tor/src/or/directory.c

/* Copyright 2001,2002,2003 Roger Dingledine. */
/* See LICENSE for licensing information */
/* $Id$ */

#include "or.h"

static int directory_send_command(connection_t *conn, int command);
static int directory_handle_command(connection_t *conn);

/********* START VARIABLES **********/

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

#define MAX_HEADERS_SIZE 2048
#define MAX_BODY_SIZE 500000

/********* END VARIABLES ************/

void directory_initiate_command(routerinfo_t *router, int command) {
  connection_t *conn;

  if (command == DIR_CONN_STATE_CONNECTING_FETCH)
    log_fn(LOG_DEBUG,"initiating directory fetch");
  else
    log_fn(LOG_DEBUG,"initiating directory upload");

  if (!router) { /* i guess they didn't have one in mind for me to use */
    log_fn(LOG_WARN,"No running dirservers known. Not trying.");
    return;
  }

  conn = connection_new(CONN_TYPE_DIR);

  /* set up conn so it's got all the data we need to remember */
  conn->addr = router->addr;
  conn->port = router->dir_port;
  conn->address = tor_strdup(router->address);
  conn->nickname = tor_strdup(router->nickname);
  assert(router->identity_pkey);
  conn->identity_pkey = crypto_pk_dup_key(router->identity_pkey);

  if(connection_add(conn) < 0) { /* no space, forget it */
    connection_free(conn);
    return;
  }

  switch(connection_connect(conn, router->address, router->addr, router->dir_port)) {
    case -1:
      router_mark_as_down(conn->nickname); /* don't try him again */
      connection_remove(conn);
      connection_free(conn);
      return;
    case 0:
      connection_set_poll_socket(conn);
      connection_watch_events(conn, POLLIN | POLLOUT | POLLERR);
      /* writable indicates finish, readable indicates broken link,
         error indicates broken link in windowsland. */
      conn->state = command;
      return;
    /* case 1: fall through */
  }

  connection_set_poll_socket(conn);
  if(directory_send_command(conn, command) < 0) {
    connection_remove(conn);
    connection_free(conn);
  }
}

static int directory_send_command(connection_t *conn, int command) {
  char fetchstring[] = "GET / HTTP/1.0\r\n\r\n";
  const char *s;
  char tmp[8192];

  assert(conn && conn->type == CONN_TYPE_DIR);

  switch(command) {
    case DIR_CONN_STATE_CONNECTING_FETCH:
      connection_write_to_buf(fetchstring, strlen(fetchstring), conn);
      conn->state = DIR_CONN_STATE_CLIENT_SENDING_FETCH;
      break;
    case DIR_CONN_STATE_CONNECTING_UPLOAD:
      s = router_get_my_descriptor();
      if(!s) {
        log_fn(LOG_WARN,"Failed to get my descriptor.");
        return -1;
      }
      snprintf(tmp, sizeof(tmp), "POST / HTTP/1.0\r\nContent-Length: %d\r\n\r\n%s",
               (int)strlen(s), s);
      connection_write_to_buf(tmp, strlen(tmp), conn);
      conn->state = DIR_CONN_STATE_CLIENT_SENDING_UPLOAD;
      break;
  }
  return 0;
}

/* Parse "HTTP/1.%d %d%s\r\n".
 * If it's well-formed, assign *code, point *message to the first
 * non-space character after code if there is one and message is non-NULL
 * (else leave it alone), and return 0.
 * Otherwise, return -1.
 */
int parse_http_response(char *headers, int *code, char **message) {
  int n1, n2;
  assert(headers && code);

  while(isspace(*headers)) headers++; /* tolerate leading whitespace */

  if(sscanf(headers, "HTTP/1.%d %d", &n1, &n2) < 2 ||
     (n1 != 0 && n1 != 1) ||
     (n2 < 100 || n2 >= 600)) {
    log_fn(LOG_WARN,"Failed to parse header '%s'",headers);
    return -1;
  }
  *code = n2;
  if(message) {
    /* XXX should set *message correctly */
  }
  return 0;
}

int connection_dir_process_inbuf(connection_t *conn) {
  char *directory;
  char *headers;
  int status_code;

  assert(conn && conn->type == CONN_TYPE_DIR);

