Commit a3eb2fb2 authored by Matt Morehouse's avatar Matt Morehouse
Browse files

[DFSan] Add custom wrapper for recvmsg. 

The wrapper clears shadow for anything written by recvmsg.

Reviewed By: stephan.yichao.zhao

Differential Revision: https://reviews.llvm.org/D92949
parent 9a72d3e3

compiler-rt/lib/dfsan/dfsan_custom.cpp

+21 −0
Original line number Diff line number Diff line
@@ -29,6 +29,7 @@ 
#include <sys/epoll.h>

#include <sys/resource.h>

#include <sys/select.h>

#include <sys/socket.h>

#include <sys/stat.h>

#include <sys/time.h>

#include <sys/types.h>
@@ -879,6 +880,26 @@ SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_nanosleep(const struct timespec *req, 
  return ret;

}



SANITIZER_INTERFACE_ATTRIBUTE ssize_t __dfsw_recvmsg(

    int sockfd, struct msghdr *msg, int flags, dfsan_label sockfd_label,

    dfsan_label msg_label, dfsan_label flags_label, dfsan_label *ret_label) {

  ssize_t ret = recvmsg(sockfd, msg, flags);

  if (ret >= 0) {

    dfsan_set_label(0, msg, sizeof(*msg));

    dfsan_set_label(0, msg->msg_name, msg->msg_namelen);

    dfsan_set_label(0, msg->msg_control, msg->msg_controllen);

    for (size_t remaining = ret, i = 0; remaining > 0; ++i) {

      assert(i < msg->msg_iovlen);

      struct iovec *iov = &msg->msg_iov[i];

      size_t written = remaining < iov->iov_len ? remaining : iov->iov_len;

      dfsan_set_label(0, iov->iov_base, written);

      remaining -= written;

    }

  }

  *ret_label = 0;

  return ret;

}



SANITIZER_INTERFACE_ATTRIBUTE int

__dfsw_socketpair(int domain, int type, int protocol, int sv[2],

                  dfsan_label domain_label, dfsan_label type_label,

compiler-rt/lib/dfsan/done_abilist.txt

+3 −0
Original line number Diff line number Diff line
@@ -116,6 +116,8 @@ fun:connect=discard 
fun:creat=discard

fun:dladdr=discard

fun:dlclose=discard

fun:epoll_create=discard

fun:epoll_create1=discard

fun:epoll_ctl=discard

fun:fclose=discard

fun:feof=discard
@@ -195,6 +197,7 @@ fun:getrusage=custom 
fun:nanosleep=custom

fun:pread=custom

fun:read=custom

fun:recvmsg=custom

fun:socketpair=custom

fun:stat=custom

fun:time=custom

compiler-rt/test/dfsan/custom.cpp

+37 −0
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ 
#include <sys/epoll.h>

#include <sys/resource.h>

#include <sys/select.h>

#include <sys/socket.h>

#include <sys/stat.h>

#include <sys/time.h>

#include <sys/types.h>
@@ -336,6 +337,41 @@ void test_calloc() { 
  free(crv);

}



void test_recvmsg() {

  int sockfds[2];

  int ret = socketpair(AF_UNIX, SOCK_DGRAM, 0, sockfds);

  assert(ret != -1);



  char sbuf[] = "abcdefghijkl";

  struct iovec siovs[2] = {{&sbuf[0], 4}, {&sbuf[4], 4}};

  struct msghdr smsg = {};

  smsg.msg_iov = siovs;

  smsg.msg_iovlen = 2;



  ssize_t sent = sendmsg(sockfds[0], &smsg, 0);

  assert(sent > 0);



  char rbuf[128];

  struct iovec riovs[2] = {{&rbuf[0], 4}, {&rbuf[4], 4}};

  struct msghdr rmsg = {};

  rmsg.msg_iov = riovs;

  rmsg.msg_iovlen = 2;



  dfsan_set_label(i_label, rbuf, sizeof(rbuf));

  dfsan_set_label(i_label, &rmsg, sizeof(rmsg));



  ssize_t received = recvmsg(sockfds[1], &rmsg, 0);

  assert(received == sent);

  assert(memcmp(sbuf, rbuf, 8) == 0);

  ASSERT_ZERO_LABEL(received);

  ASSERT_READ_ZERO_LABEL(&rmsg, sizeof(rmsg));

  ASSERT_READ_ZERO_LABEL(&rbuf[0], 8);

  ASSERT_READ_LABEL(&rbuf[8], 1, i_label);



  close(sockfds[0]);

  close(sockfds[1]);

}



void test_read() {

  char buf[16];

  dfsan_set_label(i_label, buf, 1);
@@ -1089,6 +1125,7 @@ int main(void) { 
  test_pread();

  test_pthread_create();

  test_read();

  test_recvmsg();

  test_sched_getaffinity();

  test_select();

  test_sigaction();