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Diffstat (limited to 'include/linux/skbuff.h')
| -rw-r--r-- | include/linux/skbuff.h | 2283 |
1 files changed, 2283 insertions, 0 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h new file mode 100644 index 00000000..37b643bd --- /dev/null +++ b/include/linux/skbuff.h @@ -0,0 +1,2283 @@ +/* + * Definitions for the 'struct sk_buff' memory handlers. + * + * Authors: + * Alan Cox, <gw4pts@gw4pts.ampr.org> + * Florian La Roche, <rzsfl@rz.uni-sb.de> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#ifndef _LINUX_SKBUFF_H +#define _LINUX_SKBUFF_H + +#include <linux/kernel.h> +#include <linux/kmemcheck.h> +#include <linux/compiler.h> +#include <linux/time.h> +#include <linux/cache.h> + +#include <asm/atomic.h> +#include <asm/types.h> +#include <linux/spinlock.h> +#include <linux/net.h> +#include <linux/textsearch.h> +#include <net/checksum.h> +#include <linux/rcupdate.h> +#include <linux/dmaengine.h> +#include <linux/hrtimer.h> + +/* Don't change this without changing skb_csum_unnecessary! */ +#define CHECKSUM_NONE 0 +#define CHECKSUM_UNNECESSARY 1 +#define CHECKSUM_COMPLETE 2 +#define CHECKSUM_PARTIAL 3 + +#define SKB_DATA_ALIGN(X) (((X) + (SMP_CACHE_BYTES - 1)) & \ + ~(SMP_CACHE_BYTES - 1)) +#define SKB_WITH_OVERHEAD(X) \ + ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info))) +#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)) + +/* A. Checksumming of received packets by device. + * + * NONE: device failed to checksum this packet. + * skb->csum is undefined. + * + * UNNECESSARY: device parsed packet and wouldbe verified checksum. + * skb->csum is undefined. + * It is bad option, but, unfortunately, many of vendors do this. + * Apparently with secret goal to sell you new device, when you + * will add new protocol to your host. F.e. IPv6. 8) + * + * COMPLETE: the most generic way. Device supplied checksum of _all_ + * the packet as seen by netif_rx in skb->csum. + * NOTE: Even if device supports only some protocols, but + * is able to produce some skb->csum, it MUST use COMPLETE, + * not UNNECESSARY. + * + * PARTIAL: identical to the case for output below. This may occur + * on a packet received directly from another Linux OS, e.g., + * a virtualised Linux kernel on the same host. The packet can + * be treated in the same way as UNNECESSARY except that on + * output (i.e., forwarding) the checksum must be filled in + * by the OS or the hardware. + * + * B. Checksumming on output. + * + * NONE: skb is checksummed by protocol or csum is not required. + * + * PARTIAL: device is required to csum packet as seen by hard_start_xmit + * from skb->csum_start to the end and to record the checksum + * at skb->csum_start + skb->csum_offset. + * + * Device must show its capabilities in dev->features, set + * at device setup time. + * NETIF_F_HW_CSUM - it is clever device, it is able to checksum + * everything. + * NETIF_F_NO_CSUM - loopback or reliable single hop media. + * NETIF_F_IP_CSUM - device is dumb. It is able to csum only + * TCP/UDP over IPv4. Sigh. Vendors like this + * way by an unknown reason. Though, see comment above + * about CHECKSUM_UNNECESSARY. 8) + * NETIF_F_IPV6_CSUM about as dumb as the last one but does IPv6 instead. + * + * Any questions? No questions, good. --ANK + */ + +struct net_device; +struct scatterlist; +struct pipe_inode_info; + +#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) +struct nf_conntrack { + atomic_t use; +}; +#endif + +#ifdef CONFIG_BRIDGE_NETFILTER +struct nf_bridge_info { + atomic_t use; + struct net_device *physindev; + struct net_device *physoutdev; + unsigned int mask; + unsigned long data[32 / sizeof(unsigned long)]; +}; +#endif + +struct sk_buff_head { + /* These two members must be first. */ + struct sk_buff *next; + struct sk_buff *prev; + + __u32 qlen; + spinlock_t lock; +}; + +struct sk_buff; + +/* To allow 64K frame to be packed as single skb without frag_list. Since + * GRO uses frags we allocate at least 16 regardless of page size. + */ +#if (65536/PAGE_SIZE + 2) < 16 +#define MAX_SKB_FRAGS 16UL +#else +#define MAX_SKB_FRAGS (65536/PAGE_SIZE + 2) +#endif + +typedef struct skb_frag_struct skb_frag_t; + +struct skb_frag_struct { + struct page *page; +#if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536) + __u32 page_offset; + __u32 size; +#else + __u16 page_offset; + __u16 size; +#endif +}; + +#define HAVE_HW_TIME_STAMP + +/** + * struct skb_shared_hwtstamps - hardware time stamps + * @hwtstamp: hardware time stamp transformed into duration + * since arbitrary point in time + * @syststamp: hwtstamp transformed to system time base + * + * Software time stamps generated by ktime_get_real() are stored in + * skb->tstamp. The relation between the different kinds of time + * stamps is as follows: + * + * syststamp and tstamp can be compared against each other in + * arbitrary combinations. The accuracy of a + * syststamp/tstamp/"syststamp from other device" comparison is + * limited by the accuracy of the transformation into system time + * base. This depends on the device driver and its underlying + * hardware. + * + * hwtstamps can only be compared against other hwtstamps from + * the same device. + * + * This structure is attached to packets as part of the + * &skb_shared_info. Use skb_hwtstamps() to get a pointer. + */ +struct skb_shared_hwtstamps { + ktime_t hwtstamp; + ktime_t syststamp; +}; + +/* Definitions for tx_flags in struct skb_shared_info */ +enum { + /* generate hardware time stamp */ + SKBTX_HW_TSTAMP = 1 << 0, + + /* generate software time stamp */ + SKBTX_SW_TSTAMP = 1 << 1, + + /* device driver is going to provide hardware time stamp */ + SKBTX_IN_PROGRESS = 1 << 2, + + /* ensure the originating sk reference is available on driver level */ + SKBTX_DRV_NEEDS_SK_REF = 1 << 3, +}; + +/* This data is invariant across clones and lives at + * the end of the header data, ie. at skb->end. + */ +struct skb_shared_info { + unsigned short nr_frags; + unsigned short gso_size; + /* Warning: this field is not always filled in (UFO)! */ + unsigned short gso_segs; + unsigned short gso_type; + __be32 ip6_frag_id; + __u8 tx_flags; + struct sk_buff *frag_list; + struct skb_shared_hwtstamps hwtstamps; + + /* + * Warning : all fields before dataref are cleared in __alloc_skb() + */ + atomic_t dataref; + + /* Intermediate layers must ensure that destructor_arg + * remains valid until skb destructor */ + void * destructor_arg; + /* must be last field, see pskb_expand_head() */ + skb_frag_t frags[MAX_SKB_FRAGS]; +}; + +/* We divide dataref into two halves. The higher 16 bits hold references + * to the payload part of skb->data. The lower 16 bits hold references to + * the entire skb->data. A clone of a headerless skb holds the length of + * the header in skb->hdr_len. + * + * All users must obey the rule that the skb->data reference count must be + * greater than or equal to the payload reference count. + * + * Holding a reference to the payload part means that the user does not + * care about modifications to the header part of skb->data. + */ +#define SKB_DATAREF_SHIFT 16 +#define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1) + + +enum { + SKB_FCLONE_UNAVAILABLE, + SKB_FCLONE_ORIG, + SKB_FCLONE_CLONE, +}; + +enum { + SKB_GSO_TCPV4 = 1 << 0, + SKB_GSO_UDP = 1 << 1, + + /* This indicates the skb is from an untrusted source. */ + SKB_GSO_DODGY = 1 << 2, + + /* This indicates the tcp segment has CWR set. */ + SKB_GSO_TCP_ECN = 1 << 3, + + SKB_GSO_TCPV6 = 1 << 4, + + SKB_GSO_FCOE = 1 << 5, +}; + +#if BITS_PER_LONG > 32 +#define NET_SKBUFF_DATA_USES_OFFSET 1 +#endif + +#ifdef NET_SKBUFF_DATA_USES_OFFSET +typedef unsigned int sk_buff_data_t; +#else +typedef unsigned char *sk_buff_data_t; +#endif + +#if defined(CONFIG_NF_DEFRAG_IPV4) || defined(CONFIG_NF_DEFRAG_IPV4_MODULE) || \ + defined(CONFIG_NF_DEFRAG_IPV6) || defined(CONFIG_NF_DEFRAG_IPV6_MODULE) +#define NET_SKBUFF_NF_DEFRAG_NEEDED 1 +#endif + +/** + * struct sk_buff - socket buffer + * @next: Next buffer in list + * @prev: Previous buffer in list + * @sk: