nfs_syscalls.c

早期freebsd实现

					nfsrv_rcv(slp->ns_so, (caddr_t)slp,
						M_WAIT);
					nfs_sndunlock(&slp->ns_solock);
				}
				error = nfsrv_dorec(slp, nd);
				nd->nd_flag |= NFSD_REQINPROG;
			}
		} else {
			error = 0;
			slp = nd->nd_slp;
		}
		if (error || (slp->ns_flag & SLP_VALID) == 0) {
			nd->nd_slp = (struct nfssvc_sock *)0;
			nd->nd_flag &= ~NFSD_REQINPROG;
			nfsrv_slpderef(slp);
			continue;
		}
		splx(s);
		so = slp->ns_so;
		sotype = so->so_type;
		starttime = time;
		if (so->so_proto->pr_flags & PR_CONNREQUIRED)
			solockp = &slp->ns_solock;
		else
			solockp = (int *)0;
		/*
		 * nam == nam2 for connectionless protocols such as UDP
		 * nam2 == NULL for connection based protocols to disable
		 *    recent request caching.
		 */
		if (nam2 = nd->nd_nam) {
			nam = nam2;
			cacherep = RC_CHECKIT;
		} else {
			nam = slp->ns_nam;
			cacherep = RC_DOIT;
		}

		/*
		 * Check to see if authorization is needed.
		 */
		if (nd->nd_flag & NFSD_NEEDAUTH) {
			static int logauth = 0;

			nd->nd_flag &= ~NFSD_NEEDAUTH;
			/*
			 * Check for a mapping already installed.
			 */
			uidp = slp->ns_uidh[NUIDHASH(nd->nd_cr.cr_uid)];
			while (uidp) {
				if (uidp->nu_uid == nd->nd_cr.cr_uid)
					break;
				uidp = uidp->nu_hnext;
			}
			if (!uidp) {
			    nsd->nsd_uid = nd->nd_cr.cr_uid;
			    if (nam2 && logauth++ == 0)
				log(LOG_WARNING, "Kerberized NFS using UDP\n");
			    nsd->nsd_haddr =
			      mtod(nam, struct sockaddr_in *)->sin_addr.s_addr;
			    nsd->nsd_authlen = nd->nd_authlen;
			    if (copyout(nd->nd_authstr, nsd->nsd_authstr,
				nd->nd_authlen) == 0 &&
				copyout((caddr_t)nsd, argp, sizeof (*nsd)) == 0)
				return (ENEEDAUTH);
			    cacherep = RC_DROPIT;
			}
		}
		if (cacherep == RC_CHECKIT)
			cacherep = nfsrv_getcache(nam2, nd, &mreq);

		/*
		 * Check for just starting up for NQNFS and send
		 * fake "try again later" replies to the NQNFS clients.
		 */
		if (notstarted && nqnfsstarttime <= time.tv_sec) {
			if (modify_flag) {
				nqnfsstarttime = time.tv_sec + nqsrv_writeslack;
				modify_flag = 0;
			} else
				notstarted = 0;
		}
		if (notstarted) {
			if (nd->nd_nqlflag == NQL_NOVAL)
				cacherep = RC_DROPIT;
			else if (nd->nd_procnum != NFSPROC_WRITE) {
				nd->nd_procnum = NFSPROC_NOOP;
				nd->nd_repstat = NQNFS_TRYLATER;
				cacherep = RC_DOIT;
			} else
				modify_flag = 1;
		} else if (nd->nd_flag & NFSD_AUTHFAIL) {
			nd->nd_flag &= ~NFSD_AUTHFAIL;
			nd->nd_procnum = NFSPROC_NOOP;
			nd->nd_repstat = NQNFS_AUTHERR;
			cacherep = RC_DOIT;
		}

