Add function 'afb_req_get_application_id'

This function is intended to return an identifier of the
calling application. At this time, the identifier is
just derived from the application id but it can be
changed in the future.

Change-Id: Idacde8979ac5bb525352de9cab19e3fc1ed48627
Signed-off-by: José Bollo <jose.bollo@iot.bzh>

7 files changed, 92 insertions, 8 deletions

diff --git a/bindings/samples/HelloWorld.c b/bindings/samples/HelloWorld.c
index 4125e77f..c5a79deb 100644
--- a/bindings/samples/HelloWorld.c
+++ b/bindings/samples/HelloWorld.c
@@ -421,6 +421,13 @@ static void hasperm (afb_req request)
 		afb_req_fail_f(request, "not-granted", "permission %s NOT granted", perm?:"(null)");
 }
 
+static void appid (afb_req request)
+{
+	char *aid = afb_req_get_application_id(request);
+	afb_req_success_f(request, aid ? json_object_new_string(aid) : NULL, "application is %s", aid?:"?");
+	free(aid);
+}
+
 static int preinit()
 {
 	AFB_NOTICE("hello binding comes to live");
@@ -460,6 +467,7 @@ static const afb_verb_v2 verbs[]= {
   { .verb="verbose",     .callback=verbose },
   { .verb="broadcast",   .callback=broadcast },
   { .verb="hasperm",     .callback=hasperm },
+  { .verb="appid",       .callback=appid },
   { .verb="exit",        .callback=exitnow },
   { .verb=NULL}
 };
diff --git a/docs/afb-binding-references.md b/docs/afb-binding-references.md
index f5ab66d1..185f3ef4 100644
--- a/docs/afb-binding-references.md
+++ b/docs/afb-binding-references.md
@@ -694,11 +694,11 @@ Instead, you should use the macros:
 void afb_req_verbose(struct afb_req req, int level, const char *file, int line, const char * func, const char *fmt, ...);
 ```
 
-The function below allows a binding to check whether a client
-has a permission of not.
+The functions below allow a binding involved in the platform security
+to explicitely check a permission of a client or to get the calling
+application identity.
 
