diff options
Diffstat (limited to 'fs/nfs/namespace.c')
-rw-r--r-- | fs/nfs/namespace.c | 181 |
1 files changed, 154 insertions, 27 deletions
diff --git a/fs/nfs/namespace.c b/fs/nfs/namespace.c index f32b8603dca..9166fcb66da 100644 --- a/fs/nfs/namespace.c +++ b/fs/nfs/namespace.c @@ -15,6 +15,7 @@ #include <linux/string.h> #include <linux/sunrpc/clnt.h> #include <linux/vfs.h> +#include <linux/sunrpc/gss_api.h> #include "internal.h" #define NFSDBG_FACILITY NFSDBG_VFS @@ -25,33 +26,31 @@ static LIST_HEAD(nfs_automount_list); static DECLARE_DELAYED_WORK(nfs_automount_task, nfs_expire_automounts); int nfs_mountpoint_expiry_timeout = 500 * HZ; -static struct vfsmount *nfs_do_submount(const struct vfsmount *mnt_parent, - const struct dentry *dentry, +static struct vfsmount *nfs_do_submount(struct dentry *dentry, struct nfs_fh *fh, - struct nfs_fattr *fattr); + struct nfs_fattr *fattr, + rpc_authflavor_t authflavor); /* * nfs_path - reconstruct the path given an arbitrary dentry - * @base - arbitrary string to prepend to the path - * @droot - pointer to root dentry for mountpoint + * @base - used to return pointer to the end of devname part of path * @dentry - pointer to dentry * @buffer - result buffer * @buflen - length of buffer * - * Helper function for constructing the path from the - * root dentry to an arbitrary hashed dentry. + * Helper function for constructing the server pathname + * by arbitrary hashed dentry. * * This is mainly for use in figuring out the path on the - * server side when automounting on top of an existing partition. + * server side when automounting on top of an existing partition + * and in generating /proc/mounts and friends. */ -char *nfs_path(const char *base, - const struct dentry *droot, - const struct dentry *dentry, - char *buffer, ssize_t buflen) +char *nfs_path(char **p, struct dentry *dentry, char *buffer, ssize_t buflen) { char *end; int namelen; unsigned seq; + const char *base; rename_retry: end = buffer+buflen; @@ -60,7 +59,10 @@ rename_retry: seq = read_seqbegin(&rename_lock); rcu_read_lock(); - while (!IS_ROOT(dentry) && dentry != droot) { + while (1) { + spin_lock(&dentry->d_lock); + if (IS_ROOT(dentry)) + break; namelen = dentry->d_name.len; buflen -= namelen + 1; if (buflen < 0) @@ -68,27 +70,47 @@ rename_retry: end -= namelen; memcpy(end, dentry->d_name.name, namelen); *--end = '/'; + spin_unlock(&dentry->d_lock); dentry = dentry->d_parent; } - rcu_read_unlock(); - if (read_seqretry(&rename_lock, seq)) + if (read_seqretry(&rename_lock, seq)) { + spin_unlock(&dentry->d_lock); + rcu_read_unlock(); goto rename_retry; + } if (*end != '/') { - if (--buflen < 0) + if (--buflen < 0) { + spin_unlock(&dentry->d_lock); + rcu_read_unlock(); goto Elong; + } *--end = '/'; } + *p = end; + base = dentry->d_fsdata; + if (!base) { + spin_unlock(&dentry->d_lock); + rcu_read_unlock(); + WARN_ON(1); + return end; + } namelen = strlen(base); /* Strip off excess slashes in base string */ while (namelen > 0 && base[namelen - 1] == '/') namelen--; buflen -= namelen; - if (buflen < 0) + if (buflen < 0) { + spin_unlock(&dentry->d_lock); + rcu_read_unlock(); goto Elong; + } end -= namelen; memcpy(end, base, namelen); + spin_unlock(&dentry->d_lock); + rcu_read_unlock(); return end; Elong_unlock: + spin_unlock(&dentry->d_lock); rcu_read_unlock(); if (read_seqretry(&rename_lock, seq)) goto rename_retry; @@ -96,6 +118,102 @@ Elong: return ERR_PTR(-ENAMETOOLONG); } +#ifdef CONFIG_NFS_V4 +static rpc_authflavor_t nfs_find_best_sec(struct nfs4_secinfo_flavors *flavors, struct inode *inode) +{ + struct gss_api_mech *mech; + struct xdr_netobj oid; + int i; + rpc_authflavor_t pseudoflavor = RPC_AUTH_UNIX; + + for (i = 0; i < flavors->num_flavors; i++) { + struct nfs4_secinfo_flavor *flavor; + flavor = &flavors->flavors[i]; + + if (flavor->flavor == RPC_AUTH_NULL || flavor->flavor == RPC_AUTH_UNIX) { + pseudoflavor = flavor->flavor; + break; + } else if (flavor->flavor == RPC_AUTH_GSS) { + oid.len = flavor->gss.sec_oid4.len; + oid.data = flavor->gss.sec_oid4.data; + mech = gss_mech_get_by_OID(&oid); + if (!mech) + continue; + pseudoflavor = gss_svc_to_pseudoflavor(mech, flavor->gss.service); + gss_mech_put(mech); + break; + } + } + + return pseudoflavor; +} + +static rpc_authflavor_t nfs_negotiate_security(const struct