forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
577 lines
14 KiB
577 lines
14 KiB
// SPDX-License-Identifier: GPL-2.0 |
|
/* |
|
* linux/fs/nfs/nfs4namespace.c |
|
* |
|
* Copyright (C) 2005 Trond Myklebust <[email protected]> |
|
* - Modified by David Howells <[email protected]> |
|
* |
|
* NFSv4 namespace |
|
*/ |
|
|
|
#include <linux/module.h> |
|
#include <linux/dcache.h> |
|
#include <linux/mount.h> |
|
#include <linux/namei.h> |
|
#include <linux/nfs_fs.h> |
|
#include <linux/nfs_mount.h> |
|
#include <linux/slab.h> |
|
#include <linux/string.h> |
|
#include <linux/sunrpc/clnt.h> |
|
#include <linux/sunrpc/addr.h> |
|
#include <linux/vfs.h> |
|
#include <linux/inet.h> |
|
#include "internal.h" |
|
#include "nfs4_fs.h" |
|
#include "nfs.h" |
|
#include "dns_resolve.h" |
|
|
|
#define NFSDBG_FACILITY NFSDBG_VFS |
|
|
|
/* |
|
* Work out the length that an NFSv4 path would render to as a standard posix |
|
* path, with a leading slash but no terminating slash. |
|
*/ |
|
static ssize_t nfs4_pathname_len(const struct nfs4_pathname *pathname) |
|
{ |
|
ssize_t len = 0; |
|
int i; |
|
|
|
for (i = 0; i < pathname->ncomponents; i++) { |
|
const struct nfs4_string *component = &pathname->components[i]; |
|
|
|
if (component->len > NAME_MAX) |
|
goto too_long; |
|
len += 1 + component->len; /* Adding "/foo" */ |
|
if (len > PATH_MAX) |
|
goto too_long; |
|
} |
|
return len; |
|
|
|
too_long: |
|
return -ENAMETOOLONG; |
|
} |
|
|
|
/* |
|
* Convert the NFSv4 pathname components into a standard posix path. |
|
*/ |
|
static char *nfs4_pathname_string(const struct nfs4_pathname *pathname, |
|
unsigned short *_len) |
|
{ |
|
ssize_t len; |
|
char *buf, *p; |
|
int i; |
|
|
|
len = nfs4_pathname_len(pathname); |
|
if (len < 0) |
|
return ERR_PTR(len); |
|
*_len = len; |
|
|
|
p = buf = kmalloc(len + 1, GFP_KERNEL); |
|
if (!buf) |
|
return ERR_PTR(-ENOMEM); |
|
|
|
for (i = 0; i < pathname->ncomponents; i++) { |
|
const struct nfs4_string *component = &pathname->components[i]; |
|
|
|
*p++ = '/'; |
|
memcpy(p, component->data, component->len); |
|
p += component->len; |
|
} |
|
|
|
*p = 0; |
|
return buf; |
|
} |
|
|
|
/* |
|
* return the path component of "<server>:<path>" |
|
* nfspath - the "<server>:<path>" string |
|
* end - one past the last char that could contain "<server>:" |
|
* returns NULL on failure |
|
*/ |
|
static char *nfs_path_component(const char *nfspath, const char *end) |
|
{ |
|
char *p; |
|
|
|
if (*nfspath == '[') { |
|
/* parse [] escaped IPv6 addrs */ |
|
p = strchr(nfspath, ']'); |
|
if (p != NULL && ++p < end && *p == ':') |
|
return p + 1; |
|
} else { |
|
/* otherwise split on first colon */ |
|
p = strchr(nfspath, ':'); |
|
if (p != NULL && p < end) |
|
return p + 1; |
|
} |
|
return NULL; |
|
} |
|
|
|
/* |
|
* Determine the mount path as a string |
|
*/ |
|
static char *nfs4_path(struct dentry *dentry, char *buffer, ssize_t buflen) |
|
{ |
|
char *limit; |
|
char *path = nfs_path(&limit, dentry, buffer, buflen, |
|
NFS_PATH_CANONICAL); |
|
if (!IS_ERR(path)) { |
|
char *path_component = nfs_path_component(path, limit); |
|
if (path_component) |
|
