[PATCH 5/10] 9p: marshalling changes for in-kernel server

From: Latchesar Ionkov
Date: Fri Nov 02 2007 - 13:03:19 EST


This patch implements serialization/deserialization for the server-side 9P
messages.

Signed-off-by: Latchesar Ionkov <lucho@xxxxxxxxxx>

---
include/net/9p/9p.h | 16 ++
net/9p/conv.c | 457 +++++++++++++++++++++++++++++++++++++++++++++++++--
2 files changed, 462 insertions(+), 11 deletions(-)

diff --git a/include/net/9p/9p.h b/include/net/9p/9p.h
index 8de6eef..08c4dd1 100644
--- a/include/net/9p/9p.h
+++ b/include/net/9p/9p.h
@@ -379,6 +379,7 @@ struct p9_fcall {
struct p9_idpool;
extern struct kset p9_subsys;

+int p9_serialize_stat(struct p9_wstat *wstat, u8 *buf, int buflen, int dotu);
int p9_deserialize_stat(void *buf, u32 buflen, struct p9_stat *stat,
int dotu);
int p9_deserialize_fcall(struct p9_fcall *fc, int dotu);
@@ -407,6 +408,21 @@ struct p9_fcall *p9_create_tremove(u32 fid);
struct p9_fcall *p9_create_tstat(u32 fid);
struct p9_fcall *p9_create_twstat(u32 fid, struct p9_wstat *wstat,
int dotu);
+int p9_create_rversion(struct p9_fcall *, u32 msize, char *version);
+int p9_create_rattach(struct p9_fcall *, struct p9_qid *qid);
+int p9_create_rerror(struct p9_fcall *, char *ename, u32 ecode, int dotu);
+int p9_create_rauth(struct p9_fcall *, struct p9_qid *qid);
+int p9_create_rflush(struct p9_fcall *);
+int p9_create_rwalk(struct p9_fcall *, int nwqid, struct p9_qid *wqids);
+int p9_create_ropen(struct p9_fcall *, struct p9_qid *qid, u32 iounit);
+int p9_create_rcreate(struct p9_fcall *, struct p9_qid *qid, u32 iounit);
+int p9_init_rread(struct p9_fcall *fc);
+void p9_set_rread_count(struct p9_fcall *fc, u32 count);
+int p9_create_rwrite(struct p9_fcall *, u32 count);
+int p9_create_rclunk(struct p9_fcall *);
+int p9_create_rremove(struct p9_fcall *);
+int p9_create_rstat(struct p9_fcall *, struct p9_wstat *st, int dotu);
+int p9_create_rwstat(struct p9_fcall *);

int p9_printfcall(char *buf, int buflen, struct p9_fcall *fc, int dotu);
int p9_errstr2errno(char *errstr, int len);
diff --git a/net/9p/conv.c b/net/9p/conv.c
index 74d57c7..ed119bc 100644
--- a/net/9p/conv.c
+++ b/net/9p/conv.c
@@ -41,6 +41,8 @@ struct cbuf {
unsigned char *ep;
};

+static int p9_size_wstat(struct p9_wstat *wstat, int dotu);
+
static inline void buf_init(struct cbuf *buf, void *data, int datalen)
{
buf->sp = buf->p = data;
@@ -133,6 +135,41 @@ static inline void buf_put_string(struct cbuf *buf, const char *s)
buf_put_stringn(buf, s, s?strlen(s):0);
}

