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-rw-r--r--nbd/client.c63
-rw-r--r--nbd/nbd-internal.h34
-rw-r--r--nbd/server.c84
3 files changed, 88 insertions, 93 deletions
diff --git a/nbd/client.c b/nbd/client.c
index a58fb02..6b74a62 100644
--- a/nbd/client.c
+++ b/nbd/client.c
@@ -86,9 +86,9 @@ static QTAILQ_HEAD(, NBDExport) exports = QTAILQ_HEAD_INITIALIZER(exports);
*/
-/* Discard length bytes from channel. Return -errno on failure, or
- * the amount of bytes consumed. */
-static ssize_t drop_sync(QIOChannel *ioc, size_t size)
+/* Discard length bytes from channel. Return -errno on failure and 0 on
+ * success*/
+static int drop_sync(QIOChannel *ioc, size_t size)
{
ssize_t ret = 0;
char small[1024];
@@ -96,14 +96,13 @@ static ssize_t drop_sync(QIOChannel *ioc, size_t size)
buffer = sizeof(small) >= size ? small : g_malloc(MIN(65536, size));
while (size > 0) {
- ssize_t count = read_sync(ioc, buffer, MIN(65536, size));
+ ssize_t count = MIN(65536, size);
+ ret = read_sync(ioc, buffer, MIN(65536, size));
- if (count <= 0) {
+ if (ret < 0) {
goto cleanup;
}
- assert(count <= size);
size -= count;
- ret += count;
}
cleanup:
@@ -136,12 +135,12 @@ static int nbd_send_option_request(QIOChannel *ioc, uint32_t opt,
stl_be_p(&req.option, opt);
stl_be_p(&req.length, len);
- if (write_sync(ioc, &req, sizeof(req)) != sizeof(req)) {
+ if (write_sync(ioc, &req, sizeof(req)) < 0) {
error_setg(errp, "Failed to send option request header");
return -1;
}
- if (len && write_sync(ioc, (char *) data, len) != len) {
+ if (len && write_sync(ioc, (char *) data, len) < 0) {
error_setg(errp, "Failed to send option request data");
return -1;
}
@@ -170,7 +169,7 @@ static int nbd_receive_option_reply(QIOChannel *ioc, uint32_t opt,
nbd_opt_reply *reply, Error **errp)
{
QEMU_BUILD_BUG_ON(sizeof(*reply) != 20);
- if (read_sync(ioc, reply, sizeof(*reply)) != sizeof(*reply)) {
+ if (read_sync(ioc, reply, sizeof(*reply)) < 0) {
error_setg(errp, "failed to read option reply");
nbd_send_opt_abort(ioc);
return -1;
@@ -219,7 +218,7 @@ static int nbd_handle_reply_err(QIOChannel *ioc, nbd_opt_reply *reply,
goto cleanup;
}
msg = g_malloc(reply->length + 1);
- if (read_sync(ioc, msg, reply->length) != reply->length) {
+ if (read_sync(ioc, msg, reply->length) < 0) {
error_setg(errp, "failed to read option error message");
goto cleanup;
}
@@ -321,7 +320,7 @@ static int nbd_receive_list(QIOChannel *ioc, const char *want, bool *match,
nbd_send_opt_abort(ioc);
return -1;
}
- if (read_sync(ioc, &namelen, sizeof(namelen)) != sizeof(namelen)) {
+ if (read_sync(ioc, &namelen, sizeof(namelen)) < 0) {
error_setg(errp, "failed to read option name length");
nbd_send_opt_abort(ioc);
return -1;
@@ -334,7 +333,7 @@ static int nbd_receive_list(QIOChannel *ioc, const char *want, bool *match,
return -1;
}
if (namelen != strlen(want)) {
- if (drop_sync(ioc, len) != len) {
+ if (drop_sync(ioc, len) < 0) {
error_setg(errp, "failed to skip export name with wrong length");
nbd_send_opt_abort(ioc);
return -1;
@@ -343,14 +342,14 @@ static int nbd_receive_list(QIOChannel *ioc, const char *want, bool *match,
}
assert(namelen < sizeof(name));
- if (read_sync(ioc, name, namelen) != namelen) {
+ if (read_sync(ioc, name, namelen) < 0) {
error_setg(errp, "failed to read export name");
nbd_send_opt_abort(ioc);
return -1;
}
name[namelen] = '\0';
len -= namelen;
- if (drop_sync(ioc, len) != len) {
+ if (drop_sync(ioc, len) < 0) {
error_setg(errp, "failed to read export description");
nbd_send_opt_abort(ioc);
return -1;
@@ -477,7 +476,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags,
goto fail;
}
