readme.dos
1libpcap for DOS
2---------------
3
4This file contains some notes on building and using libpcap for MS-DOS.
5Look in `README' and `pcap.man' for usage and details. These targets are
6supported:
7
8 - Borland C 4.0+ small or large model.
9 - Metaware HighC 3.1+ with PharLap DOS-extender
10 - GNU C 2.7+ with djgpp 2.01+ DOS extender
11 - Watcom C 11.x with DOS4GW extender
12
13Note: the files in the libpcap.zip contains short trucated filenames.
14 So for djgpp to work with these, disable the use of long file names by
15 setting "LFN=n" in the environment.
16
17Files specific to DOS are pcap-dos.[ch] and the assembly and C files in
18the MSDOS sub-directory. Remember to built lipcap libraries from the top
19install directory. And not from the MSDOS sub-directory.
20
21Note for djgpp users:
22 If you got the libpcap from the official site www.tcpdump, then that
23 distribution does NOT contain any sources for building 32-bit drivers.
24 Instead get the full version at
25 http://www.bgnett.no/~giva/pcap/libpcap.zip
26
27 and set "USE_32BIT_DRIVERS = 1" in msdos\common.dj.
28
29
30
31Requirements
32------------
33
34DOS-libpcap currently only works reliably with a real-mode Ethernet packet-
35driver. This driver must be installed prior to using any program (e.g.
36tcpdump) compiled with libpcap. Work is underway to implement protected-
37mode drivers for 32-bit targets (djgpp only). The 3Com 3c509 driver is
38working almost perfectly. Due to lack of LAN-cards, I've not had the
39opportunity to test other drivers. These 32-bit drivers are modified
40Linux drivers.
41
42
43Required packages
44-----------------
45
46The following packages and tools must be present for all targets.
47
481. Watt-32 tcp/ip library. This library is *not* used to send or
49 receive network data. It's mostly used to access the 'hosts'
50 file and other <netdb.h> features. Get 'watt32s*.zip' at:
51
52 http://www.bgnett.no/~giva/
53
542. Exception handler and disassember library (libexc.a) is needed if
55 "USE_EXCEPT = 1" in common.dj. Available at:
56
57 http://www.bgnett.no/~giva/misc/exc_dx07.zip
58
593. Flex & Bison is used to generate parser for the filter handler
60 pcap_compile:
61
62 ftp://ftp.simtel.net/pub/simtelnet/gnu/djgpp/v2gnu/flx254b.zip
63 ftp://ftp.simtel.net/pub/simtelnet/gnu/djgpp/v2gnu/bsn128b.zip
64
654. NASM assembler v 0.98 or later is required when building djgpp and
66 Watcom targets:
67
68 ftp://ftp.simtel.net/pub/simtelnet/gnu/djgpp/v2tk/nasm098p.zip
69
705. sed (Stream Editor) is required for doing `make depend'.
71 It's available at
72 ftp://ftp.simtel.net/pub/simtelnet/gnu/djgpp/v2gnu/sed*.zip
73
74 A touch tool to update the time-stamp of a file. E.g.
75 ftp://ftp.simtel.net/pub/simtelnet/gnu/djgpp/v2gnu/grep*.zip
76
776. For djgpp rm.exe and cp.exe are required. These should already be
78 part of your djgpp installation. Also required (experimental at the
79 time) for djgpp is DLX 2.91 or later. This tool is for the generation
80 of dynamically loadable modules.
81
82
83Compiling libpcap
84-----------------
85
86Follow these steps in building libpcap:
87
881. Make sure you've installed Watt-32 properly (see it's `INSTALL' file).
89 During that installation a environment variable `WATT_ROOT' is set.
90 This variable is used for building libpcap also (`WATT_INC' is
91 deducted from `WATT_ROOT'). djgpp users should also define environment
92 variables `C_INCLUDE_PATH' and `LIBRARY_PATH' to point to the include
93 directory and library directory respectively. E.g. put this in your
94 AUTOEXEC.BAT:
95 set C_INCLUDE_PATH=c:/net/watt/inc
96 set LIBRARY_PATH=c:/net/watt/lib
97
982. Revise the msdos/common.dj file for your djgpp/gcc installation;
99 - change the value of `GCCLIB' to match location of libgcc.a.
100 - set `USE_32BIT_DRIVERS = 1' to build 32-bit driver objects.
101
102
1033. Build pcap by using appropriate makefile. For djgpp, use:
104 `make -f msdos/makefile.dj' (i.e. GNU `make')
105
106 For a Watcom target say:
107 `wmake -f msdos\makefile.wc'
108
109 For a Borland target say:
110 `maker -f msdos\Makefile pcap_bc.lib' (Borland's `maker.exe')
111
112 And for a HighC/Pharlap target say:
113 `maker -f msdos\Makefile pcap_hc.lib' (Borland's `maker.exe')
114
115 You might like to change some `CFLAGS' -- only `DEBUG' define currently
116 have any effect. It shows a rotating "fan" in upper right corner of
117 screen. Remove `DEBUG' if you don't like it. You could add
118 `-fomit-frame-pointer' to `CFLAGS' to speed up the generated code.
119 But note, this makes debugging and crash-traceback difficult. Only
120 add it if you're fully confident your application is 100% stable.
121
122 Note: Code in `USE_NDIS2' does not work at the moment.
123
1244. The resulting libraries are put in current directory. There's no
125 test-program for `libpcap'. Linking the library with `tcpdump' is
126 the ultimate test anyway.
127
128
129
130Extensions to libpcap
131---------------------
132
133I've included some extra functions to DOS-libpcap:
134
135 `pcap_config_hook (const char *name, const char *value)'
136
137 Allows an application to set values of internal libpcap variables.
138 `name' is typically a left-side keyword with an associated `value'
139 that is called from application's configure process (see tcpdump's
140 config.c file). libpcap keeps a set of tables that are searched for
141 a name/value match. Currently only used to set debug-levels and
142 parameters for the 32-bit network drivers.
143
144 `pcap_set_wait (pcap_t *, void (*)(void), int)' :
145
146 Only effective when reading offline traffic from dump-files.
147 Function `pcap_offline_read()' will wait (and optionally yield)
148 before printing next packet. This will simulate the pace the packets
149 where actually recorded.
150
151
152
153Happy sniffing !
154
155
156Gisle Vanem <giva@bgnett.no>
157 <gvanem@broadpark.no>
158
159October 1999, 2004
160
161