X-Git-Url: https://git.decadent.org.uk/gitweb/?p=nfs-utils.git;a=blobdiff_plain;f=support%2Fexport%2Fhostname.c;h=3e949a18fe52255b51a4d77713f28b1679f16b75;hp=299fe9937b4d03606dcbc14a749cae3bd7e057a7;hb=b50ad13298b3e9519a9bdecb8c146c9ecf39cef8;hpb=282284fac3c3fe20187f892e3ce15ac319c8acb7

diff --git a/support/export/hostname.c b/support/export/hostname.c
index 299fe99..3e949a1 100644
--- a/support/export/hostname.c
+++ b/support/export/hostname.c
@@ -1,262 +1,396 @@
 /*
- * support/export/hostname.c
+ * Copyright 2010 Oracle.  All rights reserved.
  *
- * Functions for hostname.
+ * This file is part of nfs-utils.
  *
+ * nfs-utils 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 of the License, or
+ * (at your option) any later version.
+ *
+ * nfs-utils 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 nfs-utils.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include "config.h"
-
-/*
-#define TEST
-*/
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
 
 #include <string.h>
-#include <netdb.h>
-#include <netinet/in.h>
-#include <arpa/inet.h>
 #include <stdlib.h>
-#ifdef TEST
-#define xmalloc malloc
-#else
-#include "xmalloc.h"
-#include "misc.h"
-#endif
+#include <arpa/inet.h>
+#include <netdb.h>
+#include <errno.h>
 
-#define ALIGNMENT	sizeof (char *)
+#include "sockaddr.h"
+#include "exportfs.h"
 
-static int
-align (int len, int al)
+/**
+ * host_ntop - generate presentation address given a sockaddr
+ * @sap: pointer to socket address
+ * @buf: working storage
+ * @buflen: size of @buf in bytes
+ *
+ * Returns a pointer to a @buf.
+ */
+#ifdef HAVE_GETNAMEINFO
+char *
+host_ntop(const struct sockaddr *sap, char *buf, const size_t buflen)
 {
-  int i;
-  i = len % al;
-  if (i)
-    len += al - i;
-  return len;
-}
+	socklen_t salen = nfs_sockaddr_length(sap);
+	int error;
+
+	memset(buf, 0, buflen);
+
+	if (salen == 0) {
+		(void)strncpy(buf, "bad family", buflen - 1);
+		return buf;
+	}
 
-struct hostent *
-get_hostent (const char *addr, int len, int type)
+	error = getnameinfo(sap, salen, buf, (socklen_t)buflen,
+						NULL, 0, NI_NUMERICHOST);
+	if (error != 0) {
+		buf[0] = '\0';
+		(void)strncpy(buf, "bad address", buflen - 1);
+	}
+
+	return buf;
+}
+#else	/* !HAVE_GETNAMEINFO */
+char *
+host_ntop(const struct sockaddr *sap, char *buf, const size_t buflen)
 {
-  struct hostent *cp;
-  int len_ent;
-  const char *name;
-  int len_name;
-  int num_aliases = 1;
-  int len_aliases = sizeof (char *);
-  int num_addr_list = 1;
-  int len_addr_list = sizeof (char *);
-  int pos;
-  struct in_addr *ipv4;
-
-  switch (type)
-    {
-    case AF_INET:
-      ipv4 = (struct in_addr *) addr;
-      name = inet_ntoa (*ipv4);
-      break;
-
-    default:
-      return NULL;
-    }
-
-  len_ent = align (sizeof (*cp), ALIGNMENT);
-  len_name = align (strlen (name) + 1, ALIGNMENT);
-
-  num_addr_list++;
-  len_addr_list += align (len, ALIGNMENT) + sizeof (char *);
-
-  cp = (struct hostent *) xmalloc (len_ent + len_name + len_aliases
-				   + len_addr_list);
-
-  cp->h_addrtype = type;
-  cp->h_length = len;
-  pos = len_ent;
-  cp->h_name = (char *) &(((char *) cp) [pos]);
-  strcpy (cp->h_name, name);
-
-  pos += len_name;
-  cp->h_aliases = (char **) &(((char *) cp) [pos]);
-  pos += num_aliases * sizeof (char *);
-  cp->h_aliases [0] = NULL;
-
-  pos = len_ent + len_name + len_aliases;
-  cp->h_addr_list = (char **) &(((char *) cp) [pos]);
-  pos += num_addr_list * sizeof (char *);
-  cp->h_addr_list [0] = (char *) &(((char *) cp) [pos]);
-  memcpy (cp->h_addr_list [0], addr, cp->h_length);
-  pos += align (cp->h_length, ALIGNMENT);
-  cp->h_addr_list [1] = NULL;
-
-  return cp;
+	const struct sockaddr_in *sin = (const struct sockaddr_in *)(char *)sap;
+
+	memset(buf, 0, buflen);
+
+	if (sin->sin_family != AF_INET)
+		(void)strncpy(buf, "bad family", buflen - 1);
+		return buf;
+	}
+
+	if (inet_ntop(AF_INET, &sin->sin_addr.s_addr, buf, buflen) != NULL)
+		return buf;
+
+	buf[0] = '\0';
+	(void)strncpy(buf, "bad address", buflen - 1);
+	return buf;
 }
+#endif	/* !HAVE_GETNAMEINFO */
 