+static inline void buf_put_qid(struct cbuf *buf, struct p9_qid *qid)
+{
+ buf_put_int8(buf, qid->type);
+ buf_put_int32(buf, qid->version);
+ buf_put_int64(buf, qid->path);
+}
+
+static inline void buf_put_wstat(struct cbuf *bufp, struct p9_wstat *wstat,
+ int dotu)
+{
+ int statsz;
+
+ statsz = p9_size_wstat(wstat, dotu);
+ buf_put_int16(bufp, statsz);
+ buf_put_int16(bufp, wstat->type);
+ buf_put_int32(bufp, wstat->dev);
+ buf_put_qid(bufp, &wstat->qid);
+ buf_put_int32(bufp, wstat->mode);
+ buf_put_int32(bufp, wstat->atime);
+ buf_put_int32(bufp, wstat->mtime);
+ buf_put_int64(bufp, wstat->length);
+
+ buf_put_string(bufp, wstat->name);
+ buf_put_string(bufp, wstat->uid);
+ buf_put_string(bufp, wstat->gid);
+ buf_put_string(bufp, wstat->muid);
+
+ if (dotu) {
+ buf_put_string(bufp, wstat->extension);
+ buf_put_int32(bufp, wstat->n_uid);
+ buf_put_int32(bufp, wstat->n_gid);
+ buf_put_int32(bufp, wstat->n_muid);
+ }
+}
+
static u8 buf_get_int8(struct cbuf *buf)
{
u8 ret = 0;
@@ -181,6 +218,15 @@ static u64 buf_get_int64(struct cbuf *buf)
return ret;
}

