[NETLINK]: Extend netlink messaging interface
Adds:
nlmsg_get_pos() return current position in message
nlmsg_trim() trim part of message
nla_reserve_nohdr(skb, len) reserve room for an attribute w/o hdr
nla_put_nohdr(skb, len, data) add attribute w/o hdr
nla_find_nested() find attribute in nested attributes
Fixes nlmsg_new() to take allocation flags and consider size.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/netlink/attr.c b/net/netlink/attr.c
index dddbd15..136e529 100644
--- a/net/netlink/attr.c
+++ b/net/netlink/attr.c
@@ -255,6 +255,26 @@
}
/**
+ * __nla_reserve_nohdr - reserve room for attribute without header
+ * @skb: socket buffer to reserve room on
+ * @attrlen: length of attribute payload
+ *
+ * Reserves room for attribute payload without a header.
+ *
+ * The caller is responsible to ensure that the skb provides enough
+ * tailroom for the payload.
+ */
+void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen)
+{
+ void *start;
+
+ start = skb_put(skb, NLA_ALIGN(attrlen));
+ memset(start, 0, NLA_ALIGN(attrlen));
+
+ return start;
+}
+
+/**
* nla_reserve - reserve room for attribute on the skb
* @skb: socket buffer to reserve room on
* @attrtype: attribute type
@@ -275,6 +295,24 @@
}
/**
+ * nla_reserve - reserve room for attribute without header
+ * @skb: socket buffer to reserve room on
+ * @len: length of attribute payload
+ *
+ * Reserves room for attribute payload without a header.
+ *
+ * Returns NULL if the tailroom of the skb is insufficient to store
+ * the attribute payload.
+ */
+void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen)
+{
+ if (unlikely(skb_tailroom(skb) < NLA_ALIGN(attrlen)))
+ return NULL;
+
+ return __nla_reserve_nohdr(skb, attrlen);
+}
+
+/**
* __nla_put - Add a netlink attribute to a socket buffer
* @skb: socket buffer to add attribute to
* @attrtype: attribute type
@@ -293,6 +331,22 @@
memcpy(nla_data(nla), data, attrlen);
}
+/**
+ * __nla_put_nohdr - Add a netlink attribute without header
+ * @skb: socket buffer to add attribute to
+ * @attrlen: length of attribute payload
+ * @data: head of attribute payload
+ *
+ * The caller is responsible to ensure that the skb provides enough
+ * tailroom for the attribute payload.
+ */
+void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data)
+{
+ void *start;
+
+ start = __nla_reserve_nohdr(skb, attrlen);
+ memcpy(start, data, attrlen);
+}
/**
* nla_put - Add a netlink attribute to a socket buffer
@@ -313,15 +367,36 @@
return 0;
}
+/**
+ * nla_put_nohdr - Add a netlink attribute without header
+ * @skb: socket buffer to add attribute to
+ * @attrlen: length of attribute payload
+ * @data: head of attribute payload
+ *
+ * Returns -1 if the tailroom of the skb is insufficient to store
+ * the attribute payload.
+ */
+int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data)
+{
+ if (unlikely(skb_tailroom(skb) < NLA_ALIGN(attrlen)))
+ return -1;
+
+ __nla_put_nohdr(skb, attrlen, data);
+ return 0;
+}
EXPORT_SYMBOL(nla_validate);
EXPORT_SYMBOL(nla_parse);
EXPORT_SYMBOL(nla_find);
EXPORT_SYMBOL(nla_strlcpy);
EXPORT_SYMBOL(__nla_reserve);
+EXPORT_SYMBOL(__nla_reserve_nohdr);
EXPORT_SYMBOL(nla_reserve);
+EXPORT_SYMBOL(nla_reserve_nohdr);
EXPORT_SYMBOL(__nla_put);
+EXPORT_SYMBOL(__nla_put_nohdr);
EXPORT_SYMBOL(nla_put);
+EXPORT_SYMBOL(nla_put_nohdr);
EXPORT_SYMBOL(nla_memcpy);
EXPORT_SYMBOL(nla_memcmp);
EXPORT_SYMBOL(nla_strcmp);