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#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)

error("pre-execution of command '%s' on pid %d: Cannot fork 2nd time.", command, getpid());

if(pid != 0) {

// the parent

exit(0);

}

// set a new process group id for just this child

if( setpgid(0, 0) != 0 )

error("pre-execution of command '%s' on pid %d: Cannot set a new process group.", command, getpid());

if( getpgid(0) != getpid() )

error("pre-execution of command '%s' on pid %d: Cannot set a new process group. Process group set is incorrect. Expected %d, found %d", command, getpid(), getpid(), getpgid(0));

if( setsid() != 0 )

error("pre-execution of command '%s' on pid %d: Cannot set session id.", command, getpid());

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("pre-execution of command '%s' on pid %d: could not unblock signals for threads.", command, getpid());

// 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(SIGINT, &sa, NULL) == -1)

error("pre-execution of command '%s' on pid %d: failed to set default signal handler for SIGINT.", command, getpid());

if(sigaction(SIGTERM, &sa, NULL) == -1)

error("pre-execution of command '%s' on pid %d: failed to set default signal handler for SIGTERM.", command, getpid());

if(sigaction(SIGPIPE, &sa, NULL) == -1)

error("pre-execution of command '%s' on pid %d: failed to set default signal handler for SIGPIPE.", command, getpid());

if(sigaction(SIGHUP, &sa, NULL) == -1)

error("pre-execution of command '%s' on pid %d: failed to set default signal handler for SIGHUP.", command, getpid());

if(sigaction(SIGUSR1, &sa, NULL) == -1)

error("pre-execution of command '%s' on pid %d: failed to set default signal handler for SIGUSR1.", command, getpid());

if(sigaction(SIGUSR2, &sa, NULL) == -1)

error("pre-execution of command '%s' on pid %d: failed to set default signal handler for SIGUSR2.", command, getpid());

}

debug(D_CHILDS, "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);*/

// close the pipe fd

// this is required in musl

// without it the childs do not exit

close(fileno(fp));

// close the pipe file pointer

fclose(fp);

siginfo_t info;

if(waitid(P_PID, (id_t) pid, &info, WEXITED) != -1) {

switch(info.si_code) {

case CLD_EXITED:

if(info.si_status)

error("child pid %d exited with code %d.", info.si_pid, info.si_status);

return(info.si_status);

break;

case CLD_KILLED:

error("child pid %d killed by signal %d.", info.si_pid, info.si_status);

return(-1);

break;

case CLD_DUMPED:

error("child pid %d core dumped by signal %d.", info.si_pid, info.si_status);

return(-2);

break;

case CLD_STOPPED:

error("child pid %d stopped by signal %d.", info.si_pid, info.si_status);

return(0);

break;

case CLD_TRAPPED:

error("child pid %d trapped by signal %d.", info.si_pid, info.si_status);

return(-4);

break;

case CLD_CONTINUED:

error("child pid %d continued by signal %d.", info.si_pid, info.si_status);

return(0);

break;

default:

error("child 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;

}