+/******************************************************************************/
+/* postlicyd: a postfix policy daemon with a lot of features */
+/* ~~~~~~~~~ */
+/* ________________________________________________________________________ */
+/* */
+/* Redistribution and use in source and binary forms, with or without */
+/* modification, are permitted provided that the following conditions */
+/* are met: */
+/* */
+/* 1. Redistributions of source code must retain the above copyright */
+/* notice, this list of conditions and the following disclaimer. */
+/* 2. Redistributions in binary form must reproduce the above copyright */
+/* notice, this list of conditions and the following disclaimer in the */
+/* documentation and/or other materials provided with the distribution. */
+/* 3. The names of its contributors may not be used to endorse or promote */
+/* products derived from this software without specific prior written */
+/* permission. */
+/* */
+/* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND */
+/* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE */
+/* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR */
+/* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS */
+/* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR */
+/* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF */
+/* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS */
+/* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN */
+/* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) */
+/* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF */
+/* THE POSSIBILITY OF SUCH DAMAGE. */
+/******************************************************************************/
+
+/*
+ * Copyright © 2007 Pierre Habouzit
+ */
+
+#include <assert.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <sysexits.h>
+#include <syslog.h>
+
+#include "gai.h"
+
+#define GAI_SIGNO (SIGRTMIN+0)
+
+static struct {
+ gai_req **ring;
+ int start, len, size;
+} fifo = {
+ .ring = NULL,
+ .start = 0,
+ .len = 0,
+ .size = 0,
+};
+
+static int gai_fifo_end(void)
+{
+ int res = fifo.start + fifo.len;
+ return res >= fifo.size ? res - fifo.size : fifo.size;
+}
+
+static void gai_fifo_append(gai_req *rq)
+{
+ if (fifo.len >= fifo.size) {
+ p_realloc(&fifo.ring, fifo.size += 16);
+ }
+
+ fifo.ring[gai_fifo_end()] = rq;
+ fifo.len++;
+}
+
+static gai_req *gai_fifo_pop(void)
+{
+ gai_req *res = NULL;
+
+ while (!res && fifo.len) {
+ res = fifo.ring[fifo.start];
+ fifo.start++, fifo.len--;
+ if (fifo.start >= fifo.size)
+ fifo.start = 0;
+ }
+
+ return res;
+}
+
+static void gai_fifo_remove(gai_req *rq)
+{
+ int i, end = gai_fifo_end();
+
+ if (fifo.start + fifo.len <= fifo.size) {
+ for (i = fifo.start; i < end; i++) {
+ if (fifo.ring[i] == rq)
+ fifo.ring[i] = NULL;
+ }
+ } else {
+ for (i = fifo.start; i < fifo.size; i++) {
+ if (fifo.ring[i] == rq)
+ fifo.ring[i] = NULL;
+ }
+ for (i = 0; i < end; i++) {
+ if (fifo.ring[i] == rq)
+ fifo.ring[i] = NULL;
+ }
+ }
+}
+
+static gai_req *gai_req_new(void)
+{
+ gai_req *rq = p_new(gai_req, 1);
+ rq->cbp = &rq->cb;
+ return rq;
+}
+static void gai_req_delete(gai_req **rqp)
+{
+ if (*rqp) {
+ gai_req *rq = *rqp;
+
+ switch (gai_error(rq->cbp)) {
+ case EAI_INPROGRESS:
+ if (gai_cancel(rq->cbp) == EAI_NOTCANCELED) {
+ rq->caller = NULL;
+ *rqp = NULL;
+ return;
+ }
+ break;
+
+ case EAI_CANCELED:
+ break;
+
+ default: /* we are likely in the notify list remove us ! */
+ if (rq->caller) {
+ gai_fifo_remove(rq);
+ }
+ }
+
+ p_delete((char **)&rq->cb.ar_name);
+ freeaddrinfo(rq->cb.ar_result);
+ rq->cb.ar_result = NULL;
+ p_delete(rqp);
+ }
+}
+
+gai_req *gai_query(job_t *caller, const char *lookup)
+{
+ struct sigevent se = {
+ .sigev_signo = GAI_SIGNO,
+ .sigev_notify = SIGEV_SIGNAL,
+ };
+ gai_req *res;
+
+ se.sigev_value.sival_ptr = res = gai_req_new();
+ res->cb.ar_name = strdup(lookup);
+ res->caller = caller;
+ getaddrinfo_a(GAI_NOWAIT, &res->cbp, 1, &se);
+
+ return res;
+}
+
+void gai_abort(gai_req **rqp)
+{
+ gai_req_delete(rqp);
+}
+
+
+static void gai_sigaction(int sig, siginfo_t *si, void *ctx)
+{
+ gai_req *req = si->_sifields._rt.si_sigval.sival_ptr;
+
+ assert (sig == GAI_SIGNO);
+ assert (req && gai_error(req->cbp) != EAI_INPROGRESS);
+
+ if (req->caller) {
+ gai_fifo_append(req);
+ } else {
+ gai_req_delete(&req);
+ }
+}
+
+void gai_initialize(void)
+{
+ struct sigaction sa = {
+ .sa_sigaction = &gai_sigaction,
+ .sa_flags = SA_SIGINFO,
+ };
+ if (sigaction(GAI_SIGNO, &sa, NULL) < 0) {
+ syslog(LOG_ERR, "cannot hook SIGRTMIN+0: %m");
+ exit(EX_OSERR);
+ }
+}
+
+void gai_process(void)
+{
+ gai_req *req;
+
+ while ((req = gai_fifo_pop())) {
+ assert (req->caller && req->caller->process);
+ req->caller->process(req->caller);
+ req->caller = NULL; /* make delete faster: avoid gai_fifo_remove() */
+ }
+}
+
+void gai_shutdown(void)
+{
+ /* TODO: deallocate the fifo properly */
+}