nic.c

linux下从网卡远程启动

/**************************************************************************
Etherboot -  Network Bootstrap Program

Literature dealing with the network protocols:
	ARP - RFC826
	RARP - RFC903
        IP - RFC791
	UDP - RFC768
	BOOTP - RFC951, RFC2132 (vendor extensions)
	DHCP - RFC2131, RFC2132 (options)
	TFTP - RFC1350, RFC2347 (options), RFC2348 (blocksize), RFC2349 (tsize)
	RPC - RFC1831, RFC1832 (XDR), RFC1833 (rpcbind/portmapper)
	NFS - RFC1094, RFC1813 (v3, useful for clarifications, not implemented)
	IGMP - RFC1112, RFC2113, RFC2365, RFC2236, RFC3171

**************************************************************************/
#include "etherboot.h"
#include "nic.h"
#include "elf.h" /* FOR EM_CURRENT */

struct arptable_t	arptable[MAX_ARP];
#if MULTICAST_LEVEL2
unsigned long last_igmpv1 = 0;
struct igmptable_t	igmptable[MAX_IGMP];
#endif
/* Currently no other module uses rom, but it is available */
struct rom_info		rom;
static unsigned long	netmask;
/* Used by nfs.c */
char *hostname = "";
int hostnamelen = 0;
static uint32_t xid;
unsigned char *end_of_rfc1533 = NULL;
static int vendorext_isvalid;
static const unsigned char vendorext_magic[] = {0xE4,0x45,0x74,0x68}; /* 銭th */
static const unsigned char broadcast[] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
static const in_addr zeroIP = { 0L };

struct bootpd_t bootp_data;

#ifdef	NO_DHCP_SUPPORT
static unsigned char    rfc1533_cookie[5] = { RFC1533_COOKIE, RFC1533_END };
#else	/* !NO_DHCP_SUPPORT */
static int dhcp_reply;
static in_addr dhcp_server = { 0L };
static in_addr dhcp_addr = { 0L };
static unsigned char	rfc1533_cookie[] = { RFC1533_COOKIE };
#define DHCP_MACHINE_INFO_SIZE (sizeof dhcp_machine_info)
static unsigned char dhcp_machine_info[] = {
	/* Our enclosing DHCP tag */
	RFC1533_VENDOR_ETHERBOOT_ENCAP, 11,
	/* Our boot device */
	RFC1533_VENDOR_NIC_DEV_ID, 5, PCI_BUS_TYPE, 0, 0, 0, 0,
	/* Our current architecture */
	RFC1533_VENDOR_ARCH, 2, EM_CURRENT & 0xff, (EM_CURRENT >> 8) & 0xff,
#ifdef EM_CURRENT_64
	/* The 64bit version of our current architecture */
	RFC1533_VENDOR_ARCH, 2, EM_CURRENT_64 & 0xff, (EM_CURRENT_64 >> 8) & 0xff,
#undef DHCP_MACHINE_INFO_SIZE
#define DHCP_MACHINE_INFO_SIZE (sizeof(dhcp_machine_info) - (EM_CURRENT_64_PRESENT? 0: 4))
#endif /* EM_CURRENT_64 */
};
static const unsigned char dhcpdiscover[] = {
	RFC2132_MSG_TYPE,1,DHCPDISCOVER,
	RFC2132_MAX_SIZE,2,	/* request as much as we can */
	ETH_MAX_MTU / 256, ETH_MAX_MTU % 256,
	RFC2132_VENDOR_CLASS_ID,13,'E','t','h','e','r','b','o','o','t',
	'-',VERSION_MAJOR+'0','.',VERSION_MINOR+'0',
	RFC2132_PARAM_LIST,4,RFC1533_NETMASK,RFC1533_GATEWAY,
	RFC1533_HOSTNAME,RFC1533_VENDOR
};
static const unsigned char dhcprequest [] = {
	RFC2132_MSG_TYPE,1,DHCPREQUEST,
	RFC2132_SRV_ID,4,0,0,0,0,
	RFC2132_REQ_ADDR,4,0,0,0,0,
	RFC2132_MAX_SIZE,2,	/* request as much as we can */
	ETH_MAX_MTU / 256, ETH_MAX_MTU % 256,
	RFC2132_VENDOR_CLASS_ID,13,'E','t','h','e','r','b','o','o','t',
	'-',VERSION_MAJOR+'0','.',VERSION_MINOR+'0',
	/* request parameters */
	RFC2132_PARAM_LIST,
#ifdef	IMAGE_FREEBSD
	/* 5 standard + 7 vendortags + 8 motd + 16 menu items */
	5 + 7 + 8 + 16,
#else
	/* 5 standard + 6 vendortags + 8 motd + 16 menu items */
	5 + 6 + 8 + 16,
#endif
	/* Standard parameters */
	RFC1533_NETMASK, RFC1533_GATEWAY,
	RFC1533_HOSTNAME,RFC1533_VENDOR,
	RFC1533_ROOTPATH,	/* only passed to the booted image */
	/* Etherboot vendortags */
	RFC1533_VENDOR_MAGIC,
	RFC1533_VENDOR_ADDPARM,
	RFC1533_VENDOR_ETHDEV,
	RFC1533_VENDOR_ETHERBOOT_ENCAP,
#ifdef	IMAGE_FREEBSD
	RFC1533_VENDOR_HOWTO,
	RFC1533_VENDOR_KERNEL_ENV,
#endif
	RFC1533_VENDOR_MNUOPTS, RFC1533_VENDOR_SELECTION,
	/* 8 MOTD entries */
	RFC1533_VENDOR_MOTD,
	RFC1533_VENDOR_MOTD+1,
	RFC1533_VENDOR_MOTD+2,
	RFC1533_VENDOR_MOTD+3,
	RFC1533_VENDOR_MOTD+4,
	RFC1533_VENDOR_MOTD+5,
	RFC1533_VENDOR_MOTD+6,
	RFC1533_VENDOR_MOTD+7,
	/* 16 image entries */
	RFC1533_VENDOR_IMG,
	RFC1533_VENDOR_IMG+1,
	RFC1533_VENDOR_IMG+2,
	RFC1533_VENDOR_IMG+3,
	RFC1533_VENDOR_IMG+4,
	RFC1533_VENDOR_IMG+5,
	RFC1533_VENDOR_IMG+6,
	RFC1533_VENDOR_IMG+7,
	RFC1533_VENDOR_IMG+8,
	RFC1533_VENDOR_IMG+9,
	RFC1533_VENDOR_IMG+10,
	RFC1533_VENDOR_IMG+11,
	RFC1533_VENDOR_IMG+12,
	RFC1533_VENDOR_IMG+13,
	RFC1533_VENDOR_IMG+14,
	RFC1533_VENDOR_IMG+15,
};

