adb: Add ability to specify device path

For manufacturing and testing, there is a need to talk to
whatever device is connected to a given port on the host.  This
change modifies adb's "-s" option to take either a serial
number or a device path.  The device paths of the connected
devices can be listed using "adb devices -l" whose output
will resemble:

    List of devices attached
    016B75D60A00600D	usb:2-5	device
    3031D0B2E71D00EC	usb:1-4.3	device

The second column lists the device paths.  If the -l option is
not given, the output from "adb devices" will be the same as
it used to be (i.e. the paths will not be printed).

The device path can also be obtained with the get-devpath
command:

    $adb -s 3031D0B2E71D00EC get-devpath
    usb:1-4.3

Note that the format of the device paths are platform dependent.
The example above is from Linux.  On OS-X, the paths will be
"usb:" followed by hex digits.  For other platforms, the device
paths will be printed as "????????????" and the -s option will
not be able to select a device until someone implements the
underlying functionality.

Change-Id: I057d5d9f8c5bb72eddf5b8088aae110763f809d7
Signed-off-by: Scott Anderson <saa@android.com>
diff --git a/adb/SERVICES.TXT b/adb/SERVICES.TXT
index be4d50b..d9aa09c 100644
--- a/adb/SERVICES.TXT
+++ b/adb/SERVICES.TXT
@@ -17,8 +17,10 @@
     upgrade.
 
 host:devices
+host:devices-l
     Ask to return the list of available Android devices and their
-    state. After the OKAY, this is followed by a 4-byte hex len,
+    state. devices-l includes the device paths in the state.
+    After the OKAY, this is followed by a 4-byte hex len,
     and a string that will be dumped as-is by the client, then
     the connection is closed
 
@@ -88,6 +90,9 @@
     Returns the serial number of the corresponding device/emulator.
     Note that emulator serial numbers are of the form "emulator-5554"
 
+<host-prefix>:get-devpath
+    Returns the device path of the corresponding device/emulator.
+
 <host-prefix>:get-state
     Returns the state of a given device as a string.
 
diff --git a/adb/adb.c b/adb/adb.c
index e7a28d2..92ef97c 100644
--- a/adb/adb.c
+++ b/adb/adb.c
@@ -1132,16 +1132,19 @@
     }
 
     // return a list of all connected devices
-    if (!strcmp(service, "devices")) {
+    if (!strncmp(service, "devices", 7)) {
         char buffer[4096];
-        memset(buf, 0, sizeof(buf));
-        memset(buffer, 0, sizeof(buffer));
-        D("Getting device list \n");
-        list_transports(buffer, sizeof(buffer));
-        snprintf(buf, sizeof(buf), "OKAY%04x%s",(unsigned)strlen(buffer),buffer);
-        D("Wrote device list \n");
-        writex(reply_fd, buf, strlen(buf));
-        return 0;
+        int use_long = !strcmp(service+7, "-l");
+        if (use_long || service[7] == 0) {
+            memset(buf, 0, sizeof(buf));
+            memset(buffer, 0, sizeof(buffer));
+            D("Getting device list \n");
+            list_transports(buffer, sizeof(buffer), use_long);
+            snprintf(buf, sizeof(buf), "OKAY%04x%s",(unsigned)strlen(buffer),buffer);
+            D("Wrote device list \n");
+            writex(reply_fd, buf, strlen(buf));
+            return 0;
+        }
     }
 
     // add a new TCP transport, device or emulator
@@ -1207,6 +1210,16 @@
         writex(reply_fd, buf, strlen(buf));
         return 0;
     }
+    if(!strncmp(service,"get-devpath",strlen("get-devpath"))) {
+        char *out = "unknown";
+         transport = acquire_one_transport(CS_ANY, ttype, serial, NULL);
+       if (transport && transport->devpath) {
+            out = transport->devpath;
+        }
+        snprintf(buf, sizeof buf, "OKAY%04x%s",(unsigned)strlen(out),out);
+        writex(reply_fd, buf, strlen(buf));
+        return 0;
+    }
     // indicates a new emulator instance has started
     if (!strncmp(service,"emulator:",9)) {
         int  port = atoi(service+9);
diff --git a/adb/adb.h b/adb/adb.h
index ac31f11..b99d7ac 100644
--- a/adb/adb.h
+++ b/adb/adb.h
@@ -185,6 +185,7 @@
         /* used to identify transports for clients */
     char *serial;
     char *product;
+    char *devpath;
     int adb_port; // Use for emulators (local transport)
 
