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gpgrt-1.53
src/sysutils.c
637 строк
15 KB
Werner Koch
w32: Improve the detection of the need for a \\?\ prefix
04 апр 2025, 16:32
Не верифицирован
04 апр 2025, 16:32
a4a692f
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/* sysutils.c - Platform specific helper functions * Copyright (C) 2017 g10 Code GmbH * * This file is part of libgpg-error. * * libgpg-error is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public License * as published by the Free Software Foundation; either version 2.1 of * the License, or (at your option) any later version. * * libgpg-error is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this program; if not, see <https://www.gnu.org/licenses/>. * SPDX-License-Identifier: LGPL-2.1+ */ #include <config.h> #include <stdlib.h> #include <stdint.h> #include <string.h> #include <unistd.h> #include <errno.h> #ifdef HAVE_W32_SYSTEM # include <windows.h> #endif #ifdef HAVE_STAT # include <sys/stat.h> #endif #include <sys/types.h> #include <fcntl.h> #ifdef HAVE_PWD_H # include <pwd.h> #endif #include "gpgrt-int.h" /* Return true if FD is valid. */ int _gpgrt_fd_valid_p (int fd) { int d = dup (fd); if (d < 0) return 0; close (d); return 1; } /* Our variant of getenv. The returned string must be freed. If the * environment variable does not exists NULL is returned and ERRNO set * to 0. */ char * _gpgrt_getenv (const char *name) { if (!name || !*name || strchr (name, '=')) { _gpg_err_set_errno (EINVAL); return NULL; } #ifdef HAVE_W32_SYSTEM { int len, size; char *result; len = GetEnvironmentVariable (name, NULL, 0); if (!len && GetLastError () == ERROR_ENVVAR_NOT_FOUND) { _gpg_err_set_errno (0); return NULL; } again: size = len; result = _gpgrt_malloc (size); if (!result) return NULL; len = GetEnvironmentVariable (name, result, size); if (len >= size) { /* Changed in the meantime - retry. */ _gpgrt_free (result); goto again; } if (!len && GetLastError () == ERROR_ENVVAR_NOT_FOUND) { /* Deleted in the meantime. */ _gpgrt_free (result); _gpg_err_set_errno (0); return NULL; } if (!len) { /* Other error. FIXME: We need mapping fucntion. */ _gpgrt_free (result); _gpg_err_set_errno (EIO); return NULL; } return result; } #else /*!HAVE_W32_SYSTEM*/ { const char *s = getenv (name); if (!s) { _gpg_err_set_errno (0); return NULL; } return _gpgrt_strdup (s); } #endif /*!HAVE_W32_SYSTEM*/ } /* Wrapper around setenv so that we can have the same function in * Windows and Unix. In contrast to the standard setenv passing a * VALUE as NULL and setting OVERWRITE will remove the envvar. */ gpg_err_code_t _gpgrt_setenv (const char *name, const char *value, int overwrite) { if (!name || !*name || strchr (name, '=')) return GPG_ERR_EINVAL; #ifdef HAVE_W32_SYSTEM /* Windows maintains (at least) two sets of environment variables. * One set can be accessed by GetEnvironmentVariable and * SetEnvironmentVariable. This set is inherited by the children. * The other set is maintained in the C runtime, and is accessed * using getenv and putenv. We try to keep them in sync by * modifying both sets. Note that gpgrt_getenv ignores the libc * values - however, too much existing code still uses getenv. */ { int exists; char tmpbuf[10]; if (!value && overwrite) { if (!SetEnvironmentVariable (name, NULL)) return GPG_ERR_EINVAL; if (getenv (name)) #if defined(_CRT_SECURE_CPP_OVERLOAD_STANDARD_NAMES) { int e = _putenv_s (name, ""); if (e) { _gpg_err_set_errno (e); return -1; } } #else /* Deleting an envvar. Although the Microsoft specs for * putenv tell us that one may use "NAME=" to unset an envvar, * this seems not to be correct. Thus we do the same as what * we do in Unix (or well in GNU libc) and use just "NAME". */ { char *buf; /* Ugly: Leaking memory. */ buf = _gpgrt_strdup (name); if (!buf) return _gpg_err_code_from_syserror (); if (putenv (buf)) return _gpg_err_code_from_syserror (); } #endif return 0; } exists = GetEnvironmentVariable (name, tmpbuf, sizeof tmpbuf); if ((! exists || overwrite) && !SetEnvironmentVariable (name, value)) return GPG_ERR_EINVAL; /* (Might also be ENOMEM.) */ if (overwrite || !getenv (name)) #if defined(_CRT_SECURE_CPP_OVERLOAD_STANDARD_NAMES) { int e = _putenv_s (name, value); if (e) { _gpg_err_set_errno (e); return -1; } } #else { /* Ugly: Leaking memory. */ buf = _gpgrt_strconcat (name, "=", value, NULL); if (!buf) return _gpg_err_code_from_syserror (); if (putenv (buf)) return _gpg_err_code_from_syserror (); } #endif return 0; } #else /*!HAVE_W32_SYSTEM*/ # ifdef HAVE_SETENV { if (!value && overwrite) { if (unsetenv (name)) return _gpg_err_code_from_syserror (); } else { if (setenv (name, value ? value : "", overwrite)) return _gpg_err_code_from_syserror (); } return 0; } # else /*!HAVE_SETENV*/ # if __GNUC__ # warning no setenv - using putenv but leaking memory. # endif { char *buf; if (!value && overwrite) { if (getenv (name)) { buf = _gpgrt_strdup (name); if (!buf) return _gpg_err_code_from_syserror (); if (putenv (buf)) return -1; } } else if (overwrite || !getenv (name)) { buf = _gpgrt_strconcat (name, "=", value, NULL); if (!buf) return _gpg_err_code_from_syserror (); if (putenv (buf)) return _gpg_err_code_from_syserror (); } return 0; } # endif /*!HAVE_SETENV*/ #endif /*!HAVE_W32_SYSTEM*/ } #ifdef HAVE_W32_SYSTEM /* Convert an UTF-8 encode file name to wchar. If the file name is * close to the limit of MAXPATH the API functions will fail. The * method to overcome this API limitation is to use a prefix which * bypasses the checking by CreateFile. This also requires to first * convert the name to an absolute file name. To avoid looking up the * fill name in all cases we do the \\?\ prefixing only if FNAME is * longer than 60 byes or if it has any path separator. */ wchar_t * _gpgrt_fname_to_wchar (const char *fname) { wchar_t *wname; wchar_t *wfullpath = NULL; int success = 0; wname = _gpgrt_utf8_to_wchar (fname); if (!wname) return NULL; if (!strncmp (fname, "\\\\?\\", 4)) success = 1; /* Already translated. */ else if (strpbrk (fname, "/\\") || wcslen (wname) > 60) { int wlen = 1024; int extralen; DWORD res; wchar_t *w; try_again: wfullpath = xtrymalloc (wlen * sizeof *wfullpath); if (!wfullpath) goto leave; if (*fname == '\\' && fname[1] == '\\' && fname[2]) { wcscpy (wfullpath, L"\\\\?\\UNC\\"); extralen = 8; } else { wcscpy (wfullpath, L"\\\\?