1 /* $OpenBSD: check_tcp.c,v 1.61 2023/07/03 09:38:08 claudio Exp $ */ 2 3 /* 4 * Copyright (c) 2006 Pierre-Yves Ritschard <pyr@openbsd.org> 5 * 6 * Permission to use, copy, modify, and distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 */ 18 19 #include <sys/types.h> 20 #include <sys/time.h> 21 #include <sys/socket.h> 22 23 #include <netinet/in.h> 24 25 #include <limits.h> 26 #include <event.h> 27 #include <fcntl.h> 28 #include <unistd.h> 29 #include <string.h> 30 #include <stdlib.h> 31 #include <errno.h> 32 #include <fnmatch.h> 33 #include <sha1.h> 34 #include <imsg.h> 35 36 #include "relayd.h" 37 38 void tcp_write(int, short, void *); 39 void tcp_host_up(struct ctl_tcp_event *); 40 void tcp_close(struct ctl_tcp_event *, int); 41 void tcp_send_req(int, short, void *); 42 void tcp_read_buf(int, short, void *); 43 44 int check_http_code(struct ctl_tcp_event *); 45 int check_http_digest(struct ctl_tcp_event *); 46 int check_send_expect(struct ctl_tcp_event *); 47 48 void 49 check_tcp(struct ctl_tcp_event *cte) 50 { 51 int s; 52 socklen_t len; 53 struct timeval tv; 54 struct linger lng; 55 int he = HCE_TCP_SOCKET_OPTION; 56 57 switch (cte->host->conf.ss.ss_family) { 58 case AF_INET: 59 ((struct sockaddr_in *)&cte->host->conf.ss)->sin_port = 60 cte->table->conf.port; 61 break; 62 case AF_INET6: 63 ((struct sockaddr_in6 *)&cte->host->conf.ss)->sin6_port = 64 cte->table->conf.port; 65 break; 66 } 67 68 len = ((struct sockaddr *)&cte->host->conf.ss)->sa_len; 69 70 if ((s = socket(cte->host->conf.ss.ss_family, 71 SOCK_STREAM | SOCK_NONBLOCK, 0)) == -1) { 72 if (errno == EMFILE || errno == ENFILE) 73 he = HCE_TCP_SOCKET_LIMIT; 74 else 75 he = HCE_TCP_SOCKET_ERROR; 76 goto bad; 77 } 78 79 cte->s = s; 80 81 bzero(&lng, sizeof(lng)); 82 if (setsockopt(s, SOL_SOCKET, SO_LINGER, &lng, sizeof(lng)) == -1) 83 goto bad; 84 85 if (cte->host->conf.ttl > 0) 86 switch (cte->host->conf.ss.ss_family) { 87 case AF_INET: 88 if (setsockopt(s, IPPROTO_IP, IP_TTL, 89 &cte->host->conf.ttl, sizeof(int)) == -1) 90 goto bad; 91 break; 92 case AF_INET6: 93 if (setsockopt(s, IPPROTO_IPV6, IPV6_UNICAST_HOPS, 94 &cte->host->conf.ttl, sizeof(int)) == -1) 95 goto bad; 96 break; 97 } 98 99 bcopy(&cte->table->conf.timeout, &tv, sizeof(tv)); 100 if (connect(s, (struct sockaddr *)&cte->host->conf.ss, len) == -1) { 101 if (errno != EINPROGRESS) { 102 he = HCE_TCP_CONNECT_FAIL; 103 goto bad; 104 } 105 } 106 107 cte->buf = NULL; 108 cte->host->up = HOST_UP; 109 event_del(&cte->ev); 110 event_set(&cte->ev, s, EV_TIMEOUT|EV_WRITE, tcp_write, cte); 111 event_add(&cte->ev, &tv); 112 return; 113 114 bad: 115 tcp_close(cte, HOST_DOWN); 116 hce_notify_done(cte->host, he); 117 } 118 119 void 120 tcp_write(int s, short event, void *arg) 121 { 122 