  if(conn->inbuf_reached_eof) {
    if(conn->state != DIR_CONN_STATE_CLIENT_READING_FETCH &&
       conn->state != DIR_CONN_STATE_CLIENT_READING_UPLOAD) {
      log_fn(LOG_INFO,"conn reached eof, not reading. Closing.");
      connection_close_immediate(conn); /* it was an error; give up on flushing */
      connection_mark_for_close(conn,0);
      return -1;
    }

    switch(fetch_from_buf_http(conn->inbuf,
                               &headers, MAX_HEADERS_SIZE,
                               &directory, MAX_DIR_SIZE)) {
      case -1: /* overflow */
        log_fn(LOG_WARN,"'fetch' response too large. Failing.");
        connection_mark_for_close(conn,0);
        return -1;
      case 0:
        log_fn(LOG_INFO,"'fetch' response not all here, but we're at eof. Closing.");
        connection_mark_for_close(conn,0);
        return -1;
      /* case 1, fall through */
    }

    if(parse_http_response(headers, &status_code, NULL) < 0) {
      log_fn(LOG_WARN,"Unparseable headers. Closing.");
      free(directory); free(headers);
      connection_mark_for_close(conn,0);
      return -1;
    }

    if(conn->state == DIR_CONN_STATE_CLIENT_READING_FETCH) {
      /* fetch/process the directory to learn about new routers. */
      int directorylen;
      directorylen = strlen(directory);
      log_fn(LOG_INFO,"Received directory (size %d):\n%s", directorylen, directory);
      if(status_code == 503 || directorylen == 0) {
        log_fn(LOG_INFO,"Empty directory. Ignoring.");
        free(directory); free(headers);
        connection_mark_for_close(conn,0);
        return 0;
      }
      if(status_code != 200) {
        log_fn(LOG_WARN,"Received http status code %d from dirserver. Failing.",
               status_code);
        free(directory); free(headers);
        connection_mark_for_close(conn,0);
        return -1;
      }
      if(router_set_routerlist_from_directory(directory, conn->identity_pkey) < 0){
        log_fn(LOG_INFO,"...but parsing failed. Ignoring.");
      } else {
        log_fn(LOG_INFO,"updated routers.");
      }
      has_fetched_directory=1;
      if(options.ORPort) { /* connect to them all */
        router_retry_connections();
      }
      free(directory); free(headers);
      connection_mark_for_close(conn,0);
      return 0;
    }

    if(conn->state == DIR_CONN_STATE_CLIENT_READING_UPLOAD) {
      switch(status_code) {
        case 200:
          log_fn(LOG_INFO,"eof (status 200) while reading upload response: finished.");
          break;
        case 400:
          log_fn(LOG_WARN,"http status 400 (bad request) from dirserver. Is your clock skewed?");
          break;
        case 403:
          log_fn(LOG_WARN,"http status 403 (unapproved server) from dirserver. Have you mailed arma your identity fingerprint? Are you using the right key?");

          break;
      }
      free(directory); free(headers);
      connection_mark_for_close(conn,0);
      return 0;
    }
  }

  if(conn->state == DIR_CONN_STATE_SERVER_COMMAND_WAIT)
    return directory_handle_command(conn);

  /* XXX for READ states, might want to make sure inbuf isn't too big */

  log_fn(LOG_DEBUG,"Got data, not eof. Leaving on inbuf.");
  return 0;
}

static char answer200[] = "HTTP/1.0 200 OK\r\n\r\n";
static char answer400[] = "HTTP/1.0 400 Bad request\r\n\r\n";
static char answer403[] = "HTTP/1.0 403 Unapproved server\r\n\r\n";
static char answer503[] = "HTTP/1.0 503 Directory unavailable\r\n\r\n";

static int directory_handle_command_get(connection_t *conn,
                                        char *headers, char *body) {
  size_t dlen;
  const char *cp;

  /* XXX should check url and http version */
  log_fn(LOG_DEBUG,"Received GET command.");

  dlen = dirserv_get_directory(&cp);

  if(dlen == 0) {
    log_fn(LOG_WARN,"My directory is empty. Closing.");
    connection_write_to_buf(answer503, strlen(answer503), conn);
    conn->state = DIR_CONN_STATE_SERVER_WRITING;
    return 0;
  }

  log_fn(LOG_DEBUG,"Dumping directory to client.");
  connection_write_to_buf(answer200, strlen(answer200), conn);
  connection_write_to_buf(cp, dlen, conn);
  conn->state = DIR_CONN_STATE_SERVER_WRITING;
  return 0;
}

static int directory_handle_command_post(connection_t *conn,
                                         char *headers, char *body) {
  const char *cp;

