xref: /openbmc/qemu/hw/usb/ccid-card-passthru.c (revision e1fe50dc)
1 /*
2  * CCID Passthru Card Device emulation
3  *
4  * Copyright (c) 2011 Red Hat.
5  * Written by Alon Levy.
6  *
7  * This work is licensed under the terms of the GNU GPL, version 2.1 or later.
8  * See the COPYING file in the top-level directory.
9  */
10 
11 #include "sysemu/char.h"
12 #include "qemu/sockets.h"
13 #include "monitor/monitor.h"
14 #include "ccid.h"
15 #include "libcacard/vscard_common.h"
16 
17 #define DPRINTF(card, lvl, fmt, ...)                    \
18 do {                                                    \
19     if (lvl <= card->debug) {                           \
20         printf("ccid-card-passthru: " fmt , ## __VA_ARGS__);     \
21     }                                                   \
22 } while (0)
23 
24 #define D_WARN 1
25 #define D_INFO 2
26 #define D_MORE_INFO 3
27 #define D_VERBOSE 4
28 
29 /* TODO: do we still need this? */
30 uint8_t DEFAULT_ATR[] = {
31 /*
32  * From some example somewhere
33  * 0x3B, 0xB0, 0x18, 0x00, 0xD1, 0x81, 0x05, 0xB1, 0x40, 0x38, 0x1F, 0x03, 0x28
34  */
35 
36 /* From an Athena smart card */
37  0x3B, 0xD5, 0x18, 0xFF, 0x80, 0x91, 0xFE, 0x1F, 0xC3, 0x80, 0x73, 0xC8, 0x21,
38  0x13, 0x08
39 };
40 
41 
42 #define PASSTHRU_DEV_NAME "ccid-card-passthru"
43 #define VSCARD_IN_SIZE 65536
44 
45 /* maximum size of ATR - from 7816-3 */
46 #define MAX_ATR_SIZE        40
47 
48 typedef struct PassthruState PassthruState;
49 
50 struct PassthruState {
51     CCIDCardState base;
52     CharDriverState *cs;
53     uint8_t  vscard_in_data[VSCARD_IN_SIZE];
54     uint32_t vscard_in_pos;
55     uint32_t vscard_in_hdr;
56     uint8_t  atr[MAX_ATR_SIZE];
57     uint8_t  atr_length;
58     uint8_t  debug;
59 };
60 
61 /*
62  * VSCard protocol over chardev
63  * This code should not depend on the card type.
64  */
65 
66 static void ccid_card_vscard_send_msg(PassthruState *s,
67         VSCMsgType type, uint32_t reader_id,
68         const uint8_t *payload, uint32_t length)
69 {
70     VSCMsgHeader scr_msg_header;
71 
72     scr_msg_header.type = htonl(type);
73     scr_msg_header.reader_id = htonl(reader_id);
74     scr_msg_header.length = htonl(length);
75     qemu_chr_fe_write(s->cs, (uint8_t *)&scr_msg_header, sizeof(VSCMsgHeader));
76     qemu_chr_fe_write(s->cs, payload, length);
77 }
78 
79 static void ccid_card_vscard_send_apdu(PassthruState *s,
80     const uint8_t *apdu, uint32_t length)
81 {
82     ccid_card_vscard_send_msg(
83         s, VSC_APDU, VSCARD_MINIMAL_READER_ID, apdu, length);
84 }
85 
86 static void ccid_card_vscard_send_error(PassthruState *s,
87                     uint32_t reader_id, VSCErrorCode code)
88 {
89     VSCMsgError msg = {.code = htonl(code)};
90 
91     ccid_card_vscard_send_msg(
92         s, VSC_Error, reader_id, (uint8_t *)&msg, sizeof(msg));
93 }
94 
95 static void ccid_card_vscard_send_init(PassthruState *s)
96 {
97     VSCMsgInit msg = {
98         .version = htonl(VSCARD_VERSION),
99         .magic = VSCARD_MAGIC,
100         .capabilities = {0}
101     };
102 
103     ccid_card_vscard_send_msg(s, VSC_Init, VSCARD_UNDEFINED_READER_ID,
104                          (uint8_t *)&msg, sizeof(msg));
105 }
106 
107 static int ccid_card_vscard_can_read(void *opaque)
108 {
109     PassthruState *card = opaque;
110 
111     return VSCARD_IN_SIZE >= card->vscard_in_pos ?
