[adns] / src / addrfam.c

/*
 * addrfam.c
 * - address-family specific code
 */
/*
 *  This file is part of adns, which is
 *    Copyright (C) 1997-2000,2003,2006  Ian Jackson
 *    Copyright (C) 1999-2000,2003,2006  Tony Finch
 *    Copyright (C) 1991 Massachusetts Institute of Technology
 *  (See the file INSTALL for full details.)
 *  
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2, or (at your option)
 *  any later version.
 *  
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *  
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software Foundation,
 *  Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 
 */

#include <stdlib.h>
#include <errno.h>
#include <limits.h>
#include <unistd.h>
#include <inttypes.h>
#include <stddef.h>
#include <stdbool.h>

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <net/if.h>

#include "internal.h"

/*
 * General address-family operations.
 */

#define SIN(sa) ((struct sockaddr_in *)(sa))
#define CSIN(sa) ((const struct sockaddr_in *)(sa))

#define SIN6(sa) ((struct sockaddr_in6 *)(sa))
#define CSIN6(sa) ((const struct sockaddr_in6 *)(sa))

static void unknown_af(int af) NONRETURNING;
static void unknown_af(int af) {
  fprintf(stderr, "ADNS INTERNAL: unknown address family %d\n", af);
  abort();
}

/*
 * SOCKADDR_IN_IN6(CNST, struct sockaddr *sa, SIN, {
 *     // struct sockaddr_in *const SIN; // implicitly
 *     code for inet;
 *   }, {
 *     // struct sockaddr_in6 *const SIN6; // implicitly
 *     code for inet6;
 *   })
 *
 * SOCKADDR_IN_IN6_PAIR(CNST, struct sockaddr *sa, SINA,
 *                            struct sockaddr *sb, SINB, {
 *     // struct sockaddr_in *const SINA; // implicitly
 *     // struct sockaddr_in *const SINB; // implicitly
 *     code for inet;
 *   },{
 *     // struct sockaddr_in6 *const SINA6; // implicitly
 *     // struct sockaddr_in6 *const SINB6; // implicitly
 *     code for inet6;
 *   });
 *
 * SOCKADDR_IN_IN6_OTHER(CNST, struct sockaddr *sa, SIN, { in }, { in6 }, {
 *     code for other address family
 *   })
 *
 * AF_IN_IN6_OTHER(af, { in }, { in6 }, { other })
 *
 * Executes the first or second block according to the AF in sa.  CNST
 * may be `const' or empty.  For _PAIR, sa and sb must be same AF.
 *
 * All except _OTHER handle unknown AFs with unknown_af.
 *
 * Code blocks may not contain , outside parens.
 */
#define AF_IN_IN6_OTHER(af, for_inet, for_inet6, other)	\
  if ((af) == AF_INET) {					\
    for_inet							\
  } else if ((af) == AF_INET6) {				\
    for_inet6							\
  } else {							\
    other							\
  }
#define SOCKADDR_IN_IN6_OTHER(cnst, sa, sin, for_inet, for_inet6, other) \
  AF_IN_IN6_OTHER((sa)->sa_family, {				\
      cnst struct sockaddr_in *const sin = (cnst void*)(sa);		\
      for_inet								\
  }, {									\
      cnst struct sockaddr_in6 *const sin##6 = (cnst void*)(sa);	\
      for_inet6								\
  },									\
    other								\
  )
#define SOCKADDR_IN_IN6(cnst, sa, sin, for_inet, for_inet6)		\
  SOCKADDR_IN_IN6_OTHER(cnst, sa, sin, for_inet, for_inet6, {	\
      unknown_af((sa)->sa_family);					\
  })
#define SOCKADDR_IN_IN6_PAIR(cnst, sa, sina, sb, sinb, for_inet, for_inet6) \
  do{									\
    assert((sa)->sa_family == (sb)->sa_family);				\
    SOCKADDR_IN_IN6(cnst, sa, sina, {					\
	cnst struct sockaddr_in *const sinb = (cnst void*)(sb);		\
	for_inet							\
    }, {								\
	cnst struct sockaddr_in6 *const sinb##6 = (cnst void*)(sb);	\
	for_inet6							\
    });									\
  }while(0)

int adns__addrs_equal_raw(const struct sockaddr *a,
			 int bf, const void *b) {
  if (a->sa_family != bf) return 0;

  SOCKADDR_IN_IN6(const, a, sin, {
    return sin->sin_addr.s_addr == ((const struct in_addr*)b)->s_addr;
  }, {
    return !memcmp(&sin6->sin6_addr, b, sizeof(struct in6_addr));
  });
}

int adns__addrs_equal(const adns_sockaddr *a, const adns_sockaddr *b) {
  return adns__addrs_equal_raw(&a->sa, b->sa.sa_family,
			       adns__sockaddr_addr(&b->sa));
}

int adns__sockaddrs_equal(const struct sockaddr *sa,
			  const struct sockaddr *sb) {
  if (!adns__addrs_equal_raw(sa, sb->sa_family, adns__sockaddr_addr(sb)))
    return 0;
  SOCKADDR_IN_IN6_PAIR(const, sa, sina, sb, sinb, {
      return sina->sin_port == sinb->sin_port;
    }, {
      return sina6->sin6_port == sinb6->sin6_port &&
             sina6->sin6_scope_id == sinb6->sin6_scope_id;
    });
}

int adns__addr_width(int af) {
  AF_IN_IN6_OTHER(af, {
      return 32;
    }, {
      return 128;
    }, {
      unknown_af(af);
    });
}

void adns__prefix_mask(adns_sockaddr *sa, int len) {
  SOCKADDR_IN_IN6(, &sa->sa, sin, {
      assert(len <= 32);
      sin->sin_addr.s_addr= htonl(!len ? 0 : 0xffffffff << (32-len));
    }, {
      int i= len/8;
      int j= len%8;
      unsigned char *m= sin6->sin6_addr.s6_addr;
      assert(len <= 128);
      memset(m, 0xff, i);
      if (j) m[i++]= (0xff << (8-j)) & 0xff;
      memset(m+i, 0, 16-i);
    });
}

