diff options
Diffstat (limited to 'compat/mingw.c')
| -rw-r--r-- | compat/mingw.c | 131 |
1 files changed, 122 insertions, 9 deletions
diff --git a/compat/mingw.c b/compat/mingw.c index 6ded1c859f..44264fe3fd 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -5,6 +5,7 @@ #include "../strbuf.h" #include "../run-command.h" #include "../cache.h" +#include "win32/lazyload.h" #define HCAST(type, handle) ((type)(intptr_t)handle) @@ -341,12 +342,74 @@ 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; + int fd; + DWORD create = (oflags & O_CREAT) ? OPEN_ALWAYS : OPEN_EXISTING; + + /* only these flags are supported */ + if ((oflags & ~O_CREAT) != (O_WRONLY | O_APPEND)) + return errno = ENOSYS, -1; + + /* + * FILE_SHARE_WRITE is required to permit child processes + * to append to the file. + */ + handle = CreateFileW(wfilename, FILE_APPEND_DATA, + FILE_SHARE_WRITE | FILE_SHARE_READ, + 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 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) + CloseHandle(handle); + 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, ...); va_list args; unsigned mode; int fd; wchar_t wfilename[MAX_PATH]; + open_fn_t open_fn; va_start(args, oflags); mode = va_arg(args, int); @@ -355,9 +418,14 @@ int mingw_open (const char *filename, int oflags, ...) if (filename && !strcmp(filename, "/dev/null")) filename = "nul"; + if ((oflags & O_APPEND) && !is_local_named_pipe_path(filename)) + open_fn = mingw_open_append; + else + open_fn = _wopen; + if (xutftowcs_path(wfilename, filename) < 0) return -1; - fd = _wopen(wfilename, oflags, mode); + fd = open_fn(wfilename, oflags, mode); if (fd < 0 && (oflags & O_ACCMODE) != O_RDONLY && errno == EACCES) { DWORD attrs = GetFileAttributesW(wfilename); @@ -375,7 +443,7 @@ int mingw_open (const char *filename, int oflags, ...) * CREATE_ALWAYS flag of CreateFile()). */ if (fd < 0 && errno == EACCES) - fd = _wopen(wfilename, oflags & ~O_CREAT, mode); + fd = open_fn(wfilename, oflags & ~O_CREAT, mode); if (fd >= 0 && set_hidden_flag(wfilename, 1)) warning("could not mark '%s' as hidden.", filename); } @@ -1731,18 +1799,63 @@ int mingw_getpagesize(void) return si.dwAllocationGranularity; } +/* See https://msdn.microsoft.com/en-us/library/windows/desktop/ms724435.aspx */ +enum EXTENDED_NAME_FORMAT { + NameDisplay = 3, + NameUserPrincipal = 8 +}; + +static char *get_extended_user_info(enum EXTENDED_NAME_FORMAT type) +{ + DECLARE_PROC_ADDR(secur32.dll, BOOL, GetUserNameExW, + enum EXTENDED_NAME_FORMAT, LPCWSTR, PULONG); + static wchar_t wbuffer[1024]; + DWORD len; + + if (!INIT_PROC_ADDR(GetUserNameExW)) + return NULL; + + len = ARRAY_SIZE(wbuffer); + if (GetUserNameExW(type, wbuffer, &len)) { + char *converted = xmalloc((len *= 3)); + if (xwcstoutf(converted, wbuffer, len) >= 0) + return converted; + free(converted); + } + + return NULL; +} + +char *mingw_query_user_email(void) +{ + return get_extended_user_info(NameUserPrincipal); +} + struct passwd *getpwuid(int uid) { + static unsigned initialized; static char user_name[100]; - static struct passwd p; + static struct passwd *p; + DWORD len; - DWORD len = sizeof(user_name); - if (!GetUserName(user_name, &len)) + if (initialized) + return p; + + len = sizeof(user_name); + if (!GetUserName(user_name, &len)) { + initialized = 1; return NULL; - p.pw_name = user_name; - p.pw_gecos = "unknown"; - p.pw_dir = NULL; - return &p; + } + + p = xmalloc(sizeof(*p)); + p->pw_name = user_name; + p->pw_gecos = get_extended_user_info(NameDisplay); + if (!p->pw_gecos) + p->pw_gecos = "unknown"; + p->pw_dir = NULL; + + initialized = 1; + return p; } static HANDLE timer_event; |