btif_pan.c revision 285f7c6527244c749aafdc1edec39787e12bd871
1/******************************************************************************
2 *
3 *  Copyright (C) 2009-2012 Broadcom Corporation
4 *
5 *  Licensed under the Apache License, Version 2.0 (the "License");
6 *  you may not use this file except in compliance with the License.
7 *  You may obtain a copy of the License at:
8 *
9 *  http://www.apache.org/licenses/LICENSE-2.0
10 *
11 *  Unless required by applicable law or agreed to in writing, software
12 *  distributed under the License is distributed on an "AS IS" BASIS,
13 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 *  See the License for the specific language governing permissions and
15 *  limitations under the License.
16 *
17 ******************************************************************************/
18
19/************************************************************************************
20 *
21 *  Filename:      btif_pan.c
22 *
23 *  Description:   PAN Profile Bluetooth Interface
24 *
25 *
26 ***********************************************************************************/
27#include <hardware/bluetooth.h>
28#include <hardware/bt_pan.h>
29#include <assert.h>
30#include <signal.h>
31#include <ctype.h>
32#include <sys/select.h>
33#include <sys/poll.h>
34#include <sys/ioctl.h>
35#include <netinet/in.h>
36#include <netdb.h>
37#include <stdio.h>
38#include <errno.h>
39#include <fcntl.h>
40#include <sys/socket.h>
41#include <sys/wait.h>
42#include <net/if.h>
43#include <linux/sockios.h>
44#include <sys/prctl.h>
45#include <linux/if.h>
46#include <linux/if_tun.h>
47#include <linux/if_ether.h>
48
49#define LOG_TAG "BTIF_PAN"
50#include "btif_common.h"
51#include "btif_util.h"
52#include "btm_api.h"
53#include "bd.h"
54
55#include "bta_api.h"
56#include "bta_pan_api.h"
57#include "btif_sock_thread.h"
58#include "btif_sock_util.h"
59#include "btif_pan_internal.h"
60#include "gki.h"
61
62#define FORWARD_IGNORE        1
63#define FORWARD_SUCCESS       0
64#define FORWARD_FAILURE     (-1)
65#define FORWARD_CONGEST     (-2)
66//#define PANU_DISABLED TRUE
67
68#if (PAN_NAP_DISABLED == TRUE) && (PANU_DISABLED == TRUE)
69#define BTPAN_LOCAL_ROLE BTPAN_ROLE_NONE
70#elif PAN_NAP_DISABLED == TRUE
71#define BTPAN_LOCAL_ROLE BTPAN_ROLE_PANU
72#elif PANU_DISABLED == TRUE
73#define BTPAN_LOCAL_ROLE BTPAN_ROLE_PANNAP
74#else
75#define BTPAN_LOCAL_ROLE (BTPAN_ROLE_PANU | BTPAN_ROLE_PANNAP)
76#endif
77
78#define asrt(s) if(!(s)) BTIF_TRACE_ERROR("btif_pan: ## %s assert %s failed at line:%d ##",__FUNCTION__, #s, __LINE__)
79
80#define MIN(x, y) (((x) < (y)) ? (x) : (y))
81
82btpan_cb_t btpan_cb;
83
84BD_ADDR local_addr;
85static int jni_initialized, stack_initialized;
86static bt_status_t btpan_jni_init(const btpan_callbacks_t* callbacks);
87static void btpan_jni_cleanup();
88static bt_status_t btpan_connect(const bt_bdaddr_t *bd_addr, int local_role, int remote_role);
89static bt_status_t btpan_disconnect(const bt_bdaddr_t *bd_addr);
90static bt_status_t btpan_enable(int local_role);
91static int btpan_get_local_role(void);
92
93static void btpan_tap_fd_signaled(int fd, int type, int flags, uint32_t user_id);
94static void btpan_cleanup_conn(btpan_conn_t* conn);
95static void bta_pan_callback(tBTA_PAN_EVT event, tBTA_PAN *p_data);
96static void btu_exec_tap_fd_read(void *p_param);
97
98static btpan_interface_t pan_if = {
99    sizeof(pan_if),
100    btpan_jni_init,
101    btpan_enable,
102    btpan_get_local_role,
103    btpan_connect,
