/*
* linux/fs/9p/conv.c
*
* 9P protocol conversion functions
*
* Copyright (C) 2004, 2005 by Latchesar Ionkov <lucho@ionkov.net>
* Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
* Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to:
* Free Software Foundation
* 51 Franklin Street, Fifth Floor
* Boston, MA 02111-1301 USA
*
*/
#include <linux/config.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/idr.h>
#include <asm/uaccess.h>
#include "debug.h"
#include "v9fs.h"
#include "9p.h"
#include "conv.h"
/*
* Buffer to help with string parsing
*/
struct cbuf {
unsigned char *sp;
unsigned char *p;
unsigned char *ep;
};
static inline void buf_init(struct cbuf *buf, void *data, int datalen)
{
buf->sp = buf->p = data;
buf->ep = data + datalen;
}
static inline int buf_check_overflow(struct cbuf *buf)
{
return buf->p > buf->ep;
}
static int buf_check_size(struct cbuf *buf, int len)
{
if (buf->p + len > buf->ep) {
if (buf->p < buf->ep) {
eprintk(KERN_ERR, "buffer overflow: want %d has %d\n",
len, (int)(buf->ep - buf->p));
dump_stack();
buf->p = buf->ep + 1;
}
return 0;
}
return 1;
}
static void *buf_alloc(struct cbuf *buf, int len)
{
void *ret = NULL;
if (buf_check_size(buf, len)) {
ret = buf->p;
buf->p += len;
}
return ret;
}
static void buf_put_int8(struct cbuf *buf, u8 val)
{
if (buf_check_size(buf, 1)) {
buf->p[0] = val;
buf->p++;
}
}
static void buf_put_int16(struct cbuf *buf, u16 val)
{
if (buf_check_size(buf, 2)) {
*(__le16 *) buf->p = cpu_to_le16(val);
buf->p += 2;
}
}
static void buf_put_int32(struct cbuf *buf, u32 val)
{
if (buf_check_size(buf, 4)) {
*(__le32 *)buf->p = cpu_to_le32(val);
buf->p += 4;
}
}
static void buf_put_int64(struct cbuf *buf, u64 val)
{
if (buf_check_size(buf, 8)) {
*(__le64 *)buf->p = cpu_to_le64(val);
buf->p += 8;
}
}
static void buf_put_stringn(struct cbuf *buf, const char *s, u16 slen)
{
if (buf_check_size(buf, slen + 2)) {
buf_put_int16(buf, slen);
memcpy(buf->p, s, slen);
buf->p += slen;
}
}
static inline void buf_put_string(struct cbuf *buf, const char *s)
{
buf_put_stringn(buf, s, strlen(s));
}
static u8 buf_get_int8(struct cbuf *buf)
{
u8 ret = 0;
if (buf_check_size(buf, 1)) {
ret = buf->p[0];
buf->p++;
}
return ret;
}
static u16 buf_get_int16(struct cbuf *buf)
{
u16 ret = 0;
if (buf_check_size(buf, 2)) {
ret = le16_to_cpu(*(__le16 *)buf->p);
buf->p += 2;
}
return ret;
}
static u32 buf_get_int32(struct cbuf *buf)
{
u32 ret = 0;
if (buf_check_size(buf, 4)) {
ret = le32_to_cpu(*(__le32 *)buf->p);
buf->p += 4;
}
return ret;
}
static u64 buf_get_int64(struct cbuf *buf)
{
u64 ret = 0;
if (buf_check_size(buf, 8)) {
