netlink: Move netlink attribute parsing support to lib

Netlink attribute parsing may be used even if CONFIG_NET is not set.
Move it from net/netlink to lib and control its inclusion based on the new
config symbol CONFIG_NLATTR, which is selected by CONFIG_NET.

Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

3 files changed, 2 insertions, 474 deletions

diff --git a/net/Kconfig b/net/Kconfig
index cdb8fdef6c4a..eab40a481356 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -4,6 +4,7 @@
 
 menuconfig NET
 	bool "Networking support"
+	select NLATTR
 	---help---
 	  Unless you really know what you are doing, you should say Y here.
 	  The reason is that some programs need kernel networking support even
diff --git a/net/netlink/Makefile b/net/netlink/Makefile
index e3589c2de49e..bdd6ddf4e95b 100644
--- a/net/netlink/Makefile
+++ b/net/netlink/Makefile
@@ -2,4 +2,4 @@
 # Makefile for the netlink driver.
 #
 
-obj-y  				:= af_netlink.o attr.o genetlink.o
+obj-y  				:= af_netlink.o genetlink.o
diff --git a/net/netlink/attr.c b/net/netlink/attr.c
deleted file mode 100644
index 56c3ce7fe29a..000000000000
--- a/net/netlink/attr.c
+++ /dev/null
@@ -1,473 +0,0 @@
-/*
- * NETLINK      Netlink attributes
- *
- * 		Authors:	Thomas Graf <tgraf@suug.ch>
- * 				Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
- */
-
-#include <linux/module.h>
-#include <linux/kernel.h>
-#include <linux/errno.h>
-#include <linux/jiffies.h>
-#include <linux/netdevice.h>
-#include <linux/skbuff.h>
-#include <linux/string.h>
-#include <linux/types.h>
-#include <net/netlink.h>
-
-static u16 nla_attr_minlen[NLA_TYPE_MAX+1] __read_mostly = {
-	[NLA_U8]	= sizeof(u8),
-	[NLA_U16]	= sizeof(u16),
-	[NLA_U32]	= sizeof(u32),
-	[NLA_U64]	= sizeof(u64),
-	[NLA_NESTED]	= NLA_HDRLEN,
-};
-
-static int validate_nla(struct nlattr *nla, int maxtype,
-			const struct nla_policy *policy)
-{
-	const struct nla_policy *pt;
-	int minlen = 0, attrlen = nla_len(nla), type = nla_type(nla);
-
-	if (type <= 0 || type > maxtype)
-		return 0;
-
-	pt = &policy[type];
-
-	BUG_ON(pt->type > NLA_TYPE_MAX);
-
-	switch (pt->type) {
-	case NLA_FLAG:
-		if (attrlen > 0)
-			return -ERANGE;
-		break;
-
-	case NLA_NUL_STRING:
-		if (pt->len)
-			minlen = min_t(int, attrlen, pt->len + 1);
-		else
-			minlen = attrlen;
-
-		if (!minlen || memchr(nla_data(nla), '\0', minlen) == NULL)
-			return -EINVAL;
-		/* fall through */
-
-	case NLA_STRING:
-		if (attrlen < 1)
-			return -ERANGE;
-
-		if (pt->len) {
-			char *buf = nla_data(nla);
-
-			if (buf[attrlen - 1] == '\0')
-				attrlen--;
-
-			if (attrlen > pt->len)
-				return -ERANGE;
-		}
-		break;
-
-	case NLA_BINARY:
-		if (pt->len && attrlen > pt->len)
-			return -ERANGE;
-		break;
-
-	case NLA_NESTED_COMPAT:
-		if (attrlen < pt->len)
-			return -ERANGE;
-		if (attrlen < NLA_ALIGN(pt->len))
-			break;
-		if (attrlen < NLA_ALIGN(pt->len) + NLA_HDRLEN)
-			return -ERANGE;
-		nla = nla_data(nla) + NLA_ALIGN(pt->len);
-		if (attrlen < NLA_ALIGN(pt->len) + NLA_HDRLEN + nla_len(nla))
-			return -ERANGE;
-		break;
-	case NLA_NESTED:
-		/* a nested attributes is allowed to be empty; if its not,
-		 * it must have a size of at least NLA_HDRLEN.
-		 */
-		if (attrlen == 0)
-			break;
-	default:
-		if (pt->len)
-			minlen = pt->len;
-		else if (pt->type != NLA_UNSPEC)
-			minlen = nla_attr_minlen[pt->type];
-
-		if (attrlen < minlen)
-			return -ERANGE;
-	}
-
-	return 0;
-}
-
-/**
- * nla_validate - Validate a stream of attributes
- * @head: head of attribute stream
- * @len: length of attribute stream
- * @maxtype: maximum attribute type to be expected
- * @policy: validation policy
- *
