WSL2-Linux-Kernel/fs/9p/conv.c

709 строки
17 KiB
C

/*
* 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 "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 inline 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\n");
buf->p = buf->ep + 1;
return 0;
}
}
return 1;
}
static inline 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 inline void buf_put_int8(struct cbuf *buf, u8 val)
{
if (buf_check_size(buf, 1)) {
buf->p[0] = val;
buf->p++;
}
}
static inline 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 inline 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 inline 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 inline 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 inline void buf_put_data(struct cbuf *buf, void *data, u32 datalen)
{
if (buf_check_size(buf, datalen)) {
memcpy(buf->p, data, datalen);
buf->p += datalen;
}
}
static inline 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 inline 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 inline 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 inline 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 inline int
buf_get_string(struct cbuf *buf, char *data, unsigned int datalen)
{
u16 len = 0;
len = buf_get_int16(buf);
if (!buf_check_overflow(buf) && buf_check_size(buf, len) && len+1>datalen) {
memcpy(data, buf->p, len);
data[len] = 0;
buf->p += len;
len++;
}
return len;
}
static inline char *buf_get_stringb(struct cbuf *buf, struct cbuf *sbuf)
{
char *ret;
u16 len;
ret = NULL;
len = buf_get_int16(buf);
if (!buf_check_overflow(buf) && buf_check_size(buf, len) &&
buf_check_size(sbuf, len+1)) {
memcpy(sbuf->p, buf->p, len);
sbuf->p[len] = 0;
ret = sbuf->p;
buf->p += len;
sbuf->p += len + 1;
}
return ret;
}
static inline int buf_get_data(struct cbuf *buf, void *data, int datalen)
{
int ret = 0;
if (buf_check_size(buf, datalen)) {
memcpy(data, buf->p, datalen);
buf->p += datalen;
ret = datalen;
}
return ret;
}
static inline void *buf_get_datab(struct cbuf *buf, struct cbuf *dbuf,
int datalen)
{
char *ret = NULL;
int n = 0;
if (buf_check_size(dbuf, datalen)) {
n = buf_get_data(buf, dbuf->p, datalen);
if (n > 0) {
ret = dbuf->p;
dbuf->p += n;
}
}
return ret;
}
/**
* v9fs_size_stat - calculate the size of a variable length stat struct
* @v9ses: session information
* @stat: metadata (stat) structure
*
*/
static int v9fs_size_stat(struct v9fs_session_info *v9ses,
struct v9fs_stat *stat)
{
int size = 0;
if (stat == 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 (stat->name)
size += strlen(stat->name);
if (stat->uid)
size += strlen(stat->uid);
if (stat->gid)
size += strlen(stat->gid);
if (stat->muid)
size += strlen(stat->muid);
if (v9ses->extended) {
size += 4 + /* n_uid[4] */
4 + /* n_gid[4] */
4 + /* n_muid[4] */
2; /* string length of extension[4] */
if (stat->extension)
size += strlen(stat->extension);
}
return size;
}
/**
* serialize_stat - safely format a stat structure for transmission
* @v9ses: session info
* @stat: metadata (stat) structure
* @bufp: buffer to serialize structure into
*
*/
static int
serialize_stat(struct v9fs_session_info *v9ses, struct v9fs_stat *stat,
