[apple/xnu.git] / bsd / nfs / nfs_boot.c

/*
 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 * 
 * This Original Code and all software distributed under the License are
 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/* Copyright (c) 1995, 1997 NeXT Computer, Inc. All Rights Reserved */
/*
 * Copyright (c) 1994 Adam Glass, Gordon Ross
 * All rights reserved.
 *
 * This software was developed by the Computer Systems Engineering group
 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
 * contributed to Berkeley.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Lawrence Berkeley Laboratory and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *  History:
 *  14-March-97 Dieter Siegmund (dieter@next.com)
 *      - Use BOOTP instead of RARP to get the IP address at boot time
 *
 *  23-May-97  Umesh Vaishampayan  (umeshv@apple.com)
 *      - Added the ability to mount "/private" separately.
 *
 *  30-May-97   Dieter Siegmund (dieter@next.com)
 *      - Clear out the ireq structure before using it to prevent
 *        our sending using a bogus source IP address, we should use
 *        an IP address of all zeroes
 *      - Right after BOOTP, get the correct netmask using AUTONETMASK
 *  18-Jul-97   Dieter Siegmund (dieter@apple.com)
 *      - we can't restrict the netmask until we have a default route,
 *        removed AUTONETMASK call (ifdef'd out)
 *  5-Aug-97    Dieter Siegmund (dieter@apple.com)
 *      - use the default route from the bpwhoami call, enabled autonetmask
 *        again
 *  19-Feb-1999 Dieter Siegmund (dieter@apple.com)
 *      - use new BOOTP routine to get the subnet mask and router
 *        and stop using SIOCAUTOADDR
 *      - don't bother mounting private separately if it's not
 *        specified or not required because they are substrings of
 *        one another ie. root=host:/A and private=host:/A/private
 *      - allow the root path to be specified in the boot variable
 *        "rp" (AKA "rootpath")
 *  19-Jul-1999 Dieter Siegmund (dieter@apple.com)
 *      - replaced big automatic arrays with MALLOC'd data
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/conf.h>
#include <sys/ioctl.h>
#include <sys/proc.h>
#include <sys/mount.h>
#include <sys/mbuf.h>

#include <sys/malloc.h>
#include <sys/socket.h>
#include <sys/reboot.h>

#include <net/if.h>
#include <net/if_dl.h>
#include <net/if_types.h>
#include <net/route.h>

#include <netinet/in.h>
#include <netinet/if_ether.h>

#include <nfs/rpcv2.h>
#include <nfs/nfsproto.h>
#include <nfs/nfs.h>
#include <nfs/nfsdiskless.h>
#include <nfs/krpc.h>

#include <pexpert/pexpert.h>

#include "ether.h"

#include <libkern/libkern.h>

extern char *strchr(const char *str, int ch);

#if NETHER == 0

int nfs_boot_init(nd, procp)
        struct nfs_diskless *nd;
        struct proc *procp;
{
        panic("nfs_boot_init: no ether");
}

#else /* NETHER */

/*
 * Support for NFS diskless booting, specifically getting information
 * about where to boot from, what pathnames, etc.
 *
 * This implememtation uses RARP and the bootparam RPC.
 * We are forced to implement RPC anyway (to get file handles)
 * so we might as well take advantage of it for bootparam too.
 *
 * The diskless boot sequence goes as follows:
 * (1) Use RARP to get our interface address
 * (2) Use RPC/bootparam/whoami to get our hostname,
 *     our IP address, and the server's IP address.
 * (3) Use RPC/bootparam/getfile to get the root path
 * (4) Use RPC/mountd to get the root file handle
 * (5) Use RPC/bootparam/getfile to get the swap path
 * (6) Use RPC/mountd to get the swap file handle
 *
 * (This happens to be the way Sun does it too.)
 */

extern int bootp(struct ifnet * ifp, struct in_addr * iaddr_p, int max_retry,
                 struct in_addr * netmask_p, struct in_addr * router_p,
                 struct proc * procp);

