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/* SPDX-License-Identifier: GPL-2.0-only */
/* include/net/xdp.h
*
* Copyright (c) 2017 Jesper Dangaard Brouer, Red Hat Inc.
*/
#ifndef __LINUX_NET_XDP_H__
#define __LINUX_NET_XDP_H__
#include <linux/bitfield.h>
#include <linux/filter.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h> /* skb_shared_info */
/**
* DOC: XDP RX-queue information
*
* The XDP RX-queue info (xdp_rxq_info) is associated with the driver
* level RX-ring queues. It is information that is specific to how
* the driver has configured a given RX-ring queue.
*
* Each xdp_buff frame received in the driver carries a (pointer)
* reference to this xdp_rxq_info structure. This provides the XDP
* data-path read-access to RX-info for both kernel and bpf-side
* (limited subset).
*
* For now, direct access is only safe while running in NAPI/softirq
* context. Contents are read-mostly and must not be updated during
* driver NAPI/softirq poll.
*
* The driver usage API is a register and unregister API.
*
* The struct is not directly tied to the XDP prog. A new XDP prog
* can be attached as long as it doesn't change the underlying
* RX-ring. If the RX-ring does change significantly, the NIC driver
* naturally needs to stop the RX-ring before purging and reallocating
* memory. In that process the driver MUST call unregister (which
* also applies for driver shutdown and unload). The register API is
* also mandatory during RX-ring setup.
*/
enum xdp_mem_type {
MEM_TYPE_PAGE_SHARED = 0, /* Split-page refcnt based model */
MEM_TYPE_PAGE_ORDER0, /* Orig XDP full page model */
MEM_TYPE_PAGE_POOL,
MEM_TYPE_XSK_BUFF_POOL,
MEM_TYPE_MAX,
};
/* XDP flags for ndo_xdp_xmit */
#define XDP_XMIT_FLUSH (1U << 0) /* doorbell signal consumer */
#define XDP_XMIT_FLAGS_MASK XDP_XMIT_FLUSH
struct xdp_mem_info {
u32 type; /* enum xdp_mem_type, but known size type */
u32 id;
};
struct page_pool;
struct xdp_rxq_info {
struct net_device *dev;
u32 queue_index;
u32 reg_state;
struct xdp_mem_info mem;
unsigned int napi_id;
u32 frag_size;
} ____cacheline_aligned; /* perf critical, avoid false-sharing */
struct xdp_txq_info {
struct net_device *dev;
};
enum xdp_buff_flags {
XDP_FLAGS_HAS_FRAGS = BIT(0), /* non-linear xdp buff */
XDP_FLAGS_FRAGS_PF_MEMALLOC = BIT(1), /* xdp paged memory is under
* pressure
*/
};
struct xdp_buff {
void *data;
void *data_end;
void *data_meta;
void *data_hard_start;
struct xdp_rxq_info *rxq;
struct xdp_txq_info *txq;
u32 frame_sz; /* frame size to deduce data_hard_end/reserved tailroom*/
u32 flags; /* supported values defined in xdp_buff_flags */
};
static __always_inline bool xdp_buff_has_frags(struct xdp_buff *xdp)
{
return !!(xdp->flags & XDP_FLAGS_HAS_FRAGS);
}
static __always_inline void xdp_buff_set_frags_flag(struct xdp_buff *xdp)
{
xdp->flags |= XDP_FLAGS_HAS_FRAGS;
}
static __always_inline void xdp_buff_clear_frags_flag(struct xdp_buff *xdp)
{
xdp->flags &= ~XDP_FLAGS_HAS_FRAGS;
}
static __always_inline bool xdp_buff_is_frag_pfmemalloc(struct xdp_buff *xdp)
{
return !!(xdp->flags & XDP_FLAGS_FRAGS_PF_MEMALLOC);
}
static __always_inline void xdp_buff_set_frag_pfmemalloc(struct xdp_buff *xdp)
{
xdp->flags |= XDP_FLAGS_FRAGS_PF_MEMALLOC;
}
static __always_inline void
xdp_init_buff(struct xdp_buff *xdp, u32 frame_sz, struct xdp_rxq_info *rxq)
{
xdp->frame_sz = frame_sz;
xdp->rxq = rxq;
xdp->flags = 0;
}
static __always_inline void
xdp_prepare_buff(struct xdp_buff *xdp, unsigned char *hard_start,
int headroom, int data_len, const bool meta_valid)
{
unsigned char *data = hard_start + headroom;
xdp->data_hard_start = hard_start;
xdp->data = data;
xdp->data_end = data + data_len;
xdp->data_meta = meta_valid ? data : data + 1;
}
/* Reserve memory area at end-of data area.