struct ctl_tcp_event *cte = arg; 123 int err; 124 socklen_t len; 125 126 if (event == EV_TIMEOUT) { 127 tcp_close(cte, HOST_DOWN); 128 hce_notify_done(cte->host, HCE_TCP_CONNECT_TIMEOUT); 129 return; 130 } 131 132 len = sizeof(err); 133 if (getsockopt(s, SOL_SOCKET, SO_ERROR, &err, &len)) 134 fatal("%s: getsockopt", __func__); 135 if (err != 0) { 136 tcp_close(cte, HOST_DOWN); 137 hce_notify_done(cte->host, HCE_TCP_CONNECT_FAIL); 138 return; 139 } 140 141 cte->host->up = HOST_UP; 142 tcp_host_up(cte); 143 } 144 145 void 146 tcp_close(struct ctl_tcp_event *cte, int status) 147 { 148 close(cte->s); 149 cte->s = -1; 150 if (status != 0) 151 cte->host->up = status; 152 ibuf_free(cte->buf); 153 cte->buf = NULL; 154 } 155 156 void 157 tcp_host_up(struct ctl_tcp_event *cte) 158 { 159 switch (cte->table->conf.check) { 160 case CHECK_TCP: 161 if (cte->table->conf.flags & F_TLS) 162 break; 163 tcp_close(cte, 0); 164 hce_notify_done(cte->host, HCE_TCP_CONNECT_OK); 165 return; 166 case CHECK_HTTP_CODE: 167 cte->validate_read = NULL; 168 cte->validate_close = check_http_code; 169 break; 170 case CHECK_HTTP_DIGEST: 171 cte->validate_read = NULL; 172 cte->validate_close = check_http_digest; 173 break; 174 case CHECK_BINSEND_EXPECT: 175 case CHECK_SEND_EXPECT: 176 cte->validate_read = check_send_expect; 177 cte->validate_close = check_send_expect; 178 break; 179 } 180 181 if (cte->table->conf.flags & F_TLS) { 182 check_tls(cte); 183 return; 184 } 185 186 if (cte->table->sendbuf != NULL || cte->table->sendbinbuf != NULL) { 187 event_again(&cte->ev, cte->s, EV_TIMEOUT|EV_WRITE, tcp_send_req, 188 &cte->tv_start, &cte->table->conf.timeout, cte); 189 return; 190 } 191 192 if ((cte->buf = ibuf_dynamic(SMALL_READ_BUF_SIZE, UINT_MAX)) == NULL) 193 fatalx("%s: cannot create dynamic buffer", __func__); 194 event_again(&cte->ev, cte->s, EV_TIMEOUT|EV_READ, tcp_read_buf, 195 &cte->tv_start, &cte->table->conf.timeout, cte); 196 } 197 198 void 199 tcp_send_req(int s, short event, void *arg) 200 { 201 struct ctl_tcp_event *cte = arg; 202 char *req; 203 int bs; 204 int len; 205 206 if (event == EV_TIMEOUT) { 207 tcp_close(cte, HOST_DOWN); 208 hce_notify_done(cte->host, HCE_TCP_WRITE_TIMEOUT); 209 return; 210 } 211 212 if (cte->table->sendbinbuf != NULL) { 213 len = ibuf_size(cte->table->sendbinbuf); 214 req = ibuf_data(cte->table->sendbinbuf); 215 log_debug("%s: table %s sending binary", __func__, 216 cte->table->conf.name); 217 print_hex(req, 0, len); 218 } else { 219 len = strlen(cte->table->sendbuf); 220 req = cte->table->sendbuf; 221 } 222 223 do { 224 bs = write(s, req, len); 225 if (bs == -1) { 226 if (errno == EAGAIN || errno == EINTR) 227 goto retry; 228 log_warn("%s: cannot send request", __func__); 229 tcp_close(cte, HOST_DOWN); 