/* bootparam RPC */
static int bp_whoami __P((struct sockaddr_in *bpsin,
        struct in_addr *my_ip, struct in_addr *gw_ip));
static int bp_getfile __P((struct sockaddr_in *bpsin, char *key,
        struct sockaddr_in *mdsin, char *servname, char *path));

static boolean_t path_getfile __P((char * image_path, 
                                   struct sockaddr_in * sin_p, 
                                   char * serv_name, char * pathname));

static __inline__
u_long iptohl(struct in_addr ip)
{
    return (ntohl(ip.s_addr));
}

static __inline__ boolean_t
same_subnet(struct in_addr addr1, struct in_addr addr2, struct in_addr mask)
{
    u_long m = iptohl(mask);
    if ((iptohl(addr1) & m) != (iptohl(addr2) & m))
        return (FALSE);
    return (TRUE);
}

/* mountd RPC */
static int md_mount __P((struct sockaddr_in *mdsin, char *path,
        u_char *fh));

/* other helpers */
static void get_file_handle __P((char *pathname, struct nfs_dlmount *ndmntp));

#define IP_FORMAT       "%d.%d.%d.%d"
#define IP_CH(ip)       ((u_char *)ip)
#define IP_LIST(ip)     IP_CH(ip)[0],IP_CH(ip)[1],IP_CH(ip)[2],IP_CH(ip)[3]
/*
 * Called with an empty nfs_diskless struct to be filled in.
 */
int
nfs_boot_init(nd, procp)
        struct nfs_diskless *nd;
        struct proc *procp;
{
        char *          booter_path = NULL;
        boolean_t       do_bpwhoami = TRUE;
        boolean_t       do_bpgetfile = TRUE;
        struct ifreq ireq;
        struct in_addr my_ip;
        struct sockaddr_in bp_sin;
        struct sockaddr_in *sin;
        struct ifnet *ifp;
        struct in_addr gw_ip;
        struct socket *so;
        struct in_addr my_netmask;
        int error;
        char *          root_path = NULL;

        MALLOC(booter_path, char *, MAXPATHLEN, M_TEMP, M_WAITOK);
        MALLOC(root_path, char *, MAXPATHLEN, M_TEMP, M_WAITOK);

        /* booter-supplied path */
        if (!PE_parse_boot_arg("rp", booter_path)
            && !PE_parse_boot_arg("rootpath", booter_path)) {
            booter_path[0] = 0;
        }

        root_path[0] = 0;

        gw_ip.s_addr = 0;

        /* clear out the request structure */
        bzero(&ireq, sizeof(ireq));

        /*
         * Find an interface, rarp for its ip address, stuff it, the
         * implied broadcast addr, and netmask into a nfs_diskless struct.
         *
         * This was moved here from nfs_vfsops.c because this procedure
         * would be quite different if someone decides to write (i.e.) a
         * BOOTP version of this file (might not use RARP, etc.)
         */

        thread_funnel_switch(KERNEL_FUNNEL, NETWORK_FUNNEL);

        /*
         * Find a network interface.
         */
        ifp = NULL;
        { /* if the root device is set, use it */
            extern char rootdevice[];
            if (rootdevice[0])
                ifp = ifunit(rootdevice);
        }
        if (ifp == NULL) { /* search for network device */
                /* for (ifp = ifnet; ifp; ifp = ifp->if_next)*/
                TAILQ_FOREACH(ifp, &ifnet, if_link)
                        if ((ifp->if_flags &
                             (IFF_LOOPBACK|IFF_POINTOPOINT)) == 0)
                                break;
        }
        if (ifp == NULL)
                panic("nfs_boot: no suitable interface");
        sprintf(ireq.ifr_name, "%s%d", ifp->if_name, ifp->if_unit);
        printf("nfs_boot: using network interface '%s'\n", ireq.ifr_name);

        /*
         * Bring up the interface.
         */
        if ((error = socreate(AF_INET, &so, SOCK_DGRAM, 0)) != 0)
                panic("nfs_boot: socreate, error=%d", error);
        ireq.ifr_flags = ifp->if_flags | IFF_UP;
        error = ifioctl(so, SIOCSIFFLAGS, (caddr_t)&ireq, procp);
        if (error)
                panic("nfs_boot: SIFFLAGS, error=%d", error);

