search for: caml_alloc_str

...init.c. + * See: bin2c.pl, init.c. */ -extern uint8_t _binary_init_start, _binary_init_end; +#include <format-ext2-init-bin.h> value supermin_binary_init (value unitv) { CAMLparam1 (unitv); CAMLlocal1 (sv); - size_t n = &_binary_init_end - &_binary_init_start; - sv = caml_alloc_string (n); - memcpy (String_val (sv), &_binary_init_start, n); + sv = caml_alloc_string (_binary_init_len); + memcpy (String_val (sv), _binary_init, _binary_init_len); CAMLreturn (sv); } -- 2.13.5

Hi, this patch replaces the first simpler version: https://www.redhat.com/archives/libguestfs/2017-August/msg00117.html The approach now is to use a C snippet, which should pose way less compatibility issues. Thanks, Pino Toscano (1): Switch binary embedding to a C source .gitignore | 2 +- src/Makefile.am | 18 +++++++++--------- src/{bin2s.pl => bin2c.pl} |

...Int64 _ | Path _ > | SockAddrAndLen _ | StringList _ > | UInt _ | UInt32 _ -> assert false > ) args in > @@ -4021,6 +4110,8 @@ let print_ocaml_binding (name, { args; ret }) = > | BytesIn (n, len) -> > pr " %sv = caml_alloc_string (%s);\n" n len; > pr " memcpy (String_val (%sv), %s, %s);\n" n n len > + | Int n -> > + pr " %sv = caml_copy_int32 (%s);\n" n n This is wrong, it should be: %sv = Val_int (%s); Foo_bar means convert a "bar" to...

This bug was found by Eric Blake. In the .pread method we allocate a buffer in the server and pass it to the plugin. The plugin is supposed to fill it with data. The buffer was uninitialized so initially contained random heap data, but that's OK provided the plugin fully overwrote it with data. All correctly written plugins ought to do this, however there is the possibility of an

..., 4 insertions(+) diff --git a/plugins/ocaml/ocaml.c b/plugins/ocaml/ocaml.c index d854f48..7193842 100644 --- a/plugins/ocaml/ocaml.c +++ b/plugins/ocaml/ocaml.c @@ -444,6 +444,10 @@ pread_wrapper (void *h, void *buf, uint32_t count, uint64_t offset, caml_leave_blocking_section (); strv = caml_alloc_string (count); + /* Initialize the buffer with zeroes in case the plugin does not + * fill it completely. + */ + memset (String_val (strv), 0, count); offsetv = caml_copy_int64 (offset); flagsv = Val_flags (flags); -- 2.20.1

...Path _ + | Flags _ | Int64 _ | Path _ | SockAddrAndLen _ | StringList _ | UInt _ | UInt32 _ -> assert false ) args in @@ -4017,6 +4021,8 @@ let print_ocaml_binding (name, { args; ret }) = | BytesIn (n, len) -> pr " %sv = caml_alloc_string (%s);\n" n len; pr " memcpy (String_val (%sv), %s, %s);\n" n n len + | Int n -> + pr " %sv = Val_int (%s);\n" n n | String n -> pr " %sv = caml_copy_string (%s);\n" n n | UInt64 n -> @...

....c @@ -439,15 +439,16 @@ pread_wrapper (void *h, void *buf, uint32_t count, uint64_t offset, uint32_t flags) { CAMLparam0 (); - CAMLlocal4 (rv, strv, offsetv, flagsv); + CAMLlocal4 (rv, countv, offsetv, flagsv); + mlsize_t len; caml_leave_blocking_section (); - strv = caml_alloc_string (count); + countv = caml_copy_int32 (count); offsetv = caml_copy_int64 (offset); flagsv = Val_flags (flags); - value args[] = { *(value *) h, strv, offsetv, flagsv }; + value args[] = { *(value *) h, countv, offsetv, flagsv }; rv = caml_callbackN_exn (pread_fn, sizeof args / sizeof...

...t64 n -> n ^ "v" (* The following not yet implemented for callbacks XXX *) | ArrayAndLen _ | Bool _ | BytesOut _ @@ -4124,7 +4154,8 @@ let print_ocaml_binding (name, { args; ret }) = | BytesIn (n, len) -> pr " %sv = caml_alloc_string (%s);\n" n len; pr " memcpy (String_val (%sv), %s, %s);\n" n n len - | Int n -> + | Int n + | ReadStatus n -> pr " %sv = caml_copy_int32 (%s);\n" n n | String n -> pr " %sv = caml_c...

...-> assert false + | UInt32 _ -> assert false ) cbargs in pr "/* Wrapper for %s callback of %s. */\n" cbname name; @@ -4634,7 +4636,7 @@ let print_ocaml_binding (name, { args; ret }) = | BytesIn (n, len) -> pr " %sv = caml_alloc_string (%s);\n" n len; pr " memcpy (String_val (%sv), %s, %s);\n" n n len - | Int n -> + | Int n | UInt n -> pr " %sv = Val_int (%s);\n" n n | Int64 n -> pr " %sv = caml_copy_int64 (%s);\n" n...

