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-common.h"
  21 #include "bt/bt.h"
  22 #include "hw/bt.h"
  23 #include "qemu/main-loop.h"
  24
  25 #define VHCI_DEV        "/dev/vhci"
  26 #define VHCI_UDEV       "/dev/hci_vhci"
  27
  28 struct bt_vhci_s {
  29     int fd;
  30     struct HCIInfo *info;
  31
  32     uint8_t hdr[4096];
  33     int len;
  34 };
  35
  36 static void vhci_read(void *opaque)
  37 {
  38     struct bt_vhci_s *s = (struct bt_vhci_s *) opaque;
  39     uint8_t *pkt;
  40     int pktlen;
  41
  42     /* Seems that we can't read only the header first and then the amount
  43      * of data indicated in the header because Linux will discard everything
  44      * that's not been read in one go.  */
  45     s->len = read(s->fd, s->hdr, sizeof(s->hdr));
  46
  47     if (s->len < 0) {
  48         fprintf(stderr, "qemu: error %i reading the PDU\n", errno);
  49         return;
  50     }
  51
  52     pkt = s->hdr;
  53     while (s->len --)
  54         switch (*pkt ++) {
  55         case HCI_COMMAND_PKT:
  56             if (s->len < 3)
  57                 goto bad_pkt;
  58
  59             pktlen = MIN(pkt[2] + 3, s->len);
  60             s->info->cmd_send(s->info, pkt, pktlen);
  61             s->len -= pktlen;
  62             pkt += pktlen;
  63             break;
  64
  65         case HCI_ACLDATA_PKT:
  66             if (s->len < 4)
  67                 goto bad_pkt;
  68
  69             pktlen = MIN(((pkt[3] << 8) | pkt[2]) + 4, s->len);
  70             s->info->acl_send(s->info, pkt, pktlen);
  71             s->len -= pktlen;
  72             pkt += pktlen;
  73             break;
  74
  75         case HCI_SCODATA_PKT:
  76             if (s->len < 3)
  77                 goto bad_pkt;
  78
  79             pktlen = MIN(pkt[2] + 3, s->len);
  80             s->info->sco_send(s->info, pkt, pktlen);
  81             s->len -= pktlen;
  82             pkt += pktlen;
  83             break;
  84
  85         default:
  86         bad_pkt:
  87             fprintf(stderr, "qemu: bad HCI packet type %02x\n", pkt[-1]);
  88         }
  89 }
  90
  91 static void vhci_host_send(void *opaque,
  92                 int type, const uint8_t *data, int len)
  93 {
  94     struct bt_vhci_s *s = (struct bt_vhci_s *) opaque;
  95 #if 0
  96     uint8_t pkt = type;
  97     struct iovec iv[2];
  98
  99     iv[0].iov_base = &pkt;
 100     iv[0].iov_len  = 1;
 101     iv[1].iov_base = (void *) data;
 102     iv[1].iov_len  = len;
 103
 104     while (writev(s->fd, iv, 2) < 0)
 105         if (errno != EAGAIN && errno != EINTR) {
 106             fprintf(stderr, "qemu: error %i writing bluetooth packet.\n",
 107                             errno);
 108             return;
 109         }
 110 #else
 111     /* Apparently VHCI wants us to write everything in one chunk :-(  */
 112     static uint8_t buf[4096];
 113
 114     buf[0] = type;
 115     memcpy(buf + 1, data, len);
 116
 117     while (write(s->fd, buf, len + 1) < 0)
 118         if (errno != EAGAIN && errno != EINTR) {
 119             fprintf(stderr, "qemu: error %i writing bluetooth packet.\n",
 120                             errno);
 121             return;
 122         }
 123 #endif
 124 }
 125
 126 static void vhci_out_hci_packet_event(void *opaque,
 127                 const uint8_t *data, int len)
 128 {
 129     vhci_host_send(opaque, HCI_EVENT_PKT, data, len);
 130 }
 131
 132 static void vhci_out_hci_packet_acl(void *opaque,
 133                 const uint8_t *data, int len)
 134 {
 135     vhci_host_send(opaque, HCI_ACLDATA_PKT, data, len);
 136 }
 137
 138 void bt_vhci_init(struct HCIInfo *info)
 139 {
 140     struct bt_vhci_s *s;
 141     int err[2];
 142     int fd;
 143
 144     fd = open(VHCI_DEV, O_RDWR);
 145     err[0] = errno;
 146     if (fd < 0) {
 147         fd = open(VHCI_UDEV, O_RDWR);
 148         err[1] = errno;
 149     }
 150
 151     if (fd < 0) {
 152         fprintf(stderr, "qemu: Can't open `%s': %s (%i)\n",
 153                         VHCI_DEV, strerror(err[0]), err[0]);
 154         fprintf(stderr, "qemu: Can't open `%s': %s (%i)\n",
 155                         VHCI_UDEV, strerror(err[1]), err[1]);
 156         exit(-1);
 157     }
 158
 159     s = g_malloc0(sizeof(struct bt_vhci_s));
 160     s->fd = fd;
 161     s->info = info ?: qemu_next_hci();
 162     s->info->opaque = s;
 163     s->info->evt_recv = vhci_out_hci_packet_event;
 164     s->info->acl_recv = vhci_out_hci_packet_acl;
 165
 166     qemu_set_fd_handler(s->fd, vhci_read, NULL, s);
 167 }