-struct hostent *
-hostent_dup (struct hostent *hp)
+/**
+ * host_pton - return addrinfo for a given presentation address
+ * @paddr: pointer to a '\0'-terminated ASCII string containing an
+ *		IP presentation address
+ *
+ * Returns address info structure, or NULL if an error occurs.  Caller
+ * must free the returned structure with freeaddrinfo(3).
+ */
+__attribute_malloc__
+struct addrinfo *
+host_pton(const char *paddr)
 {
-  int len_ent = align (sizeof (*hp), ALIGNMENT);
-  int len_name = align (strlen (hp->h_name) + 1, ALIGNMENT);
-  int num_aliases = 1;
-  int len_aliases = sizeof (char *);
-  int num_addr_list = 1;
-  int len_addr_list = sizeof (char *);
-  int pos, i;
-  char **sp;
-  struct hostent *cp;
-
-  for (sp = hp->h_aliases; sp && *sp; sp++)
-    {
-      num_aliases++;
-      len_aliases += align (strlen (*sp) + 1, ALIGNMENT)
-		     + sizeof (char *);
-    }
-
-  for (sp = hp->h_addr_list; *sp; sp++)
-    {
-      num_addr_list++;
-      len_addr_list += align (hp->h_length, ALIGNMENT)
-		       + sizeof (char *);
-    }
-  
-  cp = (struct hostent *) xmalloc (len_ent + len_name + len_aliases
-				   + len_addr_list);
-
-  *cp = *hp;
-  pos = len_ent;
-  cp->h_name = (char *) &(((char *) cp) [pos]);
-  strcpy (cp->h_name, hp->h_name);
-
-  pos += len_name;
-  cp->h_aliases = (char **) &(((char *) cp) [pos]);
-  pos += num_aliases * sizeof (char *);
-  for (sp = hp->h_aliases, i = 0; i < num_aliases; i++, sp++)
-    if (sp && *sp)
-      {
-	cp->h_aliases [i] = (char *) &(((char *) cp) [pos]);
-	strcpy (cp->h_aliases [i], *sp);
-	pos += align (strlen (*sp) + 1, ALIGNMENT);
-      }
-    else
-      cp->h_aliases [i] = NULL;
-
-  pos = len_ent + len_name + len_aliases;
-  cp->h_addr_list = (char **) &(((char *) cp) [pos]);
-  pos += num_addr_list * sizeof (char *);
-  for (sp = hp->h_addr_list, i = 0; i < num_addr_list; i++, sp++)
-    if (*sp)
-      {
-	cp->h_addr_list [i] = (char *) &(((char *) cp) [pos]);
-	memcpy (cp->h_addr_list [i], *sp, hp->h_length);
-	pos += align (hp->h_length, ALIGNMENT);
-      }
-    else
-      cp->h_addr_list [i] = *sp;
-
-  return cp;
+	struct addrinfo *ai = NULL;
+	struct addrinfo hint = {
+		/* don't return duplicates */
+		.ai_protocol	= (int)IPPROTO_UDP,
+		.ai_flags	= AI_NUMERICHOST,
+		.ai_family	= AF_UNSPEC,
+	};
+	struct sockaddr_in sin;
+	int error, inet4;
+
+	/*
+	 * Although getaddrinfo(3) is easier to use and supports
+	 * IPv6, it recognizes incomplete addresses like "10.4"
+	 * as valid AF_INET addresses.  It also accepts presentation
+	 * addresses that end with a blank.
+	 *
+	 * inet_pton(3) is much stricter.  Use it to be certain we
+	 * have a real AF_INET presentation address, before invoking
+	 * getaddrinfo(3) to generate the full addrinfo list.
+	 */
+	inet4 = 1;
+	if (inet_pton(AF_INET, paddr, &sin.sin_addr) == 0)
+		inet4 = 0;
+
+	error = getaddrinfo(paddr, NULL, &hint, &ai);
+	switch (error) {
+	case 0:
+		if (!inet4 && ai->ai_addr->sa_family == AF_INET) {
+			freeaddrinfo(ai);
+			break;
+		}
+		return ai;
+	case EAI_NONAME:
+		if (paddr == NULL)
+			xlog(D_GENERAL, "%s: passed a NULL presentation address",
+				__func__);
+		break;
+	case EAI_SYSTEM:
+		xlog(D_GENERAL, "%s: failed to convert %s: (%d) %m",
+				__func__, paddr, errno);
+		break;
+	default:
+		xlog(D_GENERAL, "%s: failed to convert %s: %s",
+				__func__, paddr, gai_strerror(error));
+		break;
+	}
+
+	return NULL;
 }
 
