1 /* frame_data.h
2  * Definitions for frame_data structures and routines
3  *
4  * Wireshark - Network traffic analyzer
5  * By Gerald Combs <gerald@wireshark.org>
6  * Copyright 1998 Gerald Combs
7  *
8  * SPDX-License-Identifier: GPL-2.0-or-later
9  */
10 
11 #ifndef __FRAME_DATA_H__
12 #define __FRAME_DATA_H__
13 
14 #include <ws_diag_control.h>
15 #include <ws_symbol_export.h>
16 #include <wsutil/nstime.h>
17 
18 #include <wiretap/wtap.h>
19 
20 #ifdef __cplusplus
21 extern "C" {
22 #endif /* __cplusplus */
23 
24 struct _packet_info;
25 struct epan_session;
26 
27 #define PINFO_FD_VISITED(pinfo)   ((pinfo)->fd->visited)
28 
29 /** @file
30  * Low-level frame data and metadata.
31  */
32 
33 /** @defgroup framedata Frame Data
34  *
35  * @{
36  */
37 
38 /** @todo XXX - some of this stuff is used only while a packet is being dissected;
39    should we keep that stuff in the "packet_info" structure, instead, to
40    save memory? */
41 
42 /* Types of character encodings */
43 typedef enum {
44   PACKET_CHAR_ENC_CHAR_ASCII     = 0, /* ASCII */
45   PACKET_CHAR_ENC_CHAR_EBCDIC    = 1  /* EBCDIC */
46 } packet_char_enc;
47 
48 /** The frame number is the ordinal number of the frame in the capture, so
49    it's 1-origin.  In various contexts, 0 as a frame number means "frame
50    number unknown".
51 
52    There is one of these structures for every frame in the capture.
53    That means a lot of memory if we have a lot of frames.
54    They are packed into power-of-2 chunks, so their size is effectively
55    rounded up to a power of 2.
56    Try to keep it close to, and less than or equal to, a power of 2.
57    "Smaller than a power of 2" is OK for ILP32 platforms.
58 
59    XXX - shuffle the fields to try to keep the most commonly-accessed
60    fields within the first 16 or 32 bytes, so they all fit in a cache
61    line? */
62 struct _color_filter; /* Forward */
63 DIAG_OFF_PEDANTIC
64 typedef struct _frame_data {
65   guint32      num;          /**< Frame number */
66   guint32      pkt_len;      /**< Packet length */
67   guint32      cap_len;      /**< Amount actually captured */
68   guint32      cum_bytes;    /**< Cumulative bytes into the capture */
69   gint64       file_off;     /**< File offset */
70   /* These two are pointers, meaning 64-bit on LP64 (64-bit UN*X) and
71      LLP64 (64-bit Windows) platforms.  Put them here, one after the
72      other, so they don't require padding between them. */
73   GSList      *pfd;          /**< Per frame proto data */
74   const struct _color_filter *color_filter;  /**< Per-packet matching color_filter_t object */
75   guint16      subnum;       /**< subframe number, for protocols that require this */
76   /* Keep the bitfields below to 16 bits, so this plus the previous field
77      are 32 bits. */
78   unsigned int passed_dfilter   : 1; /**< 1 = display, 0 = no display */
79   unsigned int dependent_of_displayed : 1; /**< 1 if a displayed frame depends on this frame */
80   /* Do NOT use packet_char_enc enum here: MSVC compiler does not handle an enum in a bit field properly */
81   unsigned int encoding         : 1; /**< Character encoding (ASCII, EBCDIC...) */
82   unsigned int visited          : 1; /**< Has this packet been visited yet? 1=Yes,0=No*/
83   unsigned int marked           : 1; /**< 1 = marked by user, 0 = normal */
84   unsigned int ref_time         : 1; /**< 1 = marked as a reference time frame, 0 = normal */
85   unsigned int ignored          : 1; /**< 1 = ignore this frame, 0 = normal */
86   unsigned int has_ts           : 1; /**< 1 = has time stamp, 0 = no time stamp */
87   unsigned int has_modified_block : 1; /** 1 = block for this packet has been modified */
88   unsigned int need_colorize    : 1; /**< 1 = need to (re-)calculate packet color */
89   unsigned int tsprec           : 4; /**< Time stamp precision -2^tsprec gives up to femtoseconds */
90   nstime_t     abs_ts;       /**< Absolute timestamp */
91   nstime_t     shift_offset; /**< How much the abs_tm of the frame is shifted */
92   guint32      frame_ref_num; /**< Previous reference frame (0 if this is one) */
93   guint32      prev_dis_num; /**< Previous displayed frame (0 if first one) */
94 } frame_data;
95 DIAG_ON_PEDANTIC
96 
97 /** compare two frame_datas */
98 WS_DLL_PUBLIC gint frame_data_compare(const struct epan_session *epan, const frame_data *fdata1, const frame_data *fdata2, int field);
99 
100 WS_DLL_PUBLIC void frame_data_reset(frame_data *fdata);
101 
102 WS_DLL_PUBLIC void frame_data_destroy(frame_data *fdata);
103 
104 WS_DLL_PUBLIC void frame_data_init(frame_data *fdata, guint32 num,
105                 const wtap_rec *rec, gint64 offset,
106                 guint32 cum_bytes);
107 
108 extern void frame_delta_abs_time(const struct epan_session *epan, const frame_data *fdata,
109                 guint32 prev_num, nstime_t *delta);
110 /**
111  * Sets the frame data struct values before dissection.
112  */
113 WS_DLL_PUBLIC void frame_data_set_before_dissect(frame_data *fdata,
114                 nstime_t *elapsed_time,
115                 const frame_data **frame_ref,
116                 const frame_data *prev_dis);
117 
118 WS_DLL_PUBLIC void frame_data_set_after_dissect(frame_data *fdata,
119                 guint32 *cum_bytes);
120 
121 /** @} */
122 
123 #ifdef __cplusplus
124 }
125 #endif /* __cplusplus */
126 
127 #endif  /* __FRAME_DATA__ */
128 
129 /*
130  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
131  *
132  * Local variables:
133  * c-basic-offset: 2
134  * tab-width: 8
135  * indent-tabs-mode: nil
136  * End:
137  *
138  * vi: set shiftwidth=2 tabstop=8 expandtab:
139  * :indentSize=2:tabSize=8:noTabs=true:
140  */
141