| 1 | /* Name resolution using adns */ |
| 2 | |
| 3 | #include <errno.h> |
| 4 | #include "secnet.h" |
| 5 | #ifndef HAVE_LIBADNS |
| 6 | #error secnet requires ADNS version 1.0 or above |
| 7 | #endif |
| 8 | #include <adns.h> |
| 9 | |
| 10 | |
| 11 | struct adns { |
| 12 | closure_t cl; |
| 13 | struct resolver_if ops; |
| 14 | struct cloc loc; |
| 15 | adns_state ast; |
| 16 | }; |
| 17 | |
| 18 | struct query { |
| 19 | void *cst; |
| 20 | resolve_answer_fn *answer; |
| 21 | adns_query query; |
| 22 | }; |
| 23 | |
| 24 | static resolve_request_fn resolve_request; |
| 25 | static bool_t resolve_request(void *sst, cstring_t name, |
| 26 | resolve_answer_fn *cb, void *cst) |
| 27 | { |
| 28 | struct adns *st=sst; |
| 29 | struct query *q; |
| 30 | int rv; |
| 31 | |
| 32 | q=safe_malloc(sizeof *q,"resolve_request"); |
| 33 | q->cst=cst; |
| 34 | q->answer=cb; |
| 35 | |
| 36 | rv=adns_submit(st->ast, name, adns_r_a, 0, q, &q->query); |
| 37 | |
| 38 | return rv==0; |
| 39 | } |
| 40 | |
| 41 | static int resolver_beforepoll(void *sst, struct pollfd *fds, int *nfds_io, |
| 42 | int *timeout_io) |
| 43 | { |
| 44 | struct adns *st=sst; |
| 45 | return adns_beforepoll(st->ast, fds, nfds_io, timeout_io, tv_now); |
| 46 | } |
| 47 | |
| 48 | static void resolver_afterpoll(void *sst, struct pollfd *fds, int nfds) |
| 49 | { |
| 50 | struct adns *st=sst; |
| 51 | adns_query aq; |
| 52 | adns_answer *ans; |
| 53 | void *qp; |
| 54 | struct query *q; |
| 55 | int rv; |
| 56 | |
| 57 | adns_afterpoll(st->ast, fds, nfds, tv_now); |
| 58 | |
| 59 | while (True) { |
| 60 | aq=NULL; |
| 61 | rv=adns_check(st->ast, &aq, &ans, &qp); |
| 62 | if (rv==0) { |
| 63 | q=qp; |
| 64 | if (ans->status!=adns_s_ok) { |
| 65 | q->answer(q->cst,NULL); /* Failure */ |
| 66 | free(q); |
| 67 | free(ans); |
| 68 | } else { |
| 69 | q->answer(q->cst,ans->rrs.inaddr); |
| 70 | free(q); |
| 71 | free(ans); |
| 72 | } |
| 73 | } else if (rv==EAGAIN || rv==ESRCH) { |
| 74 | break; |
| 75 | } else { |
| 76 | fatal("resolver_afterpoll: adns_check() returned %d",rv); |
| 77 | } |
| 78 | } |
| 79 | |
| 80 | return; |
| 81 | } |
| 82 | |
| 83 | /* Initialise adns, using parameters supplied */ |
| 84 | static list_t *adnsresolver_apply(closure_t *self, struct cloc loc, |
| 85 | dict_t *context, list_t *args) |
| 86 | { |
| 87 | struct adns *st; |
| 88 | dict_t *d; |
| 89 | item_t *i; |
| 90 | string_t conf; |
| 91 | |
| 92 | st=safe_malloc(sizeof(*st),"adnsresolver_apply"); |
| 93 | st->cl.description="adns"; |
| 94 | st->cl.type=CL_RESOLVER; |
| 95 | st->cl.apply=NULL; |
| 96 | st->cl.interface=&st->ops; |
| 97 | st->loc=loc; |
| 98 | st->ops.st=st; |
| 99 | st->ops.request=resolve_request; |
| 100 | |
| 101 | i=list_elem(args,0); |
| 102 | if (!i || i->type!=t_dict) { |
| 103 | cfgfatal(st->loc,"adns","first argument must be a dictionary\n"); |
| 104 | } |
| 105 | d=i->data.dict; |
| 106 | conf=dict_read_string(d,"config",False,"adns",loc); |
| 107 | |
| 108 | if (conf) { |
| 109 | if (adns_init_strcfg(&st->ast, 0, 0, conf)) { |
| 110 | fatal_perror("Failed to initialise ADNS"); |
| 111 | } |
| 112 | } else { |
| 113 | if (adns_init(&st->ast, 0, 0)) { |
| 114 | fatal_perror("Failed to initialise ADNS"); |
| 115 | } |
| 116 | } |
| 117 | |
| 118 | register_for_poll(st, resolver_beforepoll, resolver_afterpoll, |
| 119 | ADNS_POLLFDS_RECOMMENDED+5,"resolver"); |
| 120 | |
| 121 | return new_closure(&st->cl); |
| 122 | } |
| 123 | |
| 124 | void resolver_module(dict_t *dict) |
| 125 | { |
| 126 | add_closure(dict,"adns",adnsresolver_apply); |
| 127 | } |