[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))

/* This gadget (thanks, Richard Kettlewell) makes sure that we handle the
 * same set of address families in each switch. */
#define AF_CASES(pre)							\
  case AF_INET: goto pre##_inet;					\
  case AF_INET6: goto pre##_inet6

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

int adns__addrs_equal_raw(const struct sockaddr *a,
			 int bf, const void *b) {
  if (a->sa_family != bf) return 0;
  switch (a->sa_family) {
  AF_CASES(af);
  af_inet:
    return ((const struct sockaddr_in*)a)->sin_addr.s_addr ==
           ((const struct in_addr*)b)->s_addr;
  af_inet6:
    return !memcmp(&((const struct sockaddr_in6*)a)->sin6_addr,
		   b, sizeof(struct in6_addr));
  default: unknown_af(a->sa_family); return -1;
  }
}

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;
  switch (sa->sa_family) {
  AF_CASES(af);
  af_inet: {
    const struct sockaddr_in *sina= CSIN(sa), *sinb= CSIN(sb);
    return sina->sin_port == sinb->sin_port;
  }
  af_inet6: {
    /* Don't check the flowlabel.  That's apparently useful for routing
     * performance, but doesn't affect the address in any important
     * respect. */
    const struct sockaddr_in6 *sin6a= CSIN6(sa), *sin6b= CSIN6(sb);
    return sin6a->sin6_port == sin6b->sin6_port &&
           sin6a->sin6_scope_id == sin6b->sin6_scope_id;
  }
  default:
    unknown_af(sa->sa_family);
    return -1;
  }
}

int adns__addr_width(int af) {
  switch (af) {
  AF_CASES(af);
  af_inet: return 32;
  af_inet6: return 128;
  default: unknown_af(af); return -1;
  }
}

void adns__prefix_mask(adns_sockaddr *sa, int len) {
  int af= sa->sa.sa_family;
  switch (af) {
  AF_CASES(af);
  af_inet:
    assert(len <= 32);
    sa->inet.sin_addr.s_addr= htonl(!len ? 0 : 0xffffffff << (32-len));
    break;
  af_inet6: {
    int i= len/8, j= len%8;
    unsigned char *m= sa->inet6.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);
  } break;
  default:
    unknown_af(af);
    break;
  }
}

int adns__guess_prefix_length(const adns_sockaddr *sa) {
  int af= sa->sa.sa_family;
  switch (af) {
  AF_CASES(af);
  af_inet: {
    unsigned a= (ntohl(sa->inet.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;
  } break;
  af_inet6:
    return 64;
  default:
    unknown_af(af);
    return -1;
  }
}

int adns__addr_matches(int af, const void *addr,
		       const adns_sockaddr *base, const adns_sockaddr *mask)
{
  assert(base->sa.sa_family == mask->sa.sa_family);
  if (af != base->sa.sa_family) return 0;
  switch (af) {
  AF_CASES(af);
  af_inet: {
    const struct in_addr *v4 = addr;
    return (v4->s_addr & mask->inet.sin_addr.s_addr)
      == base->inet.sin_addr.s_addr;
  }
  af_inet6: {
    int i;
    const char *a= addr;
    const char *b= base->inet6.sin6_addr.s6_addr;
    const char *m= mask->inet6.sin6_addr.s6_addr;
    for (i = 0; i < 16; i++)
      if ((a[i] & m[i]) != b[i]) return 0;
    return 1;
  } break;
  default:
    unknown_af(af);
    return -1;
  }
}

const void *adns__sockaddr_addr(const struct sockaddr *sa) {
  switch (sa->sa_family) {
  AF_CASES(af);
  af_inet: {
    const struct sockaddr_in *sin = CSIN(sa);
    return &sin->sin_addr;
  }
  af_inet6: {
    const struct sockaddr_in6 *sin6 = CSIN6(sa);
    return &sin6->sin6_addr;
  }
  default:
    unknown_af(sa->sa_family);
  }
}

void adns__addr_inject(const void *a, adns_sockaddr *sa) {
  switch (sa->sa.sa_family) {
  AF_CASES(af);
  af_inet: {
    struct sockaddr_in *sin = &sa->inet;
    memcpy(&sin->sin_addr, a, sizeof(sin->sin_addr));
    break;
  }
  af_inet6: {
    struct sockaddr_in6 *sin6 = &sa->inet6;
    memcpy(&sin6->sin6_addr, a, sizeof(sin6->sin6_addr));
    break;
  }
  default:
    unknown_af(sa->sa.sa_family);
  }
}

