DO NOT MERGE ANYWHERE - bionic: resolver: exclude a range of ports from random_bind in DNS

Add a new API to set a range of ports which the DNS resolver should
never try to bind

Bug: 20127213
Change-Id: Ie3fca0ec2ee2523625816edd9417a0b5d5f91614

libc/dns/include/resolv_netid.h

@@ -75,6 +75,9 @@ int android_getnameinfofornet(const struct sockaddr *, socklen_t, char *, size_t
 /* delete the cache associated with a certain network */
 extern void _resolv_delete_cache_for_net(unsigned netid);
 
+/* set a port range for exclusion in the random_bind */
+int _resolv_set_port_exclusion_range(in_port_t min, in_port_t max) __used_in_netd;
+
 __END_DECLS
 
 #endif /* _RESOLV_NETID_H */

libc/dns/resolv/res_send.c

@@ -137,6 +137,10 @@ __RCSID("$NetBSD: res_send.c,v 1.9 2006/01/24 17:41:25 christos Exp $");
 #define EXT(res) ((res)->_u._ext)
 #define DBG 0
 
+#define MAX_PORT (1 << (sizeof(in_port_t)*8))-1
+#define DNS_MIN_PORT (IPPORT_RESERVED+1)
+#define DNS_MAX_EXCLUDED_PORTS 5000
+
 static const int highestFD = FD_SETSIZE - 1;
 
 /* Forward. */
@@ -164,6 +168,27 @@ static int retrying_select(const int sock, fd_set *readset, fd_set *writeset,
 			const struct timespec *finish);
 
 /* BIONIC-BEGIN: implement source port randomization */
+static volatile in_port_t exclusion_min = 0;
+static volatile in_port_t exclusion_max = 0;
+
+int _resolv_set_port_exclusion_range(in_port_t min, in_port_t max)
+{
+    if (min == 0 && max == 0) {
+        exclusion_min = exclusion_max = 0;
+        return 0;
+    }
+
+    if (min < DNS_MIN_PORT || min > max
+            || (max - min > DNS_MAX_EXCLUDED_PORTS)) {
+        errno = ERANGE;
+        return -1;
+    }
+
+    exclusion_min = min;
+    exclusion_max = max;
+    return 0;
+}
+
 typedef union {
     struct sockaddr      sa;
     struct sockaddr_in   sin;
@@ -197,7 +222,13 @@ random_bind( int  s, int  family )
     /* first try to bind to a random source port a few times */
     for (j = 0; j < 10; j++) {
         /* find a random port between 1025 .. 65534 */
-        int  port = 1025 + (res_randomid() % (65535-1025));
+        in_port_t port;
+        do {
+            port = DNS_MIN_PORT + (res_randomid() % (MAX_PORT - DNS_MIN_PORT));
+        } while (exclusion_min
+                && exclusion_max
+                && port >= exclusion_min && port <= exclusion_max);
+
         if (family == AF_INET)
             u.sin.sin_port = htons(port);
         else

tests/sys_resource_test.cpp

@@ -14,10 +14,10 @@
  * limitations under the License.
  */
 
-#include <sys/resource.h>
-
 #include <gtest/gtest.h>
 
+#include <sys/resource.h>
+
 #if defined(__GLIBC__)
 /* The host glibc we're currently building with doesn't have prlimit64 yet. */
 static int prlimit64(pid_t, int resource, const struct rlimit64* new_limit, struct rlimit64* old_limit) {
@@ -29,7 +29,7 @@ static int prlimit64(pid_t, int resource, const struct rlimit64* new_limit, stru
 }
 #endif
 
-TEST(sys_resource, rlimit_struct_size) {
+TEST(sys_resource, smoke) {
 #if defined(__LP64__) || defined(__GLIBC__)
   ASSERT_EQ(sizeof(rlimit), sizeof(rlimit64));
   ASSERT_EQ(8U, sizeof(rlim_t));
@@ -37,75 +37,51 @@ TEST(sys_resource, rlimit_struct_size) {
   ASSERT_NE(sizeof(rlimit), sizeof(rlimit64));
   ASSERT_EQ(4U, sizeof(rlim_t));
 #endif
-}
 
