1 files changed, 130 insertions, 0 deletions
diff --git a/dynlibmod/examples/helloworld.c b/dynlibmod/examples/helloworld.c
new file mode 100644
index 0000000000000..acb6b5d9bda6a
--- /dev/null
+++ b/dynlibmod/examples/helloworld.c
@@ -0,0 +1,130 @@
+/**
+ * \file
+ *
+ * This is an example to show how dynamic libraries can be made to work with
+ * unbound. To build a .so file simply run:
+ *   gcc -I../.. -shared -Wall -Werror -fpic  -o helloworld.so helloworld.c
+ * And to build for windows, first make unbound with the --with-dynlibmod
+ * switch, then use this command:
+ *   x86_64-w64-mingw32-gcc -m64 -I../.. -shared -Wall -Werror -fpic
+ *      -o helloworld.dll helloworld.c -L../.. -l:libunbound.a
+ * to cross-compile a 64-bit Windows DLL.
+ */
+
+#include "../../config.h"
+#include "../../util/module.h"
+#include "../../sldns/parseutil.h"
+#include "../dynlibmod.h"
+
+/* Declare the EXPORT macro that expands to exporting the symbol for DLLs when
+ * compiling for Windows. All procedures marked with EXPORT in this example are
+ * called directly by the dynlib module and must be present for the module to
+ * load correctly. */
+#ifdef HAVE_WINDOWS_H
+#define EXPORT __declspec(dllexport)
+#else
+#define EXPORT
+#endif
+
+/* Forward declare a callback, implemented at the bottom of this file */
+int reply_callback(struct query_info* qinfo,
+    struct module_qstate* qstate, struct reply_info* rep, int rcode,
+    struct edns_data* edns, struct edns_option** opt_list_out,
+    struct comm_reply* repinfo, struct regional* region, int id,
+    void* callback);
+
+/* Init is called when the module is first loaded. It should be used to set up
+ * the environment for this module and do any other initialisation required. */
+EXPORT int init(struct module_env* env, int id) {
+    log_info("dynlib: hello world from init");
+    struct dynlibmod_env* de = (struct dynlibmod_env*) env->modinfo[id];
+    de->inplace_cb_register_wrapped(&reply_callback,
+                                    inplace_cb_reply,
+                                    NULL, env, id);
+    struct dynlibmod_env* local_env = env->modinfo[id];
+    local_env->dyn_env = NULL;
+    return 1;
+}
+
+/* Deinit is run as the program is shutting down. It should be used to clean up
+ * the environment and any left over data. */
+EXPORT void deinit(struct module_env* env, int id) {
+    log_info("dynlib: hello world from deinit");
+    struct dynlibmod_env* de = (struct dynlibmod_env*) env->modinfo[id];
+    de->inplace_cb_delete_wrapped(env, inplace_cb_reply, id);
+    if (de->dyn_env != NULL) free(de->dyn_env);
+}
+
+/* Operate is called every time a query passes by this module. The event can be
+ * used to determine which direction in the module chain it came from. */
+EXPORT void operate(struct module_qstate* qstate, enum module_ev event,
+                    int id, struct outbound_entry* entry) {
+    log_info("dynlib: hello world from operate");
+    log_info("dynlib: incoming query: %s %s(%d) %s(%d)",
+            qstate->qinfo.qname,
+            sldns_lookup_by_id(sldns_rr_classes, qstate->qinfo.qclass)->name,
+            qstate->qinfo.qclass,
+            sldns_rr_descript(qstate->qinfo.qtype)->_name,
+            qstate->qinfo.qtype);
+    if (event == module_event_new || event == module_event_pass) {
+        qstate->ext_state[id] = module_wait_module;
+        struct dynlibmod_env* env = qstate->env->modinfo[id];
+        if (env->dyn_env == NULL) {
+            env->dyn_env = calloc(3, sizeof(int));
+            ((int *)env->dyn_env)[0] = 42;
+            ((int *)env->dyn_env)[1] = 102;
+            ((int *)env->dyn_env)[2] = 192;
+        } else {
+            log_err("dynlib: already has data!");
+            qstate->ext_state[id] = module_error;
+        }
+    } else if (event == module_event_moddone) {
+        qstate->ext_state[id] = module_finished;
+    } else {
+        qstate->ext_state[id] = module_error;
+    }
+}
+
+/* Inform super is called when a query is completed or errors out, but only if
+ * a sub-query has been registered to it by this module. Look at
+ * mesh_attach_sub in services/mesh.h to see how this is done. */
+EXPORT void inform_super(struct module_qstate* qstate, int id,
+                         struct module_qstate* super) {
+    log_info("dynlib: hello world from inform_super");
+}
+
+/* Clear is called once a query is complete and the response has been sent
+ * back. It is used to clear up any per-query allocations. */
+EXPORT void clear(struct module_qstate* qstate, int id) {
+    log_info("dynlib: hello world from clear");
+    struct dynlibmod_env* env = qstate->env->modinfo[id];
+    if (env->dyn_env != NULL) {
+        free(env->dyn_env);
+        env->dyn_env = NULL;
+    }
+}
+
+/* Get mem is called when Unbound is printing performance information. This
+ * only happens explicitly and is only used to show memory usage to the user. */
+EXPORT size_t get_mem(struct module_env* env, int id) {
+    log_info("dynlib: hello world from get_mem");
+    return 0;
+}
+
+/* The callback that was forward declared earlier. It is registered in the init
+ * procedure to run when a query is being replied to. */
+int reply_callback(struct query_info* qinfo,
+    struct module_qstate* qstate, struct reply_info* rep, int rcode,
+    struct edns_data* edns, struct edns_option** opt_list_out,
+    struct comm_reply* repinfo, struct regional* region, int id,
+    void* callback) {
+    log_info("dynlib: hello world from callback");
+    struct dynlibmod_env* env = qstate->env->modinfo[id];
+    if (env->dyn_env != NULL) {
+        log_info("dynlib: numbers gotten from query: %d, %d, and %d",
+            ((int *)env->dyn_env)[0],
+            ((int *)env->dyn_env)[1],
+            ((int *)env->dyn_env)[2]);
+    }
+    return 0;
+}