| /* |
| * 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/config.h> |
| #include <linux/kernel.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/mm.h> |
| #include <linux/highmem.h> |
| #include <linux/poll.h> |
| #include <linux/net.h> |
| #include <linux/textsearch.h> |
| #include <net/checksum.h> |
| |
| #define HAVE_ALLOC_SKB /* For the drivers to know */ |
| #define HAVE_ALIGNABLE_SKB /* Ditto 8) */ |
| #define SLAB_SKB /* Slabified skbuffs */ |
| |
| #define CHECKSUM_NONE 0 |
| #define CHECKSUM_HW 1 |
| #define CHECKSUM_UNNECESSARY 2 |
| |
| #define SKB_DATA_ALIGN(X) (((X) + (SMP_CACHE_BYTES - 1)) & \ |
| ~(SMP_CACHE_BYTES - 1)) |
| #define SKB_MAX_ORDER(X, ORDER) (((PAGE_SIZE << (ORDER)) - (X) - \ |
| sizeof(struct skb_shared_info)) & \ |
| ~(SMP_CACHE_BYTES - 1)) |
| #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) |
| * |
| * HW: 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 HW, |
| * not UNNECESSARY. |
| * |
| * B. Checksumming on output. |
| * |
| * NONE: skb is checksummed by protocol or csum is not required. |
| * |
| * HW: device is required to csum packet as seen by hard_start_xmit |
| * from skb->h.raw to the end and to record the checksum |
| * at skb->h.raw+skb->csum. |
| * |
| * 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) |
| * |
| * Any questions? No questions, good. --ANK |
| */ |
| |
| struct net_device; |
| |
| #ifdef CONFIG_NETFILTER |
| struct nf_conntrack { |
| atomic_t use; |
| void (*destroy)(struct nf_conntrack *); |
| }; |
| |
| #ifdef CONFIG_BRIDGE_NETFILTER |
| struct nf_bridge_info { |
| atomic_t use; |
| struct net_device *physindev; |
| struct net_device *physoutdev; |
| #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE) |
| struct net_device *netoutdev; |
| #endif |
| unsigned int mask; |
| unsigned long data[32 / sizeof(unsigned long)]; |
| }; |
| #endif |
| |
| #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 */ |
| #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 2) |
| |
| typedef struct skb_frag_struct skb_frag_t; |
| |
| struct skb_frag_struct { |
| struct page *page; |
| __u16 page_offset; |
| __u16 size; |
| }; |
| |
| /* This data is invariant across clones and lives at |
| * the end of the header data, ie. at skb->end. |
| */ |
| struct skb_shared_info { |
| atomic_t dataref; |
| unsigned int nr_frags; |
| unsigned short tso_size; |
| unsigned short tso_segs; |
| struct sk_buff *frag_list; |
| 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. It is up to the users of the skb to agree on |
| * where the payload starts. |
| * |
| * 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) |
| |
| /** |
| * struct sk_buff - socket buffer |
| * @next: Next buffer in list |
| * @prev: Previous buffer in list |
| * @list: List we are on |
| * @sk: Socket we are owned by |
| * @stamp: Time we arrived |
| * @dev: Device we arrived on/are leaving by |
| * @input_dev: Device we arrived on |
| * @real_dev: The real device we are using |
| * @h: Transport layer header |
| * @nh: Network layer header |
| * @mac: Link layer header |
| * @dst: destination entry |
| * @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 |
| * @csum: Checksum |
| * @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 |
| * @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 |
| * @nfmark: Can be used for communication between hooks |
| * @nfcache: Cache info |
| * @nfct: Associated connection, if any |
| * @nfctinfo: Relationship of this skb to the connection |
| * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c |
| * @private: Data which is private to the HIPPI implementation |
| * @tc_index: Traffic control index |
| * @tc_verd: traffic control verdict |
