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| 1 | +/* SPDX-License-Identifier: GPL-2.0 */ |
| 2 | + |
| 3 | +#ifndef __SOCKET_HELPERS__ |
| 4 | +#define __SOCKET_HELPERS__ |
| 5 | + |
| 6 | +#include <linux/vm_sockets.h> |
| 7 | + |
| 8 | +/* include/linux/net.h */ |
| 9 | +#define SOCK_TYPE_MASK 0xf |
| 10 | + |
| 11 | +#define IO_TIMEOUT_SEC 30 |
| 12 | +#define MAX_STRERR_LEN 256 |
| 13 | + |
| 14 | +/* workaround for older vm_sockets.h */ |
| 15 | +#ifndef VMADDR_CID_LOCAL |
| 16 | +#define VMADDR_CID_LOCAL 1 |
| 17 | +#endif |
| 18 | + |
| 19 | +/* include/linux/cleanup.h */ |
| 20 | +#define __get_and_null(p, nullvalue) \ |
| 21 | + ({ \ |
| 22 | + __auto_type __ptr = &(p); \ |
| 23 | + __auto_type __val = *__ptr; \ |
| 24 | + *__ptr = nullvalue; \ |
| 25 | + __val; \ |
| 26 | + }) |
| 27 | + |
| 28 | +#define take_fd(fd) __get_and_null(fd, -EBADF) |
| 29 | + |
| 30 | +/* Wrappers that fail the test on error and report it. */ |
| 31 | + |
| 32 | +#define _FAIL(errnum, fmt...) \ |
| 33 | + ({ \ |
| 34 | + error_at_line(0, (errnum), __func__, __LINE__, fmt); \ |
| 35 | + CHECK_FAIL(true); \ |
| 36 | + }) |
| 37 | +#define FAIL(fmt...) _FAIL(0, fmt) |
| 38 | +#define FAIL_ERRNO(fmt...) _FAIL(errno, fmt) |
| 39 | +#define FAIL_LIBBPF(err, msg) \ |
| 40 | + ({ \ |
| 41 | + char __buf[MAX_STRERR_LEN]; \ |
| 42 | + libbpf_strerror((err), __buf, sizeof(__buf)); \ |
| 43 | + FAIL("%s: %s", (msg), __buf); \ |
| 44 | + }) |
| 45 | + |
| 46 | + |
| 47 | +#define xaccept_nonblock(fd, addr, len) \ |
| 48 | + ({ \ |
| 49 | + int __ret = \ |
| 50 | + accept_timeout((fd), (addr), (len), IO_TIMEOUT_SEC); \ |
| 51 | + if (__ret == -1) \ |
| 52 | + FAIL_ERRNO("accept"); \ |
| 53 | + __ret; \ |
| 54 | + }) |
| 55 | + |
| 56 | +#define xbind(fd, addr, len) \ |
| 57 | + ({ \ |
| 58 | + int __ret = bind((fd), (addr), (len)); \ |
| 59 | + if (__ret == -1) \ |
| 60 | + FAIL_ERRNO("bind"); \ |
| 61 | + __ret; \ |
| 62 | + }) |
| 63 | + |
| 64 | +#define xclose(fd) \ |
| 65 | + ({ \ |
| 66 | + int __ret = close((fd)); \ |
| 67 | + if (__ret == -1) \ |
| 68 | + FAIL_ERRNO("close"); \ |
| 69 | + __ret; \ |
| 70 | + }) |
| 71 | + |
| 72 | +#define xconnect(fd, addr, len) \ |
| 73 | + ({ \ |
| 74 | + int __ret = connect((fd), (addr), (len)); \ |
| 75 | + if (__ret == -1) \ |
| 76 | + FAIL_ERRNO("connect"); \ |
| 77 | + __ret; \ |
| 78 | + }) |
| 79 | + |
| 80 | +#define xgetsockname(fd, addr, len) \ |
| 81 | + ({ \ |
| 82 | + int __ret = getsockname((fd), (addr), (len)); \ |
| 83 | + if (__ret == -1) \ |
| 84 | + FAIL_ERRNO("getsockname"); \ |
| 85 | + __ret; \ |
| 86 | + }) |
| 87 | + |
| 88 | +#define xgetsockopt(fd, level, name, val, len) \ |
| 89 | + ({ \ |
| 90 | + int __ret = getsockopt((fd), (level), (name), (val), (len)); \ |
| 91 | + if (__ret == -1) \ |
| 92 | + FAIL_ERRNO("getsockopt(" #name ")"); \ |
| 93 | + __ret; \ |
| 94 | + }) |
| 95 | + |
| 96 | +#define xlisten(fd, backlog) \ |
| 97 | + ({ \ |