ret = le64_to_cpu(*(__le64 *)buf->p);
buf->p += 8;
}
return ret;
}
static void buf_get_str(struct cbuf *buf, struct v9fs_str *vstr)
{
vstr->len = buf_get_int16(buf);
if (!buf_check_overflow(buf) && buf_check_size(buf, vstr->len)) {
vstr->str = buf->p;
buf->p += vstr->len;
} else {
vstr->len = 0;
vstr->str = NULL;
}
}
static void buf_get_qid(struct cbuf *bufp, struct v9fs_qid *qid)
{
qid->type = buf_get_int8(bufp);
qid->version = buf_get_int32(bufp);
qid->path = buf_get_int64(bufp);
}
/**
* v9fs_size_wstat - calculate the size of a variable length stat struct
* @stat: metadata (stat) structure
* @extended: non-zero if 9P2000.u
*
*/
static int v9fs_size_wstat(struct v9fs_wstat *wstat, int extended)
{
int size = 0;
if (wstat == NULL) {
eprintk(KERN_ERR, "v9fs_size_stat: got a NULL stat pointer\n");
return 0;
}
size = /* 2 + *//* size[2] */
2 + /* type[2] */
4 + /* dev[4] */
1 + /* qid.type[1] */
4 + /* qid.vers[4] */
8 + /* qid.path[8] */
4 + /* mode[4] */
4 + /* atime[4] */
4 + /* mtime[4] */
8 + /* length[8] */
8; /* minimum sum of string lengths */
if (wstat->name)
size += strlen(wstat->name);
if (wstat->uid)
size += strlen(wstat->uid);
if (wstat->gid)
size += strlen(wstat->gid);
if (wstat->muid)
size += strlen(wstat->muid);
if (extended) {
size += 4 + /* n_uid[4] */
4 + /* n_gid[4] */
4 + /* n_muid[4] */
2; /* string length of extension[4] */
if (wstat->extension)
size += strlen(wstat->extension);
}
return size;
}
/**
* buf_get_stat - safely decode a recieved metadata (stat) structure
* @bufp: buffer to deserialize
* @stat: metadata (stat) structure
* @extended: non-zero if 9P2000.u
*
*/
static void
buf_get_stat(struct cbuf *bufp, struct v9fs_stat *stat, int extended)
{
stat->size = buf_get_int16(bufp);
stat->type = buf_get_int16(bufp);
stat->dev = buf_get_int32(bufp);
stat->qid.type = buf_get_int8(bufp);
stat->qid.version = buf_get_int32(bufp);
stat->qid.path = buf_get_int64(bufp);
stat->mode = buf_get_int32(bufp);
stat->atime = buf_get_int32(bufp);
stat->mtime = buf_get_int32(bufp);
stat->length = buf_get_int64(bufp);
buf_get_str(bufp, &stat->name);
buf_get_str(bufp, &stat->uid);
buf_get_str(bufp, &stat->gid);
buf_get_str(bufp, &stat->muid);
if (extended) {
buf_get_str(bufp, &stat->extension);
stat->n_uid = buf_get_int32(bufp);
stat->n_gid = buf_get_int32(bufp);
stat->n_muid = buf_get_int32(bufp);
}
}
/**
* v9fs_deserialize_stat - decode a received metadata structure
* @buf: buffer to deserialize
* @buflen: length of received buffer
* @stat: metadata structure to decode into
* @extended: non-zero if 9P2000.u
*
* Note: stat will point to the buf region.