112            VSCARD_IN_SIZE - card->vscard_in_pos : 0;
113 }
114 
115 static void ccid_card_vscard_handle_init(
116     PassthruState *card, VSCMsgHeader *hdr, VSCMsgInit *init)
117 {
118     uint32_t *capabilities;
119     int num_capabilities;
120     int i;
121 
122     capabilities = init->capabilities;
123     num_capabilities =
124         1 + ((hdr->length - sizeof(VSCMsgInit)) / sizeof(uint32_t));
125     init->version = ntohl(init->version);
126     for (i = 0 ; i < num_capabilities; ++i) {
127         capabilities[i] = ntohl(capabilities[i]);
128     }
129     if (init->magic != VSCARD_MAGIC) {
130         error_report("wrong magic");
131         /* we can't disconnect the chardev */
132     }
133     if (init->version != VSCARD_VERSION) {
134         DPRINTF(card, D_WARN,
135             "got version %d, have %d", init->version, VSCARD_VERSION);
136     }
137     /* future handling of capabilities, none exist atm */
138     ccid_card_vscard_send_init(card);
139 }
140 
141 static void ccid_card_vscard_handle_message(PassthruState *card,
142     VSCMsgHeader *scr_msg_header)
143 {
144     uint8_t *data = (uint8_t *)&scr_msg_header[1];
145 
146     switch (scr_msg_header->type) {
147     case VSC_ATR:
148         DPRINTF(card, D_INFO, "VSC_ATR %d\n", scr_msg_header->length);
149         if (scr_msg_header->length > MAX_ATR_SIZE) {
150             error_report("ATR size exceeds spec, ignoring");
151             ccid_card_vscard_send_error(card, scr_msg_header->reader_id,
152                                         VSC_GENERAL_ERROR);
153             break;
154         }
155         memcpy(card->atr, data, scr_msg_header->length);
156         card->atr_length = scr_msg_header->length;
157         ccid_card_card_inserted(&card->base);
158         ccid_card_vscard_send_error(card, scr_msg_header->reader_id,
159                                     VSC_SUCCESS);
160         break;
161     case VSC_APDU:
162         ccid_card_send_apdu_to_guest(
163             &card->base, data, scr_msg_header->length);
164         break;
165     case VSC_CardRemove:
166         DPRINTF(card, D_INFO, "VSC_CardRemove\n");
167         ccid_card_card_removed(&card->base);
168         ccid_card_vscard_send_error(card,
169             scr_msg_header->reader_id, VSC_SUCCESS);
170         break;
171     case VSC_Init:
172         ccid_card_vscard_handle_init(
173             card, scr_msg_header, (VSCMsgInit *)data);
174         break;
175     case VSC_Error:
176         ccid_card_card_error(&card->base, *(uint32_t *)data);
177         break;
178     case VSC_ReaderAdd:
179         if (ccid_card_ccid_attach(&card->base) < 0) {
180             ccid_card_vscard_send_error(card, VSCARD_UNDEFINED_READER_ID,
181                                       VSC_CANNOT_ADD_MORE_READERS);
182         } else {
183             ccid_card_vscard_send_error(card, VSCARD_MINIMAL_READER_ID,
184                                         VSC_SUCCESS);
185         }
186         break;
187     case VSC_ReaderRemove:
188         ccid_card_ccid_detach(&card->base);
189         ccid_card_vscard_send_error(card,
190             scr_msg_header->reader_id, VSC_SUCCESS);
191         break;
192     default:
193         printf("usb-ccid: chardev: unexpected message of type %X\n",
194                scr_msg_header->type);
195         ccid_card_vscard_send_error(card, scr_msg_header->reader_id,
196             VSC_GENERAL_ERROR);
197     }
198 }
199 
200 static void ccid_card_vscard_drop_connection(PassthruState *card)
201 {
202     qemu_chr_delete(card->cs);
203     card->vscard_in_pos = card->vscard_in_hdr = 0;
204 }
205 
206 static void ccid_card_vscard_read(void *opaque, const uint8_t *buf, int size)
207 {
208     PassthruState *card = opaque;
209     VSCMsgHeader *hdr;
210 
211     if (card->vscard_in_pos + size > VSCARD_IN_SIZE) {
212         error_report(
213             "no room for data: pos %d +  size %d > %d. dropping connection.",
214             card->vscard_in_pos, size, VSCARD_IN_SIZE);
215         ccid_card_vscard_drop_connection(card);
216         return;
217     }
218     assert(card->vscard_in_pos < VSCARD_IN_SIZE);
219     assert(card->vscard_in_hdr < VSCARD_IN_SIZE);
220     memcpy(card->vscard_in_data + card->vscard_in_pos, buf, size);
221     card->vscard_in_pos += size;
222     hdr = (VSCMsgHeader *)(card->vscard_in_data + card->vscard_in_hdr);