         /* a list of adisconnect callbacks called when the transport is kicked */
@@ -248,7 +249,7 @@
 ** get_device_transport does an acquire on your behalf before returning
 */
 void init_transport_registration(void);
-int  list_transports(char *buf, size_t  bufsize);
+int  list_transports(char *buf, size_t  bufsize, int show_devpath);
 void update_transports(void);
 
 asocket*  create_device_tracker(void);
@@ -281,7 +282,7 @@
 void unregister_transport(atransport *t);
 void unregister_all_tcp_transports();
 
-void register_usb_transport(usb_handle *h, const char *serial, unsigned writeable);
+void register_usb_transport(usb_handle *h, const char *serial, const char *devpath, unsigned writeable);
 
 /* this should only be used for transports with connection_state == CS_NOPERM */
 void unregister_usb_transport(usb_handle *usb);
diff --git a/adb/commandline.c b/adb/commandline.c
index ffc120f..2de0516 100644
--- a/adb/commandline.c
+++ b/adb/commandline.c
@@ -84,8 +84,8 @@
         "                                 returns an error if more than one USB device is present.\n"
         " -e                            - directs command to the only running emulator.\n"
         "                                 returns an error if more than one emulator is running.\n"
-        " -s <serial number>            - directs command to the USB device or emulator with\n"
-        "                                 the given serial number. Overrides ANDROID_SERIAL\n"
+        " -s <specific device>          - directs command to the device or emulator with the given\n"
+        "                                 serial number or device path. Overrides ANDROID_SERIAL\n"
         "                                 environment variable.\n"
         " -p <product name or path>     - simple product name like 'sooner', or\n"
         "                                 a relative/absolute path to a product\n"
@@ -93,7 +93,8 @@
         "                                 If -p is not specified, the ANDROID_PRODUCT_OUT\n"
         "                                 environment variable is used, which must\n"
         "                                 be an absolute path.\n"
-        " devices                       - list all connected devices\n"
+        " devices [-l]                  - list all connected devices\n"
+        "                                 ('-l' means list device paths)\n"
         " connect <host>[:<port>]       - connect to a device via TCP/IP\n"
         "                                 Port 5555 is used by default if no port number is specified.\n"
         " disconnect [<host>[:<port>]]  - disconnect from a TCP/IP device.\n"
@@ -157,6 +158,7 @@
         "  adb kill-server              - kill the server if it is running\n"
         "  adb get-state                - prints: offline | bootloader | device\n"
         "  adb get-serialno             - prints: <serial-number>\n"
+        "  adb get-devpath              - prints: <device-path>\n"
         "  adb status-window            - continuously print device status for a specified device\n"
         "  adb remount                  - remounts the /system partition on the device read-write\n"
         "  adb reboot [bootloader|recovery] - reboots the device, optionally into the bootloader or recovery program\n"
@@ -931,7 +933,16 @@
 
     if(!strcmp(argv[0], "devices")) {
         char *tmp;
-        snprintf(buf, sizeof buf, "host:%s", argv[0]);
+        char *listopt;
+        if (argc < 2)
+            listopt = "";
+        else if (argc == 2 && !strcmp(argv[1], "-l"))
+            listopt = argv[1];
+        else {
+            fprintf(stderr, "Usage: adb devices [-l]\n");
+            return 1;
+        }
+        snprintf(buf, sizeof buf, "host:%s%s", argv[0], listopt);
         tmp = adb_query(buf);
         if(tmp) {
             printf("List of devices attached \n");
@@ -1204,7 +1215,8 @@
     /* passthrough commands */
 
     if(!strcmp(argv[0],"get-state") ||
-        !strcmp(argv[0],"get-serialno"))
+        !strcmp(argv[0],"get-serialno") ||
+        !strcmp(argv[0],"get-devpath"))
     {
         char *tmp;
 
diff --git a/adb/transport.c b/adb/transport.c
index 83a349a..70fc58e 100644
--- a/adb/transport.c
+++ b/adb/transport.c
@@ -370,7 +370,7 @@
     char  head[5];
     int   len;
 