*/
int
v9fs_deserialize_stat(void *buf, u32 buflen, struct v9fs_stat *stat,
int extended)
{
struct cbuf buffer;
struct cbuf *bufp = &buffer;
unsigned char *p;
buf_init(bufp, buf, buflen);
p = bufp->p;
buf_get_stat(bufp, stat, extended);
if (buf_check_overflow(bufp))
return 0;
else
return bufp->p - p;
}
/**
* deserialize_fcall - unmarshal a response
* @buf: recieved buffer
* @buflen: length of received buffer
* @rcall: fcall structure to populate
* @rcalllen: length of fcall structure to populate
* @extended: non-zero if 9P2000.u
*
*/
int
v9fs_deserialize_fcall(void *buf, u32 buflen, struct v9fs_fcall *rcall,
int extended)
{
struct cbuf buffer;
struct cbuf *bufp = &buffer;
int i = 0;
buf_init(bufp, buf, buflen);
rcall->size = buf_get_int32(bufp);
rcall->id = buf_get_int8(bufp);
rcall->tag = buf_get_int16(bufp);
dprintk(DEBUG_CONV, "size %d id %d tag %d\n", rcall->size, rcall->id,
rcall->tag);
switch (rcall->id) {
default:
eprintk(KERN_ERR, "unknown message type: %d\n", rcall->id);
return -EPROTO;
case RVERSION:
rcall->params.rversion.msize = buf_get_int32(bufp);
buf_get_str(bufp, &rcall->params.rversion.version);
break;
case RFLUSH:
break;
case RATTACH:
rcall->params.rattach.qid.type = buf_get_int8(bufp);
rcall->params.rattach.qid.version = buf_get_int32(bufp);
rcall->params.rattach.qid.path = buf_get_int64(bufp);
break;
case RWALK:
rcall->params.rwalk.nwqid = buf_get_int16(bufp);
if (rcall->params.rwalk.nwqid > V9FS_MAXWELEM) {
eprintk(KERN_ERR, "Rwalk with more than %d qids: %d\n",
V9FS_MAXWELEM, rcall->params.rwalk.nwqid);
return -EPROTO;
}
for (i = 0; i < rcall->params.rwalk.nwqid; i++)
buf_get_qid(bufp, &rcall->params.rwalk.wqids[i]);
break;
case ROPEN:
buf_get_qid(bufp, &rcall->params.ropen.qid);
rcall->params.ropen.iounit = buf_get_int32(bufp);
break;
case RCREATE:
buf_get_qid(bufp, &rcall->params.rcreate.qid);
rcall->params.rcreate.iounit = buf_get_int32(bufp);
break;
case RREAD:
rcall->params.rread.count = buf_get_int32(bufp);
rcall->params.rread.data = bufp->p;
buf_check_size(bufp, rcall->params.rread.count);
break;
case RWRITE:
rcall->params.rwrite.count = buf_get_int32(bufp);
break;
case RCLUNK:
break;
case RREMOVE:
break;
case RSTAT:
buf_get_int16(bufp);
buf_get_stat(bufp, &rcall->params.rstat.stat, extended);
break;
case RWSTAT:
break;
case RERROR:
buf_get_str(bufp, &rcall->params.rerror.error);
if (extended)
rcall->params.rerror.errno = buf_get_int16(bufp);
break;
}
if (buf_check_overflow(bufp)) {
dprintk(DEBUG_ERROR, "buffer overflow\n");
return -EIO;
}
return bufp->p - bufp->sp;
}
static inline void v9fs_put_int8(struct cbuf *bufp, u8 val, u8 * p)
{
*p = val;
buf_put_int8(bufp, val);
}
static inline void v9fs_put_int16(struct cbuf *bufp, u16 val, u16 * p)
{
*p = val;
buf_put_int16(bufp, val);
}
static inline void v9fs_put_int32(struct cbuf *bufp, u32 val, u32 * p)
{
*p = val;
buf_put_int32(bufp, val);
}
static inline void v9fs_put_int64(struct cbuf *bufp, u64 val, u64 * p)