int adns__guess_prefix_length(const adns_sockaddr *sa) {
  SOCKADDR_IN_IN6(const, &sa->sa, sin, {
      unsigned a= (ntohl(sin->sin_addr.s_addr) >> 24) & 0xff;
      if (a < 128) return 8;
      else if (a < 192) return 16;
      else if (a < 224) return 24;
      else return -1;
    }, {
      (void)sin6;
      return 64;
    });
}

int adns__addr_matches(int af, const void *addr,
		       const adns_sockaddr *base, const adns_sockaddr *mask)
{
  if (af != base->sa.sa_family) return 0;
  SOCKADDR_IN_IN6_PAIR(const, &base->sa, sbase, &mask->sa, smask, {
      const struct in_addr *v4 = addr;
      return (v4->s_addr & smask->sin_addr.s_addr)
	== sbase->sin_addr.s_addr;
    }, {
      int i;
      const char *a= addr;
      const char *b= sbase6->sin6_addr.s6_addr;
      const char *m= smask6->sin6_addr.s6_addr;
      for (i = 0; i < 16; i++)
	if ((a[i] & m[i]) != b[i]) return 0;
      return 1;
    });
}

const void *adns__sockaddr_addr(const struct sockaddr *sa) {
  SOCKADDR_IN_IN6(const, sa, sin, {
      return &sin->sin_addr;
    }, {
      return &sin6->sin6_addr;
    });
}

void adns__addr_inject(const void *a, adns_sockaddr *sa) {
  SOCKADDR_IN_IN6( , &sa->sa, sin, {
      memcpy(&sin->sin_addr, a, sizeof(sin->sin_addr));
    }, {
      memcpy(&sin6->sin6_addr, a, sizeof(sin6->sin6_addr));
    });
}

/*
 * addr2text and text2addr
 */

#define ADDRFAM_DEBUG
#ifdef ADDRFAM_DEBUG
static void af_debug_func(const char *fmt, ...) {
  int esave= errno;
  va_list al;
  va_start(al,fmt);
  vfprintf(stderr,fmt,al);
  va_end(al);
  errno= esave;
}
# define af_debug(fmt,...) \
  (af_debug_func("%s: " fmt "\n", __func__, __VA_ARGS__))
#else
# define af_debug(fmt,...) ((void)("" fmt "", __VA_ARGS__))
#endif

static bool addrtext_our_errno(int e) {
  return
    e==EAFNOSUPPORT ||
    e==EINVAL ||
    e==ENOSPC ||
    e==ENOSYS;
}

static bool addrtext_scope_use_ifname(const struct sockaddr *sa) {
  const struct in6_addr *in6= &CSIN6(sa)->sin6_addr;
  return
    IN6_IS_ADDR_LINKLOCAL(in6) ||
    IN6_IS_ADDR_MC_LINKLOCAL(in6);
}

int adns_text2addr(const char *text, uint16_t port, adns_queryflags flags,
		   struct sockaddr *sa, socklen_t *salen_io) {
  int af;
  char copybuf[INET6_ADDRSTRLEN];
  const char *parse=text;
  const char *scopestr=0;
  socklen_t needlen;
  void *dst;
  uint16_t *portp;

#define INVAL(how) do{				\
  af_debug("invalid: %s: `%s'", how, text);	\
  return EINVAL;				\
}while(0)

#define AFCORE(INETx,SINx,sinx)			\
    af= AF_##INETx;				\
    dst = &SINx(sa)->sinx##_addr;		\
    portp = &SINx(sa)->sinx##_port;		\
    needlen= sizeof(*SINx(sa));

  if (!strchr(text, ':')) { /* INET */

    AFCORE(INET,SIN,sin);

  } else { /* INET6 */

    AFCORE(INET6,SIN6,sin6);

    const char *percent= strchr(text, '%');
    if (percent) {
      ptrdiff_t lhslen = percent - text;
      if (lhslen >= INET6_ADDRSTRLEN) INVAL("scoped addr lhs too long");
      memcpy(copybuf, text, lhslen);
      copybuf[lhslen]= 0;

      parse= copybuf;
      scopestr= percent+1;

      af_debug("will parse scoped addr `%s' %% `%s'", parse, scopestr);
    }

  }

#undef AFCORE

  if (scopestr && (flags & adns_qf_addrlit_scope_forbid))
    INVAL("scoped addr but _scope_forbid");

  if (*salen_io < needlen) {
    *salen_io = needlen;
    return ENOSPC;
  }

  memset(sa, 0, needlen);

  sa->sa_family= af;
  *portp = htons(port);

  if (af == AF_INET && !(flags & adns_qf_addrlit_ipv4_quadonly)) {
    /* we have to use inet_aton to deal with non-dotted-quad literals */
    int r= inet_aton(parse,&SIN(sa)->sin_addr);
    if (!r) INVAL("inet_aton rejected");
  } else {
    int r= inet_pton(af,parse,dst);
    if (!r) INVAL("inet_pton rejected");
    assert(r>0);
  }

  if (scopestr) {
    errno=0;
    char *ep;
    unsigned long scope= strtoul(scopestr,&ep,10);
    if (errno==ERANGE) INVAL("numeric scope id too large for unsigned long");
    assert(!errno);
    if (!*ep) {
      if (scope > ~(uint32_t)0)
	INVAL("numeric scope id too large for uint32_t");
    } else { /* !!*ep */
      if (flags & adns_qf_addrlit_scope_numeric)
	INVAL("non-numeric scope but _scope_numeric");
      if (!addrtext_scope_use_ifname(sa)) {
	af_debug("cannot convert non-numeric scope"
		 " in non-link-local addr `%s'", text);
	return ENOSYS;
      }
      errno= 0;
      scope= if_nametoindex(scopestr);
      if (!scope) {
	/* RFC3493 says "No errors are defined".  It's not clear
	 * whether that is supposed to mean if_nametoindex "can't
	 * fail" (other than by the supplied name not being that of an
	 * interface) which seems unrealistic, or that it conflates
	 * all its errors together by failing to set errno, or simply
	 * that they didn't bother to document the errors.
	 *
	 * glibc, FreeBSD and OpenBSD all set errno (to ENXIO when
	 * appropriate).  See Debian bug #749349.
	 *
	 * We attempt to deal with this by clearing errno to start
	 * with, and then perhaps mapping the results. */
	af_debug("if_nametoindex rejected scope name (errno=%s)",
		 strerror(errno));
	if (errno==0) {
	  return ENXIO;
	} else if (addrtext_our_errno(errno)) {
	  /* we use these for other purposes, urgh. */
	  perror("adns: adns_text2addr: if_nametoindex"
		 " failed with unexpected error");
	  return EIO;
	} else {
	  return errno;
	}
      } else { /* ix>0 */
	if (scope > ~(uint32_t)0) {
	  fprintf(stderr,"adns: adns_text2addr: if_nametoindex"
		  " returned an interface index >=2^32 which will not fit"
		  " in sockaddr_in6.sin6_scope_id");
	  return EIO;
	}
      }
    } /* else; !!*ep */

