api_msg.c

lwip-1.4.0

 * Called from netconn_disconnect.
 *
 * @param msg the api_msg_msg pointing to the connection to disconnect
 */
void
do_disconnect(struct api_msg_msg *msg)
{
#if LWIP_UDP
  if (NETCONNTYPE_GROUP(msg->conn->type) == NETCONN_UDP) {
    udp_disconnect(msg->conn->pcb.udp);
    msg->err = ERR_OK;
  } else
#endif /* LWIP_UDP */
  {
    msg->err = ERR_VAL;
  }
  TCPIP_APIMSG_ACK(msg);
}

#if LWIP_TCP
/**
 * Set a TCP pcb contained in a netconn into listen mode
 * Called from netconn_listen.
 *
 * @param msg the api_msg_msg pointing to the connection
 */
void
do_listen(struct api_msg_msg *msg)
{
  if (ERR_IS_FATAL(msg->conn->last_err)) {
    msg->err = msg->conn->last_err;
  } else {
    msg->err = ERR_CONN;
    if (msg->conn->pcb.tcp != NULL) {
      if (msg->conn->type == NETCONN_TCP) {
        if (msg->conn->state == NETCONN_NONE) {
#if TCP_LISTEN_BACKLOG
          struct tcp_pcb* lpcb = tcp_listen_with_backlog(msg->conn->pcb.tcp, msg->msg.lb.backlog);
#else  /* TCP_LISTEN_BACKLOG */
          struct tcp_pcb* lpcb = tcp_listen(msg->conn->pcb.tcp);
#endif /* TCP_LISTEN_BACKLOG */
          if (lpcb == NULL) {
            /* in this case, the old pcb is still allocated */
            msg->err = ERR_MEM;
          } else {
            /* delete the recvmbox and allocate the acceptmbox */
            if (sys_mbox_valid(&msg->conn->recvmbox)) {
              /** @todo: should we drain the recvmbox here? */
              sys_mbox_free(&msg->conn->recvmbox);
              sys_mbox_set_invalid(&msg->conn->recvmbox);
            }
            msg->err = ERR_OK;
            if (!sys_mbox_valid(&msg->conn->acceptmbox)) {
              msg->err = sys_mbox_new(&msg->conn->acceptmbox, DEFAULT_ACCEPTMBOX_SIZE);
            }
            if (msg->err == ERR_OK) {
              msg->conn->state = NETCONN_LISTEN;
              msg->conn->pcb.tcp = lpcb;
              tcp_arg(msg->conn->pcb.tcp, msg->conn);
              tcp_accept(msg->conn->pcb.tcp, accept_function);
            } else {
              /* since the old pcb is already deallocated, free lpcb now */
              tcp_close(lpcb);
              msg->conn->pcb.tcp = NULL;
            }
          }
        }
      }
    }
  }
  TCPIP_APIMSG_ACK(msg);
}
#endif /* LWIP_TCP */

/**
 * Send some data on a RAW or UDP pcb contained in a netconn
 * Called from netconn_send
 *
 * @param msg the api_msg_msg pointing to the connection
 */
void
do_send(struct api_msg_msg *msg)
{
  if (ERR_IS_FATAL(msg->conn->last_err)) {
    msg->err = msg->conn->last_err;
  } else {
    msg->err = ERR_CONN;
    if (msg->conn->pcb.tcp != NULL) {
      switch (NETCONNTYPE_GROUP(msg->conn->type)) {
#if LWIP_RAW
      case NETCONN_RAW:
        if (ip_addr_isany(&msg->msg.b->addr)) {
          msg->err = raw_send(msg->conn->pcb.raw, msg->msg.b->p);
        } else {
          msg->err = raw_sendto(msg->conn->pcb.raw, msg->msg.b->p, &msg->msg.b->addr);
        }
        break;
#endif
#if LWIP_UDP
      case NETCONN_UDP:
#if LWIP_CHECKSUM_ON_COPY
        if (ip_addr_isany(&msg->msg.b->addr)) {
          msg->err = udp_send_chksum(msg->conn->pcb.udp, msg->msg.b->p,
            msg->msg.b->flags & NETBUF_FLAG_CHKSUM, msg->msg.b->toport_chksum);
        } else {
          msg->err = udp_sendto_chksum(msg->conn->pcb.udp, msg->msg.b->p,
            &msg->msg.b->addr, msg->msg.b->port,
            msg->msg.b->flags & NETBUF_FLAG_CHKSUM, msg->msg.b->toport_chksum);
        }
#else /* LWIP_CHECKSUM_ON_COPY */
        if (ip_addr_isany(&msg->msg.b->addr)) {
          msg->err = udp_send(msg->conn->pcb.udp, msg->msg.b->p);
        } else {
          msg->err = udp_sendto(msg->conn->pcb.udp, msg->msg.b->p, &msg->msg.b->addr, msg->msg.b->port);
        }
#endif /* LWIP_CHECKSUM_ON_COPY */
        break;
#endif /* LWIP_UDP */
      default:
        break;
      }
    }
  }
  TCPIP_APIMSG_ACK(msg);
}

