/*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (c) 1989, 1993 * The Regents of the University of California. All rights reserved. * (c) UNIX System Laboratories, Inc. * All or some portions of this file are derived from material licensed * to the University of California by American Telephone and Telegraph * Co. or Unix System Laboratories, Inc. and are reproduced herein with * the permission of UNIX System Laboratories, Inc. * * 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. 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. */ #include #include "opt_inet.h" #include "opt_inet6.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static MALLOC_DEFINE(M_NETADDR, "export_host", "Export host address structure"); #if defined(INET) || defined(INET6) static struct radix_node_head *vfs_create_addrlist_af( struct radix_node_head **prnh, int off); #endif static int vfs_free_netcred(struct radix_node *rn, void *w); static void vfs_free_addrlist_af(struct radix_node_head **prnh); static int vfs_hang_addrlist(struct mount *mp, struct netexport *nep, struct export_args *argp); static struct netcred *vfs_export_lookup(struct mount *, struct sockaddr *); /* * Network address lookup element */ struct netcred { struct radix_node netc_rnodes[2]; uint64_t netc_exflags; struct ucred *netc_anon; int netc_numsecflavors; int netc_secflavors[MAXSECFLAVORS]; }; /* * Network export information */ struct netexport { struct netcred ne_defexported; /* Default export */ struct radix_node_head *ne4; struct radix_node_head *ne6; }; /* * Build hash lists of net addresses and hang them off the mount point. * Called by vfs_export() to set up the lists of export addresses. */ static int vfs_hang_addrlist(struct mount *mp, struct netexport *nep, struct export_args *argp) { struct netcred *np; struct radix_node_head *rnh; int i; struct radix_node *rn; struct sockaddr *saddr, *smask = NULL; #if defined(INET6) || defined(INET) int off; #endif int error; KASSERT(argp->ex_numsecflavors > 0, ("%s: numsecflavors <= 0", __func__)); KASSERT(argp->ex_numsecflavors < MAXSECFLAVORS, ("%s: numsecflavors >= MAXSECFLAVORS", __func__)); /* * XXX: This routine converts from a uid plus gid list * to a `struct ucred' (np->netc_anon). This * operation is questionable; for example, what should be done * with fields like cr_uidinfo and cr_prison? Currently, this * routine does not touch them (leaves them as NULL). */ if (argp->ex_addrlen == 0) { if (mp->mnt_flag & MNT_DEFEXPORTED) { vfs_mount_error(mp, "MNT_DEFEXPORTED already set for mount %p", mp); return (EPERM); } np = &nep->ne_defexported; np->netc_exflags = argp->ex_flags; np->netc_anon = crget(); np->netc_anon->cr_uid = argp->ex_uid; crsetgroups_fallback(np->netc_anon, argp->ex_ngroups, argp->ex_groups, GID_NOGROUP); np->netc_anon->cr_prison = &prison0; prison_hold(np->netc_anon->cr_prison); np->netc_numsecflavors = argp->ex_numsecflavors; bcopy(argp->ex_secflavors, np->netc_secflavors, sizeof(np->netc_secflavors)); MNT_ILOCK(mp); mp->mnt_flag |= MNT_DEFEXPORTED; MNT_IUNLOCK(mp); return (0); } #if MSIZE <= 256 if (argp->ex_addrlen > MLEN) { vfs_mount_error(mp, "ex_addrlen %d is greater than %d", argp->ex_addrlen, MLEN); return (EINVAL); } #endif i = sizeof(struct netcred) + argp->ex_addrlen + argp->ex_masklen; np = (struct netcred *) malloc(i, M_NETADDR, M_WAITOK | M_ZERO); saddr = (struct sockaddr *) (np + 1); if ((error = copyin(argp->ex_addr, saddr, argp->ex_addrlen))) goto out; if (saddr->sa_family == AF_UNSPEC || saddr->sa_family > AF_MAX) { error = EINVAL; vfs_mount_error(mp, "Invalid saddr->sa_family: %d"); goto out; } if (saddr->sa_len > argp->ex_addrlen) saddr->sa_len = argp->ex_addrlen; if (argp->ex_masklen) { smask = (struct sockaddr *)((caddr_t)saddr + argp->ex_addrlen); error = copyin(argp->ex_mask, smask, argp->ex_masklen); if (error) goto out; if (smask->sa_len > argp->ex_masklen) smask->sa_len = argp->ex_masklen; } rnh = NULL; switch (saddr->sa_family) { #ifdef INET case AF_INET: if ((rnh = nep->ne4) == NULL) { off = offsetof(struct sockaddr_in, sin_addr) << 3; rnh = vfs_create_addrlist_af(&nep->ne4, off); } break; #endif #ifdef INET6 case AF_INET6: if ((rnh = nep->ne6) == NULL) { off = offsetof(struct sockaddr_in6, sin6_addr) << 3; rnh = vfs_create_addrlist_af(&nep->ne6, off); } break; #endif } if (rnh == NULL) { error = ENOBUFS; vfs_mount_error(mp, "%s %s %d", "Unable to initialize radix node head ", "for address family", saddr->sa_family); goto out; } RADIX_NODE_HEAD_LOCK(rnh); rn = (*rnh->rnh_addaddr)(saddr, smask, &rnh->rh, np->netc_rnodes); RADIX_NODE_HEAD_UNLOCK(rnh); if (rn == NULL || np != (struct netcred *)rn) { /* already exists */ error = EPERM; vfs_mount_error(mp, "netcred already exists for given addr/mask"); goto out; } np->netc_exflags = argp->ex_flags; np->netc_anon = crget(); np->netc_anon->cr_uid = argp->ex_uid; crsetgroups_fallback(np->netc_anon, argp->ex_ngroups, argp->ex_groups, GID_NOGROUP); np->netc_anon->cr_prison = &prison0; prison_hold(np->netc_anon->cr_prison); np->netc_numsecflavors = argp->ex_numsecflavors; bcopy(argp->ex_secflavors, np->netc_secflavors, sizeof(np->netc_secflavors)); return (0); out: free(np, M_NETADDR); return (error); } /* Helper for vfs_free_addrlist. */ /* ARGSUSED */ static int vfs_free_netcred(struct radix_node *rn, void *w) { struct radix_node_head *rnh = (struct radix_node_head *) w; struct ucred *cred; (*rnh->rnh_deladdr) (rn->rn_key, rn->rn_mask, &rnh->rh); cred = ((struct netcred *)rn)->netc_anon; if (cred != NULL) crfree(cred); free(rn, M_NETADDR); return (0); } #if defined(INET) || defined(INET6) static struct radix_node_head * vfs_create_addrlist_af(struct radix_node_head **prnh, int off) { if (rn_inithead((void **)prnh, off) == 0) return (NULL); RADIX_NODE_HEAD_LOCK_INIT(*prnh); return (*prnh); } #endif static void vfs_free_addrlist_af(struct radix_node_head **prnh) { struct radix_node_head *rnh; rnh = *prnh; RADIX_NODE_HEAD_LOCK(rnh); (*rnh->rnh_walktree)(&rnh->rh, vfs_free_netcred, rnh); RADIX_NODE_HEAD_UNLOCK(rnh); RADIX_NODE_HEAD_DESTROY(rnh); rn_detachhead((void **)prnh); prnh = NULL; } /* * Free the net address hash lists that are hanging off the mount points. */ void vfs_free_addrlist(struct netexport *nep) { struct ucred *cred; if (nep->ne4 != NULL) vfs_free_addrlist_af(&nep->ne4); if (nep->ne6 != NULL) vfs_free_addrlist_af(&nep->ne6); cred = nep->ne_defexported.netc_anon; if (cred != NULL) { crfree(cred); nep->ne_defexported.netc_anon = NULL; } } /* * High level function to manipulate export options on a mount point * and the passed in netexport. * Struct export_args *argp is the variable used to twiddle options, * the structure is described in sys/mount.h * The do_exjail argument should be true if *mp is in the mountlist * and false if not. It is not in the mountlist for the NFSv4 rootfs * fake mount point just used for exports. */ int vfs_export(struct mount *mp, struct export_args *argp, bool do_exjail) { struct netexport *nep; struct ucred *cr; struct prison *pr; int error; bool new_nep; if ((argp->ex_flags & (MNT_DELEXPORT | MNT_EXPORTED)) == 0) return (EINVAL); if ((argp->ex_flags & MNT_EXPORTED) != 0 && (argp->ex_numsecflavors < 0 || argp->ex_numsecflavors >= MAXSECFLAVORS)) return (EINVAL); error = 0; pr = curthread->td_ucred->cr_prison; lockmgr(&mp->mnt_explock, LK_EXCLUSIVE, NULL); nep = mp->mnt_export; if (argp->ex_flags & MNT_DELEXPORT) { if (nep == NULL) { error = ENOENT; goto out; } MNT_ILOCK(mp); if (mp->mnt_exjail != NULL && mp->mnt_exjail->cr_prison != pr && pr == &prison0) { MNT_IUNLOCK(mp); /* EXDEV will not get logged by mountd(8). */ error = EXDEV; goto out; } else if (mp->mnt_exjail != NULL && mp->mnt_exjail->cr_prison != pr) { MNT_IUNLOCK(mp); /* EPERM will get logged by mountd(8). */ error = EPERM; goto out; } MNT_IUNLOCK(mp); if (mp->mnt_flag & MNT_EXPUBLIC) { vfs_setpublicfs(NULL, NULL, NULL); MNT_ILOCK(mp); mp->mnt_flag &= ~MNT_EXPUBLIC; MNT_IUNLOCK(mp); } vfs_free_addrlist(nep); mp->mnt_export = NULL; free(nep, M_MOUNT); nep = NULL; MNT_ILOCK(mp); cr = mp->mnt_exjail; mp->mnt_exjail = NULL; mp->mnt_flag &= ~(MNT_EXPORTED | MNT_DEFEXPORTED); MNT_IUNLOCK(mp); if (cr != NULL) { atomic_subtract_int(&pr->pr_exportcnt, 1); crfree(cr); } } if (argp->ex_flags & MNT_EXPORTED) { new_nep = false; MNT_ILOCK(mp); if (mp->mnt_exjail == NULL) { MNT_IUNLOCK(mp); if (do_exjail && nep != NULL) { vfs_free_addrlist(nep); memset(nep, 0, sizeof(*nep)); new_nep = true; } } else if (mp->mnt_exjail->cr_prison != pr) { MNT_IUNLOCK(mp); error = EPERM; goto out; } else MNT_IUNLOCK(mp); if (nep == NULL) { nep = malloc(sizeof(struct netexport), M_MOUNT, M_WAITOK | M_ZERO); mp->mnt_export = nep; new_nep = true; } if (argp->ex_flags & MNT_EXPUBLIC) { if ((error = vfs_setpublicfs(mp, nep, argp)) != 0) { if (new_nep) { mp->mnt_export = NULL; free(nep, M_MOUNT); } goto out; } new_nep = false; MNT_ILOCK(mp); if (do_exjail && mp->mnt_exjail == NULL) { mp->mnt_exjail = crhold(curthread->td_ucred); atomic_add_int(&pr->pr_exportcnt, 1); } mp->mnt_flag |= MNT_EXPUBLIC; MNT_IUNLOCK(mp); } if (argp->ex_numsecflavors == 0) { argp->ex_numsecflavors = 1; argp->ex_secflavors[0] = AUTH_SYS; } if ((error = vfs_hang_addrlist(mp, nep, argp))) { if (new_nep) { mp->mnt_export = NULL; free(nep, M_MOUNT); } goto out; } MNT_ILOCK(mp); if (do_exjail && mp->mnt_exjail == NULL) { mp->mnt_exjail = crhold(curthread->td_ucred); atomic_add_int(&pr->pr_exportcnt, 1); } mp->mnt_flag |= MNT_EXPORTED; MNT_IUNLOCK(mp); } out: lockmgr(&mp->mnt_explock, LK_RELEASE, NULL); /* * Once we have executed the vfs_export() command, we do * not want to