X-Git-Url: https://git.decadent.org.uk/gitweb/?p=nfs-utils.git;a=blobdiff_plain;f=support%2Fexport%2Fhostname.c;h=3e949a18fe52255b51a4d77713f28b1679f16b75;hp=232e04038daaa8f5b0c8592369ee5deff3a99c9e;hb=b50ad13298b3e9519a9bdecb8c146c9ecf39cef8;hpb=9c3f7a220b4812c5d560db5fcacad790fc8b17af

diff --git a/support/export/hostname.c b/support/export/hostname.c
index 232e040..3e949a1 100644
--- a/support/export/hostname.c
+++ b/support/export/hostname.c
@@ -30,20 +30,6 @@
 #include "sockaddr.h"
 #include "exportfs.h"
 
-#ifndef HAVE_DECL_AI_ADDRCONFIG
-#define AI_ADDRCONFIG	0
-#endif
-
-#ifdef HAVE_GETNAMEINFO
-static socklen_t
-sockaddr_size(const struct sockaddr *sap)
-{
-	if (sap->sa_family != AF_INET)
-		return 0;
-	return (socklen_t)sizeof(struct sockaddr_in);
-}
-#endif	/* HAVE_GETNAMEINFO */
-
 /**
  * host_ntop - generate presentation address given a sockaddr
  * @sap: pointer to socket address
@@ -56,7 +42,7 @@ sockaddr_size(const struct sockaddr *sap)
 char *
 host_ntop(const struct sockaddr *sap, char *buf, const size_t buflen)
 {
-	socklen_t salen = sockaddr_size(sap);
+	socklen_t salen = nfs_sockaddr_length(sap);
 	int error;
 
 	memset(buf, 0, buflen);
@@ -117,7 +103,7 @@ host_pton(const char *paddr)
 		.ai_family	= AF_UNSPEC,
 	};
 	struct sockaddr_in sin;
-	int error;
+	int error, inet4;
 
 	/*
 	 * Although getaddrinfo(3) is easier to use and supports
@@ -129,12 +115,17 @@ host_pton(const char *paddr)
 	 * 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)
-		return NULL;
+		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)
@@ -168,10 +159,14 @@ host_addrinfo(const char *hostname)
 {
 	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_ADDRCONFIG | AI_CANONNAME,
+		.ai_flags	= AI_CANONNAME,
 	};
 	int error;
 
@@ -208,7 +203,7 @@ __attribute_malloc__
 char *
 host_canonname(const struct sockaddr *sap)
 {
-	socklen_t salen = sockaddr_size(sap);
+	socklen_t salen = nfs_sockaddr_length(sap);
 	char buf[NI_MAXHOST];
 	int error;
 
@@ -263,17 +258,19 @@ host_canonname(const struct sockaddr *sap)
  * @sap: pointer to socket address to look up
  *
  * Reverse and forward lookups are performed to ensure the address has
- * proper forward and reverse mappings.
+ * matching forward and reverse mappings.
  *
- * Returns address info structure with ai_canonname filled in, or NULL
- * if no information is available for @sap.  Caller must free the returned
- * structure with freeaddrinfo(3).
+ * 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)
 {
-	struct addrinfo *ai;
+	struct addrinfo *ai, *a;
 	char *hostname;
 
 	hostname = host_canonname(sap);
@@ -281,9 +278,31 @@ host_reliable_addrinfo(const struct sockaddr *sap)
 		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 ai;
+	return NULL;
 }
 
 /**
@@ -298,8 +317,8 @@ __attribute_malloc__
 struct addrinfo *
 host_numeric_addrinfo(const struct sockaddr *sap)
 {
-	socklen_t salen = sockaddr_size(sap);
-	char buf[INET_ADDRSTRLEN];
+	socklen_t salen = nfs_sockaddr_length(sap);
+	char buf[INET6_ADDRSTRLEN];
 	struct addrinfo *ai;
 	int error;