Add fchmodat() and fstatat() emulation.

Note that fchmodat() emulation does not support AT_SYMLINK_NOFOLLOW

MANIFEST

@@ -111,7 +111,9 @@ lib/util/event.c
 lib/util/event_poll.c
 lib/util/event_select.c
 lib/util/fatal.c
+lib/util/fchmodat.c
 lib/util/fnmatch.c
+lib/util/fstatat.c
 lib/util/getaddrinfo.c
 lib/util/getcwd.c
 lib/util/getdelim.c

config.h.in

@@ -242,6 +242,9 @@
 /* Define to 1 if you have the `faccessat' function. */
 #undef HAVE_FACCESSAT
 
+/* Define to 1 if you have the `fchmodat' function. */
+#undef HAVE_FCHMODAT
+
 /* Define to 1 if your system has the F_CLOSEM fcntl. */
 #undef HAVE_FCNTL_CLOSEM
 
@@ -257,6 +260,9 @@
 /* Define to 1 if you have the `fseeko' function. */
 #undef HAVE_FSEEKO
 
+/* Define to 1 if you have the `fstatat' function. */
+#undef HAVE_FSTATAT
+
 /* Define to 1 if you have the `futime' function. */
 #undef HAVE_FUTIME
 

configure

@@ -20508,6 +20508,58 @@ esac
     done
 
 
+fi
+done
+
+for ac_func in fchmodat
+do :
+  ac_fn_c_check_func "$LINENO" "fchmodat" "ac_cv_func_fchmodat"
+if test "x$ac_cv_func_fchmodat" = xyes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_FCHMODAT 1
+_ACEOF
+
+else
+
+    case " $LIBOBJS " in
+  *" fchmodat.$ac_objext "* ) ;;
+  *) LIBOBJS="$LIBOBJS fchmodat.$ac_objext"
+ ;;
+esac
+
+
+    for _sym in sudo_fchmodat; do
+	COMPAT_EXP="${COMPAT_EXP}${_sym}
+"
+    done
+
+
+fi
+done
+
+for ac_func in fstatat
+do :
+  ac_fn_c_check_func "$LINENO" "fstatat" "ac_cv_func_fstatat"
+if test "x$ac_cv_func_fstatat" = xyes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_FSTATAT 1
+_ACEOF
+
+else
+
+    case " $LIBOBJS " in
+  *" fstatat.$ac_objext "* ) ;;
+  *) LIBOBJS="$LIBOBJS fstatat.$ac_objext"
+ ;;
+esac
+
+
+    for _sym in sudo_fstatat; do
+	COMPAT_EXP="${COMPAT_EXP}${_sym}
+"
+    done
+
+
 fi
 done
 

configure.ac

@@ -2732,6 +2732,14 @@ AC_CHECK_FUNCS([unlinkat], [], [
     AC_LIBOBJ(unlinkat)
     SUDO_APPEND_COMPAT_EXP(sudo_unlinkat)
 ])
+AC_CHECK_FUNCS([fchmodat], [], [
+    AC_LIBOBJ(fchmodat)
+    SUDO_APPEND_COMPAT_EXP(sudo_fchmodat)
+])
+AC_CHECK_FUNCS([fstatat], [], [
+    AC_LIBOBJ(fstatat)
+    SUDO_APPEND_COMPAT_EXP(sudo_fstatat)
+])
 AC_CHECK_FUNCS([pipe2], [], [
     AC_LIBOBJ(pipe2)
     SUDO_APPEND_COMPAT_EXP(sudo_pipe2)

include/sudo_compat.h

@@ -212,9 +212,12 @@
 #  define UTIME_NOW	-2L
 # endif
 #endif
-#if !defined(HAVE_OPENAT) || (!defined(HAVE_FUTIMENS) && !defined(HAVE_UTIMENSAT))
+#if !defined(HAVE_OPENAT) || (!defined(HAVE_FUTIMENS) && !defined(HAVE_UTIMENSAT)) || !defined(HAVE_FCHMODAT) || !defined(HAVE_FSTATAT) || !defined(HAVE_UNLINKAT)
 # ifndef AT_FDCWD
-#  define AT_FDCWD	-100
+#  define AT_FDCWD		-100
+# endif
+# ifndef AT_SYMLINK_NOFOLLOW
+#  define AT_SYMLINK_NOFOLLOW	0x02
 # endif
 #endif
 
