2001-08-20 Roland McGrath <roland@frob.com>

	Support "boot script" functionality in multiboot module strings.
	* kern/bootstrap.c: Rewrite merged from oskit-branch.
	* kern/boot_script.c, kern/boot_script.h: New files,
	copied from boot/ directory in Hurd sources.
	* Makefile.in (kern-cfiles): Add boot_script.c here.
	(kern-files): Add boot_script.h here.
	* NEWS: Mention the new feature.

1 files changed, 788 insertions, 0 deletions

diff --git a/kern/boot_script.c b/kern/boot_script.c
new file mode 100644
index 0000000..d031752
--- /dev/null
+++ b/kern/boot_script.c
@@ -0,0 +1,788 @@
+/* Boot script parser for Mach.  */
+
+/* Written by Shantanu Goel (goel@cs.columbia.edu).  */
+
+#include <mach/mach_types.h>
+#if !KERNEL || OSKIT_MACH
+#include <string.h>
+#endif
+#include "boot_script.h"
+
+
+/* This structure describes a symbol.  */
+struct sym
+{
+  /* Symbol name.  */
+  const char *name;
+
+  /* Type of value returned by function.  */
+  int type;
+
+  /* Symbol value.  */
+  int val;
+
+  /* For function symbols; type of value returned by function.  */
+  int ret_type;
+
+  /* For function symbols; if set, execute function at the time
+     of command execution, not during parsing.  A function with
+     this field set must also have `no_arg' set.  Also, the function's
+     `val' argument will always be NULL.  */
+  int run_on_exec;
+};
+
+/* Additional values symbols can take.
+   These are only used internally.  */
+#define VAL_SYM		10	/* symbol table entry */
+#define VAL_FUNC	11	/* function pointer */
+
+/* This structure describes an argument.  */
+struct arg
+{
+  /* Argument text copied verbatim.  0 if none.  */
+  char *text;
+
+  /* Type of value assigned.  0 if none.  */
+  int type;
+
+  /* Argument value.  */
+  int val;
+};
+
+/* List of commands.  */
+static struct cmd **cmds = 0;
+
+/* Amount allocated for `cmds'.  */
+static int cmds_alloc = 0;
+
+/* Next available slot in `cmds'.  */
+static int cmds_index = 0;
+
+/* Symbol table.  */
+static struct sym **symtab = 0;
+
+/* Amount allocated for `symtab'.  */
+static int symtab_alloc = 0;
+
+/* Next available slot in `symtab'.  */
+static int symtab_index = 0;
+
+/* Create a task and suspend it.  */
+static int
+create_task (struct cmd *cmd, int *val)
+{
+  int err = boot_script_task_create (cmd);
+  *val = (int) cmd->task;
+  return err;
+}
+
+/* Resume a task.  */
+static int
+resume_task (struct cmd *cmd, int *val)
+{
+  return boot_script_task_resume (cmd);
+}
+
+/* Resume a task when the user hits return.  */
+static int
+prompt_resume_task (struct cmd *cmd, int *val)
+{
+  return boot_script_prompt_task_resume (cmd);
+}
+
+/* List of builtin symbols.  */
+static struct sym builtin_symbols[] =
+{
+  { "task-create", VAL_FUNC, (int) create_task, VAL_TASK, 0 },
+  { "task-resume", VAL_FUNC, (int) resume_task, VAL_NONE, 1 },
+  { "prompt-task-resume", VAL_FUNC, (int) prompt_resume_task, VAL_NONE, 1 },
+};
+#define NUM_BUILTIN (sizeof (builtin_symbols) / sizeof (builtin_symbols[0]))
+
+/* Free CMD and all storage associated with it.
