1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* Copyright (c) 2017-2018 Covalent IO, Inc. http://covalent.io */ 3 #include <stddef.h> 4 #include <string.h> 5 #include <linux/bpf.h> 6 #include <linux/if_ether.h> 7 #include <linux/if_packet.h> 8 #include <linux/ip.h> 9 #include <linux/ipv6.h> 10 #include <linux/in.h> 11 #include <linux/udp.h> 12 #include <linux/tcp.h> 13 #include <linux/pkt_cls.h> 14 #include <sys/socket.h> 15 #include <bpf/bpf_helpers.h> 16 #include <bpf/bpf_endian.h> 17 18 /* Sockmap sample program connects a client and a backend together 19 * using cgroups. 20 * 21 * client:X <---> frontend:80 client:X <---> backend:80 22 * 23 * For simplicity we hard code values here and bind 1:1. The hard 24 * coded values are part of the setup in sockmap.sh script that 25 * is associated with this BPF program. 26 * 27 * The bpf_printk is verbose and prints information as connections 28 * are established and verdicts are decided. 29 */ 30 31 struct { 32 __uint(type, TEST_MAP_TYPE); 33 __uint(max_entries, 20); 34 __uint(key_size, sizeof(int)); 35 __uint(value_size, sizeof(int)); 36 } sock_map SEC(".maps"); 37 38 struct { 39 __uint(type, TEST_MAP_TYPE); 40 __uint(max_entries, 20); 41 __uint(key_size, sizeof(int)); 42 __uint(value_size, sizeof(int)); 43 } sock_map_txmsg SEC(".maps"); 44 45 struct { 46 __uint(type, TEST_MAP_TYPE); 47 __uint(max_entries, 20); 48 __uint(key_size, sizeof(int)); 49 __uint(value_size, sizeof(int)); 50 } sock_map_redir SEC(".maps"); 51 52 struct { 53 __uint(type, BPF_MAP_TYPE_ARRAY); 54 __uint(max_entries, 1); 55 __type(key, int); 56 __type(value, int); 57 } sock_apply_bytes SEC(".maps"); 58 59 struct { 60 __uint(type, BPF_MAP_TYPE_ARRAY); 61 __uint(max_entries, 1); 62 __type(key, int); 63 __type(value, int); 64 } sock_cork_bytes SEC(".maps"); 65 66 struct { 67 __uint(type, BPF_MAP_TYPE_ARRAY); 68 __uint(max_entries, 6); 69 __type(key, int); 70 __type(value, int); 71 } sock_bytes SEC(".maps"); 72 73 struct { 74 __uint(type, BPF_MAP_TYPE_ARRAY); 75 __uint(max_entries, 1); 76 __type(key, int); 77 __type(value, int); 78 } sock_redir_flags SEC(".maps"); 79 80 struct { 81 __uint(type, BPF_MAP_TYPE_ARRAY); 82 __uint(max_entries, 3); 83 __type(key, int); 84 __type(value, int); 85 } sock_skb_opts SEC(".maps"); 86 87 struct { 88 __uint(type, TEST_MAP_TYPE); 89 __uint(max_entries, 20); 90 __uint(key_size, sizeof(int)); 91 __uint(value_size, sizeof(int)); 92 } tls_sock_map SEC(".maps"); 93 94 SEC("sk_skb1") 95 int bpf_prog1(struct __sk_buff *skb) 96 { 97 int *f, two = 2; 98 99 f = bpf_map_lookup_elem(&sock_skb_opts, &two); 100 if (f && *f) { 101 return *f; 102 } 103 return skb->len; 104 } 105 106 SEC("sk_skb2") 107 int bpf_prog2(struct __sk_buff *skb) 108 { 109 __u32 lport = skb->local_port; 110 __u32 rport = skb->remote_port; 111 int len, *f, ret, zero = 0; 112 __u64 flags = 0; 113 114 if (lport == 10000) 115 ret = 10; 116 else 117 ret = 1; 118 119 len = (__u32)skb->data_end - (__u32)skb->data; 120 f = bpf_map_lookup_elem(&sock_skb_opts, &zero); 121 if (f && *f) { 122 ret = 3; 123 flags = *f; 124 } 125 126 #ifdef SOCKMAP 127 return bpf_sk_redirect_map(skb, &sock_map, ret, flags); 128 #else 129 return bpf_sk_redirect_hash(skb, &sock_map, &ret, flags); 130 #endif 131 132 } 133 134 