Files
libguestfs/generator/daemon.ml
Richard W.M. Jones 7d2ae9f30f daemon: Generate the code when libraries are statically not available.
Since we as developers rarely test the case where some library is
statically not available, that side of the code was hardly tested,
except by unfortunate users in the field who often hit cases where
functions were missing or misdeclared.  In fact, when making this
change I noticed several bugs like that.

Change it so that this code is autogenerated, and therefore always
correct and up to date.

Previous code which looked like this:

  int
  optgroup_acl_available (void)
  {
    return 0;
  }

  char * __attribute__((noreturn))
  do_acl_get_file (const char *path, const char *acltype)
  {
    abort ();
  }

  /* etc */

is replaced by a single line:

  OPTGROUP_ACL_NOT_AVAILABLE
2012-12-10 16:20:34 +00:00

625 lines
22 KiB
OCaml

(* libguestfs
* Copyright (C) 2009-2012 Red Hat Inc.
*
* 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 of the License, 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*)
(* Please read generator/README first. *)
open Printf
open Types
open Utils
open Pr
open Docstrings
open Optgroups
open Actions
open Structs
open C
(* Generate daemon/actions.h. *)
let generate_daemon_actions_h () =
generate_header CStyle GPLv2plus;
pr "#ifndef GUESTFSD_ACTIONS_H\n";
pr "#define GUESTFSD_ACTIONS_H\n";
pr "\n";
pr "#include \"guestfs_protocol.h\"\n";
pr "\n";
List.iter (
function
| { style = _, _, [] } -> ()
| { name = shortname; style = _, _, (_::_ as optargs) } ->
iteri (
fun i arg ->
let uc_shortname = String.uppercase shortname in
let n = name_of_optargt arg in
let uc_n = String.uppercase n in
pr "#define GUESTFS_%s_%s_BITMASK (UINT64_C(1)<<%d)\n"
uc_shortname uc_n i
) optargs
) daemon_functions;
List.iter (
fun { name = name; style = ret, args, optargs } ->
let style = ret, args @ args_of_optargs optargs, [] in
generate_prototype
~single_line:true ~newline:true ~in_daemon:true ~prefix:"do_"
name style;
) daemon_functions;
pr "\n";
pr "#endif /* GUESTFSD_ACTIONS_H */\n"
(* Generate the server-side stubs. *)
and generate_daemon_actions () =
generate_header CStyle GPLv2plus;
pr "#include <config.h>\n";
pr "\n";
pr "#include <stdio.h>\n";
pr "#include <stdlib.h>\n";
pr "#include <string.h>\n";
pr "#include <inttypes.h>\n";
pr "#include <errno.h>\n";
pr "#include <rpc/types.h>\n";
pr "#include <rpc/xdr.h>\n";
pr "\n";
pr "#include \"daemon.h\"\n";
pr "#include \"c-ctype.h\"\n";
pr "#include \"guestfs_protocol.h\"\n";
pr "#include \"actions.h\"\n";
pr "#include \"optgroups.h\"\n";
pr "\n";
List.iter (
fun { name = name; style = ret, args, optargs; optional = optional } ->
(* Generate server-side stubs. *)
pr "static void\n";
pr "%s_stub (XDR *xdr_in)\n" name;
pr "{\n";
(match ret with
| RErr | RInt _ -> pr " int r;\n"
| RInt64 _ -> pr " int64_t r;\n"
| RBool _ -> pr " int r;\n"
