diff --git a/adb/Android.mk b/adb/Android.mk
index da5015a..94cd88d 100644
--- a/adb/Android.mk
+++ b/adb/Android.mk
@@ -26,7 +26,9 @@
     transport_usb.c \
 
 LIBADB_CFLAGS := \
-    -Wall -Werror -Wno-unused-parameter \
+    -Wall -Werror \
+    -Wno-unused-parameter \
+    -Wno-missing-field-initializers \
     -D_XOPEN_SOURCE -D_GNU_SOURCE \
     -fvisibility=hidden \
 
@@ -67,6 +69,34 @@
 
 include $(BUILD_HOST_STATIC_LIBRARY)
 
+LIBADB_TEST_SRCS := \
+    transport_test.cpp \
+
+include $(CLEAR_VARS)
+LOCAL_CLANG := $(ADB_CLANG)
+LOCAL_MODULE := adbd_test
+LOCAL_CFLAGS := -DADB_HOST=0 $(LIBADB_CFLAGS)
+LOCAL_SRC_FILES := $(LIBADB_TEST_SRCS)
+LOCAL_STATIC_LIBRARIES := libadbd
+LOCAL_SHARED_LIBRARIES := liblog
+include $(BUILD_NATIVE_TEST)
+
+include $(CLEAR_VARS)
+LOCAL_CLANG := $(ADB_CLANG)
+LOCAL_MODULE := adb_test
+LOCAL_CFLAGS := -DADB_HOST=1 $(LIBADB_CFLAGS)
+LOCAL_SRC_FILES := $(LIBADB_TEST_SRCS) services.c
+LOCAL_STATIC_LIBRARIES := \
+    libadb \
+    libcrypto_static \
+    libcutils \
+
+ifeq ($(HOST_OS),linux)
+  LOCAL_LDLIBS += -lrt -ldl -lpthread
+endif
+
+include $(BUILD_HOST_NATIVE_TEST)
+
 # adb host tool
 # =========================================================
 include $(CLEAR_VARS)
diff --git a/adb/transport.c b/adb/transport.c
index 4904cd0..1951595 100644
--- a/adb/transport.c
+++ b/adb/transport.c
@@ -18,6 +18,7 @@
 
 #include "transport.h"
 
+#include <ctype.h>
 #include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -69,8 +70,7 @@
 }
 #endif
 
-void
-kick_transport(atransport*  t)
+void kick_transport(atransport* t)
 {
     if (t && !t->kicked)
     {
@@ -87,8 +87,25 @@
     }
 }
 
-void
-run_transport_disconnects(atransport*  t)
+// Each atransport contains a list of adisconnects (t->disconnects).
+// An adisconnect contains a link to the next/prev adisconnect, a function
+// pointer to a disconnect callback which takes a void* piece of user data and
+// the atransport, and some user data for the callback (helpfully named
+// "opaque").
+//
+// The list is circular. New items are added to the entry member of the list
+// (t->disconnects) by add_transport_disconnect.
+//
+// run_transport_disconnects invokes each function in the list.
+//
+// Gotchas:
+//   * run_transport_disconnects assumes that t->disconnects is non-null, so
+//     this can't be run on a zeroed atransport.
+//   * The callbacks in this list are not removed when called, and this function
+//     is not guarded against running more than once. As such, ensure that this
+//     function is not called multiple times on the same atransport.
+//     TODO(danalbert): Just fix this so that it is guarded once you have tests.
+void run_transport_disconnects(atransport* t)
 {
     adisconnect*  dis = t->disconnects.next;
 
@@ -753,17 +770,6 @@
     dis->next = dis->prev = dis;
 }
 
-static int qual_char_is_invalid(char ch)
-{
-    if ('A' <= ch && ch <= 'Z')
-        return 0;
-    if ('a' <= ch && ch <= 'z')
-        return 0;
-    if ('0' <= ch && ch <= '9')
-        return 0;
-    return 1;
-}
-
 static int qual_match(const char *to_test,
                       const char *prefix, const char *qual, int sanitize_qual)
 {
@@ -783,7 +789,7 @@
 
     while (*qual) {
         char ch = *qual++;
-        if (sanitize_qual && qual_char_is_invalid(ch))
+        if (sanitize_qual && isalnum(ch))
             ch = '_';
         if (ch != *to_test++)
             return 0;
@@ -923,7 +929,7 @@
     if (sanitize_qual) {
         char *cp;
         for (cp = *buf + prefix_len; cp < *buf + len; cp++) {
-            if (qual_char_is_invalid(*cp))
+            if (isalnum(*cp))
                 *cp = '_';
         }
     }
diff --git a/adb/transport_test.cpp b/adb/transport_test.cpp
new file mode 100644
index 0000000..2b3fe3c
--- /dev/null
+++ b/adb/transport_test.cpp
@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "transport.h"
+
+#include <gtest/gtest.h>
+
+#include "adb.h"
+
+TEST(transport, kick_transport) {
+  atransport t = {};
+  // Mutate some member so we can test that the function is run.
+  t.kick = [](atransport* trans) { trans->fd = 42; };
+  atransport expected = t;
+  expected.fd = 42;
+  expected.kicked = 1;
+  kick_transport(&t);
+  ASSERT_EQ(42, t.fd);
+  ASSERT_EQ(1, t.kicked);
+  ASSERT_EQ(0, memcmp(&expected, &t, sizeof(atransport)));
+}
+
+TEST(transport, kick_transport_already_kicked) {
+  // Ensure that the transport is not modified if the transport has already been
+  // kicked.
+  atransport t = {};
+  t.kicked = 1;
+  t.kick = [](atransport*) { FAIL() << "Kick should not have been called"; };
+  atransport expected = t;
+  kick_transport(&t);
+  ASSERT_EQ(0, memcmp(&expected, &t, sizeof(atransport)));
+}
+
+// Disabled because the function currently segfaults for a zeroed atransport. I
+// want to make sure I understand how this is working at all before I try fixing
+// that.
+TEST(transport, DISABLED_run_transport_disconnects_zeroed_atransport) {
+  atransport t = {};
+  run_transport_disconnects(&t);
+}