bpf: sockmap sample program

This program binds a program to a cgroup and then matches hard
coded IP addresses and adds these to a sockmap.

This will receive messages from the backend and send them to
the client.

     client:X <---> frontend:10000 client:X <---> backend:10001

To keep things simple this is only designed for 1:1 connections
using hard coded values. A more complete example would allow many
backends and clients.

To run,

 # sockmap <cgroup2_dir>

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 286 insertions, 0 deletions

diff --git a/samples/sockmap/sockmap_user.c b/samples/sockmap/sockmap_user.c
new file mode 100644
index 000000000000..fb78f5abefb4
--- /dev/null
+++ b/samples/sockmap/sockmap_user.c
@@ -0,0 +1,286 @@
+/* Copyright (c) 2017 Covalent IO, Inc. http://covalent.io
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/socket.h>
+#include <sys/ioctl.h>
+#include <sys/select.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <sys/ioctl.h>
+#include <stdbool.h>
+#include <signal.h>
+#include <fcntl.h>
+
+#include <sys/time.h>
+#include <sys/types.h>
+
+#include <linux/netlink.h>
+#include <linux/socket.h>
+#include <linux/sock_diag.h>
+#include <linux/bpf.h>
+#include <linux/if_link.h>
+#include <assert.h>
+#include <libgen.h>
+
+#include "../bpf/bpf_load.h"
+#include "../bpf/bpf_util.h"
+#include "../bpf/libbpf.h"
+
+int running;
+void running_handler(int a);
+
+/* randomly selected ports for testing on lo */
+#define S1_PORT 10000
+#define S2_PORT 10001
+
+static int sockmap_test_sockets(int rate, int dot)
+{
+	int i, sc, err, max_fd, one = 1;
+	int s1, s2, c1, c2, p1, p2;
+	struct sockaddr_in addr;
+	struct timeval timeout;
+	char buf[1024] = {0};
+	int *fds[4] = {&s1, &s2, &c1, &c2};
+	fd_set w;
+
+	s1 = s2 = p1 = p2 = c1 = c2 = 0;
+
+	/* Init sockets */
+	for (i = 0; i < 4; i++) {
+		*fds[i] = socket(AF_INET, SOCK_STREAM, 0);
+		if (*fds[i] < 0) {
+			perror("socket s1 failed()");
+			err = *fds[i];
+			goto out;
+		}
+	}
+
+	/* Allow reuse */
+	for (i = 0; i < 2; i++) {
+		err = setsockopt(*fds[i], SOL_SOCKET, SO_REUSEADDR,
+				 (char *)&one, sizeof(one));
+		if (err) {
+			perror("setsockopt failed()");
+			goto out;
+		}
+	}
+
+	/* Non-blocking sockets */
+	for (i = 0; i < 4; i++) {
+		err = ioctl(*fds[i], FIONBIO, (char *)&one);
+		if (err < 0) {
+			perror("ioctl s1 failed()");
+			goto out;
+		}
+	}
+
+	/* Bind server sockets */
+	memset(&addr, 0, sizeof(struct sockaddr_in));
+	addr.sin_family = AF_INET;
+	addr.sin_addr.s_addr = inet_addr("127.0.0.1");
+
+	addr.sin_port = htons(S1_PORT);
+	err = bind(s1, (struct sockaddr *)&addr, sizeof(addr));
+	if (err < 0) {
+		perror("bind s1 failed()\n");
+		goto out;
+	}
+
+	addr.sin_port = htons(S2_PORT);
+	err = bind(s2, (struct sockaddr *)&addr, sizeof(addr));
+	if (err < 0) {
+		perror("bind s2 failed()\n");
+		goto out;
+	}
+
+	/* Listen server sockets */
+	addr.sin_port = htons(S1_PORT);
+	err = listen(s1, 32);
+	if (err < 0) {
+		perror("listen s1 failed()\n");
+		goto out;
+	}
+
+	addr.sin_port = htons(S2_PORT);
+	err = listen(s2, 32);
+	if (err < 0) {
+		perror("listen s1 failed()\n");
+		goto out;
+	}
+
+	/* Initiate Connect */
+	addr.sin_port = htons(S1_PORT);
+	err = connect(c1, (struct sockaddr *)&addr, sizeof(addr));
+	if (err < 0 && errno != EINPROGRESS) {
+		perror("connect c1 failed()\n");
+		goto out;
+	}
+
+	addr.sin_port = htons(S2_PORT);
+	err = connect(c2, (struct sockaddr *)&addr, sizeof(addr));
+	if (err < 0 && errno != EINPROGRESS) {
+		perror("connect c2 failed()\n");
+		goto out;
+	}
+
+	/* Accept Connecrtions */
+	p1 = accept(s1, NULL, NULL);
+	if (p1 < 0) {
+		perror("accept s1 failed()\n");
+		goto out;
+	}
+
+	p2 = accept(s2, NULL, NULL);
+	if (p2 < 0) {
+		perror("accept s1 failed()\n");
+		goto out;
+	}
+
+	max_fd = p2;
+	timeout.tv_sec = 10;
+	timeout.tv_usec = 0;
+
+	printf("connected sockets: c1 <-> p1, c2 <-> p2\n");
+	printf("cgroups binding: c1(%i) <-> s1(%i) - - - c2(%i) <-> s2(%i)\n",
+		c1, s1, c2, s2);
+
+	/* Ping/Pong data from client to server */
+	sc = send(c1, buf, sizeof(buf), 0);
+	if (sc < 0) {
+		perror("send failed()\n");
+		goto out;
+	}
+
+	do {
+		int s, rc, i;
+
+		/* FD sets */
+		FD_ZERO(&w);
+		FD_SET(c1, &w);
+		FD_SET(c2, &w);
+		FD_SET(p1, &w);
+		FD_SET(p2, &w);
+
+		s = select(max_fd + 1, &w, NULL, NULL, &timeout);
+		if (s == -1) {
+			perror("select()");
+			break;
+		} else if (!s) {
+			fprintf(stderr, "unexpected timeout\n");
+			break;
+		}
+
+		for (i = 0; i <= max_fd && s > 0; ++i) {
+			if (!FD_ISSET(i, &w))
+				continue;
+
+			s--;
+
+			rc = recv(i, buf, sizeof(buf), 0);
+			if (rc < 0) {
+				if (errno != EWOULDBLOCK) {
+					perror("recv failed()\n");
+					break;
+				}
+			}
+
+			if (rc == 0) {
+				close(i);
+				break;
+			}
+
+			sc = send(i, buf, rc, 0);
+			if (sc < 0) {
+				perror("send failed()\n");
+				break;
+			}
+		}
+		sleep(rate);
+		if (dot) {
+			printf(".");
+			fflush(stdout);
+
+		}
+	} while (running);
+
+out:
+	close(s1);
+	close(s2);
+	close(p1);
+	close(p2);
+	close(c1);
+	close(c2);
+	return err;
+}
+
+int main(int argc, char **argv)
+{
+	int rate = 1, dot = 1;
+	char filename[256];
+	int err, cg_fd;
+	char *cg_path;
+
+	cg_path = argv[argc - 1];
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+
+	running = 1;
+
+	/* catch SIGINT */
+	signal(SIGINT, running_handler);
+
+	if (load_bpf_file(filename)) {
+		fprintf(stderr, "load_bpf_file: (%s) %s\n",
+			filename, strerror(errno));
+		return 1;
+	}
+
+	/* Cgroup configuration */
+	cg_fd = open(cg_path, O_DIRECTORY, O_RDONLY);
+	if (cg_fd < 0) {
+		fprintf(stderr, "ERROR: (%i) open cg path failed: %s\n",
+			cg_fd, cg_path);
+		return cg_fd;
+	}
+
+	/* Attach programs to sockmap */
+	err = __bpf_prog_attach(prog_fd[0], prog_fd[1], map_fd[0],
+				BPF_CGROUP_SMAP_INGRESS, 0);
+	if (err) {
+		fprintf(stderr, "ERROR: bpf_prog_attach (sockmap): %d (%s)\n",
+			err, strerror(errno));
+		return err;
+	}
+
+	/* Attach to cgroups */
+	err = bpf_prog_attach(prog_fd[2], cg_fd, BPF_CGROUP_SOCK_OPS, 0);
+	if (err) {
+		fprintf(stderr, "ERROR: bpf_prog_attach (groups): %d (%s)\n",
+			err, strerror(errno));
+		return err;
+	}
+
+	err = sockmap_test_sockets(rate, dot);
+	if (err) {
+		fprintf(stderr, "ERROR: test socket failed: %d\n", err);
+		return err;
+	}
+	return 0;
+}
+
+void running_handler(int a)
+{
+	running = 0;
+}