1 files changed, 107 insertions, 17 deletions

diff --git a/include/net/netlink.h b/include/net/netlink.h
index 640c26a90cf1..11dc2e7f679a 100644
--- a/include/net/netlink.h
+++ b/include/net/netlink.h
@@ -35,12 +35,15 @@
  *   nlmsg_put()                        add a netlink message to an skb
  *   nlmsg_put_answer()                 callback based nlmsg_put()
  *   nlmsg_end()                        finanlize netlink message
+ *   nlmsg_get_pos()                    return current position in message
+ *   nlmsg_trim()                       trim part of message
  *   nlmsg_cancel()                     cancel message construction
  *   nlmsg_free()                       free a netlink message
  *
  * Message Sending:
  *   nlmsg_multicast()                  multicast message to several groups
  *   nlmsg_unicast()                    unicast a message to a single socket
+ *   nlmsg_notify()                     send notification message
  *
  * Message Length Calculations:
  *   nlmsg_msg_size(payload)            length of message w/o padding
@@ -62,6 +65,9 @@
  *   nlmsg_validate()                   validate netlink message incl. attrs
  *   nlmsg_for_each_attr()              loop over all attributes
  *
+ * Misc:
+ *   nlmsg_report()                     report back to application?
+ *
  * ------------------------------------------------------------------------
  *                          Attributes Interface
  * ------------------------------------------------------------------------
@@ -80,8 +86,10 @@
  *   struct nlattr                      netlink attribtue header
  *
  * Attribute Construction:
- *   nla_reserve(skb, type, len)        reserve skb tailroom for an attribute
+ *   nla_reserve(skb, type, len)        reserve room for an attribute
+ *   nla_reserve_nohdr(skb, len)        reserve room for an attribute w/o hdr
  *   nla_put(skb, type, len, data)      add attribute to skb
+ *   nla_put_nohdr(skb, len, data)      add attribute w/o hdr
  *
  * Attribute Construction for Basic Types:
  *   nla_put_u8(skb, type, value)       add u8 attribute to skb
@@ -139,6 +147,7 @@
  *   nla_next(nla, remaining)           get next netlink attribute
  *   nla_validate()                     validate a stream of attributes
  *   nla_find()                         find attribute in stream of attributes
+ *   nla_find_nested()                  find attribute in nested attributes
  *   nla_parse()                        parse and validate stream of attrs
  *   nla_parse_nested()                 parse nested attribuets
  *   nla_for_each_attr()                loop over all attributes
@@ -158,6 +167,7 @@ enum {
         NLA_FLAG,
         NLA_MSECS,
         NLA_NESTED,
+        NLA_NUL_STRING,
         __NLA_TYPE_MAX,
 };
 
@@ -166,21 +176,37 @@ enum {
 /**
  * struct nla_policy - attribute validation policy
  * @type: Type of attribute or NLA_UNSPEC
- * @minlen: Minimal length of payload required to be available
+ * @len: Type specific length of payload
  *
  * Policies are defined as arrays of this struct, the array must be
  * accessible by attribute type up to the highest identifier to be expected.
  *
+ * Meaning of `len' field:
+ *    NLA_STRING           Maximum length of string
+ *    NLA_NUL_STRING       Maximum length of string (excluding NUL)
+ *    NLA_FLAG             Unused
+ *    All other            Exact length of attribute payload
+ *
  * Example:
  * static struct nla_policy my_policy[ATTR_MAX+1] __read_mostly = {
  *      [ATTR_FOO] = { .type = NLA_U16 },
- *      [ATTR_BAR] = { .type = NLA_STRING },
- *      [ATTR_BAZ] = { .minlen = sizeof(struct mystruct) },
+ *      [ATTR_BAR] = { .type = NLA_STRING, len = BARSIZ },
+ *      [ATTR_BAZ] = { .len = sizeof(struct mystruct) },
  * };
  */
 struct nla_policy {
         u16             type;
-        u16             minlen;
+        u16             len;
+};
+
+/**
+ * struct nl_info - netlink source information
+ * @nlh: Netlink message header of original request
+ * @pid: Netlink PID of requesting application
+ */
+struct nl_info {
+        struct nlmsghdr         *nlh;
+        u32                     pid;
 };
 
 extern void             netlink_run_queue(struct sock *sk, unsigned int *qlen,
@@ -188,6 +214,9 @@ extern void		netlink_run_queue(struct sock *sk, unsigned int *qlen,
                                                     struct nlmsghdr *, int *));
 extern void             netlink_queue_skip(struct nlmsghdr *nlh,
                                            struct sk_buff *skb);
+extern int              nlmsg_notify(struct sock *sk, struct sk_buff *skb,
+                                     u32 pid, unsigned int group, int report,
+                                     gfp_t flags);
 
 extern int              nla_validate(struct nlattr *head, int len, int maxtype,
                                      struct nla_policy *policy);
@@ -203,12 +232,18 @@ extern int		nla_memcmp(const struct nlattr *nla, const void *data,
 extern int              nla_strcmp(const struct nlattr *nla, const char *str);
 extern struct nlattr *  __nla_reserve(struct sk_buff *skb, int attrtype,
                                       int attrlen);
+extern void *           __nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
 extern struct nlattr *  nla_reserve(struct sk_buff *skb, int attrtype,
                                     int attrlen);
+extern void *           nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
 extern void             __nla_put(struct sk_buff *skb, int attrtype,
                                   int attrlen, const void *data);
+extern void             __nla_put_nohdr(struct sk_buff *skb, int attrlen,
+                                        const void *data);
 extern int              nla_put(struct sk_buff *skb, int attrtype,
                                 int attrlen, const void *data);
+extern int              nla_put_nohdr(struct sk_buff *skb, int attrlen,
+                                      const void *data);
 
