/*
* S390 virtio-ccw network boot loading program
*
* Copyright 2017 Thomas Huth, Red Hat Inc.
*
* Based on the S390 virtio-ccw loading program (main.c)
* Copyright (c) 2013 Alexander Graf <agraf@suse.de>
*
* And based on the network loading code from SLOF (netload.c)
* Copyright (c) 2004, 2008 IBM Corporation
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*/
#include <stdint.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <tftp.h>
#include <ethernet.h>
#include <dhcp.h>
#include <dhcpv6.h>
#include <ipv4.h>
#include <ipv6.h>
#include <dns.h>
#include <time.h>
#include "s390-ccw.h"
#include "virtio.h"
#define DEFAULT_BOOT_RETRIES 10
#define DEFAULT_TFTP_RETRIES 20
extern char _start[];
char stack[PAGE_SIZE * 8] __attribute__((aligned(PAGE_SIZE)));
IplParameterBlock iplb __attribute__((aligned(PAGE_SIZE)));
static SubChannelId net_schid = { .one = 1 };
static int ip_version = 4;
static uint64_t dest_timer;
static uint64_t get_timer_ms(void)
{
uint64_t clk;
asm volatile(" stck %0 " : : "Q"(clk) : "memory");
/* Bit 51 is incremented each microsecond */
return (clk >> (63 - 51)) / 1000;
}
void set_timer(int val)
{
dest_timer = get_timer_ms() + val;
}
int get_timer(void)
{
return dest_timer - get_timer_ms();
}
int get_sec_ticks(void)
{
return 1000; /* number of ticks in 1 second */
}
/**
* Obtain IP and configuration info from DHCP server (either IPv4 or IPv6).
* @param fn_ip contains the following configuration information:
* client MAC, client IP, TFTP-server MAC, TFTP-server IP,
* boot file name
* @param retries Number of DHCP attempts
* @return 0 : IP and configuration info obtained;
* non-0 : error condition occurred.
*/
static int dhcp(struct filename_ip *fn_ip, int retries)
{
int i = retries + 1;
int rc = -1;
printf(" Requesting information via DHCP: ");
dhcpv4_generate_transaction_id();
dhcpv6_generate_transaction_id();
do {
printf("\b\b\b%03d", i - 1);
if (!--i) {
printf("\nGiving up after %d DHCP requests\n", retries);
return -1;
}
ip_version = 4;
rc = dhcpv4(NULL, fn_ip);
if (rc == -1) {
ip_version = 6;
set_ipv6_address(fn_ip->fd, 0);
rc = dhcpv6(NULL, fn_ip);
if (rc == 0) {
memcpy(&fn_ip->own_ip6, get_ipv6_address(), 16);
break;
}
}
if (rc != -1) { /* either success or non-dhcp failure */
break;
}
} while (1);
printf("\b\b\b\bdone\n");
return rc;
}
/**
* Seed the random number generator with our mac and current timestamp
*/
static void seed_rng(uint8_t mac[])
{
uint64_t seed;
asm volatile(" stck %0 " : : "Q"(seed) : "memory");
seed ^= (mac[2] << 24) | (mac[3] << 16) | (mac[4] << 8) | mac[5];
srand(seed);
}
static int tftp_load(filename_ip_t *fnip, void *buffer, int len,
unsigned int retries, int ip_vers)
{
tftp_err_t tftp_err;
int rc;
rc = tftp(fnip, buffer, len, retries, &tftp_err, 1, 1428, ip_vers);
if (rc > 0) {
printf(" TFTP: Received %s (%d KBytes)\n", fnip->filename,
rc / 1024);
} else if (rc == -1) {
puts("unknown TFTP error");
} else if (rc == -2) {
printf("TFTP buffer of %d bytes is too small for %s\n",
len, fnip->filename);
} else if (rc == -3) {
printf("file not found: %s\n", fnip->filename);
} else if (rc == -4) {
puts("TFTP access violation");
} else if (rc == -5) {
puts("illegal TFTP operation");
} else if (rc == -6) {
puts("unknown TFTP transfer ID");
} else if (rc == -7) {
puts("no such TFTP user");
} else if (rc == -8) {
puts("TFTP blocksize negotiation failed");
} else if (rc == -9) {
puts("file exceeds maximum TFTP transfer size");
} else if (rc <= -10 && rc >= -15) {
const char *icmp_err_str;
switch (rc) {
case -ICMP_NET_UNREACHABLE - 10:
icmp_err_str = "net unreachable";
break;
case -ICMP_HOST_UNREACHABLE - 10:
icmp_err_str = "host unreachable";
break;
case -ICMP_PROTOCOL_UNREACHABLE - 10:
icmp_err_str = "protocol unreachable";
break;
case -ICMP_PORT_UNREACHABLE - 10:
icmp_err_str = "port unreachable";
break;
case -ICMP_FRAGMENTATION_NEEDED - 10:
icmp_err_str = "fragmentation needed and DF set";