| RConstString _ | RConstOptString _ ->
failwithf "RConstString|RConstOptString cannot be used by daemon functions"
| RString _ -> pr " char *r;\n"
| RStringList _ | RHashtable _ -> pr " char **r;\n"
| RStruct (_, typ) -> pr " guestfs_int_%s *r;\n" typ
| RStructList (_, typ) -> pr " guestfs_int_%s_list *r;\n" typ
| RBufferOut _ ->
pr " size_t size = 1;\n";
pr " char *r;\n"
);
if args <> [] || optargs <> [] then (
pr " struct guestfs_%s_args args;\n" name;
List.iter (
function
| Device n | Dev_or_Path n
| Pathname n
| String n
| Key n
| OptString n -> pr " char *%s;\n" n
| StringList n | DeviceList n -> pr " char **%s;\n" n
| Bool n -> pr " int %s;\n" n
| Int n -> pr " int %s;\n" n
| Int64 n -> pr " int64_t %s;\n" n
| FileIn _ | FileOut _ -> ()
| BufferIn n ->
pr " const char *%s;\n" n;
pr " size_t %s_size;\n" n
| Pointer _ -> assert false
) (args @ args_of_optargs optargs)
);
pr "\n";
let is_filein =
List.exists (function FileIn _ -> true | _ -> false) args in
(* Reject Optional functions that are not available (RHBZ#679737). *)
(match optional with
| Some group ->
pr " /* The caller should have checked before calling this. */\n";
pr " if (! optgroup_%s_available ()) {\n" group;
if is_filein then
pr " cancel_receive ();\n";
pr " reply_with_error_errno (ENOTSUP,\n";
pr " \"feature '%%s' is not available in this\\n\"\n";
pr " \"build of libguestfs. Read 'AVAILABILITY' in the guestfs(3) man page for\\n\"\n";
pr " \"how to check for the availability of features.\",\n";
pr " \"%s\");\n" group;
pr " goto done_no_free;\n";
pr " }\n";
pr "\n"
| None -> ()
);
(* Reject unknown optional arguments.
* Note this code is included even for calls with no optional
* args because the caller must not pass optargs_bitmask != 0
* in that case.
*)
if optargs <> [] then (
let len = List.length optargs in
let mask = Int64.lognot (Int64.pred (Int64.shift_left 1L len)) in
pr " if (optargs_bitmask & UINT64_C(0x%Lx)) {\n" mask;
if is_filein then
pr " cancel_receive ();\n";
pr " reply_with_error (\"unknown option in optional arguments bitmask (this can happen if a program is compiled against a newer version of libguestfs, then run against an older version of the daemon)\");\n";
pr " goto done_no_free;\n";
pr " }\n";
) else (
pr " if (optargs_bitmask != 0) {\n";
if is_filein then
pr " cancel_receive ();\n";
pr " reply_with_error (\"header optargs_bitmask field must be passed as 0 for calls that don't take optional arguments\");\n";
pr " goto done_no_free;\n";
pr " }\n";
);
pr "\n";
(* Decode arguments. *)
if args <> [] || optargs <> [] then (
pr " memset (&args, 0, sizeof args);\n";
pr "\n";
pr " if (!xdr_guestfs_%s_args (xdr_in, &args)) {\n" name;
if is_filein then
pr " cancel_receive ();\n";
pr " reply_with_error (\"daemon failed to decode procedure arguments\");\n";
pr " goto done;\n";
pr " }\n";
let pr_args n =
pr " %s = args.%s;\n" n n
in
let pr_list_handling_code n =
pr " %s = realloc (args.%s.%s_val,\n" n n n;
