linux/include/net/xdp_sock.h
Stanislav Fomichev f6e922365f xsk: Don't assume metadata is always requested in TX completion
`compl->tx_timestam != NULL` means that the user has explicitly
requested the metadata via XDP_TX_METADATA+XDP_TX_METADATA_TIMESTAMP.

Fixes: 48eb03dd26 ("xsk: Add TX timestamp and TX checksum offload support")
Reported-by: Daniele Salvatore Albano <d.albano@gmail.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Daniele Salvatore Albano <d.albano@gmail.com>
Link: https://lore.kernel.org/bpf/20240318165427.1403313-1-sdf@google.com
2024-03-19 13:47:29 +01:00

242 lines
6.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/* AF_XDP internal functions
* Copyright(c) 2018 Intel Corporation.
*/
#ifndef _LINUX_XDP_SOCK_H
#define _LINUX_XDP_SOCK_H
#include <linux/bpf.h>
#include <linux/workqueue.h>
#include <linux/if_xdp.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/mm.h>
#include <net/sock.h>
#define XDP_UMEM_SG_FLAG (1 << 1)
struct net_device;
struct xsk_queue;
struct xdp_buff;
struct xdp_umem {
void *addrs;
u64 size;
u32 headroom;
u32 chunk_size;
u32 chunks;
u32 npgs;
struct user_struct *user;
refcount_t users;
u8 flags;
u8 tx_metadata_len;
bool zc;
struct page **pgs;
int id;
struct list_head xsk_dma_list;
struct work_struct work;
};
struct xsk_map {
struct bpf_map map;
spinlock_t lock; /* Synchronize map updates */
atomic_t count;
struct xdp_sock __rcu *xsk_map[];
};
struct xdp_sock {
/* struct sock must be the first member of struct xdp_sock */
struct sock sk;
struct xsk_queue *rx ____cacheline_aligned_in_smp;
struct net_device *dev;
struct xdp_umem *umem;
struct list_head flush_node;
struct xsk_buff_pool *pool;
u16 queue_id;
bool zc;
bool sg;
enum {
XSK_READY = 0,
XSK_BOUND,
XSK_UNBOUND,
} state;
struct xsk_queue *tx ____cacheline_aligned_in_smp;
struct list_head tx_list;
/* record the number of tx descriptors sent by this xsk and
* when it exceeds MAX_PER_SOCKET_BUDGET, an opportunity needs
* to be given to other xsks for sending tx descriptors, thereby
* preventing other XSKs from being starved.
*/
u32 tx_budget_spent;
/* Protects generic receive. */
spinlock_t rx_lock;
/* Statistics */
u64 rx_dropped;
u64 rx_queue_full;
/* When __xsk_generic_xmit() must return before it sees the EOP descriptor for the current
* packet, the partially built skb is saved here so that packet building can resume in next
* call of __xsk_generic_xmit().
*/
struct sk_buff *skb;
struct list_head map_list;
/* Protects map_list */
spinlock_t map_list_lock;
/* Protects multiple processes in the control path */
struct mutex mutex;
struct xsk_queue *fq_tmp; /* Only as tmp storage before bind */
struct xsk_queue *cq_tmp; /* Only as tmp storage before bind */
};
/*
* AF_XDP TX metadata hooks for network devices.
* The following hooks can be defined; unless noted otherwise, they are
* optional and can be filled with a null pointer.
*
* void (*tmo_request_timestamp)(void *priv)
* Called when AF_XDP frame requested egress timestamp.
*
* u64 (*tmo_fill_timestamp)(void *priv)
* Called when AF_XDP frame, that had requested egress timestamp,
* received a completion. The hook needs to return the actual HW timestamp.
*
* void (*tmo_request_checksum)(u16 csum_start, u16 csum_offset, void *priv)
* Called when AF_XDP frame requested HW checksum offload. csum_start
* indicates position where checksumming should start.
* csum_offset indicates position where checksum should be stored.