- * Validates all attributes in the specified attribute stream against the
- * specified policy. Attributes with a type exceeding maxtype will be
- * ignored. See documenation of struct nla_policy for more details.
- *
- * Returns 0 on success or a negative error code.
- */
-int nla_validate(struct nlattr *head, int len, int maxtype,
-		 const struct nla_policy *policy)
-{
-	struct nlattr *nla;
-	int rem, err;
-
-	nla_for_each_attr(nla, head, len, rem) {
-		err = validate_nla(nla, maxtype, policy);
-		if (err < 0)
-			goto errout;
-	}
-
-	err = 0;
-errout:
-	return err;
-}
-
-/**
- * nla_parse - Parse a stream of attributes into a tb buffer
- * @tb: destination array with maxtype+1 elements
- * @maxtype: maximum attribute type to be expected
- * @head: head of attribute stream
- * @len: length of attribute stream
- * @policy: validation policy
- *
- * Parses a stream of attributes and stores a pointer to each attribute in
- * the tb array accessable via the attribute type. Attributes with a type
- * exceeding maxtype will be silently ignored for backwards compatibility
- * reasons. policy may be set to NULL if no validation is required.
- *
- * Returns 0 on success or a negative error code.
- */
-int nla_parse(struct nlattr *tb[], int maxtype, struct nlattr *head, int len,
-	      const struct nla_policy *policy)
-{
-	struct nlattr *nla;
-	int rem, err;
-
-	memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1));
-
-	nla_for_each_attr(nla, head, len, rem) {
-		u16 type = nla_type(nla);
-
-		if (type > 0 && type <= maxtype) {
-			if (policy) {
-				err = validate_nla(nla, maxtype, policy);
-				if (err < 0)
-					goto errout;
-			}
-
-			tb[type] = nla;
-		}
-	}
-
-	if (unlikely(rem > 0))
-		printk(KERN_WARNING "netlink: %d bytes leftover after parsing "
-		       "attributes.\n", rem);
-
-	err = 0;
-errout:
-	return err;
-}
-
-/**
- * nla_find - Find a specific attribute in a stream of attributes
- * @head: head of attribute stream
- * @len: length of attribute stream
- * @attrtype: type of attribute to look for
- *
- * Returns the first attribute in the stream matching the specified type.
- */
-struct nlattr *nla_find(struct nlattr *head, int len, int attrtype)
-{
-	struct nlattr *nla;
-	int rem;
-
-	nla_for_each_attr(nla, head, len, rem)
-		if (nla_type(nla) == attrtype)
-			return nla;
-
-	return NULL;
-}
-
-/**
- * nla_strlcpy - Copy string attribute payload into a sized buffer
- * @dst: where to copy the string to
- * @nla: attribute to copy the string from
- * @dstsize: size of destination buffer
- *
- * Copies at most dstsize - 1 bytes into the destination buffer.
- * The result is always a valid NUL-terminated string. Unlike
- * strlcpy the destination buffer is always padded out.
- *
- * Returns the length of the source buffer.
- */
-size_t nla_strlcpy(char *dst, const struct nlattr *nla, size_t dstsize)
-{
-	size_t srclen = nla_len(nla);
-	char *src = nla_data(nla);
-
-	if (srclen > 0 && src[srclen - 1] == '\0')
-		srclen--;
-
-	if (dstsize > 0) {
-		size_t len = (srclen >= dstsize) ? dstsize - 1 : srclen;
-
-		memset(dst, 0, dstsize);
-		memcpy(dst, src, len);
-	}
-
-	return srclen;
-}
-
-/**
- * nla_memcpy - Copy a netlink attribute into another memory area
- * @dest: where to copy to memcpy
- * @src: netlink attribute to copy from
- * @count: size of the destination area
- *
- * Note: The number of bytes copied is limited by the length of
- *       attribute's payload. memcpy
- *
- * Returns the number of bytes copied.
- */
-int nla_memcpy(void *dest, const struct nlattr *src, int count)
-{
-	int minlen = min_t(int, count, nla_len(src));
-
-	memcpy(dest, nla_data(src), minlen);