| * @tc_classid: traffic control classid |
| */ |
| |
| struct sk_buff { |
| /* These two members must be first. */ |
| struct sk_buff *next; |
| struct sk_buff *prev; |
| |
| struct sk_buff_head *list; |
| struct sock *sk; |
| struct timeval stamp; |
| struct net_device *dev; |
| struct net_device *input_dev; |
| struct net_device *real_dev; |
| |
| union { |
| struct tcphdr *th; |
| struct udphdr *uh; |
| struct icmphdr *icmph; |
| struct igmphdr *igmph; |
| struct iphdr *ipiph; |
| struct ipv6hdr *ipv6h; |
| unsigned char *raw; |
| } h; |
| |
| union { |
| struct iphdr *iph; |
| struct ipv6hdr *ipv6h; |
| struct arphdr *arph; |
| unsigned char *raw; |
| } nh; |
| |
| union { |
| unsigned char *raw; |
| } mac; |
| |
| struct dst_entry *dst; |
| struct sec_path *sp; |
| |
| /* |
| * 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[40]; |
| |
| unsigned int len, |
| data_len, |
| mac_len, |
| csum; |
| __u32 priority; |
| __u8 local_df:1, |
| cloned:1, |
| ip_summed:2, |
| nohdr:1; |
| /* 3 bits spare */ |
| __u8 pkt_type; |
| __be16 protocol; |
| |
| void (*destructor)(struct sk_buff *skb); |
| #ifdef CONFIG_NETFILTER |
| __u32 nfmark; |
| __u32 nfcache; |
| __u32 nfctinfo; |
| struct nf_conntrack *nfct; |
| #ifdef CONFIG_BRIDGE_NETFILTER |
| struct nf_bridge_info *nf_bridge; |
| #endif |
| #endif /* CONFIG_NETFILTER */ |
| #if defined(CONFIG_HIPPI) |
| union { |
| __u32 ifield; |
| } private; |
| #endif |
| #ifdef CONFIG_NET_SCHED |
| __u32 tc_index; /* traffic control index */ |
| #ifdef CONFIG_NET_CLS_ACT |
| __u32 tc_verd; /* traffic control verdict */ |
| __u32 tc_classid; /* traffic control classid */ |
| #endif |
| |
| #endif |
| |
| |
| /* These elements must be at the end, see alloc_skb() for details. */ |
| unsigned int truesize; |
| atomic_t users; |
| unsigned char *head, |
| *data, |
| *tail, |
| *end; |
| }; |
| |
| #ifdef __KERNEL__ |
| /* |
| * Handling routines are only of interest to the kernel |
| */ |
| #include <linux/slab.h> |
| |
| #include <asm/system.h> |
| |
| extern void __kfree_skb(struct sk_buff *skb); |
| extern struct sk_buff *alloc_skb(unsigned int size, |
| unsigned int __nocast priority); |
| extern struct sk_buff *alloc_skb_from_cache(kmem_cache_t *cp, |
| unsigned int size, |
| unsigned int __nocast priority); |
| extern void kfree_skbmem(struct sk_buff *skb); |
| extern struct sk_buff *skb_clone(struct sk_buff *skb, |
| unsigned int __nocast priority); |
| extern struct sk_buff *skb_copy(const struct sk_buff *skb, |
| unsigned int __nocast priority); |
| extern struct sk_buff *pskb_copy(struct sk_buff *skb, |
| unsigned int __nocast gfp_mask); |
| extern int pskb_expand_head(struct sk_buff *skb, |
| int nhead, int ntail, |
| unsigned int __nocast 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, |
| unsigned int __nocast priority); |
| extern struct sk_buff * skb_pad(struct sk_buff *skb, int pad); |
| #define dev_kfree_skb(a) kfree_skb(a) |
| extern void skb_over_panic(struct sk_buff *skb, int len, |
| void *here); |
| extern void skb_under_panic(struct sk_buff *skb, int len, |
| void *here); |
| |
| 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); |
| |
| /* Internal */ |
| #define skb_shinfo(SKB) ((struct skb_shared_info *)((SKB)->end)) |
| |
| /** |
| * 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_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. |
| */ |
| |
| /** |
| * kfree_skb - free an sk_buff |
| * @skb: buffer to free |
| * |
| * Drop a reference to the buffer and free it if the usage count has |
| * hit zero. |
| */ |
| static inline void kfree_skb(struct sk_buff *skb) |
| { |
| if (likely(atomic_read(&skb->users) == 1)) |
| smp_rmb(); |
| else if (likely(!atomic_dec_and_test(&skb->users))) |
