1999-11-08 Roland McGrath <roland@baalperazim.frob.com>

	* hello.c: New file.  From Gord with some cleanups and hacks from me.
	* Makefile (targets, SRCS): Add hello, hello.c.
	(hello): Add appropriate deps.

2 files changed, 290 insertions, 5 deletions

diff --git a/trans/Makefile b/trans/Makefile
index 5d5900fa..14091d72 100644
--- a/trans/Makefile
+++ b/trans/Makefile
@@ -1,5 +1,5 @@
 #
-#   Copyright (C) 1994, 1995, 1996, 1997 Free Software Foundation
+#   Copyright (C) 1994,95,96,97,99 Free Software Foundation, Inc.
 #
 #   This program is free software; you can redistribute it and/or
 #   modify it under the terms of the GNU General Public License as
@@ -18,9 +18,10 @@
 dir := trans
 makemode := servers
 
-targets = symlink firmlink ifsock magic null fifo new-fifo fwd crash password
+targets = symlink firmlink ifsock magic null fifo new-fifo fwd crash \
+	  password hello
 SRCS = ifsock.c symlink.c magic.c null.c fifo.c new-fifo.c fwd.c \
-	crash.c firmlink.c password.c
+	crash.c firmlink.c password.c hello.c
 OBJS = $(SRCS:.c=.o) fsysServer.o ifsockServer.o passwordServer.o
 HURDLIBS=ports trivfs threads fshelp pipe ihash shouldbeinlibc
 password-LDLIBS = $(LIBCRYPT)
@@ -35,8 +36,8 @@ password: passwordServer.o
 crash password: ../libports/libports.a ../libtrivfs/libtrivfs.a ../libthreads/libthreads.a ../libfshelp/libfshelp.a
 fifo new-fifo: ../libpipe/libpipe.a
 fwd new-fifo: ../libfshelp/libfshelp.a ../libports/libports.a
-magic null ifsock fifo new-fifo firmlink: ../libtrivfs/libtrivfs.a ../libfshelp/libfshelp.a ../libports/libports.a ../libihash/libihash.a
+hello magic null ifsock fifo new-fifo firmlink: ../libtrivfs/libtrivfs.a ../libfshelp/libfshelp.a ../libports/libports.a ../libihash/libihash.a
 $(targets): ../libshouldbeinlibc/libshouldbeinlibc.a
-magic fwd null ifsock fifo new-fifo firmlink: ../libthreads/libthreads.a
+hello magic fwd null ifsock fifo new-fifo firmlink: ../libthreads/libthreads.a
 
