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[Qemu-devel] [PATCH 2/3] nbd: Add exports listing support.
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From: |
Hani Benhabiles |
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Subject: |
[Qemu-devel] [PATCH 2/3] nbd: Add exports listing support. |
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Date: |
Sat, 31 May 2014 22:39:41 +0100 |
This is added by handling the NBD_OPT_LIST and NBD_OPT_ABORT options.
NBD_REP_ERR_UNSUP is also sent for unknown NBD option values.
Signed-off-by: Hani Benhabiles <address@hidden>
---
include/block/nbd.h | 5 ++
nbd.c | 197 +++++++++++++++++++++++++++++++++++++++++-----------
2 files changed, 162 insertions(+), 40 deletions(-)
diff --git a/include/block/nbd.h b/include/block/nbd.h
index 95d52ab..fd7e057 100644
--- a/include/block/nbd.h
+++ b/include/block/nbd.h
@@ -51,6 +51,11 @@ struct nbd_reply {
/* New-style client flags. */
#define NBD_FLAG_C_FIXED_NEWSTYLE (1 << 0) /* Fixed newstyle protocol. */
+/* Reply types. */
+#define NBD_REP_ACK (1) /* Data sending finished. */
+#define NBD_REP_SERVER (2) /* Export description. */
+#define NBD_REP_ERR_UNSUP ((1 << 31) | 1) /* Unknown option. */
+
#define NBD_CMD_MASK_COMMAND 0x0000ffff
#define NBD_CMD_FLAG_FUA (1 << 16)
diff --git a/nbd.c b/nbd.c
index aa2e552..012e5da 100644
--- a/nbd.c
+++ b/nbd.c
@@ -64,6 +64,7 @@
#define NBD_REPLY_MAGIC 0x67446698
#define NBD_OPTS_MAGIC 0x49484156454F5054LL
#define NBD_CLIENT_MAGIC 0x0000420281861253LL
+#define NBD_REP_MAGIC 0x3e889045565a9LL
#define NBD_SET_SOCK _IO(0xab, 0)
#define NBD_SET_BLKSIZE _IO(0xab, 1)
@@ -77,7 +78,9 @@
#define NBD_SET_TIMEOUT _IO(0xab, 9)
#define NBD_SET_FLAGS _IO(0xab, 10)
-#define NBD_OPT_EXPORT_NAME (1 << 0)
+#define NBD_OPT_EXPORT_NAME (1)
+#define NBD_OPT_ABORT (2)
+#define NBD_OPT_LIST (3)
/* Definitions for opaque data types */
@@ -215,54 +218,98 @@ static ssize_t write_sync(int fd, void *buffer, size_t
size)
*/
-static int nbd_receive_options(NBDClient *client)
+static int nbd_send_rep(int csock, uint32_t type, uint32_t opt)
{
- int csock = client->sock;
- char name[256];
- uint32_t tmp, length;
uint64_t magic;
- int rc;
-
- /* Client sends:
- [ 0 .. 3] client flags
- [ 4 .. 11] NBD_OPTS_MAGIC
- [12 .. 15] NBD_OPT_EXPORT_NAME
- [16 .. 19] length
- [20 .. xx] export name (length bytes)
- */
+ uint32_t len;
- rc = -EINVAL;
- if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) {
- LOG("read failed");
- goto fail;
+ magic = cpu_to_be64(NBD_REP_MAGIC);
+ if (write_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) {
+ LOG("write failed (rep magic)");
+ return -EINVAL;
}
- TRACE("Checking client flags");
- tmp = be32_to_cpu(tmp);
- if (tmp != 0 && tmp != NBD_FLAG_C_FIXED_NEWSTYLE) {
- LOG("Bad client flags received");
- goto fail;
+ opt = cpu_to_be32(opt);
+ if (write_sync(csock, &opt, sizeof(opt)) != sizeof(opt)) {
+ LOG("write failed (rep opt)");
+ return -EINVAL;
}
-
- if (read_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) {
- LOG("read failed");
- goto fail;
+ type = cpu_to_be32(type);
+ if (write_sync(csock, &type, sizeof(type)) != sizeof(type)) {
+ LOG("write failed (rep type)");
+ return -EINVAL;
}
- TRACE("Checking opts magic");
- if (magic != be64_to_cpu(NBD_OPTS_MAGIC)) {
- LOG("Bad magic received");
- goto fail;
+ len = cpu_to_be32(0);
+ if (write_sync(csock, &len, sizeof(len)) != sizeof(len)) {
+ LOG("write failed (rep data length)");
+ return -EINVAL;
}
+ return 0;
+}
- if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) {
- LOG("read failed");
- goto fail;
+static int nbd_send_rep_list(int csock, NBDExport *exp)
+{
+ uint64_t magic, name_len;
