Add dynamic DNS updates to FreeIPA

This adds two new options:

ipa_dyndns_update: Boolean value to select whether this client
should automatically update its IP address in FreeIPA DNS.

ipa_dyndns_iface: Choose an interface manually to use for
updating dynamic DNS. Default is to use the interface associated
with the LDAP connection to FreeIPA.

This patch supports A and AAAA records. It relies on the presence
of the nsupdate tool from the bind-utils package to perform the
actual update step. The location of this utility is set at build
time, but its availability is determined at runtime (so clients
that do not require dynamic update capability do not need to meet
this dependency).

1 files changed, 41 insertions, 0 deletions

diff --git a/src/providers/ipa/ipa_init.c b/src/providers/ipa/ipa_init.c
index 596aecfbd..9c30d9736 100644
--- a/src/providers/ipa/ipa_init.c
+++ b/src/providers/ipa/ipa_init.c
@@ -33,6 +33,7 @@
 #include "providers/ipa/ipa_auth.h"
 #include "providers/ipa/ipa_access.h"
 #include "providers/ipa/ipa_timerules.h"
+#include "providers/ipa/ipa_dyndns.h"
 
 struct ipa_options *ipa_options = NULL;
 
@@ -96,6 +97,8 @@ int sssm_ipa_id_init(struct be_ctx *bectx,
                      void **pvt_data)
 {
     struct sdap_id_ctx *ctx;
+    struct stat stat_buf;
+    errno_t err;
     int ret;
 
     if (!ipa_options) {
@@ -127,6 +130,44 @@ int sssm_ipa_id_init(struct be_ctx *bectx,
         goto done;
     }
 
+    if(dp_opt_get_bool(ipa_options->basic, IPA_DYNDNS_UPDATE)) {
+        /* Perform automatic DNS updates when the
+         * IP address changes.
+         * Register a callback for successful LDAP
+         * reconnections. This is the easiest way to
+         * identify that we have gone online.
+         */
+
+        /* Ensure that nsupdate exists */
+        errno = 0;
+        ret = stat(NSUPDATE_PATH, &stat_buf);
+        if (ret == -1) {
+            err = errno;
+            if (err == ENOENT) {
+                DEBUG(0, ("%s does not exist. Dynamic DNS updates disabled\n",
+                          NSUPDATE_PATH));
+            }
+            else {
+                DEBUG(0, ("Could not set up dynamic DNS updates: [%d][%s]\n",
+                          err, strerror(err)));
+            }
+        }
+        else {
+            /* nsupdate is available. Dynamic updates
+             * are supported
+             */
+            ret = be_add_online_cb(ctx, ctx->be,
+                                   ipa_dyndns_update,
+                                   ipa_options, NULL);
+            if (ret != EOK) {
+                DEBUG(1,("Failure setting up automatic DNS update\n"));
+                /* We will continue without DNS updating */
+            }
+        }
+    }
+
+
+
     ret = setup_tls_config(ctx->opts->basic);
     if (ret != EOK) {
         DEBUG(1, ("setup_tls_config failed [%d][%s].\n",