Commit 2927f46c authored by Matthias Andree's avatar Matthias Andree

Add getnameinfo.c.

svn path=/trunk/; revision=4277
parent 3694d3d3
/* $KAME: getnameinfo.c,v 1.72 2005/01/13 04:12:03 itojun Exp $ */
/*
* 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:
* - 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. RFC3493 says
* nothing about it, but defines a new error code EAI_OVERFLOW which seems
* to be intended the code for this case.
* - What is "local" in NI_NOFQDN? (see comments in the code)
* - 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?
* - what should we do if we should do getservbyport("sctp")?
*/
/*
* Considerations about thread-safeness
* The code in this file is thread-safe, and so the thread-safeness of
* getnameinfo() depends on the property of backend functions.
* - getservbyport() is not thread safe for most systems we are targeting.
* - getipnodebyaddr() is thread safe. However, many resolver libraries
* used in the function are not thread safe.
* - gethostbyaddr() is usually not thread safe.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#ifndef HAVE_GETNAMEINFO
#include <sys/types.h>
#include <sys/socket.h>
#include <net/if.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <arpa/nameser.h>
#include <netdb.h>
#include <resolv.h>
#include <string.h>
#include <stddef.h>
#include <errno.h>
#include <inttypes.h>
#include "fetchmail.h"
#include "getaddrinfo.h"
static const struct afd {
int a_af;
int a_addrlen;
int a_socklen;
int a_off;
int a_portoff;
} afdl [] = {
#ifdef INET6
{PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6),
offsetof(struct sockaddr_in6, sin6_addr),
offsetof(struct sockaddr_in6, sin6_port)},
#endif
{PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in),
offsetof(struct sockaddr_in, sin_addr),
offsetof(struct sockaddr_in, sin_port)},
{0, 0, 0, 0, 0},
};
#ifdef INET6
static int ip6_parsenumeric __P((const struct sockaddr *, const char *, char *,
size_t, int));
static int ip6_sa2str __P((const struct sockaddr_in6 *, char *, size_t, int));
#endif
int
getnameinfo(sa, salen, host, hostlen, serv, servlen, flags)
const struct sockaddr *sa;
#ifdef HAVE_SOCKLEN_T
socklen_t salen;
#else
unsigned int salen;
#endif
char *host;
size_t hostlen;
char *serv;
size_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;
int h_error;
char numserv[512];
char numaddr[512];
if (sa == NULL)
return EAI_FAIL;
#ifdef HAVE_SA_LEN /*XXX*/
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 */
memcpy(&port, (const char *)sa + afd->a_portoff, sizeof(port));
addr = (const char *)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: RFC3493 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 > servlen)
return EAI_OVERFLOW;
strlcpy(serv, sp->s_name, servlen);
} else {
snprintf(numserv, sizeof(numserv), "%u", ntohs(port));
if (strlen(numserv) + 1 > servlen)
return EAI_OVERFLOW;
strlcpy(serv, numserv, servlen);
}
}
switch (sa->sa_family) {
case AF_INET:
v4a = (u_int32_t)
ntohl(((const struct sockaddr_in *)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 *)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: RFC3493 says that host == NULL or hostlen == 0
* means that the caller does not want the result.
*/
} else if (flags & NI_NUMERICHOST) {
/* NUMERICHOST and NAMEREQD conflicts with each other */
if (flags & NI_NAMEREQD)
return EAI_NONAME;
goto numeric;
} else {
#ifdef USE_GETIPNODEBY
hp = getipnodebyaddr(addr, afd->a_addrlen, afd->a_af, &h_error);
#else
hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af);
#ifdef HAVE_H_ERRNO
h_error = h_errno;
#else
h_error = EINVAL;
#endif
#endif
if (hp) {
#if 0
if (flags & NI_NOFQDN) {
/*
* According to RFC3493 section 6.2, NI_NOFQDN
* means "node name portion of the FQDN shall
* be returned for local hosts." The following
* code tries to implement it by returning the
* first label (the part before the first
* period) of the FQDN. However, it is not
* clear if this always makes sense, since the
* given address may be outside of "local
* hosts." Due to the unclear description, we
* disable the code in this implementation.
*/
char *p;
p = strchr(hp->h_name, '.');
if (p)
*p = '\0';
}
#endif
if (strlen(hp->h_name) + 1 > hostlen) {
#ifdef USE_GETIPNODEBY
freehostent(hp);
#endif
return EAI_OVERFLOW;
}
strlcpy(host, hp->h_name, hostlen);
#ifdef USE_GETIPNODEBY
freehostent(hp);
#endif
} else {
if (flags & NI_NAMEREQD)
return EAI_NONAME;
numeric:
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;
size_t hostlen;
int flags;
{
int numaddrlen;
char numaddr[512];
if (inet_ntop(AF_INET6, addr, numaddr, sizeof(numaddr)) == NULL)
return EAI_SYSTEM;
numaddrlen = strlen(numaddr);
if (numaddrlen + 1 > hostlen) /* don't forget terminator */
return EAI_OVERFLOW;
strlcpy(host, numaddr, hostlen);
if (((const struct sockaddr_in6 *)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 (zonelen + 1 + numaddrlen + 1 > 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;
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) ||
IN6_IS_ADDR_MC_NODELOCAL(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 || n >= bufsiz)
return -1;
else
return n;
}
#endif /* INET6 */
#endif
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