pc-bios/s390-ccw/netmain.c

   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 "virtio.h"
  37
  38 #define DEFAULT_BOOT_RETRIES 10
  39 #define DEFAULT_TFTP_RETRIES 20
  40
  41 extern char _start[];
  42
  43 #define KERNEL_ADDR             ((void *)0L)
  44 #define KERNEL_MAX_SIZE         ((long)_start)
  45 #define ARCH_COMMAND_LINE_SIZE  896              /* Taken from Linux kernel */
  46
  47 /* STSI 3.2.2 offset of first vmdb + offset of uuid inside vmdb */
  48 #define STSI322_VMDB_UUID_OFFSET ((8 + 12) * 4)
  49
  50 char stack[PAGE_SIZE * 8] __attribute__((aligned(PAGE_SIZE)));
  51 IplParameterBlock iplb __attribute__((aligned(PAGE_SIZE)));
  52 static char cfgbuf[2048];
  53
  54 static SubChannelId net_schid = { .one = 1 };
  55 static uint8_t mac[6];
  56 static uint64_t dest_timer;
  57
  58 static uint64_t get_timer_ms(void)
  59 {
  60     uint64_t clk;
  61
  62     asm volatile(" stck %0 " : : "Q"(clk) : "memory");
  63
  64     /* Bit 51 is incremented each microsecond */
  65     return (clk >> (63 - 51)) / 1000;
  66 }
  67
  68 void set_timer(int val)
  69 {
  70     dest_timer = get_timer_ms() + val;
  71 }
  72
  73 int get_timer(void)
  74 {
  75     return dest_timer - get_timer_ms();
  76 }
  77
  78 int get_sec_ticks(void)
  79 {
  80     return 1000;    /* number of ticks in 1 second */
  81 }
  82
  83 /**
  84  * Obtain IP and configuration info from DHCP server (either IPv4 or IPv6).
  85  * @param  fn_ip     contains the following configuration information:
  86  *                   client MAC, client IP, TFTP-server MAC, TFTP-server IP,
  87  *                   boot file name
  88  * @param  retries   Number of DHCP attempts
  89  * @return           0 : IP and configuration info obtained;
  90  *                   non-0 : error condition occurred.
  91  */
  92 static int dhcp(struct filename_ip *fn_ip, int retries)
  93 {
  94     int i = retries + 1;
  95     int rc = -1;
  96
  97     printf("  Requesting information via DHCP:     ");
  98
  99     dhcpv4_generate_transaction_id();
 100     dhcpv6_generate_transaction_id();
 101
 102     do {
 103         printf("\b\b\b%03d", i - 1);
 104         if (!--i) {
 105             printf("\nGiving up after %d DHCP requests\n", retries);
 106             return -1;
 107         }
 108         fn_ip->ip_version = 4;
 109         rc = dhcpv4(NULL, fn_ip);
 110         if (rc == -1) {
 111             fn_ip->ip_version = 6;
 112             set_ipv6_address(fn_ip->fd, 0);
 113             rc = dhcpv6(NULL, fn_ip);
 114             if (rc == 0) {
 115                 memcpy(&fn_ip->own_ip6, get_ipv6_address(), 16);
 116                 break;
 117             }
 118         }
 119         if (rc != -1) {    /* either success or non-dhcp failure */
 120             break;
 121         }
 122     } while (1);
 123     printf("\b\b\b\bdone\n");
 124
 125     return rc;
 126 }
 127
 128 /**
 129  * Seed the random number generator with our mac and current timestamp
 130  */
 131 static void seed_rng(uint8_t mac[])
 132 {
 133     uint64_t seed;
 134
 135     asm volatile(" stck %0 " : : "Q"(seed) : "memory");
 136     seed ^= (mac[2] << 24) | (mac[3] << 16) | (mac[4] << 8) | mac[5];
 137     srand(seed);
 138 }
 139
 140 static int tftp_load(filename_ip_t *fnip, void *buffer, int len)
 141 {
 142     tftp_err_t tftp_err;
 143     int rc;
 144
 145     rc = tftp(fnip, buffer, len, DEFAULT_TFTP_RETRIES, &tftp_err);
 146
 147     if (rc < 0) {
 148         /* Make sure that error messages are put into a new line */
 149         printf("\n  ");
 150     }
 151
 152     if (rc > 1024) {
 153         printf("  TFTP: Received %s (%d KBytes)\n", fnip->filename, rc / 1024);
 154     } else if (rc > 0) {
 155         printf("  TFTP: Received %s (%d Bytes)\n", fnip->filename, rc);
 156     } else {
 157         const char *errstr = NULL;
 158         int ecode;
 159         tftp_get_error_info(fnip, &tftp_err, rc, &errstr, &ecode);
 160         printf("TFTP error: %s\n", errstr ? errstr : "unknown error");
 161     }
 162
 163     return rc;
 164 }
 165
 166 static int net_init(filename_ip_t *fn_ip)
 167 {
 168     int rc;
 169
 170     memset(fn_ip, 0, sizeof(filename_ip_t));
 171
 172     rc = virtio_net_init(mac);
 173     if (rc < 0) {
 174         puts("Could not initialize network device");
 175         return -101;
 176     }
 177     fn_ip->fd = rc;
 178
 179     printf("  Using MAC address: %02x:%02x:%02x:%02x:%02x:%02x\n",
 180            mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
 181
 182     set_mac_address(mac);    /* init ethernet layer */
 183     seed_rng(mac);
 184
 185     rc = dhcp(fn_ip, DEFAULT_BOOT_RETRIES);
 186     if (rc >= 0) {
 187         if (fn_ip->ip_version == 4) {
 188             set_ipv4_address(fn_ip->own_ip);
 189         }
 190     } else {
 191         puts("Could not get IP address");
 192         return -101;
 193     }
 194
 195     if (fn_ip->ip_version == 4) {
 196         printf("  Using IPv4 address: %d.%d.%d.%d\n",
 197               (fn_ip->own_ip >> 24) & 0xFF, (fn_ip->own_ip >> 16) & 0xFF,
 198               (fn_ip->own_ip >>  8) & 0xFF, fn_ip->own_ip & 0xFF);
 199     } else if (fn_ip->ip_version == 6) {
 200         char ip6_str[40];
 201         ipv6_to_str(fn_ip->own_ip6.addr, ip6_str);
 202         printf("  Using IPv6 address: %s\n", ip6_str);
 203     }
 204
 205     if (rc == -2) {
 206         printf("ARP request to TFTP server (%d.%d.%d.%d) failed\n",
 207                (fn_ip->server_ip >> 24) & 0xFF, (fn_ip->server_ip >> 16) & 0xFF,
 208                (fn_ip->server_ip >>  8) & 0xFF, fn_ip->server_ip & 0xFF);
 209         return -102;
 210     }
 211     if (rc == -4 || rc == -3) {
 212         puts("Can't obtain TFTP server IP address");
 213         return -107;
 214     }
 215
 216     printf("  Using TFTP server: ");
 217     if (fn_ip->ip_version == 4) {
 218         printf("%d.%d.%d.%d\n",
 219                (fn_ip->server_ip >> 24) & 0xFF, (fn_ip->server_ip >> 16) & 0xFF,
 220                (fn_ip->server_ip >>  8) & 0xFF, fn_ip->server_ip & 0xFF);
 221     } else if (fn_ip->ip_version == 6) {
 222         char ip6_str[40];
 223         ipv6_to_str(fn_ip->server_ip6.addr, ip6_str);
 224         printf("%s\n", ip6_str);
 225     }
 226
 227     if (strlen(fn_ip->filename) > 0) {
 228         printf("  Bootfile name: '%s'\n", fn_ip->filename);
 229     }
 230
 231     return rc;
 232 }
 233
 234 static void net_release(filename_ip_t *fn_ip)
 235 {
 236     if (fn_ip->ip_version == 4) {
 237         dhcp_send_release(fn_ip->fd);
 238     }
 239 }
 240
 241 /**
 242  * Retrieve the Universally Unique Identifier of the VM.
 243  * @return UUID string, or NULL in case of errors
 244  */
 245 static const char *get_uuid(void)
 246 {
 247     register int r0 asm("0");
 248     register int r1 asm("1");
 249     uint8_t *mem, *buf, uuid[16];
 250     int i, cc, chk = 0;
 251     static char uuid_str[37];
 252
 253     mem = malloc(2 * PAGE_SIZE);
 254     if (!mem) {
 255         puts("Out of memory ... can not get UUID.");
 256         return NULL;
 257     }
 258     buf = (uint8_t *)(((uint64_t)mem + PAGE_SIZE - 1) & ~(PAGE_SIZE - 1));
 259     memset(buf, 0, PAGE_SIZE);
 260
 261     /* Get SYSIB 3.2.2 */
 262     r0 = (3 << 28) | 2;
 263     r1 = 2;
 264     asm volatile(" stsi 0(%[addr])\n"
 265                  " ipm  %[cc]\n"
 266                  " srl  %[cc],28\n"
 267                  : [cc] "=d" (cc)
 268                  : "d" (r0), "d" (r1), [addr] "a" (buf)
 269                  : "cc", "memory");
 270     if (cc) {
 271         return NULL;
 272     }
 273
 274     for (i = 0; i < 16; i++) {
 275         uuid[i] = buf[STSI322_VMDB_UUID_OFFSET + i];
 276         chk |= uuid[i];
 277     }
 278     free(mem);
 279     if (!chk) {
 280         return NULL;
 281     }
 282
 283     sprintf(uuid_str, "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-"
 284             "%02x%02x%02x%02x%02x%02x", uuid[0], uuid[1], uuid[2], uuid[3],
 285             uuid[4], uuid[5], uuid[6], uuid[7], uuid[8], uuid[9], uuid[10],
 286             uuid[11], uuid[12], uuid[13], uuid[14], uuid[15]);
 287
 288     return uuid_str;
 289 }
 290
 291 /**
 292  * Load a kernel with initrd (i.e. with the information that we've got from
 293  * a pxelinux.cfg config file)
 294  */
 295 static int load_kernel_with_initrd(filename_ip_t *fn_ip,
 296                                    struct pl_cfg_entry *entry)
 297 {
 298     int rc;
 299
 300     printf("Loading pxelinux.cfg entry '%s'\n", entry->label);
 301
 302     if (!entry->kernel) {
 303         printf("Kernel entry is missing!\n");
 304         return -1;
 305     }
 306
 307     strncpy(fn_ip->filename, entry->kernel, sizeof(fn_ip->filename));
 308     rc = tftp_load(fn_ip, KERNEL_ADDR, KERNEL_MAX_SIZE);
 309     if (rc < 0) {
 310         return rc;
 311     }
 312
 313     if (entry->initrd) {
 314         uint64_t iaddr = (rc + 0xfff) & ~0xfffUL;
 315
 316         strncpy(fn_ip->filename, entry->initrd, sizeof(fn_ip->filename));
 317         rc = tftp_load(fn_ip, (void *)iaddr, KERNEL_MAX_SIZE - iaddr);
 318         if (rc < 0) {
 319             return rc;
 320         }
 321         /* Patch location and size: */
 322         *(uint64_t *)0x10408 = iaddr;
 323         *(uint64_t *)0x10410 = rc;
 324         rc += iaddr;
 325     }
 326
 327     if (entry->append) {
 328         strncpy((char *)0x10480, entry->append, ARCH_COMMAND_LINE_SIZE);
 329     }
 330
 331     return rc;
 332 }
 333
 334 #define MAX_PXELINUX_ENTRIES 16
 335
 336 static int net_try_pxelinux_cfg(filename_ip_t *fn_ip)
 337 {
 338     struct pl_cfg_entry entries[MAX_PXELINUX_ENTRIES];
 339     int num_ent, def_ent = 0;
 340
 341     num_ent = pxelinux_load_parse_cfg(fn_ip, mac, get_uuid(),
 342                                       DEFAULT_TFTP_RETRIES,
 343                                       cfgbuf, sizeof(cfgbuf),
 344                                       entries, MAX_PXELINUX_ENTRIES, &def_ent);
 345     if (num_ent > 0) {
 346         return load_kernel_with_initrd(fn_ip, &entries[def_ent]);
 347     }
 348
 349     return -1;
 350 }
 351
 352 /**
 353  * Load via information from a .INS file (which can be found on CD-ROMs
 354  * for example)
 355  */
 356 static int handle_ins_cfg(filename_ip_t *fn_ip, char *cfg, int cfgsize)
 357 {
 358     char *ptr;
 359     int rc = -1, llen;
 360     void *destaddr;
 361     char *insbuf = cfg;
 362
 363     ptr = strchr(insbuf, '\n');
 364     if (!ptr) {
 365         puts("Does not seem to be a valid .INS file");
 366         return -1;
 367     }
 368
 369     *ptr = 0;
 370     printf("\nParsing .INS file:\n %s\n", &insbuf[2]);
 371
 372     insbuf = ptr + 1;
 373     while (*insbuf && insbuf < cfg + cfgsize) {
 374         ptr = strchr(insbuf, '\n');
 375         if (ptr) {
 376             *ptr = 0;
 377         }
 378         llen = strlen(insbuf);
 379         if (!llen) {
 380             insbuf = ptr + 1;
 381             continue;
 382         }
 383         ptr = strchr(insbuf, ' ');
 384         if (!ptr) {
 385             puts("Missing space separator in .INS file");
 386             return -1;
 387         }
 388         *ptr = 0;
 389         strncpy(fn_ip->filename, insbuf, sizeof(fn_ip->filename));
 390         destaddr = (char *)atol(ptr + 1);
 391         rc = tftp_load(fn_ip, destaddr, (long)_start - (long)destaddr);
 392         if (rc <= 0) {
 393             break;
 394         }
 395         insbuf += llen + 1;
 396     }
 397
 398     return rc;
 399 }
 400
 401 static int net_try_direct_tftp_load(filename_ip_t *fn_ip)
 402 {
 403     int rc;
 404     void *loadaddr = (void *)0x2000;  /* Load right after the low-core */
 405
 406     rc = tftp_load(fn_ip, loadaddr, KERNEL_MAX_SIZE - (long)loadaddr);
 407     if (rc < 0) {
 408         return rc;
 409     } else if (rc < 8) {
 410         printf("'%s' is too small (%i bytes only).\n", fn_ip->filename, rc);
 411         return -1;
 412     }
 413
 414     /* Check whether it is a configuration file instead of a kernel */
 415     if (rc < sizeof(cfgbuf) - 1) {
 416         memcpy(cfgbuf, loadaddr, rc);
 417         cfgbuf[rc] = 0;    /* Make sure that it is NUL-terminated */
 418         if (!strncmp("* ", cfgbuf, 2)) {
 419             return handle_ins_cfg(fn_ip, cfgbuf, rc);
 420         }
 421         /*
 422          * pxelinux.cfg support via bootfile name is just here for developers'
 423          * convenience (it eases testing with the built-in DHCP server of QEMU
 424          * that does not support RFC 5071). The official way to configure a
 425          * pxelinux.cfg file name is to use DHCP options 209 and 210 instead.
 426          * So only use the pxelinux.cfg parser here for files that start with
 427          * a magic comment string.
