nfs_subs.c

早期freebsd实现

		m1->m_len = len+tlen;
		siz -= xfer;
		cp += xfer;
	}
	*mb = m1;
	*bpos = mtod(m1, caddr_t)+m1->m_len;
	return (0);
}

/*
 * Called once to initialize data structures...
 */
nfs_init()
{
	register int i;

	nfsrtt.pos = 0;
	rpc_vers = txdr_unsigned(RPC_VER2);
	rpc_call = txdr_unsigned(RPC_CALL);
	rpc_reply = txdr_unsigned(RPC_REPLY);
	rpc_msgdenied = txdr_unsigned(RPC_MSGDENIED);
	rpc_msgaccepted = txdr_unsigned(RPC_MSGACCEPTED);
	rpc_mismatch = txdr_unsigned(RPC_MISMATCH);
	rpc_autherr = txdr_unsigned(RPC_AUTHERR);
	rpc_rejectedcred = txdr_unsigned(AUTH_REJECTCRED);
	rpc_auth_unix = txdr_unsigned(RPCAUTH_UNIX);
	rpc_auth_kerb = txdr_unsigned(RPCAUTH_NQNFS);
	nfs_vers = txdr_unsigned(NFS_VER2);
	nfs_prog = txdr_unsigned(NFS_PROG);
	nfs_true = txdr_unsigned(TRUE);
	nfs_false = txdr_unsigned(FALSE);
	/* Loop thru nfs procids */
	for (i = 0; i < NFS_NPROCS; i++)
		nfs_procids[i] = txdr_unsigned(i);
	/* Ensure async daemons disabled */
	for (i = 0; i < NFS_MAXASYNCDAEMON; i++)
		nfs_iodwant[i] = (struct proc *)0;
	TAILQ_INIT(&nfs_bufq);
	nfs_xdrneg1 = txdr_unsigned(-1);
	nfs_nhinit();			/* Init the nfsnode table */
	nfsrv_init(0);			/* Init server data structures */
	nfsrv_initcache();		/* Init the server request cache */

	/*
	 * Initialize the nqnfs server stuff.
	 */
	if (nqnfsstarttime == 0) {
		nqnfsstarttime = boottime.tv_sec + nqsrv_maxlease
			+ nqsrv_clockskew + nqsrv_writeslack;
		NQLOADNOVRAM(nqnfsstarttime);
		nqnfs_prog = txdr_unsigned(NQNFS_PROG);
		nqnfs_vers = txdr_unsigned(NQNFS_VER1);
		nqthead.th_head[0] = &nqthead;
		nqthead.th_head[1] = &nqthead;
		nqfhead = hashinit(NQLCHSZ, M_NQLEASE, &nqfheadhash);
	}

	/*
	 * Initialize reply list and start timer
	 */
	nfsreqh.r_prev = nfsreqh.r_next = &nfsreqh;
	nfs_timer();
}

/*
 * Attribute cache routines.
 * nfs_loadattrcache() - loads or updates the cache contents from attributes
 *	that are on the mbuf list
 * nfs_getattrcache() - returns valid attributes if found in cache, returns
 *	error otherwise
 */

/*
 * Load the attribute cache (that lives in the nfsnode entry) with
 * the values on the mbuf list and
 * Iff vap not NULL
 *    copy the attributes to *vaper
 */
nfs_loadattrcache(vpp, mdp, dposp, vaper)
	struct vnode **vpp;
	struct mbuf **mdp;
	caddr_t *dposp;
	struct vattr *vaper;
{
	register struct vnode *vp = *vpp;
	register struct vattr *vap;
	register struct nfsv2_fattr *fp;
	extern int (**spec_nfsv2nodeop_p)();
	register struct nfsnode *np, *nq, **nhpp;
	register long t1;
	caddr_t dpos, cp2;
	int error = 0, isnq;
	struct mbuf *md;
	enum vtype vtyp;
	u_short vmode;
	long rdev;
	struct timespec mtime;
	struct vnode *nvp;