230 hce_notify_done(cte->host, HCE_TCP_WRITE_FAIL); 231 return; 232 } 233 req += bs; 234 len -= bs; 235 } while (len > 0); 236 237 if ((cte->buf = ibuf_dynamic(SMALL_READ_BUF_SIZE, UINT_MAX)) == NULL) 238 fatalx("%s: cannot create dynamic buffer", __func__); 239 event_again(&cte->ev, s, EV_TIMEOUT|EV_READ, tcp_read_buf, 240 &cte->tv_start, &cte->table->conf.timeout, cte); 241 return; 242 243 retry: 244 event_again(&cte->ev, s, EV_TIMEOUT|EV_WRITE, tcp_send_req, 245 &cte->tv_start, &cte->table->conf.timeout, cte); 246 } 247 248 void 249 tcp_read_buf(int s, short event, void *arg) 250 { 251 ssize_t br; 252 char rbuf[SMALL_READ_BUF_SIZE]; 253 struct ctl_tcp_event *cte = arg; 254 255 if (event == EV_TIMEOUT) { 256 if (ibuf_size(cte->buf)) 257 (void)cte->validate_close(cte); 258 else { 259 cte->host->he = HCE_TCP_READ_TIMEOUT; 260 cte->host->up = HOST_DOWN; 261 } 262 tcp_close(cte, cte->host->up == HOST_UP ? 0 : HOST_DOWN); 263 hce_notify_done(cte->host, cte->host->he); 264 return; 265 } 266 267 bzero(rbuf, sizeof(rbuf)); 268 br = read(s, rbuf, sizeof(rbuf) - 1); 269 switch (br) { 270 case -1: 271 if (errno == EAGAIN || errno == EINTR) 272 goto retry; 273 tcp_close(cte, HOST_DOWN); 274 hce_notify_done(cte->host, HCE_TCP_READ_FAIL); 275 return; 276 case 0: 277 cte->host->up = HOST_DOWN; 278 (void)cte->validate_close(cte); 279 tcp_close(cte, 0); 280 hce_notify_done(cte->host, cte->host->he); 281 return; 282 default: 283 if (ibuf_add(cte->buf, rbuf, br) == -1) 284 fatal("%s: buf_add error", __func__); 285 if (cte->validate_read != NULL) { 286 if (cte->validate_read(cte) != 0) 287 goto retry; 288 tcp_close(cte, 0); 289 hce_notify_done(cte->host, cte->host->he); 290 return; 291 } 292 break; /* retry */ 293 } 294 retry: 295 event_again(&cte->ev, s, EV_TIMEOUT|EV_READ, tcp_read_buf, 296 &cte->tv_start, &cte->table->conf.timeout, cte); 297 } 298 299 int 300 check_send_expect(struct ctl_tcp_event *cte) 301 { 302 u_char *b; 303 304 if (cte->table->conf.check == CHECK_BINSEND_EXPECT) { 305 size_t exlen; 306 307 exlen = strlen(cte->table->conf.exbuf) / 2; 308 log_debug("%s: table %s expecting binary", 309 __func__, cte->table->conf.name); 310 print_hex(cte->table->conf.exbinbuf, 0, exlen); 311 312 if (ibuf_size(cte->buf) >= exlen && memcmp(ibuf_data(cte->buf), 313 cte->table->conf.exbinbuf, exlen) == 0) { 314 cte->host->he = HCE_SEND_EXPECT_OK; 315 cte->host->up = HOST_UP; 316 return (0); 317 } else if (ibuf_size(cte->buf) >= exlen) { 318 log_debug("%s: table %s received mismatching binary", 319 __func__, cte->table->conf.name); 320 print_hex(ibuf_data(cte->buf), 0, ibuf_size(cte->buf)); 321 } 322 } else if (cte->table->conf.check == CHECK_SEND_EXPECT) { 323 /* 324 * ensure string is nul-terminated. 