{
*p = val;
buf_put_int64(bufp, val);
}
static void
v9fs_put_str(struct cbuf *bufp, char *data, struct v9fs_str *str)
{
if (data) {
str->len = strlen(data);
str->str = bufp->p;
} else {
str->len = 0;
str->str = NULL;
}
buf_put_stringn(bufp, data, str->len);
}
static int
v9fs_put_user_data(struct cbuf *bufp, const char __user * data, int count,
unsigned char **pdata)
{
*pdata = buf_alloc(bufp, count);
return copy_from_user(*pdata, data, count);
}
static void
v9fs_put_wstat(struct cbuf *bufp, struct v9fs_wstat *wstat,
struct v9fs_stat *stat, int statsz, int extended)
{
v9fs_put_int16(bufp, statsz, &stat->size);
v9fs_put_int16(bufp, wstat->type, &stat->type);
v9fs_put_int32(bufp, wstat->dev, &stat->dev);
v9fs_put_int8(bufp, wstat->qid.type, &stat->qid.type);
v9fs_put_int32(bufp, wstat->qid.version, &stat->qid.version);
v9fs_put_int64(bufp, wstat->qid.path, &stat->qid.path);
v9fs_put_int32(bufp, wstat->mode, &stat->mode);
v9fs_put_int32(bufp, wstat->atime, &stat->atime);
v9fs_put_int32(bufp, wstat->mtime, &stat->mtime);
v9fs_put_int64(bufp, wstat->length, &stat->length);
v9fs_put_str(bufp, wstat->name, &stat->name);
v9fs_put_str(bufp, wstat->uid, &stat->uid);
v9fs_put_str(bufp, wstat->gid, &stat->gid);
v9fs_put_str(bufp, wstat->muid, &stat->muid);
if (extended) {
v9fs_put_str(bufp, wstat->extension, &stat->extension);
v9fs_put_int32(bufp, wstat->n_uid, &stat->n_uid);
v9fs_put_int32(bufp, wstat->n_gid, &stat->n_gid);
v9fs_put_int32(bufp, wstat->n_muid, &stat->n_muid);
}
}
static struct v9fs_fcall *
v9fs_create_common(struct cbuf *bufp, u32 size, u8 id)
{
struct v9fs_fcall *fc;
size += 4 + 1 + 2; /* size[4] id[1] tag[2] */
fc = kmalloc(sizeof(struct v9fs_fcall) + size, GFP_KERNEL);
if (!fc)
return ERR_PTR(-ENOMEM);
fc->sdata = (char *)fc + sizeof(*fc);
buf_init(bufp, (char *)fc->sdata, size);
v9fs_put_int32(bufp, size, &fc->size);
v9fs_put_int8(bufp, id, &fc->id);
v9fs_put_int16(bufp, V9FS_NOTAG, &fc->tag);
return fc;
}
void v9fs_set_tag(struct v9fs_fcall *fc, u16 tag)
{
fc->tag = tag;
*(__le16 *) (fc->sdata + 5) = cpu_to_le16(tag);
}
struct v9fs_fcall *v9fs_create_tversion(u32 msize, char *version)
{
int size;
struct v9fs_fcall *fc;
struct cbuf buffer;
struct cbuf *bufp = &buffer;
size = 4 + 2 + strlen(version); /* msize[4] version[s] */
fc = v9fs_create_common(bufp, size, TVERSION);
if (IS_ERR(fc))
goto error;
v9fs_put_int32(bufp, msize, &fc->params.tversion.msize);
v9fs_put_str(bufp, version, &fc->params.tversion.version);
if (buf_check_overflow(bufp)) {
kfree(fc);
fc = ERR_PTR(-ENOMEM);
}
error:
return fc;
}
struct v9fs_fcall *v9fs_create_tauth(u32 afid, char *uname, char *aname)
{
int size;
struct v9fs_fcall *fc;
struct cbuf buffer;
struct cbuf *bufp = &buffer;
size = 4 + 2 + strlen(uname) + 2 + strlen(aname); /* afid[4] uname[s] aname[s] */
fc = v9fs_create_common(bufp, size, TAUTH);
if (IS_ERR(fc))
goto error;
v9fs_put_int32(bufp, afid, &fc->params.tauth.afid);