break;
case -ICMP_SOURCE_ROUTE_FAILED - 10:
icmp_err_str = "source route failed";
break;
default:
icmp_err_str = " UNKNOWN";
break;
}
printf("ICMP ERROR \"%s\"\n", icmp_err_str);
} else if (rc == -40) {
printf("TFTP error occurred after %d bad packets received",
tftp_err.bad_tftp_packets);
} else if (rc == -41) {
printf("TFTP error occurred after missing %d responses",
tftp_err.no_packets);
} else if (rc == -42) {
printf("TFTP error missing block %d, expected block was %d",
tftp_err.blocks_missed,
tftp_err.blocks_received);
}
return rc;
}
static int net_load(char *buffer, int len)
{
filename_ip_t fn_ip;
uint8_t mac[6];
int rc;
memset(&fn_ip, 0, sizeof(filename_ip_t));
rc = virtio_net_init(mac);
if (rc < 0) {
puts("Could not initialize network device");
return -101;
}
fn_ip.fd = rc;
printf(" Using MAC address: %02x:%02x:%02x:%02x:%02x:%02x\n",
mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
set_mac_address(mac); /* init ethernet layer */
seed_rng(mac);
rc = dhcp(&fn_ip, DEFAULT_BOOT_RETRIES);
if (rc >= 0) {
if (ip_version == 4) {
set_ipv4_address(fn_ip.own_ip);
}
} else {
puts("Could not get IP address");
return -101;
}
if (ip_version == 4) {
printf(" Using IPv4 address: %d.%d.%d.%d\n",
(fn_ip.own_ip >> 24) & 0xFF, (fn_ip.own_ip >> 16) & 0xFF,
(fn_ip.own_ip >> 8) & 0xFF, fn_ip.own_ip & 0xFF);
} else if (ip_version == 6) {
char ip6_str[40];
ipv6_to_str(fn_ip.own_ip6.addr, ip6_str);
printf(" Using IPv6 address: %s\n", ip6_str);
}
if (rc == -2) {
printf("ARP request to TFTP server (%d.%d.%d.%d) failed\n",
(fn_ip.server_ip >> 24) & 0xFF, (fn_ip.server_ip >> 16) & 0xFF,
(fn_ip.server_ip >> 8) & 0xFF, fn_ip.server_ip & 0xFF);
return -102;
}
if (rc == -4 || rc == -3) {
puts("Can't obtain TFTP server IP address");
return -107;
}
if (ip_version == 4) {
printf(" Requesting file \"%s\" via TFTP from %d.%d.%d.%d\n",
fn_ip.filename,
(fn_ip.server_ip >> 24) & 0xFF, (fn_ip.server_ip >> 16) & 0xFF,
(fn_ip.server_ip >> 8) & 0xFF, fn_ip.server_ip & 0xFF);
} else if (ip_version == 6) {
char ip6_str[40];
printf(" Requesting file \"%s\" via TFTP from ", fn_ip.filename);
ipv6_to_str(fn_ip.server_ip6.addr, ip6_str);
printf("%s\n", ip6_str);
}
/* Do the TFTP load and print error message if necessary */
rc = tftp_load(&fn_ip, buffer, len, DEFAULT_TFTP_RETRIES, ip_version);
if (ip_version == 4) {
dhcp_send_release(fn_ip.fd);
}
return rc;
}
void panic(const char *string)
{
sclp_print(string);
for (;;) {
disabled_wait();
}
}
static bool find_net_dev(Schib *schib, int dev_no)
{
int i, r;
for (i = 0; i < 0x10000; i++) {
net_schid.sch_no = i;
r = stsch_err(net_schid, schib);
if (r == 3 || r == -EIO) {
break;
}
if (!schib->pmcw.dnv) {
continue;
}
if (!virtio_is_supported(net_schid)) {
continue;
}
if (virtio_get_device_type() != VIRTIO_ID_NET) {
continue;
}
if (dev_no < 0 || schib->pmcw.dev == dev_no) {
return true;
}
}
return false;
}
static void virtio_setup(void)
{
Schib schib;
int ssid;
bool found = false;
uint16_t dev_no;
/*
* We unconditionally enable mss support. In every sane configuration,
* this will succeed; and even if it doesn't, stsch_err() can deal
* with the consequences.
*/
enable_mss_facility();
if (store_iplb(&iplb)) {
IPL_assert(iplb.pbt == S390_IPL_TYPE_CCW, "IPL_TYPE_CCW expected");
dev_no = iplb.ccw.devno;
debug_print_int("device no. ", dev_no);
net_schid.ssid = iplb.ccw.ssid & 0x3;
debug_print_int("ssid ", net_schid.ssid);
found = find_net_dev(&schib, dev_no);
} else {
for (ssid = 0; ssid < 0x3; ssid++) {
net_schid.ssid = ssid;
found = find_net_dev(&schib, -1);
if (found) {
break;
}
}
}
IPL_assert(found, "No virtio net device found");
}
void main(void)
{
int rc;
sclp_setup();
sclp_print("Network boot starting...\n");
virtio_setup();
rc = net_load(NULL, (long)_start);
if (rc > 0) {
sclp_print("Network loading done, starting kernel...\n");
asm volatile (" lpsw 0(%0) " : : "r"(0) : "memory");
}
panic("Failed to load OS from network\n");
}
