[network-manager-applet: 1/6] applet/vpn-request: rework the auth-dialog communication

[Lubomir Rintel <lkundrak src gnome org>]

commit 161f4274a8a61ca2d1afa289228872204fb31282
Author: Lubomir Rintel <lkundrak v3 sk>
Date:   Wed Apr 3 13:37:01 2019 +0200

    applet/vpn-request: rework the auth-dialog communication
    
    This changes the auth-dialog communication in two important ways:
    
    1.) It reworks how is the end of input determined. Previously \n\n whould
        signal a successful end of input, now it checks for EOF instead.
    
    2.) It now no longer reads and processes the input line by line, but
        accumulates the whole thing and only splits it into lines afterwards.
    
    Both changes are done so that external UI mode is easier to add, while
    sharing as input handling as possible. The external UI mode uses a GKeyFile
    formatted description of the connection secrets. It is parsed as a
    whole, not on a line-by-line basis and it is not terminated with a \n\n.
    
    It is functionally requivalent.

 src/applet-vpn-request.c | 176 ++++++++++++++++++++++++++++-------------------
 1 file changed, 107 insertions(+), 69 deletions(-)
---
diff --git a/src/applet-vpn-request.c b/src/applet-vpn-request.c
index e7ca080f..f4744f5d 100644
--- a/src/applet-vpn-request.c
+++ b/src/applet-vpn-request.c
@@ -17,7 +17,7 @@
  * with this program; if not, write to the Free Software Foundation, Inc.,
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  *
- * Copyright 2004 - 2017 Red Hat, Inc.
+ * Copyright 2004 - 2019 Red Hat, Inc.
  */
 
 #include "nm-default.h"
@@ -44,12 +44,11 @@ typedef struct {
        guint watch_id;
        GPid pid;
 
-       GSList *lines;
-       int child_stdin;
        int child_stdout;
-       int num_newlines;
+       GString *child_response;
        GIOChannel *channel;
        guint channel_eventid;
+       GVariantBuilder secrets_builder;
 } RequestData;
 
 typedef struct {
@@ -60,6 +59,7 @@ typedef struct {
 /*****************************************************************************/
 
 static void request_data_free (RequestData *req_data);
+static void complete_request (VpnSecretsInfo *info);
 
 /*****************************************************************************/
 
@@ -72,81 +72,104 @@ applet_vpn_request_get_secrets_size (void)
 /*****************************************************************************/
 
 static void
-child_finished_cb (GPid pid, gint status, gpointer user_data)
+complete_request (VpnSecretsInfo *info)
 {
-       SecretsRequest *req = user_data;
-       VpnSecretsInfo *info = (VpnSecretsInfo *) req;
+       SecretsRequest *req = (SecretsRequest *) info;
        RequestData *req_data = info->req_data;
-       gs_free_error GError *error = NULL;
+       GVariantBuilder settings_builder, vpn_builder;
        gs_unref_variant GVariant *settings = NULL;
-       GVariantBuilder settings_builder, vpn_builder, secrets_builder;
-
-       if (status == 0) {
-               GSList *iter;
-
-               g_variant_builder_init (&settings_builder, NM_VARIANT_TYPE_CONNECTION);
-               g_variant_builder_init (&vpn_builder, NM_VARIANT_TYPE_SETTING);
-               g_variant_builder_init (&secrets_builder, G_VARIANT_TYPE ("a{ss}"));
-
-               /* The length of 'lines' must be divisible by 2 since it must contain
-                * key:secret pairs with the key on one line and the associated secret
-                * on the next line.
-                */
-               for (iter = req_data->lines; iter; iter = g_slist_next (iter)) {
-                       if (!iter->next)
-                               break;
-                       g_variant_builder_add (&secrets_builder, "{ss}", iter->data, iter->next->data);
-                       iter = iter->next;
-               }
 