    SIN6(sa)->sin6_scope_id= scope;
  } /* if (scopestr) */

  *salen_io = needlen;
  return 0;
}

int adns_addr2text(const struct sockaddr *sa, adns_queryflags flags,
		   char *buffer, int *buflen_io, int *port_r) {
  const void *src;
  int port;

  if (*buflen_io < ADNS_ADDR2TEXT_BUFLEN) {
    *buflen_io = ADNS_ADDR2TEXT_BUFLEN;
    return ENOSPC;
  }

  SOCKADDR_IN_IN6_OTHER(const, sa, sin, {
      src= &sin->sin_addr;    port= sin->sin_port;
    }, {
      src= &sin6->sin6_addr;  port= sin6->sin6_port;
    }, {
      return EAFNOSUPPORT;
    });

  const char *ok= inet_ntop(sa->sa_family, src, buffer, *buflen_io);
  assert(ok);

  if (sa->sa_family == AF_INET6) {
    uint32_t scope = CSIN6(sa)->sin6_scope_id;
    if (scope) {
      if (flags & adns_qf_addrlit_scope_forbid)
	return EINVAL;
      int scopeoffset = strlen(buffer);
      int remain = *buflen_io - scopeoffset;
      char *scopeptr =  buffer + scopeoffset;
      assert(remain >= IF_NAMESIZE+1/*%*/);
      *scopeptr++= '%'; remain--;
      bool parsedname = 0;
      af_debug("will print scoped addr `%.*s' %% %"PRIu32"",
	       scopeoffset,buffer, scope);
      if (scope <= UINT_MAX /* so we can pass it to if_indextoname */
	  && !(flags & adns_qf_addrlit_scope_numeric)
	  && addrtext_scope_use_ifname(sa)) {
	parsedname = if_indextoname(scope, scopeptr);
	if (!parsedname) {
	  af_debug("if_indextoname rejected scope (errno=%s)",
		   strerror(errno));
	  if (errno==ENXIO) {
	    /* fair enough, show it as a number then */
	  } else if (addrtext_our_errno(errno)) {
	    /* we use these for other purposes, urgh. */
	    perror("adns: adns_addr2text: if_indextoname"
		   " failed with unexpected error");
	    return EIO;
	  } else {
	    return errno;
	  }
	}
      }
      if (!parsedname) {
	int r = snprintf(scopeptr, remain,
			 "%"PRIu32"", scope);
	assert(r < *buflen_io - scopeoffset);
      }
      af_debug("printed scoped addr `%s'", buffer);
    }
  }

  if (port_r) *port_r= ntohs(port);
  return 0;
}

char *adns__sockaddr_ntoa(const struct sockaddr *sa, char *buf) {
  int err;
  int len= ADNS_ADDR2TEXT_BUFLEN;

  err= adns_addr2text(sa, 0, buf, &len, 0);
  if (err == EIO)
    err= adns_addr2text(sa, adns_qf_addrlit_scope_numeric, buf, &len, 0);
  assert(!err);
  return buf;
}

/*
 * Reverse-domain parsing and construction.
 */

int adns__make_reverse_domain(const struct sockaddr *sa, const char *zone,
			      char **buf_io, size_t bufsz,
			      char **buf_free_r) {
  size_t req;
  char *p;
  unsigned c, y;
  unsigned long aa;
  const unsigned char *ap;
  int i, j;

  AF_IN_IN6_OTHER(sa->sa_family, {
      req= 4 * 4;
      if (!zone) zone= "in-addr.arpa";
    }, {
      req = 2 * 32;
      if (!zone) zone= "ip6.arpa";
    }, {
      return ENOSYS;
    });

  req += strlen(zone) + 1;
  if (req <= bufsz)
    p= *buf_io;
  else {
    p= malloc(req); if (!p) return errno;
    *buf_free_r = p;
  }

  *buf_io= p;
  SOCKADDR_IN_IN6(const, sa, sin, {
      aa= ntohl(sin->sin_addr.s_addr);
      for (i=0; i<4; i++) {
	p += sprintf(p, "%d", (int)(aa & 0xff));
	*p++= '.';
	aa >>= 8;
      }
    }, {
      ap= sin6->sin6_addr.s6_addr + 16;
      for (i=0; i<16; i++) {
	c= *--ap;
	for (j=0; j<2; j++) {
	  y= c & 0xf;
	  *p++= (y < 10) ? y + '0' : y - 10 + 'a';
	  c >>= 4;
	  *p++= '.';
	}
      }
    });

  strcpy(p, zone);
  return 0;
}


static int inet_rev_parsecomp(const char *p, size_t n) {
  int i= 0;
  if (n > 3) return -1;

  while (n--) {
    if ('0' <= *p && *p <= '9') i= 10*i + *p++ - '0';
    else return -1;
  }
  return i;
}

static void inet_rev_mkaddr(adns_sockaddr *addr, const byte *ipv) {
  struct in_addr *v4 = &addr->inet.sin_addr;
  v4->s_addr= htonl((ipv[3]<<24) | (ipv[2]<<16) |
		    (ipv[1]<<8) | (ipv[0]));
}

