Files
cgproxy/cgroup_attach.hpp
2020-05-16 10:49:47 +08:00

103 lines
2.5 KiB
C++

#ifndef CGPROUP_ATTACH_H
#define CGPROUP_ATTACH_H
#include <errno.h>
#include <fstream>
#include <iostream>
#include <regex>
#include <stdlib.h>
#include <string>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <stdio.h>
#include "common.hpp"
using namespace std;
namespace CGPROXY::CGROUP{
bool exist(string path) {
struct stat st;
if (stat(path.c_str(), &st) != -1) {
return S_ISDIR(st.st_mode);
}
return false;
}
bool validate(string pid, string cgroup) {
bool pid_v = validPid(pid);
bool cg_v = validCgroup(cgroup);
if (pid_v && cg_v)
return true;
error("attach paramater validate error");
return_error
}
string get_cgroup2_mount_point(int &status){
char cgroup2_mount_point[100]="";
FILE* fp = popen("findmnt -t cgroup2 -n -o TARGET", "r");
int count=fscanf(fp,"%s",&cgroup2_mount_point);
fclose(fp);
if (count=0){
error("cgroup2 not supported");
status=-1;
return NULL;
}
status=0;
return cgroup2_mount_point;
}
int attach(const string pid, const string cgroup_target) {
if (getuid()!=0) {
error("need root to attach cgroup");
return_error
}
debug("attaching %s to %s",pid.c_str(),cgroup_target.c_str());
int status;
if (!validate(pid, cgroup_target)) return_error
string cgroup_mount_point = get_cgroup2_mount_point(status);
if (status!=0) return_error
string cgroup_target_path = cgroup_mount_point + cgroup_target;
string cgroup_target_procs = cgroup_target_path + "/cgroup.procs";
// check if exist, we will create it if not exist
if (!exist(cgroup_target_path)) {
if (mkdir(cgroup_target_path.c_str(),
S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH) == 0) {
debug("created cgroup %s success", cgroup_target.c_str());
} else {
error("created cgroup %s failed, errno %d", cgroup_target.c_str(), errno);
return_error
}
// error("cgroup %s not exist",cgroup_target.c_str());
// return_error
}
// put pid to target cgroup
ofstream procs(cgroup_target_procs, ofstream::app);
if (!procs.is_open()) {
error("open file %s failed", cgroup_target_procs.c_str());
return_error
}
procs << pid.c_str() << endl;
procs.close();
// maybe there some write error, for example process pid may not exist
if (!procs) {
error("write %s to %s failed, maybe process %s not exist",
pid.c_str(), cgroup_target_procs.c_str(), pid.c_str());
return_error
}
return_success
}
int attach(const int pid, const string cgroup_target){
return attach(to_str(pid), cgroup_target);
}
}
#endif