	md = *mdp;
	dpos = *dposp;
	t1 = (mtod(md, caddr_t) + md->m_len) - dpos;
	isnq = (VFSTONFS(vp->v_mount)->nm_flag & NFSMNT_NQNFS);
	if (error = nfsm_disct(&md, &dpos, NFSX_FATTR(isnq), t1, &cp2))
		return (error);
	fp = (struct nfsv2_fattr *)cp2;
	vtyp = nfstov_type(fp->fa_type);
	vmode = fxdr_unsigned(u_short, fp->fa_mode);
	if (vtyp == VNON || vtyp == VREG)
		vtyp = IFTOVT(vmode);
	if (isnq) {
		rdev = fxdr_unsigned(long, fp->fa_nqrdev);
		fxdr_nqtime(&fp->fa_nqmtime, &mtime);
	} else {
		rdev = fxdr_unsigned(long, fp->fa_nfsrdev);
		fxdr_nfstime(&fp->fa_nfsmtime, &mtime);
	}
	/*
	 * If v_type == VNON it is a new node, so fill in the v_type,
	 * n_mtime fields. Check to see if it represents a special 
	 * device, and if so, check for a possible alias. Once the
	 * correct vnode has been obtained, fill in the rest of the
	 * information.
	 */
	np = VTONFS(vp);
	if (vp->v_type == VNON) {
		if (vtyp == VCHR && rdev == 0xffffffff)
			vp->v_type = vtyp = VFIFO;
		else
			vp->v_type = vtyp;
		if (vp->v_type == VFIFO) {
#ifdef FIFO
			extern int (**fifo_nfsv2nodeop_p)();
			vp->v_op = fifo_nfsv2nodeop_p;
#else
			return (EOPNOTSUPP);
#endif /* FIFO */
		}
		if (vp->v_type == VCHR || vp->v_type == VBLK) {
			vp->v_op = spec_nfsv2nodeop_p;
			if (nvp = checkalias(vp, (dev_t)rdev, vp->v_mount)) {
				/*
				 * Discard unneeded vnode, but save its nfsnode.
				 */
				if (nq = np->n_forw)
					nq->n_back = np->n_back;
				*np->n_back = nq;
				nvp->v_data = vp->v_data;
				vp->v_data = NULL;
				vp->v_op = spec_vnodeop_p;
				vrele(vp);
				vgone(vp);
				/*
				 * Reinitialize aliased node.
				 */
				np->n_vnode = nvp;
				nhpp = (struct nfsnode **)nfs_hash(&np->n_fh);
				if (nq = *nhpp)
					nq->n_back = &np->n_forw;
				np->n_forw = nq;
				np->n_back = nhpp;
				*nhpp = np;
				*vpp = vp = nvp;
			}
		}
		np->n_mtime = mtime.ts_sec;
	}
	vap = &np->n_vattr;
	vap->va_type = vtyp;
	vap->va_mode = (vmode & 07777);
	vap->va_nlink = fxdr_unsigned(u_short, fp->fa_nlink);
	vap->va_uid = fxdr_unsigned(uid_t, fp->fa_uid);
	vap->va_gid = fxdr_unsigned(gid_t, fp->fa_gid);
	vap->va_rdev = (dev_t)rdev;
	vap->va_mtime = mtime;
	vap->va_fsid = vp->v_mount->mnt_stat.f_fsid.val[0];
	if (isnq) {
		fxdr_hyper(&fp->fa_nqsize, &vap->va_size);
		vap->va_blocksize = fxdr_unsigned(long, fp->fa_nqblocksize);
		fxdr_hyper(&fp->fa_nqbytes, &vap->va_bytes);
		vap->va_fileid = fxdr_unsigned(long, fp->fa_nqfileid);
		fxdr_nqtime(&fp->fa_nqatime, &vap->va_atime);
		vap->va_flags = fxdr_unsigned(u_long, fp->fa_nqflags);
		fxdr_nqtime(&fp->fa_nqctime, &vap->va_ctime);
		vap->va_gen = fxdr_unsigned(u_long, fp->fa_nqgen);
		fxdr_hyper(&fp->fa_nqfilerev, &vap->va_filerev);
	} else {
		vap->va_size = fxdr_unsigned(u_long, fp->fa_nfssize);
		vap->va_blocksize = fxdr_unsigned(long, fp->fa_nfsblocksize);
		vap->va_bytes = fxdr_unsigned(long, fp->fa_nfsblocks) * NFS_FABLKSIZE;
		vap->va_fileid = fxdr_unsigned(long, fp->fa_nfsfileid);
		fxdr_nfstime(&fp->fa_nfsatime, &vap->va_atime);
		vap->va_flags = 0;
		vap->va_ctime.ts_sec = fxdr_unsigned(long, fp->fa_nfsctime.nfs_sec);
		vap->va_ctime.ts_nsec = 0;
		vap->va_gen = fxdr_unsigned(u_long, fp->fa_nfsctime.nfs_usec);
		vap->va_filerev = 0;
	}
	if (vap->va_size != np->n_size) {
		if (vap->va_type == VREG) {
			if (np->n_flag & NMODIFIED) {
				if (vap->va_size < np->n_size)
					vap->va_size = np->n_size;
				else
					np->n_size = vap->va_size;
			} else
				np->n_size = vap->va_size;
			vnode_pager_setsize(vp, (u_long)np->n_size);
		} else
			np->n_size = vap->va_size;
	}
	np->n_attrstamp = time.tv_sec;
	*dposp = dpos;
	*mdp = md;
	if (vaper != NULL) {
		bcopy((caddr_t)vap, (caddr_t)vaper, sizeof(*vap));
#ifdef notdef
		if ((np->n_flag & NMODIFIED) && np->n_size > vap->va_size)
		if (np->n_size > vap->va_size)
			vaper->va_size = np->n_size;
#endif
		if (np->n_flag & NCHG) {
			if (np->n_flag & NACC) {
				vaper->va_atime.ts_sec = np->n_atim.tv_sec;
				vaper->va_atime.ts_nsec =
				    np->n_atim.tv_usec * 1000;
			}
			if (np->n_flag & NUPD) {
				vaper->va_mtime.ts_sec = np->n_mtim.tv_sec;
				vaper->va_mtime.ts_nsec =
				    np->n_mtim.tv_usec * 1000;
			}
		}
	}
	return (0);
}

