nfsroot.c

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	oldfs = get_fs();
	set_fs(get_ds());
	iov.iov_base = buf;
	iov.iov_len = size;
	msg.msg_name = NULL;
	msg.msg_iov = &iov;
	msg.msg_iovlen = 1;
	msg.msg_control = NULL;
	result = sock->ops->sendmsg(sock, &msg, size, 0, 0);
	set_fs(oldfs);
	return (result != size);
}


/*
 *  Try to receive UDP packet.
 */
static inline int root_recv_udp(struct socket *sock, void *buf, int size)
{
	u32 oldfs;
	int result;
	struct msghdr msg;
	struct iovec iov;

	oldfs = get_fs();
	set_fs(get_ds());
	iov.iov_base = buf;
	iov.iov_len = size;
	msg.msg_name = NULL;
	msg.msg_iov = &iov;
	msg.msg_iovlen = 1;
	msg.msg_control = NULL;
	msg.msg_namelen = 0;
	result = sock->ops->recvmsg(sock, &msg, size, O_NONBLOCK, 0, &msg.msg_namelen);
	set_fs(oldfs);
	return result;
}


/*
 *  Initialize BOOTP extension fields in the request.
 */
static void root_bootp_init_ext(u8 *e)
{
	*e++ = 99;		/* RFC1048 Magic Cookie */
	*e++ = 130;
	*e++ = 83;
	*e++ = 99;
	*e++ = 1;		/* Subnet mask request */
	*e++ = 4;
	e += 4;
	*e++ = 3;		/* Default gateway request */
	*e++ = 4;
	e += 4;
	*e++ = 12;		/* Host name request */
	*e++ = 32;
	e += 32;
	*e++ = 40;		/* NIS Domain name request */
	*e++ = 32;
	e += 32;
	*e++ = 17;		/* Boot path */
	*e++ = 32;
	e += 32;
	*e = 255;		/* End of the list */
}


/*
 *  Deinitialize the BOOTP mechanism.
 */
static void root_bootp_close(void)
{
	if (bootp_xmit_fd != -1)
		sys_close(bootp_xmit_fd);
	if (bootp_recv_fd != -1)
		sys_close(bootp_recv_fd);
	root_del_bootp_route();
	root_free_bootp();
}


/*
 *  Initialize the BOOTP mechanism.
 */
static int root_bootp_open(void)
{
	struct open_dev *openp;
	struct device *dev, *best_dev;

	/*
	 * Select the best interface for BOOTP. We try to select a first
	 * Ethernet-like interface. It's shame I know no simple way how to send
	 * BOOTP's to all interfaces, but it doesn't apply to usual diskless
	 * stations as they don't have multiple interfaces.
	 */

	best_dev = NULL;
	for (openp = open_base; openp != NULL; openp = openp->next) {
		dev = openp->dev;
		if (dev->flags & IFF_BROADCAST) {
			if (!best_dev ||
			   ((best_dev->flags & IFF_NOARP) && !(dev->flags & IFF_NOARP)))
				best_dev = dev;
			}
		}

	if (!best_dev) {
		printk(KERN_ERR "BOOTP: This cannot happen!\n");
		return -1;
	}
	bootp_dev = best_dev;

	/* Allocate memory for BOOTP packets */
	if (root_alloc_bootp())
		return -1;

	/* Construct BOOTP request */
	memset(xmit_bootp, 0, sizeof(struct bootp_pkt));
	xmit_bootp->op = BOOTP_REQUEST;
	get_random_bytes(&xmit_bootp->xid, sizeof(xmit_bootp->xid));
	xmit_bootp->htype = best_dev->type;
	xmit_bootp->hlen = best_dev->addr_len;
	memcpy(xmit_bootp->hw_addr, best_dev->dev_addr, best_dev->addr_len);
	root_bootp_init_ext(xmit_bootp->vendor_area);
#ifdef NFSROOT_BOOTP_DEBUG
	{
		int x;
		printk(KERN_NOTICE "BOOTP: XID=%08x, DE=%s, HT=%02x, HL=%02x, HA=",
			xmit_bootp->xid,
			best_dev->name,
			xmit_bootp->htype,
			xmit_bootp->hlen);
		for(x=0; x<xmit_bootp->hlen; x++)
			printk("%02x", xmit_bootp->hw_addr[x]);
		printk("\n");
	}
#endif

	/* Create default route to that interface */
	if (root_add_bootp_route())
		return -1;

	/* Open the sockets */
	if (root_open_udp_sock(&bootp_xmit_fd, &bootp_xmit_sock) ||
	    root_open_udp_sock(&bootp_recv_fd, &bootp_recv_sock))
		return -1;