325 */ 326 b = strndup(ibuf_data(cte->buf), ibuf_size(cte->buf)); 327 if (b == NULL) 328 fatal("out of memory"); 329 if (fnmatch(cte->table->conf.exbuf, b, 0) == 0) { 330 cte->host->he = HCE_SEND_EXPECT_OK; 331 cte->host->up = HOST_UP; 332 free(b); 333 return (0); 334 } 335 free(b); 336 } 337 338 cte->host->he = HCE_SEND_EXPECT_FAIL; 339 cte->host->up = HOST_UNKNOWN; 340 return (1); 341 } 342 343 int 344 check_http_code(struct ctl_tcp_event *cte) 345 { 346 char *head; 347 char scode[4]; 348 const char *estr; 349 int code; 350 struct host *host; 351 352 /* 353 * ensure string is nul-terminated. 354 */ 355 if (ibuf_add_zero(cte->buf, 1) == -1) 356 fatal("out of memory"); 357 358 head = ibuf_data(cte->buf); 359 host = cte->host; 360 host->he = HCE_HTTP_CODE_ERROR; 361 host->code = 0; 362 363 if (strncmp(head, "HTTP/1.1 ", strlen("HTTP/1.1 ")) && 364 strncmp(head, "HTTP/1.0 ", strlen("HTTP/1.0 "))) { 365 log_debug("%s: %s failed (cannot parse HTTP version)", 366 __func__, host->conf.name); 367 host->up = HOST_DOWN; 368 return (1); 369 } 370 head += strlen("HTTP/1.1 "); 371 if (strlen(head) < 5) /* code + \r\n */ { 372 host->up = HOST_DOWN; 373 return (1); 374 } 375 (void)strlcpy(scode, head, sizeof(scode)); 376 code = strtonum(scode, 100, 999, &estr); 377 if (estr != NULL) { 378 log_debug("%s: %s failed (cannot parse HTTP code)", 379 __func__, host->conf.name); 380 host->up = HOST_DOWN; 381 return (1); 382 } 383 if (code != cte->table->conf.retcode) { 384 log_debug("%s: %s failed (invalid HTTP code %d returned)", 385 __func__, host->conf.name, code); 386 host->he = HCE_HTTP_CODE_FAIL; 387 host->up = HOST_DOWN; 388 host->code = code; 389 } else { 390 host->he = HCE_HTTP_CODE_OK; 391 host->up = HOST_UP; 392 } 393 return (!(host->up == HOST_UP)); 394 } 395 396 int 397 check_http_digest(struct ctl_tcp_event *cte) 398 { 399 char *head; 400 char digest[SHA1_DIGEST_STRING_LENGTH]; 401 struct host *host; 402 403 /* 404 * ensure string is nul-terminated. 405 */ 406 if (ibuf_add_zero(cte->buf, 1) == -1) 407 fatal("out of memory"); 408 409 head = ibuf_data(cte->buf); 410 host = cte->host; 411 host->he = HCE_HTTP_DIGEST_ERROR; 412 413 if ((head = strstr(head, "\r\n\r\n")) == NULL) { 414 log_debug("%s: %s failed (no end of headers)", 415 __func__, host->conf.name); 416 host->up = HOST_DOWN; 417 return (1); 418 } 419 head += strlen("\r\n\r\n"); 420 421 digeststr(cte->table->conf.digest_type, head, strlen(head), digest); 422 423 if (strcmp(cte->table->conf.digest, digest)) { 424 log_warnx("%s: %s failed (wrong digest)", 425 __func__, host->conf.name); 426 host->he = HCE_HTTP_DIGEST_FAIL; 427 host->up = HOST_DOWN; 428 } else { 429 host->he = HCE_HTTP_DIGEST_OK; 430 host->up = HOST_UP; 431 } 432 return (!(host->up == HOST_UP)); 433 } 434