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-rw-r--r--libnetdata/popen/popen.c161
1 files changed, 71 insertions, 90 deletions
diff --git a/libnetdata/popen/popen.c b/libnetdata/popen/popen.c
index 845363fd2..177aebfc0 100644
--- a/libnetdata/popen/popen.c
+++ b/libnetdata/popen/popen.c
@@ -45,110 +45,91 @@ static void mypopen_del(FILE *fp) {
#define PIPE_READ 0
#define PIPE_WRITE 1
-FILE *mypopen(const char *command, volatile pid_t *pidptr)
-{
- int pipefd[2];
-
- if(pipe(pipefd) == -1) return NULL;
+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;
- int pid = fork();
- if(pid == -1) {
- close(pipefd[PIPE_READ]);
- close(pipefd[PIPE_WRITE]);
+ if(pipe(pipefd) == -1)
return NULL;
+ if ((fp = fdopen(pipefd[PIPE_READ], "r")) == NULL) {
+ goto error_after_pipe;
}
- 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
+ // 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 && 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]);
+ if(i != STDIN_FILENO && i != STDERR_FILENO)
+ 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;
}
-
-#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);
+ 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.");
}
-
- // 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
- signals_unblock();
- signals_reset();
-
- debug(D_CHILDS, "executing command: '%s' on pid %d.", command, getpid());
- execl("/bin/sh", "sh", "-c", command, NULL);
- exit(1);
-}
-
-FILE *mypopene(const char *command, volatile pid_t *pidptr, char **env) {
- int pipefd[2];
-
- if(pipe(pipefd) == -1)
- return NULL;
-
- int pid = fork();
- if(pid == -1) {
+ 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());
close(pipefd[PIPE_READ]);
- close(pipefd[PIPE_WRITE]);
- return NULL;
+ fp = NULL;
}
- if(pid != 0) {
- // the parent
- *pidptr = pid;
- close(pipefd[PIPE_WRITE]);
- FILE *fp = fdopen(pipefd[PIPE_READ], "r");
- return(fp);
+ close(pipefd[PIPE_WRITE]);
+
+ if (!error) {
+ // posix_spawnattr_init() succeeded
+ if (posix_spawnattr_destroy(&attr))
+ error("posix_spawnattr_destroy");
}
- // the child
+ 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:
+ close(pipefd[PIPE_READ]);
+ close(pipefd[PIPE_WRITE]);
+ return NULL;
+}
- // 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);
+// See man environ
+extern char **environ;
- // move the pipe to stdout
- if(pipefd[PIPE_WRITE] != STDOUT_FILENO) {
- dup2(pipefd[PIPE_WRITE], STDOUT_FILENO);
- close(pipefd[PIPE_WRITE]);
- }
+FILE *mypopen(const char *command, volatile pid_t *pidptr) {
+ return custom_popene(command, pidptr, environ);
+}
- execle("/bin/sh", "sh", "-c", command, NULL, env);
- exit(1);
+FILE *mypopene(const char *command, volatile pid_t *pidptr, char **env) {
+ return custom_popene(command, pidptr, env);
}
int mypclose(FILE *fp, pid_t pid) {