linux/fs/nfs/proc.c
Chuck Lever f796f8b3ae NFS: Introduce new-style XDR decoding functions for NFSv2
We'd like to prevent local buffer overflows caused by malicious or
broken servers.  New xdr_stream style decoders can do that.

For efficiency, we also eventually want to be able to pass xdr_streams
from call_decode() to all XDR decoding functions, rather than building
an xdr_stream in every XDR decoding function in the kernel.

nfs_decode_dirent() is renamed to follow the naming convention of the
other two dirent decoders.

Static helper functions are left without the "inline" directive.  This
allows the compiler to choose automatically how to optimize these for
size or speed.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-12-16 12:37:21 -05:00

744 lines
19 KiB
C

/*
* linux/fs/nfs/proc.c
*
* Copyright (C) 1992, 1993, 1994 Rick Sladkey
*
* OS-independent nfs remote procedure call functions
*
* Tuned by Alan Cox <A.Cox@swansea.ac.uk> for >3K buffers
* so at last we can have decent(ish) throughput off a
* Sun server.
*
* Coding optimized and cleaned up by Florian La Roche.
* Note: Error returns are optimized for NFS_OK, which isn't translated via
* nfs_stat_to_errno(), but happens to be already the right return code.
*
* Also, the code currently doesn't check the size of the packet, when
* it decodes the packet.
*
* Feel free to fix it and mail me the diffs if it worries you.
*
* Completely rewritten to support the new RPC call interface;
* rewrote and moved the entire XDR stuff to xdr.c
* --Olaf Kirch June 1996
*
* The code below initializes all auto variables explicitly, otherwise
* it will fail to work as a module (gcc generates a memset call for an
* incomplete struct).
*/
#include <linux/types.h>
#include <linux/param.h>
#include <linux/time.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/in.h>
#include <linux/pagemap.h>
#include <linux/sunrpc/clnt.h>
#include <linux/nfs.h>
#include <linux/nfs2.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_page.h>
#include <linux/lockd/bind.h>
#include "internal.h"
#define NFSDBG_FACILITY NFSDBG_PROC
/*
* wrapper to handle the -EKEYEXPIRED error message. This should generally
* only happen if using krb5 auth and a user's TGT expires. NFSv2 doesn't
* support the NFSERR_JUKEBOX error code, but we handle this situation in the
* same way that we handle that error with NFSv3.
*/
static int
nfs_rpc_wrapper(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
{
int res;
do {
res = rpc_call_sync(clnt, msg, flags);
if (res != -EKEYEXPIRED)
break;
schedule_timeout_killable(NFS_JUKEBOX_RETRY_TIME);
res = -ERESTARTSYS;
} while (!fatal_signal_pending(current));
return res;
}
#define rpc_call_sync(clnt, msg, flags) nfs_rpc_wrapper(clnt, msg, flags)
static int
nfs_async_handle_expired_key(struct rpc_task *task)
{
if (task->tk_status != -EKEYEXPIRED)
return 0;
task->tk_status = 0;
rpc_restart_call(task);
rpc_delay(task, NFS_JUKEBOX_RETRY_TIME);
return 1;
}
/*
* Bare-bones access to getattr: this is for nfs_read_super.