@@ -385,6 +388,7 @@ int getdomainname(char *, size_t);
  */
 
 struct passwd;
+struct stat;
 struct timespec;
 
 #ifndef HAVE_CLOSEFROM
@@ -412,6 +416,16 @@ __dso_public int sudo_utimensat(int fd, const char *file, const struct timespec
 # undef utimensat
 # define utimensat(_a, _b, _c, _d) sudo_utimensat((_a), (_b), (_c), (_d))
 #endif /* HAVE_UTIMENSAT */
+#ifndef HAVE_FCHMODAT
+__dso_public int sudo_fchmodat(int dfd, const char *path, mode_t mode, int flag);
+# undef fchmodat
+# define fchmodat(_a, _b, _c, _d) sudo_fchmodat((_a), (_b), (_c), (_d))
+#endif /* HAVE_FCHMODAT */
+#ifndef HAVE_FSTATAT
+__dso_public int sudo_fstatat(int dfd, const char *path, struct stat *sb, int flag);
+# undef fstatat
+# define fstatat(_a, _b, _c, _d) sudo_fstatat((_a), (_b), (_c), (_d))
+#endif /* HAVE_FSTATAT */
 #ifndef HAVE_FUTIMENS
 __dso_public int sudo_futimens(int fd, const struct timespec *times);
 # undef futimens

