* - The 'out' descriptor must be opened first
* - As soon as the backend script dies, the connection to the entry is
* closed.
+ * - To avoid user-inflicted pain, all entries are opened at the time
+ * that they are created. Reopening these entries is a little complicated
+ * but nevertheless sound:
+ * * When a script dies, its fd is reopened
+ * * If a script fails to execute, its fd is closed and reopened to
+ * beat a race that can happen when the user closes the connection
+ * before the script can be launched.
*)
open Inotify
open Printf
open Splice
-let backend_prefix = ref ""
-let direct_fifo_table: (string,(string*string) option) Hashtbl.t = Hashtbl.create 1024
+let close_if_open fd = (try (ignore(close fd);) with _ -> ())
+
+
+let direct_fifo_table: (string,(string*string*string*Unix.file_descr) option) Hashtbl.t = Hashtbl.create 1024
+let pidmap: (int,string) Hashtbl.t = Hashtbl.create 1024
let rec list_check lst elt =
match lst with
| [] -> false
| car::cdr -> if (car==elt) then true else list_check cdr elt
+let openentry_int fifoin =
+ let fdin =
+ try openfile fifoin [O_RDONLY;O_NONBLOCK] 0o777 with
+ e->fprintf logfd "Error opening and connecting FIFO: %s,%o\n" fifoin 0o777;flush logfd;raise e
+ in
+ fdin
+
+
+(** Open fifos for a session. SHOULD NOt shutdown vsys if the fifos don't exist *)
+let openentry_in root_dir fqp_in backend_spec =
+ Dirwatcher.mask_watch root_dir;
+ let fd_in = openentry_int fqp_in in
+ Dirwatcher.unmask_watch root_dir [S_Open];
+ let (fqp,slice_name) = backend_spec in
+ Hashtbl.replace direct_fifo_table fqp_in (Some(root_dir,fqp,slice_name,fd_in))
+
+let openentry root_dir fqp backend_spec =
+ let fqp_in = String.concat "." [fqp;"in"] in
+ openentry_in root_dir fqp_in backend_spec
+
+let reopenentry fifoin =
+ let entry = try Hashtbl.find direct_fifo_table fifoin with _ -> None in
+ match entry with
+ | Some(dir, fqp,slice_name,fd) -> close_if_open fd;openentry_in dir fifoin (fqp,slice_name)
+ | None -> ()
+
(* vsys is activated when a client opens an in file *)
-let connect_file mask_events fqp_out =
+let connect_file fqp_in =
(* Do we care about this file? *)
let entry_info = try
- Hashtbl.find direct_fifo_table fqp_out with _ -> None in
+ Hashtbl.find direct_fifo_table fqp_in with _ -> None in
match entry_info with
- | Some(execpath,slice_name) ->
+ | Some(_,execpath,slice_name,fifo_fdin) ->
fprintf logfd "Executing %s for slice %s\n" execpath slice_name;flush logfd;
begin
- let len = String.length fqp_out in
- let fqp = String.sub fqp_out 0 (len-4) in
- mask_events true;
- let fqp_in = String.concat "." [fqp;"in"] in
- let fifo_fdin =
- try openfile fqp_in [O_RDONLY;O_NONBLOCK] 0o777 with
- e->fprintf logfd "Error opening and connecting FIFO: %s\n" fqp_in;flush logfd;raise e
- in
+ let len = String.length fqp_in in
+ let fqp = String.sub fqp_in 0 (len-3) in
+ let fqp_out = String.concat "." [fqp;"out"] in
let fifo_fdout =
try openfile fqp_out [O_WRONLY;O_NONBLOCK] 0o777 with
_->fprintf logfd "%s Output pipe not open, using stdout in place of %s\n" slice_name fqp_out;flush logfd;stdout
in
- try ignore(create_process execpath [|execpath;slice_name|] fifo_fdin fifo_fdout fifo_fdout); with e -> begin fprintf logfd "Error executing service: %s\n" execpath;flush logfd end;
- close fifo_fdin;
- close fifo_fdout;
- mask_events false;
+ ignore(sigprocmask SIG_BLOCK [Sys.sigchld]);
+ (
+ clear_nonblock fifo_fdin;
+ let pid=try Some(create_process execpath [|execpath;slice_name|] fifo_fdin fifo_fdout fifo_fdout) with e -> None in
+ match pid with
+ | Some(pid) ->Hashtbl.add pidmap pid fqp_in
+ | None ->fprintf logfd "Error executing service: %s\n" execpath;flush logfd;reopenentry fqp_in
+ );
+ ignore(sigprocmask SIG_UNBLOCK [Sys.sigchld]);
end
| None -> ()
with
e->fprintf logfd "Error creating FIFO: %s->%s. May be something wrong at the frontend.\n" fqp fifoout;flush logfd;Failed)
-(** Open fifos for a session. SHOULD NOt shutdown vsys if the fifos don't exist *)
-let openentry fqp backend_spec =
- let fqp_in = String.concat "." [fqp;"out"] in
- Hashtbl.replace direct_fifo_table fqp_in (Some(backend_spec))
(** Close fifos that just got removed *)
let closeentry fqp =
- let fqp_in = String.concat "." [fqp;"out"] in
- Hashtbl.remove direct_fifo_table fqp_in
+ let fqp_in = String.concat "." [fqp;"in"] in
+ let entry = try Hashtbl.find direct_fifo_table fqp_in with Not_found -> None in
+ match entry with
+ | None -> ()
+ | Some(_,_,_,fd) ->
+ close_if_open fd;
+ Hashtbl.remove direct_fifo_table fqp_in
-let direct_fifo_handler wd dirname evlist fname =
- let mask_events flag =
- if (flag) then Dirwatcher.mask_events wd else Dirwatcher.unmask_events wd
- in
- let is_event = list_check evlist in
- if (is_event Open) then
- let fqp_out = String.concat "/" [dirname;fname] in
- connect_file mask_events fqp_out
+let sigchld_handle s =
+ let pid,_=Unix.waitpid [Unix.WNOHANG] 0 in
+ try
+ let fqp_in = Hashtbl.find pidmap pid in
+ printf "Reopening fifo\n";flush Pervasives.stdout;
+ reopenentry fqp_in
+ with _ -> ()
-let add_dir_watch fqp =
+let rec add_dir_watch fqp =
Dirwatcher.add_watch fqp [S_Open] direct_fifo_handler
+and
+direct_fifo_handler wd dirname evlist fname =
+ let is_event = list_check evlist in
+ if (is_event Open) then
+ let fqp_in = String.concat "/" [dirname;fname] in
+ begin
+ connect_file fqp_in;
+ add_dir_watch dirname
+ end
let del_dir_watch fqp =
(* XXX Dirwatcher.del_watch fqp *)
()
+
+let initialize () =
+ Sys.set_signal Sys.sigchld (Sys.Signal_handle sigchld_handle)
(** Watches directories for events. Agnostic to vsys semantics of backends and
-frontends *)
+ frontends *)
open Inotify
open Fdwatcher
open Printf
(* I don't know if a wd corresponding to a deleted directory is evicted or just
* leaks - fix implementation of rmdir accordingly
*)
-
-type 'a handlertype = Nohandler | Activehandler of 'a | Maskedhandler of 'a
-
let wdmap = Hashtbl.create 1024
+let masks = Hashtbl.create 1024
let fd = Inotify.init ()
+let rec list_check lst elt =
+ match lst with
+ | [] -> false
+ | car::cdr -> if (car==elt) then true else list_check cdr elt
+
let handle_dir_event dirname evlist str =
- let fname = String.concat "/" [dirname;str] in
- fprintf logfd "File: %s. " fname;List.iter
- (fun e ->
- fprintf logfd "Event: %s\n" (string_of_event e))
- evlist;
- flush logfd
+ let fname = String.concat "/" [dirname;str] in
+ fprintf logfd "File: %s. " fname;List.iter
+ (fun e ->
+ fprintf logfd "Event: %s\n" (string_of_event e))
+ evlist;
+ flush logfd
let add_watch dir events handler =
- let wd = Inotify.add_watch fd dir events in
- Hashtbl.add wdmap wd (dir,Activehandler(handler))
-
-let mask_events wd =
- let (dirname,handler) = try Hashtbl.find wdmap wd with Not_found->("",Nohandler)
- in
- match handler with
- | Activehandler(func)->
- Hashtbl.replace wdmap wd (dirname,Maskedhandler(func))
- | _ ->
- ()
-
-let unmask_events wd =
- let (dirname,handler) = try Hashtbl.find wdmap wd with Not_found->("",Nohandler)
+ let evcheck = list_check events in
