The implicit cast from void * is not allowed for C++ compilers, and the arithmetic on void * generates warnings if a C++ application tries to include these UAPI headers.
$ g++ -c t.cc ip_tables.h:221:24: warning: pointer of type 'void *' used in arithmetic ip_tables.h:221:24: error: invalid conversion from 'void*' to 'xt_entry_target*' Signed-off-by: Jason Gunthorpe <jguntho...@obsidianresearch.com> --- include/uapi/linux/netfilter_ipv4/ip_tables.h | 2 +- include/uapi/linux/netfilter_ipv6/ip6_tables.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/include/uapi/linux/netfilter_ipv4/ip_tables.h b/include/uapi/linux/netfilter_ipv4/ip_tables.h index d0da53d96d93..4682b18f3f44 100644 --- a/include/uapi/linux/netfilter_ipv4/ip_tables.h +++ b/include/uapi/linux/netfilter_ipv4/ip_tables.h @@ -221,7 +221,7 @@ struct ipt_get_entries { static __inline__ struct xt_entry_target * ipt_get_target(struct ipt_entry *e) { - return (void *)e + e->target_offset; + return (struct xt_entry_target *)((__u8 *)e + e->target_offset); } /* diff --git a/include/uapi/linux/netfilter_ipv6/ip6_tables.h b/include/uapi/linux/netfilter_ipv6/ip6_tables.h index d1b22653daf2..05e0631a6d12 100644 --- a/include/uapi/linux/netfilter_ipv6/ip6_tables.h +++ b/include/uapi/linux/netfilter_ipv6/ip6_tables.h @@ -261,7 +261,7 @@ struct ip6t_get_entries { static __inline__ struct xt_entry_target * ip6t_get_target(struct ip6t_entry *e) { - return (void *)e + e->target_offset; + return (struct xt_entry_target *)((__u8 *)e + e->target_offset); } /* -- 2.1.4