[CRIU] [PATCH 2/2] libcriu: crtools:cr_service() for crtools and a few changes to handle service socket
Ruslan Kuprieiev
kupruser at gmail.com
Thu Aug 29 13:28:30 EDT 2013
Hi!
Patch 2\2 contains cr_service() for crtools and a few changes to handle
service socket:
* cr_service() is used to handle criu library requests through
socket.
It creates unix domain socket and listens to connections on
it. After request
it fork()-s a child, which gets pid through SO_PEERCRED,
receives and processes
dump arguments, dumps program and sends flag back through
socket to library.
* adding USK_LIB_CTRL macro and handling library socket when
dumping and restoring.
On dump, if library socket is detected, it will be marked
with USK_LIB_CTRL and dumped like closed one.
On restore, we will send CRIU_RESUME to it.
Signed-off-by: Ruslan Kuprieiev kupruser at gmail.com
-------------- next part --------------
diff --git a/Makefile.crtools b/Makefile.crtools
index 33a9c70..d1c37e8 100644
--- a/Makefile.crtools
+++ b/Makefile.crtools
@@ -53,6 +53,7 @@ obj-y += stats.o
obj-y += string.o
obj-y += sigframe.o
obj-y += arch/$(ARCH)/vdso.o
+obj-y += cr-service.o
ifneq ($(MAKECMDGOALS),clean)
incdeps := y
diff --git a/cr-service.c b/cr-service.c
new file mode 100644
index 0000000..45eaf3d
--- /dev/null
+++ b/cr-service.c
@@ -0,0 +1,206 @@
+#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 "util-pie.h"
+#include "log.h"
+#include "libcriu.h"
+
+static int criu_recv_dump_arg(int socket_fd, struct criu_dump_args *arg)
+{
+ int ret;
+ arg->images_dir_fd = recv_fd(socket_fd);
+ if (arg->images_dir_fd == -1) {
+ pr_perror("Can't recv file descriptor");
+ return -1;
+ }
+
+ ret = recv(socket_fd, &(arg->flags), sizeof(arg->flags), 0);
+ if (ret == -1) {
+ pr_perror("Can't recv flags");
+ return -1;
+ }
+
+ return 0;
+}
+
+static int client_fd;
+
+int get_lib_sk_ino(void)
+{
+ struct stat st;
+ if (fstat(client_fd, &st)) {
+ pr_perror("Can't get library socket stat");
+ return -1;
+ }
+
+ return st.st_ino;
+}
+
+int cr_service(void)
+{
+ /* create sockets */
+ int server_fd;
+
+ server_fd = socket(AF_LOCAL, SOCK_STREAM, 0);
+ if (server_fd == -1) {
+ pr_perror("Can't initialize service socket.");
+ return -1;
+ }
+
+ struct sockaddr_un server_addr;
+ struct sockaddr_un client_addr;
+
+ memset(&server_addr, 0, sizeof(server_addr));
+ memset(&client_addr, 0, sizeof(client_addr));
+ server_addr.sun_family = AF_LOCAL;
+
+ socklen_t server_addr_len;
+ socklen_t client_addr_len;
+
+ 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.");
+ return -1;
+ }
+
+ /* 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.");
+ return -1;
+ }
+
+ if (listen(server_fd, 16) == -1) {
+ pr_perror("Can't listen for socket connections.");
+ return -1;
+ }
+
+ struct criu_dump_args *criu_arg;
+ criu_arg = malloc(sizeof(*criu_arg));
+
+ pid_t child_pid;
+
+ int ret;
+
+ /* structure for credentials */
+ struct ucred ids;
+ socklen_t ids_len;
+ ids_len = sizeof(struct ucred);
+
+ /* ignore children's return values */
+ signal(SIGCHLD, SIG_IGN);
+
+ while (1) {
+ pr_info("Waiting for connection...\n");
+
+ client_fd = accept(server_fd, &client_addr, &client_addr_len);
+ if (client_fd == -1) {
+ pr_perror("Can't accept connection.");
+ continue;
+ }
+
+ pr_info("Connected.\n");
+
+ switch (child_pid = fork()) {
+ case -1:
+ pr_perror("Can't fork a child.");
+ continue;
+ case 0:
+ /* getting socket credentials */
+ if (getsockopt(client_fd, SOL_SOCKET,
+ SO_PEERCRED, &ids, &ids_len)) {
+ pr_perror("Can't get socket options.");
+ goto child_err;
+ }
+
+ /* recovering dump argument */
+ client_addr_len = criu_recv_dump_arg(client_fd,
+ criu_arg);
+ if (client_addr_len == -1) {
+ pr_perror("Can't recover argument");
+ goto child_err;
+ }
+
+ /* going to dir, where to place images*/
+ if (fchdir(criu_arg->images_dir_fd)) {
+ pr_perror("Can't change directory.");
+ goto child_err;
+ }
+
+ /* initiate log file in imgs dir*/
+ opts.output = malloc(sizeof(char)*PATH_MAX);
+ strcpy(opts.output, getcwd(NULL, PATH_MAX));
+ strcat(opts.output, "/dump.log");
+
+ if (open_image_dir() < 0) {
+ pr_perror("Can't open current directory.");
+ goto child_err;
+ }
+
+ log_set_loglevel(log_get_loglevel());
+ if (log_init(opts.output) == -1) {
+ pr_perror("Can't initiate log.");
+ goto child_err;
+ }
+
+ /* checking dump flags from client */
+ if (criu_arg->flags & CRIU_DUMP_AND_CONTINUE)
+ opts.final_state = TASK_ALIVE;
+
+ /* dump */
+ if (cr_dump_tasks(ids.pid) < 0) {
+ pr_perror("Dump failed.");
+ goto child_err;
+ }
+
+ /* send msg that dump was successful */
+ if (opts.final_state == TASK_ALIVE) {
+ ret = CRIU_DUMP_SUCCESS;
+ if (send(client_fd, &ret,
+ sizeof(ret), 0) == -1) {
+ pr_perror("Can't send msg to lib");
+ close(client_fd);
+ exit(1);
+ }
+ }
+
+ close(client_fd);
+ exit(0);
+
+child_err: ret = CRIU_DUMP_FAIL;
+ if (send(client_fd, &ret, sizeof(ret), 0) == -1)
+ pr_perror("Can't send msg to lib");
+
+ close(client_fd);
+ exit(1);
+
+ default:
+ close(client_fd);
+ }
+ }
+
+ return 0;
+}
diff --git a/crtools.c b/crtools.c
index c7bc8b4..6642dde 100644
--- a/crtools.c
+++ b/crtools.c
@@ -334,6 +334,9 @@ int main(int argc, char *argv[])
if (!strcmp(argv[optind], "page-server"))
return cr_page_server(opts.restore_detach);
+ if (!strcmp(argv[optind], "service"))
+ return cr_service();
+
pr_msg("Unknown command \"%s\"\n", argv[optind]);
usage:
pr_msg("\n"
@@ -344,6 +347,7 @@ usage:
" criu check [--ms]\n"
" criu exec -p PID <syscall-string>\n"
" criu page-server\n"
+" criu service [<options>]\n"
"\n"
"Commands:\n"
" dump checkpoint a process/tree identified by pid\n"
@@ -353,6 +357,7 @@ usage:
" check checks whether the kernel support is up-to-date\n"
" exec execute a system call by other task\n"
" page-server launch page server\n"
+" service launch service server\n"
);
if (argc < 2) {
@@ -403,6 +408,9 @@ usage:
" --port PORT port of page server\n"
" -d|--daemon run in the background after creating socket\n"
"\n"
+"Service server options\n"
+" --address ADDR address, where to put service socket\n"
+"\n"
"Show options:\n"
" -f|--file FILE show contents of a checkpoint file\n"
" -D|--images-dir DIR directory where to get images from\n"
diff --git a/include/crtools.h b/include/crtools.h
index 7319992..f4bb06e 100644
--- a/include/crtools.h
+++ b/include/crtools.h
@@ -119,6 +119,9 @@ int cr_show(int pid);
int convert_to_elf(char *elf_path, int fd_core);
int cr_check(void);
int cr_exec(int pid, char **opts);
+int cr_service(void);
+
+int get_lib_sk_ino(void);
#define O_DUMP (O_RDWR | O_CREAT | O_EXCL)
#define O_SHOW (O_RDONLY)
diff --git a/include/image.h b/include/image.h
index 5cd7741..b201226 100644
--- a/include/image.h
+++ b/include/image.h
@@ -18,6 +18,7 @@
#define REMAP_GHOST (1 << 31)
#define USK_EXTERN (1 << 0)
+#define USK_LIB_CTRL (1 << 1)
#define VMA_AREA_NONE (0 << 0)
#define VMA_AREA_REGULAR (1 << 0) /* Dumpable area */
diff --git a/sk-unix.c b/sk-unix.c
index cf024a5..365c5ac 100644
--- a/sk-unix.c
+++ b/sk-unix.c
@@ -21,6 +21,7 @@
#include "sockets.h"
#include "sk-queue.h"
#include "mount.h"
+#include "libcriu.h"
#include "protobuf.h"
#include "protobuf/sk-unix.pb-c.h"
@@ -138,6 +139,17 @@ static int dump_one_unix_fd(int lfd, u32 id, const struct fd_parms *p)
ue.opts = &skopts;
ue.uflags = 0;
+ /*
+ * Check if this is library socket,
+ * that is connected to criu service.
+ * Dump it like closed one and mark it for restore.
+ */
+ if (ue.peer == get_lib_sk_ino()) {
+ ue.state = TCP_CLOSE;
+ ue.peer = 0;
+ ue.uflags |= USK_LIB_CTRL;
+ }
+
if (sk->namelen && *sk->name) {
ue.file_perms = &perms;
@@ -716,7 +728,23 @@ static int open_unixsk_standalone(struct unix_sk_info *ui)
pr_info("Opening standalone socket (id %#x ino %#x peer %#x)\n",
ui->ue->id, ui->ue->ino, ui->ue->peer);
- if ((ui->ue->state == TCP_ESTABLISHED) && !ui->ue->peer) {
+ if (ui->ue->uflags & USK_LIB_CTRL) {
+ int sks[2];
+
+ if (socketpair(PF_UNIX, ui->ue->type, 0, sks)) {
+ pr_perror("Can't create socketpair");
+ return -1;
+ }
+
+ int msg = CRIU_RESUME;
+ if (write(sks[1], &msg, sizeof(msg)) != sizeof(msg)) {
+ pr_perror("Can't write msg for lib to socket");
+ return -1;
+ }
+
+ close(sks[1]);
+ sk = sks[0];
+ } else if ((ui->ue->state == TCP_ESTABLISHED) && !ui->ue->peer) {
int ret, sks[2];
if (ui->ue->type != SOCK_STREAM) {
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