#if LWIP_TCP
/**
 * Indicate data has been received from a TCP pcb contained in a netconn
 * Called from netconn_recv
 *
 * @param msg the api_msg_msg pointing to the connection
 */
void
do_recv(struct api_msg_msg *msg)
{
  msg->err = ERR_OK;
  if (msg->conn->pcb.tcp != NULL) {
    if (msg->conn->type == NETCONN_TCP) {
#if TCP_LISTEN_BACKLOG
      if (msg->conn->pcb.tcp->state == LISTEN) {
        tcp_accepted(msg->conn->pcb.tcp);
      } else
#endif /* TCP_LISTEN_BACKLOG */
      {
        u32_t remaining = msg->msg.r.len;
        do {
          u16_t recved = (remaining > 0xffff) ? 0xffff : (u16_t)remaining;
          tcp_recved(msg->conn->pcb.tcp, recved);
          remaining -= recved;
        }while(remaining != 0);
      }
    }
  }
  TCPIP_APIMSG_ACK(msg);
}

/**
 * See if more data needs to be written from a previous call to netconn_write.
 * Called initially from do_write. If the first call can't send all data
 * (because of low memory or empty send-buffer), this function is called again
 * from sent_tcp() or poll_tcp() to send more data. If all data is sent, the
 * blocking application thread (waiting in netconn_write) is released.
 *
 * @param conn netconn (that is currently in state NETCONN_WRITE) to process
 * @return ERR_OK
 *         ERR_MEM if LWIP_TCPIP_CORE_LOCKING=1 and sending hasn't yet finished
 */
static err_t
do_writemore(struct netconn *conn)
{
  err_t err = ERR_OK;
  void *dataptr;
  u16_t len, available;
  u8_t write_finished = 0;
  size_t diff;
  u8_t dontblock = netconn_is_nonblocking(conn) ||
       (conn->current_msg->msg.w.apiflags & NETCONN_DONTBLOCK);
  u8_t apiflags = conn->current_msg->msg.w.apiflags;

  LWIP_ASSERT("conn != NULL", conn != NULL);
  LWIP_ASSERT("conn->state == NETCONN_WRITE", (conn->state == NETCONN_WRITE));
  LWIP_ASSERT("conn->current_msg != NULL", conn->current_msg != NULL);
  LWIP_ASSERT("conn->pcb.tcp != NULL", conn->pcb.tcp != NULL);
  LWIP_ASSERT("conn->write_offset < conn->current_msg->msg.w.len",
    conn->write_offset < conn->current_msg->msg.w.len);