| return; |
| __kfree_skb(skb); |
| } |
| |
| /** |
| * 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, |
| unsigned int __nocast 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, |
| unsigned int __nocast 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 |
| * @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 |
| * @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; |
| } |
| |
| static inline void skb_queue_head_init(struct sk_buff_head *list) |
| { |
| spin_lock_init(&list->lock); |
| list->prev = list->next = (struct sk_buff *)list; |
| list->qlen = 0; |
| } |
| |
| /* |
| * Insert an sk_buff at the start of a list. |
| * |
| * The "__skb_xxxx()" functions are the non-atomic ones that |
| * can only be called with interrupts disabled. |
| */ |
| |
| /** |
| * __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) |
| { |
| struct sk_buff *prev, *next; |
| |
| newsk->list = list; |
| list->qlen++; |
| prev = (struct sk_buff *)list; |
| next = prev->next; |
| newsk->next = next; |
| newsk->prev = prev; |
| next->prev = prev->next = 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) |
| { |
| struct sk_buff *prev, *next; |
| |
| newsk->list = list; |
| list->qlen++; |
| next = (struct sk_buff *)list; |
| prev = next->prev; |
| newsk->next = next; |
| newsk->prev = prev; |
| next->prev = prev->next = newsk; |
| } |
| |
| |
| /** |
| * __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 *next, *prev, *result; |
| |
| prev = (struct sk_buff *) list; |
| next = prev->next; |
| result = NULL; |
| if (next != prev) { |
| result = next; |
| next = next->next; |
| list->qlen--; |
| next->prev = prev; |
| prev->next = next; |
| result->next = result->prev = NULL; |
| result->list = NULL; |
| } |
| return result; |
| } |
| |
| |
| /* |
| * Insert a packet on a list. |
| */ |
| extern void skb_insert(struct sk_buff *old, struct sk_buff *newsk); |
| 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; |
| newsk->list = list; |
| list->qlen++; |
| } |
| |
| /* |
| * Place a packet after a given packet in a list. |
| */ |
| extern void skb_append(struct sk_buff *old, struct sk_buff *newsk); |
| static inline void __skb_append(struct sk_buff *old, struct sk_buff *newsk) |
| { |
| __skb_insert(newsk, old, old->next, old->list); |
| } |
| |
| /* |
| * remove sk_buff from list. _Must_ be called atomically, and with |
| * the list known.. |
| */ |
| extern void skb_unlink(struct sk_buff *skb); |
| 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; |
| skb->list = NULL; |
| next->prev = prev; |
| prev->next = next; |
| } |
| |
| |
| /* XXX: more streamlined implementation */ |
| |
| /** |
| * __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; |
| } |
| |
| #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags) |
| #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_shinfo(skb)->frag_list) |
| #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb)) |
| |
| /* |
| * Add data to an sk_buff |
| */ |
| static inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len) |
| { |
| unsigned char *tmp = skb->tail; |
| SKB_LINEAR_ASSERT(skb); |
| skb->tail += len; |
| skb->len += len; |
| return tmp; |
| } |
| |
| /** |
| * skb_put - add data to a buffer |
| * @skb: buffer to use |
| * @len: amount of data 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. |
| */ |
| static inline unsigned char *skb_put(struct sk_buff *skb, unsigned int len) |
| { |
| unsigned char *tmp = skb->tail; |
| SKB_LINEAR_ASSERT(skb); |
| skb->tail += len; |
| skb->len += len; |
| if (unlikely(skb->tail>skb->end)) |
| skb_over_panic(skb, len, current_text_addr()); |
| return tmp; |
| } |
| |
| static inline unsigned char *__skb_push(struct sk_buff *skb, unsigned int len) |
