1/* 2 * Copyright (c) 1983, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34#include <sys/cdefs.h> 35 36#ifndef lint 37__unused static const char copyright[] = 38"@(#) Copyright (c) 1983, 1993\n\ 39 The Regents of the University of California. All rights reserved.\n"; 40#endif /* not lint */ 41 42/* Mac OS X kernel core dump server, based on the BSD trivial file 43 * transfer protocol server (FreeBSD distribution), with several 44 * modifications. This server is *not* compatible with tftp, as the 45 * protocol has changed considerably. 46 */ 47 48/* 49 * Based on the trivial file transfer protocol server. 50 * 51 * The original version included many modifications by Jim Guyton 52 * <guyton@rand-unix>. 53 */ 54 55#include <sys/param.h> 56#include <sys/ioctl.h> 57#include <sys/stat.h> 58#include <sys/socket.h> 59#include <sys/types.h> 60#include <sys/mman.h> 61 62#include <netinet/in.h> 63#include "kdump.h" 64#include <arpa/inet.h> 65 66#include <stdint.h> 67#include <ctype.h> 68#include <errno.h> 69#include <fcntl.h> 70#include <netdb.h> 71#include <pwd.h> 72#include <setjmp.h> 73#include <signal.h> 74#include <stdio.h> 75#include <stdlib.h> 76#include <string.h> 77#include <syslog.h> 78#include <unistd.h> 79#include <libkern/OSByteOrder.h> 80 81#include "kdumpsubs.h" 82 83#define TIMEOUT 2 84 85int peer; 86int rexmtval = TIMEOUT; 87int maxtimeout = 25 * TIMEOUT; 88 89#define PKTSIZE SEGSIZE+6 90 91char buf[MAXIMUM_KDP_PKTSIZE]; 92char ackbuf[MAXIMUM_KDP_PKTSIZE]; 93struct sockaddr_in from; 94socklen_t fromlen; 95 96void kdump __P((struct kdumphdr *, int)); 97 98/* 99 * Null-terminated directory prefix list for absolute pathname requests and 100 * search list for relative pathname requests. 101 * 102 * MAXDIRS should be at least as large as the number of arguments that 103 * inetd allows (currently 20). 104 */ 105#define MAXDIRS 20 106static struct dirlist { 107 char *name; 108 int len; 109} dirs[MAXDIRS+1]; 110static int suppress_naks; 111static int logging = 1; 112static int ipchroot; 113 114static char *errtomsg __P((int)); 115static void nak __P((int)); 116static char * __P(verifyhost(struct sockaddr_in *)); 117uint32_t kdp_crashdump_pkt_size = (SEGSIZE + (sizeof(struct kdumphdr))); 118uint32_t kdp_crashdump_seg_size = SEGSIZE; 119 120#define KDP_FEATURE_MASK_STRING "features" 121enum {KDP_FEATURE_LARGE_CRASHDUMPS = 1, KDP_FEATURE_LARGE_PKT_SIZE = 2}; 122 123uint32_t kdp_crashdump_feature_mask; 124uint32_t kdp_feature_large_crashdumps, kdp_feature_large_packets; 125 126int 127main(argc, argv) 128 int argc; 129 char *argv[]; 130{ 131 register struct kdumphdr *tp; 132 register int n; 133 int ch, on; 134 struct sockaddr_in sin; 135 char *chroot_dir = NULL; 136 struct passwd *nobody; 137 char *chuser = "nobody"; 138 139 openlog("kdumpd", LOG_PID | LOG_NDELAY, LOG_FTP); 140 while ((ch = getopt(argc, argv, "cClns:u:")) != -1) { 141 switch (ch) { 142 case 'c': 143 ipchroot = 1; 144 break; 145 case 'C': 146 ipchroot = 2; 147 break; 148 case 'l': 149 logging = 1; 150 break; 151 case 'n': 152 suppress_naks = 1; 153 break; 154 case 's': 155 chroot_dir = optarg; 156 break; 157 case 'u': 158 chuser = optarg; 159 break; 160 default: 161 syslog(LOG_WARNING, "ignoring unknown option -%c", ch); 162 } 163 } 164 165 if (optind < argc) { 166 struct dirlist *dirp; 167 168 /* Get list of directory prefixes. Skip relative pathnames. */ 169 for (dirp = dirs; optind < argc && dirp < &dirs[MAXDIRS]; 