/*
 * 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;
  }

  switch (sa->sa_family) {
    AF_CASES(af);
    af_inet:  src= &CSIN(sa)->sin_addr;    port= CSIN(sa)->sin_port;    break;
    af_inet6: src= &CSIN6(sa)->sin6_addr;  port= CSIN6(sa)->sin6_port;  break;
    default: 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;

  switch (sa->sa_family) {
  AF_CASES(af);
  af_inet:
    req= 4 * 4;
    if (!zone) zone= "in-addr.arpa";
    break;
  af_inet6:
    req = 2 * 32;
    if (!zone) zone= "ip6.arpa";
    break;
  default:
    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;
  switch (sa->sa_family) {
  AF_CASES(bf);
  bf_inet:
    aa= ntohl(CSIN(sa)->sin_addr.s_addr);
    for (i=0; i<4; i++) {
      p += sprintf(p, "%d", (int)(aa & 0xff));
      *p++= '.';
      aa >>= 8;
    }
    break;
  bf_inet6:
    ap= CSIN6(sa)->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++= '.';
      }
    }
    break;
  default:
    unknown_af(sa->sa_family);
  }

  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
	53	/* This gadget (thanks, Richard Kettlewell) makes sure that we handle the
	54	* same set of address families in each switch. */
	55	#define AF_CASES(pre) \
	56	case AF_INET: goto pre##_inet; \
	57	case AF_INET6: goto pre##_inet6
	58
6380363d	59	static void unknown_af(int af) NONRETURNING;
07554ccd MW	60	static void unknown_af(int af) {
	61	fprintf(stderr, "ADNS INTERNAL: unknown address family %d\n", af);
	62	abort();
	63	}
	64
82ae109e IJ	65	int adns__addrs_equal_raw(const struct sockaddr *a,
	66	int bf, const void *b) {
	67	if (a->sa_family != bf) return 0;
	68	switch (a->sa_family) {
07554ccd	69	AF_CASES(af);
82ae109e IJ	70	af_inet:
	71	return ((const struct sockaddr_in*)a)->sin_addr.s_addr ==
	72	((const struct in_addr*)b)->s_addr;
	73	af_inet6:
	74	return !memcmp(&((const struct sockaddr_in6*)a)->sin6_addr,
	75	b, sizeof(struct in6_addr));
	76	default: unknown_af(a->sa_family); return -1;
07554ccd MW	77	}
	78	}
	79
82ae109e IJ	80	int adns__addrs_equal(const adns_sockaddr a, const adns_sockaddr b) {
	81	return adns__addrs_equal_raw(&a->sa, b->sa.sa_family,
	82	adns__sockaddr_addr(&b->sa));
	83	}
	84
	85	int adns__sockaddrs_equal(const struct sockaddr *sa,
	86	const struct sockaddr *sb) {
	87	if (!adns__addrs_equal_raw(sa, sb->sa_family, adns__sockaddr_addr(sb)))
	88	return 0;
07554ccd MW	89	switch (sa->sa_family) {
	90	AF_CASES(af);
	91	af_inet: {
	92	const struct sockaddr_in sina= CSIN(sa), sinb= CSIN(sb);
82ae109e	93	return sina->sin_port == sinb->sin_port;
07554ccd MW	94	}
	95	af_inet6: {
	96	/* Don't check the flowlabel. That's apparently useful for routing
	97	* performance, but doesn't affect the address in any important
	98	* respect. */
	99	const struct sockaddr_in6 sin6a= CSIN6(sa), sin6b= CSIN6(sb);
82ae109e IJ	100	return sin6a->sin6_port == sin6b->sin6_port &&
82ae109e IJ	101	sin6a->sin6_scope_id == sin6b->sin6_scope_id;
07554ccd MW	102	}
	103	default:
	104	unknown_af(sa->sa_family);
	105	return -1;
	106	}
	107	}
	108
