vici: Fall back to heap buffer when vararg printing on stack fails

This avoids failures when building log event messages including larger hexdumps.

diff --git a/src/libcharon/plugins/vici/vici_builder.c b/src/libcharon/plugins/vici/vici_builder.c
index 62d17632b39358f0626ac23d264896ce2efbbeca..82f12c9da7d927ada4ff935a975d7f0beb013917 100644 (file)
--- a/src/libcharon/plugins/vici/vici_builder.c
+++ b/src/libcharon/plugins/vici/vici_builder.c
@@ -84,6 +84,8 @@ METHOD(vici_builder_t, add, void,
 
        if (value.len > 0xffff)
        {
+               DBG1(DBG_ENC, "vici value exceeds size limit (%zu > %u)",
+                        value.len, 0xffff);
                this->error++;
                return;
        }
@@ -125,22 +127,56 @@ METHOD(vici_builder_t, add, void,
        }
 }
 
-METHOD(vici_builder_t, vadd_kv, void,
-       private_vici_builder_t *this, char *key, char *fmt, va_list args)
+/**
+ * Add a list item or a key/value, if key given
+ */
+static void vadd_kv_or_li(private_vici_builder_t *this, char *key,
+                                                 char *fmt, va_list args)
 {
-       char buf[2048];
+       u_char buf[512];
+       chunk_t value;
        ssize_t len;
+       va_list copy;
 
-       len = vsnprintf(buf, sizeof(buf), fmt, args);
-       if (len < 0 || len >= sizeof(buf))
+       va_copy(copy, args);
+       len = vsnprintf(buf, sizeof(buf), fmt, copy);
+       va_end(copy);
+       if (len >= sizeof(buf))
+       {
+               value = chunk_alloc(len + 1);
+               len = vsnprintf(value.ptr, value.len, fmt, args);
+       }
+       else
        {
-               DBG1(DBG_ENC, "vici builder format buffer exceeds limit");
+               value = chunk_create(buf, len);
+       }
+
+       if (len < 0)
+       {
+               DBG1(DBG_ENC, "vici builder format print failed");
                this->error++;
        }
        else
        {
-               add(this, VICI_KEY_VALUE, key, chunk_create(buf, len));
+               if (key)
+               {
+                       add(this, VICI_KEY_VALUE, key, value);
+               }
+               else
+               {
+                       add(this, VICI_LIST_ITEM, value);
+               }
        }
+       if (value.ptr != buf)
+       {
+               free(value.ptr);
+       }
+}
+
+METHOD(vici_builder_t, vadd_kv, void,
+       private_vici_builder_t *this, char *key, char *fmt, va_list args)
+{
+       vadd_kv_or_li(this, key, fmt, args);
 }
 
 METHOD(vici_builder_t, add_kv, void,
@@ -153,23 +189,10 @@ METHOD(vici_builder_t, add_kv, void,
        va_end(args);
 }
 
-
 METHOD(vici_builder_t, vadd_li, void,
        private_vici_builder_t *this, char *fmt, va_list args)
 {
-       char buf[2048];
-       ssize_t len;
-
-       len = vsnprintf(buf, sizeof(buf), fmt, args);
-       if (len < 0 || len >= sizeof(buf))
-       {
-               DBG1(DBG_ENC, "vici builder format buffer exceeds limit");
-               this->error++;
-       }
-       else
-       {
-               add(this, VICI_LIST_ITEM, chunk_create(buf, len));
-       }
+       vadd_kv_or_li(this, NULL, fmt, args);
 }
 
 METHOD(vici_builder_t, add_li, void,