104    btpan_disconnect,
105    btpan_jni_cleanup
106};
107
108btpan_interface_t *btif_pan_get_interface()
109{
110    return &pan_if;
111}
112
113/*******************************************************************************
114 **
115 ** Function        btif_pan_init
116 **
117 ** Description     initializes the pan interface
118 **
119 ** Returns         bt_status_t
120 **
121 *******************************************************************************/
122void btif_pan_init()
123{
124    BTIF_TRACE_DEBUG("jni_initialized = %d, btpan_cb.enabled:%d", jni_initialized, btpan_cb.enabled);
125    stack_initialized = TRUE;
126    if (jni_initialized && !btpan_cb.enabled)
127    {
128        BTIF_TRACE_DEBUG("Enabling PAN....");
129        memset(&btpan_cb, 0, sizeof(btpan_cb));
130        btpan_cb.tap_fd = -1;
131        btpan_cb.flow = 1;
132        int i;
133        for(i = 0; i < MAX_PAN_CONNS; i++)
134            btpan_cleanup_conn(&btpan_cb.conns[i]);
135        BTA_PanEnable(bta_pan_callback);
136        btpan_cb.enabled = 1;
137        btpan_enable(BTPAN_LOCAL_ROLE);
138    }
139}
140
141static void pan_disable()
142{
143    if(btpan_cb.enabled)
144    {
145        btpan_cb.enabled = 0;
146        BTA_PanDisable();
147        if(btpan_cb.tap_fd != -1)
148        {
149            btpan_tap_close(btpan_cb.tap_fd);
150            btpan_cb.tap_fd = -1;
151        }
152    }
153}
154
155void btif_pan_cleanup()
156{
157    if(stack_initialized)
158    {
159        //bt is shuting down, invalid all bta pan handles
160        int i;
161        for(i = 0; i < MAX_PAN_CONNS; i++)
162            btpan_cleanup_conn(&btpan_cb.conns[i]);
163        pan_disable();
164    }
165    stack_initialized = FALSE;
166}
167
168static btpan_callbacks_t callback;
169static bt_status_t btpan_jni_init(const btpan_callbacks_t* callbacks)
170{
171    BTIF_TRACE_DEBUG("stack_initialized = %d, btpan_cb.enabled:%d", stack_initialized, btpan_cb.enabled);
172    jni_initialized = TRUE;
173    if(stack_initialized && !btpan_cb.enabled)
174        btif_pan_init();
175    callback = *callbacks;
176    return BT_STATUS_SUCCESS;
177}
178
179static void btpan_jni_cleanup()
180{
181    pan_disable();
182    jni_initialized = FALSE;
183}
184
185static inline int bta_role_to_btpan(int bta_pan_role)
186{
187    int btpan_role = 0;
188    BTIF_TRACE_DEBUG("bta_pan_role:0x%x", bta_pan_role);
189    if(bta_pan_role & PAN_ROLE_NAP_SERVER)
190    {
191        btpan_role |= BTPAN_ROLE_PANNAP;
192    }
193    if(bta_pan_role & PAN_ROLE_CLIENT)
194    {
195        btpan_role |= BTPAN_ROLE_PANU;
196    }
197    return btpan_role;
198}
199
200static inline int btpan_role_to_bta(int btpan_role)
201{
202    int bta_pan_role = PAN_ROLE_INACTIVE;
203    BTIF_TRACE_DEBUG("btpan_role:0x%x", btpan_role);
204    if(btpan_role & BTPAN_ROLE_PANNAP)
205    {
206        bta_pan_role |= PAN_ROLE_NAP_SERVER;
207    }
208    if(btpan_role & BTPAN_ROLE_PANU)
209    {
210        bta_pan_role |= PAN_ROLE_CLIENT;
211    }
212    return bta_pan_role;
213}
214
215static volatile int btpan_dev_local_role;
216static tBTA_PAN_ROLE_INFO bta_panu_info = {PANU_SERVICE_NAME, 0, PAN_SECURITY};
217static tBTA_PAN_ROLE_INFO bta_pan_nap_info = {PAN_NAP_SERVICE_NAME, 1, PAN_SECURITY};
218
219static bt_status_t btpan_enable(int local_role)
220{
221    int bta_pan_role;
222    BTIF_TRACE_DEBUG("local_role:%d", local_role);
223    bta_pan_role = btpan_role_to_bta(local_role);
224#if BTA_PAN_INCLUDED == TRUE
