target/linux/generic/backport-5.15/796-v6.5-03-usbnet-ipheth-add-CDC-NCM-support.patch

   1 From a2d274c62e44b1995c170595db3865c6fe701226 Mon Sep 17 00:00:00 2001
   2 From: Foster Snowhill <forst@pen.gy>
   3 Date: Wed, 7 Jun 2023 15:57:01 +0200
   4 Subject: [PATCH 3/4] usbnet: ipheth: add CDC NCM support
   5
   6 Recent iOS releases support CDC NCM encapsulation on RX. This mode is
   7 the default on macOS and Windows. In this mode, an iOS device may include
   8 one or more Ethernet frames inside a single URB.
   9
  10 Freshly booted iOS devices start in legacy mode, but are put into
  11 NCM mode by the official Apple driver. When reconnecting such a device
  12 from a macOS/Windows machine to a Linux host, the device stays in
  13 NCM mode, making it unusable with the legacy ipheth driver code.
  14
  15 To correctly support such a device, the driver has to either support
  16 the NCM mode too, or put the device back into legacy mode.
  17
  18 To match the behaviour of the macOS/Windows driver, and since there
  19 is no documented control command to revert to legacy mode, implement
  20 NCM support. The device is attempted to be put into NCM mode by default,
  21 and falls back to legacy mode if the attempt fails.
  22
  23 Signed-off-by: Foster Snowhill <forst@pen.gy>
  24 Tested-by: Georgi Valkov <gvalkov@gmail.com>
  25 Signed-off-by: David S. Miller <davem@davemloft.net>
  26 ---
  27  drivers/net/usb/ipheth.c | 180 +++++++++++++++++++++++++++++++++------
  28  1 file changed, 155 insertions(+), 25 deletions(-)
  29
  30 --- a/drivers/net/usb/ipheth.c
  31 +++ b/drivers/net/usb/ipheth.c
  32 @@ -52,6 +52,7 @@
  33  #include <linux/ethtool.h>
  34  #include <linux/usb.h>
  35  #include <linux/workqueue.h>
  36 +#include <linux/usb/cdc.h>
  37
  38  #define USB_VENDOR_APPLE        0x05ac
  39
  40 @@ -59,8 +60,12 @@
  41  #define IPHETH_USBINTF_SUBCLASS 253
  42  #define IPHETH_USBINTF_PROTO    1
  43
  44 -#define IPHETH_BUF_SIZE         1514
  45  #define IPHETH_IP_ALIGN                2       /* padding at front of URB */
  46 +#define IPHETH_NCM_HEADER_SIZE  (12 + 96) /* NCMH + NCM0 */
  47 +#define IPHETH_TX_BUF_SIZE      ETH_FRAME_LEN
  48 +#define IPHETH_RX_BUF_SIZE_LEGACY (IPHETH_IP_ALIGN + ETH_FRAME_LEN)
  49 +#define IPHETH_RX_BUF_SIZE_NCM 65536
  50 +
  51  #define IPHETH_TX_TIMEOUT       (5 * HZ)
  52
  53  #define IPHETH_INTFNUM          2
  54 @@ -71,6 +76,7 @@
  55  #define IPHETH_CTRL_TIMEOUT     (5 * HZ)
  56
  57  #define IPHETH_CMD_GET_MACADDR   0x00
  58 +#define IPHETH_CMD_ENABLE_NCM    0x04
  59  #define IPHETH_CMD_CARRIER_CHECK 0x45
  60
  61  #define IPHETH_CARRIER_CHECK_TIMEOUT round_jiffies_relative(1 * HZ)
  62 @@ -97,6 +103,8 @@ struct ipheth_device {
  63         u8 bulk_out;
  64         struct delayed_work carrier_work;
  65         bool confirmed_pairing;
  66 +       int (*rcvbulk_callback)(struct urb *urb);
  67 +       size_t rx_buf_len;
  68  };
  69
  70  static int ipheth_rx_submit(struct ipheth_device *dev, gfp_t mem_flags);
  71 @@ -116,12 +124,12 @@ static int ipheth_alloc_urbs(struct iphe
  72         if (rx_urb == NULL)
  73                 goto free_tx_urb;
  74
