event.c

P2P NAP的C实现 P2P在网络应用中越来越流行

  if (r <= 0)
  {
    t = time(0);
    wp(win, "* Transfer interrupted while sending \"%s\" to %s (%lu of %lu bytes in %lu seconds): %s\n", task->fn, task->nick, (long)(task->pos-task->bsz), (long)(task->size-task->bsz), (long)(t-task->p_time), r ? strerror(errno) : "connection lost?");
    drw(win);
    
    if (info.logfile) {
      f = fopen(info.logfile, "a");
      if (f) {
	start = strdup(ctime(&task->p_time));
	start[strlen(start)-1] = 0;
	end = strdup(ctime(&t));
	end[strlen(end)-1] = 0;
	fprintf(f, "SI %s %s \"%s\" %s\n", start, task->nick, task->lfn, end);
	fclose(f);
	free(start);
	free(end);
      }
    }
    fclose(task->f);
    task->d_time = t;
    task->state = INCOMPLETE;

    delsock(m->fd);
    return(1);
  }
  
  task->pos += n;

  /* update byte counts for bandwidth limiting */
  bandwidth_register(&m->bw, n);
  bandwidth_register(&bwup, n);
  
  return(1);
}

/* ------------------------------------------------------------------------ */
/* we have connected to a remote client in order to issue a GETLIST command.
 * The connection was initiated in scmds.c:sbrowse2acc(). */
int initgetlist(WINDOW *win, sock_t *m)
{
  int s = m->fd, r;
  char c;
 
  /* remote client should send a '1' (ASCII character 49) */
  r = recv(s, &c, 1, 0);
  if (r <= 0) {
    wp(win, ""RED"* Error browsing %s: %s"WHITE"\n", directbrowse.nick, \
        r ? strerror(errno) : "connection refused");
    drw(win);
    directbrowse.state = FAILED;
    srch = 0;
    delsock(m->fd);
    return(1);
  } 
  
  r = ssock(s, "GETLIST");
  if (r <= 0) {
    wp(win, ""RED"* Error browsing %s: %s"WHITE"\n", directbrowse.nick, \
        r ? strerror(errno) : "0 bytes written to socket");
    drw(win);
    directbrowse.state = FAILED;
    srch = 0;
    delsock(m->fd);
    return(1);
  }
 
  /* still in CONNECTING state */
  m->func = glistnick; /* wait for remote client to send its nick */
  return(1);
}

/* ------------------------------------------------------------------------ */
/* after we issue a GETLIST command, the remote client sends it nick before
 * sending its shared file list. */
int glistnick(WINDOW *win, sock_t *m)
{
  char *nick = NULL;
  FILE *f;
  
  /* we duplicate the file descriptor so the new descriptor can be closed 
   * independently of the original one when fclose() is called. */
  directbrowse.f = f = fdopen(dup(m->fd), "r");
  /* remote client sends its nick as "<nick>\n" */
  nick = nap_getline(f); /* nap_getline uses fgets() to read a line */
  if (!nick) {
    wp(win, ""RED"* Error browsing %s: remote client did not send its nick"\
        WHITE"\n", directbrowse.nick);
    drw(win);
    directbrowse.state = FAILED;
    srch = 0;
    fclose(f);
    /* closing the stream will also close the associated file descriptor,
     * but remember that this descriptor is a duplicate of m->fd, so 
     * we can safely close m->fd. */
    delsock(m->fd);
    return(1);
  }
  /* is this who we were expecting? */
  if (strcasecmp(directbrowse.nick, nick) != 0) {
    wp(win, ""RED"* Error browsing %s: remote client reports nick as %s"\
        WHITE"\n", directbrowse.nick, quote(nick));
    drw(win);
    free(nick);
    directbrowse.state = FAILED;
    srch = 0;
    fclose(f);
    delsock(m->fd);
    return(1);
  }

  free(nick);
  
  wp(win, "* Receiving shared file list from %s...\n", directbrowse.nick);
  drw(win);
  directbrowse.state = IN_PROGRESS;
  m->func = glist;
  return(1);
}

/* ------------------------------------------------------------------------ */
/* receive a shared file list from a remote client, one line per call */
int glist(WINDOW *win, sock_t *m)
{
  char *buf;
  char **tok;
  char *tmptok[7];
  int cnt, i;
  FILE *f = directbrowse.f;