*/
static int
nfs_proc_get_root(struct nfs_server *server, struct nfs_fh *fhandle,
struct nfs_fsinfo *info)
{
struct nfs_fattr *fattr = info->fattr;
struct nfs2_fsstat fsinfo;
struct rpc_message msg = {
.rpc_proc = &nfs_procedures[NFSPROC_GETATTR],
.rpc_argp = fhandle,
.rpc_resp = fattr,
};
int status;
dprintk("%s: call getattr\n", __func__);
nfs_fattr_init(fattr);
status = rpc_call_sync(server->client, &msg, 0);
/* Retry with default authentication if different */
if (status && server->nfs_client->cl_rpcclient != server->client)
status = rpc_call_sync(server->nfs_client->cl_rpcclient, &msg, 0);
dprintk("%s: reply getattr: %d\n", __func__, status);
if (status)
return status;
dprintk("%s: call statfs\n", __func__);
msg.rpc_proc = &nfs_procedures[NFSPROC_STATFS];
msg.rpc_resp = &fsinfo;
status = rpc_call_sync(server->client, &msg, 0);
/* Retry with default authentication if different */
if (status && server->nfs_client->cl_rpcclient != server->client)
status = rpc_call_sync(server->nfs_client->cl_rpcclient, &msg, 0);
dprintk("%s: reply statfs: %d\n", __func__, status);
if (status)
return status;
info->rtmax = NFS_MAXDATA;
info->rtpref = fsinfo.tsize;
info->rtmult = fsinfo.bsize;
info->wtmax = NFS_MAXDATA;
info->wtpref = fsinfo.tsize;
info->wtmult = fsinfo.bsize;
info->dtpref = fsinfo.tsize;
info->maxfilesize = 0x7FFFFFFF;
info->lease_time = 0;
return 0;
}
/*
* One function for each procedure in the NFS protocol.
*/
static int
nfs_proc_getattr(struct nfs_server *server, struct nfs_fh *fhandle,
struct nfs_fattr *fattr)
{
struct rpc_message msg = {
.rpc_proc = &nfs_procedures[NFSPROC_GETATTR],
.rpc_argp = fhandle,
.rpc_resp = fattr,
};
int status;
dprintk("NFS call getattr\n");
nfs_fattr_init(fattr);
status = rpc_call_sync(server->client, &msg, 0);
dprintk("NFS reply getattr: %d\n", status);
return status;
}
static int
nfs_proc_setattr(struct dentry *dentry, struct nfs_fattr *fattr,
struct iattr *sattr)
{
struct inode *inode = dentry->d_inode;
struct nfs_sattrargs arg = {
.fh = NFS_FH(inode),
.sattr = sattr
};
struct rpc_message msg = {
.rpc_proc = &nfs_procedures[NFSPROC_SETATTR],
.rpc_argp = &arg,
.rpc_resp = fattr,
};
int status;
/* Mask out the non-modebit related stuff from attr->ia_mode */
sattr->ia_mode &= S_IALLUGO;
dprintk("NFS call setattr\n");
if (sattr->ia_valid & ATTR_FILE)
msg.rpc_cred = nfs_file_cred(sattr->ia_file);
nfs_fattr_init(fattr);
status = rpc_call_sync(NFS_CLIENT(inode), &msg, 0);
if (status == 0)
nfs_setattr_update_inode(inode, sattr);
dprintk("NFS reply setattr: %d\n", status);
return status;
}
static int
nfs_proc_lookup(struct inode *dir, struct qstr *name,
struct nfs_fh *fhandle, struct nfs_fattr *fattr)
{
struct nfs_diropargs arg = {
.fh = NFS_FH(dir),
.name = name->name,
.len = name->len
};
struct nfs_diropok res = {
.fh = fhandle,
.fattr = fattr
};
struct rpc_message msg = {
.rpc_proc = &nfs_procedures[NFSPROC_LOOKUP],
.rpc_argp = &arg,
.rpc_resp = &res,
};
int status;
dprintk("NFS call lookup %s\n", name->name);
nfs_fattr_init(fattr);
status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
dprintk("NFS reply lookup: %d\n", status);
