1 /* 2 * S390 virtio-ccw network boot loading program 3 * 4 * Copyright 2017 Thomas Huth, Red Hat Inc. 5 * 6 * Based on the S390 virtio-ccw loading program (main.c) 7 * Copyright (c) 2013 Alexander Graf <agraf@suse.de> 8 * 9 * And based on the network loading code from SLOF (netload.c) 10 * Copyright (c) 2004, 2008 IBM Corporation 11 * 12 * This code is free software; you can redistribute it and/or modify it 13 * under the terms of the GNU General Public License as published by the 14 * Free Software Foundation; either version 2 of the License, or (at your 15 * option) any later version. 16 */ 17 18 #include <stdint.h> 19 #include <stdbool.h> 20 #include <stdio.h> 21 #include <stdlib.h> 22 #include <string.h> 23 #include <unistd.h> 24 25 #include <tftp.h> 26 #include <ethernet.h> 27 #include <dhcp.h> 28 #include <dhcpv6.h> 29 #include <ipv4.h> 30 #include <ipv6.h> 31 #include <dns.h> 32 #include <time.h> 33 #include <pxelinux.h> 34 35 #include "s390-ccw.h" 36 #include "cio.h" 37 #include "virtio.h" 38 #include "s390-time.h" 39 40 #define DEFAULT_BOOT_RETRIES 10 41 #define DEFAULT_TFTP_RETRIES 20 42 43 extern char _start[]; 44 void write_iplb_location(void) {} 45 46 #define KERNEL_ADDR ((void *)0L) 47 #define KERNEL_MAX_SIZE ((long)_start) 48 #define ARCH_COMMAND_LINE_SIZE 896 /* Taken from Linux kernel */ 49 50 /* STSI 3.2.2 offset of first vmdb + offset of uuid inside vmdb */ 51 #define STSI322_VMDB_UUID_OFFSET ((8 + 12) * 4) 52 53 IplParameterBlock iplb __attribute__((aligned(PAGE_SIZE))); 54 static char cfgbuf[2048]; 55 56 static SubChannelId net_schid = { .one = 1 }; 57 static uint8_t mac[6]; 58 static uint64_t dest_timer; 59 60 void set_timer(int val) 61 { 62 dest_timer = get_time_ms() + val; 63 } 64 65 int get_timer(void) 66 { 67 return dest_timer - get_time_ms(); 68 } 69 70 int get_sec_ticks(void) 71 { 72 return 1000; /* number of ticks in 1 second */ 73 } 74 75 /** 76 * Obtain IP and configuration info from DHCP server (either IPv4 or IPv6). 77 * @param fn_ip contains the following configuration information: 78 * client MAC, client IP, TFTP-server MAC, TFTP-server IP, 79 * boot file name 80 * @param retries Number of DHCP attempts 81 * @return 0 : IP and configuration info obtained; 82 * non-0 : error condition occurred. 83 */ 84 static int dhcp(struct filename_ip *fn_ip, int retries) 85 { 86 int i = retries + 1; 87 int rc = -1; 88 89 printf(" Requesting information via DHCP: "); 90 91 dhcpv4_generate_transaction_id(); 92 dhcpv6_generate_transaction_id(); 93 94 do { 95 printf("\b\b\b%03d", i - 1); 96 if (!--i) { 97 printf("\nGiving up after %d DHCP requests\n", retries); 98 return -1; 99 } 100 fn_ip->ip_version = 4; 101 rc = dhcpv4(NULL, fn_ip); 102 if (rc == -1) { 103 fn_ip->ip_version = 6; 104 set_ipv6_address(fn_ip->fd, 0); 105 rc = dhcpv6(NULL, fn_ip); 106 if (rc == 0) { 107 memcpy(&fn_ip->own_ip6, get_ipv6_address(), 16); 108 break; 109 } 110 } 111 if (rc != -1) { /* either success or non-dhcp failure */ 112 break; 113 } 114 } while (1); 115 printf("\b\b\b\bdone\n"); 116 117 return rc; 118 } 119 120 /** 121 * Seed the random number generator with our mac and current timestamp 122 */ 123 static void seed_rng(uint8_t mac[]) 124 { 125 uint64_t seed; 126 127 asm volatile(" stck %0 " : : "Q"(seed) : "memory"); 128 seed ^= (mac[2] << 24) | (mac[3] << 16) | (mac[4] << 8) | mac[5]; 129 srand(seed); 130 } 131 132 static int tftp_load(filename_ip_t *fnip, void *buffer, int len) 133 { 134 tftp_err_t tftp_err; 135 int rc; 136 