Some plugins want to add messages to the openvpn log file. The
plugin_log() API provides a way for them to do so.
Signed-off-by: Heiko Hund <heiko.h...@sophos.com>
---
This is the first variant of PATCH 2/2 that deals with the fact that
the original plugin_log() approach was not working on Windows.
It uses an inline function on Windows which explicitly resolves the
symbol needed to log from plug-ins, as the dynamic linker fails to do so.
OpenVPN exports the plugin_log_va() function for use by plug-ins.
Pros:
+ simple to use, just call plugin_log() in you plug-in code
+ available to any plug-in regradless of its API version
Cons:
- looks a bit messy with all the preprocessor stuff in place
- multiple symbol look-ups when including openvpn-plugin.h in two+ files
include/openvpn-plugin.h | 48 ++++++++++++++++++++++++++++++++++++++-
src/openvpn/plugin.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 103 insertions(+), 1 deletion(-)
diff --git a/include/openvpn-plugin.h b/include/openvpn-plugin.h
index 1c80eec..eaf9e7c 100644
--- a/include/openvpn-plugin.h
+++ b/include/openvpn-plugin.h
@@ -47,6 +47,52 @@ typedef X509 openvpn_x509_cert_t;
extern "C" {
#endif
+/**
+ * plugin_log() - plug-in log function.
+ *
+ * Use this function to add information to the OpenVPN log file.
+ * Messages will only be displayed if the plugin_name parameter is set.
+ * Debug messages will only be displayed with plug-in debug log verbosity.
+ *
+ */
+typedef enum
+{
+ PLOG_ERR = (1 << 0), /* Error condition message */
+ PLOG_WARN = (1 << 1), /* General warning message */
+ PLOG_NOTE = (1 << 2), /* Informational message */
+ PLOG_DEBUG = (1 << 3), /* Debug message, displayed if verb >= 7 */
+
+ PLOG_ERRNO = (1 << 8), /* Add error description to message */
+ PLOG_NOMUTE = (1 << 9), /* Mute setting does not apply for message */
+
+} openvpn_plugin_log_flags_t;
+
+#if defined(WIN32)
+#include <windows.h>
+#include <stdarg.h>
+
+static inline void
+plugin_log (openvpn_plugin_log_flags_t flags, const char *plugin_name, const
char *format, ...)
+{
+ typedef void (*log_fn_t)(openvpn_plugin_log_flags_t, const char *, const
char *, va_list);
+ static log_fn_t log = NULL;
+ if (log == NULL)
+ {
+ log = (log_fn_t) GetProcAddress (GetModuleHandle (NULL),
"plugin_log_va");
+ if (log == NULL)
+ return;
+ }
+
+ va_list arglist;
+ va_start(arglist, format);
+ log(flags, plugin_name, format, arglist);
+ va_end(arglist);
+}
+#else
+void plugin_log (openvpn_plugin_log_flags_t flags, const char *plugin_name,
const char *format, ...);
+#endif
+
+
/*
* Plug-in types. These types correspond to the set of script callbacks
* supported by OpenVPN.
@@ -145,7 +191,7 @@ typedef void *openvpn_plugin_handle_t;
/*
* For Windows (needs to be modified for MSVC)
*/
-#if defined(__MINGW32_VERSION) && !defined(OPENVPN_PLUGIN_H)
+#if defined(WIN32)
# define OPENVPN_EXPORT __declspec(dllexport)
#else
# define OPENVPN_EXPORT
diff --git a/src/openvpn/plugin.c b/src/openvpn/plugin.c
index 7ce2f5e..b146a52 100644
--- a/src/openvpn/plugin.c
+++ b/src/openvpn/plugin.c
@@ -286,6 +286,62 @@ plugin_init_item (struct plugin *p, const struct
plugin_option *o)
gc_free (&gc);
}
+OPENVPN_EXPORT void
+plugin_log_va (openvpn_plugin_log_flags_t flags, const char *name, const char
*format, va_list arglist)
+{
+ unsigned int msg_flags;
+
+ if (!format)
+ return;
+
+ if (!name || name[0] == '\0')
+ {
+ msg (D_PLUGIN_DEBUG, "PLUGIN: suppressed log message from plugin with
unknown name");
+ return;
+ }
+
+ if (flags & PLOG_ERR)
+ msg_flags = M_INFO | M_NONFATAL;
+ else if (flags & PLOG_WARN)
+ msg_flags = M_INFO | M_WARN;
+ else if (flags & PLOG_NOTE)
+ msg_flags = M_INFO;
+ else if (flags & PLOG_DEBUG)
+ msg_flags = D_PLUGIN_DEBUG;
+
+ if (flags & PLOG_ERRNO)
+ msg_flags |= M_ERRNO;
+ if (flags & PLOG_NOMUTE)
+ msg_flags |= M_NOMUTE;
+
+ if (MSG_TEST (msg_flags))
+ {
+ struct gc_arena gc;
+ char* msg_fmt;
+
+ /* Never add instance prefix; not thread safe */
+ msg_flags |= M_NOIPREFIX;
+
+ gc_init (&gc);
+ msg_fmt = gc_malloc (ERR_BUF_SIZE, false, &gc);
+ openvpn_snprintf (msg_fmt, ERR_BUF_SIZE, "PLUGIN %s: %s", name, format);
+ x_msg_va (msg_flags, msg_fmt, arglist);
+
+ gc_free (&gc);
+ }
+}
+
+#if !defined(WIN32)
+void
+plugin_log (openvpn_plugin_log_flags_t flags, const char *name, const char
*format, ...)
+{
+ va_list arglist;
+ va_start (arglist, format);
+ plugin_log_va (flags, name, format, arglist);
+ va_end (arglist);
+}
+#endif
+
static void
plugin_open_item (struct plugin *p,
const struct plugin_option *o,
--
1.7.10.4