\\"); extralen = 4; } res = GetFullPathNameW (wname, wlen-extralen, wfullpath+extralen, NULL); if (!res) { _gpgrt_w32_set_errno (-1); goto leave; } else if (res >= wlen - extralen) { /* Truncated - increase to the desired length. */ if (wlen > 1024) { /* We should never get to here. */ errno = ENAMETOOLONG; goto leave; } /* GetFullPathNameW indicated the required buffer length. */ _gpgrt_free_wchar (wfullpath); wfullpath = NULL; wlen = res + extralen; goto try_again; } _gpgrt_free_wchar (wname); wname = wfullpath; wfullpath = NULL; /* Need to make sure that all slashes are mapped. */ for (w = wname; *w; w++) if (*w == L'/') *w = L'\\'; success = 1; } else success = 1; leave: _gpgrt_free_wchar (wfullpath); if (!success) { _gpgrt_free_wchar (wname); wname = NULL; } return wname; } #endif /*HAVE_W32_SYSTEM*/ #ifndef HAVE_W32_SYSTEM static mode_t modestr_to_mode (const char *modestr) { mode_t mode = 0; if (modestr && *modestr) { modestr++; if (*modestr && *modestr++ == 'r') mode |= S_IRUSR; if (*modestr && *modestr++ == 'w') mode |= S_IWUSR; if (*modestr && *modestr++ == 'x') mode |= S_IXUSR; if (*modestr && *modestr++ == 'r') mode |= S_IRGRP; if (*modestr && *modestr++ == 'w') mode |= S_IWGRP; if (*modestr && *modestr++ == 'x') mode |= S_IXGRP; if (*modestr && *modestr++ == 'r') mode |= S_IROTH; if (*modestr && *modestr++ == 'w') mode |= S_IWOTH; if (*modestr && *modestr++ == 'x') mode |= S_IXOTH; } return mode; } #endif /* A wrapper around mkdir which takes a string for the mode argument. * This makes it easier to handle the mode argument which is not * defined on all systems. The format of the modestring is * * "-rwxrwxrwx" * * '-' is a don't care or not set. 'r', 'w', 'x' are read allowed, * write allowed, execution allowed with the first group for the user, * the second for the group and the third for all others. If the * string is shorter than above the missing mode characters are meant * to be not set. * * Note that in addition to returning an gpg-error error code ERRNO is * also set by this function. */ gpg_err_code_t _gpgrt_mkdir (const char *name, const char *modestr) { #ifdef HAVE_W32_SYSTEM wchar_t *wname; gpg_err_code_t ec; (void)modestr; /* Note: Fixme: We should set appropriate permissions. */ wname = _gpgrt_fname_to_wchar (name); if (!wname) return _gpg_err_code_from_syserror (); if (!CreateDirectoryW (wname, NULL)) { _gpgrt_w32_set_errno (-1); ec = _gpg_err_code_from_syserror (); } else ec = 0; _gpgrt_free_wchar (wname); return ec; #elif MKDIR_TAKES_ONE_ARG (void)modestr; if (mkdir (name)) return _gpg_err_code_from_syserror (); return 0; #else if (mkdir (name, modestr_to_mode (modestr))) return _gpg_err_code_from_syserror (); return 0; #endif } /* A simple wrapper around chdir. NAME is expected to be utf8 * encoded. Note that in addition to returning an gpg-error error * code ERRNO is also set by this function. */ gpg_err_code_t _gpgrt_chdir (const char *name) { #ifdef HAVE_W32_SYSTEM wchar_t *wname; gpg_err_code_t ec; /* Note that the \\?