...alue bv) @@ -83,9 +64,6 @@ nbd_internal_ocaml_buffer_to_bytes (value bv) CAMLlocal1 (rv); struct nbd_buffer *b = NBD_buffer_val (bv); - if (b->data == NULL) /* Buffer has been freed. */ - caml_invalid_argument ("NBD.Buffer.to_bytes used on freed buffer"); - rv = caml_alloc_string (b->len); memcpy (Bytes_val (rv), b->data, b->len); diff --git a/ocaml/examples/asynch_copy.ml b/ocaml/examples/asynch_copy.ml index 7dbe976..50357f9 100644 --- a/ocaml/examples/asynch_copy.ml +++ b/ocaml/examples/asynch_copy.ml @@ -31,11 +31,9 @@ let asynch_copy src dst = in...

...alue bv) @@ -83,9 +64,6 @@ nbd_internal_ocaml_buffer_to_bytes (value bv) CAMLlocal1 (rv); struct nbd_buffer *b = NBD_buffer_val (bv); - if (b->data == NULL) /* Buffer has been freed. */ - caml_invalid_argument ("NBD.Buffer.to_bytes used on freed buffer"); - rv = caml_alloc_string (b->len); memcpy (Bytes_val (rv), b->data, b->len); diff --git a/ocaml/examples/asynch_copy.ml b/ocaml/examples/asynch_copy.ml index 8057118..d5dcc60 100644 --- a/ocaml/examples/asynch_copy.ml +++ b/ocaml/examples/asynch_copy.ml @@ -31,11 +31,9 @@ let asynch_copy src dst = in...

...n ^ "v" > (* The following not yet implemented for callbacks XXX *) > | ArrayAndLen _ | Bool _ | BytesOut _ > @@ -4124,7 +4154,8 @@ let print_ocaml_binding (name, { args; ret }) = > | BytesIn (n, len) -> > pr " %sv = caml_alloc_string (%s);\n" n len; > pr " memcpy (String_val (%sv), %s, %s);\n" n n len > - | Int n -> > + | Int n > + | ReadStatus n -> > pr " %sv = caml_copy_int32 (%s);\n" n n In OCaml, a union type where there is...

...th _ @@ -3928,6 +3962,9 @@ let print_ocaml_binding (name, { args; ret }) = | ArrayAndLen (UInt32 n, count) -> pr " %sv = nbd_internal_ocaml_alloc_int32_array (%s, %s);\n" n n count; + | BytesIn (n, len) -> + pr " %sv = caml_alloc_string (%s);\n" n len; + pr " memcpy (String_val (%sv), %s, %s);\n" n n len | String n -> pr " %sv = caml_copy_string (%s);\n" n n | UInt64 n -> @@ -3937,7 +3974,7 @@ let print_ocaml_binding (name, { args; ret }) =...

...Path _ + | Flags _ | Int64 _ | Path _ | SockAddrAndLen _ | StringList _ | UInt _ | UInt32 _ -> assert false ) args in @@ -4021,6 +4110,8 @@ let print_ocaml_binding (name, { args; ret }) = | BytesIn (n, len) -> pr " %sv = caml_alloc_string (%s);\n" n len; pr " memcpy (String_val (%sv), %s, %s);\n" n n len + | Int n -> + pr " %sv = caml_copy_int32 (%s);\n" n n | String n -> pr " %sv = caml_copy_string (%s);\n" n n | UInt64 n...

On Windows, there exist at least two APIs for dealing with the Registry: The Win32 API (RegCreateKeyA, RegCreateKeyW, etc.) works with null-terminated ASCII or UTF-16 strings. The native API (ZwCreateKey, etc.), on the other hand works with UTF-16 strings that are stored as buffers+length and may contain null characters. Malware authors have been relying on the Win32 API's inability to

Version 1 was here: https://www.redhat.com/archives/libguestfs/2019-April/msg00144.html Version 2 makes a couple of much larger changes: The OCaml patch changes the API of the pread method so it matches what other language bindings are already doing, ie. get the language plugin to return a newly allocated buffer, check it is long enough, copy out the data. The server patch implements a

...uot;; - List.iter ( - function - | ArrayAndLen (UInt32 n, count) -> - pr " %sv = nbd_internal_ocaml_alloc_int32_array (%s, %s);\n" - n n count; - | BytesIn (n, len) -> - pr " %sv = caml_alloc_string (%s);\n" n len; - pr " memcpy (String_val (%sv), %s, %s);\n" n n len - | Int n -> - pr " %sv = Val_int (%s);\n" n n - | Int64 n -> - pr " %sv = caml_copy_int64 (%s);\n" n n -...

In this patch series we use the newly introduced free callback on the completion function to dererence the OCaml NBD.Buffer. I will make the same kind of change for Python later in a separate series. The completion function is always called at the C level, even if the OCaml program didn't use the optional argument. That's because the free callback doesn't run otherwise. There is a

Patches 1-4 are basically uncontroversial, straightforward refactoring and IMHO we should just push them. Possibly 1-3 should be squashed together, but I posted them separately so they are easier to review. Patches 5 and 6 together implement OClosure. Patch 5 adds the feature and is simple to understand. Patch 6 changes the Closure completion callbacks into OClosure, but because it doesn't

I've mentioned this topic before (in fact, the idea of adding NBD_CMD_FLAG_DF was first mentioned at [1]), but finally finished enough of an implementation to feel confident in posting it. I'd still like to add something under examples/ that uses the new API to implement strict checking of a server's structured replies read implementation (ensure that a server never sends data after