	/* Bind/connect the sockets */
	((struct sock *) bootp_xmit_sock->data) -> broadcast = 1;
	((struct sock *) bootp_xmit_sock->data) -> reuse = 1;
	((struct sock *) bootp_recv_sock->data) -> reuse = 1;
	if (root_bind_udp_sock(bootp_recv_sock, INADDR_ANY, 68) ||
	    root_bind_udp_sock(bootp_xmit_sock, INADDR_ANY, 68) ||
	    root_connect_udp_sock(bootp_xmit_sock, INADDR_BROADCAST, 67))
		return -1;

	return 0;
}


/*
 *  Send BOOTP request.
 */
static int root_bootp_send(u32 jiffies)
{
	xmit_bootp->secs = htons(jiffies / HZ);
	return root_send_udp(bootp_xmit_sock, xmit_bootp, sizeof(struct bootp_pkt));
}


/*
 *  Copy BOOTP-supplied string if not already set.
 */
static int root_bootp_string(char *dest, char *src, int len, int max)
{
	if (*dest || !len)
		return 0;
	if (len > max-1)
		len = max-1;
	strncpy(dest, src, len);
	dest[len] = '\0';
	return 1;
}


/*
 *  Process BOOTP extension.
 */
static void root_do_bootp_ext(u8 *ext)
{
#ifdef NFSROOT_BOOTP_DEBUG
	u8 *c;

	printk("BOOTP: Got extension %02x",*ext);
	for(c=ext+2; c<ext+2+ext[1]; c++)
		printk(" %02x", *c);
	printk("\n");
#endif

	switch (*ext++) {
		case 1:		/* Subnet mask */
			if (netmask.sin_addr.s_addr == INADDR_NONE)
				memcpy(&netmask.sin_addr.s_addr, ext+1, 4);
			break;
		case 3:		/* Default gateway */
			if (gateway.sin_addr.s_addr == INADDR_NONE)
				memcpy(&gateway.sin_addr.s_addr, ext+1, 4);
			break;
		case 12:	/* Host name */
			root_bootp_string(system_utsname.nodename, ext+1, *ext, __NEW_UTS_LEN);
			break;
		case 40:	/* NIS Domain name */
			root_bootp_string(system_utsname.domainname, ext+1, *ext, __NEW_UTS_LEN);
			break;
		case 17:	/* Root path */
			root_bootp_string(nfs_path, ext+1, *ext, NFS_MAXPATHLEN);
			break;
	}
}


/*
 *  Receive BOOTP request.
 */
static void root_bootp_recv(void)
{
	int len;
	u8 *ext, *end, *opt;

	len = root_recv_udp(bootp_recv_sock, recv_bootp, sizeof(struct bootp_pkt));
	if (len < 0)
		return;

	/* Check consistency of incoming packet */
	if (len < 300 ||			/* See RFC 1542:2.1 */
	    recv_bootp->op != BOOTP_REPLY ||
	    recv_bootp->htype != xmit_bootp->htype ||
	    recv_bootp->hlen != xmit_bootp->hlen ||
	    recv_bootp->xid != xmit_bootp->xid) {
#ifdef NFSROOT_BOOTP_DEBUG
		printk("?");
#endif
		return;
		}

	/* Record BOOTP packet arrival in the global variables */
	cli();
	if (pkt_arrived) {
		sti();
		return;
	}
	pkt_arrived = ARRIVED_BOOTP;
	sti();
	root_dev = bootp_dev;

	/* Extract basic fields */
	myaddr.sin_addr.s_addr = recv_bootp->your_ip;
	if (server.sin_addr.s_addr==INADDR_NONE)
		server.sin_addr.s_addr = recv_bootp->server_ip;

	/* Parse extensions */
	if (recv_bootp->vendor_area[0] == 99 &&	/* Check magic cookie */
	    recv_bootp->vendor_area[1] == 130 &&
	    recv_bootp->vendor_area[2] == 83 &&
	    recv_bootp->vendor_area[3] == 99) {
		ext = &recv_bootp->vendor_area[4];
		end = (u8 *) recv_bootp + len;
		while (ext < end && *ext != 255) {
			if (*ext == 0)		/* Padding */
				ext++;
			else {
				opt = ext;
				ext += ext[1] + 2;
				if (ext <= end)
					root_do_bootp_ext(opt);
			}
		}
	}
}
#endif



/***************************************************************************

			Dynamic configuration of IP.