#define DO_BOOTP
#ifdef DO_BOOTP
        { /* use BOOTP to retrieve IP address, netmask and router */
            struct sockaddr_in          sockin;
            struct in_addr              router;
            struct in_addr              netmask;
            
            my_ip.s_addr = 0;
            netmask.s_addr = 0;
            router.s_addr = 0;
            sockin.sin_family = AF_INET;
            sockin.sin_len = sizeof(sockin);
            sockin.sin_addr.s_addr = 0;
#define RETRY_COUNT     32
            while ((error = bootp(ifp, &my_ip, RETRY_COUNT,
                                  &netmask, &router, procp))) {
                if (error == ETIMEDOUT)
                    printf("nfs_boot: BOOTP timed out, retrying...\n");

                else {
                    printf("nfs_boot: bootp() failed, error = %d\n", error);
                    panic("nfs_boot");
                }
            }
            /* clear the netmask */
            ((struct sockaddr_in *)&ireq.ifr_addr)->sin_addr.s_addr = 0;
            error = ifioctl(so, SIOCSIFNETMASK, (caddr_t)&ireq, procp);
            if (error)
                printf("nfs_boot: SIOCSIFNETMASK failed: %d\n", error);

            if (netmask.s_addr) { 
                /* set our new subnet mask */
                sockin.sin_addr = netmask;
                *((struct sockaddr_in *)&ireq.ifr_addr) = sockin;
                error = ifioctl(so, SIOCSIFNETMASK, (caddr_t)&ireq, procp);
                if (error)
                    printf("nfs_boot: SIOCSIFNETMASK failed: %d\n", error);
            }

            /* set our address */
            sockin.sin_addr = my_ip;
            *((struct sockaddr_in *)&ireq.ifr_addr) = sockin;
            error = ifioctl(so, SIOCSIFADDR, (caddr_t)&ireq, procp);
            if (error) {
                printf("SIOCSIFADDR failed: %d\n", error);
                panic("nfs_boot.c");
            }
            printf("nfs_boot: IP address " IP_FORMAT, IP_LIST(&my_ip));
            if (netmask.s_addr)
                printf(" netmask " IP_FORMAT, IP_LIST(&netmask));
            if (router.s_addr) {
                gw_ip = router;
                printf(" router " IP_FORMAT, IP_LIST(&router));
            }
            printf("\n");
        }
#else
        /*
         * Do RARP for the interface address.
         */
        if ((error = revarpwhoami(&my_ip, ifp)) != 0)
                panic("revarp failed, error=%d", error);
        printf("nfs_boot: client_addr=0x%x\n", ntohl(my_ip.s_addr));

        /*
         * Do enough of ifconfig(8) so that the chosen interface
         * can talk to the servers.  (just set the address)
         */
        sin = (struct sockaddr_in *)&ireq.ifr_addr;
        bzero((caddr_t)sin, sizeof(*sin));
        sin->sin_len = sizeof(*sin);
        sin->sin_family = AF_INET;
        sin->sin_addr.s_addr = my_ip.s_addr;
        error = ifioctl(so, SIOCSIFADDR, (caddr_t)&ireq, procp);
        if (error)
                panic("nfs_boot: set if addr, error=%d", error);
#endif DO_BOOTP

        /* need netmask to determine whether NFS server local */
        sin = (struct sockaddr_in *)&ireq.ifr_addr;
        bzero((caddr_t)sin, sizeof(*sin));
        sin->sin_len = sizeof(*sin);
        sin->sin_family = AF_INET;
        error = ifioctl(so, SIOCGIFNETMASK, (caddr_t)&ireq, procp);
        if (error)
            panic("nfs_boot: SIOCGIFNETMASK error=%d", error);
        my_netmask = sin->sin_addr;

        soclose(so);