	109	int adns__addr_width(int af) {
	110	switch (af) {
	111	AF_CASES(af);
	112	af_inet: return 32;
	113	af_inet6: return 128;
	114	default: unknown_af(af); return -1;
	115	}
	116	}
	117
82ae109e IJ	118	void adns__prefix_mask(adns_sockaddr *sa, int len) {
82ae109e IJ	119	int af= sa->sa.sa_family;
07554ccd MW	120	switch (af) {
	121	AF_CASES(af);
	122	af_inet:
	123	assert(len <= 32);
82ae109e	124	sa->inet.sin_addr.s_addr= htonl(!len ? 0 : 0xffffffff << (32-len));
07554ccd MW	125	break;
	126	af_inet6: {
	127	int i= len/8, j= len%8;
82ae109e	128	unsigned char *m= sa->inet6.sin6_addr.s6_addr;
07554ccd MW	129	assert(len <= 128);
	130	memset(m, 0xff, i);
	131	if (j) m[i++]= (0xff << (8-j)) & 0xff;
	132	memset(m+i, 0, 16-i);
	133	} break;
	134	default:
	135	unknown_af(af);
	136	break;
	137	}
	138	}
	139
82ae109e IJ	140	int adns__guess_prefix_length(const adns_sockaddr *sa) {
82ae109e IJ	141	int af= sa->sa.sa_family;
07554ccd MW	142	switch (af) {
	143	AF_CASES(af);
	144	af_inet: {
82ae109e	145	unsigned a= (ntohl(sa->inet.sin_addr.s_addr) >> 24) & 0xff;
07554ccd MW	146	if (a < 128) return 8;
	147	else if (a < 192) return 16;
	148	else if (a < 224) return 24;
	149	else return -1;
	150	} break;
	151	af_inet6:
	152	return 64;
	153	default:
	154	unknown_af(af);
	155	return -1;
	156	}
	157	}
	158
82ae109e IJ	159	int adns__addr_matches(int af, const void *addr,
82ae109e IJ	160	const adns_sockaddr base, const adns_sockaddr mask)
07554ccd	161	{
82ae109e IJ	162	assert(base->sa.sa_family == mask->sa.sa_family);
	163	if (af != base->sa.sa_family) return 0;
	164	switch (af) {
07554ccd	165	AF_CASES(af);
82ae109e IJ	166	af_inet: {
	167	const struct in_addr *v4 = addr;
	168	return (v4->s_addr & mask->inet.sin_addr.s_addr)
	169	== base->inet.sin_addr.s_addr;
	170	}
07554ccd MW	171	af_inet6: {
07554ccd MW	172	int i;
82ae109e IJ	173	const char *a= addr;
	174	const char *b= base->inet6.sin6_addr.s6_addr;
	175	const char *m= mask->inet6.sin6_addr.s6_addr;
07554ccd MW	176	for (i = 0; i < 16; i++)
	177	if ((a[i] & m[i]) != b[i]) return 0;
	178	return 1;
	179	} break;
	180	default:
82ae109e	181	unknown_af(af);
07554ccd MW	182	return -1;
	183	}
	184	}
	185
82ae109e	186	const void adns__sockaddr_addr(const struct sockaddr sa) {
07554ccd MW	187	switch (sa->sa_family) {
	188	AF_CASES(af);
	189	af_inet: {
	190	const struct sockaddr_in *sin = CSIN(sa);
82ae109e	191	return &sin->sin_addr;
07554ccd MW	192	}
	193	af_inet6: {
	194	const struct sockaddr_in6 *sin6 = CSIN6(sa);
82ae109e	195	return &sin6->sin6_addr;
07554ccd MW	196	}
	197	default:
	198	unknown_af(sa->sa_family);
	199	}
	200	}
	201
82ae109e IJ	202	void adns__addr_inject(const void a, adns_sockaddr sa) {
82ae109e IJ	203	switch (sa->sa.sa_family) {
07554ccd MW	204	AF_CASES(af);
07554ccd MW	205	af_inet: {
82ae109e IJ	206	struct sockaddr_in *sin = &sa->inet;
82ae109e IJ	207	memcpy(&sin->sin_addr, a, sizeof(sin->sin_addr));
07554ccd MW	208	break;
	209	}
	210	af_inet6: {
82ae109e IJ	211	struct sockaddr_in6 *sin6 = &sa->inet6;
82ae109e IJ	212	memcpy(&sin6->sin6_addr, a, sizeof(sin6->sin6_addr));
