* [Qemu-devel] [PATCH][v3] Introduce NBD named exports.
2010-08-25 8:21 [Qemu-devel] [PATCH] " Kevin Wolf
@ 2010-08-25 20:48 ` Laurent Vivier
2010-08-25 21:10 ` Anthony Liguori
2010-08-26 14:07 ` Kevin Wolf
0 siblings, 2 replies; 4+ messages in thread
From: Laurent Vivier @ 2010-08-25 20:48 UTC (permalink / raw)
To: qemu-devel; +Cc: Laurent Vivier
This patch allows to connect Qemu using NBD protocol to an nbd-server
using named exports.
For instance, if on the host "isoserver", in /etc/nbd-server/config, you have:
[generic]
[debian-500-ppc-netinst]
exportname = /ISO/debian-500-powerpc-netinst.iso
[Fedora-10-ppc-netinst]
exportname = /ISO/Fedora-10-ppc-netinst.iso
You can connect to it, using:
qemu -cdrom nbd:isoserver:exportname=debian-500-ppc-netinst
qemu -cdrom nbd:isoserver:exportname=Fedora-10-ppc-netinst
NOTE: you need at least nbd-server 2.9.18
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
---
v3: change sizeof() by strlen()
v2: address Kevin comments (CODING STYLE)
block/nbd.c | 68 +++++++++++++++++++++++---------
nbd.c | 118 +++++++++++++++++++++++++++++++++++++++++++++++++++------
nbd.h | 5 ++-
qemu-doc.texi | 7 +++
qemu-nbd.c | 4 +-
5 files changed, 169 insertions(+), 33 deletions(-)
diff --git a/block/nbd.c b/block/nbd.c
index a1ec123..5e9d6cb 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -33,6 +33,8 @@
#include <sys/types.h>
#include <unistd.h>
+#define EN_OPTSTR ":exportname="
+
typedef struct BDRVNBDState {
int sock;
off_t size;
@@ -42,55 +44,83 @@ typedef struct BDRVNBDState {
static int nbd_open(BlockDriverState *bs, const char* filename, int flags)
{
BDRVNBDState *s = bs->opaque;
+ uint32_t nbdflags;
+
+ char *file;
+ char *name;
const char *host;
const char *unixpath;
int sock;
off_t size;
size_t blocksize;
int ret;
+ int err = -EINVAL;
+
+ file = qemu_strdup(filename);
- if (!strstart(filename, "nbd:", &host))
- return -EINVAL;
+ name = strstr(file, EN_OPTSTR);
+ if (name) {
+ if (name[strlen(EN_OPTSTR)] == 0) {
+ goto out;
+ }
+ name[0] = 0;
+ name += strlen(EN_OPTSTR);
+ }
+
+ if (!strstart(file, "nbd:", &host)) {
+ goto out;
+ }
if (strstart(host, "unix:", &unixpath)) {
- if (unixpath[0] != '/')
- return -EINVAL;
+ if (unixpath[0] != '/') {
+ goto out;
+ }
sock = unix_socket_outgoing(unixpath);
} else {
- uint16_t port;
+ uint16_t port = NBD_DEFAULT_PORT;
char *p, *r;
char hostname[128];
pstrcpy(hostname, 128, host);
p = strchr(hostname, ':');
- if (p == NULL)
- return -EINVAL;
+ if (p != NULL) {
+ *p = '\0';
+ p++;
+
+ port = strtol(p, &r, 0);
+ if (r == p) {
+ goto out;
+ }
+ } else if (name == NULL) {
+ goto out;
+ }
- *p = '\0';
- p++;
-
- port = strtol(p, &r, 0);
- if (r == p)
- return -EINVAL;
sock = tcp_socket_outgoing(hostname, port);
}
- if (sock == -1)
- return -errno;
+ if (sock == -1) {
+ err = -errno;
+ goto out;
+ }
- ret = nbd_receive_negotiate(sock, &size, &blocksize);
- if (ret == -1)
- return -errno;
+ ret = nbd_receive_negotiate(sock, name, &nbdflags, &size, &blocksize);
+ if (ret == -1) {
+ err = -errno;
+ goto out;
+ }
s->sock = sock;
s->size = size;
s->blocksize = blocksize;
+ err = 0;
- return 0;
+out:
+ qemu_free(file);
+ return err;
}
static int nbd_read(BlockDriverState *bs, int64_t sector_num,
diff --git a/nbd.c b/nbd.c
index a9f295f..30dec8d 100644
--- a/nbd.c
+++ b/nbd.c
@@ -62,6 +62,8 @@
#define NBD_SET_SIZE_BLOCKS _IO(0xab, 7)
#define NBD_DISCONNECT _IO(0xab, 8)
+#define NBD_OPT_EXPORT_NAME (1 << 0)
+
/* That's all folks */
#define read_sync(fd, buffer, size) nbd_wr_sync(fd, buffer, size, true)
@@ -296,22 +298,27 @@ int nbd_negotiate(int csock, off_t size)
return 0;
}
-int nbd_receive_negotiate(int csock, off_t *size, size_t *blocksize)
+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;
+ char buf[256];
+ uint64_t magic, s;