static int inet6_rev_parsecomp(const char *p, size_t n) {
  if (n != 1) return -1;
  else if ('0' <= *p && *p <= '9') return *p - '0';
  else if ('a' <= *p && *p <= 'f') return *p - 'a' + 10;
  else if ('A' <= *p && *p <= 'F') return *p - 'a' + 10;
  else return -1;
}

static void inet6_rev_mkaddr(adns_sockaddr *addr, const byte *ipv) {
  struct in6_addr *v6 = &addr->inet6.sin6_addr;
  unsigned char *a= v6->s6_addr;
  int i;

  for (i=0; i<16; i++)
    a[i]= (ipv[31-2*i] << 4) | (ipv[30-2*i] << 0);
}

static const struct revparse_domain {
  int af;				/* address family */
  int nrevlab;				/* n of reverse-address labels */
  adns_rrtype rrtype;			/* forward-lookup type */

  int (*rev_parsecomp)(const char *p, size_t n);
  /* parse a single component from a label; return the integer value, or -1
   * if it was unintelligible.
   */

  void (*rev_mkaddr)(adns_sockaddr *addr, const byte *ipv);
  /* write out the parsed protocol address from a vector of parsed components */

  const char *const tail[3];		/* tail label names */
} revparse_domains[NREVDOMAINS] = {
  { AF_INET, 4, adns_r_a, inet_rev_parsecomp, inet_rev_mkaddr,
    { DNS_INADDR_ARPA, 0 } },
  { AF_INET6, 32, adns_r_aaaa, inet6_rev_parsecomp, inet6_rev_mkaddr,
    { DNS_IP6_ARPA, 0 } },
};

#define REVDOMAIN_MAP(rps, labnum)					\
  ((labnum) ? (rps)->map : (1 << NREVDOMAINS) - 1)

int adns__revparse_label(struct revparse_state *rps, int labnum,
			 const char *label, int lablen) {
  unsigned f= REVDOMAIN_MAP(rps, labnum);
  const struct revparse_domain *rpd;
  const char *tp;
  unsigned d;
  int i, ac;

  for (rpd=revparse_domains, i=0, d=1; i<NREVDOMAINS; rpd++, i++, d <<= 1) {
    if (!(f & d)) continue;
    if (labnum >= rpd->nrevlab) {
      tp = rpd->tail[labnum - rpd->nrevlab];
      if (!tp || strncmp(label, tp, lablen) != 0 || tp[lablen])
	goto mismatch;
    } else {
      ac= rpd->rev_parsecomp(label, lablen);
      if (ac < 0) goto mismatch;
      assert(labnum < sizeof(rps->ipv[i]));
      rps->ipv[i][labnum]= ac;
    }
    continue;

  mismatch:
    f &= ~d;
    if (!f) return -1;
  }

  rps->map= f;
  return 0;
}

int adns__revparse_done(struct revparse_state *rps, int nlabels,
			adns_rrtype *rrtype_r, adns_sockaddr *addr_r) {
  unsigned f= REVDOMAIN_MAP(rps, nlabels);
  const struct revparse_domain *rpd;
  unsigned d;
  int i, found= -1;

  for (rpd=revparse_domains, i=0, d=1; i<NREVDOMAINS; rpd++, i++, d <<= 1) {
    if (!(f & d)) continue;
    if (nlabels >= rpd->nrevlab && !rpd->tail[nlabels - rpd->nrevlab])
      { found = i; continue; }
    f &= ~d;
    if (!f) return -1;
  }
  assert(found >= 0); assert(f == (1 << found));

