memset(buf, 0, sizeof(buf));
+ memcpy(buf, "NBDMAGIC", 8);
+ 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:
+ qemu_set_nonblock(csock);
+ return rc;
}
-int nbd_receive_negotiate(int fd, int csock)
+int nbd_receive_negotiate(int csock, const char *name, uint32_t *flags,
+ off_t *size, size_t *blocksize)
{
- char buf[8 + 8 + 8 + 128];
- uint64_t magic;
- off_t size;
- size_t blocksize;
+ char buf[256];
+ uint64_t magic, s;
+ uint16_t tmp;
+ int rc;
+
+ TRACE("Receiving negotiation.");
- TRACE("Receiving negotation.");
+ qemu_set_block(csock);
+ rc = -EINVAL;
- if (read_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
- LOG("read failed");
- errno = EINVAL;
- return -1;
- }
+ if (read_sync(csock, buf, 8) != 8) {
+ LOG("read failed");
+ goto fail;
+ }
+
+ buf[8] = '\0';
+ if (strlen(buf) == 0) {
+ LOG("server connection closed");
+ goto fail;
+ }
+
+ TRACE("Magic is %c%c%c%c%c%c%c%c",
+ qemu_isprint(buf[0]) ? buf[0] : '.',
+ qemu_isprint(buf[1]) ? buf[1] : '.',
+ qemu_isprint(buf[2]) ? buf[2] : '.',
+ qemu_isprint(buf[3]) ? buf[3] : '.',
+ qemu_isprint(buf[4]) ? buf[4] : '.',
+ qemu_isprint(buf[5]) ? buf[5] : '.',
+ qemu_isprint(buf[6]) ? buf[6] : '.',
+ qemu_isprint(buf[7]) ? buf[7] : '.');
+
+ if (memcmp(buf, "NBDMAGIC", 8) != 0) {
+ LOG("Invalid magic received");
+ goto fail;
+ }
+
+ if (read_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) {
+ LOG("read failed");
+ goto fail;
+ }
+ magic = be64_to_cpu(magic);
+ TRACE("Magic is 0x%" PRIx64, magic);
+
+ if (name) {
+ uint32_t reserved = 0;
+ uint32_t opt;
+ uint32_t namesize;
+
+ TRACE("Checking magic (opts_magic)");
+ if (magic != NBD_OPTS_MAGIC) {
+ LOG("Bad magic received");
+ goto fail;
+ }
+ if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) {
+ LOG("flags read failed");
+ goto fail;
+ }
+ *flags = be16_to_cpu(tmp) << 16;
+ /* reserved for future use */
+ if (write_sync(csock, &reserved, sizeof(reserved)) !=
+ sizeof(reserved)) {
+ LOG("write failed (reserved)");
+ goto fail;
+ }
+ /* write the export name */
+ magic = cpu_to_be64(magic);
+ if (write_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) {
+ LOG("write failed (magic)");
+ goto fail;
+ }
+ opt = cpu_to_be32(NBD_OPT_EXPORT_NAME);
+ if (write_sync(csock, &opt, sizeof(opt)) != sizeof(opt)) {
+ LOG("write failed (opt)");
+ goto fail;
+ }
+ namesize = cpu_to_be32(strlen(name));
+ if (write_sync(csock, &namesize, sizeof(namesize)) !=
+ sizeof(namesize)) {
+ LOG("write failed (namesize)");
+ goto fail;
+ }
+ if (write_sync(csock, (char*)name, strlen(name)) != strlen(name)) {
+ LOG("write failed (name)");
+ goto fail;
+ }
+ } else {
+ TRACE("Checking magic (cli_magic)");
- magic = be64_to_cpup((uint64_t*)(buf + 8));
- size = be64_to_cpup((uint64_t*)(buf + 16));
- blocksize = 1024;
+ if (magic != NBD_CLIENT_MAGIC) {
+ LOG("Bad magic received");
+ goto fail;
