4 files changed, 30 insertions, 10 deletions

diff --git a/cmd/libsnap-confine-private/snap-test.c b/cmd/libsnap-confine-private/snap-test.c
index e2cc520cc5..1141531319 100644
--- a/cmd/libsnap-confine-private/snap-test.c
+++ b/cmd/libsnap-confine-private/snap-test.c
@@ -359,7 +359,6 @@ static void test_sc_snap_drop_instance_key_no_dest(void)
 {
	if (g_test_subprocess()) {
	sc_snap_drop_instance_key("foo_bar", NULL, 0);
-	g_test_fail();
	return;
	}
	g_test_trap_subprocess(NULL, 0, 0);
@@ -373,7 +372,6 @@ static void test_sc_snap_drop_instance_key_short_dest(void)
	char dest[10] = { 0 };
	sc_snap_drop_instance_key("foo-foo-foo-foo-foo_bar", dest,
 sizeof dest);
-	g_test_fail();
	return;
	}
	g_test_trap_subprocess(NULL, 0, 0);
@@ -385,7 +383,6 @@ static void test_sc_snap_drop_instance_key_short_dest2(void)
	if (g_test_subprocess()) {
	char dest[3] = { 0 };	// "foo" sans the nil byte
	sc_snap_drop_instance_key("foo", dest, sizeof dest);
-	g_test_fail();
	return;
	}
	g_test_trap_subprocess(NULL, 0, 0);
@@ -397,7 +394,18 @@ static void test_sc_snap_drop_instance_key_no_name(void)
	if (g_test_subprocess()) {
	char dest[10] = { 0 };
	sc_snap_drop_instance_key(NULL, dest, sizeof dest);
-	g_test_fail();
+	return;
+	}
+	g_test_trap_subprocess(NULL, 0, 0);
+	g_test_trap_assert_failed();
+}
+
+static void test_sc_snap_drop_instance_key_short_dest_max(void)
+{
+	if (g_test_subprocess()) {
+	char dest[SNAP_NAME_LEN + 1] = { 0 };
+	/* 40 chars (max valid length), pretend dest is the same length, no space for terminator */
+	sc_snap_drop_instance_key("01234567890123456789012345678901234567890", dest, sizeof dest - 1);
	return;
	}
	g_test_trap_subprocess(NULL, 0, 0);
@@ -406,7 +414,7 @@ static void test_sc_snap_drop_instance_key_no_name(void)
 
 static void test_sc_snap_drop_instance_key_basic(void)
 {
-	char name[41] = { 0xff };
+	char name[SNAP_NAME_LEN + 1] = { 0xff };
 
	sc_snap_drop_instance_key("foo_bar", name, sizeof name);
	g_assert_cmpstr(name, ==, "foo");
@@ -426,6 +434,11 @@ static void test_sc_snap_drop_instance_key_basic(void)
	memset(name, 0xff, sizeof name);
	sc_snap_drop_instance_key("foo", name, sizeof name);
	g_assert_cmpstr(name, ==, "foo");
+
+	memset(name, 0xff, sizeof name);
+	/* 40 chars - snap name length */
+	sc_snap_drop_instance_key("0123456789012345678901234567890123456789", name, sizeof name);
+	g_assert_cmpstr(name, ==, "0123456789012345678901234567890123456789");
 }
 
 static void test_sc_snap_split_instance_name_trailing_nil(void)
@@ -434,7 +447,6 @@ static void test_sc_snap_split_instance_name_trailing_nil(void)
	char dest[3] = { 0 };
	// pretend there is no place for trailing \0
	sc_snap_split_instance_name("_", NULL, 0, dest, 0);
-	g_test_fail();
	return;
	}
	g_test_trap_subprocess(NULL, 0, 0);
@@ -447,7 +459,6 @@ static void test_sc_snap_split_instance_name_short_instance_dest(void)
	char dest[10] = { 0 };
	sc_snap_split_instance_name("foo_barbarbarbar", NULL, 0,
 dest, sizeof dest);
-	g_test_fail();
	return;
	}
	g_test_trap_subprocess(NULL, 0, 0);
@@ -456,7 +467,7 @@ static void test_sc_snap_split_instance_name_short_instance_dest(void)
 
