passt/tap.h
David Gibson eda4f1997e epoll: Split listening Unix domain socket into its own type
tap_handler() actually handles events on three different types of object:
the /dev/tap character device (pasta), a connected Unix domain socket
(passt) or a listening Unix domain socket (passt).

The last, in particular, really has no handling in common with the others,
so split it into its own epoll type and directly dispatch to the relevant
handler from the top level.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2023-08-13 17:30:17 +02:00

83 lines
2.6 KiB
C

/* 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
/**
* 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,
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,
void *in, size_t len);
int tap_send(const struct ctx *c, const void *data, size_t len);
void tap_send_frames(struct ctx *c, const struct iovec *iov, size_t n);
void tap_update_mac(struct tap_hdr *taph,
const unsigned char *eth_d, const unsigned char *eth_s);
void tap_listen_handler(struct ctx *c, uint32_t events);
void tap_handler(struct ctx *c, uint32_t events, const struct timespec *now);
void tap_sock_init(struct ctx *c);
#endif /* TAP_H */