--- /dev/null
+/*
+ * 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/bug.h>
+#include <linux/cache.h>
+#include <linux/rbtree.h>
+#include <linux/socket.h>
+
+#include <linux/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/hrtimer.h>
+#include <linux/dma-mapping.h>
+#include <linux/netdev_features.h>
+#include <linux/sched.h>
+#include <net/flow_keys.h>
+
+/* A. Checksumming of received packets by device.
+ *
+ * CHECKSUM_NONE:
+ *
+ * Device failed to checksum this packet e.g. due to lack of capabilities.
+ * The packet contains full (though not verified) checksum in packet but
+ * not in skb->csum. Thus, skb->csum is undefined in this case.
+ *
+ * CHECKSUM_UNNECESSARY:
+ *
+ * The hardware you're dealing with doesn't calculate the full checksum
+ * (as in CHECKSUM_COMPLETE), but it does parse headers and verify checksums
+ * for specific protocols. For such packets it will set CHECKSUM_UNNECESSARY
+ * if their checksums are okay. skb->csum is still undefined in this case
+ * though. It is a bad option, but, unfortunately, nowadays most vendors do
+ * this. Apparently with the secret goal to sell you new devices, when you
+ * will add new protocol to your host, f.e. IPv6 8)
+ *
+ * CHECKSUM_UNNECESSARY is applicable to following protocols:
+ * TCP: IPv6 and IPv4.
+ * UDP: IPv4 and IPv6. A device may apply CHECKSUM_UNNECESSARY to a
+ * zero UDP checksum for either IPv4 or IPv6, the networking stack
+ * may perform further validation in this case.
+ * GRE: only if the checksum is present in the header.
+ * SCTP: indicates the CRC in SCTP header has been validated.
+ *
+ * skb->csum_level indicates the number of consecutive checksums found in
+ * the packet minus one that have been verified as CHECKSUM_UNNECESSARY.
+ * For instance if a device receives an IPv6->UDP->GRE->IPv4->TCP packet
+ * and a device is able to verify the checksums for UDP (possibly zero),
+ * GRE (checksum flag is set), and TCP-- skb->csum_level would be set to
+ * two. If the device were only able to verify the UDP checksum and not
+ * GRE, either because it doesn't support GRE checksum of because GRE
+ * checksum is bad, skb->csum_level would be set to zero (TCP checksum is
+ * not considered in this case).
+ *
+ * CHECKSUM_COMPLETE:
+ *
+ * This is the most generic way. The device supplied checksum of the _whole_
+ * packet as seen by netif_rx() and fills out in skb->csum. Meaning, the
+ * hardware doesn't need to parse L3/L4 headers to implement this.
+ *
+ * Note: Even if device supports only some protocols, but is able to produce
+ * skb->csum, it MUST use CHECKSUM_COMPLETE, not CHECKSUM_UNNECESSARY.
+ *
+ * CHECKSUM_PARTIAL:
+ *
+ * A checksum is set up to be offloaded to a device as described in the
+ * output description for CHECKSUM_PARTIAL. This may occur on a packet
+ * received directly from another Linux OS, e.g., a virtualized Linux kernel
+ * on the same host, or it may be set in the input path in GRO or remote
+ * checksum offload. For the purposes of checksum verification, the checksum
+ * referred to by skb->csum_start + skb->csum_offset and any preceding
+ * checksums in the packet are considered verified. Any checksums in the
+ * packet that are after the checksum being offloaded are not considered to
+ * be verified.
+ *
+ * B. Checksumming on output.
+ *
+ * CHECKSUM_NONE:
+ *
+ * The skb was already checksummed by the protocol, or a checksum is not
+ * required.
+ *
+ * CHECKSUM_PARTIAL:
+ *
+ * The device is required to checksum the packet as seen by hard_start_xmit()
+ * from skb->csum_start up to the end, and to record/write the checksum at
+ * offset skb->csum_start + skb->csum_offset.
+ *
+ * The device must show its capabilities in dev->features, set up at device
+ * setup time, e.g. netdev_features.h:
+ *
+ * NETIF_F_HW_CSUM - It's a clever device, it's able to checksum everything.
+ * NETIF_F_IP_CSUM - Device is dumb, it's able to checksum only TCP/UDP over
+ * IPv4. Sigh. Vendors like this way for 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.
+ * NETIF_F_... - Well, you get the picture.
+ *
+ * CHECKSUM_UNNECESSARY:
+ *
+ * Normally, the device will do per protocol specific checksumming. Protocol
+ * implementations that do not want the NIC to perform the checksum
+ * calculation should use this flag in their outgoing skbs.
+ *
+ * NETIF_F_FCOE_CRC - This indicates that the device can do FCoE FC CRC
+ * offload. Correspondingly, the FCoE protocol driver
+ * stack should use CHECKSUM_UNNECESSARY.
+ *
+ * Any questions? No questions, good. --ANK
+ */
+
+/* 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
+
+/* Maximum value in skb->csum_level */
+#define SKB_MAX_CSUM_LEVEL 3
+
+#define SKB_DATA_ALIGN(X) ALIGN(X, SMP_CACHE_BYTES)
+#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))
+
+/* return minimum truesize of one skb containing X bytes of data */
+#define SKB_TRUESIZE(X) ((X) + \
+ SKB_DATA_ALIGN(sizeof(struct sk_buff)) + \
+ SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
+
+struct net_device;
+struct scatterlist;
+struct pipe_inode_info;
+struct iov_iter;
+struct napi_struct;
+
+#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
+struct nf_conntrack {
+ atomic_t use;
+};
+#endif
+
+#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
+struct nf_bridge_info {
+ atomic_t use;
+ enum {
+ BRNF_PROTO_UNCHANGED,
+ BRNF_PROTO_8021Q,
+ BRNF_PROTO_PPPOE
+ } orig_proto;
+ bool pkt_otherhost;
+ unsigned int mask;
+ struct net_device *physindev;
+ struct net_device *physoutdev;
+ char neigh_header[8];
+ __be32 ipv4_daddr;
+};
+#endif
+
+struct sk_buff_head {
+ /* These two members must be first. */
+ struct sk_buff *next;
+ struct sk_buff *prev;
+
+ __u32 qlen;
+ spinlock_t lock;
+ raw_spinlock_t raw_lock;
+};
+
+struct sk_buff;
+
+/* To allow 64K frame to be packed as single skb without frag_list we
+ * require 64K/PAGE_SIZE pages plus 1 additional page to allow for
+ * buffers which do not start on a page boundary.
+ *
+ * Since GRO uses frags we allocate at least 16 regardless of page
+ * size.
+ */
+#if (65536/PAGE_SIZE + 1) < 16
+#define MAX_SKB_FRAGS 16UL
+#else
+#define MAX_SKB_FRAGS (65536/PAGE_SIZE + 1)
+#endif
+
+typedef struct skb_frag_struct skb_frag_t;
+
+struct skb_frag_struct {
+ struct {
+ struct page *p;
+ } page;
+#if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536)
+ __u32 page_offset;
+ __u32 size;
+#else
+ __u16 page_offset;
+ __u16 size;
+#endif
+};
+
+static inline unsigned int skb_frag_size(const skb_frag_t *frag)
+{
+ return frag->size;
+}
+
+static inline void skb_frag_size_set(skb_frag_t *frag, unsigned int size)
+{
+ frag->size = size;
+}
+
+static inline void skb_frag_size_add(skb_frag_t *frag, int delta)
+{
+ frag->size += delta;
+}
+
+static inline void skb_frag_size_sub(skb_frag_t *frag, int delta)
+{
+ frag->size -= delta;
+}
+
+#define HAVE_HW_TIME_STAMP
+
+/**
+ * struct skb_shared_hwtstamps - hardware time stamps
+ * @hwtstamp: hardware time stamp transformed into duration
+ * since arbitrary point in time
+ *
+ * Software time stamps generated by ktime_get_real() are stored in
+ * skb->tstamp.
+ *
+ * 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;
+};
+
+/* Definitions for tx_flags in struct skb_shared_info */
+enum {
+ /* generate hardware time stamp */
+ SKBTX_HW_TSTAMP = 1 << 0,
+
+ /* generate software time stamp when queueing packet to NIC */
+ SKBTX_SW_TSTAMP = 1 << 1,
+
+ /* device driver is going to provide hardware time stamp */
+ SKBTX_IN_PROGRESS = 1 << 2,
+
+ /* device driver supports TX zero-copy buffers */
+ SKBTX_DEV_ZEROCOPY = 1 << 3,
+
+ /* generate wifi status information (where possible) */
+ SKBTX_WIFI_STATUS = 1 << 4,
+
+ /* This indicates at least one fragment might be overwritten
+ * (as in vmsplice(), sendfile() ...)