170 optind++) { 171 if (argv[optind][0] == '/') { 172 dirp->name = argv[optind]; 173 dirp->len = strlen(dirp->name); 174 dirp++; 175 } 176 } 177 } 178 else if (chroot_dir) { 179 dirs->name = "/"; 180 dirs->len = 1; 181 } 182 if (ipchroot && chroot_dir == NULL) { 183 syslog(LOG_ERR, "-c requires -s"); 184 exit(1); 185 } 186 187 on = 1; 188 if (ioctl(0, FIONBIO, &on) < 0) { 189 syslog(LOG_ERR, "ioctl(FIONBIO): %m"); 190 exit(1); 191 } 192 fromlen = sizeof (from); 193 n = recvfrom(0, buf, sizeof (buf), 0, 194 (struct sockaddr *)&from, &fromlen); 195 if (n < 0) { 196 syslog(LOG_ERR, "recvfrom: %m"); 197 exit(1); 198 } 199 /* 200 * Now that we have read the message out of the UDP 201 * socket, we fork and exit. Thus, inetd will go back 202 * to listening to the kdump port, and the next request 203 * to come in will start up a new instance of kdumpd. 204 * 205 * We do this so that inetd can run kdumpd in "wait" mode. 206 * The problem with kdumpd running in "nowait" mode is that 207 * inetd may get one or more successful "selects" on the 208 * kdump port before we do our receive, so more than one 209 * instance of kdumpd may be started up. Worse, if kdumpd 210 * breaks before doing the above "recvfrom", inetd would 211 * spawn endless instances, clogging the system. 212 */ 213 { 214 int pid; 215 int i; 216 socklen_t j; 217 218 for (i = 1; i < 20; i++) { 219 pid = fork(); 220 if (pid < 0) { 221 sleep(i); 222 /* 223 * flush out to most recently sent request. 224 * 225 * This may drop some requests, but those 226 * will be resent by the clients when 227 * they timeout. The positive effect of 228 * this flush is to (try to) prevent more 229 * than one kdumpd being started up to service 230 * a single request from a single client. 231 */ 232 j = sizeof from; 233 i = recvfrom(0, buf, sizeof (buf), 0, 234 (struct sockaddr *)&from, &j); 235 if (i > 0) { 236 n = i; 237 fromlen = j; 238 } 239 } else { 240 break; 241 } 242 } 243 if (pid < 0) { 244 syslog(LOG_ERR, "fork: %m"); 245 exit(1); 246 } else if (pid != 0) { 247 exit(0); 248 } 249 } 250 251 /* 252 * Since we exit here, we should do that only after the above 253 * recvfrom to keep inetd from constantly forking should there 254 * be a problem. See the above comment about system clogging. 255 */ 256 if (chroot_dir) { 257 if (ipchroot) { 258 char tempchroot[MAXPATHLEN]; 259 char *tempaddr; 260 struct stat sb; 261 int statret; 262 263 tempaddr = inet_ntoa(from.sin_addr); 264 snprintf(tempchroot, sizeof(tempchroot), "%s/%s", chroot_dir, tempaddr); 265 statret = stat(tempchroot, &sb); 266 if (((sb.st_mode & S_IFMT ) == S_IFDIR) && 267 (statret == 0 || (statret == -1 && ipchroot == 1))) 268 chroot_dir = tempchroot; 269 } 270 /* Must get this before chroot because /etc might go away */ 271 if ((nobody = getpwnam(chuser)) == NULL) { 272 syslog(LOG_ERR, "%s: no such user", chuser); 273 exit(1); 274 } 275 if (chroot(chroot_dir)) { 276 syslog(LOG_ERR, "chroot: %s: %m", chroot_dir); 277 exit(1); 278 } 279 chdir( "/" ); 280 setuid(nobody->pw_uid); 281 } 282 else 283 if (0 != chdir(dirs->name)) 284 syslog(LOG_ERR, "chdir%s: %m", dirs->name); 285 286 from.sin_family = AF_INET; 287 alarm(0); 288 close(0); 289 close(1); 290 peer = socket(AF_INET, SOCK_DGRAM, 0); 291 if (peer < 0) { 292 syslog(LOG_ERR, "socket: %m"); 293 exit(1); 294 } 295 memset(&sin, 0, sizeof(sin)); 296 sin.sin_family = AF_INET; 297 if (bind(peer, (struct sockaddr *)&sin, sizeof (sin)) < 