1 /*
2  * Unix SMB/CIFS implementation.
3  * Wait for process death
4  * Copyright (C) Volker Lendecke 2016
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 3 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include "replace.h"
21 #include <tevent.h>
22 #include <talloc.h>
23 #include "serverid.h"
24 #include "server_id_watch.h"
25 #include "lib/util/tevent_unix.h"
26 
27 struct server_id_watch_state {
28 	struct tevent_context *ev;
29 	struct server_id pid;
30 };
31 
32 static void server_id_watch_waited(struct tevent_req *subreq);
33 
server_id_watch_send(TALLOC_CTX * mem_ctx,struct tevent_context * ev,struct server_id pid)34 struct tevent_req *server_id_watch_send(TALLOC_CTX *mem_ctx,
35 					struct tevent_context *ev,
36 					struct server_id pid)
37 {
38 	struct tevent_req *req, *subreq;
39 	struct server_id_watch_state *state;
40 
41 	req = tevent_req_create(mem_ctx, &state, struct server_id_watch_state);
42 	if (req == NULL) {
43 		return NULL;
44 	}
45 	state->ev = ev;
46 	state->pid = pid;
47 
48 	if (!serverid_exists(&state->pid)) {
49 		tevent_req_done(req);
50 		return tevent_req_post(req, ev);
51 	}
52 
53 	subreq = tevent_wakeup_send(
54 		state, ev, tevent_timeval_current_ofs(0, 500000));
55 	if (tevent_req_nomem(subreq, req)) {
56 		return tevent_req_post(req, ev);
57 	}
58 	tevent_req_set_callback(subreq, server_id_watch_waited, req);
59 
60 	return req;
61 }
62 
server_id_watch_waited(struct tevent_req * subreq)63 static void server_id_watch_waited(struct tevent_req *subreq)
64 {
65 	struct tevent_req *req = tevent_req_callback_data(
66 		subreq, struct tevent_req);
67 	struct server_id_watch_state *state = tevent_req_data(
68 		req, struct server_id_watch_state);
69 	bool ok;
70 
71 	ok = tevent_wakeup_recv(subreq);
72 	TALLOC_FREE(subreq);
73 	if (!ok) {
74 		tevent_req_oom(req);
75 		return;
76 	}
77 
78 	if (!serverid_exists(&state->pid)) {
79 		tevent_req_done(req);
80 		return;
81 	}
82 
83 	subreq = tevent_wakeup_send(
84 		state, state->ev, tevent_timeval_current_ofs(0, 500000));
85 	if (tevent_req_nomem(subreq, req)) {
86 		return;
87 	}
88 	tevent_req_set_callback(subreq, server_id_watch_waited, req);
89 }
90 
server_id_watch_recv(struct tevent_req * req,struct server_id * pid)91 int server_id_watch_recv(struct tevent_req *req, struct server_id *pid)
92 {
93 	struct server_id_watch_state *state = tevent_req_data(
94 		req, struct server_id_watch_state);
95 	int err;
96 
97 	if (tevent_req_is_unix_error(req, &err)) {
98 		return err;
99 	}
100 	if (pid) {
101 		*pid = state->pid;
102 	}
103 	return 0;
104 }
105