+ * If we need to compute a TX checksum, we'll need to copy
+ * all frags to avoid possible bad checksum
+ */
+ SKBTX_SHARED_FRAG = 1 << 5,
+
+ /* generate software time stamp when entering packet scheduling */
+ SKBTX_SCHED_TSTAMP = 1 << 6,
+
+ /* generate software timestamp on peer data acknowledgment */
+ SKBTX_ACK_TSTAMP = 1 << 7,
+};
+
+#define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | \
+ SKBTX_SCHED_TSTAMP | \
+ SKBTX_ACK_TSTAMP)
+#define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | SKBTX_ANY_SW_TSTAMP)
+
+/*
+ * The callback notifies userspace to release buffers when skb DMA is done in
+ * lower device, the skb last reference should be 0 when calling this.
+ * The zerocopy_success argument is true if zero copy transmit occurred,
+ * false on data copy or out of memory error caused by data copy attempt.
+ * The ctx field is used to track device context.
+ * The desc field is used to track userspace buffer index.
+ */
+struct ubuf_info {
+ void (*callback)(struct ubuf_info *, bool zerocopy_success);
+ void *ctx;
+ unsigned long desc;
+};
+
+/* This data is invariant across clones and lives at
+ * the end of the header data, ie. at skb->end.
+ */
+struct skb_shared_info {
+ unsigned char nr_frags;
+ __u8 tx_flags;
+ unsigned short gso_size;
+ /* Warning: this field is not always filled in (UFO)! */
+ unsigned short gso_segs;
+ unsigned short gso_type;
+ struct sk_buff *frag_list;
+ struct skb_shared_hwtstamps hwtstamps;
+ u32 tskey;
+ __be32 ip6_frag_id;
+
+ /*
+ * 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 has no fclone (from head_cache) */
+ SKB_FCLONE_ORIG, /* orig skb (from fclone_cache) */
+ SKB_FCLONE_CLONE, /* companion fclone skb (from fclone_cache) */
+};
+
+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,
+
+ SKB_GSO_GRE = 1 << 6,
+
+ SKB_GSO_GRE_CSUM = 1 << 7,
+
+ SKB_GSO_IPIP = 1 << 8,
+
+ SKB_GSO_SIT = 1 << 9,
+
+ SKB_GSO_UDP_TUNNEL = 1 << 10,
+
+ SKB_GSO_UDP_TUNNEL_CSUM = 1 << 11,
+
+ SKB_GSO_TUNNEL_REMCSUM = 1 << 12,
+};
+
+#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
+
+/**
+ * struct skb_mstamp - multi resolution time stamps
+ * @stamp_us: timestamp in us resolution
+ * @stamp_jiffies: timestamp in jiffies
+ */
+struct skb_mstamp {
+ union {
+ u64 v64;
+ struct {
+ u32 stamp_us;
+ u32 stamp_jiffies;
+ };
+ };
+};
+
+/**
+ * skb_mstamp_get - get current timestamp
+ * @cl: place to store timestamps
+ */
+static inline void skb_mstamp_get(struct skb_mstamp *cl)
+{
+ u64 val = local_clock();
+
+ do_div(val, NSEC_PER_USEC);
+ cl->stamp_us = (u32)val;
+ cl->stamp_jiffies = (u32)jiffies;
+}
+
+/**
+ * skb_mstamp_delta - compute the difference in usec between two skb_mstamp
+ * @t1: pointer to newest sample
+ * @t0: pointer to oldest sample
+ */
+static inline u32 skb_mstamp_us_delta(const struct skb_mstamp *t1,
+ const struct skb_mstamp *t0)
+{
+ s32 delta_us = t1->stamp_us - t0->stamp_us;
+ u32 delta_jiffies = t1->stamp_jiffies - t0->stamp_jiffies;
+
+ /* If delta_us is negative, this might be because interval is too big,
+ * or local_clock() drift is too big : fallback using jiffies.
+ */
+ if (delta_us <= 0 ||
+ delta_jiffies >= (INT_MAX / (USEC_PER_SEC / HZ)))
+
+ delta_us = jiffies_to_usecs(delta_jiffies);
+
+ return delta_us;
+}
+
+
+/**
+ * struct sk_buff - socket buffer
+ * @next: Next buffer in list
+ * @prev: Previous buffer in list
+ * @tstamp: Time we arrived/left
+ * @rbnode: RB tree node, alternative to next/prev for netem/tcp
+ * @sk: Socket we are owned by
+ * @dev: Device we arrived on/are leaving by
+ * @cb: Control buffer. Free for use by every layer. Put private vars here
+ * @_skb_refdst: destination entry (with norefcount bit)
+ * @sp: the security path, used for xfrm
+ * @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
+ * @priority: Packet queueing priority
+ * @ignore_df: allow local fragmentation
+ * @cloned: Head may be cloned (check refcnt to be sure)
+ * @ip_summed: Driver fed us an IP checksum
+ * @nohdr: Payload reference only, must not modify header
+ * @nfctinfo: Relationship of this skb to the connection
+ * @pkt_type: Packet class
+ * @fclone: skbuff clone status
+ * @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
+ * @protocol: Packet protocol from driver
+ * @destructor: Destruct function
+ * @nfct: Associated connection, if any
+ * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
+ * @skb_iif: ifindex of device we arrived on
+ * @tc_index: Traffic control index
+ * @tc_verd: traffic control verdict
+ * @hash: the packet hash
+ * @queue_mapping: Queue mapping for multiqueue devices
+ * @xmit_more: More SKBs are pending for this queue
+ * @ndisc_nodetype: router type (from link layer)
+ * @ooo_okay: allow the mapping of a socket to a queue to be changed
+ * @l4_hash: indicate hash is a canonical 4-tuple hash over transport
+ * ports.
+ * @sw_hash: indicates hash was computed in software stack
+ * @wifi_acked_valid: wifi_acked was set
+ * @wifi_acked: whether frame was acked on wifi or not
+ * @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS
+ * @napi_id: id of the NAPI struct this skb came from
+ * @secmark: security marking
+ * @mark: Generic packet mark
+ * @vlan_proto: vlan encapsulation protocol
+ * @vlan_tci: vlan tag control information
+ * @inner_protocol: Protocol (encapsulation)
+ * @inner_transport_header: Inner transport layer header (encapsulation)
+ * @inner_network_header: Network layer header (encapsulation)
+ * @inner_mac_header: Link layer header (encapsulation)
+ * @transport_header: Transport layer header
+ * @network_header: Network layer header
+ * @mac_header: Link layer header
+ * @tail: Tail pointer
+ * @end: End pointer
+ * @head: Head of buffer
+ * @data: Data head pointer
+ * @truesize: Buffer size
+ * @users: User count - see {datagram,tcp}.c
+ */
+
+struct sk_buff {
+ union {
+ struct {
+ /* These two members must be first. */
+ struct sk_buff *next;
+ struct sk_buff *prev;
+
+ union {
+ ktime_t tstamp;
+ struct skb_mstamp skb_mstamp;
+ };
+ };
+ struct rb_node rbnode; /* used in netem & tcp stack */
+ };
+ 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;
+ void (*destructor)(struct sk_buff *skb);
+#ifdef CONFIG_XFRM
+ struct sec_path *sp;
+#endif
+#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
+ struct nf_conntrack *nfct;
+#endif
+#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
+ struct nf_bridge_info *nf_bridge;
+#endif
+ unsigned int len,
+ data_len;
+ __u16 mac_len,
+ hdr_len;
+
+ /* Following fields are _not_ copied in __copy_skb_header()
+ * Note that queue_mapping is here mostly to fill a hole.