v9fs_put_str(bufp, uname, &fc->params.tauth.uname);
v9fs_put_str(bufp, aname, &fc->params.tauth.aname);
if (buf_check_overflow(bufp)) {
kfree(fc);
fc = ERR_PTR(-ENOMEM);
}
error:
return fc;
}
struct v9fs_fcall *
v9fs_create_tattach(u32 fid, u32 afid, char *uname, char *aname)
{
int size;
struct v9fs_fcall *fc;
struct cbuf buffer;
struct cbuf *bufp = &buffer;
size = 4 + 4 + 2 + strlen(uname) + 2 + strlen(aname); /* fid[4] afid[4] uname[s] aname[s] */
fc = v9fs_create_common(bufp, size, TATTACH);
if (IS_ERR(fc))
goto error;
v9fs_put_int32(bufp, fid, &fc->params.tattach.fid);
v9fs_put_int32(bufp, afid, &fc->params.tattach.afid);
v9fs_put_str(bufp, uname, &fc->params.tattach.uname);
v9fs_put_str(bufp, aname, &fc->params.tattach.aname);
error:
return fc;
}
struct v9fs_fcall *v9fs_create_tflush(u16 oldtag)
{
int size;
struct v9fs_fcall *fc;
struct cbuf buffer;
struct cbuf *bufp = &buffer;
size = 2; /* oldtag[2] */
fc = v9fs_create_common(bufp, size, TFLUSH);
if (IS_ERR(fc))
goto error;
v9fs_put_int16(bufp, oldtag, &fc->params.tflush.oldtag);
if (buf_check_overflow(bufp)) {
kfree(fc);
fc = ERR_PTR(-ENOMEM);
}
error:
return fc;
}
struct v9fs_fcall *v9fs_create_twalk(u32 fid, u32 newfid, u16 nwname,
char **wnames)
{
int i, size;
struct v9fs_fcall *fc;
struct cbuf buffer;
struct cbuf *bufp = &buffer;
if (nwname > V9FS_MAXWELEM) {
dprintk(DEBUG_ERROR, "nwname > %d\n", V9FS_MAXWELEM);
return NULL;
}
size = 4 + 4 + 2; /* fid[4] newfid[4] nwname[2] ... */
for (i = 0; i < nwname; i++) {
size += 2 + strlen(wnames[i]); /* wname[s] */
}
fc = v9fs_create_common(bufp, size, TWALK);
if (IS_ERR(fc))
goto error;
v9fs_put_int32(bufp, fid, &fc->params.twalk.fid);
v9fs_put_int32(bufp, newfid, &fc->params.twalk.newfid);
v9fs_put_int16(bufp, nwname, &fc->params.twalk.nwname);
for (i = 0; i < nwname; i++) {
v9fs_put_str(bufp, wnames[i], &fc->params.twalk.wnames[i]);
}
if (buf_check_overflow(bufp)) {
kfree(fc);
fc = ERR_PTR(-ENOMEM);
}
error:
return fc;
}
struct v9fs_fcall *v9fs_create_topen(u32 fid, u8 mode)
{
int size;
struct v9fs_fcall *fc;
struct cbuf buffer;
struct cbuf *bufp = &buffer;
size = 4 + 1; /* fid[4] mode[1] */
fc = v9fs_create_common(bufp, size, TOPEN);
if (IS_ERR(fc))
goto error;
v9fs_put_int32(bufp, fid, &fc->params.topen.fid);
v9fs_put_int8(bufp, mode, &fc->params.topen.mode);
if (buf_check_overflow(bufp)) {
kfree(fc);
fc = ERR_PTR(-ENOMEM);
}
error:
return fc;
}
struct v9fs_fcall *v9fs_create_tcreate(u32 fid, char *name, u32 perm, u8 mode)
{
int size;
struct v9fs_fcall *fc;
struct cbuf buffer;
struct cbuf *bufp = &buffer;
size = 4 + 2 + strlen(name) + 4 + 1; /* fid[4] name[s] perm[4] mode[1] */
fc = v9fs_create_common(bufp, size, TCREATE);
if (IS_ERR(fc))
goto error;
v9fs_put_int32(bufp, fid, &fc->params.tcreate.fid);
v9fs_put_str(bufp, name, &fc->params.tcreate.name);
v9fs_put_int32(bufp, perm, &fc->params.tcreate.perm);
v9fs_put_int8(bufp, mode, &fc->params.tcreate.mode);
if (buf_check_overflow(bufp)) {
kfree(fc);