pr " sizeof (char *) * (args.%s.%s_len+1));\n" n n;
pr " if (%s == NULL) {\n" n;
if is_filein then
pr " cancel_receive ();\n";
pr " reply_with_perror (\"realloc\");\n";
pr " goto done;\n";
pr " }\n";
pr " %s[args.%s.%s_len] = NULL;\n" n n n;
pr " args.%s.%s_val = %s;\n" n n n;
in
List.iter (
function
| Pathname n ->
pr_args n;
pr " ABS_PATH (%s, %s, goto done);\n"
n (if is_filein then "cancel_receive ()" else "");
| Device n ->
pr_args n;
pr " RESOLVE_DEVICE (%s, %s, goto done);\n"
n (if is_filein then "cancel_receive ()" else "");
| Dev_or_Path n ->
pr_args n;
pr " REQUIRE_ROOT_OR_RESOLVE_DEVICE (%s, %s, goto done);\n"
n (if is_filein then "cancel_receive ()" else "");
| String n | Key n -> pr_args n
| OptString n -> pr " %s = args.%s ? *args.%s : NULL;\n" n n n
| StringList n ->
pr_list_handling_code n;
| DeviceList n ->
pr_list_handling_code n;
pr " /* Ensure that each is a device,\n";
pr " * and perform device name translation.\n";
pr " */\n";
pr " {\n";
pr " size_t i;\n";
pr " for (i = 0; %s[i] != NULL; ++i)\n" n;
pr " RESOLVE_DEVICE (%s[i], %s, goto done);\n" n
(if is_filein then "cancel_receive ()" else "");
pr " }\n";
| Bool n -> pr " %s = args.%s;\n" n n
| Int n -> pr " %s = args.%s;\n" n n
| Int64 n -> pr " %s = args.%s;\n" n n
| FileIn _ | FileOut _ -> ()
| BufferIn n ->
pr " %s = args.%s.%s_val;\n" n n n;
pr " %s_size = args.%s.%s_len;\n" n n n
| Pointer _ -> assert false
) (args @ args_of_optargs optargs);
pr "\n"
);
(* this is used at least for do_equal *)
if List.exists (function Pathname _ -> true | _ -> false) args then (
(* Emit NEED_ROOT just once, even when there are two or
more Pathname args *)
pr " NEED_ROOT (%s, goto done);\n"
(if is_filein then "cancel_receive ()" else "");
);
(* Don't want to call the impl with any FileIn or FileOut
* parameters, since these go "outside" the RPC protocol.
*)
let () =
let args' =
List.filter
(function FileIn _ | FileOut _ -> false | _ -> true) args in
let style = ret, args' @ args_of_optargs optargs, [] in
pr " r = do_%s " name;
generate_c_call_args style;
pr ";\n" in
(match ret with
| RConstOptString _ -> assert false
| RErr | RInt _ | RInt64 _ | RBool _
| RConstString _
| RString _ | RStringList _ | RHashtable _
| RStruct (_, _) | RStructList (_, _) ->
let errcode =
match errcode_of_ret ret with
| `CannotReturnError -> assert false
| (`ErrorIsMinusOne | `ErrorIsNULL) as e -> e in
pr " if (r == %s)\n" (string_of_errcode errcode);
pr " /* do_%s has already called reply_with_error */\n" name;
pr " goto done;\n";
pr "\n"
| RBufferOut _ ->
pr " /* size == 0 && r == NULL could be a non-error case (just\n";
pr " * an ordinary zero-length buffer), so be careful ...\n";
pr " */\n";
pr " if (size == 1 && r == NULL)\n";
pr " /* do_%s has already called reply_with_error */\n" name;
pr " goto done;\n";
pr "\n"
);
(* If there are any FileOut parameters, then the impl must
* send its own reply.