/*
 * Check the time stamp
 * If the cache is valid, copy contents to *vap and return 0
 * otherwise return an error
 */
nfs_getattrcache(vp, vaper)
	register struct vnode *vp;
	struct vattr *vaper;
{
	register struct nfsnode *np = VTONFS(vp);
	register struct vattr *vap;

	if (VFSTONFS(vp->v_mount)->nm_flag & NFSMNT_NQLOOKLEASE) {
		if (!NQNFS_CKCACHABLE(vp, NQL_READ) || np->n_attrstamp == 0) {
			nfsstats.attrcache_misses++;
			return (ENOENT);
		}
	} else if ((time.tv_sec - np->n_attrstamp) >= NFS_ATTRTIMEO(np)) {
		nfsstats.attrcache_misses++;
		return (ENOENT);
	}
	nfsstats.attrcache_hits++;
	vap = &np->n_vattr;
	if (vap->va_size != np->n_size) {
		if (vap->va_type == VREG) {
			if (np->n_flag & NMODIFIED) {
				if (vap->va_size < np->n_size)
					vap->va_size = np->n_size;
				else
					np->n_size = vap->va_size;
			} else
				np->n_size = vap->va_size;
			vnode_pager_setsize(vp, (u_long)np->n_size);
		} else
			np->n_size = vap->va_size;
	}
	bcopy((caddr_t)vap, (caddr_t)vaper, sizeof(struct vattr));
#ifdef notdef
	if ((np->n_flag & NMODIFIED) == 0) {
		np->n_size = vaper->va_size;
		vnode_pager_setsize(vp, (u_long)np->n_size);
	} else if (np->n_size > vaper->va_size)
	if (np->n_size > vaper->va_size)
		vaper->va_size = np->n_size;
#endif
	if (np->n_flag & NCHG) {
		if (np->n_flag & NACC) {
			vaper->va_atime.ts_sec = np->n_atim.tv_sec;
			vaper->va_atime.ts_nsec = np->n_atim.tv_usec * 1000;
		}
		if (np->n_flag & NUPD) {
			vaper->va_mtime.ts_sec = np->n_mtim.tv_sec;
			vaper->va_mtime.ts_nsec = np->n_mtim.tv_usec * 1000;
		}
	}
	return (0);
}