 static void test_sc_snap_split_instance_name_basic(void)
 {
-	char name[41] = { 0xff };
+	char name[SNAP_NAME_LEN + 1] = { 0xff };
	char instance[20] = { 0xff };
 
	sc_snap_split_instance_name("foo_bar", name, sizeof name, instance,
@@ -558,6 +569,8 @@ static void __attribute__((constructor)) init(void)
	test_sc_snap_drop_instance_key_short_dest);
	g_test_add_func("/snap/sc_snap_drop_instance_key/short_dest2",
	test_sc_snap_drop_instance_key_short_dest2);
+	g_test_add_func("/snap/sc_snap_drop_instance_key/short_dest_max",
+	test_sc_snap_drop_instance_key_short_dest_max);
 
	g_test_add_func("/snap/sc_snap_split_instance_name/basic",
	test_sc_snap_split_instance_name_basic);
diff --git a/cmd/libsnap-confine-private/snap.c b/cmd/libsnap-confine-private/snap.c
index 8a629f90f7..2affc650b0 100644
--- a/cmd/libsnap-confine-private/snap.c
+++ b/cmd/libsnap-confine-private/snap.c
@@ -252,7 +252,7 @@ void sc_snap_name_validate(const char *snap_name, sc_error ** errorp)
 "snap name must be longer than 1 character");
	goto out;
	}
-	if (n > 40) {
+	if (n > SNAP_NAME_LEN) {
	err = sc_error_init(SC_SNAP_DOMAIN, SC_SNAP_INVALID_NAME,
 "snap name must be shorter than 40 characters");
	goto out;
diff --git a/cmd/snap-confine/snap-confine-invocation.c b/cmd/snap-confine/snap-confine-invocation.c
index c6a743ca55..80f8f90a14 100644
--- a/cmd/snap-confine/snap-confine-invocation.c
+++ b/cmd/snap-confine/snap-confine-invocation.c
@@ -61,6 +61,10 @@ void sc_init_invocation(sc_invocation *inv, const struct sc_args *args, const ch
 die("cannot run with NULL executable");
 }
 
+ /* Instance name length + NULL termination */
+ char snap_name[SNAP_NAME_LEN + 1] = {0};
+ sc_snap_drop_instance_key(snap_instance, snap_name, sizeof snap_name);
+
 /* Invocation helps to pass relevant data to various parts of snap-confine. */
 memset(inv, 0, sizeof *inv);
 inv->base_snap_name = sc_strdup(base_snap_name);
@@ -68,6 +72,7 @@ void sc_init_invocation(sc_invocation *inv, const struct sc_args *args, const ch
 inv->executable = sc_strdup(executable);
 inv->security_tag = sc_strdup(security_tag);
 inv->snap_instance = sc_strdup(snap_instance);
+ inv->snap_name = sc_strdup(snap_name);
 inv->classic_confinement = sc_args_is_classic_confinement(args);
 
 // construct rootfs_dir based on base_snap_name
@@ -84,6 +89,7 @@ void sc_init_invocation(sc_invocation *inv, const struct sc_args *args, const ch
 void sc_cleanup_invocation(sc_invocation *inv) {
 if (inv != NULL) {
 sc_cleanup_string(&inv->snap_instance);
+ sc_cleanup_string(&inv->snap_name);
 sc_cleanup_string(&inv->base_snap_name);
 sc_cleanup_string(&inv->orig_base_snap_name);
 sc_cleanup_string(&inv->security_tag);
diff --git a/cmd/snap-confine/snap-confine-invocation.h b/cmd/snap-confine/snap-confine-invocation.h
index 5b4ffb3926..e4839683c2 100644
--- a/cmd/snap-confine/snap-confine-invocation.h
+++ b/cmd/snap-confine/snap-confine-invocation.h
@@ -29,7 +29,8 @@
 **/
 typedef struct sc_invocation {
 /* Things declared by the system. */
- char *snap_instance;
+ char *snap_instance; /* snap instance name (<snap>_<key>) */
+ char *snap_name; /* snap name (without instance key) */
 char *orig_base_snap_name;
 char *security_tag;
 char *executable;