*)
let no_reply =
List.exists (function FileOut _ -> true | _ -> false) args in
if no_reply then
pr " /* do_%s has already sent a reply */\n" name
else (
match ret with
| RErr -> pr " reply (NULL, NULL);\n"
| RInt n | RInt64 n | RBool n ->
pr " struct guestfs_%s_ret ret;\n" name;
pr " ret.%s = r;\n" n;
pr " reply ((xdrproc_t) &xdr_guestfs_%s_ret, (char *) &ret);\n"
name
| RConstString _ | RConstOptString _ ->
failwithf "RConstString|RConstOptString cannot be used by daemon functions"
| RString n ->
pr " struct guestfs_%s_ret ret;\n" name;
pr " ret.%s = r;\n" n;
pr " reply ((xdrproc_t) &xdr_guestfs_%s_ret, (char *) &ret);\n"
name;
pr " free (r);\n"
| RStringList n | RHashtable n ->
pr " struct guestfs_%s_ret ret;\n" name;
pr " ret.%s.%s_len = count_strings (r);\n" n n;
pr " ret.%s.%s_val = r;\n" n n;
pr " reply ((xdrproc_t) &xdr_guestfs_%s_ret, (char *) &ret);\n"
name;
pr " free_strings (r);\n"
| RStruct (n, _) ->
pr " struct guestfs_%s_ret ret;\n" name;
pr " ret.%s = *r;\n" n;
pr " free (r);\n";
pr " reply ((xdrproc_t) xdr_guestfs_%s_ret, (char *) &ret);\n"
name;
pr " xdr_free ((xdrproc_t) xdr_guestfs_%s_ret, (char *) &ret);\n"
name
| RStructList (n, _) ->
pr " struct guestfs_%s_ret ret;\n" name;
pr " ret.%s = *r;\n" n;
pr " free (r);\n";
pr " reply ((xdrproc_t) xdr_guestfs_%s_ret, (char *) &ret);\n"
name;
pr " xdr_free ((xdrproc_t) xdr_guestfs_%s_ret, (char *) &ret);\n"
name
| RBufferOut n ->
pr " struct guestfs_%s_ret ret;\n" name;
pr " ret.%s.%s_val = r;\n" n n;
pr " ret.%s.%s_len = size;\n" n n;
pr " reply ((xdrproc_t) &xdr_guestfs_%s_ret, (char *) &ret);\n"
name;
pr " free (r);\n"
);
(* Free the args. *)
pr "done:\n";
(match args with
| [] -> ()
| _ ->
pr " xdr_free ((xdrproc_t) xdr_guestfs_%s_args, (char *) &args);\n"
name
);
pr "done_no_free:\n";
pr " return;\n";
pr "}\n\n";
) daemon_functions;
(* Dispatch function. *)
pr "void dispatch_incoming_message (XDR *xdr_in)\n";
pr "{\n";
pr " switch (proc_nr) {\n";
List.iter (
fun { name = name } ->
pr " case GUESTFS_PROC_%s:\n" (String.uppercase name);
pr " %s_stub (xdr_in);\n" name;
pr " break;\n"
) daemon_functions;
pr " default:\n";
pr " reply_with_error (\"dispatch_incoming_message: unknown procedure number %%d, set LIBGUESTFS_PATH to point to the matching libguestfs appliance directory\", proc_nr);\n";
pr " }\n";
pr "}\n";
pr "\n";
(* LVM columns and tokenization functions. *)
(* XXX This generates crap code. We should rethink how we
* do this parsing.
*)
List.iter (
function
| typ, cols ->
pr "static const char *lvm_%s_cols = \"%s\";\n"
typ (String.concat "," (List.map fst cols));
pr "\n";
pr "static int lvm_tokenize_%s (char *str, guestfs_int_lvm_%s *r)\n" typ typ;
pr "{\n";
pr " char *tok, *p, *next;\n";
pr " size_t i, j;\n";
pr "\n";
(*
pr " fprintf (stderr, \"%%s: <<%%s>>\\n\", __func__, str);\n";
pr "\n";
*)
pr " if (!str) {\n";
pr " fprintf (stderr, \"%%s: failed: passed a NULL string\\n\", __func__);\n";
pr " return -1;\n";
pr " }\n";
pr " if (!*str || c_isspace (*str)) {\n";
pr " fprintf (stderr, \"%%s: failed: passed a empty string or one beginning with whitespace\\n\", __func__);\n";
pr " return -1;\n";
