[compiler-rt] fa4bd4b - [DFSan] Add custom wrapper for getpeername.

[Matt Morehouse via llvm-commits]

Author: Matt Morehouse
Date: 2020-12-10T12:26:06-08:00
New Revision: fa4bd4b338d1c8c0a95b63b13640b10694b8185c

URL: https://github.com/llvm/llvm-project/commit/fa4bd4b338d1c8c0a95b63b13640b10694b8185c
DIFF: https://github.com/llvm/llvm-project/commit/fa4bd4b338d1c8c0a95b63b13640b10694b8185c.diff

LOG: [DFSan] Add custom wrapper for getpeername.

The wrapper clears shadow for addr and addrlen when written to.

Reviewed By: stephan.yichao.zhao

Differential Revision: https://reviews.llvm.org/D93046

Added: 
    

Modified: 
    compiler-rt/lib/dfsan/dfsan_custom.cpp
    compiler-rt/lib/dfsan/done_abilist.txt
    compiler-rt/test/dfsan/custom.cpp

Removed: 
    


################################################################################
diff  --git a/compiler-rt/lib/dfsan/dfsan_custom.cpp b/compiler-rt/lib/dfsan/dfsan_custom.cpp
index 3b8c46d642a4..259bec4207dd 100644
--- a/compiler-rt/lib/dfsan/dfsan_custom.cpp
+++ b/compiler-rt/lib/dfsan/dfsan_custom.cpp
@@ -966,6 +966,21 @@ SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_getsockname(
   return ret;
 }
 
+SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_getpeername(
+    int sockfd, struct sockaddr *addr, socklen_t *addrlen,
+    dfsan_label sockfd_label, dfsan_label addr_label, dfsan_label addrlen_label,
+    dfsan_label *ret_label) {
+  socklen_t origlen = addrlen ? *addrlen : 0;
+  int ret = getpeername(sockfd, addr, addrlen);
+  if (ret != -1 && addr && addrlen) {
+    socklen_t written_bytes = origlen < *addrlen ? origlen : *addrlen;
+    dfsan_set_label(0, addrlen, sizeof(*addrlen));
+    dfsan_set_label(0, addr, written_bytes);
+  }
+  *ret_label = 0;
+  return ret;
+}
+
 // Type of the trampoline function passed to the custom version of
 // dfsan_set_write_callback.
 typedef void (*write_trampoline_t)(

diff  --git a/compiler-rt/lib/dfsan/done_abilist.txt b/compiler-rt/lib/dfsan/done_abilist.txt
index f4d0950e65dc..5d3d31f2e162 100644
--- a/compiler-rt/lib/dfsan/done_abilist.txt
+++ b/compiler-rt/lib/dfsan/done_abilist.txt
@@ -193,6 +193,7 @@ fun:fstat=custom
 fun:getcwd=custom
 fun:get_current_dir_name=custom
 fun:gethostname=custom
+fun:getpeername=custom
 fun:getrlimit=custom
 fun:getrusage=custom
 fun:getsockname=custom

diff  --git a/compiler-rt/test/dfsan/custom.cpp b/compiler-rt/test/dfsan/custom.cpp
index 3098616c0e50..14cddd8e2a3c 100644
--- a/compiler-rt/test/dfsan/custom.cpp
+++ b/compiler-rt/test/dfsan/custom.cpp
@@ -956,6 +956,28 @@ void test_socketpair() {
   ASSERT_READ_ZERO_LABEL(fd, sizeof(fd));
 }
 
+void test_getpeername() {
+  int sockfds[2];
+  int ret = socketpair(AF_UNIX, SOCK_DGRAM, 0, sockfds);
+  assert(ret != -1);
+
+  struct sockaddr addr = {};
+  socklen_t addrlen = sizeof(addr);
+  dfsan_set_label(i_label, &addr, addrlen);
+  dfsan_set_label(i_label, &addrlen, sizeof(addrlen));
+
+  ret = getpeername(sockfds[0], &addr, &addrlen);
+  assert(ret != -1);
+  ASSERT_ZERO_LABEL(ret);
+  ASSERT_ZERO_LABEL(addrlen);
+  assert(addrlen < sizeof(addr));
+  ASSERT_READ_ZERO_LABEL(&addr, addrlen);
+  ASSERT_READ_LABEL(((char *)&addr) + addrlen, 1, i_label);
+
+  close(sockfds[0]);
+  close(sockfds[1]);
+}
+
 void test_getsockname() {
   int sockfd = socket(AF_UNIX, SOCK_DGRAM, 0);
   assert(sockfd != -1);
@@ -1177,6 +1199,7 @@ int main(void) {
   test_get_current_dir_name();
   test_getcwd();
   test_gethostname();
+  test_getpeername();
   test_getpwuid_r();
   test_getrlimit();
   test_getrusage();