dentry *parent, const struct dentry *dentry) +{ + int status = 0; + struct page *page; + struct nfs4_secinfo_flavors *flavors; + int (*secinfo)(struct inode *, const struct qstr *, struct nfs4_secinfo_flavors *); + rpc_authflavor_t flavor = RPC_AUTH_UNIX; + + secinfo = NFS_PROTO(parent->d_inode)->secinfo; + if (secinfo != NULL) { + page = alloc_page(GFP_KERNEL); + if (!page) { + status = -ENOMEM; + goto out; + } + flavors = page_address(page); + status = secinfo(parent->d_inode, &dentry->d_name, flavors); + flavor = nfs_find_best_sec(flavors, dentry->d_inode); + put_page(page); + } + + return flavor; + +out: + status = -ENOMEM; + return status; +} + +static rpc_authflavor_t nfs_lookup_with_sec(struct nfs_server *server, struct dentry *parent, + struct dentry *dentry, struct path *path, + struct nfs_fh *fh, struct nfs_fattr *fattr) +{ + rpc_authflavor_t flavor; + struct rpc_clnt *clone; + struct rpc_auth *auth; + int err; + + flavor = nfs_negotiate_security(parent, path->dentry); + if (flavor < 0) + goto out; + clone = rpc_clone_client(server->client); + auth = rpcauth_create(flavor, clone); + if (!auth) { + flavor = -EIO; + goto out_shutdown; + } + err = server->nfs_client->rpc_ops->lookup(clone, parent->d_inode, + &path->dentry->d_name, + fh, fattr); + if (err < 0) + flavor = err; +out_shutdown: + rpc_shutdown_client(clone); +out: + return flavor; +} +#else /* CONFIG_NFS_V4 */ +static inline rpc_authflavor_t nfs_lookup_with_sec(struct nfs_server *server, + struct dentry *parent, struct dentry *dentry, + struct path *path, struct nfs_fh *fh, + struct nfs_fattr *fattr) +{ + return -EPERM; +} +#endif /* CONFIG_NFS_V4 */ + /* * nfs_d_automount - Handle crossing a mountpoint on the server * @path - The mountpoint @@ -116,6 +234,7 @@ struct vfsmount *nfs_d_automount(struct path *path) struct nfs_fh *fh = NULL; struct nfs_fattr *fattr = NULL; int err; + rpc_authflavor_t flavor = 1; dprintk("--> nfs_d_automount()\n"); @@ -133,9 +252,16 @@ struct vfsmount *nfs_d_automount(struct path *path) /* Look it up again to get its attributes */ parent = dget_parent(path->dentry); - err = server->nfs_client->rpc_ops->lookup(parent->d_inode, + err = server->nfs_client->rpc_ops->lookup(server->client, parent->d_inode, &path->dentry->d_name, fh, fattr); + if (err == -EPERM) { + flavor = nfs_lookup_with_sec(server, parent, path->dentry, path, fh, fattr); + if (flavor < 0) + err = flavor; + else + err = 0; + } dput(parent); if (err != 0) { mnt = ERR_PTR(err); @@ -143,9 +269,9 @@ struct vfsmount *nfs_d_automount(struct path *path) } if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) - mnt = nfs_do_refmount(path->mnt, path->dentry); + mnt = nfs_do_refmount(path->dentry); else - mnt = nfs_do_submount(path->mnt, path->dentry, fh, fattr); + mnt = nfs_do_submount(path->dentry, fh, fattr, flavor); if (IS_ERR(mnt)) goto out; @@ -209,22 +335,23 @@ static struct vfsmount *nfs_do_clone_mount(struct nfs_server *server, /** * nfs_do_submount - set up mountpoint when crossing a filesystem boundary - * @mnt_parent - mountpoint of parent directory * @dentry - parent directory * @fh - filehandle for new root dentry * @fattr - attributes for new root inode + * @authflavor - security flavor to use when performing the mount * */ -static struct vfsmount *nfs_do_submount(const struct vfsmount *mnt_parent, - const struct dentry *dentry, +static struct vfsmount *nfs_do_submount(struct dentry *dentry, struct nfs_fh *fh, - struct nfs_fattr *fattr) + struct nfs_fattr *fattr, + rpc_authflavor_t authflavor) { struct nfs_clone_mount mountdata = { - .sb = mnt_parent->mnt_sb, + .sb = dentry->d_sb, .dentry = dentry, .fh = fh, .fattr = fattr, + .authflavor = authflavor, }; struct vfsmount *mnt = ERR_PTR(-ENOMEM); char *page = (char *) __get_free_page(GFP_USER); @@ -237,11 +364,11 @@ static struct vfsmount *nfs_do_submount(const struct vfsmount *mnt_parent, dentry->d_name.name); if (page == NULL) goto out; - devname = nfs_devname(mnt_parent, dentry, page, PAGE_SIZE); + devname = nfs_devname(dentry, page, PAGE_SIZE); mnt = (struct vfsmount *)devname; if (IS_ERR(devname)) goto free_page; - mnt = nfs_do_clone_mount(NFS_SB(mnt_parent->mnt_sb), devname, &mountdata); + mnt = nfs_do_clone_mount(NFS_SB(dentry->d_sb), devname, &mountdata); free_page: free_page((unsigned long)page); out: |