  dataptr = (u8_t*)conn->current_msg->msg.w.dataptr + conn->write_offset;
  diff = conn->current_msg->msg.w.len - conn->write_offset;
  if (diff > 0xffffUL) { /* max_u16_t */
    len = 0xffff;
#if LWIP_TCPIP_CORE_LOCKING
    conn->flags |= NETCONN_FLAG_WRITE_DELAYED;
#endif
    apiflags |= TCP_WRITE_FLAG_MORE;
  } else {
    len = (u16_t)diff;
  }
  available = tcp_sndbuf(conn->pcb.tcp);
  if (available < len) {
    /* don't try to write more than sendbuf */
    len = available;
#if LWIP_TCPIP_CORE_LOCKING
    conn->flags |= NETCONN_FLAG_WRITE_DELAYED;
#endif
    apiflags |= TCP_WRITE_FLAG_MORE;
  }
  if (dontblock && (len < conn->current_msg->msg.w.len)) {
    /* failed to send all data at once -> nonblocking write not possible */
    err = ERR_MEM;
  }
  if (err == ERR_OK) {
    LWIP_ASSERT("do_writemore: invalid length!", ((conn->write_offset + len) <= conn->current_msg->msg.w.len));
    err = tcp_write(conn->pcb.tcp, dataptr, len, apiflags);
  }
  if (dontblock && (err == ERR_MEM)) {
    /* nonblocking write failed */
    write_finished = 1;
    err = ERR_WOULDBLOCK;
    /* let poll_tcp check writable space to mark the pcb
       writable again */
    conn->flags |= NETCONN_FLAG_CHECK_WRITESPACE;
    /* let select mark this pcb as non-writable. */
    API_EVENT(conn, NETCONN_EVT_SENDMINUS, len);
  } else {
    /* if OK or memory error, check available space */
    if (((err == ERR_OK) || (err == ERR_MEM)) &&
        ((tcp_sndbuf(conn->pcb.tcp) <= TCP_SNDLOWAT) ||
         (tcp_sndqueuelen(conn->pcb.tcp) >= TCP_SNDQUEUELOWAT))) {
      /* The queued byte- or pbuf-count exceeds the configured low-water limit,
         let select mark this pcb as non-writable. */
      API_EVENT(conn, NETCONN_EVT_SENDMINUS, len);
    }

    if (err == ERR_OK) {
      conn->write_offset += len;
      if (conn->write_offset == conn->current_msg->msg.w.len) {
        /* everything was written */
        write_finished = 1;
        conn->write_offset = 0;
      }
      tcp_output(conn->pcb.tcp);
    } else if (err == ERR_MEM) {
      /* If ERR_MEM, we wait for sent_tcp or poll_tcp to be called
         we do NOT return to the application thread, since ERR_MEM is
         only a temporary error! */

      /* tcp_write returned ERR_MEM, try tcp_output anyway */
      tcp_output(conn->pcb.tcp);

  #if LWIP_TCPIP_CORE_LOCKING
      conn->flags |= NETCONN_FLAG_WRITE_DELAYED;
  #endif
    } else {
      /* On errors != ERR_MEM, we don't try writing any more but return
         the error to the application thread. */
      write_finished = 1;
    }
  }

  if (write_finished) {
    /* everything was written: set back connection state
       and back to application task */
    conn->current_msg->err = err;
    conn->current_msg = NULL;
    conn->state = NETCONN_NONE;
#if LWIP_TCPIP_CORE_LOCKING
    if ((conn->flags & NETCONN_FLAG_WRITE_DELAYED) != 0)
#endif
    {
      sys_sem_signal(&conn->op_completed);
    }
  }
#if LWIP_TCPIP_CORE_LOCKING
  else
    return ERR_MEM;
#endif
  return ERR_OK;
}
#endif /* LWIP_TCP */

