[CRIU] [PATCH] tests: Pipe.c Test Program
Andrey Vagin
avagin at openvz.org
Tue Dec 9 02:41:25 PST 2014
From: Saied Kazemi <saied at google.com>
Hi Saied,
This patch adds your test in the criu test system.
Signed-off-by: Andrey Vagin <avagin at openvz.org>
---
test/Makefile | 2 +-
test/pipes/Makefile | 12 +
test/pipes/pipe.c | 673 ++++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 686 insertions(+), 1 deletion(-)
create mode 100644 test/pipes/Makefile
create mode 100644 test/pipes/pipe.c
diff --git a/test/Makefile b/test/Makefile
index aa27f53..1fff105 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -13,7 +13,7 @@ all:
.PHONY: all
-TESTS = unix-callback mem-snap rpc libcriu mounts/ext security
+TESTS = unix-callback mem-snap rpc libcriu mounts/ext security pipes
other: .FORCE
for t in $(TESTS); do \
diff --git a/test/pipes/Makefile b/test/pipes/Makefile
new file mode 100644
index 0000000..bd4c563
--- /dev/null
+++ b/test/pipes/Makefile
@@ -0,0 +1,12 @@
+CFLAGS += -Wall
+pipe: pipe.c
+clean:
+ rm -f pipe
+run:
+ ./pipe - && \
+ ./pipe -c && \
+ ./pipe -cl && \
+ ./pipe -d && \
+ ./pipe -dc && \
+ ./pipe -dcl && \
+ true
diff --git a/test/pipes/pipe.c b/test/pipes/pipe.c
new file mode 100644
index 0000000..4a0331c
--- /dev/null
+++ b/test/pipes/pipe.c
@@ -0,0 +1,673 @@
+/*
+ * A simple demo/test program using criu's --inherit-fd command line
+ * option to restore a process with (1) an external pipe and (2) a
+ * new log file.
+ *
+ * Note that it's possible to restore the process without --inherit-fd,
+ * but when it reads from or writes to the pipe, it will get a broken
+ * pipe signal.
+ *
+ * Also note that changing the log file during restore has nothing to do
+ * with the pipe. It's just a nice feature for cases where it's desirable
+ * to have a restored process use a different file then the original one.
+ *
+ * The parent process spawns a child that will write messages to its
+ * parent through a pipe. After a couple of messages, parent invokes
+ * criu to checkpoint the child. Since the child exits after checkpoint,
+ * its pipe will be broken. Parent sets up a new pipe and invokes criu
+ * to restore the child using the new pipe (instead of the old one).
+ * The restored child exits after writing a couple more messages.
+ *
+ * To make sure that fd clashes are correctly handled during restore,
+ * child can optionally open a regular file and move it to a clashing fd.
+ *
+ * Make sure CRIU_BINARY defined below points to the right criu.
+ *
+ * $ cc -Wall -o pipe pipe.c
+ * $ sudo ./pipe -v
+ *
+ * The following should all succeed:
+ *
+ * $ sudo ./pipe -q && echo OK
+ * $ sudo ./pipe -qc && echo OK
+ * $ sudo ./pipe -qcl && echo OK
+ * $ sudo ./pipe -qd && echo OK
+ * $ sudo ./pipe -qdc && echo OK
+ * $ sudo ./pipe -qdcl && echo OK
+ *
+ * The following should all fail:
+ *
+ * $ sudo ./pipe -qn || echo $?
+ * $ sudo ./pipe -qo || echo $?
+ * $ sudo ./pipe -qr || echo $?
