More work on remote source

datasourcetracker.cc

@@ -18,6 +18,8 @@
 
 #include "config.hpp"
 
+#include <string.h>
+
 #include "configfile.h"
 #include "getopt.h"
 #include "datasourcetracker.h"
@@ -31,6 +33,7 @@
 #include "pcapng_stream_ringbuf.h"
 #include "streamtracker.h"
 #include "kis_httpd_registry.h"
+#include "endian_magic.h"
 
 DST_DatasourceProbe::DST_DatasourceProbe(GlobalRegistry *in_globalreg, 
         string in_definition, SharedTrackerElement in_protovec) {
@@ -1655,7 +1658,7 @@ dst_incoming_remote::dst_incoming_remote(GlobalRegistry *in_globalreg,
     timerid =
         timetracker->RegisterTimer(SERVER_TIMESLICES_SEC * 10, NULL, 0, 
             [this] (int) -> int {
-                _MSG("Remote source connected but never sent a NEWSOURCE control, "
+                _MSG("Remote source connected but didn't send a NEWSOURCE control, "
                         "closing connection.", MSGFLAG_ERROR);
                 rbuf_handler->ProtocolError();
                 delete(this);
@@ -1664,6 +1667,7 @@ dst_incoming_remote::dst_incoming_remote(GlobalRegistry *in_globalreg,
 }
 
 dst_incoming_remote::~dst_incoming_remote() {
+    fprintf(stderr, "~dst_incoming_remote()\n");
     shared_ptr<Timetracker> timetracker = globalreg->FetchGlobalAs<Timetracker>("TIMETRACKER");
 
     // Kill the error timer
@@ -1677,9 +1681,155 @@ dst_incoming_remote::~dst_incoming_remote() {
 
 void dst_incoming_remote::BufferAvailable(size_t in_amt) {
     fprintf(stderr, "debug - dst - incoming remote - buffer available %lu\n", in_amt);
+    // Handle reading raw frames off the incoming buffer, but we only look for the
+    // NEWSOURCE command; any other frame is an error.
+
+    simple_cap_proto_frame_t *frame;
+    uint8_t *buf;
+    uint32_t frame_sz;
+    uint32_t header_checksum, data_checksum, calc_checksum;
+
+    string definition;
+    string srctype;
+
+    while (1) {
+        if (rbuf_handler == NULL)
+            return;
+
+        size_t buffamt = rbuf_handler->GetReadBufferUsed();
+        if (buffamt < sizeof(simple_cap_proto_t)) {
+            return;
+        }
+
+        // Allocate as much as we can and peek it from the buffer
+        buf = new uint8_t[buffamt];
+        rbuf_handler->PeekReadBufferData(buf, buffamt);
+
+        // Turn it into a frame header
+        frame = (simple_cap_proto_frame_t *) buf;
+
+        if (kis_ntoh32(frame->header.signature) != KIS_CAP_SIMPLE_PROTO_SIG) {
+            delete[] buf;
+            _MSG("Got an invalid remote data source connection, disconnecting.",
+                    MSGFLAG_ERROR);
+            rbuf_handler->ProtocolError();
+            return;
+        }
+
+        // Get the frame header checksum and validate it; to validate we need to clear
+        // both the frame and the data checksum fields so remember them both now
+        header_checksum = kis_ntoh32(frame->header.header_checksum);
+        data_checksum = kis_ntoh32(frame->header.data_checksum);
+
+        // Zero the checksum field in the packet
+        frame->header.header_checksum = 0;
+        frame->header.data_checksum = 0;
+
+        // Calc the checksum of the header
+        calc_checksum = Adler32Checksum((const char *) frame, 
+                sizeof(simple_cap_proto_t));
+
+        // Compare to the saved checksum
+        if (calc_checksum != header_checksum) {
+            delete[] buf;
+
+            _MSG("Got an invalid remote data source connection, invalid checksum, "
+                    "disconnecting.", MSGFLAG_ERROR);
+            rbuf_handler->ProtocolError();
+
+            return;
+        }
+
+        // Get the size of the frame
+        frame_sz = kis_ntoh32(frame->header.packet_sz);
+
+        if (frame_sz > buffamt) {
+            // Nothing we can do right now, not enough data to 
+            // make up a complete packet.
+            delete[] buf;
+            return;
+        }
+
+        // Calc the checksum of the rest
+        calc_checksum = Adler32Checksum((const char *) buf, frame_sz);
+
+        // Compare to the saved checksum
+        if (calc_checksum != data_checksum) {
+            delete[] buf;
+
+            _MSG("Got an invalid remote data source connection, invalid checksum, "
+                    "disconnecting.", MSGFLAG_ERROR);
+            rbuf_handler->ProtocolError();
+
+            return;
+        }
+
+        // Consume the packet in the ringbuf 
+        rbuf_handler->GetReadBufferData(NULL, frame_sz);
+
+        // Check the header type
+        if (strncmp(frame->header.type, "NEWSOURCE", 16) != 0) {
+            delete[] buf;
+
+            _MSG("Got an invalid remote data source connection, invalid frame "
+                    "(expected NEWSOURCE), disconnecting.", MSGFLAG_ERROR);
+            rbuf_handler->ProtocolError();
+
+            return;
+        }
+
+        size_t data_offt = 0;
+        for (unsigned int kvn = 0; kvn < kis_ntoh32(frame->header.num_kv_pairs); kvn++) {
+
+            if (frame_sz < sizeof(simple_cap_proto_t) + 
+                    sizeof(simple_cap_proto_kv_t) + data_offt) {
+                delete[] buf;
+
+                _MSG("Got an invalid remote data source connection, invalid frame "
+                        "(KV too long for frame), disconnecting.", MSGFLAG_ERROR);
+                rbuf_handler->ProtocolError();
+
+                return;
+            }
+
+            simple_cap_proto_kv_t *pkv =
+                (simple_cap_proto_kv_t *) &((frame->data)[data_offt]);
+
+            data_offt += 
+                sizeof(simple_cap_proto_kv_h_t) + kis_ntoh32(pkv->header.obj_sz);
+
+            // We only care about 2 KV types but will skip the rest
+            if (strncmp(pkv->header.key, "DEFINITION", 16) == 0) {
+                definition = string((char *) pkv->object, kis_ntoh32(pkv->header.obj_sz));
+            } else if (strncmp(pkv->header.key, "SOURCETYPE", 16) == 0) {
+                srctype = string((char *) pkv->object, kis_ntoh32(pkv->header.obj_sz));
+            }
+        }
+
+        delete[] buf;
+
+        if (definition == "") {
+            _MSG("Got an invalid remote data source connection, invalid frame "
+                    "(missing DEFINITION kv), disconnecting.", MSGFLAG_ERROR);
+            rbuf_handler->ProtocolError();
+
+            return;
+        }
+
+        if (srctype == "") {
+            _MSG("Got an invalid remote data source connection, invalid frame "
+                    "(missing DEFINITION kv), disconnecting.", MSGFLAG_ERROR);
+            rbuf_handler->ProtocolError();
+
+            return;
+
+        }
+
+    }
 }
 
 void dst_incoming_remote::BufferError(string in_error) {
     fprintf(stderr, "debug - dst - incoming remote - buffer error - %s\n", in_error.c_str());
+    delete(this);
 }