static inline void bpf_write_pass(struct __sk_buff *skb, int offset) 135 { 136 int err = bpf_skb_pull_data(skb, 6 + offset); 137 void *data_end; 138 char *c; 139 140 if (err) 141 return; 142 143 c = (char *)(long)skb->data; 144 data_end = (void *)(long)skb->data_end; 145 146 if (c + 5 + offset < data_end) 147 memcpy(c + offset, "PASS", 4); 148 } 149 150 SEC("sk_skb3") 151 int bpf_prog3(struct __sk_buff *skb) 152 { 153 int err, *f, ret = SK_PASS; 154 const int one = 1; 155 156 f = bpf_map_lookup_elem(&sock_skb_opts, &one); 157 if (f && *f) { 158 __u64 flags = 0; 159 160 ret = 0; 161 flags = *f; 162 163 err = bpf_skb_adjust_room(skb, -13, 0, 0); 164 if (err) 165 return SK_DROP; 166 err = bpf_skb_adjust_room(skb, 4, 0, 0); 167 if (err) 168 return SK_DROP; 169 bpf_write_pass(skb, 0); 170 #ifdef SOCKMAP 171 return bpf_sk_redirect_map(skb, &tls_sock_map, ret, flags); 172 #else 173 return bpf_sk_redirect_hash(skb, &tls_sock_map, &ret, flags); 174 #endif 175 } 176 f = bpf_map_lookup_elem(&sock_skb_opts, &one); 177 if (f && *f) 178 ret = SK_DROP; 179 err = bpf_skb_adjust_room(skb, 4, 0, 0); 180 if (err) 181 return SK_DROP; 182 bpf_write_pass(skb, 13); 183 tls_out: 184 return ret; 185 } 186 187 SEC("sockops") 188 int bpf_sockmap(struct bpf_sock_ops *skops) 189 { 190 __u32 lport, rport; 191 int op, err = 0, index, key, ret; 192 193 194 op = (int) skops->op; 195 196 switch (op) { 197 case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB: 198 lport = skops->local_port; 199 rport = skops->remote_port; 200 201 if (lport == 10000) { 202 ret = 1; 203 #ifdef SOCKMAP 204 err = bpf_sock_map_update(skops, &sock_map, &ret, 205 BPF_NOEXIST); 206 #else 207 err = bpf_sock_hash_update(skops, &sock_map, &ret, 208 BPF_NOEXIST); 209 #endif 210 } 211 break; 212 case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB: 213 lport = skops->local_port; 214 rport = skops->remote_port; 215 216 if (bpf_ntohl(rport) == 10001) { 217 ret = 10; 218 #ifdef SOCKMAP 219 err = bpf_sock_map_update(skops, &sock_map, &ret, 220 BPF_NOEXIST); 221 #else 222 err = bpf_sock_hash_update(skops, &sock_map, &ret, 223 BPF_NOEXIST); 224 #endif 225 } 226 break; 227 default: 228 break; 229 } 230 231 return 0; 232 } 233 234 SEC("sk_msg1") 235 int bpf_prog4(struct sk_msg_md *msg) 236 { 237 int *bytes, zero = 0, one = 1, two = 2, three = 3, four = 4, five = 5; 238 int *start, *end, *start_push, *end_push, *start_pop, *pop; 239 240 bytes = bpf_map_lookup_elem(&sock_apply_bytes, &zero); 241 if (bytes) 242 bpf_msg_apply_bytes(msg, *bytes); 243 bytes = bpf_map_lookup_elem(&sock_cork_bytes, &zero); 244 if (bytes) 245 bpf_msg_cork_bytes(msg, *bytes); 246 start = bpf_map_lookup_elem(&sock_bytes, &zero); 247 end = bpf_map_lookup_elem(&sock_bytes, &one); 248 if (start && end) 249 bpf_msg_pull_data(msg, *start, *end, 0); 250 start_push = bpf_map_lookup_elem(&sock_bytes, &two); 251 end_push = bpf_map_lookup_elem(&sock_bytes, &three); 252 if (start_push && end_push) 253 bpf_msg_push_data(msg, *start_push, *end_push, 0); 254 start_pop = bpf_map_lookup_elem(&sock_bytes, &four); 255 pop = bpf_map_lookup_elem(&sock_bytes, &five); 256 if (start_pop && pop) 257 bpf_msg_pop_data(msg, *start_pop, *pop, 0); 258 return SK_PASS; 259 } 260 261 SEC("sk_msg2") 262 int bpf_prog6(struct