1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2020 Google Corporation 4 */ 5 6 #include <net/bluetooth/bluetooth.h> 7 #include <net/bluetooth/hci_core.h> 8 9 #include "msft.h" 10 11 #define MSFT_OP_READ_SUPPORTED_FEATURES 0x00 12 struct msft_cp_read_supported_features { 13 __u8 sub_opcode; 14 } __packed; 15 struct msft_rp_read_supported_features { 16 __u8 status; 17 __u8 sub_opcode; 18 __le64 features; 19 __u8 evt_prefix_len; 20 __u8 evt_prefix[0]; 21 } __packed; 22 23 struct msft_data { 24 __u64 features; 25 __u8 evt_prefix_len; 26 __u8 *evt_prefix; 27 }; 28 29 static bool read_supported_features(struct hci_dev *hdev, 30 struct msft_data *msft) 31 { 32 struct msft_cp_read_supported_features cp; 33 struct msft_rp_read_supported_features *rp; 34 struct sk_buff *skb; 35 36 cp.sub_opcode = MSFT_OP_READ_SUPPORTED_FEATURES; 37 38 skb = __hci_cmd_sync(hdev, hdev->msft_opcode, sizeof(cp), &cp, 39 HCI_CMD_TIMEOUT); 40 if (IS_ERR(skb)) { 41 bt_dev_err(hdev, "Failed to read MSFT supported features (%ld)", 42 PTR_ERR(skb)); 43 return false; 44 } 45 46 if (skb->len < sizeof(*rp)) { 47 bt_dev_err(hdev, "MSFT supported features length mismatch"); 48 goto failed; 49 } 50 51 rp = (struct msft_rp_read_supported_features *)skb->data; 52 53 if (rp->sub_opcode != MSFT_OP_READ_SUPPORTED_FEATURES) 54 goto failed; 55 56 if (rp->evt_prefix_len > 0) { 57 msft->evt_prefix = kmemdup(rp->evt_prefix, rp->evt_prefix_len, 58 GFP_KERNEL); 59 if (!msft->evt_prefix) 60 goto failed; 61 } 62 63 msft->evt_prefix_len = rp->evt_prefix_len; 64 msft->features = __le64_to_cpu(rp->features); 65 66 kfree_skb(skb); 67 return true; 68 69 failed: 70 kfree_skb(skb); 71 return false; 72 } 73 74 void msft_do_open(struct hci_dev *hdev) 75 { 76 struct msft_data *msft; 77 78 if (hdev->msft_opcode == HCI_OP_NOP) 79 return; 80 81 bt_dev_dbg(hdev, "Initialize MSFT extension"); 82 83 msft = kzalloc(sizeof(*msft), GFP_KERNEL); 84 if (!msft) 85 return; 86 87 if (!read_supported_features(hdev, msft)) { 88 kfree(msft); 89 return; 90 } 91 92 hdev->msft_data = msft; 93 } 94 95 void msft_do_close(struct hci_dev *hdev) 96 { 97 struct msft_data *msft = hdev->msft_data; 98 99 if (!msft) 100 return; 101 102 bt_dev_dbg(hdev, "Cleanup of MSFT extension"); 103 104 hdev->msft_data = NULL; 105 106 kfree(msft->evt_prefix); 107 kfree(msft); 108 } 109 110 void msft_vendor_evt(struct hci_dev *hdev, struct sk_buff *skb) 111 { 112 struct msft_data *msft = hdev->msft_data; 113 u8 event; 114 115 if (!msft) 116 return; 117 118 /* When the extension has defined an event prefix, check that it 119 * matches, and otherwise just return. 120 */ 121 if (msft->evt_prefix_len > 0) { 122 if (skb->len < msft->evt_prefix_len) 123 return; 124 125 if (memcmp(skb->data, msft->evt_prefix, msft->evt_prefix_len)) 126 return; 127 128 skb_pull(skb, msft->evt_prefix_len); 129 } 130 131 /* Every event starts at least with an event code and the rest of 132 * the data is variable and depends on the event code. 133 */ 134 if (skb->len < 1) 135 return; 136 137 event = *skb->data; 138 skb_pull(skb, 1); 139 140 bt_dev_dbg(hdev, "MSFT vendor event %u", event); 141 } 142