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Diffstat (limited to 'nbd/server.c')
-rw-r--r--nbd/server.c304
1 files changed, 259 insertions, 45 deletions
diff --git a/nbd/server.c b/nbd/server.c
index 9b0c588146..49ed57455c 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -1,5 +1,5 @@
/*
- * Copyright (C) 2016 Red Hat, Inc.
+ * Copyright (C) 2016-2017 Red Hat, Inc.
* Copyright (C) 2005 Anthony Liguori <anthony@codemonkey.ws>
*
* Network Block Device Server Side
@@ -84,7 +84,6 @@ struct NBDClient {
int refcount;
void (*close_fn)(NBDClient *client, bool negotiated);
- bool no_zeroes;
NBDExport *exp;
QCryptoTLSCreds *tlscreds;
char *tlsaclname;
@@ -139,8 +138,10 @@ static int nbd_negotiate_send_rep_len(QIOChannel *ioc, uint32_t type,
{
uint64_t magic;
- trace_nbd_negotiate_send_rep_len(opt, type, len);
+ trace_nbd_negotiate_send_rep_len(opt, nbd_opt_lookup(opt),
+ type, nbd_rep_lookup(type), len);
+ assert(len < NBD_MAX_BUFFER_SIZE);
magic = cpu_to_be64(NBD_REP_MAGIC);
if (nbd_write(ioc, &magic, sizeof(magic), errp) < 0) {
error_prepend(errp, "write failed (rep magic): ");
@@ -275,10 +276,16 @@ static int nbd_negotiate_handle_list(NBDClient *client, uint32_t length,
return nbd_negotiate_send_rep(client->ioc, NBD_REP_ACK, NBD_OPT_LIST, errp);
}
+/* Send a reply to NBD_OPT_EXPORT_NAME.
+ * Return -errno on error, 0 on success. */
static int nbd_negotiate_handle_export_name(NBDClient *client, uint32_t length,
+ uint16_t myflags, bool no_zeroes,
Error **errp)
{
char name[NBD_MAX_NAME_SIZE + 1];
+ char buf[8 + 4 + 124] = "";
+ size_t len;
+ int ret;
/* Client sends:
[20 .. xx] export name (length bytes)
@@ -302,12 +309,219 @@ static int nbd_negotiate_handle_export_name(NBDClient *client, uint32_t length,
return -EINVAL;
}
+ trace_nbd_negotiate_new_style_size_flags(client->exp->size,
+ client->exp->nbdflags | myflags);
+ stq_be_p(buf, client->exp->size);
+ stw_be_p(buf + 8, client->exp->nbdflags | myflags);
+ len = no_zeroes ? 10 : sizeof(buf);
+ ret = nbd_write(client->ioc, buf, len, errp);
+ if (ret < 0) {
+ error_prepend(errp, "write failed: ");
+ return ret;
+ }
+
QTAILQ_INSERT_TAIL(&client->exp->clients, client, next);
nbd_export_get(client->exp);
return 0;
}
+/* Send a single NBD_REP_INFO, with a buffer @buf of @length bytes.
+ * The buffer does NOT include the info type prefix.
+ * Return -errno on error, 0 if ready to send more. */
+static int nbd_negotiate_send_info(NBDClient *client, uint32_t opt,
+ uint16_t info, uint32_t length, void *buf,
+ Error **errp)
+{
+ int rc;
+
+ trace_nbd_negotiate_send_info(info, nbd_info_lookup(info), length);
+ rc = nbd_negotiate_send_rep_len(client->ioc, NBD_REP_INFO, opt,
+ sizeof(info) + length, errp);
+ if (rc < 0) {
+ return rc;
+ }
+ cpu_to_be16s(&info);
+ if (nbd_write(client->ioc, &info, sizeof(info), errp) < 0) {
+ return -EIO;
+ }
+ if (nbd_write(client->ioc, buf, length, errp) < 0) {
+ return -EIO;
+ }
+ return 0;
+}
+
+/* Handle NBD_OPT_INFO and NBD_OPT_GO.