struct cbuf *bufp)
{
buf_put_int16(bufp, stat->size);
buf_put_int16(bufp, stat->type);
buf_put_int32(bufp, stat->dev);
buf_put_int8(bufp, stat->qid.type);
buf_put_int32(bufp, stat->qid.version);
buf_put_int64(bufp, stat->qid.path);
buf_put_int32(bufp, stat->mode);
buf_put_int32(bufp, stat->atime);
buf_put_int32(bufp, stat->mtime);
buf_put_int64(bufp, stat->length);
buf_put_string(bufp, stat->name);
buf_put_string(bufp, stat->uid);
buf_put_string(bufp, stat->gid);
buf_put_string(bufp, stat->muid);
if (v9ses->extended) {
buf_put_string(bufp, stat->extension);
buf_put_int32(bufp, stat->n_uid);
buf_put_int32(bufp, stat->n_gid);
buf_put_int32(bufp, stat->n_muid);
}
if (buf_check_overflow(bufp))
return 0;
return stat->size;
}
/**
* deserialize_stat - safely decode a recieved metadata (stat) structure
* @v9ses: session info
* @bufp: buffer to deserialize
* @stat: metadata (stat) structure
* @dbufp: buffer to deserialize variable strings into
*
*/
static inline int
deserialize_stat(struct v9fs_session_info *v9ses, struct cbuf *bufp,
struct v9fs_stat *stat, struct cbuf *dbufp)
{
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);
stat->name = buf_get_stringb(bufp, dbufp);
stat->uid = buf_get_stringb(bufp, dbufp);
stat->gid = buf_get_stringb(bufp, dbufp);
stat->muid = buf_get_stringb(bufp, dbufp);
if (v9ses->extended) {
stat->extension = buf_get_stringb(bufp, dbufp);
stat->n_uid = buf_get_int32(bufp);
stat->n_gid = buf_get_int32(bufp);
stat->n_muid = buf_get_int32(bufp);
}
if (buf_check_overflow(bufp) || buf_check_overflow(dbufp))
return 0;
return stat->size + 2;
}
/**
* deserialize_statb - wrapper for decoding a received metadata structure
* @v9ses: session info
* @bufp: buffer to deserialize
* @dbufp: buffer to deserialize variable strings into
*
*/
static inline struct v9fs_stat *deserialize_statb(struct v9fs_session_info
*v9ses, struct cbuf *bufp,
struct cbuf *dbufp)
{
struct v9fs_stat *ret = buf_alloc(dbufp, sizeof(struct v9fs_stat));
if (ret) {
int n = deserialize_stat(v9ses, bufp, ret, dbufp);
if (n <= 0)
return NULL;
}
return ret;
}
/**
* v9fs_deserialize_stat - decode a received metadata structure
* @v9ses: session info
* @buf: buffer to deserialize
* @buflen: length of received buffer
* @stat: metadata structure to decode into
* @statlen: length of destination metadata structure
*
*/
int
v9fs_deserialize_stat(struct v9fs_session_info *v9ses, void *buf,
u32 buflen, struct v9fs_stat *stat, u32 statlen)
{
struct cbuf buffer;
struct cbuf *bufp = &buffer;
struct cbuf dbuffer;
struct cbuf *dbufp = &dbuffer;
buf_init(bufp, buf, buflen);
buf_init(dbufp, (char *)stat + sizeof(struct v9fs_stat),
statlen - sizeof(struct v9fs_stat));
return deserialize_stat(v9ses, bufp, stat, dbufp);
}
static inline int
v9fs_size_fcall(struct v9fs_session_info *v9ses, struct v9fs_fcall *fcall)
{
int size = 4 + 1 + 2; /* size[4] msg[1] tag[2] */
int i = 0;
switch (fcall->id) {
default:
eprintk(KERN_ERR, "bad msg type %d\n", fcall->id);
return 0;
case TVERSION: /* msize[4] version[s] */
size += 4 + 2 + strlen(fcall->params.tversion.version);
break;
case TAUTH: /* afid[4] uname[s] aname[s] */
