[Qemu-devel] [PATCH -V3 02/32] vrtio-9p: Implement P9_TVERSION for 9P

["Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>]

From: Anthony Liguori <aliguori@us.ibm.com>

[kiran@linux.vnet.ibm.com: malloc to qemu_malloc coversion]

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
 hw/virtio-9p.c |  263 +++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 files changed, 261 insertions(+), 2 deletions(-)

diff --git a/hw/virtio-9p.c b/hw/virtio-9p.c
index 115c93b..53b3d78 100644
--- a/hw/virtio-9p.c
+++ b/hw/virtio-9p.c
@@ -111,10 +111,269 @@ static void free_pdu(V9fsState *s, V9fsPDU *pdu)
     }
 }
 
+static void v9fs_string_free(V9fsString *str)
+{
+    free(str->data);
+    str->data = NULL;
+    str->size = 0;
+}
+
+static size_t pdu_unpack(void *dst, V9fsPDU *pdu, size_t offset, size_t size)
+{
+    struct iovec *sg = pdu->elem.out_sg;
+    BUG_ON((offset + size) > sg[0].iov_len);
+    memcpy(dst, sg[0].iov_base + offset, size);
+    return size;
+}
+
+/* FIXME i can do this with less variables */
+static size_t pdu_pack(V9fsPDU *pdu, size_t offset, const void *src, size_t size)
+{
+    struct iovec *sg = pdu->elem.in_sg;
+    size_t off = 0;
+    size_t copied = 0;
+    int i = 0;
+
+    for (i = 0; size && i < pdu->elem.in_num; i++) {
+        size_t len;
+
+        if (offset >= off && offset < (off + sg[i].iov_len)) {
+            len = MIN(sg[i].iov_len - (offset - off), size);
+            memcpy(sg[i].iov_base + (offset - off), src, len);
+            size -= len;
+            offset += len;
+            off = offset;
+            copied += len;
+            src += len;
+        } else {
+            off += sg[i].iov_len;
+        }
+    }
+
+    return copied;
+}
+
+static int pdu_copy_sg(V9fsPDU *pdu, size_t offset, int rx, struct iovec *sg)
+{
+    size_t pos = 0;
+    int i, j;
+    struct iovec *src_sg;
+    unsigned int num;
+
+    if (rx) {
+        src_sg = pdu->elem.in_sg;
+        num = pdu->elem.in_num;
+    } else {
+        src_sg = pdu->elem.out_sg;
+        num = pdu->elem.out_num;
+    }
+
+    j = 0;
+    for (i = 0; i < num; i++) {
+        if (offset <= pos) {
+            sg[j].iov_base = src_sg[i].iov_base;
+            sg[j].iov_len = src_sg[i].iov_len;
+            j++;
+        } else if (offset < (src_sg[i].iov_len + pos)) {
+            sg[j].iov_base = src_sg[i].iov_base;
+            sg[j].iov_len = src_sg[i].iov_len;
+            sg[j].iov_base += (offset - pos);
+            sg[j].iov_len -= (offset - pos);
+            j++;
+        }
+        pos += src_sg[i].iov_len;
+    }
+
+    return j;
+}
+
+static size_t pdu_unmarshal(V9fsPDU *pdu, size_t offset, const char *fmt, ...)
+{
+    size_t old_offset = offset;
+    va_list ap;
+    int i;
+
+    va_start(ap, fmt);
+    for (i = 0; fmt[i]; i++) {
+	switch (fmt[i]) {
+	case 'b': {
+	    int8_t *valp = va_arg(ap, int8_t *);
+	    offset += pdu_unpack(valp, pdu, offset, sizeof(*valp));
+	    break;
+	}
+	case 'w': {
+	    int16_t *valp = va_arg(ap, int16_t *);
+	    offset += pdu_unpack(valp, pdu, offset, sizeof(*valp));
+	    break;
+	}
+	case 'd': {
+	    int32_t *valp = va_arg(ap, int32_t *);
+	    offset += pdu_unpack(valp, pdu, offset, sizeof(*valp));
+	    break;
+	}
+	case 'q': {
+	    int64_t *valp = va_arg(ap, int64_t *);
+	    offset += pdu_unpack(valp, pdu, offset, sizeof(*valp));
+	    break;
+	}
+	case 'v': {
+	    struct iovec *iov = va_arg(ap, struct iovec *);
+	    int *iovcnt = va_arg(ap, int *);
+	    *iovcnt = pdu_copy_sg(pdu, offset, 0, iov);
+	    break;
+	}
+	case 's': {
+	    V9fsString *str = va_arg(ap, V9fsString *);
+	    offset += pdu_unmarshal(pdu, offset, "w", &str->size);
+	    /* FIXME: sanity check str->size */
+	    str->data = qemu_malloc(str->size + 1);
+	    offset += pdu_unpack(str->data, pdu, offset, str->size);