+ * Return -errno on error, 0 if ready for next option, and 1 to move
+ * into transmission phase. */
+static int nbd_negotiate_handle_info(NBDClient *client, uint32_t length,
+ uint32_t opt, uint16_t myflags,
+ Error **errp)
+{
+ int rc;
+ char name[NBD_MAX_NAME_SIZE + 1];
+ NBDExport *exp;
+ uint16_t requests;
+ uint16_t request;
+ uint32_t namelen;
+ bool sendname = false;
+ bool blocksize = false;
+ uint32_t sizes[3];
+ char buf[sizeof(uint64_t) + sizeof(uint16_t)];
+ const char *msg;
+
+ /* Client sends:
+ 4 bytes: L, name length (can be 0)
+ L bytes: export name
+ 2 bytes: N, number of requests (can be 0)
+ N * 2 bytes: N requests
+ */
+ if (length < sizeof(namelen) + sizeof(requests)) {
+ msg = "overall request too short";
+ goto invalid;
+ }
+ if (nbd_read(client->ioc, &namelen, sizeof(namelen), errp) < 0) {
+ return -EIO;
+ }
+ be32_to_cpus(&namelen);
+ length -= sizeof(namelen);
+ if (namelen > length - sizeof(requests) || (length - namelen) % 2) {
+ msg = "name length is incorrect";
+ goto invalid;
+ }
+ if (nbd_read(client->ioc, name, namelen, errp) < 0) {
+ return -EIO;
+ }
+ name[namelen] = '\0';
+ length -= namelen;
+ trace_nbd_negotiate_handle_export_name_request(name);
+
+ if (nbd_read(client->ioc, &requests, sizeof(requests), errp) < 0) {
+ return -EIO;
+ }
+ be16_to_cpus(&requests);
+ length -= sizeof(requests);
+ trace_nbd_negotiate_handle_info_requests(requests);
+ if (requests != length / sizeof(request)) {
+ msg = "incorrect number of requests for overall length";
+ goto invalid;
+ }
+ while (requests--) {
+ if (nbd_read(client->ioc, &request, sizeof(request), errp) < 0) {
+ return -EIO;
+ }
+ be16_to_cpus(&request);
+ length -= sizeof(request);
+ trace_nbd_negotiate_handle_info_request(request,
+ nbd_info_lookup(request));
+ /* We care about NBD_INFO_NAME and NBD_INFO_BLOCK_SIZE;
+ * everything else is either a request we don't know or
+ * something we send regardless of request */
+ switch (request) {
+ case NBD_INFO_NAME:
+ sendname = true;
+ break;
+ case NBD_INFO_BLOCK_SIZE:
+ blocksize = true;
+ break;
+ }
+ }
+
+ exp = nbd_export_find(name);
+ if (!exp) {
+ return nbd_negotiate_send_rep_err(client->ioc, NBD_REP_ERR_UNKNOWN,
+ opt, errp, "export '%s' not present",
+ name);
+ }
+
+ /* Don't bother sending NBD_INFO_NAME unless client requested it */
+ if (sendname) {
+ rc = nbd_negotiate_send_info(client, opt, NBD_INFO_NAME, length, name,
+ errp);
+ if (rc < 0) {
+ return rc;
+ }
+ }
+
+ /* Send NBD_INFO_DESCRIPTION only if available, regardless of
+ * client request */
+ if (exp->description) {
+ size_t len = strlen(exp->description);
+
+ rc = nbd_negotiate_send_info(client, opt, NBD_INFO_DESCRIPTION,
+ len, exp->description, errp);
+ if (rc < 0) {
+ return rc;
+ }
+ }
+
+ /* Send NBD_INFO_BLOCK_SIZE always, but tweak the minimum size
+ * according to whether the client requested it, and according to
+ * whether this is OPT_INFO or OPT_GO. */
+ /* minimum - 1 for back-compat, or 512 if client is new enough.
+ * TODO: consult blk_bs(blk)->bl.request_alignment? */
+ sizes[0] = (opt == NBD_OPT_INFO || blocksize) ? BDRV_SECTOR_SIZE : 1;
+ /* preferred - Hard-code to 4096 for now.
+ * TODO: is blk_bs(blk)->bl.opt_transfer appropriate? */
+ sizes[1] = 4096;
+ /* maximum - At most 32M, but smaller as appropriate. */
+ sizes[2] = MIN(blk_get_max_transfer(exp->blk), NBD_MAX_BUFFER_SIZE);
+ trace_nbd_negotiate_handle_info_block_size(sizes[0], sizes[1], sizes[2]);
+ cpu_to_be32s(&sizes[0]);
+ cpu_to_be32s(&sizes[1]);
+ cpu_to_be32s(&sizes[2]);
+ rc = nbd_negotiate_send_info(client, opt, NBD_INFO_BLOCK_SIZE,
+ sizeof(sizes), sizes, errp);
+ if (rc < 0) {
+ return rc;
+ }
+
+ /* Send NBD_INFO_EXPORT always */
+ trace_nbd_negotiate_new_style_size_flags(exp->size,
+ exp->nbdflags | myflags);
+ stq_be_p(buf, exp->size);
+ stw_be_p(buf + 8, exp->nbdflags | myflags);
+ rc = nbd_negotiate_send_info(client, opt, NBD_INFO_EXPORT,
+ sizeof(buf), buf, errp);
+ if (rc < 0) {
+ return rc;
+ }
+
+ /* If the client is just asking for NBD_OPT_INFO, but forgot to
+ * request block sizes, return an error.