Socket we are owned by + * @tstamp: Time we arrived + * @dev: Device we arrived on/are leaving by + * @transport_header: Transport layer header + * @network_header: Network layer header + * @mac_header: Link layer header + * @_skb_refdst: destination entry (with norefcount bit) + * @sp: the security path, used for xfrm + * @cb: Control buffer. Free for use by every layer. Put private vars here + * @len: Length of actual data + * @data_len: Data length + * @mac_len: Length of link layer header + * @hdr_len: writable header length of cloned skb + * @csum: Checksum (must include start/offset pair) + * @csum_start: Offset from skb->head where checksumming should start + * @csum_offset: Offset from csum_start where checksum should be stored + * @local_df: allow local fragmentation + * @cloned: Head may be cloned (check refcnt to be sure) + * @nohdr: Payload reference only, must not modify header + * @pkt_type: Packet class + * @fclone: skbuff clone status + * @ip_summed: Driver fed us an IP checksum + * @priority: Packet queueing priority + * @users: User count - see {datagram,tcp}.c + * @protocol: Packet protocol from driver + * @truesize: Buffer size + * @head: Head of buffer + * @data: Data head pointer + * @tail: Tail pointer + * @end: End pointer + * @destructor: Destruct function + * @mark: Generic packet mark + * @nfct: Associated connection, if any + * @ipvs_property: skbuff is owned by ipvs + * @peeked: this packet has been seen already, so stats have been + * done for it, don't do them again + * @nf_trace: netfilter packet trace flag + * @nfctinfo: Relationship of this skb to the connection + * @nfct_reasm: netfilter conntrack re-assembly pointer + * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c + * @skb_iif: ifindex of device we arrived on + * @rxhash: the packet hash computed on receive + * @queue_mapping: Queue mapping for multiqueue devices + * @tc_index: Traffic control index + * @tc_verd: traffic control verdict + * @ndisc_nodetype: router type (from link layer) + * @dma_cookie: a cookie to one of several possible DMA operations + * done by skb DMA functions + * @secmark: security marking + * @vlan_tci: vlan tag control information + */ + +struct sk_buff { + /* These two members must be first. */ + struct sk_buff *next; + struct sk_buff *prev; + + ktime_t tstamp; + + struct sock *sk; + struct net_device *dev; + + /* + * This is the control buffer. It is free to use for every + * layer. Please put your private variables there. If you + * want to keep them across layers you have to do a skb_clone() + * first. This is owned by whoever has the skb queued ATM. + */ + char cb[48] __aligned(8); + + unsigned long _skb_refdst; +#ifdef CONFIG_XFRM + struct sec_path *sp; +#endif + unsigned int len, + data_len; + __u16 mac_len, + hdr_len; + union { + __wsum csum; + struct { + __u16 csum_start; + __u16 csum_offset; + }; + }; + __u32 priority; + kmemcheck_bitfield_begin(flags1); + __u8 local_df:1, + cloned:1, + ip_summed:2, + nohdr:1, + nfctinfo:3; + __u8 pkt_type:3, + fclone:2, + ipvs_property:1, + peeked:1, + nf_trace:1; + kmemcheck_bitfield_end(flags1); + __be16 protocol; + + void (*destructor)(struct sk_buff *skb); +#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) + struct nf_conntrack *nfct; +#endif +#ifdef NET_SKBUFF_NF_DEFRAG_NEEDED + struct sk_buff *nfct_reasm; +#endif +#ifdef CONFIG_BRIDGE_NETFILTER + struct nf_bridge_info *nf_bridge; +#endif + + int skb_iif; +#ifdef CONFIG_NET_SCHED + __u16 tc_index; /* traffic control index */ +#ifdef CONFIG_NET_CLS_ACT + __u16 tc_verd; /* traffic control verdict */ +#endif +#endif + + __u32 rxhash; + + __u16 queue_mapping; + kmemcheck_bitfield_begin(flags2); +#ifdef CONFIG_IPV6_NDISC_NODETYPE + __u8 ndisc_nodetype:2; +#endif + __u8 ooo_okay:1; + kmemcheck_bitfield_end(flags2); + + /* 0/13 bit hole */ + +#ifdef CONFIG_NET_DMA + dma_cookie_t dma_cookie; +#endif +#ifdef CONFIG_NETWORK_SECMARK + __u32 secmark; +#endif + union { + __u32 mark; + __u32 dropcount; + }; + + __u16 vlan_tci; + + sk_buff_data_t transport_header; + sk_buff_data_t network_header; + sk_buff_data_t mac_header; + /* These elements must be at the end, see alloc_skb() for details. */ + sk_buff_data_t tail; + sk_buff_data_t end; + unsigned char *head, + *data; + unsigned int truesize; + atomic_t users; +}; + +#ifdef __KERNEL__ +/* + * Handling routines are only of interest to the kernel + */ +#include <linux/slab.h> + +#include <asm/system.h> + +/* + * skb might have a dst pointer attached, refcounted or not. + * _skb_refdst low order bit is set if refcount was _not_ taken + */ +#define SKB_DST_NOREF 1UL +#define SKB_DST_PTRMASK ~(SKB_DST_NOREF) + +/** + * skb_dst - returns skb dst_entry + * @skb: buffer + * + * Returns skb dst_entry, regardless of reference taken or not. + */ +static inline struct dst_entry *skb_dst(const struct sk_buff *skb) +{ + /* If refdst was not refcounted, check we still are in a + * rcu_read_lock section + */ + WARN_ON((skb->_skb_refdst & SKB_DST_NOREF) && + !rcu_read_lock_held() && + !rcu_read_lock_bh_held()); + return (struct dst_entry *)(skb->_skb_refdst & SKB_DST_PTRMASK); +} + +/** + * skb_dst_set - sets skb dst + * @skb: buffer + * @dst: dst entry + * + * Sets skb dst, assuming a reference was taken on dst and should + * be released by skb_dst_drop() + */ +static inline void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst) +{ + skb->_skb_refdst = (unsigned long)dst; +} + +extern void skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst); + +/** + * skb_dst_is_noref - Test if skb dst isn't refcounted + * @skb: buffer + */ +static inline bool skb_dst_is_noref(const struct sk_buff *skb) +{ + return (skb->_skb_refdst & SKB_DST_NOREF) && skb_dst(skb); +} + +static inline struct rtable *skb_rtable(const struct sk_buff *skb) +{ + return (struct rtable *)skb_dst(skb); +} + +extern void kfree_skb(struct sk_buff *skb); +extern void consume_skb(struct sk_buff *skb); +extern void __kfree_skb(struct sk_buff *skb); +extern struct sk_buff *__alloc_skb(unsigned int size, + gfp_t priority, int fclone, int node); +static inline struct sk_buff *alloc_skb(unsigned int size, + gfp_t priority) +{ + return __alloc_skb(size, priority, 0, NUMA_NO_NODE); +} + +static inline struct sk_buff *alloc_skb_fclone(unsigned int size, + gfp_t priority) +{ + return __alloc_skb(size, priority, 1, NUMA_NO_NODE); +} + +extern bool skb_recycle_check(struct sk_buff *skb, int skb_size); + +extern struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src); +extern struct sk_buff *skb_clone(struct sk_buff *skb, + gfp_t priority); +extern struct sk_buff *skb_copy(const struct sk_buff *skb, + gfp_t priority); +extern struct sk_buff *pskb_copy(struct sk_buff *skb, + gfp_t gfp_mask); +extern int pskb_expand_head(struct sk_buff *skb, + int nhead, int ntail, + gfp_t gfp_mask); +extern struct sk_buff *skb_realloc_headroom(struct sk_buff *skb, + unsigned int headroom); +extern struct sk_buff *skb_copy_expand(const struct sk_buff *skb, + int newheadroom, int newtailroom, + gfp_t priority); +extern int skb_to_sgvec(struct sk_buff *skb, + struct scatterlist *sg, int offset, + int len); +extern int skb_cow_data(struct sk_buff *skb, int tailbits, + struct sk_buff **trailer); +extern int skb_pad(struct sk_buff *skb, int pad); +#define dev_kfree_skb(a) consume_skb(a) + +extern int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb, + int getfrag(void *from, char *to, int offset, + int len,int odd, struct sk_buff *skb), + void *from, int length); + +struct skb_seq_state { + __u32 lower_offset; + __u32 upper_offset; + __u32 frag_idx; + __u32 stepped_offset; + struct sk_buff *root_skb; + struct sk_buff *cur_skb; + __u8 *frag_data; +}; + +extern void skb_prepare_seq_read(struct sk_buff *skb, + unsigned int from, unsigned int to, + struct skb_seq_state *st); +extern unsigned int skb_seq_read(unsigned int consumed, const u8 **data, + struct skb_seq_state *st); +extern void skb_abort_seq_read(struct skb_seq_state *st); + +extern unsigned int skb_find_text(struct sk_buff *skb, unsigned int from, + unsigned int to, struct ts_config *config, + struct ts_state *state); + +extern __u32 __skb_get_rxhash(struct sk_buff *skb); +static inline __u32 skb_get_rxhash(struct sk_buff *skb) +{ + if (!skb->rxhash) + skb->rxhash = __skb_get_rxhash(skb); + + return skb->rxhash; +} + +#ifdef NET_SKBUFF_DATA_USES_OFFSET +static inline unsigned char *skb_end_pointer(const struct sk_buff *skb) +{ + return skb->head + skb->end; +} +#else +static inline unsigned char *skb_end_pointer(const struct sk_buff *skb) +{ + return skb->end; +} +#endif + +/* Internal */ +#define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB))) + +static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb) +{ + return &skb_shinfo(skb)->hwtstamps; +} + +/** + * skb_queue_empty - check if a queue is empty + * @list: queue head + * + * Returns true if the queue is empty, false otherwise. + */ +static inline int skb_queue_empty(const struct sk_buff_head *list) +{ + return list->next == (struct sk_buff *)list; +} + +/** + * skb_queue_is_last - check if skb is the last entry in the queue + * @list: queue head + * @skb: buffer + * + * Returns true if @skb is the last buffer on the list. + */ +static inline bool skb_queue_is_last(const struct sk_buff_head *list, + const struct sk_buff *skb) +{ + return skb->next == (struct sk_buff *)list; +} + +/** + * skb_queue_is_first - check if skb is the first entry in the queue + * @list: queue head + * @skb: buffer + * + * Returns true if @skb is the first buffer on the list. + */ +static inline bool skb_queue_is_first(const struct sk_buff_head *list, + const struct sk_buff *skb) +{ + return skb->prev == (struct sk_buff *)list; +} + +/** + * skb_queue_next - return the next packet in the queue + * @list: queue head + * @skb: current buffer + * + * Return the next packet in @list after @skb. It is only valid to + * call this if skb_queue_is_last() evaluates to false. + */ +static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list, + const struct sk_buff *skb) +{ + /* This BUG_ON may seem severe, but if we just return then we + * are going to dereference garbage. + */ + BUG_ON(skb_queue_is_last(list, skb)); + return skb->next; +} + +/** + * skb_queue_prev - return the prev packet in the queue + * @list: queue head + * @skb: current buffer + * + * Return the prev packet in @list before @skb. It is only valid to + * call this if skb_queue_is_first() evaluates to false. + */ +static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list, + const struct sk_buff *skb) +{ + /* This BUG_ON may seem severe, but if we just return then we + * are going to dereference garbage. + */ + BUG_ON(skb_queue_is_first(list, skb)); + return skb->prev; +} + +/** + * skb_get - reference buffer + * @skb: buffer to reference + * + * Makes another reference to a socket buffer and returns a pointer + * to the buffer. + */ +static inline struct sk_buff *skb_get(struct sk_buff *skb) +{ + atomic_inc(&skb->users); + return skb; +} + +/* + * If users == 1, we are the only owner and are can avoid redundant + * atomic change. + */ + +/** + * skb_cloned - is the buffer a clone + * @skb: buffer to check + * + * Returns true if the buffer was generated with skb_clone() and is + * one of multiple shared copies of the buffer. Cloned buffers are + * shared data so must not be written to under normal circumstances. + */ +static inline int skb_cloned(const struct sk_buff *skb) +{ + return skb->cloned && + (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1; +} + +/** + * skb_header_cloned - is the header a clone + * @skb: buffer to check + * + * Returns true if modifying the header part of the buffer requires + * the data to be copied. + */ +static inline int skb_header_cloned(const struct sk_buff *skb) +{ + int dataref; + + if (!skb->cloned) + return 0; + + dataref = atomic_read(&skb_shinfo(skb)->dataref); + dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT); + return dataref != 1; +} + +/** + * skb_header_release - release reference to header + * @skb: buffer to operate on + * + * Drop a reference to the header part of the buffer. This is done + * by acquiring a payload reference. You must not read from the header + * part of skb->data after this. + */ +static inline void skb_header_release(struct sk_buff *skb) +{ + BUG_ON(skb->nohdr); + skb->nohdr = 1; + atomic_add(1 << SKB_DATAREF_SHIFT, &skb_shinfo(skb)->dataref); +} + +/** + * skb_shared - is the buffer shared + * @skb: buffer to check + * + * Returns true if more than one person has a reference to this + * buffer. + */ +static inline int skb_shared(const struct sk_buff *skb) +{ + return atomic_read(&skb->users) != 1; +} + +/** + * skb_share_check - check if buffer is shared and if so clone it + * @skb: buffer to check + * @pri: priority for memory allocation + * + * If the buffer is shared the buffer is cloned and the old copy + * drops a reference. A new clone with a single reference is returned. + * If the buffer is not shared the original buffer is returned. When + * being called from interrupt status or with spinlocks held pri must + * be GFP_ATOMIC. + * + * NULL is returned on a memory allocation failure. + */ +static inline struct sk_buff *skb_share_check(struct sk_buff *skb, + gfp_t pri) +{ + might_sleep_if(pri & __GFP_WAIT); + if (skb_shared(skb)) { + struct sk_buff *nskb = skb_clone(skb, pri); + kfree_skb(skb); + skb = nskb; + } + return skb; +} + +/* + * Copy shared buffers into a new sk_buff. We effectively do COW on + * packets to handle cases where we have a local reader and forward + * and a couple of other messy ones. The normal one is tcpdumping + * a packet thats being forwarded. + */ + +/** + * skb_unshare - make a copy of a shared buffer + * @skb: buffer to check + * @pri: priority for memory allocation + * + * If the socket buffer is a clone then this function creates a new + * copy of the data, drops a reference count on the old copy and returns + * the new copy with the reference count at 1. If the buffer is not a clone + * the original buffer is returned. When called with a spinlock held or + * from interrupt state @pri must be %GFP_ATOMIC + * + * %NULL is returned on a memory allocation failure. + */ +static inline struct sk_buff *skb_unshare(struct sk_buff *skb, + gfp_t pri) +{ + might_sleep_if(pri & __GFP_WAIT); + if (skb_cloned(skb)) { + struct sk_buff *nskb = skb_copy(skb, pri); + kfree_skb(skb); /* Free our shared copy */ + skb = nskb; + } + return skb; +} + +/** + * skb_peek - peek at the head of an &sk_buff_head + * @list_: list to peek at + * + * Peek an &sk_buff. Unlike most other operations you _MUST_ + * be careful with this one. A peek leaves the buffer on the + * list and someone else may run off with it. You must hold + * the appropriate locks or have a private queue to do this. + * + * Returns %NULL for an empty list or a pointer to the head element. + * The reference count is not incremented and the reference is therefore + * volatile. Use with caution. + */ +static inline struct sk_buff *skb_peek(struct sk_buff_head *list_) +{ + struct sk_buff *list = ((struct sk_buff *)list_)->next; + if (list == (struct sk_buff *)list_) + list = NULL; + return list; +} + +/** + * skb_peek_tail - peek at the tail of an &sk_buff_head + * @list_: list to peek at + * + * Peek an &sk_buff. Unlike most other operations you _MUST_ + * be careful with this one. A peek leaves the buffer on the + * list and someone else may run off with it. You must hold + * the appropriate locks or have a private queue to do this. + * + * Returns %NULL for an empty list or a pointer to the tail element. + * The reference count is not incremented and the reference is therefore + * volatile. Use with caution. + */ +static inline struct sk_buff *skb_peek_tail(struct sk_buff_head *list_) +{ + struct sk_buff *list = ((struct sk_buff *)list_)->prev; + if (list == (struct sk_buff *)list_) + list = NULL; + return list; +} + +/** + * skb_queue_len - get queue length + * @list_: list to measure + * + * Return the length of an &sk_buff queue. + */ +static inline __u32 skb_queue_len(const struct sk_buff_head *list_) +{ + return