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 _ -> ())
25 let direct_fifo_table: (string,(string*string*string*Unix.file_descr) option) Hashtbl.t = Hashtbl.create 1024
26 let pidmap: (int,string) Hashtbl.t = Hashtbl.create 1024
28 let rec list_check lst elt =
31 | car::cdr -> if (car==elt) then true else list_check cdr elt
33 let openentry_int fifoin =
35 try openfile fifoin [O_RDONLY;O_NONBLOCK] 0o777 with
36 e->fprintf logfd "Error opening and connecting FIFO: %s,%o\n" fifoin 0o777;flush logfd;raise e
41 (** Open fifos for a session. SHOULD NOt shutdown vsys if the fifos don't exist *)
42 let openentry_in root_dir fqp_in backend_spec =
43 Dirwatcher.mask_watch root_dir;
44 let fd_in = openentry_int fqp_in in
45 Dirwatcher.unmask_watch root_dir [S_Open];
46 let (fqp,slice_name) = backend_spec in
47 Hashtbl.replace direct_fifo_table fqp_in (Some(root_dir,fqp,slice_name,fd_in))
49 let openentry root_dir fqp backend_spec =
50 let fqp_in = String.concat "." [fqp;"in"] in
51 openentry_in root_dir fqp_in backend_spec
53 let reopenentry fifoin =
54 let entry = try Hashtbl.find direct_fifo_table fifoin with _ -> None in
56 | Some(dir, fqp,slice_name,fd) -> close_if_open fd;openentry_in dir fifoin (fqp,slice_name)
59 (* vsys is activated when a client opens an in file *)
60 let connect_file fqp_in =
61 (* Do we care about this file? *)
63 Hashtbl.find direct_fifo_table fqp_in with _ -> None in
65 | Some(_,execpath,slice_name,fifo_fdin) ->
66 fprintf logfd "Executing %s for slice %s\n" execpath slice_name;flush logfd;
68 let len = String.length fqp_in in
69 let fqp = String.sub fqp_in 0 (len-3) in
70 let fqp_out = String.concat "." [fqp;"out"] in
72 try openfile fqp_out [O_WRONLY;O_NONBLOCK] 0o777 with
73 _->fprintf logfd "%s Output pipe not open, using stdout in place of %s\n" slice_name fqp_out;flush logfd;stdout
75 ignore(sigprocmask SIG_BLOCK [Sys.sigchld]);
77 clear_nonblock fifo_fdin;
78 let pid=try Some(create_process execpath [|execpath;slice_name|] fifo_fdin fifo_fdout fifo_fdout) with e -> None in
80 | Some(pid) ->Hashtbl.add pidmap pid fqp_in
81 | None ->fprintf logfd "Error executing service: %s\n" execpath;flush logfd;reopenentry fqp_in
83 ignore(sigprocmask SIG_UNBLOCK [Sys.sigchld]);
88 (** Make a pair of fifo entries *)
89 let mkentry fqp abspath perm uname =
90 fprintf logfd "Making entry %s->%s\n" fqp abspath;flush logfd;
91 let fifoin=sprintf "%s.in" fqp in
92 let fifoout=sprintf "%s.out" fqp in
93 (try Unix.unlink fifoin with _ -> ());
94 (try Unix.unlink fifoout with _ -> ());
96 let infname =(sprintf "%s.in" fqp) in
97 let outfname =(sprintf "%s.out" fqp) in
98 Unix.mkfifo infname 0o666;
99 Unix.mkfifo outfname 0o666;
100 ( (* Make the user the owner of the pipes in a non-chroot environment *)
101 if (!Globals.nochroot) then
102 let pwentry = Unix.getpwnam uname in
103 Unix.chown infname pwentry.pw_uid pwentry.pw_gid;
104 Unix.chown outfname pwentry.pw_uid pwentry.pw_gid
108 e->fprintf logfd "Error creating FIFO: %s->%s. May be something wrong at the frontend.\n" fqp fifoout;flush logfd;Failed)
111 (** Close fifos that just got removed *)
113 let fqp_in = String.concat "." [fqp;"in"] in
114 let entry = try Hashtbl.find direct_fifo_table fqp_in with Not_found -> None in
119 Hashtbl.remove direct_fifo_table fqp_in
121 let sigchld_handle s =
122 let pid,_=Unix.waitpid [Unix.WNOHANG] 0 in
124 let fqp_in = Hashtbl.find pidmap pid in
125 printf "Reopening fifo\n";flush Pervasives.stdout;
129 let rec add_dir_watch fqp =
130 Dirwatcher.add_watch fqp [S_Open] direct_fifo_handler
132 direct_fifo_handler wd dirname evlist fname =
133 let is_event = list_check evlist in
134 if (is_event Open) then
135 let fqp_in = String.concat "/" [dirname;fname] in
138 add_dir_watch dirname
141 let del_dir_watch fqp =
142 (* XXX Dirwatcher.del_watch fqp *)
146 Sys.set_signal Sys.sigchld (Sys.Signal_handle sigchld_handle)