*
* This macro reserves tailroom in the XDP buffer by limiting the
* XDP/BPF data access to data_hard_end. Notice same area (and size)
* is used for XDP_PASS, when constructing the SKB via build_skb().
*/
#define xdp_data_hard_end(xdp) \
((xdp)->data_hard_start + (xdp)->frame_sz - \
SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
static inline struct skb_shared_info *
xdp_get_shared_info_from_buff(struct xdp_buff *xdp)
{
return (struct skb_shared_info *)xdp_data_hard_end(xdp);
}
static __always_inline unsigned int xdp_get_buff_len(struct xdp_buff *xdp)
{
unsigned int len = xdp->data_end - xdp->data;
struct skb_shared_info *sinfo;
if (likely(!xdp_buff_has_frags(xdp)))
goto out;
sinfo = xdp_get_shared_info_from_buff(xdp);
len += sinfo->xdp_frags_size;
out:
return len;
}
struct xdp_frame {
void *data;
u16 len;
u16 headroom;
u32 metasize; /* uses lower 8-bits */
/* Lifetime of xdp_rxq_info is limited to NAPI/enqueue time,
* while mem info is valid on remote CPU.
*/
struct xdp_mem_info mem;
struct net_device *dev_rx; /* used by cpumap */
u32 frame_sz;
u32 flags; /* supported values defined in xdp_buff_flags */
};
static __always_inline bool xdp_frame_has_frags(struct xdp_frame *frame)
{
return !!(frame->flags & XDP_FLAGS_HAS_FRAGS);
}
static __always_inline bool xdp_frame_is_frag_pfmemalloc(struct xdp_frame *frame)
{
return !!(frame->flags & XDP_FLAGS_FRAGS_PF_MEMALLOC);
}
#define XDP_BULK_QUEUE_SIZE 16
struct xdp_frame_bulk {
int count;
void *xa;
void *q[XDP_BULK_QUEUE_SIZE];
};
static __always_inline void xdp_frame_bulk_init(struct xdp_frame_bulk *bq)
{
/* bq->count will be zero'ed when bq->xa gets updated */
bq->xa = NULL;
}
static inline struct skb_shared_info *
xdp_get_shared_info_from_frame(struct xdp_frame *frame)
{
void *data_hard_start = frame->data - frame->headroom - sizeof(*frame);
return (struct skb_shared_info *)(data_hard_start + frame->frame_sz -
SKB_DATA_ALIGN(sizeof(struct skb_shared_info)));
}
struct xdp_cpumap_stats {
unsigned int redirect;
unsigned int pass;
unsigned int drop;
};
/* Clear kernel pointers in xdp_frame */
static inline void xdp_scrub_frame(struct xdp_frame *frame)
{
frame->data = NULL;
frame->dev_rx = NULL;
}
static inline void
xdp_update_skb_shared_info(struct sk_buff *skb, u8 nr_frags,
unsigned int size, unsigned int truesize,
bool pfmemalloc)
{
skb_shinfo(skb)->nr_frags = nr_frags;
skb->len += size;
skb->data_len += size;
skb->truesize += truesize;
skb->pfmemalloc |= pfmemalloc;
}
/* Avoids inlining WARN macro in fast-path */
void xdp_warn(const char *msg, const char *func, const int line);
#define XDP_WARN(msg) xdp_warn(msg, __func__, __LINE__)
struct xdp_frame *xdp_convert_zc_to_xdp_frame(struct xdp_buff *xdp);
struct sk_buff *__xdp_build_skb_from_frame(struct xdp_frame *xdpf,
struct sk_buff *skb,
struct net_device *dev);
struct sk_buff *xdp_build_skb_from_frame(struct xdp_frame *xdpf,
struct net_device *dev);
int xdp_alloc_skb_bulk(void **skbs, int n_skb, gfp_t gfp);
struct xdp_frame *xdpf_clone(struct xdp_frame *xdpf);
static inline
void xdp_convert_frame_to_buff(struct xdp_frame *frame, struct xdp_buff *xdp)
{