return path_component; |
|
} |
|
return path; |
|
} |
|
|
|
/* |
|
* Check that fs_locations::fs_root [RFC3530 6.3] is a prefix for what we |
|
* believe to be the server path to this dentry |
|
*/ |
|
static int nfs4_validate_fspath(struct dentry *dentry, |
|
const struct nfs4_fs_locations *locations, |
|
struct nfs_fs_context *ctx) |
|
{ |
|
const char *path; |
|
char *fs_path; |
|
unsigned short len; |
|
char *buf; |
|
int n; |
|
|
|
buf = kmalloc(4096, GFP_KERNEL); |
|
if (!buf) |
|
return -ENOMEM; |
|
|
|
path = nfs4_path(dentry, buf, 4096); |
|
if (IS_ERR(path)) { |
|
kfree(buf); |
|
return PTR_ERR(path); |
|
} |
|
|
|
fs_path = nfs4_pathname_string(&locations->fs_path, &len); |
|
if (IS_ERR(fs_path)) { |
|
kfree(buf); |
|
return PTR_ERR(fs_path); |
|
} |
|
|
|
n = strncmp(path, fs_path, len); |
|
kfree(buf); |
|
kfree(fs_path); |
|
if (n != 0) { |
|
dprintk("%s: path %s does not begin with fsroot %s\n", |
|
__func__, path, ctx->nfs_server.export_path); |
|
return -ENOENT; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
size_t nfs_parse_server_name(char *string, size_t len, struct sockaddr *sa, |
|
size_t salen, struct net *net, int port) |
|
{ |
|
ssize_t ret; |
|
|
|
ret = rpc_pton(net, string, len, sa, salen); |
|
if (ret == 0) { |
|
ret = rpc_uaddr2sockaddr(net, string, len, sa, salen); |
|
if (ret == 0) { |
|
ret = nfs_dns_resolve_name(net, string, len, sa, salen); |
|
if (ret < 0) |
|
ret = 0; |
|
} |
|
} else if (port) { |
|
rpc_set_port(sa, port); |
|
} |
|
return ret; |
|
} |
|
|
|
/** |
|
* nfs_find_best_sec - Find a security mechanism supported locally |
|
* @clnt: pointer to rpc_clnt |
|
* @server: NFS server struct |
|
* @flavors: List of security tuples returned by SECINFO procedure |
|
* |
|
* Return an rpc client that uses the first security mechanism in |
|
* "flavors" that is locally supported. The "flavors" array |
|
* is searched in the order returned from the server, per RFC 3530 |
|
* recommendation and each flavor is checked for membership in the |
|
* sec= mount option list if it exists. |
|
* |
|
* Return -EPERM if no matching flavor is found in the array. |
|
* |
|
* Please call rpc_shutdown_client() when you are done with this rpc client. |
|
* |
|
*/ |
|
static struct rpc_clnt *nfs_find_best_sec(struct rpc_clnt *clnt, |
|
struct nfs_server *server, |
|
struct nfs4_secinfo_flavors *flavors) |
|
{ |
|
rpc_authflavor_t pflavor; |
|
struct nfs4_secinfo4 *secinfo; |
|
unsigned int i; |
|
|
|
for (i = 0; i < flavors->num_flavors; i++) { |
|
secinfo = &flavors->flavors[i]; |
|
|
|
switch (secinfo->flavor) { |
|
case RPC_AUTH_NULL: |
|
case RPC_AUTH_UNIX: |
|
case RPC_AUTH_GSS: |
|
pflavor = rpcauth_get_pseudoflavor(secinfo->flavor, |
|
&secinfo->flavor_info); |
|
/* does the pseudoflavor match a sec= mount opt? */ |
|
if (pflavor != RPC_AUTH_MAXFLAVOR && |
|
nfs_auth_info_match(&server->auth_info, pflavor)) { |
|
struct rpc_clnt *new; |
|
struct rpc_cred *cred; |
|
|
|
/* Cloning creates an rpc_auth for the flavor */ |
|
new = rpc_clone_client_set_auth(clnt, pflavor); |
|
if (IS_ERR(new)) |
|
continue; |
|
/** |
|
* Check that the user actually can use the |