list_->qlen; +} + +/** + * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head + * @list: queue to initialize + * + * This initializes only the list and queue length aspects of + * an sk_buff_head object. This allows to initialize the list + * aspects of an sk_buff_head without reinitializing things like + * the spinlock. It can also be used for on-stack sk_buff_head + * objects where the spinlock is known to not be used. + */ +static inline void __skb_queue_head_init(struct sk_buff_head *list) +{ + list->prev = list->next = (struct sk_buff *)list; + list->qlen = 0; +} + +/* + * This function creates a split out lock class for each invocation; + * this is needed for now since a whole lot of users of the skb-queue + * infrastructure in drivers have different locking usage (in hardirq) + * than the networking core (in softirq only). In the long run either the + * network layer or drivers should need annotation to consolidate the + * main types of usage into 3 classes. + */ +static inline void skb_queue_head_init(struct sk_buff_head *list) +{ + spin_lock_init(&list->lock); + __skb_queue_head_init(list); +} + +static inline void skb_queue_head_init_class(struct sk_buff_head *list, + struct lock_class_key *class) +{ + skb_queue_head_init(list); + lockdep_set_class(&list->lock, class); +} + +/* + * Insert an sk_buff on a list. + * + * The "__skb_xxxx()" functions are the non-atomic ones that + * can only be called with interrupts disabled. + */ +extern void skb_insert(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head *list); +static inline void __skb_insert(struct sk_buff *newsk, + struct sk_buff *prev, struct sk_buff *next, + struct sk_buff_head *list) +{ + newsk->next = next; + newsk->prev = prev; + next->prev = prev->next = newsk; + list->qlen++; +} + +static inline void __skb_queue_splice(const struct sk_buff_head *list, + struct sk_buff *prev, + struct sk_buff *next) +{ + struct sk_buff *first = list->next; + struct sk_buff *last = list->prev; + + first->prev = prev; + prev->next = first; + + last->next = next; + next->prev = last; +} + +/** + * skb_queue_splice - join two skb lists, this is designed for stacks + * @list: the new list to add + * @head: the place to add it in the first list + */ +static inline void skb_queue_splice(const struct sk_buff_head *list, + struct sk_buff_head *head) +{ + if (!skb_queue_empty(list)) { + __skb_queue_splice(list, (struct sk_buff *) head, head->next); + head->qlen += list->qlen; + } +} + +/** + * skb_queue_splice - join two skb lists and reinitialise the emptied list + * @list: the new list to add + * @head: the place to add it in the first list + * + * The list at @list is reinitialised + */ +static inline void skb_queue_splice_init(struct sk_buff_head *list, + struct sk_buff_head *head) +{ + if (!skb_queue_empty(list)) { + __skb_queue_splice(list, (struct sk_buff *) head, head->next); + head->qlen += list->qlen; + __skb_queue_head_init(list); + } +} + +/** + * skb_queue_splice_tail - join two skb lists, each list being a queue + * @list: the new list to add + * @head: the place to add it in the first list + */ +static inline void skb_queue_splice_tail(const struct sk_buff_head *list, + struct sk_buff_head *head) +{ + if (!skb_queue_empty(list)) { + __skb_queue_splice(list, head->prev, (struct sk_buff *) head); + head->qlen += list->qlen; + } +} + +/** + * skb_queue_splice_tail - join two skb lists and reinitialise the emptied list + * @list: the new list to add + * @head: the place to add it in the first list + * + * Each of the lists is a queue. + * The list at @list is reinitialised + */ +static inline void skb_queue_splice_tail_init(struct sk_buff_head *list, + struct sk_buff_head *head) +{ + if (!skb_queue_empty(list)) { + __skb_queue_splice(list, head->prev, (struct sk_buff *) head); + head->qlen += list->qlen; + __skb_queue_head_init(list); + } +} + +/** + * __skb_queue_after - queue a buffer at the list head + * @list: list to use + * @prev: place after this buffer + * @newsk: buffer to queue + * + * Queue a buffer int the middle of a list. This function takes no locks + * and you must therefore hold required locks before calling it. + * + * A buffer cannot be placed on two lists at the same time. + */ +static inline void __skb_queue_after(struct sk_buff_head *list, + struct sk_buff *prev, + struct sk_buff *newsk) +{ + __skb_insert(newsk, prev, prev->next, list); +} + +extern void skb_append(struct sk_buff *old, struct sk_buff *newsk, + struct sk_buff_head *list); + +static inline void __skb_queue_before(struct sk_buff_head *list, + struct sk_buff *next, + struct sk_buff *newsk) +{ + __skb_insert(newsk, next->prev, next, list); +} + +/** + * __skb_queue_head - queue a buffer at the list head + * @list: list to use + * @newsk: buffer to queue + * + * Queue a buffer at the start of a list. This function takes no locks + * and you must therefore hold required locks before calling it. + * + * A buffer cannot be placed on two lists at the same time. + */ +extern void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk); +static inline void __skb_queue_head(struct sk_buff_head *list, + struct sk_buff *newsk) +{ + __skb_queue_after(list, (struct sk_buff *)list, newsk); +} + +/** + * __skb_queue_tail - queue a buffer at the list tail + * @list: list to use + * @newsk: buffer to queue + * + * Queue a buffer at the end of a list. This function takes no locks + * and you must therefore hold required locks before calling it. + * + * A buffer cannot be placed on two lists at the same time. + */ +extern void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk); +static inline void __skb_queue_tail(struct sk_buff_head *list, + struct sk_buff *newsk) +{ + __skb_queue_before(list, (struct sk_buff *)list, newsk); +} + +/* + * remove sk_buff from list. _Must_ be called atomically, and with + * the list known.. + */ +extern void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list); +static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list) +{ + struct sk_buff *next, *prev; + + list->qlen--; + next = skb->next; + prev = skb->prev; + skb->next = skb->prev = NULL; + next->prev = prev; + prev->next = next; +} + +/** + * __skb_dequeue - remove from the head of the queue + * @list: list to dequeue from + * + * Remove the head of the list. This function does not take any locks + * so must be used with appropriate locks held only. The head item is + * returned or %NULL if the list is empty. + */ +extern struct sk_buff *skb_dequeue(struct sk_buff_head *list); +static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list) +{ + struct sk_buff *skb = skb_peek(list); + if (skb) + __skb_unlink(skb, list); + return skb; +} + +/** + * __skb_dequeue_tail - remove from the tail of the queue + * @list: list to dequeue from + * + * Remove the tail of the list. This function does not take any locks + * so must be used with appropriate locks held only. The tail item is + * returned or %NULL if the list is empty. + */ +extern struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list); +static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list) +{ + struct sk_buff *skb = skb_peek_tail(list); + if (skb) + __skb_unlink(skb, list); + return skb; +} + + +static inline int skb_is_nonlinear(const struct sk_buff *skb) +{ + return skb->data_len; +} + +static inline unsigned int skb_headlen(const struct sk_buff *skb) +{ + return skb->len - skb->data_len; +} + +static inline int skb_pagelen(const struct sk_buff *skb) +{ + int i, len = 0; + + for (i = (int)skb_shinfo(skb)->nr_frags - 1; i >= 0; i--) + len += skb_shinfo(skb)->frags[i].size; + return len + skb_headlen(skb); +} + +static inline void skb_fill_page_desc(struct sk_buff *skb, int i, + struct page *page, int off, int size) +{ + skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; + + frag->page = page; + frag->page_offset = off; + frag->size = size; + skb_shinfo(skb)->nr_frags = i + 1; +} + +extern void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, + int off, int