mountd: Use static buffer when constructing junction export options

[nfs-utils.git] / utils / statd / hostname.c

diff --git a/utils/statd/hostname.c b/utils/statd/hostname.c
index 7571b6f44a864318ef28425e58b07fcfea154efb..746ecc7c57b5f6aba93484f4293ab2cc39fa9028 100644 (file)
--- a/utils/statd/hostname.c
+++ b/utils/statd/hostname.c
@@ -126,6 +126,148 @@ 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);
+}
+
+/*
+ * Take care to perform an explicit reverse lookup on presentation
+ * addresses.  Otherwise we don't get a real canonical name or a
+ * complete list of addresses.
+ *
+ * Returns an addrinfo list that has ai_canonname filled in, or
+ * NULL if some error occurs.  Caller must free the returned
+ * list with freeaddrinfo(3).
+ */
+__attribute_malloc__
+static struct addrinfo *
+statd_canonical_list(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)
+                       goto out;
+       }
+       /* @hostname was a hostname or had no reverse mapping */
+       strcpy(buf, hostname);
+
+out:
+       hint.ai_flags = AI_CANONNAME;
+       return get_addrinfo(buf, &hint);
+}
+
 /**
  * statd_matchhostname - check if two hostnames are equivalent
  * @hostname1: C string containing hostname
@@ -142,11 +284,6 @@ _Bool
 statd_matchhostname(const char *hostname1, const char *hostname2)
 {
        struct addrinfo *ai1, *ai2, *results1 = NULL, *results2 = NULL;
-       struct addrinfo hint = {
-               .ai_family      = AF_UNSPEC,
-               .ai_flags       = AI_CANONNAME,
-               .ai_protocol    = (int)IPPROTO_UDP,
-       };
        _Bool result = false;
 
        if (strcasecmp(hostname1, hostname2) == 0) {
@@ -154,10 +291,10 @@ statd_matchhostname(const char *hostname1, const char *hostname2)
                goto out;
        }
 
-       results1 = get_addrinfo(hostname1, &hint);
+       results1 = statd_canonical_list(hostname1);
        if (results1 == NULL)
                goto out;
-       results2 = get_addrinfo(hostname2, &hint);
+       results2 = statd_canonical_list(hostname2);
        if (results2 == NULL)
                goto out;
 
@@ -177,7 +314,8 @@ out:
        freeaddrinfo(results2);
        freeaddrinfo(results1);
 
-       xlog(D_CALL, "%s: hostnames %s", __func__,
+       xlog(D_CALL, "%s: hostnames %s and %s %s", __func__,
+                       hostname1, hostname2,
                        (result ? "matched" : "did not match"));
        return result;
 }