        /* check for a booter-specified path */
        if (booter_path[0]) {
            nd->nd_root.ndm_saddr.sin_addr.s_addr = 0;
            nd->nd_private.ndm_saddr.sin_addr.s_addr = 0;
            if (path_getfile(booter_path, &nd->nd_root.ndm_saddr,
                             nd->nd_root.ndm_host, root_path)) {
                do_bpgetfile = FALSE;
                printf("nfs_boot: using booter-supplied path '%s'\n",
                       booter_path);
                if (same_subnet(nd->nd_root.ndm_saddr.sin_addr,
                                my_ip, my_netmask)
                    || gw_ip.s_addr) {
                    do_bpwhoami = FALSE;
                }
                else {
                    /* do bpwhoami to attempt to get the router */
                }
            }
            else {
                printf("nfs_boot: ignoring badly formed bootpath '%s'\n",
                       booter_path);
            }
        }

        if (do_bpwhoami) {
            /*
             * Get client name and gateway address.
             * RPC: bootparam/whoami
             * Use the old broadcast address for the WHOAMI
             * call because we do not yet know our netmask.
             * The server address returned by the WHOAMI call
             * is used for all subsequent booptaram RPCs.
             */
            bzero((caddr_t)&bp_sin, sizeof(bp_sin));
            bp_sin.sin_len = sizeof(bp_sin);
            bp_sin.sin_family = AF_INET;
            bp_sin.sin_addr.s_addr = INADDR_BROADCAST;
            hostnamelen = MAXHOSTNAMELEN;
            
            { /* bpwhoami also returns gateway IP address */
                
                struct in_addr router;
                
                router.s_addr = 0;
                error = bp_whoami(&bp_sin, &my_ip, &router);
                if (error) {
                    printf("nfs_boot: bootparam whoami, error=%d", error);
                    panic("nfs_boot: bootparam whoami\n");
                }
                /* if not already set by BOOTP, use the one from BPWHOAMI */
                if (gw_ip.s_addr == 0)
                    gw_ip = router;
            }
            printf("nfs_boot: BOOTPARAMS server " IP_FORMAT "\n", 
                   IP_LIST(&bp_sin.sin_addr));
            printf("nfs_boot: hostname %s\n", hostname);
        }
#define NFS_BOOT_GATEWAY        1
#ifdef  NFS_BOOT_GATEWAY
        /*
         * DWS 2/18/1999
         * The comment below does not apply to gw_ip discovered
         * via BOOTP (see DO_BOOTP loop above) since BOOTP servers
         * are supposed to be more trustworthy.
         */
        /*
         * XXX - This code is conditionally compiled only because
         * many bootparam servers (in particular, SunOS 4.1.3)
         * always set the gateway address to their own address.
         * The bootparam server is not necessarily the gateway.
         * We could just believe the server, and at worst you would
         * need to delete the incorrect default route before adding
         * the correct one, but for simplicity, ignore the gateway.
         * If your server is OK, you can turn on this option.
         *
         * If the gateway address is set, add a default route.
         * (The mountd RPCs may go across a gateway.)
         */
        if (gw_ip.s_addr) {
                struct sockaddr dst, gw, mask;
                /* Destination: (default) */
                bzero((caddr_t)&dst, sizeof(dst));
                dst.sa_len = sizeof(dst);
                dst.sa_family = AF_INET;
                /* Gateway: */
                bzero((caddr_t)&gw, sizeof(gw));
                sin = (struct sockaddr_in *)&gw;
                sin->sin_len = sizeof(gw);
                sin->sin_family = AF_INET;
                sin->sin_addr.s_addr = gw_ip.s_addr;
                /* Mask: (zero length) */
                bzero(&mask, sizeof(mask));
                printf("nfs_boot: adding default route " IP_FORMAT "\n", 
                       IP_LIST(&gw_ip));
                /* add, dest, gw, mask, flags, 0 */
                error = rtrequest(RTM_ADD, &dst, (struct sockaddr *)&gw,
                    &mask, (RTF_UP | RTF_GATEWAY | RTF_STATIC), NULL);
                if (error)
                        printf("nfs_boot: add route, error=%d\n", error);
        }
#endif
        if (do_bpgetfile) {
            error = bp_getfile(&bp_sin, "root", &nd->nd_root.ndm_saddr,
                               nd->nd_root.ndm_host, root_path);
            if (error) {
                printf("nfs_boot: bootparam get root: %d\n", error);
                panic("nfs_boot: bootparam get root");
            }
        }

        get_file_handle(root_path, &nd->nd_root);

