path: root/bus/driver-afbus.c

/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
/* driver.c  Bus client, AF_BUS bits (driver)
 *
 * Copyright (C) 2012 Collabora Ltd
 *
 * Licensed under the Academic Free License version 2.1
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

#include <config.h>

#include "driver-afbus.h"

#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <asm/types.h>
#include <errno.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>
#include <linux/connector.h>
#include <dbus/dbus-transport-afbus.h>

/* FIXME: CN_IDX_NFDBUS should be allocated and moved in include/linux/connector.h */
#define CN_IDX_NFDBUS              (CN_NETLINK_USERS + 3)
#define CN_VAL_NFDBUS              0x01

#define NFDBUS_CMD_ADDMATCH     0x01
#define NFDBUS_CMD_REMOVEMATCH  0x02

struct nfdbus_nl_cfg_req {
        __u32 cmd;
        __u32 len;
        struct sockaddr_bus addr;
        __u64 pad;
        unsigned char data[0];
};

struct nfdbus_nl_cfg_reply {
	__u32 ret_code;
};

static int
ensure_nl_sock(DBusError *error)
{
  static int nlsock = 0;

  struct sockaddr_nl l_local;
  int fd;
  int ret;

  if (nlsock > 0)
    return nlsock;

  fd = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_CONNECTOR);
  if (fd == -1) {
    dbus_set_error (error, DBUS_ERROR_NETLINK,
                    "Couldn't use the netlink socket: %s",
                    strerror(errno));
    return -1;
  }

  if (!_dbus_set_fd_nonblocking (fd, error))
    {
      _dbus_close_socket (fd, NULL);
      return -1;
    }

  l_local.nl_family = AF_NETLINK;
  l_local.nl_groups = 0;
  l_local.nl_pid = 0;
  ret = bind(fd, (struct sockaddr *)&l_local, sizeof(struct sockaddr_nl));
  if (ret == -1) {
    close(fd);
    dbus_set_error (error, DBUS_ERROR_NETLINK,
                    "Couldn't bind the netlink socket: %s",
                    strerror(errno));
    return -1;
  }

  nlsock = fd;
  return nlsock;
}

static int netlink_send(int nlsock, struct cn_msg *msg, int seq)
{
  struct nlmsghdr *nlh;
  unsigned int size;
  char buf[4096];
  struct cn_msg *m;

  size = NLMSG_SPACE(sizeof(struct cn_msg) + msg->len);

  nlh = (struct nlmsghdr *)buf;
  nlh->nlmsg_seq = seq;
  nlh->nlmsg_pid = getpid();
  nlh->nlmsg_type = NLMSG_DONE;
  nlh->nlmsg_len = NLMSG_LENGTH(size - sizeof(*nlh));
  nlh->nlmsg_flags = 0;

  m = NLMSG_DATA(nlh);
  memcpy(m, msg, sizeof(*m) + msg->len);

  return send(nlsock, nlh, size, 0);
}

dbus_bool_t
bus_driver_afbus_upload_match_rule (DBusConnection      *connection,
                                    const char          *rule,
                                    DBusError           *error)
{
  static int seq;

  int nlsock;
  int ret;

  char buf[sizeof(struct cn_msg) + sizeof(struct nfdbus_nl_cfg_req) + 1024];

  struct cn_msg *data;
  struct nlmsghdr *reply;
  struct nfdbus_nl_cfg_req *req;
  //struct nfdbus_nl_cfg_reply *req_reply;

  struct sockaddr_bus address;
  long len = sizeof(address);

  memset (&address, 0, sizeof (address));
  if (!dbus_connection_get_peer_address(connection, &address, &len))
    {
      /* Don't return an error if it is not a AF_BUS socket */
      return TRUE;
    }

  nlsock = ensure_nl_sock (error);
  if (nlsock == -1)
    return FALSE;

  memset(buf, 0, sizeof(buf));

  data = (struct cn_msg *)buf;

  data->id.idx = CN_IDX_NFDBUS;
  data->id.val = CN_VAL_NFDBUS;
  data->seq = seq++;
  data->ack = 0;
  data->len = sizeof(struct nfdbus_nl_cfg_req) + strlen(rule) + 1;
  req = (struct nfdbus_nl_cfg_req *) data->data;

  req->cmd = NFDBUS_CMD_ADDMATCH;
  req->len = strlen(rule) + 1;
  req->addr = address;
  strcpy((char *)req->data, rule);

  ret = netlink_send(nlsock, data, seq++);
  if (ret <= 0)
    {
    }

  memset(buf, 0, sizeof(buf));
  ret = recv(nlsock, buf, sizeof(buf), 0);
  if (ret <= 0)
    {
    }

  reply = (struct nlmsghdr *)buf;
  if (reply->nlmsg_type != NLMSG_DONE)
    {
    }

  return TRUE;
}

dbus_bool_t
bus_driver_afbus_append_unique_name (DBusConnection *connection,
                                     DBusString     *str)
{
  struct sockaddr_bus address;
  long len = sizeof(address);

  memset (&address, 0, sizeof (address));
  if (!dbus_connection_get_peer_address(connection, &address, &len) ||
      address.sbus_family != AF_BUS)
    {
      /* Don't return an error if it is not a AF_BUS socket */
      return TRUE;
    }

  if (!_dbus_string_append (str, "AF-BUS."))
    return FALSE;

  if (!_dbus_string_append_uint (str, address.sbus_addr.s_addr))
    return FALSE;

  if (!_dbus_string_append (str, "."))
    return FALSE;

  return TRUE;
}

dbus_bool_t
bus_driver_afbus_emit_forwarded (DBusConnection *connection,
                                 DBusConnection *addressed_recipient,
                                 const char     *service_name)
{
  struct sockaddr_bus address;
  long len = sizeof (address);
  DBusMessage *message;
  BusContext *context;
  BusTransaction *transaction = NULL;
  dbus_bool_t result = FALSE;

  memset (&address, 0, sizeof (address));
  if (!dbus_connection_get_peer_address (addressed_recipient, &address, &len))
    {
      /* Don't return an error if it is not a AF_BUS socket */
      return TRUE;
    }

  /* Prepare the message to be sent */
  message = dbus_message_new_signal (DBUS_PATH_AFBUS,
                                     DBUS_INTERFACE_AFBUS,
                                     "Forwarded");
  if (message == NULL)
    {
      _dbus_verbose ("Could not allocate AF_BUS.Forwarded signal message\n");
      return FALSE;
    }

  if (!dbus_message_set_sender (message, DBUS_SERVICE_DBUS))
    {
      _dbus_verbose ("Could not set sender for AF_BUS.Forwarded signal message\n");
      goto out;
    }

  if (!dbus_message_append_args (message,
                                 DBUS_TYPE_STRING, &service_name,
                                 DBUS_TYPE_UINT64, &address.sbus_addr.s_addr,
                                 DBUS_TYPE_INVALID))
    {
      _dbus_verbose ("Could not append arguments for AF_BUS.Forwarded signal message\n");
      goto out;
    }

  /* Prepare transaction */
  context = bus_connection_get_context (connection);
  transaction = bus_transaction_new (context);
  if (transaction == NULL)
    {
      _dbus_verbose ("Could not create transaction\n");
      goto out;
    }

  if (bus_transaction_send (transaction, addressed_recipient, message))
    result = TRUE;
  else
      _dbus_verbose ("Could not send AF_BUS.Forwarded signal message\n");

 out:
  if (transaction != NULL)
    bus_transaction_execute_and_free (transaction);

  dbus_message_unref (message);

  return result;
}