| 98 | + int __ret = listen((fd), (backlog)); \ |
| 99 | + if (__ret == -1) \ |
| 100 | + FAIL_ERRNO("listen"); \ |
| 101 | + __ret; \ |
| 102 | + }) |
| 103 | + |
| 104 | +#define xsetsockopt(fd, level, name, val, len) \ |
| 105 | + ({ \ |
| 106 | + int __ret = setsockopt((fd), (level), (name), (val), (len)); \ |
| 107 | + if (__ret == -1) \ |
| 108 | + FAIL_ERRNO("setsockopt(" #name ")"); \ |
| 109 | + __ret; \ |
| 110 | + }) |
| 111 | + |
| 112 | +#define xsend(fd, buf, len, flags) \ |
| 113 | + ({ \ |
| 114 | + ssize_t __ret = send((fd), (buf), (len), (flags)); \ |
| 115 | + if (__ret == -1) \ |
| 116 | + FAIL_ERRNO("send"); \ |
| 117 | + __ret; \ |
| 118 | + }) |
| 119 | + |
| 120 | +#define xrecv_nonblock(fd, buf, len, flags) \ |
| 121 | + ({ \ |
| 122 | + ssize_t __ret = recv_timeout((fd), (buf), (len), (flags), \ |
| 123 | + IO_TIMEOUT_SEC); \ |
| 124 | + if (__ret == -1) \ |
| 125 | + FAIL_ERRNO("recv"); \ |
| 126 | + __ret; \ |
| 127 | + }) |
| 128 | + |
| 129 | +#define xsocket(family, sotype, flags) \ |
| 130 | + ({ \ |
| 131 | + int __ret = socket(family, sotype, flags); \ |
| 132 | + if (__ret == -1) \ |
| 133 | + FAIL_ERRNO("socket"); \ |
| 134 | + __ret; \ |
| 135 | + }) |
| 136 | + |
| 137 | +static inline void close_fd(int *fd) |
| 138 | +{ |
| 139 | + if (*fd >= 0) |
| 140 | + xclose(*fd); |
| 141 | +} |
| 142 | + |
| 143 | +#define __close_fd __attribute__((cleanup(close_fd))) |
| 144 | + |
| 145 | +static inline struct sockaddr *sockaddr(struct sockaddr_storage *ss) |
| 146 | +{ |
| 147 | + return (struct sockaddr *)ss; |
| 148 | +} |
| 149 | + |
| 150 | +static inline void init_addr_loopback4(struct sockaddr_storage *ss, |
| 151 | + socklen_t *len) |
| 152 | +{ |
| 153 | + struct sockaddr_in *addr4 = memset(ss, 0, sizeof(*ss)); |
| 154 | + |
| 155 | + addr4->sin_family = AF_INET; |
| 156 | + addr4->sin_port = 0; |
| 157 | + addr4->sin_addr.s_addr = htonl(INADDR_LOOPBACK); |
| 158 | + *len = sizeof(*addr4); |
| 159 | +} |
| 160 | + |
| 161 | +static inline void init_addr_loopback6(struct sockaddr_storage *ss, |
| 162 | + socklen_t *len) |
| 163 | +{ |
| 164 | + struct sockaddr_in6 *addr6 = memset(ss, 0, sizeof(*ss)); |
| 165 | + |
| 166 | + addr6->sin6_family = AF_INET6; |
| 167 | + addr6->sin6_port = 0; |
| 168 | + addr6->sin6_addr = in6addr_loopback; |
| 169 | + *len = sizeof(*addr6); |
| 170 | +} |
| 171 | + |
| 172 | +static inline void init_addr_loopback_vsock(struct sockaddr_storage *ss, |
| 173 | + socklen_t *len) |
| 174 | +{ |
| 175 | + struct sockaddr_vm *addr = memset(ss, 0, sizeof(*ss)); |
| 176 | + |
| 177 | + addr->svm_family = AF_VSOCK; |
| 178 | + addr->svm_port = VMADDR_PORT_ANY; |
| 179 | + addr->svm_cid = VMADDR_CID_LOCAL; |
| 180 | + *len = sizeof(*addr); |
| 181 | +} |
| 182 | + |
| 183 | +static inline void init_addr_loopback(int family, struct sockaddr_storage *ss, |
| 184 | + socklen_t *len) |
| 185 | +{ |
| 186 | + switch (family) { |
| 187 | + case AF_INET: |
| 188 | + init_addr_loopback4(ss, len); |
