1 /*
2  * Copyright (c) 2009-2012 Niels Provos and Nick Mathewson
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  * 3. The name of the author may not be used to endorse or promote products
13  *    derived from this software without specific prior written permission.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 #include "../util-internal.h"
27 #include "event2/event-config.h"
28 
29 #ifdef _WIN32
30 #include <winsock2.h>
31 #endif
32 #include <sys/types.h>
33 #include <sys/stat.h>
34 #ifdef EVENT__HAVE_SYS_SOCKET_H
35 #include <sys/socket.h>
36 #endif
37 #include <fcntl.h>
38 #include <stdlib.h>
39 #include <stdio.h>
40 #include <string.h>
41 #ifndef _WIN32
42 #include <sys/time.h>
43 #include <unistd.h>
44 #endif
45 #include <errno.h>
46 
47 #include "event2/event.h"
48 #include "event2/util.h"
49 
50 #include "regress.h"
51 
52 static int was_et = 0;
53 
54 static void
55 read_cb(evutil_socket_t fd, short event, void *arg)
56 {
57 	char buf;
58 	int len;
59 
60 	len = recv(fd, &buf, sizeof(buf), 0);
61 
62 	called++;
63 	if (event & EV_ET)
64 		was_et = 1;
65 
66 	if (!len)
67 		event_del(arg);
68 }
69 
70 #ifndef SHUT_WR
71 #define SHUT_WR 1
72 #endif
73 
74 #ifdef _WIN32
75 #define LOCAL_SOCKETPAIR_AF AF_INET
76 #else
77 #define LOCAL_SOCKETPAIR_AF AF_UNIX
78 #endif
79 
80 static void
81 test_edgetriggered(void *et)
82 {
83 	struct event *ev = NULL;
84 	struct event_base *base = NULL;
85 	const char *test = "test string";
86 	evutil_socket_t pair[2] = {-1,-1};
87 	int supports_et;
88 
89 	/* On Linux 3.2.1 (at least, as patched by Fedora and tested by Nick),
90 	 * doing a "recv" on an AF_UNIX socket resets the readability of the
91 	 * socket, even though there is no state change, so we don't actually
92 	 * get edge-triggered behavior.  Yuck!  Linux 3.1.9 didn't have this
93 	 * problem.
94 	 */
95 #ifdef __linux__
96 	if (evutil_ersatz_socketpair_(AF_INET, SOCK_STREAM, 0, pair) == -1) {
97 		tt_abort_perror("socketpair");
98 	}
99 #else
100 	if (evutil_socketpair(LOCAL_SOCKETPAIR_AF, SOCK_STREAM, 0, pair) == -1) {
101 		tt_abort_perror("socketpair");
102 	}
103 #endif
104 
105 	called = was_et = 0;
106 
107 	tt_int_op(send(pair[0], test, (int)strlen(test)+1, 0), >, 0);
108 	shutdown(pair[0], SHUT_WR);
109 
110 	/* Initalize the event library */
111 	base = event_base_new();
112 
113 	if (!strcmp(event_base_get_method(base), "epoll") ||
114 	    !strcmp(event_base_get_method(base), "epoll (with changelist)") ||
115 	    !strcmp(event_base_get_method(base), "kqueue"))
116 		supports_et = 1;
117 	else
118 		supports_et = 0;
119 
120 	TT_BLATHER(("Checking for edge-triggered events with %s, which should %s"
121 				"support edge-triggering", event_base_get_method(base),
122 				supports_et?"":"not "));
123 
124 	/* Initalize one event */
125 	ev = event_new(base, pair[1], EV_READ|EV_ET|EV_PERSIST, read_cb, &ev);
126 
127 	event_add(ev, NULL);
128 
129 	/* We're going to call the dispatch function twice.  The first invocation
130 	 * will read a single byte from pair[1] in either case.  If we're edge
131 	 * triggered, we'll only see the event once (since we only see transitions
132 	 * from no data to data), so the second invocation of event_base_loop will
133 	 * do nothing.  If we're level triggered, the second invocation of
134 	 * event_base_loop will also activate the event (because there's still
135 	 * data to read). */
136 	event_base_loop(base,EVLOOP_NONBLOCK|EVLOOP_ONCE);
137 	event_base_loop(base,EVLOOP_NONBLOCK|EVLOOP_ONCE);
138 
139 	if (supports_et) {
140 		tt_int_op(called, ==, 1);
141 		tt_assert(was_et);
142 	} else {
143 		tt_int_op(called, ==, 2);
144 		tt_assert(!was_et);
145 	}
146 
147  end:
148 	if (ev) {
149 		event_del(ev);
150 		event_free(ev);
151 	}
152 	if (base)
153 		event_base_free(base);
154 	evutil_closesocket(pair[0]);
155 	evutil_closesocket(pair[1]);
156 }
157 
158 static void
159 test_edgetriggered_mix_error(void *data_)
160 {
161 	struct basic_test_data *data = data_;
162 	struct event_base *base = NULL;
163 	struct event *ev_et=NULL, *ev_lt=NULL;
164 
165 #ifdef EVENT__DISABLE_DEBUG_MODE
166 	if (1)
167 		tt_skip();
168 #endif
169 
170 	if (!libevent_tests_running_in_debug_mode)
171 		event_enable_debug_mode();
172 
173 	base = event_base_new();
174 
175 	/* try mixing edge-triggered and level-triggered to make sure it fails*/
176 	ev_et = event_new(base, data->pair[0], EV_READ|EV_ET, read_cb, ev_et);
177 	tt_assert(ev_et);
178 	ev_lt = event_new(base, data->pair[0], EV_READ, read_cb, ev_lt);
179 	tt_assert(ev_lt);
180 
181 	/* Add edge-triggered, then level-triggered.  Get an error. */
182 	tt_int_op(0, ==, event_add(ev_et, NULL));
183 	tt_int_op(-1, ==, event_add(ev_lt, NULL));
184 	tt_int_op(EV_READ, ==, event_pending(ev_et, EV_READ, NULL));
185 	tt_int_op(0, ==, event_pending(ev_lt, EV_READ, NULL));
186 
187 	tt_int_op(0, ==, event_del(ev_et));
188 	/* Add level-triggered, then edge-triggered.  Get an error. */
189 	tt_int_op(0, ==, event_add(ev_lt, NULL));
190 	tt_int_op(-1, ==, event_add(ev_et, NULL));
191 	tt_int_op(EV_READ, ==, event_pending(ev_lt, EV_READ, NULL));
192 	tt_int_op(0, ==, event_pending(ev_et, EV_READ, NULL));
193 
194 end:
195 	if (ev_et)
196 		event_free(ev_et);
197 	if (ev_lt)
198 		event_free(ev_lt);
199 	if (base)
200 		event_base_free(base);
201 }
202 
203 struct testcase_t edgetriggered_testcases[] = {
204 	{ "et", test_edgetriggered, TT_FORK, NULL, NULL },
205 	{ "et_mix_error", test_edgetriggered_mix_error,
206 	  TT_FORK|TT_NEED_SOCKETPAIR|TT_NO_LOGS, &basic_setup, NULL },
207 	END_OF_TESTCASES
208 };
209