+ uint16_t tmp;
TRACE("Receiving negotation.");
- if (read_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
+ if (read_sync(csock, buf, 8) != 8) {
LOG("read failed");
errno = EINVAL;
return -1;
}
- magic = be64_to_cpup((uint64_t*)(buf + 8));
- *size = be64_to_cpup((uint64_t*)(buf + 16));
- *blocksize = 1024;
+ buf[8] = '\0';
+ if (strlen(buf) == 0) {
+ LOG("server connection closed");
+ errno = EINVAL;
+ return -1;
+ }
TRACE("Magic is %c%c%c%c%c%c%c%c",
qemu_isprint(buf[0]) ? buf[0] : '.',
@@ -322,8 +329,6 @@ int nbd_receive_negotiate(int csock, off_t *size, size_t *blocksize)
qemu_isprint(buf[5]) ? buf[5] : '.',
qemu_isprint(buf[6]) ? buf[6] : '.',
qemu_isprint(buf[7]) ? buf[7] : '.');
- TRACE("Magic is 0x%" PRIx64, magic);
- TRACE("Size is %" PRIu64, *size);
if (memcmp(buf, "NBDMAGIC", 8) != 0) {
LOG("Invalid magic received");
@@ -331,10 +336,99 @@ int nbd_receive_negotiate(int csock, off_t *size, size_t *blocksize)
return -1;
}
- TRACE("Checking magic");
+ if (read_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) {
+ LOG("read failed");
+ errno = EINVAL;
+ return -1;
+ }
+ 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 != 0x49484156454F5054LL) {
+ LOG("Bad magic received");
+ errno = EINVAL;
+ return -1;
+ }
+ if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) {
+ LOG("flags read failed");
+ errno = EINVAL;
+ return -1;
+ }
+ *flags = be16_to_cpu(tmp) << 16;
+ /* reserved for future use */
+ if (write_sync(csock, &reserved, sizeof(reserved)) !=
+ sizeof(reserved)) {
+ LOG("write failed (reserved)");
+ errno = EINVAL;
+ return -1;
+ }
+ /* write the export name */
+ magic = cpu_to_be64(magic);
+ if (write_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) {
+ LOG("write failed (magic)");
+ errno = EINVAL;
+ return -1;
+ }
+ opt = cpu_to_be32(NBD_OPT_EXPORT_NAME);
+ if (write_sync(csock, &opt, sizeof(opt)) != sizeof(opt)) {
+ LOG("write failed (opt)");
+ errno = EINVAL;
+ return -1;
+ }
+ namesize = cpu_to_be32(strlen(name));
+ if (write_sync(csock, &namesize, sizeof(namesize)) !=
+ sizeof(namesize)) {
+ LOG("write failed (namesize)");
+ errno = EINVAL;
+ return -1;
+ }
+ if (write_sync(csock, (char*)name, strlen(name)) != strlen(name)) {
+ LOG("write failed (name)");
+ errno = EINVAL;
+ return -1;
+ }
+ } else {
+ TRACE("Checking magic (cli_magic)");
+
+ if (magic != 0x00420281861253LL) {
+ LOG("Bad magic received");
+ errno = EINVAL;
+ return -1;
+ }
+ }
+
+ if (read_sync(csock, &s, sizeof(s)) != sizeof(s)) {
+ LOG("read failed");
+ errno = EINVAL;
+ return -1;
+ }
+ *size = be64_to_cpu(s);
+ *blocksize = 1024;
+ TRACE("Size is %" PRIu64, *size);
- if (magic != 0x00420281861253LL) {
- LOG("Bad magic received");
+ if (!name) {
+ if (read_sync(csock, flags, sizeof(*flags)) != sizeof(*flags)) {
+ LOG("read failed (flags)");
+ errno = EINVAL;
+ return -1;
+ }
+ *flags = be32_to_cpup(flags);
+ } else {
+ if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) {
+ LOG("read failed (tmp)");
+ errno = EINVAL;
+ return -1;
+ }
+ *flags |= be32_to_cpu(tmp);
+ }
+ if (read_sync(csock, &buf, 124) != 124) {
+ LOG("read failed (buf)");
errno = EINVAL;
return -1;
}
diff --git a/nbd.h b/nbd.h
index 5a1fbdf..8ff65a1 100644
--- a/nbd.h
+++ b/nbd.h
@@ -42,6 +42,8 @@ enum {
NBD_CMD_DISC = 2
};
+#define NBD_DEFAULT_PORT 10809
+
size_t nbd_wr_sync(int fd, void *buffer, size_t size, bool do_read);
int tcp_socket_outgoing(const char *address, uint16_t port);
int tcp_socket_incoming(const char *address, uint16_t port);
@@ -49,7 +51,8 @@ int unix_socket_outgoing(const char *path);
int unix_socket_incoming(const char *path);
int nbd_negotiate(int csock, off_t size);
-int nbd_receive_negotiate(int csock, off_t *size, size_t *blocksize);