  rpd= &revparse_domains[found];
  *rrtype_r= rpd->rrtype;
  addr_r->sa.sa_family= rpd->af;
  rpd->rev_mkaddr(addr_r, rps->ipv[found]);
  return 0;
}
Commit	Line	Data
07554ccd MW	1	/*
	2	* addrfam.c
	3	* - address-family specific code
	4	*/
	5	/*
	6	* This file is part of adns, which is
	7	* Copyright (C) 1997-2000,2003,2006 Ian Jackson
	8	* Copyright (C) 1999-2000,2003,2006 Tony Finch
	9	* Copyright (C) 1991 Massachusetts Institute of Technology
	10	* (See the file INSTALL for full details.)
	11	*
	12	* This program is free software; you can redistribute it and/or modify
	13	* it under the terms of the GNU General Public License as published by
	14	* the Free Software Foundation; either version 2, or (at your option)
	15	* any later version.
	16	*
	17	* This program is distributed in the hope that it will be useful,
	18	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	19	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	20	* GNU General Public License for more details.
	21	*
	22	* You should have received a copy of the GNU General Public License
	23	* along with this program; if not, write to the Free Software Foundation,
	24	* Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	25	*/
	26
	27	#include <stdlib.h>
	28	#include <errno.h>
	29	#include <limits.h>
	30	#include <unistd.h>
5806b745 IJ	31	#include <inttypes.h>
	32	#include <stddef.h>
	33	#include <stdbool.h>
07554ccd MW	34
	35	#include <sys/types.h>
	36	#include <sys/socket.h>
	37	#include <netinet/in.h>
	38	#include <arpa/inet.h>
5806b745	39	#include <net/if.h>
07554ccd MW	40
	41	#include "internal.h"
	42
	43	/*
	44	* General address-family operations.
	45	*/
	46
	47	#define SIN(sa) ((struct sockaddr_in *)(sa))
	48	#define CSIN(sa) ((const struct sockaddr_in *)(sa))
	49
	50	#define SIN6(sa) ((struct sockaddr_in6 *)(sa))
	51	#define CSIN6(sa) ((const struct sockaddr_in6 *)(sa))
	52
6380363d	53	static void unknown_af(int af) NONRETURNING;
07554ccd MW	54	static void unknown_af(int af) {
	55	fprintf(stderr, "ADNS INTERNAL: unknown address family %d\n", af);
	56	abort();
	57	}
	58
e0fc85c4 IJ	59	/*
	60	* SOCKADDR_IN_IN6(CNST, struct sockaddr *sa, SIN, {
	61	* // struct sockaddr_in *const SIN; // implicitly
	62	* code for inet;
	63	* }, {
	64	* // struct sockaddr_in6 *const SIN6; // implicitly
	65	* code for inet6;
	66	* })
	67	*
	68	* SOCKADDR_IN_IN6_PAIR(CNST, struct sockaddr *sa, SINA,
	69	* struct sockaddr *sb, SINB, {
	70	* // struct sockaddr_in *const SINA; // implicitly
	71	* // struct sockaddr_in *const SINB; // implicitly
	72	* code for inet;
	73	* },{
	74	* // struct sockaddr_in6 *const SINA6; // implicitly
	75	* // struct sockaddr_in6 *const SINB6; // implicitly
	76	* code for inet6;
	77	* });
	78	*
	79	* SOCKADDR_IN_IN6_OTHER(CNST, struct sockaddr *sa, SIN, { in }, { in6 }, {
	80	* code for other address family
	81	* })
	82	*
	83	* AF_IN_IN6_OTHER(af, { in }, { in6 }, { other })
	84	*
	85	* Executes the first or second block according to the AF in sa. CNST
	86	* may be `const' or empty. For _PAIR, sa and sb must be same AF.
	87	*
	88	* All except _OTHER handle unknown AFs with unknown_af.
	89	*
	90	* Code blocks may not contain , outside parens.
	91	*/
	92	#define AF_IN_IN6_OTHER(af, for_inet, for_inet6, other) \
	93	if ((af) == AF_INET) { \
	94	for_inet \
	95	} else if ((af) == AF_INET6) { \
	96	for_inet6 \
	97	} else { \
	98	other \
	99	}
	100	#define SOCKADDR_IN_IN6_OTHER(cnst, sa, sin, for_inet, for_inet6, other) \
	101	AF_IN_IN6_OTHER((sa)->sa_family, { \
	102	cnst struct sockaddr_in const sin = (cnst void)(sa); \
	103	for_inet \
	104	}, { \
	105	cnst struct sockaddr_in6 const sin##6 = (cnst void)(sa); \
	106	for_inet6 \
	107	}, \
	108	other \
	109	)
	110	#define SOCKADDR_IN_IN6(cnst, sa, sin, for_inet, for_inet6) \
	111	SOCKADDR_IN_IN6_OTHER(cnst, sa, sin, for_inet, for_inet6, { \
	112	unknown_af((sa)->sa_family); \
	113	})
	114	#define SOCKADDR_IN_IN6_PAIR(cnst, sa, sina, sb, sinb, for_inet, for_inet6) \
	115	do{ \
	116	assert((sa)->sa_family == (sb)->sa_family); \
	117	SOCKADDR_IN_IN6(cnst, sa, sina, { \
	118	cnst struct sockaddr_in const sinb = (cnst void)(sb); \
	119	for_inet \
	120	}, { \
	121	cnst struct sockaddr_in6 const sinb##6 = (cnst void)(sb); \
	122	for_inet6 \
123	}); \
124	}while(0)
125
82ae109e IJ	126	int adns__addrs_equal_raw(const struct sockaddr *a,
	127	int bf, const void *b) {
	128	if (a->sa_family != bf) return 0;
e0fc85c4 IJ	129
	130	SOCKADDR_IN_IN6(const, a, sin, {
	131	return sin->sin_addr.s_addr == ((const struct in_addr*)b)->s_addr;
	132	}, {
	133	return !memcmp(&sin6->sin6_addr, b, sizeof(struct in6_addr));
	134	});
07554ccd MW	135	}
07554ccd MW	136
82ae109e IJ	137	int adns__addrs_equal(const adns_sockaddr a, const adns_sockaddr b) {
	138	return adns__addrs_equal_raw(&a->sa, b->sa.sa_family,
	139	adns__sockaddr_addr(&b->sa));
	140	}
	141