/**
 * Send some data on a TCP pcb contained in a netconn
 * Called from netconn_write
 *
 * @param msg the api_msg_msg pointing to the connection
 */
void
do_write(struct api_msg_msg *msg)
{
  if (ERR_IS_FATAL(msg->conn->last_err)) {
    msg->err = msg->conn->last_err;
  } else {
    if (msg->conn->type == NETCONN_TCP) {
#if LWIP_TCP
      if (msg->conn->state != NETCONN_NONE) {
        /* netconn is connecting, closing or in blocking write */
        msg->err = ERR_INPROGRESS;
      } else if (msg->conn->pcb.tcp != NULL) {
        msg->conn->state = NETCONN_WRITE;
        /* set all the variables used by do_writemore */
        LWIP_ASSERT("already writing or closing", msg->conn->current_msg == NULL &&
          msg->conn->write_offset == 0);
        LWIP_ASSERT("msg->msg.w.len != 0", msg->msg.w.len != 0);
        msg->conn->current_msg = msg;
        msg->conn->write_offset = 0;
#if LWIP_TCPIP_CORE_LOCKING
        msg->conn->flags &= ~NETCONN_FLAG_WRITE_DELAYED;
        if (do_writemore(msg->conn) != ERR_OK) {
          LWIP_ASSERT("state!", msg->conn->state == NETCONN_WRITE);
          UNLOCK_TCPIP_CORE();
          sys_arch_sem_wait(&msg->conn->op_completed, 0);
          LOCK_TCPIP_CORE();
          LWIP_ASSERT("state!", msg->conn->state == NETCONN_NONE);
        }
#else /* LWIP_TCPIP_CORE_LOCKING */
        do_writemore(msg->conn);
#endif /* LWIP_TCPIP_CORE_LOCKING */
        /* for both cases: if do_writemore was called, don't ACK the APIMSG
           since do_writemore ACKs it! */
        return;
      } else {
        msg->err = ERR_CONN;
      }
#else /* LWIP_TCP */
      msg->err = ERR_VAL;
#endif /* LWIP_TCP */
#if (LWIP_UDP || LWIP_RAW)
    } else {
      msg->err = ERR_VAL;
#endif /* (LWIP_UDP || LWIP_RAW) */
    }
  }
  TCPIP_APIMSG_ACK(msg);
}

/**
 * Return a connection's local or remote address
 * Called from netconn_getaddr
 *
 * @param msg the api_msg_msg pointing to the connection
 */
void
do_getaddr(struct api_msg_msg *msg)
{
  if (msg->conn->pcb.ip != NULL) {
    *(msg->msg.ad.ipaddr) = (msg->msg.ad.local ? msg->conn->pcb.ip->local_ip :
                             msg->conn->pcb.ip->remote_ip);

    msg->err = ERR_OK;
    switch (NETCONNTYPE_GROUP(msg->conn->type)) {
#if LWIP_RAW
    case NETCONN_RAW:
      if (msg->msg.ad.local) {
        *(msg->msg.ad.port) = msg->conn->pcb.raw->protocol;
      } else {
        /* return an error as connecting is only a helper for upper layers */
        msg->err = ERR_CONN;
      }
      break;
#endif /* LWIP_RAW */
#if LWIP_UDP
    case NETCONN_UDP:
      if (msg->msg.ad.local) {
        *(msg->msg.ad.port) = msg->conn->pcb.udp->local_port;
      } else {
        if ((msg->conn->pcb.udp->flags & UDP_FLAGS_CONNECTED) == 0) {
          msg->err = ERR_CONN;
        } else {
          *(msg->msg.ad.port) = msg->conn->pcb.udp->remote_port;
        }
      }
      break;
#endif /* LWIP_UDP */
#if LWIP_TCP
    case NETCONN_TCP:
      *(msg->msg.ad.port) = (msg->msg.ad.local?msg->conn->pcb.tcp->local_port:msg->conn->pcb.tcp->remote_port);
      break;
#endif /* LWIP_TCP */
    default:
      LWIP_ASSERT("invalid netconn_type", 0);
      break;
    }
  } else {
    msg->err = ERR_CONN;
  }
  TCPIP_APIMSG_ACK(msg);
}