-
-	return minlen;
-}
-
-/**
- * nla_memcmp - Compare an attribute with sized memory area
- * @nla: netlink attribute
- * @data: memory area
- * @size: size of memory area
- */
-int nla_memcmp(const struct nlattr *nla, const void *data,
-			     size_t size)
-{
-	int d = nla_len(nla) - size;
-
-	if (d == 0)
-		d = memcmp(nla_data(nla), data, size);
-
-	return d;
-}
-
-/**
- * nla_strcmp - Compare a string attribute against a string
- * @nla: netlink string attribute
- * @str: another string
- */
-int nla_strcmp(const struct nlattr *nla, const char *str)
-{
-	int len = strlen(str) + 1;
-	int d = nla_len(nla) - len;
-
-	if (d == 0)
-		d = memcmp(nla_data(nla), str, len);
-
-	return d;
-}
-
-/**
- * __nla_reserve - reserve room for attribute on the skb
- * @skb: socket buffer to reserve room on
- * @attrtype: attribute type
- * @attrlen: length of attribute payload
- *
- * Adds a netlink attribute header to a socket buffer and reserves
- * room for the payload but does not copy it.
- *
- * The caller is responsible to ensure that the skb provides enough
- * tailroom for the attribute header and payload.
- */
-struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen)
-{
-	struct nlattr *nla;
-
-	nla = (struct nlattr *) skb_put(skb, nla_total_size(attrlen));
-	nla->nla_type = attrtype;
-	nla->nla_len = nla_attr_size(attrlen);
-
-	memset((unsigned char *) nla + nla->nla_len, 0, nla_padlen(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
- * @attrtype: attribute type
- * @attrlen: length of attribute payload
- *
- * Adds a netlink attribute header to a socket buffer and reserves
- * room for the payload but does not copy it.
- *
- * Returns NULL if the tailroom of the skb is insufficient to store
- * the attribute header and payload.
- */
-struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen)
-{
-	if (unlikely(skb_tailroom(skb) < nla_total_size(attrlen)))
-		return NULL;
-
-	return __nla_reserve(skb, attrtype, attrlen);
-}
-
-/**
- * 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.
- *
- * 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
- * @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 header and payload.
- */
-void __nla_put(struct sk_buff *skb, int attrtype, int attrlen,
-			     const void *data)
-{
-	struct nlattr *nla;
-
-	nla = __nla_reserve(skb, attrtype, 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
- * @skb: socket buffer to add attribute to
- * @attrtype: attribute type
- * @attrlen: length of attribute payload
- * @data: head of attribute payload
- *
- * Returns -EMSGSIZE if the tailroom of the skb is insufficient to store
- * the attribute header and payload.
- */
-int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data)
-{
-	if (unlikely(skb_tailroom(skb) < nla_total_size(attrlen)))
-		return -EMSGSIZE;
-
-	__nla_put(skb, attrtype, attrlen, 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 -EMSGSIZE 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 -EMSGSIZE;
-
-	__nla_put_nohdr(skb, attrlen, data);
-	return 0;
-}
-
-/**
- * nla_append - Add a netlink attribute without header or padding
- * @skb: socket buffer to add attribute to
- * @attrlen: length of attribute payload
- * @data: head of attribute payload
- *
- * Returns -EMSGSIZE if the tailroom of the skb is insufficient to store
- * the attribute payload.
- */
-int nla_append(struct sk_buff *skb, int attrlen, const void *data)
-{
-	if (unlikely(skb_tailroom(skb) < NLA_ALIGN(attrlen)))
-		return -EMSGSIZE;
-
-	memcpy(skb_put(skb, attrlen), data, attrlen);
-	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);
-EXPORT_SYMBOL(nla_append);