| 189 | + return; |
| 190 | + case AF_INET6: |
| 191 | + init_addr_loopback6(ss, len); |
| 192 | + return; |
| 193 | + case AF_VSOCK: |
| 194 | + init_addr_loopback_vsock(ss, len); |
| 195 | + return; |
| 196 | + default: |
| 197 | + FAIL("unsupported address family %d", family); |
| 198 | + } |
| 199 | +} |
| 200 | + |
| 201 | +static inline int enable_reuseport(int s, int progfd) |
| 202 | +{ |
| 203 | + int err, one = 1; |
| 204 | + |
| 205 | + err = xsetsockopt(s, SOL_SOCKET, SO_REUSEPORT, &one, sizeof(one)); |
| 206 | + if (err) |
| 207 | + return -1; |
| 208 | + err = xsetsockopt(s, SOL_SOCKET, SO_ATTACH_REUSEPORT_EBPF, &progfd, |
| 209 | + sizeof(progfd)); |
| 210 | + if (err) |
| 211 | + return -1; |
| 212 | + |
| 213 | + return 0; |
| 214 | +} |
| 215 | + |
| 216 | +static inline int socket_loopback_reuseport(int family, int sotype, int progfd) |
| 217 | +{ |
| 218 | + struct sockaddr_storage addr; |
| 219 | + socklen_t len = 0; |
| 220 | + int err, s; |
| 221 | + |
| 222 | + init_addr_loopback(family, &addr, &len); |
| 223 | + |
| 224 | + s = xsocket(family, sotype, 0); |
| 225 | + if (s == -1) |
| 226 | + return -1; |
| 227 | + |
| 228 | + if (progfd >= 0) |
| 229 | + enable_reuseport(s, progfd); |
| 230 | + |
| 231 | + err = xbind(s, sockaddr(&addr), len); |
| 232 | + if (err) |
| 233 | + goto close; |
| 234 | + |
| 235 | + if (sotype & SOCK_DGRAM) |
| 236 | + return s; |
| 237 | + |
| 238 | + err = xlisten(s, SOMAXCONN); |
| 239 | + if (err) |
| 240 | + goto close; |
| 241 | + |
| 242 | + return s; |
| 243 | +close: |
| 244 | + xclose(s); |
| 245 | + return -1; |
| 246 | +} |
| 247 | + |
| 248 | +static inline int socket_loopback(int family, int sotype) |
| 249 | +{ |
| 250 | + return socket_loopback_reuseport(family, sotype, -1); |
| 251 | +} |
| 252 | + |
| 253 | +static inline int poll_connect(int fd, unsigned int timeout_sec) |
| 254 | +{ |
| 255 | + struct timeval timeout = { .tv_sec = timeout_sec }; |
| 256 | + fd_set wfds; |
| 257 | + int r, eval; |
| 258 | + socklen_t esize = sizeof(eval); |
| 259 | + |
| 260 | + FD_ZERO(&wfds); |
| 261 | + FD_SET(fd, &wfds); |
| 262 | + |
| 263 | + r = select(fd + 1, NULL, &wfds, NULL, &timeout); |
| 264 | + if (r == 0) |
| 265 | + errno = ETIME; |
| 266 | + if (r != 1) |
| 267 | + return -1; |
| 268 | + |
| 269 | + if (getsockopt(fd, SOL_SOCKET, SO_ERROR, &eval, &esize) < 0) |
| 270 | + return -1; |
| 271 | + if (eval != 0) { |
| 272 | + errno = eval; |
| 273 | + return -1; |
| 274 | + } |
| 275 | + |
| 276 | + return 0; |
| 277 | +} |
| 278 | + |
| 279 | +static inline int poll_read(int fd, unsigned int timeout_sec) |
| 280 | +{ |
| 281 | + struct timeval timeout = { .tv_sec = timeout_sec }; |
| 282 | + fd_set rfds; |
| 283 | + int r; |
| 284 | + |
| 285 | + FD_ZERO(&rfds); |
| 286 | + FD_SET(fd, &rfds); |
| 287 | + |
| 288 | + r = select(fd + 1, &rfds, NULL, NULL, &timeout); |
| 289 | + if (r == 0) |
| 290 | + errno = ETIME; |
| 291 | + |
