Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 | // SPDX-License-Identifier: GPL-2.0 /* Copyright (c) 2022 Red hat */ #include "vmlinux.h" #include <bpf/bpf_helpers.h> #include <bpf/bpf_tracing.h> #include "hid_bpf_helpers.h" char _license[] SEC("license") = "GPL"; struct attach_prog_args { int prog_fd; unsigned int hid; int retval; int insert_head; }; __u64 callback_check = 52; __u64 callback2_check = 52; SEC("?fmod_ret/hid_bpf_device_event") int BPF_PROG(hid_first_event, struct hid_bpf_ctx *hid_ctx) { __u8 *rw_data = hid_bpf_get_data(hid_ctx, 0 /* offset */, 3 /* size */); if (!rw_data) return 0; /* EPERM check */ callback_check = rw_data[1]; rw_data[2] = rw_data[1] + 5; return hid_ctx->size; } SEC("?fmod_ret/hid_bpf_device_event") int BPF_PROG(hid_second_event, struct hid_bpf_ctx *hid_ctx) { __u8 *rw_data = hid_bpf_get_data(hid_ctx, 0 /* offset */, 4 /* size */); if (!rw_data) return 0; /* EPERM check */ rw_data[3] = rw_data[2] + 5; return hid_ctx->size; } SEC("?fmod_ret/hid_bpf_device_event") int BPF_PROG(hid_change_report_id, struct hid_bpf_ctx *hid_ctx) { __u8 *rw_data = hid_bpf_get_data(hid_ctx, 0 /* offset */, 3 /* size */); if (!rw_data) return 0; /* EPERM check */ rw_data[0] = 2; return 9; } SEC("syscall") int attach_prog(struct attach_prog_args *ctx) { ctx->retval = hid_bpf_attach_prog(ctx->hid, ctx->prog_fd, ctx->insert_head ? HID_BPF_FLAG_INSERT_HEAD : HID_BPF_FLAG_NONE); return 0; } struct hid_hw_request_syscall_args { /* data needs to come at offset 0 so we can use it in calls */ __u8 data[10]; unsigned int hid; int retval; size_t size; enum hid_report_type type; __u8 request_type; }; SEC("syscall") int hid_user_raw_request(struct hid_hw_request_syscall_args *args) { struct hid_bpf_ctx *ctx; const size_t size = args->size; int i, ret = 0; if (size > sizeof(args->data)) return -7; /* -E2BIG */ ctx = hid_bpf_allocate_context(args->hid); if (!ctx) return -1; /* EPERM check */ ret = hid_bpf_hw_request(ctx, args->data, size, args->type, args->request_type); args->retval = ret; hid_bpf_release_context(ctx); return 0; } static const __u8 rdesc[] = { 0x05, 0x01, /* USAGE_PAGE (Generic Desktop) */ 0x09, 0x32, /* USAGE (Z) */ 0x95, 0x01, /* REPORT_COUNT (1) */ 0x81, 0x06, /* INPUT (Data,Var,Rel) */ 0x06, 0x00, 0xff, /* Usage Page (Vendor Defined Page 1) */ 0x19, 0x01, /* USAGE_MINIMUM (1) */ 0x29, 0x03, /* USAGE_MAXIMUM (3) */ 0x15, 0x00, /* LOGICAL_MINIMUM (0) */ 0x25, 0x01, /* LOGICAL_MAXIMUM (1) */ 0x95, 0x03, /* REPORT_COUNT (3) */ 0x75, 0x01, /* REPORT_SIZE (1) */ 0x91, 0x02, /* Output (Data,Var,Abs) */ 0x95, 0x01, /* REPORT_COUNT (1) */ 0x75, 0x05, /* REPORT_SIZE (5) */ 0x91, 0x01, /* Output (Cnst,Var,Abs) */ 0x06, 0x00, 0xff, /* Usage Page (Vendor Defined Page 1) */ 0x19, 0x06, /* USAGE_MINIMUM (6) */ 0x29, 0x08, /* USAGE_MAXIMUM (8) */ 0x15, 0x00, /* LOGICAL_MINIMUM (0) */ 0x25, 0x01, /* LOGICAL_MAXIMUM (1) */ 0x95, 0x03, /* REPORT_COUNT (3) */ 0x75, 0x01, /* REPORT_SIZE (1) */ 0xb1, 0x02, /* Feature (Data,Var,Abs) */ 0x95, 0x01, /* REPORT_COUNT (1) */ 0x75, 0x05, /* REPORT_SIZE (5) */ 0x91, 0x01, /* Output (Cnst,Var,Abs) */ 0xc0, /* END_COLLECTION */ 0xc0, /* END_COLLECTION */ }; SEC("?fmod_ret/hid_bpf_rdesc_fixup") int BPF_PROG(hid_rdesc_fixup, struct hid_bpf_ctx *hid_ctx) { __u8 *data = hid_bpf_get_data(hid_ctx, 0 /* offset */, 4096 /* size */); if (!data) return 0; /* EPERM check */ callback2_check = data[4]; /* insert rdesc at offset 73 */ __builtin_memcpy(&data[73], rdesc, sizeof(rdesc)); /* Change Usage Vendor globally */ data[4] = 0x42; return sizeof(rdesc) + 73; } SEC("?fmod_ret/hid_bpf_device_event") int BPF_PROG(hid_test_insert1, struct hid_bpf_ctx *hid_ctx) { __u8 *data = hid_bpf_get_data(hid_ctx, 0 /* offset */, 4 /* size */); if (!data) return 0; /* EPERM check */ /* we need to be run first */ if (data[2] || data[3]) return -1; data[1] = 1; return 0; } SEC("?fmod_ret/hid_bpf_device_event") int BPF_PROG(hid_test_insert2, struct hid_bpf_ctx *hid_ctx) { __u8 *data = hid_bpf_get_data(hid_ctx, 0 /* offset */, 4 /* size */); if (!data) return 0; /* EPERM check */ /* after insert0 and before insert2 */ if (!data[1] || data[3]) return -1; data[2] = 2; return 0; } SEC("?fmod_ret/hid_bpf_device_event") int BPF_PROG(hid_test_insert3, struct hid_bpf_ctx *hid_ctx) { __u8 *data = hid_bpf_get_data(hid_ctx, 0 /* offset */, 4 /* size */); if (!data) return 0; /* EPERM check */ /* at the end */ if (!data[1] || !data[2]) return -1; data[3] = 3; return 0; } |