lib/util/Makefile.in

@@ -562,6 +562,14 @@ fatal.i: $(srcdir)/fatal.c $(incdir)/compat/getaddrinfo.h \
 	$(CC) -E -o $@ $(CPPFLAGS) $<
 fatal.plog: fatal.i
 	rm -f $@; pvs-studio --cfg $(PVS_CFG) --sourcetree-root $(top_srcdir) --skip-cl-exe yes --source-file $(srcdir)/fatal.c --i-file $< --output-file $@
+fchmodat.lo: $(srcdir)/fchmodat.c $(incdir)/sudo_compat.h \
+             $(top_builddir)/config.h
+	$(LIBTOOL) $(LTFLAGS) --mode=compile $(CC) -c -o $@ $(CPPFLAGS) $(CFLAGS) $(ASAN_CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(srcdir)/fchmodat.c
+fchmodat.i: $(srcdir)/fchmodat.c $(incdir)/sudo_compat.h \
+             $(top_builddir)/config.h
+	$(CC) -E -o $@ $(CPPFLAGS) $<
+fchmodat.plog: fchmodat.i
+	rm -f $@; pvs-studio --cfg $(PVS_CFG) --sourcetree-root $(top_srcdir) --skip-cl-exe yes --source-file $(srcdir)/fchmodat.c --i-file $< --output-file $@
 fnm_test.lo: $(srcdir)/regress/fnmatch/fnm_test.c $(incdir)/compat/fnmatch.h \
              $(incdir)/compat/stdbool.h $(incdir)/sudo_compat.h \
              $(incdir)/sudo_util.h $(top_builddir)/config.h
@@ -582,6 +590,12 @@ fnmatch.i: $(srcdir)/fnmatch.c $(incdir)/compat/charclass.h \
 	$(CC) -E -o $@ $(CPPFLAGS) $<
 fnmatch.plog: fnmatch.i
 	rm -f $@; pvs-studio --cfg $(PVS_CFG) --sourcetree-root $(top_srcdir) --skip-cl-exe yes --source-file $(srcdir)/fnmatch.c --i-file $< --output-file $@
+fstatat.lo: $(srcdir)/fstatat.c $(incdir)/sudo_compat.h $(top_builddir)/config.h
+	$(LIBTOOL) $(LTFLAGS) --mode=compile $(CC) -c -o $@ $(CPPFLAGS) $(CFLAGS) $(ASAN_CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(srcdir)/fstatat.c
+fstatat.i: $(srcdir)/fstatat.c $(incdir)/sudo_compat.h $(top_builddir)/config.h
+	$(CC) -E -o $@ $(CPPFLAGS) $<
+fstatat.plog: fstatat.i
+	rm -f $@; pvs-studio --cfg $(PVS_CFG) --sourcetree-root $(top_srcdir) --skip-cl-exe yes --source-file $(srcdir)/fstatat.c --i-file $< --output-file $@
 getaddrinfo.lo: $(srcdir)/getaddrinfo.c $(incdir)/compat/getaddrinfo.h \
                 $(incdir)/sudo_compat.h $(top_builddir)/config.h
 	$(LIBTOOL) $(LTFLAGS) --mode=compile $(CC) -c -o $@ $(CPPFLAGS) $(CFLAGS) $(ASAN_CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(srcdir)/getaddrinfo.c
@@ -866,6 +880,12 @@ nanosleep.i: $(srcdir)/nanosleep.c $(incdir)/compat/stdbool.h \
 	$(CC) -E -o $@ $(CPPFLAGS) $<
 nanosleep.plog: nanosleep.i
 	rm -f $@; pvs-studio --cfg $(PVS_CFG) --sourcetree-root $(top_srcdir) --skip-cl-exe yes --source-file $(srcdir)/nanosleep.c --i-file $< --output-file $@
+openat.lo: $(srcdir)/openat.c $(incdir)/sudo_compat.h $(top_builddir)/config.h
+	$(LIBTOOL) $(LTFLAGS) --mode=compile $(CC) -c -o $@ $(CPPFLAGS) $(CFLAGS) $(ASAN_CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(srcdir)/openat.c
+openat.i: $(srcdir)/openat.c $(incdir)/sudo_compat.h $(top_builddir)/config.h
+	$(CC) -E -o $@ $(CPPFLAGS) $<
+openat.plog: openat.i
+	rm -f $@; pvs-studio --cfg $(PVS_CFG) --sourcetree-root $(top_srcdir) --skip-cl-exe yes --source-file $(srcdir)/openat.c --i-file $< --output-file $@
 parse_gids_test.lo: $(srcdir)/regress/parse_gids/parse_gids_test.c \
                     $(incdir)/compat/stdbool.h $(incdir)/sudo_compat.h \
                     $(incdir)/sudo_fatal.h $(incdir)/sudo_util.h \
@@ -1246,6 +1266,14 @@ ttysize.i: $(srcdir)/ttysize.c $(incdir)/compat/stdbool.h \
 	$(CC) -E -o $@ $(CPPFLAGS) $<
 ttysize.plog: ttysize.i
 	rm -f $@; pvs-studio --cfg $(PVS_CFG) --sourcetree-root $(top_srcdir) --skip-cl-exe yes --source-file $(srcdir)/ttysize.c --i-file $< --output-file $@
+unlinkat.lo: $(srcdir)/unlinkat.c $(incdir)/sudo_compat.h \
+             $(top_builddir)/config.h
+	$(LIBTOOL) $(LTFLAGS) --mode=compile $(CC) -c -o $@ $(CPPFLAGS) $(CFLAGS) $(ASAN_CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(srcdir)/unlinkat.c
+unlinkat.i: $(srcdir)/unlinkat.c $(incdir)/sudo_compat.h \
+             $(top_builddir)/config.h
+	$(CC) -E -o $@ $(CPPFLAGS) $<
+unlinkat.plog: unlinkat.i
+	rm -f $@; pvs-studio --cfg $(PVS_CFG) --sourcetree-root $(top_srcdir) --skip-cl-exe yes --source-file $(srcdir)/unlinkat.c --i-file $< --output-file $@
 utimens.lo: $(srcdir)/utimens.c $(incdir)/compat/stdbool.h \
             $(incdir)/sudo_compat.h $(incdir)/sudo_util.h \
             $(top_builddir)/config.h

lib/util/fchmodat.c

@@ -0,0 +1,71 @@
+/*
+ * SPDX-License-Identifier: ISC
+ *
+ * Copyright (c) 2019 Todd C. Miller <Todd.Miller@sudo.ws>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*
+ * This is an open source non-commercial project. Dear PVS-Studio, please check it.
+ * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
+ */
+
+#include <config.h>
+
+#include <sys/stat.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "sudo_compat.h"
+
+#ifndef HAVE_FCHMODAT
+int
+sudo_fchmodat(int dfd, const char *path, mode_t mode, int flag)
+{
+    int odfd, ret = -1;
+
+    if (ISSET(flag, AT_SYMLINK_NOFOLLOW)) {
+	errno = ENOTSUP;
+	return -1;
+    }
+
+    if (dfd == (int)AT_FDCWD)
+	return chmod(path, mode);
+
+    /* Save cwd */
+    if ((odfd = open(".", O_RDONLY)) == -1)
+	goto done;
+
+    if (fchdir(dfd) == -1)
+	goto done;
+
+    ret = chmod(path, mode);
+
+    /* Restore cwd */
+    if (fchdir(odfd) == -1) {
+	/* Should not happen */
+	ret = -1;
+    }
+
+done:
+    if (odfd != -1)
+	close(odfd);
+
+    return ret;
+}
+#endif /* HAVE_FCHMODAT */