+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_send_request(int csock, struct nbd_request *request);
int nbd_receive_reply(int csock, struct nbd_reply *reply);
diff --git a/qemu-doc.texi b/qemu-doc.texi
index 55a966f..d7d760f 100644
--- a/qemu-doc.texi
+++ b/qemu-doc.texi
@@ -620,6 +620,13 @@ qemu linux1.img -hdb nbd:unix:/tmp/my_socket
qemu linux2.img -hdb nbd:unix:/tmp/my_socket
@end example
+If the nbd-server uses named exports (since NBD 2.9.18), you must use the
+"exportname" option:
+@example
+qemu -cdrom nbd:localhost:exportname=debian-500-ppc-netinst
+qemu -cdrom nbd:localhost:exportname=openSUSE-11.1-ppc-netinst
+@end example
+
@node pcsys_network
@section Network emulation
diff --git a/qemu-nbd.c b/qemu-nbd.c
index 4e607cf..41e5c5d 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -230,6 +230,7 @@ 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) {
@@ -398,7 +399,8 @@ int main(int argc, char **argv)
goto out;
}
- ret = nbd_receive_negotiate(sock, &size, &blocksize);
+ ret = nbd_receive_negotiate(sock, NULL, &nbdflags,
+ &size, &blocksize);
if (ret == -1) {
ret = 1;
goto out;
--
1.7.0.4
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [Qemu-devel] [PATCH][v3] Introduce NBD named exports.
2010-08-25 20:48 ` [Qemu-devel] [PATCH][v3] " Laurent Vivier
@ 2010-08-25 21:10 ` Anthony Liguori
2010-08-26 14:07 ` Kevin Wolf
1 sibling, 0 replies; 4+ messages in thread
From: Anthony Liguori @ 2010-08-25 21:10 UTC (permalink / raw)
To: Laurent Vivier; +Cc: qemu-devel
On 08/25/2010 03:48 PM, Laurent Vivier wrote:
> This patch allows to connect Qemu using NBD protocol to an nbd-server
> using named exports.
>
Does using a named export make the NBD protocol incompatible with a
server that doesn't support named exports? IOW, it's essentially a new
protocol layered underneath of NBD?
Regards,
Anthony Liguori
> For instance, if on the host "isoserver", in /etc/nbd-server/config, you have:
>
> [generic]
> [debian-500-ppc-netinst]
> exportname = /ISO/debian-500-powerpc-netinst.iso
> [Fedora-10-ppc-netinst]
> exportname = /ISO/Fedora-10-ppc-netinst.iso
>
> You can connect to it, using:
>
> qemu -cdrom nbd:isoserver:exportname=debian-500-ppc-netinst
> qemu -cdrom nbd:isoserver:exportname=Fedora-10-ppc-netinst
>
> NOTE: you need at least nbd-server 2.9.18
>
> Signed-off-by: Laurent Vivier<laurent@vivier.eu>
> ---
> v3: change sizeof() by strlen()
> v2: address Kevin comments (CODING STYLE)
>
> block/nbd.c | 68 +++++++++++++++++++++++---------
> nbd.c | 118 +++++++++++++++++++++++++++++++++++++++++++++++++++------
> nbd.h | 5 ++-
> qemu-doc.texi | 7 +++
> qemu-nbd.c | 4 +-
> 5 files changed, 169 insertions(+), 33 deletions(-)
>
> diff --git a/block/nbd.c b/block/nbd.c
> index a1ec123..5e9d6cb 100644
> --- a/block/nbd.c
> +++ b/block/nbd.c
> @@ -33,6 +33,8 @@
> #include<sys/types.h>
> #include<unistd.h>
>
> +#define EN_OPTSTR ":exportname="
> +
> typedef struct BDRVNBDState {
> int sock;
> off_t size;
> @@ -42,55 +44,83 @@ typedef struct BDRVNBDState {
> static int nbd_open(BlockDriverState *bs, const char* filename, int flags)
> {
> BDRVNBDState *s = bs->opaque;
> + uint32_t nbdflags;
> +
> + char *file;
> + char *name;
> const char *host;
> const char *unixpath;
> int sock;
> off_t size;
> size_t blocksize;
> int ret;
> + int err = -EINVAL;
> +
> + file = qemu_strdup(filename);
>
> - if (!strstart(filename, "nbd:",&host))
> - return -EINVAL;
> + name = strstr(file, EN_OPTSTR);
> + if (name) {
> + if (name[strlen(EN_OPTSTR)] == 0) {
> + goto out;
> + }
> + name[0] = 0;
> + name += strlen(EN_OPTSTR);
> + }
> +
> + if (!strstart(file, "nbd:",&host)) {
> + goto out;
> + }
>
> if (strstart(host, "unix:",&unixpath)) {
>
> - if (unixpath[0] != '/')
> - return -EINVAL;
> + if (unixpath[0] != '/') {
> + goto out;
> + }
>