  /* remote client sends a list of files consisting of lines like
   * "<filename>" <md5> <size> <bitrate> <frequency> <time>\n 
   * Last line is a \n by itself. */

  buf = nap_getline(f); /* nap_getline will strip the trailing newline */
  /* last line (single newline) will be returned as an empty string */
  if (buf && *buf != '\0') {
    if (nvar("debug") == 2) {
      /* trailing newline was already stripped, so it won't show up here */
      wp(win, ""DARK GREEN"<-- [from %d=%s] <%s>"WHITE"\n", m->fd, \
          m->socknm, quote(buf));
      drw(win);
    }
    tok = form_tokso(buf, &cnt);
    /* expect exactly 6 tokens */
    if (cnt == 6) {
        /* srbrowse expects 7 tokens */
        tmptok[0] = directbrowse.nick;
        for (i = 0; i < 6; i++) {
          tmptok[i+1] = tok[i];
        }
        /* re-use the function that processes browse responses from the
         * server. The first arg is normally the file descriptor for the
         * socket connected to the server, but it isn't used by srbrowse
	 * anyway. */
        srbrowse(m->fd, buf, tmptok, 7, win);
    }
    for (i = 0; i < cnt; i++)
      free(tok[i]);
    free(tok);
    free(buf);
  } else {
    free(buf);
    fclose(f);
    directbrowse.state = COMPLETE;
    showresults(win, 0); /* also resets srch to 0 */
    delsock(m->fd);
    return(1);
  }
  
  return(1);
} 

/* ------------------------------------------------------------------------ */
/* a remote client connected to us and issued a SENDLIST command so that it 
 * can send us its shared file list. */
int dosendlist(WINDOW *win, sock_t *m)
{
  char *nick = NULL;
  FILE *f;
  
  /* were we expecting a browse list? */
  if (directbrowse.state != REQUESTED) {
    delsock(m->fd);
    return(1);
  }
  
  /* "<nick>\n" immediately follows the SENDLIST command. */
  directbrowse.f = f = fdopen(dup(m->fd), "r");
  nick = nap_getline(f); /* nap_getline will strip leading spaces if there are any */

  /* is this who we were expecting? */
  if (!nick || strcasecmp(directbrowse.nick, nick) != 0) {
    if (nvar("debug") == 2) {
      wp(win, ""DARK GREEN"<-- [from %d=%s] Got unexpected SENDLIST from %s"\
          " (%s)"WHITE"\n", m->fd, m->socknm, nick ? quote(nick):"?", \
          getpeerip(m->fd));
      drw(win);
    }
    free(nick);
    /* directbrowse.state remains REQUESTED */
    fclose(f);
    delsock(m->fd);
    return(1);
  }
  
  free(nick);

  /* rename the connection */
  free(m->socknm);
  m->socknm = strdup("dirbrowse");
  
  if (nvar("debug") == 2) {
    wp(win, ""DARK GREEN"<-- [from %d=%s] Got SENDLIST from %s"WHITE"\n", \
        m->fd, m->socknm, directbrowse.nick);
  }
  wp(win, "* Receiving shared file list from %s...\n", directbrowse.nick);
  drw(win);

  directbrowse.sk = m;
  directbrowse.state = IN_PROGRESS;
  m->func = glist;
  return(1);
}

/* ------------------------------------------------------------------------ */
/* a remote client connected to us and issued a GETLIST command
 * (this is an outgoing direct browse connection) */
int dogetlist(WINDOW *win, sock_t *m)
{
  int s = m->fd, r;
  FILE *g;
  char *libraryfile;

  /* XXX if we limit the number of outgoing browse connections,
   * check that we are within the limit here. */

  if (nvar("debug") == 2) {
    wp(win, ""DARK GREEN"<-- [from %d=%s] Got GETLIST"WHITE"\n", m->fd, m->socknm);
    drw(win);
  }

  /* rename the connection to "b #", where # is an integer */
  free(m->socknm);
  m->socknm = strdup(gnum(2));

  /* send "<mynick>\n" */
  r = ssock(s, "%s\n", info.user);
  if (r <= 0) {                         
    if (nvar("debug") == 2) {
      wp(win, ""RED"* Error sending list: %s"WHITE"\n", \
          r ? strerror(errno) : "0 bytes written to socket");
      drw(win);
    }
    delsock(m->fd);
    return(1);
  }       
  
  if (info.shared_filename) {
    libraryfile = strdup(info.shared_filename);
  } else {
    libraryfile = home_file(LIBRARYFILE);
  }

  g = fopen(libraryfile, "r");
  if (!g) {
    if (nvar("debug") == 2) {
      wp(win, ""RED"* Error sending list: cannot open %s (%s)"WHITE"\n", \
          libraryfile, strerror(errno));
      drw(win);
    }
    delsock(m->fd);
    free(libraryfile);
    return(1);
  }
  free(libraryfile);
  
  m->btask = (outbrowse_t *) malloc(sizeof(outbrowse_t));
  m->btask->g = g;
  
  m->func = slist;
  m->t = S_W;
  return(1);
}

/* ------------------------------------------------------------------------ */
/* we have connected to a remote client to issue a SENDLIST command and 
 * send our shared file list. (this is an outgoing direct browse connection)
 * The connection was initiated in scmds.c:sbrowse2req() and is named "b #",
 * where # is an integer. */
int initsendlist(WINDOW *win, sock_t *m)
{
  int s = m->fd, r;
  char c;
  FILE *g;
  char *libraryfile;
 
  /* remote client should send a '1' */
  r = recv(s, &c, 1, 0);
  if (r <= 0) {
    if (nvar("debug") == 2) {
      wp(win, ""RED"* Error sending list: %s"WHITE"\n", \
        r ? strerror(errno) : "connection refused");
      drw(win);
    }
    delsock(m->fd);
    return(1);
  } 
  