| { |
| skb->data -= len; |
| skb->len += len; |
| return skb->data; |
| } |
| |
| /** |
| * skb_push - add data to the start of a buffer |
| * @skb: buffer to use |
| * @len: amount of data to add |
| * |
| * This function extends the used data area of the buffer at the buffer |
| * start. If this would exceed the total buffer headroom the kernel will |
| * panic. A pointer to the first byte of the extra data is returned. |
| */ |
| static inline unsigned char *skb_push(struct sk_buff *skb, unsigned int len) |
| { |
| skb->data -= len; |
| skb->len += len; |
| if (unlikely(skb->data<skb->head)) |
| skb_under_panic(skb, len, current_text_addr()); |
| return skb->data; |
| } |
| |
| 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; |
| } |
| |
| /** |
| * skb_pull - remove data from the start of a buffer |
| * @skb: buffer to use |
| * @len: amount of data to remove |
| * |
| * This function removes data from the start of a buffer, returning |
| * the memory to the headroom. A pointer to the next data in the buffer |
| * is returned. Once the data has been pulled future pushes will overwrite |
| * the old data. |
| */ |
| static inline unsigned char *skb_pull(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 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, unsigned int len) |
| { |
| skb->data += len; |
| skb->tail += 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(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 |
| |
| extern int ___pskb_trim(struct sk_buff *skb, unsigned int len, int realloc); |
| |
| static inline void __skb_trim(struct sk_buff *skb, unsigned int len) |
| { |
| if (!skb->data_len) { |
| skb->len = len; |
| skb->tail = skb->data + len; |
| } else |
| ___pskb_trim(skb, len, 0); |
| } |
| |
| /** |
| * skb_trim - remove end from a buffer |
| * @skb: buffer to alter |
| * @len: new length |
| * |
| * Cut the length of a buffer down by removing data from the tail. If |
| * the buffer is already under the length specified it is not modified. |
| */ |
| static inline void skb_trim(struct sk_buff *skb, unsigned int len) |
| { |
| if (skb->len > len) |
| __skb_trim(skb, len); |
| } |
| |
| |
| static inline int __pskb_trim(struct sk_buff *skb, unsigned int len) |
| { |
| if (!skb->data_len) { |
| skb->len = len; |
| skb->tail = skb->data+len; |
| return 0; |
| } |
| return ___pskb_trim(skb, len, 1); |
| } |
| |
| static inline int pskb_trim(struct sk_buff *skb, unsigned int len) |
| { |
| return (len < skb->len) ? __pskb_trim(skb, len) : 0; |
| } |
| |
| /** |
| * 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); |
| } |
| |
| #ifndef CONFIG_HAVE_ARCH_DEV_ALLOC_SKB |
| /** |
| * __dev_alloc_skb - allocate an skbuff for sending |
| * @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 in there is no free memory. |
| */ |
| static inline struct sk_buff *__dev_alloc_skb(unsigned int length, |
| unsigned int __nocast gfp_mask) |
| { |
| struct sk_buff *skb = alloc_skb(length + 16, gfp_mask); |
| if (likely(skb)) |
| skb_reserve(skb, 16); |
| return skb; |
| } |
| #else |
| extern struct sk_buff *__dev_alloc_skb(unsigned int length, int gfp_mask); |
| #endif |
| |
| /** |
| * dev_alloc_skb - allocate an skbuff for sending |
| * @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 in there is no free memory. Although this function |
| * allocates memory it can be called from an interrupt. |
| */ |
| static inline struct sk_buff *dev_alloc_skb(unsigned int length) |
| { |
| return __dev_alloc_skb(length, GFP_ATOMIC); |
| } |
| |
| /** |
| * 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) |
| { |
| int delta = (headroom > 16 ? headroom : 16) - skb_headroom(skb); |
| |