137 rc = tftp(fnip, buffer, len, DEFAULT_TFTP_RETRIES, &tftp_err); 138 139 if (rc < 0) { 140 /* Make sure that error messages are put into a new line */ 141 printf("\n "); 142 } 143 144 if (rc > 1024) { 145 printf(" TFTP: Received %s (%d KBytes)\n", fnip->filename, rc / 1024); 146 } else if (rc > 0) { 147 printf(" TFTP: Received %s (%d Bytes)\n", fnip->filename, rc); 148 } else { 149 const char *errstr = NULL; 150 int ecode; 151 tftp_get_error_info(fnip, &tftp_err, rc, &errstr, &ecode); 152 printf("TFTP error: %s\n", errstr ? errstr : "unknown error"); 153 } 154 155 return rc; 156 } 157 158 static int net_init(filename_ip_t *fn_ip) 159 { 160 int rc; 161 162 memset(fn_ip, 0, sizeof(filename_ip_t)); 163 164 rc = virtio_net_init(mac); 165 if (rc < 0) { 166 puts("Could not initialize network device"); 167 return -101; 168 } 169 fn_ip->fd = rc; 170 171 printf(" Using MAC address: %02x:%02x:%02x:%02x:%02x:%02x\n", 172 mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]); 173 174 set_mac_address(mac); /* init ethernet layer */ 175 seed_rng(mac); 176 177 rc = dhcp(fn_ip, DEFAULT_BOOT_RETRIES); 178 if (rc >= 0) { 179 if (fn_ip->ip_version == 4) { 180 set_ipv4_address(fn_ip->own_ip); 181 } 182 } else { 183 puts("Could not get IP address"); 184 return -101; 185 } 186 187 if (fn_ip->ip_version == 4) { 188 printf(" Using IPv4 address: %d.%d.%d.%d\n", 189 (fn_ip->own_ip >> 24) & 0xFF, (fn_ip->own_ip >> 16) & 0xFF, 190 (fn_ip->own_ip >> 8) & 0xFF, fn_ip->own_ip & 0xFF); 191 } else if (fn_ip->ip_version == 6) { 192 char ip6_str[40]; 193 ipv6_to_str(fn_ip->own_ip6.addr, ip6_str); 194 printf(" Using IPv6 address: %s\n", ip6_str); 195 } 196 197 if (rc == -2) { 198 printf("ARP request to TFTP server (%d.%d.%d.%d) failed\n", 199 (fn_ip->server_ip >> 24) & 0xFF, (fn_ip->server_ip >> 16) & 0xFF, 200 (fn_ip->server_ip >> 8) & 0xFF, fn_ip->server_ip & 0xFF); 201 return -102; 202 } 203 if (rc == -4 || rc == -3) { 204 puts("Can't obtain TFTP server IP address"); 205 return -107; 206 } 207 208 printf(" Using TFTP server: "); 209 if (fn_ip->ip_version == 4) { 210 printf("%d.%d.%d.%d\n", 211 (fn_ip->server_ip >> 24) & 0xFF, (fn_ip->server_ip >> 16) & 0xFF, 212 (fn_ip->server_ip >> 8) & 0xFF, fn_ip->server_ip & 0xFF); 213 } else if (fn_ip->ip_version == 6) { 214 char ip6_str[40]; 215 ipv6_to_str(fn_ip->server_ip6.addr, ip6_str); 216 printf("%s\n", ip6_str); 217 } 218 219 if (strlen(fn_ip->filename) > 0) { 220 printf(" Bootfile name: '%s'\n", fn_ip->filename); 221 } 222 223 return rc; 224 } 225 226 static void net_release(filename_ip_t *fn_ip) 227 { 228 if (fn_ip->ip_version == 4) { 229 dhcp_send_release(fn_ip->fd); 230 } 231 } 232 233 /** 234 * Retrieve the Universally Unique Identifier of the VM. 235 * @return UUID string, or NULL in case of errors 236 */ 237 static const char *get_uuid(void) 238 { 239 register int r0 asm("0"); 240 register int r1 asm("1"); 241 uint8_t *mem, *buf, uuid[16]; 242 int i, cc, chk = 0; 243 static char uuid_str[37]; 244 245 mem = malloc(2 * PAGE_SIZE); 246 if (!mem) { 247 puts("Out of memory ... can not get UUID."); 248 return NULL; 249 } 250 buf = (uint8_t *)(((uint64_t)mem + PAGE_SIZE - 1) & ~(PAGE_SIZE - 1)); 251 memset(buf, 0, PAGE_SIZE); 252 253 /* Get SYSIB 3.2.2 */ 254 r0 = (3 << 28) | 2; 255 r1 = 2; 256 asm volatile(" stsi 0(%[addr])\n" 257 " ipm %[cc]\n" 258 " srl %[cc],28\n" 259 : [cc] "=d" (cc) 260 : "d" (r0), "d" (r1), [addr] "a" (buf) 261 : "cc", "memory"); 262 if (cc) { 263 free(mem); 264 return NULL; 265 } 266 