 ***************************************************************************/

#ifdef CONFIG_RNFS_DYNAMIC

/*
 *  Determine client and server IP numbers and appropriate device by using
 *  the RARP and BOOTP protocols.
 */
static int root_auto_config(void)
{
	int retries;
	unsigned long timeout, jiff;
	unsigned long start_jiffies;

	/*
	 * If neither BOOTP nor RARP was selected, return with an error. This
	 * routine gets only called when some pieces of information are mis-
	 * sing, and without BOOTP and RARP we are not able to get that in-
	 * formation.
	 */
	if (!bootp_flag && !rarp_flag) {
		printk(KERN_ERR "Root-NFS: Neither RARP nor BOOTP selected.\n");
		return -1;
	}

#ifdef CONFIG_RNFS_BOOTP
	if (bootp_flag && !bootp_dev_count) {
		printk(KERN_ERR "Root-NFS: No suitable device for BOOTP found.\n");
		bootp_flag = 0;
	}
#else
	bootp_flag = 0;
#endif

#ifdef CONFIG_RNFS_RARP
	if (rarp_flag && !rarp_dev_count) {
		printk(KERN_ERR "Root-NFS: No suitable device for RARP found.\n");
		rarp_flag = 0;
	}
#else
	rarp_flag = 0;
#endif

	if (!bootp_flag && !rarp_flag)
		/* Error message already printed */
		return -1;

	/*
	 * Setup RARP and BOOTP protocols
	 */
#ifdef CONFIG_RNFS_RARP
	if (rarp_flag)
		root_rarp_open();
#endif
#ifdef CONFIG_RNFS_BOOTP
	if (bootp_flag && root_bootp_open() < 0) {
		root_bootp_close();
		return -1;
	}
#endif

	/*
	 * Send requests and wait, until we get an answer. This loop
	 * seems to be a terrible waste of CPU time, but actually there is
	 * only one process running at all, so we don't need to use any
	 * scheduler functions.
	 * [Actually we could now, but the nothing else running note still 
	 *  applies.. - AC]
	 */
	printk(KERN_NOTICE "Sending %s%s%s requests...",
		bootp_flag ? "BOOTP" : "",
		bootp_flag && rarp_flag ? " and " : "",
		rarp_flag ? "RARP" : "");
	start_jiffies = jiffies;
	retries = CONF_RETRIES;
	get_random_bytes(&timeout, sizeof(timeout));
	timeout = CONF_BASE_TIMEOUT + (timeout % (unsigned) CONF_TIMEOUT_RANDOM);
	for(;;) {
#ifdef CONFIG_RNFS_BOOTP
		if (bootp_flag && root_bootp_send(jiffies - start_jiffies) < 0) {
			printk(" BOOTP failed!\n");
			root_bootp_close();
			bootp_flag = 0;
			if (!rarp_flag)
				break;
		}
#endif
#ifdef CONFIG_RNFS_RARP
		if (rarp_flag)
			root_rarp_send();
#endif
		printk(".");
		jiff = jiffies + timeout;
		while (jiffies < jiff && !pkt_arrived)
#ifdef CONFIG_RNFS_BOOTP
			root_bootp_recv();
#else
			;
#endif
		if (pkt_arrived)
			break;
		if (! --retries) {
			printk(" timed out!\n");
			break;
		}
		timeout = timeout CONF_TIMEOUT_MULT;
		if (timeout > CONF_TIMEOUT_MAX)
			timeout = CONF_TIMEOUT_MAX;
	}

#ifdef CONFIG_RNFS_RARP
	if (rarp_flag)
		root_rarp_close();
#endif
#ifdef CONFIG_RNFS_BOOTP
	if (bootp_flag)
		root_bootp_close();
#endif

	if (!pkt_arrived)
		return -1;

	printk(" OK\n");
	printk(KERN_NOTICE "Root-NFS: Got %s answer from %s, ",
		(pkt_arrived == ARRIVED_BOOTP) ? "BOOTP" : "RARP",
		in_ntoa(server.sin_addr.s_addr));
	printk("my address is %s\n", in_ntoa(myaddr.sin_addr.s_addr));

	return 0;
}
#endif



/***************************************************************************

			     Parsing of options

 ***************************************************************************/


/*
 *  The following integer options are recognized
 */
static struct nfs_int_opts {
	char *name;
	int  *val;
} root_int_opts[] = {
	{ "port",	&nfs_port },
	{ "rsize",	&nfs_data.rsize },
	{ "wsize",	&nfs_data.wsize },
	{ "timeo",	&nfs_data.timeo },
	{ "retrans",	&nfs_data.retrans },
	{ "acregmin",	&nfs_data.acregmin },
	{ "acregmax",	&nfs_data.acregmax },
	{ "acdirmin",	&nfs_data.acdirmin },
	{ "acdirmax",	&nfs_data.acdirmax },
	{ NULL,		NULL }
};