  /* send "SENDLIST" then "<mynick>\n" (this is what the Napster v2.0 BETA 8
   * and BETA 9 clients seem to do; there is no space in between.) */
  r = ssock(s, "SENDLIST");
  r = ssock(s, "%s\n", info.user);
  if (r <= 0) {
    if (nvar("debug") == 2) {
      wp(win, ""RED"* Error sending list: %s"WHITE"\n", \
          r ? strerror(errno) : "0 bytes written to socket");
      drw(win);
    }
    delsock(m->fd);
    return(1);
  }
  
  if (info.shared_filename) {
    libraryfile = strdup(info.shared_filename);
  } else {
    libraryfile = home_file(LIBRARYFILE);
  }

  g = fopen(libraryfile, "r");
  if (!g) {
    if (nvar("debug") == 2) {
      wp(win, ""RED"* Error sending list: cannot open %s (%s)"WHITE"\n", \
          libraryfile, strerror(errno));
      drw(win);
    }
    delsock(m->fd);
    free(libraryfile);
    return(1);
  }
  free(libraryfile);

  m->btask = (outbrowse_t *) malloc(sizeof(outbrowse_t));
  m->btask->g = g;
 
  m->func = slist;
  m->t = S_W;
  return(1);
}

/* ------------------------------------------------------------------------ */
/* send shared file list, one line per call */
int slist(WINDOW *win, sock_t *m)
{
  int s = m->fd, r;
  FILE *g;
  char *buf, *p;
  
  if (!m->btask) {
    delsock(m->fd);
    return(1); /* fatal error */
  }
  g = m->btask->g;
  buf = nap_getline(g); /* nap_getline strips the trailing newline */
  if (!buf) { /* EOF */
    r = ssock(s, "\n"); /* terminate the list, ignore errors */
    fclose(g);
    free(m->btask);
    delsock(m->fd);
    return(1);
  }
  if (*buf != '\"') { 
    free(buf);
    return(1); /* skip headers and junk */
  }
  for (p=buf; *p; p++) {
    if (*p == '/')
      *p = '\\';
  }
  /* send the line; don't forget to terminate with a newline */
  r = ssock(s, "%s\n", buf);
  if (r <= 0) {
    if (nvar("debug") == 2) {
      wp(win, ""RED"* Error sending list: %s"WHITE"\n",  \
          r ? strerror(errno) : "0 bytes written to socket");
      drw(win);
    }
    free(buf);
    fclose(g);
    free(m->btask);
    delsock(m->fd);
    return(1);
  }
 
  free(buf);
  return(1);
}

/* receive a raw file on socket, after initget and gsize did the
   initial communication. */
int gfile(WINDOW *win, sock_t *m)
{
  char buf[2049], *st1, *end; /* note: don't need malloc for buf */
  download_t *task = m->dtask;
  FILE *f;
  int n;
  time_t t;
  int r;
  char *lfn;

  memset(buf, 0, sizeof(buf));
  n = recv(m->fd, buf, sizeof(buf)-1, 0);
  if (n > 0) {      /* we got some bytes - write them to the local file */
    write(fileno(task->f), buf, n);
    
    task->pos += n;
    
    /* update byte counts for bandwidth limiting */
    bandwidth_register(&m->bw, n);
    bandwidth_register(&bwdown, n);
  }

  if (n<=0 || task->pos >= task->size) {  /* end of file */
    t = time(NULL);
    lfn = strdup(task->lfn);
    r = interrupt_download(win, task);
    
    switch (r) {
    case 1:
      wp(win, "* Download of \"%s\" from %s interrupted (%lu of %lu bytes in %lu seconds)\n", task->fn, task->nick, (long)(task->pos-task->bsz), (long)(task->size-task->bsz), (long)(t - task->p_time));
      break;
    case 2:
      wp(win, "* Download of \"%s\" from %s interrupted, turd removed (%lu of %lu bytes in %lu seconds)\n", task->fn, task->nick, (long)(task->pos-task->bsz), (long)(task->size-task->bsz), (long)(t - task->p_time));
      break;
    case 3:
      wp(win, "* Completed download of \"%s\" from %s (%lu of %lu bytes in %lu seconds)\n", task->fn, task->nick, (long)(task->pos-task->bsz), (long)(task->size-task->bsz), (long)(t - task->p_time));
      break;
    default:
      break;
    }
    drw(win);
    
    if (info.logfile) {
      f = fopen(info.logfile, "a");
      if (f) {
	st1 = strdup(ctime(&task->p_time));
	st1[strlen(st1)-1] = 0;
	end = strdup(ctime(&t));
	end[strlen(end)-1] = 0;
	fprintf(f, "%s %s %s \"%s\" %s\n", r==3 ? "R" : "RI", st1, task->nick, lfn, end);
	fflush(f);
	free(st1);
	free(end);
      }
    }
    
    free(lfn);
    delsock(m->fd);
  }
  return(1);
}