 $(targets): %: %.o
diff --git a/trans/hello.c b/trans/hello.c
new file mode 100644
index 00000000..f4f0e5e6
--- /dev/null
+++ b/trans/hello.c
@@ -0,0 +1,284 @@
+/* hello.c - A trivial single-file translator
+   Copyright (C) 1998, 1999 Free Software Foundation, Inc.
+   Gordon Matzigkeit <gord@fig.org>, 1999
+   This program 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.
+
+   This program 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
+
+#define _GNU_SOURCE 1
+
+#include <hurd/trivfs.h>
+#include <stdio.h>
+#include <argp.h>
+#include <argz.h>
+#include <error.h>
+#include <string.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+
+/* The message we return when we are read.  */
+static const char hello[] = "Hello, world!\n";
+static char *contents = (char *) hello;
+static size_t contents_len = sizeof hello - 1;
+
+/* Trivfs hooks. */
+int trivfs_fstype = FSTYPE_MISC;
+int trivfs_fsid = 0;
+
+int trivfs_allow_open = O_READ;
+
+int trivfs_support_read = 1;
+int trivfs_support_write = 0;
+int trivfs_support_exec = 0;
+
+/* NOTE: This example is not robust: it is possible to trigger some
+   assertion failures because we don't implement the following:
+
+   $ cd /src/hurd/libtrivfs
+   $ grep -l 'assert.*!trivfs_support_read' *.c |
+     xargs grep '^trivfs_S_' | sed 's/^[^:]*:\([^ 	]*\).*$/\1/'
+   trivfs_S_io_get_icky_async_id
+   trivfs_S_io_async
+   trivfs_S_io_map
+   trivfs_S_io_get_openmodes
+   trivfs_S_io_clear_some_openmodes
+   trivfs_S_io_set_some_openmodes
+   trivfs_S_io_set_all_openmodes
+   trivfs_S_io_get_owner
+   trivfs_S_io_mod_owner
+   trivfs_S_io_readable
+   trivfs_S_io_select
+   $
+
+   For that reason, you should run this as an active translator
+   `settrans -ac testnode /path/to/thello' so that you can see the
+   error messages when they appear. */
+
+/* A hook for us to keep track of the file descriptor state. */
+struct open
+{
+  off_t offs;
+};
+
+void
+trivfs_modify_stat (struct trivfs_protid *cred, struct stat *st)
+{
+  /* Mark the node as a read-only plain file. */
+  st->st_mode &= ~(S_IFMT | ALLPERMS);
+  st->st_mode |= (S_IFREG | S_IRUSR | S_IRGRP | S_IROTH);
+  st->st_size = sizeof (hello) - 1;
+}
+
+error_t
+trivfs_goaway (struct trivfs_control *cntl, int flags)
+{
+  exit (0);
+}
+
+
+static error_t
+open_hook (struct trivfs_peropen *peropen)
+{
+  struct open *op = malloc (sizeof (struct open));
+  if (op == NULL)
+    return ENOMEM;
+
+  /* Initialize the offset. */
+  op->offs = 0;
+  peropen->hook = op;
+  return 0;
+}
+
+
+static void
+close_hook (struct trivfs_peropen *peropen)
+{
+  free (peropen->hook);
+}
+
+
+/* Read data from an IO object.  If offset is -1, read from the object
+   maintained file pointer.  If the object is not seekable, offset is
+   ignored.  The amount desired to be read is in AMOUNT.  */
+error_t
+trivfs_S_io_read (struct trivfs_protid *cred,
+		  mach_port_t reply, mach_msg_type_name_t reply_type,
+		  vm_address_t *data, mach_msg_type_number_t *data_len,
+		  off_t offs, mach_msg_type_number_t amount)
+{
+  struct open *op;
+
+  /* Deny access if they have bad credentials. */
+  if (! cred)
+    return EOPNOTSUPP;
+  else if (! (cred->po->openmodes & O_READ))
+    return EBADF;
+
+  /* Get the offset. */
+  op = cred->po->hook;
+  if (offs == -1)
+    offs = op->offs;
+
+  /* Prune the amount they want to read. */
+  if (offs > contents_len)
+    offs = contents_len;
+  if (offs + amount > contents_len)
+    amount = contents_len - offs;
+
+  if (amount > 0)
+    {
+      /* Possibly allocate a new buffer. */
+      if (*data_len < amount)
+	*data = (vm_address_t) mmap (0, amount, PROT_READ|PROT_WRITE,
+				     MAP_ANON, 0, 0);
+
+      /* Copy the constant data into the buffer. */
+      memcpy ((char *) *data, contents + offs, amount);
+
+      /* Update the saved offset. */
+      op->offs += amount;
+    }
+
+  *data_len = amount;
+  return 0;
+}
+
+
+/* Change current read/write offset */
+error_t
+trivfs_S_io_seek (struct trivfs_protid *cred,
+		  mach_port_t reply, mach_msg_type_name_t reply_type,
+		  off_t offs, int whence, off_t *new_offs)
+{
+  struct open *op;
+  error_t err = 0;
+  if (! cred)
+    return EOPNOTSUPP;
+
+  op = cred->po->hook;
+  switch (whence)
+    {
+    case SEEK_SET:
+      op->offs = offs; break;
+    case SEEK_CUR:
+      op->offs += offs; break;
+    case SEEK_END:
+      op->offs = contents_len - offs; break;
+    default:
+      err = EINVAL;
+    }
+
+  if (! err)
+    *new_offs = op->offs;
+
+  return err;
+}
+
+
+/* If this variable is set, it is called every time a new peropen
+   structure is created and initialized. */
+error_t (*trivfs_peropen_create_hook)(struct trivfs_peropen *) = open_hook;
+
+/* If this variable is set, it is called every time a peropen structure
+   is about to be destroyed. */
+void (*trivfs_peropen_destroy_hook) (struct trivfs_peropen *) = close_hook;
+
+
+/* Options processing.  We accept the same options on the command line
+   and from fsys_set_options.  */
+
+static const struct argp_option options[] =
+{
+  {"contents",	'c', "STRING",	0, "Specify the contents of the virtual file"},
+  {0}
+};
+
+static error_t
+parse_opt (int opt, char *arg, struct argp_state *state)
+{
+  switch (opt)
+    {
+    default:
+      return ARGP_ERR_UNKNOWN;
+    case ARGP_KEY_INIT:
+    case ARGP_KEY_SUCCESS:
+    case ARGP_KEY_ERROR:
+      break;
+
+    case 'c':
+      {
+	char *new = strdup (arg);
+	if (new == NULL)
+	  return ENOMEM;
+	if (contents != hello)
+	  free (contents);
+	contents = new;
+	contents_len = strlen (new);
+	break;
+      }
+    }
+  return 0;
+}
+
+/* This will be called from libtrivfs to help construct the answer
+   to an fsys_get_options RPC.  */
+error_t
+trivfs_append_args (struct trivfs_control *fsys,
+		    char **argz, size_t *argz_len)
+{
+  error_t err;
+  char *opt;
+
+  if (asprintf (&opt, "--contents=%s", contents) < 0)
+    return ENOMEM;
+
+  err = argz_add (argz, argz_len, opt);
+
+  free (opt);
+
+  return err;
+}
+
+static struct argp hello_argp = { options, parse_opt, 0, 0 };
+
+/* Setting this variable makes libtrivfs use our argp to
+   parse options passed in an fsys_set_options RPC.  */
+struct argp *trivfs_runtime_argp = &hello_argp;
+
+
+int
+main (int argc, char **argv)
+{
+  error_t err;
+  mach_port_t bootstrap;
+  struct trivfs_control *fsys;
+
+  /* We use the same argp for options available at startup
+     as for options we'll accept in an fsys_set_options RPC.  */
+  argp_parse (&hello_argp, argc, argv, 0, 0, 0);
+
+  task_get_bootstrap_port (mach_task_self (), &bootstrap);
+  if (bootstrap == MACH_PORT_NULL)
+    error (1, 0, "Must be started as a translator");
+
+  /* Reply to our parent */
+  err = trivfs_startup (bootstrap, 0, 0, 0, 0, 0, &fsys);
+  mach_port_deallocate (mach_task_self (), bootstrap);
+  if (err)
+    error (3, err, "trivfs_startup");
+
+  /* Launch. */
+  ports_manage_port_operations_one_thread (fsys->pi.bucket, trivfs_demuxer, 0);
+
+  return 0;
+}