|
* flavor. This is mostly for RPC_AUTH_GSS |
|
* where cr_init obtains a gss context |
|
*/ |
|
cred = rpcauth_lookupcred(new->cl_auth, 0); |
|
if (IS_ERR(cred)) { |
|
rpc_shutdown_client(new); |
|
continue; |
|
} |
|
put_rpccred(cred); |
|
return new; |
|
} |
|
} |
|
} |
|
return ERR_PTR(-EPERM); |
|
} |
|
|
|
/** |
|
* nfs4_negotiate_security - in response to an NFS4ERR_WRONGSEC on lookup, |
|
* return an rpc_clnt that uses the best available security flavor with |
|
* respect to the secinfo flavor list and the sec= mount options. |
|
* |
|
* @clnt: RPC client to clone |
|
* @inode: directory inode |
|
* @name: lookup name |
|
* |
|
* Please call rpc_shutdown_client() when you are done with this rpc client. |
|
*/ |
|
struct rpc_clnt * |
|
nfs4_negotiate_security(struct rpc_clnt *clnt, struct inode *inode, |
|
const struct qstr *name) |
|
{ |
|
struct page *page; |
|
struct nfs4_secinfo_flavors *flavors; |
|
struct rpc_clnt *new; |
|
int err; |
|
|
|
page = alloc_page(GFP_KERNEL); |
|
if (!page) |
|
return ERR_PTR(-ENOMEM); |
|
|
|
flavors = page_address(page); |
|
|
|
err = nfs4_proc_secinfo(inode, name, flavors); |
|
if (err < 0) { |
|
new = ERR_PTR(err); |
|
goto out; |
|
} |
|
|
|
new = nfs_find_best_sec(clnt, NFS_SERVER(inode), flavors); |
|
|
|
out: |
|
put_page(page); |
|
return new; |
|
} |
|
|
|
static int try_location(struct fs_context *fc, |
|
const struct nfs4_fs_location *location) |
|
{ |
|
struct nfs_fs_context *ctx = nfs_fc2context(fc); |
|
unsigned int len, s; |
|
char *export_path, *source, *p; |
|
int ret = -ENOENT; |
|
|
|
/* Allocate a buffer big enough to hold any of the hostnames plus a |
|
* terminating char and also a buffer big enough to hold the hostname |
|
* plus a colon plus the path. |
|
*/ |
|
len = 0; |
|
for (s = 0; s < location->nservers; s++) { |
|
const struct nfs4_string *buf = &location->servers[s]; |
|
if (buf->len > len) |
|
len = buf->len; |
|
} |
|
|
|
kfree(ctx->nfs_server.hostname); |
|
ctx->nfs_server.hostname = kmalloc(len + 1, GFP_KERNEL); |
|
if (!ctx->nfs_server.hostname) |
|
return -ENOMEM; |
|
|
|
export_path = nfs4_pathname_string(&location->rootpath, |
|
&ctx->nfs_server.export_path_len); |
|
if (IS_ERR(export_path)) |
|
return PTR_ERR(export_path); |
|
|
|
kfree(ctx->nfs_server.export_path); |
|
ctx->nfs_server.export_path = export_path; |
|
|
|
source = kmalloc(len + 1 + ctx->nfs_server.export_path_len + 1, |
|
GFP_KERNEL); |
|
if (!source) |
|
return -ENOMEM; |
|
|
|
kfree(fc->source); |
|
fc->source = source; |
|
for (s = 0; s < location->nservers; s++) { |
|
const struct nfs4_string *buf = &location->servers[s]; |
|
|
|
if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len)) |
|
continue; |
|
|
|
ctx->nfs_server.addrlen = |
|
nfs_parse_server_name(buf->data, buf->len, |
|
&ctx->nfs_server.address, |
|
sizeof(ctx->nfs_server._address), |
|
fc->net_ns, 0); |
|
if (ctx->nfs_server.addrlen == 0) |
|
continue; |
|
|
|
rpc_set_port(&ctx->nfs_server.address, NFS_PORT); |
|
|
|
memcpy(ctx->nfs_server.hostname, buf->data, buf->len); |
|
ctx->nfs_server.hostname[buf->len] = '\0'; |
|
|
|
p = source; |
|
