adns_query next, back;
adns_query parent, child;
adns_rrtype type;
- struct adns_answer *answer;
+ adns_answer *answer;
int flags, udpretries, server;
struct timeval timeout;
void *context;
#include <errno.h>
#include <string.h>
#include <stdlib.h>
+#include <assert.h>
#include <arpa/nameser.h>
#include <sys/socket.h>
}
static void addserver(adns_state ads, struct in_addr addr) {
+ int i;
+
+ for (i=0; i<ads->nservers; i++) {
+ if (ads->servers[i].addr.s_addr == addr.s_addr) {
+ debug(ads,"duplicate nameserver %s ignored",inet_ntoa(addr));
+ return;
+ }
+ }
+
if (ads->nservers>=MAXSERVERS) {
diag(ads,"too many nameservers, ignoring %s",inet_ntoa(addr));
- } else {
- ads->servers[ads->nservers].addr= addr;
- ads->servers[ads->nservers].tcpsocket= -1;
- ads->nservers++;
+ return;
}
+
+ ads->servers[ads->nservers].addr= addr;
+ ads->servers[ads->nservers].tcpsocket= -1;
+ ads->nservers++;
}
static void configparseerr(adns_state ads, const char *fn, int lno,
const char *value;
value= getenv(envvar);
- if (!value) debug(ads,"environment variable `%s' not set",envvar);
- else debug(ads,"environment variable `%s' set to `%s'",envvar,value);
+ if (!value) debug(ads,"environment variable %s not set",envvar);
+ else debug(ads,"environment variable %s set to `%s'",envvar,value);
return value;
}
}
static void query_fail(adns_state ads, adns_query qu, adns_status stat) {
- struct adns_answer *ans;
+ adns_answer *ans;
ans= qu->answer;
if (!ans) ans= malloc(sizeof(*qu->answer));
LIST_LINK_TAIL(ads->input,qu);
}
-void adns_interest(adns_state ads,
+void adns_interest(adns_state ads, int *maxfd,
fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
- int *maxfd, struct timeval **tv_io, struct timeval *tvbuf) {
+ struct timeval **tv_io, struct timeval *tvbuf) {
abort(); /* FIXME */
}
+static void autosys(adns_state ads) {
+ if (ads->iflags & adns_if_noautosys) return;
+ adns_callback(ads,-1,0,0,0);
+}
+
+void adns_cancel(adns_state ads, adns_query query) {
+ abort(); /* FIXME */
+}
+
+int adns_callback(adns_state ads, int maxfd,
+ const fd_set *readfds, const fd_set *writefds,
+ const fd_set *exceptfds) {
+ abort(); /* FIXME */
+}
+
+static int internal_check(adns_state ads,
+ adns_query *query_io,
+ adns_answer *answer,
+ void *context_r) {
+ abort(); /* FIXME */
+}
+
+int adns_wait(adns_state ads,
+ adns_query *query_io,
+ adns_answer *answer,
+ void *context_r) {
+ int r, maxfd, rsel, rcb;
+ fd_set readfds, writefds, exceptfds;
+ struct timeval tvbuf, *tvp;
+
+ for (;;) {
+ r= internal_check(ads,query_io,answer,context_r);
+ if (r && r != EWOULDBLOCK) return r;
+ FD_ZERO(&readfds); FD_ZERO(&writefds); FD_ZERO(&exceptfds);
+ maxfd= 0; tvp= 0;
+ adns_interest(ads,&maxfd,&readfds,&writefds,&exceptfds,&tvp,&tvbuf);
+ rsel= select(maxfd,&readfds,&writefds,&exceptfds,tvp);
+ if (rsel==-1) return r;
+ rcb= adns_callback(ads,maxfd,&readfds,&writefds,&exceptfds);
+ assert(rcb==rsel);
+ }
+}
+
+int adns_check(adns_state ads,
+ adns_query *query_io,
+ adns_answer *answer,
+ void *context_r) {
+ autosys(ads);
+ return internal_check(ads,query_io,answer,context_r);
+}
+
+int adns_synchronous(adns_state ads,
+ const char *owner,
+ adns_rrtype type,
+ int flags,
+ adns_answer *answer) {
+ adns_query qu;
+ int r;
+
+ r= adns_submit(ads,owner,type,flags,0,&qu);
+ if (r) return r;
+
+ r= adns_wait(ads,&qu,answer,0);
+ if (r) adns_cancel(ads,qu);
+ return r;
+}
+
int adns_submit(adns_state ads,
const char *owner,
adns_rrtype type,
query_fail(ads,qu,stat);
} else {
LIST_LINK_TAIL(ads->input,qu);
- adns_interest(ads,0,0,0,0,0,0);
+ autosys(ads);
}
*query_r= qu;
-
- abort(); /* FIXME */
+ return 0;
}
adns_if_noenv= 0x0001, /* do not look at environment */
adns_if_noerrprint= 0x0002, /* never print output to stderr */
adns_if_debug= 0x0004, /* print debugging output to stderr */
+ adns_if_noautosys= 0x0008, /* do not do full flow-of-control whenever we can */
} adns_initflags;
typedef enum {
* used.
