/* Copyright 2001,2002 Roger Dingledine, Matej Pfajfar. */
/* See LICENSE for licensing information */
/* $Id$ */

#include "or.h"

extern or_options_t options; /* command-line and config-file options */

void command_time_process_cell(cell_t *cell, connection_t *conn,
                               int *num, int *time,
                               void (*func)(cell_t *, connection_t *)) {
  struct timeval start, end;
  int time_passed; 

  *num += 1;

  if(gettimeofday(&start,NULL) < 0) {
    log(LOG_ERR,"command_time_process_cell(): gettimeofday failed.");
    return;
  }

  (*func)(cell, conn);

  if(gettimeofday(&end,NULL) < 0) {
    log(LOG_ERR,"command_time_process_cell(): gettimeofday failed.");
    return;
  }

  if(end.tv_usec < start.tv_usec) {
    end.tv_sec--;
    end.tv_usec += 1000000;
  }
  time_passed = ((end.tv_sec - start.tv_sec)*1000000) + (end.tv_usec - start.tv_usec);
  if(time_passed > 5000) { /* more than 5ms */
    log(LOG_INFO,"command_time_process_cell(): That call just took %d ms.",time_passed/1000);
  }
  *time += time_passed;
}

void command_process_cell(cell_t *cell, connection_t *conn) {
  static int num_create=0, num_data=0, num_destroy=0, num_sendme=0, num_connected=0;
  static int create_time=0, data_time=0, destroy_time=0, sendme_time=0, connected_time=0;
  static long current_second = 0; /* from previous calls to gettimeofday */
  struct timeval now;

  if(gettimeofday(&now,NULL) < 0) {
    log(LOG_ERR,"command_process_cell(): gettimeofday failed.");
    return;
  }

  if(now.tv_sec > current_second) { /* the second has rolled over */
    /* print stats */
    log(LOG_INFO,"At end of second:"); 
    log(LOG_INFO,"Create:    %d (%d ms)", num_create, create_time/1000);
    log(LOG_INFO,"Data:      %d (%d ms)", num_data, data_time/1000);
    log(LOG_INFO,"Destroy:   %d (%d ms)", num_destroy, destroy_time/1000);
    log(LOG_INFO,"Sendme:    %d (%d ms)", num_sendme, sendme_time/1000);
    log(LOG_INFO,"Connected: %d (%d ms)", num_connected, connected_time/1000);

    /* zero out stats */
    num_create = num_data = num_destroy = num_sendme = num_connected = 0;
    create_time = data_time = destroy_time = sendme_time = connected_time = 0;

    /* remember which second it is, for next time */
    current_second = now.tv_sec; 
  }

  switch(cell->command) {
    case CELL_PADDING:
      /* do nothing */
      break;
    case CELL_CREATE:
      command_time_process_cell(cell, conn, &num_create, &create_time,
                                command_process_create_cell);
      break;
    case CELL_DATA:
      command_time_process_cell(cell, conn, &num_data, &data_time,
                                command_process_data_cell);
      break;
    case CELL_DESTROY:
      command_time_process_cell(cell, conn, &num_destroy, &destroy_time,
                                command_process_destroy_cell);
      break;
    case CELL_SENDME:
      command_time_process_cell(cell, conn, &num_sendme, &sendme_time,
                                command_process_sendme_cell);
      break;
    case CELL_CONNECTED:
      command_time_process_cell(cell, conn, &num_connected, &connected_time,
                                command_process_connected_cell);
      break;
    default:
      log(LOG_DEBUG,"Cell of unknown type (%d) received. Dropping.", cell->command);
      break;
  }
}

void command_process_create_cell(cell_t *cell, connection_t *conn) {
  circuit_t *circ;

  circ = circuit_get_by_aci_conn(cell->aci, conn);

  if(circ && circ->state != CIRCUIT_STATE_ONION_WAIT) {
    log(LOG_DEBUG,"command_process_create_cell(): received CREATE cell, not in onion_wait. Dropping.");
    return;
  }

  if(!circ) { /* if it's not there, create it */
    circ = circuit_new(cell->aci, conn);
    circ->state = CIRCUIT_STATE_ONION_WAIT;
    circ->onionlen = ntohl(*(int*)cell->payload);
    log(LOG_DEBUG,"command_process_create_cell():  Onion length is %u.",circ->onionlen);
    if(circ->onionlen > 50000 || circ->onionlen < 1) { /* too big or too small */
      log(LOG_DEBUG,"That's ludicrous. Closing.");
      circuit_close(circ);
      return;
    }
    circ->onion = (unsigned char *)malloc(circ->onionlen);
    if(!circ->onion) { 
      log(LOG_DEBUG,"command_process_create_cell(): Out of memory. Closing.");
      circuit_close(circ);
      return;
    }
    if(circ->onionlen < cell->length-4) { /* protect from buffer overflow */
      log(LOG_DEBUG,"command_process_create_cell(): Onion too small. Closing.");
      circuit_close(circ);
      return;
    }
    memcpy((void *)circ->onion,(void *)(cell->payload+4),cell->length-4);
    circ->recvlen = cell->length-4;
    log(LOG_DEBUG,"command_process_create_cell(): Primary create cell handled, have received %d of %d onion bytes.",
        circ->recvlen,circ->onionlen);