225    BTA_PanSetRole(bta_pan_role, &bta_panu_info, NULL, &bta_pan_nap_info);
226    btpan_dev_local_role = local_role;
227    return BT_STATUS_SUCCESS;
228#else
229    return BT_STATUS_FAIL;
230#endif
231}
232
233static int btpan_get_local_role()
234{
235    BTIF_TRACE_DEBUG("btpan_dev_local_role:%d", btpan_dev_local_role);
236    return btpan_dev_local_role;
237}
238
239static bt_status_t btpan_connect(const bt_bdaddr_t *bd_addr, int local_role, int remote_role)
240{
241    BTIF_TRACE_DEBUG("local_role:%d, remote_role:%d", local_role, remote_role);
242    int bta_local_role = btpan_role_to_bta(local_role);
243    int bta_remote_role = btpan_role_to_bta(remote_role);
244    btpan_new_conn(-1, bd_addr->address, bta_local_role, bta_remote_role);
245    BTA_PanOpen((UINT8*)bd_addr->address, bta_local_role, bta_remote_role);
246    return BT_STATUS_SUCCESS;
247}
248
249static void btif_in_pan_generic_evt(UINT16 event, char *p_param)
250{
251    BTIF_TRACE_EVENT("%s: event=%d", __FUNCTION__, event);
252    switch (event) {
253        case BTIF_PAN_CB_DISCONNECTING:
254        {
255            bt_bdaddr_t *bd_addr = (bt_bdaddr_t*)p_param;
256            btpan_conn_t* conn = btpan_find_conn_addr(bd_addr->address);
257            int btpan_conn_local_role;
258            int btpan_remote_role;
259            asrt(conn != NULL);
260            if (conn) {
261                btpan_conn_local_role = bta_role_to_btpan(conn->local_role);
262                btpan_remote_role = bta_role_to_btpan(conn->remote_role);
263                callback.connection_state_cb(BTPAN_STATE_DISCONNECTING, BT_STATUS_SUCCESS,
264                        (const bt_bdaddr_t*)conn->peer, btpan_conn_local_role, btpan_remote_role);
265            }
266        } break;
267        default:
268        {
269            BTIF_TRACE_WARNING("%s : Unknown event 0x%x", __FUNCTION__, event);
270        }
271        break;
272    }
273}
274
275static bt_status_t btpan_disconnect(const bt_bdaddr_t *bd_addr)
276{
277    btpan_conn_t* conn = btpan_find_conn_addr(bd_addr->address);
278    if(conn && conn->handle >= 0)
279    {
280        BTA_PanClose(conn->handle);
281        /* Inform the application that the disconnect has been initiated successfully */
282        btif_transfer_context(btif_in_pan_generic_evt, BTIF_PAN_CB_DISCONNECTING,
283                              (char *)bd_addr, sizeof(bt_bdaddr_t), NULL);
284        return BT_STATUS_SUCCESS;
285    }
286    return BT_STATUS_FAIL;
287}
288
289static int pan_pth = -1;
290void create_tap_read_thread(int tap_fd)
291{
292    if(pan_pth < 0)
293        pan_pth = btsock_thread_create(btpan_tap_fd_signaled, NULL);
294    if(pan_pth >= 0)
295        btsock_thread_add_fd(pan_pth, tap_fd, 0, SOCK_THREAD_FD_RD, 0);
296}
297
298void destroy_tap_read_thread(void)
299{
300    if(pan_pth >= 0)
301    {
302        btsock_thread_exit(pan_pth);
303        pan_pth = -1;
304    }
305}
306
307static int tap_if_up(const char *devname, BD_ADDR addr)
308{
309    struct ifreq ifr;
310    int sk, err;
311
312    sk = socket(AF_INET, SOCK_DGRAM, 0);
313
314    //set mac addr
315    memset(&ifr, 0, sizeof(ifr));
316    strncpy(ifr.ifr_name, devname, IFNAMSIZ - 1);
317    err = ioctl(sk, SIOCGIFHWADDR, &ifr);
318    if(err < 0)
319    {
320        BTIF_TRACE_ERROR("Could not get network hardware for interface:%s, errno:%s", devname, strerror(errno));
321        close(sk);
322        return -1;
323    }
324    /* debug("found mac address for interface:%s = %02x:%02x:%02x:%02x:%02x:%02x", devname, */
