Attachment 132757 Details for Bug 92853 – config-parser: Clarify how <allow>, <deny> attributes work

[patch] config-parser: Clarify how <allow>, <deny> attributes work

config-parser-Clarify-how-allow-deny-attributes-wo.patch (text/plain), 10.69 KB, created by Simon McVittie on 2017-07-19 15:30:49 UTC

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Creator: Simon McVittie

Created: 2017-07-19 15:30:49 UTC

Size: 10.69 KB

patch

obsolete

>From 8c578d5ea54972a0b2fa0f4648f0445d8058ba9c Mon Sep 17 00:00:00 2001
>From: Simon McVittie <smcv@collabora.com>
>Date: Wed, 31 May 2017 14:51:31 +0100
>Subject: [PATCH] config-parser: Clarify how <allow>, <deny> attributes work
>
>The giant conditionals used to check policy attributes are increasingly
>unwieldy, so let's try something else. Bundle together the send_
>attributes, the receive_ attributes, the eavesdrop attribute
>(which can go on either send or receive rules) and the other attributes
>into equivalence classes, and write the conditionals in terms of those
>equivalence classes.
>
>In particular, this correctly forbids
>    <allow receive_type="..." send_destination="..."/>
>which was previously allowed but nonsensical (the send part took
>precedence and the receive part was ignored).
>
>Signed-off-by: Simon McVittie <smcv@collabora.com>
>---
> bus/config-parser.c | 194 +++++++++++++++++++++++-----------------------------
> 1 file changed, 85 insertions(+), 109 deletions(-)
>
>diff --git a/bus/config-parser.c b/bus/config-parser.c
>index 7b3aabb2..4dc7d927 100644
>--- a/bus/config-parser.c
>+++ b/bus/config-parser.c
>@@ -1285,28 +1285,42 @@ append_rule_from_element (BusConfigParser   *parser,
>                           DBusError         *error)
> {
>   const char *log;
>+
>+  /* Group: send_ attributes */
>   const char *send_interface;
>   const char *send_member;
>   const char *send_error;
>   const char *send_destination;
>   const char *send_path;
>   const char *send_type;
>+  const char *send_requested_reply;
>+  /* TRUE if any send_ attribute is present */
>+  dbus_bool_t any_send_attribute;
>+
>+  /* Group: receive_ attributes */
>   const char *receive_interface;
>   const char *receive_member;
>   const char *receive_error;
>   const char *receive_sender;
>   const char *receive_path;
>   const char *receive_type;
>-  const char *eavesdrop;
>-  const char *send_requested_reply;
>   const char *receive_requested_reply;
>+  /* TRUE if any receive_ attribute is present */
>+  dbus_bool_t any_receive_attribute;
>+
>+  /* Group: message-matching modifiers that can go on send_ or receive_ */
>+  const char *eavesdrop;
>+  /* TRUE if any message-matching modifier is present */
>+  dbus_bool_t any_message_attribute;
>+
>+  /* Non-message-related attributes */
>   const char *own;
>   const char *own_prefix;
>   const char *user;
>   const char *group;
> 
>   BusPolicyRule *rule;
>-  
>+
>   if (!locate_attributes (parser, element_name,
>                           attribute_names,
>                           attribute_values,
>@@ -1334,11 +1348,32 @@ append_rule_from_element (BusConfigParser   *parser,
>                           NULL))
>     return FALSE;
> 
>-  if (!(send_interface || send_member || send_error || send_destination ||
>-        send_type || send_path ||
>-        receive_interface || receive_member || receive_error || receive_sender ||
>-        receive_type || receive_path || eavesdrop ||
>-        send_requested_reply || receive_requested_reply ||
>+  any_send_attribute = (send_destination != NULL ||
>+                        send_path != NULL ||
>+                        send_type != NULL ||
>+                        send_interface != NULL ||
>+                        send_member != NULL ||
>+                        send_error != NULL ||
>+                        send_requested_reply != NULL);
>+  any_receive_attribute = (receive_sender != NULL ||
>+                           receive_path != NULL ||
>+                           receive_type != NULL ||
>+                           receive_interface != NULL ||
>+                           receive_member != NULL ||
>+                           receive_error != NULL ||
>+                           receive_requested_reply != NULL ||
>+                           /* <allow eavesdrop="true"/> means the same as
>+                            * <allow receive_sender="*" eavesdrop="true"/>,
>+                            * but <allow send_anything="anything"/> can also
>+                            * take the eavesdrop attribute and still counts
>+                            * as a send rule. */
>+                           (!any_send_attribute && eavesdrop != NULL));
>+  any_message_attribute = (any_send_attribute ||
>+                           any_receive_attribute ||
>+                           eavesdrop != NULL);
>+
>+  if (!(any_send_attribute ||
>+        any_receive_attribute ||
>         own || own_prefix || user || group))
>     {
>       dbus_set_error (error, DBUS_ERROR_FAILED,
>@@ -1364,113 +1399,56 @@ append_rule_from_element (BusConfigParser   *parser,
>    *     interface + member
>    *     error
>    * 
>-   *   base send_ can combine with send_destination, send_path, send_type, send_requested_reply
>+   *   base send_ can combine with send_destination, send_path, send_type, send_requested_reply, eavesdrop
>    *   base receive_ with receive_sender, receive_path, receive_type, receive_requested_reply, eavesdrop
>    *
>    *   user, group, own, own_prefix must occur alone
>-   *
>-   * Pretty sure the below stuff is broken, FIXME think about it more.
>    */
> 
>-  if ((send_interface && (send_error ||
>-                          receive_interface ||
>-                          receive_member ||
>-                          receive_error ||
>-                          receive_sender ||
>-                          receive_requested_reply ||
>-                          own || own_prefix ||
>-                          user ||
