1f7b422b1SDavid Howells /* 2f7b422b1SDavid Howells * linux/fs/nfs/nfs4namespace.c 3f7b422b1SDavid Howells * 4f7b422b1SDavid Howells * Copyright (C) 2005 Trond Myklebust <Trond.Myklebust@netapp.com> 554ceac45SDavid Howells * - Modified by David Howells <dhowells@redhat.com> 6f7b422b1SDavid Howells * 7f7b422b1SDavid Howells * NFSv4 namespace 8f7b422b1SDavid Howells */ 9f7b422b1SDavid Howells 10f7b422b1SDavid Howells #include <linux/dcache.h> 11f7b422b1SDavid Howells #include <linux/mount.h> 12f7b422b1SDavid Howells #include <linux/namei.h> 13f7b422b1SDavid Howells #include <linux/nfs_fs.h> 145a0e3ad6STejun Heo #include <linux/slab.h> 15f7b422b1SDavid Howells #include <linux/string.h> 16f7b422b1SDavid Howells #include <linux/sunrpc/clnt.h> 17f7b422b1SDavid Howells #include <linux/vfs.h> 18f7b422b1SDavid Howells #include <linux/inet.h> 19f7b422b1SDavid Howells #include "internal.h" 20c228fd3aSTrond Myklebust #include "nfs4_fs.h" 217d7ea882STrond Myklebust #include "dns_resolve.h" 22f7b422b1SDavid Howells 23f7b422b1SDavid Howells #define NFSDBG_FACILITY NFSDBG_VFS 24f7b422b1SDavid Howells 25f7b422b1SDavid Howells /* 26ef95d31eSTrond Myklebust * Convert the NFSv4 pathname components into a standard posix path. 27ef95d31eSTrond Myklebust * 28ef95d31eSTrond Myklebust * Note that the resulting string will be placed at the end of the buffer 29f7b422b1SDavid Howells */ 30509de811SDavid Howells static inline char *nfs4_pathname_string(const struct nfs4_pathname *pathname, 31f7b422b1SDavid Howells char *buffer, ssize_t buflen) 32f7b422b1SDavid Howells { 33f7b422b1SDavid Howells char *end = buffer + buflen; 34f7b422b1SDavid Howells int n; 35f7b422b1SDavid Howells 36f7b422b1SDavid Howells *--end = '\0'; 37f7b422b1SDavid Howells buflen--; 38f7b422b1SDavid Howells 39f7b422b1SDavid Howells n = pathname->ncomponents; 40f7b422b1SDavid Howells while (--n >= 0) { 41509de811SDavid Howells const struct nfs4_string *component = &pathname->components[n]; 42f7b422b1SDavid Howells buflen -= component->len + 1; 43f7b422b1SDavid Howells if (buflen < 0) 44f7b422b1SDavid Howells goto Elong; 45f7b422b1SDavid Howells end -= component->len; 46f7b422b1SDavid Howells memcpy(end, component->data, component->len); 47f7b422b1SDavid Howells *--end = '/'; 48f7b422b1SDavid Howells } 49f7b422b1SDavid Howells return end; 50f7b422b1SDavid Howells Elong: 51f7b422b1SDavid Howells return ERR_PTR(-ENAMETOOLONG); 52f7b422b1SDavid Howells } 53f7b422b1SDavid Howells 5454ceac45SDavid Howells /* 5554ceac45SDavid Howells * Determine the mount path as a string 5654ceac45SDavid Howells */ 57b514f872SAl Viro static char *nfs4_path(struct dentry *dentry, char *buffer, ssize_t buflen) 5854ceac45SDavid Howells { 59b514f872SAl Viro char *limit; 60b514f872SAl Viro char *path = nfs_path(&limit, dentry, buffer, buflen); 61b514f872SAl Viro if (!IS_ERR(path)) { 62b514f872SAl Viro char *colon = strchr(path, ':'); 63b514f872SAl Viro if (colon && colon < limit) 64b514f872SAl Viro path = colon + 1; 65b514f872SAl Viro } 66b514f872SAl Viro return path; 6754ceac45SDavid Howells } 6854ceac45SDavid Howells 6954ceac45SDavid Howells /* 7054ceac45SDavid Howells * Check that fs_locations::fs_root [RFC3530 6.3] is a prefix for what we 7154ceac45SDavid Howells * believe to be the server path to this