	142	int adns__sockaddrs_equal(const struct sockaddr *sa,
	143	const struct sockaddr *sb) {
	144	if (!adns__addrs_equal_raw(sa, sb->sa_family, adns__sockaddr_addr(sb)))
	145	return 0;
e0fc85c4 IJ	146	SOCKADDR_IN_IN6_PAIR(const, sa, sina, sb, sinb, {
	147	return sina->sin_port == sinb->sin_port;
	148	}, {
	149	return sina6->sin6_port == sinb6->sin6_port &&
	150	sina6->sin6_scope_id == sinb6->sin6_scope_id;
	151	});
07554ccd MW	152	}
	153
	154	int adns__addr_width(int af) {
e0fc85c4 IJ	155	AF_IN_IN6_OTHER(af, {
	156	return 32;
	157	}, {
	158	return 128;
	159	}, {
	160	unknown_af(af);
	161	});
07554ccd MW	162	}
07554ccd MW	163
82ae109e	164	void adns__prefix_mask(adns_sockaddr *sa, int len) {
e0fc85c4 IJ	165	SOCKADDR_IN_IN6(, &sa->sa, sin, {
	166	assert(len <= 32);
	167	sin->sin_addr.s_addr= htonl(!len ? 0 : 0xffffffff << (32-len));
	168	}, {
	169	int i= len/8;
	170	int j= len%8;
	171	unsigned char *m= sin6->sin6_addr.s6_addr;
	172	assert(len <= 128);
	173	memset(m, 0xff, i);
	174	if (j) m[i++]= (0xff << (8-j)) & 0xff;
	175	memset(m+i, 0, 16-i);
	176	});
07554ccd MW	177	}
07554ccd MW	178
82ae109e	179	int adns__guess_prefix_length(const adns_sockaddr *sa) {
e0fc85c4 IJ	180	SOCKADDR_IN_IN6(const, &sa->sa, sin, {
	181	unsigned a= (ntohl(sin->sin_addr.s_addr) >> 24) & 0xff;
	182	if (a < 128) return 8;
	183	else if (a < 192) return 16;
	184	else if (a < 224) return 24;
	185	else return -1;
	186	}, {
	187	(void)sin6;
	188	return 64;
	189	});
07554ccd MW	190	}
07554ccd MW	191
82ae109e IJ	192	int adns__addr_matches(int af, const void *addr,
82ae109e IJ	193	const adns_sockaddr base, const adns_sockaddr mask)
07554ccd	194	{
82ae109e	195	if (af != base->sa.sa_family) return 0;
e0fc85c4 IJ	196	SOCKADDR_IN_IN6_PAIR(const, &base->sa, sbase, &mask->sa, smask, {
	197	const struct in_addr *v4 = addr;
	198	return (v4->s_addr & smask->sin_addr.s_addr)
	199	== sbase->sin_addr.s_addr;
	200	}, {
	201	int i;
	202	const char *a= addr;
	203	const char *b= sbase6->sin6_addr.s6_addr;
	204	const char *m= smask6->sin6_addr.s6_addr;
	205	for (i = 0; i < 16; i++)
	206	if ((a[i] & m[i]) != b[i]) return 0;
	207	return 1;
	208	});
07554ccd MW	209	}
07554ccd MW	210
82ae109e	211	const void adns__sockaddr_addr(const struct sockaddr sa) {
e0fc85c4 IJ	212	SOCKADDR_IN_IN6(const, sa, sin, {
	213	return &sin->sin_addr;
	214	}, {
	215	return &sin6->sin6_addr;
	216	});
07554ccd MW	217	}
07554ccd MW	218
82ae109e	219	void adns__addr_inject(const void a, adns_sockaddr sa) {
e0fc85c4 IJ	220	SOCKADDR_IN_IN6( , &sa->sa, sin, {
	221	memcpy(&sin->sin_addr, a, sizeof(sin->sin_addr));
	222	}, {
	223	memcpy(&sin6->sin6_addr, a, sizeof(sin6->sin6_addr));
	224	});
07554ccd	225	}
5806b745 IJ	226
	227	/*
	228	* addr2text and text2addr
	229	*/
	230
	231	#define ADDRFAM_DEBUG
	232	#ifdef ADDRFAM_DEBUG
	233	static void af_debug_func(const char *fmt, ...) {
	234	int esave= errno;
	235	va_list al;
	236	va_start(al,fmt);
	237	vfprintf(stderr,fmt,al);
	238	va_end(al);
	239	errno= esave;
	240	}
	241	# define af_debug(fmt,...) \
	242	(af_debug_func("%s: " fmt "\n", __func__, __VA_ARGS__))
	243	#else
	244	# define af_debug(fmt,...) ((void)("" fmt "", __VA_ARGS__))
	245	#endif
	246
	247	static bool addrtext_our_errno(int e) {
	248	return
	249	e==EAFNOSUPPORT \|\|
	250	e==EINVAL \|\|
	251	e==ENOSPC \|\|
	252	e==ENOSYS;
	253	}
	254
	255	static bool addrtext_scope_use_ifname(const struct sockaddr *sa) {
	256	const struct in6_addr *in6= &CSIN6(sa)->sin6_addr;
	257	return
	258	IN6_IS_ADDR_LINKLOCAL(in6) \|\|
	259	IN6_IS_ADDR_MC_LINKLOCAL(in6);
	260	}
	261
	262	int adns_text2addr(const char *text, uint16_t port, adns_queryflags flags,
	263	struct sockaddr sa, socklen_t salen_io) {
	264	int af;
	265	char copybuf[INET6_ADDRSTRLEN];
	266	const char *parse=text;
	267	const char *scopestr=0;
	268	socklen_t needlen;
	269	void *dst;
	270	uint16_t *portp;
	271
	272	#define INVAL(how) do{ \
	273	af_debug("invalid: %s: `%s'", how, text); \
	274	return EINVAL; \
	275	}while(0)
	276
	277	#define AFCORE(INETx,SINx,sinx) \
	278	af= AF_##INETx; \
	279	dst = &SINx(sa)->sinx##_addr; \
	280	portp = &SINx(sa)->sinx##_port; \
	281	needlen= sizeof(*SINx(sa));
	282
	283	if (!strchr(text, ':')) { /* INET */
	284
	285	AFCORE(INET,SIN,sin);
	286
	287	} else { /* INET6 */
	288
	289	AFCORE(INET6,SIN6,sin6);
290
291	const char *percent= strchr(text, '%');
292	if (percent) {
293	ptrdiff_t lhslen = percent - text;
294	if (lhslen >= INET6_ADDRSTRLEN) INVAL("scoped addr lhs too long");
295	memcpy(copybuf, text, lhslen);
296	copybuf[lhslen]= 0;
297
298	parse= copybuf;
299	scopestr= percent+1;
300
301	af_debug("will parse scoped addr `%s' %% `%s'", parse, scopestr);
302	}
303
304	}
305
306	#undef AFCORE
307
308	if (scopestr && (flags & adns_qf_addrlit_scope_forbid))
309	INVAL("scoped addr but _scope_forbid");
310
311	if (*salen_io < needlen) {
312	*salen_io = needlen;
313	return ENOSPC;