-class SysResourceTest : public ::testing::Test {
- protected:
-  virtual void SetUp() {
-    ASSERT_EQ(0, getrlimit(RLIMIT_CORE, &l32_));
-    ASSERT_EQ(0, getrlimit64(RLIMIT_CORE, &l64_));
-    ASSERT_EQ(0, prlimit64(0, RLIMIT_CORE, NULL, &pr_l64_));
-  }
-
-  void CheckResourceLimits();
-
- protected:
-  rlimit l32_;
-  rlimit64 l64_;
-  rlimit64 pr_l64_;
-};
-
-void SysResourceTest::CheckResourceLimits() {
-  ASSERT_EQ(0, getrlimit(RLIMIT_CORE, &l32_));
-  ASSERT_EQ(0, getrlimit64(RLIMIT_CORE, &l64_));
-  ASSERT_EQ(0, prlimit64(0, RLIMIT_CORE, NULL, &pr_l64_));
-  ASSERT_EQ(l64_.rlim_cur, pr_l64_.rlim_cur);
-  if (l64_.rlim_cur == RLIM64_INFINITY) {
-    ASSERT_EQ(RLIM_INFINITY, l32_.rlim_cur);
+  // Read with getrlimit, getrlimit64, and prlimit64.
+  // (prlimit is prlimit64 on LP64 and unimplemented on 32-bit.)
+  rlimit l32;
+  rlimit64 l64;
+  rlimit64 pr_l64;
+  ASSERT_EQ(0, getrlimit(RLIMIT_CORE, &l32));
+  ASSERT_EQ(0, getrlimit64(RLIMIT_CORE, &l64));
+  ASSERT_EQ(0, prlimit64(0, RLIMIT_CORE, NULL, &pr_l64));
+  ASSERT_EQ(l64.rlim_cur, l32.rlim_cur);
+  ASSERT_EQ(l64.rlim_cur, pr_l64.rlim_cur);
+  ASSERT_EQ(l64.rlim_max, pr_l64.rlim_max);
+  if (l64.rlim_max == RLIM64_INFINITY) {
+    ASSERT_EQ(RLIM_INFINITY, l32.rlim_max);
   } else {
-    ASSERT_EQ(l64_.rlim_cur, l32_.rlim_cur);
+    ASSERT_EQ(l64.rlim_max, l32.rlim_max);
   }
 
-  ASSERT_EQ(l64_.rlim_max, pr_l64_.rlim_max);
-  if (l64_.rlim_max == RLIM64_INFINITY) {
-    ASSERT_EQ(RLIM_INFINITY, l32_.rlim_max);
-  } else {
-    ASSERT_EQ(l64_.rlim_max, l32_.rlim_max);
-  }
-}
+  // Write with setrlimit and read back with everything.
+  l32.rlim_cur = 123;
+  ASSERT_EQ(0, setrlimit(RLIMIT_CORE, &l32));
+  ASSERT_EQ(0, getrlimit(RLIMIT_CORE, &l32));
+  ASSERT_EQ(0, getrlimit64(RLIMIT_CORE, &l64));
+  ASSERT_EQ(0, prlimit64(0, RLIMIT_CORE, NULL, &pr_l64));
+  ASSERT_EQ(123U, l32.rlim_cur);
+  ASSERT_EQ(l64.rlim_cur, l32.rlim_cur);
+  ASSERT_EQ(l64.rlim_cur, pr_l64.rlim_cur);
 
-// Force rlim_max to be bigger than a constant so we can continue following test.
-// Change resource limit setting with "ulimit -Hc" in the shell if this test fails.
-TEST_F(SysResourceTest, RLIMIT_CORE_rlim_max_not_zero) {
-  ASSERT_TRUE(l32_.rlim_max == RLIM_INFINITY || l32_.rlim_max >= 456U) <<
-    "RLIMIT_CORE rlim_max = " << l32_.rlim_max;
-}
+  // Write with setrlimit64 and read back with everything.
+  l64.rlim_cur = 456;
+  ASSERT_EQ(0, setrlimit64(RLIMIT_CORE, &l64));
+  ASSERT_EQ(0, getrlimit(RLIMIT_CORE, &l32));
+  ASSERT_EQ(0, getrlimit64(RLIMIT_CORE, &l64));
+  ASSERT_EQ(0, prlimit64(0, RLIMIT_CORE, NULL, &pr_l64));
+  ASSERT_EQ(456U, l32.rlim_cur);
+  ASSERT_EQ(l64.rlim_cur, l32.rlim_cur);
+  ASSERT_EQ(l64.rlim_cur, pr_l64.rlim_cur);
 