0) { 298 syslog(LOG_ERR, "bind: %m"); 299 exit(1); 300 } 301 if (connect(peer, (struct sockaddr *)&from, sizeof(from)) < 0) { 302 syslog(LOG_ERR, "connect: %m"); 303 exit(1); 304 } 305 tp = (struct kdumphdr *)buf; 306 tp->th_opcode = ntohs(tp->th_opcode); 307 if (tp->th_opcode == WRQ) 308 kdump(tp, n); 309 exit(1); 310} 311 312struct formats; 313int validate_access __P((char **, int)); 314 315void recvfile __P((struct formats *)); 316 317struct formats { 318 char *f_mode; 319 int (*f_validate) __P((char **, int)); 320 321 void (*f_recv) __P((struct formats *)); 322 int f_convert; 323} formats[] = { 324 { "netascii", validate_access, recvfile, 1 }, 325 { "octet", validate_access, recvfile, 0 }, 326 { 0 } 327}; 328 329/* 330 * Handle initial connection protocol. 331 */ 332void 333kdump(tp, size) 334 struct kdumphdr *tp; 335 int size; 336{ 337 register char *cp; 338 int first = 1, ecode; 339 register struct formats *pf; 340 char *filename, *mode = NULL; 341 342 filename = cp = tp->th_stuff; 343again: 344 while (cp < buf + size) { 345 if (*cp == '\0') 346 break; 347 cp++; 348 } 349 if (*cp != '\0') { 350 nak(EBADOP); 351 exit(1); 352 } 353 if (first) { 354 mode = ++cp; 355 first = 0; 356 goto again; 357 } 358 for (cp = mode; *cp; cp++) 359 if (isupper(*cp)) 360 *cp = tolower(*cp); 361 362 cp++; 363 if (strncmp(KDP_FEATURE_MASK_STRING, cp, sizeof(KDP_FEATURE_MASK_STRING)) == 0) { 364 kdp_crashdump_feature_mask = ntohl(*(uint32_t *) (cp + sizeof(KDP_FEATURE_MASK_STRING))); 365 kdp_feature_large_crashdumps = kdp_crashdump_feature_mask & KDP_FEATURE_LARGE_CRASHDUMPS; 366 kdp_feature_large_packets = kdp_crashdump_feature_mask & KDP_FEATURE_LARGE_PKT_SIZE; 367 368 if (kdp_feature_large_packets) { 369 kdp_crashdump_pkt_size = KDP_LARGE_CRASHDUMP_PKT_SIZE; 370 kdp_crashdump_seg_size = kdp_crashdump_pkt_size - sizeof(struct kdumphdr); 371 } 372 syslog(KDUMPD_DEBUG_LEVEL, "Received feature mask %s:0x%x", cp, kdp_crashdump_feature_mask); 373 } else 374 syslog(KDUMPD_DEBUG_LEVEL, "Unable to locate feature mask, mode: %s", mode); 375 376 for (pf = formats; pf->f_mode; pf++) 377 if (strcmp(pf->f_mode, mode) == 0) 378 break; 379 if (pf->f_mode == 0) { 380 nak(EBADOP); 381 exit(1); 382 } 383 ecode = (*pf->f_validate)(&filename, tp->th_opcode); 384 if (logging) { 385 syslog(KDUMPD_DEBUG_LEVEL, "%s: %s request for %s: %s", verifyhost(&from), 386 tp->th_opcode == WRQ ? "write" : "read", 387 filename, errtomsg(ecode)); 388 } 389 if (ecode) { 390 /* 391 * Avoid storms of naks to a RRQ broadcast for a relative 392 * bootfile pathname from a diskless Sun. 393 */ 394 if (suppress_naks && *filename != '/' && ecode == ENOTFOUND) 395 exit(0); 396 nak(ecode); 397 exit(1); 398 } 399 if (tp->th_opcode == WRQ) 400 (*pf->f_recv)(pf); 401 402 exit(0); 403} 404 405 406FILE *file; 407 408/* 409 * Validate file access. We only allow storage of files that do not already 410 * exist, and that do not include directory specifiers in their pathnames. 411 * This is because kernel coredump filenames should always be of the form 412 * "core-version-IP as dotted quad-random string" as in : 413 * core-custom-17.202.40.204-a75b4eec 414 * The file is written to the directory supplied as the first argument 415 * in inetd.conf 416 */ 417 418int 419validate_access(char **filep, int mode) 420{ 421 struct stat stbuf; 422 int fd; 423 char *filename = *filep; 424 static char pathname[MAXPATHLEN]; 425 426 if (strstr(filename, "/") || strstr(filename, "..")) 