Prepare for 2.14.0.1. Better ip6_scan().

Signed-off-by: Laurent Bercot <ska@appnovation.com>

1 files changed, 74 insertions, 22 deletions

diff --git a/src/libstddjb/ip6_scan.c b/src/libstddjb/ip6_scan.c
index b0e5b56..d2cdad6 100644
--- a/src/libstddjb/ip6_scan.c
+++ b/src/libstddjb/ip6_scan.c
@@ -1,37 +1,89 @@
 /* ISC license. */
 
-#include <errno.h>
+#include <stdint.h>
 
 #include <skalibs/uint16.h>
 #include <skalibs/fmtscan.h>
 
+
+/* IPv6 scanner
+
+class   |       0       1       2       3
+st\ev   |       other   hex     :       .
+
+START   |               m
+00      |       X       LIMB    COLON1  X
+
+COLON1  |                       p
+01      |       X       X       NEW     X
+
+NEW     |               m
+02      |       END     LIMB    X       X
+
+LIMB    |       h               h
+03      |       END     LIMB    COLON   V4
+
+COLON   |               m       p
+04      |       X       LIMB    NEW     X
+
+
+END = 05
+V4 = 06
+X = 07
+
+0x10    m       mark
+0x20    p       set doublecolon pos
+0x40    h       scan hex, next limb
+
+*/
+
 size_t ip6_scan (char const *s, char *ip6)
 {
-  static unsigned char const class[256] = "2222222222222222222222222222222222222222222222220000000000122222200000022222222222222222222222222000000222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222" ;
-  static unsigned char const table[5][3] = { "\024#\005", "\024\"\005", "\024\005\006", "\005\002\005", "\024\t\016" } ;
-  uint16_t tmp[8] = { 0, 0, 0, 0, 0, 0, 0, 0 } ;
-  size_t i = 0 ;
-  unsigned int pos = 8, j = 0, state = 0 ;
+  static unsigned char const class[256] = "0000000000000000000000000000000000000000000000301111111111200000011111100000000000000000000000000111111000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000" ;
+  static uint8_t const table[5][4] =
+  {
+    { 0x07, 0x13, 0x01, 0x07 },
+    { 0x07, 0x07, 0x22, 0x07 },
+    { 0x05, 0x13, 0x07, 0x07 },
+    { 0x45, 0x03, 0x44, 0x06 },
+    { 0x07, 0x13, 0x22, 0x07 }
+  } ;
+  size_t i = 0, mark = 0 ;
+  uint16_t limb[8] = { 0, 0, 0, 0, 0, 0, 0, 0 } ;
+  uint8_t pos = 8, j = 0, state = 0 ;
 
-  while (state < 5)
+  for (; state < 0x05 ; i++)
   {
-    unsigned char c = table[state][class[(unsigned char)s[i]] - '0'] ;
-    state = c & 7 ;
-    if (c & 0x20) { if (pos < 8) state = 5 ; else pos = j ; }
-    if (c & 0x10)
+    uint8_t c = table[state][class[(unsigned char)s[i]] - '0'] ;
+    state = c & 0x07 ;
+    if (c & 0x10) mark = i ;
+    if (c & 0x20) { if (pos < 8) state = 0x07 ; else pos = j ; }
+    if (c & 0x40)
+      if (j >= 8 || uint16_xscan(s + mark, limb + j++) != i - mark) state = 0x07 ;
+  }
+
+  switch (state)
+  {
+    case 0x05:
+      if (pos == 8 && j < 8 || (pos < 8 && j > 6)) return 0 ;
+      i-- ;
+      break ;
+    case 0x06:
     {
-     if (tmp[j] & 0xf000) state = 5 ;
-     else tmp[j] = (tmp[j] << 4) + fmtscan_num(s[i], 16) ;
+      uint32_t ip4 ;
+      if (pos == 8 && j != 6 || (pos < 8 && j > 4)) return 0 ;
+      i = ip4_scanu32(s + mark, &ip4) ;
+      if (!i) return 0 ;
+      limb[j++] = ip4 >> 16 ;
+      limb[j++] = ip4 & 0xffff ;
+      i += mark ;
+      break ;
     }
-    if (c & 0x08) if ((++j > 7) && (state < 5)) state = 5 ;
-    i++ ;
+    default : return 0 ;
   }
 
-  if (((pos < 8) && (j > 6)) || ((pos == 8) && (j < 8))) state = 5 ;
-  if (state == 5) return (errno = EINVAL, 0) ; 
-  for (state = j ; state > pos ; state--) tmp[state - j + 7] = tmp[state - 1] ;
-  for (; state < pos + 8 - j ; state++) tmp[state] = 0 ;
-
-  for (j = 0 ; j < 8 ; j++) uint16_pack_big(ip6 + (j<<1), tmp[j]) ;
-  return i - 1 ;
+  for (state = j ; state > pos ; state--) limb[state - j + 7] = limb[state - 1] ;
+  for (; state < pos + 8 - j ; state++) limb[state] = 0 ;
+  for (j = 0 ; j < 8 ; j++) uint16_pack_big(ip6 + (j<<1), limb[j]) ;
+  return i ;
 }