aliyun: reuse ipv4 gateway address returned by metadata server

The default ipv4 gateway address of the VPC in Aliyun cloud is not the
first IP address in the CIDR subnet block, we should instead use the
ipv4 gateway address retrieved from the metadata server in
`_nmc_mangle_connection()`.

https://bugzilla.redhat.com/show_bug.cgi?id=1823315

https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/merge_requests/958

Signed-off-by: Wen Liang <liangwen12year@gmail.com>
(cherry picked from commit 778e1f8493babb8e015e5334806de7099c66bafb)

4 files changed, 53 insertions, 9 deletions

diff --git a/man/nm-cloud-setup.xml b/man/nm-cloud-setup.xml
index 63a805eb6b..7493cc1d7f 100644
--- a/man/nm-cloud-setup.xml
+++ b/man/nm-cloud-setup.xml
@@ -410,8 +410,8 @@ ln -s /etc/systemd/system/timers.target.wants/nm-cloud-setup.timer /usr/lib/syst
               <listitem>
                   <para>Choose a route table 30400 + the index of the interface and
                   add a default route <literal>0.0.0.0/0</literal>. The gateway
-                  is the first IP address in the CIDR subnet block. For
-                  example, we might get a route <literal>"0.0.0.0/0 10.0.0.1 10 table=30400"</literal>.</para>
+                  is the default gateway retrieved from metadata server. For
+                  example, we might get a route <literal>"0.0.0.0/0 10.0.0.253 10 table=30400"</literal>.</para>
               </listitem>
               <listitem>
                   <para>Finally, add a policy routing rule for each address. For example
@@ -419,7 +419,7 @@ ln -s /etc/systemd/system/timers.target.wants/nm-cloud-setup.timer /usr/lib/syst
               </listitem>
             </itemizedlist>
             With above example, this roughly corresponds for interface <literal>eth0</literal> to
-            <command>nmcli device modify "eth0" ipv4.addresses "10.0.0.150/24,10.0.0.150/24" ipv4.routes "0.0.0.0/0 10.0.0.1 10 table=30400" ipv4.routing-rules "priority 30400 from 10.0.0.150/32 table 30400, priority 30400 from 10.0.0.152/32 table 30400"</command>.
+            <command>nmcli device modify "eth0" ipv4.addresses "10.0.0.150/24,10.0.0.152/24" ipv4.routes "0.0.0.0/0 10.0.0.253 10 table=30400" ipv4.routing-rules "priority 30400 from 10.0.0.150/32 table 30400, priority 30400 from 10.0.0.152/32 table 30400"</command>.
             Note that this replaces the previous addresses, routes and rules with the new information.
             But also note that this only changes the run time configuration of the device. The
             connection profile on disk is not affected.
diff --git a/src/nm-cloud-setup/main.c b/src/nm-cloud-setup/main.c
index dc87ac42e0..8dc6785179 100644
--- a/src/nm-cloud-setup/main.c
+++ b/src/nm-cloud-setup/main.c
@@ -340,11 +340,13 @@ _nmc_mangle_connection(NMDevice *                            device,
             if (entry)
                 g_ptr_array_add(addrs_new, entry);
         }
-
-        gateway = nm_utils_ip4_address_clear_host_address(config_data->cidr_addr,
-                                                          config_data->cidr_prefix);
-        ((guint8 *) &gateway)[3] += 1;
-
+        if (config_data->has_gateway && config_data->gateway) {
+            gateway = config_data->gateway;
+        } else {
+            gateway = nm_utils_ip4_address_clear_host_address(config_data->cidr_addr,
+                                                              config_data->cidr_prefix);
+            ((guint8 *) &gateway)[3] += 1;
+        }
         rt_metric = 10;
         rt_table  = 30400 + config_data->iface_idx;
 
diff --git a/src/nm-cloud-setup/nmcs-provider-aliyun.c b/src/nm-cloud-setup/nmcs-provider-aliyun.c
index b430b452d0..01a4af0ff5 100644
--- a/src/nm-cloud-setup/nmcs-provider-aliyun.c
+++ b/src/nm-cloud-setup/nmcs-provider-aliyun.c
@@ -123,7 +123,8 @@ detect(NMCSProvider *provider, GTask *task)
 typedef enum {
     GET_CONFIG_FETCH_DONE_TYPE_SUBNET_VPC_CIDR_BLOCK,
     GET_CONFIG_FETCH_DONE_TYPE_PRIVATE_IPV4S,
-    GET_CONFIG_FETCH_DONE_TYPE_NETMASK
+    GET_CONFIG_FETCH_DONE_TYPE_NETMASK,
+    GET_CONFIG_FETCH_DONE_TYPE_GATEWAY,
 } GetConfigFetchDoneType;
 