427 return (EACCESS); 428 429 snprintf(pathname, sizeof(pathname), "./%s", filename); 430 431 if (0 == stat(pathname, &stbuf)) 432 return (EEXIST); 433 434 if (errno != ENOENT) 435 return (errno); 436 437 438 fd = open(filename, O_RDWR|O_CREAT|O_TRUNC , S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH); 439 440 if (fd < 0) 441 return (errno + 100); 442 443 file = fdopen(fd, (mode == RRQ)? "r":"w"); 444 if (file == NULL) { 445 return errno+100; 446 } 447 448 return (0); 449} 450 451int timeout; 452jmp_buf timeoutbuf; 453 454void 455timer() 456{ 457 458 timeout += rexmtval; 459 if (timeout >= maxtimeout) 460 { 461 longjmp(timeoutbuf, 2); 462 } 463 longjmp(timeoutbuf, 1); 464} 465 466void 467justquit() 468{ 469 exit(0); 470} 471 472/* 473 * Receive a file. 474 */ 475void 476recvfile(pf) 477 struct formats *pf; 478{ 479 struct kdumphdr *dp, *w_init(); 480 register struct kdumphdr *ap; /* ack buffer */ 481 register int n, size; 482 volatile unsigned int block; 483 volatile unsigned int jmpval = 0; 484 485 signal(SIGALRM, timer); 486 dp = w_init(); 487 ap = (struct kdumphdr *)ackbuf; 488 block = 0; 489 do { 490send_seek_ack: timeout = 0; 491 if (block == 0) 492 ap->th_opcode = htons((u_short)ACK | ((kdp_feature_large_crashdumps | kdp_feature_large_packets) << 8)); 493 else 494 ap->th_opcode = htons((u_short)ACK); 495 ap->th_block = htonl((unsigned int)block); 496 block++; 497 jmpval = setjmp(timeoutbuf); 498 if (2 == jmpval) 499 { 500 syslog (LOG_ERR, "Timing out and flushing file to disk"); 501 goto flushfile; 502 } 503send_ack: 504 if (send(peer, ackbuf, 6 , 0) != 6) { 505 syslog(LOG_ERR, "write: %m"); 506 goto abort; 507 } 508 write_behind(file, pf->f_convert); 509 for ( ; ; ) { 510 alarm(rexmtval); 511 n = recv(peer, dp, kdp_crashdump_pkt_size, 0); 512 alarm(0); 513 if (n < 0) { /* really? */ 514 syslog(LOG_ERR, "read: %m"); 515 goto abort; 516 } 517 dp->th_opcode = ntohs((u_short)dp->th_opcode); 518 dp->th_block = ntohl((unsigned int)dp->th_block); 519#if DEBUG 520 syslog(KDUMPD_DEBUG_LEVEL, "Received packet type %u, block %u\n", (unsigned)dp->th_opcode, (unsigned)dp->th_block); 521#endif 522 523 if (dp->th_opcode == ERROR) 524 goto abort; 525 526 if (dp->th_opcode == KDP_EOF) 527 { 528 syslog (LOG_ERR, "Received last panic dump packet"); 529 goto final_ack; 530 } 531 if (dp->th_opcode == KDP_SEEK) 532 { 533 if (dp->th_block == block) 534 { 535 off_t crashdump_offset = 0; 536 unsigned int tempoff = 0; 537 538 if (kdp_feature_large_crashdumps) { 539 crashdump_offset = OSSwapBigToHostInt64((*(uint64_t *)dp->th_data)); 540 } 541 else { 542 bcopy (dp->th_data, &tempoff, sizeof(unsigned int)); 543 crashdump_offset = ntohl(tempoff); 544 } 545 546#if DEBUG 547 syslog(KDUMPD_DEBUG_LEVEL, "Seeking to offset 0x%llx\n", crashdump_offset); 548#endif 549 errno = 0; 550 lseek(fileno (file), crashdump_offset, SEEK_SET); 551 if (errno) 552 syslog (LOG_ERR, "lseek: %m"); 553 554 goto send_seek_ack; 555 } 556 (void) synchnet(peer); 557 if (dp->th_block == (block-1)) 558 { 559 syslog (LOG_DAEMON|LOG_ERR, "Retransmitting seek ack - current block %u, received block %u", block, dp->th_block); 560 goto send_ack; /* rexmit */ 561 } 562 } 563 564 if (dp->th_opcode == DATA) { 565 if (dp->th_block == block) { 566 break; /* normal */ 567 } 568 /* Re-synchronize with the other side */ 569 (void) synchnet(peer); 570 if (dp->th_block == (block-1)) 571 { 572 syslog (LOG_DAEMON|LOG_ERR, "Retransmitting