xdp->data_hard_start = frame->data - frame->headroom - sizeof(*frame);
xdp->data = frame->data;
xdp->data_end = frame->data + frame->len;
xdp->data_meta = frame->data - frame->metasize;
xdp->frame_sz = frame->frame_sz;
xdp->flags = frame->flags;
}
static inline
int xdp_update_frame_from_buff(struct xdp_buff *xdp,
struct xdp_frame *xdp_frame)
{
int metasize, headroom;
/* Assure headroom is available for storing info */
headroom = xdp->data - xdp->data_hard_start;
metasize = xdp->data - xdp->data_meta;
metasize = metasize > 0 ? metasize : 0;
if (unlikely((headroom - metasize) < sizeof(*xdp_frame)))
return -ENOSPC;
/* Catch if driver didn't reserve tailroom for skb_shared_info */
if (unlikely(xdp->data_end > xdp_data_hard_end(xdp))) {
XDP_WARN("Driver BUG: missing reserved tailroom");
return -ENOSPC;
}
xdp_frame->data = xdp->data;
xdp_frame->len = xdp->data_end - xdp->data;
xdp_frame->headroom = headroom - sizeof(*xdp_frame);
xdp_frame->metasize = metasize;
xdp_frame->frame_sz = xdp->frame_sz;
xdp_frame->flags = xdp->flags;
return 0;
}
/* Convert xdp_buff to xdp_frame */
static inline
struct xdp_frame *xdp_convert_buff_to_frame(struct xdp_buff *xdp)
{
struct xdp_frame *xdp_frame;
if (xdp->rxq->mem.type == MEM_TYPE_XSK_BUFF_POOL)
return xdp_convert_zc_to_xdp_frame(xdp);
/* Store info in top of packet */
xdp_frame = xdp->data_hard_start;
if (unlikely(xdp_update_frame_from_buff(xdp, xdp_frame) < 0))
return NULL;
/* rxq only valid until napi_schedule ends, convert to xdp_mem_info */
xdp_frame->mem = xdp->rxq->mem;
return xdp_frame;
}
void __xdp_return(void *data, struct xdp_mem_info *mem, bool napi_direct,
struct xdp_buff *xdp);
void xdp_return_frame(struct xdp_frame *xdpf);
void xdp_return_frame_rx_napi(struct xdp_frame *xdpf);
void xdp_return_buff(struct xdp_buff *xdp);
void xdp_flush_frame_bulk(struct xdp_frame_bulk *bq);
void xdp_return_frame_bulk(struct xdp_frame *xdpf,
struct xdp_frame_bulk *bq);
static __always_inline unsigned int xdp_get_frame_len(struct xdp_frame *xdpf)
{
struct skb_shared_info *sinfo;
unsigned int len = xdpf->len;
if (likely(!xdp_frame_has_frags(xdpf)))
goto out;
sinfo = xdp_get_shared_info_from_frame(xdpf);
len += sinfo->xdp_frags_size;
out:
return len;
}
int __xdp_rxq_info_reg(struct xdp_rxq_info *xdp_rxq,
struct net_device *dev, u32 queue_index,
unsigned int napi_id, u32 frag_size);
static inline int
xdp_rxq_info_reg(struct xdp_rxq_info *xdp_rxq,
struct net_device *dev, u32 queue_index,
unsigned int napi_id)
{
return __xdp_rxq_info_reg(xdp_rxq, dev, queue_index, napi_id, 0);
}
void xdp_rxq_info_unreg(struct xdp_rxq_info *xdp_rxq);
void xdp_rxq_info_unused(struct xdp_rxq_info *xdp_rxq);
bool xdp_rxq_info_is_reg(struct xdp_rxq_info *xdp_rxq);
int xdp_rxq_info_reg_mem_model(struct xdp_rxq_info *xdp_rxq,
enum xdp_mem_type type, void *allocator);
void xdp_rxq_info_unreg_mem_model(struct xdp_rxq_info *xdp_rxq);
int xdp_reg_mem_model(struct xdp_mem_info *mem,
enum xdp_mem_type type, void *allocator);
void xdp_unreg_mem_model(struct xdp_mem_info *mem);
/* Drivers not supporting XDP metadata can use this helper, which
* rejects any room expansion for metadata as a result.