size += 4 + 2 + strlen(fcall->params.tauth.uname) +
2 + strlen(fcall->params.tauth.aname);
break;
case TFLUSH: /* oldtag[2] */
size += 2;
break;
case TATTACH: /* fid[4] afid[4] uname[s] aname[s] */
size += 4 + 4 + 2 + strlen(fcall->params.tattach.uname) +
2 + strlen(fcall->params.tattach.aname);
break;
case TWALK: /* fid[4] newfid[4] nwname[2] nwname*(wname[s]) */
size += 4 + 4 + 2;
/* now compute total for the array of names */
for (i = 0; i < fcall->params.twalk.nwname; i++)
size += 2 + strlen(fcall->params.twalk.wnames[i]);
break;
case TOPEN: /* fid[4] mode[1] */
size += 4 + 1;
break;
case TCREATE: /* fid[4] name[s] perm[4] mode[1] */
size += 4 + 2 + strlen(fcall->params.tcreate.name) + 4 + 1;
break;
case TREAD: /* fid[4] offset[8] count[4] */
size += 4 + 8 + 4;
break;
case TWRITE: /* fid[4] offset[8] count[4] data[count] */
size += 4 + 8 + 4 + fcall->params.twrite.count;
break;
case TCLUNK: /* fid[4] */
size += 4;
break;
case TREMOVE: /* fid[4] */
size += 4;
break;
case TSTAT: /* fid[4] */
size += 4;
break;
case TWSTAT: /* fid[4] stat[n] */
fcall->params.twstat.stat->size =
v9fs_size_stat(v9ses, fcall->params.twstat.stat);
size += 4 + 2 + 2 + fcall->params.twstat.stat->size;
}
return size;
}
/*
* v9fs_serialize_fcall - marshall fcall struct into a packet
* @v9ses: session information
* @fcall: structure to convert
* @data: buffer to serialize fcall into
* @datalen: length of buffer to serialize fcall into
*
*/
int
v9fs_serialize_fcall(struct v9fs_session_info *v9ses, struct v9fs_fcall *fcall,
void *data, u32 datalen)
{
int i = 0;
struct v9fs_stat *stat = NULL;
struct cbuf buffer;
struct cbuf *bufp = &buffer;
buf_init(bufp, data, datalen);
if (!fcall) {
eprintk(KERN_ERR, "no fcall\n");
return -EINVAL;
}
fcall->size = v9fs_size_fcall(v9ses, fcall);
buf_put_int32(bufp, fcall->size);
buf_put_int8(bufp, fcall->id);
buf_put_int16(bufp, fcall->tag);
dprintk(DEBUG_CONV, "size %d id %d tag %d\n", fcall->size, fcall->id,
fcall->tag);
/* now encode it */
switch (fcall->id) {
default:
eprintk(KERN_ERR, "bad msg type: %d\n", fcall->id);
return -EPROTO;
case TVERSION:
buf_put_int32(bufp, fcall->params.tversion.msize);
buf_put_string(bufp, fcall->params.tversion.version);
break;
case TAUTH:
buf_put_int32(bufp, fcall->params.tauth.afid);
buf_put_string(bufp, fcall->params.tauth.uname);
buf_put_string(bufp, fcall->params.tauth.aname);
break;
case TFLUSH:
buf_put_int16(bufp, fcall->params.tflush.oldtag);
break;
case TATTACH:
buf_put_int32(bufp, fcall->params.tattach.fid);
buf_put_int32(bufp, fcall->params.tattach.afid);
buf_put_string(bufp, fcall->params.tattach.uname);
buf_put_string(bufp, fcall->params.tattach.aname);
break;
case TWALK:
buf_put_int32(bufp, fcall->params.twalk.fid);
buf_put_int32(bufp, fcall->params.twalk.newfid);
buf_put_int16(bufp, fcall->params.twalk.nwname);
for (i = 0; i < fcall->params.twalk.nwname; i++)
buf_put_string(bufp, fcall->params.twalk.wnames[i]);
break;
case TOPEN:
buf_put_int32(bufp, fcall->params.topen.fid);
buf_put_int8(bufp, fcall->params.topen.mode);
break;
case TCREATE:
buf_put_int32(bufp, fcall->params.tcreate.fid);
buf_put_string(bufp, fcall->params.tcreate.name);