07554ccd MW	213	break;
	214	}
	215	default:
82ae109e	216	unknown_af(sa->sa.sa_family);
07554ccd MW	217	}
07554ccd MW	218	}
5806b745 IJ	219
	220	/*
	221	* addr2text and text2addr
	222	*/
	223
	224	#define ADDRFAM_DEBUG
	225	#ifdef ADDRFAM_DEBUG
	226	static void af_debug_func(const char *fmt, ...) {
	227	int esave= errno;
	228	va_list al;
	229	va_start(al,fmt);
	230	vfprintf(stderr,fmt,al);
	231	va_end(al);
	232	errno= esave;
	233	}
	234	# define af_debug(fmt,...) \
	235	(af_debug_func("%s: " fmt "\n", __func__, __VA_ARGS__))
	236	#else
	237	# define af_debug(fmt,...) ((void)("" fmt "", __VA_ARGS__))
	238	#endif
	239
	240	static bool addrtext_our_errno(int e) {
	241	return
	242	e==EAFNOSUPPORT \|\|
	243	e==EINVAL \|\|
	244	e==ENOSPC \|\|
	245	e==ENOSYS;
	246	}
	247
	248	static bool addrtext_scope_use_ifname(const struct sockaddr *sa) {
	249	const struct in6_addr *in6= &CSIN6(sa)->sin6_addr;
	250	return
	251	IN6_IS_ADDR_LINKLOCAL(in6) \|\|
	252	IN6_IS_ADDR_MC_LINKLOCAL(in6);
	253	}
	254
	255	int adns_text2addr(const char *text, uint16_t port, adns_queryflags flags,
	256	struct sockaddr sa, socklen_t salen_io) {
	257	int af;
	258	char copybuf[INET6_ADDRSTRLEN];
	259	const char *parse=text;
	260	const char *scopestr=0;
	261	socklen_t needlen;
	262	void *dst;
	263	uint16_t *portp;
	264
	265	#define INVAL(how) do{ \
	266	af_debug("invalid: %s: `%s'", how, text); \
	267	return EINVAL; \
	268	}while(0)
	269
	270	#define AFCORE(INETx,SINx,sinx) \
	271	af= AF_##INETx; \
	272	dst = &SINx(sa)->sinx##_addr; \
	273	portp = &SINx(sa)->sinx##_port; \
	274	needlen= sizeof(*SINx(sa));
	275
	276	if (!strchr(text, ':')) { /* INET */
	277
	278	AFCORE(INET,SIN,sin);
	279
	280	} else { /* INET6 */
	281
	282	AFCORE(INET6,SIN6,sin6);
283
284	const char *percent= strchr(text, '%');
285	if (percent) {
286	ptrdiff_t lhslen = percent - text;
287	if (lhslen >= INET6_ADDRSTRLEN) INVAL("scoped addr lhs too long");
288	memcpy(copybuf, text, lhslen);
289	copybuf[lhslen]= 0;
290
291	parse= copybuf;
292	scopestr= percent+1;
293
294	af_debug("will parse scoped addr `%s' %% `%s'", parse, scopestr);
295	}
296
297	}
298
299	#undef AFCORE
300
301	if (scopestr && (flags & adns_qf_addrlit_scope_forbid))
302	INVAL("scoped addr but _scope_forbid");
303
304	if (*salen_io < needlen) {
305	*salen_io = needlen;
306	return ENOSPC;
307	}
308
309	memset(sa, 0, needlen);
310
311	sa->sa_family= af;
312	*portp = htons(port);
313
314	if (af == AF_INET && !(flags & adns_qf_addrlit_ipv4_quadonly)) {
315	/* we have to use inet_aton to deal with non-dotted-quad literals */
316	int r= inet_aton(parse,&SIN(sa)->sin_addr);
317	if (!r) INVAL("inet_aton rejected");
318	} else {
319	int r= inet_pton(af,parse,dst);
320	if (!r) INVAL("inet_pton rejected");
321	assert(r>0);
322	}
323
324	if (scopestr) {
325	errno=0;
326	char *ep;
327	unsigned long scope= strtoul(scopestr,&ep,10);
328	if (errno==ERANGE) INVAL("numeric scope id too large for unsigned long");
329	assert(!errno);
330	if (!*ep) {
331	if (scope > ~(uint32_t)0)
