diff options
| -rw-r--r-- | Makefile | 1 | ||||
| -rw-r--r-- | compat/mingw.c | 36 | ||||
| -rw-r--r-- | t/helper/test-tool.c | 3 | ||||
| -rw-r--r-- | t/helper/test-tool.h | 3 | ||||
| -rw-r--r-- | t/helper/test-windows-named-pipe.c | 72 | ||||
| -rwxr-xr-x | t/t0051-windows-named-pipe.sh | 17 |
6 files changed, 129 insertions, 3 deletions
@@ -740,6 +740,7 @@ TEST_BUILTINS_OBJS += test-submodule-config.o TEST_BUILTINS_OBJS += test-subprocess.o TEST_BUILTINS_OBJS += test-urlmatch-normalization.o TEST_BUILTINS_OBJS += test-wildmatch.o +TEST_BUILTINS_OBJS += test-windows-named-pipe.o TEST_BUILTINS_OBJS += test-write-cache.o TEST_PROGRAMS_NEED_X += test-dump-fsmonitor diff --git a/compat/mingw.c b/compat/mingw.c index 858ca14..18caf21 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -341,6 +341,19 @@ int mingw_mkdir(const char *path, int mode) return ret; } +/* + * Calling CreateFile() using FILE_APPEND_DATA and without FILE_WRITE_DATA + * is documented in [1] as opening a writable file handle in append mode. + * (It is believed that) this is atomic since it is maintained by the + * kernel unlike the O_APPEND flag which is racily maintained by the CRT. + * + * [1] https://docs.microsoft.com/en-us/windows/desktop/fileio/file-access-rights-constants + * + * This trick does not appear to work for named pipes. Instead it creates + * a named pipe client handle that cannot be written to. Callers should + * just use the regular _wopen() for them. (And since client handle gets + * bound to a unique server handle, it isn't really an issue.) + */ static int mingw_open_append(wchar_t const *wfilename, int oflags, ...) { HANDLE handle; @@ -360,10 +373,12 @@ static int mingw_open_append(wchar_t const *wfilename, int oflags, ...) NULL, create, FILE_ATTRIBUTE_NORMAL, NULL); if (handle == INVALID_HANDLE_VALUE) return errno = err_win_to_posix(GetLastError()), -1; + /* * No O_APPEND here, because the CRT uses it only to reset the - * file pointer to EOF on write(); but that is not necessary - * for a file created with FILE_APPEND_DATA. + * file pointer to EOF before each write(); but that is not + * necessary (and may lead to races) for a file created with + * FILE_APPEND_DATA. */ fd = _open_osfhandle((intptr_t)handle, O_BINARY); if (fd < 0) @@ -371,6 +386,21 @@ static int mingw_open_append(wchar_t const *wfilename, int oflags, ...) return fd; } +/* + * Does the pathname map to the local named pipe filesystem? + * That is, does it have a "//./pipe/" prefix? + */ +static int is_local_named_pipe_path(const char *filename) +{ + return (is_dir_sep(filename[0]) && + is_dir_sep(filename[1]) && + filename[2] == '.' && + is_dir_sep(filename[3]) && + !strncasecmp(filename+4, "pipe", 4) && + is_dir_sep(filename[8]) && + filename[9]); +} + int mingw_open (const char *filename, int oflags, ...) { typedef int (*open_fn_t)(wchar_t const *wfilename, int oflags, ...); @@ -387,7 +417,7 @@ int mingw_open (const char *filename, int oflags, ...) if (filename && !strcmp(filename, "/dev/null")) filename = "nul"; - if (oflags & O_APPEND) + if ((oflags & O_APPEND) && !is_local_named_pipe_path(filename)) open_fn = mingw_open_append; else open_fn = _wopen; diff --git a/t/helper/test-tool.c b/t/helper/test-tool.c index bef50c4..b87a8c1 100644 --- a/t/helper/test-tool.c +++ b/t/helper/test-tool.c @@ -45,6 +45,9 @@ static struct test_cmd cmds[] = { { "subprocess", cmd__subprocess }, { "urlmatch-normalization", cmd__urlmatch_normalization }, { "wildmatch", cmd__wildmatch }, +#ifdef GIT_WINDOWS_NATIVE + { "windows-named-pipe", cmd__windows_named_pipe }, +#endif { "write-cache", cmd__write_cache }, }; diff --git a/t/helper/test-tool.h b/t/helper/test-tool.h index 321982e..e074957 100644 --- a/t/helper/test-tool.h +++ b/t/helper/test-tool.h @@ -41,6 +41,9 @@ int cmd__submodule_config(int argc, const char **argv); int cmd__subprocess(int argc, const char **argv); int cmd__urlmatch_normalization(int argc, const char **argv); int cmd__wildmatch(int argc, const char **argv); +#ifdef GIT_WINDOWS_NATIVE +int cmd__windows_named_pipe(int argc, const char **argv); +#endif int cmd__write_cache(int argc, const char **argv); #endif diff --git a/t/helper/test-windows-named-pipe.c b/t/helper/test-windows-named-pipe.c new file mode 100644 index 0000000..b4b752b --- /dev/null +++ b/t/helper/test-windows-named-pipe.c @@ -0,0 +1,72 @@ +#include "test-tool.h" +#include "git-compat-util.h" +#include "strbuf.h" + +#ifdef GIT_WINDOWS_NATIVE +static const char *usage_string = "<pipe-filename>"; + +#define TEST_BUFSIZE (4096) + +int cmd__windows_named_pipe(int argc, const char **argv) +{ + const char *filename; + struct strbuf pathname = STRBUF_INIT; + int err; + HANDLE h; + BOOL connected; + char buf[TEST_BUFSIZE + 1]; + + if (argc < 2) + goto print_usage; + filename = argv[1]; + if (strchr(filename, '/') || strchr(filename, '\\')) + goto print_usage; + strbuf_addf(&pathname, "//./pipe/%s", filename); + + /* + * Create a single instance of the server side of the named pipe. + * This will allow exactly one client instance to connect to it. + */ + h = CreateNamedPipeA( + pathname.buf, + PIPE_ACCESS_INBOUND | FILE_FLAG_FIRST_PIPE_INSTANCE, + PIPE_TYPE_MESSAGE | PIPE_READMODE_MESSAGE | PIPE_WAIT, + PIPE_UNLIMITED_INSTANCES, + TEST_BUFSIZE, TEST_BUFSIZE, 0, NULL); + if (h == INVALID_HANDLE_VALUE) { + err = err_win_to_posix(GetLastError()); + fprintf(stderr, "CreateNamedPipe failed: %s\n", + strerror(err)); + return err; + } + + connected = ConnectNamedPipe(h, NULL) + ? TRUE + : (GetLastError() == ERROR_PIPE_CONNECTED); + if (!connected) { + err = err_win_to_posix(GetLastError()); + fprintf(stderr, "ConnectNamedPipe failed: %s\n", + strerror(err)); + CloseHandle(h); + return err; + } + + while (1) { + DWORD nbr; + BOOL success = ReadFile(h, buf, TEST_BUFSIZE, &nbr, NULL); + if (!success || nbr == 0) + break; + buf[nbr] = 0; + + write(1, buf, nbr); + } + + DisconnectNamedPipe(h); + CloseHandle(h); + return 0; + +print_usage: + fprintf(stderr, "usage: %s %s\n", argv[0], usage_string); + return 1; +} +#endif diff --git a/t/t0051-windows-named-pipe.sh b/t/t0051-windows-named-pipe.sh new file mode 100755 index 0000000..10ac92d --- /dev/null +++ b/t/t0051-windows-named-pipe.sh @@ -0,0 +1,17 @@ +#!/bin/sh + +test_description='Windows named pipes' + +. ./test-lib.sh + +test_expect_success MINGW 'o_append write to named pipe' ' + GIT_TRACE="$(pwd)/expect" git status >/dev/null 2>&1 && + { test-tool windows-named-pipe t0051 >actual 2>&1 & } && + pid=$! && + sleep 1 && + GIT_TRACE=//./pipe/t0051 git status >/dev/null 2>warning && + wait $pid && + test_cmp expect actual +' + +test_done |