Fix phase 2 and 3 audit logging in case of internal redirect

Phase 2 and 3 log entries were not logged in the audit log in case of an
internal redirect. Only phase 1 and 4 ones were logged, the former because
early logging was explicitly enabled and the latter because the internal
redirect does not work in this phase.

This commit unconditionally enables early logging in all ModSecurity
phases. Since the Nginx log phase may not be executed in case of an
intervention, the process intervention function is the only place which is
guaranteed to call the log handler in such a case.

Co-authored-by: Dimitris Kolotouros <[email protected]>
Co-authored-by: Thanos Giannopoulos <[email protected]>

src/ngx_http_modsecurity_body_filter.c

@@ -147,7 +147,7 @@ ngx_http_modsecurity_body_filter(ngx_http_request_t *r, ngx_chain_t *in)
         int ret;
 
         msc_append_response_body(ctx->modsec_transaction, data, chain->buf->last - data);
-        ret = ngx_http_modsecurity_process_intervention(ctx->modsec_transaction, r, 0);
+        ret = ngx_http_modsecurity_process_intervention(ctx->modsec_transaction, r);
         if (ret > 0) {
             return ngx_http_filter_finalize_request(r,
                 &ngx_http_modsecurity_module, ret);
@@ -165,7 +165,7 @@ ngx_http_modsecurity_body_filter(ngx_http_request_t *r, ngx_chain_t *in)
 
 /* XXX: I don't get how body from modsec being transferred to nginx's buffer.  If so - after adjusting of nginx's
    XXX: body we can proceed to adjust body size (content-length).  see xslt_body_filter() for example */
-            ret = ngx_http_modsecurity_process_intervention(ctx->modsec_transaction, r, 0);
+            ret = ngx_http_modsecurity_process_intervention(ctx->modsec_transaction, r);
             if (ret > 0) {
                 return ret;
             }

src/ngx_http_modsecurity_common.h

@@ -137,7 +137,7 @@ typedef struct {
 extern ngx_module_t ngx_http_modsecurity_module;
 
 /* ngx_http_modsecurity_module.c */
-int ngx_http_modsecurity_process_intervention (Transaction *transaction, ngx_http_request_t *r, ngx_int_t early_log);
+int ngx_http_modsecurity_process_intervention (Transaction *transaction, ngx_http_request_t *r);
 ngx_http_modsecurity_ctx_t *ngx_http_modsecurity_create_ctx(ngx_http_request_t *r);
 char *ngx_str_to_char(ngx_str_t a, ngx_pool_t *p);
 #if (NGX_PCRE2)

src/ngx_http_modsecurity_header_filter.c

@@ -528,7 +528,7 @@ ngx_http_modsecurity_header_filter(ngx_http_request_t *r)
     old_pool = ngx_http_modsecurity_pcre_malloc_init(r->pool);
     msc_process_response_headers(ctx->modsec_transaction, status, http_response_ver);
     ngx_http_modsecurity_pcre_malloc_done(old_pool);
-    ret = ngx_http_modsecurity_process_intervention(ctx->modsec_transaction, r, 0);
+    ret = ngx_http_modsecurity_process_intervention(ctx->modsec_transaction, r);
     if (r->error_page) {
         return ngx_http_next_header_filter(r);
     }

src/ngx_http_modsecurity_log.c

@@ -78,6 +78,7 @@ ngx_http_modsecurity_log_handler(ngx_http_request_t *r)
     old_pool = ngx_http_modsecurity_pcre_malloc_init(r->pool);
     msc_process_logging(ctx->modsec_transaction);
     ngx_http_modsecurity_pcre_malloc_done(old_pool);
+    ctx->logged = 1;
 
     return NGX_OK;
 }

src/ngx_http_modsecurity_module.c

@@ -137,7 +137,7 @@ ngx_inline char *ngx_str_to_char(ngx_str_t a, ngx_pool_t *p)
 
 
 int
-ngx_http_modsecurity_process_intervention (Transaction *transaction, ngx_http_request_t *r, ngx_int_t early_log)
+ngx_http_modsecurity_process_intervention (Transaction *transaction, ngx_http_request_t *r)
 {
     char *log = NULL;
     ModSecurityIntervention intervention;
@@ -222,11 +222,8 @@ ngx_http_modsecurity_process_intervention (Transaction *transaction, ngx_http_re
          */
         msc_update_status_code(ctx->modsec_transaction, intervention.status);
 
-        if (early_log) {
-            dd("intervention -- calling log handler manually with code: %d", intervention.status);
-            ngx_http_modsecurity_log_handler(r);
-            ctx->logged = 1;
-	}
+        dd("intervention -- calling log handler manually with code: %d", intervention.status);
+        ngx_http_modsecurity_log_handler(r);
 
         if (r->header_sent)
         {

src/ngx_http_modsecurity_pre_access.c

@@ -195,7 +195,7 @@ ngx_http_modsecurity_pre_access_handler(ngx_http_request_t *r)
              * it may ask for a intervention in consequence of that.
              *
              */
-            ret = ngx_http_modsecurity_process_intervention(ctx->modsec_transaction, r, 0);
+            ret = ngx_http_modsecurity_process_intervention(ctx->modsec_transaction, r);
             if (ret > 0) {
                 return ret;
             }
@@ -214,7 +214,7 @@ ngx_http_modsecurity_pre_access_handler(ngx_http_request_t *r)
         msc_process_request_body(ctx->modsec_transaction);
         ngx_http_modsecurity_pcre_malloc_done(old_pool);
 
-        ret = ngx_http_modsecurity_process_intervention(ctx->modsec_transaction, r, 0);
+        ret = ngx_http_modsecurity_process_intervention(ctx->modsec_transaction, r);
         if (r->error_page) {
             return NGX_DECLINED;
             }

src/ngx_http_modsecurity_rewrite.c

@@ -117,7 +117,7 @@ ngx_http_modsecurity_rewrite_handler(ngx_http_request_t *r)
          *
          */
         dd("Processing intervention with the connection information filled in");
-        ret = ngx_http_modsecurity_process_intervention(ctx->modsec_transaction, r, 1);
+        ret = ngx_http_modsecurity_process_intervention(ctx->modsec_transaction, r);
         if (ret > 0) {
             ctx->intervention_triggered = 1;
             return ret;
@@ -166,7 +166,7 @@ ngx_http_modsecurity_rewrite_handler(ngx_http_request_t *r)
         ngx_http_modsecurity_pcre_malloc_done(old_pool);
 
         dd("Processing intervention with the transaction information filled in (uri, method and version)");
-        ret = ngx_http_modsecurity_process_intervention(ctx->modsec_transaction, r, 1);
+        ret = ngx_http_modsecurity_process_intervention(ctx->modsec_transaction, r);
         if (ret > 0) {
             ctx->intervention_triggered = 1;
             return ret;
@@ -215,7 +215,7 @@ ngx_http_modsecurity_rewrite_handler(ngx_http_request_t *r)
         msc_process_request_headers(ctx->modsec_transaction);
         ngx_http_modsecurity_pcre_malloc_done(old_pool);
         dd("Processing intervention with the request headers information filled in");
-        ret = ngx_http_modsecurity_process_intervention(ctx->modsec_transaction, r, 1);
+        ret = ngx_http_modsecurity_process_intervention(ctx->modsec_transaction, r);
         if (r->error_page) {
             return NGX_DECLINED;
             }