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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
/*
* TCP frame iovec array:
* TCP_IOV_VNET vnet length
* TCP_IOV_ETH ethernet header
* TCP_IOV_IP IP (v4/v6) header
* TCP_IOV_PAYLOAD IP payload (TCP header + data)
* TCP_IOV_NUM is the number of entries in the iovec array
*/
#define TCP_IOV_VNET 0
#define TCP_IOV_ETH 1
#define TCP_IOV_IP 2
#define TCP_IOV_PAYLOAD 3
#define TCP_IOV_NUM 4
/**
* struct tap_hdr - L2 and tap specific headers
* @vnet_len: Frame length (for qemu socket transport)
* @eh: Ethernet header
*/
struct tap_hdr {
uint32_t vnet_len;
struct ethhdr eh;
} __attribute__((packed));
#define TAP_HDR_INIT(proto) { .eh.h_proto = htons_constant(proto) }
static inline size_t tap_hdr_len_(const struct ctx *c)
{
if (c->mode == MODE_PASST)
return sizeof(struct tap_hdr);
else
return sizeof(struct ethhdr);
}
/**
* tap_iov_base() - Find start of tap frame
* @c: Execution context
* @taph: Pointer to L2 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_iov_base(const struct ctx *c, struct tap_hdr *taph)
{
return (char *)(taph + 1) - tap_hdr_len_(c);
}
/**
* tap_iov_len() - Finalize tap frame and return total length
* @c: Execution context
* @taph: Tap header to finalize
* @plen: L2 payload length (excludes L2 and tap specific headers)
*
* Returns: length of the tap frame including L2 and tap specific
* headers - suitable for an iov_len to be passed to
* tap_send_frames()
*/
static inline size_t tap_iov_len(const struct ctx *c, struct tap_hdr *taph,
size_t plen)
{
if (c->mode == MODE_PASST)
taph->vnet_len = htonl(plen + sizeof(taph->eh));
return plen + 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 len);
void tap_icmp4_send(const struct ctx *c, struct in_addr src, struct in_addr dst,
const void *in, size_t len);
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 len);
void tap_icmp6_send(const struct ctx *c,
const struct in6_addr *src, const struct in6_addr *dst,
const void *in, size_t len);
int tap_send(const struct ctx *c, const void *data, size_t len);
size_t tap_send_frames(const struct ctx *c, const struct iovec *iov, size_t n);
size_t tap_send_iov(const struct ctx *c, struct iovec iov[][TCP_IOV_NUM],
size_t n);
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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