lib/util/fstatat.c

@@ -0,0 +1,72 @@
+/*
+ * SPDX-License-Identifier: ISC
+ *
+ * Copyright (c) 2019 Todd C. Miller <Todd.Miller@sudo.ws>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*
+ * This is an open source non-commercial project. Dear PVS-Studio, please check it.
+ * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
+ */
+
+#include <config.h>
+
+#include <sys/stat.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "sudo_compat.h"
+
+#ifndef HAVE_FSTATAT
+int
+sudo_fstatat(int dfd, const char *path, struct stat *sb, int flag)
+{
+    int odfd, ret = -1;
+
+    if (dfd == (int)AT_FDCWD) {
+	if (ISSET(flag, AT_SYMLINK_NOFOLLOW))
+	    return lstat(path, sb);
+	else
+	    return stat(path, sb);
+    }
+
+    /* Save cwd */
+    if ((odfd = open(".", O_RDONLY)) == -1)
+	goto done;
+
+    if (fchdir(dfd) == -1)
+	goto done;
+
+    if (ISSET(flag, AT_SYMLINK_NOFOLLOW))
+	ret = lstat(path, sb);
+    else
+	ret = stat(path, sb);
+
+    /* Restore cwd */
+    if (fchdir(odfd) == -1) {
+	/* Should not happen */
+	ret = -1;
+    }
+
+done:
+    if (odfd != -1)
+	close(odfd);
+
+    return ret;
+}
+#endif /* HAVE_FSTATAT */

mkdep.pl

@@ -116,7 +116,7 @@ sub mkdep {
     # XXX - fill in AUTH_OBJS from contents of the auth dir instead
     $makefile =~ s:\@AUTH_OBJS\@:afs.lo aix_auth.lo bsdauth.lo dce.lo fwtk.lo getspwuid.lo kerb5.lo pam.lo passwd.lo rfc1938.lo secureware.lo securid5.lo sia.lo:;
     $makefile =~ s:\@DIGEST\@:digest.lo digest_openssl.lo digest_gcrypt.lo:;
-    $makefile =~ s:\@LTLIBOBJS\@:arc4random.lo arc4random_uniform.lo closefrom.lo fnmatch.lo getaddrinfo.lo getcwd.lo getentropy.lo getgrouplist.lo getdelim.lo getopt_long.lo glob.lo inet_ntop_lo inet_pton.lo isblank.lo memrchr.lo memset_s.lo mksiglist.lo mksigname.lo mktemp.lo nanosleep.lo pw_dup.lo reallocarray.lo sha2.lo sig2str.lo siglist.lo signame.lo snprintf.lo str2sig.lo strlcat.lo strlcpy.lo strndup.lo strnlen.lo strsignal.lo utimens.lo vsyslog.lo pipe2.lo:;
+    $makefile =~ s:\@LTLIBOBJS\@:arc4random.lo arc4random_uniform.lo closefrom.lo fchmodat.lo fstatat.lo fnmatch.lo getaddrinfo.lo getcwd.lo getentropy.lo getgrouplist.lo getdelim.lo getopt_long.lo glob.lo inet_ntop_lo inet_pton.lo isblank.lo memrchr.lo memset_s.lo mksiglist.lo mksigname.lo mktemp.lo nanosleep.lo openat.lo pipe2.lo pw_dup.lo reallocarray.lo sha2.lo sig2str.lo siglist.lo signame.lo snprintf.lo str2sig.lo strlcat.lo strlcpy.lo strndup.lo strnlen.lo strsignal.lo unlinkat.lo utimens.lo vsyslog.lo:;
 
     # Parse OBJS lines
     my %objs;