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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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6503b9f29a
Augment the current set of options that are accessible via bpf_{g,s}etsockopt to also support SO_REUSEPORT. Signed-off-by: Manu Bretelle <chantra@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20210310182305.1910312-1-chantra@fb.com
178 lines
4.5 KiB
C
178 lines
4.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <string.h>
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#include <linux/stddef.h>
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#include <linux/bpf.h>
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#include <linux/in.h>
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#include <linux/in6.h>
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#include <sys/socket.h>
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#include <netinet/tcp.h>
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#include <linux/if.h>
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#include <errno.h>
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#include <bpf/bpf_helpers.h>
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#include <bpf/bpf_endian.h>
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#define SERV6_IP_0 0xfaceb00c /* face:b00c:1234:5678::abcd */
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#define SERV6_IP_1 0x12345678
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#define SERV6_IP_2 0x00000000
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#define SERV6_IP_3 0x0000abcd
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#define SERV6_PORT 6060
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#define SERV6_REWRITE_IP_0 0x00000000
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#define SERV6_REWRITE_IP_1 0x00000000
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#define SERV6_REWRITE_IP_2 0x00000000
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#define SERV6_REWRITE_IP_3 0x00000001
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#define SERV6_REWRITE_PORT 6666
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#ifndef IFNAMSIZ
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#define IFNAMSIZ 16
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#endif
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static __inline int bind_to_device(struct bpf_sock_addr *ctx)
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{
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char veth1[IFNAMSIZ] = "test_sock_addr1";
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char veth2[IFNAMSIZ] = "test_sock_addr2";
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char missing[IFNAMSIZ] = "nonexistent_dev";
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char del_bind[IFNAMSIZ] = "";
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int veth1_idx, veth2_idx;
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if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE,
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&veth1, sizeof(veth1)))
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return 1;
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if (bpf_getsockopt(ctx, SOL_SOCKET, SO_BINDTOIFINDEX,
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&veth1_idx, sizeof(veth1_idx)) || !veth1_idx)
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return 1;
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if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE,
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&veth2, sizeof(veth2)))
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return 1;
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if (bpf_getsockopt(ctx, SOL_SOCKET, SO_BINDTOIFINDEX,
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&veth2_idx, sizeof(veth2_idx)) || !veth2_idx ||
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veth1_idx == veth2_idx)
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return 1;
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if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE,
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&missing, sizeof(missing)) != -ENODEV)
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return 1;
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if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTOIFINDEX,
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&veth1_idx, sizeof(veth1_idx)))
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return 1;
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if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE,
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&del_bind, sizeof(del_bind)))
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return 1;
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return 0;
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}
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static __inline int bind_reuseport(struct bpf_sock_addr *ctx)
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{
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int val = 1;
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if (bpf_setsockopt(ctx, SOL_SOCKET, SO_REUSEPORT,
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&val, sizeof(val)))
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return 1;
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if (bpf_getsockopt(ctx, SOL_SOCKET, SO_REUSEPORT,
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&val, sizeof(val)) || !val)
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return 1;
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val = 0;
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if (bpf_setsockopt(ctx, SOL_SOCKET, SO_REUSEPORT,
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&val, sizeof(val)))
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return 1;
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if (bpf_getsockopt(ctx, SOL_SOCKET, SO_REUSEPORT,
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&val, sizeof(val)) || val)
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return 1;
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return 0;
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}
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static __inline int misc_opts(struct bpf_sock_addr *ctx, int opt)
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{
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int old, tmp, new = 0xeb9f;
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/* Socket in test case has guarantee that old never equals to new. */
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if (bpf_getsockopt(ctx, SOL_SOCKET, opt, &old, sizeof(old)) ||
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old == new)
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return 1;
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if (bpf_setsockopt(ctx, SOL_SOCKET, opt, &new, sizeof(new)))
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return 1;
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if (bpf_getsockopt(ctx, SOL_SOCKET, opt, &tmp, sizeof(tmp)) ||
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tmp != new)
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return 1;
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if (bpf_setsockopt(ctx, SOL_SOCKET, opt, &old, sizeof(old)))
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return 1;
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return 0;
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}
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SEC("cgroup/bind6")
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int bind_v6_prog(struct bpf_sock_addr *ctx)
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{
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struct bpf_sock *sk;
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__u32 user_ip6;
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__u16 user_port;
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int i;
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sk = ctx->sk;
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if (!sk)
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return 0;
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if (sk->family != AF_INET6)
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return 0;
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if (ctx->type != SOCK_STREAM && ctx->type != SOCK_DGRAM)
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return 0;
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if (ctx->user_ip6[0] != bpf_htonl(SERV6_IP_0) ||
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ctx->user_ip6[1] != bpf_htonl(SERV6_IP_1) ||
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ctx->user_ip6[2] != bpf_htonl(SERV6_IP_2) ||
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ctx->user_ip6[3] != bpf_htonl(SERV6_IP_3) ||
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ctx->user_port != bpf_htons(SERV6_PORT))
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return 0;
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// u8 narrow loads:
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for (i = 0; i < 4; i++) {
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user_ip6 = 0;
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user_ip6 |= ((volatile __u8 *)&ctx->user_ip6[i])[0] << 0;
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user_ip6 |= ((volatile __u8 *)&ctx->user_ip6[i])[1] << 8;
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user_ip6 |= ((volatile __u8 *)&ctx->user_ip6[i])[2] << 16;
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user_ip6 |= ((volatile __u8 *)&ctx->user_ip6[i])[3] << 24;
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if (ctx->user_ip6[i] != user_ip6)
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return 0;
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}
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user_port = 0;
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user_port |= ((volatile __u8 *)&ctx->user_port)[0] << 0;
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user_port |= ((volatile __u8 *)&ctx->user_port)[1] << 8;
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if (ctx->user_port != user_port)
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return 0;
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// u16 narrow loads:
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for (i = 0; i < 4; i++) {
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user_ip6 = 0;
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user_ip6 |= ((volatile __u16 *)&ctx->user_ip6[i])[0] << 0;
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user_ip6 |= ((volatile __u16 *)&ctx->user_ip6[i])[1] << 16;
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if (ctx->user_ip6[i] != user_ip6)
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return 0;
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}
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/* Bind to device and unbind it. */
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if (bind_to_device(ctx))
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return 0;
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/* Test for misc socket options. */
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if (misc_opts(ctx, SO_MARK) || misc_opts(ctx, SO_PRIORITY))
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return 0;
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/* Set reuseport and unset */
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if (bind_reuseport(ctx))
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return 0;
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ctx->user_ip6[0] = bpf_htonl(SERV6_REWRITE_IP_0);
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ctx->user_ip6[1] = bpf_htonl(SERV6_REWRITE_IP_1);
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ctx->user_ip6[2] = bpf_htonl(SERV6_REWRITE_IP_2);
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ctx->user_ip6[3] = bpf_htonl(SERV6_REWRITE_IP_3);
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ctx->user_port = bpf_htons(SERV6_REWRITE_PORT);
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return 1;
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}
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char _license[] SEC("license") = "GPL";
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