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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 | // SPDX-License-Identifier: GPL-2.0 #include <string.h> #include <linux/stddef.h> #include <linux/bpf.h> #include <linux/in.h> #include <linux/in6.h> #include <linux/if.h> #include <errno.h> #include <bpf/bpf_helpers.h> #include <bpf/bpf_endian.h> #define SERV6_IP_0 0xfaceb00c /* face:b00c:1234:5678::abcd */ #define SERV6_IP_1 0x12345678 #define SERV6_IP_2 0x00000000 #define SERV6_IP_3 0x0000abcd #define SERV6_PORT 6060 #define SERV6_REWRITE_IP_0 0x00000000 #define SERV6_REWRITE_IP_1 0x00000000 #define SERV6_REWRITE_IP_2 0x00000000 #define SERV6_REWRITE_IP_3 0x00000001 #define SERV6_REWRITE_PORT 6666 #ifndef IFNAMSIZ #define IFNAMSIZ 16 #endif 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] = ""; int veth1_idx, veth2_idx; if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE, &veth1, sizeof(veth1))) return 1; if (bpf_getsockopt(ctx, SOL_SOCKET, SO_BINDTOIFINDEX, &veth1_idx, sizeof(veth1_idx)) || !veth1_idx) return 1; if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE, &veth2, sizeof(veth2))) return 1; if (bpf_getsockopt(ctx, SOL_SOCKET, SO_BINDTOIFINDEX, &veth2_idx, sizeof(veth2_idx)) || !veth2_idx || veth1_idx == veth2_idx) return 1; if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE, &missing, sizeof(missing)) != -ENODEV) return 1; if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTOIFINDEX, &veth1_idx, sizeof(veth1_idx))) return 1; if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE, &del_bind, sizeof(del_bind))) return 1; return 0; } static __inline int bind_reuseport(struct bpf_sock_addr *ctx) { int val = 1; if (bpf_setsockopt(ctx, SOL_SOCKET, SO_REUSEPORT, &val, sizeof(val))) return 1; if (bpf_getsockopt(ctx, SOL_SOCKET, SO_REUSEPORT, &val, sizeof(val)) || !val) return 1; val = 0; if (bpf_setsockopt(ctx, SOL_SOCKET, SO_REUSEPORT, &val, sizeof(val))) return 1; if (bpf_getsockopt(ctx, SOL_SOCKET, SO_REUSEPORT, &val, sizeof(val)) || val) return 1; return 0; } static __inline int misc_opts(struct bpf_sock_addr *ctx, int opt) { int old, tmp, new = 0xeb9f; /* Socket in test case has guarantee that old never equals to new. */ if (bpf_getsockopt(ctx, SOL_SOCKET, opt, &old, sizeof(old)) || old == new) return 1; if (bpf_setsockopt(ctx, SOL_SOCKET, opt, &new, sizeof(new))) return 1; if (bpf_getsockopt(ctx, SOL_SOCKET, opt, &tmp, sizeof(tmp)) || tmp != new) return 1; if (bpf_setsockopt(ctx, SOL_SOCKET, opt, &old, sizeof(old))) return 1; return 0; } SEC("cgroup/bind6") int bind_v6_prog(struct bpf_sock_addr *ctx) { struct bpf_sock *sk; __u32 user_ip6; __u16 user_port; int i; sk = ctx->sk; if (!sk) return 0; if (sk->family != AF_INET6) return 0; if (ctx->type != SOCK_STREAM && ctx->type != SOCK_DGRAM) return 0; if (ctx->user_ip6[0] != bpf_htonl(SERV6_IP_0) || ctx->user_ip6[1] != bpf_htonl(SERV6_IP_1) || ctx->user_ip6[2] != bpf_htonl(SERV6_IP_2) || ctx->user_ip6[3] != bpf_htonl(SERV6_IP_3) || ctx->user_port != bpf_htons(SERV6_PORT)) return 0; // u8 narrow loads: for (i = 0; i < 4; i++) { user_ip6 = 0; user_ip6 |= ((volatile __u8 *)&ctx->user_ip6[i])[0] << 0; user_ip6 |= ((volatile __u8 *)&ctx->user_ip6[i])[1] << 8; user_ip6 |= ((volatile __u8 *)&ctx->user_ip6[i])[2] << 16; user_ip6 |= ((volatile __u8 *)&ctx->user_ip6[i])[3] << 24; if (ctx->user_ip6[i] != user_ip6) return 0; } user_port = 0; user_port |= ((volatile __u8 *)&ctx->user_port)[0] << 0; user_port |= ((volatile __u8 *)&ctx->user_port)[1] << 8; if (ctx->user_port != user_port) return 0; // u16 narrow loads: for (i = 0; i < 4; i++) { user_ip6 = 0; user_ip6 |= ((volatile __u16 *)&ctx->user_ip6[i])[0] << 0; user_ip6 |= ((volatile __u16 *)&ctx->user_ip6[i])[1] << 16; if (ctx->user_ip6[i] != user_ip6) return 0; } /* Bind to device and unbind it. */ if (bind_to_device(ctx)) return 0; /* Test for misc socket options. */ if (misc_opts(ctx, SO_MARK) || misc_opts(ctx, SO_PRIORITY)) return 0; /* Set reuseport and unset */ if (bind_reuseport(ctx)) return 0; ctx->user_ip6[0] = bpf_htonl(SERV6_REWRITE_IP_0); ctx->user_ip6[1] = bpf_htonl(SERV6_REWRITE_IP_1); ctx->user_ip6[2] = bpf_htonl(SERV6_REWRITE_IP_2); ctx->user_ip6[3] = bpf_htonl(SERV6_REWRITE_IP_3); ctx->user_port = bpf_htons(SERV6_REWRITE_PORT); return 1; } char _license[] SEC("license") = "GPL"; |