-TEST_F(SysResourceTest, get_resource_limit_equal) {
-  CheckResourceLimits();
-}
-
-TEST_F(SysResourceTest, setrlimit) {
-  l32_.rlim_cur = 123U;
-  ASSERT_EQ(0, setrlimit(RLIMIT_CORE, &l32_));
-  CheckResourceLimits();
-  ASSERT_EQ(123U, l32_.rlim_cur);
-}
-
-TEST_F(SysResourceTest, setrlimit64) {
-  l64_.rlim_cur = 456U;
-  ASSERT_EQ(0, setrlimit64(RLIMIT_CORE, &l64_));
-  CheckResourceLimits();
-  ASSERT_EQ(456U, l64_.rlim_cur);
-}
-
-TEST_F(SysResourceTest, prlimit64) {
-  pr_l64_.rlim_cur = pr_l64_.rlim_max;
-  ASSERT_EQ(0, prlimit64(0, RLIMIT_CORE, &pr_l64_, NULL));
-  CheckResourceLimits();
-  ASSERT_EQ(pr_l64_.rlim_max, pr_l64_.rlim_cur);
-}
-
-TEST_F(SysResourceTest, prlimit) {
-  // prlimit is prlimit64 on LP64 and unimplemented on 32-bit. So we only test prlimit64.
+  // Write with prlimit64 and read back with everything.
+  l64.rlim_cur = 789;
+  ASSERT_EQ(0, prlimit64(0, RLIMIT_CORE, &l64, NULL));
+  ASSERT_EQ(0, getrlimit(RLIMIT_CORE, &l32));
+  ASSERT_EQ(0, getrlimit64(RLIMIT_CORE, &l64));
+  ASSERT_EQ(0, prlimit64(0, RLIMIT_CORE, NULL, &pr_l64));
+  ASSERT_EQ(789U, l32.rlim_cur);
+  ASSERT_EQ(l64.rlim_cur, l32.rlim_cur);
+  ASSERT_EQ(l64.rlim_cur, pr_l64.rlim_cur);
 }

tests/time_test.cpp

@@ -21,7 +21,6 @@
 #include <gtest/gtest.h>
 #include <pthread.h>
 #include <signal.h>
-#include <stdatomic.h>
 #include <sys/syscall.h>
 #include <sys/types.h>
 #include <sys/wait.h>
@@ -140,7 +139,7 @@ void SetTime(timer_t t, time_t value_s, time_t value_ns, time_t interval_s, time
   ts.it_value.tv_nsec = value_ns;
   ts.it_interval.tv_sec = interval_s;
   ts.it_interval.tv_nsec = interval_ns;
-  ASSERT_EQ(0, timer_settime(t, 0, &ts, NULL));
+  ASSERT_EQ(0, timer_settime(t, TIMER_ABSTIME, &ts, NULL));
 }
 
 static void NoOpNotifyFunction(sigval_t) {
@@ -172,7 +171,7 @@ TEST(time, timer_create) {
   ASSERT_EQ(0, timer_delete(timer_id));
 }
 
-static int timer_create_SIGEV_SIGNAL_signal_handler_invocation_count;
+static int timer_create_SIGEV_SIGNAL_signal_handler_invocation_count = 0;
 static void timer_create_SIGEV_SIGNAL_signal_handler(int signal_number) {
   ++timer_create_SIGEV_SIGNAL_signal_handler_invocation_count;
   ASSERT_EQ(SIGUSR1, signal_number);
@@ -187,7 +186,6 @@ TEST(time, timer_create_SIGEV_SIGNAL) {
   timer_t timer_id;
   ASSERT_EQ(0, timer_create(CLOCK_MONOTONIC, &se, &timer_id));
 
-  timer_create_SIGEV_SIGNAL_signal_handler_invocation_count = 0;
   ScopedSignalHandler ssh(SIGUSR1, timer_create_SIGEV_SIGNAL_signal_handler);
 
   ASSERT_EQ(0, timer_create_SIGEV_SIGNAL_signal_handler_invocation_count);
@@ -204,20 +202,12 @@ TEST(time, timer_create_SIGEV_SIGNAL) {
 }
 
 struct Counter {
- private:
-  atomic_int value;
+  volatile int value;
   timer_t timer_id;
   sigevent_t se;
   bool timer_valid;
 