- if (read_sync(ioc, buf, 8) != 8) {
+ if (read_sync(ioc, buf, 8) < 0) {
error_setg(errp, "Failed to read data");
goto fail;
}
@@ -503,7 +502,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags,
goto fail;
}
- if (read_sync(ioc, &magic, sizeof(magic)) != sizeof(magic)) {
+ if (read_sync(ioc, &magic, sizeof(magic)) < 0) {
error_setg(errp, "Failed to read magic");
goto fail;
}
@@ -515,8 +514,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags,
uint16_t globalflags;
bool fixedNewStyle = false;
- if (read_sync(ioc, &globalflags, sizeof(globalflags)) !=
- sizeof(globalflags)) {
+ if (read_sync(ioc, &globalflags, sizeof(globalflags)) < 0) {
error_setg(errp, "Failed to read server flags");
goto fail;
}
@@ -534,8 +532,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags,
}
/* client requested flags */
clientflags = cpu_to_be32(clientflags);
- if (write_sync(ioc, &clientflags, sizeof(clientflags)) !=
- sizeof(clientflags)) {
+ if (write_sync(ioc, &clientflags, sizeof(clientflags)) < 0) {
error_setg(errp, "Failed to send clientflags field");
goto fail;
}
@@ -573,13 +570,13 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags,
}
/* Read the response */
- if (read_sync(ioc, &s, sizeof(s)) != sizeof(s)) {
+ if (read_sync(ioc, &s, sizeof(s)) < 0) {
error_setg(errp, "Failed to read export length");
goto fail;
}
*size = be64_to_cpu(s);
- if (read_sync(ioc, flags, sizeof(*flags)) != sizeof(*flags)) {
+ if (read_sync(ioc, flags, sizeof(*flags)) < 0) {
error_setg(errp, "Failed to read export flags");
goto fail;
}
@@ -596,14 +593,14 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags,
goto fail;
}
- if (read_sync(ioc, &s, sizeof(s)) != sizeof(s)) {
+ if (read_sync(ioc, &s, sizeof(s)) < 0) {
error_setg(errp, "Failed to read export length");
goto fail;
}
*size = be64_to_cpu(s);
TRACE("Size is %" PRIu64, *size);
- if (read_sync(ioc, &oldflags, sizeof(oldflags)) != sizeof(oldflags)) {
+ if (read_sync(ioc, &oldflags, sizeof(oldflags)) < 0) {
error_setg(errp, "Failed to read export flags");
goto fail;
}
@@ -619,7 +616,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags,
}
TRACE("Size is %" PRIu64 ", export flags %" PRIx16, *size, *flags);
- if (zeroes && drop_sync(ioc, 124) != 124) {
+ if (zeroes && drop_sync(ioc, 124) < 0) {
error_setg(errp, "Failed to read reserved block");
goto fail;
}
@@ -744,7 +741,6 @@ int nbd_disconnect(int fd)
ssize_t nbd_send_request(QIOChannel *ioc, NBDRequest *request)
{
uint8_t buf[NBD_REQUEST_SIZE];
- ssize_t ret;
TRACE("Sending request to server: "
"{ .from = %" PRIu64", .len = %" PRIu32 ", .handle = %" PRIu64
@@ -759,16 +755,7 @@ ssize_t nbd_send_request(QIOChannel *ioc, NBDRequest *request)
stq_be_p(buf + 16, request->from);
stl_be_p(buf + 24, request->len);
- ret = write_sync(ioc, buf, sizeof(buf));
- if (ret < 0) {
- return ret;
- }
-
- if (ret != sizeof(buf)) {
- LOG("writing to socket failed");
- return -EINVAL;
- }
- return 0;
+ return write_sync(ioc, buf, sizeof(buf));
}
ssize_t nbd_receive_reply(QIOChannel *ioc, NBDReply *reply)
@@ -777,7 +764,7 @@ ssize_t nbd_receive_reply(QIOChannel *ioc, NBDReply *reply)
uint32_t magic;
ssize_t ret;
- ret = read_sync(ioc, buf, sizeof(buf));
+ ret = read_sync_eof(ioc, buf, sizeof(buf));
if (ret <= 0) {
return ret;
}
diff --git a/nbd/nbd-internal.h b/nbd/nbd-internal.h
index f43d990..e6bbc7c 100644
--- a/nbd/nbd-internal.h
+++ b/nbd/nbd-internal.h
@@ -94,7 +94,13 @@
#define NBD_ENOSPC 28
#define NBD_ESHUTDOWN 108
-static inline ssize_t read_sync(QIOChannel *ioc, void *buffer, size_t size)
+/* read_sync_eof
+ * Tries to read @size bytes from @ioc. Returns number of bytes actually read.