+static void buf_get_data(struct cbuf *buf, u32 count, u8 **data)
+{
+ if (buf_check_size(buf, count)) {
+ *data = buf->p;
+ buf->p += count;
+ } else
+ *data = NULL;
+}
+
static void buf_get_str(struct cbuf *buf, struct p9_str *vstr)
{
vstr->len = buf_get_int16(buf);
@@ -346,17 +392,63 @@ int p9_deserialize_fcall(struct p9_fcall *rcall, int dotu)
default:
P9_EPRINTK(KERN_ERR, "unknown message type: %d\n", rcall->id);
return -EPROTO;
+ case P9_TVERSION:
+ rcall->params.tversion.msize = buf_get_int32(bufp);
+ buf_get_str(bufp, &rcall->params.tversion.version);
+ break;
case P9_RVERSION:
rcall->params.rversion.msize = buf_get_int32(bufp);
buf_get_str(bufp, &rcall->params.rversion.version);
break;
+ case P9_TAUTH:
+ rcall->params.tauth.afid = buf_get_int32(bufp);
+ buf_get_str(bufp, &rcall->params.tauth.uname);
+ buf_get_str(bufp, &rcall->params.tauth.aname);
+ if (dotu)
+ rcall->params.tauth.n_uname = buf_get_int32(bufp);
+ else
+ rcall->params.tauth.n_uname = ~0;
+ break;
+ case P9_RAUTH:
+ rcall->params.rauth.qid.type = buf_get_int8(bufp);
+ rcall->params.rauth.qid.version = buf_get_int32(bufp);
+ rcall->params.rauth.qid.path = buf_get_int64(bufp);
+ break;
+ case P9_TFLUSH:
+ rcall->params.tflush.oldtag = buf_get_int16(bufp);
+ break;
case P9_RFLUSH:
break;
+ case P9_TATTACH:
+ rcall->params.tattach.fid = buf_get_int32(bufp);
+ rcall->params.tattach.afid = buf_get_int32(bufp);
+ buf_get_str(bufp, &rcall->params.tattach.uname);
+ buf_get_str(bufp, &rcall->params.tattach.aname);
+ if (dotu)
+ rcall->params.tattach.n_uname = buf_get_int32(bufp);
+ else
+ rcall->params.tattach.n_uname = ~0;
+
+ break;
case P9_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 P9_TWALK:
+ rcall->params.twalk.fid = buf_get_int32(bufp);
+ rcall->params.twalk.newfid = buf_get_int32(bufp);
+ rcall->params.twalk.nwname = buf_get_int16(bufp);
+ if (rcall->params.twalk.nwname > P9_MAXWELEM) {
+ P9_EPRINTK(KERN_ERR,
+ "Rwalk with more than %d qids: %d\n",
+ P9_MAXWELEM, rcall->params.twalk.nwname);
+ return -EPROTO;
+ }
+
+ for (i = 0; i < rcall->params.twalk.nwname; i++)
+ buf_get_str(bufp, &rcall->params.twalk.wnames[i]);
+ break;
case P9_RWALK:
rcall->params.rwalk.nwqid = buf_get_int16(bufp);
if (rcall->params.rwalk.nwqid > P9_MAXWELEM) {
@@ -369,30 +461,68 @@ int p9_deserialize_fcall(struct p9_fcall *rcall, int dotu)
for (i = 0; i < rcall->params.rwalk.nwqid; i++)
buf_get_qid(bufp, &rcall->params.rwalk.wqids[i]);
break;
+ case P9_TOPEN:
+ rcall->params.topen.fid = buf_get_int32(bufp);
+ rcall->params.topen.mode = buf_get_int8(bufp);
+ break;
case P9_ROPEN:
buf_get_qid(bufp, &rcall->params.ropen.qid);
rcall->params.ropen.iounit = buf_get_int32(bufp);
break;
+ case P9_TCREATE:
+ rcall->params.tcreate.fid = buf_get_int32(bufp);
+ buf_get_str(bufp, &rcall->params.tcreate.name);
+ rcall->params.tcreate.perm = buf_get_int32(bufp);
+ rcall->params.tcreate.mode = buf_get_int8(bufp);
+ if (dotu)
+ buf_get_str(bufp, &rcall->params.tcreate.extension);
+ break;
case P9_RCREATE:
buf_get_qid(bufp, &rcall->params.rcreate.qid);
rcall->params.rcreate.iounit = buf_get_int32(bufp);
break;
+ case P9_TREAD:
+ rcall->params.tread.fid = buf_get_int32(bufp);
+ rcall->params.tread.offset = buf_get_int64(bufp);
+ rcall->params.tread.count = buf_get_int32(bufp);
+ break;
case P9_RREAD:
rcall->params.rread.count = buf_get_int32(bufp);
- rcall->params.rread.data = bufp->p;
- buf_check_size(bufp, rcall->params.rread.count);
+ buf_get_data(bufp, rcall->params.rread.count,
+ &rcall->params.rread.data);
+ break;
+ case P9_TWRITE:
+ rcall->params.twrite.fid = buf_get_int32(bufp);
+ rcall->params.twrite.offset = buf_get_int64(bufp);
+ rcall->params.twrite.count = buf_get_int32(bufp);
+ buf_get_data(bufp, rcall->params.twrite.count,
+ &rcall->params.twrite.data);
break;
case P9_RWRITE:
rcall->params.rwrite.count = buf_get_int32(bufp);
break;
+ case P9_TCLUNK:
+ rcall->params.tclunk.fid = buf_get_int32(bufp);
+ break;
case P9_RCLUNK:
break;
+ case P9_TREMOVE:
+ rcall->params.tremove.fid = buf_get_int32(bufp);
+ break;
case P9_RREMOVE:
break;
+ case P9_TSTAT:
+ rcall->params.tstat.fid = buf_get_int32(bufp);
+ break;
case P9_RSTAT:
buf_get_int16(bufp);
buf_get_stat(bufp, &rcall->params.rstat.stat, dotu);
break;
+ case P9_TWSTAT:
+ rcall->params.twstat.fid = buf_get_int32(bufp);
+ buf_get_int16(bufp);
+ buf_get_stat(bufp, &rcall->params.twstat.stat, dotu);
+ break;
case P9_RWSTAT:
break;
case P9_RERROR:
@@ -453,6 +583,14 @@ p9_put_str(struct cbuf *bufp, char *data, struct p9_str *str)
}
}

+static void p9_put_qid(struct cbuf *buf, struct p9_qid *qid,
+ struct p9_qid *pqid)
+{
+ p9_put_int8(buf, qid->type, &pqid->type);
+ p9_put_int32(buf, qid->version, &pqid->version);
+ p9_put_int64(buf, qid->path, &pqid->path);
+}
+
static int
p9_put_data(struct cbuf *bufp, const char *data, int count,
unsigned char **pdata)
@@ -498,6 +636,23 @@ p9_put_wstat(struct cbuf *bufp, struct p9_wstat *wstat,
}
}