325    /*         ifr.ifr_hwaddr.sa_data[0], ifr.ifr_hwaddr.sa_data[1], ifr.ifr_hwaddr.sa_data[2], */
326    /*         ifr.ifr_hwaddr.sa_data[3], ifr.ifr_hwaddr.sa_data[4], ifr.ifr_hwaddr.sa_data[5]); */
327    strncpy(ifr.ifr_name, devname, IFNAMSIZ - 1);
328    memcpy(ifr.ifr_hwaddr.sa_data, addr, 6);
329    /* debug("setting bt address for interface:%s = %02x:%02x:%02x:%02x:%02x:%02x", devname, */
330    /*         ifr.ifr_hwaddr.sa_data[0], ifr.ifr_hwaddr.sa_data[1], ifr.ifr_hwaddr.sa_data[2], */
331    /*         ifr.ifr_hwaddr.sa_data[3], ifr.ifr_hwaddr.sa_data[4], ifr.ifr_hwaddr.sa_data[5]); */
332
333    /* The IEEE has specified that the most significant bit of the most significant byte is used to
334     * determine a multicast address. If its a 1, that means multicast, 0 means unicast.
335     * Kernel returns an error if we try to set a multicast address for the tun-tap ethernet interface.
336     * Mask this bit to avoid any issue with auto generated address.
337     */
338    if (ifr.ifr_hwaddr.sa_data[0] & 0x01) {
339        BTIF_TRACE_WARNING("Not a unicast MAC address, force multicast bit flipping");
340        ifr.ifr_hwaddr.sa_data[0] &= ~0x01;
341    }
342
343    err = ioctl(sk, SIOCSIFHWADDR, (caddr_t)&ifr);
344
345    if (err < 0) {
346        BTIF_TRACE_ERROR("Could not set bt address for interface:%s, errno:%s", devname, strerror(errno));
347        close(sk);
348        return -1;
349    }
350
351    //bring it up
352    memset(&ifr, 0, sizeof(ifr));
353    strncpy(ifr.ifr_name, devname, IF_NAMESIZE - 1);
354
355    ifr.ifr_flags |= IFF_UP;
356    ifr.ifr_flags |= IFF_MULTICAST;
357
358    err = ioctl(sk, SIOCSIFFLAGS, (caddr_t) &ifr);
359
360
361    if (err < 0) {
362        BTIF_TRACE_ERROR("Could not bring up network interface:%s, errno:%d", devname, errno);
363        close(sk);
364        return -1;
365    }
366    close(sk);
367    BTIF_TRACE_DEBUG("network interface: %s is up", devname);
368    return 0;
369}
370
371static int tap_if_down(const char *devname)
372{
373    struct ifreq ifr;
374    int sk, err;
375
376    sk = socket(AF_INET, SOCK_DGRAM, 0);
377
378    memset(&ifr, 0, sizeof(ifr));
379    strncpy(ifr.ifr_name, devname, IF_NAMESIZE - 1);
380
381    ifr.ifr_flags &= ~IFF_UP;
382
383    err = ioctl(sk, SIOCSIFFLAGS, (caddr_t) &ifr);
384
385    close(sk);
386
387    return 0;
388}
389
390void btpan_set_flow_control(BOOLEAN enable) {
391    if (btpan_cb.tap_fd == -1)
392        return;
393
394    btpan_cb.flow = enable;
395    if (enable) {
396        btsock_thread_add_fd(pan_pth, btpan_cb.tap_fd, 0, SOCK_THREAD_FD_RD, 0);
397        bta_dmexecutecallback(btu_exec_tap_fd_read, (void *)btpan_cb.tap_fd);
398    }
399}
400
401int btpan_tap_open()
402{
403    struct ifreq ifr;
404    int fd, err;
405    const char *clonedev = "/dev/tun";
406
407    /* open the clone device */
408
409    //system("insmod /system/lib/modules/tun.ko");
410    if( (fd = open(clonedev, O_RDWR)) < 0 ) {
411
412        BTIF_TRACE_DEBUG("could not open %s, err:%d", clonedev, errno);
413        return fd;
414    }
415
416    memset(&ifr, 0, sizeof(ifr));
417    ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
418
419    strncpy(ifr.ifr_name, TAP_IF_NAME, IFNAMSIZ);
420
421    /* try to create the device */
422    if( (err = ioctl(fd, TUNSETIFF, (void *) &ifr)) < 0 )//|| tap_setup_ip(TAP_IF_NAME) == FALSE)
423    {
424        BTIF_TRACE_DEBUG("ioctl error:%d, errno:%s", err, strerror(errno));
425        close(fd);