-    len = list_transports(buffer+4, bufferlen-4);
+    len = list_transports(buffer+4, bufferlen-4, 0);
     snprintf(head, sizeof(head), "%04x", len);
     memcpy(buffer, head, 4);
     len += 4;
@@ -601,6 +601,8 @@
             free(t->product);
         if (t->serial)
             free(t->serial);
+        if (t->devpath)
+            free(t->devpath);
 
         memset(t,0xee,sizeof(atransport));
         free(t);
@@ -762,6 +764,10 @@
                 result = t;
                 break;
             }
+            if (t->devpath && !strcmp(serial, t->devpath)) {
+                result = t;
+                break;
+            }
         } else {
             if (ttype == kTransportUsb && t->type == kTransportUsb) {
                 if (result) {
@@ -836,7 +842,7 @@
     }
 }
 
-int list_transports(char *buf, size_t  bufsize)
+int list_transports(char *buf, size_t  bufsize, int show_devpath)
 {
     char*       p   = buf;
     char*       end = buf + bufsize;
@@ -849,7 +855,13 @@
         const char* serial = t->serial;
         if (!serial || !serial[0])
             serial = "????????????";
-        len = snprintf(p, end - p, "%s\t%s\n", serial, statename(t));
+        if (show_devpath) {
+            const char* devpath = t->devpath;
+            if (!devpath || !devpath[0])
+                devpath = "????????????";
+            len = snprintf(p, end - p, "%s\t%s\t%s\n", serial, devpath, statename(t));
+        } else
+            len = snprintf(p, end - p, "%s\t%s\n", serial, statename(t));
 
         if (p + len >= end) {
             /* discard last line if buffer is too short */
@@ -910,6 +922,9 @@
         if (t->serial && !strcmp(serial, t->serial)) {
             break;
         }
+        if (t->devpath && !strcmp(serial, t->devpath)) {
+            break;
+        }
      }
     adb_mutex_unlock(&transport_lock);
 
@@ -955,7 +970,7 @@
 
 #endif
 
-void register_usb_transport(usb_handle *usb, const char *serial, unsigned writeable)
+void register_usb_transport(usb_handle *usb, const char *serial, const char *devpath, unsigned writeable)
 {
     atransport *t = calloc(1, sizeof(atransport));
     D("transport: %p init'ing for usb_handle %p (sn='%s')\n", t, usb,
@@ -964,6 +979,9 @@
     if(serial) {
         t->serial = strdup(serial);
     }
+    if(devpath) {
+        t->devpath = strdup(devpath);
+    }
     register_transport(t);
 }
 
diff --git a/adb/usb_libusb.c b/adb/usb_libusb.c
index 8c75266..06ff5dc 100644
--- a/adb/usb_libusb.c
+++ b/adb/usb_libusb.c
@@ -347,7 +347,7 @@
 
     adb_mutex_unlock(&usb_lock);
 
-    register_usb_transport(usb, serial, 1); 
+    register_usb_transport(usb, serial, NULL, 1); 
 
     return (1);
 }
diff --git a/adb/usb_linux.c b/adb/usb_linux.c
index 4d55b74..7bf2057 100644
--- a/adb/usb_linux.c
+++ b/adb/usb_linux.c
@@ -116,7 +116,8 @@
 
 }
 
-static void register_device(const char *dev_name, unsigned char ep_in, unsigned char ep_out,
+static void register_device(const char *dev_name, const char *devpath,
+                            unsigned char ep_in, unsigned char ep_out,
                             int ifc, int serial_index, unsigned zero_mask);
 
 static inline int badname(const char *name)
@@ -129,7 +130,7 @@
 
 static void find_usb_device(const char *base,
         void (*register_device_callback)
-                (const char *, unsigned char, unsigned char, int, int, unsigned))
+                (const char *, const char *, unsigned char, unsigned char, int, int, unsigned))
 {
     char busname[32], devname[32];
     unsigned char local_ep_in, local_ep_out;
@@ -227,6 +228,11 @@
                             is_adb_interface(vid, pid, interface->bInterfaceClass,
                             interface->bInterfaceSubClass, interface->bInterfaceProtocol))  {
 
+                        struct stat st;
+                        char pathbuf[128];
+                        char link[256];
+                        char *devpath = NULL;
+
                         DBGX("looking for bulk endpoints\n");
                             // looks like ADB...
                         ep1 = (struct usb_endpoint_descriptor *)bufptr;
@@ -263,7 +269,26 @@
                             local_ep_out = ep1->bEndpointAddress;
                         }
 
