Parse the GUID ourselves; that leaves fewer error cases to worry about,

and thus fewer places where we would need to report an error rather than
just saying "well, this name doesn't end in a GUID, so it doesn't
correspond to an interface whose friendly name we can ask for".

svn path=/trunk/; revision=46149

1 files changed, 133 insertions, 33 deletions

diff --git a/capture_win_ifnames.c b/capture_win_ifnames.c
index eaa5e0541d..c68ebe736e 100644
--- a/capture_win_ifnames.c
+++ b/capture_win_ifnames.c
@@ -238,6 +238,54 @@ static int GetInterfaceFriendlyNameFromDeviceGuid(__in GUID *guid, __out char **
     return 0;
 }
 
+static int gethexdigit(const char *p)
+{
+    if(*p >= '0' && *p <= '9'){
+        return *p - '0';
+    }else if(*p >= 'A' && *p <= 'F'){
+        return *p - 'A' + 0xA;
+    }else if(*p >= 'a' && *p <= 'f'){
+        return *p - 'a' + 0xa;
+    }else{
+        return -1; /* Not a hex digit */
+    }
+}
+
+static gboolean get8hexdigits(const char *p, DWORD *d)
+{
+    int digit;
+    DWORD val;
+    int i;
+
+    val = 0;
+    for(i = 0; i < 8; i++){
+        digit = gethexdigit(p++);
+        if(digit == -1){
+            return FALSE; /* Not a hex digit */
+        }
+        val = (val << 4) | digit;
+    }
+    *d = val;
+    return TRUE;
+}
+
+static gboolean get4hexdigits(const char *p, WORD *w)
+{
+    int digit;
+    WORD val;
+    int i;
+
+    val = 0;
+    for(i = 0; i < 4; i++){
+        digit = gethexdigit(p++);
+        if(digit == -1){
+            return FALSE; /* Not a hex digit */
+        }
+        val = (val << 4) | digit;
+    }
+    *w = val;
+    return TRUE;
+}
 
 /**********************************************************************************/
 /* returns the interface friendly name for a device name, if it is unable to
@@ -246,6 +294,8 @@ void get_windows_interface_friendlyname(/* IN */ char *interface_devicename, /*
 {
     const char* guid_text;
     GUID guid;
+    int i;
+    int digit1, digit2;
 
     g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_DEBUG, "test, 1,2,3");
 
@@ -265,41 +315,91 @@ void get_windows_interface_friendlyname(/* IN */ char *interface_devicename, /*
         guid_text=interface_devicename;
     }
 
-    /*** Convert the GUID text to a GUID structure */
-    {
-        /* Part 1: (presumed) ASCII guid_text to UTF-16 */
-        WCHAR wGuidText[39];
-        HRESULT hr;
-        int size=39; /* a guid should always been 38 unicode characters in length (+1 for null termination) */
-        size=MultiByteToWideChar(CP_ACP, 0, guid_text, -1, wGuidText, size);
-        if(size!=39){
-            /*
-             * GUID text to UTF-16 conversion failed.
-             * XXX - is this assuming the GUID text is in the local
-             * code page?  If so, the error might just indicate that
-             * it's not in the local code page; should we assume it's
-             * UTF-8?  If so, what if it's not *valid* UTF-8? Should
-             * we just silently return "no friendly name" if this
-             * fails?
-             */
-            g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_ERROR,
-                "Failed the extract guid from interface devicename, unicode convert result=%d, guid input ='%s', LastErrorCode=0x%08x.",
-                size, guid_text, GetLastError());
-            return;
+    /*
+     * If what follows is a GUID in {}, then convert it to a GUID structure
+     * and use that to look up the interface to get its friendly name.
+     */
+    if(*guid_text != '{'){
+        return; /* Nope, not enclosed in {} */
+    }
+    guid_text++;
+    /* There must be 8 hex digits; if so, they go into guid.Data1 */
+    if(!get8hexdigits(guid_text, &guid.Data1)){
+        return; /* nope, not 8 hex digits */
+    }
+    guid_text += 8;
+    /* Now there must be a hyphen */
+    if(*guid_text != '-'){
+        return; /* Nope */
+    }
+    guid_text++;
+    /* There must be 4 hex digits; if so, they go into guid.Data2 */
+    if(!get4hexdigits(guid_text, &guid.Data2)){
+        return; /* nope, not 4 hex digits */
+    }
+    guid_text += 4;
+    /* Now there must be a hyphen */
+    if(*guid_text != '-'){
+        return; /* Nope */
+    }
+    guid_text++;
+    /* There must be 4 hex digits; if so, they go into guid.Data3 */
+    if(!get4hexdigits(guid_text, &guid.Data3)){
+        return; /* nope, not 4 hex digits */
+    }
+    guid_text += 4;
+    /* Now there must be a hyphen */
+    if(*guid_text != '-'){
+        return; /* Nope */
+    }
+    guid_text++;
+    /*
+     * There must be 4 hex digits; if so, they go into the first 2 bytes
+     * of guid.Data4.
+     */
+    for(i = 0; i < 2; i++){
+        digit1 = gethexdigit(guid_text);
+        if(digit1 == -1){
+            return; /* Not a hex digit */
         }
-        /* Part 2: UTF-16 GUID text to GUID structure */
-        hr = CLSIDFromString(wGuidText, (LPCLSID)&guid);
-        if (hr != S_OK){
-            /*
-             * GUID text to CLSID conversion failed; this probably
-             * means that there isn't a GUID in the name, in which
-             * case we can't get a friendly name for that name.
-             *
-             * Don't complain - this isn't an error; not all
-             * interface names correspond to interfaces with GUIDs.
-             */
-            return;
+        guid_text++;
+        digit2 = gethexdigit(guid_text);
+        if(digit2 == -1){
+            return; /* Not a hex digit */
+        }
+        guid_text++;
+        guid.Data4[i] = (digit1 << 4)|(digit2);
+    }
+    /* Now there must be a hyphen */
+    if(*guid_text != '-'){
+        return; /* Nope */
+    }
+    guid_text++;
+    /*
+     * There must be 12 hex digits; if so,t hey go into the next 6 bytes
+     * of guid.Data4.
+     */
+    for(i = 0; i < 6; i++){
+        digit1 = gethexdigit(guid_text);
+        if(digit1 == -1){
+            return; /* Not a hex digit */
         }
+        guid_text++;
+        digit2 = gethexdigit(guid_text);
+        if(digit2 == -1){
+            return; /* Not a hex digit */
+        }
+        guid_text++;
+        guid.Data4[i+2] = (digit1 << 4)|(digit2);
+    }
+    /* Now there must be a closing } */
+    if(*guid_text != '}'){
+        return; /* Nope */
+    }
+    guid_text++;
+    /* And that must be the end of the string */
+    if(*guid_text != '\0'){
+        return; /* Nope */
     }
 
     /* guid okay, get the interface friendly name associated with the guid */