/*
 * Set up nameidata for a lookup() call and do it
 */
nfs_namei(ndp, fhp, len, slp, nam, mdp, dposp, p)
	register struct nameidata *ndp;
	fhandle_t *fhp;
	int len;
	struct nfssvc_sock *slp;
	struct mbuf *nam;
	struct mbuf **mdp;
	caddr_t *dposp;
	struct proc *p;
{
	register int i, rem;
	register struct mbuf *md;
	register char *fromcp, *tocp;
	struct vnode *dp;
	int error, rdonly;
	struct componentname *cnp = &ndp->ni_cnd;

	MALLOC(cnp->cn_pnbuf, char *, len + 1, M_NAMEI, M_WAITOK);
	/*
	 * Copy the name from the mbuf list to ndp->ni_pnbuf
	 * and set the various ndp fields appropriately.
	 */
	fromcp = *dposp;
	tocp = cnp->cn_pnbuf;
	md = *mdp;
	rem = mtod(md, caddr_t) + md->m_len - fromcp;
	cnp->cn_hash = 0;
	for (i = 0; i < len; i++) {
		while (rem == 0) {
			md = md->m_next;
			if (md == NULL) {
				error = EBADRPC;
				goto out;
			}
			fromcp = mtod(md, caddr_t);
			rem = md->m_len;
		}
		if (*fromcp == '\0' || *fromcp == '/') {
			error = EINVAL;
			goto out;
		}
		cnp->cn_hash += (unsigned char)*fromcp;
		*tocp++ = *fromcp++;
		rem--;
	}
	*tocp = '\0';
	*mdp = md;
	*dposp = fromcp;
	len = nfsm_rndup(len)-len;
	if (len > 0) {
		if (rem >= len)
			*dposp += len;
		else if (error = nfs_adv(mdp, dposp, len, rem))
			goto out;
	}
	ndp->ni_pathlen = tocp - cnp->cn_pnbuf;
	cnp->cn_nameptr = cnp->cn_pnbuf;
	/*
	 * Extract and set starting directory.
	 */
	if (error = nfsrv_fhtovp(fhp, FALSE, &dp, ndp->ni_cnd.cn_cred, slp,
	    nam, &rdonly))
		goto out;
	if (dp->v_type != VDIR) {
		vrele(dp);
		error = ENOTDIR;
		goto out;
	}
	ndp->ni_startdir = dp;
	if (rdonly)
		cnp->cn_flags |= (NOCROSSMOUNT | RDONLY);
	else
		cnp->cn_flags |= NOCROSSMOUNT;
	/*
	 * And call lookup() to do the real work
	 */
	cnp->cn_proc = p;
	if (error = lookup(ndp))
		goto out;
	/*
	 * Check for encountering a symbolic link
	 */
	if (cnp->cn_flags & ISSYMLINK) {
		if ((cnp->cn_flags & LOCKPARENT) && ndp->ni_pathlen == 1)
			vput(ndp->ni_dvp);
		else
			vrele(ndp->ni_dvp);
		vput(ndp->ni_vp);
		ndp->ni_vp = NULL;
		error = EINVAL;
		goto out;
	}
	/*
	 * Check for saved name request
	 */
	if (cnp->cn_flags & (SAVENAME | SAVESTART)) {
		cnp->cn_flags |= HASBUF;
		return (0);
	}
out:
	FREE(cnp->cn_pnbuf, M_NAMEI);
	return (error);
}

/*
 * A fiddled version of m_adj() that ensures null fill to a long
 * boundary and only trims off the back end
 */
void
nfsm_adj(mp, len, nul)
	struct mbuf *mp;
	register int len;
	int nul;
{
	register struct mbuf *m;
	register int count, i;
	register char *cp;

	/*
	 * Trim from tail.  Scan the mbuf chain,
	 * calculating its length and finding the last mbuf.
	 * If the adjustment only affects this mbuf, then just
	 * adjust and return.  Otherwise, rescan and truncate
	 * after the remaining size.
	 */
	count = 0;
	m = mp;
	for (;;) {
		count += m->m_len;
		if (m->m_next == (struct mbuf *)0)
			break;
		m = m->m_next;
	}
	if (m->m_len > len) {
		m->m_len -= len;
		if (nul > 0) {
			cp = mtod(m, caddr_t)+m->m_len-nul;
			for (i = 0; i < nul; i++)
				*cp++ = '\0';
		}
		return;
	}
	count -= len;
	if (count < 0)
		count = 0;
	/*
	 * Correct length for chain is "count".
	 * Find the mbuf with last data, adjust its length,
	 * and toss data from remaining mbufs on chain.
	 */
	for (m = mp; m; m = m->m_next) {
		if (m->m_len >= count) {
			m->m_len = count;
			if (nul > 0) {
				cp = mtod(m, caddr_t)+m->m_len-nul;
				for (i = 0; i < nul; i++)
					*cp++ = '\0';
			}
			break;
		}
		count -= m->m_len;
	}
	while (m = m->m_next)
		m->m_len = 0;
}