+ */
+ kmemcheck_bitfield_begin(flags1);
+ __u16 queue_mapping;
+ __u8 cloned:1,
+ nohdr:1,
+ fclone:2,
+ peeked:1,
+ head_frag:1,
+ xmit_more:1;
+ /* one bit hole */
+ kmemcheck_bitfield_end(flags1);
+
+ /* fields enclosed in headers_start/headers_end are copied
+ * using a single memcpy() in __copy_skb_header()
+ */
+ /* private: */
+ __u32 headers_start[0];
+ /* public: */
+
+/* if you move pkt_type around you also must adapt those constants */
+#ifdef __BIG_ENDIAN_BITFIELD
+#define PKT_TYPE_MAX (7 << 5)
+#else
+#define PKT_TYPE_MAX 7
+#endif
+#define PKT_TYPE_OFFSET() offsetof(struct sk_buff, __pkt_type_offset)
+
+ __u8 __pkt_type_offset[0];
+ __u8 pkt_type:3;
+ __u8 pfmemalloc:1;
+ __u8 ignore_df:1;
+ __u8 nfctinfo:3;
+
+ __u8 nf_trace:1;
+ __u8 ip_summed:2;
+ __u8 ooo_okay:1;
+ __u8 l4_hash:1;
+ __u8 sw_hash:1;
+ __u8 wifi_acked_valid:1;
+ __u8 wifi_acked:1;
+
+ __u8 no_fcs:1;
+ /* Indicates the inner headers are valid in the skbuff. */
+ __u8 encapsulation:1;
+ __u8 encap_hdr_csum:1;
+ __u8 csum_valid:1;
+ __u8 csum_complete_sw:1;
+ __u8 csum_level:2;
+ __u8 csum_bad:1;
+
+#ifdef CONFIG_IPV6_NDISC_NODETYPE
+ __u8 ndisc_nodetype:2;
+#endif
+ __u8 ipvs_property:1;
+ __u8 inner_protocol_type:1;
+ __u8 remcsum_offload:1;
+ /* 3 or 5 bit hole */
+
+#ifdef CONFIG_NET_SCHED
+ __u16 tc_index; /* traffic control index */
+#ifdef CONFIG_NET_CLS_ACT
+ __u16 tc_verd; /* traffic control verdict */
+#endif
+#endif
+
+ union {
+ __wsum csum;
+ struct {
+ __u16 csum_start;
+ __u16 csum_offset;
+ };
+ };
+ __u32 priority;
+ int skb_iif;
+ __u32 hash;
+ __be16 vlan_proto;
+ __u16 vlan_tci;
+#if defined(CONFIG_NET_RX_BUSY_POLL) || defined(CONFIG_XPS)
+ union {
+ unsigned int napi_id;
+ unsigned int sender_cpu;
+ };
+#endif
+#ifdef CONFIG_NETWORK_SECMARK
+ __u32 secmark;
+#endif
+ union {
+ __u32 mark;
+ __u32 reserved_tailroom;
+ };
+
+ union {
+ __be16 inner_protocol;
+ __u8 inner_ipproto;
+ };
+
+ __u16 inner_transport_header;
+ __u16 inner_network_header;
+ __u16 inner_mac_header;
+
+ __be16 protocol;
+ __u16 transport_header;
+ __u16 network_header;
+ __u16 mac_header;
+
+ /* private: */
+ __u32 headers_end[0];
+ /* public: */
+
+ /* 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>
+
+
+#define SKB_ALLOC_FCLONE 0x01
+#define SKB_ALLOC_RX 0x02
+#define SKB_ALLOC_NAPI 0x04
+
+/* Returns true if the skb was allocated from PFMEMALLOC reserves */
+static inline bool skb_pfmemalloc(const struct sk_buff *skb)
+{
+ return unlikely(skb->pfmemalloc);
+}
+
+/*
+ * 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;
+}
+
+/**
+ * skb_dst_set_noref - sets skb dst, hopefully, without taking reference
+ * @skb: buffer
+ * @dst: dst entry
+ *
+ * Sets skb dst, assuming a reference was not taken on dst.
+ * If dst entry is cached, we do not take reference and dst_release
+ * will be avoided by refdst_drop. If dst entry is not cached, we take
+ * reference, so that last dst_release can destroy the dst immediately.
+ */
+static inline void skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst)
+{
+ WARN_ON(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
+ skb->_skb_refdst = (unsigned long)dst | SKB_DST_NOREF;
+}
+
+/**
+ * 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);
+}
+
+void kfree_skb(struct sk_buff *skb);
+void kfree_skb_list(struct sk_buff *segs);
+void skb_tx_error(struct sk_buff *skb);
+void consume_skb(struct sk_buff *skb);
+void __kfree_skb(struct sk_buff *skb);
+extern struct kmem_cache *skbuff_head_cache;
+
+void kfree_skb_partial(struct sk_buff *skb, bool head_stolen);
+bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from,
+ bool *fragstolen, int *delta_truesize);
+
+struct sk_buff *__alloc_skb(unsigned int size, gfp_t priority, int flags,
+ int node);
+struct sk_buff *__build_skb(void *data, unsigned int frag_size);
+struct sk_buff *build_skb(void *data, unsigned int frag_size);
+static inline struct sk_buff *alloc_skb(unsigned int size,
+ gfp_t priority)
+{
+ return __alloc_skb(size, priority, 0, NUMA_NO_NODE);
+}
+
+struct sk_buff *alloc_skb_with_frags(unsigned long header_len,
+ unsigned long data_len,
+ int max_page_order,
+ int *errcode,
+ gfp_t gfp_mask);
+
+/* Layout of fast clones : [skb1][skb2][fclone_ref] */
+struct sk_buff_fclones {
+ struct sk_buff skb1;
+
+ struct sk_buff skb2;
+
+ atomic_t fclone_ref;
+};
+
+/**
+ * skb_fclone_busy - check if fclone is busy
+ * @skb: buffer
+ *
+ * Returns true is skb is a fast clone, and its clone is not freed.
+ * Some drivers call skb_orphan() in their ndo_start_xmit(),
+ * so we also check that this didnt happen.
+ */
+static inline bool skb_fclone_busy(const struct sock *sk,
+ const struct sk_buff *skb)
+{
+ const struct sk_buff_fclones *fclones;
+
+ fclones = container_of(skb, struct sk_buff_fclones, skb1);
+
+ return skb->fclone == SKB_FCLONE_ORIG &&
+ atomic_read(&fclones->fclone_ref) > 1 &&
+ fclones->skb2.sk == sk;
+}
+
+static inline struct sk_buff *alloc_skb_fclone(unsigned int size,
+ gfp_t priority)
+{
+ return __alloc_skb(size, priority, SKB_ALLOC_FCLONE, NUMA_NO_NODE);
+}
+
+struct sk_buff *__alloc_skb_head(gfp_t priority, int node);
+static inline struct sk_buff *alloc_skb_head(gfp_t priority)
+{
+ return __alloc_skb_head(priority, -1);
+}
+
+struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src);
+int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask);
+struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t priority);
+struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t priority);
+struct sk_buff *__pskb_copy_fclone(struct sk_buff *skb, int headroom,
+ gfp_t gfp_mask, bool fclone);
+static inline struct sk_buff *__pskb_copy(struct sk_buff *skb, int headroom,
+ gfp_t gfp_mask)
+{
+ return __pskb_copy_fclone(skb, headroom, gfp_mask, false);
+}
+
+int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, gfp_t gfp_mask);
+struct sk_buff *skb_realloc_headroom(struct sk_buff *skb,
+ unsigned int headroom);
+struct sk_buff *skb_copy_expand(const struct sk_buff *skb, int newheadroom,
+ int newtailroom, gfp_t priority);
+int skb_to_sgvec_nomark(struct sk_buff *skb, struct scatterlist *sg,
+ int offset, int len);
+int skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset,
+ int len);
+int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer);
+int skb_pad(struct sk_buff *skb, int pad);
+#define dev_kfree_skb(a) consume_skb(a)
+
+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;
+};
+
+void skb_prepare_seq_read(struct sk_buff *skb, unsigned int from,
+ unsigned int to, struct skb_seq_state *st);
+unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
+ struct skb_seq_state *st);
+void skb_abort_seq_read(struct skb_seq_state *st);
+
+unsigned int skb_find_text(struct sk_buff *skb, unsigned int from,
+ unsigned int to, struct ts_config *config);
+
+/*
+ * Packet hash types specify the type of hash in skb_set_hash.
+ *
+ * Hash types refer to the protocol layer addresses which are used to
+ * construct a packet's hash. The hashes are used to differentiate or identify
+ * flows of the protocol layer for the hash type. Hash types are either
+ * layer-2 (L2), layer-3 (L3), or layer-4 (L4).