-               g_variant_builder_add (&vpn_builder, "{sv}",
-                                      NM_SETTING_VPN_SECRETS,
-                                      g_variant_builder_end (&secrets_builder));
-               g_variant_builder_add (&settings_builder, "{sa{sv}}",
-                                      NM_SETTING_VPN_SETTING_NAME,
-                                      &vpn_builder);
-               settings = g_variant_builder_end (&settings_builder);
-       } else {
+       g_variant_builder_init (&settings_builder, NM_VARIANT_TYPE_CONNECTION);
+       g_variant_builder_init (&vpn_builder, NM_VARIANT_TYPE_SETTING);
+
+       g_variant_builder_add (&vpn_builder, "{sv}",
+                              NM_SETTING_VPN_SECRETS,
+                              g_variant_builder_end (&req_data->secrets_builder));
+       g_variant_builder_add (&settings_builder, "{sa{sv}}",
+                              NM_SETTING_VPN_SETTING_NAME,
+                              &vpn_builder);
+       settings = g_variant_builder_end (&settings_builder);
+
+       applet_secrets_request_complete (req, settings, NULL);
+       applet_secrets_request_free (req);
+}
+
+static void
+process_child_response (VpnSecretsInfo *info)
+{
+       RequestData *req_data = info->req_data;
+       gs_free_error GError *error = NULL;
+       char **lines = g_strsplit (req_data->child_response->str, "\n", -1);
+       int i;
+
+       for (i = 0; lines[i] && *(lines[i]); i += 2) {
+               if (lines[i + 1] == NULL)
+                       break;
+               g_variant_builder_add (&req_data->secrets_builder, "{ss}", lines[i], lines[i + 1]);
+       }
+
+       g_strfreev (lines);
+       complete_request (info);
+}
+
+static void
+child_finished_cb (GPid pid, int status, gpointer user_data)
+{
+       VpnSecretsInfo *info = user_data;
+       SecretsRequest *req = (SecretsRequest *) info;
+       RequestData *req_data = info->req_data;
+       gs_free_error GError *error = NULL;
+
+       req_data->pid = 0;
+       req_data->watch_id = 0;
+
+       if (status) {
                error = g_error_new (NM_SECRET_AGENT_ERROR,
                                     NM_SECRET_AGENT_ERROR_USER_CANCELED,
                                     "%s.%d (%s): canceled", __FILE__, __LINE__, __func__);
-       }
 
-       /* Complete the secrets request */
-       applet_secrets_request_complete (req, settings, error);
-       applet_secrets_request_free (req);
+               applet_secrets_request_complete (req, NULL, error);
+               applet_secrets_request_free (req);
+       } else if (req_data->channel_eventid == 0) {
+               /* We now have both the child response and its exit status. Process it. */
+               process_child_response (info);
+       }
 }
 
-/*****************************************************************************/
-
 static gboolean
 child_stdout_data_cb (GIOChannel *source, GIOCondition condition, gpointer user_data)
 {
-       VpnSecretsInfo *info = user_data;
+       SecretsRequest *req = user_data;
+       VpnSecretsInfo *info = (VpnSecretsInfo *) req;
        RequestData *req_data = info->req_data;
-       char *str;
-       int len;
-
-       if (!(condition & G_IO_IN))
-               return TRUE;
-
-       if (g_io_channel_read_line (source, &str, NULL, NULL, NULL) == G_IO_STATUS_NORMAL) {
-               len = strlen (str);
-               if (len == 1 && str[0] == '\n') {
-                       /* on second line with a newline newline */
-                       if (++req_data->num_newlines == 2) {
-                               const char *buf = "QUIT\n\n";
-
-                               /* terminate the child */
-                               if (write (req_data->child_stdin, buf, strlen (buf)) == -1)
-                                       return TRUE;
-                       }
-               } else if (len > 0) {
-                       /* remove terminating newline */
-                       str[len - 1] = '\0';
-                       req_data->lines = g_slist_append (req_data->lines, str);
+       GIOStatus status;
+       char buf[4096];
+       size_t bytes_read;
+       gs_free_error GError *error = NULL;
+
+       status = g_io_channel_read_chars (source, buf, sizeof (buf)-1, &bytes_read, &error);
+       switch (status) {
+       case G_IO_STATUS_ERROR:
+               req_data->channel_eventid = 0;
+               applet_secrets_request_complete (req, NULL, error);
+               applet_secrets_request_free (req);
+               return FALSE;
+       case G_IO_STATUS_EOF:
+               req_data->channel_eventid = 0;
+               if (req_data->pid == 0) {
+                       /* We now have both the childe respons and
+                        * its exit status. Process it. */
+                       process_child_response (info);
                }
+               return FALSE;
+       case G_IO_STATUS_NORMAL:
+               g_string_append_len (req_data->child_response, buf, bytes_read);
+               break;
+       default:
+               /* What just happened... */
+               g_return_val_if_reached (FALSE);
        }
+
        return TRUE;
 }
 
