aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorDavid S. Miller <davem@davemloft.net>2007-03-25 20:27:59 -0700
committerDavid S. Miller <davem@sunset.davemloft.net>2007-04-25 22:23:45 -0700
commitfc910a27839584209726537698b596576940add4 (patch)
treee03b021dcb5046ffb1e8154f0f4d4bc72c4c1c1d
parent[IPV6] ADDRCONF: Fix possible inet6_ifaddr leakage with CONFIG_OPTIMISTIC_DAD. (diff)
downloadlinux-dev-fc910a27839584209726537698b596576940add4.tar.xz
linux-dev-fc910a27839584209726537698b596576940add4.zip
[NETLINK]: Limit NLMSG_GOODSIZE to 8K.
Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/linux/netlink.h11
-rw-r--r--include/linux/skbuff.h8
2 files changed, 14 insertions, 5 deletions
diff --git a/include/linux/netlink.h b/include/linux/netlink.h
index 2a20f488ac1b..a9d3ad5bc80f 100644
--- a/include/linux/netlink.h
+++ b/include/linux/netlink.h
@@ -171,9 +171,16 @@ int netlink_sendskb(struct sock *sk, struct sk_buff *skb, int protocol);
/*
* skb should fit one page. This choice is good for headerless malloc.
+ * But we should limit to 8K so that userspace does not have to
+ * use enormous buffer sizes on recvmsg() calls just to avoid
+ * MSG_TRUNC when PAGE_SIZE is very large.
*/
-#define NLMSG_GOODORDER 0
-#define NLMSG_GOODSIZE (SKB_MAX_ORDER(0, NLMSG_GOODORDER))
+#if PAGE_SIZE < 8192UL
+#define NLMSG_GOODSIZE SKB_WITH_OVERHEAD(PAGE_SIZE)
+#else
+#define NLMSG_GOODSIZE SKB_WITH_OVERHEAD(8192UL)
+#endif
+
#define NLMSG_DEFAULT_SIZE (NLMSG_GOODSIZE - NLMSG_HDRLEN)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index f9441b5f8d13..30089adb2e78 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -39,9 +39,11 @@
#define SKB_DATA_ALIGN(X) (((X) + (SMP_CACHE_BYTES - 1)) & \
~(SMP_CACHE_BYTES - 1))
-#define SKB_MAX_ORDER(X, ORDER) (((PAGE_SIZE << (ORDER)) - (X) - \
- sizeof(struct skb_shared_info)) & \
- ~(SMP_CACHE_BYTES - 1))
+#define SKB_WITH_OVERHEAD(X) \
+ (((X) - sizeof(struct skb_shared_info)) & \
+ ~(SMP_CACHE_BYTES - 1))
+#define SKB_MAX_ORDER(X, ORDER) \
+ SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
#define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
#define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))