 ```C
-
 /*
  * Check whether the 'permission' is granted or not to the client
  * identified by 'req'.
@@ -706,6 +706,18 @@ has a permission of not.
  * Returns 1 if the permission is granted or 0 otherwise.
  */
 int afb_req_has_permission(struct afb_req req, const char *permission);
+
+/*
+ * Get the application identifier of the client application for the
+ * request 'req'.
+ *
+ * Returns the application identifier or NULL when the application
+ * can not be identified.
+ *
+ * The returned value if not NULL must be freed by the caller
+ */
+inline char *afb_req_get_application_id(struct afb_req req);
+
 ```
 
 ## Logging macros
diff --git a/include/afb/afb-req-common.h b/include/afb/afb-req-common.h
index 8bb25f75..7d4473c5 100644
--- a/include/afb/afb-req-common.h
+++ b/include/afb/afb-req-common.h
@@ -76,6 +76,7 @@ struct afb_req_itf
 	void (*subcall_req)(void *closure, const char *api, const char *verb, struct json_object *args, void (*callback)(void*, int, struct json_object*, struct afb_req), void *cb_closure);
 
 	int (*has_permission)(void *closure, const char *permission);
+	char *(*get_application_id)(void *closure);
 };
 
 /*
@@ -445,3 +446,17 @@ static inline int afb_req_has_permission(struct afb_req req, const char *permiss
 	return req.itf->has_permission(req.closure, permission);
 }
 
+/*
+ * Get the application identifier of the client application for the
+ * request 'req'.
+ *
+ * Returns the application identifier or NULL when the application
+ * can not be identified.
+ *
+ * The returned value if not NULL must be freed by the caller
+ */
+static inline char *afb_req_get_application_id(struct afb_req req)
+{
+	return req.itf->get_application_id(req.closure);
+}
+
diff --git a/src/afb-hook.c b/src/afb-hook.c
index 92a4c829..188aabae 100644
--- a/src/afb-hook.c
+++ b/src/afb-hook.c
@@ -354,6 +354,11 @@ static void hook_xreq_has_permission_default_cb(void *closure, const struct afb_
 	_hook_xreq_(xreq, "has_permission(%s) -> %d", permission, result);
 }
 
+static void hook_xreq_get_application_id_default_cb(void *closure, const struct afb_hookid *hookid, const struct afb_xreq *xreq, char *result)
+{
+	_hook_xreq_(xreq, "get_application_id() -> %s", result);
+}
+
 static struct afb_hook_xreq_itf hook_xreq_default_itf = {
 	.hook_xreq_begin = hook_xreq_begin_default_cb,
 	.hook_xreq_end = hook_xreq_end_default_cb,
@@ -378,7 +383,8 @@ static struct afb_hook_xreq_itf hook_xreq_default_itf = {
 	.hook_xreq_unstore = hook_xreq_unstore_default_cb,
 	.hook_xreq_subcall_req = hook_xreq_subcall_req_default_cb,
 	.hook_xreq_subcall_req_result = hook_xreq_subcall_req_result_default_cb,
-	.hook_xreq_has_permission = hook_xreq_has_permission_default_cb
+	.hook_xreq_has_permission = hook_xreq_has_permission_default_cb,
+	.hook_xreq_get_application_id = hook_xreq_get_application_id_default_cb
 };
 
 /******************************************************************************
@@ -532,6 +538,12 @@ int afb_hook_xreq_has_permission(const struct afb_xreq *xreq, const char *permis
 	return result;
 }
 
+char *afb_hook_xreq_get_application_id(const struct afb_xreq *xreq, char *result)
+{
+	_HOOK_XREQ_(get_application_id, xreq, result);
+	return result;
+}
+
 /******************************************************************************
  * section: hooking xreqs
  *****************************************************************************/
diff --git a/src/afb-hook.h b/src/afb-hook.h
index a9c3894e..b3707a6d 100644
--- a/src/afb-hook.h
+++ b/src/afb-hook.h
@@ -75,6 +75,7 @@ struct afb_hookid
 #define afb_hook_flag_req_subcall_req		0x00200000
 #define afb_hook_flag_req_subcall_req_result	0x00400000
 #define afb_hook_flag_req_has_permission	0x00800000
+#define afb_hook_flag_req_get_application_id	0x01000000
 
 /* common flags */
 #define afb_hook_flags_req_life		(afb_hook_flag_req_begin|afb_hook_flag_req_end)
@@ -85,6 +86,7 @@ struct afb_hookid
 #define afb_hook_flags_req_subcalls	(afb_hook_flag_req_subcall|afb_hook_flag_req_subcall_result\
 					|afb_hook_flag_req_subcall_req|afb_hook_flag_req_subcall_req_result\
 					|afb_hook_flag_req_subcallsync|afb_hook_flag_req_subcallsync_result)
+#define afb_hook_flags_req_security	(afb_hook_flag_req_has_permission|afb_hook_flag_req_get_application_id)
 
 /* extra flags */
 #define afb_hook_flags_req_ref		(afb_hook_flag_req_addref|afb_hook_flag_req_unref)
@@ -94,7 +96,7 @@ struct afb_hookid
 /* predefined groups */
 #define afb_hook_flags_req_common	(afb_hook_flags_req_life|afb_hook_flags_req_args|afb_hook_flags_req_result\
 					|afb_hook_flags_req_session|afb_hook_flags_req_event|afb_hook_flags_req_subcalls\
-					|afb_hook_flag_req_vverbose|afb_hook_flag_req_has_permission)
+					|afb_hook_flag_req_vverbose|afb_hook_flags_req_security)
 #define afb_hook_flags_req_extra	(afb_hook_flags_req_common|afb_hook_flags_req_ref|afb_hook_flags_req_context\
 					|afb_hook_flags_req_stores)
 #define afb_hook_flags_req_all		(afb_hook_flags_req_extra)
@@ -124,6 +126,7 @@ struct afb_hook_xreq_itf {
 	void (*hook_xreq_subcall_req)(void *closure, const struct afb_hookid *hookid, const struct afb_xreq *xreq, const char *api, const char *verb, struct json_object *args);