return status;
}
static int nfs_proc_readlink(struct inode *inode, struct page *page,
unsigned int pgbase, unsigned int pglen)
{
struct nfs_readlinkargs args = {
.fh = NFS_FH(inode),
.pgbase = pgbase,
.pglen = pglen,
.pages = &page
};
struct rpc_message msg = {
.rpc_proc = &nfs_procedures[NFSPROC_READLINK],
.rpc_argp = &args,
};
int status;
dprintk("NFS call readlink\n");
status = rpc_call_sync(NFS_CLIENT(inode), &msg, 0);
dprintk("NFS reply readlink: %d\n", status);
return status;
}
struct nfs_createdata {
struct nfs_createargs arg;
struct nfs_diropok res;
struct nfs_fh fhandle;
struct nfs_fattr fattr;
};
static struct nfs_createdata *nfs_alloc_createdata(struct inode *dir,
struct dentry *dentry, struct iattr *sattr)
{
struct nfs_createdata *data;
data = kmalloc(sizeof(*data), GFP_KERNEL);
if (data != NULL) {
data->arg.fh = NFS_FH(dir);
data->arg.name = dentry->d_name.name;
data->arg.len = dentry->d_name.len;
data->arg.sattr = sattr;
nfs_fattr_init(&data->fattr);
data->fhandle.size = 0;
data->res.fh = &data->fhandle;
data->res.fattr = &data->fattr;
}
return data;
};
static void nfs_free_createdata(const struct nfs_createdata *data)
{
kfree(data);
}
static int
nfs_proc_create(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
int flags, struct nfs_open_context *ctx)
{
struct nfs_createdata *data;
struct rpc_message msg = {
.rpc_proc = &nfs_procedures[NFSPROC_CREATE],
};
int status = -ENOMEM;
dprintk("NFS call create %s\n", dentry->d_name.name);
data = nfs_alloc_createdata(dir, dentry, sattr);
if (data == NULL)
goto out;
msg.rpc_argp = &data->arg;
msg.rpc_resp = &data->res;
status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
nfs_mark_for_revalidate(dir);
if (status == 0)
status = nfs_instantiate(dentry, data->res.fh, data->res.fattr);
nfs_free_createdata(data);
out:
dprintk("NFS reply create: %d\n", status);
return status;
}
/*
* In NFSv2, mknod is grafted onto the create call.
*/
static int
nfs_proc_mknod(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
dev_t rdev)
{
struct nfs_createdata *data;
struct rpc_message msg = {
.rpc_proc = &nfs_procedures[NFSPROC_CREATE],
};
umode_t mode;
int status = -ENOMEM;
dprintk("NFS call mknod %s\n", dentry->d_name.name);
mode = sattr->ia_mode;
if (S_ISFIFO(mode)) {
sattr->ia_mode = (mode & ~S_IFMT) | S_IFCHR;
sattr->ia_valid &= ~ATTR_SIZE;
} else if (S_ISCHR(mode) || S_ISBLK(mode)) {
sattr->ia_valid |= ATTR_SIZE;
sattr->ia_size = new_encode_dev(rdev);/* get out your barf bag */
}
data = nfs_alloc_createdata(dir, dentry, sattr);
if (data == NULL)
goto out;
msg.rpc_argp = &data->arg;
msg.rpc_resp = &data->res;
status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
nfs_mark_for_revalidate(dir);
if (status == -EINVAL && S_ISFIFO(mode)) {
sattr->ia_mode = mode;
nfs_fattr_init(data->res.fattr);
status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
}
if (status == 0)
status = nfs_instantiate(dentry, data->res.fh, data->res.fattr);
nfs_free_createdata(data);
out:
dprintk("NFS reply mknod: %d\n", status);
return status;
}
static int
nfs_proc_remove(struct inode *dir, struct qstr *name)
{
struct nfs_removeargs arg = {