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <unistd.h>
+#include <errno.h>
+#include <signal.h>
+#include <time.h>
+#include <string.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+#include <sys/wait.h>
+#include <sys/prctl.h>
+
+typedef void (*sighandler_t)(int);
+typedef unsigned long ulong;
+
+/* colors */
+#define CS_PARENT "\033[00;32m"
+#define CS_CHILD "\033[00;33m"
+#define CS_DUMP "\033[00;34m"
+#define CS_RESTORE "\033[00;35m"
+#define CE "\033[0m"
+
+#define die(fmt, ...) do { \
+ if (!qflag) \
+ fprintf(stderr, fmt ": %m\n", __VA_ARGS__); \
+ if (getpid() == parent_pid) { \
+ (void)kill(0, 9); \
+ exit(1); \
+ } \
+ _exit(1); \
+} while (0)
+
+#define READ_FD 0 /* pipe read fd */
+#define WRITE_FD 1 /* pipe write fd */
+#define CLASH_FD 3 /* force inherit fd clash */
+
+#define MAX_FORKS 3 /* child, checkpoint, restore */
+
+#define CRIU_BINARY "../../criu"
+#define IMG_DIR "images"
+#define DUMP_LOG_FILE "dump.log"
+#define RESTORE_LOG_FILE "restore.log"
+#define RESTORE_PID_FILE "restore.pid"
+#define INHERIT_FD_OPTION "--inherit-fd"
+#define OLD_LOG_FILE "/tmp/oldlog"
+#define NEW_LOG_FILE "/tmp/newlog"
+
+/*
+ * Command line options (see usage()).
+ */
+char *cli_flags = "cdhlnoqrv";
+
+int cflag;
+int dflag;
+int lflag;
+int nflag;
+int oflag;
+int qflag;
+int rflag;
+int vflag;
+
+char pid_number[8];
+char inh_pipe_opt[16];
+char inh_pipe_arg[64];
+char inh_file_opt[16];
+char inh_file_arg[64];
+
+char *dump_argv[] = {
+ "criu", "dump",
+ "-D", IMG_DIR, "-o", DUMP_LOG_FILE,
+ "-v4", "-j",
+ "-t", pid_number,
+ NULL
+};
+
+char *restore_argv[] = {
+ "criu", "restore", "-d",
+ "-D", IMG_DIR, "-o", RESTORE_LOG_FILE,
+ "--pidfile", RESTORE_PID_FILE,
+ "-v4", "-j",
+ inh_pipe_opt, inh_pipe_arg,
+ inh_file_opt, inh_file_arg,
+ NULL
+};
+
+int max_msgs;
+int max_forks;
+int parent_pid;
+int child_pid;
+int criu_dump_pid;
+int criu_restore_pid;
+
+/* prototypes */
+void chld_handler(int signum);
+int parent(int *pipefd);
+int child(int *pipefd, int dupfd, int newfd);
+void checkpoint_child(int child_pid, int *pipefd);
+void restore_child(int *new_pipefd, char *old_pipe_name);
+void write_to_fd(int fd, char *name, int i, int newline);
+void ls_proc_fd(int fd);
+char *pipe_name(int fd);
+char *who(pid_t pid);
+void pipe_safe(int pipefd[2]);
+pid_t fork_safe(void);
+void signal_safe(int signum, sighandler_t handler);
+int open_safe(char *pathname, int flags);
+void close_safe(int fd);
+void write_safe(int fd, char *buf, int count);
+int read_safe(int fd, char *buf, int count);
+int dup_safe(int oldfd);
+void move_fd(int oldfd, int newfd);
+void mkdir_safe(char *dirname, int mode);
+void unlink_safe(char *pathname);
+void execv_safe(char *path, char *argv[], int ls);
+pid_t waitpid_safe(pid_t pid, int *status, int options, int id);
+void prctl_safe(int option, ulong arg2, ulong arg3, ulong arg4, ulong arg5);
+
+void usage(char *cmd)
+{
+ printf("Usage: %s [%s]\n", cmd, cli_flags);
+ printf("-c\tcause a clash during restore by opening %s as fd %d\n",
+ OLD_LOG_FILE, CLASH_FD);
+ printf("-d\tdup the pipe and write to it\n");
