/* $OpenBSD: addr.c,v 1.9 2024/10/18 04:30:09 djm Exp $ */

/*

 * Copyright (c) 2004-2008 Damien Miller <djm@mindrot.org>

 *

 * Permission to use, copy, modify, and distribute this software for any

 * purpose with or without fee is hereby granted, provided that the above

 * copyright notice and this permission notice appear in all copies.

 *

 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES

 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF

 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR

 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES

 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN

 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF

 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

 */

#include "includes.h"

#include <sys/types.h>

#include <sys/socket.h>

#include <netinet/in.h>

#include <arpa/inet.h>

#include <netdb.h>

#include <string.h>

#include <stdlib.h>

#include <stdio.h>

#include <limits.h>

#include "addr.h"

#define _SA(x)  ((struct sockaddr *)(x))

static int

addr_unicast_masklen(int af)

{

  switch (af) {

  case AF_INET:

    return 32;

  case AF_INET6:

    return 128;

  default:

    return -1;

  }

}

static inline int

masklen_valid(int af, u_int masklen)

{

  switch (af) {

  case AF_INET:

    return masklen <= 32 ? 0 : -1;

  case AF_INET6:

    return masklen <= 128 ? 0 : -1;

  default:

    return -1;

  }

}

static int

addr_xaddr_to_sa(const struct xaddr *xa, struct sockaddr *sa, socklen_t *len,

    u_int16_t port)

{

  struct sockaddr_in *in4 = (struct sockaddr_in *)sa;

  struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)sa;

  if (xa == NULL || sa == NULL || len == NULL)

    return -1;

  switch (xa->af) {

  case AF_INET:

    if (*len < sizeof(*in4))

      return -1;

    memset(sa, '\0', sizeof(*in4));

    *len = sizeof(*in4);

#ifdef SOCK_HAS_LEN

    in4->sin_len = sizeof(*in4);

#endif

    in4->sin_family = AF_INET;

    in4->sin_port = htons(port);

    memcpy(&in4->sin_addr, &xa->v4, sizeof(in4->sin_addr));

    break;

  case AF_INET6:

    if (*len < sizeof(*in6))

      return -1;

    memset(sa, '\0', sizeof(*in6));

    *len = sizeof(*in6);

#ifdef SOCK_HAS_LEN

    in6->sin6_len = sizeof(*in6);

#endif

    in6->sin6_family = AF_INET6;

    in6->sin6_port = htons(port);

    memcpy(&in6->sin6_addr, &xa->v6, sizeof(in6->sin6_addr));

#ifdef HAVE_STRUCT_SOCKADDR_IN6_SIN6_SCOPE_ID

    in6->sin6_scope_id = xa->scope_id;

#endif

    break;

  default:

    return -1;

  }

  return 0;

}

/*

 * Convert struct sockaddr to struct xaddr

 * Returns 0 on success, -1 on failure.

 */

int

addr_sa_to_xaddr(struct sockaddr *sa, socklen_t slen, struct xaddr *xa)

{

  struct sockaddr_in *in4 = (struct sockaddr_in *)sa;

  struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)sa;

  memset(xa, '\0', sizeof(*xa));

  switch (sa->sa_family) {

  case AF_INET:

    if (slen < (socklen_t)sizeof(*in4))

      return -1;

    xa->af = AF_INET;

    memcpy(&xa->v4, &in4->sin_addr, sizeof(xa->v4));

    break;

  case AF_INET6:

    if (slen < (socklen_t)sizeof(*in6))

      return -1;

    xa->af = AF_INET6;

    memcpy(&xa->v6, &in6->sin6_addr, sizeof(xa->v6));

#ifdef HAVE_STRUCT_SOCKADDR_IN6_SIN6_SCOPE_ID

    xa->scope_id = in6->sin6_scope_id;

#endif

    break;

  default:

    return -1;

  }

  return 0;

}

static int

addr_invert(struct xaddr *n)

{

  int i;

  if (n == NULL)

    return -1;

  switch (n->af) {

  case AF_INET:

    n->v4.s_addr = ~n->v4.s_addr;

    return 0;

  case AF_INET6:

    for (i = 0; i < 4; i++)

      n->addr32[i] = ~n->addr32[i];

    return 0;

  default:

    return -1;

  }

}

/*

 * Calculate a netmask of length 'l' for address family 'af' and

 * store it in 'n'.

 * Returns 0 on success, -1 on failure.

