Added APIs for creating and parsing nested netlink attributes.
APIs are on similar lines as userspace netlink code.
Signed-off-by: Ankur Sharma <ankursha...@vmware.com>
---
datapath-windows/ovsext/Netlink/Netlink.c | 94 ++++++++++++++++++++++++++++++-
datapath-windows/ovsext/Netlink/Netlink.h | 12 ++++
2 files changed, 103 insertions(+), 3 deletions(-)
diff --git a/datapath-windows/ovsext/Netlink/Netlink.c
b/datapath-windows/ovsext/Netlink/Netlink.c
index 99cdc0e..b304e13 100644
--- a/datapath-windows/ovsext/Netlink/Netlink.c
+++ b/datapath-windows/ovsext/Netlink/Netlink.c
@@ -418,6 +418,75 @@ NlMsgPutHeadString(PNL_BUFFER buf, UINT16 type, PCHAR
value)
(UINT16)strLen));
}
+/*
+ * ---------------------------------------------------------------------------
+ * Adds the header for nested netlink attributes. It
+ * returns the offset of this header. If addition of header fails
+ * then returned value of offset will be zero.
+ * Refer nl_msg_start_nested for more details.
+ * ---------------------------------------------------------------------------
+ */
+UINT32
+NlMsgStartNested(PNL_BUFFER buf, UINT16 type)
+{
+ UINT32 offset = NlBufSize(buf);
+ PCHAR nlaData = NULL;
+
+ nlaData = NlMsgPutTailUnspecUninit(buf, type, 0);
+
+ if (!nlaData) {
+ /* Value zero must be reated as error by the caller.
+ * This is because an attribute can never be added
+ * at offset zero, it will always come after NL_MSG_HDR,
+ * GENL_HDR and OVS_HEADER. */
+ offset = 0;
+ }
+
+ return offset;
+}
+
+/*
+ * ---------------------------------------------------------------------------
+ * Finalizes the nested netlink attribute by updating the nla_len.
+ * offset should be the one returned by NlMsgStartNested.
+ * Refer nl_msg_end_nested for more details.
+ * ---------------------------------------------------------------------------
+ */
+VOID
+NlMsgEndNested(PNL_BUFFER buf, UINT32 offset)
+{
+ PNL_ATTR attr = (PNL_ATTR)(NlBufAt(buf, offset, sizeof *attr));
+
+ /* Typecast to keep compiler happy.
+ * Attribute length would never exceed MAX UINT16.*/
+ attr->nlaLen = (UINT16)(NlBufSize(buf) - offset);
+}
+
+/*
+ * --------------------------------------------------------------------------
+ * Appends a nested Netlink attribute of the given 'type', with the 'size'
+ * bytes of content starting at 'data', to 'msg'.
+ * Refer nl_msg_put_nested for more details.
+ * --------------------------------------------------------------------------
+ */
+VOID
+NlMsgPutNested(PNL_BUFFER buf, UINT16 type,
+ const PVOID data, UINT32 size)
+{
+ UINT32 offset = NlMsgStartNested(buf, type);
+
+ UNREFERENCED_PARAMETER(data);
+ UNREFERENCED_PARAMETER(size);
+
+ ASSERT(offset);
+
+ ASSERT(NlMsgPutTail(buf, data, size));
+
+ NlMsgEndNested(buf, offset);
+
+ return;
+}
+
/* Accessing netlink message payload */
/*
@@ -807,9 +876,10 @@ NlAttrFindNested(const PNL_ATTR nla, UINT16 type)
* Returns BOOLEAN to indicate success/failure.
*----------------------------------------------------------------------------
*/
-BOOLEAN NlAttrParse(const PNL_MSG_HDR nlMsg, UINT32 attrOffset,
- const NL_POLICY policy[],
- PNL_ATTR attrs[], UINT32 n_attrs)
+BOOLEAN
+NlAttrParse(const PNL_MSG_HDR nlMsg, UINT32 attrOffset,
+ const NL_POLICY policy[],
+ PNL_ATTR attrs[], UINT32 n_attrs)
{
PNL_ATTR nla;
UINT32 left;
@@ -862,3 +932,21 @@ BOOLEAN NlAttrParse(const PNL_MSG_HDR nlMsg, UINT32
attrOffset,
done:
return ret;
}
+
+/*
+ *----------------------------------------------------------------------------
+ * Parses the netlink message for nested attributes. attrOffset must be the
+ * offset of nla which is the header of the nested attribute series.
+ * Refer nl_parse_nested for more details.
+ *
+ * Returns BOOLEAN to indicate success/failure.
+ *----------------------------------------------------------------------------
+ */
+BOOLEAN
+NlAttrParseNested(const PNL_MSG_HDR nlMsg, UINT32 attrOffset,
+ const NL_POLICY policy[],
+ PNL_ATTR attrs[], UINT32 n_attrs)
+{
+ return NlAttrParse(nlMsg, attrOffset + NLA_HDRLEN,
+ policy, attrs, n_attrs);
+}
diff --git a/datapath-windows/ovsext/Netlink/Netlink.h
b/datapath-windows/ovsext/Netlink/Netlink.h
index 7ca67d7..9964da6 100644
--- a/datapath-windows/ovsext/Netlink/Netlink.h
+++ b/datapath-windows/ovsext/Netlink/Netlink.h
@@ -98,6 +98,8 @@ const PNL_ATTR NlAttrFindNested(const PNL_ATTR nla,
BOOLEAN NlAttrParse(const PNL_MSG_HDR nlMsg, UINT32 attrOffset,
const NL_POLICY policy[],
PNL_ATTR attrs[], UINT32 n_attrs);
+BOOLEAN NlParseNested(const PNL_ATTR, const NL_POLICY policy[],
+ PNL_ATTR attrs[], UINT32 n_attrs);
/* Netlink attribute validation */
BOOLEAN NlAttrValidate(const PNL_ATTR, const PNL_POLICY);
@@ -128,5 +130,15 @@ BOOLEAN NlMsgPutHeadU16(PNL_BUFFER buf, UINT16 type,
UINT16 value);
BOOLEAN NlMsgPutHeadU32(PNL_BUFFER buf, UINT16 type, UINT32 value);
BOOLEAN NlMsgPutHeadU64(PNL_BUFFER buf, UINT16 type, UINT64 value);
BOOLEAN NlMsgPutHeadString(PNL_BUFFER buf, UINT16 type, PCHAR value);
+UINT32 NlMsgStartNested(PNL_BUFFER buf, UINT16 type);
+VOID NlMsgEndNested(PNL_BUFFER buf, UINT32 offset);
+VOID NlMsgPutNested(PNL_BUFFER buf, UINT16 type,
+ const PVOID data, UINT32 size);
+
+/* These variants are convenient for iterating nested attributes. */
+#define NL_NESTED_FOR_EACH(ITER, LEFT, A) \
+ NL_ATTR_FOR_EACH(ITER, LEFT, NlAttrGet(A), NlAttrGetSize(A))
+#define NL_NESTED_FOR_EACH_UNSAFE(ITER, LEFT, A) \
+ NL_ATTR_FOR_EACH_UNSAFE(ITER, LEFT, NlAttrGet(A), NlAttrGetSize(A))
#endif /* __NETLINK_H_ */
--
1.9.1
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