+ *
+ * Properties of hashes:
+ *
+ * 1) Two packets in different flows have different hash values
+ * 2) Two packets in the same flow should have the same hash value
+ *
+ * A hash at a higher layer is considered to be more specific. A driver should
+ * set the most specific hash possible.
+ *
+ * A driver cannot indicate a more specific hash than the layer at which a hash
+ * was computed. For instance an L3 hash cannot be set as an L4 hash.
+ *
+ * A driver may indicate a hash level which is less specific than the
+ * actual layer the hash was computed on. For instance, a hash computed
+ * at L4 may be considered an L3 hash. This should only be done if the
+ * driver can't unambiguously determine that the HW computed the hash at
+ * the higher layer. Note that the "should" in the second property above
+ * permits this.
+ */
+enum pkt_hash_types {
+ PKT_HASH_TYPE_NONE, /* Undefined type */
+ PKT_HASH_TYPE_L2, /* Input: src_MAC, dest_MAC */
+ PKT_HASH_TYPE_L3, /* Input: src_IP, dst_IP */
+ PKT_HASH_TYPE_L4, /* Input: src_IP, dst_IP, src_port, dst_port */
+};
+
+static inline void
+skb_set_hash(struct sk_buff *skb, __u32 hash, enum pkt_hash_types type)
+{
+ skb->l4_hash = (type == PKT_HASH_TYPE_L4);
+ skb->sw_hash = 0;
+ skb->hash = hash;
+}
+
+void __skb_get_hash(struct sk_buff *skb);
+static inline __u32 skb_get_hash(struct sk_buff *skb)
+{
+ if (!skb->l4_hash && !skb->sw_hash)
+ __skb_get_hash(skb);
+
+ return skb->hash;
+}
+
+static inline __u32 skb_get_hash_raw(const struct sk_buff *skb)
+{
+ return skb->hash;
+}
+
+static inline void skb_clear_hash(struct sk_buff *skb)
+{
+ skb->hash = 0;
+ skb->sw_hash = 0;
+ skb->l4_hash = 0;
+}
+
+static inline void skb_clear_hash_if_not_l4(struct sk_buff *skb)
+{
+ if (!skb->l4_hash)
+ skb_clear_hash(skb);
+}
+
+static inline void skb_copy_hash(struct sk_buff *to, const struct sk_buff *from)
+{
+ to->hash = from->hash;
+ to->sw_hash = from->sw_hash;
+ to->l4_hash = from->l4_hash;
+};
+
+static inline void skb_sender_cpu_clear(struct sk_buff *skb)
+{
+#ifdef CONFIG_XPS
+ skb->sender_cpu = 0;
+#endif
+}
+
+#ifdef NET_SKBUFF_DATA_USES_OFFSET
+static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
+{
+ return skb->head + skb->end;
+}
+
+static inline unsigned int skb_end_offset(const struct sk_buff *skb)
+{
+ return skb->end;
+}
+#else
+static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
+{
+ return skb->end;
+}
+
+static inline unsigned int skb_end_offset(const struct sk_buff *skb)
+{
+ return skb->end - skb->head;
+}
+#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 == (const 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 == (const 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 == (const 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;
+}
+
+static inline int skb_unclone(struct sk_buff *skb, gfp_t pri)
+{
+ might_sleep_if(pri & __GFP_WAIT);
+
+ if (skb_cloned(skb))
+ return pskb_expand_head(skb, 0, 0, pri);
+
+ return 0;
+}
+
+/**
+ * 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.
+ * Note : Check if you can use __skb_header_release() instead.
+ */
+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_header_release - release reference to header
+ * @skb: buffer to operate on
+ *
+ * Variant of skb_header_release() assuming skb is private to caller.
+ * We can avoid one atomic operation.
+ */
+static inline void __skb_header_release(struct sk_buff *skb)
+{
+ skb->nohdr = 1;
+ atomic_set(&skb_shinfo(skb)->dataref, 1 + (1 << SKB_DATAREF_SHIFT));
+}
+
+
+/**
+ * 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);
+
+ if (likely(nskb))
+ consume_skb(skb);
+ else
+ 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);
+
+ /* Free our shared copy */
+ if (likely(nskb))
+ consume_skb(skb);
+ else
+ kfree_skb(skb);
+ 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(const struct sk_buff_head *list_)
+{
+ struct sk_buff *skb = list_->next;
+
+ if (skb == (struct sk_buff *)list_)
+ skb = NULL;
+ return skb;
+}
+
+/**
+ * skb_peek_next - peek skb following the given one from a queue
+ * @skb: skb to start from
+ * @list_: list to peek at
+ *
+ * Returns %NULL when the end of the list is met or a pointer to the
+ * next element. The reference count is not incremented and the
+ * reference is therefore volatile. Use with caution.
+ */
+static inline struct sk_buff *skb_peek_next(struct sk_buff *skb,
+ const struct sk_buff_head *list_)
+{
+ struct sk_buff *next = skb->next;
+
+ if (next == (struct sk_buff *)list_)
+ next = NULL;
+ return next;
+}
+
+/**
+ * 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(const struct sk_buff_head *list_)
+{
+ struct sk_buff *skb = list_->prev;
+
+ if (skb == (struct sk_buff *)list_)
+ skb = NULL;
+ return skb;
+
+}
+
+/**
+ * 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_raw(struct sk_buff_head *list)
+{
+ raw_spin_lock_init(&list->raw_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.
+ */
+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_init - 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_init - 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);
+}
+
+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.
+ */
+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.
+ */
+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..
+ */
+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.
+ */
+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.
+ */
+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 bool 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_frag_size(&skb_shinfo(skb)->frags[i]);
+ return len + skb_headlen(skb);
+}
+
+/**
+ * __skb_fill_page_desc - initialise a paged fragment in an skb
+ * @skb: buffer containing fragment to be initialised
+ * @i: paged fragment index to initialise
+ * @page: the page to use for this fragment
+ * @off: the offset to the data with @page
+ * @size: the length of the data
+ *
+ * Initialises the @i'th fragment of @skb to point to &size bytes at
+ * offset @off within @page.
+ *
+ * Does not take any additional reference on the fragment.
+ */
+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];
+
+ /*
+ * Propagate page->pfmemalloc to the skb if we can. The problem is
+ * that not all callers have unique ownership of the page. If
+ * pfmemalloc is set, we check the mapping as a mapping implies
+ * page->index is set (index and pfmemalloc share space).
+ * If it's a valid mapping, we cannot use page->pfmemalloc but we
+ * do not lose pfmemalloc information as the pages would not be
+ * allocated using __GFP_MEMALLOC.
+ */
+ frag->page.p = page;
+ frag->page_offset = off;
+ skb_frag_size_set(frag, size);
+
+ page = compound_head(page);
+ if (page->pfmemalloc && !page->mapping)
+ skb->pfmemalloc = true;
+}
+
+/**
+ * skb_fill_page_desc - initialise a paged fragment in an skb
+ * @skb: buffer containing fragment to be initialised
+ * @i: paged fragment index to initialise
+ * @page: the page to use for this fragment
+ * @off: the offset to the data with @page
+ * @size: the length of the data
+ *
+ * As per __skb_fill_page_desc() -- initialises the @i'th fragment of
+ * @skb to point to @size bytes at offset @off within @page. In
+ * addition updates @skb such that @i is the last fragment.
+ *
+ * Does not take any additional reference on the fragment.
