openbsd: Hide errors written by dlopen() if we wanted to ignore them.

doveadm loads all plugins at startup that it can. It shouldn't be printing
unnecessary error messages to stderr.

--HG--
branch : HEAD

diff --git a/src/lib/module-dir.c b/src/lib/module-dir.c
index a4004ea6e7bcaeb2096d2957a7e3f234a7a69863..7d9bbe1f586a768d4536830541325bcb742c123c 100644 (file)
--- a/src/lib/module-dir.c
+++ b/src/lib/module-dir.c
@@ -8,6 +8,7 @@
 
 #include <stdlib.h>
 #include <unistd.h>
+#include <fcntl.h>
 #include <dirent.h>
 #include <dlfcn.h>
 
@@ -96,6 +97,35 @@ module_check_missing_dependencies(struct module *module,
        return TRUE;
 }
 
+static void *quiet_dlopen(const char *path, int flags)
+{
+#ifndef __OpenBSD__
+       return dlopen(path, flags);
+#else
+       void *handle;
+       int fd, fd_null;
+
+       /* OpenBSD likes to print all "undefined symbol" errors to stderr.
+          Hide them by sending them to /dev/null. */
+       fd_null = open("/dev/null", O_WRONLY);
+       if (fd_null == -1)
+               i_fatal("open(/dev/null) failed: %m");
+       fd = dup(STDERR_FILENO);
+       if (fd == -1)
+               i_fatal("dup() failed: %m");
+       if (dup2(fd_null, STDERR_FILENO) < 0)
+               i_fatal("dup2() failed: %m");
+       handle = dlopen(path, flags);
+       if (dup2(fd, STDERR_FILENO) < 0)
+               i_fatal("dup2() failed: %m");
+       if (close(fd) < 0)
+               i_error("close() failed: %m");
+       if (close(fd_null) < 0)
+               i_error("close() failed: %m");
+       return handle;
+#endif
+}
+
 static struct module *
 module_load(const char *path, const char *name,
            const struct module_dir_load_settings *set,
@@ -105,11 +135,16 @@ module_load(const char *path, const char *name,
        struct module *module;
        const char *const *module_version;
 
-       handle = dlopen(path, RTLD_GLOBAL | RTLD_NOW);
-       if (handle == NULL) {
-               if (!set->ignore_dlopen_errors)
+       if (set->ignore_dlopen_errors) {
+               handle = quiet_dlopen(path, RTLD_GLOBAL | RTLD_NOW);
+               if (handle == NULL)
+                       return NULL;
+       } else {
+               handle = dlopen(path, RTLD_GLOBAL | RTLD_NOW);
+               if (handle == NULL) {
                        i_error("dlopen(%s) failed: %s", path, dlerror());
-               return NULL;
+                       return NULL;
+               }
        }
 
        module = i_new(struct module, 1);