common/src/kernel_interface.cpp

/*
 * Copyright (c) 2022 Huawei Device Co., Ltd.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "kernel_interface.h"
#include "memmgr_log.h"

#include "directory_ex.h"
#include "file_ex.h"

#include <securec.h>
#include <sys/stat.h>
#include <unistd.h>
#include <dirent.h>

#include <fstream>
#include <regex>
#include <sstream>
#include <csignal>

namespace OHOS {
namespace Memory {
namespace {
const std::string TAG = "KernelInterface";
}

IMPLEMENT_SINGLE_INSTANCE(KernelInterface);

const std::string KernelInterface::ROOT_PROC_PATH = "/proc";
const std::string KernelInterface::MEMCG_BASE_PATH = "/dev/memcg";

const std::string KernelInterface::ZWAPD_PRESSURE_SHOW_PATH = "/dev/memcg/memory.zswapd_pressure_show";
const std::string KernelInterface::ZWAPD_PRESSURE_SHOW_BUFFER_SIZE = "buffer_size";

bool KernelInterface::EchoToPath(const char* path, const char* content)
{
    int fd = open(path, O_RDWR, FILE_MODE_666);
    if (fd == -1) {
        HILOGE("echo %{public}s > %{public}s failed: file is not open", content, path);
        return false;
    }
    if (write(fd, content, strlen(content)) < 0) {
        HILOGE("echo %{public}s > %{public}s failed: write failed", content, path);
        close(fd);
        return false;
    }
    close(fd);
    HILOGI("echo %{public}s > %{public}s", content, path);
    return true;
}

bool KernelInterface::IsFileExists(const std::string& path)
{
    if (path.empty()) {
        return false;
    }
    struct stat st = {};
    if (stat(path.c_str(), &st) == 0 && S_ISREG(st.st_mode)) {
        return true;
    }
    return false;
}

bool KernelInterface::CreateFile(const std::string& path, const mode_t& mode)
{
    if (path.empty()) {
        return false;
    }
    if (IsFileExists(path)) {
        return true;
    }

    std::ofstream fout(path);
    if (!fout.is_open()) {
        return false;
    }
    fout.flush();
    fout.close();
    if (chmod(path.c_str(), mode) != 0) {
        return false;
    }

    return true;
}

bool KernelInterface::CreateFile(const std::string& path)
{
    return CreateFile(path, FILE_MODE_644);
}

bool KernelInterface::RemoveFile(const std::string& path)
{
    return OHOS::RemoveFile(path);
}

bool KernelInterface::WriteToFile(const std::string& path, const std::string& content, bool truncated)
{
    int fd;
    char actualPath[PATH_MAX + 1] = {0};
    char* ptrRet = NULL;

    if (strlen(path.c_str()) == 0 || strlen(path.c_str()) > PATH_MAX) {
        HILOGE("file path is invalid");
        return false;
    }
    ptrRet = realpath(path.c_str(), actualPath);
    if (!ptrRet) {
        HILOGE("file path cannot be canonicalized");
        return false;
    }
    HILOGD("path:%{public}s, actualPath:%{public}s", path.c_str(), actualPath);
    fd = open(actualPath, O_RDWR | (truncated ? O_TRUNC : O_APPEND));
    if (fd == -1) {
        HILOGE("echo %{public}s %{public}s %{public}s failed: file is not open",
            content.c_str(), truncated ? ">" : ">>", path.c_str());
        ptrRet = NULL;
        return false;
    }
    if (write(fd, content.c_str(), strlen(content.c_str())) < 0) {
        HILOGE("echo %{public}s %{public}s %{public}s failed: write failed",
            content.c_str(), truncated ? ">" : ">>", path.c_str());
        ptrRet = NULL;
        close(fd);
        return false;
    }
    ptrRet = NULL;
    close(fd);
    HILOGD("echo %{public}s %{public}s %{public}s", content.c_str(), truncated ? ">" : ">>", path.c_str());
    return true;
}

bool KernelInterface::ReadFromFile(const std::string& path, std::string& content)
{
    return OHOS::LoadStringFromFile(path, content);
}

bool KernelInterface::ReadLinesFromFile(const std::string& path, std::vector<std::string>& lines)
{
    if (!IsFileExists(path)) {
        HILOGE("no such file: %{public}s", path.c_str());
        return false;
    }
    std::string line;
    std::ifstream inf(path, std::ifstream::in);
    if (!inf) {
        HILOGE("ifstream(%{public}s) failed", path.c_str());
        return false;
    }
    lines.clear();
    while (!inf.eof()) {
        getline(inf, line);
        lines.push_back(line);
    }
    inf.close();
    return true;
}

bool KernelInterface::IsDirExists(const std::string& path)
{
    if (path.empty()) {
        return false;
    }
    struct stat st = {};
    if (stat(path.c_str(), &st) == 0 && S_ISDIR(st.st_mode)) {
        return true;
    }
    return false;
}

