1 // Copyright 2012 The Kyua Authors.
2 // All rights reserved.
3 //
4 // Redistribution and use in source and binary forms, with or without
5 // modification, are permitted provided that the following conditions are
6 // met:
7 //
8 // * Redistributions of source code must retain the above copyright
9 // notice, this list of conditions and the following disclaimer.
10 // * Redistributions in binary form must reproduce the above copyright
11 // notice, this list of conditions and the following disclaimer in the
12 // documentation and/or other materials provided with the distribution.
13 // * Neither the name of Google Inc. nor the names of its contributors
14 // may be used to endorse or promote products derived from this software
15 // without specific prior written permission.
16 //
17 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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22 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
23 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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26 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
27 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28
29 #include "utils/signals/interrupts.hpp"
30
31 extern "C" {
32 #include <signal.h>
33 #include <unistd.h>
34 }
35
36 #include <cstdlib>
37 #include <iostream>
38
39 #include <atf-c++.hpp>
40
41 #include "utils/format/macros.hpp"
42 #include "utils/fs/path.hpp"
43 #include "utils/process/child.ipp"
44 #include "utils/process/status.hpp"
45 #include "utils/signals/exceptions.hpp"
46 #include "utils/signals/programmer.hpp"
47
48 namespace fs = utils::fs;
49 namespace process = utils::process;
50 namespace signals = utils::signals;
51
52
53 namespace {
54
55
56 /// Set to the signal that fired; -1 if none.
57 static volatile int fired_signal = -1;
58
59
60 /// Test handler for signals.
61 ///
62 /// \post fired_signal is set to the signal that triggered the handler.
63 ///
64 /// \param signo The signal that triggered the handler.
65 static void
signal_handler(const int signo)66 signal_handler(const int signo)
67 {
68 PRE(fired_signal == -1 || fired_signal == signo);
69 fired_signal = signo;
70 }
71
72
73 /// Child process that pauses waiting to be killed.
74 static void
pause_child(void)75 pause_child(void)
76 {
77 sigset_t mask;
78 sigemptyset(&mask);
79 // We loop waiting for signals because we want the parent process to send us
80 // a SIGKILL that we cannot handle, not just any non-deadly signal.
81 for (;;) {
82 std::cerr << F("Waiting for any signal; pid=%s\n") % ::getpid();
83 ::sigsuspend(&mask);
84 std::cerr << F("Signal received; pid=%s\n") % ::getpid();
85 }
86 }
87
88
89 /// Checks that interrupts_handler() handles a particular signal.
90 ///
91 /// This indirectly checks the check_interrupt() function, which is not part of
92 /// the class but is tightly related.
93 ///
94 /// \param signo The signal to check.
95 /// \param explicit_unprogram Whether to call interrupts_handler::unprogram()
96 /// explicitly before letting the object go out of scope.
97 static void
check_interrupts_handler(const int signo,const bool explicit_unprogram)98 check_interrupts_handler(const int signo, const bool explicit_unprogram)
99 {
100 fired_signal = -1;
101
102 signals::programmer test_handler(signo, signal_handler);
103
104 {
105 signals::interrupts_handler interrupts;
106
107 // No pending interrupts at first.
108 signals::check_interrupt();
109
110 // Send us an interrupt and check for it.
111 ::kill(getpid(), signo);
112 ATF_REQUIRE_THROW_RE(signals::interrupted_error,
113 F("Interrupted by signal %s") % signo,
114 signals::check_interrupt());
115
116 // Interrupts should have been cleared now, so this should not throw.
117 signals::check_interrupt();
118
119 // Check to see if a second interrupt is detected.
120 ::kill(getpid(), signo);
121 ATF_REQUIRE_THROW_RE(signals::interrupted_error,
122 F("Interrupted by signal %s") % signo,
123 signals::check_interrupt());
124
125 // And ensure the interrupt was cleared again.
126 signals::check_interrupt();
127
128 if (explicit_unprogram) {
129 interrupts.unprogram();
130 }
131 }
132
133 ATF_REQUIRE_EQ(-1, fired_signal);
134 ::kill(getpid(), signo);
135 ATF_REQUIRE_EQ(signo, fired_signal);
136
137 test_handler.unprogram();
138 }
139
140
141 /// Checks that interrupts_inhibiter() handles a particular signal.
142 ///
143 /// \param signo The signal to check.
144 static void
check_interrupts_inhibiter(const int signo)145 check_interrupts_inhibiter(const int signo)
146 {
147 signals::programmer test_handler(signo, signal_handler);
148
149 {
150 signals::interrupts_inhibiter inhibiter;
151 {
152 signals::interrupts_inhibiter nested_inhibiter;
153 ::kill(::getpid(), signo);
154 ATF_REQUIRE_EQ(-1, fired_signal);
155 }
156 ::kill(::getpid(), signo);
157 ATF_REQUIRE_EQ(-1, fired_signal);
158 }
159 ATF_REQUIRE_EQ(signo, fired_signal);
160
161 test_handler.unprogram();
162 }
163
164
165 } // anonymous namespace
166
167
168 ATF_TEST_CASE_WITHOUT_HEAD(interrupts_handler__sighup);
ATF_TEST_CASE_BODY(interrupts_handler__sighup)169 ATF_TEST_CASE_BODY(interrupts_handler__sighup)
170 {
171 // We run this twice in sequence to ensure that we can actually program two
172 // interrupts handlers in a row.
