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cr-service.c
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cr-service.c
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#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include "crtools.h"
#include "cr_options.h"
#include "util.h"
#include "log.h"
#include "pstree.h"
#include "cr-service.h"
#include "cr-service-const.h"
#include "sd-daemon.h"
unsigned int service_sk_ino = -1;
static int recv_criu_msg(int socket_fd, CriuReq **msg)
{
unsigned char buf[CR_MAX_MSG_SIZE];
int len;
len = read(socket_fd, buf, CR_MAX_MSG_SIZE);
if (len == -1) {
pr_perror("Can't read request");
return -1;
}
if (len == 0) {
pr_info("Client exited unexpectedly\n");
errno = ECONNRESET;
return -1;
}
*msg = criu_req__unpack(NULL, len, buf);
if (!*msg) {
pr_perror("Failed unpacking request");
return -1;
}
return 0;
}
static int send_criu_msg(int socket_fd, CriuResp *msg)
{
unsigned char buf[CR_MAX_MSG_SIZE];
int len;
len = criu_resp__get_packed_size(msg);
if (criu_resp__pack(msg, buf) != len) {
pr_perror("Failed packing response");
return -1;
}
if (write(socket_fd, buf, len) == -1) {
pr_perror("Can't send response");
return -1;
}
return 0;
}
int send_criu_dump_resp(int socket_fd, bool success, bool restored)
{
CriuResp msg = CRIU_RESP__INIT;
CriuDumpResp resp = CRIU_DUMP_RESP__INIT;
msg.type = CRIU_REQ_TYPE__DUMP;
msg.success = success;
msg.dump = &resp;
resp.has_restored = true;
resp.restored = restored;
return send_criu_msg(socket_fd, &msg);
}
int send_criu_restore_resp(int socket_fd, bool success, int pid)
{
CriuResp msg = CRIU_RESP__INIT;
CriuRestoreResp resp = CRIU_RESTORE_RESP__INIT;
msg.type = CRIU_REQ_TYPE__RESTORE;
msg.success = success;
msg.restore = &resp;
resp.pid = pid;
return send_criu_msg(socket_fd, &msg);
}
static int setup_opts_from_req(int sk, CriuOpts *req)
{
struct ucred ids;
struct stat st;
socklen_t ids_len = sizeof(struct ucred);
char images_dir_path[PATH_MAX];
if (getsockopt(sk, SOL_SOCKET, SO_PEERCRED, &ids, &ids_len)) {
pr_perror("Can't get socket options");
return -1;
}
restrict_uid(ids.uid, ids.gid);
if (fstat(sk, &st)) {
pr_perror("Can't get socket stat");
return -1;
}
BUG_ON(st.st_ino == -1);
service_sk_ino = st.st_ino;
/* going to dir, where to place/get images*/
sprintf(images_dir_path, "/proc/%d/fd/%d", ids.pid, req->images_dir_fd);
if (chdir(images_dir_path)) {
pr_perror("Can't chdir to images directory");
return -1;
}
if (open_image_dir(".") < 0)
return -1;
/* initiate log file in imgs dir */
if (req->log_file)
opts.output = req->log_file;
else
opts.output = DEFAULT_LOG_FILENAME;
log_set_loglevel(req->log_level);
if (log_init(opts.output) == -1) {
pr_perror("Can't initiate log");
return -1;
}
/* checking flags from client */
if (req->has_leave_running && req->leave_running)
opts.final_state = TASK_ALIVE;
if (!req->has_pid) {
req->has_pid = true;
req->pid = ids.pid;
}
if (req->has_ext_unix_sk)
opts.ext_unix_sk = req->ext_unix_sk;
if (req->has_tcp_established)
opts.tcp_established_ok = req->tcp_established;
if (req->has_evasive_devices)
opts.evasive_devices = req->evasive_devices;
if (req->has_shell_job)
opts.shell_job = req->shell_job;
if (req->has_file_locks)
opts.handle_file_locks = req->file_locks;
return 0;
}
static int dump_using_req(int sk, CriuOpts *req)
{
bool success = false;
bool self_dump = !req->pid;
if (setup_opts_from_req(sk, req) == -1) {
pr_perror("Arguments treating fail");
goto exit;
}
/*
* FIXME -- cr_dump_tasks() may return code from custom
* scripts, that can be positive. However, right now we
* don't have ability to push scripts via RPC, so psitive
* ret values are impossible here.
*/
if (cr_dump_tasks(req->pid))
goto exit;
success = true;
exit:
if (req->leave_running || !self_dump || !success) {
if (send_criu_dump_resp(sk, success, false) == -1) {
pr_perror("Can't send response");
success = false;
}
}
return success ? 0 : 1;
}
static int restore_using_req(int sk, CriuOpts *req)
{
bool success = false;
/*
* We can't restore processes under arbitrary task yet.
* Thus for now we force the detached restore under the
* cr service task.
*/
opts.restore_detach = true;
if (setup_opts_from_req(sk, req) == -1) {
pr_perror("Arguments treating fail");
goto exit;
}
if (cr_restore_tasks())
goto exit;
success = true;
exit:
if (send_criu_restore_resp(sk, success,
root_item ? root_item->pid.real : -1) == -1) {
pr_perror("Can't send response");
success = false;
}
return success ? 0 : 1;
}
static int check(int sk)
{
CriuResp resp = CRIU_RESP__INIT;
resp.type = CRIU_REQ_TYPE__CHECK;
/* Check only minimal kernel support */
opts.check_ms_kernel = true;
if (!cr_check())
resp.success = true;
return send_criu_msg(sk, &resp);
}
static int cr_service_work(int sk)
{
CriuReq *msg = 0;
init_opts();
if (recv_criu_msg(sk, &msg) == -1) {
pr_perror("Can't recv request");
goto err;
}
switch (msg->type) {
case CRIU_REQ_TYPE__DUMP:
return dump_using_req(sk, msg->opts);
case CRIU_REQ_TYPE__RESTORE:
return restore_using_req(sk, msg->opts);
case CRIU_REQ_TYPE__CHECK:
return check(sk);
default: {
CriuResp resp = CRIU_RESP__INIT;
resp.type = CRIU_REQ_TYPE__EMPTY;
resp.success = false;
/* XXX -- add optional error code to CriuResp */
pr_perror("Invalid request");
send_criu_msg(sk, &resp);
goto err;
}
}
err:
return -1;
}
static void reap_worker(int signo)
{
int saved_errno;
int status;
pid_t pid;
saved_errno = errno;
/*
* As we block SIGCHLD, lets wait for every child that has
* already changed state.
*/
while (1) {
pid = waitpid(-1, &status, WNOHANG);
if (pid <= 0) {
errno = saved_errno;
return;
}
if (WIFEXITED(status))
pr_info("Worker(pid %d) exited with %d\n",
pid, WEXITSTATUS(status));
else if (WIFSIGNALED(status))
pr_info("Worker(pid %d) was killed by %d\n",
pid, WTERMSIG(status));
}
}
static int setup_sigchld_handler()
{
struct sigaction action;
sigemptyset(&action.sa_mask);
sigaddset(&action.sa_mask, SIGCHLD);
action.sa_handler = reap_worker;
action.sa_flags = SA_RESTART;
if (sigaction(SIGCHLD, &action, NULL)) {
pr_perror("Can't setup SIGCHLD handler");
return -1;
}
return 0;
}
static int restore_sigchld_handler()
{
struct sigaction action;
sigemptyset(&action.sa_mask);
sigaddset(&action.sa_mask, SIGCHLD);
action.sa_handler = SIG_DFL;
action.sa_flags = SA_RESTART;
if (sigaction(SIGCHLD, &action, NULL)) {
pr_perror("Can't restore SIGCHLD handler");
return -1;
}
return 0;
}
int cr_service(bool daemon_mode)
{
int server_fd = -1, n;
int child_pid;
struct sockaddr_un client_addr;
socklen_t client_addr_len;
n = sd_listen_fds(0);
if (n > 1) {
pr_err("Too many file descriptors (%d) recieved", n);
goto err;
} else if (n == 1)
server_fd = SD_LISTEN_FDS_START + 0;
else {
struct sockaddr_un server_addr;
socklen_t server_addr_len;
server_fd = socket(AF_LOCAL, SOCK_SEQPACKET, 0);
if (server_fd == -1) {
pr_perror("Can't initialize service socket");
goto err;
}
memset(&server_addr, 0, sizeof(server_addr));
memset(&client_addr, 0, sizeof(client_addr));
server_addr.sun_family = AF_LOCAL;
if (opts.addr == NULL)
opts.addr = CR_DEFAULT_SERVICE_ADDRESS;
strcpy(server_addr.sun_path, opts.addr);
server_addr_len = strlen(server_addr.sun_path)
+ sizeof(server_addr.sun_family);
client_addr_len = sizeof(client_addr);
unlink(server_addr.sun_path);
if (bind(server_fd, (struct sockaddr *) &server_addr,
server_addr_len) == -1) {
pr_perror("Can't bind");
goto err;
}
pr_info("The service socket is bound to %s\n", server_addr.sun_path);
/* change service socket permissions, so anyone can connect to it */
if (chmod(server_addr.sun_path, 0666)) {
pr_perror("Can't change permissions of the service socket");
goto err;
}
if (listen(server_fd, 16) == -1) {
pr_perror("Can't listen for socket connections");
goto err;
}
}
if (daemon_mode) {
if (daemon(1, 0) == -1) {
pr_perror("Can't run service server in the background");
goto err;
}
}
if (opts.pidfile) {
if (write_pidfile(getpid()) == -1) {
pr_perror("Can't write pidfile");
goto err;
}
}
if (setup_sigchld_handler())
goto err;
while (1) {
int sk;
pr_info("Waiting for connection...\n");
sk = accept(server_fd, &client_addr, &client_addr_len);
if (sk == -1) {
pr_perror("Can't accept connection");
goto err;
}
pr_info("Connected.\n");
child_pid = fork();
if (child_pid == 0) {
int ret;
if (restore_sigchld_handler())
exit(1);
close(server_fd);
ret = cr_service_work(sk);
close(sk);
exit(ret != 0);
}
if (child_pid < 0)
pr_perror("Can't fork a child");
close(sk);
}
err:
close_safe(&server_fd);
return 1;
}