+   If ABORTING is set, terminate the task associated with CMD,
+   otherwise just deallocate the send right.  */
+static void
+free_cmd (struct cmd *cmd, int aborting)
+{
+  if (cmd->task)
+    boot_script_free_task (cmd->task, aborting);
+  if (cmd->args)
+    {
+      int i;
+      for (i = 0; i < cmd->args_index; i++)
+	boot_script_free (cmd->args[i], sizeof *cmd->args[i]);
+      boot_script_free (cmd->args, sizeof cmd->args[0] * cmd->args_alloc);
+    }
+  if (cmd->exec_funcs)
+    boot_script_free (cmd->exec_funcs,
+		      sizeof cmd->exec_funcs[0] * cmd->exec_funcs_alloc);
+  boot_script_free (cmd, sizeof *cmd);
+}
+
+/* Free all storage allocated by the parser.
+   If ABORTING is set, terminate all tasks.  */
+static void
+cleanup (int aborting)
+{
+  int i;
+
+  for (i = 0; i < cmds_index; i++)
+    free_cmd (cmds[i], aborting);
+  boot_script_free (cmds, sizeof cmds[0] * cmds_alloc);
+  cmds = 0;
+  cmds_index = cmds_alloc = 0;
+
+  for (i = 0; i < symtab_index; i++)
+    boot_script_free (symtab[i], sizeof *symtab[i]);
+  boot_script_free (symtab, sizeof symtab[0] * symtab_alloc);
+  symtab = 0;
+  symtab_index = symtab_alloc = 0;
+}
+
+/* Add PTR to the list of pointers PTR_LIST, which
+   currently has ALLOC amount of space allocated to it, and
+   whose next available slot is INDEX.  If more space
+   needs to to allocated, INCR is the amount by which
+   to increase it.  Return 0 on success, non-zero otherwise.  */
+static int
+add_list (void *ptr, void ***ptr_list, int *alloc, int *index, int incr)
+{
+  if (*index == *alloc)
+    {
+      void **p;
+
+      *alloc += incr;
+      p = boot_script_malloc (*alloc * sizeof (void *));
+      if (! p)
+	{
+	  *alloc -= incr;
+	  return 1;
+	}
+      if (*ptr_list)
+	{
+	  memcpy (p, *ptr_list, *index * sizeof (void *));
+	  boot_script_free (*ptr_list, (*alloc - incr) * sizeof (void *));
+	}
+      *ptr_list = p;
+    }
+  *(*ptr_list + *index) = ptr;
+  *index += 1;
+  return 0;
+}
+
+/* Create an argument with TEXT, value type TYPE, and value VAL.
+   Add the argument to the argument list of CMD.  */
+static struct arg *
+add_arg (struct cmd *cmd, char *text, int type, int val)
+{
+  struct arg *arg;
+
+  arg = boot_script_malloc (sizeof (struct arg));
+  if (arg)
+    {
+      arg->text = text;
+      arg->type = type;
+      arg->val = val;
+      if (add_list (arg, (void ***) &cmd->args,
+		    &cmd->args_alloc, &cmd->args_index, 5))
+	{
+	  boot_script_free (arg, sizeof *arg);
+	  return 0;
+	}
+    }
+  return arg;
+}
+
+/* Search for the symbol NAME in the symbol table.  */
+static struct sym *
+sym_lookup (const char *name)
+{
+  int i;
+
+  for (i = 0; i < symtab_index; i++)
+    if (! strcmp (name, symtab[i]->name))
+      return symtab[i];
+  return 0;
+}
+
+/* Create an entry for symbol NAME in the symbol table.  */
+static struct sym *
+sym_enter (const char *name)
+{
+  struct sym *sym;
+
+  sym = boot_script_malloc (sizeof (struct sym));
+  if (sym)
+    {
+      memset (sym, 0, sizeof (struct sym));
+      sym->name = name;
+      if (add_list (sym, (void ***) &symtab, &symtab_alloc, &symtab_index, 20))
+	{
+	  boot_script_free (sym, sizeof *sym);
+	  return 0;
+	}
+    }
+  return sym;
+}
+
+/* Parse the command line CMDLINE.  */
+int
+boot_script_parse_line (void *hook, char *cmdline)
+{
+  char *p, *q;
+  int error;
+  struct cmd *cmd;
+  struct arg *arg;
+
