mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-24 12:44:11 +08:00
[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>
This commit is contained in:
parent
e1ef4bf23b
commit
fe4944e59c
@ -35,6 +35,8 @@
|
||||
* 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
|
||||
*
|
||||
@ -80,8 +82,10 @@
|
||||
* 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 +143,7 @@
|
||||
* 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
|
||||
@ -203,12 +208,18 @@ 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
|
||||
@ -453,12 +464,13 @@ 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);
|
||||
}
|
||||
|
||||
/**
|
||||
@ -479,6 +491,32 @@ static inline int nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh)
|
||||
return skb->len;
|
||||
}
|
||||
|
||||
/**
|
||||
* 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
|
||||
@ -489,9 +527,7 @@ 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);
|
||||
}
|
||||
|
||||
/**
|
||||
@ -630,6 +666,18 @@ static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
|
||||
return (struct nlattr *) ((char *) nla + totlen);
|
||||
}
|
||||
|
||||
/**
|
||||
* 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
|
||||
@ -862,10 +910,7 @@ 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 +925,13 @@ 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
|
||||
|
@ -75,7 +75,7 @@ static int prepare_reply(struct genl_info *info, u8 cmd, struct sk_buff **skbp,
|
||||
/*
|
||||
* If new attributes are added, please revisit this allocation
|
||||
*/
|
||||
skb = nlmsg_new(size);
|
||||
skb = nlmsg_new(size, GFP_KERNEL);
|
||||
if (!skb)
|
||||
return -ENOMEM;
|
||||
|
||||
|
@ -254,6 +254,26 @@ struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen)
|
||||
return nla;
|
||||
}
|
||||
|
||||
/**
|
||||
* __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
|
||||
@ -274,6 +294,24 @@ struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen)
|
||||
return __nla_reserve(skb, attrtype, attrlen);
|
||||
}
|
||||
|
||||
/**
|
||||
* 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
|
||||
@ -293,6 +331,22 @@ void __nla_put(struct sk_buff *skb, int attrtype, int attrlen,
|
||||
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 @@ int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data)
|
||||
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);
|
||||
|
@ -440,7 +440,7 @@ static struct sk_buff *ctrl_build_msg(struct genl_family *family, u32 pid,
|
||||
struct sk_buff *skb;
|
||||
int err;
|
||||
|
||||
skb = nlmsg_new(NLMSG_GOODSIZE);
|
||||
skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
|
||||
if (skb == NULL)
|
||||
return ERR_PTR(-ENOBUFS);
|
||||
|
||||
|
Loading…
Reference in New Issue
Block a user