/* $NetBSD: getnameinfo.c,v 1.43 2006/02/17 15:58:26 ginsbach Exp $ */
/* $KAME: getnameinfo.c,v 1.45 2000/09/25 22:43:56 itojun Exp $ */
/*
* Copyright (c) 2000 Ben Harris.
* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the project nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* Issues to be discussed:
* - Thread safe-ness must be checked
* - RFC2553 says that we should raise error on short buffer. X/Open says
* we need to truncate the result. We obey RFC2553 (and X/Open should be
* modified). ipngwg rough consensus seems to follow RFC2553.
* - What is "local" in NI_FQDN?
* - NI_NAMEREQD and NI_NUMERICHOST conflict with each other.
* - (KAME extension) always attach textual scopeid (fe80::1%lo0), if
* sin6_scope_id is filled - standardization status?
* XXX breaks backward compat for code that expects no scopeid.
* beware on merge.
*/
#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
__RCSID("$NetBSD: getnameinfo.c,v 1.43 2006/02/17 15:58:26 ginsbach Exp $");
#endif /* LIBC_SCCS and not lint */
#include <sys/types.h>
#include <sys/socket.h>
#include <net/if.h>
#include <net/if_dl.h>
#include <net/if_ieee1394.h>
#include <net/if_types.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include "arpa_nameser.h"
#include <assert.h>
#include <limits.h>
#include <netdb.h>
#ifdef ANDROID_CHANGES
#include "resolv_private.h"
#include <sys/system_properties.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/un.h>
#include <errno.h>
#else
#include <resolv.h>
#endif
#include <stddef.h>
#include <string.h>
static const struct afd {
int a_af;
socklen_t a_addrlen;
socklen_t a_socklen;
int a_off;
} afdl [] = {
#ifdef INET6
{PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6),
offsetof(struct sockaddr_in6, sin6_addr)},
#endif
{PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in),
offsetof(struct sockaddr_in, sin_addr)},
{0, 0, 0, 0},
};
struct sockinet {
u_char si_len;
u_char si_family;
u_short si_port;
};
static int getnameinfo_inet __P((const struct sockaddr *, socklen_t, char *,
socklen_t, char *, socklen_t, int));
#ifdef INET6
static int ip6_parsenumeric __P((const struct sockaddr *, const char *, char *,
socklen_t, int));
static int ip6_sa2str __P((const struct sockaddr_in6 *, char *, size_t,
int));
#endif
static int getnameinfo_link __P((const struct sockaddr *, socklen_t, char *,
socklen_t, char *, socklen_t, int));
static int hexname __P((const u_int8_t *, size_t, char *, socklen_t));
// This should be synchronized to ResponseCode.h
static const int DnsProxyQueryResult = 222;
/*
* Top-level getnameinfo() code. Look at the address family, and pick an
* appropriate function to call.
*/
int getnameinfo(const struct sockaddr* sa, socklen_t salen, char* host, size_t hostlen, char* serv, size_t servlen, int flags)
{
switch (sa->sa_family) {
case AF_INET:
case AF_INET6:
return getnameinfo_inet(sa, salen, host, hostlen,
serv, servlen, flags);
#if 0
case AF_LINK:
return getnameinfo_link(sa, salen, host, hostlen,
serv, servlen, flags);
#endif
default:
return EAI_FAMILY;
}
}
#ifdef ANDROID_CHANGES
/* On success length of the host name is returned. A return
* value of 0 means there's no host name associated with
* the address. On failure -1 is returned in which case
* normal execution flow shall continue. */
static int
android_gethostbyaddr_proxy(char* nameBuf, size_t nameBufLen, const void *addr, socklen_t addrLen, int addrFamily) {
int sock;
const int one = 1;
struct sockaddr_un proxy_addr;
const char* cache_mode = getenv("ANDROID_DNS_MODE");
FILE* proxy = NULL;
int result = -1;
if (cache_mode != NULL && strcmp(cache_mode, "local") == 0) {
// Don't use the proxy in local mode. This is used by the
// proxy itself.
return -1;
}
// Temporary cautious hack to disable the DNS proxy for processes
// requesting special treatment. Ideally the DNS proxy should
// accomodate these apps, though.