+ */
+static inline void skb_fill_page_desc(struct sk_buff *skb, int i,
+ struct page *page, int off, int size)
+{
+ __skb_fill_page_desc(skb, i, page, off, size);
+ skb_shinfo(skb)->nr_frags = i + 1;
+}
+
+void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, int off,
+ int size, unsigned int truesize);
+
+void skb_coalesce_rx_frag(struct sk_buff *skb, int i, int size,
+ unsigned int truesize);
+
+#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
+ */
+unsigned char *pskb_put(struct sk_buff *skb, struct sk_buff *tail, int len);
+unsigned char *skb_put(struct sk_buff *skb, unsigned int len);
+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;
+}
+
+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;
+}
+
+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);
+}
+
+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_availroom - bytes at buffer end
+ * @skb: buffer to check
+ *
+ * Return the number of bytes of free space at the tail of an sk_buff
+ * allocated by sk_stream_alloc()
+ */
+static inline int skb_availroom(const struct sk_buff *skb)
+{
+ if (skb_is_nonlinear(skb))
+ return 0;
+
+ return skb->end - skb->tail - skb->reserved_tailroom;
+}
+
+/**
+ * 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;
+}
+
+#define ENCAP_TYPE_ETHER 0
+#define ENCAP_TYPE_IPPROTO 1
+
+static inline void skb_set_inner_protocol(struct sk_buff *skb,
+ __be16 protocol)
+{
+ skb->inner_protocol = protocol;
+ skb->inner_protocol_type = ENCAP_TYPE_ETHER;
+}
+
+static inline void skb_set_inner_ipproto(struct sk_buff *skb,
+ __u8 ipproto)
+{
+ skb->inner_ipproto = ipproto;
+ skb->inner_protocol_type = ENCAP_TYPE_IPPROTO;
+}
+
+static inline void skb_reset_inner_headers(struct sk_buff *skb)
+{
+ skb->inner_mac_header = skb->mac_header;
+ skb->inner_network_header = skb->network_header;
+ skb->inner_transport_header = skb->transport_header;
+}
+
+static inline void skb_reset_mac_len(struct sk_buff *skb)
+{
+ skb->mac_len = skb->network_header - skb->mac_header;
+}
+
+static inline unsigned char *skb_inner_transport_header(const struct sk_buff
+ *skb)
+{
+ return skb->head + skb->inner_transport_header;
+}
+
+static inline void skb_reset_inner_transport_header(struct sk_buff *skb)
+{
+ skb->inner_transport_header = skb->data - skb->head;
+}
+
+static inline void skb_set_inner_transport_header(struct sk_buff *skb,
+ const int offset)
+{
+ skb_reset_inner_transport_header(skb);
+ skb->inner_transport_header += offset;
+}
+
+static inline unsigned char *skb_inner_network_header(const struct sk_buff *skb)
+{
+ return skb->head + skb->inner_network_header;
+}
+
+static inline void skb_reset_inner_network_header(struct sk_buff *skb)
+{
+ skb->inner_network_header = skb->data - skb->head;
+}
+
+static inline void skb_set_inner_network_header(struct sk_buff *skb,
+ const int offset)
+{
+ skb_reset_inner_network_header(skb);
+ skb->inner_network_header += offset;
+}
+
+static inline unsigned char *skb_inner_mac_header(const struct sk_buff *skb)
+{
+ return skb->head + skb->inner_mac_header;
+}
+
+static inline void skb_reset_inner_mac_header(struct sk_buff *skb)
+{
+ skb->inner_mac_header = skb->data - skb->head;
+}
+
+static inline void skb_set_inner_mac_header(struct sk_buff *skb,
+ const int offset)
+{
+ skb_reset_inner_mac_header(skb);
+ skb->inner_mac_header += offset;
+}
+static inline bool skb_transport_header_was_set(const struct sk_buff *skb)
+{
+ return skb->transport_header != (typeof(skb->transport_header))~0U;
+}
+
+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 != (typeof(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;
+}
+
+static inline void skb_pop_mac_header(struct sk_buff *skb)
+{
+ skb->mac_header = skb->network_header;
+}
+
+static inline void skb_probe_transport_header(struct sk_buff *skb,
+ const int offset_hint)
+{
+ struct flow_keys keys;
+
+ if (skb_transport_header_was_set(skb))
+ return;
+ else if (skb_flow_dissect(skb, &keys))
+ skb_set_transport_header(skb, keys.thoff);
+ else
+ skb_set_transport_header(skb, offset_hint);
+}
+
+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 u32 skb_inner_network_header_len(const struct sk_buff *skb)
+{
+ return skb->inner_transport_header - skb->inner_network_header;
+}
+
+static inline int skb_network_offset(const struct sk_buff *skb)
+{
+ return skb_network_header(skb) - skb->data;
+}
+
+static inline int skb_inner_network_offset(const struct sk_buff *skb)
+{
+ return skb_inner_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
+
+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);
+}
+
+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;
+ } else {
+ BUG_ON(skb->sk);
+ }
+}
+
+/**
+ * skb_orphan_frags - orphan the frags contained in a buffer
+ * @skb: buffer to orphan frags from
+ * @gfp_mask: allocation mask for replacement pages
+ *
+ * For each frag in the SKB which needs a destructor (i.e. has an
+ * owner) create a copy of that frag and release the original
+ * page by calling the destructor.
+ */
+static inline int skb_orphan_frags(struct sk_buff *skb, gfp_t gfp_mask)
+{
+ if (likely(!(skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY)))
+ return 0;
+ return skb_copy_ubufs(skb, gfp_mask);
+}
+
+/**
+ * __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.
+ */
+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);
+}
+
+#define NETDEV_FRAG_PAGE_MAX_ORDER get_order(32768)
+#define NETDEV_FRAG_PAGE_MAX_SIZE (PAGE_SIZE << NETDEV_FRAG_PAGE_MAX_ORDER)
+#define NETDEV_PAGECNT_MAX_BIAS NETDEV_FRAG_PAGE_MAX_SIZE
+
+void *netdev_alloc_frag(unsigned int fragsz);
+
+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);
+}
+
+/* legacy helper around __netdev_alloc_skb() */
+static inline struct sk_buff *__dev_alloc_skb(unsigned int length,
+ gfp_t gfp_mask)
+{
+ return __netdev_alloc_skb(NULL, length, gfp_mask);
+}
+
+/* legacy helper around netdev_alloc_skb() */
+static inline struct sk_buff *dev_alloc_skb(unsigned int length)
+{
+ return netdev_alloc_skb(NULL, length);
+}
+
+
+static inline struct sk_buff *__netdev_alloc_skb_ip_align(struct net_device *dev,
+ unsigned int length, gfp_t gfp)
+{
+ struct sk_buff *skb = __netdev_alloc_skb(dev, length + NET_IP_ALIGN, gfp);
+
+ if (NET_IP_ALIGN && skb)
+ skb_reserve(skb, NET_IP_ALIGN);
+ return skb;
+}
+
+static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev,
+ unsigned int length)
+{
+ return __netdev_alloc_skb_ip_align(dev, length, GFP_ATOMIC);
+}
+
+void *napi_alloc_frag(unsigned int fragsz);
+struct sk_buff *__napi_alloc_skb(struct napi_struct *napi,
+ unsigned int length, gfp_t gfp_mask);
+static inline struct sk_buff *napi_alloc_skb(struct napi_struct *napi,
+ unsigned int length)
+{
+ return __napi_alloc_skb(napi, length, GFP_ATOMIC);
+}
+
+/**
+ * __dev_alloc_pages - allocate page for network Rx
+ * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
+ * @order: size of the allocation
+ *
+ * Allocate a new page.
+ *
+ * %NULL is returned if there is no free memory.
+*/
+static inline struct page *__dev_alloc_pages(gfp_t gfp_mask,
+ unsigned int order)
+{
+ /* This piece of code contains several assumptions.
+ * 1. This is for device Rx, therefor a cold page is preferred.
+ * 2. The expectation is the user wants a compound page.
+ * 3. If requesting a order 0 page it will not be compound
+ * due to the check to see if order has a value in prep_new_page
+ * 4. __GFP_MEMALLOC is ignored if __GFP_NOMEMALLOC is set due to
+ * code in gfp_to_alloc_flags that should be enforcing this.
+ */
+ gfp_mask |= __GFP_COLD | __GFP_COMP | __GFP_MEMALLOC;
+
+ return alloc_pages_node(NUMA_NO_NODE, gfp_mask, order);
+}
+
+static inline struct page *dev_alloc_pages(unsigned int order)
+{
+ return __dev_alloc_pages(GFP_ATOMIC, order);
+}
+
+/**
+ * __dev_alloc_page - allocate a page for network Rx
+ * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
+ *
+ * Allocate a new page.
+ *
+ * %NULL is returned if there is no free memory.
+ */
+static inline struct page *__dev_alloc_page(gfp_t gfp_mask)
+{
+ return __dev_alloc_pages(gfp_mask, 0);
+}
+
+static inline struct page *dev_alloc_page(void)
+{
+ return __dev_alloc_page(GFP_ATOMIC);
+}
+
+/**
+ * skb_propagate_pfmemalloc - Propagate pfmemalloc if skb is allocated after RX page
+ * @page: The page that was allocated from skb_alloc_page
+ * @skb: The skb that may need pfmemalloc set
+ */
+static inline void skb_propagate_pfmemalloc(struct page *page,
+ struct sk_buff *skb)
+{
+ if (page && page->pfmemalloc)
+ skb->pfmemalloc = true;
+}
+
+/**
+ * skb_frag_page - retrieve the page referred to by a paged fragment
+ * @frag: the paged fragment
+ *
+ * Returns the &struct page associated with @frag.
