unix: fail with ENAMETOOLONG in uv_pipe_*

Fail with ENAMETOOLONG when the name of a Unix socket exceeds
`sizeof(saddr.sun_path)`. Previously the path was just truncated,
which could result in nasty bugs, and even though that behaviour
has been always been around, it’s hard to imagine a situation in
which ending up with an incorrect path is better than not creating
a socket at all.

Ref: nodejs/node#12601
Ref: nodejs/node#12708

src/unix/pipe.c

@@ -45,9 +45,14 @@ int uv_pipe_bind(uv_pipe_t* handle, const char* name) {
  const char* pipe_fname;
  int sockfd;
  int err;
+ size_t name_len;
 
  pipe_fname = NULL;
  sockfd = -1;
+ name_len = strlen(name) + 1;
+
+ if (name_len > sizeof(saddr.sun_path))
+ return -ENAMETOOLONG;
 
  /* Already bound? */
  if (uv__stream_fd(handle) >= 0)
@@ -67,8 +72,7 @@ int uv_pipe_bind(uv_pipe_t* handle, const char* name) {
  sockfd = err;
 
  memset(&saddr, 0, sizeof saddr);
- strncpy(saddr.sun_path, pipe_fname, sizeof(saddr.sun_path) - 1);
- saddr.sun_path[sizeof(saddr.sun_path) - 1] = '\0';
+ memcpy(saddr.sun_path, pipe_fname, name_len);
  saddr.sun_family = AF_UNIX;
 
  if (bind(sockfd, (struct sockaddr*)&saddr, sizeof saddr)) {
@@ -160,6 +164,14 @@ void uv_pipe_connect(uv_connect_t* req,
  int new_sock;
  int err;
  int r;
+ size_t name_len;
+
+ name_len = strlen(name) + 1;
+
+ if (name_len > sizeof(saddr.sun_path)) {
+ err = -ENAMETOOLONG;
+ goto out;
+ }
 
  new_sock = (uv__stream_fd(handle) == -1);
 
@@ -171,8 +183,7 @@ void uv_pipe_connect(uv_connect_t* req,
  }
 
  memset(&saddr, 0, sizeof saddr);
- strncpy(saddr.sun_path, name, sizeof(saddr.sun_path) - 1);
- saddr.sun_path[sizeof(saddr.sun_path) - 1] = '\0';
+ memcpy(saddr.sun_path, name, name_len);
  saddr.sun_family = AF_UNIX;
 
  do {

test/test-list.h

@@ -135,10 +135,12 @@ TEST_DECLARE (udp_try_send)
 TEST_DECLARE (pipe_bind_error_addrinuse)
 TEST_DECLARE (pipe_bind_error_addrnotavail)
 TEST_DECLARE (pipe_bind_error_inval)
+TEST_DECLARE (pipe_bind_error_long_path)
 TEST_DECLARE (pipe_connect_multiple)
 TEST_DECLARE (pipe_listen_without_bind)
 TEST_DECLARE (pipe_connect_bad_name)
 TEST_DECLARE (pipe_connect_to_file)
+TEST_DECLARE (pipe_connect_to_long_path)
 TEST_DECLARE (pipe_connect_on_prepare)
 TEST_DECLARE (pipe_getsockname)
 TEST_DECLARE (pipe_getsockname_abstract)
@@ -398,6 +400,7 @@ TASK_LIST_START
 
  TEST_ENTRY (pipe_connect_bad_name)
  TEST_ENTRY (pipe_connect_to_file)
+ TEST_ENTRY (pipe_connect_to_long_path)
  TEST_ENTRY (pipe_connect_on_prepare)
 
  TEST_ENTRY (pipe_server_close)
@@ -523,6 +526,7 @@ TASK_LIST_START
  TEST_ENTRY (pipe_bind_error_addrinuse)
  TEST_ENTRY (pipe_bind_error_addrnotavail)
  TEST_ENTRY (pipe_bind_error_inval)
+ TEST_ENTRY (pipe_bind_error_long_path)
  TEST_ENTRY (pipe_connect_multiple)
  TEST_ENTRY (pipe_listen_without_bind)
  TEST_ENTRY (pipe_getsockname)

test/test-pipe-bind-error.c

@@ -23,6 +23,7 @@
 #include "task.h"
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 
 
 #ifdef _WIN32
@@ -134,3 +135,27 @@ TEST_IMPL(pipe_listen_without_bind) {
  MAKE_VALGRIND_HAPPY();
  return 0;
 }
+
+
+TEST_IMPL(pipe_bind_error_long_path) {
+ char path[256];
+ uv_pipe_t server;
+ int r;
+
+ memset(path, '.', 255);
+ path[255] = '\0';
+
+ r = uv_pipe_init(uv_default_loop(), &server, 0);
+ ASSERT(r == 0);
+ r = uv_pipe_bind(&server, path);
+ ASSERT(r == UV_ENAMETOOLONG);
+
+ uv_close((uv_handle_t*)&server, close_cb);
+
+ uv_run(uv_default_loop(), UV_RUN_DEFAULT);
+
+ ASSERT(close_cb_called == 1);
+
+ MAKE_VALGRIND_HAPPY();
+ return 0;
+}

test/test-pipe-connect-error.c

@@ -23,6 +23,7 @@
 #include "task.h"
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 
 
 #ifdef _WIN32
@@ -56,6 +57,13 @@ static void connect_cb_file(uv_connect_t* connect_req, int status) {
 }
 
 
+static void connect_cb_long_path(uv_connect_t* connect_req, int status) {
+ ASSERT(status == UV_ENAMETOOLONG);
+ uv_close((uv_handle_t*)connect_req->handle, close_cb);
+ connect_cb_called++;
+}
+
+
 TEST_IMPL(pipe_connect_bad_name) {
  uv_pipe_t client;
  uv_connect_t req;
@@ -93,3 +101,26 @@ TEST_IMPL(pipe_connect_to_file) {
  MAKE_VALGRIND_HAPPY();
  return 0;
 }
+
+
+TEST_IMPL(pipe_connect_to_long_path) {
+ char path[256];
+ uv_pipe_t client;
+ uv_connect_t req;
+ int r;
+
+ memset(path, '.', 255);
+ path[255] = '\0';
+
+ r = uv_pipe_init(uv_default_loop(), &client, 0);
+ ASSERT(r == 0);
+ uv_pipe_connect(&req, &client, path, connect_cb_long_path);
+
+ uv_run(uv_default_loop(), UV_RUN_DEFAULT);
+
+ ASSERT(close_cb_called == 1);
+ ASSERT(connect_cb_called == 1);
+
+ MAKE_VALGRIND_HAPPY();
+ return 0;
+}