+ * TODO: consult blk_bs(blk)->request_align, and only error if it
+ * is not 1? */
+ if (opt == NBD_OPT_INFO && !blocksize) {
+ return nbd_negotiate_send_rep_err(client->ioc,
+ NBD_REP_ERR_BLOCK_SIZE_REQD, opt,
+ errp,
+ "request NBD_INFO_BLOCK_SIZE to "
+ "use this export");
+ }
+
+ /* Final reply */
+ rc = nbd_negotiate_send_rep(client->ioc, NBD_REP_ACK, opt, errp);
+ if (rc < 0) {
+ return rc;
+ }
+
+ if (opt == NBD_OPT_GO) {
+ client->exp = exp;
+ QTAILQ_INSERT_TAIL(&client->exp->clients, client, next);
+ nbd_export_get(client->exp);
+ rc = 1;
+ }
+ return rc;
+
+ invalid:
+ if (nbd_drop(client->ioc, length, errp) < 0) {
+ return -EIO;
+ }
+ return nbd_negotiate_send_rep_err(client->ioc, NBD_REP_ERR_INVALID, opt,
+ errp, "%s", msg);
+}
+
+
/* Handle NBD_OPT_STARTTLS. Return NULL to drop connection, or else the
* new channel for all further (now-encrypted) communication. */
static QIOChannel *nbd_negotiate_handle_starttls(NBDClient *client,
@@ -365,22 +579,25 @@ static QIOChannel *nbd_negotiate_handle_starttls(NBDClient *client,
}
/* nbd_negotiate_options
- * Process all NBD_OPT_* client option commands.
+ * Process all NBD_OPT_* client option commands, during fixed newstyle
+ * negotiation.
* Return:
* -errno on error, errp is set
* 0 on successful negotiation, errp is not set
* 1 if client sent NBD_OPT_ABORT, i.e. on valid disconnect,
* errp is not set
*/
-static int nbd_negotiate_options(NBDClient *client, Error **errp)
+static int nbd_negotiate_options(NBDClient *client, uint16_t myflags,
+ Error **errp)
{
uint32_t flags;
bool fixedNewstyle = false;
- Error *local_err = NULL;
+ bool no_zeroes = false;
/* Client sends:
[ 0 .. 3] client flags
+ Then we loop until NBD_OPT_EXPORT_NAME or NBD_OPT_GO:
[ 0 .. 7] NBD_OPTS_MAGIC
[ 8 .. 11] NBD option
[12 .. 15] Data length
@@ -396,21 +613,19 @@ static int nbd_negotiate_options(NBDClient *client, Error **errp)
error_prepend(errp, "read failed: ");
return -EIO;
}
- trace_nbd_negotiate_options_flags();
be32_to_cpus(&flags);
+ trace_nbd_negotiate_options_flags(flags);
if (flags & NBD_FLAG_C_FIXED_NEWSTYLE) {
- trace_nbd_negotiate_options_newstyle();
fixedNewstyle = true;
flags &= ~NBD_FLAG_C_FIXED_NEWSTYLE;
}
if (flags & NBD_FLAG_C_NO_ZEROES) {
- trace_nbd_negotiate_options_no_zeroes();
- client->no_zeroes = true;
+ no_zeroes = true;
flags &= ~NBD_FLAG_C_NO_ZEROES;
}
if (flags != 0) {
error_setg(errp, "Unknown client flags 0x%" PRIx32 " received", flags);
- return -EIO;
+ return -EINVAL;
}
while (1) {
@@ -442,7 +657,8 @@ static int nbd_negotiate_options(NBDClient *client, Error **errp)
}
length = be32_to_cpu(length);
- trace_nbd_negotiate_options_check_option(option);
+ trace_nbd_negotiate_options_check_option(option,
+ nbd_opt_lookup(option));
if (client->tlscreds &&
client->ioc == (QIOChannel *)client->sioc) {
QIOChannel *tioc;
@@ -479,7 +695,9 @@ static int nbd_negotiate_options(NBDClient *client, Error **errp)
if (ret < 0) {
return ret;
}
- /* Let the client keep trying, unless they asked to quit */
+ /* Let the client keep trying, unless they asked to
+ * quit. In this mode, we've already sent an error, so
+ * we can't ack the abort. */
if (option == NBD_OPT_ABORT) {
return 1;
}
@@ -498,19 +716,26 @@ static int nbd_negotiate_options(NBDClient *client, Error **errp)
/* NBD spec says we must try to reply before
* disconnecting, but that we must also tolerate