314	}
315
316	memset(sa, 0, needlen);
317
318	sa->sa_family= af;
319	*portp = htons(port);
320
321	if (af == AF_INET && !(flags & adns_qf_addrlit_ipv4_quadonly)) {
322	/* we have to use inet_aton to deal with non-dotted-quad literals */
323	int r= inet_aton(parse,&SIN(sa)->sin_addr);
324	if (!r) INVAL("inet_aton rejected");
325	} else {
326	int r= inet_pton(af,parse,dst);
327	if (!r) INVAL("inet_pton rejected");
328	assert(r>0);
329	}
330
331	if (scopestr) {
332	errno=0;
333	char *ep;
334	unsigned long scope= strtoul(scopestr,&ep,10);
335	if (errno==ERANGE) INVAL("numeric scope id too large for unsigned long");
336	assert(!errno);
337	if (!*ep) {
338	if (scope > ~(uint32_t)0)
339	INVAL("numeric scope id too large for uint32_t");
340	} else { /* !!ep /
341	if (flags & adns_qf_addrlit_scope_numeric)
342	INVAL("non-numeric scope but _scope_numeric");
343	if (!addrtext_scope_use_ifname(sa)) {
344	af_debug("cannot convert non-numeric scope"
345	" in non-link-local addr `%s'", text);
346	return ENOSYS;
347	}
348	errno= 0;
349	scope= if_nametoindex(scopestr);
350	if (!scope) {
351	/* RFC3493 says "No errors are defined". It's not clear
352	* whether that is supposed to mean if_nametoindex "can't
353	* fail" (other than by the supplied name not being that of an
354	* interface) which seems unrealistic, or that it conflates
355	* all its errors together by failing to set errno, or simply
356	* that they didn't bother to document the errors.
357	*
358	* glibc, FreeBSD and OpenBSD all set errno (to ENXIO when
359	* appropriate). See Debian bug #749349.
360	*
361	* We attempt to deal with this by clearing errno to start
362	* with, and then perhaps mapping the results. */
363	af_debug("if_nametoindex rejected scope name (errno=%s)",
364	strerror(errno));
365	if (errno==0) {
366	return ENXIO;
367	} else if (addrtext_our_errno(errno)) {
368	/* we use these for other purposes, urgh. */
369	perror("adns: adns_text2addr: if_nametoindex"
370	" failed with unexpected error");
371	return EIO;
372	} else {
373	return errno;
374	}
375	} else { /* ix>0 */
376	if (scope > ~(uint32_t)0) {
377	fprintf(stderr,"adns: adns_text2addr: if_nametoindex"
378	" returned an interface index >=2^32 which will not fit"
379	" in sockaddr_in6.sin6_scope_id");
380	return EIO;
381	}
382	}
383	} /* else; !!ep /
384
385	SIN6(sa)->sin6_scope_id= scope;
386	} /* if (scopestr) */
387
388	*salen_io = needlen;
389	return 0;
390	}
391
392	int adns_addr2text(const struct sockaddr *sa, adns_queryflags flags,
393	char buffer, int buflen_io, int *port_r) {
394	const void *src;
395	int port;
396
397	if (*buflen_io < ADNS_ADDR2TEXT_BUFLEN) {
398	*buflen_io = ADNS_ADDR2TEXT_BUFLEN;
399	return ENOSPC;
400	}
401
e0fc85c4 IJ	402	SOCKADDR_IN_IN6_OTHER(const, sa, sin, {
	403	src= &sin->sin_addr; port= sin->sin_port;
	404	}, {
	405	src= &sin6->sin6_addr; port= sin6->sin6_port;
	406	}, {
	407	return EAFNOSUPPORT;
	408	});
5806b745 IJ	409
	410	const char ok= inet_ntop(sa->sa_family, src, buffer, buflen_io);
	411	assert(ok);
	412
	413	if (sa->sa_family == AF_INET6) {
	414	uint32_t scope = CSIN6(sa)->sin6_scope_id;
	415	if (scope) {
	416	if (flags & adns_qf_addrlit_scope_forbid)
	417	return EINVAL;
	418	int scopeoffset = strlen(buffer);
	419	int remain = *buflen_io - scopeoffset;
	420	char *scopeptr = buffer + scopeoffset;
	421	assert(remain >= IF_NAMESIZE+1/%/);
	422	*scopeptr++= '%'; remain--;
	423	bool parsedname = 0;
c3a165f5 MW	424	af_debug("will print scoped addr `%.*s' %% %"PRIu32"",
c3a165f5 MW	425	scopeoffset,buffer, scope);
5806b745 IJ	426	if (scope <= UINT_MAX /* so we can pass it to if_indextoname */
	427	&& !(flags & adns_qf_addrlit_scope_numeric)
	428	&& addrtext_scope_use_ifname(sa)) {
	429	parsedname = if_indextoname(scope, scopeptr);
	430	if (!parsedname) {
	431	af_debug("if_indextoname rejected scope (errno=%s)",
	432	strerror(errno));
	433	if (errno==ENXIO) {
	434	/* fair enough, show it as a number then */
	435	} else if (addrtext_our_errno(errno)) {
	436	/* we use these for other purposes, urgh. */
	437	perror("adns: adns_addr2text: if_indextoname"
	438	" failed with unexpected error");
	439	return EIO;
	440	} else {
	441	return errno;
	442	}
	443	}
	444	}
	445	if (!parsedname) {
	446	int r = snprintf(scopeptr, remain,
	447	"%"PRIu32"", scope);
	448	assert(r < *buflen_io - scopeoffset);
	449	}
	450	af_debug("printed scoped addr `%s'", buffer);
	451	}
	452	}
	453
	454	if (port_r) *port_r= ntohs(port);
	455	return 0;
	456	}
b0e8338a MW	457
	458	char adns__sockaddr_ntoa(const struct sockaddr sa, char *buf) {
	459	int err;
	460	int len= ADNS_ADDR2TEXT_BUFLEN;
	461
	462	err= adns_addr2text(sa, 0, buf, &len, 0);
	463	if (err == EIO)
	464	err= adns_addr2text(sa, adns_qf_addrlit_scope_numeric, buf, &len, 0);
	465	assert(!err);
	466	return buf;
	467	}
51cb3de3 MW	468
	469	/*
	470	* Reverse-domain parsing and construction.