> sock = unix_socket_outgoing(unixpath);
>
> } else {
> - uint16_t port;
> + uint16_t port = NBD_DEFAULT_PORT;
> char *p, *r;
> char hostname[128];
>
> pstrcpy(hostname, 128, host);
>
> p = strchr(hostname, ':');
> - if (p == NULL)
> - return -EINVAL;
> + if (p != NULL) {
> + *p = '\0';
> + p++;
> +
> + port = strtol(p,&r, 0);
> + if (r == p) {
> + goto out;
> + }
> + } else if (name == NULL) {
> + goto out;
> + }
>
> - *p = '\0';
> - p++;
> -
> - port = strtol(p,&r, 0);
> - if (r == p)
> - return -EINVAL;
> sock = tcp_socket_outgoing(hostname, port);
> }
>
> - if (sock == -1)
> - return -errno;
> + if (sock == -1) {
> + err = -errno;
> + goto out;
> + }
>
> - ret = nbd_receive_negotiate(sock,&size,&blocksize);
> - if (ret == -1)
> - return -errno;
> + ret = nbd_receive_negotiate(sock, name,&nbdflags,&size,&blocksize);
> + if (ret == -1) {
> + err = -errno;
> + goto out;
> + }
>
> s->sock = sock;
> s->size = size;
> s->blocksize = blocksize;
> + err = 0;
>
> - return 0;
> +out:
> + qemu_free(file);
> + return err;
> }
>
> static int nbd_read(BlockDriverState *bs, int64_t sector_num,
> diff --git a/nbd.c b/nbd.c
> index a9f295f..30dec8d 100644
> --- a/nbd.c
> +++ b/nbd.c
> @@ -62,6 +62,8 @@
> #define NBD_SET_SIZE_BLOCKS _IO(0xab, 7)
> #define NBD_DISCONNECT _IO(0xab, 8)
>
> +#define NBD_OPT_EXPORT_NAME (1<< 0)
> +
> /* That's all folks */
>
> #define read_sync(fd, buffer, size) nbd_wr_sync(fd, buffer, size, true)
> @@ -296,22 +298,27 @@ int nbd_negotiate(int csock, off_t size)
> return 0;
> }
>
> -int nbd_receive_negotiate(int csock, off_t *size, size_t *blocksize)
> +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;
> + char buf[256];
> + uint64_t magic, s;
> + uint16_t tmp;
>
> TRACE("Receiving negotation.");
>
> - if (read_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
> + if (read_sync(csock, buf, 8) != 8) {
> LOG("read failed");
> errno = EINVAL;
> return -1;
> }
>
> - magic = be64_to_cpup((uint64_t*)(buf + 8));
> - *size = be64_to_cpup((uint64_t*)(buf + 16));
> - *blocksize = 1024;
> + buf[8] = '\0';
> + if (strlen(buf) == 0) {
> + LOG("server connection closed");
> + errno = EINVAL;
> + return -1;
> + }
>
> TRACE("Magic is %c%c%c%c%c%c%c%c",
> qemu_isprint(buf[0]) ? buf[0] : '.',
> @@ -322,8 +329,6 @@ int nbd_receive_negotiate(int csock, off_t *size, size_t *blocksize)
> qemu_isprint(buf[5]) ? buf[5] : '.',
> qemu_isprint(buf[6]) ? buf[6] : '.',
> qemu_isprint(buf[7]) ? buf[7] : '.');
> - TRACE("Magic is 0x%" PRIx64, magic);
> - TRACE("Size is %" PRIu64, *size);
>
> if (memcmp(buf, "NBDMAGIC", 8) != 0) {
> LOG("Invalid magic received");
> @@ -331,10 +336,99 @@ int nbd_receive_negotiate(int csock, off_t *size, size_t *blocksize)
> return -1;
> }
>
> - TRACE("Checking magic");
> + if (read_sync(csock,&magic, sizeof(magic)) != sizeof(magic)) {
> + LOG("read failed");
> + errno = EINVAL;
> + return -1;
> + }
> + 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 != 0x49484156454F5054LL) {
> + LOG("Bad magic received");
> + errno = EINVAL;
> + return -1;
> + }
> + if (read_sync(csock,&tmp, sizeof(tmp)) != sizeof(tmp)) {
> + LOG("flags read failed");
> + errno = EINVAL;
> + return -1;
> + }
> + *flags = be16_to_cpu(tmp)<< 16;
> + /* reserved for future use */
> + if (write_sync(csock,&reserved, sizeof(reserved)) !=
> + sizeof(reserved)) {
> + LOG("write failed (reserved)");
> + errno = EINVAL;
> + return -1;
> + }
> + /* write the export name */
> + magic = cpu_to_be64(magic);
> + if (write_sync(csock,&magic, sizeof(magic)) != sizeof(magic)) {
> + LOG("write failed (magic)");
> + errno = EINVAL;
> + return -1;
> + }
> + opt = cpu_to_be32(NBD_OPT_EXPORT_NAME);
> + if (write_sync(csock,&opt, sizeof(opt)) != sizeof(opt)) {
> + LOG("write failed (opt)");
> + errno = EINVAL;
> + return -1;