-static int
-is_hostname(const char *sp)
+/**
+ * host_addrinfo - return addrinfo for a given hostname
+ * @hostname: pointer to a '\0'-terminated ASCII string containing a hostname
+ *
+ * Returns address info structure with ai_canonname filled in, or NULL
+ * if no information is available for @hostname.  Caller must free the
+ * returned structure with freeaddrinfo(3).
+ */
+__attribute_malloc__
+struct addrinfo *
+host_addrinfo(const char *hostname)
 {
-  if (*sp == '\0' || *sp == '@')
-    return 0;
-
-  for (; *sp; sp++)
-    {
-      if (*sp == '*' || *sp == '?' || *sp == '[' || *sp == '/')
-	return 0;
-      if (*sp == '\\' && sp[1])
-	sp++;
-    }
-
-  return 1;
+	struct addrinfo *ai = NULL;
+	struct addrinfo hint = {
+#ifdef IPV6_SUPPORTED
+		.ai_family	= AF_UNSPEC,
+#else
+		.ai_family	= AF_INET,
+#endif
+		/* don't return duplicates */
+		.ai_protocol	= (int)IPPROTO_UDP,
+		.ai_flags	= AI_CANONNAME,
+	};
+	int error;
+
+	error = getaddrinfo(hostname, NULL, &hint, &ai);
+	switch (error) {
+	case 0:
+		return ai;
+	case EAI_SYSTEM:
+		xlog(D_GENERAL, "%s: failed to resolve %s: (%d) %m",
+				__func__, hostname, errno);
+		break;
+	default:
+		xlog(D_GENERAL, "%s: failed to resolve %s: %s",
+				__func__, hostname, gai_strerror(error));
+		break;
+	}
+
+	return NULL;
 }
 
