detect/filemagic: fix thread ctx registration; reloads

Make sure thread ctx registration happens and id remains correct
in case of reloads.

To do so, move id var into the detect ctx.

(cherry picked from commit 2cac440f7d)

src/detect-engine.c

@@ -1986,6 +1986,7 @@ static DetectEngineCtx *DetectEngineCtxInitReal(enum DetectEngineType type, cons
     TAILQ_INIT(&de_ctx->sig_stat.failed_sigs);
     de_ctx->sigerror = NULL;
     de_ctx->type = type;
+    de_ctx->filemagic_thread_ctx_id = -1;
 
     if (type == DETECT_ENGINE_TYPE_DD_STUB || type == DETECT_ENGINE_TYPE_MT_STUB) {
         de_ctx->version = DetectEngineGetVersion();

src/detect-filemagic.c

@@ -92,8 +92,6 @@ static int DetectEngineInspectFilemagic(
         const Signature *s,
         Flow *f, uint8_t flags, void *alstate, void *txv, uint64_t tx_id);
 
-static int g_magic_thread_ctx_id = -1;
-
 /**
  * \brief Registration function for keyword: filemagic
  */
@@ -251,10 +249,10 @@ static int DetectFilemagicSetup (DetectEngineCtx *de_ctx, Signature *s, const ch
                 de_ctx, s, NULL, DETECT_FILE_MAGIC, g_file_magic_buffer_id, s->alproto) < 0)
         return -1;
 
-    if (g_magic_thread_ctx_id == -1) {
-        g_magic_thread_ctx_id = DetectRegisterThreadCtxFuncs(
+    if (de_ctx->filemagic_thread_ctx_id == -1) {
+        de_ctx->filemagic_thread_ctx_id = DetectRegisterThreadCtxFuncs(
                 de_ctx, "filemagic", DetectFilemagicThreadInit, NULL, DetectFilemagicThreadFree, 1);
-        if (g_magic_thread_ctx_id == -1)
+        if (de_ctx->filemagic_thread_ctx_id == -1)
             return -1;
     }
     return 0;
@@ -276,11 +274,10 @@ static int DetectFilemagicSetupSticky(DetectEngineCtx *de_ctx, Signature *s, con
     if (DetectBufferSetActiveList(s, g_file_magic_buffer_id) < 0)
         return -1;
 
-    if (g_magic_thread_ctx_id == -1) {
-        g_magic_thread_ctx_id = DetectRegisterThreadCtxFuncs(de_ctx, "filemagic",
-                DetectFilemagicThreadInit, NULL,
-                DetectFilemagicThreadFree, 1);
-        if (g_magic_thread_ctx_id == -1)
+    if (de_ctx->filemagic_thread_ctx_id == -1) {
+        de_ctx->filemagic_thread_ctx_id = DetectRegisterThreadCtxFuncs(
+                de_ctx, "filemagic", DetectFilemagicThreadInit, NULL, DetectFilemagicThreadFree, 1);
+        if (de_ctx->filemagic_thread_ctx_id == -1)
             return -1;
     }
     return 0;
@@ -301,7 +298,8 @@ static InspectionBuffer *FilemagicGetDataCallback(DetectEngineThreadCtx *det_ctx
 
     if (cur_file->magic == NULL) {
         DetectFilemagicThreadData *tfilemagic =
-            (DetectFilemagicThreadData *)DetectThreadCtxGetKeywordThreadCtx(det_ctx, g_magic_thread_ctx_id);
+                (DetectFilemagicThreadData *)DetectThreadCtxGetKeywordThreadCtx(
+                        det_ctx, det_ctx->de_ctx->filemagic_thread_ctx_id);
         if (tfilemagic == NULL) {
             return NULL;
         }

src/detect.h

@@ -807,6 +807,9 @@ typedef struct DetectEngineCtx_ {
     uint16_t mpm_matcher; /**< mpm matcher this ctx uses */
     uint16_t spm_matcher; /**< spm matcher this ctx uses */
 
+    /* registration id for per thread ctx for the filemagic/file.magic keywords */
+    int filemagic_thread_ctx_id;
+
     /* spm thread context prototype, built as spm matchers are constructed and
      * later used to construct thread context for each thread. */
     SpmGlobalThreadCtx *spm_global_thread_ctx;