* guests that don't wait for our reply. */
- nbd_negotiate_send_rep(client->ioc, NBD_REP_ACK, option,
- &local_err);
-
- if (local_err != NULL) {
- const char *error = error_get_pretty(local_err);
- trace_nbd_opt_abort_reply_failed(error);
- error_free(local_err);
- }
-
+ nbd_negotiate_send_rep(client->ioc, NBD_REP_ACK, option, NULL);
return 1;
case NBD_OPT_EXPORT_NAME:
- return nbd_negotiate_handle_export_name(client, length, errp);
+ return nbd_negotiate_handle_export_name(client, length,
+ myflags, no_zeroes,
+ errp);
+
+ case NBD_OPT_INFO:
+ case NBD_OPT_GO:
+ ret = nbd_negotiate_handle_info(client, length, option,
+ myflags, errp);
+ if (ret == 1) {
+ assert(option == NBD_OPT_GO);
+ return 0;
+ }
+ if (ret) {
+ return ret;
+ }
+ break;
case NBD_OPT_STARTTLS:
if (nbd_drop(client->ioc, length, errp) < 0) {
@@ -539,8 +764,8 @@ static int nbd_negotiate_options(NBDClient *client, Error **errp)
NBD_REP_ERR_UNSUP,
option, errp,
"Unsupported option 0x%"
- PRIx32,
- option);
+ PRIx32 " (%s)", option,
+ nbd_opt_lookup(option));
if (ret < 0) {
return ret;
}
@@ -553,10 +778,13 @@ static int nbd_negotiate_options(NBDClient *client, Error **errp)
*/
switch (option) {
case NBD_OPT_EXPORT_NAME:
- return nbd_negotiate_handle_export_name(client, length, errp);
+ return nbd_negotiate_handle_export_name(client, length,
+ myflags, no_zeroes,
+ errp);
default:
- error_setg(errp, "Unsupported option 0x%" PRIx32, option);
+ error_setg(errp, "Unsupported option 0x%" PRIx32 " (%s)",
+ option, nbd_opt_lookup(option));
return -EINVAL;
}
}
@@ -578,7 +806,6 @@ static coroutine_fn int nbd_negotiate(NBDClient *client, Error **errp)
NBD_FLAG_SEND_FLUSH | NBD_FLAG_SEND_FUA |
NBD_FLAG_SEND_WRITE_ZEROES);
bool oldStyle;
- size_t len;
/* Old style negotiation header without options
[ 0 .. 7] passwd ("NBDMAGIC")
@@ -592,10 +819,7 @@ static coroutine_fn int nbd_negotiate(NBDClient *client, Error **errp)
[ 0 .. 7] passwd ("NBDMAGIC")
[ 8 .. 15] magic (NBD_OPTS_MAGIC)
[16 .. 17] server flags (0)
- ....options sent....
- [18 .. 25] size
- [26 .. 27] export flags
- [28 .. 151] reserved (0, omit if no_zeroes)
+ ....options sent, ending in NBD_OPT_EXPORT_NAME or NBD_OPT_GO....
*/
qio_channel_set_blocking(client->ioc, false, NULL);
@@ -624,24 +848,13 @@ static coroutine_fn int nbd_negotiate(NBDClient *client, Error **errp)
error_prepend(errp, "write failed: ");
return -EINVAL;
}
- ret = nbd_negotiate_options(client, errp);
+ ret = nbd_negotiate_options(client, myflags, errp);
if (ret != 0) {
if (ret < 0) {
error_prepend(errp, "option negotiation failed: ");
}
return ret;
}
-
- trace_nbd_negotiate_new_style_size_flags(
- client->exp->size, client->exp->nbdflags | myflags);
- 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;
- ret = nbd_write(client->ioc, buf + 18, len, errp);
- if (ret < 0) {
- error_prepend(errp, "write failed: ");
- return ret;
- }
}
trace_nbd_negotiate_success();
@@ -1040,7 +1253,8 @@ static int nbd_co_receive_request(NBDRequestData *req, NBDRequest *request,
return -EIO;
}
- trace_nbd_co_receive_request_decode_type(request->handle, request->type);
+ trace_nbd_co_receive_request_decode_type(request->handle, request->type,
+ nbd_cmd_lookup(request->type));
if (request->type != NBD_CMD_WRITE) {
/* No payload, we are ready to read the next request. */
generated by cgit v1.2.3 (git 2.26.2) at 2024-12-16 16:41:49 +0000