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Line 1: + + − <pre>+ − #include <sys/socket.h>+ − #include <linux/types.h>+ − #include <sys/types.h>+ − #include <arpa/inet.h>+ − #include <unistd.h> − #include <string.h> − #include <stdlib.h> − #include <stdio.h> − #include <signal.h> − − static int serve_new_conn(int sk) − { − int rd, wr; − char buf[1024]; − − printf("New connection\n"); − − while (1) { − rd = read(sk, buf, sizeof(buf)); − if (!rd) − break; − − if (rd < 0) { − perror("Can't read socket"); − return 1; − } − − wr = 0; − while (wr < rd) { − int w; − − w = write(sk, buf + wr, rd - wr); − if (w <= 0) { − perror("Can't write socket"); − return 1; − } − − wr += w; − } − } − − printf("Done\n"); − return 0; − } − − static int main_srv(int argc, char **argv) − − int sk, port, ret; − struct sockaddr_in addr; − − /* − * Let kids die themselves − */ − − signal(SIGCHLD, SIG_IGN); − − sk = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP); − if (sk < 0) { − perror("Can't create socket"); − return -1; − } − − port = atoi(argv[1]); − memset(&addr, 0, sizeof(addr)); − addr.sin_family = AF_INET; − addr.sin_addr.s_addr = htonl(INADDR_ANY); − addr.sin_port = htons(port); − − printf("Binding to port %d\n", port); − − ret = bind(sk, (struct sockaddr *)&addr, sizeof(addr)); − if (ret < 0) { − perror("Can't bind socket"); − return -1; − } − − ret = listen(sk, 16); − if (ret < 0) { − perror("Can't put sock to listen"); − return -1; − } − printf("Waiting for connections\n");+ − while (1) { − int ask, pid; − ask = accept(sk, NULL, NULL);+ − if (ask < 0) { − perror("Can't accept new conn"); − return -1; − } − pid = fork();+ − if (pid < 0) { − perror("Can't fork"); − return -1; − } − if (pid > 0)+ − close(ask); − else { − close(sk); − ret = serve_new_conn(ask); − exit(ret); − } − } − } − − static int main_cl(int argc, char **argv) − { − int sk, port, ret, val = 1, rval; − struct sockaddr_in addr; − − sk = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP); − if (sk < 0) { − perror("Can't create socket"); − return -1; − } − − port = atoi(argv[2]); − printf("Connecting to %s:%d\n", argv[1], port); − memset(&addr, 0, sizeof(addr)); − addr.sin_family = AF_INET; − ret = inet_aton(argv[1], &addr.sin_addr); − if (ret < 0) { − perror("Can't convert addr"); − return -1; − } − addr.sin_port = htons(port); − − ret = connect(sk, (struct sockaddr *)&addr, sizeof(addr)); − if (ret < 0) { − perror("Can't connect"); − return -1; − } − − while (1) { − write(sk, &val, sizeof(val)); − rval = -1; − read(sk, &rval, sizeof(rval)); − printf("PP %d -> %d\n", val, rval); − sleep(2); − val++; − } − } − − int main(int argc, char **argv) − { − if (argc == 2) − return main_srv(argc, argv); − else if (argc == 3) − return main_cl(argc, argv); − − printf("Bad usage\n"); − return 1; − } − </pre> − − So compile it and run server − <pre> − # ./tcp-howto <some-port> − </pre> − and on another terminal (for better output readability) -- the client − <pre> − − </pre> − + Line 184:
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→Then restore the client
This page describes step-by-step how to play with TCP dumping and restoring.
This page describes step-by-step how to play with TCP dumping and restoring.
__TOC__
== Compile and run simple TCP client and server ==
== Compile and run simple TCP client and server ==
The below program is a simple echo server and a client, that pings server with increasing numbers once a second. In this howto we will dump and restore the client part.
The below program is a simple echo server and a client, that pings server with increasing numbers once a second. In this howto we will dump and restore the client part.
{| class="mw-collapsible mw-collapsed wikitable"
! <code>tcp-howto.c</code>
|-
| {{:Simple_TCP_pair/tcp-howto.c}}
|}
{
Compile it and run the server:
# ./tcp-howto <some-port>
On another terminal (for better output readability) run the client:
# ./tcp-howto 127.0.0.1 <some-port>
# ./tcp-howto 127.0.0.1 <some-port>
== Try to dump the client ==
== Try to dump the client ==
Create a directory for images (<code>img-dir/</code> below) and dump the client
Create a directory for images (<code>img-dir/</code> below) and dump the client
<pre>
<pre>
# crtools dump --tree <tcp-howto-client-pid> --images-dir img-dir/ -v 4 -o dump.log --shell-job --tcp-established
# criu dump --tree <tcp-howto-client-pid> --images-dir img-dir/ -v4 -o dump.log --shell-job --tcp-established
</pre>
</pre>
It's done like this
It's done like this
<pre>
<pre>
# crtools restore --tree <tcp-howto-client-pid> --images-dir img-dir/ -v 4 -o rst.log --shell-job --tcp-established
# criu restore --images-dir img-dir/ -v4 -o rst.log --shell-job --tcp-established
</pre>
</pre>
That's it. After this in the terminal you launched crtools from you should see the contunuing output of the tcp client.
That's it. After this in the terminal you launched criu from you should see the continuing output of the tcp client.
== See also ==
* [[TCP connection]]
[[Category:HOWTO]]
[[Category:Sockets]]