Signed-off-by: Hani Benhabiles <h...@linux.com>
---
include/block/nbd.h | 4 +++
nbd.c | 97 +++++++++++++++++++++++++++++++++++++++++++++++++++--
2 files changed, 99 insertions(+), 2 deletions(-)
diff --git a/include/block/nbd.h b/include/block/nbd.h
index 95d52ab..23e9a84 100644
--- a/include/block/nbd.h
+++ b/include/block/nbd.h
@@ -51,6 +51,10 @@ 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_CMD_MASK_COMMAND 0x0000ffff
#define NBD_CMD_FLAG_FUA (1 << 16)
diff --git a/nbd.c b/nbd.c
index fb0a9cf..9150fa6 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 +78,8 @@
#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_LIST (3)
/* Definitions for opaque data types */
@@ -215,6 +217,88 @@ static ssize_t write_sync(int fd, void *buffer, size_t
size)
*/
+static int nbd_send_rep_ack(int csock)
+{
+ uint64_t magic;
+ uint32_t opt, type, len;
+
+ magic = cpu_to_be64(NBD_REP_MAGIC);
+ if (write_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) {
+ LOG("write failed (rep magic)");
+ return -EINVAL;
+ }
+ opt = cpu_to_be32(NBD_OPT_LIST);
+ if (write_sync(csock, &opt, sizeof(opt)) != sizeof(opt)) {
+ LOG("write failed (opt list)");
+ return -EINVAL;
+ }
+ type = cpu_to_be32(NBD_REP_ACK);
+ if (write_sync(csock, &type, sizeof(type)) != sizeof(type)) {
+ LOG("write failed (rep ack)");
+ return -EINVAL;
+ }
+ len = cpu_to_be32(0);
+ if (write_sync(csock, &len, sizeof(len)) != sizeof(len)) {
+ LOG("write failed (rep data length)");
+ return -EINVAL;
+ }
+ return 0;
+}
+
+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;
+ }
+ 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_ack(csock);
+}
+
static int nbd_receive_options(NBDClient *client)
{
int csock = client->sock;
@@ -258,6 +342,13 @@ static int nbd_receive_options(NBDClient *client)
goto fail;
}
TRACE("Checking option");
+ if (tmp == be32_to_cpu(NBD_OPT_LIST)) {
+ if (nbd_send_list(client) < 0) {
+ return -EINVAL;
+ } else {
+ return 1;
+ }
+ }
if (tmp != be32_to_cpu(NBD_OPT_EXPORT_NAME)) {
LOG("Bad option received");
goto fail;
@@ -351,6 +442,8 @@ 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 +1268,7 @@ 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