426        return err;
427    }
428    BTM_GetLocalDeviceAddr (local_addr);
429    if(tap_if_up(TAP_IF_NAME, local_addr) == 0)
430    {
431        int flags = fcntl(fd, F_GETFL, 0);
432        fcntl(fd, F_SETFL, flags | O_NONBLOCK);
433        return fd;
434    }
435    BTIF_TRACE_ERROR("can not bring up tap interface:%s", TAP_IF_NAME);
436    close(fd);
437    return -1;
438}
439
440int btpan_tap_send(int tap_fd, const BD_ADDR src, const BD_ADDR dst, UINT16 proto, const char* buf,
441                    UINT16 len, BOOLEAN ext, BOOLEAN forward)
442{
443    UNUSED(ext);
444    UNUSED(forward);
445    if(tap_fd != -1)
446    {
447        tETH_HDR eth_hdr;
448        //if(is_empty_eth_addr(dst))
449        //    memcpy(&eth_hdr.h_dest, local_addr, ETH_ADDR_LEN);
450        //else
451        memcpy(&eth_hdr.h_dest, dst, ETH_ADDR_LEN);
452        memcpy(&eth_hdr.h_src, src, ETH_ADDR_LEN);
453        eth_hdr.h_proto = htons(proto);
454        char packet[2000];
455        memcpy(packet, &eth_hdr, sizeof(tETH_HDR));
456        if(len > 2000)
457        {
458            ALOGE("btpan_tap_send eth packet size:%d is exceeded limit!", len);
459            return -1;
460        }
461        memcpy(packet + sizeof(tETH_HDR), buf, len);
462
463        /* Send data to network interface */
464        //btnet_send(btpan_cb.conn[i].sock.sock, &buffer, (len + sizeof(tETH_HDR)));
465        //dump_bin("packet to network", packet, len + sizeof(tETH_HDR));
466        int ret = write(tap_fd, packet, len + sizeof(tETH_HDR));
467        BTIF_TRACE_DEBUG("ret:%d", ret);
468        return ret;
469    }
470    return -1;
471
472}
473
474int btpan_tap_close(int fd)
475{
476    tap_if_down(TAP_IF_NAME);
477    close(fd);
478    if(pan_pth >= 0)
479        btsock_thread_wakeup(pan_pth);
480    return 0;
481}
482
483btpan_conn_t * btpan_find_conn_handle(UINT16 handle)
484{
485    int i;
486    for(i = 0; i < MAX_PAN_CONNS; i++)
487        if(btpan_cb.conns[i].handle == handle)
488            return &btpan_cb.conns[i];
489    return NULL;
490}
491
492btpan_conn_t* btpan_find_conn_addr(const BD_ADDR addr)
493{
494    int i;
495    for(i = 0; i < MAX_PAN_CONNS; i++)
496        if(memcmp(btpan_cb.conns[i].peer, addr, sizeof(BD_ADDR)) == 0)
497            return &btpan_cb.conns[i];
498    return NULL;
499}
500
501static void btpan_cleanup_conn(btpan_conn_t* conn)
502{
503    if(conn)
504    {
505        conn->handle = -1;
506        conn->state = -1;
507        memset(&conn->peer, 0, sizeof(conn->peer));
508        memset(&conn->eth_addr, 0, sizeof(conn->eth_addr));
509        conn->local_role = conn->remote_role = 0;
510    }
511}
512
513btpan_conn_t* btpan_new_conn(int handle, const BD_ADDR addr, int local_role, int remote_role )
514{
515    int i;
516    for(i = 0; i < MAX_PAN_CONNS; i++)
517    {
518        BTIF_TRACE_DEBUG("conns[%d]:%d", i, btpan_cb.conns[i].handle);
519        if(btpan_cb.conns[i].handle == -1)
520        {
521            BTIF_TRACE_DEBUG("handle:%d, local_role:%d, remote_role:%d", handle, local_role, remote_role);
522
523            btpan_cb.conns[i].handle = handle;
524            bdcpy(btpan_cb.conns[i].peer, addr);
525            btpan_cb.conns[i].local_role = local_role;
526            btpan_cb.conns[i].remote_role = remote_role;
527            return &btpan_cb.conns[i];
528        }
529    }
530    BTIF_TRACE_DEBUG("MAX_PAN_CONNS:%d exceeded, return NULL as failed", MAX_PAN_CONNS);
531    return NULL;
532}
533
534void btpan_close_handle(btpan_conn_t *p)
535{