sk_msg_md *msg) 263 { 264 int zero = 0, one = 1, two = 2, three = 3, four = 4, five = 5, key = 0; 265 int *bytes, *start, *end, *start_push, *end_push, *start_pop, *pop, *f; 266 __u64 flags = 0; 267 268 bytes = bpf_map_lookup_elem(&sock_apply_bytes, &zero); 269 if (bytes) 270 bpf_msg_apply_bytes(msg, *bytes); 271 bytes = bpf_map_lookup_elem(&sock_cork_bytes, &zero); 272 if (bytes) 273 bpf_msg_cork_bytes(msg, *bytes); 274 275 start = bpf_map_lookup_elem(&sock_bytes, &zero); 276 end = bpf_map_lookup_elem(&sock_bytes, &one); 277 if (start && end) 278 bpf_msg_pull_data(msg, *start, *end, 0); 279 280 start_push = bpf_map_lookup_elem(&sock_bytes, &two); 281 end_push = bpf_map_lookup_elem(&sock_bytes, &three); 282 if (start_push && end_push) 283 bpf_msg_push_data(msg, *start_push, *end_push, 0); 284 285 start_pop = bpf_map_lookup_elem(&sock_bytes, &four); 286 pop = bpf_map_lookup_elem(&sock_bytes, &five); 287 if (start_pop && pop) 288 bpf_msg_pop_data(msg, *start_pop, *pop, 0); 289 290 f = bpf_map_lookup_elem(&sock_redir_flags, &zero); 291 if (f && *f) { 292 key = 2; 293 flags = *f; 294 } 295 #ifdef SOCKMAP 296 return bpf_msg_redirect_map(msg, &sock_map_redir, key, flags); 297 #else 298 return bpf_msg_redirect_hash(msg, &sock_map_redir, &key, flags); 299 #endif 300 } 301 302 SEC("sk_msg3") 303 int bpf_prog8(struct sk_msg_md *msg) 304 { 305 void *data_end = (void *)(long) msg->data_end; 306 void *data = (void *)(long) msg->data; 307 int ret = 0, *bytes, zero = 0; 308 309 bytes = bpf_map_lookup_elem(&sock_apply_bytes, &zero); 310 if (bytes) { 311 ret = bpf_msg_apply_bytes(msg, *bytes); 312 if (ret) 313 return SK_DROP; 314 } else { 315 return SK_DROP; 316 } 317 return SK_PASS; 318 } 319 SEC("sk_msg4") 320 int bpf_prog9(struct sk_msg_md *msg) 321 { 322 void *data_end = (void *)(long) msg->data_end; 323 void *data = (void *)(long) msg->data; 324 int ret = 0, *bytes, zero = 0; 325 326 bytes = bpf_map_lookup_elem(&sock_cork_bytes, &zero); 327 if (bytes) { 328 if (((__u64)data_end - (__u64)data) >= *bytes) 329 return SK_PASS; 330 ret = bpf_msg_cork_bytes(msg, *bytes); 331 if (ret) 332 return SK_DROP; 333 } 334 return SK_PASS; 335 } 336 337 SEC("sk_msg5") 338 int bpf_prog10(struct sk_msg_md *msg) 339 { 340 int *bytes, *start, *end, *start_push, *end_push, *start_pop, *pop; 341 int zero = 0, one = 1, two = 2, three = 3, four = 4, five = 5; 342 343 bytes = bpf_map_lookup_elem(&sock_apply_bytes, &zero); 344 if (bytes) 345 bpf_msg_apply_bytes(msg, *bytes); 346 bytes = bpf_map_lookup_elem(&sock_cork_bytes, &zero); 347 if (bytes) 348 bpf_msg_cork_bytes(msg, *bytes); 349 start = bpf_map_lookup_elem(&sock_bytes, &zero); 350 end = bpf_map_lookup_elem(&sock_bytes, &one); 351 if (start && end) 352 bpf_msg_pull_data(msg, *start, *end, 0); 353 start_push = bpf_map_lookup_elem(&sock_bytes, &two); 354 end_push = bpf_map_lookup_elem(&sock_bytes, &three); 355 if (start_push && end_push) 356 bpf_msg_push_data(msg, *start_push, *end_push, 0); 357 start_pop = bpf_map_lookup_elem(&sock_bytes, &four); 358 pop = bpf_map_lookup_elem(&sock_bytes, &five); 359 if (start_pop && pop) 360 bpf_msg_pop_data(msg, *start_pop, *pop, 0); 361 return SK_DROP; 362 } 363 364 int _version SEC("version") = 1; 365 char _license[] SEC("license") = "GPL"; 366