Changeset 994

Timestamp:

09/17/06 18:36:13 (7 years ago)

Author:

smr26

Message:

Fix get_payload_from_link for prism and radiotap.
Make sure to use bswap when looking at radiotap length.
Tidy up exported API, don't export get_payload_from_prism or _from_radiotap.

Location:

trunk/lib

Files:

• libtrace.h.in (modified) (2 diffs)
• link_wireless.c (modified) (1 diff)
• protocols.c (modified) (1 diff)

trunk/lib/libtrace.h.in

@@ -495 +495 @@
  * specified in the it_present bitmask. If bit 31 of it_present is set, then
  * another bitmask follows.
- * NB: All of the radiotap data fields are in little-endian byte-order.
+ * @note All of the radiotap data fields are in little-endian byte-order.
  */
 typedef struct libtrace_radiotap_t {
@@ -851 +851 @@
 DLLEXPORT void *trace_get_payload_from_ip(libtrace_ip_t *ip, uint8_t *proto,
                 uint32_t *remaining);
-
-
-/** Gets a pointer to the payload given a pointer to the Radiotap header
- * @param link a pointer to the Radiotap header
- * @param[out] type     An output variable of the ethernet type
- * @param[in,out] remaining Updated with the number of bytes remaining
- *
- * @return a pointer to the 802.11 header, or NULL if header isn't
- * present.
- *
- * Remaining may be NULL.  If Remaining is not NULL it must point to the number
- * of bytes captured of the linklayer and beyond.  It will be updated after
- * this function to the number of bytes remaining after the Radiotap header has been 
- * removed.
- *
- * type may be NULL if not needed.
- */
-DLLEXPORT void *trace_get_payload_from_radiotap(void *link,
-                uint16_t *type, uint32_t *remaining);
-
-
-/** Gets a pointer to the payload given a pointer to the Prism monitoring header
- * @param link a pointer to the Prism monitoring header
- * @param[out] type     An output variable of the ethernet type
- * @param[in,out] remaining Updated with the number of bytes remaining
- *
- * @return a pointer to the 802.11 header, or NULL if header isn't
- * present.
- *
- * Remaining may be NULL.  If Remaining is not NULL it must point to the number
- * of bytes captured of the linklayer and beyond.  It will be updated after
- * this function to the number of bytes remaining after the Radiotap header has been 
- * removed.
- *
- * type may be NULL if not needed.
- */
-DLLEXPORT void *trace_get_payload_from_prism(void *link,
-                uint16_t *type, uint32_t *remaining);
-
 
 /** Gets a pointer to the payload given a pointer to the link header

trunk/lib/link_wireless.c

@@ -48 +48 @@
  * @note Radiotap fields are always little-endian
  */
-DLLEXPORT void *trace_get_radiotap_field(void *link, libtrace_radiotap_field_t field)
+static void *trace_get_radiotap_field(void *link, libtrace_radiotap_field_t field)
 {
     struct libtrace_radiotap_t *rtap = (struct libtrace_radiotap_t *)link;

trunk/lib/protocols.c

@@ -190 +190 @@
 /* Returns the 'payload' of the prism header, which is the 802.11 frame */
 static void *trace_get_payload_from_prism (void *link,
-        uint16_t *type, uint32_t *remaining)
-{
-    if (remaining) {
-        if (*remaining<144) 
-            return NULL;
-        *remaining-=144;
-    }
-
-    if (type) *type = 0;
-
-    return (void *) ((char*)link+144);
+                uint16_t *type, uint32_t *remaining)
+{
+        if (remaining) {
+                if (*remaining<144) 
+                        return NULL;
+                *remaining-=144;
+        }
+
+        if (type) *type = 0;
+
+        return (void *) ((char*)link+144);
 }
 
 /* Returns the 'payload' of the radiotap header, which is the 802.11 frame */
 static void *trace_get_payload_from_radiotap (void *link, 
-        uint16_t *type, uint32_t *remaining)
-{
-    struct libtrace_radiotap_t *rtap = (struct libtrace_radiotap_t*)link;
-    if (remaining) {
-                if (*remaining<rtap->it_len) 
-                        return NULL;
-                *remaining-=rtap->it_len;
+                uint16_t *type, uint32_t *remaining)
+{
+        struct libtrace_radiotap_t *rtap = (struct libtrace_radiotap_t*)link;
+        uint16_t rtaplen = bswap_le_to_host16(rtap->it_len);
+        if (remaining) {
+                if (*remaining < rtaplen)
+                        return NULL;
+                *remaining -= rtaplen;
         }
 
         if (type) *type = 0;
-    
-        return (void*) ((char*)link + rtap->it_len);
-}
-        
+
+        return (void*) ((char*)link + rtaplen);
+}
+
 void *trace_get_payload_from_link(void *link, libtrace_linktype_t linktype, 
                 uint16_t *type, uint32_t *remaining)
 {
-    void *l;
-    
+        void *l = NULL;
+
         switch(linktype) {
                 case TRACE_TYPE_80211_PRISM:
-            l = trace_get_payload_from_prism(link,type,remaining);
-            l ? trace_get_payload_from_80211(l,type,remaining) : NULL;
-        case TRACE_TYPE_80211_RADIO:
-            l = trace_get_payload_from_radiotap(link,type,remaining);
-            l ? trace_get_payload_from_80211(l,type,remaining) : NULL ;
+                        l = trace_get_payload_from_prism(link,type,remaining);
+                        return(l ? trace_get_payload_from_80211(l,type,remaining) : NULL);
+                case TRACE_TYPE_80211_RADIO:
+                        l = trace_get_payload_from_radiotap(link,type,remaining);
+                        return(l ? trace_get_payload_from_80211(l,type,remaining) : NULL);
                 case TRACE_TYPE_80211:
                         return trace_get_payload_from_80211(link,type,remaining);