1 /**
2 * \file
3 *
4 * This is an example to show how dynamic libraries can be made to work with
5 * unbound. To build a .so file simply run:
6 * gcc -I../.. -shared -Wall -Werror -fpic -o helloworld.so helloworld.c
7 * And to build for windows, first make unbound with the --with-dynlibmod
8 * switch, then use this command:
9 * x86_64-w64-mingw32-gcc -m64 -I../.. -shared -Wall -Werror -fpic
10 * -o helloworld.dll helloworld.c -L../.. -l:libunbound.dll.a
11 * to cross-compile a 64-bit Windows DLL. The libunbound.dll.a is produced
12 * by the compile step that makes unbound.exe and allows the dynlib dll to
13 * access definitions in unbound.exe.
14 */
15
16 #include "../../config.h"
17 #include "../../util/module.h"
18 #include "../../sldns/parseutil.h"
19 #include "../dynlibmod.h"
20
21 /* Declare the EXPORT macro that expands to exporting the symbol for DLLs when
22 * compiling for Windows. All procedures marked with EXPORT in this example are
23 * called directly by the dynlib module and must be present for the module to
24 * load correctly. */
25 #ifdef HAVE_WINDOWS_H
26 #define EXPORT __declspec(dllexport)
27 #else
28 #define EXPORT
29 #endif
30
31 /* Forward declare a callback, implemented at the bottom of this file */
32 int reply_callback(struct query_info* qinfo,
33 struct module_qstate* qstate, struct reply_info* rep, int rcode,
34 struct edns_data* edns, struct edns_option** opt_list_out,
35 struct comm_reply* repinfo, struct regional* region,
36 struct timeval* start_time, int id, void* callback);
37
38 /* Init is called when the module is first loaded. It should be used to set up
39 * the environment for this module and do any other initialisation required. */
init(struct module_env * env,int id)40 EXPORT int init(struct module_env* env, int id) {
41 log_info("dynlib: hello world from init");
42 struct dynlibmod_env* de = (struct dynlibmod_env*) env->modinfo[id];
43 de->inplace_cb_register_wrapped(&reply_callback,
44 inplace_cb_reply,
45 NULL, env, id);
46 struct dynlibmod_env* local_env = env->modinfo[id];
47 local_env->dyn_env = NULL;
48 return 1;
49 }
50
51 /* Deinit is run as the program is shutting down. It should be used to clean up
52 * the environment and any left over data. */
deinit(struct module_env * env,int id)53 EXPORT void deinit(struct module_env* env, int id) {
54 log_info("dynlib: hello world from deinit");
55 struct dynlibmod_env* de = (struct dynlibmod_env*) env->modinfo[id];
56 de->inplace_cb_delete_wrapped(env, inplace_cb_reply, id);
57 if (de->dyn_env != NULL) free(de->dyn_env);
58 }
59
60 /* Operate is called every time a query passes by this module. The event can be
61 * used to determine which direction in the module chain it came from. */
operate(struct module_qstate * qstate,enum module_ev event,int id,struct outbound_entry * entry)62 EXPORT void operate(struct module_qstate* qstate, enum module_ev event,
63 int id, struct outbound_entry* entry) {
64 log_info("dynlib: hello world from operate");
65 log_info("dynlib: incoming query: %s %s(%d) %s(%d)",
66 qstate->qinfo.qname,
67 sldns_lookup_by_id(sldns_rr_classes, qstate->qinfo.qclass)->name,
68 qstate->qinfo.qclass,
69 sldns_rr_descript(qstate->qinfo.qtype)->_name,
70 qstate->qinfo.qtype);
71 if (event == module_event_new || event == module_event_pass) {
72 qstate->ext_state[id] = module_wait_module;
73 struct dynlibmod_env* env = qstate->env->modinfo[id];
74 if (env->dyn_env == NULL) {
75 env->dyn_env = calloc(3, sizeof(int));
76 ((int *)env->dyn_env)[0] = 42;
77 ((int *)env->dyn_env)[1] = 102;
78 ((int *)env->dyn_env)[2] = 192;
79 } else {
80 log_err("dynlib: already has data!");
81 qstate->ext_state[id] = module_error;
82 }
83 } else if (event == module_event_moddone) {
84 qstate->ext_state[id] = module_finished;
85 } else {
86 qstate->ext_state[id] = module_error;
87 }
88 }
89
90 /* Inform super is called when a query is completed or errors out, but only if
91 * a sub-query has been registered to it by this module. Look at
92 * mesh_attach_sub in services/mesh.h to see how this is done. */
inform_super(struct module_qstate * qstate,int id,struct module_qstate * super)93 EXPORT void inform_super(struct module_qstate* qstate, int id,
94 struct module_qstate* super) {
95 log_info("dynlib: hello world from inform_super");
96 }
97
98 /* Clear is called once a query is complete and the response has been sent
99 * back. It is used to clear up any per-query allocations. */
clear(struct module_qstate * qstate,int id)100 EXPORT void clear(struct module_qstate* qstate, int id) {
101 log_info("dynlib: hello world from clear");
102 struct dynlibmod_env* env = qstate->env->modinfo[id];
103 if (env->dyn_env != NULL) {
104 free(env->dyn_env);
105 env->dyn_env = NULL;
106 }
107 }
108
109 /* Get mem is called when Unbound is printing performance information. This
110 * only happens explicitly and is only used to show memory usage to the user. */
get_mem(struct module_env * env,int id)111 EXPORT size_t get_mem(struct module_env* env, int id) {
112 log_info("dynlib: hello world from get_mem");
113 return 0;
114 }
115
116 /* The callback that was forward declared earlier. It is registered in the init
117 * procedure to run when a query is being replied to. */
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,struct timeval * start_time,int id,void * callback)118 int reply_callback(struct query_info* qinfo,
119 struct module_qstate* qstate, struct reply_info* rep, int rcode,
120 struct edns_data* edns, struct edns_option** opt_list_out,
121 struct comm_reply* repinfo, struct regional* region,
122 struct timeval* start_time, int id, void* callback) {
123 log_info("dynlib: hello world from callback");
124 struct dynlibmod_env* env = qstate->env->modinfo[id];
125 if (env->dyn_env != NULL) {
126 log_info("dynlib: numbers gotten from query: %d, %d, and %d",
127 ((int *)env->dyn_env)[0],
128 ((int *)env->dyn_env)[1],
129 ((int *)env->dyn_env)[2]);
130 }
131 return 0;
132 }
133