+ }
+ }
- TRACE("Magic is %c%c%c%c%c%c%c%c",
- isprint(buf[0]) ? buf[0] : '.',
- isprint(buf[1]) ? buf[1] : '.',
- isprint(buf[2]) ? buf[2] : '.',
- isprint(buf[3]) ? buf[3] : '.',
- isprint(buf[4]) ? buf[4] : '.',
- isprint(buf[5]) ? buf[5] : '.',
- isprint(buf[6]) ? buf[6] : '.',
- isprint(buf[7]) ? buf[7] : '.');
- TRACE("Magic is 0x%" PRIx64, magic);
- TRACE("Size is %" PRIu64, size);
+ if (read_sync(csock, &s, sizeof(s)) != sizeof(s)) {
+ LOG("read failed");
+ goto fail;
+ }
+ *size = be64_to_cpu(s);
+ *blocksize = 1024;
+ TRACE("Size is %" PRIu64, *size);
+
+ if (!name) {
+ if (read_sync(csock, flags, sizeof(*flags)) != sizeof(*flags)) {
+ LOG("read failed (flags)");
+ goto fail;
+ }
+ *flags = be32_to_cpup(flags);
+ } else {
+ if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) {
+ LOG("read failed (tmp)");
+ goto fail;
+ }
+ *flags |= be32_to_cpu(tmp);
+ }
+ if (read_sync(csock, &buf, 124) != 124) {
+ LOG("read failed (buf)");
+ goto fail;
+ }
+ rc = 0;
- if (memcmp(buf, "NBDMAGIC", 8) != 0) {
- LOG("Invalid magic received");
- errno = EINVAL;
- return -1;
- }
+fail:
+ qemu_set_nonblock(csock);
+ return rc;
+}
- TRACE("Checking magic");
+#ifdef __linux__
+int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize)
+{
+ TRACE("Setting NBD socket");
- if (magic != 0x00420281861253LL) {
- LOG("Bad magic received");
- errno = EINVAL;
- return -1;
- }
+ if (ioctl(fd, NBD_SET_SOCK, csock) < 0) {
+ int serrno = errno;
+ LOG("Failed to set NBD socket");
+ return -serrno;
+ }
- TRACE("Setting block size to %lu", (unsigned long)blocksize);
+ TRACE("Setting block size to %lu", (unsigned long)blocksize);
- if (ioctl(fd, NBD_SET_BLKSIZE, blocksize) == -1) {
- int serrno = errno;
- LOG("Failed setting NBD block size");
- errno = serrno;
- return -1;
- }
+ if (ioctl(fd, NBD_SET_BLKSIZE, blocksize) < 0) {
+ int serrno = errno;
+ LOG("Failed setting NBD block size");
+ return -serrno;
+ }
- TRACE("Setting size to %llu block(s)",
- (unsigned long long)(size / blocksize));
+ TRACE("Setting size to %zd block(s)", (size_t)(size / blocksize));
- if (ioctl(fd, NBD_SET_SIZE_BLOCKS, size / blocksize) == -1) {
- int serrno = errno;
- LOG("Failed setting size (in blocks)");
- errno = serrno;
- return -1;
- }
+ if (ioctl(fd, NBD_SET_SIZE_BLOCKS, size / blocksize) < 0) {
+ int serrno = errno;
+ LOG("Failed setting size (in blocks)");
+ return -serrno;
+ }
- TRACE("Clearing NBD socket");
+ 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, NBD_CLEAR_SOCK) == -1) {
- int serrno = errno;
- LOG("Failed clearing NBD socket");
- errno = serrno;
- return -1;
- }
+ 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 flags");
+ return -serrno;
+ }
+ }
- TRACE("Setting NBD socket");
-
- if (ioctl(fd, NBD_SET_SOCK, csock) == -1) {
- int serrno = errno;
- LOG("Failed to set NBD socket");
- errno = serrno;