		switch (cacherep) {
		case RC_DOIT:
			error = (*(nfsrv_procs[nd->nd_procnum]))(nd,
				nd->nd_mrep, nd->nd_md, nd->nd_dpos, &nd->nd_cr,
				nam, &mreq);
			if (nd->nd_cr.cr_ref != 1) {
				printf("nfssvc cref=%d\n", nd->nd_cr.cr_ref);
				panic("nfssvc cref");
			}
			if (error) {
				if (nd->nd_procnum != NQNFSPROC_VACATED)
					nfsstats.srv_errs++;
				if (nam2) {
					nfsrv_updatecache(nam2, nd, FALSE, mreq);
					m_freem(nam2);
				}
				break;
			}
			nfsstats.srvrpccnt[nd->nd_procnum]++;
			if (nam2)
				nfsrv_updatecache(nam2, nd, TRUE, mreq);
			nd->nd_mrep = (struct mbuf *)0;
		case RC_REPLY:
			m = mreq;
			siz = 0;
			while (m) {
				siz += m->m_len;
				m = m->m_next;
			}
			if (siz <= 0 || siz > NFS_MAXPACKET) {
				printf("mbuf siz=%d\n",siz);
				panic("Bad nfs svc reply");
			}
			m = mreq;
			m->m_pkthdr.len = siz;
			m->m_pkthdr.rcvif = (struct ifnet *)0;
			/*
			 * For stream protocols, prepend a Sun RPC
			 * Record Mark.
			 */
			if (sotype == SOCK_STREAM) {
				M_PREPEND(m, NFSX_UNSIGNED, M_WAIT);
				*mtod(m, u_long *) = htonl(0x80000000 | siz);
			}
			if (solockp)
				(void) nfs_sndlock(solockp, (struct nfsreq *)0);
			if (slp->ns_flag & SLP_VALID)
			    error = nfs_send(so, nam2, m, (struct nfsreq *)0);
			else {
			    error = EPIPE;
			    m_freem(m);
			}
			if (nfsrtton)
				nfsd_rt(&starttime, sotype, nd, nam, cacherep);
			if (nam2)
				MFREE(nam2, m);
			if (nd->nd_mrep)
				m_freem(nd->nd_mrep);
			if (error == EPIPE)
				nfsrv_zapsock(slp);
			if (solockp)
				nfs_sndunlock(solockp);
			if (error == EINTR || error == ERESTART) {
				nfsrv_slpderef(slp);
				s = splnet();
				goto done;
			}
			break;
		case RC_DROPIT:
			if (nfsrtton)
				nfsd_rt(&starttime, sotype, nd, nam, cacherep);
			m_freem(nd->nd_mrep);
			m_freem(nam2);
			break;
		};
		s = splnet();
		if (nfsrv_dorec(slp, nd)) {
			nd->nd_flag &= ~NFSD_REQINPROG;
			nd->nd_slp = (struct nfssvc_sock *)0;
			nfsrv_slpderef(slp);
		}
	}
done:
	remque(nd);
	splx(s);
	free((caddr_t)nd, M_NFSD);
	nsd->nsd_nfsd = (struct nfsd *)0;
	if (--nfs_numnfsd == 0)
		nfsrv_init(TRUE);	/* Reinitialize everything */
	return (error);
}

/*
 * Asynchronous I/O daemons for client nfs.
 * They do read-ahead and write-behind operations on the block I/O cache.
 * Never returns unless it fails or gets killed.
 */
nfssvc_iod(p)
	struct proc *p;
{
	register struct buf *bp;
	register int i, myiod;
	int error = 0;

	/*
	 * Assign my position or return error if too many already running
	 */
	myiod = -1;
	for (i = 0; i < NFS_MAXASYNCDAEMON; i++)
		if (nfs_asyncdaemon[i] == 0) {
			nfs_asyncdaemon[i]++;
			myiod = i;
			break;
		}
	if (myiod == -1)
		return (EBUSY);
	nfs_numasync++;
	/*
	 * Just loop around doin our stuff until SIGKILL
	 */
	for (;;) {
		while (nfs_bufq.tqh_first == NULL && error == 0) {
			nfs_iodwant[myiod] = p;
			error = tsleep((caddr_t)&nfs_iodwant[myiod],
				PWAIT | PCATCH, "nfsidl", 0);
		}
		while ((bp = nfs_bufq.tqh_first) != NULL) {
			/* Take one off the front of the list */
			TAILQ_REMOVE(&nfs_bufq, bp, b_freelist);
			if (bp->b_flags & B_READ)
			    (void) nfs_doio(bp, bp->b_rcred, (struct proc *)0);
			else
			    (void) nfs_doio(bp, bp->b_wcred, (struct proc *)0);
		}
		if (error) {
			nfs_asyncdaemon[myiod] = 0;
			nfs_numasync--;
			return (error);
		}
	}
}