-                        register_device_callback(devname, local_ep_in, local_ep_out,
+                            // Determine the device path
+                        if (!fstat(fd, &st) && S_ISCHR(st.st_mode)) {
+                            char *slash;
+                            ssize_t link_len;
+                            snprintf(pathbuf, sizeof(pathbuf), "/sys/dev/char/%d:%d",
+                                     major(st.st_rdev), minor(st.st_rdev));
+                            link_len = readlink(pathbuf, link, sizeof(link) - 1);
+                            if (link_len > 0) {
+                                link[link_len] = '\0';
+                                slash = strrchr(link, '/');
+                                if (slash) {
+                                    snprintf(pathbuf, sizeof(pathbuf),
+                                             "usb:%s", slash + 1);
+                                    devpath = pathbuf;
+                                }
+                            }
+                        }
+
+                        register_device_callback(devname, devpath,
+                                local_ep_in, local_ep_out,
                                 interface->bInterfaceNumber, device->iSerialNumber, zero_mask);
                         break;
                     }
@@ -532,7 +557,7 @@
     return 0;
 }
 
-static void register_device(const char *dev_name,
+static void register_device(const char *dev_name, const char *devpath,
                             unsigned char ep_in, unsigned char ep_out,
                             int interface, int serial_index, unsigned zero_mask)
 {
@@ -644,7 +669,7 @@
     usb->next->prev = usb;
     adb_mutex_unlock(&usb_lock);
 
-    register_usb_transport(usb, serial, usb->writeable);
+    register_usb_transport(usb, serial, devpath, usb->writeable);
     return;
 
 fail:
diff --git a/adb/usb_linux_client.c b/adb/usb_linux_client.c
index 635fa4b..b110ed8 100644
--- a/adb/usb_linux_client.c
+++ b/adb/usb_linux_client.c
@@ -72,7 +72,7 @@
         usb->fd = fd;
 
         D("[ usb_thread - registering device ]\n");
-        register_usb_transport(usb, 0, 1);
+        register_usb_transport(usb, 0, 0, 1);
     }
 
     // never gets here
diff --git a/adb/usb_osx.c b/adb/usb_osx.c
index 00d02da..45ce444 100644
--- a/adb/usb_osx.c
+++ b/adb/usb_osx.c
@@ -125,10 +125,13 @@
     IOUSBDeviceInterface197  **dev = NULL;
     HRESULT                  result;
     SInt32                   score;
+    UInt32                   locationId;
     UInt16                   vendor;
     UInt16                   product;
     UInt8                    serialIndex;
     char                     serial[256];
+    char                     devpathBuf[64];
+    char                     *devpath = NULL;
 
     while ((usbInterface = IOIteratorNext(iterator))) {
         //* Create an intermediate interface plugin
@@ -192,6 +195,11 @@
 
         kr = (*dev)->GetDeviceVendor(dev, &vendor);
         kr = (*dev)->GetDeviceProduct(dev, &product);
+        kr = (*dev)->GetLocationID(dev, &locationId);
+        if (kr == 0) {
+            snprintf(devpathBuf, sizeof(devpathBuf), "usb:%lX", locationId);
+            devpath = devpathBuf;
+        }
         kr = (*dev)->USBGetSerialNumberStringIndex(dev, &serialIndex);
 
 	if (serialIndex > 0) {
@@ -256,7 +264,7 @@
         }
 
         DBG("AndroidDeviceAdded calling register_usb_transport\n");
-        register_usb_transport(handle, (serial[0] ? serial : NULL), 1);
+        register_usb_transport(handle, (serial[0] ? serial : NULL), devpath, 1);
 
         // Register for an interest notification of this device being removed.
         // Pass the reference to our private data as the refCon for the
diff --git a/adb/usb_windows.c b/adb/usb_windows.c
index b216999..a2fbb79 100644
--- a/adb/usb_windows.c
+++ b/adb/usb_windows.c
@@ -490,7 +490,7 @@
                                 true)) {
             // Lets make sure that we don't duplicate this device
             if (register_new_device(handle)) {
-              register_usb_transport(handle, serial_number, 1);
+              register_usb_transport(handle, serial_number, NULL, 1);
             } else {
               D("register_new_device failed for %s\n", interf_name);
               usb_cleanup_handle(handle);