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      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 #pragma ident	"%Z%%M%	%I%	%E% SMI"
     28 
     29 /*
     30  * Protocol interpreter for the Hypertext Transfer Protocol (HTTP)
     31  *
     32  * Relevant standards:
     33  *	Berners-Lee, T., et al: Hypertext Transfer Protocol -- HTTP/1.0.
     34  *	    RFC 1945, May 1996
     35  *	Fielding, R., et al: Hypertext Transfer Protocol -- HTTP/1.1.
     36  *	    RFC 2068, June 1999
     37  */
     38 
     39 #include <netinet/in.h>
     40 #include <stdio.h>
     41 #include <string.h>
     42 #include <ctype.h>
     43 #include "snoop.h"
     44 
     45 #define	CR	13			/* "carriage return" character */
     46 #define	LF	10			/* "line feed" character */
     47 
     48 /*
     49  * Summary lines: packet contents starting with less than MINCHARS
     50  * printable characters will not be printed. MAXCHARS is the maximum
     51  * number of characters printed.
     52  * Detail lines: NLINES is the maximum number of content lines to print
     53  */
     54 #define	MINCHARS	10
     55 #define	MAXCHARS	80
     56 #define	NLINES		5
     57 
     58 #define	MIN(a, b) (((a) < (b)) ? (a) : (b))
     59 
     60 static int printable(const char *line, const char *endp);
     61 
     62 int
     63 interpret_http(int flags, char *line, int fraglen)
     64 {
     65 	char *p, *q, *endp;
     66 	int c;
     67 	int lineno;
     68 
     69 	endp = line + fraglen;
     70 
     71 	if (flags & F_SUM) {
     72 		c = printable(line, endp - 1);
     73 		if (c < MINCHARS) {
     74 			(void) snprintf(get_sum_line(), MAXLINE,
     75 				"HTTP (body)");
     76 		} else {
     77 			(void) snprintf(get_sum_line(), MAXLINE,
     78 			    "HTTP %.*s", MIN(c, MAXCHARS), line);
     79 		}
     80 	}
     81 
     82 	if (flags & F_DTAIL) {
     83 		show_header("HTTP: ", "HyperText Transfer Protocol", fraglen);
     84 		show_space();
     85 
     86 		lineno = 0;
     87 		for (p = line; p < endp && lineno < NLINES; p = q + 1) {
     88 			c = printable(p, endp - 1);
     89 
     90 			/* stop if no printables, except if at line end */
     91 			if (c == 0 && *p != CR && *p != LF)
     92 				break;
     93 
     94 			/*
     95 			 * A line may be terminated either by an CR LF sequence
     96 			 * (DOS, Mac), or by LF alone
     97 			 */
     98 
     99 			q = memchr(p, CR, (endp - p));
    100 			if (q != NULL) {
    101 			    if (q < endp - 1 && q[1] == LF)
    102 				++q;	/* ignore subsequent LF character */
    103 			} else {
    104 			    q = memchr(p, LF, (endp - p));
    105 			    /* no CR/LF: use end of buffer */
    106 			    if (q == NULL)
    107 				q = endp - 1;
    108 			}
    109 
    110 			/* truncate lines containing non-printable characters */
    111 			(void) snprintf(get_line(0, c), get_line_remain(),
    112 			    "%.*s", c, p);
    113 			++lineno;
    114 		}
    115 
    116 		if (p < endp)	/* there was more data to be printed */
    117 			(void) snprintf(get_line(0, 5), get_line_remain(),
    118 			    "[...]");
    119 
    120 		show_space();
    121 	}
    122 
    123 	return (fraglen);
    124 }
    125 
    126 /*
    127  * Return the length of the initial string starting with "startp" and
    128  * ending with "endp" (inclusively) consisting only of printable
    129  * characters.
    130  */
    131 
    132 static int
    133 printable(const char *startp, const char *endp)
    134 {
    135 	const char *p = startp;
    136 
    137 	while (p <= endp && (isprint(*p) || *p == '\t'))
    138 		p++;
    139 
    140 	return (p - startp);
    141 }
    142