Files
cgproxy/src/cgroup_attach.cpp

104 lines
2.9 KiB
C++

#include "cgroup_attach.h"
#include "common.h"
#include <errno.h>
#include <fstream>
#include <iostream>
#include <regex>
#include <stdio.h>
#include <stdlib.h>
#include <string>
#include <sys/stat.h>
#include <sys/types.h>
#include <thread>
#include <unistd.h>
namespace CGPROXY::CGROUP {
string cgroup2_mount_point = get_cgroup2_mount_point();
string get_cgroup2_mount_point() {
stringstream buffer;
unique_ptr<FILE, decltype(&pclose)> fp(popen("findmnt -t cgroup2 -n -o TARGET", "r"),
&pclose);
if (!fp) return "";
char buf[READ_SIZE_MAX];
while (fgets(buf, READ_SIZE_MAX, fp.get()) != NULL) { buffer << buf; }
string s = buffer.str();
s.pop_back(); // remove newline character
return s;
}
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;
}
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());
if (!validate(pid, cgroup_target)) return_error;
if (cgroup2_mount_point.empty()) return_error;
string cgroup_target_path = cgroup2_mount_point + cgroup_target;
string cgroup_target_procs = cgroup_target_path + "/cgroup.procs";
// check if exist, we will create it if not exist
if (!dirExist(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
}
if (getCgroup(pid) == cgroup_target) {
debug("%s already in %s", pid.c_str(), cgroup_target.c_str());
return_success;
}
// put pid to target cgroup
if (write2procs(pid, cgroup_target_procs) != 0) return_error;
// wait for small period and check again
this_thread::sleep_for(std::chrono::milliseconds(100));
if (getCgroup(pid) != cgroup_target && write2procs(pid, cgroup_target_procs) != 0)
return_error;
return_success;
}
int write2procs(string pid, string procspath) {
ofstream procs(procspath, ofstream::app);
if (!procs.is_open()) {
error("open file %s failed", procspath.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(),
procspath.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);
}
} // namespace CGPROXY::CGROUP