+  /* Extract command name.  Ignore line if it lacks a command.  */
+  for (p = cmdline; *p == ' ' || *p == '\t'; p++)
+    ;
+  if (*p == '#')
+    /* Ignore comment line.  */
+    return 0;
+
+#if 0
+  if (*p && *p != ' ' && *p != '\t' && *p != '\n')
+    {
+      printf ("(bootstrap): %s\n", cmdline);
+    }
+#endif
+
+  for (q = p; *q && *q != ' ' && *q != '\t' && *q != '\n'; q++)
+    ;
+  if (p == q)
+      return 0;
+
+  *q = '\0';
+
+  /* Allocate a command structure.  */
+  cmd = boot_script_malloc (sizeof (struct cmd));
+  if (! cmd)
+    return BOOT_SCRIPT_NOMEM;
+  memset (cmd, 0, sizeof (struct cmd));
+  cmd->hook = hook;
+  cmd->path = p;
+  p = q + 1;
+
+  for (arg = 0;;)
+    {
+      if (! arg)
+	{
+	  /* Skip whitespace.  */
+	  while (*p == ' ' || *p == '\t')
+	    p++;
+
+	  /* End of command line.  */
+	  if (! *p || *p == '\n')
+	    {
+	      /* Add command to list.  */
+	      if (add_list (cmd, (void ***) &cmds,
+			    &cmds_alloc, &cmds_index, 10))
+		{
+		  error = BOOT_SCRIPT_NOMEM;
+		  goto bad;
+		}
+	      return 0;
+	    }
+	}
+
+      /* Look for a symbol.  */
+      if (arg || (*p == '$' && (*(p + 1) == '{' || *(p + 1) == '(')))
+	{
+	  char end_char = (*(p + 1) == '{') ? '}' : ')';
+	  struct sym *sym = 0;
+
+	  for (p += 2;;)
+	    {
+	      char c;
+	      int i, val, type;
+	      struct sym *s;
+
+	      /* Parse symbol name.  */
+	      for (q = p; *q && *q != '\n' && *q != end_char && *q != '='; q++)
+		;
+	      if (p == q || ! *q || *q == '\n'
+		  || (end_char == '}' && *q != '}'))
+		{
+		  error = BOOT_SCRIPT_SYNTAX_ERROR;
+		  goto bad;
+		}
+	      c = *q;
+	      *q = '\0';
+
+	      /* See if this is a builtin symbol.  */
+	      for (i = 0; i < NUM_BUILTIN; i++)
+		if (! strcmp (p, builtin_symbols[i].name))
+		  break;
+
+	      if (i < NUM_BUILTIN)
+		s = &builtin_symbols[i];
+	      else
+		{
+		  /* Look up symbol in symbol table.
+		     If no entry exists, create one.  */
+		  s = sym_lookup (p);
+		  if (! s)
+		    {
+		      s = sym_enter (p);
+		      if (! s)
+			{
+			  error = BOOT_SCRIPT_NOMEM;
+			  goto bad;
+			}
+		    }
+		}
+
+	      /* Only values are allowed in ${...} constructs.  */
+	      if (end_char == '}' && s->type == VAL_FUNC)
+		return BOOT_SCRIPT_INVALID_SYM;
+
+	      /* Check that assignment is valid.  */
+	      if (c == '=' && s->type == VAL_FUNC)
+		{
+		  error = BOOT_SCRIPT_INVALID_ASG;
+		  goto bad;
+		}
+
+	      /* For function symbols, execute the function.  */
+	      if (s->type == VAL_FUNC)
+		{
+		  if (! s->run_on_exec)
+		    {
+		      (error
+		       = ((*((int (*) (struct cmd *, int *)) s->val))
+			  (cmd, &val)));
+		      if (error)
+			goto bad;
+		      type = s->ret_type;
+		    }
+		  else
+		    {
+		      if (add_list (s, (void ***) &cmd->exec_funcs,
+				    &cmd->exec_funcs_alloc,
+				    &cmd->exec_funcs_index, 5))
+			{
+			  error = BOOT_SCRIPT_NOMEM;
+			  goto bad;
+			}
+		      type = VAL_NONE;
+		      goto out;
+		    }
+		}
+	      else if (s->type == VAL_NONE)
+		{
+		  type = VAL_SYM;
+		  val = (int) s;
+ 		}
+	      else
+		{
+		  type = s->type;
+		  val = s->val;
+		}
+
+	      if (sym)
+		{
+		  sym->type = type;
+		  sym->val = val;
+		}
+	      else if (arg)
+		{
+		  arg->type = type;
+		  arg->val = val;
+		}
+
+	    out:
+	      p = q + 1;
+	      if (c == end_char)
+		{
+		  /* Create an argument if necessary.
+		     We create an argument if the symbol appears
+		     in the expression by itself.
+
+		     NOTE: This is temporary till the boot filesystem
+		     servers support arguments.  When that happens,
+		     symbol values will only be printed if they're
+		     associated with an argument.  */
+		  if (! arg && end_char == '}')
+		    {
+		      if (! add_arg (cmd, 0, type, val))
+			{
+			  error = BOOT_SCRIPT_NOMEM;
+			  goto bad;
+			}
+		    }
+		  arg = 0;
+		  break;
+		}
+	      if (s->type != VAL_FUNC)
+		sym = s;
+	    }
+	}
+      else
+	{
+	  char c;
+
+	  /* Command argument; just copy the text.  */
+	  for (q = p;; q++)
+	    {
+	      if (! *q || *q == ' ' || *q == '\t' || *q == '\n')
+		break;
+	      if (*q == '$' && *(q + 1) == '{')
+		break;
+	    }
+	  c = *q;
+	  *q = '\0';
+
+	  /* Add argument to list.  */
+	  arg = add_arg (cmd, p, VAL_NONE, 0);
+	  if (! arg)
+	    {
+	      error = BOOT_SCRIPT_NOMEM;
+	      goto bad;
+	    }
+	  if (c == '$')
+	    p = q;
+	  else
+	    {
+	      if (c)
+		p = q + 1;
+	      else
+		p = q;
+	      arg = 0;
+	    }
+	}
+    }
+
+
+ bad:
+  free_cmd (cmd, 1);
+  cleanup (1);
+  return error;
+}
+
+/* Ensure that the command line buffer can accommodate LEN bytes of space.  */
+#define CHECK_CMDLINE_LEN(len) \
+{ \
+  if (cmdline_alloc - cmdline_index < len) \
+    { \
+      char *ptr; \
+      int alloc, i; \
+      alloc = cmdline_alloc + len - (cmdline_alloc - cmdline_index) + 100; \
+      ptr = boot_script_malloc (alloc); \
+      if (! ptr) \
+	{ \
+	  error = BOOT_SCRIPT_NOMEM; \
+	  goto done; \
+	} \
+      memcpy (ptr, cmdline, cmdline_index); \
+      for (i = 0; i < argc; ++i) \
+	argv[i] = ptr + (argv[i] - cmdline); \
+      boot_script_free (cmdline, cmdline_alloc); \
+      cmdline = ptr; \
+      cmdline_alloc = alloc; \
+    } \
+}
+
+/* Execute commands previously parsed.  */
+int
+boot_script_exec ()
+{
+  int cmd_index;
+
+  for (cmd_index = 0; cmd_index < cmds_index; cmd_index++)
+    {
+      char **argv, *cmdline;
+      int i, argc, cmdline_alloc;
+      int cmdline_index, error, arg_index;
+      struct cmd *cmd = cmds[cmd_index];
+
+      /* Skip command if it doesn't have an associated task.  */
+      if (cmd->task == 0)
+	continue;
+
+      /* Allocate a command line and copy command name.  */
+      cmdline_index = strlen (cmd->path) + 1;
+      cmdline_alloc = cmdline_index + 100;
+      cmdline = boot_script_malloc (cmdline_alloc);
+      if (! cmdline)
+	{
+	  cleanup (1);
+	  return BOOT_SCRIPT_NOMEM;
+	}
+      memcpy (cmdline, cmd->path, cmdline_index);
+
+      /* Allocate argument vector.  */
+      argv = boot_script_malloc (sizeof (char *) * (cmd->args_index + 2));
+      if (! argv)
+	{
+	  boot_script_free (cmdline, cmdline_alloc);
+	  cleanup (1);
+	  return BOOT_SCRIPT_NOMEM;
+	}
+      argv[0] = cmdline;
+      argc = 1;
+
+      /* Build arguments.  */