> + }
> + namesize = cpu_to_be32(strlen(name));
> + if (write_sync(csock,&namesize, sizeof(namesize)) !=
> + sizeof(namesize)) {
> + LOG("write failed (namesize)");
> + errno = EINVAL;
> + return -1;
> + }
> + if (write_sync(csock, (char*)name, strlen(name)) != strlen(name)) {
> + LOG("write failed (name)");
> + errno = EINVAL;
> + return -1;
> + }
> + } else {
> + TRACE("Checking magic (cli_magic)");
> +
> + if (magic != 0x00420281861253LL) {
> + LOG("Bad magic received");
> + errno = EINVAL;
> + return -1;
> + }
> + }
> +
> + if (read_sync(csock,&s, sizeof(s)) != sizeof(s)) {
> + LOG("read failed");
> + errno = EINVAL;
> + return -1;
> + }
> + *size = be64_to_cpu(s);
> + *blocksize = 1024;
> + TRACE("Size is %" PRIu64, *size);
>
> - if (magic != 0x00420281861253LL) {
> - LOG("Bad magic received");
> + if (!name) {
> + if (read_sync(csock, flags, sizeof(*flags)) != sizeof(*flags)) {
> + LOG("read failed (flags)");
> + errno = EINVAL;
> + return -1;
> + }
> + *flags = be32_to_cpup(flags);
> + } else {
> + if (read_sync(csock,&tmp, sizeof(tmp)) != sizeof(tmp)) {
> + LOG("read failed (tmp)");
> + errno = EINVAL;
> + return -1;
> + }
> + *flags |= be32_to_cpu(tmp);
> + }
> + if (read_sync(csock,&buf, 124) != 124) {
> + LOG("read failed (buf)");
> errno = EINVAL;
> return -1;
> }
> diff --git a/nbd.h b/nbd.h
> index 5a1fbdf..8ff65a1 100644
> --- a/nbd.h
> +++ b/nbd.h
> @@ -42,6 +42,8 @@ enum {
> NBD_CMD_DISC = 2
> };
>
> +#define NBD_DEFAULT_PORT 10809
> +
> size_t nbd_wr_sync(int fd, void *buffer, size_t size, bool do_read);
> int tcp_socket_outgoing(const char *address, uint16_t port);
> int tcp_socket_incoming(const char *address, uint16_t port);
> @@ -49,7 +51,8 @@ int unix_socket_outgoing(const char *path);
> int unix_socket_incoming(const char *path);
>
> int nbd_negotiate(int csock, off_t size);
> -int nbd_receive_negotiate(int csock, off_t *size, size_t *blocksize);
> +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_send_request(int csock, struct nbd_request *request);
> int nbd_receive_reply(int csock, struct nbd_reply *reply);
> diff --git a/qemu-doc.texi b/qemu-doc.texi
> index 55a966f..d7d760f 100644
> --- a/qemu-doc.texi
> +++ b/qemu-doc.texi
> @@ -620,6 +620,13 @@ qemu linux1.img -hdb nbd:unix:/tmp/my_socket
> qemu linux2.img -hdb nbd:unix:/tmp/my_socket
> @end example
>
> +If the nbd-server uses named exports (since NBD 2.9.18), you must use the
> +"exportname" option:
> +@example
> +qemu -cdrom nbd:localhost:exportname=debian-500-ppc-netinst
> +qemu -cdrom nbd:localhost:exportname=openSUSE-11.1-ppc-netinst
> +@end example
> +
> @node pcsys_network
> @section Network emulation
>
> diff --git a/qemu-nbd.c b/qemu-nbd.c
> index 4e607cf..41e5c5d 100644
> --- a/qemu-nbd.c
> +++ b/qemu-nbd.c
> @@ -230,6 +230,7 @@ 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) {
> @@ -398,7 +399,8 @@ int main(int argc, char **argv)
> goto out;
> }
>
> - ret = nbd_receive_negotiate(sock,&size,&blocksize);
> + ret = nbd_receive_negotiate(sock, NULL,&nbdflags,
> + &size,&blocksize);
> if (ret == -1) {
> ret = 1;
> goto out;
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [Qemu-devel] [PATCH][v3] Introduce NBD named exports.
@ 2010-08-26 10:20 Laurent Vivier
0 siblings, 0 replies; 4+ messages in thread
From: Laurent Vivier @ 2010-08-26 10:20 UTC (permalink / raw)
To: laurent, anthony; +Cc: qemu-devel
>On 08/25/2010 03:48 PM, Laurent Vivier wrote:
>> This patch allows to connect Qemu using NBD protocol to an nbd-server
>> using named exports.
>>
>
>Does using a named export make the NBD protocol incompatible with a
>server that doesn't support named exports? IOW, it's essentially a new
>protocol layered underneath of NBD?
Named exports is fully compatible with old nbd-server protocol.