fc = ERR_PTR(-ENOMEM);
}
error:
return fc;
}
struct v9fs_fcall *v9fs_create_tread(u32 fid, u64 offset, u32 count)
{
int size;
struct v9fs_fcall *fc;
struct cbuf buffer;
struct cbuf *bufp = &buffer;
size = 4 + 8 + 4; /* fid[4] offset[8] count[4] */
fc = v9fs_create_common(bufp, size, TREAD);
if (IS_ERR(fc))
goto error;
v9fs_put_int32(bufp, fid, &fc->params.tread.fid);
v9fs_put_int64(bufp, offset, &fc->params.tread.offset);
v9fs_put_int32(bufp, count, &fc->params.tread.count);
if (buf_check_overflow(bufp)) {
kfree(fc);
fc = ERR_PTR(-ENOMEM);
}
error:
return fc;
}
struct v9fs_fcall *v9fs_create_twrite(u32 fid, u64 offset, u32 count,
const char __user * data)
{
int size, err;
struct v9fs_fcall *fc;
struct cbuf buffer;
struct cbuf *bufp = &buffer;
size = 4 + 8 + 4 + count; /* fid[4] offset[8] count[4] data[count] */
fc = v9fs_create_common(bufp, size, TWRITE);
if (IS_ERR(fc))
goto error;
v9fs_put_int32(bufp, fid, &fc->params.twrite.fid);
v9fs_put_int64(bufp, offset, &fc->params.twrite.offset);
v9fs_put_int32(bufp, count, &fc->params.twrite.count);
err = v9fs_put_user_data(bufp, data, count, &fc->params.twrite.data);
if (err) {
kfree(fc);
fc = ERR_PTR(err);
}
if (buf_check_overflow(bufp)) {
kfree(fc);
fc = ERR_PTR(-ENOMEM);
}
error:
return fc;
}
struct v9fs_fcall *v9fs_create_tclunk(u32 fid)
{
int size;
struct v9fs_fcall *fc;
struct cbuf buffer;
struct cbuf *bufp = &buffer;
size = 4; /* fid[4] */
fc = v9fs_create_common(bufp, size, TCLUNK);
if (IS_ERR(fc))
goto error;
v9fs_put_int32(bufp, fid, &fc->params.tclunk.fid);
if (buf_check_overflow(bufp)) {
kfree(fc);
fc = ERR_PTR(-ENOMEM);
}
error:
return fc;
}
struct v9fs_fcall *v9fs_create_tremove(u32 fid)
{
int size;
struct v9fs_fcall *fc;
struct cbuf buffer;
struct cbuf *bufp = &buffer;
size = 4; /* fid[4] */
fc = v9fs_create_common(bufp, size, TREMOVE);
if (IS_ERR(fc))
goto error;
v9fs_put_int32(bufp, fid, &fc->params.tremove.fid);
if (buf_check_overflow(bufp)) {
kfree(fc);
fc = ERR_PTR(-ENOMEM);
}
error:
return fc;
}
struct v9fs_fcall *v9fs_create_tstat(u32 fid)
{
int size;
struct v9fs_fcall *fc;
struct cbuf buffer;
struct cbuf *bufp = &buffer;
size = 4; /* fid[4] */
fc = v9fs_create_common(bufp, size, TSTAT);
if (IS_ERR(fc))
goto error;
v9fs_put_int32(bufp, fid, &fc->params.tstat.fid);
if (buf_check_overflow(bufp)) {
kfree(fc);
fc = ERR_PTR(-ENOMEM);
}
error:
return fc;
}
struct v9fs_fcall *v9fs_create_twstat(u32 fid, struct v9fs_wstat *wstat,
int extended)
{
int size, statsz;
struct v9fs_fcall *fc;
struct cbuf buffer;
struct cbuf *bufp = &buffer;
statsz = v9fs_size_wstat(wstat, extended);
size = 4 + 2 + 2 + statsz; /* fid[4] stat[n] */
fc = v9fs_create_common(bufp, size, TWSTAT);
if (IS_ERR(fc))
goto error;
v9fs_put_int32(bufp, fid, &fc->params.twstat.fid);
buf_put_int16(bufp, statsz + 2);
v9fs_put_wstat(bufp, wstat, &fc->params.twstat.stat, statsz, extended);
if (buf_check_overflow(bufp)) {
kfree(fc);
fc = ERR_PTR(-ENOMEM);
}
error:
return fc;
}