332	INVAL("numeric scope id too large for uint32_t");
333	} else { /* !!ep /
334	if (flags & adns_qf_addrlit_scope_numeric)
335	INVAL("non-numeric scope but _scope_numeric");
336	if (!addrtext_scope_use_ifname(sa)) {
337	af_debug("cannot convert non-numeric scope"
338	" in non-link-local addr `%s'", text);
339	return ENOSYS;
340	}
341	errno= 0;
342	scope= if_nametoindex(scopestr);
343	if (!scope) {
344	/* RFC3493 says "No errors are defined". It's not clear
345	* whether that is supposed to mean if_nametoindex "can't
346	* fail" (other than by the supplied name not being that of an
347	* interface) which seems unrealistic, or that it conflates
348	* all its errors together by failing to set errno, or simply
349	* that they didn't bother to document the errors.
350	*
351	* glibc, FreeBSD and OpenBSD all set errno (to ENXIO when
352	* appropriate). See Debian bug #749349.
353	*
354	* We attempt to deal with this by clearing errno to start
355	* with, and then perhaps mapping the results. */
356	af_debug("if_nametoindex rejected scope name (errno=%s)",
357	strerror(errno));
358	if (errno==0) {
359	return ENXIO;
360	} else if (addrtext_our_errno(errno)) {
361	/* we use these for other purposes, urgh. */
362	perror("adns: adns_text2addr: if_nametoindex"
363	" failed with unexpected error");
364	return EIO;
365	} else {
366	return errno;
367	}
368	} else { /* ix>0 */
369	if (scope > ~(uint32_t)0) {
370	fprintf(stderr,"adns: adns_text2addr: if_nametoindex"
371	" returned an interface index >=2^32 which will not fit"
372	" in sockaddr_in6.sin6_scope_id");
373	return EIO;
374	}
375	}
376	} /* else; !!ep /
377
378	SIN6(sa)->sin6_scope_id= scope;
379	} /* if (scopestr) */
380
381	*salen_io = needlen;
382	return 0;
383	}
384
385	int adns_addr2text(const struct sockaddr *sa, adns_queryflags flags,
386	char buffer, int buflen_io, int *port_r) {
387	const void *src;
388	int port;
389
390	if (*buflen_io < ADNS_ADDR2TEXT_BUFLEN) {
391	*buflen_io = ADNS_ADDR2TEXT_BUFLEN;
392	return ENOSPC;
393	}
394
395	switch (sa->sa_family) {
396	AF_CASES(af);
397	af_inet: src= &CSIN(sa)->sin_addr; port= CSIN(sa)->sin_port; break;
398	af_inet6: src= &CSIN6(sa)->sin6_addr; port= CSIN6(sa)->sin6_port; break;
399	default: return EAFNOSUPPORT;
400	}
401
402	const char ok= inet_ntop(sa->sa_family, src, buffer, buflen_io);
403	assert(ok);
404
405	if (sa->sa_family == AF_INET6) {
406	uint32_t scope = CSIN6(sa)->sin6_scope_id;
407	if (scope) {
408	if (flags & adns_qf_addrlit_scope_forbid)
409	return EINVAL;
410	int scopeoffset = strlen(buffer);
411	int remain = *buflen_io - scopeoffset;
412	char *scopeptr = buffer + scopeoffset;
413	assert(remain >= IF_NAMESIZE+1/%/);
414	*scopeptr++= '%'; remain--;
415	bool parsedname = 0;
c3a165f5 MW	416	af_debug("will print scoped addr `%.*s' %% %"PRIu32"",
c3a165f5 MW	417	scopeoffset,buffer, scope);
5806b745 IJ	418	if (scope <= UINT_MAX /* so we can pass it to if_indextoname */
	419	&& !(flags & adns_qf_addrlit_scope_numeric)
	420	&& addrtext_scope_use_ifname(sa)) {