All is done in the "negotiate" part: there is a new magic number which is used when nbd-server uses named exports, this magic number allows the client to send a name to select the exported disk. Then client receives disk size and data as usual.
I have tested this patch with current "qemu-nbd" (witch tcp and unix socket) and it is working fine.
Regards,
Laurent
>Regards,
>
>Anthony Liguori
>
>> For instance, if on the host "isoserver", in /etc/nbd-server/config, you
>have:
>>
>> [generic]
>> [debian-500-ppc-netinst]
>> exportname = /ISO/debian-500-powerpc-netinst.iso
>> [Fedora-10-ppc-netinst]
>> exportname = /ISO/Fedora-10-ppc-netinst.iso
>>
>> You can connect to it, using:
>>
>> qemu -cdrom nbd:isoserver:exportname=debian-500-ppc-netinst
>> qemu -cdrom nbd:isoserver:exportname=Fedora-10-ppc-netinst
>>
>> NOTE: you need at least nbd-server 2.9.18
>>
>> Signed-off-by: Laurent Vivier<laurent@vivier.eu>
>> ---
>> v3: change sizeof() by strlen()
>> v2: address Kevin comments (CODING STYLE)
>>
>> block/nbd.c | 68 +++++++++++++++++++++++---------
>> nbd.c | 118
>+++++++++++++++++++++++++++++++++++++++++++++++++++------
>> nbd.h | 5 ++-
>> qemu-doc.texi | 7 +++
>> qemu-nbd.c | 4 +-
>> 5 files changed, 169 insertions(+), 33 deletions(-)
>>
>> diff --git a/block/nbd.c b/block/nbd.c
>> index a1ec123..5e9d6cb 100644
>> --- a/block/nbd.c
>> +++ b/block/nbd.c
>> @@ -33,6 +33,8 @@
>> #include<sys/types.h>
>> #include<unistd.h>
>>
>> +#define EN_OPTSTR ":exportname="
>> +
>> typedef struct BDRVNBDState {
>> int sock;
>> off_t size;
>> @@ -42,55 +44,83 @@ typedef struct BDRVNBDState {
>> static int nbd_open(BlockDriverState *bs, const char* filename, int
>flags)
>> {
>> BDRVNBDState *s = bs->opaque;
>> + uint32_t nbdflags;
>> +
>> + char *file;
>> + char *name;
>> const char *host;
>> const char *unixpath;
>> int sock;
>> off_t size;
>> size_t blocksize;
>> int ret;
>> + int err = -EINVAL;
>> +
>> + file = qemu_strdup(filename);
>>
>> - if (!strstart(filename, "nbd:",&host))
>> - return -EINVAL;
>> + name = strstr(file, EN_OPTSTR);
>> + if (name) {
>> + if (name[strlen(EN_OPTSTR)] == 0) {
>> + goto out;
>> + }
>> + name[0] = 0;
>> + name += strlen(EN_OPTSTR);
>> + }
>> +
>> + if (!strstart(file, "nbd:",&host)) {
>> + goto out;
>> + }
>>
>> if (strstart(host, "unix:",&unixpath)) {
>>
>> - if (unixpath[0] != '/')
>> - return -EINVAL;
>> + if (unixpath[0] != '/') {
>> + goto out;
>> + }
>>
>> sock = unix_socket_outgoing(unixpath);
>>
>> } else {
>> - uint16_t port;
>> + uint16_t port = NBD_DEFAULT_PORT;
>> char *p, *r;
>> char hostname[128];
>>
>> pstrcpy(hostname, 128, host);
>>
>> p = strchr(hostname, ':');
>> - if (p == NULL)
>> - return -EINVAL;
>> + if (p != NULL) {
>> + *p = '\0';
>> + p++;
>> +
>> + port = strtol(p,&r, 0);
>> + if (r == p) {
>> + goto out;
>> + }
>> + } else if (name == NULL) {
>> + goto out;
>> + }
>>
>> - *p = '\0';
>> - p++;
>> -
>> - port = strtol(p,&r, 0);
>> - if (r == p)
>> - return -EINVAL;
>> sock = tcp_socket_outgoing(hostname, port);
>> }
>>
>> - if (sock == -1)
>> - return -errno;
>> + if (sock == -1) {
>> + err = -errno;
>> + goto out;
>> + }
>>
>> - ret = nbd_receive_negotiate(sock,&size,&blocksize);
>> - if (ret == -1)
>> - return -errno;
>> + ret = nbd_receive_negotiate(sock, name,&nbdflags,&size,&blocksize);
>> + if (ret == -1) {
>> + err = -errno;
>> + goto out;
>> + }
>>
>> s->sock = sock;
>> s->size = size;
>> s->blocksize = blocksize;
>> + err = 0;
>>
>> - return 0;
>> +out:
>> + qemu_free(file);
>> + return err;
>> }
>>
>> static int nbd_read(BlockDriverState *bs, int64_t sector_num,
>> diff --git a/nbd.c b/nbd.c
>> index a9f295f..30dec8d 100644
>> --- a/nbd.c
>> +++ b/nbd.c
>> @@ -62,6 +62,8 @@