char propname[PROP_NAME_MAX];
char propvalue[PROP_VALUE_MAX];
snprintf(propname, sizeof(propname), "net.dns1.%d", getpid());
if (__system_property_get(propname, propvalue) > 0) {
return -1;
}
// create socket
sock = socket(AF_UNIX, SOCK_STREAM, 0);
if (sock < 0) {
return -1;
}
setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
memset(&proxy_addr, 0, sizeof(proxy_addr));
proxy_addr.sun_family = AF_UNIX;
strlcpy(proxy_addr.sun_path, "/dev/socket/dnsproxyd",
sizeof(proxy_addr.sun_path));
if (TEMP_FAILURE_RETRY(connect(sock, (const struct sockaddr*) (void*) &proxy_addr,
sizeof(proxy_addr))) != 0) {
close(sock);
return -1;
}
// send request to DnsProxyListener
proxy = fdopen(sock,"r+");
if (proxy == NULL) {
goto exit;
}
char buf[INET6_ADDRSTRLEN]; // big enough for IPv4 and IPv6
const char* addrStr = inet_ntop(addrFamily, addr, buf, sizeof(buf));
if (addrStr == NULL) {
goto exit;
}
if (fprintf(proxy, "gethostbyaddr %s %d %d", addrStr, addrLen, addrFamily) < 0) {
goto exit;
}
// literal NULL byte at end, required by FrameworkListener
if (fputc(0, proxy) == EOF || fflush(proxy) != 0) {
goto exit;
}
result = 0;
char msg_buf[4];
// read result code for gethostbyaddr
if (fread(msg_buf, 1, sizeof(msg_buf), proxy) != sizeof(msg_buf)) {
goto exit;
}
int result_code = (int)strtol(msg_buf, NULL, 10);
// verify the code itself
if (result_code != DnsProxyQueryResult) {
goto exit;
}
uint32_t name_len;
if (fread(&name_len, sizeof(name_len), 1, proxy) != 1) {
goto exit;
}
name_len = ntohl(name_len);
if (name_len <= 0 || name_len >= nameBufLen) {
goto exit;
}
if (fread(nameBuf, name_len, 1, proxy) != 1) {
goto exit;
}
result = name_len;
exit:
if (proxy != NULL) {
fclose(proxy);
}
return result;
}
#endif
/*
* getnameinfo_inet():
* Format an IPv4 or IPv6 sockaddr into a printable string.
*/
static int
getnameinfo_inet(sa, salen, host, hostlen, serv, servlen, flags)
const struct sockaddr *sa;
socklen_t salen;
char *host;
socklen_t hostlen;
char *serv;
socklen_t servlen;
int flags;
{
const struct afd *afd;
struct servent *sp;
struct hostent *hp;
u_short port;
int family, i;
const char *addr;
u_int32_t v4a;
char numserv[512];
char numaddr[512];
/* sa is checked below */
/* host may be NULL */
/* serv may be NULL */
if (sa == NULL)
return EAI_FAIL;
#ifdef BSD4_4
if (sa->sa_len != salen)
return EAI_FAIL;
#endif
family = sa->sa_family;
for (i = 0; afdl[i].a_af; i++)
if (afdl[i].a_af == family) {
afd = &afdl[i];
goto found;
}
return EAI_FAMILY;
found:
if (salen != afd->a_socklen)
return EAI_FAIL;
/* network byte order */
port = ((const struct sockinet *)(const void *)sa)->si_port;
addr = (const char *)(const void *)sa + afd->a_off;
if (serv == NULL || servlen == 0) {
/*
* do nothing in this case.
* in case you are wondering if "&&" is more correct than
* "||" here: rfc2553bis-03 says that serv == NULL OR
* servlen == 0 means that the caller does not want the result.
*/
} else {
if (flags & NI_NUMERICSERV)
sp = NULL;
else {
sp = getservbyport(port,
(flags & NI_DGRAM) ? "udp" : "tcp");
}
if (sp) {
if (strlen(sp->s_name) + 1 > (size_t)servlen)
return EAI_MEMORY;
strlcpy(serv, sp->s_name, servlen);
} else {
snprintf(numserv, sizeof(numserv), "%u", ntohs(port));
if (strlen(numserv) + 1 > (size_t)servlen)
return EAI_MEMORY;
strlcpy(serv, numserv, servlen);
}
}
switch (sa->sa_family) {
case AF_INET:
v4a = (u_int32_t)
ntohl(((const struct sockaddr_in *)
(const void *)sa)->sin_addr.s_addr);
if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a))
flags |= NI_NUMERICHOST;
v4a >>= IN_CLASSA_NSHIFT;
if (v4a == 0)
flags |= NI_NUMERICHOST;
break;
#ifdef INET6
case AF_INET6:
{
const struct sockaddr_in6 *sin6;
sin6 = (const struct sockaddr_in6 *)(const void *)sa;
switch (sin6->sin6_addr.s6_addr[0]) {
case 0x00:
if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr))
;
else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr))
;
else
flags |= NI_NUMERICHOST;
break;
default:
if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) {
flags |= NI_NUMERICHOST;
}
else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
flags |= NI_NUMERICHOST;
break;
}
}
break;
#endif
}
if (host == NULL || hostlen == 0) {
/*
* do nothing in this case.