536    BTIF_TRACE_DEBUG("btpan_close_handle : close handle %d", p->handle);
537    p->handle = -1;
538    p->local_role = -1;
539    p->remote_role = -1;
540    memset(&p->peer, 0, 6);
541}
542
543static inline bool should_forward(tETH_HDR* hdr)
544{
545    uint16_t proto = ntohs(hdr->h_proto);
546    if(proto == ETH_P_IP || proto == ETH_P_ARP || proto == ETH_P_IPV6)
547        return true;
548    BTIF_TRACE_DEBUG("unknown proto:%x", proto);
549    return false;
550}
551
552static int forward_bnep(tETH_HDR* eth_hdr, BT_HDR *hdr) {
553    int broadcast = eth_hdr->h_dest[0] & 1;
554    int i;
555
556    // Find the right connection to send this frame over.
557    for (i = 0; i < MAX_PAN_CONNS; i++) {
558        UINT16 handle = btpan_cb.conns[i].handle;
559        if (handle != (UINT16)-1 &&
560                (broadcast || memcmp(btpan_cb.conns[i].eth_addr, eth_hdr->h_dest, sizeof(BD_ADDR)) == 0
561                 || memcmp(btpan_cb.conns[i].peer, eth_hdr->h_dest, sizeof(BD_ADDR)) == 0)) {
562            int result = PAN_WriteBuf(handle, eth_hdr->h_dest, eth_hdr->h_src, ntohs(eth_hdr->h_proto), hdr, 0);
563            switch (result) {
564                case PAN_Q_SIZE_EXCEEDED:
565                    return FORWARD_CONGEST;
566                case PAN_SUCCESS:
567                    return FORWARD_SUCCESS;
568                default:
569                    return FORWARD_FAILURE;
570            }
571        }
572    }
573    GKI_freebuf(hdr);
574    return FORWARD_IGNORE;
575}
576
577static void bta_pan_callback_transfer(UINT16 event, char *p_param)
578{
579    tBTA_PAN *p_data = (tBTA_PAN *)p_param;
580    switch(event)
581    {
582        case BTA_PAN_ENABLE_EVT:
583            BTIF_TRACE_DEBUG("BTA_PAN_ENABLE_EVT");
584            break;
585        case BTA_PAN_SET_ROLE_EVT:
586            {
587                int btpan_role = bta_role_to_btpan(p_data->set_role.role);
588                bt_status_t status = p_data->set_role.status == BTA_PAN_SUCCESS ? BT_STATUS_SUCCESS : BT_STATUS_FAIL;
589                btpan_control_state_t state = btpan_role == 0 ? BTPAN_STATE_DISABLED : BTPAN_STATE_ENABLED;
590                callback.control_state_cb(state, btpan_role, status, TAP_IF_NAME);
591                break;
592            }
593        case BTA_PAN_OPENING_EVT:
594            {
595                btpan_conn_t* conn;
596                bdstr_t bds;
597                bd2str((bt_bdaddr_t*)p_data->opening.bd_addr, &bds);
598                BTIF_TRACE_DEBUG("BTA_PAN_OPENING_EVT handle %d, addr: %s", p_data->opening.handle, bds);
599                conn = btpan_find_conn_addr(p_data->opening.bd_addr);
600
601                asrt(conn != NULL);
602                if (conn)
603                {
604                    conn->handle = p_data->opening.handle;
605                    int btpan_conn_local_role = bta_role_to_btpan(conn->local_role);
606                    int btpan_remote_role = bta_role_to_btpan(conn->remote_role);
607                    callback.connection_state_cb(BTPAN_STATE_CONNECTING, BT_STATUS_SUCCESS,
608                            (const bt_bdaddr_t*)p_data->opening.bd_addr, btpan_conn_local_role, btpan_remote_role);
609                }
610                else
611                    BTIF_TRACE_ERROR("connection not found");
612                break;
613            }
614        case BTA_PAN_OPEN_EVT:
615            {
616                /* debug("BTA_PAN_OPEN_EVT, open status:%d, bd_addr = [%02X:%02X:%02X:%02X:%02X:%02X]", */
