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-rw-r--r--block/nbd.c4
-rw-r--r--nbd.c32
-rw-r--r--nbd.h9
-rw-r--r--qemu-nbd.c13
4 files changed, 39 insertions, 19 deletions
diff --git a/block/nbd.c b/block/nbd.c
index 70edd81bd6..76f04d863c 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -48,6 +48,7 @@
typedef struct BDRVNBDState {
int sock;
+ uint32_t nbdflags;
off_t size;
size_t blocksize;
char *export_name; /* An NBD server may export several devices */
@@ -111,7 +112,6 @@ static int nbd_establish_connection(BlockDriverState *bs)
int ret;
off_t size;
size_t blocksize;
- uint32_t nbdflags;
if (s->host_spec[0] == '/') {
sock = unix_socket_outgoing(s->host_spec);
@@ -126,7 +126,7 @@ static int nbd_establish_connection(BlockDriverState *bs)
}
/* NBD handshake */
- ret = nbd_receive_negotiate(sock, s->export_name, &nbdflags, &size,
+ ret = nbd_receive_negotiate(sock, s->export_name, &s->nbdflags, &size,
&blocksize);
if (ret == -1) {
logout("Failed to negotiate with the NBD server\n");
diff --git a/nbd.c b/nbd.c
index 6d81cfbcd0..47ecb2234b 100644
--- a/nbd.c
+++ b/nbd.c
@@ -30,6 +30,10 @@
#include <ctype.h>
#include <inttypes.h>
+#ifdef __linux__
+#include <linux/fs.h>
+#endif
+
#include "qemu_socket.h"
//#define DEBUG_NBD
@@ -172,7 +176,7 @@ int unix_socket_outgoing(const char *path)
Request (type == 2)
*/
-int nbd_negotiate(int csock, off_t size)
+int nbd_negotiate(int csock, off_t size, uint32_t flags)
{
char buf[8 + 8 + 8 + 128];
@@ -180,14 +184,16 @@ int nbd_negotiate(int csock, off_t size)
[ 0 .. 7] passwd ("NBDMAGIC")
[ 8 .. 15] magic (0x00420281861253)
[16 .. 23] size
- [24 .. 151] reserved (0)
+ [24 .. 27] flags
+ [28 .. 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);
+ cpu_to_be32w((uint32_t*)(buf + 24), flags | NBD_FLAG_HAS_FLAGS);
+ memset(buf + 28, 0, 124);
if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
LOG("write failed");
@@ -337,8 +343,8 @@ int nbd_receive_negotiate(int csock, const char *name, uint32_t *flags,
return 0;
}
-#ifndef _WIN32
-int nbd_init(int fd, int csock, off_t size, size_t blocksize)
+#ifdef __linux__
+int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize)
{
TRACE("Setting block size to %lu", (unsigned long)blocksize);
@@ -358,6 +364,18 @@ int nbd_init(int fd, int csock, off_t size, size_t blocksize)
return -1;
}
+ if (flags & NBD_FLAG_READ_ONLY) {
+ int read_only = 1;
+ TRACE("Setting readonly attribute");
+
+ if (ioctl(fd, BLKROSET, (unsigned long) &read_only) < 0) {
+ int serrno = errno;
+ LOG("Failed setting read-only attribute");
+ errno = serrno;
+ return -1;
+ }
+ }
+
TRACE("Clearing NBD socket");
if (ioctl(fd, NBD_CLEAR_SOCK) == -1) {
@@ -548,7 +566,7 @@ static int nbd_send_reply(int csock, struct nbd_reply *reply)
}
int nbd_trip(BlockDriverState *bs, int csock, off_t size, uint64_t dev_offset,
- off_t *offset, bool readonly, uint8_t *data, int data_size)
+ off_t *offset, uint32_t nbdflags, uint8_t *data, int data_size)
{
struct nbd_request request;
struct nbd_reply reply;
@@ -632,7 +650,7 @@ int nbd_trip(BlockDriverState *bs, int csock, off_t size, uint64_t dev_offset,
return -1;
}