.fh = NFS_FH(dir),
.name.len = name->len,
.name.name = name->name,
};
struct rpc_message msg = {
.rpc_proc = &nfs_procedures[NFSPROC_REMOVE],
.rpc_argp = &arg,
};
int status;
dprintk("NFS call remove %s\n", name->name);
status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
nfs_mark_for_revalidate(dir);
dprintk("NFS reply remove: %d\n", status);
return status;
}
static void
nfs_proc_unlink_setup(struct rpc_message *msg, struct inode *dir)
{
msg->rpc_proc = &nfs_procedures[NFSPROC_REMOVE];
}
static int nfs_proc_unlink_done(struct rpc_task *task, struct inode *dir)
{
if (nfs_async_handle_expired_key(task))
return 0;
nfs_mark_for_revalidate(dir);
return 1;
}
static void
nfs_proc_rename_setup(struct rpc_message *msg, struct inode *dir)
{
msg->rpc_proc = &nfs_procedures[NFSPROC_RENAME];
}
static int
nfs_proc_rename_done(struct rpc_task *task, struct inode *old_dir,
struct inode *new_dir)
{
if (nfs_async_handle_expired_key(task))
return 0;
nfs_mark_for_revalidate(old_dir);
nfs_mark_for_revalidate(new_dir);
return 1;
}
static int
nfs_proc_rename(struct inode *old_dir, struct qstr *old_name,
struct inode *new_dir, struct qstr *new_name)
{
struct nfs_renameargs arg = {
.old_dir = NFS_FH(old_dir),
.old_name = old_name,
.new_dir = NFS_FH(new_dir),
.new_name = new_name,
};
struct rpc_message msg = {
.rpc_proc = &nfs_procedures[NFSPROC_RENAME],
.rpc_argp = &arg,
};
int status;
dprintk("NFS call rename %s -> %s\n", old_name->name, new_name->name);
status = rpc_call_sync(NFS_CLIENT(old_dir), &msg, 0);
nfs_mark_for_revalidate(old_dir);
nfs_mark_for_revalidate(new_dir);
dprintk("NFS reply rename: %d\n", status);
return status;
}
static int
nfs_proc_link(struct inode *inode, struct inode *dir, struct qstr *name)
{
struct nfs_linkargs arg = {
.fromfh = NFS_FH(inode),
.tofh = NFS_FH(dir),
.toname = name->name,
.tolen = name->len
};
struct rpc_message msg = {
.rpc_proc = &nfs_procedures[NFSPROC_LINK],
.rpc_argp = &arg,
};
int status;
dprintk("NFS call link %s\n", name->name);
status = rpc_call_sync(NFS_CLIENT(inode), &msg, 0);
nfs_mark_for_revalidate(inode);
nfs_mark_for_revalidate(dir);
dprintk("NFS reply link: %d\n", status);
return status;
}
static int
nfs_proc_symlink(struct inode *dir, struct dentry *dentry, struct page *page,
unsigned int len, struct iattr *sattr)
{
struct nfs_fh *fh;
struct nfs_fattr *fattr;
struct nfs_symlinkargs arg = {
.fromfh = NFS_FH(dir),
.fromname = dentry->d_name.name,
.fromlen = dentry->d_name.len,
.pages = &page,
.pathlen = len,
.sattr = sattr
};
struct rpc_message msg = {
.rpc_proc = &nfs_procedures[NFSPROC_SYMLINK],
.rpc_argp = &arg,
};
int status = -ENAMETOOLONG;
dprintk("NFS call symlink %s\n", dentry->d_name.name);
if (len > NFS2_MAXPATHLEN)
goto out;
fh = nfs_alloc_fhandle();
fattr = nfs_alloc_fattr();
status = -ENOMEM;
if (fh == NULL || fattr == NULL)
goto out;
status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
nfs_mark_for_revalidate(dir);
/*
* V2 SYMLINK requests don't return any attributes. Setting the
* filehandle size to zero indicates to nfs_instantiate that it
* should fill in the data with a LOOKUP call on the wire.
