This allows globally limiting the allowed entities for security purposes
by the application
Signed-off-by: Michael Niedermayer <michae...@gmx.at>
---
libavcodec/allcodecs.c | 49 ++++++++++++++++++++++++++++++++++--------------
libavcodec/avcodec.h | 20 ++++++++++++++++++++
2 files changed, 55 insertions(+), 14 deletions(-)
diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index 7650543..9fea0b9 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -27,51 +27,65 @@
#include "config.h"
#include "avcodec.h"
#include "version.h"
+#include "libavutil/avstring.h"
#define REGISTER_HWACCEL(X, x) \
- { \
+ if (!list || av_match_list(AV_STRINGIFY(x##_hwaccel), list, ',')) { \
extern AVHWAccel ff_##x##_hwaccel; \
- if (CONFIG_##X##_HWACCEL) \
+ if (CONFIG_##X##_HWACCEL) { \
av_register_hwaccel(&ff_##x##_hwaccel); \
+ found++; \
+ } \
}
#define REGISTER_ENCODER(X, x) \
- { \
+ if (!list || av_match_list(AV_STRINGIFY(x##_encoder), list, ',')) { \
extern AVCodec ff_##x##_encoder; \
- if (CONFIG_##X##_ENCODER) \
+ if (CONFIG_##X##_ENCODER) { \
avcodec_register(&ff_##x##_encoder); \
+ found++; \
+ } \
}
#define REGISTER_DECODER(X, x) \
- { \
+ if (!list || av_match_list(AV_STRINGIFY(x##_decoder), list, ',')) { \
extern AVCodec ff_##x##_decoder; \
- if (CONFIG_##X##_DECODER) \
+ if (CONFIG_##X##_DECODER) { \
avcodec_register(&ff_##x##_decoder); \
+ found++; \
+ } \
}
#define REGISTER_ENCDEC(X, x) REGISTER_ENCODER(X, x); REGISTER_DECODER(X, x)
#define REGISTER_PARSER(X, x) \
- { \
+ if (!list || av_match_list(AV_STRINGIFY(x##_parser), list, ',')) { \
extern AVCodecParser ff_##x##_parser; \
- if (CONFIG_##X##_PARSER) \
+ if (CONFIG_##X##_PARSER) { \
av_register_codec_parser(&ff_##x##_parser); \
+ found++; \
+ } \
}
#define REGISTER_BSF(X, x) \
- { \
+ if (!list || av_match_list(AV_STRINGIFY(x##_bsf), list, ',')) { \
extern AVBitStreamFilter ff_##x##_bsf; \
- if (CONFIG_##X##_BSF) \
+ if (CONFIG_##X##_BSF) { \
av_register_bitstream_filter(&ff_##x##_bsf); \
+ found++; \
+ } \
}
-void avcodec_register_all(void)
+int avcodec_register_list(const char *list)
{
- static int initialized;
+ static const char *initialized;
+ const char *nonnull_list = list ? list : "all";
+ int found = 0;
if (initialized)
- return;
- initialized = 1;
+ return strcmp(nonnull_list, initialized) ? -1 : 0;
+
+ initialized = nonnull_list;
/* hardware accelerators */
REGISTER_HWACCEL(H263_VAAPI, h263_vaapi);
@@ -588,4 +602,11 @@ void avcodec_register_all(void)
REGISTER_BSF(NOISE, noise);
REGISTER_BSF(REMOVE_EXTRADATA, remove_extradata);
REGISTER_BSF(TEXT2MOVSUB, text2movsub);
+
+ return found;
+}
+
+void avcodec_register_all(void)
+{
+ avcodec_register_list(NULL);
}
diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index 94e82f7..b804460 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -3472,6 +3472,26 @@ void avcodec_register(AVCodec *codec);
void avcodec_register_all(void);
/**
+ * Registers only the specified list of ',' seperated entities
+ *
+ * @param list ',' seperated list of entities to register, the list used must
+ * have a sufficient lifetime so future calls to avcodec_register_list()
+ * can access it for comparission.
+ *
+ * @note What is registered with the first call to avcodec_register_list() is
+ * permanent, future calls to avcodec_register_list() and
+ * avcodec_register_all() cannot override it until application exit.
+ * @note This function is intended to be used for restricting the allowed
+ * decoders and other entities for security purposes in end user
+ * applications, it is not intended to be called by libraries.
+ *
+ * @returns the number of newly registered entities, or 0 if the exact same
list
+ * has been registered previously or negative value if a differnet
list
+ * is already registered.
+ */
+int avcodec_register_list(const char *list);
+
+/**
* Allocate an AVCodecContext and set its fields to default values. The
* resulting struct should be freed with avcodec_free_context().
*
--
1.7.9.5
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