[RFC PATCH net-next 1/8] skb: Add skb_put_uchar
From: Joe Perches <joe@perches.com>
Date: 2015-05-04 20:06:06
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
skb_put currently returns an unsigned char *. There are uses like "*skb_put(skb, 1) = <char>" that might be better represented by a new skb_put_uchar(<char>) function. This would allow the skb_put function to be converted to return void and eliminate many casts of the unsigned char * return to some other type. Signed-off-by: Joe Perches <joe@perches.com> --- include/linux/skbuff.h | 1 + net/core/skbuff.c | 26 ++++++++++++++++++++++++++ 2 files changed, 27 insertions(+)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index acb83e2..894071e1 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h@@ -1679,6 +1679,7 @@ static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset) */ unsigned char *pskb_put(struct sk_buff *skb, struct sk_buff *tail, int len); unsigned char *skb_put(struct sk_buff *skb, unsigned int len); +void *skb_put_uchar(struct sk_buff *skb, unsigned char uc); static inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len) { unsigned char *tmp = skb_tail_pointer(skb);
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 3cfff2a..73e20ad 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c@@ -1410,6 +1410,32 @@ unsigned char *skb_put(struct sk_buff *skb, unsigned int len) EXPORT_SYMBOL(skb_put); /** + * skb_put_uchar - add an unsigned char to a buffer + * @skb: buffer to use + * @uc: unsigned char to add + * + * This function extends the used data area of the buffer. If this would + * exceed the total buffer size the kernel will panic. A pointer to the + * first byte of the extra data is returned. + */ +void *skb_put_uchar(struct sk_buff *skb, unsigned char uc) +{ + unsigned char *tmp = skb_tail_pointer(skb); + + SKB_LINEAR_ASSERT(skb); + + skb->tail++; + skb->len++; + if (unlikely(skb->tail > skb->end)) + skb_over_panic(skb, 1, __builtin_return_address(0)); + + *tmp = uc; + + return tmp; +} +EXPORT_SYMBOL(skb_put_uchar); + +/** * skb_push - add data to the start of a buffer * @skb: buffer to use * @len: amount of data to add
--
2.1.4