>> #define NBD_SET_SIZE_BLOCKS _IO(0xab, 7)
>> #define NBD_DISCONNECT _IO(0xab, 8)
>>
>> +#define NBD_OPT_EXPORT_NAME (1<< 0)
>> +
>> /* That's all folks */
>>
>> #define read_sync(fd, buffer, size) nbd_wr_sync(fd, buffer, size, true)
>> @@ -296,22 +298,27 @@ int nbd_negotiate(int csock, off_t size)
>> return 0;
>> }
>>
>> -int nbd_receive_negotiate(int csock, off_t *size, size_t *blocksize)
>> +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;
>> + char buf[256];
>> + uint64_t magic, s;
>> + uint16_t tmp;
>>
>> TRACE("Receiving negotation.");
>>
>> - if (read_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
>> + if (read_sync(csock, buf, 8) != 8) {
>> LOG("read failed");
>> errno = EINVAL;
>> return -1;
>> }
>>
>> - magic = be64_to_cpup((uint64_t*)(buf + 8));
>> - *size = be64_to_cpup((uint64_t*)(buf + 16));
>> - *blocksize = 1024;
>> + buf[8] = '\0';
>> + if (strlen(buf) == 0) {
>> + LOG("server connection closed");
>> + errno = EINVAL;
>> + return -1;
>> + }
>>
>> TRACE("Magic is %c%c%c%c%c%c%c%c",
>> qemu_isprint(buf[0]) ? buf[0] : '.',
>> @@ -322,8 +329,6 @@ int nbd_receive_negotiate(int csock, off_t *size, size_t
>*blocksize)
>> qemu_isprint(buf[5]) ? buf[5] : '.',
>> qemu_isprint(buf[6]) ? buf[6] : '.',
>> qemu_isprint(buf[7]) ? buf[7] : '.');
>> - TRACE("Magic is 0x%" PRIx64, magic);
>> - TRACE("Size is %" PRIu64, *size);
>>
>> if (memcmp(buf, "NBDMAGIC", 8) != 0) {
>> LOG("Invalid magic received");
>> @@ -331,10 +336,99 @@ int nbd_receive_negotiate(int csock, off_t *size,
>size_t *blocksize)
>> return -1;
>> }
>>
>> - TRACE("Checking magic");
>> + if (read_sync(csock,&magic, sizeof(magic)) != sizeof(magic)) {
>> + LOG("read failed");
>> + errno = EINVAL;
>> + return -1;
>> + }
>> + 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 != 0x49484156454F5054LL) {
>> + LOG("Bad magic received");
>> + errno = EINVAL;
>> + return -1;
>> + }
>> + if (read_sync(csock,&tmp, sizeof(tmp)) != sizeof(tmp)) {
>> + LOG("flags read failed");
>> + errno = EINVAL;
>> + return -1;
>> + }
>> + *flags = be16_to_cpu(tmp)<< 16;
>> + /* reserved for future use */
>> + if (write_sync(csock,&reserved, sizeof(reserved)) !=
>> + sizeof(reserved)) {
>> + LOG("write failed (reserved)");
>> + errno = EINVAL;
>> + return -1;
>> + }
>> + /* write the export name */
>> + magic = cpu_to_be64(magic);
>> + if (write_sync(csock,&magic, sizeof(magic)) != sizeof(magic)) {
>> + LOG("write failed (magic)");
>> + errno = EINVAL;
>> + return -1;
>> + }
>> + opt = cpu_to_be32(NBD_OPT_EXPORT_NAME);
>> + if (write_sync(csock,&opt, sizeof(opt)) != sizeof(opt)) {
>> + LOG("write failed (opt)");
>> + errno = EINVAL;
>> + return -1;
>> + }
>> + namesize = cpu_to_be32(strlen(name));
>> + if (write_sync(csock,&namesize, sizeof(namesize)) !=
>> + sizeof(namesize)) {
>> + LOG("write failed (namesize)");
>> + errno = EINVAL;
>> + return -1;
>> + }
>> + if (write_sync(csock, (char*)name, strlen(name)) != strlen(name)) {
>> + LOG("write failed (name)");
>> + errno = EINVAL;
>> + return -1;
>> + }
>> + } else {
>> + TRACE("Checking magic (cli_magic)");
>> +
>> + if (magic != 0x00420281861253LL) {
>> + LOG("Bad magic received");
>> + errno = EINVAL;
>> + return -1;
>> + }
>> + }
>> +
>> + if (read_sync(csock,&s, sizeof(s)) != sizeof(s)) {
>> + LOG("read failed");
>> + errno = EINVAL;
>> + return -1;
>> + }
>> + *size = be64_to_cpu(s);
>> + *blocksize = 1024;
>> + TRACE("Size is %" PRIu64, *size);
>>
>> - if (magic != 0x00420281861253LL) {
>> - LOG("Bad magic received");
>> + if (!name) {
>> + if (read_sync(csock, flags, sizeof(*flags)) != sizeof(*flags)) {
>> + LOG("read failed (flags)");
>> + errno = EINVAL;
>> + return -1;
>> + }
>> + *flags = be32_to_cpup(flags);
