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| | /* SPDX-License-Identifier: GPL-2.0-or-later
* Copyright (c) 2021 Red Hat GmbH
* Author: Stefano Brivio <sbrivio@redhat.com>
*/
#ifndef TAP_H
#define TAP_H
#define ETH_HDR_INIT(proto) { .h_proto = htons_constant(proto) }
/**
* struct tap_hdr - tap backend specific headers
* @vnet_len: Frame length (for qemu socket transport)
*/
struct tap_hdr {
uint32_t vnet_len;
} __attribute__((packed));
/**
* tap_hdr_iov() - struct iovec for a tap header
* @c: Execution context
* @taph: Pointer to tap specific header buffer
*
* Returns: A struct iovec covering the correct portion of @taph to use as the
* tap specific header in the current configuration.
*/
static inline struct iovec tap_hdr_iov(const struct ctx *c,
struct tap_hdr *thdr)
{
return (struct iovec){
.iov_base = thdr,
.iov_len = c->mode == MODE_PASST ? sizeof(*thdr) : 0,
};
}
/**
* tap_hdr_update() - Update the tap specific header for a frame
* @taph: Tap specific header buffer to update
* @l2len: Frame length (including L2 headers)
*/
static inline void tap_hdr_update(struct tap_hdr *thdr, size_t l2len)
{
thdr->vnet_len = htonl(l2len);
}
static inline size_t tap_hdr_len_(const struct ctx *c)
{
if (c->mode == MODE_PASST)
return sizeof(struct tap_hdr);
else
return 0;
}
/**
* tap_frame_base() - Find start of tap frame
* @c: Execution context
* @taph: Pointer to tap specific header buffer
*
* Returns: pointer to the start of tap frame - suitable for an
* iov_base to be passed to tap_send_frames())
*/
static inline void *tap_frame_base(const struct ctx *c, struct tap_hdr *taph)
{
return (char *)(taph + 1) - tap_hdr_len_(c);
}
/**
* tap_frame_len() - Finalize tap frame and return total length
* @c: Execution context
* @taph: Tap header to finalize
* @l2len: L2 packet length (includes L2, excludes tap specific headers)
*
* Returns: length of the tap frame including tap specific headers - suitable
* for an iov_len to be passed to tap_send_frames()
*/
static inline size_t tap_frame_len(const struct ctx *c, struct tap_hdr *taph,
size_t l2len)
{
if (c->mode == MODE_PASST)
taph->vnet_len = htonl(l2len);
return l2len + tap_hdr_len_(c);
}
struct in_addr tap_ip4_daddr(const struct ctx *c);
void tap_udp4_send(const struct ctx *c, struct in_addr src, in_port_t sport,
struct in_addr dst, in_port_t dport,
const void *in, size_t dlen);
void tap_icmp4_send(const struct ctx *c, struct in_addr src, struct in_addr dst,
const void *in, size_t l4len);
const struct in6_addr *tap_ip6_daddr(const struct ctx *c,
const struct in6_addr *src);
void tap_udp6_send(const struct ctx *c,
const struct in6_addr *src, in_port_t sport,
const struct in6_addr *dst, in_port_t dport,
uint32_t flow, const void *in, size_t dlen);
void tap_icmp6_send(const struct ctx *c,
const struct in6_addr *src, const struct in6_addr *dst,
const void *in, size_t l4len);
void tap_send_single(const struct ctx *c, const void *data, size_t l2len);
size_t tap_send_frames(const struct ctx *c, const struct iovec *iov,
size_t bufs_per_frame, size_t nframes);
void eth_update_mac(struct ethhdr *eh,
const unsigned char *eth_d, const unsigned char *eth_s);
void tap_listen_handler(struct ctx *c, uint32_t events);
void tap_handler_pasta(struct ctx *c, uint32_t events,
const struct timespec *now);
void tap_handler_passt(struct ctx *c, uint32_t events,
const struct timespec *now);
void tap_sock_init(struct ctx *c);
#endif /* TAP_H */
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