| /* |
| * Copyright (C) Bull S.A. 1996 |
| * Copyright (c) International Business Machines Corp., 2001 |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See |
| * the GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| */ |
| /*---------------------------------------------------------------------+ |
| | signal_test_05 | |
| | ==================================================================== | |
| | | |
| | Description: Verify that signals can be ignored by the receiving | |
| | process. | |
| | | |
| | Algorithm: o Spawn a child | |
| | | |
| | (parent) | |
| | o Use sigaction (SIG_IGN) to ignore all catchable | |
| | signals from child, except for sigchild | |
| | o Wait until sigchld signal is received | |
| | o Verify that the sigchild interrupt was received | |
| | o Additionally check to verify that child process | |
| | exited successfully | |
| | | |
| | (child) | |
| | o Send all catchable signals to the parent | |
| | o exit (implicitly send sigchild signal to parent) | |
| | | |
| | | |
| | System calls: The following system calls are tested: | |
| | | |
| | sigaction () - Specify the action to take upon | |
| | delivery of a signal | |
| | wait () - Waits for a child process to stop or | |
| | terminate | |
| | kill () - Sends a signal to a process | |
| | | |
| | Usage: signal_test_05 | |
| | | |
| | To compile: cc -o signal_test_05 signal_test_05 | |
| | | |
| | Last update: Ver. 1.2, 2/7/94 23:24:05 | |
| | | |
| | Change Activity | |
| | | |
| | Version Date Name Reason | |
| | 0.1 050689 CTU Initial version | |
| | 0.2 112993 DJK Rewrite for AIX version 4.1 | |
| | 1.2 020794 DJK Move to "prod" directory | |
| | | |
| +---------------------------------------------------------------------*/ |
| |
| #include <stdio.h> |
| #include <string.h> |
| #ifdef _LINUX_ |
| # define __USE_XOPEN |
| # include <sys/types.h> |
| # include <sys/stat.h> |
| #endif |
| #include <unistd.h> |
| #include <sys/signal.h> |
| #include <sys/wait.h> |
| #include <stdlib.h> |
| #include <errno.h> |
| |
| #ifdef _LINUX_ |
| // bits/signum.h defines _NSIG as 64 |
| #define SIGMAX 64 |
| #endif |
| |
| /* Function prototypes */ |
| void ignore_signals (); |
| void child (int); |
| void handler (int, int, struct sigcontext *); |
| void sys_error (const char *, int); |
| void error (const char *, int); |
| |
| /* Flag set upon receiving SIGCHLD signal */ |
| int sigchld_flag = 0; |
| |
| /*---------------------------------------------------------------------+ |
| | main () | |
| | ==================================================================== | |
| | | |
| | Function: Main program (see prolog for more details) | |
| | | |
| +---------------------------------------------------------------------*/ |
| int main (int argc, char **argv) |
| { |
| |
| pid_t pid = getpid (); /* Process ID (of parent process) */ |
| int status; /* Child's exit status */ |
| |
| /* Print out program header */ |
| printf ("%s: IPC TestSuite program\n\n", *argv); |
| |
| /* Set up our signal handler */ |
| ignore_signals (); |
| |
| /* |
| * Spawn a child process & have the child process send all of the |
| * catchable signals to the parent. |
| */ |
| printf ("\n\tSpawning child process\n"); |
| switch (fork ()) { |
| case -1: /* Unable to create child process */ |
| sys_error ("fork failed", __LINE__); |
| |
| case 0: /* Child process */ |
| child (pid); |
| |
| default: /* Parent process */ |
| break; |
| } |
| |
| /* |
| * Wait for the child process to complete |
| * |
| * Suspend execution of the parent process until either a signal |
| * that is not blocked or ignored, or until the child process |
| * completes. |
| * |
| * Use the POSIX macro to insure that the child process exited |
| * normally. |
| * |
| * Check to insure that the SIGCHLD signal was caught. |
| */ |
| wait (&status); |
| |
| if (!WIFEXITED (status)) |
| error ("child process exited abnormally", __LINE__); |
| |
| if (sigchld_flag != 1) |
| error ("child process failed to send SIGCHLD signal", __LINE__); |
| |
| printf ("\n\tChild process exited successfully\n"); |
| |
| /* Program completed successfully -- exit */ |
| printf ("\nsuccessful!\n"); |
| |
| return 0; |
| } |
| |
| /*---------------------------------------------------------------------+ |
| | child () | |
| | ==================================================================== | |
| | | |
| | Function: Child process | |
| | o Send all catchable signals (except sigchild) to parent | |