ack - current block %u, received block %u", block, dp->th_block); 573 goto send_ack; /* rexmit */ 574 } 575 else 576 syslog (LOG_DAEMON|LOG_ERR, "Not retransmitting ack - current block %u, received block %u", block, dp->th_block); 577 } 578 } 579#if DEBUG 580 syslog(KDUMPD_DEBUG_LEVEL, "Writing block sized %u, current offset 0x%llx\n", n - 6, ftello(file)); 581#endif 582 size = writeit(file, &dp, n - 6, pf->f_convert); 583 if (size != (n-6)) { /* ahem */ 584 if (size < 0) nak(errno + 100); 585 else nak(ENOSPACE); 586 goto abort; 587 } 588 } while (dp->th_opcode != KDP_EOF); 589 590final_ack: 591 ap->th_opcode = htons((u_short)ACK); /* send the "final" ack */ 592 ap->th_block = htonl((unsigned int) (block)); 593 (void) send(peer, ackbuf, 6, 0); 594flushfile: 595 write_behind(file, pf->f_convert); 596 (void) fclose(file); /* close data file */ 597 syslog (LOG_ERR, "file closed, sending final ACK\n"); 598 599 signal(SIGALRM, justquit); /* just quit on timeout */ 600 alarm(rexmtval); 601 n = recv(peer, buf, sizeof (buf), 0); /* normally times out and quits */ 602 alarm(0); 603 if (n >= 6 && /* if read some data */ 604 dp->th_opcode == DATA && /* and got a data block */ 605 block == dp->th_block) { /* then my last ack was lost */ 606 (void) send(peer, ackbuf, 6, 0); /* resend final ack */ 607 } 608abort: 609 return; 610} 611 612/* update if needed, when adding new errmsgs */ 613#define MAXERRMSGLEN 40 614 615struct errmsg { 616 int e_code; 617 char *e_msg; 618} errmsgs[] = { 619 { EUNDEF, "Undefined error code" }, 620 { ENOTFOUND, "File not found" }, 621 { EACCESS, "Access violation" }, 622 { ENOSPACE, "Disk full or allocation exceeded" }, 623 { EBADOP, "Illegal KDUMP operation" }, 624 { EBADID, "Unknown transfer ID" }, 625 { EEXISTS, "File already exists" }, 626 { ENOUSER, "No such user" }, 627 { -1, 0 } 628}; 629 630static char * 631errtomsg(error) 632 int error; 633{ 634 static char buf[20]; 635 register struct errmsg *pe; 636 if (error == 0) 637 return "success"; 638 for (pe = errmsgs; pe->e_code >= 0; pe++) 639 if (pe->e_code == error) 640 return pe->e_msg; 641 snprintf(buf, sizeof(buf), "error %d", error); 642 return buf; 643} 644 645/* 646 * Send a nak packet (error message). 647 * Error code passed in is one of the 648 * standard KDUMP codes, or a UNIX errno 649 * offset by 100. 650 */ 651static void 652nak(error) 653 int error; 654{ 655 register struct kdumphdr *tp; 656 int length; 657 register struct errmsg *pe; 658 659 tp = (struct kdumphdr *)buf; 660 tp->th_opcode = htons((u_short)ERROR); 661 tp->th_code = htons((unsigned int)error); 662 for (pe = errmsgs; pe->e_code >= 0; pe++) 663 if (pe->e_code == error) 664 break; 665 if (pe->e_code < 0) { 666 pe->e_msg = strerror(error - 100); 667 tp->th_code = EUNDEF; /* set 'undef' errorcode */ 668 } 669 if (strlen(pe->e_msg) > MAXERRMSGLEN) { 670 syslog(LOG_ERR, "nak: error msg too long"); 671 return; 672 } 673 674 strlcpy(tp->th_msg, pe->e_msg, MAXERRMSGLEN); 675 length = strlen(pe->e_msg); 676 tp->th_msg[length] = '\0'; 677 length += 5; 678 if (send(peer, buf, length, 0) != length) 679 syslog(LOG_ERR, "nak: %m"); 680 681 return; 682} 683 684static char * 685verifyhost(fromp) 686 struct sockaddr_in *fromp; 687{ 688 struct hostent *hp; 689 690 hp = gethostbyaddr((char *)&fromp->sin_addr, sizeof(fromp->sin_addr), 691 fromp->sin_family); 692 if(hp) 693 return hp->h_name; 694 else 695 return inet_ntoa(fromp->sin_addr); 696} 697