+int p9_serialize_stat(struct p9_wstat *wstat, u8 *buf, int buflen, int dotu)
+{
+ struct cbuf buffer;
+ struct cbuf *bufp = &buffer;
+ unsigned char *p;
+
+ buf_init(bufp, buf, buflen);
+ p = bufp->p;
+ buf_put_wstat(bufp, wstat, dotu);
+
+ if (buf_check_overflow(bufp))
+ return 0;
+ else
+ return bufp->p - p;
+}
+EXPORT_SYMBOL(p9_serialize_stat);
+
struct p9_fcall *p9_fcall_alloc(u32 size)
{
struct p9_fcall *fc;
@@ -512,23 +667,46 @@ struct p9_fcall *p9_fcall_alloc(u32 size)
}
EXPORT_SYMBOL(p9_fcall_alloc);

-static struct p9_fcall *
-p9_create_common(struct cbuf *bufp, u32 size, u8 id)
+static int p9_fcall_init(struct cbuf *bufp, struct p9_fcall *fc,
+ u32 size, u8 id)
{
- struct p9_fcall *fc;
-
size += 4 + 1 + 2; /* size[4] id[1] tag[2] */
- fc = kmalloc(sizeof(struct p9_fcall) + size, GFP_KERNEL);
- if (!fc)
- return ERR_PTR(-ENOMEM);
-
- fc->sdata = (char *)fc + sizeof(*fc);
+ if (fc->size < size)
+ return -ENOMEM;

buf_init(bufp, (char *)fc->sdata, size);
p9_put_int32(bufp, size, &fc->size);
p9_put_int8(bufp, id, &fc->id);
p9_put_int16(bufp, P9_NOTAG, &fc->tag);

+ return 0;
+}
+
+static inline int p9_fcall_finish(struct cbuf *bufp)
+{
+ int ret;
+
+ ret = buf_check_overflow(bufp)?-ENOMEM:0;
+ return ret;
+}
+
+static struct p9_fcall *
+p9_create_common(struct cbuf *bufp, u32 size, u8 id)
+{
+ int n, err;
+ struct p9_fcall *fc;
+
+ n = size + 4 + 1 + 2; /* size[4] id[1] tag[2] */
+ fc = p9_fcall_alloc(n);
+ if (IS_ERR(fc))
+ return fc;
+
+ err = p9_fcall_init(bufp, fc, size, id);
+ if (err < 0) {
+ kfree(fc);
+ return ERR_PTR(err);
+ }
+
return fc;
}

@@ -944,6 +1122,263 @@ error:
}
EXPORT_SYMBOL(p9_create_twstat);