size); + +#define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags) +#define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frag_list(skb)) +#define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb)) + +#ifdef NET_SKBUFF_DATA_USES_OFFSET +static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb) +{ + return skb->head + skb->tail; +} + +static inline void skb_reset_tail_pointer(struct sk_buff *skb) +{ + skb->tail = skb->data - skb->head; +} + +static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset) +{ + skb_reset_tail_pointer(skb); + skb->tail += offset; +} +#else /* NET_SKBUFF_DATA_USES_OFFSET */ +static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb) +{ + return skb->tail; +} + +static inline void skb_reset_tail_pointer(struct sk_buff *skb) +{ + skb->tail = skb->data; +} + +static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset) +{ + skb->tail = skb->data + offset; +} + +#endif /* NET_SKBUFF_DATA_USES_OFFSET */ + +/* + * Add data to an sk_buff + */ +extern unsigned char *skb_put(struct sk_buff *skb, unsigned int len); +static inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len) +{ + unsigned char *tmp = skb_tail_pointer(skb); + SKB_LINEAR_ASSERT(skb); + skb->tail += len; + skb->len += len; + return tmp; +} + +extern unsigned char *skb_push(struct sk_buff *skb, unsigned int len); +static inline unsigned char *__skb_push(struct sk_buff *skb, unsigned int len) +{ + skb->data -= len; + skb->len += len; + return skb->data; +} + +extern unsigned char *skb_pull(struct sk_buff *skb, unsigned int len); +static inline unsigned char *__skb_pull(struct sk_buff *skb, unsigned int len) +{ + skb->len -= len; + BUG_ON(skb->len < skb->data_len); + return skb->data += len; +} + +static inline unsigned char *skb_pull_inline(struct sk_buff *skb, unsigned int len) +{ + return unlikely(len > skb->len) ? NULL : __skb_pull(skb, len); +} + +extern unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta); + +static inline unsigned char *__pskb_pull(struct sk_buff *skb, unsigned int len) +{ + if (len > skb_headlen(skb) && + !__pskb_pull_tail(skb, len - skb_headlen(skb))) + return NULL; + skb->len -= len; + return skb->data += len; +} + +static inline unsigned char *pskb_pull(struct sk_buff *skb, unsigned int len) +{ + return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len); +} + +static inline int pskb_may_pull(struct sk_buff *skb, unsigned int len) +{ + if (likely(len <= skb_headlen(skb))) + return 1; + if (unlikely(len > skb->len)) + return 0; + return __pskb_pull_tail(skb, len - skb_headlen(skb)) != NULL; +} + +/** + * skb_headroom - bytes at buffer head + * @skb: buffer to check + * + * Return the number of bytes of free space at the head of an &sk_buff. + */ +static inline unsigned int skb_headroom(const struct sk_buff *skb) +{ + return skb->data - skb->head; +} + +/** + * skb_tailroom - bytes at buffer end + * @skb: buffer to check + * + * Return the number of bytes of free space at the tail of an sk_buff + */ +static inline int skb_tailroom(const struct sk_buff *skb) +{ + return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail; +} + +/** + * skb_reserve - adjust headroom + * @skb: buffer to alter + * @len: bytes to move + * + * Increase the headroom of an empty &sk_buff by reducing the tail + * room. This is only allowed for an empty buffer. + */ +static inline void skb_reserve(struct sk_buff *skb, int len) +{ + skb->data += len; + skb->tail += len; +} + +static inline void skb_reset_mac_len(struct sk_buff *skb) +{ + skb->mac_len = skb->network_header - skb->mac_header; +} + +#ifdef NET_SKBUFF_DATA_USES_OFFSET +static inline unsigned char *skb_transport_header(const struct sk_buff *skb) +{ + return skb->head + skb->transport_header; +} + +static inline void skb_reset_transport_header(struct sk_buff *skb) +{ + skb->transport_header = skb->data - skb->head; +} + +static inline void skb_set_transport_header(struct sk_buff *skb, + const int offset) +{ + skb_reset_transport_header(skb); + skb->transport_header += offset; +} + +static inline unsigned char *skb_network_header(const struct sk_buff *skb) +{ + return skb->head + skb->network_header; +} + +static inline void skb_reset_network_header(struct sk_buff *skb) +{ + skb->network_header = skb->data - skb->head; +} + +static inline void skb_set_network_header(struct sk_buff *skb, const int offset) +{ + skb_reset_network_header(skb); + skb->network_header += offset; +} + +static inline unsigned char *skb_mac_header(const struct sk_buff *skb) +{ + return skb->head + skb->mac_header; +} + +static inline int skb_mac_header_was_set(const struct sk_buff *skb) +{ + return skb->mac_header != ~0U; +} + +static inline void skb_reset_mac_header(struct sk_buff *skb) +{ + skb->mac_header = skb->data - skb->head; +} + +static inline void skb_set_mac_header(struct sk_buff *skb, const int offset) +{ + skb_reset_mac_header(skb); + skb->mac_header += offset; +} + +#else /* NET_SKBUFF_DATA_USES_OFFSET */ + +static inline unsigned char *skb_transport_header(const struct sk_buff *skb) +{ + return skb->transport_header; +} + +static inline void skb_reset_transport_header(struct sk_buff *skb) +{ + skb->transport_header = skb->data; +} + +static inline void skb_set_transport_header(struct sk_buff *skb, + const int offset) +{ + skb->transport_header = skb->data + offset; +} + +static inline unsigned char *skb_network_header(const struct sk_buff *skb) +{ + return skb->network_header; +} + +static inline void skb_reset_network_header(struct sk_buff *skb) +{ + skb->network_header = skb->data; +} + +static inline void skb_set_network_header(struct sk_buff *skb, const int offset) +{ + skb->network_header = skb->data + offset; +} + +static inline unsigned char *skb_mac_header(const struct sk_buff *skb) +{ + return skb->mac_header; +} + +static inline int skb_mac_header_was_set(const struct sk_buff *skb) +{ + return skb->mac_header != NULL; +} + +static inline void skb_reset_mac_header(struct sk_buff *skb) +{ + skb->mac_header = skb->data; +} + +static inline void skb_set_mac_header(struct sk_buff *skb, const int offset) +{ + skb->mac_header = skb->data + offset; +} +#endif /* NET_SKBUFF_DATA_USES_OFFSET */ + +static inline void skb_mac_header_rebuild(struct sk_buff *skb) +{ + if (skb_mac_header_was_set(skb)) { + const unsigned char *old_mac = skb_mac_header(skb); + + skb_set_mac_header(skb, -skb->mac_len); + memmove(skb_mac_header(skb), old_mac, skb->mac_len); + } +} + +static inline int skb_checksum_start_offset(const struct sk_buff *skb) +{ + return skb->csum_start - skb_headroom(skb); +} + +static inline int skb_transport_offset(const struct sk_buff *skb) +{ + return skb_transport_header(skb) - skb->data; +} + +static inline u32 skb_network_header_len(const struct sk_buff *skb) +{ + return skb->transport_header - skb->network_header; +} + +static inline int skb_network_offset(const struct sk_buff *skb) +{ + return skb_network_header(skb) - skb->data; +} + +static inline int pskb_network_may_pull(struct sk_buff *skb, unsigned int len) +{ + return pskb_may_pull(skb, skb_network_offset(skb) + len); +} + +/* + * CPUs often take a performance hit when accessing unaligned memory + * locations. The actual performance hit varies, it can be small if the + * hardware handles it or large if we have to take an exception and fix it + * in software. + * + * Since an ethernet header is 14 bytes network drivers often end up with + * the IP header at an unaligned offset. The IP header can be aligned by + * shifting the start of the packet by 2 bytes. Drivers should do this + * with: + * + * skb_reserve(skb, NET_IP_ALIGN); + * + * The downside to this alignment of the IP header is that the DMA is now + * unaligned. On some architectures the cost of an unaligned DMA is high + * and this cost outweighs the gains made by aligning the IP header. + * + * Since this trade off varies between architectures, we allow NET_IP_ALIGN + * to be overridden. + */ +#ifndef NET_IP_ALIGN +#define NET_IP_ALIGN 2 +#endif + +/* + * The networking layer reserves some headroom in skb data (via + * dev_alloc_skb). This is used to avoid having to reallocate skb data when + * the header