usr/src/sys/nfs/nfs_syscalls.c

/*
 * Copyright (c) 1989 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Rick Macklem at The University of Guelph.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 *      @(#)nfs_syscalls.c      7.4 (Berkeley) %G%
 */

#include "param.h"
#include "systm.h"
#include "user.h"
#include "kernel.h"
#include "file.h"
#include "stat.h"
#include "vnode.h"
#include "mount.h"
#include "proc.h"
#include "uio.h"
#include "malloc.h"
#include "buf.h"
#include "mbuf.h"
#include "socket.h"
#include "socketvar.h"
#include "nfsv2.h"
#include "nfs.h"

/* Global defs. */
extern u_long nfs_prog, nfs_vers;
extern int (*nfsrv_procs[NFS_NPROCS])();
extern struct buf nfs_bqueue;
extern int nfs_asyncdaemons;
extern struct proc *nfs_iodwant[MAX_ASYNCDAEMON];
struct file *getsock();

/*
 * NFS server system calls
 * getfh() lives here too, but maybe should move to kern/vfs_syscalls.c
 */
#define RETURN(value)   { u.u_error = (value); return; }

/*
 * Get file handle system call
 */
getfh()
{
        register struct a {
                char    *fname;
                fhandle_t *fhp;
        } *uap = (struct a *)u.u_ap;
        register struct nameidata *ndp = &u.u_nd;
        register struct vnode *vp;
        fhandle_t fh;
        int error;

        /*
         * Must be super user
         */
        if (error = suser(u.u_cred, &u.u_acflag))
                RETURN (error);
        ndp->ni_nameiop = LOOKUP | LOCKLEAF | FOLLOW;
        ndp->ni_segflg = UIO_USERSPACE;
        ndp->ni_dirp = uap->fname;
        if (error = namei(ndp))
                RETURN (error);
        vp = ndp->ni_vp;
        bzero((caddr_t)&fh, sizeof(fh));
        fh.fh_fsid = vp->v_mount->m_fsid;
        error = VFS_VPTOFH(vp, &fh.fh_fid);
        vput(vp);
        if (error)
                RETURN (error);
        error = copyout((caddr_t)&fh, (caddr_t)uap->fhp, sizeof (fh));
        RETURN (error);
}

/*
 * Mark a mount point in the filesystem exported
 */
exportfs()
{
        register struct a {
                char    *fname;
                int     rootuid;
                int     exflags;
        } *uap = (struct a *)u.u_ap;
        register struct nameidata *ndp = &u.u_nd;
        register struct vnode *vp;
        register struct mount *mp;
        int error;

        /*
         * Must be super user
         */
        if (error = suser(u.u_cred, &u.u_acflag))
                RETURN (error);
        ndp->ni_nameiop = LOOKUP | LOCKLEAF | FOLLOW;   /* Or NOFOLLOW ?? */
        ndp->ni_segflg = UIO_USERSPACE;
        ndp->ni_dirp = uap->fname;
        if (error = namei(ndp))
                RETURN (error);
        vp = ndp->ni_vp;
        if (vp->v_type != VDIR) {
                vput(vp);
                RETURN (ENOENT);
        }
        mp = vp->v_mount;

        /*
         * If the filesystem has already been exported, just relax
         * security as required.
         * Otherwise export it with the given security
         */
        if (mp->m_flag & M_EXPORTED) {
                if (uap->rootuid == 0)
                        mp->m_exroot = 0;
                if ((uap->exflags & M_EXRDONLY) == 0)
                        mp->m_flag &= ~M_EXRDONLY;
        } else {
                mp->m_exroot = uap->rootuid;
                if (uap->exflags & M_EXRDONLY)
                        mp->m_flag |= M_EXRDONLY;
                mp->m_flag |= M_EXPORTED;
        }
        vput(vp);
        RETURN (0);
}

/*
 * Nfs server psuedo system call for the nfsd's
 * Never returns unless it fails or gets killed
 */
nfssvc()
{
        register struct a {
                int s;
        } *uap = (struct a *)u.u_ap;
        register struct mbuf *m;
        register int siz;
        register struct ucred *cr;
        struct file *fp;
        struct mbuf *mreq, *mrep, *nam, *md;
        struct socket *so;
        caddr_t dpos;
        int procid;
        u_long retxid;
        int error;

        /*
         * Must be super user
         */
        if (error = suser(u.u_cred, &u.u_acflag))
                RETURN (error);
        fp = getsock(uap->s);
        if (fp == 0)
                return;
        so = (struct socket *)fp->f_data;
        cr = u.u_cred = crcopy(u.u_cred);       /* Copy it so others don't see changes */
        /*
         * Just loop arround doin our stuff until SIGKILL
         */
        for (;;) {
                if (error = nfs_getreq(so, nfs_prog, nfs_vers, NFS_NPROCS-1,
                        &nam, &mrep, &md, &dpos, &retxid, &procid, cr)) {
                        m_freem(nam);
                        continue;
                }
                if (error = (*(nfsrv_procs[procid]))(mrep, md, dpos,
                        cr, retxid, &mreq)) {
                        m_freem(nam);
                        nfsstats.srv_errs++;
                        continue;
                } else
                        nfsstats.srvrpccnt[procid]++;
                m = mreq;
                siz = 0;
                while (m) {
                        siz += m->m_len;
                        m = m->m_next;
                }
                if (siz <= 0 || siz > 9216) {
                        printf("mbuf siz=%d\n",siz);
                        panic("Bad nfs svc reply");
                }
                error = nfs_udpsend(so, nam, mreq, 0, siz);
                m_freem(nam);
        }
}

/*
 * Nfs pseudo system call for asynchronous i/o daemons.
 * These babies just pretend to be disk interrupt service routines
 * for client nfs. They are mainly here for read ahead/write behind.
 * Never returns unless it fails or gets killed
 */
async_daemon()
{
        register struct buf *bp, *dp;
        int error;
        int myiod;

        /*
         * Must be super user
         */
        if (error = suser(u.u_cred, &u.u_acflag))
                RETURN (error);
        /*
         * Assign my position or return error if too many already running
         */
        if (nfs_asyncdaemons > MAX_ASYNCDAEMON)
                RETURN (EBUSY);
        myiod = nfs_asyncdaemons++;
        dp = &nfs_bqueue;
        /*
         * Just loop around doin our stuff until SIGKILL
         */
        for (;;) {
                while (dp->b_actf == NULL) {
                        nfs_iodwant[myiod] = u.u_procp;
                        sleep((caddr_t)&nfs_iodwant[myiod], PZERO+1);
                }
                /* Take one off the end of the list */
                bp = dp->b_actl;
                if (bp->b_actl == dp) {
                        dp->b_actf = dp->b_actl = (struct buf *)0;
                } else {
                        dp->b_actl = bp->b_actl;
                        bp->b_actl->b_actf = dp;
                }
                (void) nfs_doio(bp);
        }
}