buf_put_int32(bufp, fcall->params.tcreate.perm);
buf_put_int8(bufp, fcall->params.tcreate.mode);
break;
case TREAD:
buf_put_int32(bufp, fcall->params.tread.fid);
buf_put_int64(bufp, fcall->params.tread.offset);
buf_put_int32(bufp, fcall->params.tread.count);
break;
case TWRITE:
buf_put_int32(bufp, fcall->params.twrite.fid);
buf_put_int64(bufp, fcall->params.twrite.offset);
buf_put_int32(bufp, fcall->params.twrite.count);
buf_put_data(bufp, fcall->params.twrite.data,
fcall->params.twrite.count);
break;
case TCLUNK:
buf_put_int32(bufp, fcall->params.tclunk.fid);
break;
case TREMOVE:
buf_put_int32(bufp, fcall->params.tremove.fid);
break;
case TSTAT:
buf_put_int32(bufp, fcall->params.tstat.fid);
break;
case TWSTAT:
buf_put_int32(bufp, fcall->params.twstat.fid);
stat = fcall->params.twstat.stat;
buf_put_int16(bufp, stat->size + 2);
serialize_stat(v9ses, stat, bufp);
break;
}
if (buf_check_overflow(bufp))
return -EIO;
return fcall->size;
}
/**
* deserialize_fcall - unmarshal a response
* @v9ses: session information
* @msgsize: size of rcall message
* @buf: recieved buffer
* @buflen: length of received buffer
* @rcall: fcall structure to populate
* @rcalllen: length of fcall structure to populate
*
*/
int
v9fs_deserialize_fcall(struct v9fs_session_info *v9ses, u32 msgsize,
void *buf, u32 buflen, struct v9fs_fcall *rcall,
int rcalllen)
{
struct cbuf buffer;
struct cbuf *bufp = &buffer;
struct cbuf dbuffer;
struct cbuf *dbufp = &dbuffer;
int i = 0;
buf_init(bufp, buf, buflen);
buf_init(dbufp, (char *)rcall + sizeof(struct v9fs_fcall),
rcalllen - sizeof(struct v9fs_fcall));
rcall->size = msgsize;
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);
rcall->params.rversion.version = buf_get_stringb(bufp, dbufp);
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);
rcall->params.rwalk.wqids = buf_alloc(dbufp,
rcall->params.rwalk.nwqid * sizeof(struct v9fs_qid));
if (rcall->params.rwalk.wqids)
for (i = 0; i < rcall->params.rwalk.nwqid; i++) {
rcall->params.rwalk.wqids[i].type =
buf_get_int8(bufp);
rcall->params.rwalk.wqids[i].version =
buf_get_int16(bufp);
rcall->params.rwalk.wqids[i].path =
buf_get_int64(bufp);
}
break;
case ROPEN:
rcall->params.ropen.qid.type = buf_get_int8(bufp);
rcall->params.ropen.qid.version = buf_get_int32(bufp);
rcall->params.ropen.qid.path = buf_get_int64(bufp);
rcall->params.ropen.iounit = buf_get_int32(bufp);
break;
case RCREATE:
rcall->params.rcreate.qid.type = buf_get_int8(bufp);
rcall->params.rcreate.qid.version = buf_get_int32(bufp);
rcall->params.rcreate.qid.path = buf_get_int64(bufp);
rcall->params.rcreate.iounit = buf_get_int32(bufp);
break;
case RREAD:
rcall->params.rread.count = buf_get_int32(bufp);
rcall->params.rread.data = buf_get_datab(bufp, dbufp,
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);
rcall->params.rstat.stat =
deserialize_statb(v9ses, bufp, dbufp);
break;
case RWSTAT:
break;
case RERROR:
rcall->params.rerror.error = buf_get_stringb(bufp, dbufp);
if (v9ses->extended)
rcall->params.rerror.errno = buf_get_int16(bufp);
break;
}
if (buf_check_overflow(bufp) || buf_check_overflow(dbufp))
return -EIO;
return rcall->size;
}