- if (readonly) {
+ if (nbdflags & NBD_FLAG_READ_ONLY) {
TRACE("Server is read-only, return error");
reply.error = 1;
} else {
diff --git a/nbd.h b/nbd.h
index df7b7af7c0..b9c3b391d6 100644
--- a/nbd.h
+++ b/nbd.h
@@ -37,6 +37,9 @@ struct nbd_reply {
uint64_t handle;
} QEMU_PACKED;
+#define NBD_FLAG_HAS_FLAGS (1 << 0) /* Flags are there */
+#define NBD_FLAG_READ_ONLY (1 << 1) /* Device is read-only */
+
enum {
NBD_CMD_READ = 0,
NBD_CMD_WRITE = 1,
@@ -53,14 +56,14 @@ int tcp_socket_incoming_spec(const char *address_and_port);
int unix_socket_outgoing(const char *path);
int unix_socket_incoming(const char *path);
-int nbd_negotiate(int csock, off_t size);
+int nbd_negotiate(int csock, off_t size, uint32_t flags);
int nbd_receive_negotiate(int csock, const char *name, uint32_t *flags,
off_t *size, size_t *blocksize);
-int nbd_init(int fd, int csock, off_t size, size_t blocksize);
+int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize);
int nbd_send_request(int csock, struct nbd_request *request);
int nbd_receive_reply(int csock, struct nbd_reply *reply);
int nbd_trip(BlockDriverState *bs, int csock, off_t size, uint64_t dev_offset,
- off_t *offset, bool readonly, uint8_t *data, int data_size);
+ off_t *offset, uint32_t nbdflags, uint8_t *data, int data_size);
int nbd_client(int fd);
int nbd_disconnect(int fd);
diff --git a/qemu-nbd.c b/qemu-nbd.c
index 3a39145174..d8d3e15a84 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -185,7 +185,7 @@ int main(int argc, char **argv)
BlockDriverState *bs;
off_t dev_offset = 0;
off_t offset = 0;
- bool readonly = false;
+ uint32_t nbdflags = 0;
bool disconnect = false;
const char *bindto = "0.0.0.0";
int port = NBD_DEFAULT_PORT;
@@ -230,7 +230,6 @@ int main(int argc, char **argv)
int nb_fds = 0;
int max_fd;
int persistent = 0;
- uint32_t nbdflags;
while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
switch (ch) {
@@ -263,7 +262,7 @@ int main(int argc, char **argv)
}
break;
case 'r':
- readonly = true;
+ nbdflags |= NBD_FLAG_READ_ONLY;
flags &= ~BDRV_O_RDWR;
break;
case 'P':
@@ -398,13 +397,13 @@ int main(int argc, char **argv)
}
ret = nbd_receive_negotiate(sock, NULL, &nbdflags,
- &size, &blocksize);
+ &size, &blocksize);
if (ret == -1) {
ret = 1;
goto out;
}
- ret = nbd_init(fd, sock, size, blocksize);
+ ret = nbd_init(fd, sock, nbdflags, size, blocksize);
if (ret == -1) {
ret = 1;
goto out;
@@ -463,7 +462,7 @@ int main(int argc, char **argv)
for (i = 1; i < nb_fds && ret; i++) {
if (FD_ISSET(sharing_fds[i], &fds)) {
if (nbd_trip(bs, sharing_fds[i], fd_size, dev_offset,
- &offset, readonly, data, NBD_BUFFER_SIZE) != 0) {
+ &offset, nbdflags, data, NBD_BUFFER_SIZE) != 0) {
close(sharing_fds[i]);
nb_fds--;
sharing_fds[i] = sharing_fds[nb_fds];
@@ -479,7 +478,7 @@ int main(int argc, char **argv)
(struct sockaddr *)&addr,
&addr_len);
if (sharing_fds[nb_fds] != -1 &&
- nbd_negotiate(sharing_fds[nb_fds], fd_size) != -1) {
+ nbd_negotiate(sharing_fds[nb_fds], fd_size, nbdflags) != -1) {
if (sharing_fds[nb_fds] > max_fd)
max_fd = sharing_fds[nb_fds];
nb_fds++;
generated by cgit v1.2.3 (git 2.26.2) at 2024-11-23 02:58:35 +0000