267 for (i = 0; i < 16; i++) { 268 uuid[i] = buf[STSI322_VMDB_UUID_OFFSET + i]; 269 chk |= uuid[i]; 270 } 271 free(mem); 272 if (!chk) { 273 return NULL; 274 } 275 276 sprintf(uuid_str, "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-" 277 "%02x%02x%02x%02x%02x%02x", uuid[0], uuid[1], uuid[2], uuid[3], 278 uuid[4], uuid[5], uuid[6], uuid[7], uuid[8], uuid[9], uuid[10], 279 uuid[11], uuid[12], uuid[13], uuid[14], uuid[15]); 280 281 return uuid_str; 282 } 283 284 /** 285 * Load a kernel with initrd (i.e. with the information that we've got from 286 * a pxelinux.cfg config file) 287 */ 288 static int load_kernel_with_initrd(filename_ip_t *fn_ip, 289 struct pl_cfg_entry *entry) 290 { 291 int rc; 292 293 printf("Loading pxelinux.cfg entry '%s'\n", entry->label); 294 295 if (!entry->kernel) { 296 printf("Kernel entry is missing!\n"); 297 return -1; 298 } 299 300 strncpy(fn_ip->filename, entry->kernel, sizeof(fn_ip->filename)); 301 rc = tftp_load(fn_ip, KERNEL_ADDR, KERNEL_MAX_SIZE); 302 if (rc < 0) { 303 return rc; 304 } 305 306 if (entry->initrd) { 307 uint64_t iaddr = (rc + 0xfff) & ~0xfffUL; 308 309 strncpy(fn_ip->filename, entry->initrd, sizeof(fn_ip->filename)); 310 rc = tftp_load(fn_ip, (void *)iaddr, KERNEL_MAX_SIZE - iaddr); 311 if (rc < 0) { 312 return rc; 313 } 314 /* Patch location and size: */ 315 *(uint64_t *)0x10408 = iaddr; 316 *(uint64_t *)0x10410 = rc; 317 rc += iaddr; 318 } 319 320 if (entry->append) { 321 strncpy((char *)0x10480, entry->append, ARCH_COMMAND_LINE_SIZE); 322 } 323 324 return rc; 325 } 326 327 #define MAX_PXELINUX_ENTRIES 16 328 329 static int net_try_pxelinux_cfg(filename_ip_t *fn_ip) 330 { 331 struct pl_cfg_entry entries[MAX_PXELINUX_ENTRIES]; 332 int num_ent, def_ent = 0; 333 334 num_ent = pxelinux_load_parse_cfg(fn_ip, mac, get_uuid(), 335 DEFAULT_TFTP_RETRIES, 336 cfgbuf, sizeof(cfgbuf), 337 entries, MAX_PXELINUX_ENTRIES, &def_ent); 338 if (num_ent > 0) { 339 return load_kernel_with_initrd(fn_ip, &entries[def_ent]); 340 } 341 342 return -1; 343 } 344 345 /** 346 * Load via information from a .INS file (which can be found on CD-ROMs 347 * for example) 348 */ 349 static int handle_ins_cfg(filename_ip_t *fn_ip, char *cfg, int cfgsize) 350 { 351 char *ptr; 352 int rc = -1, llen; 353 void *destaddr; 354 char *insbuf = cfg; 355 356 ptr = strchr(insbuf, '\n'); 357 if (!ptr) { 358 puts("Does not seem to be a valid .INS file"); 359 return -1; 360 } 361 362 *ptr = 0; 363 printf("\nParsing .INS file:\n %s\n", &insbuf[2]); 364 365 insbuf = ptr + 1; 366 while (*insbuf && insbuf < cfg + cfgsize) { 367 ptr = strchr(insbuf, '\n'); 368 if (ptr) { 369 *ptr = 0; 370 } 371 llen = strlen(insbuf); 372 if (!llen) { 373 insbuf = ptr + 1; 374 continue; 375 } 376 ptr = strchr(insbuf, ' '); 377 if (!ptr) { 378 puts("Missing space separator in .INS file"); 379 return -1; 380 } 381 *ptr = 0; 382 strncpy(fn_ip->filename, insbuf, sizeof(fn_ip->filename)); 383 destaddr = (char *)atol(ptr + 1); 384 rc = tftp_load(fn_ip, destaddr, (long)_start - (long)destaddr); 385 if (rc <= 0) { 386 break; 387 } 388 insbuf += llen + 1; 389 } 390 391 return rc; 392 } 393 394 static int net_try_direct_tftp_load(filename_ip_t *fn_ip) 395 { 396 int rc; 397 void *loadaddr = (void *)0x2000; /* Load right after the low-core */ 398 399 rc = tftp_load(fn_ip, loadaddr, KERNEL_MAX_SIZE - (long)loadaddr); 400 if (rc < 0) { 401 return rc; 402 } else if (rc < 8) { 403 printf("'%s' is too small (%i bytes only).