pr " }\n";
pr " tok = str;\n";
List.iter (
fun (name, coltype) ->
pr " if (!tok) {\n";
pr " fprintf (stderr, \"%%s: failed: string finished early, around token %%s\\n\", __func__, \"%s\");\n" name;
pr " return -1;\n";
pr " }\n";
pr " p = strchrnul (tok, ',');\n";
pr " if (*p) next = p+1; else next = NULL;\n";
pr " *p = '\\0';\n";
(match coltype with
| FString ->
pr " r->%s = strdup (tok);\n" name;
pr " if (r->%s == NULL) {\n" name;
pr " perror (\"strdup\");\n";
pr " return -1;\n";
pr " }\n"
| FUUID ->
pr " for (i = j = 0; i < 32; ++j) {\n";
pr " if (tok[j] == '\\0') {\n";
pr " fprintf (stderr, \"%%s: failed to parse UUID from '%%s'\\n\", __func__, tok);\n";
pr " return -1;\n";
pr " } else if (tok[j] != '-')\n";
pr " r->%s[i++] = tok[j];\n" name;
pr " }\n";
| FBytes ->
pr " if (sscanf (tok, \"%%\"SCNu64, &r->%s) != 1) {\n" name;
pr " fprintf (stderr, \"%%s: failed to parse size '%%s' from token %%s\\n\", __func__, tok, \"%s\");\n" name;
pr " return -1;\n";
pr " }\n";
| FInt64 ->
pr " if (sscanf (tok, \"%%\"SCNi64, &r->%s) != 1) {\n" name;
pr " fprintf (stderr, \"%%s: failed to parse int '%%s' from token %%s\\n\", __func__, tok, \"%s\");\n" name;
pr " return -1;\n";
pr " }\n";
| FOptPercent ->
pr " if (tok[0] == '\\0')\n";
pr " r->%s = -1;\n" name;
pr " else if (sscanf (tok, \"%%f\", &r->%s) != 1) {\n" name;
pr " fprintf (stderr, \"%%s: failed to parse float '%%s' from token %%s\\n\", __func__, tok, \"%s\");\n" name;
pr " return -1;\n";
pr " }\n";
| FBuffer | FInt32 | FUInt32 | FUInt64 | FChar ->
assert false (* can never be an LVM column *)
);
pr " tok = next;\n";
) cols;
pr " if (tok != NULL) {\n";
pr " fprintf (stderr, \"%%s: failed: extra tokens at end of string\\n\", __func__);\n";
pr " return -1;\n";
pr " }\n";
pr " return 0;\n";
pr "}\n";
pr "\n";
pr "guestfs_int_lvm_%s_list *\n" typ;
pr "parse_command_line_%ss (void)\n" typ;
pr "{\n";
pr " char *out, *err;\n";
pr " char *p, *pend;\n";
pr " int r, i;\n";
pr " guestfs_int_lvm_%s_list *ret;\n" typ;
pr " void *newp;\n";
pr "\n";
pr " ret = malloc (sizeof *ret);\n";
pr " if (!ret) {\n";
pr " reply_with_perror (\"malloc\");\n";
pr " return NULL;\n";
pr " }\n";
pr "\n";
pr " ret->guestfs_int_lvm_%s_list_len = 0;\n" typ;
pr " ret->guestfs_int_lvm_%s_list_val = NULL;\n" typ;
pr "\n";
pr " r = command (&out, &err,\n";
pr " \"lvm\", \"%ss\",\n" typ;
pr " \"-o\", lvm_%s_cols, \"--unbuffered\", \"--noheadings\",\n" typ;
pr " \"--nosuffix\", \"--separator\", \",\", \"--units\", \"b\", NULL);\n";
pr " if (r == -1) {\n";
pr " reply_with_error (\"%%s\", err);\n";
pr " free (out);\n";
pr " free (err);\n";
pr " free (ret);\n";
pr " return NULL;\n";
pr " }\n";
pr "\n";
pr " free (err);\n";
pr "\n";
pr " /* Tokenize each line of the output. */\n";
pr " p = out;\n";
pr " i = 0;\n";
pr " while (p) {\n";
pr " pend = strchr (p, '\\n'); /* Get the next line of output. */\n";
pr " if (pend) {\n";
pr " *pend = '\\0';\n";
pr " pend++;\n";
pr " }\n";
pr "\n";
pr " while (*p && c_isspace (*p)) /* Skip any leading whitespace. */\n";
pr " p++;\n";
pr "\n";
pr " if (!*p) { /* Empty line? Skip it. */\n";
pr " p = pend;\n";
pr " continue;\n";
