Add libprocessgroup

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)

LOCAL_SRC_FILES := processgroup.cpp

LOCAL_MODULE := libprocessgroup

LOCAL_SHARED_LIBRARIES := liblog

LOCAL_C_INCLUDES := $(LOCAL_PATH)/include

LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)/include

LOCAL_CFLAGS := -Wall -Werror

LOCAL_REQUIRED_MODULE := processgroup_cleanup

include external/libcxx/libcxx.mk

include $(BUILD_SHARED_LIBRARY)

include $(CLEAR_VARS)

LOCAL_SRC_FILES := cleanup.cpp

LOCAL_MODULE := processgroup_cleanup

LOCAL_C_INCLUDES := $(LOCAL_PATH)/include

LOCAL_CFLAGS := -Wall -Werror

LOCAL_FORCE_STATIC_EXECUTABLE := true

LOCAL_STATIC_LIBRARIES := libc libcutils

include $(BUILD_EXECUTABLE)

/*

 *  Copyright 2014 Google, Inc

 *

 *  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 <string.h>

#include <unistd.h>

#include <sys/syslimits.h>

#include "processgroup_priv.h"

int main(int argc, char **argv)

{

    char buf[PATH_MAX];

    if (argc != 2)

        return -1;

    memcpy(buf, PROCESSGROUP_CGROUP_PATH, sizeof(PROCESSGROUP_CGROUP_PATH));

    strlcat(buf, argv[1], sizeof(buf));

    return rmdir(buf);

}

/*

 *  Copyright 2014 Google, Inc

 *

 *  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.

 */

#ifndef _PROCESSGROUP_H_

#define _PROCESSGROUP_H_

#include <sys/cdefs.h>

#include <sys/types.h>

__BEGIN_DECLS

int killProcessGroup(uid_t uid, int initialPid, int signal);

int createProcessGroup(uid_t uid, int initialPid);

void removeAllProcessGroups(void);

__END_DECLS

#endif

/*

 *  Copyright 2014 Google, Inc

 *

 *  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.

 */

//#define LOG_NDEBUG 0

#define LOG_TAG "libprocessgroup"

#include <assert.h>

#include <dirent.h>

#include <fcntl.h>

#include <stdbool.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <sys/stat.h>

#include <sys/types.h>

#include <log/log.h>

#include <private/android_filesystem_config.h>

#include <processgroup/processgroup.h>

#include "processgroup_priv.h"

struct ctx {

    bool initialized;

    int fd;

    char buf[128];

    char *buf_ptr;

    size_t buf_len;

};

static int convertUidToPath(char *path, size_t size, uid_t uid)

{

    return snprintf(path, size, "%s/%s%d",

            PROCESSGROUP_CGROUP_PATH,

            PROCESSGROUP_UID_PREFIX,

            uid);

}

static int convertUidPidToPath(char *path, size_t size, uid_t uid, int pid)

{

    return snprintf(path, size, "%s/%s%d/%s%d",

            PROCESSGROUP_CGROUP_PATH,

            PROCESSGROUP_UID_PREFIX,

            uid,

            PROCESSGROUP_PID_PREFIX,

            pid);

}

static int initCtx(uid_t uid, int pid, struct ctx *ctx)

{

    int ret;

    char path[PROCESSGROUP_MAX_PATH_LEN] = {0};

    convertUidPidToPath(path, sizeof(path), uid, pid);

    strlcat(path, PROCESSGROUP_CGROUP_PROCS_FILE, sizeof(path));

    int fd = open(path, O_RDONLY);

    if (fd < 0) {

        ret = -errno;

        SLOGV("failed to open %s: %s", path, strerror(errno));

        return ret;

    }

    ctx->fd = fd;

    ctx->buf_ptr = ctx->buf;

    ctx->buf_len = 0;

    ctx->initialized = true;

    return 0;

}

static int refillBuffer(struct ctx *ctx)