*/
-struct adns_answer {
+typedef struct {
adns_status status;
char *cname; /* always NULL if query was for CNAME records */
adns_rrtype type;
} soa[1]; /* soa, soa_raw */
/* NULL is empty */
} rrs;
-};
+} adns_answer;
/* Memory management:
* adns_state and adns_query are actually pointers to malloc'd state;
* are returned in the status field of the answer. If status is
* nonzero then nrrs will be 0, otherwise it will be >0.
* type will always be the type requested;
- * If no (appropriate) requests are done adns_query returns EWOULDBLOCK;
- * If no requests are outstanding adns_query and adns_wait return ESRCH;
+ * If no (appropriate) requests are done adns_check returns EWOULDBLOCK;
+ * If no (appropriate) requests are outstanding adns_query and adns_wait return ESRCH;
* If malloc failure occurs during internal allocation or processing
- * ands_query, _wait and _answer set *answer to 0.
+ * ands_check and _wait set *answer to 0.
*/
int adns_init(adns_state *newstate_r, adns_initflags flags);
const char *owner,
adns_rrtype type,
int flags,
- struct adns_answer *answer);
+ adns_answer *answer);
+
+/* NB: if you set adns_if_noautosys then _submit and _check do not
+ * make any system calls; you must use adns_callback (possibly after
+ * adns_interest) to actually get things to happen.
+ */
int adns_submit(adns_state ads,
const char *owner,
int adns_check(adns_state ads,
adns_query *query_io,
- struct adns_answer *answer,
+ adns_answer *answer,
void *context_r);
int adns_wait(adns_state ads,
adns_query *query_io,
- struct adns_answer *answer,
+ adns_answer *answer,
void *context_r);
-int adns_cancel(adns_state ads, adns_query query);
+void adns_cancel(adns_state ads, adns_query query);
int adns_finish(adns_state);
-void adns_interest(adns_state, fd_set *readfds_mod,
- fd_set *writefds_mod, fd_set *exceptfds_mod,
- int *maxfd_mod, struct timeval **tv_mod, struct timeval *tv_buf);
-/* You may call this with *_mod=0 to allow adns to have flow-of-control
- * briefly, or with *fds_mod=*maxfd_mod=0 but tv_mod!=0 if you are
- * not going to sleep, or with all !=0 if you are going to sleep.
- * If tv_mod!=0 and *tv_mod=0 then tv_buf must be !0 and *tv_buf is irrelevant
- * and may be overwritten (and *tv_mod set to tv_buf); otherwise tv_buf is ignored.
+int adns_callback(adns_state, int maxfd, const fd_set *readfds, const fd_set *writefds,
+ const fd_set *exceptfds);
+/* Gives adns flow-of-control for a bit. This will never block.
+ * If maxfd == -1 then adns will check (make nonblocking system calls on)
+ * all of its own filedescriptors; otherwise it will only use those
+ * < maxfd and specified in the fd_set's, as if select had returned them.
+ * Other fd's may be in the fd_sets, and will be ignored.
+ * _callback returns how many adns fd's were in the various sets, so
+ * you can tell if your select handling code has missed something and is going awol.
*/
-int adns_callback(adns_state, fd_set readfds, fd_set writefds,
- fd_set exceptfds, int maxfd);
-/* For select-driven programs, this allows adns to know which fd's are relevant,
- * so that it doesn't need to make syscalls on others of its fd's. It's a kind
- * of limited flow-of-control allowance. It will return how many adns fd's were
- * in the set, so you can tell if your select handling code is missing things.
+void adns_interest(adns_state, int *maxfd_io, fd_set *readfds_io,
+ fd_set *writefds_io, fd_set *exceptfds_io,
+ struct timeval **tv_mod, struct timeval *tv_buf);
+/* Find out file descriptors adns is interested in, and when it
+ * would like the opportunity to time something out. If you do not plan to
+ * block then tv_mod may be 0. Otherwise, tv_mod may point to 0 meaning
+ * you have no timeout of your own, in which case tv_buf must be non-null and
+ * _interest may fill it in and set *tv_mod=tv_buf.
+ * readfds, writefds, exceptfds and maxfd may not be 0.
*/
/* Example expected/legal calling sequences:
* ....
* adns_finish
*
- * adns_init
- * adns_submit ...
+ * adns_init _noautosys
* loop {
- * adns_check
* adns_interest
* select
* adns_callback
- * other things
+ * ...
+ * adns_submit / adns_check
+ * ...
* }
*/
~ianmdlvl / adns.git / commitdiff