>-                          group)) ||
>-
>-      (send_member && (send_error ||
>-                       receive_interface ||
>-                       receive_member ||
>-                       receive_error ||
>-                       receive_sender ||
>-                       receive_requested_reply ||
>-                       own || own_prefix ||
>-                       user ||
>-                       group)) ||
>-
>-      (send_error && (receive_interface ||
>-                      receive_member ||
>-                      receive_error ||
>-                      receive_sender ||
>-                      receive_requested_reply ||
>-                      own || own_prefix ||
>-                      user ||
>-                      group)) ||
>-
>-      (send_destination && (receive_interface ||
>-                            receive_member ||
>-                            receive_error ||
>-                            receive_sender ||
>-                            receive_requested_reply ||
>-                            own || own_prefix ||
>-                            user ||
>-                            group)) ||
>-
>-      (send_type && (receive_interface ||
>-                     receive_member ||
>-                     receive_error ||
>-                     receive_sender ||
>-                     receive_requested_reply ||
>-                     own || own_prefix ||
>-                     user ||
>-                     group)) ||
>-
>-      (send_path && (receive_interface ||
>-                     receive_member ||
>-                     receive_error ||
>-                     receive_sender ||
>-                     receive_requested_reply ||
>-                     own || own_prefix ||
>-                     user ||
>-                     group)) ||
>-
>-      (send_requested_reply && (receive_interface ||
>-                                receive_member ||
>-                                receive_error ||
>-                                receive_sender ||
>-                                receive_requested_reply ||
>-                                own || own_prefix ||
>-                                user ||
>-                                group)) ||
>-
>-      (receive_interface && (receive_error ||
>-                             own || own_prefix ||
>-                             user ||
>-                             group)) ||
>-
>-      (receive_member && (receive_error ||
>-                          own || own_prefix ||
>-                          user ||
>-                          group)) ||
>-
>-      (receive_error && (own || own_prefix ||
>-                         user ||
>-                         group)) ||
>-
>-      (eavesdrop && (own || own_prefix ||
>-                     user ||
>-                     group)) ||
>-
>-      (receive_requested_reply && (own || own_prefix ||
>-                                   user ||
>-                                   group)) ||
>-
>-      (own && (own_prefix || user || group)) ||
>-
>-      (own_prefix && (own || user || group)) ||
>-
>-      (user && group))
>+  if (any_message_attribute +
>+      ((own != NULL) +
>+       (own_prefix != NULL) +
>+       (user != NULL) +
>+       (group != NULL)) > 1)
>     {
>       dbus_set_error (error, DBUS_ERROR_FAILED,
>-                      "Invalid combination of attributes on element <%s>",
>+                      "Invalid combination of attributes on element <%s>: "
>+                      "own, own_prefix, user, group and the message-related "
>+                      "attributes cannot be combined",
>                       element_name);
>       return FALSE;
>     }
>-  
>+
>+  if (any_send_attribute && any_receive_attribute)
>+    {
>+      dbus_set_error (error, DBUS_ERROR_FAILED,
>+                      "Invalid combination of attributes on element <%s>: "
>+                      "send and receive attributes cannot be combined",
>+                      element_name);
>+      return FALSE;
>+    }
>+
>+  if ((send_member != NULL || send_interface != NULL) && send_error != NULL)
>+    {
>+      dbus_set_error (error, DBUS_ERROR_FAILED,
>+                      "Invalid combination of attributes on element <%s>: "
>+                      "send_error cannot be combined with send_member or "
>+                      "send_interface",
>+                      element_name);
>+      return FALSE;
>+    }
>+
>+  if ((receive_member != NULL || receive_interface != NULL) &&
>+      receive_error != NULL)
>+    {
>+      dbus_set_error (error, DBUS_ERROR_FAILED,
>+                      "Invalid combination of attributes on element <%s>: "
>+                      "receive_error cannot be combined with receive_member "
>+                      "or receive_interface",
>+                      element_name);
>+      return FALSE;
>+    }
>+
>   rule = NULL;
> 
>   /* In BusPolicyRule, NULL represents wildcard.
>@@ -1478,8 +1456,7 @@ append_rule_from_element (BusConfigParser   *parser,
>    */
> #define IS_WILDCARD(str) ((str) && ((str)[0]) == '*' && ((str)[1]) == '\0')
> 
>-  if (send_interface || send_member || send_error || send_destination ||
>-      send_path || send_type || send_requested_reply)
>+  if (any_send_attribute)
>     {
>       int message_type;
>       
>@@ -1559,8 +1536,7 @@ append_rule_from_element (BusConfigParser   *parser,
>       if (send_destination && rule->d.send.destination == NULL)
>         goto nomem;
>     }
>-  else if (receive_interface || receive_member || receive_error || receive_sender ||
>-           receive_path || receive_type || eavesdrop || receive_requested_reply)
>+  else if (any_receive_attribute)
>     {
>       int message_type;
>       
>-- 
>2.13.3

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Attachments on bug 92853: 119459 | 119460 | 131602 | 131603 | 131604 | 132757 | 132758 | 132759 | 132760 | 132761 | 132762 | 132763 | 132764 | 132765 | 132766 | 133096 | 133097

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