bt-vhci.c

   1 /*
   2  * Support for host VHCIs inside qemu scatternets.
   3  *
   4  * Copyright (C) 2008 Andrzej Zaborowski  <balrog@zabor.org>
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License as
   8  * published by the Free Software Foundation; either version 2 or
   9  * (at your option) version 3 of the License.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include "qemu/osdep.h"
  21 #include "qemu-common.h"
  22 #include "sysemu/bt.h"
  23 #include "hw/bt.h"
  24 #include "qemu/main-loop.h"
  25
  26 #define VHCI_DEV        "/dev/vhci"
  27 #define VHCI_UDEV       "/dev/hci_vhci"
  28
  29 struct bt_vhci_s {
  30     int fd;
  31     struct HCIInfo *info;
  32
  33     uint8_t hdr[4096];
  34     int len;
  35 };
  36
  37 static void vhci_read(void *opaque)
  38 {
  39     struct bt_vhci_s *s = (struct bt_vhci_s *) opaque;
  40     uint8_t *pkt;
  41     int pktlen;
  42
  43     /* Seems that we can't read only the header first and then the amount
  44      * of data indicated in the header because Linux will discard everything
  45      * that's not been read in one go.  */
  46     s->len = read(s->fd, s->hdr, sizeof(s->hdr));
  47
  48     if (s->len < 0) {
  49         fprintf(stderr, "qemu: error %i reading the PDU\n", errno);
  50         return;
  51     }
  52
  53     pkt = s->hdr;
  54     while (s->len --)
  55         switch (*pkt ++) {
  56         case HCI_COMMAND_PKT:
  57             if (s->len < 3)
  58                 goto bad_pkt;
  59
  60             pktlen = MIN(pkt[2] + 3, s->len);
  61             s->info->cmd_send(s->info, pkt, pktlen);
  62             s->len -= pktlen;
  63             pkt += pktlen;
  64             break;
  65
  66         case HCI_ACLDATA_PKT:
  67             if (s->len < 4)
  68                 goto bad_pkt;
  69
  70             pktlen = MIN(((pkt[3] << 8) | pkt[2]) + 4, s->len);
  71             s->info->acl_send(s->info, pkt, pktlen);
  72             s->len -= pktlen;
  73             pkt += pktlen;
  74             break;
  75
  76         case HCI_SCODATA_PKT:
  77             if (s->len < 3)
  78                 goto bad_pkt;
  79
  80             pktlen = MIN(pkt[2] + 3, s->len);
  81             s->info->sco_send(s->info, pkt, pktlen);
  82             s->len -= pktlen;
  83             pkt += pktlen;
  84             break;
  85
  86         default:
  87         bad_pkt:
  88             fprintf(stderr, "qemu: bad HCI packet type %02x\n", pkt[-1]);
  89         }
  90 }
  91
  92 static void vhci_host_send(void *opaque,
  93                 int type, const uint8_t *data, int len)
  94 {
  95     struct bt_vhci_s *s = (struct bt_vhci_s *) opaque;
  96 #if 0
  97     uint8_t pkt = type;
  98     struct iovec iv[2];
  99
 100     iv[0].iov_base = &pkt;
 101     iv[0].iov_len  = 1;
 102     iv[1].iov_base = (void *) data;
 103     iv[1].iov_len  = len;
 104
 105     while (writev(s->fd, iv, 2) < 0)
 106         if (errno != EAGAIN && errno != EINTR) {
 107             fprintf(stderr, "qemu: error %i writing bluetooth packet.\n",
 108                             errno);
 109             return;
 110         }
 111 #else
 112     /* Apparently VHCI wants us to write everything in one chunk :-(  */
 113     static uint8_t buf[4096];
 114
 115     buf[0] = type;
 116     memcpy(buf + 1, data, len);
 117
 118     while (write(s->fd, buf, len + 1) < 0)
 119         if (errno != EAGAIN && errno != EINTR) {
 120             fprintf(stderr, "qemu: error %i writing bluetooth packet.\n",
 121                             errno);
 122             return;
 123         }
 124 #endif
 125 }
 126
 127 static void vhci_out_hci_packet_event(void *opaque,
 128                 const uint8_t *data, int len)
 129 {
 130     vhci_host_send(opaque, HCI_EVENT_PKT, data, len);
 131 }
 132
 133 static void vhci_out_hci_packet_acl(void *opaque,
 134                 const uint8_t *data, int len)
 135 {
 136     vhci_host_send(opaque, HCI_ACLDATA_PKT, data, len);
 137 }
 138
 139 void bt_vhci_init(struct HCIInfo *info)
 140 {
 141     struct bt_vhci_s *s;
 142     int err[2];
 143     int fd;
 144
 145     fd = open(VHCI_DEV, O_RDWR);
 146     err[0] = errno;
 147     if (fd < 0) {
 148         fd = open(VHCI_UDEV, O_RDWR);
 149         err[1] = errno;
 150     }
 151
 152     if (fd < 0) {
 153         fprintf(stderr, "qemu: Can't open `%s': %s (%i)\n",
 154                         VHCI_DEV, strerror(err[0]), err[0]);
 155         fprintf(stderr, "qemu: Can't open `%s': %s (%i)\n",
 156                         VHCI_UDEV, strerror(err[1]), err[1]);
 157         exit(-1);
 158     }
 159
 160     s = g_malloc0(sizeof(struct bt_vhci_s));
 161     s->fd = fd;
 162     s->info = info ?: qemu_next_hci();
 163     s->info->opaque = s;
 164     s->info->evt_recv = vhci_out_hci_packet_event;
 165     s->info->acl_recv = vhci_out_hci_packet_acl;
 166
 167     qemu_set_fd_handler(s->fd, vhci_read, NULL, s);
 168 }