pr " }\n";
pr "\n";
pr " /* Allocate some space to store this next entry. */\n";
pr " newp = realloc (ret->guestfs_int_lvm_%s_list_val,\n" typ;
pr " sizeof (guestfs_int_lvm_%s) * (i+1));\n" typ;
pr " if (newp == NULL) {\n";
pr " reply_with_perror (\"realloc\");\n";
pr " free (ret->guestfs_int_lvm_%s_list_val);\n" typ;
pr " free (ret);\n";
pr " free (out);\n";
pr " return NULL;\n";
pr " }\n";
pr " ret->guestfs_int_lvm_%s_list_val = newp;\n" typ;
pr "\n";
pr " /* Tokenize the next entry. */\n";
pr " r = lvm_tokenize_%s (p, &ret->guestfs_int_lvm_%s_list_val[i]);\n" typ typ;
pr " if (r == -1) {\n";
pr " reply_with_error (\"failed to parse output of '%ss' command\");\n" typ;
pr " free (ret->guestfs_int_lvm_%s_list_val);\n" typ;
pr " free (ret);\n";
pr " free (out);\n";
pr " return NULL;\n";
pr " }\n";
pr "\n";
pr " ++i;\n";
pr " p = pend;\n";
pr " }\n";
pr "\n";
pr " ret->guestfs_int_lvm_%s_list_len = i;\n" typ;
pr "\n";
pr " free (out);\n";
pr " return ret;\n";
pr "}\n"
) ["pv", lvm_pv_cols; "vg", lvm_vg_cols; "lv", lvm_lv_cols]
(* Generate a list of function names, for debugging in the daemon.. *)
and generate_daemon_names () =
generate_header CStyle GPLv2plus;
pr "#include <config.h>\n";
pr "\n";
pr "#include \"daemon.h\"\n";
pr "\n";
pr "/* This array is indexed by proc_nr. See guestfs_protocol.x. */\n";
pr "const char *function_names[] = {\n";
List.iter (
function
| { name = name; proc_nr = Some proc_nr } ->
pr " [%d] = \"%s\",\n" proc_nr name
| { proc_nr = None } -> assert false
) daemon_functions;
pr "};\n";
(* Generate the optional groups for the daemon to implement
* guestfs_available.
*)
and generate_daemon_optgroups_c () =
generate_header CStyle GPLv2plus;
pr "#include <config.h>\n";
pr "\n";
pr "#include \"daemon.h\"\n";
pr "#include \"optgroups.h\"\n";
pr "\n";
pr "struct optgroup optgroups[] = {\n";
List.iter (
fun (group, _) ->
pr " { \"%s\", optgroup_%s_available },\n" group group
) optgroups;
pr " { NULL, NULL }\n";
pr "};\n"
and generate_daemon_optgroups_h () =
generate_header CStyle GPLv2plus;
pr "#ifndef GUESTFSD_OPTGROUPS_H\n";
pr "#define GUESTFSD_OPTGROUPS_H\n";
pr "\n";
List.iter (
fun (group, _) ->
pr "extern int optgroup_%s_available (void);\n" group
) optgroups;
pr "\n";
pr "\
/* These macros can be used to disable an entire group of functions.
* The advantage of generating this code is that it avoids an
* undetected error when a new function in a group is added, but
* the appropriate abort function is not added to the daemon (because
* the developers rarely test that the daemon builds when a library
* is not present).
*/
";
List.iter (
fun (group, fns) ->
pr "#define OPTGROUP_%s_NOT_AVAILABLE \\\n" (String.uppercase group);
List.iter (
fun { name = name; style = ret, args, optargs } ->
let style = ret, args @ args_of_optargs optargs, [] in
pr " ";
generate_prototype
~prefix:"do_"
~attribute_noreturn:true
~single_line:true ~newline:false
~extern:false ~in_daemon:true
~semicolon:false
name style;
pr " { abort (); } \\\n"
) fns;
pr " int optgroup_%s_available (void) { return 0; }\n" group;
pr "\n"
) optgroups;
pr "#endif /* GUESTFSD_OPTGROUPS_H */\n"