+ */
+static inline struct page *skb_frag_page(const skb_frag_t *frag)
+{
+ return frag->page.p;
+}
+
+/**
+ * __skb_frag_ref - take an addition reference on a paged fragment.
+ * @frag: the paged fragment
+ *
+ * Takes an additional reference on the paged fragment @frag.
+ */
+static inline void __skb_frag_ref(skb_frag_t *frag)
+{
+ get_page(skb_frag_page(frag));
+}
+
+/**
+ * skb_frag_ref - take an addition reference on a paged fragment of an skb.
+ * @skb: the buffer
+ * @f: the fragment offset.
+ *
+ * Takes an additional reference on the @f'th paged fragment of @skb.
+ */
+static inline void skb_frag_ref(struct sk_buff *skb, int f)
+{
+ __skb_frag_ref(&skb_shinfo(skb)->frags[f]);
+}
+
+/**
+ * __skb_frag_unref - release a reference on a paged fragment.
+ * @frag: the paged fragment
+ *
+ * Releases a reference on the paged fragment @frag.
+ */
+static inline void __skb_frag_unref(skb_frag_t *frag)
+{
+ put_page(skb_frag_page(frag));
+}
+
+/**
+ * skb_frag_unref - release a reference on a paged fragment of an skb.
+ * @skb: the buffer
+ * @f: the fragment offset
+ *
+ * Releases a reference on the @f'th paged fragment of @skb.
+ */
+static inline void skb_frag_unref(struct sk_buff *skb, int f)
+{
+ __skb_frag_unref(&skb_shinfo(skb)->frags[f]);
+}
+
+/**
+ * skb_frag_address - gets the address of the data contained in a paged fragment
+ * @frag: the paged fragment buffer
+ *
+ * Returns the address of the data within @frag. The page must already
+ * be mapped.
+ */
+static inline void *skb_frag_address(const skb_frag_t *frag)
+{
+ return page_address(skb_frag_page(frag)) + frag->page_offset;
+}
+
+/**
+ * skb_frag_address_safe - gets the address of the data contained in a paged fragment
+ * @frag: the paged fragment buffer
+ *
+ * Returns the address of the data within @frag. Checks that the page
+ * is mapped and returns %NULL otherwise.
+ */
+static inline void *skb_frag_address_safe(const skb_frag_t *frag)
+{
+ void *ptr = page_address(skb_frag_page(frag));
+ if (unlikely(!ptr))
+ return NULL;
+
+ return ptr + frag->page_offset;
+}
+
+/**
+ * __skb_frag_set_page - sets the page contained in a paged fragment
+ * @frag: the paged fragment
+ * @page: the page to set
+ *
+ * Sets the fragment @frag to contain @page.
+ */
+static inline void __skb_frag_set_page(skb_frag_t *frag, struct page *page)
+{
+ frag->page.p = page;
+}
+
+/**
+ * skb_frag_set_page - sets the page contained in a paged fragment of an skb
+ * @skb: the buffer
+ * @f: the fragment offset
+ * @page: the page to set
+ *
+ * Sets the @f'th fragment of @skb to contain @page.
+ */
+static inline void skb_frag_set_page(struct sk_buff *skb, int f,
+ struct page *page)
+{
+ __skb_frag_set_page(&skb_shinfo(skb)->frags[f], page);
+}
+
+bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t prio);
+
+/**
+ * skb_frag_dma_map - maps a paged fragment via the DMA API
+ * @dev: the device to map the fragment to
+ * @frag: the paged fragment to map
+ * @offset: the offset within the fragment (starting at the
+ * fragment's own offset)
+ * @size: the number of bytes to map
+ * @dir: the direction of the mapping (%PCI_DMA_*)
+ *
+ * Maps the page associated with @frag to @device.
+ */
+static inline dma_addr_t skb_frag_dma_map(struct device *dev,
+ const skb_frag_t *frag,
+ size_t offset, size_t size,
+ enum dma_data_direction dir)
+{
+ return dma_map_page(dev, skb_frag_page(frag),
+ frag->page_offset + offset, size, dir);
+}
+
+static inline struct sk_buff *pskb_copy(struct sk_buff *skb,
+ gfp_t gfp_mask)
+{
+ return __pskb_copy(skb, skb_headroom(skb), gfp_mask);
+}
+
+
+static inline struct sk_buff *pskb_copy_for_clone(struct sk_buff *skb,
+ gfp_t gfp_mask)
+{
+ return __pskb_copy_fclone(skb, skb_headroom(skb), gfp_mask, true);
+}
+
+
+/**
+ * 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(const 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);
+}
+
+/**
+ * skb_put_padto - increase size and 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_put_padto(struct sk_buff *skb, unsigned int len)
+{
+ unsigned int size = skb->len;
+
+ if (unlikely(size < len)) {
+ len -= size;
+ if (skb_pad(skb, len))
+ return -ENOMEM;
+ __skb_put(skb, len);
+ }
+ return 0;
+}
+
+static inline int skb_add_data(struct sk_buff *skb,
+ struct iov_iter *from, int copy)
+{
+ const int off = skb->len;
+
+ if (skb->ip_summed == CHECKSUM_NONE) {
+ __wsum csum = 0;
+ if (csum_and_copy_from_iter(skb_put(skb, copy), copy,
+ &csum, from) == copy) {
+ skb->csum = csum_block_add(skb->csum, csum, off);
+ return 0;
+ }
+ } else if (copy_from_iter(skb_put(skb, copy), copy, from) == copy)
+ return 0;
+
+ __skb_trim(skb, off);
+ return -EFAULT;
+}
+
+static inline bool skb_can_coalesce(struct sk_buff *skb, int i,
+ const struct page *page, int off)
+{
+ if (i) {
+ const struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i - 1];
+
+ return page == skb_frag_page(frag) &&
+ off == frag->page_offset + skb_frag_size(frag);
+ }
+ return false;
+}
+
+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_has_shared_frag - can any frag be overwritten
+ * @skb: buffer to test
+ *
+ * Return true if the skb has at least one frag that might be modified
+ * by an external entity (as in vmsplice()/sendfile())
+ */
+static inline bool skb_has_shared_frag(const struct sk_buff *skb)
+{
+ return skb_is_nonlinear(skb) &&
+ skb_shinfo(skb)->tx_flags & SKBTX_SHARED_FRAG;
+}
+
+/**
+ * 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)
+
+struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags,
+ int *peeked, int *off, int *err);
+struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags, int noblock,
+ int *err);
+unsigned int datagram_poll(struct file *file, struct socket *sock,
+ struct poll_table_struct *wait);
+int skb_copy_datagram_iter(const struct sk_buff *from, int offset,
+ struct iov_iter *to, int size);
+static inline int skb_copy_datagram_msg(const struct sk_buff *from, int offset,
+ struct msghdr *msg, int size)
+{
+ return skb_copy_datagram_iter(from, offset, &msg->msg_iter, size);
+}
+int skb_copy_and_csum_datagram_msg(struct sk_buff *skb, int hlen,
+ struct msghdr *msg);
+int skb_copy_datagram_from_iter(struct sk_buff *skb, int offset,
+ struct iov_iter *from, int len);
+int zerocopy_sg_from_iter(struct sk_buff *skb, struct iov_iter *frm);
+void skb_free_datagram(struct sock *sk, struct sk_buff *skb);
+void skb_free_datagram_locked(struct sock *sk, struct sk_buff *skb);
+int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, unsigned int flags);
+int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len);
+int skb_store_bits(struct sk_buff *skb, int offset, const void *from, int len);
+__wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, u8 *to,
+ int len, __wsum csum);
+int skb_splice_bits(struct sk_buff *skb, unsigned int offset,
+ struct pipe_inode_info *pipe, unsigned int len,
+ unsigned int flags);
+void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
+unsigned int skb_zerocopy_headlen(const struct sk_buff *from);
+int skb_zerocopy(struct sk_buff *to, struct sk_buff *from,
+ int len, int hlen);
+void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len);
+int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen);
+void skb_scrub_packet(struct sk_buff *skb, bool xnet);
+unsigned int skb_gso_transport_seglen(const struct sk_buff *skb);
+struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features);
+struct sk_buff *skb_vlan_untag(struct sk_buff *skb);
+int skb_ensure_writable(struct sk_buff *skb, int write_len);
+int skb_vlan_pop(struct sk_buff *skb);
+int skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci);
+
+static inline int memcpy_from_msg(void *data, struct msghdr *msg, int len)
+{
+ return copy_from_iter(data, len, &msg->msg_iter) == len ? 0 : -EFAULT;
+}
+
+static inline int memcpy_to_msg(struct msghdr *msg, void *data, int len)
+{
+ return copy_to_iter(data, len, &msg->msg_iter) == len ? 0 : -EFAULT;
+}
+
+struct skb_checksum_ops {
+ __wsum (*update)(const void *mem, int len, __wsum wsum);
+ __wsum (*combine)(__wsum csum, __wsum csum2, int offset, int len);
+};
+
+__wsum __skb_checksum(const struct sk_buff *skb, int offset, int len,
+ __wsum csum, const struct skb_checksum_ops *ops);
+__wsum skb_checksum(const struct sk_buff *skb, int offset, int len,
+ __wsum csum);
+
+static inline void *__skb_header_pointer(const struct sk_buff *skb, int offset,
+ int len, void *data, int hlen, void *buffer)
+{
+ if (hlen - offset >= len)
+ return data + offset;
+
+ if (!skb ||
+ skb_copy_bits(skb, offset, buffer, len) < 0)
+ return NULL;
+
+ return buffer;
+}
+
+static inline void *skb_header_pointer(const struct sk_buff *skb, int offset,
+ int len, void *buffer)
+{
+ return __skb_header_pointer(skb, offset, len, skb->data,
+ skb_headlen(skb), buffer);
+}
+
+/**
+ * skb_needs_linearize - check if we need to linearize a given skb
+ * depending on the given device features.