\n", fn_ip->filename, rc); 404 return -1; 405 } 406 407 /* Check whether it is a configuration file instead of a kernel */ 408 if (rc < sizeof(cfgbuf) - 1) { 409 memcpy(cfgbuf, loadaddr, rc); 410 cfgbuf[rc] = 0; /* Make sure that it is NUL-terminated */ 411 if (!strncmp("* ", cfgbuf, 2)) { 412 return handle_ins_cfg(fn_ip, cfgbuf, rc); 413 } 414 /* 415 * pxelinux.cfg support via bootfile name is just here for developers' 416 * convenience (it eases testing with the built-in DHCP server of QEMU 417 * that does not support RFC 5071). The official way to configure a 418 * pxelinux.cfg file name is to use DHCP options 209 and 210 instead. 419 * So only use the pxelinux.cfg parser here for files that start with 420 * a magic comment string. 421 */ 422 if (!strncasecmp("# pxelinux", cfgbuf, 10)) { 423 struct pl_cfg_entry entries[MAX_PXELINUX_ENTRIES]; 424 int num_ent, def_ent = 0; 425 426 num_ent = pxelinux_parse_cfg(cfgbuf, sizeof(cfgbuf), entries, 427 MAX_PXELINUX_ENTRIES, &def_ent); 428 if (num_ent <= 0) { 429 return -1; 430 } 431 return load_kernel_with_initrd(fn_ip, &entries[def_ent]); 432 } 433 } 434 435 /* Move kernel to right location */ 436 memmove(KERNEL_ADDR, loadaddr, rc); 437 438 return rc; 439 } 440 441 void write_subsystem_identification(void) 442 { 443 SubChannelId *schid = (SubChannelId *) 184; 444 uint32_t *zeroes = (uint32_t *) 188; 445 446 *schid = net_schid; 447 *zeroes = 0; 448 } 449 450 static bool find_net_dev(Schib *schib, int dev_no) 451 { 452 int i, r; 453 454 for (i = 0; i < 0x10000; i++) { 455 net_schid.sch_no = i; 456 r = stsch_err(net_schid, schib); 457 if (r == 3 || r == -EIO) { 458 break; 459 } 460 if (!schib->pmcw.dnv) { 461 continue; 462 } 463 enable_subchannel(net_schid); 464 if (!virtio_is_supported(net_schid)) { 465 continue; 466 } 467 if (virtio_get_device_type() != VIRTIO_ID_NET) { 468 continue; 469 } 470 if (dev_no < 0 || schib->pmcw.dev == dev_no) { 471 return true; 472 } 473 } 474 475 return false; 476 } 477 478 static void virtio_setup(void) 479 { 480 Schib schib; 481 int ssid; 482 bool found = false; 483 uint16_t dev_no; 484 485 /* 486 * We unconditionally enable mss support. In every sane configuration, 487 * this will succeed; and even if it doesn't, stsch_err() can deal 488 * with the consequences. 489 */ 490 enable_mss_facility(); 491 492 if (store_iplb(&iplb)) { 493 IPL_assert(iplb.pbt == S390_IPL_TYPE_CCW, "IPL_TYPE_CCW expected"); 494 dev_no = iplb.ccw.devno; 495 debug_print_int("device no. ", dev_no); 496 net_schid.ssid = iplb.ccw.ssid & 0x3; 497 debug_print_int("ssid ", net_schid.ssid); 498 found = find_net_dev(&schib, dev_no); 499 } else { 500 for (ssid = 0; ssid < 0x3; ssid++) { 501 net_schid.ssid = ssid; 502 found = find_net_dev(&schib, -1); 503 if (found) { 504 break; 505 } 506 } 507 } 508 509 IPL_assert(found, "No virtio net device found"); 510 } 511 512 void main(void) 513 { 514 filename_ip_t fn_ip; 515 int rc, fnlen; 516 517 sclp_setup(); 518 sclp_print("Network boot starting...\n"); 519 520 virtio_setup(); 521 522 rc = net_init(&fn_ip); 523 if (rc) { 524 panic("Network initialization failed. Halting.\n"); 525 } 526 527 fnlen = strlen(fn_ip.filename); 528 if (fnlen > 0 && fn_ip.filename[fnlen - 1] != '/') { 529 rc = net_try_direct_tftp_load(&fn_ip); 530 } 531 if (rc <= 0) { 532 rc = net_try_pxelinux_cfg(&fn_ip); 533 } 534 535 net_release(&fn_ip); 536 537 if (rc > 0) { 538 sclp_print("Network loading done, starting kernel...\n"); 539 jump_to_low_kernel(); 540 } 541 542 panic("Failed to load OS from network\n"); 543 } 544