#if !defined(NO_MOUNT_PRIVATE) 
        if (do_bpgetfile) { /* get private path */
            char * private_path = NULL;

            MALLOC(private_path, char *, MAXPATHLEN, M_TEMP, M_WAITOK);
            error = bp_getfile(&bp_sin, "private", 
                               &nd->nd_private.ndm_saddr,
                               nd->nd_private.ndm_host, private_path);
            if (!error) {
                char * check_path = NULL;

                MALLOC(check_path, char *, MAXPATHLEN, M_TEMP, M_WAITOK);
                sprintf(check_path, "%s/private", root_path);
                if ((nd->nd_root.ndm_saddr.sin_addr.s_addr 
                     == nd->nd_private.ndm_saddr.sin_addr.s_addr)
                    && (strcmp(check_path, private_path) == 0)) {
                    /* private path is prefix of root path, don't mount */
                    nd->nd_private.ndm_saddr.sin_addr.s_addr = 0;
                }
                else {
                    get_file_handle(private_path, &nd->nd_private);
                }
                _FREE(check_path, M_TEMP);
            }
            else { 
                /* private key not defined, don't mount */
                nd->nd_private.ndm_saddr.sin_addr.s_addr = 0;
            }
            _FREE(private_path, M_TEMP);
        }
#endif NO_MOUNT_PRIVATE
        thread_funnel_switch(NETWORK_FUNNEL, KERNEL_FUNNEL);
        _FREE(booter_path, M_TEMP);
        _FREE(root_path, M_TEMP);
        return (0);
}

int
inet_aton(char * cp, struct in_addr * pin)
{
    u_char * b = (char *)pin;
    int    i;
    char * p;

    for (p = cp, i = 0; i < 4; i++) {
        u_long l = strtoul(p, 0, 0);
        if (l > 255)
            return (FALSE);
        b[i] = l;
        p = strchr(p, '.');
        if (i < 3 && p == NULL)
            return (FALSE);
        p++;
    }
    return (TRUE);
}

/*
 * Function: parse_image_path
 * Purpose:
 *   Parse a string of the form "<IP>:<host>:<path>" into
 *   the given ip address and host and pathnames.
 * Example: 
 *   "17.202.16.17:seaport:/release/.images/Image9/CurrentHera"
 */
static __inline__ boolean_t
parse_image_path(char * c, struct in_addr * iaddr_p, char * hostname,
                 char * pathname)
{
    char *              d;
    char *              p;
#define TMP_SIZE        128
    char                tmp[TMP_SIZE];

    p = strchr(c, ':');
    if (p == NULL)
        return (FALSE);
    if ((p - c) >= TMP_SIZE)
        return (FALSE);
    strncpy(tmp, c, p - c);
    tmp[p - c] = 0;
    if (inet_aton(tmp, iaddr_p) != 1)
        return (FALSE);
    p++;
    d = strchr(p, ':');
    if (d == NULL)
        return (FALSE);
    strncpy(hostname, p, d - p);
    hostname[d - p] = 0;
    d++;
    strcpy(pathname, d);
    return (TRUE);
}

static boolean_t
path_getfile(char * image_path, struct sockaddr_in * sin_p, 
             char * serv_name, char * pathname)
{
    bzero((caddr_t)sin_p, sizeof(*sin_p));
    sin_p->sin_len = sizeof(*sin_p);
    sin_p->sin_family = AF_INET;
    if (parse_image_path(image_path, &sin_p->sin_addr, serv_name, pathname)
        == FALSE)
        return (FALSE);
    return (TRUE);
}

static void
get_file_handle(pathname, ndmntp)
        char               *pathname;   /* path on server */
        struct nfs_dlmount *ndmntp;     /* output */
{
        char *sp, *dp, *endp;
        int error;

