Android User version increases ADB privilege "go"

This article was reproduced from: http://blog.csdn.net/liyongming1982/article/details/14108111

Some user version of the log is not complete, and push/pull some files or properties file

Often encounter insufficient permissions, to debug a lot of things:

For the user version of the ADB shell to open or shell permissions, rather than root permissions,
If you need root privileges, you need to change the SYSTEM/CORE/ADB/ADB.C inside the Should_drop_privileges ()
This function, return 0 at #ifndef Allow_adbd_root; instead of return 1; Can.

To determine whether to lower permissions:

[CPP]View PlainCopy

2. static int should_drop_privileges () {
4. #ifndef Allow_adbd_root
6. return 1;
8. #else/* Allow_adbd_root */
10. int secure = 0;
12. Char Value[property_value_max];
16. / * Run ADBD in secure mode if Ro.secure is set and
18. * * We is not in the emulator
20. */
22. Property_get ("Ro.kernel.qemu", Value, "");
24. if (strcmp (Value, "1")! = 0) {
26. Property_get ("Ro.secure", Value, "1");
28. if (strcmp (Value, "1") = = 0) {
30. //don ' t run as root if Ro.secure is set ...
32. secure = 1;
36. //... except we allow running as root in Userdebug builds if the
38. //Service.adb.root property had been set by the "ADB root" command
40. Property_get ("ro.debuggable", Value, "");
42. if (strcmp (Value, "1") = = 0) {
44. Property_get ("Service.adb.root", Value, "");
46. if (strcmp (Value, "1") = = 0) {
48. secure = 0;
50. }
52. }
54. }
56. }
58. return secure;
60. #endif/* Allow_adbd_root */
62. }

Specifically how to reduce permissions:

[CPP]View PlainCopy

2. if (Should_drop_privileges ()) {
4. struct __user_cap_header_struct header;
6. struct __user_cap_data_struct cap;
10. if (Prctl (pr_set_keepcaps, 1, 0, 0, 0)! = 0) {
12. Exit (1);
14. }
18. /* Add extra Groups:
20. * * AID_ADB to access the USB driver
22. * * Aid_log to read system logs (ADB logcat)
24. * * Aid_input to diagnose INPUT issues (getevent)
26. * * Aid_inet to diagnose network issues (netcfg, ping)
28. * * Aid_graphics to access the frame buffer
30. * * AID_NET_BT and aid_net_bt_admin to diagnose Bluetooth (hcidump)
32. * * Aid_sdcard_r to allow reading from the SD card
34. * * AID_SDCARD_RW to allow writing to the SD card
36. * * Aid_mount to allow unmounting the SD card before rebooting
38. * * Aid_net_bw_stats to read out Qtaguid statistics
40. */
42. gid_t groups[] = {aid_adb, aid_log, Aid_input, Aid_inet, Aid_graphics,
44. AID_NET_BT, Aid_net_bt_admin, Aid_sdcard_r, AID_SDCARD_RW,
46. Aid_mount, aid_net_bw_stats};
48. if (setgroups (sizeof (groups)/sizeof (Groups[0]), groups)! = 0) {
50. Exit (1);
52. }
56. / * Then switch the user and group to "Shell" * /
58. if (setgid (aid_shell)! = 0) {
60. Exit (1);
62. }
64. if (setuid (aid_shell)! = 0) {
66. Exit (1);
68. }
72. / * Set cap_sys_boot capability, so "adb reboot" would succeed * /
74. Header.version = _linux_capability_version;
76. header.pid = 0;
78. cap.effective = cap.permitted = (1 << cap_sys_boot);
80. cap.inheritable = 0;
82. Capset (&header, &cap);
86. D ("Local Port disabled\n");
88. }

Android User version increases ADB privilege "go"