+int p9_create_rversion(struct p9_fcall *fc, u32 msize, char *version)
+{
+ int err, size;
+ struct cbuf buffer;
+ struct cbuf *bufp = &buffer;
+
+ size = 4 + 2 + strlen(version); /* msize[4] version[s] */
+ err = p9_fcall_init(bufp, fc, size, P9_RVERSION);
+ if (err < 0)
+ return err;
+
+ p9_put_int32(bufp, msize, &fc->params.rversion.msize);
+ p9_put_str(bufp, version, &fc->params.rversion.version);
+
+ return p9_fcall_finish(bufp);
+}
+EXPORT_SYMBOL(p9_create_rversion);
+
+int p9_create_rattach(struct p9_fcall *fc, struct p9_qid *qid)
+{
+ int err, size;
+ struct cbuf buffer;
+ struct cbuf *bufp = &buffer;
+
+ size = 13; /* qid[13] */
+ err = p9_fcall_init(bufp, fc, size, P9_RATTACH);
+ if (err < 0)
+ return err;
+
+ p9_put_qid(bufp, qid, &fc->params.rattach.qid);
+
+ return p9_fcall_finish(bufp);
+}
+EXPORT_SYMBOL(p9_create_rattach);
+
+int p9_create_rerror(struct p9_fcall *fc, char *ename, u32 ecode, int dotu)
+{
+ int err, size;
+ struct cbuf buffer;
+ struct cbuf *bufp = &buffer;
+
+ size = 2 + strlen(ename); /* ename[s] */
+ if (dotu)
+ size += 4; /* ecode[4] */
+
+ err = p9_fcall_init(bufp, fc, size, P9_RERROR);
+ if (err < 0)
+ return err;
+
+ p9_put_str(bufp, ename, &fc->params.rerror.error);
+ if (dotu)
+ p9_put_int32(bufp, ecode, &fc->params.rerror.errno);
+
+ return p9_fcall_finish(bufp);
+}
+EXPORT_SYMBOL(p9_create_rerror);
+
+int p9_create_rauth(struct p9_fcall *fc, struct p9_qid *qid)
+{
+ int err, size;
+ struct cbuf buffer;
+ struct cbuf *bufp = &buffer;
+
+ size = 13; /* qid[13] */
+ err = p9_fcall_init(bufp, fc, size, P9_RAUTH);
+ if (err < 0)
+ return err;
+
+ p9_put_qid(bufp, qid, &fc->params.rattach.qid);
+
+ return p9_fcall_finish(bufp);
+}
+EXPORT_SYMBOL(p9_create_rauth);
+
+int p9_create_rflush(struct p9_fcall *fc)
+{
+ int err, size;
+ struct cbuf buffer;
+ struct cbuf *bufp = &buffer;
+
+ size = 0;
+ err = p9_fcall_init(bufp, fc, size, P9_RFLUSH);
+ if (err < 0)
+ return err;
+
+ return p9_fcall_finish(bufp);
+}
+EXPORT_SYMBOL(p9_create_rflush);
+
+int p9_create_rwalk(struct p9_fcall *fc, int nwqid, struct p9_qid *wqids)
+{
+ int i, err, size;
+ struct cbuf buffer;
+ struct cbuf *bufp = &buffer;
+
+ size = 2 + nwqid * 13; /* nwqid[2] nwqid*wqid[13] */
+ err = p9_fcall_init(bufp, fc, size, P9_RWALK);
+ if (err < 0)
+ return err;
+
+ p9_put_int16(bufp, nwqid, &fc->params.rwalk.nwqid);
+ for (i = 0; i < nwqid; i++)
+ p9_put_qid(bufp, &wqids[i], &fc->params.rwalk.wqids[i]);
+
+ return p9_fcall_finish(bufp);
+}
+EXPORT_SYMBOL(p9_create_rwalk);
+
+int p9_create_ropen(struct p9_fcall *fc, struct p9_qid *qid, u32 iounit)
+{
+ int err, size;
+ struct cbuf buffer;
+ struct cbuf *bufp = &buffer;
+
+ size = 13 + 4; /* qid[13] iounit[4] */
+ err = p9_fcall_init(bufp, fc, size, P9_ROPEN);
+ if (err < 0)
+ return err;
+
+ p9_put_qid(bufp, qid, &fc->params.ropen.qid);
+ p9_put_int32(bufp, iounit, &fc->params.ropen.iounit);
+
+ return p9_fcall_finish(bufp);
+}
+EXPORT_SYMBOL(p9_create_ropen);
+
+int p9_create_rcreate(struct p9_fcall *fc, struct p9_qid *qid, u32 iounit)
