diff options
Diffstat (limited to 'tools/testing/selftests/bpf/progs/connect4_prog.c')
| -rw-r--r-- | tools/testing/selftests/bpf/progs/connect4_prog.c | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/connect4_prog.c b/tools/testing/selftests/bpf/progs/connect4_prog.c new file mode 100644 index 000000000..38ab1ce32 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/connect4_prog.c @@ -0,0 +1,201 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2018 Facebook + +#include <string.h> + +#include <linux/stddef.h> +#include <linux/bpf.h> +#include <linux/in.h> +#include <linux/in6.h> +#include <sys/socket.h> +#include <netinet/tcp.h> +#include <linux/if.h> +#include <errno.h> + +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_endian.h> + +#define SRC_REWRITE_IP4 0x7f000004U +#define DST_REWRITE_IP4 0x7f000001U +#define DST_REWRITE_PORT4 4444 + +#ifndef TCP_CA_NAME_MAX +#define TCP_CA_NAME_MAX 16 +#endif + +#ifndef TCP_NOTSENT_LOWAT +#define TCP_NOTSENT_LOWAT 25 +#endif + +#ifndef IFNAMSIZ +#define IFNAMSIZ 16 +#endif + +int _version SEC("version") = 1; + +__attribute__ ((noinline)) __weak +int do_bind(struct bpf_sock_addr *ctx) +{ + struct sockaddr_in sa = {}; + + sa.sin_family = AF_INET; + sa.sin_port = bpf_htons(0); + sa.sin_addr.s_addr = bpf_htonl(SRC_REWRITE_IP4); + + if (bpf_bind(ctx, (struct sockaddr *)&sa, sizeof(sa)) != 0) + return 0; + + return 1; +} + +static __inline int verify_cc(struct bpf_sock_addr *ctx, + char expected[TCP_CA_NAME_MAX]) +{ + char buf[TCP_CA_NAME_MAX]; + int i; + + if (bpf_getsockopt(ctx, SOL_TCP, TCP_CONGESTION, &buf, sizeof(buf))) + return 1; + + for (i = 0; i < TCP_CA_NAME_MAX; i++) { + if (buf[i] != expected[i]) + return 1; + if (buf[i] == 0) + break; + } + + return 0; +} + +static __inline int set_cc(struct bpf_sock_addr *ctx) +{ + char reno[TCP_CA_NAME_MAX] = "reno"; + char cubic[TCP_CA_NAME_MAX] = "cubic"; + + if (bpf_setsockopt(ctx, SOL_TCP, TCP_CONGESTION, &reno, sizeof(reno))) + return 1; + if (verify_cc(ctx, reno)) + return 1; + + if (bpf_setsockopt(ctx, SOL_TCP, TCP_CONGESTION, &cubic, sizeof(cubic))) + return 1; + if (verify_cc(ctx, cubic)) + return 1; + + return 0; +} + +static __inline int bind_to_device(struct bpf_sock_addr *ctx) +{ + char veth1[IFNAMSIZ] = "test_sock_addr1"; + char veth2[IFNAMSIZ] = "test_sock_addr2"; + char missing[IFNAMSIZ] = "nonexistent_dev"; + char del_bind[IFNAMSIZ] = ""; + + if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE, + &veth1, sizeof(veth1))) + return 1; + if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE, + &veth2, sizeof(veth2))) + return 1; + if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE, + &missing, sizeof(missing)) != -ENODEV) + return 1; + if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE, + &del_bind, sizeof(del_bind))) + return 1; + + return 0; +} + +static __inline int set_keepalive(struct bpf_sock_addr *ctx) +{ + int zero = 0, one = 1; + + if (bpf_setsockopt(ctx, SOL_SOCKET, SO_KEEPALIVE, &one, sizeof(one))) + return 1; + if (ctx->type == SOCK_STREAM) { + if (bpf_setsockopt(ctx, SOL_TCP, TCP_KEEPIDLE, &one, sizeof(one))) + return 1; + if (bpf_setsockopt(ctx, SOL_TCP, TCP_KEEPINTVL, &one, sizeof(one))) + return 1; + if (bpf_setsockopt(ctx, SOL_TCP, TCP_KEEPCNT, &one, sizeof(one))) + return 1; + if (bpf_setsockopt(ctx, SOL_TCP, TCP_SYNCNT, &one, sizeof(one))) + return 1; + if (bpf_setsockopt(ctx, SOL_TCP, TCP_USER_TIMEOUT, &one, sizeof(one))) + return 1; + } + if (bpf_setsockopt(ctx, SOL_SOCKET, SO_KEEPALIVE, &zero, sizeof(zero))) + return 1; + + return 0; +} + +static __inline int set_notsent_lowat(struct bpf_sock_addr *ctx) +{ + int lowat = 65535; + + if (ctx->type == SOCK_STREAM) { + if (bpf_setsockopt(ctx, SOL_TCP, TCP_NOTSENT_LOWAT, &lowat, sizeof(lowat))) + return 1; + } + + return 0; +} + +SEC("cgroup/connect4") +int connect_v4_prog(struct bpf_sock_addr *ctx) +{ + struct bpf_sock_tuple tuple = {}; + struct bpf_sock *sk; + + /* Verify that new destination is available. */ + memset(&tuple.ipv4.saddr, 0, sizeof(tuple.ipv4.saddr)); + memset(&tuple.ipv4.sport, 0, sizeof(tuple.ipv4.sport)); + + tuple.ipv4.daddr = bpf_htonl(DST_REWRITE_IP4); + tuple.ipv4.dport = bpf_htons(DST_REWRITE_PORT4); + + /* Bind to device and unbind it. */ + if (bind_to_device(ctx)) + return 0; + + if (set_keepalive(ctx)) + return 0; + + if (set_notsent_lowat(ctx)) + return 0; + + if (ctx->type != SOCK_STREAM && ctx->type != SOCK_DGRAM) + return 0; + else if (ctx->type == SOCK_STREAM) + sk = bpf_sk_lookup_tcp(ctx, &tuple, sizeof(tuple.ipv4), + BPF_F_CURRENT_NETNS, 0); + else + sk = bpf_sk_lookup_udp(ctx, &tuple, sizeof(tuple.ipv4), + BPF_F_CURRENT_NETNS, 0); + + if (!sk) + return 0; + + if (sk->src_ip4 != tuple.ipv4.daddr || + sk->src_port != DST_REWRITE_PORT4) { + bpf_sk_release(sk); + return 0; + } + + bpf_sk_release(sk); + + /* Rewrite congestion control. */ + if (ctx->type == SOCK_STREAM && set_cc(ctx)) + return 0; + + /* Rewrite destination. */ + ctx->user_ip4 = bpf_htonl(DST_REWRITE_IP4); + ctx->user_port = bpf_htons(DST_REWRITE_PORT4); + + return do_bind(ctx) ? 1 : 0; +} + +char _license[] SEC("license") = "GPL"; |