usr/src/cmd/cmd-inet/usr.sbin/snoop/snoop_http.c

   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 }