  } else { /* pull over as much of the onion as we can */
    if(cell->length + circ->recvlen > circ->onionlen) { /* protect from buffer overflow */
      log(LOG_DEBUG,"command_process_create_cell(): payload too big for onion. Closing.");
      circuit_close(circ);
      return;
    }
    memcpy((void *)(circ->onion+circ->recvlen),(void *)cell->payload,cell->length);
    circ->recvlen += cell->length;
    log(LOG_DEBUG,"command_process_create_cell(): Secondary create cell handled, have received %d of %d onion bytes.",
        circ->recvlen,circ->onionlen);
  }

  if(circ->recvlen != circ->onionlen) {
    log(LOG_DEBUG,"command_process_create_cell(): Onion not all here yet. Ok.");
    return;
  }

  /* add it to the pending onions queue, and then return */
  circ->state = CIRCUIT_STATE_ONION_PENDING;

  if(onion_pending_add(circ) < 0) {
    log(LOG_DEBUG,"command_process_create_cell(): Failed to queue onion. Closing.");
    circuit_close(circ);
  }
  return;
}

#if 0
  conn->onions_handled_this_second++;
  log(LOG_DEBUG,"command_process_create_cell(): Processing onion %d for this second.",conn->onions_handled_this_second);
  if(conn->onions_handled_this_second > options.OnionsPerSecond) {
    log(LOG_INFO,"command_process_create_cell(): Received too many onions (now %d) this second. Closing.", conn->onions_handled_this_second);
    circuit_close(circ);
    return;
  }
#endif

void command_process_sendme_cell(cell_t *cell, connection_t *conn) {
  circuit_t *circ;

  circ = circuit_get_by_aci_conn(cell->aci, conn);

  if(!circ) {
    log(LOG_DEBUG,"command_process_sendme_cell(): unknown circuit %d. Dropping.", cell->aci);
    return;
  }

  if(circ->state == CIRCUIT_STATE_ONION_WAIT) {
    log(LOG_DEBUG,"command_process_sendme_cell(): circuit in onion_wait. Dropping.");
    return;
  }
  if(circ->state == CIRCUIT_STATE_OR_WAIT) {
    log(LOG_DEBUG,"command_process_sendme_cell(): circuit in or_wait. Dropping.");
    return;
  }

  /* at this point both circ->n_conn and circ->p_conn are guaranteed to be set */

  if(cell->length != RECEIVE_WINDOW_INCREMENT) {
    log(LOG_WARNING,"command_process_sendme_cell(): non-standard sendme value %d.",cell->length);
  }
//  assert(cell->length == RECEIVE_WINDOW_INCREMENT);

  if(cell->aci == circ->p_aci) { /* it's an outgoing cell */
    circ->n_receive_window += cell->length;
    log(LOG_DEBUG,"connection_process_sendme_cell(): n_receive_window for aci %d is %d.",circ->n_aci,circ->n_receive_window);
    if(circ->n_conn->type == CONN_TYPE_EXIT) {
      connection_start_reading(circ->n_conn);
      connection_package_raw_inbuf(circ->n_conn); /* handle whatever might still be on the inbuf */
    } else {
      cell->aci = circ->n_aci; /* switch it */
      if(connection_write_cell_to_buf(cell, circ->n_conn) < 0) { /* (clobbers cell) */
        circuit_close(circ);
        return;
      }
    }
  } else { /* it's an ingoing cell */
    circ->p_receive_window += cell->length;
    log(LOG_DEBUG,"connection_process_sendme_cell(): p_receive_window for aci %d is %d.",circ->p_aci,circ->p_receive_window);
    if(circ->p_conn->type == CONN_TYPE_AP) {
      connection_start_reading(circ->p_conn);
      connection_package_raw_inbuf(circ->p_conn); /* handle whatever might still be on the inbuf */
    } else {
      cell->aci = circ->p_aci; /* switch it */
      if(connection_write_cell_to_buf(cell, circ->p_conn) < 0) { /* (clobbers cell) */
        circuit_close(circ);
        return;
      }
    }
  } 
}