/*
 * Shut down a socket associated with an nfssvc_sock structure.
 * Should be called with the send lock set, if required.
 * The trick here is to increment the sref at the start, so that the nfsds
 * will stop using it and clear ns_flag at the end so that it will not be
 * reassigned during cleanup.
 */
nfsrv_zapsock(slp)
	register struct nfssvc_sock *slp;
{
	register struct nfsuid *nuidp, *onuidp;
	register int i;
	struct socket *so;
	struct file *fp;
	struct mbuf *m;

	slp->ns_flag &= ~SLP_ALLFLAGS;
	if (fp = slp->ns_fp) {
		slp->ns_fp = (struct file *)0;
		so = slp->ns_so;
		so->so_upcall = NULL;
		soshutdown(so, 2);
		closef(fp, (struct proc *)0);
		if (slp->ns_nam)
			MFREE(slp->ns_nam, m);
		m_freem(slp->ns_raw);
		m_freem(slp->ns_rec);
		nuidp = slp->ns_lrunext;
		while (nuidp != (struct nfsuid *)slp) {
			onuidp = nuidp;
			nuidp = nuidp->nu_lrunext;
			free((caddr_t)onuidp, M_NFSUID);
		}
		slp->ns_lrunext = slp->ns_lruprev = (struct nfsuid *)slp;
		for (i = 0; i < NUIDHASHSIZ; i++)
			slp->ns_uidh[i] = (struct nfsuid *)0;
	}
}

/*
 * Get an authorization string for the uid by having the mount_nfs sitting
 * on this mount point porpous out of the kernel and do it.
 */
nfs_getauth(nmp, rep, cred, auth_type, auth_str, auth_len)
	register struct nfsmount *nmp;
	struct nfsreq *rep;
	struct ucred *cred;
	int *auth_type;
	char **auth_str;
	int *auth_len;
{
	int error = 0;

	while ((nmp->nm_flag & NFSMNT_WAITAUTH) == 0) {
		nmp->nm_flag |= NFSMNT_WANTAUTH;
		(void) tsleep((caddr_t)&nmp->nm_authtype, PSOCK,
			"nfsauth1", 2 * hz);
		if (error = nfs_sigintr(nmp, rep, rep->r_procp)) {
			nmp->nm_flag &= ~NFSMNT_WANTAUTH;
			return (error);
		}
	}
	nmp->nm_flag &= ~(NFSMNT_WAITAUTH | NFSMNT_WANTAUTH);
	nmp->nm_authstr = *auth_str = (char *)malloc(RPCAUTH_MAXSIZ, M_TEMP, M_WAITOK);
	nmp->nm_authuid = cred->cr_uid;
	wakeup((caddr_t)&nmp->nm_authstr);

	/*
	 * And wait for mount_nfs to do its stuff.
	 */
	while ((nmp->nm_flag & NFSMNT_HASAUTH) == 0 && error == 0) {
		(void) tsleep((caddr_t)&nmp->nm_authlen, PSOCK,
			"nfsauth2", 2 * hz);
		error = nfs_sigintr(nmp, rep, rep->r_procp);
	}
	if (nmp->nm_flag & NFSMNT_AUTHERR) {
		nmp->nm_flag &= ~NFSMNT_AUTHERR;
		error = EAUTH;
	}
	if (error)
		free((caddr_t)*auth_str, M_TEMP);
	else {
		*auth_type = nmp->nm_authtype;
		*auth_len = nmp->nm_authlen;
	}
	nmp->nm_flag &= ~NFSMNT_HASAUTH;
	nmp->nm_flag |= NFSMNT_WAITAUTH;
	if (nmp->nm_flag & NFSMNT_WANTAUTH) {
		nmp->nm_flag &= ~NFSMNT_WANTAUTH;
		wakeup((caddr_t)&nmp->nm_authtype);
	}
	return (error);
}

/*
 * Derefence a server socket structure. If it has no more references and
 * is no longer valid, you can throw it away.
 */
void
nfsrv_slpderef(slp)
	register struct nfssvc_sock *slp;
{
	if (--(slp->ns_sref) == 0 && (slp->ns_flag & SLP_VALID) == 0) {
		slp->ns_prev->ns_next = slp->ns_next;
		slp->ns_next->ns_prev = slp->ns_prev;
		free((caddr_t)slp, M_NFSSVC);
	}
}

