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| | // SPDX-License-Identifier: GPL-2.0-or-later
/* PASST - Plug A Simple Socket Transport
* for qemu/UNIX domain socket mode
*
* PASTA - Pack A Subtle Tap Abstraction
* for network namespace/tap device mode
*
* PESTO - Programmable Extensible Socket Translation Orchestrator
* front-end for passt(1) and pasta(1) forwarding configuration
*
* ip.c - IP related functions
*
* Copyright (c) 2020-2021 Red Hat GmbH
* Author: Stefano Brivio <sbrivio@redhat.com>
*/
#include <assert.h>
#include <stddef.h>
#include <netinet/in.h>
#include "ip.h"
/**
* ipproto_name() - Get IP protocol name from number
* @proto: IP protocol number
*
* Return: pointer to name of protocol @proto (<= IPPROTO_STRLEN bytes)
*
* Usually this would be done with getprotobynumber(3) but that reads
* /etc/protocols and might allocate, which isn't possible for us once
* self-isolated.
*/
const char *ipproto_name(uint8_t proto)
{
switch (proto) {
#define CASE(s) \
static_assert(sizeof(s) <= IPPROTO_STRLEN, \
"Increase IPPROTO_STRLEN to contain " #s); \
return s;
case IPPROTO_ICMP:
CASE("ICMP");
case IPPROTO_TCP:
CASE("TCP");
case IPPROTO_UDP:
CASE("UDP");
case IPPROTO_ICMPV6:
CASE("ICMPv6");
default:
CASE("<unknown protocol>");
#undef CASE
}
}
/**
* ip4_class_prefix_len() - Get class based prefix length for IPv4 address
* @addr: IPv4 address
*
* Return: prefix length based on address class, or 32 for other
*/
int ip4_class_prefix_len(const struct in_addr *addr)
{
in_addr_t a = ntohl(addr->s_addr);
if (IN_CLASSA(a))
return 32 - IN_CLASSA_NSHIFT;
if (IN_CLASSB(a))
return 32 - IN_CLASSB_NSHIFT;
if (IN_CLASSC(a))
return 32 - IN_CLASSC_NSHIFT;
return 32;
}
|