void command_process_data_cell(cell_t *cell, connection_t *conn) {
  circuit_t *circ;

  circ = circuit_get_by_aci_conn(cell->aci, conn);

  if(!circ) {
    log(LOG_DEBUG,"command_process_data_cell(): unknown circuit %d. Dropping.", cell->aci);
    return;
  }

  if(circ->state == CIRCUIT_STATE_ONION_WAIT) {
    log(LOG_DEBUG,"command_process_data_cell(): circuit in onion_wait. Dropping data cell.");
    return;
  }
  if(circ->state == CIRCUIT_STATE_OR_WAIT) {
    log(LOG_DEBUG,"command_process_data_cell(): circuit in or_wait. Dropping data cell.");
    return;
  }
  if(circ->state == CIRCUIT_STATE_ONION_PENDING) {
    log(LOG_DEBUG,"command_process_data_cell(): circuit in create_wait. Queueing data cell.");
    onion_pending_data_add(circ, cell);
    return;
  }
  /* at this point both circ->n_conn and circ->p_conn are guaranteed to be set */

  if(cell->aci == circ->p_aci) { /* it's an outgoing cell */
    cell->aci = circ->n_aci; /* switch it */
    if(--circ->p_receive_window < 0) { /* is it less than 0 after decrement? */
      log(LOG_DEBUG,"connection_process_data_cell(): Too many data cells on aci %d. Closing.", circ->p_aci);
      circuit_close(circ);
      return;
    }
    log(LOG_DEBUG,"connection_process_data_cell(): p_receive_window for aci %d is %d.",circ->p_aci,circ->p_receive_window);
    if(circuit_deliver_data_cell(cell, circ, circ->n_conn, 'd') < 0) {
      log(LOG_DEBUG,"command_process_data_cell(): circuit_deliver_data_cell (forward) failed. Closing.");
      circuit_close(circ);
      return;
    }
  } else { /* it's an ingoing cell */
    cell->aci = circ->p_aci; /* switch it */
    if(--circ->n_receive_window < 0) { /* is it less than 0 after decrement? */
      log(LOG_DEBUG,"connection_process_data_cell(): Too many data cells on aci %d. Closing.", circ->n_aci);
      circuit_close(circ);
      return;
    }
    log(LOG_DEBUG,"connection_process_data_cell(): n_receive_window for aci %d is %d.",circ->n_aci,circ->n_receive_window);
    if(circ->p_conn->type == CONN_TYPE_AP) { /* we want to decrypt, not encrypt */
      if(circuit_deliver_data_cell(cell, circ, circ->p_conn, 'd') < 0) {
        log(LOG_DEBUG,"command_process_data_cell(): circuit_deliver_data_cell (backward to AP) failed. Closing.");
        circuit_close(circ);
        return;
      }
    } else {
      if(circuit_deliver_data_cell(cell, circ, circ->p_conn, 'e') < 0) {
        log(LOG_DEBUG,"command_process_data_cell(): circuit_deliver_data_cell (backward) failed. Closing.");
        circuit_close(circ);
        return;
      }
    }
  }
}

void command_process_destroy_cell(cell_t *cell, connection_t *conn) {
  circuit_t *circ;

  circ = circuit_get_by_aci_conn(cell->aci, conn);

  if(!circ) {
    log(LOG_DEBUG,"command_process_destroy_cell(): unknown circuit %d. Dropping.", cell->aci);
    return;
  }

  log(LOG_DEBUG,"command_process_destroy_cell(): Received for aci %d.",cell->aci);
  if(circ->state == CIRCUIT_STATE_ONION_PENDING) {
    onion_pending_remove(circ);
  }
  circuit_remove(circ);
  if(cell->aci == circ->p_aci) /* the destroy came from behind */
    connection_send_destroy(circ->n_aci, circ->n_conn);
  if(cell->aci == circ->n_aci) /* the destroy came from ahead */
    connection_send_destroy(circ->p_aci, circ->p_conn);
  circuit_free(circ);
}

void command_process_connected_cell(cell_t *cell, connection_t *conn) {
  circuit_t *circ;

  circ = circuit_get_by_aci_conn(cell->aci, conn);

  if(!circ) {
    log(LOG_DEBUG,"command_process_connected_cell(): unknown circuit %d. Dropping.", cell->aci);
    return;
  }

  if(circ->n_conn != conn) {
    log(LOG_WARNING,"command_process_connected_cell(): cell didn't come from n_conn! (aci %d)",cell->aci);
    return;
  }

  log(LOG_DEBUG,"command_process_connected_cell(): Received for aci %d.",cell->aci);
  connection_send_connected(circ->p_aci, circ->p_conn);
}