+ * May return a value >= 0 and < size only on EOF, i.e. when iteratively called
+ * qio_channel_readv() returns 0. So, there are no needs to call read_sync_eof
+ * iteratively.
+ */
+static inline ssize_t read_sync_eof(QIOChannel *ioc, void *buffer, size_t size)
{
struct iovec iov = { .iov_base = buffer, .iov_len = size };
/* Sockets are kept in blocking mode in the negotiation phase. After
@@ -105,12 +111,32 @@ static inline ssize_t read_sync(QIOChannel *ioc, void *buffer, size_t size)
return nbd_wr_syncv(ioc, &iov, 1, size, true);
}
-static inline ssize_t write_sync(QIOChannel *ioc, const void *buffer,
- size_t size)
+/* read_sync
+ * Reads @size bytes from @ioc. Returns 0 on success.
+ */
+static inline int read_sync(QIOChannel *ioc, void *buffer, size_t size)
+{
+ ssize_t ret = read_sync_eof(ioc, buffer, size);
+
+ if (ret >= 0 && ret != size) {
+ ret = -EINVAL;
+ }
+
+ return ret < 0 ? ret : 0;
+}
+
+/* write_sync
+ * Writes @size bytes to @ioc. Returns 0 on success.
+ */
+static inline int write_sync(QIOChannel *ioc, const void *buffer, size_t size)
{
struct iovec iov = { .iov_base = (void *) buffer, .iov_len = size };
- return nbd_wr_syncv(ioc, &iov, 1, size, false);
+ ssize_t ret = nbd_wr_syncv(ioc, &iov, 1, size, false);
+
+ assert(ret < 0 || ret == size);
+
+ return ret < 0 ? ret : 0;
}
struct NBDTLSHandshakeData {
diff --git a/nbd/server.c b/nbd/server.c
index 924a1fe..1e1096c 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -112,7 +112,7 @@ static gboolean nbd_negotiate_continue(QIOChannel *ioc,
return TRUE;
}
-static ssize_t nbd_negotiate_read(QIOChannel *ioc, void *buffer, size_t size)
+static int nbd_negotiate_read(QIOChannel *ioc, void *buffer, size_t size)
{
ssize_t ret;
guint watch;
@@ -130,8 +130,7 @@ static ssize_t nbd_negotiate_read(QIOChannel *ioc, void *buffer, size_t size)
}
-static ssize_t nbd_negotiate_write(QIOChannel *ioc, const void *buffer,
- size_t size)
+static int nbd_negotiate_write(QIOChannel *ioc, const void *buffer, size_t size)
{
ssize_t ret;
guint watch;
@@ -148,24 +147,24 @@ static ssize_t nbd_negotiate_write(QIOChannel *ioc, const void *buffer,
return ret;
}
-static ssize_t nbd_negotiate_drop_sync(QIOChannel *ioc, size_t size)
+static int nbd_negotiate_drop_sync(QIOChannel *ioc, size_t size)
{
- ssize_t ret, dropped = size;
+ ssize_t ret;
uint8_t *buffer = g_malloc(MIN(65536, size));
while (size > 0) {
- ret = nbd_negotiate_read(ioc, buffer, MIN(65536, size));
+ size_t count = MIN(65536, size);
+ ret = nbd_negotiate_read(ioc, buffer, count);
if (ret < 0) {
g_free(buffer);
return ret;
}
- assert(ret <= size);
- size -= ret;
+ size -= count;
}
g_free(buffer);
- return dropped;
+ return 0;
}
/* Basic flow for negotiation
@@ -206,22 +205,22 @@ static int nbd_negotiate_send_rep_len(QIOChannel *ioc, uint32_t type,
type, opt, len);
magic = cpu_to_be64(NBD_REP_MAGIC);
- if (nbd_negotiate_write(ioc, &magic, sizeof(magic)) != sizeof(magic)) {
+ if (nbd_negotiate_write(ioc, &magic, sizeof(magic)) < 0) {
LOG("write failed (rep magic)");
return -EINVAL;
}
opt = cpu_to_be32(opt);
- if (nbd_negotiate_write(ioc, &opt, sizeof(opt)) != sizeof(opt)) {
+ if (nbd_negotiate_write(ioc, &opt, sizeof(opt)) < 0) {
LOG("write failed (rep opt)");
return -EINVAL;
}
type = cpu_to_be32(type);
