debuggerd: switch to base::{Send,Receive}FileDescriptors.

Bug: http://b/12204763
Test: debuggerd_test
Change-Id: I0be40916214de51ab36fd6bd6d44090a84312e51

debuggerd/client/debuggerd_client.cpp

@@ -26,6 +26,7 @@
 
 #include <chrono>
 
+#include <android-base/cmsg.h>
 #include <android-base/file.h>
 #include <android-base/logging.h>
 #include <android-base/parseint.h>
@@ -41,6 +42,7 @@
 
 using namespace std::chrono_literals;
 
+using android::base::SendFileDescriptors;
 using android::base::unique_fd;
 
 static bool send_signal(pid_t pid, const DebuggerdDumpType dump_type) {
@@ -146,15 +148,16 @@ bool debuggerd_trigger_dump(pid_t tid, DebuggerdDumpType dump_type, unsigned int
     PLOG(ERROR) << "failed to set pipe buffer size";
   }
 
-  if (send_fd(set_timeout(sockfd), &req, sizeof(req), std::move(pipe_write)) != sizeof(req)) {
+  ssize_t rc = SendFileDescriptors(set_timeout(sockfd), &req, sizeof(req), pipe_write.get());
+  pipe_write.reset();
+  if (rc != sizeof(req)) {
     PLOG(ERROR) << "libdebuggerd_client: failed to send output fd to tombstoned";
     return false;
   }
 
   // Check to make sure we've successfully registered.
   InterceptResponse response;
-  ssize_t rc =
-      TEMP_FAILURE_RETRY(recv(set_timeout(sockfd.get()), &response, sizeof(response), MSG_TRUNC));
+  rc = TEMP_FAILURE_RETRY(recv(set_timeout(sockfd.get()), &response, sizeof(response), MSG_TRUNC));
   if (rc == 0) {
     LOG(ERROR) << "libdebuggerd_client: failed to read initial response from tombstoned: "
                << "timeout reached?";

debuggerd/debuggerd_test.cpp

@@ -32,6 +32,7 @@
 #include <android/fdsan.h>
 #include <android/set_abort_message.h>
 
+#include <android-base/cmsg.h>
 #include <android-base/file.h>
 #include <android-base/logging.h>
 #include <android-base/macros.h>
@@ -53,6 +54,8 @@
 #include "util.h"
 
 using namespace std::chrono_literals;
+
+using android::base::SendFileDescriptors;
 using android::base::unique_fd;
 
 #if defined(__LP64__)
@@ -123,12 +126,14 @@ static void tombstoned_intercept(pid_t target_pid, unique_fd* intercept_fd, uniq
 
   ASSERT_GE(pipe_buffer_size, 1024 * 1024);
 
-  if (send_fd(intercept_fd->get(), &req, sizeof(req), std::move(output_pipe_write)) != sizeof(req)) {
+  ssize_t rc = SendFileDescriptors(intercept_fd->get(), &req, sizeof(req), output_pipe_write.get());
+  output_pipe_write.reset();
+  if (rc != sizeof(req)) {
     FAIL() << "failed to send output fd to tombstoned: " << strerror(errno);
   }
 
   InterceptResponse response;
-  ssize_t rc = TEMP_FAILURE_RETRY(read(intercept_fd->get(), &response, sizeof(response)));
+  rc = TEMP_FAILURE_RETRY(read(intercept_fd->get(), &response, sizeof(response)));
   if (rc == -1) {
     FAIL() << "failed to read response from tombstoned: " << strerror(errno);
   } else if (rc == 0) {

debuggerd/tombstoned/intercept_manager.cpp

@@ -24,6 +24,7 @@
 #include <event2/event.h>
 #include <event2/listener.h>
 
+#include <android-base/cmsg.h>
 #include <android-base/logging.h>
 #include <android-base/unique_fd.h>
 #include <cutils/sockets.h>
@@ -31,6 +32,7 @@
 #include "protocol.h"
 #include "util.h"
 
+using android::base::ReceiveFileDescriptors;
 using android::base::unique_fd;
 
 static void intercept_close_cb(evutil_socket_t sockfd, short event, void* arg) {
@@ -96,7 +98,8 @@ static void intercept_request_cb(evutil_socket_t sockfd, short ev, void* arg) {
   {
     unique_fd rcv_fd;
     InterceptRequest intercept_request;
-    ssize_t result = recv_fd(sockfd, &intercept_request, sizeof(intercept_request), &rcv_fd);
+    ssize_t result =
+        ReceiveFileDescriptors(sockfd, &intercept_request, sizeof(intercept_request), &rcv_fd);
 
     if (result == -1) {
       PLOG(WARNING) << "failed to read from intercept socket";

debuggerd/tombstoned/tombstoned.cpp

@@ -31,6 +31,7 @@
 #include <event2/listener.h>
 #include <event2/thread.h>
 
+#include <android-base/cmsg.h>
 #include <android-base/logging.h>
 #include <android-base/properties.h>
 #include <android-base/stringprintf.h>
@@ -45,6 +46,7 @@
 #include "intercept_manager.h"
 
 using android::base::GetIntProperty;
+using android::base::SendFileDescriptors;
 using android::base::StringPrintf;
 using android::base::unique_fd;
 
@@ -224,7 +226,10 @@ static void perform_request(Crash* crash) {
   TombstonedCrashPacket response = {
     .packet_type = CrashPacketType::kPerformDump
   };
-  ssize_t rc = send_fd(crash->crash_socket_fd, &response, sizeof(response), std::move(output_fd));
+  ssize_t rc =
+      SendFileDescriptors(crash->crash_socket_fd, &response, sizeof(response), output_fd.get());
+  output_fd.reset();
+
   if (rc == -1) {
     PLOG(WARNING) << "failed to send response to CrashRequest";
     goto fail;

debuggerd/tombstoned/tombstoned_client.cpp

@@ -21,6 +21,7 @@
 
 #include <utility>
 
+#include <android-base/cmsg.h>
 #include <android-base/unique_fd.h>
 #include <async_safe/log.h>
 #include <cutils/sockets.h>
@@ -28,6 +29,7 @@
 #include "protocol.h"
 #include "util.h"
 
