From 62ab0812137ec4f9884dd7de346238841ac03283 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 6 Dec 2010 20:50:09 +0000 Subject: filter: constify sk_run_filter() sk_run_filter() doesnt write on skb, change its prototype to reflect this. Fix two af_packet comments. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- include/linux/filter.h | 2 +- net/core/filter.c | 7 ++++--- net/core/timestamping.c | 2 +- net/packet/af_packet.c | 31 ++++++++++++++++--------------- 4 files changed, 22 insertions(+), 20 deletions(-) diff --git a/include/linux/filter.h b/include/linux/filter.h index 5334ada..45266b7 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -148,7 +148,7 @@ struct sk_buff; struct sock; extern int sk_filter(struct sock *sk, struct sk_buff *skb); -extern unsigned int sk_run_filter(struct sk_buff *skb, +extern unsigned int sk_run_filter(const struct sk_buff *skb, const struct sock_filter *filter); extern int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk); extern int sk_detach_filter(struct sock *sk); diff --git a/net/core/filter.c b/net/core/filter.c index ac4920a..25500f1 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -88,7 +88,7 @@ enum { }; /* No hurry in this branch */ -static void *__load_pointer(struct sk_buff *skb, int k) +static void *__load_pointer(const struct sk_buff *skb, int k) { u8 *ptr = NULL; @@ -102,7 +102,7 @@ static void *__load_pointer(struct sk_buff *skb, int k) return NULL; } -static inline void *load_pointer(struct sk_buff *skb, int k, +static inline void *load_pointer(const struct sk_buff *skb, int k, unsigned int size, void *buffer) { if (k >= 0) @@ -160,7 +160,8 @@ EXPORT_SYMBOL(sk_filter); * and last instruction guaranteed to be a RET, we dont need to check * flen. (We used to pass to this function the length of filter) */ -unsigned int sk_run_filter(struct sk_buff *skb, const struct sock_filter *fentry) +unsigned int sk_run_filter(const struct sk_buff *skb, + const struct sock_filter *fentry) { void *ptr; u32 A = 0; /* Accumulator */ diff --git a/net/core/timestamping.c b/net/core/timestamping.c index dac7ed6..b124d28 100644 --- a/net/core/timestamping.c +++ b/net/core/timestamping.c @@ -26,7 +26,7 @@ static struct sock_filter ptp_filter[] = { PTP_FILTER }; -static unsigned int classify(struct sk_buff *skb) +static unsigned int classify(const struct sk_buff *skb) { if (likely(skb->dev && skb->dev->phydev && diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index a11c731..17eafe5 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -517,7 +517,8 @@ out_free: return err; } -static inline unsigned int run_filter(struct sk_buff *skb, struct sock *sk, +static inline unsigned int run_filter(const struct sk_buff *skb, + const struct sock *sk, unsigned int res) { struct sk_filter *filter; @@ -532,15 +533,15 @@ static inline unsigned int run_filter(struct sk_buff *skb, struct sock *sk, } /* - This function makes lazy skb cloning in hope that most of packets - are discarded by BPF. - - Note tricky part: we DO mangle shared skb! skb->data, skb->len - and skb->cb are mangled. It works because (and until) packets - falling here are owned by current CPU. Output packets are cloned - by dev_queue_xmit_nit(), input packets are processed by net_bh - sequencially, so that if we return skb to original state on exit, - we will not harm anyone. + * This function makes lazy skb cloning in hope that most of packets + * are discarded by BPF. + * + * Note tricky part: we DO mangle shared skb! skb->data, skb->len + * and skb->cb are mangled. It works because (and until) packets + * falling here are owned by current CPU. Output packets are cloned + * by dev_queue_xmit_nit(), input packets are processed by net_bh + * sequencially, so that if we return skb to original state on exit, + * we will not harm anyone. */ static int packet_rcv(struct sk_buff *skb, struct net_device *dev, @@ -566,11 +567,11 @@ static int packet_rcv(struct sk_buff *skb, struct net_device *dev, if (dev->header_ops) { /* The device has an explicit notion of ll header, - exported to higher levels. - - Otherwise, the device hides datails of it frame - structure, so that corresponding packet head - never delivered to user. + * exported to higher levels. + * + * Otherwise, the device hides details of its frame + * structure, so that corresponding packet head is + * never delivered to user. */ if (sk->sk_type != SOCK_DGRAM) skb_push(skb, skb->data - skb_mac_header(skb)); -- cgit v1.1