Add fchownat() systems without it.

MANIFEST

@@ -220,6 +220,7 @@ lib/util/event_select.c
 lib/util/explicit_bzero.c
 lib/util/fatal.c
 lib/util/fchmodat.c
+lib/util/fchownat.c
 lib/util/fnmatch.c
 lib/util/freezero.c
 lib/util/fstatat.c

config.h.in

@@ -298,6 +298,9 @@
 /* Define to 1 if you have the `fchmodat' function. */
 #undef HAVE_FCHMODAT
 
+/* Define to 1 if you have the `fchownat' function. */
+#undef HAVE_FCHOWNAT
+
 /* Define to 1 if your system has the F_CLOSEM fcntl. */
 #undef HAVE_FCNTL_CLOSEM
 

configure

@@ -22747,6 +22747,32 @@ esac
 fi
 
 
+fi
+
+done
+
+  for ac_func in fchownat
+do :
+  ac_fn_c_check_func "$LINENO" "fchownat" "ac_cv_func_fchownat"
+if test "x$ac_cv_func_fchownat" = xyes
+then :
+  printf "%s\n" "#define HAVE_FCHOWNAT 1" >>confdefs.h
+
+else $as_nop
+
+    case " $LIBOBJS " in
+  *" fchownat.$ac_objext "* ) ;;
+  *) LIBOBJS="$LIBOBJS fchownat.$ac_objext"
+ ;;
+esac
+
+
+    for _sym in sudo_fchownat; do
+	COMPAT_EXP="${COMPAT_EXP}${_sym}
+"
+    done
+
+
 fi
 
 done

configure.ac

@@ -2873,6 +2873,10 @@ AC_CHECK_FUNCS(nanosleep, [], [
 	SUDO_APPEND_COMPAT_EXP(sudo_nanosleep)
     ])
 ])
+AC_CHECK_FUNCS([fchownat], [], [
+    AC_LIBOBJ(fchownat)
+    SUDO_APPEND_COMPAT_EXP(sudo_fchownat)
+])
 AC_CHECK_FUNCS([mkdirat], [], [
     AC_LIBOBJ(mkdirat)
     SUDO_APPEND_COMPAT_EXP(sudo_mkdirat)

include/sudo_compat.h

@@ -484,6 +484,11 @@ sudo_dso_public size_t sudo_strnlen(const char *str, size_t maxlen);
 # undef strnlen
 # define strnlen(_a, _b) sudo_strnlen((_a), (_b))
 #endif /* HAVE_STRNLEN */
+#ifndef HAVE_FCHOWNAT
+sudo_dso_public int sudo_fchownat(int dfd, const char *path, uid_t uid, gid_t gid, int flag);
+# undef fchownat
+# define fchownat(_a, _b, _c, _d, _e) sudo_fchownat((_a), (_b), (_c), (_d), (_e))
+#endif /* HAVE_FCHOWNAT */
 #ifndef HAVE_MEMRCHR
 sudo_dso_public void *sudo_memrchr(const void *s, int c, size_t n);
 # undef memrchr

lib/util/Makefile.in

@@ -703,6 +703,14 @@ fchmodat.i: $(srcdir)/fchmodat.c $(incdir)/sudo_compat.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 $@
+fchownat.lo: $(srcdir)/fchownat.c $(incdir)/sudo_compat.h \
+             $(top_builddir)/config.h
+	$(LIBTOOL) $(LTFLAGS) --mode=compile $(CC) -c -o $@ $(CPPFLAGS) $(CFLAGS) $(ASAN_CFLAGS) $(PIE_CFLAGS) $(HARDENING_CFLAGS) $(srcdir)/fchownat.c
+fchownat.i: $(srcdir)/fchownat.c $(incdir)/sudo_compat.h \
+             $(top_builddir)/config.h
+	$(CC) -E -o $@ $(CPPFLAGS) $<
+fchownat.plog: fchownat.i
+	rm -f $@; pvs-studio --cfg $(PVS_CFG) --sourcetree-root $(top_srcdir) --skip-cl-exe yes --source-file $(srcdir)/fchownat.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

scripts/mkdep.pl

@@ -2,7 +2,7 @@
 #
 # SPDX-License-Identifier: ISC
 #
-# Copyright (c) 2011-2021 Todd C. Miller <Todd.Miller@sudo.ws>
+# Copyright (c) 2011-2022 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
@@ -120,7 +120,7 @@ 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_buf.lo arc4random_uniform.lo cfmakeraw.lo closefrom.lo dup3.lo explicit_bzero.lo fchmodat.lo freezero.lo fstatat.lo fnmatch.lo getaddrinfo.lo getcwd.lo getentropy.lo getgrouplist.lo getdelim.lo getopt_long.lo getusershell.lo glob.lo gmtime_r.lo inet_ntop_lo inet_pton.lo isblank.lo localtime_r.lo memrchr.lo mkdirat.lo mksiglist.lo mksigname.lo mktemp.lo nanosleep.lo openat.lo pipe2.lo pread.lo pwrite.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 timegm.lo unlinkat.lo utimens.lo:;
+    $makefile =~ s:\@LTLIBOBJS\@:arc4random.lo arc4random_buf.lo arc4random_uniform.lo cfmakeraw.lo closefrom.lo dup3.lo explicit_bzero.lo fchmodat.lo fchownat.lo freezero.lo fstatat.lo fnmatch.lo getaddrinfo.lo getcwd.lo getentropy.lo getgrouplist.lo getdelim.lo getopt_long.lo getusershell.lo glob.lo gmtime_r.lo inet_ntop_lo inet_pton.lo isblank.lo localtime_r.lo memrchr.lo mkdirat.lo mksiglist.lo mksigname.lo mktemp.lo nanosleep.lo openat.lo pipe2.lo pread.lo pwrite.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 timegm.lo unlinkat.lo utimens.lo:;
 
     # Parse OBJS lines
     my %objs;