/* 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

#include <stddef.h>
#include <stdint.h>

#include "passt.h"
#include "tap_hdr.h"

struct udphdr;

/**
 * tap_hdr_iov() - struct iovec for a tap header
 * @c:		Execution context
 * @taph:	Pointer to tap specific header buffer
 *
 * Return: 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)
{
	struct iovec ret = {
		.iov_base = thdr,
	};

	if ((c->vhost.fd != -1)) {
		ret.iov_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
	} else {
		ret.iov_len = c->mode == MODE_PASST ? sizeof(thdr->vnet_len) : 0;
	};

	return ret;
}

/**
 * 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);
}

void tap_vhost_input(struct ctx *c, union epoll_ref ref,
		     const struct timespec *now);
unsigned long tap_l2_max_len(const struct ctx *c);
void *tap_push_l2h(const struct ctx *c, void *buf,
		   const void *src_mac, uint16_t proto);
void *tap_push_ip4h(struct iphdr *ip4h, struct in_addr src,
		     struct in_addr dst, size_t l4len, uint8_t proto);
void *tap_push_uh4(struct udphdr *uh, struct in_addr src, in_port_t sport,
		   struct in_addr dst, in_port_t dport,
		   const void *in, size_t dlen);
void *tap_push_uh6(struct udphdr *uh,
		   const struct in6_addr *src, in_port_t sport,
		   const struct in6_addr *dst, in_port_t dport,
		   void *in, size_t dlen);
void *tap_push_ip4h(struct iphdr *ip4h, struct in_addr src,
		    struct in_addr dst, size_t l4len, uint8_t proto);
void *tap_push_ip6h(struct ipv6hdr *ip6h,
		    const struct in6_addr *src,
		    const struct in6_addr *dst,
		    size_t l4len, uint8_t proto, uint32_t flow);
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, const void *src_mac, size_t l4len);
void *tap_push_ip6h(struct ipv6hdr *ip6h,
		    const struct in6_addr *src, const struct in6_addr *dst,
		    size_t l4len, uint8_t proto, uint32_t flow);
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, 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, const void *src_mac, 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);
bool tap_is_ready(const struct ctx *c);
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);
int tap_sock_unix_open(char *sock_path);
void tap_sock_reset(struct ctx *c);
void tap_backend_init(struct ctx *c);
void tap_flush_pools(void);
void tap_handler(struct ctx *c, const struct timespec *now);
void tap_add_packet(struct ctx *c, struct iov_tail *data,
		    const struct timespec *now);
#endif /* TAP_H */