1 (** directfifowatcher.ml: Routines to handle non-persistent scripts *)
3 * - The 'out' descriptor must be opened first
4 * - As soon as the backend script dies, the connection to the entry is
6 * - To avoid user-inflicted pain, all entries are opened at the time
7 * that they are created. Reopening these entries is a little complicated
8 * but nevertheless sound:
9 * * When a script dies, its fd is reopened
10 * * If a script fails to execute, its fd is closed and reopened to
11 * beat a race that can happen when the user closes the connection
12 * before the script can be launched.
22 let close_if_open fd = (try (ignore(close fd);) with _ -> ())
24 let direct_fifo_table: (string,(string*string*string*Unix.file_descr) option) Hashtbl.t = Hashtbl.create 1024
25 let pidmap: (int,string*Unix.file_descr) Hashtbl.t = Hashtbl.create 1024
27 let rec list_check lst elt =
30 | car::cdr -> if (car==elt) then true else list_check cdr elt
32 let openentry_int fifoin =
34 try openfile fifoin [O_RDONLY;O_NONBLOCK] 0o777 with
35 e->fprintf logfd "Error opening and connecting FIFO: %s,%o\n" fifoin 0o777;flush logfd;raise e
40 (** Open fifos for a session. SHOULD NOt shutdown vsys if the fifos don't exist *)
41 let openentry_in root_dir fqp_in backend_spec =
42 Dirwatcher.mask_watch root_dir;
43 let fd_in = openentry_int fqp_in in
44 Dirwatcher.unmask_watch root_dir [S_Open];
45 let (fqp,slice_name) = backend_spec in
46 Hashtbl.replace direct_fifo_table fqp_in (Some(root_dir,fqp,slice_name,fd_in))
48 let openentry root_dir fqp backend_spec =
49 let fqp_in = String.concat "." [fqp;"in"] in
50 openentry_in root_dir fqp_in backend_spec
52 let reopenentry fifoin =
53 let entry = try Hashtbl.find direct_fifo_table fifoin with _ -> None in
55 | Some(dir, fqp,slice_name,fd) -> close_if_open fd;openentry_in dir fifoin (fqp,slice_name)
58 (* vsys is activated when a client opens an in file *)
59 let connect_file fqp_in =
60 (* Do we care about this file? *)
62 Hashtbl.find direct_fifo_table fqp_in with _ -> None in
64 | Some(_,execpath,slice_name,fifo_fdin) ->
65 fprintf logfd "Executing %s for slice %s\n" execpath slice_name;flush logfd;
67 let len = String.length fqp_in in
68 let fqp = String.sub fqp_in 0 (len-3) in
69 let fqp_out = String.concat "." [fqp;"out"] in
71 try openfile fqp_out [O_WRONLY;O_NONBLOCK] 0o777 with
72 _->fprintf logfd "%s Output pipe not open, using stdout in place of %s\n" slice_name fqp_out;flush logfd;stdout
74 ignore(sigprocmask SIG_BLOCK [Sys.sigchld]);
76 clear_nonblock fifo_fdin;
77 let pid=try Some(create_process execpath [|execpath;slice_name|] fifo_fdin fifo_fdout fifo_fdout) with e -> None in
79 | Some(pid) ->Hashtbl.add pidmap pid (fqp_in,fifo_fdout)
80 | None ->fprintf logfd "Error executing service: %s\n" execpath;flush logfd;reopenentry fqp_in
82 ignore(sigprocmask SIG_UNBLOCK [Sys.sigchld]);
87 (** Make a pair of fifo entries *)
88 let mkentry fqp abspath perm uname =
89 fprintf logfd "Making entry %s->%s\n" fqp abspath;flush logfd;
90 let fifoin=sprintf "%s.in" fqp in
91 let fifoout=sprintf "%s.out" fqp in
92 (try Unix.unlink fifoin with _ -> ());
93 (try Unix.unlink fifoout with _ -> ());
95 let infname =(sprintf "%s.in" fqp) in
96 let outfname =(sprintf "%s.out" fqp) in
97 Unix.mkfifo infname 0o666;
98 Unix.mkfifo outfname 0o666;
99 ( (* Make the user the owner of the pipes in a non-chroot environment *)
100 if (!Globals.nochroot) then
101 let pwentry = Unix.getpwnam uname in
102 Unix.chown infname pwentry.pw_uid pwentry.pw_gid;
103 Unix.chown outfname pwentry.pw_uid pwentry.pw_gid
107 e->fprintf logfd "Error creating FIFO: %s->%s. May be something wrong at the frontend.\n" fqp fifoout;flush logfd;Failed)
110 (** Close fifos that just got removed *)
112 let fqp_in = String.concat "." [fqp;"in"] in
113 let entry = try Hashtbl.find direct_fifo_table fqp_in with Not_found -> None in
118 Hashtbl.remove direct_fifo_table fqp_in
120 let sigchld_handle s =
121 let pid,_=Unix.waitpid [Unix.WNOHANG] 0 in
123 let fqp_in,fd_out = Hashtbl.find pidmap pid in
126 if (fd_out <> stdout) then close_if_open fd_out
131 let rec add_dir_watch fqp =
132 Dirwatcher.add_watch fqp [S_Open] direct_fifo_handler
134 direct_fifo_handler wd dirname evlist fname =
135 let is_event = list_check evlist in
136 if (is_event Open) then
137 let fqp_in = String.concat "/" [dirname;fname] in
140 add_dir_watch dirname
143 let del_dir_watch fqp =
144 (* XXX Dirwatcher.del_watch fqp *)
148 Sys.set_signal Sys.sigchld (Sys.Signal_handle sigchld_handle)