[NETLINK]: Do precise netlink message allocations where possible
Account for the netlink message header size directly in nlmsg_new()
instead of relying on the caller calculate it correctly.
Replaces error handling of message construction functions when
constructing notifications with bug traps since a failure implies
a bug in calculating the size of the skb.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Acked-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 6a98f68..967ea32 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -3098,10 +3098,9 @@
static inline int inet6_ifaddr_msgsize(void)
{
- return nlmsg_total_size(sizeof(struct ifaddrmsg) +
- nla_total_size(16) +
- nla_total_size(sizeof(struct ifa_cacheinfo)) +
- 128);
+ return NLMSG_ALIGN(sizeof(struct ifaddrmsg))
+ + nla_total_size(16) /* IFA_ADDRESS */
+ + nla_total_size(sizeof(struct ifa_cacheinfo));
}
static int inet6_fill_ifaddr(struct sk_buff *skb, struct inet6_ifaddr *ifa,
@@ -3329,10 +3328,8 @@
err = inet6_fill_ifaddr(skb, ifa, NETLINK_CB(in_skb).pid,
nlh->nlmsg_seq, RTM_NEWADDR, 0);
- if (err < 0) {
- kfree_skb(skb);
- goto errout_ifa;
- }
+ /* failure implies BUG in inet6_ifaddr_msgsize() */
+ BUG_ON(err < 0);
err = rtnl_unicast(skb, NETLINK_CB(in_skb).pid);
errout_ifa:
@@ -3351,10 +3348,8 @@
goto errout;
err = inet6_fill_ifaddr(skb, ifa, 0, 0, event, 0);
- if (err < 0) {
- kfree_skb(skb);
- goto errout;
- }
+ /* failure implies BUG in inet6_ifaddr_msgsize() */
+ BUG_ON(err < 0);
err = rtnl_notify(skb, 0, RTNLGRP_IPV6_IFADDR, NULL, GFP_ATOMIC);
errout:
@@ -3397,16 +3392,19 @@
array[DEVCONF_PROXY_NDP] = cnf->proxy_ndp;
}
-/* Maximum length of ifinfomsg attributes */
-#define INET6_IFINFO_RTA_SPACE \
- RTA_SPACE(IFNAMSIZ) /* IFNAME */ + \
- RTA_SPACE(MAX_ADDR_LEN) /* ADDRESS */ + \
- RTA_SPACE(sizeof(u32)) /* MTU */ + \
- RTA_SPACE(sizeof(int)) /* LINK */ + \
- RTA_SPACE(0) /* PROTINFO */ + \
- RTA_SPACE(sizeof(u32)) /* FLAGS */ + \
- RTA_SPACE(sizeof(struct ifla_cacheinfo)) /* CACHEINFO */ + \
- RTA_SPACE(sizeof(__s32[DEVCONF_MAX])) /* CONF */
+static inline size_t inet6_if_nlmsg_size(void)
+{
+ return NLMSG_ALIGN(sizeof(struct ifinfomsg))
+ + nla_total_size(IFNAMSIZ) /* IFLA_IFNAME */
+ + nla_total_size(MAX_ADDR_LEN) /* IFLA_ADDRESS */
+ + nla_total_size(4) /* IFLA_MTU */
+ + nla_total_size(4) /* IFLA_LINK */
+ + nla_total_size( /* IFLA_PROTINFO */
+ nla_total_size(4) /* IFLA_INET6_FLAGS */
+ + nla_total_size(sizeof(struct ifla_cacheinfo))
+ + nla_total_size(DEVCONF_MAX * 4) /* IFLA_INET6_CONF */
+ );
+}
static int inet6_fill_ifinfo(struct sk_buff *skb, struct inet6_dev *idev,
u32 pid, u32 seq, int event, unsigned int flags)
@@ -3501,18 +3499,15 @@
void inet6_ifinfo_notify(int event, struct inet6_dev *idev)
{
struct sk_buff *skb;
- int payload = sizeof(struct ifinfomsg) + INET6_IFINFO_RTA_SPACE;
int err = -ENOBUFS;
- skb = nlmsg_new(nlmsg_total_size(payload), GFP_ATOMIC);
+ skb = nlmsg_new(inet6_if_nlmsg_size(), GFP_ATOMIC);
if (skb == NULL)
goto errout;
err = inet6_fill_ifinfo(skb, idev, 0, 0, event, 0);
- if (err < 0) {
- kfree_skb(skb);
- goto errout;
- }
+ /* failure implies BUG in inet6_if_nlmsg_size() */
+ BUG_ON(err < 0);
err = rtnl_notify(skb, 0, RTNLGRP_IPV6_IFADDR, NULL, GFP_ATOMIC);
errout:
@@ -3520,10 +3515,12 @@
rtnl_set_sk_err(RTNLGRP_IPV6_IFADDR, err);
}
-/* Maximum length of prefix_cacheinfo attributes */
-#define INET6_PREFIX_RTA_SPACE \
- RTA_SPACE(sizeof(((struct prefix_info *)NULL)->prefix)) /* ADDRESS */ + \
- RTA_SPACE(sizeof(struct prefix_cacheinfo)) /* CACHEINFO */
+static inline size_t inet6_prefix_nlmsg_size(void)
+{
+ return NLMSG_ALIGN(sizeof(struct prefixmsg))
+ + nla_total_size(sizeof(struct in6_addr))
+ + nla_total_size(sizeof(struct prefix_cacheinfo));
+}
static int inet6_fill_prefix(struct sk_buff *skb, struct inet6_dev *idev,
struct prefix_info *pinfo, u32 pid, u32 seq,
@@ -3569,18 +3566,15 @@
struct prefix_info *pinfo)
{
struct sk_buff *skb;
- int payload = sizeof(struct prefixmsg) + INET6_PREFIX_RTA_SPACE;
int err = -ENOBUFS;
- skb = nlmsg_new(nlmsg_total_size(payload), GFP_ATOMIC);
+ skb = nlmsg_new(inet6_prefix_nlmsg_size(), GFP_ATOMIC);
if (skb == NULL)
goto errout;
err = inet6_fill_prefix(skb, idev, pinfo, 0, 0, event, 0);
- if (err < 0) {
- kfree_skb(skb);
- goto errout;
- }
+ /* failure implies BUG in inet6_prefix_nlmsg_size() */
+ BUG_ON(err < 0);
err = rtnl_notify(skb, 0, RTNLGRP_IPV6_PREFIX, NULL, GFP_ATOMIC);
errout: