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authorJohn Fastabend <john.fastabend@gmail.com>2017-08-15 22:33:32 -0700
committerDavid S. Miller <davem@davemloft.net>2017-08-16 11:27:53 -0700
commit69e8cc134bcbf0ccfcf852c400b8e6788d1d0038 (patch)
tree181f7fc9d1a8204f93aa705e2725e7c5b766610c /samples
parent8a31db5615667956c513d205cfb06885c3ec6d0b (diff)
download96b-common-69e8cc134bcbf0ccfcf852c400b8e6788d1d0038.tar.gz
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>
Diffstat (limited to 'samples')
-rw-r--r--samples/bpf/bpf_load.c8
-rw-r--r--samples/sockmap/Makefile78
-rw-r--r--samples/sockmap/sockmap_kern.c110
-rw-r--r--samples/sockmap/sockmap_user.c286
4 files changed, 480 insertions, 2 deletions
diff --git a/samples/bpf/bpf_load.c b/samples/bpf/bpf_load.c
index 899f40310bc3..a8552b8a2ab6 100644
--- a/samples/bpf/bpf_load.c
+++ b/samples/bpf/bpf_load.c
@@ -65,6 +65,7 @@ static int load_and_attach(const char *event, struct bpf_insn *prog, int size)
bool is_cgroup_skb = strncmp(event, "cgroup/skb", 10) == 0;
bool is_cgroup_sk = strncmp(event, "cgroup/sock", 11) == 0;
bool is_sockops = strncmp(event, "sockops", 7) == 0;
+ bool is_sk_skb = strncmp(event, "sk_skb", 6) == 0;
size_t insns_cnt = size / sizeof(struct bpf_insn);
enum bpf_prog_type prog_type;
char buf[256];
@@ -92,6 +93,8 @@ static int load_and_attach(const char *event, struct bpf_insn *prog, int size)
prog_type = BPF_PROG_TYPE_CGROUP_SOCK;
} else if (is_sockops) {
prog_type = BPF_PROG_TYPE_SOCK_OPS;
+ } else if (is_sk_skb) {
+ prog_type = BPF_PROG_TYPE_SK_SKB;
} else {
printf("Unknown event '%s'\n", event);
return -1;
@@ -109,7 +112,7 @@ static int load_and_attach(const char *event, struct bpf_insn *prog, int size)
if (is_xdp || is_perf_event || is_cgroup_skb || is_cgroup_sk)
return 0;
- if (is_socket || is_sockops) {
+ if (is_socket || is_sockops || is_sk_skb) {
if (is_socket)
event += 6;
else
@@ -567,7 +570,8 @@ static int do_load_bpf_file(const char *path, fixup_map_cb fixup_map)
memcmp(shname, "perf_event", 10) == 0 ||
memcmp(shname, "socket", 6) == 0 ||
memcmp(shname, "cgroup/", 7) == 0 ||
- memcmp(shname, "sockops", 7) == 0) {
+ memcmp(shname, "sockops", 7) == 0 ||
+ memcmp(shname, "sk_skb", 6) == 0) {
ret = load_and_attach(shname, data->d_buf,
data->d_size);
if (ret != 0)
diff --git a/samples/sockmap/Makefile b/samples/sockmap/Makefile
new file mode 100644
index 000000000000..9291ab8e0f8c
--- /dev/null
+++ b/samples/sockmap/Makefile
@@ -0,0 +1,78 @@
+# kbuild trick to avoid linker error. Can be omitted if a module is built.
+obj- := dummy.o
+
+# List of programs to build
+hostprogs-y := sockmap
+
+# Libbpf dependencies
+LIBBPF := ../../tools/lib/bpf/bpf.o
+
+HOSTCFLAGS += -I$(objtree)/usr/include
+HOSTCFLAGS += -I$(srctree)/tools/lib/
+HOSTCFLAGS += -I$(srctree)/tools/testing/selftests/bpf/
+HOSTCFLAGS += -I$(srctree)/tools/lib/ -I$(srctree)/tools/include
+HOSTCFLAGS += -I$(srctree)/tools/perf
+
+sockmap-objs := ../bpf/bpf_load.o $(LIBBPF) sockmap_user.o
+
+# Tell kbuild to always build the programs
+always := $(hostprogs-y)
+always += sockmap_kern.o
+
+HOSTLOADLIBES_sockmap += -lelf -lpthread
+
+# Allows pointing LLC/CLANG to a LLVM backend with bpf support, redefine on cmdline:
+# make samples/bpf/ LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang
+LLC ?= llc
+CLANG ?= clang
+
+# Trick to allow make to be run from this directory
+all:
+ $(MAKE) -C ../../ $(CURDIR)/
+
+clean:
+ $(MAKE) -C ../../ M=$(CURDIR) clean
+ @rm -f *~
+
+$(obj)/syscall_nrs.s: $(src)/syscall_nrs.c
+ $(call if_changed_dep,cc_s_c)
+
+$(obj)/syscall_nrs.h: $(obj)/syscall_nrs.s FORCE
+ $(call filechk,offsets,__SYSCALL_NRS_H__)
+
+clean-files += syscall_nrs.h
+
+FORCE:
+
+
+# Verify LLVM compiler tools are available and bpf target is supported by llc
+.PHONY: verify_cmds verify_target_bpf $(CLANG) $(LLC)
+
+verify_cmds: $(CLANG) $(LLC)
+ @for TOOL in $^ ; do \
+ if ! (which -- "$${TOOL}" > /dev/null 2>&1); then \
+ echo "*** ERROR: Cannot find LLVM tool $${TOOL}" ;\
+ exit 1; \
+ else true; fi; \
+ done
+
+verify_target_bpf: verify_cmds
+ @if ! (${LLC} -march=bpf -mattr=help > /dev/null 2>&1); then \
+ echo "*** ERROR: LLVM (${LLC}) does not support 'bpf' target" ;\
+ echo " NOTICE: LLVM version >= 3.7.1 required" ;\
+ exit 2; \
+ else true; fi
+
+$(src)/*.c: verify_target_bpf
+
+# asm/sysreg.h - inline assembly used by it is incompatible with llvm.
+# But, there is no easy way to fix it, so just exclude it since it is
+# useless for BPF samples.
+$(obj)/%.o: $(src)/%.c
+ $(CLANG) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(EXTRA_CFLAGS) -I$(obj) \
+ -D__KERNEL__ -D__ASM_SYSREG_H -Wno-unused-value -Wno-pointer-sign \
+ -Wno-compare-distinct-pointer-types \
+ -Wno-gnu-variable-sized-type-not-at-end \
+ -Wno-address-of-packed-member -Wno-tautological-compare \
+ -Wno-unknown-warning-option \
+ -O2 -emit-llvm -c $< -o -| $(LLC) -march=bpf -filetype=obj -o $@
diff --git a/samples/sockmap/sockmap_kern.c b/samples/sockmap/sockmap_kern.c
new file mode 100644
index 000000000000..6ff986f7059b
--- /dev/null
+++ b/samples/sockmap/sockmap_kern.c
@@ -0,0 +1,110 @@
+/* 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 <uapi/linux/bpf.h>
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/if_packet.h>
+#include <uapi/linux/ip.h>
+#include "../../tools/testing/selftests/bpf/bpf_helpers.h"
+#include "../../tools/testing/selftests/bpf/bpf_endian.h"
+
+/* Sockmap sample program connects a client and a backend together
+ * using cgroups.
+ *
+ * client:X <---> frontend:80 client:X <---> backend:80
+ *
+ * For simplicity we hard code values here and bind 1:1. The hard
+ * coded values are part of the setup in sockmap.sh script that
+ * is associated with this BPF program.
+ *
+ * The bpf_printk is verbose and prints information as connections
+ * are established and verdicts are decided.
+ */
+
+#define bpf_printk(fmt, ...) \
+({ \
+ char ____fmt[] = fmt; \
+ bpf_trace_printk(____fmt, sizeof(____fmt), \
+ ##__VA_ARGS__); \
+})
+
+struct bpf_map_def SEC("maps") sock_map = {
+ .type = BPF_MAP_TYPE_SOCKMAP,
+ .key_size = sizeof(int),
+ .value_size = sizeof(int),
+ .max_entries = 20,
+};
+
+SEC("sk_skb1")
+int bpf_prog1(struct __sk_buff *skb)
+{
+ return skb->len;
+}
+
+SEC("sk_skb2")
+int bpf_prog2(struct __sk_buff *skb)
+{
+ __u32 lport = skb->local_port;
+ __u32 rport = skb->remote_port;
+ int ret = 0;
+
+ if (lport == 10000)
+ ret = 10;
+ else
+ ret = 1;
+
+ bpf_printk("sockmap: %d -> %d @ %d\n", lport, bpf_ntohl(rport), ret);
+ return bpf_sk_redirect_map(&sock_map, ret, 0);
+}
+
+SEC("sockops")
+int bpf_sockmap(struct bpf_sock_ops *skops)
+{
+ __u32 lport, rport;
+ int op, err = 0, index, key, ret;
+
+
+ op = (int) skops->op;
+
+ switch (op) {
+ case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB:
+ lport = skops->local_port;
+ rport = skops->remote_port;
+
+ if (lport == 10000) {
+ ret = 1;
+ err = bpf_sock_map_update(skops, &sock_map, &ret,
+ BPF_NOEXIST,
+ BPF_SOCKMAP_STRPARSER);
+ bpf_printk("passive(%i -> %i) map ctx update err: %d\n",
+ lport, bpf_ntohl(rport), err);
+ }
+ break;
+ case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:
+ lport = skops->local_port;
+ rport = skops->remote_port;
+
+ if (bpf_ntohl(rport) == 10001) {
+ ret = 10;
+ err = bpf_sock_map_update(skops, &sock_map, &ret,
+ BPF_NOEXIST,
+ BPF_SOCKMAP_STRPARSER);
+ bpf_printk("active(%i -> %i) map ctx update err: %d\n",
+ lport, bpf_ntohl(rport), err);
+ }
+ break;
+ default:
+ break;
+ }
+
+ return 0;
+}
+char _license[] SEC("license") = "GPL";
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;
+}