bool KernelInterface::IsExists(const std::string& path)
{
    return OHOS::FileExists(path);
}

bool KernelInterface::IsEmptyDir(const std::string& path)
{
    return OHOS::IsEmptyFolder(path);
}

bool KernelInterface::CreateDir(const std::string& path)
{
    return OHOS::ForceCreateDirectory(path); // default mode 755
}

bool KernelInterface::RemoveDirRecursively(const std::string& path)
{
    return OHOS::ForceRemoveDirectory(path) || (remove(path.c_str()) == 0);
}

std::string KernelInterface::RmDelimiter(const std::string& path)
{
    return OHOS::ExcludeTrailingPathDelimiter(path);
}

std::string KernelInterface::AddDelimiter(const std::string& path)
{
    return OHOS::IncludeTrailingPathDelimiter(path);
}

std::string KernelInterface::JoinPath(const std::string& prefixPath, const std::string& subPath)
{
    return AddDelimiter(prefixPath) + subPath;
}

std::string KernelInterface::JoinPath(const std::string& prefixPath, const std::string& midPath,
                                      const std::string& subPath)
{
    return JoinPath(JoinPath(prefixPath, midPath), subPath);
}

bool KernelInterface::GetPidProcInfo(struct ProcInfo &procInfo)
{
    HILOGD("called!");

    std::string statPath = JoinPath("/proc/", std::to_string(procInfo.pid), "/stat");

    // format like:
    // 1 (init) S 0 0 0 0 -1 4210944 1 ...
    std::string stat, statm, statPid, vss, rss;
    if (!ReadFromFile(statPath, stat)) {
        HILOGD("stat file error!");
        return false;
    }
    std::istringstream isStat(stat);
    isStat >> statPid >> procInfo.name >> procInfo.status;

    if (statPid != std::to_string(procInfo.pid)) {
        HILOGD("pid error!");
        return false;
    }

    std::string statmPath = JoinPath("/proc/", std::to_string(procInfo.pid), "/statm");
    // format like:
    // 640 472 369 38 0 115 0
    if (!ReadFromFile(statmPath, statm)) {
        HILOGD("statm file error!");
        return false;
    }
    std::istringstream isStatm(statm);
    isStatm >> vss >> rss; // pages

    procInfo.size = atoi(rss.c_str()) * PAGE_TO_KB;
    HILOGI("GetProcInfo success: name is %{public}s, status is %{public}s, size = %{public}d KB",
           procInfo.name.c_str(), procInfo.status.c_str(), procInfo.size);
    return true;
}

bool KernelInterface::GetProcNameByPid(int pid, std::string &name)
{
    std::string statusPath = JoinPath("/proc/", std::to_string(pid), "/status");
    std::string statusContent, nameTag;
    if (!ReadFromFile(statusPath, statusContent)) {
        HILOGE("status file [%{public}s] error!", statusPath.c_str());
        return false;
    }
    std::istringstream statusStream(statusContent);
    statusStream >> nameTag >> name;
    return true;
}

void KernelInterface::ReadZswapdPressureShow(std::map<std::string, std::string>& result)
{
    std::string contentStr;
    if (!ReadFromFile(ZWAPD_PRESSURE_SHOW_PATH, contentStr)) {
        HILOGE("read %{public}s faild, content=[%{public}s]", ZWAPD_PRESSURE_SHOW_PATH.c_str(), contentStr.c_str());
        return;
    }
    char *contentPtr = new char[contentStr.size() + 1];
    if (contentPtr == nullptr) {
        HILOGE("alloc buffer fail");
        return;
    }
    if (strcpy_s(contentPtr, contentStr.size() + 1, contentStr.c_str()) != EOK) {
        HILOGE("copy fail");
        delete [] contentPtr;
        return;
    }
    char *restPtr;
    char *line = strtok_r(contentPtr, "\n", &restPtr);
    do {
        for (size_t i = 0; i < strlen(line); i++) {
            if (line[i] == ':') {
                line[i] = ' ';
            }
        }
        std::string lineStr(line);
        std::istringstream is(lineStr);
        std::string name, value;
        is >> name >> value;
        result.insert(std::make_pair(name, value));

        line = strtok_r(NULL, "\n", &restPtr);
    } while (line);
    if (restPtr) {
        delete [] restPtr;
    }
    if (contentPtr) {
        delete [] contentPtr;
    }
    return;
}

int KernelInterface::GetCurrentBuffer()
{
    std::map<std::string, std::string> result;
    ReadZswapdPressureShow(result);
    auto value = result.find(ZWAPD_PRESSURE_SHOW_BUFFER_SIZE);
    if (value != result.end()) {
        HILOGD("buffer_size=%{public}s MB", result[ZWAPD_PRESSURE_SHOW_BUFFER_SIZE].c_str());
        return atoi(result[ZWAPD_PRESSURE_SHOW_BUFFER_SIZE].c_str()) * KB_PER_MB;
    }
    return MAX_BUFFER_KB;
}