memcpy(p, buf->data, buf->len); |
|
p += buf->len; |
|
*p++ = ':'; |
|
memcpy(p, ctx->nfs_server.export_path, ctx->nfs_server.export_path_len); |
|
p += ctx->nfs_server.export_path_len; |
|
*p = 0; |
|
|
|
ret = nfs4_get_referral_tree(fc); |
|
if (ret == 0) |
|
return 0; |
|
} |
|
|
|
return ret; |
|
} |
|
|
|
/** |
|
* nfs_follow_referral - set up mountpoint when hitting a referral on moved error |
|
* @fc: pointer to struct nfs_fs_context |
|
* @locations: array of NFSv4 server location information |
|
* |
|
*/ |
|
static int nfs_follow_referral(struct fs_context *fc, |
|
const struct nfs4_fs_locations *locations) |
|
{ |
|
struct nfs_fs_context *ctx = nfs_fc2context(fc); |
|
int loc, error; |
|
|
|
if (locations == NULL || locations->nlocations <= 0) |
|
return -ENOENT; |
|
|
|
dprintk("%s: referral at %pd2\n", __func__, ctx->clone_data.dentry); |
|
|
|
/* Ensure fs path is a prefix of current dentry path */ |
|
error = nfs4_validate_fspath(ctx->clone_data.dentry, locations, ctx); |
|
if (error < 0) |
|
return error; |
|
|
|
error = -ENOENT; |
|
for (loc = 0; loc < locations->nlocations; loc++) { |
|
const struct nfs4_fs_location *location = &locations->locations[loc]; |
|
|
|
if (location == NULL || location->nservers <= 0 || |
|
location->rootpath.ncomponents == 0) |
|
continue; |
|
|
|
error = try_location(fc, location); |
|
if (error == 0) |
|
return 0; |
|
} |
|
|
|
return error; |
|
} |
|
|
|
/* |
|
* nfs_do_refmount - handle crossing a referral on server |
|
* @dentry - dentry of referral |
|
* |
|
*/ |
|
static int nfs_do_refmount(struct fs_context *fc, struct rpc_clnt *client) |
|
{ |
|
struct nfs_fs_context *ctx = nfs_fc2context(fc); |
|
struct dentry *dentry, *parent; |
|
struct nfs4_fs_locations *fs_locations = NULL; |
|
struct page *page; |
|
int err = -ENOMEM; |
|
|
|
/* BUG_ON(IS_ROOT(dentry)); */ |
|
page = alloc_page(GFP_KERNEL); |
|
if (!page) |
|
return -ENOMEM; |
|
|
|
fs_locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL); |
|
if (!fs_locations) |
|
goto out_free; |
|
fs_locations->fattr = nfs_alloc_fattr(); |
|
if (!fs_locations->fattr) |
|
goto out_free_2; |
|
|
|
/* Get locations */ |
|
dentry = ctx->clone_data.dentry; |
|
parent = dget_parent(dentry); |
|
dprintk("%s: getting locations for %pd2\n", |
|
__func__, dentry); |
|
|
|
err = nfs4_proc_fs_locations(client, d_inode(parent), &dentry->d_name, fs_locations, page); |
|
dput(parent); |
|
if (err != 0) |
|
goto out_free_3; |
|
|
|
err = -ENOENT; |
|
if (fs_locations->nlocations <= 0 || |
|
fs_locations->fs_path.ncomponents <= 0) |
|
goto out_free_3; |
|
|
|
err = nfs_follow_referral(fc, fs_locations); |
|
out_free_3: |
|
kfree(fs_locations->fattr); |
|
out_free_2: |
|
kfree(fs_locations); |
|
out_free: |
|
__free_page(page); |
|
return err; |
|
} |
|
|
|
int nfs4_submount(struct fs_context *fc, struct nfs_server *server) |
|
{ |
|
struct nfs_fs_context *ctx = nfs_fc2context(fc); |
|
struct dentry *dentry = ctx->clone_data.dentry; |
|
struct dentry *parent = dget_parent(dentry); |
|
struct inode *dir = d_inode(parent); |
|
struct rpc_clnt *client; |
|
int ret; |
|
|
|
/* Look it up again to get its attributes and sec flavor */ |