+	    str->data[str->size] = 0;
+	    break;
+	}
+	case 'Q': {
+	    V9fsQID *qidp = va_arg(ap, V9fsQID *);
+	    offset += pdu_unmarshal(pdu, offset, "bdq",
+				    &qidp->type, &qidp->version, &qidp->path);
+	    break;
+	}
+	case 'S': {
+	    V9fsStat *statp = va_arg(ap, V9fsStat *);
+	    offset += pdu_unmarshal(pdu, offset, "wwdQdddqsssssddd",
+				    &statp->size, &statp->type, &statp->dev,
+				    &statp->qid, &statp->mode, &statp->atime,
+				    &statp->mtime, &statp->length,
+				    &statp->name, &statp->uid, &statp->gid,
+				    &statp->muid, &statp->extension,
+				    &statp->n_uid, &statp->n_gid,
+				    &statp->n_muid);
+	    break;
+	}
+	default:
+	    break;
+	}
+    }
+
+    va_end(ap);
+
+    return offset - old_offset;
+}
+
+static size_t pdu_marshal(V9fsPDU *pdu, size_t offset, const char *fmt, ...)
+{
+    size_t old_offset = offset;
+    va_list ap;
+    int i;
+
+    va_start(ap, fmt);
+    for (i = 0; fmt[i]; i++) {
+	switch (fmt[i]) {
+	case 'b': {
+	    int8_t val = va_arg(ap, int);
+	    offset += pdu_pack(pdu, offset, &val, sizeof(val));
+	    break;
+	}
+	case 'w': {
+	    int16_t val = va_arg(ap, int);
+	    offset += pdu_pack(pdu, offset, &val, sizeof(val));
+	    break;
+	}
+	case 'd': {
+	    int32_t val = va_arg(ap, int);
+	    offset += pdu_pack(pdu, offset, &val, sizeof(val));
+	    break;
+	}
+	case 'q': {
+	    int64_t val = va_arg(ap, int64_t);
+	    offset += pdu_pack(pdu, offset, &val, sizeof(val));
+	    break;
+	}
+	case 'v': {
+	    struct iovec *iov = va_arg(ap, struct iovec *);
+	    int *iovcnt = va_arg(ap, int *);
+	    *iovcnt = pdu_copy_sg(pdu, offset, 1, iov);
+	    break;
+	}
+	case 's': {
+	    V9fsString *str = va_arg(ap, V9fsString *);
+	    offset += pdu_marshal(pdu, offset, "w", str->size);
+	    offset += pdu_pack(pdu, offset, str->data, str->size);
+	    break;
+	}
+	case 'Q': {
+	    V9fsQID *qidp = va_arg(ap, V9fsQID *);
+	    offset += pdu_marshal(pdu, offset, "bdq",
+				  qidp->type, qidp->version, qidp->path);
+	    break;
+	}
+	case 'S': {
+	    V9fsStat *statp = va_arg(ap, V9fsStat *);
+	    offset += pdu_marshal(pdu, offset, "wwdQdddqsssssddd",
+				  statp->size, statp->type, statp->dev,
+				  &statp->qid, statp->mode, statp->atime,
+				  statp->mtime, statp->length, &statp->name,
+				  &statp->uid, &statp->gid, &statp->muid,
+				  &statp->extension, statp->n_uid,
+				  statp->n_gid, statp->n_muid);
+	    break;
+	}
+	default:
+	    break;
+	}
+    }
+    va_end(ap);
+
+    return offset - old_offset;
+}
+
+static void complete_pdu(V9fsState *s, V9fsPDU *pdu, ssize_t len)
+{
+    int8_t id = pdu->id + 1; /* Response */
+
+    if (len < 0) {
+        V9fsString str;
+        int err = -len;
+
+        str.data = strerror(err);
+        str.size = strlen(str.data);
+
+        len = 7;
+        len += pdu_marshal(pdu, len, "s", &str);
+        if (dotu)
+            len += pdu_marshal(pdu, len, "d", err);
+
+        id = P9_RERROR;
+    }
+
+    /* fill out the header */
+    pdu_marshal(pdu, 0, "dbw", (int32_t)len, id, pdu->tag);
+
+    /* keep these in sync */
+    pdu->size = len;
+    pdu->id = id;
+
+    /* push onto queue and notify */
+    virtqueue_push(s->vq, &pdu->elem, len);
+
+    /* FIXME: we should batch these completions */
+    virtio_notify(&s->vdev, s->vq);
+
+    free_pdu(s, pdu);
+}
+
 static void v9fs_version(V9fsState *s, V9fsPDU *pdu)
 {
-    if (debug_9p_pdu)
-        pprint_pdu(pdu);
+    int32_t msize;
+    V9fsString version;
+    size_t offset = 7;
+
+    pdu_unmarshal(pdu, offset, "ds", &msize, &version);
+    BUG_ON(strcmp(version.data, "9P2000.u") != 0);
+
+    offset += pdu_marshal(pdu, offset, "ds", msize, &version);
+    complete_pdu(s, pdu, offset);
+
+    v9fs_string_free(&version);
 }
 
 static void v9fs_attach(V9fsState *s, V9fsPDU *pdu)
-- 
1.7.0.2.323.g0d092