Put special pipe-handling code into libwsutil.

Ask, in a comment, why we're doing PeekNamedPipe() when we're trying
to read everyting in the pipe, up to the EOF, into a string.

On UN*X, do the same "read up to an EOF and then NUL-terminate the
result" stuff that we did on Windows; nothing guarantees that, on all
UN*Xes, in all circumstances, until the end of time, world without end,
amen, we can do one read and get the entire string.

Change-Id: I578802b23fec1051139eaefd9a09fe2a6de06a11
Reviewed-on: https://code.wireshark.org/review/24959
Petri-Dish: Guy Harris <guy@alum.mit.edu>
Tested-by: Petri Dish Buildbot
Reviewed-by: Guy Harris <guy@alum.mit.edu>

1 files changed, 2 insertions, 30 deletions

diff --git a/extcap_spawn.c b/extcap_spawn.c
index a5d9f4df53..42434df819 100644
--- a/extcap_spawn.c
+++ b/extcap_spawn.c
@@ -18,6 +18,7 @@
 
 #include <wsutil/file_util.h>
 #include <wsutil/filesystem.h>
+#include <wsutil/ws_pipe.h>
 #ifdef _WIN32
 #include <wsutil/win32-utils.h>
 #endif
@@ -27,35 +28,6 @@
 #include "extcap.h"
 #include "extcap_spawn.h"
 
-#ifdef _WIN32
-
-void win32_readfrompipe(HANDLE read_pipe, gint32 max_buffer, gchar *buffer)
-{
-    gboolean bSuccess = FALSE;
-    gint32 bytes_written = 0;
-    gint32 max_bytes = 0;
-
-    DWORD dwRead;
-    DWORD bytes_avail = 0;
-
-    for (;;)
-    {
-        if (!PeekNamedPipe(read_pipe, NULL, 0, NULL, &bytes_avail, NULL)) break;
-        if (bytes_avail <= 0) break;
-
-        max_bytes = max_buffer - bytes_written - 1;
-
-        bSuccess = ReadFile(read_pipe, &buffer[bytes_written], max_bytes, &dwRead, NULL);
-        if (!bSuccess || dwRead == 0) break;
-
-        bytes_written += dwRead;
-        if ((bytes_written + 1) >= max_buffer) break;
-    }
-
-    buffer[bytes_written] = '\0';
-}
-#endif
-
 gboolean extcap_spawn_sync(gchar *dirname, gchar *command, gint argc, gchar **args, gchar **command_output)
 {
     gboolean status = FALSE;
@@ -148,7 +120,7 @@ gboolean extcap_spawn_sync(gchar *dirname, gchar *command, gint argc, gchar **ar
     if (CreateProcess(NULL, wcommandline, NULL, NULL, TRUE, CREATE_NEW_CONSOLE, NULL, NULL, &info, &processInfo))
     {
         WaitForSingleObject(processInfo.hProcess, INFINITE);
-        win32_readfrompipe(child_stdout_rd, BUFFER_SIZE, buffer);
+        ws_read_string_from_pipe(child_stdout_rd, buffer, BUFFER_SIZE);
         local_output = g_strdup_printf("%s", buffer);
 
         CloseHandle(child_stdout_rd);