sync_pipe.h

   1 /* sync_pipe.h
   2  * Low-level synchronization pipe routines for use by Wireshark/TShark
   3  * and dumpcap
   4  *
   5  * Wireshark - Network traffic analyzer
   6  * By Gerald Combs <gerald@wireshark.org>
   7  * Copyright 1998 Gerald Combs
   8  *
   9  * SPDX-License-Identifier: GPL-2.0-or-later
  10  */
  11
  12
  13 /** @file
  14  *
  15  *  Low-level sync pipe interfaces.
  16  */
  17
  18 #ifndef __SYNC_PIPE_H__
  19 #define __SYNC_PIPE_H__
  20
  21 #include <ws_posix_compat.h>
  22
  23 /*
  24  * Maximum length of sync pipe message data.  Must be < 2^24, as the
  25  * message length is 3 bytes.
  26  * XXX - this must be large enough to handle a Really Big Filter
  27  * Expression, as the error message for an incorrect filter expression
  28  * is a bit larger than the filter expression, and large enough to
  29  * handle a large interface list.
  30  * 4096 is a typical PIPE_BUF size for atomic writes, but we should have
  31  * only one writer and one reader so that shouldn't be an issue.
  32  */
  33 #define SP_MAX_MSG_LEN  (512 * 1000)
  34
  35 /*
  36  * Indications sent out on the sync pipe (from child to parent).
  37  * We might want to switch to something like Thrift
  38  * (http://thrift.apache.org/) or Protocol Buffers
  39  * (http://code.google.com/p/protobuf-c/) if we ever need to use more
  40  * complex messages.
  41  */
  42 #define SP_EXEC_FAILED  'X'     /* errno value for the exec failing */
  43 #define SP_FILE         'F'     /* the name of the recently opened file */
  44 #define SP_ERROR_MSG    'E'     /* error message */
  45 #define SP_LOG_MSG      'L'     /* log message */
  46 #define SP_BAD_FILTER   'B'     /* error message for bad capture filter */
  47 #define SP_PACKET_COUNT 'P'     /* count of packets captured since last message */
  48 #define SP_DROPS        'D'     /* count of packets dropped in capture */
  49 #define SP_SUCCESS      'S'     /* success indication, no extra data */
  50 #define SP_TOOLBAR_CTRL 'T'     /* interface toolbar control packet */
  51 #define SP_IFACE_LIST   'I'     /* interface list */
  52 /*
  53  * Win32 only: Indications sent out on the signal pipe (from parent to child)
  54  * (UNIX-like sends signals for this)
  55  */
  56 #define SP_QUIT         'Q'     /* "gracefully" capture quit message (SIGUSR1) */
  57
  58 /* Write a message, with a string body, to the recipient pipe in the
  59    standard format (1-byte message indicator, 3-byte message length
  60    (excluding length and indicator field), and the string.
  61    If msg is NULL, the message has only a length and indicator. */
  62 extern void
  63 sync_pipe_write_string_msg(int pipe_fd, char indicator, const char *msg);
  64
  65 /* Write a message, with an unsigned integer body, to the recipient
  66    pipe in the standard format (1-byte message indicator, 3-byte
  67    message length (excluding length and indicator field), and the
  68    unsigned integer, as a string. */
  69 extern void
  70 sync_pipe_write_uint_msg(int pipe_fd, char indicator, unsigned int num);
  71
  72 /* Write a message, with an integer body, to the recipient pipe in the
  73    standard format (1-byte message indicator, 3-byte message length
  74    (excluding length and indicator field), and the integer, as a string. */
  75 extern void
  76 sync_pipe_write_int_msg(int pipe_fd, char indicator, int num);
  77
  78 /** the child encountered an error, notify the parent */
  79 extern void
  80 sync_pipe_write_errmsgs_to_parent(int pipe_fd, const char *error_msg,
  81                                   const char *secondary_error_msg);
  82
  83 /** Has the parent signalled the child to stop? */
  84 #define SIGNAL_PIPE_CTRL_ID_NONE "none"
  85 #ifdef _WIN32
  86 #define SIGNAL_PIPE_FORMAT "\\\\.\\pipe\\wireshark.%s.signal"
  87 #endif
  88
  89 #endif /* sync_pipe.h */
  90
  91 /*
  92  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
  93  *
  94  * Local variables:
  95  * c-basic-offset: 4
  96  * tab-width: 8
  97  * indent-tabs-mode: nil
  98  * End:
  99  *
 100  * vi: set shiftwidth=4 tabstop=8 expandtab:
 101  * :indentSize=4:tabSize=8:noTabs=true:
 102  */