| 292 | + return r == 1 ? 0 : -1; |
| 293 | +} |
| 294 | + |
| 295 | +static inline int accept_timeout(int fd, struct sockaddr *addr, socklen_t *len, |
| 296 | + unsigned int timeout_sec) |
| 297 | +{ |
| 298 | + if (poll_read(fd, timeout_sec)) |
| 299 | + return -1; |
| 300 | + |
| 301 | + return accept(fd, addr, len); |
| 302 | +} |
| 303 | + |
| 304 | +static inline int recv_timeout(int fd, void *buf, size_t len, int flags, |
| 305 | + unsigned int timeout_sec) |
| 306 | +{ |
| 307 | + if (poll_read(fd, timeout_sec)) |
| 308 | + return -1; |
| 309 | + |
| 310 | + return recv(fd, buf, len, flags); |
| 311 | +} |
| 312 | + |
| 313 | + |
| 314 | +static inline int create_pair(int family, int sotype, int *p0, int *p1) |
| 315 | +{ |
| 316 | + __close_fd int s, c = -1, p = -1; |
| 317 | + struct sockaddr_storage addr; |
| 318 | + socklen_t len = sizeof(addr); |
| 319 | + int err; |
| 320 | + |
| 321 | + s = socket_loopback(family, sotype); |
| 322 | + if (s < 0) |
| 323 | + return s; |
| 324 | + |
| 325 | + err = xgetsockname(s, sockaddr(&addr), &len); |
| 326 | + if (err) |
| 327 | + return err; |
| 328 | + |
| 329 | + c = xsocket(family, sotype, 0); |
| 330 | + if (c < 0) |
| 331 | + return c; |
| 332 | + |
| 333 | + err = connect(c, sockaddr(&addr), len); |
| 334 | + if (err) { |
| 335 | + if (errno != EINPROGRESS) { |
| 336 | + FAIL_ERRNO("connect"); |
| 337 | + return err; |
| 338 | + } |
| 339 | + |
| 340 | + err = poll_connect(c, IO_TIMEOUT_SEC); |
| 341 | + if (err) { |
| 342 | + FAIL_ERRNO("poll_connect"); |
| 343 | + return err; |
| 344 | + } |
| 345 | + } |
| 346 | + |
| 347 | + switch (sotype & SOCK_TYPE_MASK) { |
| 348 | + case SOCK_DGRAM: |
| 349 | + err = xgetsockname(c, sockaddr(&addr), &len); |
| 350 | + if (err) |
| 351 | + return err; |
| 352 | + |
| 353 | + err = xconnect(s, sockaddr(&addr), len); |
| 354 | + if (err) |
| 355 | + return err; |
| 356 | + |
| 357 | + *p0 = take_fd(s); |
| 358 | + break; |
| 359 | + case SOCK_STREAM: |
| 360 | + case SOCK_SEQPACKET: |
| 361 | + p = xaccept_nonblock(s, NULL, NULL); |
| 362 | + if (p < 0) |
| 363 | + return p; |
| 364 | + |
| 365 | + *p0 = take_fd(p); |
| 366 | + break; |
| 367 | + default: |
| 368 | + FAIL("Unsupported socket type %#x", sotype); |
| 369 | + return -EOPNOTSUPP; |
| 370 | + } |
| 371 | + |
| 372 | + *p1 = take_fd(c); |
| 373 | + return 0; |
| 374 | +} |
| 375 | + |
| 376 | +static inline int create_socket_pairs(int family, int sotype, int *c0, int *c1, |
| 377 | + int *p0, int *p1) |
| 378 | +{ |
| 379 | + int err; |
| 380 | + |
| 381 | + err = create_pair(family, sotype, c0, p0); |
| 382 | + if (err) |
| 383 | + return err; |
| 384 | + |
| 385 | + err = create_pair(family, sotype, c1, p1); |
| 386 | + if (err) { |
| 387 | + close(*c0); |
| 388 | + close(*p0); |
| 389 | + } |
| 390 | + |
| 391 | + return err; |
| 392 | +} |
| 393 | + |
| 394 | +#endif // __SOCKET_HELPERS__ |
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