1#include <errno.h>
2#include <sys/capability.h>
3#include <sys/prctl.h>
4#include <sys/stat.h>
5
6#include <cutils/properties.h>
7#include <cutils/sched_policy.h>
8#include <log/log.h>
9#include <sys/resource.h>
10#include <utils/threads.h>
11
12#include <pdx/default_transport/service_dispatcher.h>
13#include <private/android_filesystem_config.h>
14
15#include "performance_service.h"
16
17namespace {
18
19// Annoying that sys/capability.h doesn't define this directly.
20constexpr int kMaxCapNumber = (CAP_TO_INDEX(CAP_LAST_CAP) + 1);
21
22}  // anonymous namespace
23
24int main(int /*argc*/, char** /*argv*/) {
25  int ret = -1;
26
27  struct __user_cap_header_struct capheader;
28  struct __user_cap_data_struct capdata[kMaxCapNumber];
29
30  std::shared_ptr<android::pdx::Service> service;
31  std::unique_ptr<android::pdx::ServiceDispatcher> dispatcher;
32
33  ALOGI("Starting up...");
34
35  // We need to be able to create endpoints with full perms.
36  umask(0000);
37
38  // Keep capabilities when switching UID to AID_SYSTEM.
39  ret = prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0);
40  CHECK_ERROR(ret < 0, error, "Failed to set KEEPCAPS: %s", strerror(errno));
41
42  // Set UID and GID to system.
43  ret = setresgid(AID_SYSTEM, AID_SYSTEM, AID_SYSTEM);
44  CHECK_ERROR(ret < 0, error, "Failed to set GID: %s", strerror(errno));
45  ret = setresuid(AID_SYSTEM, AID_SYSTEM, AID_SYSTEM);
46  CHECK_ERROR(ret < 0, error, "Failed to set UID: %s", strerror(errno));
47
48  // Keep CAP_SYS_NICE, allowing control of scheduler class, priority, and
49  // cpuset for other tasks in the system.
50  memset(&capheader, 0, sizeof(capheader));
51  memset(&capdata, 0, sizeof(capdata));
52  capheader.version = _LINUX_CAPABILITY_VERSION_3;
53  capdata[CAP_TO_INDEX(CAP_SYS_NICE)].effective |= CAP_TO_MASK(CAP_SYS_NICE);
54  capdata[CAP_TO_INDEX(CAP_SYS_NICE)].permitted |= CAP_TO_MASK(CAP_SYS_NICE);
55
56  // Drop all caps but the ones configured above.
57  ret = capset(&capheader, capdata);
58  CHECK_ERROR(ret < 0, error, "Could not set capabilities: %s",
59              strerror(errno));
60
61  dispatcher = android::pdx::default_transport::ServiceDispatcher::Create();
62  CHECK_ERROR(!dispatcher, error, "Failed to create service dispatcher.");
63
64  service = android::dvr::PerformanceService::Create();
65  CHECK_ERROR(!service, error, "Failed to create performance service service.");
66  dispatcher->AddService(service);
67
68  ALOGI("Entering message loop.");
69
70  ret = dispatcher->EnterDispatchLoop();
71  CHECK_ERROR(ret < 0, error, "Dispatch loop exited because: %s\n",
72              strerror(-ret));
73
74error:
75  return ret;
76}
77