 */

int

addr_netmask(int af, u_int l, struct xaddr *n)

{

  int i;

  if (masklen_valid(af, l) != 0 || n == NULL)

    return -1;

  memset(n, '\0', sizeof(*n));

  switch (af) {

  case AF_INET:

    n->af = AF_INET;

    if (l == 0)

      return 0;

    n->v4.s_addr = htonl((0xffffffff << (32 - l)) & 0xffffffff);

    return 0;

  case AF_INET6:

    n->af = AF_INET6;

    for (i = 0; i < 4 && l >= 32; i++, l -= 32)

      n->addr32[i] = 0xffffffffU;

    if (i < 4 && l != 0)

      n->addr32[i] = htonl((0xffffffff << (32 - l)) &

          0xffffffff);

    return 0;

  default:

    return -1;

  }

}

static int

addr_hostmask(int af, u_int l, struct xaddr *n)

{

  if (addr_netmask(af, l, n) == -1 || addr_invert(n) == -1)

    return -1;

  return 0;

}

/*

 * Perform logical AND of addresses 'a' and 'b', storing result in 'dst'.

 * Returns 0 on success, -1 on failure.

 */

int

addr_and(struct xaddr *dst, const struct xaddr *a, const struct xaddr *b)

{

  int i;

  if (dst == NULL || a == NULL || b == NULL || a->af != b->af)

    return -1;

  memcpy(dst, a, sizeof(*dst));

  switch (a->af) {

  case AF_INET:

    dst->v4.s_addr &= b->v4.s_addr;

    return 0;

  case AF_INET6:

    dst->scope_id = a->scope_id;

    for (i = 0; i < 4; i++)

      dst->addr32[i] &= b->addr32[i];

    return 0;

  default:

    return -1;

  }

}

static int

addr_or(struct xaddr *dst, const struct xaddr *a, const struct xaddr *b)

{

  int i;

  if (dst == NULL || a == NULL || b == NULL || a->af != b->af)

    return (-1);

  memcpy(dst, a, sizeof(*dst));

  switch (a->af) {

  case AF_INET:

    dst->v4.s_addr |= b->v4.s_addr;

    return (0);

  case AF_INET6:

    for (i = 0; i < 4; i++)

      dst->addr32[i] |= b->addr32[i];

    return (0);

  default:

    return (-1);

  }

}

int

addr_cmp(const struct xaddr *a, const struct xaddr *b)

{

  int i;

  if (a->af != b->af)

    return (a->af == AF_INET6 ? 1 : -1);

  switch (a->af) {

  case AF_INET:

    /*

     * Can't just subtract here as 255.255.255.255 - 0.0.0.0 is

     * too big to fit into a signed int

     */

    if (a->v4.s_addr == b->v4.s_addr)

      return 0;

    return (ntohl(a->v4.s_addr) > ntohl(b->v4.s_addr) ? 1 : -1);

  case AF_INET6:

    /*

     * Do this a byte at a time to avoid the above issue and

     * any endian problems

     */

    for (i = 0; i < 16; i++)

      if (a->addr8[i] - b->addr8[i] != 0)

        return (a->addr8[i] - b->addr8[i]);

    if (a->scope_id == b->scope_id)

      return (0);

    return (a->scope_id > b->scope_id ? 1 : -1);

  default:

    return (-1);

  }

}

static int

addr_is_all0s(const struct xaddr *a)

{

  int i;

  switch (a->af) {

  case AF_INET:

    return (a->v4.s_addr == 0 ? 0 : -1);

  case AF_INET6:

    for (i = 0; i < 4; i++)

      if (a->addr32[i] != 0)

        return -1;

    return 0;

  default:

    return -1;

  }

}

/* Increment the specified address. Note, does not do overflow checking */

void

addr_increment(struct xaddr *a)

{

  int i;

  uint32_t n;

  switch (a->af) {

  case AF_INET:

    a->v4.s_addr = htonl(ntohl(a->v4.s_addr) + 1);

    break;

  case AF_INET6:

    for (i = 0; i < 4; i++) {

      /* Increment with carry */

      n = ntohl(a->addr32[3 - i]) + 1;

      a->addr32[3 - i] = htonl(n);

      if (n != 0)

        break;

    }

    break;

  }

}

/*

 * Test whether host portion of address 'a', as determined by 'masklen'

 * is all zeros.

 * Returns 0 if host portion of address is all-zeros,

 * -1 if not all zeros or on failure.