/*
 *  And now the flag options
 */
static struct nfs_bool_opts {
	char *name;
	int  and_mask;
	int  or_mask;
} root_bool_opts[] = {
	{ "soft",	~NFS_MOUNT_SOFT,	NFS_MOUNT_SOFT },
	{ "hard",	~NFS_MOUNT_SOFT,	0 },
	{ "intr",	~NFS_MOUNT_INTR,	NFS_MOUNT_INTR },
	{ "nointr",	~NFS_MOUNT_INTR,	0 },
	{ "posix",	~NFS_MOUNT_POSIX,	NFS_MOUNT_POSIX },
	{ "noposix",	~NFS_MOUNT_POSIX,	0 },
	{ "cto",	~NFS_MOUNT_NOCTO,	0 },
	{ "nocto",	~NFS_MOUNT_NOCTO,	NFS_MOUNT_NOCTO },
	{ "ac",		~NFS_MOUNT_NOAC,	0 },
	{ "noac",	~NFS_MOUNT_NOAC,	NFS_MOUNT_NOAC },
	{ NULL,		0,			0 }
};


/*
 *  Prepare the NFS data structure and parse any options. This tries to
 *  set as many values in the nfs_data structure as known right now.
 */
static int root_nfs_name(char *name)
{
	char buf[NFS_MAXPATHLEN];
	char *cp, *cq, *options, *val;
	int octets = 0;

	/* It is possible to override the server IP number here */
	cp = cq = name;
	while (octets < 4) {
		while (*cp >= '0' && *cp <= '9')
			cp++;
		if (cp == cq || cp - cq > 3)
			break;
		if (*cp == '.' || octets == 3)
			octets++;
		if (octets < 4)
			cp++;
		cq = cp;
	}
	if (octets == 4 && (*cp == ':' || *cp == '\0')) {
		if (*cp == ':')
			*cp++ = '\0';
		server.sin_addr.s_addr = in_aton(name);
		name = cp;
	}

	/* Clear the nfs_data structure and setup the server hostname */
	memset(&nfs_data, 0, sizeof(nfs_data));
	strncpy(nfs_data.hostname, in_ntoa(server.sin_addr.s_addr),
						sizeof(nfs_data.hostname)-1);

	/* Set the name of the directory to mount */
	if (nfs_path[0] == '\0' || strncmp(name, "default", 7))
		strncpy(buf, name, NFS_MAXPATHLEN);
	else
		strncpy(buf, nfs_path, NFS_MAXPATHLEN);
	if ((options = strchr(buf, ',')))
		*options++ = '\0';
	if (!strcmp(buf, "default"))
		strcpy(buf, NFS_ROOT);
	cp = in_ntoa(myaddr.sin_addr.s_addr);
	if (strlen(buf) + strlen(cp) > NFS_MAXPATHLEN) {
		printk(KERN_ERR "Root-NFS: Pathname for remote directory too long.\n");
		return -1;
	}
	/* update nfs_path with path from nfsroot=... command line parameter */
	if (*buf)
		sprintf(nfs_path, buf, cp);

	/* Set some default values */
	nfs_port          = -1;
	nfs_data.version  = NFS_MOUNT_VERSION;
	nfs_data.flags    = 0;
	nfs_data.rsize    = NFS_DEF_FILE_IO_BUFFER_SIZE;
	nfs_data.wsize    = NFS_DEF_FILE_IO_BUFFER_SIZE;
	nfs_data.timeo    = 7;
	nfs_data.retrans  = 3;
	nfs_data.acregmin = 3;
	nfs_data.acregmax = 60;
	nfs_data.acdirmin = 30;
	nfs_data.acdirmax = 60;

	/* Process any options */
	if (options) {
		cp = strtok(options, ",");
		while (cp) {
			if ((val = strchr(cp, '='))) {
				struct nfs_int_opts *opts = root_int_opts;
				*val++ = '\0';
				while (opts->name && strcmp(opts->name, cp))
					opts++;
				if (opts->name)
					*(opts->val) = (int) simple_strtoul(val, NULL, 10);
			} else {
				struct nfs_bool_opts *opts = root_bool_opts;
				while (opts->name && strcmp(opts->name, cp))
					opts++;
				if (opts->name) {
					nfs_data.flags &= opts->and_mask;
					nfs_data.flags |= opts->or_mask;
				}
			}
			cp = strtok(NULL, ",");
		}
	}
	return 0;
}


/*
 *  Tell the user what's going on.
 */
#ifdef NFSROOT_DEBUG
static void root_nfs_print(void)
{
#define IN_NTOA(x) (((x) == INADDR_NONE) ? "none" : in_ntoa(x))

	printk(KERN_NOTICE "Root-NFS: IP config: dev=%s, ",
		root_dev ? root_dev->name : "none");