flow/pkts: allow matching on either direction

For flow.bytes and flow.pkts keywords, allow matching in either direction. Feature 5646
OISF · Nov 29, 2024 · 8801b03 · 8801b03
1 parent ac98119
commit 8801b03
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Showing 2 changed files with 25 additions and 0 deletions.
diff --git a/doc/userguide/rules/flow-keywords.rst b/doc/userguide/rules/flow-keywords.rst
@@ -331,6 +331,8 @@ following directions:
 
 * toserver
 
+* either
+
 Syntax::
 
  flow.pkts:<direction>,[op]<number>
@@ -339,6 +341,7 @@ The number of packets can be matched exactly, or compared using the _op_ setting
 
  flow.pkts:toclient,3    # exactly 3
  flow.pkts:toserver,<3   # smaller than 3
+ flow.pkts:either,>=2  # greater than or equal to 2
 
 Signature example::
 
@@ -358,6 +361,8 @@ following directions:
 
 * toserver
 
+* either
+
 Syntax::
 
  flow.bytes:<direction>,[op]<number>
@@ -366,6 +371,7 @@ The number of bytes can be matched exactly, or compared using the _op_ setting::
 
  flow.bytes:toclient,3    # exactly 3
  flow.bytes:toserver,<3   # smaller than 3
+ flow.bytes:either,>=2  # greater than or equal to 2
 
 Signature example::
 

diff --git a/src/detect-flow-pkts.c b/src/detect-flow-pkts.c
@@ -25,6 +25,7 @@
 
 #define DETECT_FLOW_TO_SERVER 1
 #define DETECT_FLOW_TO_CLIENT 2
+#define DETECT_FLOW_TO_EITHER 3
 
 typedef struct DetectFlow_ {
     DetectU32Data *pkt_data;
@@ -44,6 +45,13 @@ static int DetectFlowPktsMatch(
         return DetectU32Match(p->flow->todstpktcnt, df->pkt_data);
     } else if (df->dir == DETECT_FLOW_TO_CLIENT) {
         return DetectU32Match(p->flow->tosrcpktcnt, df->pkt_data);
+    } else if (df->dir == DETECT_FLOW_TO_EITHER) {
+        if (DetectU32Match(p->flow->tosrcpktcnt, df->pkt_data)) {
+            return 1;
+        }
+        if (DetectU32Match(p->flow->todstpktcnt, df->pkt_data)) {
+            return 1;
+        }
     }
     return 0;
 }
@@ -131,6 +139,8 @@ static int DetectFlowPktsSetup(DetectEngineCtx *de_ctx, Signature *s, const char
             df->dir = DETECT_FLOW_TO_SERVER;
         } else if (strcmp(token, "toclient") == 0) {
             df->dir = DETECT_FLOW_TO_CLIENT;
+        } else if (strcmp(token, "either") == 0) {
+            df->dir = DETECT_FLOW_TO_EITHER;
         }
 
         if (dir_set) {
@@ -234,6 +244,13 @@ static int DetectFlowBytesMatch(
         return DetectU64Match(p->flow->todstbytecnt, df->byte_data);
     } else if (df->dir == DETECT_FLOW_TO_CLIENT) {
         return DetectU64Match(p->flow->tosrcbytecnt, df->byte_data);
+    } else if (df->dir == DETECT_FLOW_TO_EITHER) {
+        if (DetectU64Match(p->flow->tosrcbytecnt, df->byte_data)) {
+            return 1;
+        }
+        if (DetectU64Match(p->flow->todstbytecnt, df->byte_data)) {
+            return 1;
+        }
     }
     return 0;
 }
@@ -321,6 +338,8 @@ static int DetectFlowBytesSetup(DetectEngineCtx *de_ctx, Signature *s, const cha
             df->dir = DETECT_FLOW_TO_SERVER;
         } else if (strcmp(token, "toclient") == 0) {
             df->dir = DETECT_FLOW_TO_CLIENT;
+        } else if (strcmp(token, "either") == 0) {
+            df->dir = DETECT_FLOW_TO_EITHER;
         }
 
         if (dir_set) {