- return -1;
- }
+ TRACE("Negotiation ended");
- TRACE("Negotiation ended");
-
- return 0;
+ return 0;
}
int nbd_disconnect(int fd)
{
- ioctl(fd, NBD_CLEAR_QUE);
- ioctl(fd, NBD_DISCONNECT);
- ioctl(fd, NBD_CLEAR_SOCK);
- return 0;
+ ioctl(fd, NBD_CLEAR_QUE);
+ ioctl(fd, NBD_DISCONNECT);
+ ioctl(fd, NBD_CLEAR_SOCK);
+ return 0;
}
-int nbd_client(int fd, int csock)
+int nbd_client(int fd)
{
- int ret;
- int serrno;
+ int ret;
+ int serrno;
- TRACE("Doing NBD loop");
+ TRACE("Doing NBD loop");
- ret = ioctl(fd, NBD_DO_IT);
- serrno = errno;
+ ret = ioctl(fd, NBD_DO_IT);
+ if (ret < 0 && errno == EPIPE) {
+ /* NBD_DO_IT normally returns EPIPE when someone has disconnected
+ * the socket via NBD_DISCONNECT. We do not want to return 1 in
+ * that case.
+ */
+ ret = 0;
+ }
+ serrno = errno;
- TRACE("NBD loop returned %d: %s", ret, strerror(serrno));
+ TRACE("NBD loop returned %d: %s", ret, strerror(serrno));
- TRACE("Clearing NBD queue");
- ioctl(fd, NBD_CLEAR_QUE);
+ TRACE("Clearing NBD queue");
+ ioctl(fd, NBD_CLEAR_QUE);
- TRACE("Clearing NBD socket");
- ioctl(fd, NBD_CLEAR_SOCK);
+ TRACE("Clearing NBD socket");
+ ioctl(fd, NBD_CLEAR_SOCK);
- errno = serrno;
- return ret;
+ errno = serrno;
+ return ret;
+}
+#else
+int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize)
+{
+ return -ENOTSUP;
}
-int nbd_trip(BlockDriverState *bs, int csock, off_t size, uint64_t dev_offset, off_t *offset, bool readonly)
+int nbd_disconnect(int fd)
{
-#ifndef _REENTRANT
- static uint8_t data[1024 * 1024]; // keep this off of the stack
-#else
- uint8_t data[1024 * 1024];
+ return -ENOTSUP;
+}
+
+int nbd_client(int fd)
+{
+ return -ENOTSUP;
+}
#endif
- uint8_t buf[4 + 4 + 8 + 8 + 4];
- uint32_t magic;
- uint32_t type;
- uint64_t from;
- uint32_t len;
-
- TRACE("Reading request.");
-
- if (read_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
- LOG("read failed");
- errno = EINVAL;
- return -1;
- }
-
- /* Request
- [ 0 .. 3] magic (NBD_REQUEST_MAGIC)
- [ 4 .. 7] type (0 == READ, 1 == WRITE)
- [ 8 .. 15] handle
- [16 .. 23] from
- [24 .. 27] len
- */
-
- magic = be32_to_cpup((uint32_t*)buf);
- type = be32_to_cpup((uint32_t*)(buf + 4));
- from = be64_to_cpup((uint64_t*)(buf + 16));
- len = be32_to_cpup((uint32_t*)(buf + 24));
-
- TRACE("Got request: "
- "{ magic = 0x%x, .type = %d, from = %" PRIu64" , len = %u }",
- magic, type, from, len);
-
-
- if (magic != NBD_REQUEST_MAGIC) {
- LOG("invalid magic (got 0x%x)", magic);
- errno = EINVAL;
- return -1;
- }
-
- if (len > sizeof(data)) {
- LOG("len (%u) is larger than max len (%lu)",
- len, sizeof(data));
- errno = EINVAL;
- return -1;
- }
-
- if ((from + len) < from) {
- LOG("integer overflow detected! "
- "you're probably being attacked");
- errno = EINVAL;
- return -1;
- }
-
- if ((from + len) > size) {
- LOG("From: %" PRIu64 ", Len: %u, Size: %" PRIu64