dentry 7254ceac45SDavid Howells */ 73b514f872SAl Viro static int nfs4_validate_fspath(struct dentry *dentry, 7454ceac45SDavid Howells const struct nfs4_fs_locations *locations, 7554ceac45SDavid Howells char *page, char *page2) 7654ceac45SDavid Howells { 7754ceac45SDavid Howells const char *path, *fs_path; 7854ceac45SDavid Howells 79b514f872SAl Viro path = nfs4_path(dentry, page, PAGE_SIZE); 8054ceac45SDavid Howells if (IS_ERR(path)) 8154ceac45SDavid Howells return PTR_ERR(path); 8254ceac45SDavid Howells 8354ceac45SDavid Howells fs_path = nfs4_pathname_string(&locations->fs_path, page2, PAGE_SIZE); 8454ceac45SDavid Howells if (IS_ERR(fs_path)) 8554ceac45SDavid Howells return PTR_ERR(fs_path); 8654ceac45SDavid Howells 8754ceac45SDavid Howells if (strncmp(path, fs_path, strlen(fs_path)) != 0) { 8854ceac45SDavid Howells dprintk("%s: path %s does not begin with fsroot %s\n", 893110ff80SHarvey Harrison __func__, path, fs_path); 9054ceac45SDavid Howells return -ENOENT; 9154ceac45SDavid Howells } 9254ceac45SDavid Howells 9354ceac45SDavid Howells return 0; 9454ceac45SDavid Howells } 9554ceac45SDavid Howells 967d7ea882STrond Myklebust static size_t nfs_parse_server_name(char *string, size_t len, 971b340d01SStanislav Kinsbursky struct sockaddr *sa, size_t salen, struct nfs_server *server) 987d7ea882STrond Myklebust { 997d7ea882STrond Myklebust ssize_t ret; 10033faaa38SStanislav Kinsbursky struct net *net = server->client->cl_xprt->xprt_net; 1017d7ea882STrond Myklebust 10233faaa38SStanislav Kinsbursky ret = rpc_pton(net, string, len, sa, salen); 1037d7ea882STrond Myklebust if (ret == 0) { 10433faaa38SStanislav Kinsbursky ret = nfs_dns_resolve_name(net, string, len, sa, salen); 1057d7ea882STrond Myklebust if (ret < 0) 1067d7ea882STrond Myklebust ret = 0; 1077d7ea882STrond Myklebust } 1087d7ea882STrond Myklebust return ret; 1097d7ea882STrond Myklebust } 1107d7ea882STrond Myklebust 1114ada29d5SJ. Bruce Fields static struct vfsmount *try_location(struct nfs_clone_mount *mountdata, 1124ada29d5SJ. Bruce Fields char *page, char *page2, 1134ada29d5SJ. Bruce Fields const struct nfs4_fs_location *location) 1144ada29d5SJ. Bruce Fields { 115364d015eSTrond Myklebust const size_t addr_bufsize = sizeof(struct sockaddr_storage); 1164ada29d5SJ. Bruce Fields struct vfsmount *mnt = ERR_PTR(-ENOENT); 1174ada29d5SJ. Bruce Fields char *mnt_path; 118ef95d31eSTrond Myklebust unsigned int maxbuflen; 119460cdbc8SJ. Bruce Fields unsigned int s; 1204ada29d5SJ. Bruce Fields 1214ada29d5SJ. Bruce Fields mnt_path = nfs4_pathname_string(&location->rootpath, page2, PAGE_SIZE); 1224ada29d5SJ. Bruce Fields if (IS_ERR(mnt_path)) 123517be09dSTrond Myklebust return ERR_CAST(mnt_path); 1244ada29d5SJ. Bruce Fields mountdata->mnt_path = mnt_path; 125ef95d31eSTrond Myklebust maxbuflen = mnt_path - 1 - page2; 1264ada29d5SJ. Bruce Fields 127364d015eSTrond Myklebust mountdata->addr = kmalloc(addr_bufsize, GFP_KERNEL); 128364d015eSTrond Myklebust if (mountdata->addr == NULL) 129364d015eSTrond Myklebust return ERR_PTR(-ENOMEM); 130364d015eSTrond Myklebust 131460cdbc8SJ. Bruce Fields for (s = 0; s < location->nservers; s++) { 132ea31a443SJ. Bruce Fields const struct nfs4_string *buf = &location->servers[s]; 1334ada29d5SJ. Bruce Fields 134ef95d31eSTrond Myklebust if (buf->len <= 