+using android::base::ReceiveFileDescriptors;
 using android::base::unique_fd;
 
 bool tombstoned_connect(pid_t pid, unique_fd* tombstoned_socket, unique_fd* output_fd,
@@ -53,7 +55,7 @@ bool tombstoned_connect(pid_t pid, unique_fd* tombstoned_socket, unique_fd* outp
   }
 
   unique_fd tmp_output_fd;
-  ssize_t rc = recv_fd(sockfd, &packet, sizeof(packet), &tmp_output_fd);
+  ssize_t rc = ReceiveFileDescriptors(sockfd, &packet, sizeof(packet), &tmp_output_fd);
   if (rc == -1) {
     async_safe_format_log(ANDROID_LOG_ERROR, "libc",
                           "failed to read response to DumpRequest packet: %s", strerror(errno));

debuggerd/util.cpp

@@ -24,73 +24,9 @@
 #include <android-base/file.h>
 #include <android-base/stringprintf.h>
 #include <android-base/strings.h>
-#include <android-base/unique_fd.h>
 #include <cutils/sockets.h>
 #include "protocol.h"
 
-using android::base::unique_fd;
-
-ssize_t send_fd(int sockfd, const void* data, size_t len, unique_fd fd) {
-  char cmsg_buf[CMSG_SPACE(sizeof(int))];
-
-  iovec iov = { .iov_base = const_cast<void*>(data), .iov_len = len };
-  msghdr msg = {
-    .msg_iov = &iov, .msg_iovlen = 1, .msg_control = cmsg_buf, .msg_controllen = sizeof(cmsg_buf),
-  };
-  auto cmsg = CMSG_FIRSTHDR(&msg);
-  cmsg->cmsg_level = SOL_SOCKET;
-  cmsg->cmsg_type = SCM_RIGHTS;
-  cmsg->cmsg_len = CMSG_LEN(sizeof(int));
-  *reinterpret_cast<int*>(CMSG_DATA(cmsg)) = fd.get();
-
-  return TEMP_FAILURE_RETRY(sendmsg(sockfd, &msg, 0));
-}
-
-ssize_t recv_fd(int sockfd, void* _Nonnull data, size_t len, unique_fd* _Nullable out_fd) {
-  char cmsg_buf[CMSG_SPACE(sizeof(int))];
-
-  iovec iov = { .iov_base = const_cast<void*>(data), .iov_len = len };
-  msghdr msg = {
-    .msg_iov = &iov,
-    .msg_iovlen = 1,
-    .msg_control = cmsg_buf,
-    .msg_controllen = sizeof(cmsg_buf),
-    .msg_flags = 0,
-  };
-  auto cmsg = CMSG_FIRSTHDR(&msg);
-  cmsg->cmsg_level = SOL_SOCKET;
-  cmsg->cmsg_type = SCM_RIGHTS;
-  cmsg->cmsg_len = CMSG_LEN(sizeof(int));
-
-  ssize_t result = TEMP_FAILURE_RETRY(recvmsg(sockfd, &msg, 0));
-  if (result == -1) {
-    return -1;
-  }
-
-  unique_fd fd;
-  bool received_fd = msg.msg_controllen == sizeof(cmsg_buf);
-  if (received_fd) {
-    fd.reset(*reinterpret_cast<int*>(CMSG_DATA(cmsg)));
-  }
-
-  if ((msg.msg_flags & MSG_TRUNC) != 0) {
-    errno = EFBIG;
-    return -1;
-  } else if ((msg.msg_flags & MSG_CTRUNC) != 0) {
-    errno = ERANGE;
-    return -1;
-  }
-
-  if (out_fd) {
-    *out_fd = std::move(fd);
-  } else if (received_fd) {
-    errno = ERANGE;
-    return -1;
-  }
-
-  return result;
-}
-
 std::string get_process_name(pid_t pid) {
   std::string result = "<unknown>";
   android::base::ReadFileToString(android::base::StringPrintf("/proc/%d/cmdline", pid), &result);

debuggerd/util.h

@@ -21,29 +21,5 @@
 #include <sys/cdefs.h>
 #include <sys/types.h>
 
-#include <android-base/unique_fd.h>
-
-// *** WARNING ***
-// tombstoned's sockets are SOCK_SEQPACKET sockets.
-// Short reads are treated as errors and short writes are assumed to not happen.
-
-// Sends a packet with an attached fd.
-ssize_t send_fd(int sockfd, const void* _Nonnull data, size_t len, android::base::unique_fd fd);
-
-// Receives a packet and optionally, its attached fd.
-// If out_fd is non-null, packets can optionally have an attached fd.
-// If out_fd is null, received packets must not have an attached fd.
-//
-// Errors:
-//   EOVERFLOW: sockfd is SOCK_DGRAM or SOCK_SEQPACKET and buffer is too small.
-//              The first len bytes of the packet are stored in data, but the
-//              rest of the packet is dropped.
-//   ERANGE:    too many file descriptors were attached to the packet.
-//   ENOMSG:    not enough file descriptors were attached to the packet.
-//
-//   plus any errors returned by the underlying recvmsg.
-ssize_t recv_fd(int sockfd, void* _Nonnull data, size_t len,
-                android::base::unique_fd* _Nullable out_fd);
-
 std::string get_process_name(pid_t pid);
 std::string get_thread_name(pid_t tid);