1 /*
2 * Copyright (c) International Business Machines Corp., 2007
3 * This program is free software; you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License as published by
5 * the Free Software Foundation; either version 2 of the License, or
6 * (at your option) any later version.
7 * This program is distributed in the hope that it will be useful,
8 * but WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
10 * the GNU General Public License for more details.
11 * You should have received a copy of the GNU General Public License
12 * along with this program; if not, write to the Free Software
13 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
14 *
15 ***************************************************************************
16 * File: pidns20.c
17 * *
18 * * Description:
19 * * The pidns20.c testcase verifies that signal handler of SIGUSR1 is called
20 * * (and cinit is NOT terminated) when:
21 * * - container-init blocks SIGUSR1,
22 * * - parent queues SIGUSR1 and
23 * * - a handler is specified for SIGUSR1 before it is unblocked.
24 * *
25 * * Test Assertion & Strategy:
26 * * Create a PID namespace container.
27 * * Block SIGUSR1 signal inside it.
28 * * Let parent to deliver SIGUSR1 signal to container.
29 * * Redefine SIGUSR1 handler of cinit to user function.
30 * * Unblock SIGUSR1 from blocked queue.
31 * * Check if user function is called.
32 * *
33 * * Usage: <for command-line>
34 * * pidns20
35 * *
36 * * History:
37 * * DATE NAME DESCRIPTION
38 * * 13/11/08 Gowrishankar M Creation of this test.
39 * * <gowrishankar.m@in.ibm.com>
40 *
41 ******************************************************************************/
42 #define _GNU_SOURCE 1
43 #include <sys/wait.h>
44 #include <sys/types.h>
45 #include <signal.h>
46 #include <stdlib.h>
47 #include <unistd.h>
48 #include <stdio.h>
49 #include "pidns_helper.h"
50 #include "test.h"
51 #include "safe_macros.h"
52
53 char *TCID = "pidns20";
54 int TST_TOTAL = 1;
55
56 int parent_cinit[2];
57 int cinit_parent[2];
58 int broken = 1; /* broken should be 0 when test completes properly */
59
60 #define CHILD_PID 1
61 #define PARENT_PID 0
62
63 /*
64 * child_signal_handler() - to handle SIGUSR1
65 */
child_signal_handler(int sig,siginfo_t * si,void * unused)66 static void child_signal_handler(int sig, siginfo_t * si, void *unused)
67 {
68 if (si->si_signo != SIGUSR1)
69 tst_resm(TBROK, "cinit: received %s unexpectedly!",
70 strsignal(si->si_signo));
71 else
72 tst_resm(TPASS, "cinit: user function is called as expected");
73
74 /* Disable broken flag */
75 broken = 0;
76 }
77
78 /*
79 * child_fn() - Inside container
80 */
child_fn(void * arg)81 int child_fn(void *arg)
82 {
83 pid_t pid, ppid;
84 sigset_t newset;
85 struct sigaction sa;
86 char buf[5];
87
88 /* Setup pipe read and write ends */
89 pid = getpid();
90 ppid = getppid();
91
92 if (pid != CHILD_PID || ppid != PARENT_PID) {
93 printf("cinit: pidns was not created properly\n");
94 exit(1);
95 }
96
97 /* Setup pipes to communicate with parent */
98 close(cinit_parent[0]);
99 close(parent_cinit[1]);
100
101 /* Block SIGUSR1 signal */
102 sigemptyset(&newset);
103 sigaddset(&newset, SIGUSR1);
104 if (sigprocmask(SIG_BLOCK, &newset, 0) == -1) {
105 perror("cinit: sigprocmask() failed");
106 exit(1);
107 }
108 tst_resm(TINFO, "cinit: blocked SIGUSR1");
109
110 /* Let parent to queue SIGUSR1 in pending */
111 if (write(cinit_parent[1], "c:go", 5) != 5) {
112 perror("cinit: pipe is broken to write");
113 exit(1);
114 }
115
116 /* Check if parent has queued up SIGUSR1 */
117 read(parent_cinit[0], buf, 5);
118 if (strcmp(buf, "p:go") != 0) {
119 printf("cinit: parent did not respond!\n");
120 exit(1);
121 }
122
123 /* Now redefine handler for SIGUSR1 */
124 sa.sa_flags = SA_SIGINFO;
125 sigfillset(&sa.sa_mask);
126 sa.sa_sigaction = child_signal_handler;
127 if (sigaction(SIGUSR1, &sa, NULL) == -1) {
128 perror("cinit: sigaction failed");
129 exit(1);
130 }
131
132 /* Unblock traffic on SIGUSR1 queue */
133 tst_resm(TINFO, "cinit: unblocking SIGUSR1");
134 sigprocmask(SIG_UNBLOCK, &newset, 0);
135
136 /* Check if new handler is called */
137 if (broken == 1) {
138 printf("cinit: broken flag didn't change\n");
139 exit(1);
140 }
141
142 /* Cleanup and exit */
143 close(cinit_parent[1]);
144 close(parent_cinit[0]);
145 exit(0);
146 }
147
setup(void)148 static void setup(void)
149 {
150 tst_require_root();
151 check_newpid();
152 }
153
main(void)154 int main(void)
155 {
156 int status;
157 char buf[5];
158 pid_t cpid;
159
160 setup();
161
162 /* Create pipes for intercommunication */
163 if (pipe(parent_cinit) == -1 || pipe(cinit_parent) == -1) {
164 tst_brkm(TBROK | TERRNO, NULL, "pipe failed");
165 }
166
167 cpid = ltp_clone_quick(CLONE_NEWPID | SIGCHLD, child_fn, NULL);
168 if (cpid == -1) {
169 tst_brkm(TBROK | TERRNO, NULL, "clone failed");
170 }
171
172 /* Setup pipe read and write ends */
173 close(cinit_parent[1]);
174 close(parent_cinit[0]);
175
176 /* Is container ready */
177 read(cinit_parent[0], buf, 5);
178 if (strcmp(buf, "c:go") != 0) {
179 tst_brkm(TBROK, NULL, "parent: container did not respond!");
180 }
181
182 /* Enqueue SIGUSR1 in pending signal queue of container */
183 SAFE_KILL(NULL, cpid, SIGUSR1);
184
185 tst_resm(TINFO, "parent: signalled SIGUSR1 to container");
186 if (write(parent_cinit[1], "p:go", 5) != 5) {
187 tst_brkm(TBROK | TERRNO, NULL, "write failed");
188 }
189
190 /* collect exit status of child */
191 SAFE_WAIT(NULL, &status);
192
193 if (WIFSIGNALED(status)) {
194 if (WTERMSIG(status) == SIGUSR1)
195 tst_resm(TFAIL,
196 "user function was not called inside cinit");
197 else
198 tst_resm(TBROK,
199 "cinit was terminated by %d",
200 WTERMSIG(status));
201 }
202
203 /* Cleanup and exit */
204 close(parent_cinit[1]);
205 close(cinit_parent[0]);
206 tst_exit();
207 }
208