0 || buf->len >= maxbuflen) 1354ada29d5SJ. Bruce Fields continue; 1364ada29d5SJ. Bruce Fields 137ea31a443SJ. Bruce Fields if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len)) 138ea31a443SJ. Bruce Fields continue; 139517be09dSTrond Myklebust 140517be09dSTrond Myklebust mountdata->addrlen = nfs_parse_server_name(buf->data, buf->len, 1411b340d01SStanislav Kinsbursky mountdata->addr, addr_bufsize, 1421b340d01SStanislav Kinsbursky NFS_SB(mountdata->sb)); 14353a0b9c4SChuck Lever if (mountdata->addrlen == 0) 144ea31a443SJ. Bruce Fields continue; 145517be09dSTrond Myklebust 146ec6ee612SChuck Lever rpc_set_port(mountdata->addr, NFS_PORT); 147ea31a443SJ. Bruce Fields 148ef95d31eSTrond Myklebust memcpy(page2, buf->data, buf->len); 149ef95d31eSTrond Myklebust page2[buf->len] = '\0'; 150ea31a443SJ. Bruce Fields mountdata->hostname = page2; 1514ada29d5SJ. Bruce Fields 1524ada29d5SJ. Bruce Fields snprintf(page, PAGE_SIZE, "%s:%s", 1534ada29d5SJ. Bruce Fields mountdata->hostname, 1544ada29d5SJ. Bruce Fields mountdata->mnt_path); 1554ada29d5SJ. Bruce Fields 1564ada29d5SJ. Bruce Fields mnt = vfs_kern_mount(&nfs4_referral_fs_type, 0, page, mountdata); 1574ada29d5SJ. Bruce Fields if (!IS_ERR(mnt)) 1584ada29d5SJ. Bruce Fields break; 1594ada29d5SJ. Bruce Fields } 160364d015eSTrond Myklebust kfree(mountdata->addr); 1614ada29d5SJ. Bruce Fields return mnt; 1624ada29d5SJ. Bruce Fields } 1634ada29d5SJ. Bruce Fields 164f7b422b1SDavid Howells /** 165f7b422b1SDavid Howells * nfs_follow_referral - set up mountpoint when hitting a referral on moved error 166f7b422b1SDavid Howells * @dentry - parent directory 1673f43c666SChuck Lever * @locations - array of NFSv4 server location information 168f7b422b1SDavid Howells * 169f7b422b1SDavid Howells */ 170f8ad9c4bSAl Viro static struct vfsmount *nfs_follow_referral(struct dentry *dentry, 171509de811SDavid Howells const struct nfs4_fs_locations *locations) 172f7b422b1SDavid Howells { 173f7b422b1SDavid Howells struct vfsmount *mnt = ERR_PTR(-ENOENT); 174f7b422b1SDavid Howells struct nfs_clone_mount mountdata = { 175f8ad9c4bSAl Viro .sb = dentry->d_sb, 176f7b422b1SDavid Howells .dentry = dentry, 177f8ad9c4bSAl Viro .authflavor = NFS_SB(dentry->d_sb)->client->cl_auth->au_flavor, 178f7b422b1SDavid Howells }; 17954ceac45SDavid Howells char *page = NULL, *page2 = NULL; 1803f43c666SChuck Lever int loc, error; 181f7b422b1SDavid Howells 182f7b422b1SDavid Howells if (locations == NULL || locations->nlocations <= 0) 183f7b422b1SDavid Howells goto out; 184f7b422b1SDavid Howells 1853110ff80SHarvey Harrison dprintk("%s: referral at %s/%s\n", __func__, 186f7b422b1SDavid Howells dentry->d_parent->d_name.name, dentry->d_name.name); 187f7b422b1SDavid Howells 188f7b422b1SDavid Howells page = (char *) __get_free_page(GFP_USER); 18954ceac45SDavid Howells if (!page) 190f7b422b1SDavid Howells goto out; 19154ceac45SDavid Howells 192f7b422b1SDavid Howells page2 = (char *) __get_free_page(GFP_USER); 19354ceac45SDavid Howells if (!page2) 194f7b422b1SDavid Howells goto out; 195f7b422b1SDavid Howells 19654ceac45SDavid Howells /* Ensure fs path is a prefix of current dentry path */ 197b514f872SAl Viro error = nfs4_validate_fspath(dentry, locations, page, page2); 19854ceac45SDavid Howells if (error < 0) { 19954ceac45SDavid Howells