[PATCH 0/4] ofono: Make the oFono Plugin Modem Interface Order Tolerant

[PATCH 0/4] ofono: Make the oFono Plugin Modem Interface Order Tolerant

[Grant Erickson]

This addresses and closes #135 by providing a secondary opportunity to
send D-Bus request to get Connection Manager interface properties and
contexts at the successful closure of 'try_create_device' since the
primary opportunity in 'modem_update_interfaces' is missed in the
following test case:

    # connmanctl disable cellular
    # /etc/init.d/connman stop
    # /etc/init.d/ofono stop
    # rm -rf /var/lib/ofono/*
    # rm -rf /var/lib/connman/cellular*
    # /etc/init.d/ofono start
    # /etc/init.d/connman start
    # connmanctl enable cellular

At this point, ofonod will create a fully-provisioned and -functional
Cellular service, with both IPv4 and IPv6 Cellular network
contexts. However, connmand has no network and no service associated
with it so, so any Connection Manager client observing the Cellular
service state will observe it failing, on timeout.

In this use case, the ordering of the oFono 'lte' (Long-term
Evolution) and 'cm' (Connection Manager) modem interfaces shared
between 'ofonod' and 'connmand' is different from what they normally
are in the case where a Cellular connection has already been
established. Consequently, when the 'cm' interface state change
notification addition arrives, the connman device has not yet been
created because in 'modem_update_interfaces' executing
'cm_get_properties' and 'cm_get_contexts' is dependent on the presence
of 'modem->device':

    if (api_added(old_ifaces, new_ifaces, OFONO_API_CM)) {
        if (modem->device) {
            cm_get_properties(modem);
            cm_get_contexts(modem);
        }
    }

Unfortunately, that does not and cannot happen until the 'lte' modem
interface is added because 'try_create_device' has these conditionals:

    if ((modem->capabilities & LTE_CAPABLE) &&
            !has_interface(modem->interfaces, OFONO_API_LTE))
        return false;

and the 'lte' interface is added only moments later (rather than
moments earlier as is normal outside this use case), but too late
nonetheless. So, the ofono plugin will never get 'cm' interface
properties or Cellular network contexts.

With this change, each call to 'try_create_device' now has an
opportunity to check if the 'cm' interface has been added and, if it
has, to request 'cm' properties and contexts.

Grant Erickson (4):
  ofono: Add additional 'DBG' statements.
  ofono: Use goto error-handling semantics in 'add_cm_context'.
  ofono: Documentation: Add comment about entry condition for
    'context_changed'.
  ofono: Provide a secondary opportunity to get CM props and contexts.

 plugins/ofono.c | 78 ++++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 71 insertions(+), 7 deletions(-)

-- 
2.45.0

[PATCH 1/4] ofono: Add additional 'DBG' statements.

[Grant Erickson]

Adds additional 'DBG' statements to make debugging current and future
ofono integration and interactions easier.
---
 plugins/ofono.c | 33 ++++++++++++++++++++++++++++++---
 1 file changed, 30 insertions(+), 3 deletions(-)

diff --git a/plugins/ofono.c b/plugins/ofono.c
index 062905c8a3a6..47f289f605e0 100644
--- a/plugins/ofono.c
+++ b/plugins/ofono.c
@@ -289,7 +289,7 @@ static void set_connected(struct modem_data *modem,
 	char *nameservers;
 	int index;
 
-	DBG("%s", modem->path);
+	DBG("modem %p path %s context %p path %s", modem, modem->path, context, context->path);
 
 	index = context->index;
 
@@ -300,10 +300,14 @@ static void set_connected(struct modem_data *modem,
 		return;
 	}
 
+	DBG("context->network %p", context->network);
+
 	service = connman_service_lookup_from_network(context->network);
 	if (!service)
 		return;
 
+	DBG("service %p", service);
+
 	connman_service_create_ip4config(service, index);
 	connman_network_set_ipv4_method(context->network, method);
 
