From: Yifan Gu <gyf304(a)gmail.com&gt; This patch adds in indirection for API functions, as PE DLL loader does not resolve undefined symbols. This patch only includes header changes. --- include/nbdkit-common.h | 133 +++++++++++++++++++++++++++++++++++++++- include/nbdkit-compat.h | 97 +++++++++++++++++++++++++++++ include/nbdkit-filter.h | 39 ++++++++++++ include/nbdkit-plugin.h | 27 ++++++++ include/Makefile.am | 1 + 5 files changed, 295 insertions(+), 2 deletions(-) diff --git a/include/nbdkit-common.h b/include/nbdkit-common.h index 9d1d89d0..57abc423 100644 --- a/include/nbdkit-common.h +++ b/include/nbdkit-common.h @@ -40,10 +40,14 @@ #include <stdarg.h> #include <stdint.h> #include <errno.h> -#include <sys/socket.h> +#include <nbdkit-compat.h> #include <nbdkit-version.h> +#if defined(NBDKIT_INTERNAL) || !defined(WINDOWS_COMPAT) +#include <sys/socket.h> +#endif + #ifdef __cplusplus extern "C" { #endif @@ -76,6 +80,7 @@ extern "C" { #define NBDKIT_EXTENT_HOLE (1<<0) /* Same as NBD_STATE_HOLE */ #define NBDKIT_EXTENT_ZERO (1<<1) /* Same as NBD_STATE_ZERO */ +#if defined(NBDKIT_INTERNAL) || !defined(WINDOWS_COMPAT) extern void nbdkit_error (const char *msg, ...) ATTRIBUTE_FORMAT_PRINTF (1, 2); extern void nbdkit_verror (const char *msg, va_list args) ATTRIBUTE_FORMAT_PRINTF (1, 0); @@ -113,9 +118,133 @@ extern const char *nbdkit_export_name (void); extern int nbdkit_peer_name (struct sockaddr *addr, socklen_t *addrlen); extern void nbdkit_shutdown (void); -struct nbdkit_extents; extern int nbdkit_add_extent (struct nbdkit_extents *, uint64_t offset, uint64_t length, uint32_t type); +#else +static void nbdkit_error (const char *msg, ...) + ATTRIBUTE_FORMAT_PRINTF (1, 2); +static void nbdkit_error (const char *msg, ...) +{ + va_list args; + va_start(args, msg); + _nbdkit_functions.verror(msg, args); + va_end(args); +} +static void nbdkit_verror (const char *msg, va_list args) + ATTRIBUTE_FORMAT_PRINTF (1, 0); +static void nbdkit_verror (const char *msg, va_list args) +{ + _nbdkit_functions.verror (msg, args); +} +static void nbdkit_debug (const char *msg, ...) + ATTRIBUTE_FORMAT_PRINTF (1, 2); +static void nbdkit_debug (const char *msg, ...) +{ + va_list args; + va_start (args, msg); + _nbdkit_functions.vdebug (msg, args); + va_end (args); +} +static void nbdkit_vdebug (const char *msg, va_list args) + ATTRIBUTE_FORMAT_PRINTF (1, 0); +static void nbdkit_vdebug (const char *msg, va_list args) +{ + _nbdkit_functions.vdebug (msg, args); +} + +static char *nbdkit_absolute_path (const char *path) +{ + return _nbdkit_functions.absolute_path (path); +} +static int64_t nbdkit_parse_size (const char *str) +{ + return _nbdkit_functions.parse_size (str); +} +static int nbdkit_parse_bool (const char *str) +{ + return _nbdkit_functions.parse_bool (str); +} +static int nbdkit_parse_int (const char *what, const char *str, + int *r) +{ + return _nbdkit_functions.parse_int (what, str, r); +} +static int nbdkit_parse_unsigned (const char *what, const char *str, + unsigned *r) +{ + return _nbdkit_functions.parse_unsigned (what, str, r); +} +static int nbdkit_parse_int8_t (const char *what, const char *str, + int8_t *r) +{ + return _nbdkit_functions.parse_int8_t (what, str, r); +} +static int nbdkit_parse_uint8_t (const char *what, const char *str, + uint8_t *r) +{ + return _nbdkit_functions.parse_uint8_t (what, str, r); +} +static int nbdkit_parse_int16_t (const char *what, const char *str, + int16_t *r) +{ + return _nbdkit_functions.parse_int16_t (what, str, r); +} +static int nbdkit_parse_uint16_t (const char *what, const char *str, + uint16_t *r) +{ + return _nbdkit_functions.parse_uint16_t (what, str, r); +} +static int nbdkit_parse_int32_t (const char *what, const char *str, + int32_t *r) +{ + return _nbdkit_functions.parse_int32_t (what, str, r); +} +static int nbdkit_parse_uint32_t (const char *what, const char *str, + uint32_t *r) +{ + return _nbdkit_functions.parse_uint32_t (what, str, r); +} +static int nbdkit_parse_int64_t (const char *what, const char *str, + int64_t *r) +{ + return _nbdkit_functions.parse_int64_t (what, str, r); +} +static int nbdkit_parse_uint64_t (const char *what, const char *str, + uint64_t *r) +{ + return _nbdkit_functions.parse_uint64_t(what, str, r); +} +static int nbdkit_read_password (const char *value, char **password) +{ + return _nbdkit_functions.read_password(value, password); +} +static char *nbdkit_realpath (const char *path) +{ + return _nbdkit_functions.realpath(path); +} +static int nbdkit_nanosleep (unsigned sec, unsigned nsec) +{ + return _nbdkit_functions.nanosleep(sec, nsec); +} +static const char *nbdkit_export_name (void) +{ + return _nbdkit_functions.export_name(); +} +static int nbdkit_peer_name (void *addr, void *addrlen) +{ + return _nbdkit_functions.peer_name(addr, addrlen); +} +static void nbdkit_shutdown (void) +{ + _nbdkit_functions.shutdown(); +} + +static int nbdkit_add_extent (struct nbdkit_extents *extents, + uint64_t offset, uint64_t length, uint32_t type) +{ + return _nbdkit_functions.add_extent(extents, offset, length, type); +} +#endif /* A static non-NULL pointer which can be used when you don't need a * per-connection handle. diff --git a/include/nbdkit-compat.h b/include/nbdkit-compat.h new file mode 100644 index 00000000..a0a4cb69 --- /dev/null +++ b/include/nbdkit-compat.h @@ -0,0 +1,97 @@ +/* nbdkit + * Copyright (C) 2013-2020 Red Hat Inc. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * * Neither the name of Red Hat nor the names of its contributors may be + * used to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, + * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A + * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF + * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND + * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#ifndef NBDKIT_COMPAT_H +#define NBDKIT_COMPAT_H + +#if !defined (NBDKIT_PLUGIN_H) && !defined (NBDKIT_FILTER_H) +#error this header file should not be directly included +#endif + +#if defined(_WIN32) || defined(__MINGW32__) || defined(__CYGWIN__) || \ + defined(_MSC_VER) +#define WINDOWS_COMPAT +#endif + +struct nbdkit_extents; + +#if defined(WINDOWS_COMPAT) +#include <string.h> +#include <stdarg.h> +#include <stdint.h> + +#ifdef __cplusplus +extern "C" { +#endif + +#ifdef WINDOWS_COMPAT +struct nbdkit_functions { + void (*verror) (const char *msg, va_list args); + void (*vdebug) (const char *msg, va_list args); + char * (*absolute_path) (const char *path); + int64_t (*parse_size) (const char *str); + int (*parse_bool) (const char *str); + int (*parse_int) (const char *what, const char *str, int *r); + int (*parse_unsigned) (const char *what, const char *str, unsigned *r); + int (*parse_int8_t) (const char *what, const char *str, int8_t *r); + int (*parse_uint8_t) (const char *what, const char *str, uint8_t *r); + int (*parse_int16_t) (const char *what, const char *str, int16_t *r); + int (*parse_uint16_t) (const char *what, const char *str, uint16_t *r); + int (*parse_int32_t) (const char *what, const char *str, int32_t *r); + int (*parse_uint32_t) (const char *what, const char *str, uint32_t *r); + int (*parse_int64_t) (const char *what, const char *str, int64_t *r); + int (*parse_uint64_t) (const char *what, const char *str, uint64_t *r); + int (*read_password) (const char *value, char **password); + char * (*realpath) (const char *path); + int (*nanosleep) (unsigned sec, unsigned nsec); + const char * (*export_name) (void); + int (*peer_name) (void *addr, void *addrlen); + void (*shutdown) (void); + + struct nbdkit_extents *(*extents_new) (uint64_t start, uint64_t end); + void (*extents_free) (struct nbdkit_extents *); + size_t (*extents_count) (const struct nbdkit_extents *); + struct nbdkit_extent (*get_extent) (const struct nbdkit_extents *, size_t); + int (*add_extent) (struct nbdkit_extents *, uint64_t offset, uint64_t length, + uint32_t type); + + void (*set_error) (int err); +}; + +struct nbdkit_functions _nbdkit_functions; +#endif + +#ifdef __cplusplus +} +#endif +#endif +#endif diff --git a/include/nbdkit-filter.h b/include/nbdkit-filter.h index ca58e496..40ab4345 100644 --- a/include/nbdkit-filter.h +++ b/include/nbdkit-filter.h @@ -110,11 +110,31 @@ struct nbdkit_extent { uint32_t type; }; +#if defined(NBDKIT_INTERNAL) || !defined(WINDOWS_COMPAT) extern struct nbdkit_extents *nbdkit_extents_new (uint64_t start, uint64_t end); extern void nbdkit_extents_free (struct nbdkit_extents *); extern size_t nbdkit_extents_count (const struct nbdkit_extents *); extern struct nbdkit_extent nbdkit_get_extent (const struct nbdkit_extents *, size_t); +#else +static struct nbdkit_extents *nbdkit_extents_new (uint64_t start, uint64_t end) +{ + return _nbdkit_functions.extents_new(start, end); +} +static void nbdkit_extents_free (struct nbdkit_extents *extents) +{ + _nbdkit_functions.extents_free(extents); +} +static size_t nbdkit_extents_count (const struct nbdkit_extents *extents) +{ + return _nbdkit_functions.extents_count(extents); +} +static struct nbdkit_extent nbdkit_get_extent (const struct nbdkit_extents *extents, + size_t size) +{ + return _nbdkit_functions.get_extent(extents, size); +} +#endif /* Filter struct. */ struct nbdkit_filter { @@ -204,6 +224,24 @@ struct nbdkit_filter { int *err); }; +#if defined(WINDOWS_COMPAT) +#define NBDKIT_REGISTER_FILTER(filter) \ + NBDKIT_CXX_LANG_C __declspec(dllexport) \ + struct nbdkit_filter * \ + filter_init (void) \ + { \ + (filter)._api_version = NBDKIT_FILTER_API_VERSION; \ + (filter)._version = NBDKIT_VERSION_STRING; \ + return &(filter); \ + } \ + NBDKIT_CXX_LANG_C __declspec(dllexport) \ + void \ + functions_init (struct nbdkit_functions *functions) \ + { \ + memcpy(&_nbdkit_functions, functions, \ + sizeof(struct nbdkit_functions)); \ + } +#else #define NBDKIT_REGISTER_FILTER(filter) \ NBDKIT_CXX_LANG_C \ struct nbdkit_filter * \ @@ -213,6 +251,7 @@ struct nbdkit_filter { (filter)._version = NBDKIT_VERSION_STRING; \ return &(filter); \ } +#endif #ifdef __cplusplus } diff --git a/include/nbdkit-plugin.h b/include/nbdkit-plugin.h index 7ff7bcee..6b6d99d3 100644 --- a/include/nbdkit-plugin.h +++ b/include/nbdkit-plugin.h @@ -140,8 +140,34 @@ struct nbdkit_plugin { int (*get_ready) (void); }; +#if defined(NBDKIT_INTERNAL) || !defined(WINDOWS_COMPAT) extern void nbdkit_set_error (int err); +#else +static void nbdkit_set_error (int err) +{ + _nbdkit_functions.set_error (err); +} +#endif +#if defined(WINDOWS_COMPAT) +#define NBDKIT_REGISTER_PLUGIN(plugin) \ + NBDKIT_CXX_LANG_C __declspec(dllexport) \ + struct nbdkit_plugin * \ + plugin_init (void) \ + { \ + (plugin)._struct_size = sizeof (plugin); \ + (plugin)._api_version = NBDKIT_API_VERSION; \ + (plugin)._thread_model = THREAD_MODEL; \ + return &(plugin); \ + } \ + NBDKIT_CXX_LANG_C __declspec(dllexport) \ + void \ + functions_init (struct nbdkit_functions *functions) \ + { \ + memcpy(&_nbdkit_functions, functions, \ + sizeof(struct nbdkit_functions)); \ + } +#else #define NBDKIT_REGISTER_PLUGIN(plugin) \ NBDKIT_CXX_LANG_C \ struct nbdkit_plugin * \ @@ -152,6 +178,7 @@ extern void nbdkit_set_error (int err); (plugin)._thread_model = THREAD_MODEL; \ return &(plugin); \ } +#endif #ifdef __cplusplus } diff --git a/include/Makefile.am b/include/Makefile.am index cf46abc6..8b413570 100644 --- a/include/Makefile.am +++ b/include/Makefile.am @@ -32,6 +32,7 @@ include $(top_srcdir)/common-rules.mk include_HEADERS = \ + nbdkit-compat.h \ nbdkit-common.h \ nbdkit-plugin.h \ nbdkit-filter.h \ -- 2.25.0