+ printf("-l\tchange log file from %s to %s during restore\n",
+ OLD_LOG_FILE, NEW_LOG_FILE);
+
+ printf("\n");
+ printf("The following flags should cause restore failure\n");
+ printf("-n\tdo not use the %s option\n", INHERIT_FD_OPTION);
+ printf("-o\topen the pipe via /proc/<pid>/fd and write to it\n");
+ printf("-r\tspecify read end of pipe during restore\n");
+
+ printf("\n");
+ printf("Miscellaneous flags\n");
+ printf("-h\tprint this help and exit\n");
+ printf("-q\tquiet mode, don't print anything\n");
+ printf("-v\tverbose mode (list contents of /proc/<pid>/fd)\n");
+
+}
+
+int main(int argc, char *argv[])
+{
+ int ret;
+ int opt;
+ int pipefd[2];
+
+ max_msgs = 4;
+ while ((opt = getopt(argc, argv, cli_flags)) != -1) {
+ switch (opt) {
+ case 'c': cflag++; break;
+ case 'd': dflag++; max_msgs += 4; break;
+ case 'h': usage(argv[0]); return 0;
+ case 'l': lflag++; break;
+ case 'n': nflag++; break;
+ case 'o': oflag++; max_msgs += 4; break;
+ case 'q': qflag++; vflag = 0;break;
+ case 'r': rflag++; break;
+ case 'v': vflag++; qflag = 0; break;
+ default: usage(argv[0]); return 1;
+ }
+ }
+
+ setbuf(stdout, NULL);
+ setbuf(stderr, NULL);
+ mkdir_safe(IMG_DIR, 0700);
+
+ pipe_safe(pipefd);
+ child_pid = fork_safe();
+ if (child_pid > 0) {
+ parent_pid = getpid();
+
+ signal_safe(SIGCHLD, chld_handler);
+ prctl_safe(PR_SET_CHILD_SUBREAPER, 1, 0, 0, 0);
+
+ close_safe(pipefd[WRITE_FD]);
+
+ ret = parent(pipefd);
+ } else {
+ /* child */
+ int dupfd = -1;
+ int openfd = -1;
+
+ child_pid = getpid();
+
+ close_safe(pipefd[READ_FD]);
+
+ /* open a regular file and move it to CLASH_FD */
+ if (cflag)
+ move_fd(open_safe(OLD_LOG_FILE, O_WRONLY | O_APPEND | O_CREAT), CLASH_FD);
+
+ /* open additional descriptors on the pipe and use them all */
+ if (dflag)
+ dupfd = dup_safe(pipefd[WRITE_FD]);
+ if (oflag) {
+ char buf[128];
+ snprintf(buf, sizeof buf, "/proc/self/fd/%d", pipefd[WRITE_FD]);
+ openfd = open_safe(buf, O_WRONLY);
+ }
+
+ ret = child(pipefd, dupfd, openfd);
+ }
+
+ return ret;
+}
+
+/*
+ * Parent reads message from its pipe with the child.
+ * After a couple of messages, it checkpoints the child
+ * which causes the child to exit. Parent then creates
+ * a new pipe and restores the child.
+ */
+int parent(int *pipefd)
+{
+ char buf[32];
+ char old_pipe[32];
+ int nread;
+
+ nread = 0;
+ while (max_forks <= MAX_FORKS) {
+ if (read_safe(pipefd[READ_FD], buf, sizeof buf) == 0)
+ continue;
+ nread++;
+ if (vflag && nread == 1)
+ ls_proc_fd(-1);
+
+ if (!qflag) {
+ printf("%s read %s from %s\n", who(0), buf,
+ pipe_name(pipefd[READ_FD]));
+ }
+
+ if (nread == (max_msgs / 2)) {
+ checkpoint_child(child_pid, pipefd);
+
+ if (!nflag) {
+ /* save the old pipe's name before closing it */
+ snprintf(old_pipe, sizeof old_pipe, "%s",
+ pipe_name(pipefd[READ_FD]));
+ close_safe(pipefd[READ_FD]);
+
+ /* create a new one */
+ if (!qflag)
+ printf("%s creating a new pipe\n", who(0));
+ pipe_safe(pipefd);
+ }
+ restore_child(pipefd, old_pipe);
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * Child sends a total of max_messages messages to its
+ * parent, half before checkpoint and half after restore.