>> + } else {
>> + if (read_sync(csock,&tmp, sizeof(tmp)) != sizeof(tmp)) {
>> + LOG("read failed (tmp)");
>> + errno = EINVAL;
>> + return -1;
>> + }
>> + *flags |= be32_to_cpu(tmp);
>> + }
>> + if (read_sync(csock,&buf, 124) != 124) {
>> + LOG("read failed (buf)");
>> errno = EINVAL;
>> return -1;
>> }
>> diff --git a/nbd.h b/nbd.h
>> index 5a1fbdf..8ff65a1 100644
>> --- a/nbd.h
>> +++ b/nbd.h
>> @@ -42,6 +42,8 @@ enum {
>> NBD_CMD_DISC = 2
>> };
>>
>> +#define NBD_DEFAULT_PORT 10809
>> +
>> size_t nbd_wr_sync(int fd, void *buffer, size_t size, bool do_read);
>> int tcp_socket_outgoing(const char *address, uint16_t port);
>> int tcp_socket_incoming(const char *address, uint16_t port);
>> @@ -49,7 +51,8 @@ int unix_socket_outgoing(const char *path);
>> int unix_socket_incoming(const char *path);
>>
>> int nbd_negotiate(int csock, off_t size);
>> -int nbd_receive_negotiate(int csock, off_t *size, size_t *blocksize);
>> +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_send_request(int csock, struct nbd_request *request);
>> int nbd_receive_reply(int csock, struct nbd_reply *reply);
>> diff --git a/qemu-doc.texi b/qemu-doc.texi
>> index 55a966f..d7d760f 100644
>> --- a/qemu-doc.texi
>> +++ b/qemu-doc.texi
>> @@ -620,6 +620,13 @@ qemu linux1.img -hdb nbd:unix:/tmp/my_socket
>> qemu linux2.img -hdb nbd:unix:/tmp/my_socket
>> @end example
>>
>> +If the nbd-server uses named exports (since NBD 2.9.18), you must use the
>> +"exportname" option:
>> +@example
>> +qemu -cdrom nbd:localhost:exportname=debian-500-ppc-netinst
>> +qemu -cdrom nbd:localhost:exportname=openSUSE-11.1-ppc-netinst
>> +@end example
>> +
>> @node pcsys_network
>> @section Network emulation
>>
>> diff --git a/qemu-nbd.c b/qemu-nbd.c
>> index 4e607cf..41e5c5d 100644
>> --- a/qemu-nbd.c
>> +++ b/qemu-nbd.c
>> @@ -230,6 +230,7 @@ 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) {
>> @@ -398,7 +399,8 @@ int main(int argc, char **argv)
>> goto out;
>> }
>>
>> - ret = nbd_receive_negotiate(sock,&size,&blocksize);
>> + ret = nbd_receive_negotiate(sock, NULL,&nbdflags,
>> + &size,&blocksize);
>> if (ret == -1) {
>> ret = 1;
>> goto out;
>>
>
>
--
--------------------- Laurent@vivier.eu ---------------------
"Tout ce qui est impossible reste à accomplir" Jules Verne
"Things are only impossible until they're not" Jean-Luc Picard
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [Qemu-devel] [PATCH][v3] Introduce NBD named exports.
2010-08-25 20:48 ` [Qemu-devel] [PATCH][v3] " Laurent Vivier
2010-08-25 21:10 ` Anthony Liguori
@ 2010-08-26 14:07 ` Kevin Wolf
1 sibling, 0 replies; 4+ messages in thread
From: Kevin Wolf @ 2010-08-26 14:07 UTC (permalink / raw)
To: Laurent Vivier; +Cc: qemu-devel
Am 25.08.2010 22:48, schrieb Laurent Vivier:
> This patch allows to connect Qemu using NBD protocol to an nbd-server
> using named exports.
>
> For instance, if on the host "isoserver", in /etc/nbd-server/config, you have:
>
> [generic]
> [debian-500-ppc-netinst]
> exportname = /ISO/debian-500-powerpc-netinst.iso
> [Fedora-10-ppc-netinst]
> exportname = /ISO/Fedora-10-ppc-netinst.iso
>
> You can connect to it, using:
>
> qemu -cdrom nbd:isoserver:exportname=debian-500-ppc-netinst
> qemu -cdrom nbd:isoserver:exportname=Fedora-10-ppc-netinst
>
> NOTE: you need at least nbd-server 2.9.18
>
> Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Thanks, applied to the block branch.
Kevin
^ permalink raw reply [flat|nested] 4+ messages in thread
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2010-08-25 8:21 [Qemu-devel] [PATCH] " Kevin Wolf
2010-08-25 20:48 ` [Qemu-devel] [PATCH][v3] " Laurent Vivier
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