  75 -       tx_buf = usb_alloc_coherent(iphone->udev, IPHETH_BUF_SIZE,
  76 +       tx_buf = usb_alloc_coherent(iphone->udev, IPHETH_TX_BUF_SIZE,
  77                                     GFP_KERNEL, &tx_urb->transfer_dma);
  78         if (tx_buf == NULL)
  79                 goto free_rx_urb;
  80
  81 -       rx_buf = usb_alloc_coherent(iphone->udev, IPHETH_BUF_SIZE + IPHETH_IP_ALIGN,
  82 +       rx_buf = usb_alloc_coherent(iphone->udev, iphone->rx_buf_len,
  83                                     GFP_KERNEL, &rx_urb->transfer_dma);
  84         if (rx_buf == NULL)
  85                 goto free_tx_buf;
  86 @@ -134,7 +142,7 @@ static int ipheth_alloc_urbs(struct iphe
  87         return 0;
  88
  89  free_tx_buf:
  90 -       usb_free_coherent(iphone->udev, IPHETH_BUF_SIZE, tx_buf,
  91 +       usb_free_coherent(iphone->udev, IPHETH_TX_BUF_SIZE, tx_buf,
  92                           tx_urb->transfer_dma);
  93  free_rx_urb:
  94         usb_free_urb(rx_urb);
  95 @@ -146,9 +154,9 @@ error_nomem:
  96
  97  static void ipheth_free_urbs(struct ipheth_device *iphone)
  98  {
  99 -       usb_free_coherent(iphone->udev, IPHETH_BUF_SIZE + IPHETH_IP_ALIGN, iphone->rx_buf,
 100 +       usb_free_coherent(iphone->udev, iphone->rx_buf_len, iphone->rx_buf,
 101                           iphone->rx_urb->transfer_dma);
 102 -       usb_free_coherent(iphone->udev, IPHETH_BUF_SIZE, iphone->tx_buf,
 103 +       usb_free_coherent(iphone->udev, IPHETH_TX_BUF_SIZE, iphone->tx_buf,
 104                           iphone->tx_urb->transfer_dma);
 105         usb_free_urb(iphone->rx_urb);
 106         usb_free_urb(iphone->tx_urb);
 107 @@ -160,15 +168,106 @@ static void ipheth_kill_urbs(struct iphe
 108         usb_kill_urb(dev->rx_urb);
 109  }
 110
 111 -static void ipheth_rcvbulk_callback(struct urb *urb)
 112 +static int ipheth_consume_skb(char *buf, int len, struct ipheth_device *dev)
 113  {
 114 -       struct ipheth_device *dev;
 115         struct sk_buff *skb;
 116 -       int status;
 117 +
 118 +       skb = dev_alloc_skb(len);
 119 +       if (!skb) {
 120 +               dev->net->stats.rx_dropped++;
 121 +               return -ENOMEM;
 122 +       }
 123 +
 124 +       skb_put_data(skb, buf, len);
 125 +       skb->dev = dev->net;
 126 +       skb->protocol = eth_type_trans(skb, dev->net);
 127 +
 128 +       dev->net->stats.rx_packets++;
 129 +       dev->net->stats.rx_bytes += len;
 130 +       netif_rx(skb);
 131 +
 132 +       return 0;
 133 +}
 134 +
 135 +static int ipheth_rcvbulk_callback_legacy(struct urb *urb)
 136 +{
 137 +       struct ipheth_device *dev;
 138 +       char *buf;
 139 +       int len;
 140 +
 141 +       dev = urb->context;
 142 +
 143 +       if (urb->actual_length <= IPHETH_IP_ALIGN) {
 144 +               dev->net->stats.rx_length_errors++;
 145 +               return -EINVAL;
 146 +       }
 147 +       len = urb->actual_length - IPHETH_IP_ALIGN;
 148 +       buf = urb->transfer_buffer + IPHETH_IP_ALIGN;
 149 +
 150 +       return ipheth_consume_skb(buf, len, dev);
 151 +}
 152 +
 153 +static int ipheth_rcvbulk_callback_ncm(struct urb *urb)
 154 +{
 155 +       struct usb_cdc_ncm_nth16 *ncmh;