mnt = ERR_PTR(error); 20054ceac45SDavid Howells goto out; 201f7b422b1SDavid Howells } 202f7b422b1SDavid Howells 203460cdbc8SJ. Bruce Fields for (loc = 0; loc < locations->nlocations; loc++) { 204509de811SDavid Howells const struct nfs4_fs_location *location = &locations->locations[loc]; 205f7b422b1SDavid Howells 206f7b422b1SDavid Howells if (location == NULL || location->nservers <= 0 || 207460cdbc8SJ. Bruce Fields location->rootpath.ncomponents == 0) 208f7b422b1SDavid Howells continue; 209f7b422b1SDavid Howells 2104ada29d5SJ. Bruce Fields mnt = try_location(&mountdata, page, page2, location); 2114ada29d5SJ. Bruce Fields if (!IS_ERR(mnt)) 212f7b422b1SDavid Howells break; 213f7b422b1SDavid Howells } 214f7b422b1SDavid Howells 21554ceac45SDavid Howells out: 216f7b422b1SDavid Howells free_page((unsigned long) page); 217f7b422b1SDavid Howells free_page((unsigned long) page2); 2183110ff80SHarvey Harrison dprintk("%s: done\n", __func__); 219f7b422b1SDavid Howells return mnt; 220f7b422b1SDavid Howells } 221f7b422b1SDavid Howells 222f7b422b1SDavid Howells /* 223f7b422b1SDavid Howells * nfs_do_refmount - handle crossing a referral on server 224f7b422b1SDavid Howells * @dentry - dentry of referral 225f7b422b1SDavid Howells * 226f7b422b1SDavid Howells */ 227f8ad9c4bSAl Viro struct vfsmount *nfs_do_refmount(struct dentry *dentry) 228f7b422b1SDavid Howells { 22954ceac45SDavid Howells struct vfsmount *mnt = ERR_PTR(-ENOMEM); 230f7b422b1SDavid Howells struct dentry *parent; 231f7b422b1SDavid Howells struct nfs4_fs_locations *fs_locations = NULL; 232f7b422b1SDavid Howells struct page *page; 233f7b422b1SDavid Howells int err; 234f7b422b1SDavid Howells 235f7b422b1SDavid Howells /* BUG_ON(IS_ROOT(dentry)); */ 2363110ff80SHarvey Harrison dprintk("%s: enter\n", __func__); 237f7b422b1SDavid Howells 238f7b422b1SDavid Howells page = alloc_page(GFP_KERNEL); 239f7b422b1SDavid Howells if (page == NULL) 240f7b422b1SDavid Howells goto out; 241f7b422b1SDavid Howells 242f7b422b1SDavid Howells fs_locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL); 243f7b422b1SDavid Howells if (fs_locations == NULL) 244f7b422b1SDavid Howells goto out_free; 245f7b422b1SDavid Howells 246f7b422b1SDavid Howells /* Get locations */ 24754ceac45SDavid Howells mnt = ERR_PTR(-ENOENT); 24854ceac45SDavid Howells 249f7b422b1SDavid Howells parent = dget_parent(dentry); 25054ceac45SDavid Howells dprintk("%s: getting locations for %s/%s\n", 2513110ff80SHarvey Harrison __func__, parent->d_name.name, dentry->d_name.name); 25254ceac45SDavid Howells 253c228fd3aSTrond Myklebust err = nfs4_proc_fs_locations(parent->d_inode, &dentry->d_name, fs_locations, page); 254f7b422b1SDavid Howells dput(parent); 25554ceac45SDavid Howells if (err != 0 || 25654ceac45SDavid Howells fs_locations->nlocations <= 0 || 257f7b422b1SDavid Howells fs_locations->fs_path.ncomponents <= 0) 258f7b422b1SDavid Howells goto out_free; 259f7b422b1SDavid Howells 260f8ad9c4bSAl Viro mnt = nfs_follow_referral(dentry, fs_locations); 261f7b422b1SDavid Howells out_free: 262f7b422b1SDavid Howells __free_page(page); 263f7b422b1SDavid Howells kfree(fs_locations); 264f7b422b1SDavid Howells out: 2653110ff80SHarvey Harrison dprintk("%s: done\n", __func__); 266f7b422b1SDavid Howells return mnt; 267f7b422b1SDavid Howells } 268