Fix undefined behavior (detected by gcc):

ndpi_define.h.in:218: Macros NDPI_SET(), NDPI_CLR(), NDPI_ISSET()
  runtime error: left shift of 1 by 31 places cannot be represented in type 'int'

http.c:364: strncpy((char*)flow->protos.http.nat_ip,(char*)packet->forwarded_line.ptr,len);
 runtime error: null pointer passed as argument 2, which is declared to never be null

ndpi_patricia.c:ndpi_comp_with_mask(): int m = ((-1) << (8 - (mask % 8)));
  runtime error: left shift of negative value -1

Original function ndpi_comp_with_mask() is unreadable and slow.
We have only 2 type of address: 32 bit and 128 bit. The optimized version works 6 times faster (IPv4).

1 files changed, 5 insertions, 3 deletions

diff --git a/src/lib/protocols/http.c b/src/lib/protocols/http.c
index 4ff65096b..6cc1033ba 100644
--- a/src/lib/protocols/http.c
+++ b/src/lib/protocols/http.c
@@ -360,9 +360,11 @@ static void check_content_type_and_change_protocol(struct ndpi_detection_module_
     strncpy((char*)flow->host_server_name, (char*)packet->host_line.ptr, len);
     flow->host_server_name[len] = '\0', flow->server_id = flow->dst;
 
-    len = ndpi_min(packet->forwarded_line.len, sizeof(flow->protos.http.nat_ip)-1);
-    strncpy((char*)flow->protos.http.nat_ip, (char*)packet->forwarded_line.ptr, len);
-    flow->protos.http.nat_ip[len] = '\0';
+    if(packet->forwarded_line.ptr) {
+        len = ndpi_min(packet->forwarded_line.len, sizeof(flow->protos.http.nat_ip)-1);
+        strncpy((char*)flow->protos.http.nat_ip, (char*)packet->forwarded_line.ptr, len);
+        flow->protos.http.nat_ip[len] = '\0';
+    }
 
     if(ndpi_struct->http_dont_dissect_response)
       parseHttpSubprotocol(ndpi_struct, flow);