 static void
@@ -140,6 +141,7 @@ _get_config_fetch_done_cb(NMHttpClient *         http_client,
     in_addr_t                       tmp_addr;
     int                             tmp_prefix;
     in_addr_t                       netmask_bin;
+    in_addr_t                       gateway_bin;
     gs_free const char **           s_addrs = NULL;
     gsize                           i;
     gsize                           len;
@@ -200,6 +202,17 @@ _get_config_fetch_done_cb(NMHttpClient *         http_client,
             config_iface_data->cidr_prefix = nm_utils_ip4_netmask_to_prefix(netmask_bin);
         };
         break;
+
+    case GET_CONFIG_FETCH_DONE_TYPE_GATEWAY:
+
+        if (nm_utils_parse_inaddr_bin(AF_INET,
+                                      g_bytes_get_data(response, NULL),
+                                      NULL,
+                                      &gateway_bin)) {
+            config_iface_data->has_gateway = TRUE;
+            config_iface_data->gateway     = gateway_bin;
+        };
+        break;
     }
 
 out:
@@ -234,6 +247,15 @@ _get_config_fetch_done_cb_netmask(GObject *source, GAsyncResult *result, gpointe
                               GET_CONFIG_FETCH_DONE_TYPE_NETMASK);
 }
 
+static void
+_get_config_fetch_done_cb_gateway(GObject *source, GAsyncResult *result, gpointer user_data)
+{
+    _get_config_fetch_done_cb(NM_HTTP_CLIENT(source),
+                              result,
+                              user_data,
+                              GET_CONFIG_FETCH_DONE_TYPE_GATEWAY);
+}
+
 typedef struct {
     gssize iface_idx;
     char   path[0];
@@ -277,6 +299,7 @@ _get_config_metadata_ready_cb(GObject *source, GAsyncResult *result, gpointer us
         gs_free char *                  uri1 = NULL;
         gs_free char *                  uri2 = NULL;
         gs_free char *                  uri3 = NULL;
+        gs_free char *                  uri4 = NULL;
         const char *                    hwaddr;
 
         if (!g_hash_table_lookup_extended(get_config_data->result_dict,
@@ -354,6 +377,23 @@ _get_config_metadata_ready_cb(GObject *source, GAsyncResult *result, gpointer us
             NULL,
             _get_config_fetch_done_cb_netmask,
             nm_utils_user_data_pack(get_config_data, hwaddr));
+
+        get_config_data->n_pending++;
+        nm_http_client_poll_get(
+            http_client,
+            (uri4 = _aliyun_uri_interfaces(v_mac_data->path,
+                                           NM_STR_HAS_SUFFIX(v_mac_data->path, "/") ? "" : "/",
+                                           "gateway")),
+            HTTP_TIMEOUT_MS,
+            512 * 1024,
+            10000,
+            1000,
+            NULL,
+            get_config_data->intern_cancellable,
+            NULL,
+            NULL,
+            _get_config_fetch_done_cb_gateway,
+            nm_utils_user_data_pack(get_config_data, hwaddr));
     }
 
     _nmcs_provider_get_config_task_maybe_return(get_config_data, NULL);
diff --git a/src/nm-cloud-setup/nmcs-provider.h b/src/nm-cloud-setup/nmcs-provider.h
index 3b0c2529ed..13212b8e4c 100644
--- a/src/nm-cloud-setup/nmcs-provider.h
+++ b/src/nm-cloud-setup/nmcs-provider.h
@@ -19,9 +19,11 @@ typedef struct {
     gssize iface_idx;
 
     in_addr_t cidr_addr;
+    in_addr_t gateway;
     guint8    cidr_prefix;
     bool      has_ipv4s : 1;
     bool      has_cidr : 1;
+    bool      has_gateway : 1;
 
     NMIPRoute **iproutes_arr;
     gsize       iproutes_len;