 156 +       struct usb_cdc_ncm_ndp16 *ncm0;
 157 +       struct usb_cdc_ncm_dpe16 *dpe;
 158 +       struct ipheth_device *dev;
 159 +       int retval = -EINVAL;
 160         char *buf;
 161         int len;
 162
 163         dev = urb->context;
 164 +
 165 +       if (urb->actual_length < IPHETH_NCM_HEADER_SIZE) {
 166 +               dev->net->stats.rx_length_errors++;
 167 +               return retval;
 168 +       }
 169 +
 170 +       ncmh = urb->transfer_buffer;
 171 +       if (ncmh->dwSignature != cpu_to_le32(USB_CDC_NCM_NTH16_SIGN) ||
 172 +           le16_to_cpu(ncmh->wNdpIndex) >= urb->actual_length) {
 173 +               dev->net->stats.rx_errors++;
 174 +               return retval;
 175 +       }
 176 +
 177 +       ncm0 = urb->transfer_buffer + le16_to_cpu(ncmh->wNdpIndex);
 178 +       if (ncm0->dwSignature != cpu_to_le32(USB_CDC_NCM_NDP16_NOCRC_SIGN) ||
 179 +           le16_to_cpu(ncmh->wHeaderLength) + le16_to_cpu(ncm0->wLength) >=
 180 +           urb->actual_length) {
 181 +               dev->net->stats.rx_errors++;
 182 +               return retval;
 183 +       }
 184 +
 185 +       dpe = ncm0->dpe16;
 186 +       while (le16_to_cpu(dpe->wDatagramIndex) != 0 &&
 187 +              le16_to_cpu(dpe->wDatagramLength) != 0) {
 188 +               if (le16_to_cpu(dpe->wDatagramIndex) >= urb->actual_length ||
 189 +                   le16_to_cpu(dpe->wDatagramIndex) +
 190 +                   le16_to_cpu(dpe->wDatagramLength) > urb->actual_length) {
 191 +                       dev->net->stats.rx_length_errors++;
 192 +                       return retval;
 193 +               }
 194 +
 195 +               buf = urb->transfer_buffer + le16_to_cpu(dpe->wDatagramIndex);
 196 +               len = le16_to_cpu(dpe->wDatagramLength);
 197 +
 198 +               retval = ipheth_consume_skb(buf, len, dev);
 199 +               if (retval != 0)
 200 +                       return retval;
 201 +
 202 +               dpe++;
 203 +       }
 204 +
 205 +       return 0;
 206 +}
 207 +
 208 +static void ipheth_rcvbulk_callback(struct urb *urb)
 209 +{
 210 +       struct ipheth_device *dev;
 211 +       int retval, status;
 212 +
 213 +       dev = urb->context;
 214         if (dev == NULL)
 215                 return;
 216
 217 @@ -191,25 +290,27 @@ static void ipheth_rcvbulk_callback(stru
 218                 dev->net->stats.rx_length_errors++;
 219                 return;
 220         }
 221 -       len = urb->actual_length - IPHETH_IP_ALIGN;
 222 -       buf = urb->transfer_buffer + IPHETH_IP_ALIGN;
 223
 224 -       skb = dev_alloc_skb(len);
 225 -       if (!skb) {
 226 -               dev_err(&dev->intf->dev, "%s: dev_alloc_skb: -ENOMEM\n",
 227 -                       __func__);
 228 -               dev->net->stats.rx_dropped++;
 229 +       /* RX URBs starting with 0x00 0x01 do not encapsulate Ethernet frames,
 230 +        * but rather are control frames. Their purpose is not documented, and
 231 +        * they don't affect driver functionality, okay to drop them.
 232 +        * There is usually just one 4-byte control frame as the very first
 233 +        * URB received from the bulk IN endpoint.