\ trick does not work with SetCurrentDirectoryW * Thus we use the plain conversion function. */ wname = _gpgrt_utf8_to_wchar (name); if (!wname) return _gpg_err_code_from_syserror (); if (!SetCurrentDirectoryW (wname)) { _gpgrt_w32_set_errno (-1); ec = _gpg_err_code_from_syserror (); } else ec = 0; _gpgrt_free_wchar (wname); return ec; #else /*!HAVE_W32_SYSTEM*/ if (chdir (name)) return _gpg_err_code_from_syserror (); return 0; #endif /*!HAVE_W32_SYSTEM*/ } /* Return the current working directory as a malloced string. Return * NULL and sets ERRNO on error. */ char * _gpgrt_getcwd (void) { #if defined(HAVE_W32_SYSTEM) wchar_t wbuffer[MAX_PATH + sizeof(wchar_t)]; DWORD wlen; char *buf, *p; wlen = GetCurrentDirectoryW (MAX_PATH, wbuffer); if (!wlen) { _gpgrt_w32_set_errno (-1); return NULL; } else if (wlen > MAX_PATH) { /* FWIW: I tried to use GetFullPathNameW (L".") but found no way * to execute a test program at a too long cwd. */ _gpg_err_set_errno (ENAMETOOLONG); return NULL; } buf = _gpgrt_wchar_to_utf8 (wbuffer, wlen); if (buf) { for (p=buf; *p; p++) if (*p == '\\') *p = '/'; } return buf; #else /*Unix*/ char *buffer; size_t size = 100; for (;;) { buffer = xtrymalloc (size+1); if (!buffer) return NULL; if (getcwd (buffer, size) == buffer) return buffer; xfree (buffer); if (errno != ERANGE) return NULL; size *= 2; } #endif /*Unix*/ } /* Wrapper around access to handle file name encoding under Windows. * Returns 0 if FNAME can be accessed in MODE or an error code. ERRNO * is also set on error. */ gpg_err_code_t _gpgrt_access (const char *fname, int mode) { gpg_err_code_t ec; #ifdef HAVE_W32_SYSTEM wchar_t *wfname; DWORD attribs; wfname = _gpgrt_fname_to_wchar (fname); if (!wfname) return _gpg_err_code_from_syserror (); attribs = GetFileAttributesW (wfname); if (attribs == (DWORD)(-1)) ec = _gpgrt_w32_get_last_err_code (); else { if ((mode & W_OK) && (attribs & FILE_ATTRIBUTE_READONLY)) { _gpg_err_set_errno (EACCES); ec = _gpg_err_code_from_syserror (); } else ec = 0; } _gpgrt_free_wchar (wfname); #else /* Unix */ ec = access (fname, mode)? _gpg_err_code_from_syserror () : 0; #endif /* Unix */ return ec; } /* Get the standard home directory for user NAME. If NAME is NULL the * directory for the current user is returned. Caller must release * the returned string. */ char * _gpgrt_getpwdir (const char *name) { char *result = NULL; #ifdef HAVE_PWD_H struct passwd *pwd = NULL; if (name) { #ifdef HAVE_GETPWNAM /* Fixme: We should use getpwnam_r if available. */ pwd = getpwnam (name); #endif } else { #ifdef HAVE_GETPWUID /* Fixme: We should use getpwuid_r if available. */ pwd = getpwuid (getuid()); #endif } if (pwd) { result = _gpgrt_strdup (pwd->pw_dir); } #else /*!HAVE_PWD_H*/ /* No support at all. */ (void)name; #endif /*HAVE_PWD_H*/ return result; } /* Return a malloced copy of the current user's account name; this may * return NULL on memory failure. */ char * _gpgrt_getusername (void) { char *result = NULL; #ifdef HAVE_W32_SYSTEM wchar_t wtmp[1]; wchar_t *wbuf; DWORD wsize = 1; char *buf; GetUserNameW (wtmp, &wsize); wbuf = _gpgrt_malloc (wsize * sizeof *wbuf); if (!wbuf) { _gpgrt_w32_set_errno (-1); return NULL; } if (!GetUserNameW (wbuf, &wsize)) { _gpgrt_w32_set_errno (-1); xfree (wbuf); return NULL; } buf = _gpgrt_wchar_to_utf8 (wbuf, wsize); xfree (wbuf); return buf; #else /* !HAVE_W32_SYSTEM */ # if defined(HAVE_PWD_H) && defined(HAVE_GETPWUID) struct passwd *pwd; pwd = getpwuid (getuid()); if (pwd) { result = _gpgrt_strdup (pwd->pw_name); } # endif /*HAVE_PWD_H*/ #endif /* !HAVE_W32_SYSTEM */ return result; }