258 lines
6.0 KiB
C
258 lines
6.0 KiB
C
/*
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* IPv4/v6 address functions.
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* Copyright (C) 2017 by Harald Welte <laforge@gnumonks.org>
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*
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* The contents of this file may be used under the terms of the GNU
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* General Public License Version 2, provided that the above copyright
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* notice and this permission notice is included in all copies or
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* substantial portions of the software.
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*
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*/
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#include "../lib/in46_addr.h"
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#include <osmocom/core/utils.h>
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#include <sys/types.h>
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#include <netinet/in.h>
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#include <sys/socket.h>
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#include <arpa/inet.h>
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#include <netdb.h>
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#include <stdlib.h>
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#include <string.h>
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/*! Return the address family of given \reff in46_addr argument */
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int in46a_to_af(const struct in46_addr *in)
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{
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switch (in->len) {
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case 4:
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return AF_INET;
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case 8:
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case 16:
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return AF_INET6;
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default:
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OSMO_ASSERT(0);
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return -1;
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}
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}
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/*! Convert \ref in46_addr to sockaddr_storage */
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int in46a_to_sas(struct sockaddr_storage *out, const struct in46_addr *in)
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{
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struct sockaddr_in *sin = (struct sockaddr_in *)out;
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struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)out;
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switch (in->len) {
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case 4:
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sin->sin_family = AF_INET;
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sin->sin_addr = in->v4;
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break;
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case 16:
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sin6->sin6_family = AF_INET;
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sin6->sin6_addr = in->v6;
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break;
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default:
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OSMO_ASSERT(0);
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return -1;
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}
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return 0;
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}
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/*! Convenience wrapper around inet_ntop() for \ref in46_addr */
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const char *in46a_ntop(const struct in46_addr *in, char *dst, socklen_t dst_size)
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{
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int af;
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if (!in || in->len == 0) {
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strncpy(dst, "UNDEFINED", dst_size);
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return dst;
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}
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af = in46a_to_af(in);
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if (af < 0)
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return NULL;
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return inet_ntop(af, (const void *) &in->v4, dst, dst_size);
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}
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/* like inet_ntoa() */
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const char *in46a_ntoa(const struct in46_addr *in46)
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{
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static char addrstr_buf[256];
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if (in46a_ntop(in46, addrstr_buf, sizeof(addrstr_buf)) < 0)
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return "INVALID";
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else
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return addrstr_buf;
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}
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const char *in46p_ntoa(const struct in46_prefix *in46p)
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{
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static char addrstr_buf[256];
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snprintf(addrstr_buf, sizeof(addrstr_buf), "%s/%u", in46a_ntoa(&in46p->addr), in46p->prefixlen);
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return addrstr_buf;
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}
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/*! Determine if two in46_addr are equal or not
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* \returns 1 in case they are equal; 0 otherwise */
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int in46a_equal(const struct in46_addr *a, const struct in46_addr *b)
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{
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if (a->len == b->len && !memcmp(&a->v6, &b->v6, a->len))
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return 1;
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else
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return 0;
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}
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/*! Determine if two in46_addr prefix are equal or not
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* The prefix length is determined by the shortest of the prefixes of a and b
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* \returns 1 in case the common prefix are equal; 0 otherwise */
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int in46a_prefix_equal(const struct in46_addr *a, const struct in46_addr *b)
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{
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unsigned int len;
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if (a->len > b->len)
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len = b->len;
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else
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len = a->len;
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if (!memcmp(&a->v6, &b->v6, len))
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return 1;
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else
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return 0;
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}
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/*! Match if IPv6 addr1 + addr2 are within same \a mask */
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static int ipv6_within_mask(const struct in6_addr *addr1, const struct in6_addr *addr2,
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const struct in6_addr *mask)
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{
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struct in6_addr masked = *addr2;
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#if defined(__linux__)
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masked.s6_addr32[0] &= mask->s6_addr32[0];
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masked.s6_addr32[1] &= mask->s6_addr32[1];
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masked.s6_addr32[2] &= mask->s6_addr32[2];
