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#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <signal.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/wait.h>
#include "log.h"
#include "popen.h"
#include "common.h"
/*
struct mypopen {
pid_t pid;
FILE *fp;
struct mypopen *next;
struct mypopen *prev;
};
static struct mypopen *mypopen_root = NULL;
static void mypopen_add(FILE *fp, pid_t *pid) {
struct mypopen *mp = malloc(sizeof(struct mypopen));
if(!mp) {
fatal("Cannot allocate %zu bytes", sizeof(struct mypopen))
return;
}
mp->fp = fp;
mp->pid = pid;
mp->next = popen_root;
mp->prev = NULL;
if(mypopen_root) mypopen_root->prev = mp;
mypopen_root = mp;
}
static void mypopen_del(FILE *fp) {
struct mypopen *mp;
for(mp = mypopen_root; mp; mp = mp->next)
if(mp->fd == fp) break;
if(!mp) error("Cannot find mypopen() file pointer in open childs.");
else {
if(mp->next) mp->next->prev = mp->prev;
if(mp->prev) mp->prev->next = mp->next;
if(mypopen_root == mp) mypopen_root = mp->next;
free(mp);
}
}
*/
#define PIPE_READ 0
#define PIPE_WRITE 1
FILE *mypopen(const char *command, pid_t *pidptr)
{
int pipefd[2];
if(pipe(pipefd) == -1) return NULL;
int pid = fork();
if(pid == -1) {
close(pipefd[PIPE_READ]);
close(pipefd[PIPE_WRITE]);
return NULL;
}
if(pid != 0) {
// the parent
*pidptr = pid;
close(pipefd[PIPE_WRITE]);
FILE *fp = fdopen(pipefd[PIPE_READ], "r");
/*mypopen_add(fp, pid);*/
return(fp);
}
// the child
// close all files
int i;
for(i = (int) (sysconf(_SC_OPEN_MAX) - 1); i > 0; i--)
if(i != STDIN_FILENO && i != STDERR_FILENO && i != pipefd[PIPE_WRITE]) close(i);
// move the pipe to stdout
if(pipefd[PIPE_WRITE] != STDOUT_FILENO) {
dup2(pipefd[PIPE_WRITE], STDOUT_FILENO);
close(pipefd[PIPE_WRITE]);
}
#ifdef DETACH_PLUGINS_FROM_NETDATA
// this was an attempt to detach the child and use the suspend mode charts.d
// unfortunatelly it does not work as expected.
// fork again to become session leader
pid = fork();
if(pid == -1) fprintf(stderr, "Cannot fork again on pid %d\n", getpid());
if(pid != 0) {
// the parent
exit(0);
}
// set a new process group id for just this child
if( setpgid(0, 0) != 0 )
error("Cannot set a new process group for pid %d (%s)", getpid(), strerror(errno));
if( getpgid(0) != getpid() )
error("Process group set is incorrect. Expected %d, found %d", getpid(), getpgid(0));
if( setsid() != 0 )
error("Cannot set session id for pid %d (%s)", getpid(), strerror(errno));
fprintf(stdout, "MYPID %d\n", getpid());
fflush(NULL);
#endif
// reset all signals
{
sigset_t sigset;
sigfillset(&sigset);
if(pthread_sigmask(SIG_UNBLOCK, &sigset, NULL) == -1) {
error("Could not block signals for threads");
}
// We only need to reset ignored signals.
// Signals with signal handlers are reset by default.
struct sigaction sa;
sigemptyset(&sa.sa_mask);
sa.sa_handler = SIG_DFL;
sa.sa_flags = 0;
if(sigaction(SIGPIPE, &sa, NULL) == -1) {
error("Failed to change signal handler for SIGTERM");
}
}
info("executing command: '%s' on pid %d.", command, getpid());
execl("/bin/sh", "sh", "-c", command, NULL);
exit(1);
}
int mypclose(FILE *fp, pid_t pid) {
debug(D_EXIT, "Request to mypclose() on pid %d", pid);
/*mypopen_del(fp);*/
fclose(fp);
siginfo_t info;
if(waitid(P_PID, (id_t) pid, &info, WEXITED) != -1) {
switch(info.si_code) {
case CLD_EXITED:
error("pid %d exited with code %d.", info.si_pid, info.si_status);
return(info.si_status);
break;
case CLD_KILLED:
error("pid %d killed by signal %d.", info.si_pid, info.si_status);
return(-1);
break;
case CLD_DUMPED:
error("pid %d core dumped by signal %d.", info.si_pid, info.si_status);
return(-2);
break;
case CLD_STOPPED:
error("pid %d stopped by signal %d.", info.si_pid, info.si_status);
return(0);
break;
case CLD_TRAPPED:
error("pid %d trapped by signal %d.", info.si_pid, info.si_status);
return(-4);
break;
case CLD_CONTINUED:
error("pid %d continued by signal %d.", info.si_pid, info.si_status);
return(0);
break;
default:
error("pid %d gave us a SIGCHLD with code %d and status %d.", info.si_pid, info.si_code, info.si_status);
return(-5);
break;
}
}
else error("Cannot waitid() for pid %d", pid);
return 0;
}
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