From: Yifan Gu <gyf304(a)gmail.com&gt; Windows PE DLL needs function indirection, this patch injects API functions for plugins / filters if on Windows. Note that nbdkit_peer_name is explicitly disabled due to potential ABI incompatibilities. --- server/main.c | 73 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+) diff --git a/server/main.c b/server/main.c index b303146c..373918cf 100644 --- a/server/main.c +++ b/server/main.c @@ -104,6 +104,7 @@ unsigned int socket_activation /* $LISTEN_FDS and $LISTEN_PID set */; /* The linked list of zero or more filters, and one plugin. */ struct backend *top; +struct nbdkit_functions *functions = NULL; static char *random_fifo_dir = NULL; static char *random_fifo = NULL; @@ -152,6 +153,49 @@ dump_config (void) printf ("%s=%d\n", "version_minor", NBDKIT_VERSION_MINOR); } +#ifdef WINDOWS_COMPAT +static int dummy_peer_name (void *addr, void *addrlen) +{ + nbdkit_error ("nbdkit_peer_name not implemented on this platform"); + return -1; +} + +static void init_functions () +{ + functions = malloc (sizeof *functions); + if (functions == NULL) { + perror ("malloc"); + exit (EXIT_FAILURE); + } + functions->verror = nbdkit_verror; + functions->vdebug = nbdkit_vdebug; + functions->absolute_path = nbdkit_absolute_path; + functions->parse_size = nbdkit_parse_size; + functions->parse_bool = nbdkit_parse_bool; + functions->parse_int = nbdkit_parse_int; + functions->parse_unsigned = nbdkit_parse_unsigned; + functions->parse_int8_t = nbdkit_parse_int8_t; + functions->parse_uint8_t = nbdkit_parse_uint8_t; + functions->parse_int16_t = nbdkit_parse_int16_t; + functions->parse_uint16_t = nbdkit_parse_uint16_t; + functions->parse_int32_t = nbdkit_parse_int32_t; + functions->parse_uint32_t = nbdkit_parse_uint32_t; + functions->parse_int64_t = nbdkit_parse_int64_t; + functions->parse_uint64_t = nbdkit_parse_uint64_t; + functions->read_password = nbdkit_read_password; + functions->realpath = nbdkit_realpath; + functions->nanosleep = nbdkit_nanosleep; + functions->export_name = nbdkit_export_name; + functions->peer_name = dummy_peer_name; + functions->shutdown = nbdkit_shutdown; + functions->add_extent = nbdkit_add_extent; + functions->extents_new = nbdkit_extents_new; + functions->extents_free = nbdkit_extents_free; + functions->extents_count = nbdkit_extents_count; + functions->get_extent = nbdkit_get_extent; +} +#endif + int main (int argc, char *argv[]) { @@ -178,6 +222,9 @@ main (int argc, char *argv[]) perror ("expecting stdin/stdout to be opened"); exit (EXIT_FAILURE); } +#ifdef WINDOWS_COMPAT + init_functions (); +#endif #if !ENABLE_LIBFUZZER threadlocal_init (); @@ -772,6 +819,7 @@ open_plugin_so (size_t i, const char *name, int short_name) bool free_filename = false; void *dl; struct nbdkit_plugin *(*plugin_init) (void); + void *(*functions_init) (struct nbdkit_functions *); char *error; if (short_name) { @@ -797,6 +845,18 @@ open_plugin_so (size_t i, const char *name, int short_name) /* Initialize the plugin. See dlopen(3) to understand C weirdness. */ dlerror (); +#ifdef WINDOWS_COMPAT + *(void **) (&functions_init) = dlsym (dl, "functions_init"); + if ((error = dlerror ()) != NULL) { + fprintf (stderr, "%s: %s: %s\n", program_name, name, error); + exit (EXIT_FAILURE); + } + if (!functions_init) { + fprintf (stderr, "%s: %s: invalid functions_init\n", program_name, name); + exit (EXIT_FAILURE); + } + functions_init (functions); +#endif *(void **) (&plugin_init) = dlsym (dl, "plugin_init"); if ((error = dlerror ()) != NULL) { fprintf (stderr, "%s: %s: %s\n", program_name, name, error); @@ -825,6 +885,7 @@ open_filter_so (struct backend *next, size_t i, bool free_filename = false; void *dl; struct nbdkit_filter *(*filter_init) (void); + void *(*functions_init) (struct nbdkit_functions *); char *error; if (short_name) { @@ -846,6 +907,18 @@ open_filter_so (struct backend *next, size_t i, /* Initialize the filter. See dlopen(3) to understand C weirdness. */ dlerror (); +#ifdef WINDOWS_COMPAT + *(void **) (&functions_init) = dlsym (dl, "functions_init"); + if ((error = dlerror ()) != NULL) { + fprintf (stderr, "%s: %s: %s\n", program_name, name, error); + exit (EXIT_FAILURE); + } + if (!functions_init) { + fprintf (stderr, "%s: %s: invalid functions_init\n", program_name, name); + exit (EXIT_FAILURE); + } + functions_init (functions); +#endif *(void **) (&filter_init) = dlsym (dl, "filter_init"); if ((error = dlerror ()) != NULL) { fprintf (stderr, "%s: %s: %s\n", program_name, name, error); -- 2.25.0

From: Yifan Gu <gyf304(a)gmail.com&gt; The create_nbdkit_module function is intended to be exported, therefore the static keyword is not needed and prevents building on MSYS2. --- plugins/python/python.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/plugins/python/python.c b/plugins/python/python.c index a1a0438b..adc1aaa5 100644 --- a/plugins/python/python.c +++ b/plugins/python/python.c @@ -224,7 +224,7 @@ static struct PyModuleDef moduledef = { NULL }; -static PyMODINIT_FUNC +PyMODINIT_FUNC create_nbdkit_module (void) { PyObject *m; -- 2.25.0

The error is the following libtool: link: (cd .libs/nbdkit-perl-plugin.lax/libutils.a && ar x "/c/Users/yifangu/Documents/devel/nbdkit/plugins/perl/../../common/utils/.libs/libutils.a") libtool: link: ar cru .libs/nbdkit-perl-plugin.a .libs/nbdkit_perl_plugin_la-perl.o .libs/nbdkit-perl-plugin.lax/libutils.a/libutils_la-cleanup-nbdkit.o .libs/nbdkit-perl-plugin.lax/libutils.a/libutils_la-cleanup.o .libs/nbdkit-perl-plugin.lax/libutils.a/libutils_la-quote.o .libs/nbdkit-perl-plugin.lax/libutils.a/libutils_la-utils.o libtool: link: ranlib .libs/nbdkit-perl-plugin.a libtool: link: rm -fr .libs/nbdkit-perl-plugin.lax libtool: link: ( cd ".libs" && rm -f "nbdkit-perl-plugin.la" && cp -pR "../ nbdkit-perl-plugin.la" "nbdkit-perl-plugin.la" ) make[3]: Leaving directory '/c/Users/yifangu/Documents/devel/nbdkit/plugins/perl' Making all in python make[3]: Entering directory '/c/Users/yifangu/Documents/devel/nbdkit/plugins/python' /bin/sh ../../libtool --tag=CC --mode=compile gcc -DHAVE_CONFIG_H -I. -I../.. -I../../include -I../../common/utils -I/usr/include/python3.7m -g -O2 -MT nbdkit_python_plugin_la-python.lo -MD -MP -MF .deps/nbdkit_python_plugin_la-python.Tpo -c -o nbdkit_python_plugin_la-python.lo `test -f 'python.c' || echo './'`python.c libtool: compile: gcc -DHAVE_CONFIG_H -I. -I../.. -I../../include -I../../common/utils -I/usr/include/python3.7m -g -O2 -MT nbdkit_python_plugin_la-python.lo -MD -MP -MF .deps/nbdkit_python_plugin_la-python.Tpo -c python.c -DDLL_EXPORT -DPIC -o .libs/nbdkit_python_plugin_la-python.o python.c:228:1: error: external linkage required for symbol ‘create_nbdkit_module’ because of ‘dllexport’ attribute 228 | create_nbdkit_module (void) | ^~~~~~~~~~~~~~~~~~~~ make[3]: *** [Makefile:638: nbdkit_python_plugin_la-python.lo] Error 1 make[3]: Leaving directory '/c/Users/yifangu/Documents/devel/nbdkit/plugins/python' make[2]: *** [Makefile:505: all-recursive] Error 1 make[2]: Leaving directory '/c/Users/yifangu/Documents/devel/nbdkit/plugins' make[1]: *** [Makefile:696: all-recursive] Error 1 make[1]: Leaving directory '/c/Users/yifangu/Documents/devel/nbdkit' make: *** [Makefile:562: all] Error 2 On Mon, Mar 23, 2020 at 8:49 AM Richard W.M. Jones <rjones(a)redhat.com&gt; wrote: