qemu/pc-bios/s390-ccw/netmain.c
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   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
  34#include "s390-ccw.h"
  35#include "virtio.h"
  36
  37#define DEFAULT_BOOT_RETRIES 10
  38#define DEFAULT_TFTP_RETRIES 20
  39
  40extern char _start[];
  41
  42char stack[PAGE_SIZE * 8] __attribute__((aligned(PAGE_SIZE)));
  43IplParameterBlock iplb __attribute__((aligned(PAGE_SIZE)));
  44
  45static SubChannelId net_schid = { .one = 1 };
  46static int ip_version = 4;
  47static uint64_t dest_timer;
  48
  49static uint64_t get_timer_ms(void)
  50{
  51    uint64_t clk;
  52
  53    asm volatile(" stck %0 " : : "Q"(clk) : "memory");
  54
  55    /* Bit 51 is incremented each microsecond */
  56    return (clk >> (63 - 51)) / 1000;
  57}
  58
  59void set_timer(int val)
  60{
  61    dest_timer = get_timer_ms() + val;
  62}
  63
  64int get_timer(void)
  65{
  66    return dest_timer - get_timer_ms();
  67}
  68
  69int get_sec_ticks(void)
  70{
  71    return 1000;    /* number of ticks in 1 second */
  72}
  73
  74/**
  75 * Obtain IP and configuration info from DHCP server (either IPv4 or IPv6).
  76 * @param  fn_ip     contains the following configuration information:
  77 *                   client MAC, client IP, TFTP-server MAC, TFTP-server IP,
  78 *                   boot file name
  79 * @param  retries   Number of DHCP attempts
  80 * @return           0 : IP and configuration info obtained;
  81 *                   non-0 : error condition occurred.
  82 */
  83static int dhcp(struct filename_ip *fn_ip, int retries)
  84{
  85    int i = retries + 1;
  86    int rc = -1;
  87
  88    printf("  Requesting information via DHCP:     ");
  89
  90    dhcpv4_generate_transaction_id();
  91    dhcpv6_generate_transaction_id();
  92
  93    do {
  94        printf("\b\b\b%03d", i - 1);
  95        if (!--i) {
  96            printf("\nGiving up after %d DHCP requests\n", retries);
  97            return -1;
  98        }
  99        ip_version = 4;
 100        rc = dhcpv4(NULL, fn_ip);
 101        if (rc == -1) {
 102            ip_version = 6;
 103            set_ipv6_address(fn_ip->fd, 0);
 104            rc = dhcpv6(NULL, fn_ip);
 105            if (rc == 0) {
 106                memcpy(&fn_ip->own_ip6, get_ipv6_address(), 16);
 107                break;
 108            }
 109        }
 110        if (rc != -1) {    /* either success or non-dhcp failure */
 111            break;
 112        }
 113    } while (1);
 114    printf("\b\b\b\bdone\n");
 115
 116    return rc;
 117}
 118
 119/**
 120 * Seed the random number generator with our mac and current timestamp
 121 */
 122static void seed_rng(uint8_t mac[])
 123{
 124    uint64_t seed;
 125
 126    asm volatile(" stck %0 " : : "Q"(seed) : "memory");
 127    seed ^= (mac[2] << 24) | (mac[3] << 16) | (mac[4] << 8) | mac[5];
 128    srand(seed);
 129}
 130
 131static int tftp_load(filename_ip_t *fnip, void *buffer, int len,
 132                     unsigned int retries, int ip_vers)
 133{
 134    tftp_err_t tftp_err;
 135    int rc;
 136
 137    rc = tftp(fnip, buffer, len, retries, &tftp_err, 1, 1428, ip_vers);
 138
 139    if (rc > 0) {
 140        printf("  TFTP: Received %s (%d KBytes)\n", fnip->filename,
 141               rc / 1024);
 142    } else if (rc == -1) {
 143        puts("unknown TFTP error");
 144    } else if (rc == -2) {
 145        printf("TFTP buffer of %d bytes is too small for %s\n",
 146            len, fnip->filename);
 147    } else if (rc == -3) {
 148        printf("file not found: %s\n", fnip->filename);
 149    } else if (rc == -4) {
 150        puts("TFTP access violation");
 151    } else if (rc == -5) {
 152        puts("illegal TFTP operation");
 153    } else if (rc == -6) {
 154        puts("unknown TFTP transfer ID");
 155    } else if (rc == -7) {
 156        puts("no such TFTP user");
 157    } else if (rc == -8) {
 158        puts("TFTP blocksize negotiation failed");
 159    } else if (rc == -9) {
 160        puts("file exceeds maximum TFTP transfer size");
 161    } else if (rc <= -10 && rc >= -15) {
 162        const char *icmp_err_str;
 163        switch (rc) {
 164        case -ICMP_NET_UNREACHABLE - 10:
 165            icmp_err_str = "net unreachable";
 166            break;
 167        case -ICMP_HOST_UNREACHABLE - 10:
 168            icmp_err_str = "host unreachable";
 169            break;
 170        case -ICMP_PROTOCOL_UNREACHABLE - 10:
 171            icmp_err_str = "protocol unreachable";
 172            break;
 173        case -ICMP_PORT_UNREACHABLE - 10:
 174            icmp_err_str = "port unreachable";
 175            break;
 176        case -ICMP_FRAGMENTATION_NEEDED - 10:
 177            icmp_err_str = "fragmentation needed and DF set";
 178            break;
 179        case -ICMP_SOURCE_ROUTE_FAILED - 10:
 180            icmp_err_str = "source route failed";
 181            break;
 182        default:
 183            icmp_err_str = " UNKNOWN";
 184            break;
 185        }
 186        printf("ICMP ERROR \"%s\"\n", icmp_err_str);
 187    } else if (rc == -40) {
 188        printf("TFTP error occurred after %d bad packets received",
 189            tftp_err.bad_tftp_packets);
 190    } else if (rc == -41) {
 191        printf("TFTP error occurred after missing %d responses",
 192            tftp_err.no_packets);
 193    } else if (rc == -42) {
 194        printf("TFTP error missing block %d, expected block was %d",
 195            tftp_err.blocks_missed,
 196            tftp_err.blocks_received);
 197    }
 198
 199    return rc;
 200}
 201
 202static int net_load(char *buffer, int len)
 203{
 204    filename_ip_t fn_ip;
 205    uint8_t mac[6];
 206    int rc;
 207
 208    memset(&fn_ip, 0, sizeof(filename_ip_t));
 209
 210    rc = virtio_net_init(mac);
 211    if (rc < 0) {
 212        puts("Could not initialize network device");
 213        return -101;
 214    }
 215    fn_ip.fd = rc;
 216
 217    printf("  Using MAC address: %02x:%02x:%02x:%02x:%02x:%02x\n",
 218           mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
 219
 220    set_mac_address(mac);    /* init ethernet layer */
 221    seed_rng(mac);
 222
 223    rc = dhcp(&fn_ip, DEFAULT_BOOT_RETRIES);
 224    if (rc >= 0) {
 225        if (ip_version == 4) {
 226            set_ipv4_address(fn_ip.own_ip);
 227        }
 228    } else {
 229        puts("Could not get IP address");
 230        return -101;
 231    }
 232
 233    if (ip_version == 4) {
 234        printf("  Using IPv4 address: %d.%d.%d.%d\n",
 235              (fn_ip.own_ip >> 24) & 0xFF, (fn_ip.own_ip >> 16) & 0xFF,
 236              (fn_ip.own_ip >>  8) & 0xFF, fn_ip.own_ip & 0xFF);
 237    } else if (ip_version == 6) {
 238        char ip6_str[40];
 239        ipv6_to_str(fn_ip.own_ip6.addr, ip6_str);
 240        printf("  Using IPv6 address: %s\n", ip6_str);
 241    }
 242
 243    if (rc == -2) {
 244        printf("ARP request to TFTP server (%d.%d.%d.%d) failed\n",
 245               (fn_ip.server_ip >> 24) & 0xFF, (fn_ip.server_ip >> 16) & 0xFF,
 246               (fn_ip.server_ip >>  8) & 0xFF, fn_ip.server_ip & 0xFF);
 247        return -102;
 248    }
 249    if (rc == -4 || rc == -3) {
 250        puts("Can't obtain TFTP server IP address");
 251        return -107;
 252    }
 253
 254    if (ip_version == 4) {
 255        printf("  Requesting file \"%s\" via TFTP from %d.%d.%d.%d\n",
 256               fn_ip.filename,
 257               (fn_ip.server_ip >> 24) & 0xFF, (fn_ip.server_ip >> 16) & 0xFF,
 258               (fn_ip.server_ip >>  8) & 0xFF, fn_ip.server_ip & 0xFF);
 259    } else if (ip_version == 6) {
 260        char ip6_str[40];
 261        printf("  Requesting file \"%s\" via TFTP from ", fn_ip.filename);
 262        ipv6_to_str(fn_ip.server_ip6.addr, ip6_str);
 263        printf("%s\n", ip6_str);
 264    }
 265
 266    /* Do the TFTP load and print error message if necessary */
 267    rc = tftp_load(&fn_ip, buffer, len, DEFAULT_TFTP_RETRIES, ip_version);
 268
 269    if (ip_version == 4) {
 270        dhcp_send_release(fn_ip.fd);
 271    }
 272
 273    return rc;
 274}
 275
 276void panic(const char *string)
 277{
 278    sclp_print(string);
 279    for (;;) {
 280        disabled_wait();
 281    }
 282}
 283
 284static bool find_net_dev(Schib *schib, int dev_no)
 285{
 286    int i, r;
 287
 288    for (i = 0; i < 0x10000; i++) {
 289        net_schid.sch_no = i;
 290        r = stsch_err(net_schid, schib);
 291        if (r == 3 || r == -EIO) {
 292            break;
 293        }
 294        if (!schib->pmcw.dnv) {
 295            continue;
 296        }
 297        if (!virtio_is_supported(net_schid)) {
 298            continue;
 299        }
 300        if (virtio_get_device_type() != VIRTIO_ID_NET) {
 301            continue;
 302        }
 303        if (dev_no < 0 || schib->pmcw.dev == dev_no) {
 304            return true;
 305        }
 306    }
 307
 308    return false;
 309}
 310
 311static void virtio_setup(void)
 312{
 313    Schib schib;
 314    int ssid;
 315    bool found = false;
 316    uint16_t dev_no;
 317
 318    /*
 319     * We unconditionally enable mss support. In every sane configuration,
 320     * this will succeed; and even if it doesn't, stsch_err() can deal
 321     * with the consequences.
 322     */
 323    enable_mss_facility();
 324
 325    if (store_iplb(&iplb)) {
 326        IPL_assert(iplb.pbt == S390_IPL_TYPE_CCW, "IPL_TYPE_CCW expected");
 327        dev_no = iplb.ccw.devno;
 328        debug_print_int("device no. ", dev_no);
 329        net_schid.ssid = iplb.ccw.ssid & 0x3;
 330        debug_print_int("ssid ", net_schid.ssid);
 331        found = find_net_dev(&schib, dev_no);
 332    } else {
 333        for (ssid = 0; ssid < 0x3; ssid++) {
 334            net_schid.ssid = ssid;
 335            found = find_net_dev(&schib, -1);
 336            if (found) {
 337                break;
 338            }
 339        }
 340    }
 341
 342    IPL_assert(found, "No virtio net device found");
 343}
 344
 345void main(void)
 346{
 347    int rc;
 348
 349    sclp_setup();
 350    sclp_print("Network boot starting...\n");
 351
 352    virtio_setup();
 353
 354    rc = net_load(NULL, (long)_start);
 355    if (rc > 0) {
 356        sclp_print("Network loading done, starting kernel...\n");
 357        asm volatile (" lpsw 0(%0) " : : "r"(0) : "memory");
 358    }
 359
 360    panic("Failed to load OS from network\n");
 361}
 362