/*
 * Initialize the data structures for the server.
 * Handshake with any new nfsds starting up to avoid any chance of
 * corruption.
 */
void
nfsrv_init(terminating)
	int terminating;
{
	register struct nfssvc_sock *slp;
	struct nfssvc_sock *oslp;

	if (nfssvc_sockhead.ns_flag & SLP_INIT)
		panic("nfsd init");
	nfssvc_sockhead.ns_flag |= SLP_INIT;
	if (terminating) {
		slp = nfssvc_sockhead.ns_next;
		while (slp != &nfssvc_sockhead) {
			if (slp->ns_flag & SLP_VALID)
				nfsrv_zapsock(slp);
			slp->ns_next->ns_prev = slp->ns_prev;
			slp->ns_prev->ns_next = slp->ns_next;
			oslp = slp;
			slp = slp->ns_next;
			free((caddr_t)oslp, M_NFSSVC);
		}
		nfsrv_cleancache();	/* And clear out server cache */
	}
	nfs_udpsock = (struct nfssvc_sock *)
	    malloc(sizeof (struct nfssvc_sock), M_NFSSVC, M_WAITOK);
	bzero((caddr_t)nfs_udpsock, sizeof (struct nfssvc_sock));
	nfs_cltpsock = (struct nfssvc_sock *)
	    malloc(sizeof (struct nfssvc_sock), M_NFSSVC, M_WAITOK);
	bzero((caddr_t)nfs_cltpsock, sizeof (struct nfssvc_sock));
	nfssvc_sockhead.ns_next = nfs_udpsock;
	nfs_udpsock->ns_next = nfs_cltpsock;
	nfs_cltpsock->ns_next = &nfssvc_sockhead;
	nfssvc_sockhead.ns_prev = nfs_cltpsock;
	nfs_cltpsock->ns_prev = nfs_udpsock;
	nfs_udpsock->ns_prev = &nfssvc_sockhead;
	nfs_udpsock->ns_lrunext = nfs_udpsock->ns_lruprev =
		(struct nfsuid *)nfs_udpsock;
	nfs_cltpsock->ns_lrunext = nfs_cltpsock->ns_lruprev =
		(struct nfsuid *)nfs_cltpsock;
	nfsd_head.nd_next = nfsd_head.nd_prev = &nfsd_head;
	nfsd_head.nd_flag = 0;
	nfssvc_sockhead.ns_flag &= ~SLP_INIT;
	if (nfssvc_sockhead.ns_flag & SLP_WANTINIT) {
		nfssvc_sockhead.ns_flag &= ~SLP_WANTINIT;
		wakeup((caddr_t)&nfssvc_sockhead);
	}
}

/*
 * Add entries to the server monitor log.
 */
static void
nfsd_rt(startp, sotype, nd, nam, cacherep)
	struct timeval *startp;
	int sotype;
	register struct nfsd *nd;
	struct mbuf *nam;
	int cacherep;
{
	register struct drt *rt;

	rt = &nfsdrt.drt[nfsdrt.pos];
	if (cacherep == RC_DOIT)
		rt->flag = 0;
	else if (cacherep == RC_REPLY)
		rt->flag = DRT_CACHEREPLY;
	else
		rt->flag = DRT_CACHEDROP;
	if (sotype == SOCK_STREAM)
		rt->flag |= DRT_TCP;
	if (nd->nd_nqlflag != NQL_NOVAL)
		rt->flag |= DRT_NQNFS;
	rt->proc = nd->nd_procnum;
	if (mtod(nam, struct sockaddr *)->sa_family == AF_INET)
		rt->ipadr = mtod(nam, struct sockaddr_in *)->sin_addr.s_addr;
	else
		rt->ipadr = INADDR_ANY;
	rt->resptime = ((time.tv_sec - startp->tv_sec) * 1000000) +
		(time.tv_usec - startp->tv_usec);
	rt->tstamp = time;
	nfsdrt.pos = (nfsdrt.pos + 1) % NFSRTTLOGSIZ;
}