Re: The patch of boot to open a virtual network interface

[zhengda]

Neal H. Walfield wrote:
> At Tue, 19 Aug 2008 17:37:14 +0200,
> zhengda wrote:
>   
> > Since boot only uses one interface, boot probably accepts only one 
> > interface name from subhurd.
> >     
>
> This needn't be the case.  In fact, it should be able to expose any
> number of objects as devices.  A good interface might be:
>
>   -d foo=filename1 -d bar=filename2 ...
>
> Where foo is hd0 or eth0 and filename is some file name interpreted in
> the context of boot.
>   
Hi,

The patch in the attachment implements the interface.

Zheng Da

Needed for Hurd 0.3

2008-08-19 Zheng Da <zhengda1936@gmail.com>

        * boot/boot.c: Add '-f' option.
        (dev_map): New structure.
        (dev_map_head): New variable.
        (add_dev_map): New function.
        (lookup_dev): New function.
        (parse_opt): Handle the '-f' option.
        (ds_device_open): Open the device from the device file.

diff -u boot.old/boot.c boot/boot.c
--- boot.old/boot.c     2008-08-17 18:38:02.000000000 +0200
+++ boot/boot.c 2008-08-18 00:19:40.830000000 +0200
@@ -432,14 +432,53 @@
     "Pause for user confirmation at various times during booting" },
   { "isig",      'I', 0, 0,
     "Do not disable terminal signals, so you can suspend and interrupt boot."},
+  { "device",     'f', "device name=device file", 0,
+    "Specify the device file used by subhurd and its name."},
   { 0 }
 };
 static char args_doc[] = "BOOT-SCRIPT";
 static char doc[] = "Boot a second hurd";
 
+struct dev_map 
+{
+  char *name;
+  mach_port_t port;
+  struct dev_map *next;
+};
+
+static struct dev_map *dev_map_head;
+
+static struct dev_map *add_dev_map (char *dev_name, char *dev_file)
+{
+  struct dev_map *map = (struct dev_map *) malloc (sizeof (*map));
+
+  assert (map);
+  map->name = dev_name;
+  map->port = file_name_lookup (dev_file, 0, 0);
+  if (map->port == MACH_PORT_NULL)
+    error (1, errno, "file_name_lookup: %s", dev_file);
+  map->next = dev_map_head;
+  dev_map_head = map;
+  return map;
+}
+
+static struct dev_map *lookup_dev (char *dev_name)
+{
+  struct dev_map *map;
+
+  for (map = dev_map_head; map; map = map->next)
+    {
+      if (strcmp (map->name, dev_name) == 0)
+       return map;
+    }
+  return NULL;
+}
+
 static error_t
 parse_opt (int key, char *arg, struct argp_state *state)
 {
+  char *dev_file;
+
   switch (key)
     {
       size_t len;
@@ -458,6 +497,14 @@
       bootstrap_args[len] = '\0';
       break;
 
+    case 'f':
+      dev_file = strstr (arg, "=");
+      if (dev_file == NULL)
+       return ARGP_ERR_UNKNOWN;
+      *dev_file = 0;
+      add_dev_map (arg, dev_file+1);
+      break;
+
     case ARGP_KEY_ARG:
       if (state->arg_num == 0)
        bootscript = arg;
@@ -942,6 +989,8 @@
                mach_port_t *device,
                mach_msg_type_name_t *devicetype)
 {
+  struct dev_map *map;
+
   if (master_port != pseudo_master_device_port)
     return D_INVALID_OPERATION;
 
@@ -965,6 +1014,13 @@
       return 0;
     }
 
+  map = lookup_dev (name);
+  if (map)
+    {
+      *devicetype = MACH_MSG_TYPE_MOVE_SEND;
+      return device_open (map->port, mode, "", device);
+    }
+
   *devicetype = MACH_MSG_TYPE_MOVE_SEND;
   return device_open (master_device_port, mode, name, device);
 }