 	void (*hook_xreq_subcall_req_result)(void *closure, const struct afb_hookid *hookid, const struct afb_xreq *xreq, int status, struct json_object *result);
 	void (*hook_xreq_has_permission)(void *closure, const struct afb_hookid *hookid, const struct afb_xreq *xreq, const char *permission, int result);
+	void (*hook_xreq_get_application_id)(void *closure, const struct afb_hookid *hookid, const struct afb_xreq *xreq, char *result);
 };
 
 extern void afb_hook_init_xreq(struct afb_xreq *xreq);
@@ -157,6 +160,7 @@ extern void afb_hook_xreq_unstore(const struct afb_xreq *xreq);
 extern void afb_hook_xreq_subcall_req(const struct afb_xreq *xreq, const char *api, const char *verb, struct json_object *args);
 extern void afb_hook_xreq_subcall_req_result(const struct afb_xreq *xreq, int status, struct json_object *result);
 extern int afb_hook_xreq_has_permission(const struct afb_xreq *xreq, const char *permission, int result);
+extern char *afb_hook_xreq_get_application_id(const struct afb_xreq *xreq, char *result);
 
 /*********************************************************
 * section hooking export (daemon interface)
diff --git a/src/afb-trace.c b/src/afb-trace.c
index c581611b..bf8db690 100644
--- a/src/afb-trace.c
+++ b/src/afb-trace.c
@@ -227,10 +227,13 @@ static struct flag xreq_flags[] = { /* must be sorted by names */
 		{ "extra",		afb_hook_flags_req_extra },
 		{ "fail",		afb_hook_flag_req_fail },
 		{ "get",		afb_hook_flag_req_get },
+		{ "get_application_id",	afb_hook_flag_req_get_application_id },
+		{ "has_permission",	afb_hook_flag_req_has_permission },
 		{ "json",		afb_hook_flag_req_json },
 		{ "life",		afb_hook_flags_req_life },
 		{ "ref",		afb_hook_flags_req_ref },
 		{ "result",		afb_hook_flags_req_result },
+		{ "security",		afb_hook_flags_req_security },
 		{ "session",		afb_hook_flags_req_session },
 		{ "session_close",	afb_hook_flag_req_session_close },
 		{ "session_set_LOA",	afb_hook_flag_req_session_set_LOA },
@@ -456,6 +459,19 @@ static void hook_xreq_subcall_req_result(void *closure, const struct afb_hookid
 					"result", result);
 }
 
+static void hook_xreq_has_permission(void *closure, const struct afb_hookid *hookid, const struct afb_xreq *xreq, const char *permission, int result)
+{
+	hook_xreq(closure, hookid, xreq, "has_permission", "{ss sb}",
+					"permission", permission,
+					"result", result);
+}
+
+static void hook_xreq_get_application_id(void *closure, const struct afb_hookid *hookid, const struct afb_xreq *xreq, char *result)
+{
+	hook_xreq(closure, hookid, xreq, "get_application_id", "{ss?}",
+					"result", result);
+}
+
 static struct afb_hook_xreq_itf hook_xreq_itf = {
 	.hook_xreq_begin = hook_xreq_begin,
 	.hook_xreq_end = hook_xreq_end,
@@ -479,7 +495,9 @@ static struct afb_hook_xreq_itf hook_xreq_itf = {
 	.hook_xreq_store = hook_xreq_store,
 	.hook_xreq_unstore = hook_xreq_unstore,
 	.hook_xreq_subcall_req = hook_xreq_subcall_req,
-	.hook_xreq_subcall_req_result = hook_xreq_subcall_req_result
+	.hook_xreq_subcall_req_result = hook_xreq_subcall_req_result,
+	.hook_xreq_has_permission = hook_xreq_has_permission,
+	.hook_xreq_get_application_id = hook_xreq_get_application_id
 };
 
 /*******************************************************************************/
diff --git a/src/afb-xreq.c b/src/afb-xreq.c
index 8a133519..de0710de 100644
--- a/src/afb-xreq.c
+++ b/src/afb-xreq.c
@@ -520,6 +520,12 @@ static int xreq_has_permission_cb(void*closure, const char *permission)
 	return afb_auth_has_permission(xreq, permission);
 }
 
+static char *xreq_get_application_id_cb(void*closure)
+{
+	struct afb_xreq *xreq = closure;
+	return xreq->cred && xreq->cred->id ? strdup(xreq->cred->id) : NULL;
+}
+
 /******************************************************************************/
 
 static struct json_object *xreq_hooked_json_cb(void *closure)
@@ -682,6 +688,13 @@ static int xreq_hooked_has_permission_cb(void*closure, const char *permission)
 	return afb_hook_xreq_has_permission(xreq, permission, r);
 }
 
+static char *xreq_hooked_get_application_id_cb(void*closure)
+{
+	struct afb_xreq *xreq = closure;
+	char *r = xreq_get_application_id_cb(closure);
+	return afb_hook_xreq_get_application_id(xreq, r);
+}
+
 /******************************************************************************/
 
 const struct afb_req_itf xreq_itf = {
@@ -704,7 +717,8 @@ const struct afb_req_itf xreq_itf = {
 	.vverbose = xreq_vverbose_cb,
 	.store = xreq_store_cb,
 	.subcall_req = xreq_subcall_req_cb,
-	.has_permission = xreq_has_permission_cb
+	.has_permission = xreq_has_permission_cb,
+	.get_application_id = xreq_get_application_id_cb
 };
 
 const struct afb_req_itf xreq_hooked_itf = {
@@ -727,7 +741,8 @@ const struct afb_req_itf xreq_hooked_itf = {
 	.vverbose = xreq_hooked_vverbose_cb,
 	.store = xreq_hooked_store_cb,
 	.subcall_req = xreq_hooked_subcall_req_cb,
-	.has_permission = xreq_hooked_has_permission_cb
+	.has_permission = xreq_hooked_has_permission_cb,
+	.get_application_id = xreq_hooked_get_application_id_cb
 };
 
 /******************************************************************************/