 428          */
 429         if (!strncasecmp("# pxelinux", cfgbuf, 10)) {
 430             struct pl_cfg_entry entries[MAX_PXELINUX_ENTRIES];
 431             int num_ent, def_ent = 0;
 432
 433             num_ent = pxelinux_parse_cfg(cfgbuf, sizeof(cfgbuf), entries,
 434                                          MAX_PXELINUX_ENTRIES, &def_ent);
 435             if (num_ent <= 0) {
 436                 return -1;
 437             }
 438             return load_kernel_with_initrd(fn_ip, &entries[def_ent]);
 439         }
 440     }
 441
 442     /* Move kernel to right location */
 443     memmove(KERNEL_ADDR, loadaddr, rc);
 444
 445     return rc;
 446 }
 447
 448 void panic(const char *string)
 449 {
 450     sclp_print(string);
 451     for (;;) {
 452         disabled_wait();
 453     }
 454 }
 455
 456 void write_subsystem_identification(void)
 457 {
 458     SubChannelId *schid = (SubChannelId *) 184;
 459     uint32_t *zeroes = (uint32_t *) 188;
 460
 461     *schid = net_schid;
 462     *zeroes = 0;
 463 }
 464
 465 static bool find_net_dev(Schib *schib, int dev_no)
 466 {
 467     int i, r;
 468
 469     for (i = 0; i < 0x10000; i++) {
 470         net_schid.sch_no = i;
 471         r = stsch_err(net_schid, schib);
 472         if (r == 3 || r == -EIO) {
 473             break;
 474         }
 475         if (!schib->pmcw.dnv) {
 476             continue;
 477         }
 478         if (!virtio_is_supported(net_schid)) {
 479             continue;
 480         }
 481         if (virtio_get_device_type() != VIRTIO_ID_NET) {
 482             continue;
 483         }
 484         if (dev_no < 0 || schib->pmcw.dev == dev_no) {
 485             return true;
 486         }
 487     }
 488
 489     return false;
 490 }
 491
 492 static void virtio_setup(void)
 493 {
 494     Schib schib;
 495     int ssid;
 496     bool found = false;
 497     uint16_t dev_no;
 498
 499     /*
 500      * We unconditionally enable mss support. In every sane configuration,
 501      * this will succeed; and even if it doesn't, stsch_err() can deal
 502      * with the consequences.
 503      */
 504     enable_mss_facility();
 505
 506     if (store_iplb(&iplb)) {
 507         IPL_assert(iplb.pbt == S390_IPL_TYPE_CCW, "IPL_TYPE_CCW expected");
 508         dev_no = iplb.ccw.devno;
 509         debug_print_int("device no. ", dev_no);
 510         net_schid.ssid = iplb.ccw.ssid & 0x3;
 511         debug_print_int("ssid ", net_schid.ssid);
 512         found = find_net_dev(&schib, dev_no);
 513     } else {
 514         for (ssid = 0; ssid < 0x3; ssid++) {
 515             net_schid.ssid = ssid;
 516             found = find_net_dev(&schib, -1);
 517             if (found) {
 518                 break;
 519             }
 520         }
 521     }
 522
 523     IPL_assert(found, "No virtio net device found");
 524 }
 525
 526 void main(void)
 527 {
 528     filename_ip_t fn_ip;
 529     int rc, fnlen;
 530
 531     sclp_setup();
 532     sclp_print("Network boot starting...\n");
 533
 534     virtio_setup();
 535
 536     rc = net_init(&fn_ip);
 537     if (rc) {
 538         panic("Network initialization failed. Halting.\n");
 539     }
 540
 541     fnlen = strlen(fn_ip.filename);
 542     if (fnlen > 0 && fn_ip.filename[fnlen - 1] != '/') {
 543         rc = net_try_direct_tftp_load(&fn_ip);
 544     }
 545     if (rc <= 0) {
 546         rc = net_try_pxelinux_cfg(&fn_ip);
 547     }
 548
 549     net_release(&fn_ip);
 550
 551     if (rc > 0) {
 552         sclp_print("Network loading done, starting kernel...\n");
 553         jump_to_low_kernel();
 554     }
 555
 556     panic("Failed to load OS from network\n");
 557 }