has to grow. In the default case, if the header has to grow + * 32 bytes or less we avoid the reallocation. + * + * Unfortunately this headroom changes the DMA alignment of the resulting + * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive + * on some architectures. An architecture can override this value, + * perhaps setting it to a cacheline in size (since that will maintain + * cacheline alignment of the DMA). It must be a power of 2. + * + * Various parts of the networking layer expect at least 32 bytes of + * headroom, you should not reduce this. + * + * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS) + * to reduce average number of cache lines per packet. + * get_rps_cpus() for example only access one 64 bytes aligned block : + * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8) + */ +#ifndef NET_SKB_PAD +#define NET_SKB_PAD max(32, L1_CACHE_BYTES) +#endif + +extern int ___pskb_trim(struct sk_buff *skb, unsigned int len); + +static inline void __skb_trim(struct sk_buff *skb, unsigned int len) +{ + if (unlikely(skb_is_nonlinear(skb))) { + WARN_ON(1); + return; + } + skb->len = len; + skb_set_tail_pointer(skb, len); +} + +extern void skb_trim(struct sk_buff *skb, unsigned int len); + +static inline int __pskb_trim(struct sk_buff *skb, unsigned int len) +{ + if (skb->data_len) + return ___pskb_trim(skb, len); + __skb_trim(skb, len); + return 0; +} + +static inline int pskb_trim(struct sk_buff *skb, unsigned int len) +{ + return (len < skb->len) ? __pskb_trim(skb, len) : 0; +} + +/** + * pskb_trim_unique - remove end from a paged unique (not cloned) buffer + * @skb: buffer to alter + * @len: new length + * + * This is identical to pskb_trim except that the caller knows that + * the skb is not cloned so we should never get an error due to out- + * of-memory. + */ +static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len) +{ + int err = pskb_trim(skb, len); + BUG_ON(err); +} + +/** + * skb_orphan - orphan a buffer + * @skb: buffer to orphan + * + * If a buffer currently has an owner then we call the owner's + * destructor function and make the @skb unowned. The buffer continues + * to exist but is no longer charged to its former owner. + */ +static inline void skb_orphan(struct sk_buff *skb) +{ + if (skb->destructor) + skb->destructor(skb); + skb->destructor = NULL; + skb->sk = NULL; +} + +/** + * __skb_queue_purge - empty a list + * @list: list to empty + * + * Delete all buffers on an &sk_buff list. Each buffer is removed from + * the list and one reference dropped. This function does not take the + * list lock and the caller must hold the relevant locks to use it. + */ +extern void skb_queue_purge(struct sk_buff_head *list); +static inline void __skb_queue_purge(struct sk_buff_head *list) +{ + struct sk_buff *skb; + while ((skb = __skb_dequeue(list)) != NULL) + kfree_skb(skb); +} + +/** + * __dev_alloc_skb - allocate an skbuff for receiving + * @length: length to allocate + * @gfp_mask: get_free_pages mask, passed to alloc_skb + * + * Allocate a new &sk_buff and assign it a usage count of one. The + * buffer has unspecified headroom built in. Users should allocate + * the headroom they think they need without accounting for the + * built in space. The built in space is used for optimisations. + * + * %NULL is returned if there is no free memory. + */ +static inline struct sk_buff *__dev_alloc_skb(unsigned int length, + gfp_t gfp_mask) +{ + struct sk_buff *skb = alloc_skb(length + NET_SKB_PAD, gfp_mask); + if (likely(skb)) + skb_reserve(skb, NET_SKB_PAD); + return skb; +} + +extern struct sk_buff *dev_alloc_skb(unsigned int length); + +extern struct sk_buff *__netdev_alloc_skb(struct net_device *dev, + unsigned int length, gfp_t gfp_mask); + +/** + * netdev_alloc_skb - allocate an skbuff for rx on a specific device + * @dev: network device to receive on + * @length: length to allocate + * + * Allocate a new &sk_buff and assign it a usage count of one. The + * buffer has unspecified headroom built in. Users should allocate + * the headroom they think they need without accounting for the + * built in space. The built in space is used for optimisations. + * + * %NULL is returned if there is no free memory. Although this function + * allocates memory it can be called from an interrupt. + */ +static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev, + unsigned int length) +{ + return __netdev_alloc_skb(dev, length, GFP_ATOMIC); +} + +static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev, + unsigned int length) +{ + struct sk_buff *skb = netdev_alloc_skb(dev, length + NET_IP_ALIGN); + + if (NET_IP_ALIGN && skb) + skb_reserve(skb, NET_IP_ALIGN); + return skb; +} + +/** + * __netdev_alloc_page - allocate a page for ps-rx on a specific device + * @dev: network device to receive on + * @gfp_mask: alloc_pages_node mask + * + * Allocate a new page. dev currently unused. + * + * %NULL is returned if there is no free memory. + */ +static inline struct page *__netdev_alloc_page(struct net_device *dev, gfp_t gfp_mask) +{ + return alloc_pages_node(NUMA_NO_NODE, gfp_mask, 0); +} + +/** + * netdev_alloc_page - allocate a page for ps-rx on a specific device + * @dev: network device to receive on + * + * Allocate a new page. dev currently unused. + * + * %NULL is returned if there is no free memory. + */ +static inline struct page *netdev_alloc_page(struct net_device *dev) +{ + return __netdev_alloc_page(dev, GFP_ATOMIC); +} + +static inline void netdev_free_page(struct net_device *dev, struct page *page) +{ + __free_page(page); +} + +/** + * skb_clone_writable - is the header of a clone writable + * @skb: buffer to check + * @len: length up to which to write + * + * Returns true if modifying the header part of the cloned buffer + * does not requires the data to be copied. + */ +static inline int skb_clone_writable(struct sk_buff *skb, unsigned int len) +{ + return !skb_header_cloned(skb) && + skb_headroom(skb) + len <= skb->hdr_len; +} + +static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom, + int cloned) +{ + int delta = 0; + + if (headroom > skb_headroom(skb)) + delta = headroom - skb_headroom(skb); + + if (delta || cloned) + return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0, + GFP_ATOMIC); + return 0; +} + +/** + * skb_cow - copy header of skb when it is required + * @skb: buffer to cow + * @headroom: needed headroom + * + * If the skb passed lacks sufficient headroom or its data part + * is shared, data is reallocated. If reallocation fails, an error + * is returned and original skb is not changed. + * + * The result is skb with writable area skb->head...skb->tail + * and at least @headroom of space at head. + */ +static inline int skb_cow(struct sk_buff *skb, unsigned int headroom) +{ + return __skb_cow(skb, headroom, skb_cloned(skb)); +} + +/** + * skb_cow_head - skb_cow but only making the head writable + * @skb: buffer to cow + * @headroom: needed headroom + * + * This function is identical to skb_cow except that we replace the + * skb_cloned check by skb_header_cloned. It should be used when + * you only need to push on some header and do not need to modify + * the data. + */ +static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom) +{ + return __skb_cow(skb, headroom, skb_header_cloned(skb)); +} + +/** + * skb_padto - pad an skbuff up to a minimal size + * @skb: buffer to pad + * @len: minimal length + * + * Pads up a buffer to ensure the trailing bytes exist and are + * blanked. If the buffer already contains sufficient data it + * is untouched. Otherwise it is extended. Returns zero on + * success. The skb is freed on error. + */ + +static inline int skb_padto(struct sk_buff *skb, unsigned int len) +{ + unsigned int size = skb->len; + if (likely(size >= len)) + return 0; + return skb_pad(skb, len - size); +} + +static inline int skb_add_data(struct sk_buff *skb, + char __user *from, int copy) +{ + const int off = skb->len; + + if (skb->ip_summed == CHECKSUM_NONE) { + int err = 0; + __wsum csum = csum_and_copy_from_user(from, skb_put(skb, copy), + copy, 0, &err); + if (!err) { + skb->csum = csum_block_add(skb->csum, csum, off); + return 0; + } + } else if (!copy_from_user(skb_put(skb, copy), from, copy)) + return 0; + + __skb_trim(skb, off); + return -EFAULT; +} + +static inline int skb_can_coalesce(struct sk_buff *skb, int i, + struct page *page, int off) +{ + if (i) { + struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i - 1]; + + return page == frag->page && + off == frag->page_offset + frag->size; + } + return 0; +} + +static inline int __skb_linearize(struct sk_buff *skb) +{ + return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM; +} + +/** + * skb_linearize - convert paged skb to linear one + * @skb: buffer to linarize + * + * If there is no free memory -ENOMEM is returned, otherwise zero + * is returned and the old skb data released. + */ +static inline int skb_linearize(struct sk_buff *skb) +{ + return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0; +} + +/** + * skb_linearize_cow - make sure skb is linear and writable + * @skb: buffer to process + * + * If there is no free memory -ENOMEM is returned, otherwise zero + * is returned and the old skb data released. + */ +static inline int skb_linearize_cow(struct sk_buff *skb) +{ + return skb_is_nonlinear(skb) || skb_cloned(skb) ? + __skb_linearize(skb) : 0; +} + +/** + * skb_postpull_rcsum - update checksum for received skb after pull + * @skb: buffer to update + * @start: start of data before pull + * @len: length of data pulled + * + * After doing a pull on a received packet, you need to call this to + * update the CHECKSUM_COMPLETE checksum, or set ip_summed to + * CHECKSUM_NONE so that it can be recomputed from scratch. + */ + +static inline void skb_postpull_rcsum(struct sk_buff *skb, + const void *start, unsigned int len) +{ + if (skb->ip_summed == CHECKSUM_COMPLETE) + skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0)); +} + +unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len); + +/** + * pskb_trim_rcsum - trim received skb and update checksum + * @skb: buffer to trim + * @len: new length + * + * This is exactly the same as pskb_trim except that it ensures the + * checksum of received packets are still valid after the operation. + */ + +static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len) +{ + if (likely(len >= skb->len)) + return 0; + if (skb->ip_summed == CHECKSUM_COMPLETE) + skb->ip_summed = CHECKSUM_NONE; + return __pskb_trim(skb, len); +} + +#define skb_queue_walk(queue, skb) \ + for (skb = (queue)->next; \ + skb != (struct sk_buff *)(queue); \ + skb = skb->next) + +#define skb_queue_walk_safe(queue, skb, tmp) \ + for (skb = (queue)->next, tmp = skb->next; \ + skb != (struct sk_buff *)(queue); \ + skb = tmp, tmp = skb->next) + +#define skb_queue_walk_from(queue, skb) \ + for (; skb != (struct sk_buff *)(queue); \ + skb = skb->next) + +#define skb_queue_walk_from_safe(queue, skb, tmp) \ + for (tmp = skb->next; \ + skb != (struct sk_buff *)(queue); \ + skb = tmp, tmp = skb->next) + +#define skb_queue_reverse_walk(queue, skb) \ + for (skb = (queue)->prev; \ + skb != (struct sk_buff *)(queue); \ + skb = skb->prev) + +#define skb_queue_reverse_walk_safe(queue, skb, tmp) \ + for (skb = (queue)->prev, tmp = skb->prev; \ + skb != (struct sk_buff *)(queue); \ + skb = tmp, tmp = skb->prev) + +#define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \ + for (tmp = skb->prev; \ + skb != (struct sk_buff *)(queue); \ + skb = tmp, tmp = skb->prev) + +static inline bool skb_has_frag_list(const struct sk_buff *skb) +{ + return skb_shinfo(skb)->frag_list != NULL; +} + +static inline void skb_frag_list_init(struct sk_buff *skb) +{ + skb_shinfo(skb)->frag_list = NULL; +} + +static inline void skb_frag_add_head(struct sk_buff *skb, struct sk_buff *frag) +{ + frag->next = skb_shinfo(skb)->frag_list; + skb_shinfo(skb)->frag_list = frag; +} + +#define skb_walk_frags(skb, iter) \ + for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next) + +extern struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags, + int *peeked, int *err); +extern struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags, + int noblock, int *err); +extern unsigned int datagram_poll(struct file *file, struct socket *sock, + struct poll_table_struct *wait); +extern int skb_copy_datagram_iovec(const struct sk_buff *from, + int offset, struct iovec *to, + int size); +extern int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb, + int hlen, + struct iovec *iov); +extern int skb_copy_datagram_from_iovec(struct sk_buff *skb, + int offset, + const struct iovec *from, + int from_offset, + int len); +extern int skb_copy_datagram_const_iovec(const struct sk_buff *from, + int offset, + const struct iovec *to, + int to_offset, + int size); +extern void skb_free_datagram(struct sock *sk, struct sk_buff *skb); +extern void skb_free_datagram_locked(struct sock *sk, + struct sk_buff *skb); +extern int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, + unsigned int flags); +extern __wsum skb_checksum(const struct sk_buff *skb, int offset, + int len, __wsum csum); +extern int skb_copy_bits(const struct sk_buff *skb, int offset, + void *to, int len); +extern int skb_store_bits(struct sk_buff *skb, int offset, + const void *from, int len); +extern __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, + int offset, u8 *to, int len, + __wsum csum); +extern int skb_splice_bits(struct sk_buff *skb, + unsigned int offset, + struct pipe_inode_info *pipe, + unsigned int len, + unsigned int flags); +extern void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to); +extern void skb_split(struct sk_buff *skb, + struct sk_buff *skb1, const u32 len); +extern int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, + int shiftlen); + +extern struct sk_buff *skb_segment(struct sk_buff *skb, u32 features); + +static inline void *skb_header_pointer(const struct sk_buff *skb, int offset, + int len, void *buffer) +{ + int hlen = skb_headlen(skb); + + if (hlen - offset >= len) + return skb->data + offset; + + if (skb_copy_bits(skb, offset, buffer, len) < 0) + return NULL; + + return buffer; +} + +static inline void skb_copy_from_linear_data(const struct sk_buff *skb, + void *to, + const unsigned int len) +{ + memcpy(to, skb->data, len); +} + +static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb, + const int offset, void *to, + const unsigned int len) +{ + memcpy(to, skb->data + offset, len); +} + +static inline void skb_copy_to_linear_data(struct sk_buff *skb, + const void *from, + const unsigned int len) +{ + memcpy(skb->data, from, len); +} + +static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb, + const int offset, + const void *from, + const unsigned int len) +{ + memcpy(skb->data + offset, from, len); +} + +extern void skb_init(void); + +static inline ktime_t skb_get_ktime(const struct sk_buff *skb) +{ + return skb->tstamp; +} + +/** + * skb_get_timestamp - get timestamp from a skb + * @skb: skb to get stamp from + * @stamp: pointer to struct timeval to store stamp in + * + * Timestamps are stored in the skb as offsets to a base timestamp. + * This function converts the offset back to a struct timeval and stores + * it in stamp. + */ +static inline void skb_get_timestamp(const struct sk_buff *skb, + struct timeval *stamp) +{ + *stamp = ktime_to_timeval(skb->tstamp); +} + +static inline void skb_get_timestampns(const struct sk_buff *skb, + struct timespec *stamp) +{ + *stamp = ktime_to_timespec(skb->tstamp); +} + +static inline void __net_timestamp(struct sk_buff *skb) +{ + skb->tstamp = ktime_get_real(); +} + +static inline ktime_t net_timedelta(ktime_t t) +{ + return ktime_sub(ktime_get_real(), t); +} + +static inline ktime_t net_invalid_timestamp(void) +{ + return ktime_set(0, 0); +} + +extern void skb_timestamping_init(void); + +#ifdef CONFIG_NETWORK_PHY_TIMESTAMPING + +extern void skb_clone_tx_timestamp(struct sk_buff *skb); +extern bool skb_defer_rx_timestamp(struct sk_buff *skb); + +#else /* CONFIG_NETWORK_PHY_TIMESTAMPING */ + +static inline void skb_clone_tx_timestamp(struct sk_buff *skb) +{ +} + +static inline bool