  /* XXX should check url and http version */
  log_fn(LOG_DEBUG,"Received POST command.");
  cp = body;
  switch(dirserv_add_descriptor(&cp)) {
    case -1:
      /* malformed descriptor, or clock is skewed, or something wrong */
      connection_write_to_buf(answer400, strlen(answer400), conn);
      break;
    case 0:
      /* descriptor was well-formed but server has not been approved */
      connection_write_to_buf(answer403, strlen(answer403), conn);
      break;
    case 1:
      dirserv_get_directory(&cp); /* rebuild and write to disk */
      connection_write_to_buf(answer200, strlen(answer200), conn);
      break;
  }
  conn->state = DIR_CONN_STATE_SERVER_WRITING;
  return 0;
}

static int directory_handle_command(connection_t *conn) {
  char *headers=NULL, *body=NULL;
  int r;

  assert(conn && conn->type == CONN_TYPE_DIR);

  switch(fetch_from_buf_http(conn->inbuf,
                             &headers, MAX_HEADERS_SIZE, &body, MAX_BODY_SIZE)) {
    case -1: /* overflow */
      log_fn(LOG_WARN,"input too large. Failing.");
      return -1;
    case 0:
      log_fn(LOG_DEBUG,"command not all here yet.");
      return 0;
    /* case 1, fall through */
  }

  log_fn(LOG_DEBUG,"headers '%s', body '%s'.", headers, body);

  if(!strncasecmp(headers,"GET",3))
    r = directory_handle_command_get(conn, headers, body);
  else if (!strncasecmp(headers,"POST",4))
    r = directory_handle_command_post(conn, headers, body);
  else {
    log_fn(LOG_WARN,"Got headers '%s' with unknown command. Closing.", headers);
    r = -1;
  }

  tor_free(headers); tor_free(body);
  return r;
}

int connection_dir_finished_flushing(connection_t *conn) {
  int e, len=sizeof(e);

  assert(conn && conn->type == CONN_TYPE_DIR);

  switch(conn->state) {
    case DIR_CONN_STATE_CONNECTING_FETCH:
    case DIR_CONN_STATE_CONNECTING_UPLOAD:
      if (getsockopt(conn->s, SOL_SOCKET, SO_ERROR, (void*)&e, &len) < 0)  { /* not yet */
        if(!ERRNO_CONN_EINPROGRESS(errno)) {
          log_fn(LOG_DEBUG,"in-progress connect failed. Removing.");
          router_mark_as_down(conn->nickname); /* don't try him again */
          connection_mark_for_close(conn,0);
          return -1;
        } else {
          return 0; /* no change, see if next time is better */
        }
      }
      /* the connect has finished. */

      log_fn(LOG_INFO,"Dir connection to router %s:%u established.",
          conn->address,conn->port);

      return directory_send_command(conn, conn->state);
    case DIR_CONN_STATE_CLIENT_SENDING_FETCH:
      log_fn(LOG_DEBUG,"client finished sending fetch command.");
      conn->state = DIR_CONN_STATE_CLIENT_READING_FETCH;
      connection_watch_events(conn, POLLIN);
      return 0;
    case DIR_CONN_STATE_CLIENT_SENDING_UPLOAD:
      log_fn(LOG_DEBUG,"client finished sending upload command.");
      conn->state = DIR_CONN_STATE_CLIENT_READING_UPLOAD;
      connection_watch_events(conn, POLLIN);
      return 0;
    case DIR_CONN_STATE_SERVER_WRITING:
      log_fn(LOG_INFO,"Finished writing server response. Closing.");
      connection_mark_for_close(conn,0);
      return 0;
    default:
      log_fn(LOG_WARN,"BUG: called in unexpected state %d.", conn->state);
      return -1;
  }
  return 0;
}

/*
  Local Variables:
  mode:c
  indent-tabs-mode:nil
  c-basic-offset:2
  End:
*/