Changeset 65579 in vbox for trunk/src/VBox/Runtime/common/net

Timestamp:

Feb 1, 2017 9:32:38 PM (8 years ago)

Author:

vboxsync

svn:sync-xref-src-repo-rev:

113233

Message:

IPRT: RTNetMaskToPrefixIPv4 and RTNetPrefixToMaskIPv4.

File:

• trunk/src/VBox/Runtime/common/net/netaddrstr2.cpp (modified) (1 diff)

trunk/src/VBox/Runtime/common/net/netaddrstr2.cpp

@@ -153 +153 @@
 
 
+RTDECL(int) RTNetMaskToPrefixIPv4(PCRTNETADDRIPV4 pMask, int *piPrefix)
+{
+    AssertReturn(pMask != NULL, VERR_INVALID_PARAMETER);
+
+    if (pMask->u == 0)
+    {
+        if (piPrefix != NULL)
+            *piPrefix = 0;
+        return VINF_SUCCESS;
+    }
+
+    const uint32_t uMask = RT_N2H_U32(pMask->u);
+
+    uint32_t uPrefixMask = UINT32_C(0xffffffff);
+    int iPrefixLen = 32;
+
+    while (iPrefixLen > 0) { 
+        if (uMask == uPrefixMask)
+        {
+            if (piPrefix != NULL)
+                *piPrefix = iPrefixLen;
+            return VINF_SUCCESS;
+        }
+
+        --iPrefixLen;
+        uPrefixMask <<= 1;
+    }
+
+    return VERR_INVALID_PARAMETER;
+}
+RT_EXPORT_SYMBOL(RTNetMaskToPrefixIPv4);
+
+
+RTDECL(int) RTNetPrefixToMaskIPv4(int iPrefix, PRTNETADDRIPV4 pMask)
+{
+    AssertReturn(pMask != NULL, VERR_INVALID_PARAMETER);
+
+    if (RT_UNLIKELY(iPrefix < 0 || 32 < iPrefix))
+        return VERR_INVALID_PARAMETER;
+
+    if (RT_LIKELY(iPrefix != 0))
+        pMask->u = RT_H2N_U32(UINT32_C(0xffffffff) << (32 - iPrefix));
+    else /* avoid UB in the shift */
+        pMask->u = 0;
+
+    return VINF_SUCCESS;
+}
+RT_EXPORT_SYMBOL(RTNetPrefixToMaskIPv4);
+
+
 static int rtNetStrToHexGroup(const char *pcszValue, char **ppszNext,
                               uint16_t *pu16)