* in case you are wondering if "&&" is more correct than
* "||" here: rfc2553bis-03 says that host == NULL or
* hostlen == 0 means that the caller does not want the result.
*/
} else if (flags & NI_NUMERICHOST) {
size_t numaddrlen;
/* NUMERICHOST and NAMEREQD conflicts with each other */
if (flags & NI_NAMEREQD)
return EAI_NONAME;
switch(afd->a_af) {
#ifdef INET6
case AF_INET6:
{
int error;
if ((error = ip6_parsenumeric(sa, addr, host,
hostlen, flags)) != 0)
return(error);
break;
}
#endif
default:
if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr))
== NULL)
return EAI_SYSTEM;
numaddrlen = strlen(numaddr);
if (numaddrlen + 1 > (size_t)hostlen) /* don't forget terminator */
return EAI_MEMORY;
strlcpy(host, numaddr, hostlen);
break;
}
} else {
#ifdef ANDROID_CHANGES
struct hostent android_proxy_hostent;
char android_proxy_buf[MAXDNAME];
int hostnamelen = android_gethostbyaddr_proxy(android_proxy_buf,
MAXDNAME, addr, afd->a_addrlen, afd->a_af);
if (hostnamelen > 0) {
hp = &android_proxy_hostent;
hp->h_name = android_proxy_buf;
} else if (!hostnamelen) {
hp = NULL;
} else {
hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af);
}
#else
hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af);
#endif
if (hp) {
#if 0
/*
* commented out, since "for local host" is not
* implemented here - see RFC2553 p30
*/
if (flags & NI_NOFQDN) {
char *p;
p = strchr(hp->h_name, '.');
if (p)
*p = '\0';
}
#endif
if (strlen(hp->h_name) + 1 > (size_t)hostlen) {
return EAI_MEMORY;
}
strlcpy(host, hp->h_name, hostlen);
} else {
if (flags & NI_NAMEREQD)
return EAI_NONAME;
switch(afd->a_af) {
#ifdef INET6
case AF_INET6:
{
int error;
if ((error = ip6_parsenumeric(sa, addr, host,
hostlen,
flags)) != 0)
return(error);
break;
}
#endif
default:
if (inet_ntop(afd->a_af, addr, host,
hostlen) == NULL)
return EAI_SYSTEM;
break;
}
}
}
return(0);
}
#ifdef INET6
static int
ip6_parsenumeric(sa, addr, host, hostlen, flags)
const struct sockaddr *sa;
const char *addr;
char *host;
socklen_t hostlen;
int flags;
{
size_t numaddrlen;
char numaddr[512];
assert(sa != NULL);
assert(addr != NULL);
assert(host != NULL);
if (hostlen < 0)
return EAI_OVERFLOW;
if (inet_ntop(AF_INET6, addr, numaddr, sizeof(numaddr)) == NULL)
return EAI_SYSTEM;
numaddrlen = strlen(numaddr);
if (numaddrlen + 1 > (size_t)hostlen) /* don't forget terminator */
return EAI_OVERFLOW;
strlcpy(host, numaddr, hostlen);
if (((const struct sockaddr_in6 *)(const void *)sa)->sin6_scope_id) {
char zonebuf[MAXHOSTNAMELEN];
int zonelen;
zonelen = ip6_sa2str(
(const struct sockaddr_in6 *)(const void *)sa,
zonebuf, sizeof(zonebuf), flags);
if (zonelen < 0)
return EAI_OVERFLOW;
if ((size_t) zonelen + 1 + numaddrlen + 1 > (size_t)hostlen)
return EAI_OVERFLOW;
/* construct <numeric-addr><delim><zoneid> */
memcpy(host + numaddrlen + 1, zonebuf,
(size_t)zonelen);
host[numaddrlen] = SCOPE_DELIMITER;
host[numaddrlen + 1 + zonelen] = '\0';
}
return 0;
}
/* ARGSUSED */
static int
ip6_sa2str(sa6, buf, bufsiz, flags)
const struct sockaddr_in6 *sa6;
char *buf;
size_t bufsiz;
int flags;
{
unsigned int ifindex;
const struct in6_addr *a6;
int n;
assert(sa6 != NULL);
assert(buf != NULL);
ifindex = (unsigned int)sa6->sin6_scope_id;
a6 = &sa6->sin6_addr;
#ifdef NI_NUMERICSCOPE
if ((flags & NI_NUMERICSCOPE) != 0) {
n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id);
if (n < 0 || n >= bufsiz)
return -1;
else
return n;
}
#endif
/* if_indextoname() does not take buffer size. not a good api... */
if ((IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) &&
bufsiz >= IF_NAMESIZE) {
char *p = if_indextoname(ifindex, buf);
if (p) {
return(strlen(p));
}
}
/* last resort */
n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id);
if (n < 0 || (size_t) n >= bufsiz)
return -1;
else
return n;
}
#endif /* INET6 */
/*
* getnameinfo_link():
* Format a link-layer address into a printable format, paying attention to
* the interface type.
