Allow QEMU to connect directly to an NBD server, by Laurent Vivier.

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4838 c046a42c-6fe2-441c-8c8c-71466251a162

1 files changed, 194 insertions, 0 deletions

diff --git a/block-nbd.c b/block-nbd.c
new file mode 100644
index 0000000..f350050
--- /dev/null
+++ b/block-nbd.c
@@ -0,0 +1,194 @@
+/*
+ * QEMU Block driver for  NBD
+ *
+ * Copyright (C) 2008 Bull S.A.S.
+ *     Author: Laurent Vivier <Laurent.Vivier@bull;net>
+ *
+ * Some parts:
+ *    Copyright (C) 2007 Anthony Liguori <anthony@codemonkey.ws>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "qemu-common.h"
+#include "nbd.h"
+
+#include <sys/types.h>
+#include <unistd.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <pthread.h>
+
+typedef struct BDRVNBDState {
+    int sock;
+    off_t size;
+    size_t blocksize;
+} BDRVNBDState;
+
+static int nbd_open(BlockDriverState *bs, const char* filename, int flags)
+{
+    BDRVNBDState *s = bs->opaque;
+    const char *host;
+    const char *unixpath;
+    int sock;
+    off_t size;
+    size_t blocksize;
+    int ret;
+
+    if ((flags & BDRV_O_CREAT))
+        return -EINVAL;
+
+    if (!strstart(filename, "nbd:", &host))
+        return -EINVAL;
+
+    if (strstart(host, "unix:", &unixpath)) {
+
+        if (unixpath[0] != '/')
+            return -EINVAL;
+
+        sock = unix_socket_outgoing(unixpath);
+
+    } else {
+        uint16_t port;
+        char *p, *r;
+        char hostname[128];
+
+        pstrcpy(hostname, 128, host);
+
+        p = strchr(hostname, ':');
+        if (p == NULL)
+            return -EINVAL;
+
+        *p = '\0';
+        p++;
+
+        port = strtol(p, &r, 0);
+        if (r == p)
+            return -EINVAL;
+        sock = tcp_socket_outgoing(hostname, port);
+    }
+
+    if (sock == -1)
+        return -errno;
+
+    ret = nbd_receive_negotiate(sock, &size, &blocksize);
+    if (ret == -1)
+        return -errno;
+
+    s->sock = sock;
+    s->size = size;
+    s->blocksize = blocksize;
+
+    return 0;
+}
+
+static int nbd_read(BlockDriverState *bs, int64_t sector_num,
+                    uint8_t *buf, int nb_sectors)
+{
+    BDRVNBDState *s = bs->opaque;
+    struct nbd_request request;
+    struct nbd_reply reply;
+
+    request.type = NBD_CMD_READ;
+    request.handle = (uint64_t)(intptr_t)bs;
+    request.from = sector_num * 512;;
+    request.len = nb_sectors * 512;
+
+    if (nbd_send_request(s->sock, &request) == -1)
+        return -errno;
+
+    if (nbd_receive_reply(s->sock, &reply) == -1)
+        return -errno;
+
+    if (reply.error !=0)
+        return -reply.error;
+
+    if (reply.handle != request.handle)
+        return -EIO;
+
+    if (nbd_wr_sync(s->sock, buf, request.len, 1) != request.len)
+        return -EIO;
+
+    return 0;
+}
+
+static int nbd_write(BlockDriverState *bs, int64_t sector_num,
+                     const uint8_t *buf, int nb_sectors)
+{
+    BDRVNBDState *s = bs->opaque;
+    struct nbd_request request;
+    struct nbd_reply reply;
+
+    request.type = NBD_CMD_WRITE;
+    request.handle = (uint64_t)(intptr_t)bs;
+    request.from = sector_num * 512;;
+    request.len = nb_sectors * 512;
+
+    if (nbd_send_request(s->sock, &request) == -1)
+        return -errno;
+
+    if (nbd_wr_sync(s->sock, (uint8_t*)buf, request.len, 0) != request.len)
+        return -EIO;
+
+    if (nbd_receive_reply(s->sock, &reply) == -1)
+        return -errno;
+
+    if (reply.error !=0)
+        return -reply.error;
+
+    if (reply.handle != request.handle)
+        return -EIO;
+
+    return 0;
+}
+
+static void nbd_close(BlockDriverState *bs)
+{
+    BDRVNBDState *s = bs->opaque;
+    struct nbd_request request;
+
+    request.type = NBD_CMD_DISC;
+    request.handle = (uint64_t)(intptr_t)bs;
+    request.from = 0;
+    request.len = 0;
+    nbd_send_request(s->sock, &request);
+
+    close(s->sock);
+}
+
+static int64_t nbd_getlength(BlockDriverState *bs)
+{
+    BDRVNBDState *s = bs->opaque;
+
+    return s->size;
+}
+
+BlockDriver bdrv_nbd = {
+    "nbd",
+    sizeof(BDRVNBDState),
+    NULL, /* no probe for protocols */
+    nbd_open,
+    nbd_read,
+    nbd_write,
+    nbd_close,
+    .bdrv_getlength = nbd_getlength,
+    .protocol_name = "nbd",
+};