From 5629f47a59b48f2604fd8e9e4af7209b138aef21 Mon Sep 17 00:00:00 2001
From: Aleksander Morgado <aleksander@aleksander.es>
Date: Mon, 30 Nov 2020 21:51:32 +0100
Subject: libmm-glib,bearer-properties: allow loose comparisons

When comparing bearer properties provided by the user versus loaded
from the modem, we shouldn't be very strict, e.g.:
 * Password or other fields may not be readable from the device.
 * Some fields may not apply at all (e.g. RM protocol for EPS bearers)
 * NULL strings could be assumed equal to empty strings.
 * If no explicit IP type specified, an IPv4 default may be assumed.
 * If no explicit allowed auth specified, 'none' default may be
   assumed.

These loose comparisons are applied when managing the initial EPS
bearer settings and status, and we keep the strict comparison only
during the connection attempt lookup of a bearer with certain
settings, as those bearer objects are all created in the same place
with the same rules.
---
 libmm-glib/mm-bearer-properties.c | 101 ++++++++++++++++++++++++++++++++++----
 1 file changed, 91 insertions(+), 10 deletions(-)

(limited to 'libmm-glib/mm-bearer-properties.c')

diff --git a/libmm-glib/mm-bearer-properties.c b/libmm-glib/mm-bearer-properties.c
index 5ed4438e..904d1248 100644
--- a/libmm-glib/mm-bearer-properties.c
+++ b/libmm-glib/mm-bearer-properties.c
@@ -667,21 +667,102 @@ mm_bearer_properties_new_from_dictionary (GVariant *dictionary,
 
 /*****************************************************************************/
 
+static gboolean
+cmp_str (const gchar                *a,
+         const gchar                *b,
+         MMBearerPropertiesCmpFlags  flags)
+{
+    /* Strict match */
+    if ((!a && !b) || (a && b && g_strcmp0 (a, b) == 0))
+        return TRUE;
+    /* Additional loose match, consider NULL and EMPTY string equal */
+    if (flags & MM_BEARER_PROPERTIES_CMP_FLAGS_LOOSE) {
+        if ((!a && !b[0]) || (!b && !a[0]))
+            return TRUE;
+    }
+    return FALSE;
+}
+
+static gboolean
+cmp_ip_type (MMBearerIpFamily           a,
+             MMBearerIpFamily           b,
+             MMBearerPropertiesCmpFlags flags)
+{
+    /* Strict match */
+    if (a == b)
+        return TRUE;
+    /* Additional loose match NONE == IPV4 */
+    if (flags & MM_BEARER_PROPERTIES_CMP_FLAGS_LOOSE) {
+        if ((a == MM_BEARER_IP_FAMILY_NONE && b == MM_BEARER_IP_FAMILY_IPV4) ||
+            (b == MM_BEARER_IP_FAMILY_NONE && a == MM_BEARER_IP_FAMILY_IPV4))
+            return TRUE;
+    }
+    return FALSE;
+}
+
+static gboolean
+cmp_allowed_auth (MMBearerAllowedAuth        a,
+                  MMBearerAllowedAuth        b,
+                  MMBearerPropertiesCmpFlags flags)
+{
+    /* Strict match */
+    if (a == b)
+        return TRUE;
+    /* Additional loose match UNKNOWN == NONE */
+    if (flags & MM_BEARER_PROPERTIES_CMP_FLAGS_LOOSE) {
+        if ((a == MM_BEARER_ALLOWED_AUTH_UNKNOWN && b == MM_BEARER_ALLOWED_AUTH_NONE) ||
+            (b == MM_BEARER_ALLOWED_AUTH_UNKNOWN && a == MM_BEARER_ALLOWED_AUTH_NONE))
+            return TRUE;
+    }
+    return FALSE;
+}
+
+static gboolean
+cmp_allow_roaming (gboolean                   a,
+                   gboolean                   a_set,
+                   gboolean                   b,
+                   gboolean                   b_set,
+                   MMBearerPropertiesCmpFlags flags)
+{
+    /* Strict match */
+    if (a == b && a_set == b_set)
+        return TRUE;
+    /* Additional loose match UNSET ==  */
+    if (flags & MM_BEARER_PROPERTIES_CMP_FLAGS_LOOSE) {
+        if ((a == MM_BEARER_ALLOWED_AUTH_UNKNOWN && b == MM_BEARER_ALLOWED_AUTH_NONE) ||
+            (b == MM_BEARER_ALLOWED_AUTH_UNKNOWN && a == MM_BEARER_ALLOWED_AUTH_NONE))
+            return TRUE;
+    }
+    return FALSE;
+}
+
 /**
  * mm_bearer_properties_cmp: (skip)
  */
 gboolean
-mm_bearer_properties_cmp (MMBearerProperties *a,
-                          MMBearerProperties *b)
+mm_bearer_properties_cmp (MMBearerProperties         *a,
+                          MMBearerProperties         *b,
+                          MMBearerPropertiesCmpFlags  flags)
 {
-    return ((!g_strcmp0 (a->priv->apn, b->priv->apn)) &&
-            (a->priv->ip_type == b->priv->ip_type) &&
-            (a->priv->allowed_auth == b->priv->allowed_auth) &&
-            (!g_strcmp0 (a->priv->user, b->priv->user)) &&
-            (!g_strcmp0 (a->priv->password, b->priv->password)) &&
-            (a->priv->allow_roaming == b->priv->allow_roaming) &&
-            (a->priv->allow_roaming_set == b->priv->allow_roaming_set) &&
-            (a->priv->rm_protocol == b->priv->rm_protocol));
+    if (!cmp_str (a->priv->apn, b->priv->apn, flags))
+        return FALSE;
+    if (!cmp_ip_type (a->priv->ip_type, b->priv->ip_type, flags))
+        return FALSE;
+    if (!cmp_allowed_auth (a->priv->allowed_auth, a->priv->allowed_auth, flags))
+        return FALSE;
+    if (!cmp_str (a->priv->user, b->priv->user, flags))
+        return FALSE;
+    if (!(flags & MM_BEARER_PROPERTIES_CMP_FLAGS_NO_PASSWORD) && !cmp_str (a->priv->password, b->priv->password, flags))
+        return FALSE;
+    if (!(flags & MM_BEARER_PROPERTIES_CMP_FLAGS_NO_ALLOW_ROAMING)) {
+        if (a->priv->allow_roaming != b->priv->allow_roaming)
+            return FALSE;
+        if (a->priv->allow_roaming_set != b->priv->allow_roaming)
+            return FALSE;
+    }
+    if (a->priv->rm_protocol != b->priv->rm_protocol)
+        return FALSE;
+    return TRUE;
 }
 
 /*****************************************************************************/
-- 
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