*/
/* ARGSUSED */
static int
getnameinfo_link(const struct sockaddr *sa, socklen_t salen,
char *host, socklen_t hostlen, char *serv, socklen_t servlen,
int flags)
{
const struct sockaddr_dl *sdl =
(const struct sockaddr_dl *)(const void *)sa;
const struct ieee1394_hwaddr *iha;
int n;
if (serv != NULL && servlen > 0)
*serv = '\0';
if (sdl->sdl_nlen == 0 && sdl->sdl_alen == 0 && sdl->sdl_slen == 0) {
n = snprintf(host, hostlen, "link#%u", sdl->sdl_index);
if (n < 0 || (socklen_t) n > hostlen) {
*host = '\0';
return EAI_MEMORY;
}
return 0;
}
switch (sdl->sdl_type) {
#ifdef IFT_ECONET
case IFT_ECONET:
if (sdl->sdl_alen < 2)
return EAI_FAMILY;
if (CLLADDR(sdl)[1] == 0)
n = snprintf(host, hostlen, "%u", CLLADDR(sdl)[0]);
else
n = snprintf(host, hostlen, "%u.%u",
CLLADDR(sdl)[1], CLLADDR(sdl)[0]);
if (n < 0 || (socklen_t) n >= hostlen) {
*host = '\0';
return EAI_MEMORY;
} else
return 0;
#endif
case IFT_IEEE1394:
if (sdl->sdl_alen < sizeof(iha->iha_uid))
return EAI_FAMILY;
iha =
(const struct ieee1394_hwaddr *)(const void *)CLLADDR(sdl);
return hexname(iha->iha_uid, sizeof(iha->iha_uid),
host, hostlen);
/*
* The following have zero-length addresses.
* IFT_ATM (net/if_atmsubr.c)
* IFT_FAITH (net/if_faith.c)
* IFT_GIF (net/if_gif.c)
* IFT_LOOP (net/if_loop.c)
* IFT_PPP (net/if_ppp.c, net/if_spppsubr.c)
* IFT_SLIP (net/if_sl.c, net/if_strip.c)
* IFT_STF (net/if_stf.c)
* IFT_L2VLAN (net/if_vlan.c)
* IFT_PROPVIRTUAL (net/if_bridge.h>
*/
/*
* The following use IPv4 addresses as link-layer addresses:
* IFT_OTHER (net/if_gre.c)
*/
case IFT_ARCNET: /* default below is believed correct for all these. */
case IFT_ETHER:
case IFT_FDDI:
case IFT_HIPPI:
case IFT_ISO88025:
default:
return hexname((const u_int8_t *)CLLADDR(sdl),
(size_t)sdl->sdl_alen, host, hostlen);
}
}
static int
hexname(cp, len, host, hostlen)
const u_int8_t *cp;
char *host;
size_t len;
socklen_t hostlen;
{
int n;
size_t i;
char *outp = host;
*outp = '\0';
for (i = 0; i < len; i++) {
n = snprintf(outp, hostlen, "%s%02x",
i ? ":" : "", cp[i]);
if (n < 0 || (socklen_t) n >= hostlen) {
*host = '\0';
return EAI_MEMORY;
}
outp += n;
hostlen -= n;
}
return 0;
}