Don't include control characters in BufferIn trace output (RHBZ#646822).

The example below shows what the output looks like for a large
random buffer.

$ guestfish -N fs -m /dev/sda1 -x -- \
    touch /test : \
    pwrite /test "$(dd if=/dev/urandom bs=128k count=1)" 0
[...]
pwrite "/test" "\x7f\xa0/\xb3\x80\xd3\xbc\xc3\xc3.\xb1\xe0\x1b\xafC\x06\xd5;\x0ajJ[o\xc1\xdd\xae\x1f\xce\xb2\x8d\xb3\xd0\x11\xcc$%\xe6<\xc7\xc7\xe7BU*\xc4l%\xaa\xea\xe9\x1an\xda]\xc6I\x0eC\xf9;\xec\x12a\x1f\xeaRH\xb2P\xd6+\xc4\xe6\xa5bW\x99\\x9d\xc8\x9bJ\xef\x99-\x16:h5\xe2\x0f\xa2\xa08\x9bU\x0b$\x138\xcf\xd4j\x9b\x83{%\xac0\xdaa1Xx\xbd`\x8e\xdd\x82\x87\x07\x98\xd2\x9ed\x8bq\xd0\x1f5\x8f\xab\xad4z1\xda\xc4b\xc1\xbc\x0f\xaa\xea\xc1\x15(\xfd1\xc2\x0bF\xe6\x9e\xb0+/g\\xab\xb0b\xde_\xca\xf9\xad\xe1?%\x17\xad\x98\xa4e\xc1\xe0f'\x89\xe9>\xff\xadhYi\xe7\x8c]%\xef\xe0\xa1R\xe5\xd5\x03K\xefI\xdf\xad\xd3\x82\xdb\x0f\xdd\xc3\x8f"\xf1G\xea\xf9r\xdd\xff\x88\x81\xb7\xf2\x0e\x0f\x1d;:\xf2F1\xdb\xb5D\xa1^\x928\xf5\x8e)\xab\xc4\xc3H(\xd0ol\xc6\xe4\xd6\xa3L\x1c\x06\xf4"<truncated, original size 130567 bytes> 0
[...]

diff --git a/generator/generator_c.ml b/generator/generator_c.ml
index 0a9060b..dad3ac3 100644 (file)
--- a/generator/generator_c.ml
+++ b/generator/generator_c.ml
@@ -591,7 +591,6 @@ check_state (guestfs_h *g, const char *caller)
       | Dev_or_Path n
       | FileIn n
       | FileOut n
-      | BufferIn n
       | Key n ->
           (* guestfish doesn't support string escaping, so neither do we *)
           pr "    fprintf (stderr, \" \\\"%%s\\\"\", %s);\n" n
@@ -613,6 +612,9 @@ check_state (guestfs_h *g, const char *caller)
           pr "    fprintf (stderr, \" %%d\", %s);\n" n
       | Int64 n ->
           pr "    fprintf (stderr, \" %%\" PRIi64, %s);\n" n
+      | BufferIn n ->                   (* RHBZ#646822 *)
+          pr "    fputc (' ', stderr);\n";
+          pr "    guestfs___print_BufferIn (stderr, %s, %s_size);\n" n n
     ) args;
 
     (* Optional arguments. *)

diff --git a/src/guestfs-internal.h b/src/guestfs-internal.h
index 212006d..a42375f 100644 (file)
--- a/src/guestfs-internal.h
+++ b/src/guestfs-internal.h
@@ -212,6 +212,7 @@ extern int guestfs___send_to_daemon (guestfs_h *g, const void *v_buf, size_t n);
 extern int guestfs___recv_from_daemon (guestfs_h *g, uint32_t *size_rtn, void **buf_rtn);
 extern int guestfs___accept_from_daemon (guestfs_h *g);
 extern int guestfs___build_appliance (guestfs_h *g, char **kernel, char **initrd, char **appliance);
+extern void guestfs___print_BufferIn (FILE *out, const char *buf, size_t buf_size);
 
 #define error guestfs_error
 #define perrorf guestfs_perrorf

diff --git a/src/guestfs.c b/src/guestfs.c
index f79aaed..325bdb0 100644 (file)
--- a/src/guestfs.c
+++ b/src/guestfs.c
@@ -61,6 +61,7 @@
 #include <arpa/inet.h>
 #include <netinet/in.h>
 
+#include "c-ctype.h"
 #include "glthread/lock.h"
 #include "hash.h"
 #include "hash-pjw.h"
@@ -731,3 +732,31 @@ guestfs_get_private (guestfs_h *g, const char *key)
   else
     return NULL;
 }
+
+/* When tracing, be careful how we print BufferIn parameters which
+ * usually contain large amounts of binary data (RHBZ#646822).
+ */
+void
+guestfs___print_BufferIn (FILE *out, const char *buf, size_t buf_size)
+{
+  size_t i;
+  size_t orig_size = buf_size;
+
+  if (buf_size > 256)
+    buf_size = 256;
+
+  fputc ('"', out);
+
+  for (i = 0; i < buf_size; ++i) {
+    if (c_isprint (buf[i]))
+      fputc (buf[i], out);
+    else
+      fprintf (out, "\\x%02x", (unsigned char) buf[i]);
+  }
+
+  fputc ('"', out);
+
+  if (orig_size > buf_size)
+    fprintf (out,
+             _("<truncated, original size %zu bytes>"), orig_size);
+}