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
52 char *TCID = "pidns20";
53 int TST_TOTAL = 1;
54
55 int parent_cinit[2];
56 int cinit_parent[2];
57 int broken = 1; /* broken should be 0 when test completes properly */
58
59 #define CHILD_PID 1
60 #define PARENT_PID 0
61
62 /*
63 * child_signal_handler() - to handle SIGUSR1
64 */
child_signal_handler(int sig,siginfo_t * si,void * unused)65 static void child_signal_handler(int sig, siginfo_t * si, void *unused)
66 {
67 if (si->si_signo != SIGUSR1)
68 tst_resm(TBROK, "cinit: recieved %s unexpectedly!",
69 strsignal(si->si_signo));
70 else
71 tst_resm(TPASS, "cinit: user function is called as expected");
72
73 /* Disable broken flag */
74 broken = 0;
75 }
76
77 /*
78 * child_fn() - Inside container
79 */
child_fn(void * arg)80 int child_fn(void *arg)
81 {
82 pid_t pid, ppid;
83 sigset_t newset;
84 struct sigaction sa;
85 char buf[5];
86
87 /* Setup pipe read and write ends */
88 pid = getpid();
89 ppid = getppid();
90
91 if (pid != CHILD_PID || ppid != PARENT_PID) {
92 printf("cinit: pidns was not created properly\n");
93 exit(1);
94 }
95
96 /* Setup pipes to communicate with parent */
97 close(cinit_parent[0]);
98 close(parent_cinit[1]);
99
100 /* Block SIGUSR1 signal */
101 sigemptyset(&newset);
102 sigaddset(&newset, SIGUSR1);
103 if (sigprocmask(SIG_BLOCK, &newset, 0) == -1) {
104 perror("cinit: sigprocmask() failed");
105 exit(1);
106 }
107 tst_resm(TINFO, "cinit: blocked SIGUSR1");
108
109 /* Let parent to queue SIGUSR1 in pending */
110 if (write(cinit_parent[1], "c:go", 5) != 5) {
111 perror("cinit: pipe is broken to write");
112 exit(1);
113 }
114
115 /* Check if parent has queued up SIGUSR1 */
116 read(parent_cinit[0], buf, 5);
117 if (strcmp(buf, "p:go") != 0) {
118 printf("cinit: parent did not respond!\n");
119 exit(1);
120 }
121
122 /* Now redefine handler for SIGUSR1 */
123 sa.sa_flags = SA_SIGINFO;
124 sigfillset(&sa.sa_mask);
125 sa.sa_sigaction = child_signal_handler;
126 if (sigaction(SIGUSR1, &sa, NULL) == -1) {
127 perror("cinit: sigaction failed");
128 exit(1);
129 }
130
131 /* Unblock traffic on SIGUSR1 queue */
132 tst_resm(TINFO, "cinit: unblocking SIGUSR1");
133 sigprocmask(SIG_UNBLOCK, &newset, 0);
134
135 /* Check if new handler is called */
136 if (broken == 1) {
137 printf("cinit: broken flag didn't change\n");
138 exit(1);
139 }
140
141 /* Cleanup and exit */
142 close(cinit_parent[1]);
143 close(parent_cinit[0]);
144 exit(0);
145 }
146
setup(void)147 static void setup(void)
148 {
149 tst_require_root();
150 check_newpid();
151 }
152
main(int argc,char * argv[])153 int main(int argc, char *argv[])
154 {
155 int status;
156 char buf[5];
157 pid_t cpid;
158
159 setup();
160
161 /* Create pipes for intercommunication */
162 if (pipe(parent_cinit) == -1 || pipe(cinit_parent) == -1) {
163 tst_brkm(TBROK | TERRNO, NULL, "pipe failed");
164 }
165
166 cpid = ltp_clone_quick(CLONE_NEWPID | SIGCHLD, child_fn, NULL);
167 if (cpid == -1) {
168 tst_brkm(TBROK | TERRNO, NULL, "clone failed");
169 }
170
171 /* Setup pipe read and write ends */
172 close(cinit_parent[1]);
173 close(parent_cinit[0]);
174
175 /* Is container ready */
176 read(cinit_parent[0], buf, 5);
177 if (strcmp(buf, "c:go") != 0) {
178 tst_brkm(TBROK, NULL, "parent: container did not respond!");
179 }
180
181 /* Enqueue SIGUSR1 in pending signal queue of container */
182 if (kill(cpid, SIGUSR1) == -1) {
183 tst_brkm(TBROK | TERRNO, NULL, "kill() failed");
184 }
185
186 tst_resm(TINFO, "parent: signalled SIGUSR1 to container");
187 if (write(parent_cinit[1], "p:go", 5) != 5) {
188 tst_brkm(TBROK | TERRNO, NULL, "write failed");
189 }
190
191 /* collect exit status of child */
192 if (wait(&status) == -1) {
193 tst_brkm(TBROK | TERRNO, NULL, "wait failed");
194 }
195
196 if (WIFSIGNALED(status)) {
197 if (WTERMSIG(status) == SIGUSR1)
198 tst_resm(TFAIL,
199 "user function was not called inside cinit");
200 else
201 tst_resm(TBROK,
202 "cinit was terminated by %d",
203 WTERMSIG(status));
204 }
205
206 /* Cleanup and exit */
207 close(parent_cinit[1]);
208 close(cinit_parent[0]);
209 tst_exit();
210 }
211