-int
-matchhostname (const char *h1, const char *h2)
+/**
+ * host_canonname - return canonical hostname bound to an address
+ * @sap: pointer to socket address to look up
+ *
+ * Discover the canonical hostname associated with the given socket
+ * address.  The host's reverse mapping is verified in the process.
+ *
+ * Returns a '\0'-terminated ASCII string containing a hostname, or
+ * NULL if no hostname can be found for @sap.  Caller must free
+ * the string.
+ */
+#ifdef HAVE_GETNAMEINFO
+__attribute_malloc__
+char *
+host_canonname(const struct sockaddr *sap)
 {
-  struct hostent *hp1, *hp2;
-  int status;
-
-  if (strcasecmp (h1, h2) == 0)
-    return 1;
-
-  if (!is_hostname (h1) || !is_hostname (h2))
-    return 0;
-
-  hp1 = gethostbyname (h1);
-  if (hp1 == NULL)
-    return 0;
-
-  hp1 = hostent_dup (hp1);
-
-  hp2 = gethostbyname (h2);
-  if (hp2)
-    {
-      if (strcasecmp (hp1->h_name, hp2->h_name) == 0)
-	status = 1;
-      else
-	{
-	  char **ap1, **ap2;
-
-	  status = 0;
-	  for (ap1 = hp1->h_addr_list; *ap1 && status == 0; ap1++)
-	    for (ap2 = hp2->h_addr_list; *ap2; ap2++)
-	      if (memcmp (*ap1, *ap2, sizeof (struct in_addr)) == 0)
-		{
-		  status = 1;
-		  break;
-		}
+	socklen_t salen = nfs_sockaddr_length(sap);
+	char buf[NI_MAXHOST];
+	int error;
+
+	if (salen == 0) {
+		xlog(D_GENERAL, "%s: unsupported address family %d",
+				__func__, sap->sa_family);
+		return NULL;
+	}
+
+	memset(buf, 0, sizeof(buf));
+	error = getnameinfo(sap, salen, buf, (socklen_t)sizeof(buf),
+							NULL, 0, NI_NAMEREQD);
+	switch (error) {
+	case 0:
+		break;
+	case EAI_SYSTEM:
+		xlog(D_GENERAL, "%s: getnameinfo(3) failed: (%d) %m",
+				__func__, errno);
+		return NULL;
+	default:
+		(void)getnameinfo(sap, salen, buf, (socklen_t)sizeof(buf),
+							NULL, 0, NI_NUMERICHOST);
+		xlog(D_GENERAL, "%s: failed to resolve %s: %s",
+				__func__, buf, gai_strerror(error));
+		return NULL;
 	}
-    }
-  else
-    status = 0;
 
-  free (hp1);
-  return status;
+	return strdup(buf);
 }
+#else	/* !HAVE_GETNAMEINFO */
+__attribute_malloc__
+char *
+host_canonname(const struct sockaddr *sap)
+{
+	const struct sockaddr_in *sin = (const struct sockaddr_in *)(char *)sap;
+	const struct in_addr *addr = &sin->sin_addr;
+	struct hostent *hp;
+
+	if (sap->sa_family != AF_INET)
+		return NULL;
+
+	hp = gethostbyaddr(addr, (socklen_t)sizeof(addr), AF_INET);
+	if (hp == NULL)
+		return NULL;
+
+	return strdup(hp->h_name);
+}
+#endif	/* !HAVE_GETNAMEINFO */
 
-#ifdef TEST
-void
-print_host (struct hostent *hp)
+/**
+ * host_reliable_addrinfo - return addrinfo for a given address
+ * @sap: pointer to socket address to look up
+ *
+ * Reverse and forward lookups are performed to ensure the address has
+ * matching forward and reverse mappings.
+ *
+ * Returns addrinfo structure with just the provided address with
+ * ai_canonname filled in. If there is a problem with resolution or
+ * the resolved records don't match up properly then it returns NULL
+ *
+ * Caller must free the returned structure with freeaddrinfo(3).
+ */
+__attribute_malloc__
+struct addrinfo *
+host_reliable_addrinfo(const struct sockaddr *sap)
 {
-  char **sp;
-
-  if (hp)
-    {
-      printf ("official hostname: %s\n", hp->h_name); 
-      printf ("aliases:\n");
-      for (sp = hp->h_aliases; *sp; sp++)
-	printf ("  %s\n", *sp);
-      printf ("IP addresses:\n");
-      for (sp = hp->h_addr_list; *sp; sp++)
-	printf ("  %s\n", inet_ntoa (*(struct in_addr *) *sp));
-    }
-  else
-    printf ("Not host information\n");
+	struct addrinfo *ai, *a;
+	char *hostname;
+
+	hostname = host_canonname(sap);
+	if (hostname == NULL)
+		return NULL;
+
+	ai = host_addrinfo(hostname);
+	if (!ai)
+		goto out_free_hostname;
+
+	/* make sure there's a matching address in the list */
+	for (a = ai; a; a = a->ai_next)
+		if (nfs_compare_sockaddr(a->ai_addr, sap))
+			break;
+
+	freeaddrinfo(ai);
+	if (!a)
+		goto out_free_hostname;
+
+	/* get addrinfo with just the original address */
+	ai = host_numeric_addrinfo(sap);
+	if (!ai)
+		goto out_free_hostname;
+
+	/* and populate its ai_canonname field */
+	free(ai->ai_canonname);
+	ai->ai_canonname = hostname;
+	return ai;
+
+out_free_hostname:
+	free(hostname);
+	return NULL;
 }
 