| | o exit & implicitly send sigchild signal to parent | |
| | | |
| | Parms: pid - process id of parent process | |
| | | |
| +---------------------------------------------------------------------*/ |
| void child (pid_t pid) |
| { |
| int i; |
| |
| /* Send one of each of the possible signals to the process */ |
| printf ("\n\tChild: sending ALL signals to parent!\n"); |
| for (i=1; i< (SIGMAX + 1); i++) { |
| |
| /* Cannot catch or ignore the following signals */ |
| #ifdef _LINUX_ |
| if ((i == SIGKILL) || (i == SIGSTOP) || ((i>=32)&&(i<=34))) continue; |
| #else |
| if (i == SIGKILL || i == SIGSTOP || i == SIGCONT) continue; |
| #endif |
| |
| /* Skip sigchild too */ |
| if (i == SIGCHLD) continue; |
| #ifdef _IA64 |
| /* RESERVED - DON'T USE */ |
| if (i == SIGWAITING) continue; |
| #endif |
| |
| printf ("\tSending (%d)\n", i); |
| |
| if (kill (pid, i) < 0) |
| sys_error ("kill failed", __LINE__); |
| } |
| |
| /* Exit & implicitly send a sigchild interrupt to the parent process */ |
| exit (0); |
| } |
| |
| /*---------------------------------------------------------------------+ |
| | handler () | |
| | ==================================================================== | |
| | | |
| | Function: Signal handler | |
| | o Send all catchable signals (except sigchild) to parent | |
| | | |
| | Parms: signal - signal number caught | |
| | | |
| | Returns: Aborts if an unexpected signal is caught | |
| | | |
| +---------------------------------------------------------------------*/ |
| void handler (int signal, int code, struct sigcontext *scp) |
| { |
| char msg [100]; |
| |
| if (signal == SIGCHLD) { |
| printf ("\tcaught SIGCHLD(%d) signal\n", signal); |
| sigchld_flag = 1; |
| } else { |
| sprintf (msg, "caught an unexpected signal (%d)", signal); |
| error (msg, __LINE__); |
| } |
| } |
| |
| /*---------------------------------------------------------------------+ |
| | ignore_signals () | |
| | ==================================================================== | |
| | | |
| | Function: Force all signals to be ignored, except for the following | |
| | signals: | |
| | | |
| | (Sent when child process stops or exits) | |
| | | |
| | o SIGCHLD (20) | |
| | | |
| | (Theses cannot be caught or ignored) | |
| | | |
| | o SIGKILL (9) | |
| | o SIGSTOP (17) | |
| | o SIGCONT (19) | |
| | | |
| | Returns: n/a | |
| | | |
| +---------------------------------------------------------------------*/ |
| void ignore_signals () |
| { |
| struct sigaction action; |
| char msg [100]; |
| int i; |
| |
| for (i=1; i< (SIGMAX + 1); i++) { |
| |
| /* Cannot catch or ignore the following signals: */ |
| #ifdef _LINUX_ |
| if ((i == SIGKILL) || (i == SIGSTOP) || ((i>=32)&&(i<=34))) continue; |
| #else |
| if (i == SIGKILL || i == SIGSTOP || i == SIGCONT) continue; |
| #endif |
| |
| /* Do not ignore SIGCHILD signal */ |
| if (i == SIGCHLD) continue; |
| |
| action.sa_handler = SIG_IGN; |
| sigfillset (&action.sa_mask); |
| action.sa_flags = SA_RESTART; |
| |
| if (sigaction (i, &action, (struct sigaction *) NULL) < 0) { |
| perror("ignore_signals: sigaction"); |
| sprintf (msg, "sigaction failed on signal %d", i); |
| error (msg, __LINE__); |
| } |
| } |
| |
| /* Setup signal handler for SIGCHLD signal */ |
| action.sa_handler = (void (*)(int)) handler; |
| sigfillset (&action.sa_mask); |
| action.sa_flags = SA_RESTART; |
| if (sigaction (SIGCHLD, &action, (struct sigaction *) NULL) < 0) |
| sys_error ("sigaction (SIGCHLD) failed", __LINE__); |
| } |
| |
| /*---------------------------------------------------------------------+ |
| | sys_error () | |
| | ==================================================================== | |
| | | |
| | Function: Creates system error message and calls error () | |
| | | |
| +---------------------------------------------------------------------*/ |
| void sys_error (const char *msg, int line) |
| { |
| char syserr_msg [256]; |
| |
| sprintf (syserr_msg, "%s: %s\n", msg, strerror (errno)); |
| error (syserr_msg, line); |
| } |
| |
| /*---------------------------------------------------------------------+ |
| | error () | |
| | ==================================================================== | |
| | | |
| | Function: Prints out message and exits... | |
| | | |
| +---------------------------------------------------------------------*/ |
| void error (const char *msg, int line) |
| { |
| fprintf (stderr, "ERROR [line: %d] %s\n", line, msg); |
| exit (-1); |
| } |