+ */
+int child(int *pipefd, int dupfd, int openfd)
+{
+ int i;
+ int fd;
+ int num_wfds;
+ struct timespec req = { 1, 0 };
+
+ /*
+ * Count the number of pipe descriptors we'll be
+ * writing to. At least 1 (for pipefd[WRITE_FD])
+ * and at most 3.
+ */
+ num_wfds = 1;
+ if (dupfd >= 0)
+ num_wfds++;
+ if (openfd >= 0)
+ num_wfds++;
+
+ for (i = 0; i < max_msgs; i++) {
+ /* print first time and after checkpoint */
+ if (vflag && (i == 0 || i == (max_msgs / 2)))
+ ls_proc_fd(-1);
+
+ switch (i % num_wfds) {
+ case 0: fd = pipefd[WRITE_FD]; break;
+ case 1: fd = dflag ? dupfd : openfd; break;
+ case 2: fd = openfd; break;
+ }
+
+ write_to_fd(fd, pipe_name(pipefd[WRITE_FD]), i+1, 0);
+ if (cflag)
+ write_to_fd(CLASH_FD, "log file", i+1, 1);
+
+ /*
+ * Since sleep will be interrupted by C/R, make sure
+ * to sleep an entire second to minimize the chance of
+ * writing before criu restore has exited. If criu is
+ * still around and we write to a broken pipe, we'll be
+ * killed but SIGCHLD will be delivered to criu instead
+ * of parent.
+ */
+ while (nanosleep(&req, NULL))
+ ;
+ if (!qflag)
+ printf("\n");
+ }
+
+ return 0;
+}
+
+void chld_handler(int signum)
+{
+ int status;
+ pid_t pid;
+
+ pid = waitpid_safe(-1, &status, WNOHANG, 1);
+ if (WIFEXITED(status))
+ status = WEXITSTATUS(status);
+ if (pid == child_pid) {
+ if (!qflag) {
+ printf("%s %s exited with status %d\n", who(0),
+ who(pid), status);
+ }
+ /* if child exited successfully, we're done */
+ if (status == 0)
+ exit(0);
+ /* checkpoint kills the child */
+ if (status != 9)
+ exit(status);
+ }
+}
+
+void checkpoint_child(int child_pid, int *pipefd)
+{
+ /* prepare -t <pid> */
+ snprintf(pid_number, sizeof pid_number, "%d", child_pid);
+
+ criu_dump_pid = fork_safe();
+ if (criu_dump_pid > 0) {
+ int status;
+ pid_t pid;
+
+ pid = waitpid_safe(criu_dump_pid, &status, 0, 2);
+ if (WIFEXITED(status))
+ status = WEXITSTATUS(status);
+ if (!qflag) {
+ printf("%s %s exited with status %d\n", who(0),
+ who(pid), status);
+ }
+ if (status)
+ exit(status);
+ } else {
+ close(pipefd[READ_FD]);
+ criu_dump_pid = getpid();
+ execv_safe(CRIU_BINARY, dump_argv, 0);
+ }
+}
+
+void restore_child(int *new_pipefd, char *old_pipe_name)
+{
+ char buf[64];
+
+ criu_restore_pid = fork_safe();
+ if (criu_restore_pid > 0) {
+ int status;
+ pid_t pid;
+
+ if (!nflag)
+ close_safe(new_pipefd[WRITE_FD]);
+
+ pid = waitpid_safe(criu_restore_pid, &status, 0, 3);
+ if (WIFEXITED(status))
+ status = WEXITSTATUS(status);
+ if (!qflag) {
+ printf("%s %s exited with status %d\n", who(0),
+ who(pid), status);
+ }
+ if (status)
+ exit(status);
+ } else {
+ criu_restore_pid = getpid();
+
+ if (!nflag) {
+ /*
+ * We should close the read descriptor of the new pipe
+ * and use its write descriptor to call criu restore.