+      for (arg_index = 0; arg_index < cmd->args_index; arg_index++)
+	{
+	  struct arg *arg = cmd->args[arg_index];
+
+	  /* Copy argument text.  */
+	  if (arg->text)
+	    {
+	      int len = strlen (arg->text);
+
+	      if (arg->type == VAL_NONE)
+		len++;
+	      CHECK_CMDLINE_LEN (len);
+	      memcpy (cmdline + cmdline_index, arg->text, len);
+	      argv[argc++] = &cmdline[cmdline_index];
+	      cmdline_index += len;
+	    }
+
+	  /* Add value of any symbol associated with this argument.  */
+	  if (arg->type != VAL_NONE)
+	    {
+	      char *p, buf[50];
+	      int len;
+	      mach_port_t name;
+
+	      if (arg->type == VAL_SYM)
+		{
+		  struct sym *sym = (struct sym *) arg->val;
+
+		  /* Resolve symbol value.  */
+		  while (sym->type == VAL_SYM)
+		    sym = (struct sym *) sym->val;
+		  if (sym->type == VAL_NONE)
+		    {
+		      error = BOOT_SCRIPT_UNDEF_SYM;
+		      goto done;
+		    }
+		  arg->type = sym->type;
+		  arg->val = sym->val;
+		}
+
+	      /* Print argument value.  */
+	      switch (arg->type)
+		{
+		case VAL_STR:
+		  p = (char *) arg->val;
+		  len = strlen (p);
+		  break;
+
+		case VAL_TASK:
+		case VAL_PORT:
+		  if (arg->type == VAL_TASK)
+		    /* Insert send right to task port.  */
+		    error = boot_script_insert_task_port
+		      (cmd, (task_t) arg->val, &name);
+		  else
+		    /* Insert send right.  */
+		    error = boot_script_insert_right (cmd,
+						      (mach_port_t) arg->val,
+						      &name);
+		  if (error)
+		    goto done;
+
+		  i = name;
+		  p = buf + sizeof (buf);
+		  len = 0;
+		  do
+		    {
+		      *--p = i % 10 + '0';
+		      len++;
+		    }
+		  while (i /= 10);
+		  break;
+
+		default:
+		  error = BOOT_SCRIPT_BAD_TYPE;
+		  goto done;
+		}
+	      len++;
+	      CHECK_CMDLINE_LEN (len);
+	      memcpy (cmdline + cmdline_index, p, len - 1);
+	      *(cmdline + cmdline_index + len - 1) = '\0';
+	      if (! arg->text)
+		  argv[argc++] = &cmdline[cmdline_index];
+	      cmdline_index += len;
+	    }
+	}
+
+      /* Terminate argument vector.  */
+      argv[argc] = 0;
+
+      /* Execute the command.  */
+      if (boot_script_exec_cmd (cmd->hook, cmd->task, cmd->path,
+				argc, argv, cmdline, cmdline_index))
+	{
+	  error = BOOT_SCRIPT_EXEC_ERROR;
+	  goto done;
+	}
+
+      error = 0;
+
+    done:
+      boot_script_free (cmdline, cmdline_alloc);
+      boot_script_free (argv, sizeof (char *) * (cmd->args_index + 2));
+      if (error)
+	{
+	  cleanup (1);
+	  return error;
+	}
+    }
+
+  for (cmd_index = 0; cmd_index < cmds_index; cmd_index++)
+    {
+      int i;
+      struct cmd *cmd = cmds[cmd_index];
+
+      /* Execute functions that want to be run on exec.  */
+      for (i = 0; i < cmd->exec_funcs_index; i++)
+	{
+	  struct sym *sym = cmd->exec_funcs[i];
+	  int error = ((*((int (*) (struct cmd *, int *)) sym->val))
+		       (cmd, 0));
+	  if (error)
+	    {
+	      cleanup (1);