/*
 * nfsrv_fhtovp() - convert a fh to a vnode ptr (optionally locked)
 * 	- look up fsid in mount list (if not found ret error)
 *	- get vp and export rights by calling VFS_FHTOVP()
 *	- if cred->cr_uid == 0 or MNT_EXPORTANON set it to credanon
 *	- if not lockflag unlock it with VOP_UNLOCK()
 */
nfsrv_fhtovp(fhp, lockflag, vpp, cred, slp, nam, rdonlyp)
	fhandle_t *fhp;
	int lockflag;
	struct vnode **vpp;
	struct ucred *cred;
	struct nfssvc_sock *slp;
	struct mbuf *nam;
	int *rdonlyp;
{
	register struct mount *mp;
	register struct nfsuid *uidp;
	register int i;
	struct ucred *credanon;
	int error, exflags;

	*vpp = (struct vnode *)0;
	if ((mp = getvfs(&fhp->fh_fsid)) == NULL)
		return (ESTALE);
	if (error = VFS_FHTOVP(mp, &fhp->fh_fid, nam, vpp, &exflags, &credanon))
		return (error);
	/*
	 * Check/setup credentials.
	 */
	if (exflags & MNT_EXKERB) {
		uidp = slp->ns_uidh[NUIDHASH(cred->cr_uid)];
		while (uidp) {
			if (uidp->nu_uid == cred->cr_uid)
				break;
			uidp = uidp->nu_hnext;
		}
		if (uidp) {
			cred->cr_uid = uidp->nu_cr.cr_uid;
			for (i = 0; i < uidp->nu_cr.cr_ngroups; i++)
				cred->cr_groups[i] = uidp->nu_cr.cr_groups[i];
		} else {
			vput(*vpp);
			return (NQNFS_AUTHERR);
		}
	} else if (cred->cr_uid == 0 || (exflags & MNT_EXPORTANON)) {
		cred->cr_uid = credanon->cr_uid;
		for (i = 0; i < credanon->cr_ngroups && i < NGROUPS; i++)
			cred->cr_groups[i] = credanon->cr_groups[i];
	}
	if (exflags & MNT_EXRDONLY)
		*rdonlyp = 1;
	else
		*rdonlyp = 0;
	if (!lockflag)
		VOP_UNLOCK(*vpp);
	return (0);
}

/*
 * This function compares two net addresses by family and returns TRUE
 * if they are the same host.
 * If there is any doubt, return FALSE.
 * The AF_INET family is handled as a special case so that address mbufs
 * don't need to be saved to store "struct in_addr", which is only 4 bytes.
 */
netaddr_match(family, haddr, nam)
	int family;
	union nethostaddr *haddr;
	struct mbuf *nam;
{
	register struct sockaddr_in *inetaddr;

	switch (family) {
	case AF_INET:
		inetaddr = mtod(nam, struct sockaddr_in *);
		if (inetaddr->sin_family == AF_INET &&
		    inetaddr->sin_addr.s_addr == haddr->had_inetaddr)
			return (1);
		break;
#ifdef ISO
	case AF_ISO:
	    {
		register struct sockaddr_iso *isoaddr1, *isoaddr2;

		isoaddr1 = mtod(nam, struct sockaddr_iso *);
		isoaddr2 = mtod(haddr->had_nam, struct sockaddr_iso *);
		if (isoaddr1->siso_family == AF_ISO &&
		    isoaddr1->siso_nlen > 0 &&
		    isoaddr1->siso_nlen == isoaddr2->siso_nlen &&
		    SAME_ISOADDR(isoaddr1, isoaddr2))
			return (1);
		break;
	    }
#endif	/* ISO */
	default:
		break;
	};
	return (0);
}