@@ -1054,7 +1058,9 @@ static void add_network(struct modem_data *modem,
 {
 	const char *group;
 
-	DBG("%s", modem->path);
+	DBG("modem %p path %s context %p path %s network %p",
+		modem, modem->path,
+		context, context->path, context->network);
 
 	if (context->network)
 		return;
@@ -1295,10 +1301,14 @@ static gboolean context_changed(DBusConnection *conn,
 	if (!modem)
 		return TRUE;
 
+	DBG("modem %p", modem);
+
 	context = get_context_with_path(modem->context_list, context_path);
 	if (!context)
 		return TRUE;
 
+	DBG("context %p", context);
+
 	if (!dbus_message_iter_init(message, &iter))
 		return TRUE;
 
@@ -1371,6 +1381,8 @@ static gboolean context_changed(DBusConnection *conn,
 
 		dbus_message_iter_get_basic(&value, &ip_protocol);
 
+		DBG("%s Protocol %s", modem->path, ip_protocol);
+
 		set_context_ipconfig(context, ip_protocol);
 	}
 
@@ -1520,7 +1532,12 @@ static gboolean cm_context_removed(DBusConnection *conn,
 	if (!modem)
 		return TRUE;
 
+	DBG("modem %p", modem);
+
 	context = get_context_with_path(modem->context_list, context_path);
+
+	DBG("context %p", context);
+
 	remove_cm_context(modem, context);
 
 	return TRUE;
@@ -1772,10 +1789,14 @@ static gboolean cm_changed(DBusConnection *conn, DBusMessage *message,
 	DBusMessageIter iter, value;
 	const char *key;
 
+	DBG("");
+
 	modem = g_hash_table_lookup(modem_hash, path);
 	if (!modem)
 		return TRUE;
 
+	DBG("modem %p modem->ignore %u", modem, modem->ignore);
+
 	if (modem->ignore)
 		return TRUE;
 
@@ -1849,6 +1870,8 @@ static gboolean sim_changed(DBusConnection *conn, DBusMessage *message,
 	if (!modem)
 		return TRUE;
 
+	DBG("modem %p modem->ignore %u", modem, modem->ignore);
+
 	if (modem->ignore)
 		return TRUE;
 
@@ -1860,6 +1883,8 @@ static gboolean sim_changed(DBusConnection *conn, DBusMessage *message,
 	dbus_message_iter_next(&iter);
 	dbus_message_iter_recurse(&iter, &value);
 
+	DBG("key %s", key);
+
 	if (g_str_equal(key, "SubscriberIdentity")) {
 		sim_update_imsi(modem, &value);
 		try_create_device(modem);
@@ -1943,9 +1968,10 @@ static void modem_update_interfaces(struct modem_data *modem,
 				uint8_t old_ifaces,
 				uint8_t new_ifaces)
 {
-	DBG("%s", modem->path);
+	DBG("modem %p path %s", modem, modem->path);
 
 	if (api_added(old_ifaces, new_ifaces, OFONO_API_SIM)) {
+		DBG("modem->imsi %p modem->set_powered %u", modem->imsi, modem->set_powered);
 		if (!modem->imsi &&
 				!modem->set_powered) {
 			/*
@@ -1957,6 +1983,7 @@ static void modem_update_interfaces(struct modem_data *modem,
 	}
 
 	if (api_added(old_ifaces, new_ifaces, OFONO_API_CM)) {
+		DBG("modem->device %p", modem->device);
 		if (modem->device) {
 			cm_get_properties(modem);
 			cm_get_contexts(modem);
-- 
2.45.0

[PATCH 2/4] ofono: Use goto error-handling semantics in 'add_cm_context'.

