xref: /illumos-gate/usr/src/cmd/cmd-inet/usr.sbin/snoop/snoop_http.c (revision b02947bf393d39f68e6c7fa8ccb98688f7f9c407)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright (c) 1996-1998,2001 by Sun Microsystems, Inc.
24  * All rights reserved.
25  */
26 
27 /*
28  * Protocol interpreter for the Hypertext Transfer Protocol (HTTP)
29  *
30  * Relevant standards:
31  *	Berners-Lee, T., et al: Hypertext Transfer Protocol -- HTTP/1.0.
32  *	    RFC 1945, May 1996
33  *	Fielding, R., et al: Hypertext Transfer Protocol -- HTTP/1.1.
34  *	    RFC 2068, June 1999
35  */
36 
37 #include <netinet/in.h>
38 #include <stdio.h>
39 #include <string.h>
40 #include <ctype.h>
41 #include "snoop.h"
42 
43 #define	CR	13			/* "carriage return" character */
44 #define	LF	10			/* "line feed" character */
45 
46 /*
47  * Summary lines: packet contents starting with less than MINCHARS
48  * printable characters will not be printed. MAXCHARS is the maximum
49  * number of characters printed.
50  * Detail lines: NLINES is the maximum number of content lines to print
51  */
52 #define	MINCHARS	10
53 #define	MAXCHARS	80
54 #define	NLINES		5
55 
56 #define	MIN(a, b) (((a) < (b)) ? (a) : (b))
57 
58 static int printable(const char *line, const char *endp);
59 
60 int
61 interpret_http(int flags, char *line, int fraglen)
62 {
63 	char *p, *q, *endp;
64 	int c;
65 	int lineno;
66 
67 	endp = line + fraglen;
68 
69 	if (flags & F_SUM) {
70 		c = printable(line, endp - 1);
71 		if (c < MINCHARS) {
72 			(void) snprintf(get_sum_line(), MAXLINE,
73 				"HTTP (body)");
74 		} else {
75 			(void) snprintf(get_sum_line(), MAXLINE,
76 			    "HTTP %.*s", MIN(c, MAXCHARS), line);
77 		}
78 	}
79 
80 	if (flags & F_DTAIL) {
81 		show_header("HTTP: ", "HyperText Transfer Protocol", fraglen);
82 		show_space();
83 
84 		lineno = 0;
85 		for (p = line; p < endp && lineno < NLINES; p = q + 1) {
86 			c = printable(p, endp - 1);
87 
88 			/* stop if no printables, except if at line end */
89 			if (c == 0 && *p != CR && *p != LF)
90 				break;
91 
92 			/*
93 			 * A line may be terminated either by an CR LF sequence
94 			 * (DOS, Mac), or by LF alone
95 			 */
96 
97 			q = memchr(p, CR, (endp - p));
98 			if (q != NULL) {
99 			    if (q < endp - 1 && q[1] == LF)
100 				++q;	/* ignore subsequent LF character */
101 			} else {
102 			    q = memchr(p, LF, (endp - p));
103 			    /* no CR/LF: use end of buffer */
104 			    if (q == NULL)
105 				q = endp - 1;
106 			}
107 
108 			/* truncate lines containing non-printable characters */
109 			(void) snprintf(get_line(0, c), get_line_remain(),
110 			    "%.*s", c, p);
111 			++lineno;
112 		}
113 
114 		if (p < endp)	/* there was more data to be printed */
115 			(void) snprintf(get_line(0, 5), get_line_remain(),
116 			    "[...]");
117 
118 		show_space();
119 	}
120 
121 	return (fraglen);
122 }
123 
124 /*
125  * Return the length of the initial string starting with "startp" and
126  * ending with "endp" (inclusively) consisting only of printable
127  * characters.
128  */
129 
130 static int
131 printable(const char *startp, const char *endp)
132 {
133 	const char *p = startp;
134 
135 	while (p <= endp && (isprint(*p) || *p == '\t'))
136 		p++;
137 
138 	return (p - startp);
139 }
140