- ", Offset: %" PRIu64 "\n",
- from, len, size, dev_offset);
- LOG("requested operation past EOF--bad client?");
- errno = EINVAL;
- return -1;
- }
-
- /* Reply
- [ 0 .. 3] magic (NBD_REPLY_MAGIC)
- [ 4 .. 7] error (0 == no error)
- [ 7 .. 15] handle
- */
- cpu_to_be32w((uint32_t*)buf, NBD_REPLY_MAGIC);
- cpu_to_be32w((uint32_t*)(buf + 4), 0);
-
- TRACE("Decoding type");
-
- switch (type) {
- case 0:
- TRACE("Request type is READ");
-
- if (bdrv_read(bs, (from + dev_offset) / 512, data, len / 512) == -1) {
- LOG("reading from file failed");
- errno = EINVAL;
- return -1;
- }
- *offset += len;
-
- TRACE("Read %u byte(s)", len);
-
- TRACE("Sending OK response");
-
- if (write_sync(csock, buf, 16) != 16) {
- LOG("writing to socket failed");
- errno = EINVAL;
- return -1;
- }
-
- TRACE("Sending data to client");
-
- if (write_sync(csock, data, len) != len) {
- LOG("writing to socket failed");
- errno = EINVAL;
- return -1;
- }
- break;
- case 1:
- TRACE("Request type is WRITE");
-
- TRACE("Reading %u byte(s)", len);
-
- if (read_sync(csock, data, len) != len) {
- LOG("reading from socket failed");
- errno = EINVAL;
- return -1;
- }
-
- if (readonly) {
- TRACE("Server is read-only, return error");
-
- cpu_to_be32w((uint32_t*)(buf + 4), 1);
- } else {
- TRACE("Writing to device");
-
- if (bdrv_write(bs, (from + dev_offset) / 512, data, len / 512) == -1) {
- LOG("writing to file failed");
- errno = EINVAL;
- return -1;
- }
-
- *offset += len;
- }
-
- TRACE("Sending response to client");
-
- if (write_sync(csock, buf, 16) != 16) {
- LOG("writing to socket failed");
- errno = EINVAL;
- return -1;
- }
- break;
- case 2:
- TRACE("Request type is DISCONNECT");
- errno = 0;
- return 1;
- default:
- LOG("invalid request type (%u) received", type);
- errno = EINVAL;
- return -1;
- }
-
- TRACE("Request/Reply complete");
-
- return 0;
+
+ssize_t nbd_send_request(int csock, struct nbd_request *request)
+{
+ uint8_t buf[NBD_REQUEST_SIZE];
+ ssize_t ret;
+
+ cpu_to_be32w((uint32_t*)buf, NBD_REQUEST_MAGIC);
+ cpu_to_be32w((uint32_t*)(buf + 4), request->type);
+ cpu_to_be64w((uint64_t*)(buf + 8), request->handle);
+ cpu_to_be64w((uint64_t*)(buf + 16), request->from);
+ cpu_to_be32w((uint32_t*)(buf + 24), request->len);
+
+ TRACE("Sending request to client: "
+ "{ .from = %" PRIu64", .len = %u, .handle = %" PRIu64", .type=%i}",
+ request->from, request->len, request->handle, request->type);
+
+ ret = write_sync(csock, buf, sizeof(buf));
+ if (ret < 0) {
+ return ret;
+ }
+
+ if (ret != sizeof(buf)) {
+ LOG("writing to socket failed");
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static ssize_t nbd_receive_request(int csock, struct nbd_request *request)
+{
+ uint8_t buf[NBD_REQUEST_SIZE];
+ uint32_t magic;
+ ssize_t ret;
+
+ ret = read_sync(csock, buf, sizeof(buf));
+ if (ret < 0) {
+ return ret;