|
client = nfs4_proc_lookup_mountpoint(dir, dentry, ctx->mntfh, |
|
ctx->clone_data.fattr); |
|
dput(parent); |
|
if (IS_ERR(client)) |
|
return PTR_ERR(client); |
|
|
|
ctx->selected_flavor = client->cl_auth->au_flavor; |
|
if (ctx->clone_data.fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) { |
|
ret = nfs_do_refmount(fc, client); |
|
} else { |
|
ret = nfs_do_submount(fc); |
|
} |
|
|
|
rpc_shutdown_client(client); |
|
return ret; |
|
} |
|
|
|
/* |
|
* Try one location from the fs_locations array. |
|
* |
|
* Returns zero on success, or a negative errno value. |
|
*/ |
|
static int nfs4_try_replacing_one_location(struct nfs_server *server, |
|
char *page, char *page2, |
|
const struct nfs4_fs_location *location) |
|
{ |
|
const size_t addr_bufsize = sizeof(struct sockaddr_storage); |
|
struct net *net = rpc_net_ns(server->client); |
|
struct sockaddr *sap; |
|
unsigned int s; |
|
size_t salen; |
|
int error; |
|
|
|
sap = kmalloc(addr_bufsize, GFP_KERNEL); |
|
if (sap == NULL) |
|
return -ENOMEM; |
|
|
|
error = -ENOENT; |
|
for (s = 0; s < location->nservers; s++) { |
|
const struct nfs4_string *buf = &location->servers[s]; |
|
char *hostname; |
|
|
|
if (buf->len <= 0 || buf->len > PAGE_SIZE) |
|
continue; |
|
|
|
if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len) != NULL) |
|
continue; |
|
|
|
salen = nfs_parse_server_name(buf->data, buf->len, |
|
sap, addr_bufsize, net, 0); |
|
if (salen == 0) |
|
continue; |
|
rpc_set_port(sap, NFS_PORT); |
|
|
|
error = -ENOMEM; |
|
hostname = kmemdup_nul(buf->data, buf->len, GFP_KERNEL); |
|
if (hostname == NULL) |
|
break; |
|
|
|
error = nfs4_update_server(server, hostname, sap, salen, net); |
|
kfree(hostname); |
|
if (error == 0) |
|
break; |
|
} |
|
|
|
kfree(sap); |
|
return error; |
|
} |
|
|
|
/** |
|
* nfs4_replace_transport - set up transport to destination server |
|
* |
|
* @server: export being migrated |
|
* @locations: fs_locations array |
|
* |
|
* Returns zero on success, or a negative errno value. |
|
* |
|
* The client tries all the entries in the "locations" array, in the |
|
* order returned by the server, until one works or the end of the |
|
* array is reached. |
|
*/ |
|
int nfs4_replace_transport(struct nfs_server *server, |
|
const struct nfs4_fs_locations *locations) |
|
{ |
|
char *page = NULL, *page2 = NULL; |
|
int loc, error; |
|
|
|
error = -ENOENT; |
|
if (locations == NULL || locations->nlocations <= 0) |
|
goto out; |
|
|
|
error = -ENOMEM; |
|
page = (char *) __get_free_page(GFP_USER); |
|
if (!page) |
|
goto out; |
|
page2 = (char *) __get_free_page(GFP_USER); |
|
if (!page2) |
|
goto out; |
|
|
|
for (loc = 0; loc < locations->nlocations; loc++) { |
|
const struct nfs4_fs_location *location = |
|
&locations->locations[loc]; |
|
|
|
if (location == NULL || location->nservers <= 0 || |
|
location->rootpath.ncomponents == 0) |
|
continue; |
|
|
|
error = nfs4_try_replacing_one_location(server, page, |
|
page2, location); |
|
if (error == 0) |
|
break; |
|
} |
|
|
|
out: |
|
free_page((unsigned long)page); |
|
free_page((unsigned long)page2); |
|
return error; |
|
}
|
|
|