+{
+ int err, size;
+ struct cbuf buffer;
+ struct cbuf *bufp = &buffer;
+
+ size = 13 + 4; /* qid[13] iounit[4] */
+ err = p9_fcall_init(bufp, fc, size, P9_RCREATE);
+ if (err < 0)
+ return err;
+
+ p9_put_qid(bufp, qid, &fc->params.rcreate.qid);
+ p9_put_int32(bufp, iounit, &fc->params.rcreate.iounit);
+
+ return p9_fcall_finish(bufp);
+}
+EXPORT_SYMBOL(p9_create_rcreate);
+
+int p9_init_rread(struct p9_fcall *fc)
+{
+ int err, size;
+ struct cbuf buffer;
+ struct cbuf *bufp = &buffer;
+
+ size = fc->size - 7;
+ err = p9_fcall_init(bufp, fc, size, P9_RREAD);
+ if (err < 0)
+ return err;
+
+ p9_put_int32(bufp, 0, &fc->params.rread.count);
+ buf_get_data(bufp, fc->size - P9_IOHDRSZ, &fc->params.rread.data);
+
+ return p9_fcall_finish(bufp);
+}
+EXPORT_SYMBOL(p9_init_rread);
+
+void p9_set_rread_count(struct p9_fcall *fc, u32 count)
+{
+ int n;
+ char *p;
+
+ n = 4 + 1 + 2 + 4 + count;/*size[4] id[1] tag[2] count[4] data[count]*/
+ fc->params.rread.count = count;
+ fc->size = n;
+ p = fc->sdata;
+ *(__le32 *) p = cpu_to_le32(n);
+ *(__le32 *) (p + 7) = cpu_to_le32(count);
+}
+EXPORT_SYMBOL(p9_set_rread_count);
+
+int p9_create_rwrite(struct p9_fcall *fc, u32 count)
+{
+ int err, size;
+ struct cbuf buffer;
+ struct cbuf *bufp = &buffer;
+
+ size = 4; /* count[4] */
+ err = p9_fcall_init(bufp, fc, size, P9_RWRITE);
+ if (err < 0)
+ return err;
+
+ p9_put_int32(bufp, count, &fc->params.rwrite.count);
+
+ return p9_fcall_finish(bufp);
+}
+EXPORT_SYMBOL(p9_create_rwrite);
+
+int p9_create_rclunk(struct p9_fcall *fc)
+{
+ int err, size;
+ struct cbuf buffer;
+ struct cbuf *bufp = &buffer;
+
+ size = 0;
+ err = p9_fcall_init(bufp, fc, size, P9_RCLUNK);
+ if (err < 0)
+ return err;
+
+ return p9_fcall_finish(bufp);
+}
+EXPORT_SYMBOL(p9_create_rclunk);
+
+int p9_create_rremove(struct p9_fcall *fc)
+{
+ int err, size;
+ struct cbuf buffer;
+ struct cbuf *bufp = &buffer;
+
+ size = 0;
+ err = p9_fcall_init(bufp, fc, size, P9_RREMOVE);
+ if (err < 0)
+ return err;
+
+ return p9_fcall_finish(bufp);
+}
+EXPORT_SYMBOL(p9_create_rremove);
+
+int p9_create_rstat(struct p9_fcall *fc, struct p9_wstat *st, int dotu)
+{
+ int err, size, statsz;
+ struct cbuf buffer;
+ struct cbuf *bufp = &buffer;
+
+ statsz = p9_size_wstat(st, dotu);
+ size = 2 + 2 + statsz; /* stat[n] */
+ err = p9_fcall_init(bufp, fc, size, P9_RSTAT);
+ if (err < 0)
+ return err;
+
+ buf_put_int16(bufp, statsz + 2);
+ p9_put_wstat(bufp, st, &fc->params.rstat.stat, statsz, dotu);
+
+ return p9_fcall_finish(bufp);
+}
+EXPORT_SYMBOL(p9_create_rstat);
+
+int p9_create_rwstat(struct p9_fcall *fc)
+{
+ int err, size;
+ struct cbuf buffer;
+ struct cbuf *bufp = &buffer;
+
+ size = 0;
+ err = p9_fcall_init(bufp, fc, size, P9_RWSTAT);
+ if (err < 0)
+ return err;
+
+ return p9_fcall_finish(bufp);
+}
+EXPORT_SYMBOL(p9_create_rwstat);
+
int p9_fcall_get(char *dst, int dstlen, struct p9_fcall *fc)
{
if (dstlen > fc->size)
-
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