+	      return error;
+	    }
+	}
+    }
+
+  cleanup (0);
+  return 0;
+}
+
+/* Create an entry for the variable NAME with TYPE and value VAL,
+   in the symbol table.  */
+int
+boot_script_set_variable (const char *name, int type, int val)
+{
+  struct sym *sym = sym_enter (name);
+
+  if (sym)
+    {
+      sym->type = type;
+      sym->val = val;
+    }
+  return sym ? 0 : 1;
+}
+
+
+/* Define the function NAME, which will return type RET_TYPE.  */
+int
+boot_script_define_function (const char *name, int ret_type,
+			     int (*func) (const struct cmd *cmd, int *val))
+{
+  struct sym *sym = sym_enter (name);
+
+  if (sym)
+    {
+      sym->type = VAL_FUNC;
+      sym->val = (int) func;
+      sym->ret_type = ret_type;
+      sym->run_on_exec = ret_type == VAL_NONE;
+    }
+  return sym ? 0 : 1;
+}
+
+
+/* Return a string describing ERR.  */
+char *
+boot_script_error_string (int err)
+{
+  switch (err)
+    {
+    case BOOT_SCRIPT_NOMEM:
+      return "no memory";
+
+    case BOOT_SCRIPT_SYNTAX_ERROR:
+      return "syntax error";
+
+    case BOOT_SCRIPT_INVALID_ASG:
+      return "invalid variable in assignment";
+
+    case BOOT_SCRIPT_MACH_ERROR:
+      return "mach error";
+
+    case BOOT_SCRIPT_UNDEF_SYM:
+      return "undefined symbol";
+
+    case BOOT_SCRIPT_EXEC_ERROR:
+      return "exec error";
+
+    case BOOT_SCRIPT_INVALID_SYM:
+      return "invalid variable in expression";
+
+    case BOOT_SCRIPT_BAD_TYPE:
+      return "invalid value type";
+    }
+  return 0;
+}
+
+#ifdef BOOT_SCRIPT_TEST
+#include <stdio.h>
+
+int
+boot_script_exec_cmd (void *hook,
+		      mach_port_t task, char *path, int argc,
+		      char **argv, char *strings, int stringlen)
+{
+  int i;
+
+  printf ("port = %d: ", (int) task);
+  for (i = 0; i < argc; i++)
+    printf ("%s ", argv[i]);
+  printf ("\n");
+  return 0;
+}
+
+void
+main (int argc, char **argv)
+{
+  char buf[500], *p;
+  int len;
+  FILE *fp;
+  mach_port_t host_port, device_port;
+
+  if (argc < 2)
+    {
+      fprintf (stderr, "Usage: %s <script>\n", argv[0]);
+      exit (1);
+    }
+  fp = fopen (argv[1], "r");
+  if (! fp)
+    {
+      fprintf (stderr, "Can't open %s\n", argv[1]);
+      exit (1);
+    }
+  host_port = 1;
+  device_port = 2;
+  boot_script_set_variable ("host-port", VAL_PORT, (int) host_port);
+  boot_script_set_variable ("device-port", VAL_PORT, (int) device_port);
+  boot_script_set_variable ("root-device", VAL_STR, (int) "hd0a");
+  boot_script_set_variable ("boot-args", VAL_STR, (int) "-ad");
+  p = buf;
+  len = sizeof (buf);
+  while (fgets (p, len, fp))
+    {
+      int i, err;
+
+      i = strlen (p) + 1;
+      err = boot_script_parse_line (0, p);
+      if (err)
+	{
+	  fprintf (stderr, "error %s\n", boot_script_error_string (err));
+	  exit (1);
+	}
+      p += i;
+      len -= i;
+    }
+  boot_script_exec ();
+  exit (0);
+}
+#endif /* BOOT_SCRIPT_TEST */