diff options
| -rw-r--r-- | include/net/netlink.h | 39 | ||||
| -rw-r--r-- | lib/nlattr.c | 99 |
2 files changed, 130 insertions, 8 deletions
diff --git a/include/net/netlink.h b/include/net/netlink.h index 3c1fd92a52c8..6f51a8a06498 100644 --- a/include/net/netlink.h +++ b/include/net/netlink.h @@ -244,13 +244,21 @@ int nla_memcpy(void *dest, const struct nlattr *src, int count); int nla_memcmp(const struct nlattr *nla, const void *data, size_t size); int nla_strcmp(const struct nlattr *nla, const char *str); struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen); +struct nlattr *__nla_reserve_64bit(struct sk_buff *skb, int attrtype, + int attrlen, int padattr); void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen); struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen); +struct nlattr *nla_reserve_64bit(struct sk_buff *skb, int attrtype, + int attrlen, int padattr); void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen); void __nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data); +void __nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen, + const void *data, int padattr); void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data); int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data); +int nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen, + const void *data, int padattr); int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data); int nla_append(struct sk_buff *skb, int attrlen, const void *data); @@ -1231,6 +1239,27 @@ static inline int nla_validate_nested(const struct nlattr *start, int maxtype, } /** + * nla_need_padding_for_64bit - test 64-bit alignment of the next attribute + * @skb: socket buffer the message is stored in + * + * Return true if padding is needed to align the next attribute (nla_data()) to + * a 64-bit aligned area. + */ +static inline bool nla_need_padding_for_64bit(struct sk_buff *skb) +{ +#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS + /* The nlattr header is 4 bytes in size, that's why we test + * if the skb->data _is_ aligned. A NOP attribute, plus + * nlattr header for next attribute, will make nla_data() + * 8-byte aligned. + */ + if (IS_ALIGNED((unsigned long)skb_tail_pointer(skb), 8)) + return true; +#endif + return false; +} + +/** * nla_align_64bit - 64-bit align the nla_data() of next attribute * @skb: socket buffer the message is stored in * @padattr: attribute type for the padding @@ -1244,16 +1273,10 @@ static inline int nla_validate_nested(const struct nlattr *start, int maxtype, */ static inline int nla_align_64bit(struct sk_buff *skb, int padattr) { -#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS - /* The nlattr header is 4 bytes in size, that's why we test - * if the skb->data _is_ aligned. This NOP attribute, plus - * nlattr header for next attribute, will make nla_data() - * 8-byte aligned. - */ - if (IS_ALIGNED((unsigned long)skb_tail_pointer(skb), 8) && + if (nla_need_padding_for_64bit(skb) && !nla_reserve(skb, padattr, 0)) return -EMSGSIZE; -#endif + return 0; } diff --git a/lib/nlattr.c b/lib/nlattr.c index f5907d23272d..2b82f1e2ebc2 100644 --- a/lib/nlattr.c +++ b/lib/nlattr.c @@ -355,6 +355,29 @@ struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen) EXPORT_SYMBOL(__nla_reserve); /** + * __nla_reserve_64bit - reserve room for attribute on the skb and align it + * @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. It also ensure that this + * attribute will be 64-bit aign. + * + * The caller is responsible to ensure that the skb provides enough + * tailroom for the attribute header and payload. + */ +struct nlattr *__nla_reserve_64bit(struct sk_buff *skb, int attrtype, + int attrlen, int padattr) +{ + if (nla_need_padding_for_64bit(skb)) + nla_align_64bit(skb, padattr); + + return __nla_reserve(skb, attrtype, attrlen); +} +EXPORT_SYMBOL(__nla_reserve_64bit); + +/** * __nla_reserve_nohdr - reserve room for attribute without header * @skb: socket buffer to reserve room on * @attrlen: length of attribute payload @@ -397,6 +420,35 @@ struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen) EXPORT_SYMBOL(nla_reserve); /** + * nla_reserve_64bit - reserve room for attribute on the skb and align it + * @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. It also ensure that this + * attribute will be 64-bit aign. + * + * Returns NULL if the tailroom of the skb is insufficient to store + * the attribute header and payload. + */ +struct nlattr *nla_reserve_64bit(struct sk_buff *skb, int attrtype, int attrlen, + int padattr) +{ + size_t len; + + if (nla_need_padding_for_64bit(skb)) + len = nla_total_size_64bit(attrlen); + else + len = nla_total_size(attrlen); + if (unlikely(skb_tailroom(skb) < len)) + return NULL; + + return __nla_reserve_64bit(skb, attrtype, attrlen, padattr); +} +EXPORT_SYMBOL(nla_reserve_64bit); + +/** * nla_reserve_nohdr - reserve room for attribute without header * @skb: socket buffer to reserve room on * @attrlen: length of attribute payload @@ -436,6 +488,26 @@ void __nla_put(struct sk_buff *skb, int attrtype, int attrlen, EXPORT_SYMBOL(__nla_put); /** + * __nla_put_64bit - Add a netlink attribute to a socket buffer and align it + * @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_64bit(struct sk_buff *skb, int attrtype, int attrlen, + const void *data, int padattr) +{ + struct nlattr *nla; + + nla = __nla_reserve_64bit(skb, attrtype, attrlen, padattr); + memcpy(nla_data(nla), data, attrlen); +} +EXPORT_SYMBOL(__nla_put_64bit); + +/** * __nla_put_nohdr - Add a netlink attribute without header * @skb: socket buffer to add attribute to * @attrlen: length of attribute payload @@ -474,6 +546,33 @@ int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data) EXPORT_SYMBOL(nla_put); /** + * nla_put_64bit - Add a netlink attribute to a socket buffer and align it + * @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_64bit(struct sk_buff *skb, int attrtype, int attrlen, + const void *data, int padattr) +{ + size_t len; + + if (nla_need_padding_for_64bit(skb)) + len = nla_total_size_64bit(attrlen); + else + len = nla_total_size(attrlen); + if (unlikely(skb_tailroom(skb) < len)) + return -EMSGSIZE; + + __nla_put_64bit(skb, attrtype, attrlen, data, padattr); + return 0; +} +EXPORT_SYMBOL(nla_put_64bit); + +/** * nla_put_nohdr - Add a netlink attribute without header * @skb: socket buffer to add attribute to * @attrlen: length of attribute payload |