[PATCH net-next v2 8/9] ipv4: add inet_fill_args

From: Christian Brauner
Date: Tue Sep 04 2018 - 15:54:26 EST


inet_fill_ifaddr() already took 6 arguments which meant the 7th argument
would need to be pushed onto the stack on x86.
Add a new struct inet_fill_args which holds common information passed
to inet_fill_ifaddr() and shortens the function to three pointer arguments.

Signed-off-by: Christian Brauner <christian@xxxxxxxxxx>
Cc: Kirill Tkhai <ktkhai@xxxxxxxxxxxxx>
---
v1->v2:
- patch added

v0->v1:
- patch not present
---
net/ipv4/devinet.c | 48 +++++++++++++++++++++++++++++++---------------
1 file changed, 33 insertions(+), 15 deletions(-)

diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 5cb849300b81..44d931a3cd50 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -103,6 +103,14 @@ static const struct nla_policy ifa_ipv4_policy[IFA_MAX+1] = {
[IFA_TARGET_NETNSID] = { .type = NLA_S32 },
};

+struct inet_fill_args {
+ u32 portid;
+ u32 seq;
+ int event;
+ unsigned int flags;
+ int netnsid;
+};
+
#define IN4_ADDR_HSIZE_SHIFT 8
#define IN4_ADDR_HSIZE (1U << IN4_ADDR_HSIZE_SHIFT)

@@ -1585,14 +1593,14 @@ static int put_cacheinfo(struct sk_buff *skb, unsigned long cstamp,
}

static int inet_fill_ifaddr(struct sk_buff *skb, struct in_ifaddr *ifa,
- u32 portid, u32 seq, int event, unsigned int flags,
- int netnsid)
+ struct inet_fill_args *args)
{
struct ifaddrmsg *ifm;
struct nlmsghdr *nlh;
u32 preferred, valid;

- nlh = nlmsg_put(skb, portid, seq, event, sizeof(*ifm), flags);
+ nlh = nlmsg_put(skb, args->portid, args->seq, args->event, sizeof(*ifm),
+ args->flags);
if (!nlh)
return -EMSGSIZE;

@@ -1603,7 +1611,8 @@ static int inet_fill_ifaddr(struct sk_buff *skb, struct in_ifaddr *ifa,
ifm->ifa_scope = ifa->ifa_scope;
ifm->ifa_index = ifa->ifa_dev->dev->ifindex;

- if (netnsid >= 0 && nla_put_s32(skb, IFA_TARGET_NETNSID, netnsid))
+ if (args->netnsid >= 0 &&
+ nla_put_s32(skb, IFA_TARGET_NETNSID, args->netnsid))
goto nla_put_failure;

if (!(ifm->ifa_flags & IFA_F_PERMANENT)) {
@@ -1652,10 +1661,16 @@ static int inet_fill_ifaddr(struct sk_buff *skb, struct in_ifaddr *ifa,

static int inet_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
{
+ struct inet_fill_args fillargs = {
+ .portid = NETLINK_CB(cb->skb).portid,
+ .seq = cb->nlh->nlmsg_seq,
+ .event = RTM_NEWADDR,
+ .flags = NLM_F_MULTI,
+ .netnsid = -1,
+ };
struct net *net = sock_net(skb->sk);
struct nlattr *tb[IFA_MAX+1];
struct net *tgt_net = net;
- int netnsid = -1;
int h, s_h;
int idx, s_idx;
int ip_idx, s_ip_idx;
@@ -1671,9 +1686,10 @@ static int inet_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
if (nlmsg_parse(cb->nlh, sizeof(struct ifaddrmsg), tb, IFA_MAX,
ifa_ipv4_policy, NULL) >= 0) {
if (tb[IFA_TARGET_NETNSID]) {
- netnsid = nla_get_s32(tb[IFA_TARGET_NETNSID]);
+ fillargs.netnsid = nla_get_s32(tb[IFA_TARGET_NETNSID]);

- tgt_net = rtnl_get_net_ns_capable(skb->sk, netnsid);
+ tgt_net = rtnl_get_net_ns_capable(skb->sk,
+ fillargs.netnsid);
if (IS_ERR(tgt_net))
return PTR_ERR(tgt_net);
}
@@ -1698,11 +1714,7 @@ static int inet_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
ifa = ifa->ifa_next, ip_idx++) {
if (ip_idx < s_ip_idx)
continue;
- if (inet_fill_ifaddr(skb, ifa,
- NETLINK_CB(cb->skb).portid,
- cb->nlh->nlmsg_seq,
- RTM_NEWADDR, NLM_F_MULTI,
- netnsid) < 0) {
+ if (inet_fill_ifaddr(skb, ifa, &fillargs) < 0) {
rcu_read_unlock();
goto done;
}
@@ -1718,7 +1730,7 @@ static int inet_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
cb->args[0] = h;
cb->args[1] = idx;
cb->args[2] = ip_idx;
- if (netnsid >= 0)
+ if (fillargs.netnsid >= 0)
put_net(tgt_net);

return skb->len;
@@ -1727,8 +1739,14 @@ static int inet_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
static void rtmsg_ifa(int event, struct in_ifaddr *ifa, struct nlmsghdr *nlh,
u32 portid)
{
+ struct inet_fill_args fillargs = {
+ .portid = portid,
+ .seq = nlh ? nlh->nlmsg_seq : 0,
+ .event = event,
+ .flags = 0,
+ .netnsid = -1,
+ };
struct sk_buff *skb;
- u32 seq = nlh ? nlh->nlmsg_seq : 0;
int err = -ENOBUFS;
struct net *net;

@@ -1737,7 +1755,7 @@ static void rtmsg_ifa(int event, struct in_ifaddr *ifa, struct nlmsghdr *nlh,
if (!skb)
goto errout;

- err = inet_fill_ifaddr(skb, ifa, portid, seq, event, 0, -1);
+ err = inet_fill_ifaddr(skb, ifa, &fillargs);
if (err < 0) {
/* -EMSGSIZE implies BUG in inet_nlmsg_size() */
WARN_ON(err == -EMSGSIZE);
--
2.17.1