*/
if (status == 0)
status = nfs_instantiate(dentry, fh, fattr);
nfs_free_fattr(fattr);
nfs_free_fhandle(fh);
out:
dprintk("NFS reply symlink: %d\n", status);
return status;
}
static int
nfs_proc_mkdir(struct inode *dir, struct dentry *dentry, struct iattr *sattr)
{
struct nfs_createdata *data;
struct rpc_message msg = {
.rpc_proc = &nfs_procedures[NFSPROC_MKDIR],
};
int status = -ENOMEM;
dprintk("NFS call mkdir %s\n", dentry->d_name.name);
data = nfs_alloc_createdata(dir, dentry, sattr);
if (data == NULL)
goto out;
msg.rpc_argp = &data->arg;
msg.rpc_resp = &data->res;
status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
nfs_mark_for_revalidate(dir);
if (status == 0)
status = nfs_instantiate(dentry, data->res.fh, data->res.fattr);
nfs_free_createdata(data);
out:
dprintk("NFS reply mkdir: %d\n", status);
return status;
}
static int
nfs_proc_rmdir(struct inode *dir, struct qstr *name)
{
struct nfs_diropargs arg = {
.fh = NFS_FH(dir),
.name = name->name,
.len = name->len
};
struct rpc_message msg = {
.rpc_proc = &nfs_procedures[NFSPROC_RMDIR],
.rpc_argp = &arg,
};
int status;
dprintk("NFS call rmdir %s\n", name->name);
status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
nfs_mark_for_revalidate(dir);
dprintk("NFS reply rmdir: %d\n", status);
return status;
}
/*
* The READDIR implementation is somewhat hackish - we pass a temporary
* buffer to the encode function, which installs it in the receive
* the receive iovec. The decode function just parses the reply to make
* sure it is syntactically correct; the entries itself are decoded
* from nfs_readdir by calling the decode_entry function directly.
*/
static int
nfs_proc_readdir(struct dentry *dentry, struct rpc_cred *cred,
u64 cookie, struct page **pages, unsigned int count, int plus)
{
struct inode *dir = dentry->d_inode;
struct nfs_readdirargs arg = {
.fh = NFS_FH(dir),
.cookie = cookie,
.count = count,
.pages = pages,
};
struct rpc_message msg = {
.rpc_proc = &nfs_procedures[NFSPROC_READDIR],
.rpc_argp = &arg,
.rpc_cred = cred,
};
int status;
dprintk("NFS call readdir %d\n", (unsigned int)cookie);
status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
nfs_invalidate_atime(dir);
dprintk("NFS reply readdir: %d\n", status);
return status;
}
static int
nfs_proc_statfs(struct nfs_server *server, struct nfs_fh *fhandle,
struct nfs_fsstat *stat)
{
struct nfs2_fsstat fsinfo;
struct rpc_message msg = {
.rpc_proc = &nfs_procedures[NFSPROC_STATFS],
.rpc_argp = fhandle,
.rpc_resp = &fsinfo,
};
int status;
dprintk("NFS call statfs\n");
nfs_fattr_init(stat->fattr);
status = rpc_call_sync(server->client, &msg, 0);
dprintk("NFS reply statfs: %d\n", status);
if (status)
goto out;
stat->tbytes = (u64)fsinfo.blocks * fsinfo.bsize;
stat->fbytes = (u64)fsinfo.bfree * fsinfo.bsize;
stat->abytes = (u64)fsinfo.bavail * fsinfo.bsize;
stat->tfiles = 0;
stat->ffiles = 0;
stat->afiles = 0;
out:
return status;
}
static int
nfs_proc_fsinfo(struct nfs_server *server, struct nfs_fh *fhandle,
struct nfs_fsinfo *info)
{
struct nfs2_fsstat fsinfo;
struct rpc_message msg = {
.rpc_proc = &nfs_procedures[NFSPROC_STATFS],
.rpc_argp = fhandle,
.rpc_resp = &fsinfo,
};
int status;
dprintk("NFS call fsinfo\n");
nfs_fattr_init(info->fattr);
status = rpc_call_sync(server->client, &msg, 0);
dprintk("NFS reply fsinfo: %d\n", status);
if (status)
goto out;
info->rtmax = NFS_MAXDATA;
info->rtpref = fsinfo.tsize;
info->rtmult = fsinfo.bsize;
