usb: split packet result into actual_length + status

Since with the ehci and xhci controllers a single packet can be larger
then maxpacketsize, it is possible for the result of a single packet
to be both having transferred some data as well as the transfer to have
an error.

An example would be an input transfer from a bulk endpoint successfully
receiving 1 or more maxpacketsize packets from the device, followed
by a packet signalling halt.

While already touching all the devices and controllers handle_packet /
handle_data / handle_control code, also change the return type of
these functions to void, solely storing the status in the packet. To
make the code paths for regular versus async packet handling more
uniform.

This patch unfortunately is somewhat invasive, since makeing the qemu
usb core deal with this requires changes everywhere. This patch only
prepares the usb core for this, all the hcd / device changes are done
in such a way that there are no functional changes.

This patch has been tested with uhci and ehci hcds, together with usb-audio,
usb-hid and usb-storage devices, as well as with usb-redir redirection
with a wide variety of real devices.

Note that there is usually no need to directly set packet->actual_length
form devices handle_data callback, as that is done by usb_packet_copy()

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

1 files changed, 49 insertions, 52 deletions

diff --git a/hw/usb/dev-network.c b/hw/usb/dev-network.c
index e4a43599b5..14d9e5aa5b 100644
--- a/hw/usb/dev-network.c
+++ b/hw/usb/dev-network.c
@@ -1048,7 +1048,7 @@ static void usb_net_handle_reset(USBDevice *dev)
 {
 }
 
-static int usb_net_handle_control(USBDevice *dev, USBPacket *p,
+static void usb_net_handle_control(USBDevice *dev, USBPacket *p,
                int request, int value, int index, int length, uint8_t *data)
 {
     USBNetState *s = (USBNetState *) dev;
@@ -1056,10 +1056,9 @@ static int usb_net_handle_control(USBDevice *dev, USBPacket *p,
 
     ret = usb_desc_handle_control(dev, p, request, value, index, length, data);
     if (ret >= 0) {
-        return ret;
+        return;
     }
 
-    ret = 0;
     switch(request) {
     case ClassInterfaceOutRequest | USB_CDC_SEND_ENCAPSULATED_COMMAND:
         if (!is_rndis(s) || value || index != 0) {
@@ -1078,22 +1077,25 @@ static int usb_net_handle_control(USBDevice *dev, USBPacket *p,
         }
 #endif
         ret = rndis_parse(s, data, length);
+        if (ret < 0) {
+            p->status = ret;
+        }
         break;
 
     case ClassInterfaceRequest | USB_CDC_GET_ENCAPSULATED_RESPONSE:
         if (!is_rndis(s) || value || index != 0) {
             goto fail;
         }
-        ret = rndis_get_response(s, data);
-        if (!ret) {
+        p->actual_length = rndis_get_response(s, data);
+        if (p->actual_length == 0) {
             data[0] = 0;
-            ret = 1;
+            p->actual_length = 1;
         }
 #ifdef TRAFFIC_DEBUG
         {
             unsigned int i;
             fprintf(stderr, "GET_ENCAPSULATED_RESPONSE:");
-            for (i = 0; i < ret; i++) {
+            for (i = 0; i < p->actual_length; i++) {
                 if (!(i & 15))
                     fprintf(stderr, "\n%04x:", i);
                 fprintf(stderr, " %02x", data[i]);
@@ -1108,72 +1110,67 @@ static int usb_net_handle_control(USBDevice *dev, USBPacket *p,
         fprintf(stderr, "usbnet: failed control transaction: "
                         "request 0x%x value 0x%x index 0x%x length 0x%x\n",
                         request, value, index, length);
-        ret = USB_RET_STALL;
+        p->status = USB_RET_STALL;
         break;
     }
-    return ret;
 }
 
-static int usb_net_handle_statusin(USBNetState *s, USBPacket *p)
+static void usb_net_handle_statusin(USBNetState *s, USBPacket *p)
 {
     le32 buf[2];
-    int ret = 8;
 
     if (p->iov.size < 8) {
-        return USB_RET_STALL;
+        p->status = USB_RET_STALL;
+        return;
     }
 
     buf[0] = cpu_to_le32(1);
     buf[1] = cpu_to_le32(0);
     usb_packet_copy(p, buf, 8);
-    if (!s->rndis_resp.tqh_first)
-        ret = USB_RET_NAK;
+    if (!s->rndis_resp.tqh_first) {
+        p->status = USB_RET_NAK;
+    }
 
 #ifdef TRAFFIC_DEBUG
     fprintf(stderr, "usbnet: interrupt poll len %zu return %d",
-            p->iov.size, ret);
-    iov_hexdump(p->iov.iov, p->iov.niov, stderr, "usbnet", ret);
+            p->iov.size, p->status);
+    iov_hexdump(p->iov.iov, p->iov.niov, stderr, "usbnet", p->status);
 #endif
-
-    return ret;
 }
 