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masked.s6_addr32[3] &= mask->s6_addr32[3];
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#else
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masked.__u6_addr.__u6_addr32[0] &= mask->__u6_addr.__u6_addr32[0];
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masked.__u6_addr.__u6_addr32[1] &= mask->__u6_addr.__u6_addr32[1];
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masked.__u6_addr.__u6_addr32[2] &= mask->__u6_addr.__u6_addr32[2];
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masked.__u6_addr.__u6_addr32[3] &= mask->__u6_addr.__u6_addr32[3];
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#endif
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if (!memcmp(addr1, &masked, sizeof(struct in6_addr)))
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return 1;
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else
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return 0;
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}
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/*! Create an IPv6 netmask from the given prefix length */
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static void create_ipv6_netmask(struct in6_addr *netmask, int prefixlen)
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{
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uint32_t *p_netmask;
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memset(netmask, 0, sizeof(struct in6_addr));
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if (prefixlen < 0)
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prefixlen = 0;
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else if (128 < prefixlen)
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prefixlen = 128;
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#if defined(__linux__)
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p_netmask = &netmask->s6_addr32[0];
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#else
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p_netmask = &netmask->__u6_addr.__u6_addr32[0];
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#endif
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while (32 < prefixlen) {
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*p_netmask = 0xffffffff;
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p_netmask++;
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prefixlen -= 32;
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}
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if (prefixlen != 0) {
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*p_netmask = htonl(0xFFFFFFFF << (32 - prefixlen));
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}
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}
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/*! Determine if given \a addr is within given \a net + \a prefixlen
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* Builds the netmask from \a net + \a prefixlen and matches it to \a addr
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* \returns 1 in case of a match, 0 otherwise */
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int in46a_within_mask(const struct in46_addr *addr, const struct in46_addr *net, size_t prefixlen)
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{
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struct in_addr netmask;
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struct in6_addr netmask6;
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if (addr->len != net->len)
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return 0;
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switch (addr->len) {
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case 4:
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netmask.s_addr = htonl(0xFFFFFFFF << (32 - prefixlen));
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if ((addr->v4.s_addr & netmask.s_addr) == net->v4.s_addr)
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return 1;
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else
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return 0;
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case 16:
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create_ipv6_netmask(&netmask6, prefixlen);
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return ipv6_within_mask(&addr->v6, &net->v6, &netmask6);
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default:
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OSMO_ASSERT(0);
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return 0;
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}
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}
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/*! Convert given PDP End User Address to in46_addr
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* \returns 0 on success; negative on error */
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int in46a_to_eua(const struct in46_addr *src, struct ul66_t *eua)
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{
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switch (src->len) {
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case 4:
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eua->l = 6;
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eua->v[0] = 0xf1; /* IETF */
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eua->v[1] = 0x21; /* IPv4 */
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memcpy(&eua->v[2], &src->v4, 4); /* Copy a 4 byte address */
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break;
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case 8:
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case 16:
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eua->l = 18;
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eua->v[0] = 0xf1; /* IETF */
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eua->v[1] = 0x57; /* IPv6 */
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memcpy(&eua->v[2], &src->v6, 16); /* Copy a 16 byte address */
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break;
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default:
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OSMO_ASSERT(0);
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return -1;
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}
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return 0;
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}
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/*! Convert given in46_addr to PDP End User Address
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* \returns 0 on success; negative on error */
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int in46a_from_eua(const struct ul66_t *eua, struct in46_addr *dst)
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{
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if (eua->l < 2)
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goto default_to_dyn_v4;
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if (eua->v[0] != 0xf1)
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return -1;
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switch (eua->v[1]) {
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case 0x21:
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dst->len = 4;
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if (eua->l >= 6)
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memcpy(&dst->v4, &eua->v[2], 4); /* Copy a 4 byte address */
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else
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dst->v4.s_addr = 0;
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break;
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case 0x57:
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dst->len = 16;
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if (eua->l >= 18)
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memcpy(&dst->v6, &eua->v[2], 16); /* Copy a 16 byte address */
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else
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memset(&dst->v6, 0, 16);
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break;
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default:
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return -1;
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}
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return 0;
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default_to_dyn_v4:
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/* assume dynamic IPv4 by default */
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dst->len = 4;
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dst->v4.s_addr = 0;
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return 0;
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}
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