+ * @skb: socket buffer to check
+ * @features: net device features
+ *
+ * Returns true if either:
+ * 1. skb has frag_list and the device doesn't support FRAGLIST, or
+ * 2. skb is fragmented and the device does not support SG.
+ */
+static inline bool skb_needs_linearize(struct sk_buff *skb,
+ netdev_features_t features)
+{
+ return skb_is_nonlinear(skb) &&
+ ((skb_has_frag_list(skb) && !(features & NETIF_F_FRAGLIST)) ||
+ (skb_shinfo(skb)->nr_frags && !(features & NETIF_F_SG)));
+}
+
+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);
+}
+
+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);
+}
+
+struct sk_buff *skb_clone_sk(struct sk_buff *skb);
+
+#ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
+
+void skb_clone_tx_timestamp(struct sk_buff *skb);
+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);
+
+void __skb_tstamp_tx(struct sk_buff *orig_skb,
+ struct skb_shared_hwtstamps *hwtstamps,
+ struct sock *sk, int tstype);
+
+/**
+ * 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.
+ */
+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 immediately before giving the sk_buff to the MAC hardware.
+ *
+ * Specifically, one should make absolutely sure that this function is
+ * called before TX completion of this packet can trigger. Otherwise
+ * the packet could potentially already be freed.
+ *
+ * @skb: A socket buffer.
+ */
+static inline void skb_tx_timestamp(struct sk_buff *skb)
+{
+ skb_clone_tx_timestamp(skb);
+ sw_tx_timestamp(skb);
+}
+
+/**
+ * skb_complete_wifi_ack - deliver skb with wifi status
+ *
+ * @skb: the original outgoing packet
+ * @acked: ack status
+ *
+ */
+void skb_complete_wifi_ack(struct sk_buff *skb, bool acked);
+
+__sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len);
+__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->csum_valid ||
+ (skb->ip_summed == CHECKSUM_PARTIAL &&
+ skb_checksum_start_offset(skb) >= 0));
+}
+
+/**
+ * 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);
+}
+
+static inline void __skb_decr_checksum_unnecessary(struct sk_buff *skb)
+{
+ if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
+ if (skb->csum_level == 0)
+ skb->ip_summed = CHECKSUM_NONE;
+ else
+ skb->csum_level--;
+ }
+}
+
+static inline void __skb_incr_checksum_unnecessary(struct sk_buff *skb)
+{
+ if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
+ if (skb->csum_level < SKB_MAX_CSUM_LEVEL)
+ skb->csum_level++;
+ } else if (skb->ip_summed == CHECKSUM_NONE) {
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+ skb->csum_level = 0;
+ }
+}
+
+static inline void __skb_mark_checksum_bad(struct sk_buff *skb)
+{
+ /* Mark current checksum as bad (typically called from GRO
+ * path). In the case that ip_summed is CHECKSUM_NONE
+ * this must be the first checksum encountered in the packet.
+ * When ip_summed is CHECKSUM_UNNECESSARY, this is the first
+ * checksum after the last one validated. For UDP, a zero
+ * checksum can not be marked as bad.
+ */
+
+ if (skb->ip_summed == CHECKSUM_NONE ||
+ skb->ip_summed == CHECKSUM_UNNECESSARY)
+ skb->csum_bad = 1;
+}
+
+/* Check if we need to perform checksum complete validation.
+ *
+ * Returns true if checksum complete is needed, false otherwise
+ * (either checksum is unnecessary or zero checksum is allowed).
+ */
+static inline bool __skb_checksum_validate_needed(struct sk_buff *skb,
+ bool zero_okay,
+ __sum16 check)
+{
+ if (skb_csum_unnecessary(skb) || (zero_okay && !check)) {
+ skb->csum_valid = 1;
+ __skb_decr_checksum_unnecessary(skb);
+ return false;
+ }
+
+ return true;
+}
+
+/* For small packets <= CHECKSUM_BREAK peform checksum complete directly
+ * in checksum_init.
+ */
+#define CHECKSUM_BREAK 76
+
+/* Unset checksum-complete
+ *
+ * Unset checksum complete can be done when packet is being modified
+ * (uncompressed for instance) and checksum-complete value is
+ * invalidated.
+ */
+static inline void skb_checksum_complete_unset(struct sk_buff *skb)
+{
+ if (skb->ip_summed == CHECKSUM_COMPLETE)
+ skb->ip_summed = CHECKSUM_NONE;
+}
+
+/* Validate (init) checksum based on checksum complete.
+ *
+ * Return values:
+ * 0: checksum is validated or try to in skb_checksum_complete. In the latter
+ * case the ip_summed will not be CHECKSUM_UNNECESSARY and the pseudo
+ * checksum is stored in skb->csum for use in __skb_checksum_complete
+ * non-zero: value of invalid checksum
+ *
+ */
+static inline __sum16 __skb_checksum_validate_complete(struct sk_buff *skb,
+ bool complete,
+ __wsum psum)
+{
+ if (skb->ip_summed == CHECKSUM_COMPLETE) {
+ if (!csum_fold(csum_add(psum, skb->csum))) {
+ skb->csum_valid = 1;
+ return 0;
+ }
+ } else if (skb->csum_bad) {
+ /* ip_summed == CHECKSUM_NONE in this case */
+ return 1;
+ }
+
+ skb->csum = psum;
+
+ if (complete || skb->len <= CHECKSUM_BREAK) {
+ __sum16 csum;
+
+ csum = __skb_checksum_complete(skb);
+ skb->csum_valid = !csum;
+ return csum;
+ }
+
+ return 0;
+}
+
+static inline __wsum null_compute_pseudo(struct sk_buff *skb, int proto)
+{
+ return 0;
+}
+
+/* Perform checksum validate (init). Note that this is a macro since we only
+ * want to calculate the pseudo header which is an input function if necessary.
+ * First we try to validate without any computation (checksum unnecessary) and
+ * then calculate based on checksum complete calling the function to compute
+ * pseudo header.
