From: Guy Harris <guy@alum.mit.edu>
Date: Thu, 16 Feb 2017 00:11:46 +0000 (-0800)
Subject: Clean up addrtostr6().
X-Git-Tag: tcpdump-4.99-bp~1945
X-Git-Url: https://git.tcpdump.org/tcpdump/commitdiff_plain/761e1c46996b388e5ab00bf5e0fe2148be163c16

Clean up addrtostr6().

"Word" in "words" means "16-bit words", or "16-bit piece of an IPv6
address".  Declare it so.

Instead of going over the IPv6 address a byte at a time, process 2 bytes
at a time; it makes what the code's doing more obvious.

Should squelch Coverity CID 1324572.
---

diff --git a/addrtostr.c b/addrtostr.c
index 6f6ef11a..6b067675 100644
--- a/addrtostr.c
+++ b/addrtostr.c
@@ -113,16 +113,15 @@ addrtostr6 (const void *src, char *dst, size_t size)
     int base;
     int len;
   } best, cur;
-  u_long words [IN6ADDRSZ / INT16SZ];
+  uint16_t words [IN6ADDRSZ / INT16SZ];
   int  i;
 
   /* Preprocess:
    *  Copy the input (bytewise) array into a wordwise array.
    *  Find the longest run of 0x00's in src[] for :: shorthanding.
    */
-  memset (words, 0, sizeof(words));
-  for (i = 0; i < IN6ADDRSZ; i++)
-      words[i/2] |= (srcaddr[i] << ((1 - (i % 2)) << 3));
+  for (i = 0; i < (IN6ADDRSZ / INT16SZ); i++)
+      words[i] = (srcaddr[2*i] << 8) | srcaddr[2*i + 1];
 
   best.len = 0;
   best.base = -1;
@@ -192,7 +191,7 @@ addrtostr6 (const void *src, char *dst, size_t size)
       space_left -= added_space;
       break;
     }
-    snprintfed = snprintf (dp, space_left, "%lx", words[i]);
+    snprintfed = snprintf (dp, space_left, "%x", words[i]);
     if (snprintfed < 0)
         return (NULL);
     if ((size_t) snprintfed >= space_left)