drop json: make alerts logging optional

Make logging out alerts that caused the drop optional.

src/output-json-drop.c

@@ -61,9 +61,15 @@
 #ifdef HAVE_LIBJANSSON
 #include <jansson.h>
 
+#define LOG_DROP_ALERTS 1
+
+typedef struct JsonDropOutputCtx_ {
+    LogFileCtx *file_ctx;
+    uint8_t flags;
+} JsonDropOutputCtx;
+
 typedef struct JsonDropLogThread_ {
-    /** LogFileCtx has the pointer to the file and a mutex to allow multithreading */
-    LogFileCtx* file_ctx;
+    JsonDropOutputCtx *drop_ctx;
     MemBuffer *buffer;
 } JsonDropLogThread;
 
@@ -135,20 +141,22 @@ static int DropLogJSON (JsonDropLogThread *aft, const Packet *p)
     }
     json_object_set_new(js, "drop", djs);
 
-    int i;
-    for (i = 0; i < p->alerts.cnt; i++) {
-        const PacketAlert *pa = &p->alerts.alerts[i];
-        if (unlikely(pa->s == NULL)) {
-            continue;
-        }
-        if ((pa->action & (ACTION_REJECT|ACTION_REJECT_DST|ACTION_REJECT_BOTH)) ||
-           ((pa->action & ACTION_DROP) && EngineModeIsIPS()))
-        {
-            AlertJsonHeader(pa, js);
+    if (aft->drop_ctx->flags & LOG_DROP_ALERTS) {
+        int i;
+        for (i = 0; i < p->alerts.cnt; i++) {
+            const PacketAlert *pa = &p->alerts.alerts[i];
+            if (unlikely(pa->s == NULL)) {
+                continue;
+            }
+            if ((pa->action & (ACTION_REJECT|ACTION_REJECT_DST|ACTION_REJECT_BOTH)) ||
+               ((pa->action & ACTION_DROP) && EngineModeIsIPS()))
+            {
+                AlertJsonHeader(pa, js);
+            }
         }
     }
 
-    OutputJSONBuffer(js, aft->file_ctx, buffer);
+    OutputJSONBuffer(js, aft->drop_ctx->file_ctx, buffer);
     json_object_del(js, "drop");
     json_object_clear(js);
     json_decref(js);
@@ -163,6 +171,7 @@ static TmEcode JsonDropLogThreadInit(ThreadVars *t, void *initdata, void **data)
     if (unlikely(aft == NULL))
         return TM_ECODE_FAILED;
     memset(aft, 0, sizeof(*aft));
+
     if(initdata == NULL)
     {
         SCLogDebug("Error getting context for AlertFastLog.  \"initdata\" argument NULL");
@@ -177,7 +186,7 @@ static TmEcode JsonDropLogThreadInit(ThreadVars *t, void *initdata, void **data)
     }
 
     /** Use the Ouptut Context (file pointer and mutex) */
-    aft->file_ctx = ((OutputCtx *)initdata)->data;
+    aft->drop_ctx = ((OutputCtx *)initdata)->data;
 
     *data = (void *)aft;
     return TM_ECODE_OK;
@@ -216,6 +225,15 @@ static void JsonDropLogDeInitCtxSub(OutputCtx *output_ctx)
     SCFree(output_ctx);
 }
 
+static void JsonDropOutputCtxFree(JsonDropOutputCtx *drop_ctx)
+{
+    if (drop_ctx != NULL) {
+        if (drop_ctx->file_ctx != NULL)
+            LogFileFreeCtx(drop_ctx->file_ctx);
+        SCFree(drop_ctx);
+    }
+}
+
 #define DEFAULT_LOG_FILENAME "drop.json"
 static OutputCtx *JsonDropLogInitCtx(ConfNode *conf)
 {
@@ -225,22 +243,37 @@ static OutputCtx *JsonDropLogInitCtx(ConfNode *conf)
         return NULL;
     }
 
-    LogFileCtx *logfile_ctx = LogFileNewCtx();
-    if (logfile_ctx == NULL) {
+    JsonDropOutputCtx *drop_ctx = SCCalloc(1, sizeof(*drop_ctx));
+    if (drop_ctx == NULL)
+        return NULL;
+
+    drop_ctx->file_ctx = LogFileNewCtx();
+    if (drop_ctx->file_ctx == NULL) {
+        JsonDropOutputCtxFree(drop_ctx);
         return NULL;
     }
 
-    if (SCConfLogOpenGeneric(conf, logfile_ctx, DEFAULT_LOG_FILENAME) < 0) {
-        LogFileFreeCtx(logfile_ctx);
+    if (SCConfLogOpenGeneric(conf, drop_ctx->file_ctx, DEFAULT_LOG_FILENAME) < 0) {
+        JsonDropOutputCtxFree(drop_ctx);
         return NULL;
     }
 
     OutputCtx *output_ctx = SCCalloc(1, sizeof(OutputCtx));
     if (unlikely(output_ctx == NULL)) {
+        JsonDropOutputCtxFree(drop_ctx);
         return NULL;
     }
 
-    output_ctx->data = logfile_ctx;
+    if (conf) {
+        const char *extended = ConfNodeLookupChildValue(conf, "alerts");
+        if (extended != NULL) {
+            if (ConfValIsTrue(extended)) {
+                drop_ctx->flags = LOG_DROP_ALERTS;
+            }
+        }
+    }
+
+    output_ctx->data = drop_ctx;
     output_ctx->DeInit = JsonDropLogDeInitCtx;
     return output_ctx;
 }
@@ -255,12 +288,28 @@ static OutputCtx *JsonDropLogInitCtxSub(ConfNode *conf, OutputCtx *parent_ctx)
 
     AlertJsonThread *ajt = parent_ctx->data;
 
+    JsonDropOutputCtx *drop_ctx = SCCalloc(1, sizeof(*drop_ctx));
+    if (drop_ctx == NULL)
+        return NULL;
+
     OutputCtx *output_ctx = SCCalloc(1, sizeof(OutputCtx));
     if (unlikely(output_ctx == NULL)) {
+        JsonDropOutputCtxFree(drop_ctx);
         return NULL;
     }
 
-    output_ctx->data = ajt->file_ctx;
+    if (conf) {
+        const char *extended = ConfNodeLookupChildValue(conf, "alerts");
+        if (extended != NULL) {
+            if (ConfValIsTrue(extended)) {
+                drop_ctx->flags = LOG_DROP_ALERTS;
+            }
+        }
+    }
+
+    drop_ctx->file_ctx = ajt->file_ctx;
+
+    output_ctx->data = drop_ctx;
     output_ctx->DeInit = JsonDropLogDeInitCtxSub;
     return output_ctx;
 }

suricata.yaml.in

@@ -136,7 +136,8 @@ outputs:
         - files:
             force-magic: no   # force logging magic on all logged files
             force-md5: no     # force logging of md5 checksums
-        #- drop
+        #- drop:
+        #    alerts: no       # log alerts that caused drops
         - smtp
         - ssh
         # bi-directional flows