Add remap translator

* trans/remap.c: New file.
* trans/Makefile (targets): Add remap.
(SRCS): Add remap.c.
(remap): Add rule.
* utils/remap.sh: New script.
* utils/Makefile (targets): Add remap.
(special-targets): Add remap.
(SRCS): Add remap.sh.
* NEWS: Advertise new translator

2 files changed, 67 insertions, 3 deletions

diff --git a/utils/Makefile b/utils/Makefile
index 00f6142f..e3bed0bf 100644
--- a/utils/Makefile
+++ b/utils/Makefile
@@ -21,14 +21,14 @@ makemode := utilities
 targets = shd ps settrans showtrans syncfs fsysopts \
 	storeinfo login w uptime ids loginpr sush vmstat portinfo \
 	devprobe vminfo addauth rmauth unsu setauth ftpcp ftpdir storecat \
-	storeread msgport rpctrace mount gcore fakeauth fakeroot
-special-targets = loginpr sush uptime fakeroot
+	storeread msgport rpctrace mount gcore fakeauth fakeroot remap
+special-targets = loginpr sush uptime fakeroot remap
 SRCS = shd.c ps.c settrans.c syncfs.c showtrans.c addauth.c rmauth.c \
 	fsysopts.c storeinfo.c login.c loginpr.sh sush.sh w.c \
 	uptime.sh psout.c ids.c vmstat.c portinfo.c devprobe.c vminfo.c \
 	parse.c frobauth.c frobauth-mod.c setauth.c pids.c nonsugid.c \
 	unsu.c ftpcp.c ftpdir.c storeread.c storecat.c msgport.c \
-	rpctrace.c mount.c gcore.c fakeauth.c fakeroot.sh
+	rpctrace.c mount.c gcore.c fakeauth.c fakeroot.sh remap.sh
 
 OBJS = $(filter-out %.sh,$(SRCS:.c=.o))
 HURDLIBS = ps ihash store fshelp ports ftpconn shouldbeinlibc
diff --git a/utils/remap.sh b/utils/remap.sh
new file mode 100644
index 00000000..106109e8
--- /dev/null
+++ b/utils/remap.sh
@@ -0,0 +1,64 @@
+#!/bin/sh
+# Execute a command in an environment where some paths are remapped
+#
+# Copyright (C) 2002, 2013 Free Software Foundation, Inc.
+#
+# This file is part of the GNU Hurd.
+#
+# The GNU Hurd is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation; either version 2, or (at
+# your option) any later version.
+#
+# The GNU Hurd 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
+# General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+#
+
+USAGE="Usage: $0 [OPTION...] [FROM1 TO1 [FROM2 TO2 [...]] -- [COMMAND...]"
+DOC="Execute COMMAND in an environment where some paths are remapped."
+
+while :; do
+  case "$1" in
+    --help|"-?")
+      echo "$USAGE"
+      echo "$DOC"
+      echo ""
+      echo "  -?, --help                 Give this help list"
+      echo "      --usage                Give a short usage message"
+      echo "  -V, --version              Print program version"
+      exit 0;;
+    --usage)
+      echo "Usage: $0 [-V?] [--help] [--usage] [--version]"
+      exit 0;;
+    --version|-V)
+      echo "STANDARD_HURD_VERSION_remap_"; exit 0;;
+    --)
+      shift
+      break;;
+    -*)
+      echo 1>&2 "$0: unrecognized option \`$1'"
+      echo 1>&2 "Try \`$0 --help' or \`$0 --usage' for more information";
+      exit 1;;
+    *)
+      MAPPED="$MAPPED $1"
+      break;;
+  esac
+done
+
+if [ $# -eq 0 ]; then
+  set -- ${SHELL:-/bin/sh}
+fi
+
+# We exec settrans, which execs the "fakeauth" command in the chroot context.
+# The `pwd` is evaluated here and now, and that result interpreted inside
+# the shell running under fakeauth to chdir there inside the chroot world.
+# That shell then execs our arguments as a command line.
+exec /bin/settrans --chroot \
+     /bin/sh -c "cd `pwd`; $*" \
+     -- / /hurd/remap $MAPPED