+ }
+
+ if (ret != sizeof(buf)) {
+ LOG("read failed");
+ return -EINVAL;
+ }
+
+ /* Request
+ [ 0 .. 3] magic (NBD_REQUEST_MAGIC)
+ [ 4 .. 7] type (0 == READ, 1 == WRITE)
+ [ 8 .. 15] handle
+ [16 .. 23] from
+ [24 .. 27] len
+ */
+
+ magic = be32_to_cpup((uint32_t*)buf);
+ request->type = be32_to_cpup((uint32_t*)(buf + 4));
+ request->handle = be64_to_cpup((uint64_t*)(buf + 8));
+ request->from = be64_to_cpup((uint64_t*)(buf + 16));
+ request->len = be32_to_cpup((uint32_t*)(buf + 24));
+
+ TRACE("Got request: "
+ "{ magic = 0x%x, .type = %d, from = %" PRIu64" , len = %u }",
+ magic, request->type, request->from, request->len);
+
+ if (magic != NBD_REQUEST_MAGIC) {
+ LOG("invalid magic (got 0x%x)", magic);
+ return -EINVAL;
+ }
+ return 0;
+}
+
+ssize_t nbd_receive_reply(int csock, struct nbd_reply *reply)
+{
+ uint8_t buf[NBD_REPLY_SIZE];
+ uint32_t magic;
+ ssize_t ret;
+
+ ret = read_sync(csock, buf, sizeof(buf));
+ if (ret < 0) {
+ return ret;
+ }
+
+ if (ret != sizeof(buf)) {
+ LOG("read failed");
+ return -EINVAL;
+ }
+
+ /* Reply
+ [ 0 .. 3] magic (NBD_REPLY_MAGIC)
+ [ 4 .. 7] error (0 == no error)
+ [ 7 .. 15] handle
+ */
+
+ magic = be32_to_cpup((uint32_t*)buf);
+ reply->error = be32_to_cpup((uint32_t*)(buf + 4));
+ reply->handle = be64_to_cpup((uint64_t*)(buf + 8));
+
+ TRACE("Got reply: "
+ "{ magic = 0x%x, .error = %d, handle = %" PRIu64" }",
+ magic, reply->error, reply->handle);
+
+ if (magic != NBD_REPLY_MAGIC) {
+ LOG("invalid magic (got 0x%x)", magic);
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static ssize_t nbd_send_reply(int csock, struct nbd_reply *reply)
+{
+ uint8_t buf[NBD_REPLY_SIZE];
+ ssize_t ret;
+
+ /* Reply
+ [ 0 .. 3] magic (NBD_REPLY_MAGIC)
+ [ 4 .. 7] error (0 == no error)
+ [ 7 .. 15] handle
+ */
+ cpu_to_be32w((uint32_t*)buf, NBD_REPLY_MAGIC);
+ cpu_to_be32w((uint32_t*)(buf + 4), reply->error);
+ cpu_to_be64w((uint64_t*)(buf + 8), reply->handle);
+
+ TRACE("Sending response to client");
+
+ ret = write_sync(csock, buf, sizeof(buf));
+ if (ret < 0) {
+ return ret;
+ }
+
+ if (ret != sizeof(buf)) {
+ LOG("writing to socket failed");
+ return -EINVAL;
+ }
+ return 0;
+}
+
+#define MAX_NBD_REQUESTS 16
+
+void nbd_client_get(NBDClient *client)
+{
+ client->refcount++;
+}
+
+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);
+ }
+}
+
+void nbd_client_close(NBDClient *client)
+{
+ 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);
+ }
+}
+
+static NBDRequest *nbd_request_get(NBDClient *client)
+{
+ NBDRequest *req;
+
+ assert(client->nb_requests <= MAX_NBD_REQUESTS - 1);
+ client->nb_requests++;
+
+ 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;
+
+ if (req->data) {
+ qemu_vfree(req->data);
+ }
+ g_slice_free(NBDRequest, req);
+
+ if (client->nb_requests-- == MAX_NBD_REQUESTS) {
+ qemu_notify_event();
+ }
+ nbd_client_put(client);
