Changeset 3040 for pjproject/trunk

Timestamp:

Dec 30, 2009 8:39:14 AM (15 years ago)

Author:

bennylp

Message:

Few fixes and enhancements to Windows IP helper, related to #1000:

• enum_ipv4_ipv6_interface() function:
  • bug fix: function should return error if no interface is found
  • do not include interfaces that are down, loopback interface, interface with 0.0.0.0/24 address, interface with zero address, etc.
• improve buffer robustness for enum_ipv4_interface() and enum_ipv4_ipv6_interface() functions, by supplying only small buffer, but added fallback to allocating the buffer from heap if the buffer is not large enough to contain the result.

File:

• pjproject/trunk/pjlib/src/pj/ip_helper_win32.c (modified) (4 diffs)

pjproject/trunk/pjlib/src/pj/ip_helper_win32.c

@@ -200 +200 @@
                                        pj_sockaddr ifs[])
 {
-    /* Provide enough buffer or otherwise it will fail with 
-     * error 22 ("Not Enough Buffer") error.
-     */
-    char ipTabBuff[1024];
-    MIB_IPADDRTABLE *pTab;
-    ULONG tabSize;
+    char ipTabBuff[512];
+    MIB_IPADDRTABLE *pTab = (MIB_IPADDRTABLE*)ipTabBuff;
+    ULONG tabSize = sizeof(ipTabBuff);
     unsigned i, count;
     DWORD rc = NO_ERROR;
@@ -211 +208 @@
     PJ_ASSERT_RETURN(p_cnt && ifs, PJ_EINVAL);
 
-    pTab = (MIB_IPADDRTABLE*)ipTabBuff;
-
     /* Get IP address table */
-    tabSize = sizeof(ipTabBuff);
-
     rc = MyGetIpAddrTable(pTab, &tabSize, FALSE);
-    if (rc != NO_ERROR)
-        return PJ_RETURN_OS_ERROR(rc);
+    if (rc != NO_ERROR) {
+        if (rc == ERROR_INSUFFICIENT_BUFFER) {
+            /* Retry with larger buffer */
+            pTab = (MIB_IPADDRTABLE*)malloc(tabSize);
+            if (pTab)
+                rc = MyGetIpAddrTable(pTab, &tabSize, FALSE);
+        }
+
+        if (rc != NO_ERROR) {
+            if (pTab != (MIB_IPADDRTABLE*)ipTabBuff)
+                free(pTab);
+            return PJ_RETURN_OS_ERROR(rc);
+        }
+    }
 
     /* Reset result */
@@ -255 +260 @@
     }
 
+    if (pTab != (MIB_IPADDRTABLE*)ipTabBuff)
+        free(pTab);
+
     return (*p_cnt) ? PJ_SUCCESS : PJ_ENOTFOUND;
 }
-
 
 /* Enumerate local IP interface using GetAdapterAddresses(),
@@ -266 +273 @@
                                             pj_sockaddr ifs[])
 {
-    pj_uint8_t buffer[1600];
+    pj_uint8_t buffer[600];
     IP_ADAPTER_ADDRESSES *adapter = (IP_ADAPTER_ADDRESSES*)buffer;
     ULONG size = sizeof(buffer);
+    ULONG flags;
     unsigned i;
     DWORD rc;
 
-    rc = MyGetAdapterAddresses(af, 0, NULL, adapter, &size);
-    if (rc != ERROR_SUCCESS)
-        return PJ_RETURN_OS_ERROR(rc);
-
+    flags = GAA_FLAG_SKIP_FRIENDLY_NAME |
+            GAA_FLAG_SKIP_DNS_SERVER |
+            GAA_FLAG_SKIP_MULTICAST;
+
+    rc = MyGetAdapterAddresses(af, flags, NULL, adapter, &size);
+    if (rc != ERROR_SUCCESS) {
+        if (rc == ERROR_BUFFER_OVERFLOW) {
+            /* Retry with larger memory size */
+            adapter = (IP_ADAPTER_ADDRESSES*) malloc(size);
+            if (adapter != NULL)
+                rc = MyGetAdapterAddresses(af, flags, NULL, adapter, &size);
+        } 
+
+        if (rc != ERROR_SUCCESS) {
+            if (adapter != (IP_ADAPTER_ADDRESSES*)buffer)
+                free(adapter);
+            return PJ_RETURN_OS_ERROR(rc);
+        }
+    }
+
+    /* Reset result */
+    pj_bzero(ifs, sizeof(ifs[0]) * (*p_cnt));
+
+    /* Enumerate interface */
     for (i=0; i<*p_cnt && adapter; adapter = adapter->Next) {
         if (adapter->FirstUnicastAddress) {
             SOCKET_ADDRESS *pAddr = &adapter->FirstUnicastAddress->Address;
-            if (pAddr->lpSockaddr->sa_family == PJ_AF_INET ||
-                pAddr->lpSockaddr->sa_family == PJ_AF_INET6)
+
+            /* Ignore address family which we didn't request, just in case */
+            if (pAddr->lpSockaddr->sa_family != PJ_AF_INET &&
+                pAddr->lpSockaddr->sa_family != PJ_AF_INET6)
             {
-                ifs[i].addr.sa_family = pAddr->lpSockaddr->sa_family;
-                pj_memcpy(&ifs[i], pAddr->lpSockaddr, pAddr->iSockaddrLength);
-                ++i;
+                continue;
             }
-        }
-    }
+
+            /* Apply some filtering to known IPv4 unusable addresses */
+            if (pAddr->lpSockaddr->sa_family == PJ_AF_INET) {
+                const pj_sockaddr_in *addr_in = 
+                    (const pj_sockaddr_in*)pAddr->lpSockaddr;
+
+                /* Ignore 0.0.0.0 address (interface is down?) */
+                if (addr_in->sin_addr.s_addr == 0)
+                    continue;
+
+                /* Ignore 0.0.0.0/8 address. This is a special address
+                 * which doesn't seem to have practical use.
+                 */
+                if ((pj_ntohl(addr_in->sin_addr.s_addr) >> 24) == 0)
+                    continue;
+            }
+
+#if PJ_IP_HELPER_IGNORE_LOOPBACK_IF
+            /* Ignore loopback interfaces */
+            /* This should have been IF_TYPE_SOFTWARE_LOOPBACK according to
+             * MSDN, and this macro should have been declared in Ipifcons.h, 
+             * but some SDK versions don't have it.
+             */
+            if (adapter->IfType == MIB_IF_TYPE_LOOPBACK)
+                continue;
+#endif
+
+            /* Ignore down interface */
+            if (adapter->OperStatus != IfOperStatusUp)
+                continue;
+
+            ifs[i].addr.sa_family = pAddr->lpSockaddr->sa_family;
+            pj_memcpy(&ifs[i], pAddr->lpSockaddr, pAddr->iSockaddrLength);
+            ++i;
+        }
+    }
+
+    if (adapter != (IP_ADAPTER_ADDRESSES*)buffer)
+        free(adapter);
 
     *p_cnt = i;
-    return PJ_SUCCESS;
+    return (*p_cnt) ? PJ_SUCCESS : PJ_ENOTFOUND;
 }