223 
224     while ((card->vscard_in_pos - card->vscard_in_hdr >= sizeof(VSCMsgHeader))
225          &&(card->vscard_in_pos - card->vscard_in_hdr >=
226                                   sizeof(VSCMsgHeader) + ntohl(hdr->length))) {
227         hdr->reader_id = ntohl(hdr->reader_id);
228         hdr->length = ntohl(hdr->length);
229         hdr->type = ntohl(hdr->type);
230         ccid_card_vscard_handle_message(card, hdr);
231         card->vscard_in_hdr += hdr->length + sizeof(VSCMsgHeader);
232         hdr = (VSCMsgHeader *)(card->vscard_in_data + card->vscard_in_hdr);
233     }
234     if (card->vscard_in_hdr == card->vscard_in_pos) {
235         card->vscard_in_pos = card->vscard_in_hdr = 0;
236     }
237 }
238 
239 static void ccid_card_vscard_event(void *opaque, int event)
240 {
241     PassthruState *card = opaque;
242 
243     switch (event) {
244     case CHR_EVENT_BREAK:
245         card->vscard_in_pos = card->vscard_in_hdr = 0;
246         break;
247     case CHR_EVENT_FOCUS:
248         break;
249     case CHR_EVENT_OPENED:
250         DPRINTF(card, D_INFO, "%s: CHR_EVENT_OPENED\n", __func__);
251         break;
252     }
253 }
254 
255 /* End VSCard handling */
256 
257 static void passthru_apdu_from_guest(
258     CCIDCardState *base, const uint8_t *apdu, uint32_t len)
259 {
260     PassthruState *card = DO_UPCAST(PassthruState, base, base);
261 
262     if (!card->cs) {
263         printf("ccid-passthru: no chardev, discarding apdu length %d\n", len);
264         return;
265     }
266     ccid_card_vscard_send_apdu(card, apdu, len);
267 }
268 
269 static const uint8_t *passthru_get_atr(CCIDCardState *base, uint32_t *len)
270 {
271     PassthruState *card = DO_UPCAST(PassthruState, base, base);
272 
273     *len = card->atr_length;
274     return card->atr;
275 }
276 
277 static int passthru_initfn(CCIDCardState *base)
278 {
279     PassthruState *card = DO_UPCAST(PassthruState, base, base);
280 
281     card->vscard_in_pos = 0;
282     card->vscard_in_hdr = 0;
283     if (card->cs) {
284         DPRINTF(card, D_INFO, "initing chardev\n");
285         qemu_chr_add_handlers(card->cs,
286             ccid_card_vscard_can_read,
287             ccid_card_vscard_read,
288             ccid_card_vscard_event, card);
289         ccid_card_vscard_send_init(card);
290     } else {
291         error_report("missing chardev");
292         return -1;
293     }
294     assert(sizeof(DEFAULT_ATR) <= MAX_ATR_SIZE);
295     memcpy(card->atr, DEFAULT_ATR, sizeof(DEFAULT_ATR));
296     card->atr_length = sizeof(DEFAULT_ATR);
297     return 0;
298 }
299 
300 static int passthru_exitfn(CCIDCardState *base)
301 {
302     return 0;
303 }
304 
305 static VMStateDescription passthru_vmstate = {
306     .name = PASSTHRU_DEV_NAME,
307     .version_id = 1,
308     .minimum_version_id = 1,
309     .fields = (VMStateField[]) {
310         VMSTATE_BUFFER(vscard_in_data, PassthruState),
311         VMSTATE_UINT32(vscard_in_pos, PassthruState),
312         VMSTATE_UINT32(vscard_in_hdr, PassthruState),
313         VMSTATE_BUFFER(atr, PassthruState),
314         VMSTATE_UINT8(atr_length, PassthruState),
315         VMSTATE_END_OF_LIST()
316     }
317 };
318 
319 static Property passthru_card_properties[] = {
320     DEFINE_PROP_CHR("chardev", PassthruState, cs),
321     DEFINE_PROP_UINT8("debug", PassthruState, debug, 0),
322     DEFINE_PROP_END_OF_LIST(),
323 };
324 
325 static void passthru_class_initfn(ObjectClass *klass, void *data)
326 {
327     DeviceClass *dc = DEVICE_CLASS(klass);
328     CCIDCardClass *cc = CCID_CARD_CLASS(klass);
329 
330     cc->initfn = passthru_initfn;
331     cc->exitfn = passthru_exitfn;
332     cc->get_atr = passthru_get_atr;
333     cc->apdu_from_guest = passthru_apdu_from_guest;
334     dc->desc = "passthrough smartcard";
335     dc->vmsd = &passthru_vmstate;
336     dc->props = passthru_card_properties;
337 }
338 
339 static const TypeInfo passthru_card_info = {
340     .name          = PASSTHRU_DEV_NAME,
341     .parent        = TYPE_CCID_CARD,
342     .instance_size = sizeof(PassthruState),
343     .class_init    = passthru_class_initfn,
344 };
345 
346 static void ccid_card_passthru_register_types(void)
347 {
348     type_register_static(&passthru_card_info);
349 }
350 
351 type_init(ccid_card_passthru_register_types)
352