Handle zero prefix length in getifaddrs (BZ #17371)

(cherry picked from commit a7b872687073decdcc7effc2289877d69058aca9)

Conflicts:
	NEWS

diff --git a/ChangeLog b/ChangeLog
index cc99818..ed6b9ab 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2014-09-15  Andreas Schwab  <schwab@linux-m68k.org>
+
+       [BZ #17371]
+       * sysdeps/unix/sysv/linux/ifaddrs.c (getifaddrs_internal): Fix
+       last change to handle zero prefix length.
+
 2014-09-12  Joseph Myers  <joseph@codesourcery.com>
 
        * sysdeps/gnu/netinet/udp.h (UDP_NO_CHECK6_TX): New macro.

diff --git a/NEWS b/NEWS
index 721b457..3373c96 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -5,6 +5,12 @@ See the end for copying conditions.
 Please send GNU C library bug reports via <http://sourceware.org/bugzilla/>
 using `glibc' in the "product" field.
 \f
+Version 2.20.1
+
+* The following bugs are resolved with this release:
+
+  17371.
+\f
 Version 2.20
 
 * The following bugs are resolved with this release:

diff --git a/sysdeps/unix/sysv/linux/ifaddrs.c b/sysdeps/unix/sysv/linux/ifaddrs.c
index 2c04e17..a47b2ed 100644 (file)
--- a/sysdeps/unix/sysv/linux/ifaddrs.c
+++ b/sysdeps/unix/sysv/linux/ifaddrs.c
@@ -770,20 +770,17 @@ getifaddrs_internal (struct ifaddrs **ifap)
 
                  if (cp != NULL)
                    {
-                     char c;
                      unsigned int preflen;
 
-                     if ((max_prefixlen > 0) &&
-                         (ifam->ifa_prefixlen > max_prefixlen))
+                     if (ifam->ifa_prefixlen > max_prefixlen)
                        preflen = max_prefixlen;
                      else
                        preflen = ifam->ifa_prefixlen;
 
-                     for (i = 0; i < ((preflen - 1) / 8); i++)
+                     for (i = 0; i < preflen / 8; i++)
                        *cp++ = 0xff;
-                     c = 0xff;
-                     c <<= ((128 - preflen) % 8);
-                     *cp = c;
+                     if (preflen % 8)
+                       *cp = 0xff << (8 - preflen % 8);
                    }
                }
            }