{

    memmove(ctx->buf, ctx->buf_ptr, ctx->buf_len);

    ctx->buf_ptr = ctx->buf;

    ssize_t ret = read(ctx->fd, ctx->buf_ptr + ctx->buf_len,

                sizeof(ctx->buf) - ctx->buf_len);

    if (ret < 0) {

        return -errno;

    } else if (ret == 0) {

        return 0;

    }

    ctx->buf_len += ret;

    assert(ctx->buf_len <= sizeof(ctx->buf));

    return ret;

}

static pid_t getOneAppProcess(uid_t uid, int appProcessPid, struct ctx *ctx)

{

    if (!ctx->initialized) {

        int ret = initCtx(uid, appProcessPid, ctx);

        if (ret < 0) {

            return ret;

        }

    }

    char *eptr;

    while ((eptr = (char *)memchr(ctx->buf_ptr, '\n', ctx->buf_len)) == NULL) {

        int ret = refillBuffer(ctx);

        if (ret == 0) {

            return -ERANGE;

        }

        if (ret < 0) {

            return ret;

        }

    }

    *eptr = '\0';

    char *pid_eptr = NULL;

    errno = 0;

    long pid = strtol(ctx->buf_ptr, &pid_eptr, 10);

    if (errno != 0) {

        return -errno;

    }

    if (pid_eptr != eptr) {

        return -EINVAL;

    }

    ctx->buf_ptr = eptr + 1;

    return (pid_t)pid;

}

static int removeProcessGroup(uid_t uid, int pid)

{

    int ret;

    char path[PROCESSGROUP_MAX_PATH_LEN] = {0};

    convertUidPidToPath(path, sizeof(path), uid, pid);

    ret = rmdir(path);

    convertUidToPath(path, sizeof(path), uid);

    rmdir(path);

    return ret;

}

static void removeUidProcessGroups(const char *uid_path)

{

    DIR *uid = opendir(uid_path);

    if (uid != NULL) {

        struct dirent cur;

        struct dirent *dir;

        while ((readdir_r(uid, &cur, &dir) == 0) && dir) {

            char path[PROCESSGROUP_MAX_PATH_LEN];

            if (dir->d_type != DT_DIR) {

                continue;

            }

            if (strncmp(dir->d_name, PROCESSGROUP_PID_PREFIX, strlen(PROCESSGROUP_PID_PREFIX))) {

                continue;

            }

            snprintf(path, sizeof(path), "%s/%s", uid_path, dir->d_name);

            SLOGV("removing %s\n", path);

            rmdir(path);

        }

    }

}

void removeAllProcessGroups()

{

    SLOGV("removeAllProcessGroups()");

    DIR *root = opendir(PROCESSGROUP_CGROUP_PATH);

    if (root == NULL) {

        SLOGE("failed to open %s: %s", PROCESSGROUP_CGROUP_PATH, strerror(errno));

    }

    if (root != NULL) {

        struct dirent cur;

        struct dirent *dir;

        while ((readdir_r(root, &cur, &dir) == 0) && dir) {

            char path[PROCESSGROUP_MAX_PATH_LEN];

            if (dir->d_type != DT_DIR) {

                continue;

            }

            if (strncmp(dir->d_name, PROCESSGROUP_UID_PREFIX, strlen(PROCESSGROUP_UID_PREFIX))) {

                continue;

            }

            snprintf(path, sizeof(path), "%s/%s", PROCESSGROUP_CGROUP_PATH, dir->d_name);

            removeUidProcessGroups(path);

            SLOGV("removing %s\n", path);

            rmdir(path);

        }

    }

}

static int killProcessGroupOnce(uid_t uid, int initialPid, int signal)

{

    int processes = 0;

    struct ctx ctx;

    pid_t pid;

    ctx.initialized = false;

    while ((pid = getOneAppProcess(uid, initialPid, &ctx)) >= 0) {

        processes++;