+ * But if rflag was set (for testing purposes), use the
+ * read descriptor which should cause the application to
+ * fail.
+ *
+ * Regardless of read or write descriptor, move it to a
+ * clashing fd to test inherit fd clash resolve code.
+ */
+ if (rflag)
+ move_fd(new_pipefd[READ_FD], CLASH_FD);
+ else {
+ close_safe(new_pipefd[READ_FD]);
+ move_fd(new_pipefd[WRITE_FD], CLASH_FD);
+ }
+
+ /* --inherit-fd fd[CLASH_FD]:pipe[xxxxxx] */
+ snprintf(inh_pipe_opt, sizeof inh_pipe_opt,
+ "%s", INHERIT_FD_OPTION);
+ snprintf(inh_pipe_arg, sizeof inh_pipe_arg, "fd[%d]:%s",
+ CLASH_FD, old_pipe_name);
+
+ if (lflag) {
+ /* create a new log file to replace the old one */
+ int filefd = open_safe(NEW_LOG_FILE, O_WRONLY | O_APPEND | O_CREAT);
+
+ /* --inherit-fd fd[x]:tmp/oldlog */
+ snprintf(inh_file_opt, sizeof inh_file_opt,
+ "%s", INHERIT_FD_OPTION);
+ snprintf(inh_file_arg, sizeof inh_file_arg,
+ "fd[%d]:%s", filefd, OLD_LOG_FILE + 1);
+ }
+ }
+
+ snprintf(buf, sizeof buf, "%s/%s", IMG_DIR, RESTORE_PID_FILE);
+ unlink_safe(buf);
+ execv_safe(CRIU_BINARY, restore_argv, 1);
+ }
+}
+
+void write_to_fd(int fd, char *name, int i, int newline)
+{
+ int n;
+ char buf[16]; /* fit "hello d\n" for small d */
+
+ n = snprintf(buf, sizeof buf, "hello %d", i);
+ if (!qflag)
+ printf("%s writing %s to %s via fd %d\n", who(0), buf, name, fd);
+
+ if (newline) {
+ buf[n++] = '\n';
+ buf[n] = '\0';
+ }
+ write_safe(fd, buf, strlen(buf));
+}
+
+void ls_proc_fd(int fd)
+{
+ char cmd[128];
+
+ if (qflag)
+ return;
+
+ if (fd == -1)
+ snprintf(cmd, sizeof cmd, "ls -l /proc/%d/fd", getpid());
+ else
+ snprintf(cmd, sizeof cmd, "ls -l /proc/%d/fd/%d", getpid(), fd);
+ printf("%s %s\n", who(0), cmd);
+ system(cmd);
+}
+
+char *pipe_name(int fd)
+{
+ static char pipe_name[64];
+ char path[64];
+
+ snprintf(path, sizeof path, "/proc/self/fd/%d", fd);
+ if (readlink(path, pipe_name, sizeof pipe_name) == -1)
+ die("readlink: path=%s", path);
+ return pipe_name;
+}
+
+/*
+ * Use two buffers to support two calls to
+ * this function in a printf argument list.