        /*
         * Get file handle for "key" (root or swap)
         * using RPC to mountd/mount
         */
        error = md_mount(&ndmntp->ndm_saddr, pathname, ndmntp->ndm_fh);
        if (error)
                panic("nfs_boot: mountd, error=%d", error);

        /* Construct remote path (for getmntinfo(3)) */
        dp = ndmntp->ndm_host;
        endp = dp + MNAMELEN - 1;
        dp += strlen(dp);
        *dp++ = ':';
        for (sp = pathname; *sp && dp < endp;)
                *dp++ = *sp++;
        *dp = '\0';

}


/*
 * Get an mbuf with the given length, and
 * initialize the pkthdr length field.
 */
static struct mbuf *
m_get_len(int msg_len)
{
        struct mbuf *m;
        m = m_gethdr(M_WAIT, MT_DATA);
        if (m == NULL)
                return NULL;
        if (msg_len > MHLEN) {
                if (msg_len > MCLBYTES)
                        panic("nfs_boot: msg_len > MCLBYTES");
                MCLGET(m, M_WAIT);
                if (m == NULL)
                        return NULL;
        }
        m->m_len = msg_len;
        m->m_pkthdr.len = m->m_len;
        return (m);
}


/*
 * String representation for RPC.
 */
struct rpc_string {
        u_long len;             /* length without null or padding */
        u_char data[4]; /* data (longer, of course) */
    /* data is padded to a long-word boundary */
};
/* Compute space used given string length. */
#define RPC_STR_SIZE(slen) (4 + ((slen + 3) & ~3))

/*
 * Inet address in RPC messages
 * (Note, really four longs, NOT chars.  Blech.)
 */
struct bp_inaddr {
        u_long  atype;
        long    addr[4];
};


/*
 * RPC: bootparam/whoami
 * Given client IP address, get:
 *      client name     (hostname)
 *      domain name (domainname)
 *      gateway address
 *
 * The hostname and domainname are set here for convenience.
 *
 * Note - bpsin is initialized to the broadcast address,
 * and will be replaced with the bootparam server address
 * after this call is complete.  Have to use PMAP_PROC_CALL
 * to make sure we get responses only from a servers that
 * know about us (don't want to broadcast a getport call).
 */
static int
bp_whoami(bpsin, my_ip, gw_ip)
        struct sockaddr_in *bpsin;
        struct in_addr *my_ip;
        struct in_addr *gw_ip;
{
        /* RPC structures for PMAPPROC_CALLIT */
        struct whoami_call {
                u_long call_prog;
                u_long call_vers;
                u_long call_proc;
                u_long call_arglen;
                struct bp_inaddr call_ia;
        } *call;

        struct rpc_string *str;
        struct bp_inaddr *bia;
        struct mbuf *m;
        struct sockaddr_in *sin;
        int error, msg_len;
        int cn_len, dn_len;
        u_char *p;
        long *lp;

        /*
         * Get message buffer of sufficient size.
         */
        msg_len = sizeof(*call);
        m = m_get_len(msg_len);
        if (m == NULL)
                return ENOBUFS;

        /*
         * Build request message for PMAPPROC_CALLIT.
         */
        call = mtod(m, struct whoami_call *);
        call->call_prog = htonl(BOOTPARAM_PROG);
        call->call_vers = htonl(BOOTPARAM_VERS);
        call->call_proc = htonl(BOOTPARAM_WHOAMI);
        call->call_arglen = htonl(sizeof(struct bp_inaddr));

        /* client IP address */
        call->call_ia.atype = htonl(1);
        p = (u_char*)my_ip;
        lp = call->call_ia.addr;
        *lp++ = htonl(*p);      p++;
        *lp++ = htonl(*p);      p++;
        *lp++ = htonl(*p);      p++;
        *lp++ = htonl(*p);      p++;