skb_defer_rx_timestamp(struct sk_buff *skb) +{ + return false; +} + +#endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */ + +/** + * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps + * + * PHY drivers may accept clones of transmitted packets for + * timestamping via their phy_driver.txtstamp method. These drivers + * must call this function to return the skb back to the stack, with + * or without a timestamp. + * + * @skb: clone of the the original outgoing packet + * @hwtstamps: hardware time stamps, may be NULL if not available + * + */ +void skb_complete_tx_timestamp(struct sk_buff *skb, + struct skb_shared_hwtstamps *hwtstamps); + +/** + * skb_tstamp_tx - queue clone of skb with send time stamps + * @orig_skb: the original outgoing packet + * @hwtstamps: hardware time stamps, may be NULL if not available + * + * If the skb has a socket associated, then this function clones the + * skb (thus sharing the actual data and optional structures), stores + * the optional hardware time stamping information (if non NULL) or + * generates a software time stamp (otherwise), then queues the clone + * to the error queue of the socket. Errors are silently ignored. + */ +extern void skb_tstamp_tx(struct sk_buff *orig_skb, + struct skb_shared_hwtstamps *hwtstamps); + +static inline void sw_tx_timestamp(struct sk_buff *skb) +{ + if (skb_shinfo(skb)->tx_flags & SKBTX_SW_TSTAMP && + !(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS)) + skb_tstamp_tx(skb, NULL); +} + +/** + * skb_tx_timestamp() - Driver hook for transmit timestamping + * + * Ethernet MAC Drivers should call this function in their hard_xmit() + * function as soon as possible after giving the sk_buff to the MAC + * hardware, but before freeing the sk_buff. + * + * @skb: A socket buffer. + */ +static inline void skb_tx_timestamp(struct sk_buff *skb) +{ + skb_clone_tx_timestamp(skb); + sw_tx_timestamp(skb); +} + +extern __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len); +extern __sum16 __skb_checksum_complete(struct sk_buff *skb); + +static inline int skb_csum_unnecessary(const struct sk_buff *skb) +{ + return skb->ip_summed & CHECKSUM_UNNECESSARY; +} + +/** + * skb_checksum_complete - Calculate checksum of an entire packet + * @skb: packet to process + * + * This function calculates the checksum over the entire packet plus + * the value of skb->csum. The latter can be used to supply the + * checksum of a pseudo header as used by TCP/UDP. It returns the + * checksum. + * + * For protocols that contain complete checksums such as ICMP/TCP/UDP, + * this function can be used to verify that checksum on received + * packets. In that case the function should return zero if the + * checksum is correct. In particular, this function will return zero + * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the + * hardware has already verified the correctness of the checksum. + */ +static inline __sum16 skb_checksum_complete(struct sk_buff *skb) +{ + return skb_csum_unnecessary(skb) ? + 0 : __skb_checksum_complete(skb); +} + +#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) +extern void nf_conntrack_destroy(struct nf_conntrack *nfct); +static inline void nf_conntrack_put(struct nf_conntrack *nfct) +{ + if (nfct && atomic_dec_and_test(&nfct->use)) + nf_conntrack_destroy(nfct); +} +static inline void nf_conntrack_get(struct nf_conntrack *nfct) +{ + if (nfct) + atomic_inc(&nfct->use); +} +#endif +#ifdef NET_SKBUFF_NF_DEFRAG_NEEDED +static inline void nf_conntrack_get_reasm(struct sk_buff *skb) +{ + if (skb) + atomic_inc(&skb->users); +} +static inline void nf_conntrack_put_reasm(struct sk_buff *skb) +{ + if (skb) + kfree_skb(skb); +} +#endif +#ifdef CONFIG_BRIDGE_NETFILTER +static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge) +{ + if (nf_bridge && atomic_dec_and_test(&nf_bridge->use)) + kfree(nf_bridge); +} +static inline void nf_bridge_get(struct nf_bridge_info *nf_bridge) +{ + if (nf_bridge) + atomic_inc(&nf_bridge->use); +} +#endif /* CONFIG_BRIDGE_NETFILTER */ +static inline void nf_reset(struct sk_buff *skb) +{ +#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) + nf_conntrack_put(skb->nfct); + skb->nfct = NULL; +#endif +#ifdef NET_SKBUFF_NF_DEFRAG_NEEDED + nf_conntrack_put_reasm(skb->nfct_reasm); + skb->nfct_reasm = NULL; +#endif +#ifdef CONFIG_BRIDGE_NETFILTER + nf_bridge_put(skb->nf_bridge); + skb->nf_bridge = NULL; +#endif +} + +/* Note: This doesn't put any conntrack and bridge info in dst. */ +static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src) +{ +#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) + dst->nfct = src->nfct; + nf_conntrack_get(src->nfct); + dst->nfctinfo = src->nfctinfo; +#endif +#ifdef NET_SKBUFF_NF_DEFRAG_NEEDED + dst->nfct_reasm = src->nfct_reasm; + nf_conntrack_get_reasm(src->nfct_reasm); +#endif +#ifdef CONFIG_BRIDGE_NETFILTER + dst->nf_bridge = src->nf_bridge; + nf_bridge_get(src->nf_bridge); +#endif +} + +static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src) +{ +#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) + nf_conntrack_put(dst->nfct); +#endif +#ifdef NET_SKBUFF_NF_DEFRAG_NEEDED + nf_conntrack_put_reasm(dst->nfct_reasm); +#endif +#ifdef CONFIG_BRIDGE_NETFILTER + nf_bridge_put(dst->nf_bridge); +#endif + __nf_copy(dst, src); +} + +#ifdef CONFIG_NETWORK_SECMARK +static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from) +{ + to->secmark = from->secmark; +} + +static inline void skb_init_secmark(struct sk_buff *skb) +{ + skb->secmark = 0; +} +#else +static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from) +{ } + +static inline void skb_init_secmark(struct sk_buff *skb) +{ } +#endif + +static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping) +{ + skb->queue_mapping = queue_mapping; +} + +static inline u16 skb_get_queue_mapping(const struct sk_buff *skb) +{ + return skb->queue_mapping; +} + +static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from) +{ + to->queue_mapping = from->queue_mapping; +} + +static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue) +{ + skb->queue_mapping = rx_queue + 1; +} + +static inline u16 skb_get_rx_queue(const struct sk_buff *skb) +{ + return skb->queue_mapping - 1; +} + +static inline bool skb_rx_queue_recorded(const struct sk_buff *skb) +{ + return skb->queue_mapping != 0; +} + +extern u16 __skb_tx_hash(const struct net_device *dev, + const struct sk_buff *skb, + unsigned int num_tx_queues); + +#ifdef CONFIG_XFRM +static inline struct sec_path *skb_sec_path(struct sk_buff *skb) +{ + return skb->sp; +} +#else +static inline struct sec_path *skb_sec_path(struct sk_buff *skb) +{ + return NULL; +} +#endif + +static inline int skb_is_gso(const struct sk_buff *skb) +{ + return skb_shinfo(skb)->gso_size; +} + +static inline int skb_is_gso_v6(const struct sk_buff *skb) +{ + return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6; +} + +extern void __skb_warn_lro_forwarding(const struct sk_buff *skb); + +static inline bool skb_warn_if_lro(const struct sk_buff *skb) +{ + /* LRO sets gso_size but not gso_type, whereas if GSO is really + * wanted then gso_type will be set. */ + struct skb_shared_info *shinfo = skb_shinfo(skb); + if (skb_is_nonlinear(skb) && shinfo->gso_size != 0 && + unlikely(shinfo->gso_type == 0)) { + __skb_warn_lro_forwarding(skb); + return true; + } + return false; +} + +static inline void skb_forward_csum(struct sk_buff *skb) +{ + /* Unfortunately we don't support this one. Any brave souls? */ + if (skb->ip_summed == CHECKSUM_COMPLETE) + skb->ip_summed = CHECKSUM_NONE; +} + +/** + * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE + * @skb: skb to check + * + * fresh skbs have their ip_summed set to CHECKSUM_NONE. + * Instead of forcing ip_summed to CHECKSUM_NONE, we can + * use this helper, to document places where we make this assertion. + */ +static inline void skb_checksum_none_assert(struct sk_buff *skb) +{ +#ifdef DEBUG + BUG_ON(skb->ip_summed != CHECKSUM_NONE); +#endif +} + +bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off); +#endif /* __KERNEL__ */ +#endif /* _LINUX_SKBUFF_H */ |