+ let oneshot = if (evcheck S_Oneshot) then true else false
in
- match handler with
- | Maskedhandler(func)->
- Hashtbl.replace wdmap wd (dirname,Activehandler(func))
- | _ ->
- ()
+ let wd = Inotify.add_watch fd dir events in
+ Hashtbl.add masks dir (wd,handler);
+ Hashtbl.add wdmap wd (dir,Some(handler),oneshot)
+let mask_watch dir =
+ try
+ let wd,_ = Hashtbl.find masks dir in
+ Inotify.rm_watch fd wd;
+ Hashtbl.remove wdmap wd
+ with _ ->
+ ()
- (* XXX
-let del_watch dir =
- fprintf logfd "Removing watch for %s\n" dir;flush logfd;
- let wd = Inotify.rm_watch fd dir in
- Hashtbl.remove wdmap wd
- *)
+let unmask_watch dir events =
+ let _,handler = Hashtbl.find masks dir in
+ try
+ Hashtbl.remove masks dir;
+ add_watch dir events handler
+ with Not_found -> ()
let asciiz s =
let rec findfirstnul str idx len =
if ((idx==len) ||
- (str.[idx]==(char_of_int 0))) then idx
- else
- findfirstnul str (idx+1) len
+ (str.[idx]==(char_of_int 0))) then idx
+ else
+ findfirstnul str (idx+1) len
in
let nulterm = findfirstnul s 0 (String.length s) in
String.sub s 0 nulterm
let receive_event (eventdescriptor:fname_and_fd) (bla:fname_and_fd) =
let (_,fd) = eventdescriptor in
- let evs = Inotify.read fd in
- List.iter (fun x->
- match x with
- | (wd,evlist,_,Some(str)) ->
- let purestr = asciiz(str) in
- let (dirname,handler) =
- try Hashtbl.find wdmap wd with Not_found->("",Nohandler)
- in
- (
- match handler with
- | Nohandler->fprintf logfd "Unhandled watch descriptor\n";flush logfd
- | Activehandler(handler)->handler wd dirname evlist purestr
- | Maskedhandler(_)->()
- )
- | _ -> ())
- evs
+ let evs = Inotify.read fd in
+ List.iter (fun x->
+ match x with
+ | (wd,evlist,_,Some(str)) ->
+ let purestr = asciiz(str) in
+ let (dirname,handler,oneshot) =
+ try Hashtbl.find wdmap wd with Not_found->("",None,false)
+ in
+ printf "Received event: %s " dirname;
+ List.iter (fun l->printf "%s " (string_of_event l)) evlist;
+ printf "\n";flush Pervasives.stdout;
+ if (oneshot) then Hashtbl.remove wdmap wd;
+ (
+ match handler with
+ | None->fprintf logfd "Unhandled watch descriptor\n";flush logfd
+ | Some(handler)->handler wd dirname evlist purestr
+ )
+ | _ -> ())
+ evs
let initialize () =
Fdwatcher.add_fd (None,fd) (None,fd) receive_event
let res = Directfifowatcher.mkentry fqp abspath realperm slice_name in
match res with
| Success ->
- Directfifowatcher.openentry fqp (abspath,slice_name)
+ Directfifowatcher.openentry root_dir fqp (abspath,slice_name)
| _ -> ()
(** A new directory was created at the backend, make a corresponding directory
fprintf logfd "Hm. %s disappeared or not empty. Looks like slice %s shot itself in the foot\n" fqp (this#get_slice_name ());flush logfd
initializer
- Directfifowatcher.add_dir_watch root_dir
+ try
+ let s = Unix.stat root_dir in
+ if (s.st_kind<>S_DIR) then
+ begin
+ Unix.unlink root_dir;
+ Unix.mkdir root_dir 0o700
+ end
+ else if (s.st_perm <> 0o700) then
+ begin
+ Unix.rmdir root_dir;
+ Unix.mkdir root_dir 0o700
+ end;
+ with Unix.Unix_error(_,_,_) ->
+ try
+ Unix.mkdir root_dir 0o700;
+ with _ -> ();
+ Directfifowatcher.add_dir_watch root_dir
end
end;
Dirwatcher.initialize ();
+ Directfifowatcher.initialize ();
+
if (!Globals.conffile <> "") then
begin
let frontends = Conffile.read_frontends !Globals.conffile in
char lineread[2048];
int ret;
ret=read(0,lineread,2048);
+ lineread[ret]='\0';
+ printf ("writing %s\n",lineread);
write(vfd1,lineread,ret);
FD_CLR(0,&set);
} if (FD_ISSET(vfd0,&set)) {
git://git.onelab.eu / vsys.git / commitdiff