7388 Support DHCP Client FQDN. Allow IAID/DUID for all v4.

@@ -20,10 +20,11 @@
  */
 
 /*
  * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
  * Copyright 2014 Nexenta Systems, Inc.  All rights reserved.
+ * Copyright (c) 2016, Chris Fraire <cfraire@me.com>.
  */
 
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>

@@ -726,16 +727,17 @@
                         if (is_ngz)
                                 af = atoi(afstr);
                 } else if (nvlist_lookup_string(nvl, IPADM_NVP_AOBJNAME,
                     &aobjstr) == 0) {
                         /*
-                         * For a static address, we need to search for
-                         * the prefixlen in the nvlist `ifnvl'.
+                         * For addresses, we need to relocate addrprops from the
+                         * nvlist `ifnvl'.
                          */
                         if (nvlist_exists(nvl, IPADM_NVP_IPV4ADDR) ||
-                            nvlist_exists(nvl, IPADM_NVP_IPV6ADDR)) {
-                                status = i_ipadm_merge_prefixlen_from_nvl(ifnvl,
+                            nvlist_exists(nvl, IPADM_NVP_IPV6ADDR) ||
+                            nvlist_exists(nvl, IPADM_NVP_DHCP)) {
+                                status = i_ipadm_merge_addrprops_from_nvl(ifnvl,
                                     nvl, aobjstr);
                                 if (status != IPADM_SUCCESS)
                                         continue;
                         }
                         status = i_ipadm_init_addrobj(iph, nvl);

@@ -953,6 +955,83 @@
         } else {
                 if (darg.rsize != rsize)
                         err = EBADE;
         }
         return (err);
+}
+
+/*
+ * ipadm_is_nil_hostname() : Determine if the `hostname' is nil: i.e.,
+ *                      NULL, empty, or a single space (e.g., as returned by
+ *                      domainname(1M)/sysinfo).
+ *
+ *   input: const char *: the hostname to inspect;
+ *  output: boolean_t: B_TRUE if `hostname' is not NULL satisfies the
+ *                      criteria above; otherwise, B_FALSE;
+ */
+
+boolean_t
+ipadm_is_nil_hostname(const char *hostname)
+{
+        return (hostname == NULL || *hostname == '\0'
+            || (*hostname == ' ' && hostname[1] == '\0'));
+}
+
+/*
+ * ipadm_is_valid_hostname(): check whether a string is a valid hostname
+ *
+ *   input: const char *: the string to verify as a hostname
+ *  output: boolean_t: B_TRUE if the string is a valid hostname
+ *
+ * Note that we accept host names beginning with a digit, which is not
+ * strictly legal according to the RFCs but is in common practice, so we
+ * endeavour to not break what customers are using.
+ *
+ * RFC 1035 limits a wire-format domain name to 255 octets. For a printable
+ * `hostname' as we have, the limit is therefore 253 characters (excluding
+ * the terminating '\0'--or 254 characters if the last character of
+ * `hostname' is a '.'.
+ *
+ * Excerpt from section 2.3.1., Preferred name syntax:
+ *
+ * <domain> ::= <subdomain> | " "
+ * <subdomain> ::= <label> | <subdomain> "." <label>
+ * <label> ::= <letter> [ [ <ldh-str> ] <let-dig> ]
+ * <ldh-str> ::= <let-dig-hyp> | <let-dig-hyp> <ldh-str>
+ * <let-dig-hyp> ::= <let-dig> | "-"
+ * <let-dig> ::= <letter> | <digit>
+ */
+boolean_t
+ipadm_is_valid_hostname(const char *hostname)
+{
+        const size_t MAX_READABLE_NAME_LEN = 253;
+        char last_char;
+        size_t has_last_dot, namelen, i;
+
+        if (hostname == NULL)
+                return B_FALSE;
+
+        namelen = strlen(hostname);
+        if (namelen < 1)
+                return B_FALSE;
+
+        last_char = hostname[namelen - 1];
+        has_last_dot = last_char == '.';
+
+        if (namelen > MAX_READABLE_NAME_LEN + has_last_dot
+            || last_char == '-')
+                return B_FALSE;
+
+        for (i = 0; hostname[i] != '\0'; i++) {
+                /*
+                 * As noted above, this deviates from RFC 1035 in that it allows a
+                 * leading digit.
+                 */
+                if (isalpha(hostname[i]) || isdigit(hostname[i]) ||
+                    (((hostname[i] == '-') || (hostname[i] == '.')) && (i > 0)))
+                        continue;
+
+                return (B_FALSE);
+        }
+
+        return B_TRUE;
 }