-  void Create() {
-    ASSERT_FALSE(timer_valid);
-    ASSERT_EQ(0, timer_create(CLOCK_REALTIME, &se, &timer_id));
-    timer_valid = true;
-  }
-
- public:
-  Counter(void (*fn)(sigval_t)) : value(ATOMIC_VAR_INIT(0)), timer_valid(false) {
+  Counter(void (*fn)(sigval_t)) : value(0), timer_valid(false) {
     memset(&se, 0, sizeof(se));
     se.sigev_notify = SIGEV_THREAD;
     se.sigev_notify_function = fn;
@@ -225,6 +215,12 @@ struct Counter {
     Create();
   }
 
+  void Create() {
+    ASSERT_FALSE(timer_valid);
+    ASSERT_EQ(0, timer_create(CLOCK_REALTIME, &se, &timer_id));
+    timer_valid = true;
+  }
+
   void DeleteTimer() {
     ASSERT_TRUE(timer_valid);
     ASSERT_EQ(0, timer_delete(timer_id));
@@ -237,30 +233,26 @@ struct Counter {
     }
   }
 
-  int Value() {
-    return atomic_load(&value);
-  }
-
   void SetTime(time_t value_s, time_t value_ns, time_t interval_s, time_t interval_ns) {
     ::SetTime(timer_id, value_s, value_ns, interval_s, interval_ns);
   }
 
   bool ValueUpdated() {
-    int current_value = atomic_load(&value);
+    volatile int current_value = value;
     time_t start = time(NULL);
-    while (current_value == atomic_load(&value) && (time(NULL) - start) < 5) {
+    while (current_value == value && (time(NULL) - start) < 5) {
     }
-    return current_value != atomic_load(&value);
+    return current_value != value;
   }
 
   static void CountNotifyFunction(sigval_t value) {
     Counter* cd = reinterpret_cast<Counter*>(value.sival_ptr);
-    atomic_fetch_add(&cd->value, 1);
+    ++cd->value;
   }
 
   static void CountAndDisarmNotifyFunction(sigval_t value) {
     Counter* cd = reinterpret_cast<Counter*>(value.sival_ptr);
-    atomic_fetch_add(&cd->value, 1);
+    ++cd->value;
 
     // Setting the initial expiration time to 0 disarms the timer.
     cd->SetTime(0, 0, 1, 0);
@@ -269,29 +261,30 @@ struct Counter {
 
 TEST(time, timer_settime_0) {
   Counter counter(Counter::CountAndDisarmNotifyFunction);
-  ASSERT_EQ(0, counter.Value());
+  ASSERT_TRUE(counter.timer_valid);
 
-  counter.SetTime(0, 500000000, 1, 0);
-  sleep(1);
+  ASSERT_EQ(0, counter.value);
+
+  counter.SetTime(0, 1, 1, 0);
+  usleep(500000);
 
   // The count should just be 1 because we disarmed the timer the first time it fired.
-  ASSERT_EQ(1, counter.Value());
+  ASSERT_EQ(1, counter.value);
 }
 
 TEST(time, timer_settime_repeats) {
   Counter counter(Counter::CountNotifyFunction);
-  ASSERT_EQ(0, counter.Value());
+  ASSERT_TRUE(counter.timer_valid);
+
+  ASSERT_EQ(0, counter.value);
 
   counter.SetTime(0, 1, 0, 10);
   ASSERT_TRUE(counter.ValueUpdated());
   ASSERT_TRUE(counter.ValueUpdated());
   ASSERT_TRUE(counter.ValueUpdated());
-  counter.DeleteTimer();
-  // Add a sleep as other threads may be calling the callback function when the timer is deleted.
-  usleep(500000);
 }
 
-static int timer_create_NULL_signal_handler_invocation_count;
+static int timer_create_NULL_signal_handler_invocation_count = 0;
 static void timer_create_NULL_signal_handler(int signal_number) {
   ++timer_create_NULL_signal_handler_invocation_count;
   ASSERT_EQ(SIGALRM, signal_number);
@@ -302,7 +295,6 @@ TEST(time, timer_create_NULL) {
   timer_t timer_id;
   ASSERT_EQ(0, timer_create(CLOCK_MONOTONIC, NULL, &timer_id));
 
-  timer_create_NULL_signal_handler_invocation_count = 0;
   ScopedSignalHandler ssh(SIGALRM, timer_create_NULL_signal_handler);
 
   ASSERT_EQ(0, timer_create_NULL_signal_handler_invocation_count);
@@ -349,59 +341,22 @@ TEST(time, timer_delete_multiple) {
 
