diff options
Diffstat (limited to 'include/linux/skbuff.h')
-rw-r--r-- | include/linux/skbuff.h | 58 |
1 files changed, 54 insertions, 4 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index c9525bce80f6..7cdfb4d52847 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h | |||
@@ -264,7 +264,7 @@ typedef unsigned char *sk_buff_data_t; | |||
264 | * @transport_header: Transport layer header | 264 | * @transport_header: Transport layer header |
265 | * @network_header: Network layer header | 265 | * @network_header: Network layer header |
266 | * @mac_header: Link layer header | 266 | * @mac_header: Link layer header |
267 | * @_skb_dst: destination entry | 267 | * @_skb_refdst: destination entry (with norefcount bit) |
268 | * @sp: the security path, used for xfrm | 268 | * @sp: the security path, used for xfrm |
269 | * @cb: Control buffer. Free for use by every layer. Put private vars here | 269 | * @cb: Control buffer. Free for use by every layer. Put private vars here |
270 | * @len: Length of actual data | 270 | * @len: Length of actual data |
@@ -328,7 +328,7 @@ struct sk_buff { | |||
328 | */ | 328 | */ |
329 | char cb[48] __aligned(8); | 329 | char cb[48] __aligned(8); |
330 | 330 | ||
331 | unsigned long _skb_dst; | 331 | unsigned long _skb_refdst; |
332 | #ifdef CONFIG_XFRM | 332 | #ifdef CONFIG_XFRM |
333 | struct sec_path *sp; | 333 | struct sec_path *sp; |
334 | #endif | 334 | #endif |
@@ -419,14 +419,64 @@ struct sk_buff { | |||
419 | 419 | ||
420 | #include <asm/system.h> | 420 | #include <asm/system.h> |
421 | 421 | ||
422 | /* | ||
423 | * skb might have a dst pointer attached, refcounted or not. | ||
424 | * _skb_refdst low order bit is set if refcount was _not_ taken | ||
425 | */ | ||
426 | #define SKB_DST_NOREF 1UL | ||
427 | #define SKB_DST_PTRMASK ~(SKB_DST_NOREF) | ||
428 | |||
429 | /** | ||
430 | * skb_dst - returns skb dst_entry | ||
431 | * @skb: buffer | ||
432 | * | ||
433 | * Returns skb dst_entry, regardless of reference taken or not. | ||
434 | */ | ||
422 | static inline struct dst_entry *skb_dst(const struct sk_buff *skb) | 435 | static inline struct dst_entry *skb_dst(const struct sk_buff *skb) |
423 | { | 436 | { |
424 | return (struct dst_entry *)skb->_skb_dst; | 437 | /* If refdst was not refcounted, check we still are in a |
438 | * rcu_read_lock section | ||
439 | */ | ||
440 | WARN_ON((skb->_skb_refdst & SKB_DST_NOREF) && | ||
441 | !rcu_read_lock_held() && | ||
442 | !rcu_read_lock_bh_held()); | ||
443 | return (struct dst_entry *)(skb->_skb_refdst & SKB_DST_PTRMASK); | ||
425 | } | 444 | } |
426 | 445 | ||
446 | /** | ||
447 | * skb_dst_set - sets skb dst | ||
448 | * @skb: buffer | ||
449 | * @dst: dst entry | ||
450 | * | ||
451 | * Sets skb dst, assuming a reference was taken on dst and should | ||
452 | * be released by skb_dst_drop() | ||
453 | */ | ||
427 | static inline void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst) | 454 | static inline void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst) |
428 | { | 455 | { |
429 | skb->_skb_dst = (unsigned long)dst; | 456 | skb->_skb_refdst = (unsigned long)dst; |
457 | } | ||
458 | |||
459 | /** | ||
460 | * skb_dst_set_noref - sets skb dst, without a reference | ||
461 | * @skb: buffer | ||
462 | * @dst: dst entry | ||
463 | * | ||
464 | * Sets skb dst, assuming a reference was not taken on dst | ||
465 | * skb_dst_drop() should not dst_release() this dst | ||
466 | */ | ||
467 | static inline void skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst) | ||
468 | { | ||
469 | WARN_ON(!rcu_read_lock_held() && !rcu_read_lock_bh_held()); | ||
470 | skb->_skb_refdst = (unsigned long)dst | SKB_DST_NOREF; | ||
471 | } | ||
472 | |||
473 | /** | ||
474 | * skb_dst_is_noref - Test if skb dst isnt refcounted | ||
475 | * @skb: buffer | ||
476 | */ | ||
477 | static inline bool skb_dst_is_noref(const struct sk_buff *skb) | ||
478 | { | ||
479 | return (skb->_skb_refdst & SKB_DST_NOREF) && skb_dst(skb); | ||
430 | } | 480 | } |
431 | 481 | ||
432 | static inline struct rtable *skb_rtable(const struct sk_buff *skb) | 482 | static inline struct rtable *skb_rtable(const struct sk_buff *skb) |