[PATCHv1 net-next 1/5] netlink: mmap: introduce mmaped skb helper functions
From: Ken-ichirou MATSUZAWA <hidden>
Date: 2015-08-12 08:31:09
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
It seems that we need helper functions for skb which is allocated at netlink_alloc_skb() since it does not have skb_shared_info. Signed-off-by: Ken-ichirou MATSUZAWA <redacted> --- include/linux/netlink.h | 21 +++++------------- net/netlink/af_netlink.c | 55 ++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 60 insertions(+), 16 deletions(-)
diff --git a/include/linux/netlink.h b/include/linux/netlink.h
index 9120edb..60492bf 100644
--- a/include/linux/netlink.h
+++ b/include/linux/netlink.h@@ -70,6 +70,11 @@ extern void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err); extern int netlink_has_listeners(struct sock *sk, unsigned int group); extern struct sk_buff *netlink_alloc_skb(struct sock *ssk, unsigned int size, u32 dst_portid, gfp_t gfp_mask); +extern struct sk_buff *netlink_skb_copy(const struct sk_buff *skb, gfp_t gfp_mask); +extern struct sk_buff *netlink_skb_clone(struct sk_buff *skb, gfp_t gfp_mask); +extern void netlink_free_skb(struct sk_buff *skb); +void netlink_consume_skb(struct sk_buff *skb); + extern int netlink_unicast(struct sock *ssk, struct sk_buff *skb, __u32 portid, int nonblock); extern int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, __u32 portid, __u32 group, gfp_t allocation);
@@ -88,22 +93,6 @@ int netlink_attachskb(struct sock *sk, struct sk_buff *skb, void netlink_detachskb(struct sock *sk, struct sk_buff *skb); int netlink_sendskb(struct sock *sk, struct sk_buff *skb); -static inline struct sk_buff * -netlink_skb_clone(struct sk_buff *skb, gfp_t gfp_mask) -{ - struct sk_buff *nskb; - - nskb = skb_clone(skb, gfp_mask); - if (!nskb) - return NULL; - - /* This is a large skb, set destructor callback to release head */ - if (is_vmalloc_addr(skb->head)) - nskb->destructor = skb->destructor; - - return nskb; -} - /* * 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
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index d8e2e39..98ed579 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c@@ -1894,6 +1894,61 @@ out: } EXPORT_SYMBOL_GPL(netlink_alloc_skb); +struct sk_buff *netlink_skb_copy(const struct sk_buff *skb, gfp_t gfp_mask) +{ +#ifdef CONFIG_NETLINK_MMAP + if (netlink_skb_is_mmaped(skb)) { + struct sk_buff *n = alloc_skb(skb->len, gfp_mask); + if (!n) + return NULL; + + skb_put(n, skb->len); + NETLINK_CB(n).portid = NETLINK_CB(skb).portid; + memcpy(n->data, skb->data, skb->len); + return n; + } else +#endif + return skb_copy(skb, gfp_mask); +} +EXPORT_SYMBOL_GPL(netlink_skb_copy); + +struct sk_buff *netlink_skb_clone(struct sk_buff *skb, gfp_t gfp_mask) +{ + struct sk_buff *nskb; + +#ifdef CONFIG_NETLINK_MMAP + if (netlink_skb_is_mmaped(skb)) + return netlink_skb_copy(skb, gfp_mask); +#endif + nskb = skb_clone(skb, gfp_mask); + if (!nskb) + return NULL; + + /* This is a large skb, set destructor callback to release head */ + if (is_vmalloc_addr(skb->head)) + nskb->destructor = skb->destructor; + + return nskb; +} +EXPORT_SYMBOL_GPL(netlink_skb_clone); + +void netlink_free_skb(struct sk_buff *skb) +{ + kfree_skb_partial(skb, netlink_skb_is_mmaped(skb)); +} +EXPORT_SYMBOL_GPL(netlink_free_skb); + +void netlink_consume_skb(struct sk_buff *skb) +{ +#ifdef CONFIG_NETLINK_MMAP + if (netlink_skb_is_mmaped(skb)) + kfree_skb_partial(skb, true); + else +#endif + consume_skb(skb); +} +EXPORT_SYMBOL_GPL(netlink_consume_skb); + int netlink_has_listeners(struct sock *sk, unsigned int group) { int res = 0;
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1.7.10.4