xref: /netbsd-src/external/bsd/tcpdump/dist/print-ascii.c (revision 63372caa2f74032c7c1cb34e7cd32f28ad65b703)
1 /*	NetBSD: print-ascii.c,v 1.1 1999/09/30 14:49:12 sjg Exp 	*/
2 
3 /*-
4  * Copyright (c) 1997, 1998 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Alan Barrett and Simon J. Gerraty.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #ifndef lint
34 __RCSID("$NetBSD: print-ascii.c,v 1.9 2024/09/02 16:15:30 christos Exp $");
35 #endif
36 
37 /* \summary: ASCII packet dump printer */
38 
39 #include <config.h>
40 
41 #include "netdissect-stdinc.h"
42 
43 #include <stdio.h>
44 
45 #include "netdissect-ctype.h"
46 
47 #include "netdissect.h"
48 #include "extract.h"
49 
50 #define ASCII_LINELENGTH 300
51 #define HEXDUMP_BYTES_PER_LINE 16
52 #define HEXDUMP_SHORTS_PER_LINE (HEXDUMP_BYTES_PER_LINE / 2)
53 #define HEXDUMP_HEXSTUFF_PER_SHORT 5 /* 4 hex digits and a space */
54 #define HEXDUMP_HEXSTUFF_PER_LINE \
55 		(HEXDUMP_HEXSTUFF_PER_SHORT * HEXDUMP_SHORTS_PER_LINE)
56 
57 void
58 ascii_print(netdissect_options *ndo,
59             const u_char *cp, u_int length)
60 {
61 	u_int caplength;
62 	u_char s;
63 	int truncated = FALSE;
64 
65 	ndo->ndo_protocol = "ascii";
66 	caplength = ND_BYTES_AVAILABLE_AFTER(cp);
67 	if (length > caplength) {
68 		length = caplength;
69 		truncated = TRUE;
70 	}
71 	ND_PRINT("\n");
72 	while (length > 0) {
73 		s = GET_U_1(cp);
74 		cp++;
75 		length--;
76 		if (s == '\r') {
77 			/*
78 			 * Don't print CRs at the end of the line; they
79 			 * don't belong at the ends of lines on UN*X,
80 			 * and the standard I/O library will give us one
81 			 * on Windows so we don't need to print one
82 			 * ourselves.
83 			 *
84 			 * In the middle of a line, just print a '.'.
85 			 */
86 			if (length > 1 && GET_U_1(cp) != '\n')
87 				ND_PRINT(".");
88 		} else {
89 			if (!ND_ASCII_ISGRAPH(s) &&
90 			    (s != '\t' && s != ' ' && s != '\n'))
91 				ND_PRINT(".");
92 			else
93 				ND_PRINT("%c", s);
94 		}
95 	}
96 	if (truncated)
97 		nd_trunc_longjmp(ndo);
98 }
99 
100 static void
101 hex_and_ascii_print_with_offset(netdissect_options *ndo, const char *ident,
102     const u_char *cp, u_int length, u_int oset)
103 {
104 	u_int caplength;
105 	u_int i;
106 	u_int s1, s2;
107 	u_int nshorts;
108 	int truncated = FALSE;
109 	char hexstuff[HEXDUMP_SHORTS_PER_LINE*HEXDUMP_HEXSTUFF_PER_SHORT+1], *hsp;
110 	char asciistuff[ASCII_LINELENGTH+1], *asp;
111 
112 	caplength = ND_BYTES_AVAILABLE_AFTER(cp);
113 	if (length > caplength) {
114 		length = caplength;
115 		truncated = TRUE;
116 	}
117 	nshorts = length / sizeof(u_short);
118 	i = 0;
119 	hsp = hexstuff; asp = asciistuff;
120 	while (nshorts != 0) {
121 		s1 = GET_U_1(cp);
122 		cp++;
123 		s2 = GET_U_1(cp);
124 		cp++;
125 		(void)snprintf(hsp, sizeof(hexstuff) - (hsp - hexstuff),
126 		    " %02x%02x", s1, s2);
