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// SPDX-License-Identifier: GPL-3.0-or-later
#include "../libnetdata.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
static inline FILE *custom_popene(const char *command, volatile pid_t *pidptr, char **env) {
FILE *fp;
int pipefd[2], error;
pid_t pid;
char *const spawn_argv[] = {
"sh",
"-c",
(char *)command,
NULL
};
posix_spawnattr_t attr;
posix_spawn_file_actions_t fa;
if(pipe(pipefd) == -1)
return NULL;
if ((fp = fdopen(pipefd[PIPE_READ], "r")) == NULL) {
goto error_after_pipe;
}
// Mark all files to be closed by the exec() stage of posix_spawn()
int i;
for(i = (int) (sysconf(_SC_OPEN_MAX) - 1); i >= 0; i--)
if(i != STDIN_FILENO && i != STDERR_FILENO)
(void)fcntl(i, F_SETFD, FD_CLOEXEC);
if (!posix_spawn_file_actions_init(&fa)) {
// move the pipe to stdout in the child
if (posix_spawn_file_actions_adddup2(&fa, pipefd[PIPE_WRITE], STDOUT_FILENO)) {
error("posix_spawn_file_actions_adddup2() failed");
goto error_after_posix_spawn_file_actions_init;
}
} else {
error("posix_spawn_file_actions_init() failed.");
goto error_after_pipe;
}
if (!(error = posix_spawnattr_init(&attr))) {
// reset all signals in the child
sigset_t mask;
if (posix_spawnattr_setflags(&attr, POSIX_SPAWN_SETSIGMASK | POSIX_SPAWN_SETSIGDEF))
error("posix_spawnattr_setflags() failed.");
sigemptyset(&mask);
if (posix_spawnattr_setsigmask(&attr, &mask))
error("posix_spawnattr_setsigmask() failed.");
} else {
error("posix_spawnattr_init() failed.");
}
if (!posix_spawn(&pid, "/bin/sh", &fa, &attr, spawn_argv, env)) {
*pidptr = pid;
debug(D_CHILDS, "Spawned command: '%s' on pid %d from parent pid %d.", command, pid, getpid());
} else {
error("Failed to spawn command: '%s' from parent pid %d.", command, getpid());
fclose(fp);
fp = NULL;
}
close(pipefd[PIPE_WRITE]);
if (!error) {
// posix_spawnattr_init() succeeded
if (posix_spawnattr_destroy(&attr))
error("posix_spawnattr_destroy");
}
if (posix_spawn_file_actions_destroy(&fa))
error("posix_spawn_file_actions_destroy");
return fp;
error_after_posix_spawn_file_actions_init:
if (posix_spawn_file_actions_destroy(&fa))
error("posix_spawn_file_actions_destroy");
error_after_pipe:
if (fp)
fclose(fp);
else
close(pipefd[PIPE_READ]);
close(pipefd[PIPE_WRITE]);
return NULL;
}
// See man environ
extern char **environ;
FILE *mypopen(const char *command, volatile pid_t *pidptr) {
return custom_popene(command, pidptr, environ);
}
FILE *mypopene(const char *command, volatile pid_t *pidptr, char **env) {
return custom_popene(command, pidptr, env);
}
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);
errno = 0;
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);
case CLD_KILLED:
error("child pid %d killed by signal %d.", info.si_pid, info.si_status);
return(-1);
case CLD_DUMPED:
error("child pid %d core dumped by signal %d.", info.si_pid, info.si_status);
return(-2);
case CLD_STOPPED:
error("child pid %d stopped by signal %d.", info.si_pid, info.si_status);
return(0);
case CLD_TRAPPED:
error("child pid %d trapped by signal %d.", info.si_pid, info.si_status);
return(-4);
case CLD_CONTINUED:
error("child pid %d continued by signal %d.", info.si_pid, info.si_status);
return(0);
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);
}
}
else
error("Cannot waitid() for pid %d", pid);
return 0;
}
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