pc-bios/s390-ccw: Link libnet into the netboot image and do the TFTP load

Most of the code has been taken from SLOF's netload.c file. Now we
can finally load an image via TFTP and execute the downloaded kernel.

Acked-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <1499863793-18627-12-git-send-email-thuth@redhat.com>
Tested-by: Viktor Mihajlovski <mihajlov@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

2 files changed, 238 insertions, 1 deletions

diff --git a/pc-bios/s390-ccw/netboot.mak b/pc-bios/s390-ccw/netboot.mak
index eb7043095b..a9e1374e97 100644
--- a/pc-bios/s390-ccw/netboot.mak
+++ b/pc-bios/s390-ccw/netboot.mak
@@ -1,7 +1,7 @@
 
 SLOF_DIR := $(SRC_PATH)/roms/SLOF
 
-NETOBJS := start.o sclp.o virtio.o virtio-net.o netmain.o libc.a
+NETOBJS := start.o sclp.o virtio.o virtio-net.o netmain.o libnet.a libc.a
 
 LIBC_INC := -nostdinc -I$(SLOF_DIR)/lib/libc/include
 LIBNET_INC := -I$(SLOF_DIR)/lib/libnet
@@ -45,3 +45,15 @@ LIBCOBJS := $(STRING_OBJS) $(CTYPE_OBJS) $(STDLIB_OBJS) $(STDIO_OBJS) sbrk.o
 
 libc.a: $(LIBCOBJS)
 	$(call quiet-command,$(AR) -rc $@ $^,"AR","$(TARGET_DIR)$@")
+
+# libnet files:
+
+LIBNETOBJS := args.o dhcp.o dns.o icmpv6.o ipv6.o tcp.o udp.o bootp.o \
+	      dhcpv6.o ethernet.o ipv4.o ndp.o tftp.o
+LIBNETCFLAGS := $(QEMU_CFLAGS) $(LIBC_INC) $(LIBNET_INC)
+
+%.o : $(SLOF_DIR)/lib/libnet/%.c
+	$(call quiet-command,$(CC) $(LIBNETCFLAGS) -c -o $@ $<,"CC","$(TARGET_DIR)$@")
+
+libnet.a: $(LIBNETOBJS)
+	$(call quiet-command,$(AR) -rc $@ $^,"AR","$(TARGET_DIR)$@")
diff --git a/pc-bios/s390-ccw/netmain.c b/pc-bios/s390-ccw/netmain.c
index a69b3dd181..d86d46b03f 100644
--- a/pc-bios/s390-ccw/netmain.c
+++ b/pc-bios/s390-ccw/netmain.c
@@ -6,6 +6,9 @@
  * 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
@@ -18,17 +21,29 @@
 #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)
@@ -56,6 +71,208 @@ 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);
@@ -127,10 +344,18 @@ static void virtio_setup(void)
 
 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");
 }