        SLOGV("sending processgroup kill to pid %d\n", pid);

        int ret = kill(pid, signal);

        if (ret == -1) {

            SLOGV("failed to kill pid %d: %s", pid, strerror(errno));

        }

    }

    if (ctx.initialized) {

        close(ctx.fd);

    }

    return processes;

}

int killProcessGroup(uid_t uid, int initialPid, int signal)

{

    int processes;

    int sleep_us = 100;

    while ((processes = killProcessGroupOnce(uid, initialPid, signal)) > 0) {

        SLOGV("killed %d processes for processgroup %d\n", processes, initialPid);

        if (sleep_us < 128000) {

            usleep(sleep_us);

            sleep_us *= 2;

        } else {

            SLOGE("failed to kill %d processes for processgroup %d\n",

                    processes, initialPid);

            break;

        }

    }

    if (processes == 0) {

        return removeProcessGroup(uid, initialPid);

    } else {

        return -1;

    }

}

static int mkdirAndChown(const char *path, mode_t mode, uid_t uid, gid_t gid)

{

    int ret;

    ret = mkdir(path, 0750);

    if (ret < 0 && errno != EEXIST) {

        return -errno;

    }

    ret = chown(path, AID_SYSTEM, AID_SYSTEM);

    if (ret < 0) {

        ret = -errno;

        rmdir(path);

        return ret;

    }

    return 0;

}

int createProcessGroup(uid_t uid, int initialPid)

{

    char path[PROCESSGROUP_MAX_PATH_LEN] = {0};

    int ret;

    convertUidToPath(path, sizeof(path), uid);

    ret = mkdirAndChown(path, 0750, AID_SYSTEM, AID_SYSTEM);

    if (ret < 0) {

        SLOGE("failed to make and chown %s: %s", path, strerror(-ret));

        return ret;

    }

    convertUidPidToPath(path, sizeof(path), uid, initialPid);

    ret = mkdirAndChown(path, 0750, AID_SYSTEM, AID_SYSTEM);

    if (ret < 0) {

        SLOGE("failed to make and chown %s: %s", path, strerror(-ret));

        return ret;

    }

    strlcat(path, PROCESSGROUP_CGROUP_PROCS_FILE, sizeof(path));

    int fd = open(path, O_WRONLY);

    if (fd < 0) {

        ret = -errno;

        SLOGE("failed to open %s: %s", path, strerror(errno));

        return ret;

    }

    char pid[PROCESSGROUP_MAX_PID_LEN + 1] = {0};

    int len = snprintf(pid, sizeof(pid), "%d", initialPid);

    ret = write(fd, pid, len);

    if (ret < 0) {

        ret = -errno;

        SLOGE("failed to write '%s' to %s: %s", pid, path, strerror(errno));

    } else {

        ret = 0;

    }

    close(fd);

    return ret;

}

/*

 *  Copyright 2014 Google, Inc

 *

 *  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.

 */

#ifndef _PROCESSGROUP_PRIV_H_

#define _PROCESSGROUP_PRIV_H_

#define PROCESSGROUP_CGROUP_PATH "/acct"

#define PROCESSGROUP_UID_PREFIX "uid_"

#define PROCESSGROUP_PID_PREFIX "pid_"

#define PROCESSGROUP_CGROUP_PROCS_FILE "/cgroup.procs"

#define PROCESSGROUP_MAX_UID_LEN 11

#define PROCESSGROUP_MAX_PID_LEN 11

#define PROCESSGROUP_MAX_PATH_LEN \

        (sizeof(PROCESSGROUP_CGROUP_PATH) + \

         sizeof(PROCESSGROUP_UID_PREFIX) + 1 + \

         PROCESSGROUP_MAX_UID_LEN + \

         sizeof(PROCESSGROUP_PID_PREFIX) + 1 + \

         PROCESSGROUP_MAX_PID_LEN + \

         sizeof(PROCESSGROUP_CGROUP_PROCS_FILE) + \

         1)

#endif