| if (delta < 0) |
| delta = 0; |
| |
| if (delta || skb_cloned(skb)) |
| return pskb_expand_head(skb, (delta + 15) & ~15, 0, GFP_ATOMIC); |
| return 0; |
| } |
| |
| /** |
| * 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. Returns the buffer, which may be a replacement |
| * for the original, or NULL for out of memory - in which case |
| * the original buffer is still freed. |
| */ |
| |
| static inline struct sk_buff *skb_padto(struct sk_buff *skb, unsigned int len) |
| { |
| unsigned int size = skb->len; |
| if (likely(size >= len)) |
| return skb; |
| 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; |
| unsigned int 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; |
| } |
| |
| /** |
| * skb_linearize - convert paged skb to linear one |
| * @skb: buffer to linarize |
| * @gfp: allocation mode |
| * |
| * If there is no free memory -ENOMEM is returned, otherwise zero |
| * is returned and the old skb data released. |
| */ |
| extern int __skb_linearize(struct sk_buff *skb, unsigned int __nocast gfp); |
| static inline int skb_linearize(struct sk_buff *skb, unsigned int __nocast gfp) |
| { |
| return __skb_linearize(skb, gfp); |
| } |
| |
| /** |
| * 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_HW 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, int len) |
| { |
| if (skb->ip_summed == CHECKSUM_HW) |
| skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0)); |
| } |
| |
| /** |
| * 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 (len >= skb->len) |
| return 0; |
| if (skb->ip_summed == CHECKSUM_HW) |
| skb->ip_summed = CHECKSUM_NONE; |
| return __pskb_trim(skb, len); |
| } |
| |
| static inline void *kmap_skb_frag(const skb_frag_t *frag) |
| { |
| #ifdef CONFIG_HIGHMEM |
| BUG_ON(in_irq()); |
| |
| local_bh_disable(); |
| #endif |
| return kmap_atomic(frag->page, KM_SKB_DATA_SOFTIRQ); |
| } |
| |
| static inline void kunmap_skb_frag(void *vaddr) |
| { |
| kunmap_atomic(vaddr, KM_SKB_DATA_SOFTIRQ); |
| #ifdef CONFIG_HIGHMEM |
| local_bh_enable(); |
| #endif |
| } |
| |
| #define skb_queue_walk(queue, skb) \ |
| for (skb = (queue)->next; \ |
| prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \ |
| skb = skb->next) |
| |
| |
| 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(const |
| struct sk_buff *skb, |
| int hlen, |
| struct iovec *iov); |
| extern void skb_free_datagram(struct sock *sk, struct sk_buff *skb); |
| extern unsigned int skb_checksum(const struct sk_buff *skb, int offset, |
| int len, unsigned int csum); |
| extern int skb_copy_bits(const struct sk_buff *skb, int offset, |
| void *to, int len); |
| extern int skb_store_bits(const struct sk_buff *skb, int offset, |
| void *from, int len); |
| extern unsigned int skb_copy_and_csum_bits(const struct sk_buff *skb, |
| int offset, u8 *to, int len, |
| unsigned int csum); |
| 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); |
| |
| 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; |
| } |
| |
| extern void skb_init(void); |
| extern void skb_add_mtu(int mtu); |
| |
| #ifdef CONFIG_NETFILTER |
| static inline void nf_conntrack_put(struct nf_conntrack *nfct) |
| { |
| if (nfct && atomic_dec_and_test(&nfct->use)) |
| nfct->destroy(nfct); |
| } |
| static inline void nf_conntrack_get(struct nf_conntrack *nfct) |
| { |
| if (nfct) |
| atomic_inc(&nfct->use); |
| } |
| static inline void nf_reset(struct sk_buff *skb) |
| { |
| nf_conntrack_put(skb->nfct); |
| skb->nfct = NULL; |
| } |
| |
| #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 */ |
| #else /* CONFIG_NETFILTER */ |
| static inline void nf_reset(struct sk_buff *skb) {} |
| #endif /* CONFIG_NETFILTER */ |
| |
| #endif /* __KERNEL__ */ |
| #endif /* _LINUX_SKBUFF_H */ |