*
*/
struct xsk_tx_metadata_ops {
void (*tmo_request_timestamp)(void *priv);
u64 (*tmo_fill_timestamp)(void *priv);
void (*tmo_request_checksum)(u16 csum_start, u16 csum_offset, void *priv);
};
#ifdef CONFIG_XDP_SOCKETS
int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp);
int __xsk_map_redirect(struct xdp_sock *xs, struct xdp_buff *xdp);
void __xsk_map_flush(void);
/**
* xsk_tx_metadata_to_compl - Save enough relevant metadata information
* to perform tx completion in the future.
* @meta: pointer to AF_XDP metadata area
* @compl: pointer to output struct xsk_tx_metadata_to_compl
*
* This function should be called by the networking device when
* it prepares AF_XDP egress packet. The value of @compl should be stored
* and passed to xsk_tx_metadata_complete upon TX completion.
*/
static inline void xsk_tx_metadata_to_compl(struct xsk_tx_metadata *meta,
struct xsk_tx_metadata_compl *compl)
{
if (!meta)
return;
if (meta->flags & XDP_TXMD_FLAGS_TIMESTAMP)
compl->tx_timestamp = &meta->completion.tx_timestamp;
else
compl->tx_timestamp = NULL;
}
/**
* xsk_tx_metadata_request - Evaluate AF_XDP TX metadata at submission
* and call appropriate xsk_tx_metadata_ops operation.
* @meta: pointer to AF_XDP metadata area
* @ops: pointer to struct xsk_tx_metadata_ops
* @priv: pointer to driver-private aread
*
* This function should be called by the networking device when
* it prepares AF_XDP egress packet.
*/
static inline void xsk_tx_metadata_request(const struct xsk_tx_metadata *meta,
const struct xsk_tx_metadata_ops *ops,
void *priv)
{
if (!meta)
return;
if (ops->tmo_request_timestamp)
if (meta->flags & XDP_TXMD_FLAGS_TIMESTAMP)
ops->tmo_request_timestamp(priv);
if (ops->tmo_request_checksum)
if (meta->flags & XDP_TXMD_FLAGS_CHECKSUM)
ops->tmo_request_checksum(meta->request.csum_start,
meta->request.csum_offset, priv);
}
/**
* xsk_tx_metadata_complete - Evaluate AF_XDP TX metadata at completion
* and call appropriate xsk_tx_metadata_ops operation.
* @compl: pointer to completion metadata produced from xsk_tx_metadata_to_compl
* @ops: pointer to struct xsk_tx_metadata_ops
* @priv: pointer to driver-private aread
*
* This function should be called by the networking device upon
* AF_XDP egress completion.
*/
static inline void xsk_tx_metadata_complete(struct xsk_tx_metadata_compl *compl,
const struct xsk_tx_metadata_ops *ops,
void *priv)
{
if (!compl)
return;
if (!compl->tx_timestamp)
return;
*compl->tx_timestamp = ops->tmo_fill_timestamp(priv);
}
#else
static inline int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
{
return -ENOTSUPP;
}
static inline int __xsk_map_redirect(struct xdp_sock *xs, struct xdp_buff *xdp)
{
return -EOPNOTSUPP;
}
static inline void __xsk_map_flush(void)
{
}
static inline void xsk_tx_metadata_to_compl(struct xsk_tx_metadata *meta,
struct xsk_tx_metadata_compl *compl)
{
}
static inline void xsk_tx_metadata_request(struct xsk_tx_metadata *meta,
const struct xsk_tx_metadata_ops *ops,
void *priv)
{
}
static inline void xsk_tx_metadata_complete(struct xsk_tx_metadata_compl *compl,
const struct xsk_tx_metadata_ops *ops,
void *priv)
{
}
#endif /* CONFIG_XDP_SOCKETS */
#if defined(CONFIG_XDP_SOCKETS) && defined(CONFIG_DEBUG_NET)
bool xsk_map_check_flush(void);
#else
static inline bool xsk_map_check_flush(void)
{
return false;
}
#endif
#endif /* _LINUX_XDP_SOCK_H */