 /**************************************************************************
  * Netlink Messages
@@ -364,6 +399,17 @@ static inline int nlmsg_validate(struct nlmsghdr *nlh, int hdrlen, int maxtype,
 }
 
 /**
+ * nlmsg_report - need to report back to application?
+ * @nlh: netlink message header
+ *
+ * Returns 1 if a report back to the application is requested.
+ */
+static inline int nlmsg_report(struct nlmsghdr *nlh)
+{
+        return !!(nlh->nlmsg_flags & NLM_F_ECHO);
+}
+
+/**
  * nlmsg_for_each_attr - iterate over a stream of attributes
  * @pos: loop counter, set to current attribute
  * @nlh: netlink message header
@@ -453,12 +499,13 @@ static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb,
 /**
  * nlmsg_new - Allocate a new netlink message
  * @size: maximum size of message
+ * @flags: the type of memory to allocate.
  *
  * Use NLMSG_GOODSIZE if size isn't know and you need a good default size.
  */
-static inline struct sk_buff *nlmsg_new(int size)
+static inline struct sk_buff *nlmsg_new(int size, gfp_t flags)
 {
-        return alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
+        return alloc_skb(size, flags);
 }
 
 /**
@@ -480,6 +527,32 @@ static inline int nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh)
 }
 
 /**
+ * nlmsg_get_pos - return current position in netlink message
+ * @skb: socket buffer the message is stored in
+ *
+ * Returns a pointer to the current tail of the message.
+ */
+static inline void *nlmsg_get_pos(struct sk_buff *skb)
+{
+        return skb->tail;
+}
+
+/**
+ * nlmsg_trim - Trim message to a mark
+ * @skb: socket buffer the message is stored in
+ * @mark: mark to trim to
+ *
+ * Trims the message to the provided mark. Returns -1.
+ */
+static inline int nlmsg_trim(struct sk_buff *skb, void *mark)
+{
+        if (mark)
+                skb_trim(skb, (unsigned char *) mark - skb->data);
+
+        return -1;
+}
+
+/**
  * nlmsg_cancel - Cancel construction of a netlink message
  * @skb: socket buffer the message is stored in
  * @nlh: netlink message header
@@ -489,9 +562,7 @@ static inline int nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh)
  */
 static inline int nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh)
 {
-        skb_trim(skb, (unsigned char *) nlh - skb->data);
-
-        return -1;
+        return nlmsg_trim(skb, nlh);
 }
 
 /**
@@ -509,15 +580,16 @@ static inline void nlmsg_free(struct sk_buff *skb)
  * @skb: netlink message as socket buffer
  * @pid: own netlink pid to avoid sending to yourself
  * @group: multicast group id
+ * @flags: allocation flags
  */
 static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb,
-                                  u32 pid, unsigned int group)
+                                  u32 pid, unsigned int group, gfp_t flags)
 {
         int err;
 
         NETLINK_CB(skb).dst_group = group;
 
-        err = netlink_broadcast(sk, skb, pid, group, GFP_KERNEL);
+        err = netlink_broadcast(sk, skb, pid, group, flags);
         if (err > 0)
                 err = 0;
 
@@ -631,6 +703,18 @@ static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
 }
 
 /**
+ * nla_find_nested - find attribute in a set of nested attributes
+ * @nla: attribute containing the nested attributes
+ * @attrtype: type of attribute to look for
+ *
+ * Returns the first attribute which matches the specified type.
+ */
+static inline struct nlattr *nla_find_nested(struct nlattr *nla, int attrtype)
+{
+        return nla_find(nla_data(nla), nla_len(nla), attrtype);
+}
+
+/**
  * nla_parse_nested - parse nested attributes
  * @tb: destination array with maxtype+1 elements
  * @maxtype: maximum attribute type to be expected
@@ -751,7 +835,7 @@ static inline int nla_put_msecs(struct sk_buff *skb, int attrtype,
 #define NLA_PUT_STRING(skb, attrtype, value) \
         NLA_PUT(skb, attrtype, strlen(value) + 1, value)
 
-#define NLA_PUT_FLAG(skb, attrtype, value) \
+#define NLA_PUT_FLAG(skb, attrtype) \
         NLA_PUT(skb, attrtype, 0, NULL)
 
 #define NLA_PUT_MSECS(skb, attrtype, jiffies) \
@@ -862,10 +946,7 @@ static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start)
  */
 static inline int nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)
 {
-        if (start)
-                skb_trim(skb, (unsigned char *) start - skb->data);
-
-        return -1;
+        return nlmsg_trim(skb, start);
 }
 
 /**
@@ -880,4 +961,13 @@ static inline int nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)
              nla_ok(pos, rem); \
              pos = nla_next(pos, &(rem)))
 
+/**
+ * nla_for_each_nested - iterate over nested attributes
+ * @pos: loop counter, set to current attribute
+ * @nla: attribute containing the nested attributes
+ * @rem: initialized to len, holds bytes currently remaining in stream
+ */
+#define nla_for_each_nested(pos, nla, rem) \
+        nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem)
+
 #endif