info->wtmax = NFS_MAXDATA;
info->wtpref = fsinfo.tsize;
info->wtmult = fsinfo.bsize;
info->dtpref = fsinfo.tsize;
info->maxfilesize = 0x7FFFFFFF;
info->lease_time = 0;
out:
return status;
}
static int
nfs_proc_pathconf(struct nfs_server *server, struct nfs_fh *fhandle,
struct nfs_pathconf *info)
{
info->max_link = 0;
info->max_namelen = NFS2_MAXNAMLEN;
return 0;
}
static int nfs_read_done(struct rpc_task *task, struct nfs_read_data *data)
{
if (nfs_async_handle_expired_key(task))
return -EAGAIN;
nfs_invalidate_atime(data->inode);
if (task->tk_status >= 0) {
nfs_refresh_inode(data->inode, data->res.fattr);
/* Emulate the eof flag, which isn't normally needed in NFSv2
* as it is guaranteed to always return the file attributes
*/
if (data->args.offset + data->args.count >= data->res.fattr->size)
data->res.eof = 1;
}
return 0;
}
static void nfs_proc_read_setup(struct nfs_read_data *data, struct rpc_message *msg)
{
msg->rpc_proc = &nfs_procedures[NFSPROC_READ];
}
static int nfs_write_done(struct rpc_task *task, struct nfs_write_data *data)
{
if (nfs_async_handle_expired_key(task))
return -EAGAIN;
if (task->tk_status >= 0)
nfs_post_op_update_inode_force_wcc(data->inode, data->res.fattr);
return 0;
}
static void nfs_proc_write_setup(struct nfs_write_data *data, struct rpc_message *msg)
{
/* Note: NFSv2 ignores @stable and always uses NFS_FILE_SYNC */
data->args.stable = NFS_FILE_SYNC;
msg->rpc_proc = &nfs_procedures[NFSPROC_WRITE];
}
static void
nfs_proc_commit_setup(struct nfs_write_data *data, struct rpc_message *msg)
{
BUG();
}
static int
nfs_proc_lock(struct file *filp, int cmd, struct file_lock *fl)
{
struct inode *inode = filp->f_path.dentry->d_inode;
return nlmclnt_proc(NFS_SERVER(inode)->nlm_host, cmd, fl);
}
/* Helper functions for NFS lock bounds checking */
#define NFS_LOCK32_OFFSET_MAX ((__s32)0x7fffffffUL)
static int nfs_lock_check_bounds(const struct file_lock *fl)
{
__s32 start, end;
start = (__s32)fl->fl_start;
if ((loff_t)start != fl->fl_start)
goto out_einval;
if (fl->fl_end != OFFSET_MAX) {
end = (__s32)fl->fl_end;
if ((loff_t)end != fl->fl_end)
goto out_einval;
} else
end = NFS_LOCK32_OFFSET_MAX;
if (start < 0 || start > end)
goto out_einval;
return 0;
out_einval:
return -EINVAL;
}
const struct nfs_rpc_ops nfs_v2_clientops = {
.version = 2, /* protocol version */
.dentry_ops = &nfs_dentry_operations,
.dir_inode_ops = &nfs_dir_inode_operations,
.file_inode_ops = &nfs_file_inode_operations,
.getroot = nfs_proc_get_root,
.getattr = nfs_proc_getattr,
.setattr = nfs_proc_setattr,
.lookup = nfs_proc_lookup,
.access = NULL, /* access */
.readlink = nfs_proc_readlink,
.create = nfs_proc_create,
.remove = nfs_proc_remove,
.unlink_setup = nfs_proc_unlink_setup,
.unlink_done = nfs_proc_unlink_done,
.rename = nfs_proc_rename,
.rename_setup = nfs_proc_rename_setup,
.rename_done = nfs_proc_rename_done,
.link = nfs_proc_link,
.symlink = nfs_proc_symlink,
.mkdir = nfs_proc_mkdir,
.rmdir = nfs_proc_rmdir,
.readdir = nfs_proc_readdir,
.mknod = nfs_proc_mknod,
.statfs = nfs_proc_statfs,
.fsinfo = nfs_proc_fsinfo,
.pathconf = nfs_proc_pathconf,
.decode_dirent = nfs2_decode_dirent,
.read_setup = nfs_proc_read_setup,
.read_done = nfs_read_done,
.write_setup = nfs_proc_write_setup,
.write_done = nfs_write_done,
.commit_setup = nfs_proc_commit_setup,
.lock = nfs_proc_lock,
.lock_check_bounds = nfs_lock_check_bounds,
.close_context = nfs_close_context,
};