#ifdef	REQUIRE_VCI_ETHERBOOT
int	vci_etherboot;
#endif
#endif	/* NO_DHCP_SUPPORT */

static int dummy(void *unused __unused)
{
	return (0);
}

/* Careful.  We need an aligned buffer to avoid problems on machines
 * that care about alignment.  To trivally align the ethernet data
 * (the ip hdr and arp requests) we offset the packet by 2 bytes.
 * leaving the ethernet data 16 byte aligned.  Beyond this
 * we use memmove but this makes the common cast simple and fast.
 */
static char	packet[ETH_FRAME_LEN + ETH_DATA_ALIGN] __aligned;

struct nic	nic =
{
	{
		0,				/* dev.disable */
		{
			0,
			0,
			PCI_BUS_TYPE,
		},				/* dev.devid */
		0,				/* index */
		0,				/* type */
		PROBE_FIRST,			/* how_pobe */
		PROBE_NONE,			/* to_probe */
		0,				/* failsafe */
		0,				/* type_index */
		{},				/* state */
	},
	(int (*)(struct nic *))dummy,		/* poll */
	(void (*)(struct nic *, const char *,
		unsigned int, unsigned int,
		const char *))dummy,		/* transmit */
	0,					/* flags */
	&rom,					/* rom_info */
	arptable[ARP_CLIENT].node,		/* node_addr */
	packet + ETH_DATA_ALIGN,		/* packet */
	0,					/* packetlen */
	0,					/* priv_data */
};

