Add getnameinfo.c.

svn path=/trunk/; revision=4277

1 files changed, 380 insertions, 0 deletions

diff --git a/KAME/getnameinfo.c b/KAME/getnameinfo.c
new file mode 100644
index 00000000..9549600c
--- /dev/null
+++ b/KAME/getnameinfo.c
@@ -0,0 +1,380 @@
+/*	$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