        /* RPC: portmap/callit */
        bpsin->sin_port = htons(PMAPPORT);

        error = krpc_call(bpsin, PMAPPROG, PMAPVERS,
                        PMAPPROC_CALLIT, &m, &sin);
        if (error)
                return error;

        /*
         * Parse result message.
         */
        msg_len = m->m_len;
        lp = mtod(m, long *);

        /* bootparam server port (also grab from address). */
        if (msg_len < sizeof(*lp))
                goto bad;
        msg_len -= sizeof(*lp);
        bpsin->sin_port = htons((short)ntohl(*lp++));
        bpsin->sin_addr.s_addr = sin->sin_addr.s_addr;

        /* length of encapsulated results */
        if (msg_len < (ntohl(*lp) + sizeof(*lp)))
                goto bad;
        msg_len = ntohl(*lp++);
        p = (char*)lp;

        /* client name */
        if (msg_len < sizeof(*str))
                goto bad;
        str = (struct rpc_string *)p;
        cn_len = ntohl(str->len);
        if (msg_len < cn_len)
                goto bad;
        if (cn_len >= MAXHOSTNAMELEN)
                goto bad;
        bcopy(str->data, hostname, cn_len);
        hostname[cn_len] = '\0';
        hostnamelen = cn_len;
        p += RPC_STR_SIZE(cn_len);
        msg_len -= RPC_STR_SIZE(cn_len);

        /* domain name */
        if (msg_len < sizeof(*str))
                goto bad;
        str = (struct rpc_string *)p;
        dn_len = ntohl(str->len);
        if (msg_len < dn_len)
                goto bad;
        if (dn_len >= MAXHOSTNAMELEN)
                goto bad;
        bcopy(str->data, domainname, dn_len);
        domainname[dn_len] = '\0';
        domainnamelen = dn_len;
        p += RPC_STR_SIZE(dn_len);
        msg_len -= RPC_STR_SIZE(dn_len);

        /* gateway address */
        if (msg_len < sizeof(*bia))
                goto bad;
        bia = (struct bp_inaddr *)p;
        if (bia->atype != htonl(1))
                goto bad;
        p = (u_char*)gw_ip;
        *p++ = ntohl(bia->addr[0]);
        *p++ = ntohl(bia->addr[1]);
        *p++ = ntohl(bia->addr[2]);
        *p++ = ntohl(bia->addr[3]);
        goto out;

bad:
        printf("nfs_boot: bootparam_whoami: bad reply\n");
        error = EBADRPC;

out:
        if (sin)
            FREE(sin, M_SONAME);

        m_freem(m);
        return(error);
}


/*
 * RPC: bootparam/getfile
 * Given client name and file "key", get:
 *      server name
 *      server IP address
 *      server pathname
 */
static int
bp_getfile(bpsin, key, md_sin, serv_name, pathname)
        struct sockaddr_in *bpsin;
        char *key;
        struct sockaddr_in *md_sin;
        char *serv_name;
        char *pathname;
{
        struct rpc_string *str;
        struct mbuf *m;
        struct bp_inaddr *bia;
        struct sockaddr_in *sin;
        u_char *p, *q;
        int error, msg_len;
        int cn_len, key_len, sn_len, path_len;

        /*
         * Get message buffer of sufficient size.
         */
        cn_len = hostnamelen;
        key_len = strlen(key);
        msg_len = 0;
        msg_len += RPC_STR_SIZE(cn_len);
        msg_len += RPC_STR_SIZE(key_len);
        m = m_get_len(msg_len);
        if (m == NULL)
                return ENOBUFS;

        /*
         * Build request message.
         */
        p = mtod(m, u_char *);
        bzero(p, msg_len);
        /* client name (hostname) */
        str = (struct rpc_string *)p;
        str->len = htonl(cn_len);
        bcopy(hostname, str->data, cn_len);
        p += RPC_STR_SIZE(cn_len);
        /* key name (root or swap) */
        str = (struct rpc_string *)p;
        str->len = htonl(key_len);
        bcopy(key, str->data, key_len);