#ifdef RARP_NOT_BOOTP
static int rarp(void);
#else
static int bootp(void);
#endif
static unsigned short udpchksum(struct iphdr *ip, struct udphdr *udp);


int eth_probe(struct dev *dev)
{
	return probe(dev);
}

int eth_poll(void)
{
	return ((*nic.poll)(&nic));
}

void eth_transmit(const char *d, unsigned int t, unsigned int s, const void *p)
{
	(*nic.transmit)(&nic, d, t, s, p);
	if (t == IP) twiddle();
}

void eth_disable(void)
{
#ifdef MULTICAST_LEVEL2
	int i;
	for(i = 0; i < MAX_IGMP; i++) {
		leave_group(i);
	}
#endif
	disable(&nic.dev);
}

/*
 * Find out what our boot parameters are
 */
int eth_load_configuration(struct dev *dev __unused)
{
	int server_found;
	/* Find a server to get BOOTP reply from */
#ifdef	RARP_NOT_BOOTP
	printf("Searching for server (RARP)...\n");
#else
#ifndef	NO_DHCP_SUPPORT
	printf("Searching for server (DHCP)...\n");
#else
	printf("Searching for server (BOOTP)...\n");
#endif
#endif

#ifdef	RARP_NOT_BOOTP
	server_found = rarp();
#else
	server_found = bootp();
#endif
	if (!server_found) {
		printf("No Server found\n");
		longjmp(restart_etherboot, -1);
	}
	return 0;
}


/**************************************************************************
LOAD - Try to get booted
**************************************************************************/
int eth_load(struct dev *dev __unused)
{
	const char	*kernel;
	printf("Me: %@, Server: %@",
		arptable[ARP_CLIENT].ipaddr.s_addr,
		arptable[ARP_SERVER].ipaddr.s_addr);
	if (BOOTP_DATA_ADDR->bootp_reply.bp_giaddr.s_addr)
		printf(", Relay: %@",
			BOOTP_DATA_ADDR->bootp_reply.bp_giaddr.s_addr);
	if (arptable[ARP_GATEWAY].ipaddr.s_addr)
		printf(", Gateway %@", arptable[ARP_GATEWAY].ipaddr.s_addr);
	putchar('\n');

#ifdef	MDEBUG
	printf("\n=>>"); getchar();
#endif

	/* Now use TFTP to load file */
#ifdef	DOWNLOAD_PROTO_NFS
	rpc_init();
#endif
#ifdef	DEFAULT_BOOTFILE
	kernel = KERNEL_BUF[0] != '\0' ? KERNEL_BUF : DEFAULT_BOOTFILE;
#else
	kernel = KERNEL_BUF;
#endif
	loadkernel(kernel); /* We don't return except on error */
	printf("Unable to load file.\n");
	interruptible_sleep(2);		/* lay off the server for a while */
	longjmp(restart_etherboot, -1);
}


/**************************************************************************
DEFAULT_NETMASK - Return default netmask for IP address
**************************************************************************/
static inline unsigned long default_netmask(void)
{
	int net = ntohl(arptable[ARP_CLIENT].ipaddr.s_addr) >> 24;
	if (net <= 127)
		return(htonl(0xff000000));
	else if (net < 192)
		return(htonl(0xffff0000));
	else
		return(htonl(0xffffff00));
}

/**************************************************************************
IP_TRANSMIT - Send an IP datagram
**************************************************************************/
static int await_arp(int ival, void *ptr,
	unsigned short ptype, struct iphdr *ip __unused, struct udphdr *udp __unused)
{
	struct	arprequest *arpreply;
	if (ptype != ARP)
		return 0;
	if (nic.packetlen < ETH_HLEN + sizeof(struct arprequest))
		return 0;
	arpreply = (struct arprequest *)&nic.packet[ETH_HLEN];

	if (arpreply->opcode != htons(ARP_REPLY)) 
		return 0;
	if (memcmp(arpreply->sipaddr, ptr, sizeof(in_addr)) != 0)
		return 0;
	memcpy(arptable[ival].node, arpreply->shwaddr, ETH_ALEN);
	return 1;
}

int ip_transmit(int len, const void *buf)
{
	unsigned long destip;
	struct iphdr *ip;
	struct arprequest arpreq;
	int arpentry, i;
	int retry;