int KernelInterface::KillOneProcessByPid(int pid)
{
    HILOGD("called! pid=%{public}d", pid);
    struct ProcInfo procInfo;
    int freedBuffer = 0;
    procInfo.pid = pid;

    if (!GetPidProcInfo(procInfo)) {
        HILOGE("GetPidProcInfo fail !!!");
        goto out;
    }

    if (procInfo.status == "D") {
        HILOGE("Task %{public}s is at D status!", procInfo.name.c_str());
        goto out;
    }

    if (kill(pid, SIGKILL)) {
        HILOGE("Kill %{public}s errno=%{public}d!", procInfo.name.c_str(), errno);
    }
    HILOGE("%{public}s has been Killed ! (pid=%{public}d, freedSize=%{public}d KB)",
        procInfo.name.c_str(), procInfo.pid, procInfo.size);

    freedBuffer = procInfo.size;
out:
    return freedBuffer;
}

bool KernelInterface::GetAllProcPids(std::vector<unsigned int> &pids)
{
    pids.clear();
    DIR *dir = opendir(ROOT_PROC_PATH.c_str());
    if (dir == nullptr) {
        HILOGE("dir %{public}s is not exist", ROOT_PROC_PATH.c_str());
        return false;
    }
    struct dirent *ptr = nullptr;
    while ((ptr = readdir(dir)) != nullptr) {
        if ((strcmp(ptr->d_name, ".") == 0) || (strcmp(ptr->d_name, "..") == 0)) {
            // current dir OR parent dir
            continue;
        } else if (ptr->d_type == DT_DIR) {
            int pid = atoi(ptr->d_name);
            if (pid > 0) {
                pids.push_back((unsigned int)pid);
            }
        }
    }
    if (dir) {
        closedir(dir);
    }
    HILOGD("there are %{public}zu pids under %{public}s", pids.size(), ROOT_PROC_PATH.c_str());
    return true;
}

bool KernelInterface::GetUidByPid(unsigned int pid, unsigned int& uid)
{
    std::string path = JoinPath(ROOT_PROC_PATH, std::to_string(pid), "status");
    std::string content;
    if (!ReadFromFile(path, content)) {
        HILOGE("read file failed. %{public}s", path.c_str());
        return false;
    }
    content = std::regex_replace(content, std::regex("\n+"), " "); // replace \n with space
    std::regex re(".*Uid:[[:s:]]*([[:d:]]+)[[:s:]]*([[:d:]]+)[[:s:]]*([[:d:]]+)[[:s:]]*([[:d:]]+).*");
    std::smatch res;
    if (!std::regex_match(content, res, re)) {
        HILOGD("re not match. %{public}s", content.c_str());
        return false;
    }
    try {
        uid = (unsigned int)std::stoi(res.str(1)); // 1: Uid index
    } catch (...) {
        HILOGE("stoi(%{public}s) failed", res.str(1).c_str());
        return false;
    }
    return true;
}

bool KernelInterface::ReadSwapOutKBSinceKernelBoot(const std::string &path, const std::string &tagStr,
    unsigned long long &ret)
{
    std::string contentStr;
    if (!ReadFromFile(path, contentStr)) {
        return false;
    }
    char *contentPtr = new char[contentStr.size() + 1];
    if (contentPtr == nullptr) {
        HILOGE("alloc buffer fail");
        return false;
    }
    if (strcpy_s(contentPtr, contentStr.size() + 1, contentStr.c_str()) != EOK) {
        HILOGE("copy fail");
        return false;
    }
    char *restPtr;
    char *line = strtok_r(contentPtr, "\n", &restPtr);
    do {
        std::string lineStr(line);

        size_t i = 0;
        for (; i < strlen(line); i++) {
            if (line[i] == ':') {
                break;
            }
        }
        if (i >= strlen(line) - 2) { // 2: no : in the line or : is at end of line
            line = strtok_r(NULL, "\n", &restPtr);
            continue;
        }
        std::string tag = lineStr.substr(0, i);
        if (tag == tagStr) {
            std::string value = lineStr.substr(i + 1);
            std::istringstream iss(value);
            std::string sizeStr, unitStr;
            iss >> sizeStr >> unitStr;
            try {
                ret = std::strtoull(sizeStr.c_str(), nullptr, 10); // 10:Decimal
                return true;
            } catch (...) {
                HILOGE("parse [%{public}s] to unsigned long long error!", sizeStr.c_str());
                return false;
            }
        }

        line = strtok_r(NULL, "\n", &restPtr);
    } while (line);
    if (restPtr) {
        delete [] restPtr;
    }
    if (contentPtr) {
        delete [] contentPtr;
    }
    return false;
}
} // namespace Memory
} // namespace OHOS