sync_pipe.h

   1 /* sync_pipe.h
   2  * Low-level synchronization pipe routines for use by Wireshark/TShark
   3  * and dumpcap
   4  *
   5  * $Id$
   6  *
   7  * Wireshark - Network traffic analyzer
   8  * By Gerald Combs <gerald@wireshark.org>
   9  * Copyright 1998 Gerald Combs
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License
  13  * as published by the Free Software Foundation; either version 2
  14  * of the License, or (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  24  */
  25
  26
  27 /** @file
  28  *
  29  *  Low-level sync pipe interfaces.
  30  */
  31
  32 #ifndef __SYNC_PIPE_H__
  33 #define __SYNC_PIPE_H__
  34
  35
  36 /*
  37  * Maximum length of sync pipe message data.  Must be < 2^24, as the
  38  * message length is 3 bytes.
  39  * XXX - this must be large enough to handle a Really Big Filter
  40  * Expression, as the error message for an incorrect filter expression
  41  * is a bit larger than the filter expression.
  42  */
  43 #define SP_MAX_MSG_LEN  4096
  44
  45
  46 /* Size of buffer to hold decimal representation of
  47    signed/unsigned 64-bit int */
  48 #define SP_DECISIZE 20
  49
  50 /*
  51  * Indications sent out on the sync pipe (from child to parent).
  52  * We might want to switch to something like Thrift
  53  * (http://thrift.apache.org/) or Protocol Buffers
  54  * (http://code.google.com/p/protobuf-c/) if we ever need to use more
  55  * complex messages.
  56  */
  57 #define SP_FILE         'F'     /* the name of the recently opened file */
  58 #define SP_ERROR_MSG    'E'     /* error message */
  59 #define SP_BAD_FILTER   'B'     /* error message for bad capture filter */
  60 #define SP_PACKET_COUNT 'P'     /* count of packets captured since last message */
  61 #define SP_DROPS        'D'     /* count of packets dropped in capture */
  62 #define SP_SUCCESS      'S'     /* success indication, no extra data */
  63 /*
  64  * Win32 only: Indications sent out on the signal pipe (from parent to child)
  65  * (UNIX-like sends signals for this)
  66  */
  67 #define SP_QUIT         'Q'     /* "gracefully" capture quit message (SIGUSR1) */
  68
  69 /* write a single message header to the recipient pipe */
  70 extern ssize_t
  71 pipe_write_header(int pipe_fd, char indicator, int length);
  72
  73 /* write a message to the recipient pipe in the standard format
  74    (3 digit message length (excluding length and indicator field),
  75    1 byte message indicator and the rest is the message).
  76    If msg is NULL, the message has only a length and indicator. */
  77 extern void
  78 pipe_write_block(int pipe_fd, char indicator, const char *msg);
  79
  80 /** the child encountered an error, notify the parent */
  81 extern void
  82 sync_pipe_errmsg_to_parent(int pipe_fd, const char *error_msg,
  83                            const char *secondary_error_msg);
  84
  85 /** Has the parent signalled the child to stop? */
  86 #define SIGNAL_PIPE_CTRL_ID_NONE "none"
  87 #ifdef _WIN32
  88 #define SIGNAL_PIPE_FORMAT "\\\\.\\pipe\\wireshark.%s.signal"
  89 #endif
  90
  91 #endif /* sync_pipe.h */