From 1f810f8928624dc8bce04922d2fb309add13bcba Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Vladim=C3=ADr=20=C4=8Cun=C3=A1t?= <vladimir.cunat@nic.cz>
Date: Tue, 8 Feb 2022 12:59:31 +0100
Subject: [PATCH] modules/dnstap: improve UX for common errors
The main thing is the "failed to open socket" message.
But let's also elevate other fatal one-off logs to ERROR level.
---
modules/dnstap/README.rst | 2 ++
modules/dnstap/dnstap.c | 13 ++++++++-----
2 files changed, 10 insertions(+), 5 deletions(-)
diff --git a/modules/dnstap/README.rst b/modules/dnstap/README.rst
index 8a98d07eb..456d2188c 100644
--- a/modules/dnstap/README.rst
+++ b/modules/dnstap/README.rst
@@ -10,6 +10,8 @@ socket in `dnstap format <https://dnstap.info>`_ using fstrm framing library.
This logging is useful if you need effectively log all DNS traffic.
The unix socket and the socket reader must be present before starting resolver instances.
+Also it needs appropriate filesystem permissions;
+the typical user and group of the daemon are called ``knot-resolver``.
Tunables:
diff --git a/modules/dnstap/dnstap.c b/modules/dnstap/dnstap.c
index a137dadb7..a41138de7 100644
--- a/modules/dnstap/dnstap.c
+++ b/modules/dnstap/dnstap.c
@@ -22,6 +22,7 @@
#include <uv.h>
#define DEBUG_MSG(fmt, ...) kr_log_debug(DNSTAP, fmt, ##__VA_ARGS__);
+#define ERROR_MSG(fmt, ...) kr_log_error(DNSTAP, fmt, ##__VA_ARGS__);
#define CFG_SOCK_PATH "socket_path"
#define CFG_IDENTITY_STRING "identity"
#define CFG_VERSION_STRING "version"
@@ -415,7 +416,7 @@ int dnstap_config(struct kr_module *module, const char *conf) {
JsonNode *root_node = json_decode(conf);
if (!root_node) {
- DEBUG_MSG("error parsing json\n");
+ ERROR_MSG("error parsing json\n");
return kr_error(EINVAL);
}
@@ -484,13 +485,15 @@ int dnstap_config(struct kr_module *module, const char *conf) {
DEBUG_MSG("opening sock file %s\n",sock_path);
struct fstrm_writer *writer = dnstap_unix_writer(sock_path);
if (!writer) {
- DEBUG_MSG("can't create unix writer\n");
+ ERROR_MSG("failed to open socket %s\n"
+ "Please ensure that it exists beforehand and has appropriate access permissions.\n",
+ sock_path);
return kr_error(EINVAL);
}
struct fstrm_iothr_options *opt = fstrm_iothr_options_init();
if (!opt) {
- DEBUG_MSG("can't init fstrm options\n");
+ ERROR_MSG("can't init fstrm options\n");
fstrm_writer_destroy(&writer);
return kr_error(EINVAL);
}
@@ -499,7 +502,7 @@ int dnstap_config(struct kr_module *module, const char *conf) {
data->iothread = fstrm_iothr_init(opt, &writer);
fstrm_iothr_options_destroy(&opt);
if (!data->iothread) {
- DEBUG_MSG("can't init fstrm_iothr\n");
+ ERROR_MSG("can't init fstrm_iothr\n");
fstrm_writer_destroy(&writer);
return kr_error(ENOMEM);
}
@@ -510,7 +513,7 @@ int dnstap_config(struct kr_module *module, const char *conf) {
data->ioq = fstrm_iothr_get_input_queue_idx(data->iothread, 0);
if (!data->ioq) {
fstrm_iothr_destroy(&data->iothread);
- DEBUG_MSG("can't get fstrm queue\n");
+ ERROR_MSG("can't get fstrm queue\n");
return kr_error(EBUSY);
}
--
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