X-Git-Url: https://git.decadent.org.uk/gitweb/?p=nfs-utils.git;a=blobdiff_plain;f=utils%2Fstatd%2Fhostname.c;h=616a3cbf45e2668ea57efe69c5aacf6995f80cd5;hp=3d10d6f1fa1f59e489388615ec2b80b69bf2d26e;hb=1ea2c3be33f2eb4630c5cdb78edf2bb670b294ab;hpb=cbd3a131e5c02bbd7b92a72b3ac467d71cfee1c4

diff --git a/utils/statd/hostname.c b/utils/statd/hostname.c
index 3d10d6f..616a3cb 100644
--- a/utils/statd/hostname.c
+++ b/utils/statd/hostname.c
@@ -30,13 +30,77 @@
 
 #include <stdlib.h>
 #include <stdbool.h>
+#include <string.h>
 #include <strings.h>
 #include <netdb.h>
+#include <arpa/inet.h>
 
 #include "sockaddr.h"
 #include "statd.h"
 #include "xlog.h"
 
+/**
+ * statd_present_address - convert sockaddr to presentation address
+ * @sap: pointer to socket address to convert
+ * @buf: pointer to buffer to fill in
+ * @buflen: length of buffer
+ *
+ * Convert the passed-in sockaddr-style address to presentation format.
+ * The presentation format address is placed in @buf and is
+ * '\0'-terminated.
+ *
+ * Returns true if successful; otherwise false.
+ *
+ * getnameinfo(3) is preferred, since it can parse IPv6 scope IDs.
+ * An alternate version of statd_present_address() is available to
+ * handle older glibcs that do not have getnameinfo(3).
+ */
+#ifdef HAVE_GETNAMEINFO
+_Bool
+statd_present_address(const struct sockaddr *sap, char *buf, const size_t buflen)
+{
+	socklen_t salen;
+	int error;
+
+	salen = nfs_sockaddr_length(sap);
+	if (salen == 0) {
+		xlog(D_GENERAL, "%s: unsupported address family",
+				__func__);
+		return false;
+	}
+
+	error = getnameinfo(sap, salen, buf, (socklen_t)buflen,
+						NULL, 0, NI_NUMERICHOST);
+	if (error != 0) {
+		xlog(D_GENERAL, "%s: getnameinfo(3): %s",
+				__func__, gai_strerror(error));
+		return false;
+	}
+	return true;
+}
+#else	/* !HAVE_GETNAMEINFO */
+_Bool
+statd_present_address(const struct sockaddr *sap, char *buf, const size_t buflen)
+{
+	const struct sockaddr_in *sin = (const struct sockaddr_in *)sap;
+
+	if (sin->sin_family != AF_INET) {
+		xlog(D_GENERAL, "%s: unsupported address family", __func__);
+		return false;
+	}
+
+	/* ensure '\0' termination */
+	memset(buf, 0, buflen);
+
+	if (inet_ntop(AF_INET, (char *)&sin->sin_addr,
+					buf, (socklen_t)buflen) == NULL) {
+		xlog(D_GENERAL, "%s: inet_ntop(3): %m", __func__);
+		return false;
+	}
+	return true;
+}
+#endif	/* !HAVE_GETNAMEINFO */
+
 /*
  * Look up the hostname; report exceptional errors.  Caller must
  * call freeaddrinfo(3) if a valid addrinfo is returned.
@@ -62,6 +126,105 @@ get_addrinfo(const char *hostname, const struct addrinfo *hint)
 	return NULL;
 }
 
+#ifdef HAVE_GETNAMEINFO
+static _Bool
+get_nameinfo(const struct sockaddr *sap, const socklen_t salen,
+		/*@out@*/ char *buf, const socklen_t buflen)
+{
+	int error;
+
+	error = getnameinfo(sap, salen, buf, buflen, NULL, 0, NI_NAMEREQD);
+	if (error != 0) {
+		xlog(D_GENERAL, "%s: failed to resolve address: %s",
+				__func__, gai_strerror(error));
+		return false;
+	}
+
+	return true;
+}
+#else	/* !HAVE_GETNAMEINFO */
+static _Bool
+get_nameinfo(const struct sockaddr *sap,
+		__attribute__ ((unused)) const socklen_t salen,
+		/*@out@*/ char *buf, socklen_t buflen)
+{
+	struct sockaddr_in *sin = (struct sockaddr_in *)(char *)sap;
+	struct hostent *hp;
+
+	if (sin->sin_family != AF_INET) {
+		xlog(D_GENERAL, "%s: unknown address family: %d",
+				sin->sin_family);
+		return false;
+	}
+
+	hp = gethostbyaddr((const char *)&(sin->sin_addr.s_addr),
+				sizeof(struct in_addr), AF_INET);
+	if (hp == NULL) {
+		xlog(D_GENERAL, "%s: failed to resolve address: %m", __func__);
+		return false;
+	}
+
+	strncpy(buf, hp->h_name, (size_t)buflen);
+	return true;
+}
+#endif	/* !HAVE_GETNAMEINFO */
+
+/**
+ * statd_canonical_name - choose file name for monitor record files
+ * @hostname: C string containing hostname or presentation address
+ *
+ * Returns a '\0'-terminated ASCII string containing a fully qualified
+ * canonical hostname, or NULL if @hostname does not have a reverse
+ * mapping.  Caller must free the result with free(3).
+ *
+ * Incoming hostnames are looked up to determine the canonical hostname,
+ * and incoming presentation addresses are converted to canonical
+ * hostnames.
+ *
+ * We won't monitor peers that don't have a reverse map.  The canonical
+ * name gives us a key for our monitor list.
+ */
+__attribute_malloc__
+char *
+statd_canonical_name(const char *hostname)
+{
+	struct addrinfo hint = {
+#ifdef IPV6_SUPPORTED
+		.ai_family	= AF_UNSPEC,
+#else	/* !IPV6_SUPPORTED */
+		.ai_family	= AF_INET,
+#endif	/* !IPV6_SUPPORTED */
+		.ai_flags	= AI_NUMERICHOST,
+		.ai_protocol	= (int)IPPROTO_UDP,
+	};
+	char buf[NI_MAXHOST];
+	struct addrinfo *ai;
+
+	ai = get_addrinfo(hostname, &hint);
+	if (ai != NULL) {
+		/* @hostname was a presentation address */
+		_Bool result;
+		result = get_nameinfo(ai->ai_addr, ai->ai_addrlen,
+					buf, (socklen_t)sizeof(buf));
+		freeaddrinfo(ai);
+		if (!result)
+			/* OK to use presentation address,
+			 * if no reverse map exists */
+			return strdup(hostname);
+		return strdup(buf);
+	}
+
+	/* @hostname was a hostname */
+	hint.ai_flags = AI_CANONNAME;
+	ai = get_addrinfo(hostname, &hint);
+	if (ai == NULL)
+		return NULL;
+	strcpy(buf, ai->ai_canonname);
+	freeaddrinfo(ai);
+
+	return strdup(buf);
+}
+
 /**
  * statd_matchhostname - check if two hostnames are equivalent
  * @hostname1: C string containing hostname