 TEST(time, timer_create_multiple) {
   Counter counter1(Counter::CountNotifyFunction);
+  ASSERT_TRUE(counter1.timer_valid);
   Counter counter2(Counter::CountNotifyFunction);
+  ASSERT_TRUE(counter2.timer_valid);
   Counter counter3(Counter::CountNotifyFunction);
+  ASSERT_TRUE(counter3.timer_valid);
 
-  ASSERT_EQ(0, counter1.Value());
-  ASSERT_EQ(0, counter2.Value());
-  ASSERT_EQ(0, counter3.Value());
+  ASSERT_EQ(0, counter1.value);
+  ASSERT_EQ(0, counter2.value);
+  ASSERT_EQ(0, counter3.value);
 
-  counter2.SetTime(0, 500000000, 0, 0);
-  sleep(1);
-
-  EXPECT_EQ(0, counter1.Value());
-  EXPECT_EQ(1, counter2.Value());
-  EXPECT_EQ(0, counter3.Value());
-}
-
-// Test to verify that disarming a repeatable timer disables the callbacks.
-TEST(time, timer_disarm_terminates) {
-  Counter counter(Counter::CountNotifyFunction);
-  ASSERT_EQ(0, counter.Value());
-
-  counter.SetTime(0, 1, 0, 1);
-  ASSERT_TRUE(counter.ValueUpdated());
-  ASSERT_TRUE(counter.ValueUpdated());
-  ASSERT_TRUE(counter.ValueUpdated());
-
-  counter.SetTime(0, 0, 0, 0);
-  // Add a sleep as the kernel may have pending events when the timer is disarmed.
-  usleep(500000);
-  int value = counter.Value();
+  counter2.SetTime(0, 1, 0, 0);
   usleep(500000);
 
-  // Verify the counter has not been incremented.
-  ASSERT_EQ(value, counter.Value());
-}
-
-// Test to verify that deleting a repeatable timer disables the callbacks.
-TEST(time, timer_delete_terminates) {
-  Counter counter(Counter::CountNotifyFunction);
-  ASSERT_EQ(0, counter.Value());
-
-  counter.SetTime(0, 1, 0, 1);
-  ASSERT_TRUE(counter.ValueUpdated());
-  ASSERT_TRUE(counter.ValueUpdated());
-  ASSERT_TRUE(counter.ValueUpdated());
-
-  counter.DeleteTimer();
-  // Add a sleep as other threads may be calling the callback function when the timer is deleted.
-  usleep(500000);
-  int value = counter.Value();
-  usleep(500000);
-
-  // Verify the counter has not been incremented.
-  ASSERT_EQ(value, counter.Value());
+  EXPECT_EQ(0, counter1.value);
+  EXPECT_EQ(1, counter2.value);
+  EXPECT_EQ(0, counter3.value);
 }
 
 struct TimerDeleteData {
@@ -469,3 +424,45 @@ TEST(time, clock_gettime) {
   ASSERT_EQ(0, ts2.tv_sec);
   ASSERT_LT(ts2.tv_nsec, 1000000);
 }
+
+// Test to verify that disarming a repeatable timer disables the
+// callbacks.
+TEST(time, timer_disarm_terminates) {
+  Counter counter(Counter::CountNotifyFunction);
+  ASSERT_TRUE(counter.timer_valid);
+
+  ASSERT_EQ(0, counter.value);
+
+  counter.SetTime(0, 1, 0, 1);
+  ASSERT_TRUE(counter.ValueUpdated());
+  ASSERT_TRUE(counter.ValueUpdated());
+  ASSERT_TRUE(counter.ValueUpdated());
+
+  counter.SetTime(0, 0, 1, 0);
+  volatile int value = counter.value;
+  usleep(500000);
+
+  // Verify the counter has not been incremented.
+  ASSERT_EQ(value, counter.value);
+}
+
+// Test to verify that deleting a repeatable timer disables the
+// callbacks.
+TEST(time, timer_delete_terminates) {
+  Counter counter(Counter::CountNotifyFunction);
+  ASSERT_TRUE(counter.timer_valid);
+
+  ASSERT_EQ(0, counter.value);
+
+  counter.SetTime(0, 1, 0, 1);
+  ASSERT_TRUE(counter.ValueUpdated());
+  ASSERT_TRUE(counter.ValueUpdated());
+  ASSERT_TRUE(counter.ValueUpdated());
+
+  counter.DeleteTimer();
+  volatile int value = counter.value;
+  usleep(500000);
+
+  // Verify the counter has not been incremented.
+  ASSERT_EQ(value, counter.value);
+}