127 		hsp += HEXDUMP_HEXSTUFF_PER_SHORT;
128 		*(asp++) = (char)(ND_ASCII_ISGRAPH(s1) ? s1 : '.');
129 		*(asp++) = (char)(ND_ASCII_ISGRAPH(s2) ? s2 : '.');
130 		i++;
131 		if (i >= HEXDUMP_SHORTS_PER_LINE) {
132 			*hsp = *asp = '\0';
133 			ND_PRINT("%s0x%04x: %-*s  %s",
134 			    ident, oset, HEXDUMP_HEXSTUFF_PER_LINE,
135 			    hexstuff, asciistuff);
136 			i = 0; hsp = hexstuff; asp = asciistuff;
137 			oset += HEXDUMP_BYTES_PER_LINE;
138 		}
139 		nshorts--;
140 	}
141 	if (length & 1) {
142 		s1 = GET_U_1(cp);
143 		cp++;
144 		(void)snprintf(hsp, sizeof(hexstuff) - (hsp - hexstuff),
145 		    " %02x", s1);
146 		hsp += 3;
147 		*(asp++) = (char)(ND_ASCII_ISGRAPH(s1) ? s1 : '.');
148 		++i;
149 	}
150 	if (i > 0) {
151 		*hsp = *asp = '\0';
152 		ND_PRINT("%s0x%04x: %-*s  %s",
153 		     ident, oset, HEXDUMP_HEXSTUFF_PER_LINE,
154 		     hexstuff, asciistuff);
155 	}
156 	if (truncated)
157 		nd_trunc_longjmp(ndo);
158 }
159 
160 void
161 hex_and_ascii_print(netdissect_options *ndo, const char *ident,
162     const u_char *cp, u_int length)
163 {
164 	hex_and_ascii_print_with_offset(ndo, ident, cp, length, 0);
165 }
166 
167 /*
168  * telnet_print() wants this.  It is essentially default_print_unaligned()
169  */
170 void
171 hex_print_with_offset(netdissect_options *ndo,
172                       const char *ident, const u_char *cp, u_int length,
173 		      u_int oset)
174 {
175 	u_int caplength;
176 	u_int i, s;
177 	u_int nshorts;
178 	int truncated = FALSE;
179 
180 	caplength = ND_BYTES_AVAILABLE_AFTER(cp);
181 	if (length > caplength) {
182 		length = caplength;
183 		truncated = TRUE;
184 	}
185 	nshorts = length / sizeof(u_short);
186 	i = 0;
187 	while (nshorts != 0) {
188 		if ((i++ % 8) == 0) {
189 			ND_PRINT("%s0x%04x: ", ident, oset);
190 			oset += HEXDUMP_BYTES_PER_LINE;
191 		}
192 		s = GET_U_1(cp);
193 		cp++;
194 		ND_PRINT(" %02x%02x", s, GET_U_1(cp));
195 		cp++;
196 		nshorts--;
197 	}
198 	if (length & 1) {
199 		if ((i % 8) == 0)
200 			ND_PRINT("%s0x%04x: ", ident, oset);
201 		ND_PRINT(" %02x", GET_U_1(cp));
202 	}
203 	if (truncated)
204 		nd_trunc_longjmp(ndo);
205 }
206 
207 void
208 hex_print(netdissect_options *ndo,
209 	  const char *ident, const u_char *cp, u_int length)
210 {
211 	hex_print_with_offset(ndo, ident, cp, length, 0);
212 }
213 
214 #ifdef MAIN
215 int
216 main(int argc, char *argv[])
217 {
218 	hex_print("\n\t", "Hello, World!\n", 14);
219 	printf("\n");
220 	hex_and_ascii_print("\n\t", "Hello, World!\n", 14);
221 	printf("\n");
222 	ascii_print("Hello, World!\n", 14);
223 	printf("\n");
224 #define TMSG "Now is the winter of our discontent...\n"
225 	hex_print_with_offset("\n\t", TMSG, sizeof(TMSG) - 1, 0x100);
226 	printf("\n");
227 	hex_and_ascii_print_with_offset("\n\t", TMSG, sizeof(TMSG) - 1, 0x100);
228 	printf("\n");
229 	exit(0);
230 }
231 #endif /* MAIN */
232