+}
+
+NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset,
+ off_t size, uint32_t nbdflags,
+ void (*close)(NBDExport *))
+{
+ NBDExport *exp = g_malloc0(sizeof(NBDExport));
+ 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;
+ 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)
+{
+ 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);
+}
+
+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);
+static void nbd_read(void *opaque);
+static void nbd_restart_write(void *opaque);
+
+static ssize_t nbd_co_send_reply(NBDRequest *req, struct nbd_reply *reply,
+ int len)
+{
+ NBDClient *client = req->client;
+ int csock = client->sock;
+ ssize_t rc, ret;
+
+ qemu_co_mutex_lock(&client->send_lock);
+ qemu_set_fd_handler2(csock, nbd_can_read, nbd_read,
+ nbd_restart_write, client);
+ client->send_coroutine = qemu_coroutine_self();
+
+ if (!len) {
+ rc = nbd_send_reply(csock, reply);
+ } else {
+ socket_set_cork(csock, 1);
+ rc = nbd_send_reply(csock, reply);
+ if (rc >= 0) {
+ ret = qemu_co_send(csock, req->data, len);
+ if (ret != len) {
+ rc = -EIO;
+ }
+ }
+ socket_set_cork(csock, 0);
+ }
+
+ client->send_coroutine = NULL;
+ qemu_set_fd_handler2(csock, nbd_can_read, nbd_read, NULL, client);
+ qemu_co_mutex_unlock(&client->send_lock);
+ return rc;
+}
+
+static ssize_t nbd_co_receive_request(NBDRequest *req, struct nbd_request *request)
+{
+ NBDClient *client = req->client;
+ int csock = client->sock;
+ uint32_t command;
+ ssize_t rc;
+
+ client->recv_coroutine = qemu_coroutine_self();
+ rc = nbd_receive_request(csock, request);
+ if (rc < 0) {
+ if (rc != -EAGAIN) {
+ rc = -EIO;
+ }
+ goto out;
+ }
+
+ if (request->len > NBD_MAX_BUFFER_SIZE) {
+ LOG("len (%u) is larger than max len (%u)",
+ request->len, NBD_MAX_BUFFER_SIZE);
+ rc = -EINVAL;
+ goto out;
+ }
+
+ if ((request->from + request->len) < request->from) {
+ LOG("integer overflow detected! "
+ "you're probably being attacked");
+ rc = -EINVAL;
+ goto out;
+ }
+
+ TRACE("Decoding type");
+
+ 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) {
+ LOG("reading from socket failed");
+ rc = -EIO;
+ goto out;
+ }
+ }
+ rc = 0;
+
+out:
+ client->recv_coroutine = NULL;
+ return rc;
+}
+
+static void nbd_trip(void *opaque)
+{
+ NBDClient *client = opaque;
+ 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;
+ }
+ if (ret == -EIO) {
+ goto out;
+ }
+
+ reply.handle = request.handle;
+ reply.error = 0;
+
+ if (ret < 0) {
+ reply.error = -ret;
+ goto error_reply;
+ }
+
+ if ((request.from + request.len) > exp->size) {
+ LOG("From: %" PRIu64 ", Len: %u, Size: %" PRIu64
+ ", Offset: %" PRIu64 "\n",
+ request.from, request.len,
+ (uint64_t)exp->size, (uint64_t)exp->dev_offset);
+ LOG("requested operation past EOF--bad client?");
+ goto invalid_request;
+ }
+
+ switch (request.type & NBD_CMD_MASK_COMMAND) {
+ case NBD_CMD_READ:
+ TRACE("Request type is READ");
+
+ if (request.type & NBD_CMD_FLAG_FUA) {
+ ret = bdrv_co_flush(exp->bs);
+ if (ret < 0) {
+ LOG("flush failed");
+ reply.error = -ret;
+ goto error_reply;
+ }
+ }
+
+ ret = bdrv_read(exp->bs, (request.from + exp->dev_offset) / 512,
+ req->data, request.len / 512);
+ if (ret < 0) {
+ LOG("reading from file failed");
+ reply.error = -ret;
+ goto error_reply;
+ }
+
+ TRACE("Read %u byte(s)", request.len);
+ if (nbd_co_send_reply(req, &reply, request.len) < 0)
+ goto out;
+ break;
+ case NBD_CMD_WRITE:
+ TRACE("Request type is WRITE");
+
+ if (exp->nbdflags & NBD_FLAG_READ_ONLY) {
+ TRACE("Server is read-only, return error");
+ reply.error = EROFS;
+ goto error_reply;
+ }
+
+ TRACE("Writing to device");
+
+ ret = bdrv_write(exp->bs, (request.from + exp->dev_offset) / 512,
+ req->data, request.len / 512);
+ if (ret < 0) {
+ LOG("writing to file failed");
+ reply.error = -ret;
+ goto error_reply;
+ }
+
+ if (request.type & NBD_CMD_FLAG_FUA) {
+ ret = bdrv_co_flush(exp->bs);
+ if (ret < 0) {
+ LOG("flush failed");
+ reply.error = -ret;
+ goto error_reply;
+ }
+ }
+
+ if (nbd_co_send_reply(req, &reply, 0) < 0) {
+ goto out;
+ }
+ break;
+ case NBD_CMD_DISC:
+ TRACE("Request type is DISCONNECT");
+ errno = 0;
+ goto out;
+ case NBD_CMD_FLUSH:
+ TRACE("Request type is FLUSH");
+
+ ret = bdrv_co_flush(exp->bs);
+ if (ret < 0) {
+ LOG("flush failed");
+ reply.error = -ret;
+ }
+ if (nbd_co_send_reply(req, &reply, 0) < 0) {
+ goto out;
+ }
+ break;
+ case NBD_CMD_TRIM:
+ TRACE("Request type is TRIM");
+ ret = bdrv_co_discard(exp->bs, (request.from + exp->dev_offset) / 512,
+ request.len / 512);
+ if (ret < 0) {
+ LOG("discard failed");
+ reply.error = -ret;
+ }
+ if (nbd_co_send_reply(req, &reply, 0) < 0) {
+ goto out;
+ }
+ break;
+ default:
+ LOG("invalid request type (%u) received", request.type);
+ invalid_request:
+ reply.error = -EINVAL;
+ error_reply:
+ if (nbd_co_send_reply(req, &reply, 0) < 0) {
+ goto out;
+ }
+ break;
+ }
+
+ TRACE("Request/Reply complete");
+
+done:
+ nbd_request_put(req);
+ return;
+
+out:
+ nbd_request_put(req);
+ nbd_client_close(client);
+}
+
+static int nbd_can_read(void *opaque)
+{
+ NBDClient *client = opaque;
+
+ return client->recv_coroutine || client->nb_requests < MAX_NBD_REQUESTS;
+}
+
+static void nbd_read(void *opaque)
+{
+ NBDClient *client = opaque;
+
+ if (client->recv_coroutine) {
+ qemu_coroutine_enter(client->recv_coroutine, NULL);
+ } else {
+ qemu_coroutine_enter(qemu_coroutine_create(nbd_trip), client);
+ }
+}
+
+static void nbd_restart_write(void *opaque)
+{
+ NBDClient *client = opaque;
+
+ qemu_coroutine_enter(client->send_coroutine, NULL);
+}
+
+NBDClient *nbd_client_new(NBDExport *exp, int csock,
+ void (*close)(NBDClient *))
+{
+ NBDClient *client;
+ 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