[Grant Erickson]

Eases current and future debugging of ofono cellular context additions
by allowing for a single point of DBG instrumentation for the
'add_cm_context' return value, indicating whether or not the proposed
context was added successfully.
---
 plugins/ofono.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/plugins/ofono.c b/plugins/ofono.c
index 47f289f605e0..b7a5f80bda5c 100644
--- a/plugins/ofono.c
+++ b/plugins/ofono.c
@@ -1160,12 +1160,15 @@ static int add_cm_context(struct modem_data *modem, const char *context_path,
 	struct network_context *context = NULL;
 	dbus_bool_t active = FALSE;
 	const char *ip_protocol = NULL;
+	int err = 0;
 
 	DBG("%s context path %s", modem->path, context_path);
 
 	context = network_context_alloc(context_path);
-	if (!context)
-		return -ENOMEM;
+	if (!context) {
+		err = -ENOMEM;
+		goto done;
+	}
 
 	while (dbus_message_iter_get_arg_type(dict) == DBUS_TYPE_DICT_ENTRY) {
 		DBusMessageIter entry, value;
@@ -1217,7 +1220,8 @@ static int add_cm_context(struct modem_data *modem, const char *context_path,
 
 	if (g_strcmp0(context_type, "internet") != 0) {
 		network_context_unref(context);
-		return -EINVAL;
+		err = -EINVAL;
+		goto done;
 	}
 
 	if (ip_protocol)
@@ -1232,7 +1236,10 @@ static int add_cm_context(struct modem_data *modem, const char *context_path,
 	    has_interface(modem->interfaces, OFONO_API_NETREG))
 		add_network(modem, context);
 
-	return 0;
+done:
+	DBG("err %d", err);
+
+	return err;
 }
 
 static void remove_cm_context(struct modem_data *modem,
-- 
2.45.0

[PATCH 3/4] ofono: Documentation: Add comment about entry condition for 'context_changed'.

[Grant Erickson]

Adds a comment to the head of 'context_changed' detailing why the
early exit condition exists: changed cellular contexts cannot be
processed before they are added.
---
 plugins/ofono.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/plugins/ofono.c b/plugins/ofono.c
index b7a5f80bda5c..820299765c67 100644
--- a/plugins/ofono.c
+++ b/plugins/ofono.c
@@ -1304,6 +1304,12 @@ static gboolean context_changed(DBusConnection *conn,
 
 	DBG("context_path %s", context_path);
 
+	/*
+	 * If there is no modem in the context hash for the associated
+	 * context path, then there is nothing to do at the moment as
+	 * the context must first be added before we can process changes
+	 * to it.
+	 */
 	modem = g_hash_table_lookup(context_hash, context_path);
 	if (!modem)
 		return TRUE;
-- 
2.45.0

[PATCH 4/4] ofono: Provide a secondary opportunity to get CM props and contexts.

[Grant Erickson]

Provides a secondary opportunity to send D-Bus request to get
Connection Manager interface properties and contexts at the successful
closure of 'try_create_device' since the primary opportunity in
'modem_update_interfaces' is missed in the following test case:

    # connmanctl disable cellular
    # /etc/init.d/connman stop
    # /etc/init.d/ofono stop
    # rm -rf /var/lib/ofono/*
    # rm -rf /var/lib/connman/cellular*
    # /etc/init.d/ofono start
    # /etc/init.d/connman start
    # connmanctl enable cellular

At this point, ofonod will create a fully-provisioned and -functional
Cellular service, with both IPv4 and IPv6 Cellular network
contexts. However, connmand has no network and no service associated
with it so, so any Connection Manager client observing the Cellular
service state will observe it failing, on timeout.