*/
static __always_inline void
xdp_set_data_meta_invalid(struct xdp_buff *xdp)
{
xdp->data_meta = xdp->data + 1;
}
static __always_inline bool
xdp_data_meta_unsupported(const struct xdp_buff *xdp)
{
return unlikely(xdp->data_meta > xdp->data);
}
static inline bool xdp_metalen_invalid(unsigned long metalen)
{
unsigned long meta_max;
meta_max = type_max(typeof_member(struct skb_shared_info, meta_len));
BUILD_BUG_ON(!__builtin_constant_p(meta_max));
return !IS_ALIGNED(metalen, sizeof(u32)) || metalen > meta_max;
}
struct xdp_attachment_info {
struct bpf_prog *prog;
u32 flags;
};
struct netdev_bpf;
void xdp_attachment_setup(struct xdp_attachment_info *info,
struct netdev_bpf *bpf);
#define DEV_MAP_BULK_SIZE XDP_BULK_QUEUE_SIZE
/* Define the relationship between xdp-rx-metadata kfunc and
* various other entities:
* - xdp_rx_metadata enum
* - netdev netlink enum (Documentation/netlink/specs/netdev.yaml)
* - kfunc name
* - xdp_metadata_ops field
*/
#define XDP_METADATA_KFUNC_xxx \
XDP_METADATA_KFUNC(XDP_METADATA_KFUNC_RX_TIMESTAMP, \
NETDEV_XDP_RX_METADATA_TIMESTAMP, \
bpf_xdp_metadata_rx_timestamp, \
xmo_rx_timestamp) \
XDP_METADATA_KFUNC(XDP_METADATA_KFUNC_RX_HASH, \
NETDEV_XDP_RX_METADATA_HASH, \
bpf_xdp_metadata_rx_hash, \
xmo_rx_hash) \
XDP_METADATA_KFUNC(XDP_METADATA_KFUNC_RX_VLAN_TAG, \
NETDEV_XDP_RX_METADATA_VLAN_TAG, \
bpf_xdp_metadata_rx_vlan_tag, \
xmo_rx_vlan_tag) \
enum xdp_rx_metadata {
#define XDP_METADATA_KFUNC(name, _, __, ___) name,
XDP_METADATA_KFUNC_xxx
#undef XDP_METADATA_KFUNC
MAX_XDP_METADATA_KFUNC,
};
enum xdp_rss_hash_type {
/* First part: Individual bits for L3/L4 types */
XDP_RSS_L3_IPV4 = BIT(0),
XDP_RSS_L3_IPV6 = BIT(1),
/* The fixed (L3) IPv4 and IPv6 headers can both be followed by
* variable/dynamic headers, IPv4 called Options and IPv6 called
* Extension Headers. HW RSS type can contain this info.
*/
XDP_RSS_L3_DYNHDR = BIT(2),
/* When RSS hash covers L4 then drivers MUST set XDP_RSS_L4 bit in
* addition to the protocol specific bit. This ease interaction with
* SKBs and avoids reserving a fixed mask for future L4 protocol bits.
*/
XDP_RSS_L4 = BIT(3), /* L4 based hash, proto can be unknown */
XDP_RSS_L4_TCP = BIT(4),
XDP_RSS_L4_UDP = BIT(5),
XDP_RSS_L4_SCTP = BIT(6),
XDP_RSS_L4_IPSEC = BIT(7), /* L4 based hash include IPSEC SPI */
XDP_RSS_L4_ICMP = BIT(8),
/* Second part: RSS hash type combinations used for driver HW mapping */
XDP_RSS_TYPE_NONE = 0,
XDP_RSS_TYPE_L2 = XDP_RSS_TYPE_NONE,
XDP_RSS_TYPE_L3_IPV4 = XDP_RSS_L3_IPV4,
XDP_RSS_TYPE_L3_IPV6 = XDP_RSS_L3_IPV6,
XDP_RSS_TYPE_L3_IPV4_OPT = XDP_RSS_L3_IPV4 | XDP_RSS_L3_DYNHDR,
XDP_RSS_TYPE_L3_IPV6_EX = XDP_RSS_L3_IPV6 | XDP_RSS_L3_DYNHDR,
