Commit b5c3ce63 authored by Tyler Hicks's avatar Tyler Hicks Committed by Steve Beattie

parser: Adjust writeu16() to output escaped byte sequences

The writeu16() function was outputting unescaped byte sequences to the
rule buffer. That resulted the generation of in an incomplete rule if
one of those unescaped byte sequences contained 0x00.

This patch uses u8 pointers, instead of char pointers, when writing out
the big endian u16 value. More importantly, it casts the u8 values to
unsigned ints, which is what's needed to get the properly escaped byte
sequences.

Before:

  $ echo "/t { unix (connect,read,write) type=stream, }" |
apparmor_parser -qQD dfa-states
  {1} <== (allow/deny/audit/quiet)
  {2} (0x 4/0/0/0)
  {3} (0x 4/0/0/0)
  {5} (0x 46/0/0/0)
  
  {1} -> {2}: 0x2
  {1} -> {3}: 0x4
  {1} -> {2}: 0x7
  {1} -> {2}: 0x9
  {1} -> {2}: 0xa
  {1} -> {2}: 0x20 \ 
  {1} -> {4}: 0x34 4
  {3}  (0x 4/0/0/0) -> {5}: 0x0
  {4} -> {6}: 0x0
  {6} -> {2}: 0x31 1
  

After (the next patch fixes the pointer values that are being written
out):

  $ echo "/t { unix (connect,read,write) type=stream, }" |
apparmor_parser -qQD dfa-states
  {1} <== (allow/deny/audit/quiet)
  {2} (0x 4/0/0/0)
  {3} (0x 4/0/0/0)
  {43} (0x 46/0/0/0)
  {44} (0x 46/0/0/0)
  
  {1} -> {2}: 0x2
  {1} -> {3}: 0x4
  {1} -> {2}: 0x7
  {1} -> {2}: 0x9
  {1} -> {2}: 0xa
  {1} -> {2}: 0x20 \ 
  {1} -> {4}: 0x34 4
  {3}  (0x 4/0/0/0) -> {5}: 0x0
  {4} -> {6}: 0x0
  {5} -> {7}: 0x1
  {6} -> {2}: 0x31 1
  {7} -> {8}: 0x30 0
  {8} -> {9}: 0x78 x
  {9} -> {10}: 0x37 7
  {10} -> {11}: 0x66 f
  {11} -> {12}: 0x66 f
  {12} -> {13}: 0x66 f
  {13} -> {14}: 0x31 1
  {14} -> {15}: 0x30 0
  {15} -> {16}: 0x34 4
  {16} -> {17}: 0x66 f
  {17} -> {18}: 0x33 3
  {18} -> {19}: 0x35 5
  {19} -> {20}: 0x31 1
  {20} -> {21}: 0x38 8
  {21} -> {22}: 0x0
  {22} -> {23}: 0x1
  {23} -> {24}: 0x30 0
  {24} -> {25}: 0x78 x
  {25} -> {26}: 0x37 7
  {26} -> {27}: 0x66 f
  {27} -> {28}: 0x66 f
  {28} -> {29}: 0x66 f
  {29} -> {30}: 0x31 1
  {30} -> {31}: 0x30 0
  {31} -> {32}: 0x34 4
  {32} -> {33}: 0x66 f
  {33} -> {34}: 0x33 3
  {34} -> {35}: 0x35 5
  {35} -> {36}: 0x31 1
  {36} -> {37}: 0x38 8
  {37} -> {38}: []
  {38} -> {39}: []
  {39} -> {40}: 0x0
  {39} -> {39}: []
  {40} -> {40}: 0x0
  {40} -> {41}: 0x1
  {40} -> {39}: []
  {41} -> {42}: 0x0
  {41} -> {39}: []
  {42} -> {40}: 0x0
  {42} -> {44}: 0x1
  {42} -> {43}: []
  {43}  (0x 46/0/0/0) -> {40}: 0x0
  {43}  (0x 46/0/0/0) -> {43}: []
  {44}  (0x 46/0/0/0) -> {42}: 0x0
  {44}  (0x 46/0/0/0) -> {43}: []
Signed-off-by: Tyler Hicks's avatarTyler Hicks <tyhicks@canonical.com>
Acked-by: default avatarSeth Arnold <seth.arnold@canonical.com>
parent 4ed3dd09
......@@ -192,9 +192,11 @@ static void warn_once(const char *name)
std::ostringstream &writeu16(std::ostringstream &o, int v)
{
u16 tmp = htobe16((u16) v);
char *c = (char *) &tmp;
o << "\\x" << std::setfill('0') << std::setw(2) << std::hex << *c++;
o << "\\x" << std::setfill('0') << std::setw(2) << std::hex << *c;
u8 *byte1 = (u8 *)&tmp;
u8 *byte2 = byte1 + 1;
o << "\\x" << std::setfill('0') << std::setw(2) << std::hex << static_cast<unsigned int>(*byte1);
o << "\\x" << std::setfill('0') << std::setw(2) << std::hex << static_cast<unsigned int>(*byte2);
return o;
}
......
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