@@ -218,7 +241,7 @@ connection_to_data (NMConnection *connection,
        }
        nm_clear_g_free (&keys);
 
-       g_string_append (buf, "DONE\n\n");
+       g_string_append (buf, "DONE\n\nQUIT\n\n");
        NM_SET_OUT (out_length, buf->len);
        return g_string_free (buf, FALSE);
 }
@@ -301,7 +324,7 @@ auth_dialog_spawn (const char *con_id,
        g_return_val_if_fail (out_stdout, FALSE);
 
        hints_len = NM_PTRARRAY_LEN (hints);
-       argv = g_new (const char *, 10 + (2 * hints_len));
+       argv = g_new (const char *, 11 + (2 * hints_len));
        i = 0;
        argv[i++] = auth_dialog;
        argv[i++] = "-u";
@@ -371,6 +394,7 @@ applet_vpn_request_get_secrets (SecretsRequest *req, GError **error)
        const char *service_type;
        const char *auth_dialog;
        gs_unref_object NMVpnPluginInfo *plugin = NULL;
+       int child_stdin;
 
        applet_secrets_request_set_free_func (req, free_vpn_secrets_info);
 
@@ -404,6 +428,8 @@ applet_vpn_request_get_secrets (SecretsRequest *req, GError **error)
        }
        req_data = info->req_data;
 
+       g_variant_builder_init (&req_data->secrets_builder, G_VARIANT_TYPE ("a{ss}"));
+
        if (!auth_dialog_spawn (nm_setting_connection_get_id (s_con),
                                nm_setting_connection_get_uuid (s_con),
                                (const char *const*) req->hints,
@@ -412,7 +438,7 @@ applet_vpn_request_get_secrets (SecretsRequest *req, GError **error)
                                nm_vpn_plugin_info_supports_hints (plugin),
                                req->flags,
                                &req_data->pid,
-                               &req_data->child_stdin,
+                               &child_stdin,
                                &req_data->child_stdout,
                                error))
                return FALSE;
@@ -422,11 +448,20 @@ applet_vpn_request_get_secrets (SecretsRequest *req, GError **error)
 
        /* listen to what child has to say */
        req_data->channel = g_io_channel_unix_new (req_data->child_stdout);
-       req_data->channel_eventid = g_io_add_watch (req_data->channel, G_IO_IN, child_stdout_data_cb, info);
+       req_data->child_response = g_string_sized_new (4096);
+       req_data->channel_eventid = g_io_add_watch (req_data->channel,
+                                                   G_IO_IN  | G_IO_ERR | G_IO_HUP | G_IO_NVAL,
+                                                   child_stdout_data_cb,
+                                                   info);
+
+       if (!connection_to_fd (req->connection, child_stdin, error))
+               return FALSE;
+       close (child_stdin);
+
        g_io_channel_set_encoding (req_data->channel, NULL, NULL);
 
        /* Dump parts of the connection to the child */
-       return connection_to_fd (req->connection, req_data->child_stdin, error);
+       return TRUE;
 }
 
 /*****************************************************************************/
@@ -470,6 +505,9 @@ request_data_free (RequestData *req_data)
                }
        }
 
-       g_slist_free_full (req_data->lines, g_free);
+       if (req_data->child_response)
+               g_string_free (req_data->child_response, TRUE);
+
+       g_variant_builder_clear (&req_data->secrets_builder);
        g_slice_free (RequestData, req_data);
 }