Using file_check for the pipe protocol doesn't make sense. For example, for a URL like “pipe:0” it would end up checking whether the “pipe:0” file exists. This patch instead makes it check the access modes on the corresponding file descriptor using fcntl on *nix and DuplicateHandle on Windows.
v2: Use DuplicateHandle on Windows to check whether the duplicated handle can have the corresponding access flags. Signed-off-by: Neil Roberts <bpee...@yahoo.co.uk> --- libavformat/file.c | 74 ++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 71 insertions(+), 3 deletions(-) diff --git a/libavformat/file.c b/libavformat/file.c index 98c9e81bcb..b3f7bc9282 100644 --- a/libavformat/file.c +++ b/libavformat/file.c @@ -375,9 +375,8 @@ const URLProtocol ff_file_protocol = { #if CONFIG_PIPE_PROTOCOL -static int pipe_open(URLContext *h, const char *filename, int flags) +static int pipe_get_fd(const char *filename, int flags) { - FileContext *c = h->priv_data; int fd; char *final; av_strstart(filename, "pipe:", &filename); @@ -390,6 +389,14 @@ static int pipe_open(URLContext *h, const char *filename, int flags) fd = 0; } } + + return fd; +} + +static int pipe_open(URLContext *h, const char *filename, int flags) +{ + FileContext *c = h->priv_data; + int fd = pipe_get_fd(filename, flags); #if HAVE_SETMODE setmode(fd, O_BINARY); #endif @@ -398,13 +405,74 @@ static int pipe_open(URLContext *h, const char *filename, int flags) return 0; } +static int pipe_check(URLContext *h, int mask) +{ + int fd = pipe_get_fd(h->filename, mask); + int access = 0; + +#ifdef _WIN32 + + HANDLE pipe_handle = (HANDLE) _get_osfhandle(fd); + HANDLE tmp_handle; + + if (pipe_handle == INVALID_HANDLE_VALUE) + return AVERROR(errno); + + if (mask & AVIO_FLAG_READ && + DuplicateHandle(GetCurrentProcess(), /* hSourceProcessHandle */ + pipe_handle, + GetCurrentProcess(), /* hTargetProcessHandle */ + &tmp_handle, + FILE_READ_DATA, + FALSE, /* bInheritHandle */ + 0 /* options */)) { + access |= AVIO_FLAG_READ; + CloseHandle(tmp_handle); + } + + if (mask & AVIO_FLAG_WRITE && + DuplicateHandle(GetCurrentProcess(), /* hSourceProcessHandle */ + pipe_handle, + GetCurrentProcess(), /* hTargetProcessHandle */ + &tmp_handle, + FILE_WRITE_DATA, + FALSE, /* bInheritHandle */ + 0 /* options */)) { + access |= AVIO_FLAG_WRITE; + CloseHandle(tmp_handle); + } + +#else /* _WIN32 */ + + int status_flags = fcntl(fd, F_GETFL); + + if (status_flags == -1) + return AVERROR(errno); + + switch (status_flags & O_ACCMODE) { + case O_RDONLY: + access = AVIO_FLAG_READ; + break; + case O_WRONLY: + access = AVIO_FLAG_WRITE; + break; + case O_RDWR: + access = AVIO_FLAG_READ | AVIO_FLAG_WRITE; + break; + } + +#endif /* _WIN32 */ + + return access & mask; +} + const URLProtocol ff_pipe_protocol = { .name = "pipe", .url_open = pipe_open, .url_read = file_read, .url_write = file_write, .url_get_file_handle = file_get_handle, - .url_check = file_check, + .url_check = pipe_check, .priv_data_size = sizeof(FileContext), .priv_data_class = &pipe_class, .default_whitelist = "crypto,data" -- 2.37.2 _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".