+ uint32_t opt, type, len;
+
+ name_len = strlen(exp->name);
+ magic = cpu_to_be64(NBD_REP_MAGIC);
+ if (write_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) {
+ LOG("write failed (magic)");
+ return -EINVAL;
}
- TRACE("Checking option");
- if (tmp != be32_to_cpu(NBD_OPT_EXPORT_NAME)) {
- LOG("Bad option received");
- goto fail;
+ opt = cpu_to_be32(NBD_OPT_LIST);
+ if (write_sync(csock, &opt, sizeof(opt)) != sizeof(opt)) {
+ LOG("write failed (opt)");
+ return -EINVAL;
+ }
+ type = cpu_to_be32(NBD_REP_SERVER);
+ if (write_sync(csock, &type, sizeof(type)) != sizeof(type)) {
+ LOG("write failed (reply type)");
+ return -EINVAL;
+ }
+ len = cpu_to_be32(name_len + sizeof(len));
+ if (write_sync(csock, &len, sizeof(len)) != sizeof(len)) {
+ LOG("write failed (length)");
+ return -EINVAL;
+ }
+ len = cpu_to_be32(name_len);
+ if (write_sync(csock, &len, sizeof(len)) != sizeof(len)) {
+ LOG("write failed (length)");
+ return -EINVAL;
+ }
+ if (write_sync(csock, exp->name, name_len) != name_len) {
+ LOG("write failed (buffer)");
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static int nbd_send_list(NBDClient *client)
+{
+ int csock;
+ NBDExport *exp;
+
+ csock = client->sock;
+ /* For each export, send a NBD_REP_SERVER reply. */
+ QTAILQ_FOREACH(exp, &exports, next) {
+ if (nbd_send_rep_list(csock, exp)) {
+ return -EINVAL;
+ }
}
+ /* Finish with a NBD_REP_ACK. */
+ return nbd_send_rep(csock, NBD_REP_ACK, NBD_OPT_LIST);
+}
+
+static int nbd_handle_export_name(NBDClient *client)
+{
+ int rc = -EINVAL, csock = client->sock;
+ char name[256];
+ uint32_t length;
+ /* Client sends:
+ [16 .. 19] length
+ [20 .. xx] export name (length bytes)
+ */
if (read_sync(csock, &length, sizeof(length)) != sizeof(length)) {
LOG("read failed");
goto fail;
@@ -287,8 +334,76 @@ static int nbd_receive_options(NBDClient *client)
QTAILQ_INSERT_TAIL(&client->exp->clients, client, next);
nbd_export_get(client->exp);
+ rc = 0;
+fail:
+ return rc;
+}
+
+static int nbd_receive_options(NBDClient *client)
+{
+ int rc = -EINVAL;
- TRACE("Option negotiation succeeded.");
+ while (1) {
+ int csock = client->sock;
+ uint32_t tmp;
+ uint64_t magic;
+
+ /* Client sends:
+ [ 0 .. 3] client flags
+ [ 4 .. 11] NBD_OPTS_MAGIC
+ [12 .. 15] NBD option
+ ... Rest of request
+ */
+
+ if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) {
+ LOG("read failed");
+ goto fail;
+ }
+ TRACE("Checking client flags");
+ tmp = be32_to_cpu(tmp);
+ if (tmp != 0 && tmp != NBD_FLAG_C_FIXED_NEWSTYLE) {
+ LOG("Bad client flags received");
+ goto fail;
+ }
+
+ if (read_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) {
+ LOG("read failed");
+ goto fail;
+ }
+ TRACE("Checking opts magic");
+ 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");
+ switch (be32_to_cpu(tmp)) {
+ case NBD_OPT_LIST:
+ if (nbd_send_list(client) < 0) {
+ return -EINVAL;
+ }
+ break;
+
+ case NBD_OPT_ABORT:
+ return 1;
+
+ case NBD_OPT_EXPORT_NAME:
+ return nbd_handle_export_name(client);
+
+ default:
+ tmp = be32_to_cpu(tmp);
+ LOG("Unsupported option 0x%x", tmp);
+ if (nbd_send_rep(client->sock, NBD_REP_ERR_UNSUP, tmp)) {
+ return -EINVAL;
+ }
+ return 1;
+ }
+ }
rc = 0;
fail:
return rc;
@@ -351,6 +466,8 @@ static int nbd_send_negotiate(NBDClient *client)
if (rc < 0) {
LOG("option negotiation failed");
goto fail;
+ } else if (rc > 0) {
+ goto fail;
}
assert ((client->exp->nbdflags & ~65535) == 0);
@@ -1175,7 +1292,7 @@ NBDClient *nbd_client_new(NBDExport *exp, int csock,
client->refcount = 1;
client->exp = exp;
client->sock = csock;
- if (nbd_send_negotiate(client) < 0) {
+ if (nbd_send_negotiate(client)) {
g_free(client);
return NULL;
}
--
1.8.3.2