[PATCH iproute2-next v3 1/4] utils: Introduce and use inet_prefix_reset()

[Serhey Popovych]

Initializing @inet_prefix using C initializers or memset() seems
inefficient and unnecessary: only small part of ->data[] field will be
used to store address corresponding to ->family.

Instead initialize ->flags with zero and assume no other fields accessed
before checking corresponding bits in ->flags. For example special
helpers (e.g. is_addrtype_*()) can be used to ensure that @inet_prefix
contains valid ip or ipv6 address.

Signed-off-by: Serhey Popovych <serhe.popov...@gmail.com>
---
 include/utils.h    |    5 +++++
 ip/iplink_geneve.c |    2 +-
 ip/iplink_vxlan.c  |    7 ++++---
 3 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/include/utils.h b/include/utils.h
index 4dc514d..867e540 100644
--- a/include/utils.h
+++ b/include/utils.h
@@ -65,6 +65,11 @@ enum {
        ADDRTYPE_INET_MULTI     = ADDRTYPE_INET | ADDRTYPE_MULTI
 };
 
+static inline void inet_prefix_reset(inet_prefix *p)
+{
+       p->flags = 0;
+}
+
 static inline bool is_addrtype_inet(const inet_prefix *p)
 {
        return p->flags & ADDRTYPE_INET;
diff --git a/ip/iplink_geneve.c b/ip/iplink_geneve.c
index c666072..1fcdd83 100644
--- a/ip/iplink_geneve.c
+++ b/ip/iplink_geneve.c
@@ -71,7 +71,7 @@ static int geneve_parse_opt(struct link_util *lu, int argc, 
char **argv,
        bool set_op = (n->nlmsg_type == RTM_NEWLINK &&
                       !(n->nlmsg_flags & NLM_F_CREATE));
 
-       daddr.flags = 0;
+       inet_prefix_reset(&daddr);
 
        while (argc > 0) {
                if (!matches(*argv, "id") ||
diff --git a/ip/iplink_vxlan.c b/ip/iplink_vxlan.c
index 00875ba..d768c07 100644
--- a/ip/iplink_vxlan.c
+++ b/ip/iplink_vxlan.c
@@ -74,8 +74,7 @@ static void check_duparg(__u64 *attrs, int type, const char 
*key,
 static int vxlan_parse_opt(struct link_util *lu, int argc, char **argv,
                          struct nlmsghdr *n)
 {
-       inet_prefix saddr;
-       inet_prefix daddr;
+       inet_prefix saddr, daddr;
        __u32 vni = 0;
        __u8 learning = 1;
        __u16 dstport = 0;
@@ -85,7 +84,9 @@ static int vxlan_parse_opt(struct link_util *lu, int argc, 
char **argv,
                       !(n->nlmsg_flags & NLM_F_CREATE));
 
        saddr.family = daddr.family = AF_UNSPEC;
-       saddr.flags = daddr.flags = 0;
+
+       inet_prefix_reset(&saddr);
+       inet_prefix_reset(&daddr);
 
        while (argc > 0) {
                if (!matches(*argv, "id") ||
-- 
1.7.10.4