        /* RPC: bootparam/getfile */
        error = krpc_call(bpsin, BOOTPARAM_PROG, BOOTPARAM_VERS,
                        BOOTPARAM_GETFILE, &m, NULL);
        if (error)
                return error;

        /*
         * Parse result message.
         */
        p = mtod(m, u_char *);
        msg_len = m->m_len;

        /* server name */
        if (msg_len < sizeof(*str))
                goto bad;
        str = (struct rpc_string *)p;
        sn_len = ntohl(str->len);
        if (msg_len < sn_len)
                goto bad;
        if (sn_len >= MNAMELEN)
                goto bad;
        bcopy(str->data, serv_name, sn_len);
        serv_name[sn_len] = '\0';
        p += RPC_STR_SIZE(sn_len);
        msg_len -= RPC_STR_SIZE(sn_len);

        /* server IP address (mountd) */
        if (msg_len < sizeof(*bia))
                goto bad;
        bia = (struct bp_inaddr *)p;
        if (bia->atype != htonl(1))
                goto bad;
        sin = md_sin;
        bzero((caddr_t)sin, sizeof(*sin));
        sin->sin_len = sizeof(*sin);
        sin->sin_family = AF_INET;
        q = (u_char*) &sin->sin_addr;
        *q++ = ntohl(bia->addr[0]);
        *q++ = ntohl(bia->addr[1]);
        *q++ = ntohl(bia->addr[2]);
        *q++ = ntohl(bia->addr[3]);
        p += sizeof(*bia);
        msg_len -= sizeof(*bia);

        /* server pathname */
        if (msg_len < sizeof(*str))
                goto bad;
        str = (struct rpc_string *)p;
        path_len = ntohl(str->len);
        if (msg_len < path_len)
                goto bad;
        if (path_len >= MAXPATHLEN)
                goto bad;
        bcopy(str->data, pathname, path_len);
        pathname[path_len] = '\0';
        goto out;

bad:
        printf("nfs_boot: bootparam_getfile: bad reply\n");
        error = EBADRPC;

out:
        m_freem(m);
        return(0);
}


/*
 * RPC: mountd/mount
 * Given a server pathname, get an NFS file handle.
 * Also, sets sin->sin_port to the NFS service port.
 */
static int
md_mount(mdsin, path, fhp)
        struct sockaddr_in *mdsin;              /* mountd server address */
        char *path;
        u_char *fhp;
{
        /* The RPC structures */
        struct rpc_string *str;
        struct rdata {
                u_long  errno;
                u_char  fh[NFSX_V2FH];
        } *rdata;
        struct mbuf *m;
        int error, mlen, slen;

        /* Get port number for MOUNTD. */
        error = krpc_portmap(mdsin, RPCPROG_MNT, RPCMNT_VER1,
                                                 &mdsin->sin_port);
        if (error) return error;

        slen = strlen(path);
        mlen = RPC_STR_SIZE(slen);

        m = m_get_len(mlen);
        if (m == NULL)
                return ENOBUFS;
        str = mtod(m, struct rpc_string *);
        str->len = htonl(slen);
        bcopy(path, str->data, slen);

        /* Do RPC to mountd. */
        error = krpc_call(mdsin, RPCPROG_MNT, RPCMNT_VER1,
                        RPCMNT_MOUNT, &m, NULL);
        if (error)
                return error;   /* message already freed */

        mlen = m->m_len;
        if (mlen < sizeof(*rdata))
                goto bad;
        rdata = mtod(m, struct rdata *);
        error = ntohl(rdata->errno);
        if (error)
                goto bad;
        bcopy(rdata->fh, fhp, NFSX_V2FH);

        /* Set port number for NFS use. */
        error = krpc_portmap(mdsin, NFS_PROG, NFS_VER2,
                                                 &mdsin->sin_port);
        goto out;

bad:
        error = EBADRPC;

out:
        m_freem(m);
        return error;
}

#endif /* NETHER */