- if (nbd_negotiate_write(ioc, &type, sizeof(type)) != sizeof(type)) {
+ if (nbd_negotiate_write(ioc, &type, sizeof(type)) < 0) {
LOG("write failed (rep type)");
return -EINVAL;
}
len = cpu_to_be32(len);
- if (nbd_negotiate_write(ioc, &len, sizeof(len)) != sizeof(len)) {
+ if (nbd_negotiate_write(ioc, &len, sizeof(len)) < 0) {
LOG("write failed (rep data length)");
return -EINVAL;
}
@@ -256,7 +255,7 @@ nbd_negotiate_send_rep_err(QIOChannel *ioc, uint32_t type,
if (ret < 0) {
goto out;
}
- if (nbd_negotiate_write(ioc, msg, len) != len) {
+ if (nbd_negotiate_write(ioc, msg, len) < 0) {
LOG("write failed (error message)");
ret = -EIO;
} else {
@@ -287,15 +286,15 @@ static int nbd_negotiate_send_rep_list(QIOChannel *ioc, NBDExport *exp)
}
len = cpu_to_be32(name_len);
- if (nbd_negotiate_write(ioc, &len, sizeof(len)) != sizeof(len)) {
+ if (nbd_negotiate_write(ioc, &len, sizeof(len)) < 0) {
LOG("write failed (name length)");
return -EINVAL;
}
- if (nbd_negotiate_write(ioc, name, name_len) != name_len) {
+ if (nbd_negotiate_write(ioc, name, name_len) < 0) {
LOG("write failed (name buffer)");
return -EINVAL;
}
- if (nbd_negotiate_write(ioc, desc, desc_len) != desc_len) {
+ if (nbd_negotiate_write(ioc, desc, desc_len) < 0) {
LOG("write failed (description buffer)");
return -EINVAL;
}
@@ -309,7 +308,7 @@ static int nbd_negotiate_handle_list(NBDClient *client, uint32_t length)
NBDExport *exp;
if (length) {
- if (nbd_negotiate_drop_sync(client->ioc, length) != length) {
+ if (nbd_negotiate_drop_sync(client->ioc, length) < 0) {
return -EIO;
}
return nbd_negotiate_send_rep_err(client->ioc,
@@ -340,7 +339,7 @@ static int nbd_negotiate_handle_export_name(NBDClient *client, uint32_t length)
LOG("Bad length received");
goto fail;
}
- if (nbd_negotiate_read(client->ioc, name, length) != length) {
+ if (nbd_negotiate_read(client->ioc, name, length) < 0) {
LOG("read failed");
goto fail;
}
@@ -373,7 +372,7 @@ static QIOChannel *nbd_negotiate_handle_starttls(NBDClient *client,
TRACE("Setting up TLS");
ioc = client->ioc;
if (length) {
- if (nbd_negotiate_drop_sync(ioc, length) != length) {
+ if (nbd_negotiate_drop_sync(ioc, length) < 0) {
return NULL;
}
nbd_negotiate_send_rep_err(ioc, NBD_REP_ERR_INVALID, NBD_OPT_STARTTLS,
@@ -437,8 +436,7 @@ static int nbd_negotiate_options(NBDClient *client)
... Rest of request
*/
- if (nbd_negotiate_read(client->ioc, &flags, sizeof(flags)) !=
- sizeof(flags)) {
+ if (nbd_negotiate_read(client->ioc, &flags, sizeof(flags)) < 0) {
LOG("read failed");
return -EIO;
}
@@ -464,8 +462,7 @@ static int nbd_negotiate_options(NBDClient *client)
uint32_t clientflags, length;
uint64_t magic;
- if (nbd_negotiate_read(client->ioc, &magic, sizeof(magic)) !=
- sizeof(magic)) {
+ if (nbd_negotiate_read(client->ioc, &magic, sizeof(magic)) < 0) {
LOG("read failed");
return -EINVAL;
}
@@ -476,14 +473,14 @@ static int nbd_negotiate_options(NBDClient *client)
}
if (nbd_negotiate_read(client->ioc, &clientflags,
- sizeof(clientflags)) != sizeof(clientflags)) {
+ sizeof(clientflags)) < 0)
+ {
LOG("read failed");
return -EINVAL;
}
clientflags = be32_to_cpu(clientflags);
- if (nbd_negotiate_read(client->ioc, &length, sizeof(length)) !=
- sizeof(length)) {
+ if (nbd_negotiate_read(client->ioc, &length, sizeof(length)) < 0) {
LOG("read failed");
return -EINVAL;
}