keep the "export" option around in the * options list, since that will cause subsequent MNT_UPDATE * calls to fail. The export information is saved in * mp->mnt_export, so we can safely delete the "export" mount option * here. */ vfs_deleteopt(mp->mnt_optnew, "export"); vfs_deleteopt(mp->mnt_opt, "export"); return (error); } /* * Get rid of credential references for this prison. */ void vfs_exjail_delete(struct prison *pr) { struct mount *mp; struct ucred *cr; int error, i; /* * Since this function is called from prison_cleanup() after * all processes in the prison have exited, the value of * pr_exportcnt can no longer increase. It is possible for * a dismount of a file system exported within this prison * to be in progress. In this case, the file system is no * longer in the mountlist and the mnt_exjail will be free'd * by vfs_mount_destroy() at some time. As such, pr_exportcnt * and, therefore "i", is the upper bound on the number of * mnt_exjail entries to be found by this function. */ i = atomic_load_int(&pr->pr_exportcnt); KASSERT(i >= 0, ("vfs_exjail_delete: pr_exportcnt negative")); if (i == 0) return; mtx_lock(&mountlist_mtx); tryagain: TAILQ_FOREACH(mp, &mountlist, mnt_list) { MNT_ILOCK(mp); if (mp->mnt_exjail != NULL && mp->mnt_exjail->cr_prison == pr) { MNT_IUNLOCK(mp); error = vfs_busy(mp, MBF_MNTLSTLOCK | MBF_NOWAIT); if (error != 0) { /* * If the vfs_busy() fails, we still want to * get rid of mnt_exjail for two reasons: * - a credential reference will result in * a prison not being removed * - setting mnt_exjail NULL indicates that * the exports are no longer valid * The now invalid exports will be deleted * when the file system is dismounted or * the file system is re-exported by mountd. */ cr = NULL; MNT_ILOCK(mp); if (mp->mnt_exjail != NULL && mp->mnt_exjail->cr_prison == pr) { cr = mp->mnt_exjail; mp->mnt_exjail = NULL; } MNT_IUNLOCK(mp); if (cr != NULL) { crfree(cr); i--; } if (i == 0) break; continue; } cr = NULL; lockmgr(&mp->mnt_explock, LK_EXCLUSIVE, NULL); MNT_ILOCK(mp); if (mp->mnt_exjail != NULL && mp->mnt_exjail->cr_prison == pr) { cr = mp->mnt_exjail; mp->mnt_exjail = NULL; mp->mnt_flag &= ~(MNT_EXPORTED | MNT_DEFEXPORTED); MNT_IUNLOCK(mp); vfs_free_addrlist(mp->mnt_export); free(mp->mnt_export, M_MOUNT); mp->mnt_export = NULL; } else MNT_IUNLOCK(mp); lockmgr(&mp->mnt_explock, LK_RELEASE, NULL); if (cr != NULL) { crfree(cr); i--; } mtx_lock(&mountlist_mtx); vfs_unbusy(mp); if (i == 0) break; goto tryagain; } MNT_IUNLOCK(mp); } mtx_unlock(&mountlist_mtx); } /* * Set the publicly exported filesystem (WebNFS). Currently, only * one public filesystem is possible in the spec (RFC 2054 and 2055) */ int vfs_setpublicfs(struct mount *mp, struct netexport *nep, struct export_args *argp) { int error; struct vnode *rvp; char *cp; /* * mp == NULL -> invalidate the current info, the FS is * no longer exported. May be called from either vfs_export * or unmount, so check if it hasn't already been done. */ if (mp == NULL) { if (nfs_pub.np_valid) { nfs_pub.np_valid = 0; if (nfs_pub.np_index != NULL) { free(nfs_pub.np_index, M_TEMP); nfs_pub.np_index = NULL; } } return (0); } /* * Only one allowed at a time. */ if (nfs_pub.np_valid != 0 && mp != nfs_pub.np_mount) return (EBUSY); /* * Get real filehandle for root of exported FS. */ bzero(&nfs_pub.np_handle, sizeof(nfs_pub.np_handle)); nfs_pub.np_handle.fh_fsid = mp->mnt_stat.f_fsid; if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rvp))) return (error); if ((error = VOP_VPTOFH(rvp, &nfs_pub.np_handle.fh_fid))) return (error); vput(rvp); /* * If an indexfile was specified, pull it in. */ if (argp->ex_indexfile != NULL) { if (nfs_pub.np_index == NULL) nfs_pub.np_index = malloc(MAXNAMLEN + 1, M_TEMP, M_WAITOK); error = copyinstr(argp->ex_indexfile, nfs_pub.np_index, MAXNAMLEN, (size_t *)0); if (!error) { /* * Check for illegal filenames. */ for (cp = nfs_pub.np_index; *cp; cp++) { if (*cp == '/') { error = EINVAL; break; } } } if (error) { free(nfs_pub.np_index, M_TEMP); nfs_pub.np_index = NULL; return (error); } } nfs_pub.np_mount = mp; nfs_pub.np_valid = 1; return (0); } /* * Used by the filesystems to determine if a given network address * (passed in 'nam') is present in their exports list, returns a pointer * to struct netcred so that the filesystem can examine it for * access rights (read/write/etc). */ static struct netcred * vfs_export_lookup(struct mount *mp, struct sockaddr *nam) { RADIX_NODE_HEAD_RLOCK_TRACKER; struct netexport *nep; struct netcred *np = NULL; struct radix_node_head *rnh; struct sockaddr *saddr; nep = mp->mnt_export; if (nep == NULL) return (NULL); if ((mp->mnt_flag & MNT_EXPORTED) == 0) return (NULL); /* * Lookup in the export list */ if (nam != NULL) { saddr = nam; rnh = NULL; switch (saddr->sa_family) { case AF_INET: rnh = nep->ne4; break; case AF_INET6: rnh = nep->ne6; break; } if (rnh != NULL) { RADIX_NODE_HEAD_RLOCK(rnh); np = (struct netcred *) (*rnh->rnh_matchaddr)(saddr, &rnh->rh); RADIX_NODE_HEAD_RUNLOCK(rnh); if (np != NULL && (np->netc_rnodes->rn_flags & RNF_ROOT) != 0) return (NULL); } } /* * If no address match, use the default if it exists. */ if (np == NULL && (mp->mnt_flag & MNT_DEFEXPORTED) != 0) return (&nep->ne_defexported); return (np); } /* * XXX: This comment comes from the deprecated ufs_check_export() * XXX: and may not entirely apply, but lacking something better: * This is the generic part of fhtovp called after the underlying * filesystem has validated the file handle. * * Verify that a host should have access to a filesystem. */ int vfs_stdcheckexp(struct mount *mp, struct sockaddr *nam, uint64_t *extflagsp, struct ucred **credanonp, int *numsecflavors, int *secflavors) { struct netcred *np; lockmgr(&mp->mnt_explock, LK_SHARED, NULL); np = vfs_export_lookup(mp, nam); if (np == NULL) { lockmgr(&mp->mnt_explock, LK_RELEASE, NULL); *credanonp = NULL; return (EACCES); } *extflagsp = np->netc_exflags; if ((*credanonp = np->netc_anon) != NULL) crhold(*credanonp); if (numsecflavors) { *numsecflavors = np->netc_numsecflavors; KASSERT(*numsecflavors > 0, ("%s: numsecflavors <= 0", __func__)); KASSERT(*numsecflavors < MAXSECFLAVORS, ("%s: numsecflavors >= MAXSECFLAVORS", __func__)); } if (secflavors && np->netc_numsecflavors > 0) memcpy(secflavors, np->netc_secflavors, np->netc_numsecflavors * sizeof(int)); lockmgr(&mp->mnt_explock, LK_RELEASE, NULL); return (0); }