lib/libcaps/caps_msgbuf.c

   1 /*
   2  * Copyright (c) 2003 Matthew Dillon <dillon@backplane.com>
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  *
  26  * $DragonFly: src/lib/libcaps/caps_msgbuf.c,v 1.1 2004/03/07 23:36:44 dillon Exp $
  27  */
  28
  29 #include "defs.h"
  30
  31 void
  32 caps_init_msgbuf(caps_msgbuf_t msg, void *data, int size)
  33 {
  34     msg->base = data;
  35     msg->index = 0;
  36     msg->bufsize = size;
  37     msg->error = 0;
  38 }
  39
  40 void
  41 caps_msgbuf_error(caps_msgbuf_t msg, int eno, int undo)
  42 {
  43     if (eno)
  44         msg->error = eno;
  45     if (msg->index < undo)
  46         msg->index = 0;
  47     else
  48         msg->index -= undo;
  49 }
  50
  51 /*
  52  * Extract the next class specification.  A class specification is an upper
  53  * case letter followed by quoted data or non-quoted data.  Non-quoted data
  54  * may only contain the characters 0-9 and LOWER CASE a-z, '.', or '_'.
  55  * The returned (ptr,len) tuple includes the quotes in quoted data.
  56  */
  57 u_int8_t
  58 caps_msgbuf_getclass(caps_msgbuf_t msg, u_int8_t **pptr, int *plen)
  59 {
  60     u_int8_t c;
  61     u_int8_t cc;
  62     int i;
  63
  64     while (msg->index < msg->bufsize) {
  65         c = msg->base[msg->index++];
  66         if (c >= 'A' && c <= 'Z') {
  67             i = msg->index;
  68             *pptr = msg->base + i;
  69             if (i < msg->bufsize && msg->base[i] == '\"') {
  70                 for (++i; i < msg->bufsize; ++i) {
  71                     cc = msg->base[i];
  72                     if ((cc >= 'a' && cc <= 'z') ||
  73                         (cc >= 'A' && cc <= 'Z') ||
  74                         (cc >= '0' && cc <= '9') ||
  75                         cc == '_' || cc == '.' || cc == '/' || cc == '+' ||
  76                         cc == '-' || cc == '%'
  77                     ) {
  78                         continue;
  79                     }
  80                     if (cc == '"')      /* quote end string, else error */
  81                         ++i;
  82                     else
  83                         msg->error = EINVAL;
  84                     break;
  85                 }
  86             } else {
  87                 for (; i < msg->bufsize; ++i) {
  88                     cc = msg->base[i];
  89                     if (cc >= 'a' && cc <= 'z')
  90                         continue;
  91                     if (cc >= '0' && cc <= '9')
  92                         continue;
  93                     if (cc == '.' || cc == '_')
  94                         continue;
  95                     break;
  96                 }
  97             }
  98             *plen = i - msg->index;
  99             msg->index = i;
 100             return(c);
 101         }
 102         if (c == ',' || c == '{' || c == '}')
 103             return(c);
 104         if (c != '\t' && c != ' ' && c != '\r' && c != '\n') {
 105             msg->error = EINVAL;
 106             break;
 107         }
 108         /* loop on whitespce */
 109     }
 110     return(0);
 111 }
 112
 113 /*
 114  * Support routines for encoding/decoding
 115  */
 116 void
 117 caps_msgbuf_printf(caps_msgbuf_t msg, const char *ctl, ...)
 118 {
 119     va_list va;
 120     int i;
 121
 122     va_start(va, ctl);
 123     i = msg->index;
 124     if (i <= msg->bufsize)
 125         i += vsnprintf(msg->base + i, msg->bufsize - i, ctl, va);
 126     else
 127         i += vsnprintf(NULL, 0, ctl, va);
 128     msg->index = i;
 129     va_end(va);
 130 }
 131