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>

2 files changed, 1 insertions, 474 deletions

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);