	ip = (struct iphdr *)buf;
	destip = ip->dest.s_addr;
	if (destip == IP_BROADCAST) {
		eth_transmit(broadcast, IP, len, buf);
#ifdef MULTICAST_LEVEL1 
	} else if ((destip & htonl(MULTICAST_MASK)) == htonl(MULTICAST_NETWORK)) {
		unsigned char multicast[6];
		unsigned long hdestip;
		hdestip = ntohl(destip);
		multicast[0] = 0x01;
		multicast[1] = 0x00;
		multicast[2] = 0x5e;
		multicast[3] = (hdestip >> 16) & 0x7;
		multicast[4] = (hdestip >> 8) & 0xff;
		multicast[5] = hdestip & 0xff;
		eth_transmit(multicast, IP, len, buf);
#endif
	} else {
		if (((destip & netmask) !=
			(arptable[ARP_CLIENT].ipaddr.s_addr & netmask)) &&
			arptable[ARP_GATEWAY].ipaddr.s_addr)
				destip = arptable[ARP_GATEWAY].ipaddr.s_addr;
		for(arpentry = 0; arpentry<MAX_ARP; arpentry++)
			if (arptable[arpentry].ipaddr.s_addr == destip) break;
		if (arpentry == MAX_ARP) {
			printf("%@ is not in my arp table!\n", destip);
			return(0);
		}
		for (i = 0; i < ETH_ALEN; i++)
			if (arptable[arpentry].node[i])
				break;
		if (i == ETH_ALEN) {	/* Need to do arp request */
			arpreq.hwtype = htons(1);
			arpreq.protocol = htons(IP);
			arpreq.hwlen = ETH_ALEN;
			arpreq.protolen = 4;
			arpreq.opcode = htons(ARP_REQUEST);
			memcpy(arpreq.shwaddr, arptable[ARP_CLIENT].node, ETH_ALEN);
			memcpy(arpreq.sipaddr, &arptable[ARP_CLIENT].ipaddr, sizeof(in_addr));
			memset(arpreq.thwaddr, 0, ETH_ALEN);
			memcpy(arpreq.tipaddr, &destip, sizeof(in_addr));
			for (retry = 1; retry <= MAX_ARP_RETRIES; retry++) {
				long timeout;
				eth_transmit(broadcast, ARP, sizeof(arpreq),
					&arpreq);
				timeout = rfc2131_sleep_interval(TIMEOUT, retry);
				if (await_reply(await_arp, arpentry,
					arpreq.tipaddr, timeout)) goto xmit;
			}
			return(0);
		}
xmit:
		eth_transmit(arptable[arpentry].node, IP, len, buf);
	}
	return 1;
}

void build_ip_hdr(unsigned long destip, int ttl, int protocol, int option_len,
	int len, const void *buf)
{
	struct iphdr *ip;
	ip = (struct iphdr *)buf;
	ip->verhdrlen = 0x45;
	ip->verhdrlen += (option_len/4);
	ip->service = 0;
	ip->len = htons(len);
	ip->ident = 0;
	ip->frags = 0; /* Should we set don't fragment? */
	ip->ttl = ttl;
	ip->protocol = protocol;
	ip->chksum = 0;
	ip->src.s_addr = arptable[ARP_CLIENT].ipaddr.s_addr;
	ip->dest.s_addr = destip;
	ip->chksum = ipchksum(buf, sizeof(struct iphdr) + option_len);
}

void build_udp_hdr(unsigned long destip, 
	unsigned int srcsock, unsigned int destsock, int ttl,
	int len, const void *buf)
{
	struct iphdr *ip;
	struct udphdr *udp;
	ip = (struct iphdr *)buf;
	build_ip_hdr(destip, ttl, IP_UDP, 0, len, buf);
	udp = (struct udphdr *)((char *)buf + sizeof(struct iphdr));
	udp->src = htons(srcsock);
	udp->dest = htons(destsock);
	udp->len = htons(len - sizeof(struct iphdr));
	udp->chksum = 0;
	if ((udp->chksum = udpchksum(ip, udp)) == 0)
		udp->chksum = 0xffff;
}


/**************************************************************************
UDP_TRANSMIT - Send an UDP datagram
**************************************************************************/
int udp_transmit(unsigned long destip, unsigned int srcsock,
	unsigned int destsock, int len, const void *buf)
{
	build_udp_hdr(destip, srcsock, destsock, 60, len, buf);
	return ip_transmit(len, buf);
}

/**************************************************************************
QDRAIN - clear the nic's receive queue
**************************************************************************/
static int await_qdrain(int ival __unused, void *ptr __unused,
	unsigned short ptype __unused, 
	struct iphdr *ip __unused, struct udphdr *udp __unused)
{
	return 0;
}