617                /*         p_data->open.status, */
618                /*         p_data->open.bd_addr[0], p_data->open.bd_addr[1], p_data->open.bd_addr[2], */
619                /*         p_data->open.bd_addr[3], p_data->open.bd_addr[4], p_data->open.bd_addr[5]); */
620                btpan_connection_state_t state;
621                bt_status_t status;
622                btpan_conn_t *conn = btpan_find_conn_handle(p_data->open.handle);
623
624                ALOGV("%s pan connection open status: %d", __func__, p_data->open.status);
625                if(p_data->open.status == BTA_PAN_SUCCESS)
626                {
627                    state = BTPAN_STATE_CONNECTED;
628                    status = BT_STATUS_SUCCESS;
629                }
630                else
631                {
632                    state = BTPAN_STATE_DISCONNECTED;
633                    status = BT_STATUS_FAIL;
634                    btpan_cleanup_conn(conn);
635                }
636                /* debug("BTA_PAN_OPEN_EVT handle:%d, conn:%p",  p_data->open.handle, conn); */
637                /* debug("conn bta local_role:%d, bta remote role:%d", conn->local_role, conn->remote_role); */
638                int btpan_conn_local_role = bta_role_to_btpan(p_data->open.local_role);
639                /* debug("bta local_role:%d, bta remote role:%d", p_data->open.local_role, p_data->open.peer_role); */
640                int btpan_remote_role = bta_role_to_btpan(p_data->open.peer_role);
641                callback.connection_state_cb(state, status, (const bt_bdaddr_t*)p_data->open.bd_addr,
642                        btpan_conn_local_role, btpan_remote_role);
643                break;
644            }
645        case BTA_PAN_CLOSE_EVT:
646            {
647                btpan_conn_t* conn = btpan_find_conn_handle(p_data->close.handle);
648
649                ALOGI("%s: event = BTA_PAN_CLOSE_EVT handle %d", __FUNCTION__, p_data->close.handle);
650
651                if(conn && conn->handle >= 0)
652                {
653                    /* debug("BTA_PAN_CLOSE_EVT, conn local_role:%d, remote_role:%d", conn->local_role, conn->remote_role); */
654                    int btpan_conn_local_role = bta_role_to_btpan(conn->local_role);
655                    int btpan_remote_role = bta_role_to_btpan(conn->remote_role);
656                    callback.connection_state_cb(BTPAN_STATE_DISCONNECTED, 0, (const bt_bdaddr_t*)conn->peer,
657                            btpan_conn_local_role, btpan_remote_role);
658                    btpan_cleanup_conn(conn);
659                }
660                else
661                    BTIF_TRACE_ERROR("pan handle not found (%d)", p_data->close.handle);
662                break;
663            }
664        default:
665            BTIF_TRACE_WARNING("Unknown pan event %d", event);
666            break;
667    }
668}
669
670static void bta_pan_callback(tBTA_PAN_EVT event, tBTA_PAN *p_data)
671{
672    btif_transfer_context(bta_pan_callback_transfer, event, (char*)p_data, sizeof(tBTA_PAN), NULL);
673}
674
675#define IS_EXCEPTION(e) ((e) & (POLLHUP | POLLRDHUP | POLLERR | POLLNVAL))
676static void btu_exec_tap_fd_read(void *p_param) {
677    struct pollfd ufd;
678    int fd = (int)p_param;
679
680    if (fd == -1 || fd != btpan_cb.tap_fd)
681        return;
682
683    // Don't occupy BTU context too long, avoid GKI buffer overruns and
684    // give other profiles a chance to run by limiting the amount of memory
685    // PAN can use from the shared pool buffer.