@@ -513,7 +510,7 @@ static int nbd_negotiate_options(NBDClient *client)
return -EINVAL;
default:
- if (nbd_negotiate_drop_sync(client->ioc, length) != length) {
+ if (nbd_negotiate_drop_sync(client->ioc, length) < 0) {
return -EIO;
}
ret = nbd_negotiate_send_rep_err(client->ioc,
@@ -551,7 +548,7 @@ static int nbd_negotiate_options(NBDClient *client)
return nbd_negotiate_handle_export_name(client, length);
case NBD_OPT_STARTTLS:
- if (nbd_negotiate_drop_sync(client->ioc, length) != length) {
+ if (nbd_negotiate_drop_sync(client->ioc, length) < 0) {
return -EIO;
}
if (client->tlscreds) {
@@ -570,7 +567,7 @@ static int nbd_negotiate_options(NBDClient *client)
}
break;
default:
- if (nbd_negotiate_drop_sync(client->ioc, length) != length) {
+ if (nbd_negotiate_drop_sync(client->ioc, length) < 0) {
return -EIO;
}
ret = nbd_negotiate_send_rep_err(client->ioc,
@@ -659,12 +656,12 @@ static coroutine_fn int nbd_negotiate(NBDClientNewData *data)
TRACE("TLS cannot be enabled with oldstyle protocol");
goto fail;
}
- if (nbd_negotiate_write(client->ioc, buf, sizeof(buf)) != sizeof(buf)) {
+ if (nbd_negotiate_write(client->ioc, buf, sizeof(buf)) < 0) {
LOG("write failed");
goto fail;
}
} else {
- if (nbd_negotiate_write(client->ioc, buf, 18) != 18) {
+ if (nbd_negotiate_write(client->ioc, buf, 18) < 0) {
LOG("write failed");
goto fail;
}
@@ -679,7 +676,7 @@ static coroutine_fn int nbd_negotiate(NBDClientNewData *data)
stq_be_p(buf + 18, client->exp->size);
stw_be_p(buf + 26, client->exp->nbdflags | myflags);
len = client->no_zeroes ? 10 : sizeof(buf) - 18;
- if (nbd_negotiate_write(client->ioc, buf + 18, len) != len) {
+ if (nbd_negotiate_write(client->ioc, buf + 18, len) < 0) {
LOG("write failed");
goto fail;
}
@@ -702,11 +699,6 @@ static ssize_t nbd_receive_request(QIOChannel *ioc, NBDRequest *request)
return ret;
}
- if (ret != sizeof(buf)) {
- LOG("read failed");
- return -EINVAL;
- }
-
/* Request
[ 0 .. 3] magic (NBD_REQUEST_MAGIC)
[ 4 .. 5] flags (NBD_CMD_FLAG_FUA, ...)
@@ -737,7 +729,6 @@ static ssize_t nbd_receive_request(QIOChannel *ioc, NBDRequest *request)
static ssize_t nbd_send_reply(QIOChannel *ioc, NBDReply *reply)
{
uint8_t buf[NBD_REPLY_SIZE];
- ssize_t ret;
reply->error = system_errno_to_nbd_errno(reply->error);
@@ -754,16 +745,7 @@ static ssize_t nbd_send_reply(QIOChannel *ioc, NBDReply *reply)
stl_be_p(buf + 4, reply->error);
stq_be_p(buf + 8, reply->handle);
- ret = write_sync(ioc, buf, sizeof(buf));
- if (ret < 0) {
- return ret;
- }
-
- if (ret != sizeof(buf)) {
- LOG("writing to socket failed");
- return -EINVAL;
- }
- return 0;
+ return write_sync(ioc, buf, sizeof(buf));
}
#define MAX_NBD_REQUESTS 16
@@ -1067,7 +1049,7 @@ static ssize_t nbd_co_send_reply(NBDRequestData *req, NBDReply *reply,
rc = nbd_send_reply(client->ioc, reply);
if (rc >= 0) {
ret = write_sync(client->ioc, req->data, len);
- if (ret != len) {
+ if (ret < 0) {
rc = -EIO;
}
}
@@ -1141,7 +1123,7 @@ static ssize_t nbd_co_receive_request(NBDRequestData *req,
if (request->type == NBD_CMD_WRITE) {
TRACE("Reading %" PRIu32 " byte(s)", request->len);
- if (read_sync(client->ioc, req->data, request->len) != request->len) {
+ if (read_sync(client->ioc, req->data, request->len) < 0) {
LOG("reading from socket failed");
rc = -EIO;
goto out;
generated by cgit v1.1 at 2024-09-06 00:16:57 +0000