-int
-main (int argc, char **argv)
+/**
+ * host_numeric_addrinfo - return addrinfo without doing DNS queries
+ * @sap: pointer to socket address
+ *
+ * Returns address info structure, or NULL if an error occurred.
+ * Caller must free the returned structure with freeaddrinfo(3).
+ */
+#ifdef HAVE_GETNAMEINFO
+__attribute_malloc__
+struct addrinfo *
+host_numeric_addrinfo(const struct sockaddr *sap)
+{
+	socklen_t salen = nfs_sockaddr_length(sap);
+	char buf[INET6_ADDRSTRLEN];
+	struct addrinfo *ai;
+	int error;
+
+	if (salen == 0) {
+		xlog(D_GENERAL, "%s: unsupported address family %d",
+				__func__, sap->sa_family);
+		return NULL;
+	}
+
+	memset(buf, 0, sizeof(buf));
+	error = getnameinfo(sap, salen, buf, (socklen_t)sizeof(buf),
+						NULL, 0, NI_NUMERICHOST);
+	switch (error) {
+	case 0:
+		break;
+	case EAI_SYSTEM:
+		xlog(D_GENERAL, "%s: getnameinfo(3) failed: (%d) %m",
+				__func__, errno);
+		return NULL;
+	default:
+		xlog(D_GENERAL, "%s: getnameinfo(3) failed: %s",
+				__func__, gai_strerror(error));
+		return NULL;
+	}
+
+	ai = host_pton(buf);
+
+	/*
+	 * getaddrinfo(AI_NUMERICHOST) never fills in ai_canonname
+	 */
+	if (ai != NULL) {
+		free(ai->ai_canonname);		/* just in case */
+		ai->ai_canonname = strdup(buf);
+		if (ai->ai_canonname == NULL) {
+			freeaddrinfo(ai);
+			ai = NULL;
+		}
+	}
+
+	return ai;
+}
+#else	/* !HAVE_GETNAMEINFO */
+__attribute_malloc__
+struct addrinfo *
+host_numeric_addrinfo(const struct sockaddr *sap)
 {
-  struct hostent *hp = gethostbyname (argv [1]);
-  struct hostent *cp;
-  struct in_addr addr;
-
-  print_host (hp);
-
-  if (hp)
-    {
-      cp = hostent_dup (hp);
-      print_host (cp);
-      free (cp);
-    }
-  printf ("127.0.0.1 == %s: %d\n", argv [1],
-	  matchhostname ("127.0.0.1", argv [1]));
-  addr.s_addr = inet_addr(argv [2]);
-  printf ("%s\n", inet_ntoa (addr));
-  cp = get_hostent ((const char *)&addr, sizeof(addr), AF_INET);
-  print_host (cp);
-  return 0;
+	const struct sockaddr_in *sin = (const struct sockaddr_in *)sap;
+	const struct in_addr *addr = &sin->sin_addr;
+	char buf[INET_ADDRSTRLEN];
+	struct addrinfo *ai;
+
+	if (sap->sa_family != AF_INET)
+		return NULL;
+
+	memset(buf, 0, sizeof(buf));
+	if (inet_ntop(AF_INET, (char *)addr, buf,
+					(socklen_t)sizeof(buf)) == NULL)
+		return NULL;
+
+	ai = host_pton(buf);
+
+	/*
+	 * getaddrinfo(AI_NUMERICHOST) never fills in ai_canonname
+	 */
+	if (ai != NULL) {
+		ai->ai_canonname = strdup(buf);
+		if (ai->ai_canonname == NULL) {
+			freeaddrinfo(ai);
+			ai = NULL;
+		}
+	}
+
+	return ai;
 }
-#endif
+#endif	/* !HAVE_GETNAMEINFO */