/**
 * Close a TCP pcb contained in a netconn
 * Called from netconn_close
 *
 * @param msg the api_msg_msg pointing to the connection
 */
void
do_close(struct api_msg_msg *msg)
{
#if LWIP_TCP
  /* @todo: abort running write/connect? */
  if ((msg->conn->state != NETCONN_NONE) && (msg->conn->state != NETCONN_LISTEN)) {
    /* this only happens for TCP netconns */
    LWIP_ASSERT("msg->conn->type == NETCONN_TCP", msg->conn->type == NETCONN_TCP);
    msg->err = ERR_INPROGRESS;
  } else if ((msg->conn->pcb.tcp != NULL) && (msg->conn->type == NETCONN_TCP)) {
    if ((msg->msg.sd.shut != NETCONN_SHUT_RDWR) && (msg->conn->state == NETCONN_LISTEN)) {
      /* LISTEN doesn't support half shutdown */
      msg->err = ERR_CONN;
    } else {
      if (msg->msg.sd.shut & NETCONN_SHUT_RD) {
        /* Drain and delete mboxes */
        netconn_drain(msg->conn);
      }
      LWIP_ASSERT("already writing or closing", msg->conn->current_msg == NULL &&
        msg->conn->write_offset == 0);
      msg->conn->state = NETCONN_CLOSE;
      msg->conn->current_msg = msg;
      do_close_internal(msg->conn);
      /* for tcp netconns, do_close_internal ACKs the message */
      return;
    }
  } else
#endif /* LWIP_TCP */
  {
    msg->err = ERR_VAL;
  }
  sys_sem_signal(&msg->conn->op_completed);
}

#if LWIP_IGMP
/**
 * Join multicast groups for UDP netconns.
 * Called from netconn_join_leave_group
 *
 * @param msg the api_msg_msg pointing to the connection
 */
void
do_join_leave_group(struct api_msg_msg *msg)
{ 
  if (ERR_IS_FATAL(msg->conn->last_err)) {
    msg->err = msg->conn->last_err;
  } else {
    if (msg->conn->pcb.tcp != NULL) {
      if (NETCONNTYPE_GROUP(msg->conn->type) == NETCONN_UDP) {
#if LWIP_UDP
        if (msg->msg.jl.join_or_leave == NETCONN_JOIN) {
          msg->err = igmp_joingroup(msg->msg.jl.netif_addr, msg->msg.jl.multiaddr);
        } else {
          msg->err = igmp_leavegroup(msg->msg.jl.netif_addr, msg->msg.jl.multiaddr);
        }
#endif /* LWIP_UDP */
#if (LWIP_TCP || LWIP_RAW)
      } else {
        msg->err = ERR_VAL;
#endif /* (LWIP_TCP || LWIP_RAW) */
      }
    } else {
      msg->err = ERR_CONN;
    }
  }
  TCPIP_APIMSG_ACK(msg);
}
#endif /* LWIP_IGMP */

#if LWIP_DNS
/**
 * Callback function that is called when DNS name is resolved
 * (or on timeout). A waiting application thread is waked up by
 * signaling the semaphore.
 */
static void
do_dns_found(const char *name, ip_addr_t *ipaddr, void *arg)
{
  struct dns_api_msg *msg = (struct dns_api_msg*)arg;

  LWIP_ASSERT("DNS response for wrong host name", strcmp(msg->name, name) == 0);
  LWIP_UNUSED_ARG(name);

  if (ipaddr == NULL) {
    /* timeout or memory error */
    *msg->err = ERR_VAL;
  } else {
    /* address was resolved */
    *msg->err = ERR_OK;
    *msg->addr = *ipaddr;
  }
  /* wake up the application task waiting in netconn_gethostbyname */
  sys_sem_signal(msg->sem);
}

/**
 * Execute a DNS query
 * Called from netconn_gethostbyname
 *
 * @param arg the dns_api_msg pointing to the query
 */
void
do_gethostbyname(void *arg)
{
  struct dns_api_msg *msg = (struct dns_api_msg*)arg;

  *msg->err = dns_gethostbyname(msg->name, msg->addr, do_dns_found, msg);
  if (*msg->err != ERR_INPROGRESS) {
    /* on error or immediate success, wake up the application
     * task waiting in netconn_gethostbyname */
    sys_sem_signal(msg->sem);
  }
}
#endif /* LWIP_DNS */

#endif /* LWIP_NETCONN */