XDP_RSS_TYPE_L4_ANY = XDP_RSS_L4,
XDP_RSS_TYPE_L4_IPV4_TCP = XDP_RSS_L3_IPV4 | XDP_RSS_L4 | XDP_RSS_L4_TCP,
XDP_RSS_TYPE_L4_IPV4_UDP = XDP_RSS_L3_IPV4 | XDP_RSS_L4 | XDP_RSS_L4_UDP,
XDP_RSS_TYPE_L4_IPV4_SCTP = XDP_RSS_L3_IPV4 | XDP_RSS_L4 | XDP_RSS_L4_SCTP,
XDP_RSS_TYPE_L4_IPV4_IPSEC = XDP_RSS_L3_IPV4 | XDP_RSS_L4 | XDP_RSS_L4_IPSEC,
XDP_RSS_TYPE_L4_IPV4_ICMP = XDP_RSS_L3_IPV4 | XDP_RSS_L4 | XDP_RSS_L4_ICMP,
XDP_RSS_TYPE_L4_IPV6_TCP = XDP_RSS_L3_IPV6 | XDP_RSS_L4 | XDP_RSS_L4_TCP,
XDP_RSS_TYPE_L4_IPV6_UDP = XDP_RSS_L3_IPV6 | XDP_RSS_L4 | XDP_RSS_L4_UDP,
XDP_RSS_TYPE_L4_IPV6_SCTP = XDP_RSS_L3_IPV6 | XDP_RSS_L4 | XDP_RSS_L4_SCTP,
XDP_RSS_TYPE_L4_IPV6_IPSEC = XDP_RSS_L3_IPV6 | XDP_RSS_L4 | XDP_RSS_L4_IPSEC,
XDP_RSS_TYPE_L4_IPV6_ICMP = XDP_RSS_L3_IPV6 | XDP_RSS_L4 | XDP_RSS_L4_ICMP,
XDP_RSS_TYPE_L4_IPV6_TCP_EX = XDP_RSS_TYPE_L4_IPV6_TCP | XDP_RSS_L3_DYNHDR,
XDP_RSS_TYPE_L4_IPV6_UDP_EX = XDP_RSS_TYPE_L4_IPV6_UDP | XDP_RSS_L3_DYNHDR,
XDP_RSS_TYPE_L4_IPV6_SCTP_EX = XDP_RSS_TYPE_L4_IPV6_SCTP | XDP_RSS_L3_DYNHDR,
};
struct xdp_metadata_ops {
int (*xmo_rx_timestamp)(const struct xdp_md *ctx, u64 *timestamp);
int (*xmo_rx_hash)(const struct xdp_md *ctx, u32 *hash,
enum xdp_rss_hash_type *rss_type);
int (*xmo_rx_vlan_tag)(const struct xdp_md *ctx, __be16 *vlan_proto,
u16 *vlan_tci);
};
#ifdef CONFIG_NET
u32 bpf_xdp_metadata_kfunc_id(int id);
bool bpf_dev_bound_kfunc_id(u32 btf_id);
void xdp_set_features_flag(struct net_device *dev, xdp_features_t val);
void xdp_features_set_redirect_target(struct net_device *dev, bool support_sg);
void xdp_features_clear_redirect_target(struct net_device *dev);
#else
static inline u32 bpf_xdp_metadata_kfunc_id(int id) { return 0; }
static inline bool bpf_dev_bound_kfunc_id(u32 btf_id) { return false; }
static inline void
xdp_set_features_flag(struct net_device *dev, xdp_features_t val)
{
}
static inline void
xdp_features_set_redirect_target(struct net_device *dev, bool support_sg)
{
}
static inline void
xdp_features_clear_redirect_target(struct net_device *dev)
{
}
#endif
static inline void xdp_clear_features_flag(struct net_device *dev)
{
xdp_set_features_flag(dev, 0);
}
static __always_inline u32 bpf_prog_run_xdp(const struct bpf_prog *prog,
struct xdp_buff *xdp)
{
/* Driver XDP hooks are invoked within a single NAPI poll cycle and thus
* under local_bh_disable(), which provides the needed RCU protection
* for accessing map entries.
*/
u32 act = __bpf_prog_run(prog, xdp, BPF_DISPATCHER_FUNC(xdp));
if (static_branch_unlikely(&bpf_master_redirect_enabled_key)) {
if (act == XDP_TX && netif_is_bond_slave(xdp->rxq->dev))
act = xdp_master_redirect(xdp);
}
return act;
}
#endif /* __LINUX_NET_XDP_H__ */