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 "test.h"
50 #include <libclone.h>
51 #include "pidns_helper.h"
52
53 char *TCID = "pidns20";
54 int TST_TOTAL = 1;
55
56 int errno;
57 int parent_cinit[2];
58 int cinit_parent[2];
59 int broken = 1; /* broken should be 0 when test completes properly */
60
61 #define CHILD_PID 1
62 #define PARENT_PID 0
63
64 /*
65 * child_signal_handler() - to handle SIGUSR1
66 */
child_signal_handler(int sig,siginfo_t * si,void * unused)67 static void child_signal_handler(int sig, siginfo_t * si, void *unused)
68 {
69 if (si->si_signo != SIGUSR1)
70 tst_resm(TBROK, "cinit: recieved %s unexpectedly!",
71 strsignal(si->si_signo));
72 else
73 tst_resm(TPASS, "cinit: user function is called as expected");
74
75 /* Disable broken flag */
76 broken = 0;
77 }
78
79 /*
80 * child_fn() - Inside container
81 */
child_fn(void * arg)82 int child_fn(void *arg)
83 {
84 pid_t pid, ppid;
85 sigset_t newset;
86 struct sigaction sa;
87 char buf[5];
88
89 /* Setup pipe read and write ends */
90 pid = getpid();
91 ppid = getppid();
92
93 if (pid != CHILD_PID || ppid != PARENT_PID) {
94 printf("cinit: pidns was not created properly\n");
95 exit(1);
96 }
97
98 /* Setup pipes to communicate with parent */
99 close(cinit_parent[0]);
100 close(parent_cinit[1]);
101
102 /* Block SIGUSR1 signal */
103 sigemptyset(&newset);
104 sigaddset(&newset, SIGUSR1);
105 if (sigprocmask(SIG_BLOCK, &newset, 0) == -1) {
106 perror("cinit: sigprocmask() failed");
107 exit(1);
108 }
109 tst_resm(TINFO, "cinit: blocked SIGUSR1");
110
111 /* Let parent to queue SIGUSR1 in pending */
112 if (write(cinit_parent[1], "c:go", 5) != 5) {
113 perror("cinit: pipe is broken to write");
114 exit(1);
115 }
116
117 /* Check if parent has queued up SIGUSR1 */
118 read(parent_cinit[0], buf, 5);
119 if (strcmp(buf, "p:go") != 0) {
120 printf("cinit: parent did not respond!\n");
121 exit(1);
122 }
123
124 /* Now redefine handler for SIGUSR1 */
125 sa.sa_flags = SA_SIGINFO;
126 sigfillset(&sa.sa_mask);
127 sa.sa_sigaction = child_signal_handler;
128 if (sigaction(SIGUSR1, &sa, NULL) == -1) {
129 perror("cinit: sigaction failed");
130 exit(1);
131 }
132
133 /* Unblock traffic on SIGUSR1 queue */
134 tst_resm(TINFO, "cinit: unblocking SIGUSR1");
135 sigprocmask(SIG_UNBLOCK, &newset, 0);
136
137 /* Check if new handler is called */
138 if (broken == 1) {
139 printf("cinit: broken flag didn't change\n");
140 exit(1);
141 }
142
143 /* Cleanup and exit */
144 close(cinit_parent[1]);
145 close(parent_cinit[0]);
146 exit(0);
147 }
148
setup(void)149 static void setup(void)
150 {
151 tst_require_root();
152 check_newpid();
153 }
154
main(int argc,char * argv[])155 int main(int argc, char *argv[])
156 {
157 int status;
158 char buf[5];
159 pid_t cpid;
160
161 setup();
162
163 /* Create pipes for intercommunication */
164 if (pipe(parent_cinit) == -1 || pipe(cinit_parent) == -1) {
165 tst_brkm(TBROK | TERRNO, NULL, "pipe failed");
166 }
167
168 cpid = ltp_clone_quick(CLONE_NEWPID | SIGCHLD, child_fn, NULL);
169 if (cpid == -1) {
170 tst_brkm(TBROK | TERRNO, NULL, "clone failed");
171 }
172
173 /* Setup pipe read and write ends */
174 close(cinit_parent[1]);
175 close(parent_cinit[0]);
176
177 /* Is container ready */
178 read(cinit_parent[0], buf, 5);
179 if (strcmp(buf, "c:go") != 0) {
180 tst_brkm(TBROK, NULL, "parent: container did not respond!");
181 }
182
183 /* Enqueue SIGUSR1 in pending signal queue of container */
184 if (kill(cpid, SIGUSR1) == -1) {
185 tst_brkm(TBROK | TERRNO, NULL, "kill() failed");
186 }
187
188 tst_resm(TINFO, "parent: signalled SIGUSR1 to container");
189 if (write(parent_cinit[1], "p:go", 5) != 5) {
190 tst_brkm(TBROK | TERRNO, NULL, "write failed");
191 }
192
193 /* collect exit status of child */
194 if (wait(&status) == -1) {
195 tst_brkm(TBROK | TERRNO, NULL, "wait failed");
196 }
197
198 if (WIFSIGNALED(status)) {
199 if (WTERMSIG(status) == SIGUSR1)
200 tst_resm(TFAIL,
201 "user function was not called inside cinit");
202 else
203 tst_resm(TBROK,
204 "cinit was terminated by %d",
205 WTERMSIG(status));
206 }
207
208 /* Cleanup and exit */
209 close(parent_cinit[1]);
210 close(cinit_parent[0]);
211 tst_exit();
212 }
213