	421	parsedname = if_indextoname(scope, scopeptr);
	422	if (!parsedname) {
	423	af_debug("if_indextoname rejected scope (errno=%s)",
	424	strerror(errno));
	425	if (errno==ENXIO) {
	426	/* fair enough, show it as a number then */
	427	} else if (addrtext_our_errno(errno)) {
	428	/* we use these for other purposes, urgh. */
	429	perror("adns: adns_addr2text: if_indextoname"
	430	" failed with unexpected error");
	431	return EIO;
	432	} else {
	433	return errno;
	434	}
	435	}
	436	}
	437	if (!parsedname) {
	438	int r = snprintf(scopeptr, remain,
	439	"%"PRIu32"", scope);
	440	assert(r < *buflen_io - scopeoffset);
	441	}
	442	af_debug("printed scoped addr `%s'", buffer);
	443	}
	444	}
	445
	446	if (port_r) *port_r= ntohs(port);
	447	return 0;
	448	}
b0e8338a MW	449
	450	char adns__sockaddr_ntoa(const struct sockaddr sa, char *buf) {
	451	int err;
	452	int len= ADNS_ADDR2TEXT_BUFLEN;
	453
	454	err= adns_addr2text(sa, 0, buf, &len, 0);
	455	if (err == EIO)
	456	err= adns_addr2text(sa, adns_qf_addrlit_scope_numeric, buf, &len, 0);
	457	assert(!err);
	458	return buf;
	459	}
51cb3de3 MW	460
	461	/*
	462	* Reverse-domain parsing and construction.
	463	*/
	464
	465	int adns__make_reverse_domain(const struct sockaddr sa, const char zone,
	466	char **buf_io, size_t bufsz,
	467	char **buf_free_r) {
	468	size_t req;
	469	char *p;
	470	unsigned c, y;
	471	unsigned long aa;
	472	const unsigned char *ap;
	473	int i, j;
	474
	475	switch (sa->sa_family) {
	476	AF_CASES(af);
	477	af_inet:
	478	req= 4 * 4;
	479	if (!zone) zone= "in-addr.arpa";
	480	break;
	481	af_inet6:
	482	req = 2 * 32;
	483	if (!zone) zone= "ip6.arpa";
	484	break;
	485	default:
	486	return ENOSYS;
	487	}
	488
	489	req += strlen(zone) + 1;
	490	if (req <= bufsz)
	491	p= *buf_io;
	492	else {
	493	p= malloc(req); if (!p) return errno;
	494	*buf_free_r = p;
	495	}
	496
	497	*buf_io= p;
	498	switch (sa->sa_family) {
	499	AF_CASES(bf);
	500	bf_inet:
	501	aa= ntohl(CSIN(sa)->sin_addr.s_addr);
	502	for (i=0; i<4; i++) {
	503	p += sprintf(p, "%d", (int)(aa & 0xff));
	504	*p++= '.';
	505	aa >>= 8;
	506	}
	507	break;
	508	bf_inet6:
	509	ap= CSIN6(sa)->sin6_addr.s6_addr + 16;
	510	for (i=0; i<16; i++) {
	511	c= *--ap;
	512	for (j=0; j<2; j++) {
	513	y= c & 0xf;
	514	*p++= (y < 10) ? y + '0' : y - 10 + 'a';
	515	c >>= 4;
	516	*p++= '.';
	517	}
	518	}
	519	break;
	520	default:
	521	unknown_af(sa->sa_family);
	522	}
	523
524	strcpy(p, zone);
525	return 0;
526	}
527
528
529	static int inet_rev_parsecomp(const char *p, size_t n) {
530	int i= 0;
531	if (n > 3) return -1;
532
533	while (n--) {
534	if ('0' <= p && p <= '9') i= 10i + p++ - '0';
535	else return -1;
536	}
537	return i;
538	}
539
82ae109e IJ	540	static void inet_rev_mkaddr(adns_sockaddr addr, const byte ipv) {
	541	struct in_addr *v4 = &addr->inet.sin_addr;
	542	v4->s_addr= htonl((ipv[3]<<24) \| (ipv[2]<<16) \|
	543	(ipv[1]<<8) \| (ipv[0]));
51cb3de3 MW	544	}
	545
	546	static int inet6_rev_parsecomp(const char *p, size_t n) {
	547	if (n != 1) return -1;
	548	else if ('0' <= p && p <= '9') return *p - '0';