	471	*/
	472
	473	int adns__make_reverse_domain(const struct sockaddr sa, const char zone,
	474	char **buf_io, size_t bufsz,
	475	char **buf_free_r) {
	476	size_t req;
	477	char *p;
	478	unsigned c, y;
	479	unsigned long aa;
	480	const unsigned char *ap;
	481	int i, j;
	482
e0fc85c4 IJ	483	AF_IN_IN6_OTHER(sa->sa_family, {
	484	req= 4 * 4;
	485	if (!zone) zone= "in-addr.arpa";
	486	}, {
	487	req = 2 * 32;
	488	if (!zone) zone= "ip6.arpa";
	489	}, {
	490	return ENOSYS;
	491	});
51cb3de3 MW	492
	493	req += strlen(zone) + 1;
	494	if (req <= bufsz)
	495	p= *buf_io;
	496	else {
	497	p= malloc(req); if (!p) return errno;
	498	*buf_free_r = p;
	499	}
	500
	501	*buf_io= p;
e0fc85c4 IJ	502	SOCKADDR_IN_IN6(const, sa, sin, {
	503	aa= ntohl(sin->sin_addr.s_addr);
	504	for (i=0; i<4; i++) {
	505	p += sprintf(p, "%d", (int)(aa & 0xff));
51cb3de3	506	*p++= '.';
e0fc85c4	507	aa >>= 8;
51cb3de3	508	}
e0fc85c4 IJ	509	}, {
	510	ap= sin6->sin6_addr.s6_addr + 16;
	511	for (i=0; i<16; i++) {
	512	c= *--ap;
	513	for (j=0; j<2; j++) {
	514	y= c & 0xf;
	515	*p++= (y < 10) ? y + '0' : y - 10 + 'a';
	516	c >>= 4;
	517	*p++= '.';
	518	}
	519	}
	520	});
51cb3de3 MW	521
	522	strcpy(p, zone);
	523	return 0;
	524	}
	525
	526
	527	static int inet_rev_parsecomp(const char *p, size_t n) {
	528	int i= 0;
	529	if (n > 3) return -1;
	530
	531	while (n--) {
	532	if ('0' <= p && p <= '9') i= 10i + p++ - '0';
	533	else return -1;
	534	}
	535	return i;
	536	}
	537
82ae109e IJ	538	static void inet_rev_mkaddr(adns_sockaddr addr, const byte ipv) {
	539	struct in_addr *v4 = &addr->inet.sin_addr;
	540	v4->s_addr= htonl((ipv[3]<<24) \| (ipv[2]<<16) \|
	541	(ipv[1]<<8) \| (ipv[0]));
51cb3de3 MW	542	}
	543
	544	static int inet6_rev_parsecomp(const char *p, size_t n) {
	545	if (n != 1) return -1;
	546	else if ('0' <= p && p <= '9') return *p - '0';
	547	else if ('a' <= p && p <= 'f') return *p - 'a' + 10;
	548	else if ('A' <= p && p <= 'F') return *p - 'a' + 10;
	549	else return -1;
	550	}
	551
82ae109e IJ	552	static void inet6_rev_mkaddr(adns_sockaddr addr, const byte ipv) {
	553	struct in6_addr *v6 = &addr->inet6.sin6_addr;
	554	unsigned char *a= v6->s6_addr;
51cb3de3 MW	555	int i;
	556
	557	for (i=0; i<16; i++)
	558	a[i]= (ipv[31-2i] << 4) \| (ipv[30-2i] << 0);
	559	}
	560
	561	static const struct revparse_domain {
	562	int af; /* address family */
	563	int nrevlab; /* n of reverse-address labels */
	564	adns_rrtype rrtype; /* forward-lookup type */
	565
	566	int (rev_parsecomp)(const char p, size_t n);
	567	/* parse a single component from a label; return the integer value, or -1
	568	* if it was unintelligible.
	569	*/
	570
82ae109e IJ	571	void (rev_mkaddr)(adns_sockaddr addr, const byte *ipv);
82ae109e IJ	572	/* write out the parsed protocol address from a vector of parsed components */
51cb3de3 MW	573
	574	const char const tail[3]; / tail label names */
	575	} revparse_domains[NREVDOMAINS] = {
	576	{ AF_INET, 4, adns_r_a, inet_rev_parsecomp, inet_rev_mkaddr,
	577	{ DNS_INADDR_ARPA, 0 } },
	578	{ AF_INET6, 32, adns_r_aaaa, inet6_rev_parsecomp, inet6_rev_mkaddr,
	579	{ DNS_IP6_ARPA, 0 } },
	580	};
	581
	582	#define REVDOMAIN_MAP(rps, labnum) \
	583	((labnum) ? (rps)->map : (1 << NREVDOMAINS) - 1)
	584
	585	int adns__revparse_label(struct revparse_state *rps, int labnum,
	586	const char *label, int lablen) {
	587	unsigned f= REVDOMAIN_MAP(rps, labnum);
	588	const struct revparse_domain *rpd;
	589	const char *tp;
	590	unsigned d;
	591	int i, ac;
	592
	593	for (rpd=revparse_domains, i=0, d=1; i<NREVDOMAINS; rpd++, i++, d <<= 1) {
	594	if (!(f & d)) continue;
	595	if (labnum >= rpd->nrevlab) {
	596	tp = rpd->tail[labnum - rpd->nrevlab];
	597	if (!tp \|\| strncmp(label, tp, lablen) != 0 \|\| tp[lablen])
	598	goto mismatch;
	599	} else {
	600	ac= rpd->rev_parsecomp(label, lablen);
	601	if (ac < 0) goto mismatch;
	602	assert(labnum < sizeof(rps->ipv[i]));
	603	rps->ipv[i][labnum]= ac;
	604	}
	605	continue;
	606
	607	mismatch:
	608	f &= ~d;
	609	if (!f) return -1;
	610	}
	611
	612	rps->map= f;
	613	return 0;
	614	}
	615
	616	int adns__revparse_done(struct revparse_state *rps, int nlabels,
82ae109e	617	adns_rrtype rrtype_r, adns_sockaddr addr_r) {
51cb3de3 MW	618	unsigned f= REVDOMAIN_MAP(rps, nlabels);
	619	const struct revparse_domain *rpd;
	620	unsigned d;
	621	int i, found= -1;
	622
	623	for (rpd=revparse_domains, i=0, d=1; i<NREVDOMAINS; rpd++, i++, d <<= 1) {
	624	if (!(f & d)) continue;
	625	if (nlabels >= rpd->nrevlab && !rpd->tail[nlabels - rpd->nrevlab])
	626	{ found = i; continue; }
	627	f &= ~d;
	628	if (!f) return -1;
	629	}
	630	assert(found >= 0); assert(f == (1 << found));
	631
	632	rpd= &revparse_domains[found];
	633	*rrtype_r= rpd->rrtype;
82ae109e IJ	634	addr_r->sa.sa_family= rpd->af;
82ae109e IJ	635	rpd->rev_mkaddr(addr_r, rps->ipv[found]);
51cb3de3 MW	636	return 0;
51cb3de3 MW	637	}