release/src-rt-6.x.4708/linux/linux-2.6.36/include/linux/netfilter_mime.h

   1 /*
   2  * MIME functions for netfilter modules.  This file provides implementations
   3  * for basic MIME parsing.  MIME headers are used in many protocols, such as
   4  * HTTP, RTSP, SIP, etc.
   5  *
   6  * gcc will warn for defined but unused functions, so we only include the
   7  * functions requested.  The following macros are used:
   8  *   NF_NEED_MIME_NEXTLINE      nf_mime_nextline()
   9  */
  10 #ifndef _NETFILTER_MIME_H
  11 #define _NETFILTER_MIME_H
  12
  13 /* Only include these functions for kernel code. */
  14 #ifdef __KERNEL__
  15
  16 #include <linux/ctype.h>
  17
  18 /*
  19  * Given a buffer and length, advance to the next line and mark the current
  20  * line.  If the current line is empty, *plinelen will be set to zero.  If
  21  * not, it will be set to the actual line length (including CRLF).
  22  *
  23  * 'line' in this context means logical line (includes LWS continuations).
  24  * Returns 1 on success, 0 on failure.
  25  */
  26 #ifdef NF_NEED_MIME_NEXTLINE
  27 static int
  28 nf_mime_nextline(char* p, uint len, uint* poff, uint* plineoff, uint* plinelen)
  29 {
  30     uint    off = *poff;
  31     uint    physlen = 0;
  32     int     is_first_line = 1;
  33
  34     if (off >= len)
  35     {
  36         return 0;
  37     }
  38
  39     do
  40     {
  41         while (p[off] != '\n')
  42         {
  43             if (len-off <= 1)
  44             {
  45                 return 0;
  46             }
  47
  48             physlen++;
  49             off++;
  50         }
  51
  52         /* if we saw a crlf, physlen needs adjusted */
  53         if (physlen > 0 && p[off] == '\n' && p[off-1] == '\r')
  54         {
  55             physlen--;
  56         }
  57
  58         /* advance past the newline */
  59         off++;
  60
  61         /* check for an empty line */
  62         if (physlen == 0)
  63         {
  64             break;
  65         }
  66
  67         /* check for colon on the first physical line */
  68         if (is_first_line)
  69         {
  70             is_first_line = 0;
  71             if (memchr(p+(*poff), ':', physlen) == NULL)
  72             {
  73                 return 0;
  74             }
  75         }
  76     }
  77     while (p[off] == ' ' || p[off] == '\t');
  78
  79     *plineoff = *poff;
  80     *plinelen = (physlen == 0) ? 0 : (off - *poff);
  81     *poff = off;
  82
  83     return 1;
  84 }
  85 #endif /* NF_NEED_MIME_NEXTLINE */
  86
  87 #endif /* __KERNEL__ */
  88
  89 #endif /* _NETFILTER_MIME_H */