+ */
+char *who(pid_t pid)
+{
+ static char pidstr1[64];
+ static char pidstr2[64];
+ static char *cp;
+ char *np;
+ char *ep;
+ int p;
+
+ p = pid ? pid : getpid();
+ if (p == parent_pid) {
+ np = "parent";
+ ep = CS_PARENT;
+ } else if (p == child_pid) {
+ np = "child";
+ ep = CS_CHILD;
+ } else if (p == criu_dump_pid) {
+ np = "dump";
+ ep = CS_DUMP;
+ } else if (p == criu_restore_pid) {
+ np = "restore";
+ ep = CS_RESTORE;
+ } else
+ np = "???";
+
+ cp = (cp == pidstr1) ? pidstr2 : pidstr1;
+ snprintf(cp, sizeof pidstr1, "%s[%s %d]", pid ? "" : ep, np, p);
+ return cp;
+}
+
+void pipe_safe(int pipefd[2])
+{
+ if (pipe(pipefd) == -1)
+ die("pipe: %p", pipefd);
+}
+
+pid_t fork_safe(void)
+{
+ pid_t pid;
+
+ if ((pid = fork()) == -1)
+ die("fork: pid=%d", pid);
+ max_forks++;
+ return pid;
+}
+
+void signal_safe(int signum, sighandler_t handler)
+{
+ if (signal(signum, handler) == SIG_ERR)
+ die("signal: signum=%d", signum);
+}
+
+int open_safe(char *pathname, int flags)
+{
+ int fd;
+
+ if ((fd = open(pathname, flags)) == -1)
+ die("open: pathname=%s", pathname);
+ return fd;
+}
+
+void close_safe(int fd)
+{
+ if (close(fd) == -1)
+ die("close: fd=%d", fd);
+}
+
+void write_safe(int fd, char *buf, int count)
+{
+ if (write(fd, buf, count) != count) {
+ die("write: fd=%d buf=\"%s\" count=%d errno=%d",
+ fd, buf, count, errno);
+ }
+}
+
+int read_safe(int fd, char *buf, int count)
+{
+ int n;
+
+ if ((n = read(fd, buf, count)) < 0)
+ die("read: fd=%d count=%d", fd, count);
+ buf[n] = '\0';
+ return n;
+}
+
+int dup_safe(int oldfd)
+{
+ int newfd;
+
+ if ((newfd = dup(oldfd)) == -1)
+ die("dup: oldfd=%d", oldfd);
+ return newfd;
+}
+
+int dup2_safe(int oldfd, int newfd)
+{
+ if (dup2(oldfd, newfd) != newfd)
+ die("dup2: oldfd=%d newfd=%d", oldfd, newfd);
+ return newfd;
+}
+
+void move_fd(int oldfd, int newfd)
+{
+ if (oldfd != newfd) {
+ dup2_safe(oldfd, newfd);
+ close_safe(oldfd);
+ }
+}
+
+void mkdir_safe(char *dirname, int mode)
+{
+ if (mkdir(dirname, mode) == -1 && errno != EEXIST)
+ die("mkdir dirname=%s mode=0x%x\n", dirname, mode);
+}
+
+void unlink_safe(char *pathname)
+{
+ if (unlink(pathname) == -1 && errno != ENOENT) {
+ die("unlink: pathname=%s\n", pathname);
+ }
+}
+
+void execv_safe(char *path, char *argv[], int ls)
+{
+ int i;
+ struct timespec req = { 0, 1000000 };
+
+ if (!qflag) {
+ printf("\n%s ", who(0));
+ for (i = 0; argv[i] != NULL; i++)
+ printf("%s ", argv[i]);
+ printf("\n");
+ }
+
+ /* give parent a chance to wait for us */
+ while (nanosleep(&req, NULL))
+ ;
+
+ if (vflag && ls)
+ ls_proc_fd(-1);
+
+ execv(path, argv);
+ die("execv: path=%s", path);
+}
+
+pid_t waitpid_safe(pid_t pid, int *status, int options, int id)
+{
+ pid_t p;
+
+ p = waitpid(pid, status, options);
+ if (p == -1)
+ fprintf(stderr, "waitpid pid=%d id=%d %m\n", pid, id);
+ return p;
+}
+
+void prctl_safe(int option, ulong arg2, ulong arg3, ulong arg4, ulong arg5)
+{
+ if (prctl(option, arg2, arg3, arg4, arg5) == -1)
+ die("prctl: option=0x%x", option);
+}
--
1.9.3
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