 */

static int

addr_host_is_all0s(const struct xaddr *a, u_int masklen)

{

  struct xaddr tmp_addr, tmp_mask, tmp_result;

  memcpy(&tmp_addr, a, sizeof(tmp_addr));

  if (addr_hostmask(a->af, masklen, &tmp_mask) == -1)

    return -1;

  if (addr_and(&tmp_result, &tmp_addr, &tmp_mask) == -1)

    return -1;

  return addr_is_all0s(&tmp_result);

}

#if 0

static int

addr_host_to_all0s(struct xaddr *a, u_int masklen)

{

  struct xaddr tmp_mask;

  if (addr_netmask(a->af, masklen, &tmp_mask) == -1)

    return (-1);

  if (addr_and(a, a, &tmp_mask) == -1)

    return (-1);

  return (0);

}

#endif

int

addr_host_to_all1s(struct xaddr *a, u_int masklen)

{

  struct xaddr tmp_mask;

  if (addr_hostmask(a->af, masklen, &tmp_mask) == -1)

    return (-1);

  if (addr_or(a, a, &tmp_mask) == -1)

    return (-1);

  return (0);

}

/*

 * Parse string address 'p' into 'n'.

 * Returns 0 on success, -1 on failure.

 */

int

addr_pton(const char *p, struct xaddr *n)

{

  struct addrinfo hints, *ai;

  memset(&hints, '\0', sizeof(hints));

  hints.ai_flags = AI_NUMERICHOST;

  if (p == NULL || getaddrinfo(p, NULL, &hints, &ai) != 0)

    return -1;

  if (ai == NULL)

    return -1;

  if (ai->ai_addr == NULL) {

    freeaddrinfo(ai);

    return -1;

  }

  if (n != NULL && addr_sa_to_xaddr(ai->ai_addr, ai->ai_addrlen,

      n) == -1) {

    freeaddrinfo(ai);

    return -1;

  }

  freeaddrinfo(ai);

  return 0;

}

#if 0

static int

addr_sa_pton(const char *h, const char *s, struct sockaddr *sa, socklen_t slen)

{

  struct addrinfo hints, *ai;

  memset(&hints, '\0', sizeof(hints));

  hints.ai_flags = AI_NUMERICHOST;

  if (h == NULL || getaddrinfo(h, s, &hints, &ai) != 0)

    return -1;

  if (ai == NULL)

    return -1;

  if (ai->ai_addr == NULL) {

    freeaddrinfo(ai);

    return -1;

  }

  if (sa != NULL) {

    if (slen < ai->ai_addrlen) {

      freeaddrinfo(ai);

      return -1;

    }

    memcpy(sa, &ai->ai_addr, ai->ai_addrlen);

  }

  freeaddrinfo(ai);

  return 0;

}

#endif

int

addr_ntop(const struct xaddr *n, char *p, size_t len)

{

  struct sockaddr_storage ss;

  socklen_t slen = sizeof(ss);

  if (addr_xaddr_to_sa(n, _SA(&ss), &slen, 0) == -1)

    return -1;

  if (p == NULL || len == 0)

    return -1;

  if (getnameinfo(_SA(&ss), slen, p, len, NULL, 0,

      NI_NUMERICHOST) != 0)

    return -1;

  return 0;

}

/*

 * Parse a CIDR address (x.x.x.x/y or xxxx:yyyy::/z).

 * Return -1 on parse error, -2 on inconsistency or 0 on success.

 */

int

addr_pton_cidr(const char *p, struct xaddr *n, u_int *l)

{

  struct xaddr tmp;

  u_int masklen = 999;

  char addrbuf[64], *mp;

  const char *errstr;

  /* Don't modify argument */

  if (p == NULL || strlcpy(addrbuf, p, sizeof(addrbuf)) >= sizeof(addrbuf))

    return -1;

  if ((mp = strchr(addrbuf, '/')) != NULL) {

    *mp = '\0';

    mp++;

    masklen = (u_int)strtonum(mp, 0, INT_MAX, &errstr);

    if (errstr)

      return -1;

  }

  if (addr_pton(addrbuf, &tmp) == -1)

    return -1;

  if (mp == NULL)

    masklen = addr_unicast_masklen(tmp.af);

  if (masklen_valid(tmp.af, masklen) == -1)

    return -2;

  if (addr_host_is_all0s(&tmp, masklen) != 0)

    return -2;

  if (n != NULL)

    memcpy(n, &tmp, sizeof(*n));

  if (l != NULL)

    *l = masklen;

  return 0;

}

int

addr_netmatch(const struct xaddr *host, const struct xaddr *net, u_int masklen)

{

  struct xaddr tmp_mask, tmp_result;

  if (host->af != net->af)

    return -1;

  if (addr_netmask(host->af, masklen, &tmp_mask) == -1)

    return -1;

  if (addr_and(&tmp_result, host, &tmp_mask) == -1)

    return -1;

  return addr_cmp(&tmp_result, net);

}