	549	else if ('a' <= p && p <= 'f') return *p - 'a' + 10;
	550	else if ('A' <= p && p <= 'F') return *p - 'a' + 10;
	551	else return -1;
	552	}
	553
82ae109e IJ	554	static void inet6_rev_mkaddr(adns_sockaddr addr, const byte ipv) {
	555	struct in6_addr *v6 = &addr->inet6.sin6_addr;
	556	unsigned char *a= v6->s6_addr;
51cb3de3 MW	557	int i;
	558
	559	for (i=0; i<16; i++)
	560	a[i]= (ipv[31-2i] << 4) \| (ipv[30-2i] << 0);
	561	}
	562
	563	static const struct revparse_domain {
	564	int af; /* address family */
	565	int nrevlab; /* n of reverse-address labels */
	566	adns_rrtype rrtype; /* forward-lookup type */
	567
	568	int (rev_parsecomp)(const char p, size_t n);
	569	/* parse a single component from a label; return the integer value, or -1
	570	* if it was unintelligible.
	571	*/
	572
82ae109e IJ	573	void (rev_mkaddr)(adns_sockaddr addr, const byte *ipv);
82ae109e IJ	574	/* write out the parsed protocol address from a vector of parsed components */
51cb3de3 MW	575
	576	const char const tail[3]; / tail label names */
	577	} revparse_domains[NREVDOMAINS] = {
	578	{ AF_INET, 4, adns_r_a, inet_rev_parsecomp, inet_rev_mkaddr,
	579	{ DNS_INADDR_ARPA, 0 } },
	580	{ AF_INET6, 32, adns_r_aaaa, inet6_rev_parsecomp, inet6_rev_mkaddr,
	581	{ DNS_IP6_ARPA, 0 } },
	582	};
	583
	584	#define REVDOMAIN_MAP(rps, labnum) \
	585	((labnum) ? (rps)->map : (1 << NREVDOMAINS) - 1)
	586
	587	int adns__revparse_label(struct revparse_state *rps, int labnum,
	588	const char *label, int lablen) {
	589	unsigned f= REVDOMAIN_MAP(rps, labnum);
	590	const struct revparse_domain *rpd;
	591	const char *tp;
	592	unsigned d;
	593	int i, ac;
	594
	595	for (rpd=revparse_domains, i=0, d=1; i<NREVDOMAINS; rpd++, i++, d <<= 1) {
	596	if (!(f & d)) continue;
	597	if (labnum >= rpd->nrevlab) {
	598	tp = rpd->tail[labnum - rpd->nrevlab];
	599	if (!tp \|\| strncmp(label, tp, lablen) != 0 \|\| tp[lablen])
	600	goto mismatch;
	601	} else {
	602	ac= rpd->rev_parsecomp(label, lablen);
	603	if (ac < 0) goto mismatch;
	604	assert(labnum < sizeof(rps->ipv[i]));
	605	rps->ipv[i][labnum]= ac;
	606	}
	607	continue;
	608
	609	mismatch:
	610	f &= ~d;
	611	if (!f) return -1;
	612	}
	613
	614	rps->map= f;
	615	return 0;
	616	}
	617
	618	int adns__revparse_done(struct revparse_state *rps, int nlabels,
82ae109e	619	adns_rrtype rrtype_r, adns_sockaddr addr_r) {
51cb3de3 MW	620	unsigned f= REVDOMAIN_MAP(rps, nlabels);
	621	const struct revparse_domain *rpd;
	622	unsigned d;
	623	int i, found= -1;
	624
	625	for (rpd=revparse_domains, i=0, d=1; i<NREVDOMAINS; rpd++, i++, d <<= 1) {
	626	if (!(f & d)) continue;
	627	if (nlabels >= rpd->nrevlab && !rpd->tail[nlabels - rpd->nrevlab])
	628	{ found = i; continue; }
	629	f &= ~d;
	630	if (!f) return -1;
	631	}
	632	assert(found >= 0); assert(f == (1 << found));
	633
	634	rpd= &revparse_domains[found];
	635	*rrtype_r= rpd->rrtype;
82ae109e IJ	636	addr_r->sa.sa_family= rpd->af;
82ae109e IJ	637	rpd->rev_mkaddr(addr_r, rps->ipv[found]);
51cb3de3 MW	638	return 0;
51cb3de3 MW	639	}