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Diffstat (limited to 'kernel/include/linux/skbuff.h')
| -rw-r--r-- | kernel/include/linux/skbuff.h | 3464 |
1 files changed, 3464 insertions, 0 deletions
diff --git a/kernel/include/linux/skbuff.h b/kernel/include/linux/skbuff.h new file mode 100644 index 000000000..26a910316 --- /dev/null +++ b/kernel/include/linux/skbuff.h @@ -0,0 +1,3464 @@ +/* + * 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 */ |