In this use case, the ordering of the oFono 'lte' (Long-term
Evolution) and 'cm' (Connection Manager) modem interfaces shared
between ofonod and connmand is different from what they normally are
in the case where a Cellular connection has already been
established. Consequently, when the 'cm' interface state change
notification addition arrives, the connman device has not yet been
created because in 'modem_update_interfaces' executing
'cm_get_properties' and 'cm_get_contexts' is dependent on the presence
of 'modem->device':

	if (api_added(old_ifaces, new_ifaces, OFONO_API_CM)) {
		if (modem->device) {
			cm_get_properties(modem);
			cm_get_contexts(modem);
		}
	}

Unfortunately, that does not and cannot happen until the 'lte' modem
interface is added because 'try_create_device' has these conditionals:

	if ((modem->capabilities & LTE_CAPABLE) &&
			!has_interface(modem->interfaces, OFONO_API_LTE))
		return false;

and the 'lte' interface is added only moments later (rather than
moments earlier as is normal outside this use case), but too late
nonetheless. So, the ofono plugin will never get 'cm' interface
properties or Cellular network contexts.

With this change, each call to 'try_create_device' now has an
opportunity to check if the 'cm' interface has been added and, if it
has, to request 'cm' properties and contexts.
---
 plugins/ofono.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/plugins/ofono.c b/plugins/ofono.c
index 820299765c67..f5248e57488b 100644
--- a/plugins/ofono.c
+++ b/plugins/ofono.c
@@ -167,6 +167,9 @@ struct modem_data {
 	DBusPendingCall *call_get_contexts;
 };
 
+static int cm_get_contexts(struct modem_data *modem);
+static int cm_get_properties(struct modem_data *modem);
+
 static const char *api2string(enum ofono_api api)
 {
 	switch (api) {
@@ -1038,6 +1041,27 @@ static bool try_create_device(struct modem_data *modem)
 	modem->device = device;
 	connman_device_set_powered(modem->device, modem->online);
 
+	/*
+	 * The order in which the LTE and Connection Manager interfaces
+	 * arrive may not always be the same.
+	 *
+	 * If the latter arrived before the former and a modem device was
+	 * successfully created, this represents a secondary opportunity
+	 * to get Connection Manager properties and contexts, both
+	 * essential to successfully creating a Connection Manager
+	 * Cellular network and service.
+	 *
+	 * The primary opportunity would have been with api_added in
+	 * modem_update_interfaces; however, that would have been skipped
+	 * since the LTE interface did not yet exist in such a scenario
+	 * and this call would exit early due to the LTE_CAPABLE and
+	 * OFONO_API_LTE conditional checks above.
+	 */
+	if (has_interface(modem->interfaces, OFONO_API_CM)) {
+		cm_get_properties(modem);
+		cm_get_contexts(modem);
+	}
+
 	return true;
 }
 
-- 
2.45.0

Re: [PATCH 0/4] ofono: Make the oFono Plugin Modem Interface Order Tolerant

[patchwork-bot+connman]

Hello:

This series was applied to connman.git (master)
by Denis Kenzior <denkenz@gmail.com>:

On Wed, 12 Feb 2025 15:39:29 -0800 you wrote:
> This addresses and closes #135 by providing a secondary opportunity to
> send D-Bus request to get Connection Manager interface properties and
> contexts at the successful closure of 'try_create_device' since the
> primary opportunity in 'modem_update_interfaces' is missed in the
> following test case:
> 
>     # connmanctl disable cellular
>     # /etc/init.d/connman stop
>     # /etc/init.d/ofono stop
>     # rm -rf /var/lib/ofono/*
>     # rm -rf /var/lib/connman/cellular*
>     # /etc/init.d/ofono start
>     # /etc/init.d/connman start
>     # connmanctl enable cellular
> 
> [...]

Here is the summary with links:
  - [1/4] ofono: Add additional 'DBG' statements.
    (no matching commit)
  - [2/4] ofono: Use goto error-handling semantics in 'add_cm_context'.
    https://git.kernel.org/pub/scm/network/connman/connman.git/?id=36154342e546
  - [3/4] ofono: Documentation: Add comment about entry condition for 'context_changed'.
    https://git.kernel.org/pub/scm/network/connman/connman.git/?id=00e7dc2d528f
  - [4/4] ofono: Provide a secondary opportunity to get CM props and contexts.
    https://git.kernel.org/pub/scm/network/connman/connman.git/?id=0b091dd8fc8f

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html