686    for(int i = 0; i < PAN_POOL_MAX && btif_is_enabled() && btpan_cb.flow; i++) {
687        BT_HDR *buffer = (BT_HDR *)GKI_getpoolbuf(PAN_POOL_ID);
688        if (!buffer) {
689            BTIF_TRACE_WARNING("%s unable to allocate buffer for packet.", __func__);
690            break;
691        }
692        buffer->offset = PAN_MINIMUM_OFFSET;
693        buffer->len = GKI_get_buf_size(buffer) - sizeof(BT_HDR) - buffer->offset;
694
695        UINT8 *packet = (UINT8 *)buffer + sizeof(BT_HDR) + buffer->offset;
696
697        // If we don't have an undelivered packet left over, pull one from the TAP driver.
698        // We save it in the congest_packet right away in case we can't deliver it in this
699        // attempt.
700        if (!btpan_cb.congest_packet_size) {
701            ssize_t ret = read(fd, btpan_cb.congest_packet, sizeof(btpan_cb.congest_packet));
702            switch (ret) {
703                case -1:
704                    BTIF_TRACE_ERROR("%s unable to read from driver: %s", __func__, strerror(errno));
705                    GKI_freebuf(buffer);
706                    //add fd back to monitor thread to try it again later
707                    btsock_thread_add_fd(pan_pth, fd, 0, SOCK_THREAD_FD_RD, 0);
708                    return;
709                case 0:
710                    BTIF_TRACE_WARNING("%s end of file reached.", __func__);
711                    GKI_freebuf(buffer);
712                    //add fd back to monitor thread to process the exception
713                    btsock_thread_add_fd(pan_pth, fd, 0, SOCK_THREAD_FD_RD, 0);
714                    return;
715                default:
716                    btpan_cb.congest_packet_size = ret;
717                    break;
718            }
719        }
720
721        memcpy(packet, btpan_cb.congest_packet, MIN(btpan_cb.congest_packet_size, buffer->len));
722        buffer->len = MIN(btpan_cb.congest_packet_size, buffer->len);
723
724        if (buffer->len > sizeof(tETH_HDR) && should_forward((tETH_HDR *)packet)) {
725            // Extract the ethernet header from the buffer since the PAN_WriteBuf inside
726            // forward_bnep can't handle two pointers that point inside the same GKI buffer.
727            tETH_HDR hdr;
728            memcpy(&hdr, packet, sizeof(tETH_HDR));
729
730            // Skip the ethernet header.
731            buffer->len -= sizeof(tETH_HDR);
732            buffer->offset += sizeof(tETH_HDR);
733            if (forward_bnep(&hdr, buffer) != FORWARD_CONGEST)
734                btpan_cb.congest_packet_size = 0;
735        } else {
736            BTIF_TRACE_WARNING("%s dropping packet of length %d", __func__, buffer->len);
737            btpan_cb.congest_packet_size = 0;
738            GKI_freebuf(buffer);
739        }
740
741        // Bail out of the loop if reading from the TAP fd would block.
742        ufd.fd = fd;
743        ufd.events = POLLIN;
744        ufd.revents = 0;
745        if(poll(&ufd, 1, 0) <= 0 || IS_EXCEPTION(ufd.revents))
746            break;
747    }
748    //add fd back to monitor thread
749    btsock_thread_add_fd(pan_pth, fd, 0, SOCK_THREAD_FD_RD, 0);
750}
751
752static void btif_pan_close_all_conns() {
753    int i;
754    if (!stack_initialized)
755        return;
756
757    for (i = 0; i < MAX_PAN_CONNS; ++i)
758        if (btpan_cb.conns[i].handle != -1)
759            BTA_PanClose(btpan_cb.conns[i].handle);
760}
761
762static void btpan_tap_fd_signaled(int fd, int type, int flags, uint32_t user_id) {
763    assert(btpan_cb.tap_fd == fd);
764
765    if (btpan_cb.tap_fd != fd)
766        return;
767
768    if(flags & SOCK_THREAD_FD_EXCEPTION) {
769        btpan_cb.tap_fd = -1;
770        btpan_tap_close(fd);
771        btif_pan_close_all_conns();
772    } else if(flags & SOCK_THREAD_FD_RD)
773        bta_dmexecutecallback(btu_exec_tap_fd_read, (void *)fd);
774}
775