diff options
| -rw-r--r-- | include/net/netlink.h | 37 | ||||
| -rw-r--r-- | net/core/rtnetlink.c | 24 |
2 files changed, 42 insertions, 19 deletions
diff --git a/include/net/netlink.h b/include/net/netlink.h index 0e3172751755..e644b3489acf 100644 --- a/include/net/netlink.h +++ b/include/net/netlink.h @@ -1231,6 +1231,43 @@ static inline int nla_validate_nested(const struct nlattr *start, int maxtype, } /** + * 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 + * + * Conditionally emit a padding netlink attribute in order to make + * the next attribute we emit have a 64-bit aligned nla_data() area. + * This will only be done in architectures which do not have + * HAVE_EFFICIENT_UNALIGNED_ACCESS defined. + * + * Returns zero on success or a negative error code. + */ +static inline int nla_align_64bit(struct sk_buff *skb, int padattr) +{ +#ifndef HAVE_EFFICIENT_UNALIGNED_ACCESS + if (IS_ALIGNED((unsigned long)skb->data, 8)) { + struct nlattr *attr = nla_reserve(skb, padattr, 0); + if (!attr) + return -EMSGSIZE; + } +#endif + return 0; +} + +/** + * nla_total_size_64bit - total length of attribute including padding + * @payload: length of payload + */ +static inline int nla_total_size_64bit(int payload) +{ + return NLA_ALIGN(nla_attr_size(payload)) +#ifndef HAVE_EFFICIENT_UNALIGNED_ACCESS + + NLA_ALIGN(nla_attr_size(0)) +#endif + ; +} + +/** * nla_for_each_attr - iterate over a stream of attributes * @pos: loop counter, set to current attribute * @head: head of attribute stream diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 198ca2c99510..d3694a13c85a 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -878,10 +878,7 @@ static noinline size_t if_nlmsg_size(const struct net_device *dev, + nla_total_size(IFNAMSIZ) /* IFLA_QDISC */ + nla_total_size(sizeof(struct rtnl_link_ifmap)) + nla_total_size(sizeof(struct rtnl_link_stats)) -#ifndef HAVE_EFFICIENT_UNALIGNED_ACCESS - + nla_total_size(0) /* IFLA_PAD */ -#endif - + nla_total_size(sizeof(struct rtnl_link_stats64)) + + nla_total_size_64bit(sizeof(struct rtnl_link_stats64)) + nla_total_size(MAX_ADDR_LEN) /* IFLA_ADDRESS */ + nla_total_size(MAX_ADDR_LEN) /* IFLA_BROADCAST */ + nla_total_size(4) /* IFLA_TXQLEN */ @@ -1054,22 +1051,11 @@ static noinline_for_stack int rtnl_fill_stats(struct sk_buff *skb, { struct rtnl_link_stats64 *sp; struct nlattr *attr; + int err; -#ifndef HAVE_EFFICIENT_UNALIGNED_ACCESS - /* IF necessary, add a zero length NOP attribute so that the - * nla_data() of the IFLA_STATS64 will be 64-bit aligned. - * - * 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 IFLA_STATS64, will make nla_data() 8-byte - * aligned. - */ - if (IS_ALIGNED((unsigned long)skb->data, 8)) { - attr = nla_reserve(skb, IFLA_PAD, 0); - if (!attr) - return -EMSGSIZE; - } -#endif + err = nla_align_64bit(skb, IFLA_PAD); + if (err) + return err; attr = nla_reserve(skb, IFLA_STATS64, sizeof(struct rtnl_link_stats64)); |