-static int usb_net_handle_datain(USBNetState *s, USBPacket *p)
+static void usb_net_handle_datain(USBNetState *s, USBPacket *p)
 {
-    int ret = USB_RET_NAK;
+    int len;
 
     if (s->in_ptr > s->in_len) {
         usb_net_reset_in_buf(s);
-        ret = USB_RET_NAK;
-        return ret;
+        p->status = USB_RET_NAK;
+        return;
     }
     if (!s->in_len) {
-        ret = USB_RET_NAK;
-        return ret;
+        p->status = USB_RET_NAK;
+        return;
     }
-    ret = s->in_len - s->in_ptr;
-    if (ret > p->iov.size) {
-        ret = p->iov.size;
+    len = s->in_len - s->in_ptr;
+    if (len > p->iov.size) {
+        len = p->iov.size;
     }
-    usb_packet_copy(p, &s->in_buf[s->in_ptr], ret);
-    s->in_ptr += ret;
+    usb_packet_copy(p, &s->in_buf[s->in_ptr], len);
+    s->in_ptr += len;
     if (s->in_ptr >= s->in_len &&
-                    (is_rndis(s) || (s->in_len & (64 - 1)) || !ret)) {
+                    (is_rndis(s) || (s->in_len & (64 - 1)) || !len)) {
         /* no short packet necessary */
         usb_net_reset_in_buf(s);
     }
 
 #ifdef TRAFFIC_DEBUG
-    fprintf(stderr, "usbnet: data in len %zu return %d", p->iov.size, ret);
-    iov_hexdump(p->iov.iov, p->iov.niov, stderr, "usbnet", ret);
+    fprintf(stderr, "usbnet: data in len %zu return %d", p->iov.size, len);
+    iov_hexdump(p->iov.iov, p->iov.niov, stderr, "usbnet", len);
 #endif
-
-    return ret;
 }
 
-static int usb_net_handle_dataout(USBNetState *s, USBPacket *p)
+static void usb_net_handle_dataout(USBNetState *s, USBPacket *p)
 {
-    int ret = p->iov.size;
     int sz = sizeof(s->out_buf) - s->out_ptr;
     struct rndis_packet_msg_type *msg =
             (struct rndis_packet_msg_type *) s->out_buf;
@@ -1184,21 +1181,23 @@ static int usb_net_handle_dataout(USBNetState *s, USBPacket *p)
     iov_hexdump(p->iov.iov, p->iov.niov, stderr, "usbnet", p->iov.size);
 #endif
 
-    if (sz > ret)
-        sz = ret;
+    if (sz > p->iov.size) {
+        sz = p->iov.size;
+    }
     usb_packet_copy(p, &s->out_buf[s->out_ptr], sz);
     s->out_ptr += sz;
 
     if (!is_rndis(s)) {
-        if (ret < 64) {
+        if (p->iov.size < 64) {
             qemu_send_packet(&s->nic->nc, s->out_buf, s->out_ptr);
             s->out_ptr = 0;
         }
-        return ret;
+        return;
     }
     len = le32_to_cpu(msg->MessageLength);
-    if (s->out_ptr < 8 || s->out_ptr < len)
-        return ret;
+    if (s->out_ptr < 8 || s->out_ptr < len) {
+        return;
+    }
     if (le32_to_cpu(msg->MessageType) == RNDIS_PACKET_MSG) {
         uint32_t offs = 8 + le32_to_cpu(msg->DataOffset);
         uint32_t size = le32_to_cpu(msg->DataLength);
@@ -1207,24 +1206,21 @@ static int usb_net_handle_dataout(USBNetState *s, USBPacket *p)
     }
     s->out_ptr -= len;
     memmove(s->out_buf, &s->out_buf[len], s->out_ptr);
-
-    return ret;
 }
 
-static int usb_net_handle_data(USBDevice *dev, USBPacket *p)
+static void usb_net_handle_data(USBDevice *dev, USBPacket *p)
 {
     USBNetState *s = (USBNetState *) dev;
-    int ret = 0;
 
     switch(p->pid) {
     case USB_TOKEN_IN:
         switch (p->ep->nr) {
         case 1:
-            ret = usb_net_handle_statusin(s, p);
+            usb_net_handle_statusin(s, p);
             break;
 
         case 2:
-            ret = usb_net_handle_datain(s, p);
+            usb_net_handle_datain(s, p);
             break;
 
         default:
@@ -1235,7 +1231,7 @@ static int usb_net_handle_data(USBDevice *dev, USBPacket *p)
     case USB_TOKEN_OUT:
         switch (p->ep->nr) {
         case 2:
-            ret = usb_net_handle_dataout(s, p);
+            usb_net_handle_dataout(s, p);
             break;
 
         default:
@@ -1245,14 +1241,15 @@ static int usb_net_handle_data(USBDevice *dev, USBPacket *p)
 
     default:
     fail:
-        ret = USB_RET_STALL;
+        p->status = USB_RET_STALL;
         break;
     }
-    if (ret == USB_RET_STALL)
+
+    if (p->status == USB_RET_STALL) {
         fprintf(stderr, "usbnet: failed data transaction: "
                         "pid 0x%x ep 0x%x len 0x%zx\n",
                         p->pid, p->ep->nr, p->iov.size);
-    return ret;
+    }
 }
 
 static ssize_t usbnet_receive(NetClientState *nc, const uint8_t *buf, size_t size)