+ *
+ * Return values:
+ * 0: checksum is validated or try to in skb_checksum_complete
+ * non-zero: value of invalid checksum
+ */
+#define __skb_checksum_validate(skb, proto, complete, \
+ zero_okay, check, compute_pseudo) \
+({ \
+ __sum16 __ret = 0; \
+ skb->csum_valid = 0; \
+ if (__skb_checksum_validate_needed(skb, zero_okay, check)) \
+ __ret = __skb_checksum_validate_complete(skb, \
+ complete, compute_pseudo(skb, proto)); \
+ __ret; \
+})
+
+#define skb_checksum_init(skb, proto, compute_pseudo) \
+ __skb_checksum_validate(skb, proto, false, false, 0, compute_pseudo)
+
+#define skb_checksum_init_zero_check(skb, proto, check, compute_pseudo) \
+ __skb_checksum_validate(skb, proto, false, true, check, compute_pseudo)
+
+#define skb_checksum_validate(skb, proto, compute_pseudo) \
+ __skb_checksum_validate(skb, proto, true, false, 0, compute_pseudo)
+
+#define skb_checksum_validate_zero_check(skb, proto, check, \
+ compute_pseudo) \
+ __skb_checksum_validate(skb, proto, true, true, check, compute_pseudo)
+
+#define skb_checksum_simple_validate(skb) \
+ __skb_checksum_validate(skb, 0, true, false, 0, null_compute_pseudo)
+
+static inline bool __skb_checksum_convert_check(struct sk_buff *skb)
+{
+ return (skb->ip_summed == CHECKSUM_NONE &&
+ skb->csum_valid && !skb->csum_bad);
+}
+
+static inline void __skb_checksum_convert(struct sk_buff *skb,
+ __sum16 check, __wsum pseudo)
+{
+ skb->csum = ~pseudo;
+ skb->ip_summed = CHECKSUM_COMPLETE;
+}
+
+#define skb_checksum_try_convert(skb, proto, check, compute_pseudo) \
+do { \
+ if (__skb_checksum_convert_check(skb)) \
+ __skb_checksum_convert(skb, check, \
+ compute_pseudo(skb, proto)); \
+} while (0)
+
+static inline void skb_remcsum_adjust_partial(struct sk_buff *skb, void *ptr,
+ u16 start, u16 offset)
+{
+ skb->ip_summed = CHECKSUM_PARTIAL;
+ skb->csum_start = ((unsigned char *)ptr + start) - skb->head;
+ skb->csum_offset = offset - start;
+}
+
+/* Update skbuf and packet to reflect the remote checksum offload operation.
+ * When called, ptr indicates the starting point for skb->csum when
+ * ip_summed is CHECKSUM_COMPLETE. If we need create checksum complete
+ * here, skb_postpull_rcsum is done so skb->csum start is ptr.
+ */
+static inline void skb_remcsum_process(struct sk_buff *skb, void *ptr,
+ int start, int offset, bool nopartial)
+{
+ __wsum delta;
+
+ if (!nopartial) {
+ skb_remcsum_adjust_partial(skb, ptr, start, offset);
+ return;
+ }
+
+ if (unlikely(skb->ip_summed != CHECKSUM_COMPLETE)) {
+ __skb_checksum_complete(skb);
+ skb_postpull_rcsum(skb, skb->data, ptr - (void *)skb->data);
+ }
+
+ delta = remcsum_adjust(ptr, skb->csum, start, offset);
+
+ /* Adjust skb->csum since we changed the packet */
+ skb->csum = csum_add(skb->csum, delta);
+}
+
+#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
+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
+#if IS_ENABLED(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
+#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
+ nf_bridge_put(skb->nf_bridge);
+ skb->nf_bridge = NULL;
+#endif
+}
+
+static inline void nf_reset_trace(struct sk_buff *skb)
+{
+#if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES)
+ skb->nf_trace = 0;
+#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,
+ bool copy)
+{
+#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
+ dst->nfct = src->nfct;
+ nf_conntrack_get(src->nfct);
+ if (copy)
+ dst->nfctinfo = src->nfctinfo;
+#endif
+#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
+ dst->nf_bridge = src->nf_bridge;
+ nf_bridge_get(src->nf_bridge);
+#endif
+#if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES)
+ if (copy)
+ dst->nf_trace = src->nf_trace;
+#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
+#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
+ nf_bridge_put(dst->nf_bridge);
+#endif
+ __nf_copy(dst, src, true);
+}
+
+#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 bool skb_irq_freeable(const struct sk_buff *skb)
+{
+ return !skb->destructor &&
+#if IS_ENABLED(CONFIG_XFRM)
+ !skb->sp &&
+#endif
+#if IS_ENABLED(CONFIG_NF_CONNTRACK)
+ !skb->nfct &&
+#endif
+ !skb->_skb_refdst &&
+ !skb_has_frag_list(skb);
+}
+
+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;
+}
+
+u16 __skb_tx_hash(const struct net_device *dev, struct sk_buff *skb,
+ unsigned int num_tx_queues);
+
+static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
+{
+#ifdef CONFIG_XFRM
+ return skb->sp;
+#else
+ return NULL;
+#endif
+}
+
+/* Keeps track of mac header offset relative to skb->head.
+ * It is useful for TSO of Tunneling protocol. e.g. GRE.
+ * For non-tunnel skb it points to skb_mac_header() and for
+ * tunnel skb it points to outer mac header.
+ * Keeps track of level of encapsulation of network headers.
+ */
+struct skb_gso_cb {
+ int mac_offset;
+ int encap_level;
+ __u16 csum_start;
+};
+#define SKB_GSO_CB(skb) ((struct skb_gso_cb *)(skb)->cb)
+
+static inline int skb_tnl_header_len(const struct sk_buff *inner_skb)
+{
+ return (skb_mac_header(inner_skb) - inner_skb->head) -
+ SKB_GSO_CB(inner_skb)->mac_offset;
+}
+
+static inline int gso_pskb_expand_head(struct sk_buff *skb, int extra)
+{
+ int new_headroom, headroom;
+ int ret;
+
+ headroom = skb_headroom(skb);
+ ret = pskb_expand_head(skb, extra, 0, GFP_ATOMIC);
+ if (ret)
+ return ret;
+
+ new_headroom = skb_headroom(skb);
+ SKB_GSO_CB(skb)->mac_offset += (new_headroom - headroom);
+ return 0;
+}
+
+/* Compute the checksum for a gso segment. First compute the checksum value
+ * from the start of transport header to SKB_GSO_CB(skb)->csum_start, and
+ * then add in skb->csum (checksum from csum_start to end of packet).
+ * skb->csum and csum_start are then updated to reflect the checksum of the
+ * resultant packet starting from the transport header-- the resultant checksum
+ * is in the res argument (i.e. normally zero or ~ of checksum of a pseudo
+ * header.
+ */
+static inline __sum16 gso_make_checksum(struct sk_buff *skb, __wsum res)
+{
+ int plen = SKB_GSO_CB(skb)->csum_start - skb_headroom(skb) -
+ skb_transport_offset(skb);
+ __u16 csum;
+
+ csum = csum_fold(csum_partial(skb_transport_header(skb),
+ plen, skb->csum));
+ skb->csum = res;
+ SKB_GSO_CB(skb)->csum_start -= plen;
+
+ return csum;
+}
+
+static inline bool skb_is_gso(const struct sk_buff *skb)
+{
+ return skb_shinfo(skb)->gso_size;
+}
+
+/* Note: Should be called only if skb_is_gso(skb) is true */
+static inline bool skb_is_gso_v6(const struct sk_buff *skb)
+{
+ return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6;
+}
+
+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. */
+ const 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(const 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);
+
+int skb_checksum_setup(struct sk_buff *skb, bool recalculate);
+
+u32 skb_get_poff(const struct sk_buff *skb);
+u32 __skb_get_poff(const struct sk_buff *skb, void *data,
+ const struct flow_keys *keys, int hlen);
+
+/**
+ * skb_head_is_locked - Determine if the skb->head is locked down
+ * @skb: skb to check
+ *
+ * The head on skbs build around a head frag can be removed if they are
+ * not cloned. This function returns true if the skb head is locked down
+ * due to either being allocated via kmalloc, or by being a clone with
+ * multiple references to the head.
+ */
+static inline bool skb_head_is_locked(const struct sk_buff *skb)
+{
+ return !skb->head_frag || skb_cloned(skb);
+}
+
+/**
+ * skb_gso_network_seglen - Return length of individual segments of a gso packet
+ *
+ * @skb: GSO skb
+ *
+ * skb_gso_network_seglen is used to determine the real size of the
+ * individual segments, including Layer3 (IP, IPv6) and L4 headers (TCP/UDP).
+ *
+ * The MAC/L2 header is not accounted for.
+ */
+static inline unsigned int skb_gso_network_seglen(const struct sk_buff *skb)
+{
+ unsigned int hdr_len = skb_transport_header(skb) -
+ skb_network_header(skb);
+ return hdr_len + skb_gso_transport_seglen(skb);
+}
+#endif /* __KERNEL__ */
+#endif /* _LINUX_SKBUFF_H */
Code Review / kvmfornfv.git / blobdiff