173 check_interrupts_handler(SIGHUP, true);
174 check_interrupts_handler(SIGHUP, false);
175 }
176
177
178 ATF_TEST_CASE_WITHOUT_HEAD(interrupts_handler__sigint);
ATF_TEST_CASE_BODY(interrupts_handler__sigint)179 ATF_TEST_CASE_BODY(interrupts_handler__sigint)
180 {
181 // We run this twice in sequence to ensure that we can actually program two
182 // interrupts handlers in a row.
183 check_interrupts_handler(SIGINT, true);
184 check_interrupts_handler(SIGINT, false);
185 }
186
187
188 ATF_TEST_CASE_WITHOUT_HEAD(interrupts_handler__sigterm);
ATF_TEST_CASE_BODY(interrupts_handler__sigterm)189 ATF_TEST_CASE_BODY(interrupts_handler__sigterm)
190 {
191 // We run this twice in sequence to ensure that we can actually program two
192 // interrupts handlers in a row.
193 check_interrupts_handler(SIGTERM, true);
194 check_interrupts_handler(SIGTERM, false);
195 }
196
197
198 ATF_TEST_CASE(interrupts_handler__kill_children);
ATF_TEST_CASE_HEAD(interrupts_handler__kill_children)199 ATF_TEST_CASE_HEAD(interrupts_handler__kill_children)
200 {
201 set_md_var("timeout", "10");
202 }
ATF_TEST_CASE_BODY(interrupts_handler__kill_children)203 ATF_TEST_CASE_BODY(interrupts_handler__kill_children)
204 {
205 std::auto_ptr< process::child > child1(process::child::fork_files(
206 pause_child, fs::path("/dev/stdout"), fs::path("/dev/stderr")));
207 std::auto_ptr< process::child > child2(process::child::fork_files(
208 pause_child, fs::path("/dev/stdout"), fs::path("/dev/stderr")));
209
210 signals::interrupts_handler interrupts;
211
212 // Our children pause until the reception of a signal. Interrupting
213 // ourselves will cause the signal to be re-delivered to our children due to
214 // the interrupts_handler semantics. If this does not happen, the wait
215 // calls below would block indefinitely and cause our test to time out.
216 ::kill(::getpid(), SIGHUP);
217
218 const process::status status1 = child1->wait();
219 ATF_REQUIRE(status1.signaled());
220 ATF_REQUIRE_EQ(SIGKILL, status1.termsig());
221 const process::status status2 = child2->wait();
222 ATF_REQUIRE(status2.signaled());
223 ATF_REQUIRE_EQ(SIGKILL, status2.termsig());
224 }
225
226
227 ATF_TEST_CASE_WITHOUT_HEAD(interrupts_inhibiter__sigalrm);
ATF_TEST_CASE_BODY(interrupts_inhibiter__sigalrm)228 ATF_TEST_CASE_BODY(interrupts_inhibiter__sigalrm)
229 {
230 check_interrupts_inhibiter(SIGALRM);
231 }
232
233
234 ATF_TEST_CASE_WITHOUT_HEAD(interrupts_inhibiter__sighup);
ATF_TEST_CASE_BODY(interrupts_inhibiter__sighup)235 ATF_TEST_CASE_BODY(interrupts_inhibiter__sighup)
236 {
237 check_interrupts_inhibiter(SIGHUP);
238 }
239
240
241 ATF_TEST_CASE_WITHOUT_HEAD(interrupts_inhibiter__sigint);
ATF_TEST_CASE_BODY(interrupts_inhibiter__sigint)242 ATF_TEST_CASE_BODY(interrupts_inhibiter__sigint)
243 {
244 check_interrupts_inhibiter(SIGINT);
245 }
246
247
248 ATF_TEST_CASE_WITHOUT_HEAD(interrupts_inhibiter__sigterm);
ATF_TEST_CASE_BODY(interrupts_inhibiter__sigterm)249 ATF_TEST_CASE_BODY(interrupts_inhibiter__sigterm)
250 {
251 check_interrupts_inhibiter(SIGTERM);
252 }
253
254
ATF_INIT_TEST_CASES(tcs)255 ATF_INIT_TEST_CASES(tcs)
256 {
257 ATF_ADD_TEST_CASE(tcs, interrupts_handler__sighup);
258 ATF_ADD_TEST_CASE(tcs, interrupts_handler__sigint);
259 ATF_ADD_TEST_CASE(tcs, interrupts_handler__sigterm);
260 ATF_ADD_TEST_CASE(tcs, interrupts_handler__kill_children);
261
262 ATF_ADD_TEST_CASE(tcs, interrupts_inhibiter__sigalrm);
263 ATF_ADD_TEST_CASE(tcs, interrupts_inhibiter__sighup);
264 ATF_ADD_TEST_CASE(tcs, interrupts_inhibiter__sigint);
265 ATF_ADD_TEST_CASE(tcs, interrupts_inhibiter__sigterm);
266 }
267