 234 +        */
 235 +       if (unlikely
 236 +               (((char *)urb->transfer_buffer)[0] == 0 &&
 237 +                ((char *)urb->transfer_buffer)[1] == 1))
 238 +               goto rx_submit;
 239 +
 240 +       retval = dev->rcvbulk_callback(urb);
 241 +       if (retval != 0) {
 242 +               dev_err(&dev->intf->dev, "%s: callback retval: %d\n",
 243 +                       __func__, retval);
 244                 return;
 245         }
 246
 247 -       skb_put_data(skb, buf, len);
 248 -       skb->dev = dev->net;
 249 -       skb->protocol = eth_type_trans(skb, dev->net);
 250 -
 251 -       dev->net->stats.rx_packets++;
 252 -       dev->net->stats.rx_bytes += len;
 253 +rx_submit:
 254         dev->confirmed_pairing = true;
 255 -       netif_rx(skb);
 256         ipheth_rx_submit(dev, GFP_ATOMIC);
 257  }
 258
 259 @@ -310,6 +411,27 @@ static int ipheth_get_macaddr(struct iph
 260         return retval;
 261  }
 262
 263 +static int ipheth_enable_ncm(struct ipheth_device *dev)
 264 +{
 265 +       struct usb_device *udev = dev->udev;
 266 +       int retval;
 267 +
 268 +       retval = usb_control_msg(udev,
 269 +                                usb_sndctrlpipe(udev, IPHETH_CTRL_ENDP),
 270 +                                IPHETH_CMD_ENABLE_NCM, /* request */
 271 +                                0x41, /* request type */
 272 +                                0x00, /* value */
 273 +                                0x02, /* index */
 274 +                                NULL,
 275 +                                0,
 276 +                                IPHETH_CTRL_TIMEOUT);
 277 +
 278 +       dev_info(&dev->intf->dev, "%s: usb_control_msg: %d\n",
 279 +                __func__, retval);
 280 +
 281 +       return retval;
 282 +}
 283 +
 284  static int ipheth_rx_submit(struct ipheth_device *dev, gfp_t mem_flags)
 285  {
 286         struct usb_device *udev = dev->udev;
 287 @@ -317,7 +439,7 @@ static int ipheth_rx_submit(struct iphet
 288
 289         usb_fill_bulk_urb(dev->rx_urb, udev,
 290                           usb_rcvbulkpipe(udev, dev->bulk_in),
 291 -                         dev->rx_buf, IPHETH_BUF_SIZE + IPHETH_IP_ALIGN,
 292 +                         dev->rx_buf, dev->rx_buf_len,
 293                           ipheth_rcvbulk_callback,
 294                           dev);
 295         dev->rx_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 296 @@ -365,7 +487,7 @@ static netdev_tx_t ipheth_tx(struct sk_b
 297         int retval;
 298
 299         /* Paranoid */
 300 -       if (skb->len > IPHETH_BUF_SIZE) {
 301 +       if (skb->len > IPHETH_TX_BUF_SIZE) {
 302                 WARN(1, "%s: skb too large: %d bytes\n", __func__, skb->len);
 303                 dev->net->stats.tx_dropped++;
 304                 dev_kfree_skb_any(skb);
 305 @@ -448,6 +570,8 @@ static int ipheth_probe(struct usb_inter
 306         dev->net = netdev;
 307         dev->intf = intf;
 308         dev->confirmed_pairing = false;
 309 +       dev->rx_buf_len = IPHETH_RX_BUF_SIZE_LEGACY;
 310 +       dev->rcvbulk_callback = ipheth_rcvbulk_callback_legacy;
 311         /* Set up endpoints */
 312         hintf = usb_altnum_to_altsetting(intf, IPHETH_ALT_INTFNUM);
 313         if (hintf == NULL) {
 314 @@ -479,6 +603,12 @@ static int ipheth_probe(struct usb_inter
 315         if (retval)
 316                 goto err_get_macaddr;
 317
 318 +       retval = ipheth_enable_ncm(dev);
 319 +       if (!retval) {
 320 +               dev->rx_buf_len = IPHETH_RX_BUF_SIZE_NCM;
 321 +               dev->rcvbulk_callback = ipheth_rcvbulk_callback_ncm;
 322 +       }
 323 +
 324         INIT_DELAYED_WORK(&dev->carrier_work, ipheth_carrier_check_work);
 325
 326         retval = ipheth_alloc_urbs(dev);