--- /dev/null
+/* -*-c-*-
+ *
+ * $Id: bres-adns.c,v 1.1 2003/12/13 20:37:59 mdw Exp $
+ *
+ * Background reverse name resolution (ADNS version)
+ *
+ * (c) 2003 Straylight/Edgeware
+ */
+
+/*----- Licensing notice --------------------------------------------------*
+ *
+ * This file is part of the mLib utilities library.
+ *
+ * mLib is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Library General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * mLib is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with mLib; if not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ *
+ *
+ * HOWEVER, since GNU adns is covered by the full GNU General Public
+ * License, this file (only) is also covered by the full GNU GPL, and
+ * you may NOT take advantage of the more liberal conditions of the
+ * LGPL when modifying or redistributing this file. This doesn't mean
+ * that a program which uses the interface provided by this file is
+ * covered by the GPL, since @bres.c@ provides the same interface and
+ * is LGPL. However, it does mean that if your program depends, for
+ * some reason (e.g., to meet particular performance criteria), on
+ * this adns-based implementation of mLib's background resolver then it
+ * must be licensed under the full GPL.
+ */
+
+/*----- Revision history --------------------------------------------------*
+ *
+ * $Log: bres-adns.c,v $
+ * Revision 1.1 2003/12/13 20:37:59 mdw
+ * Add adns support in background resolver.
+ *
+ */
+
+#ifndef HAVE_ADNS
+# error "You need the ADNS library to compile this file."
+#endif
+
+/*----- Header files ------------------------------------------------------*/
+
+#include <assert.h>
+#include <errno.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <sys/types.h>
+#include <sys/time.h>
+#include <unistd.h>
+#include <sys/wait.h>
+
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+
+#include <adns.h>
+
+#include "alloc.h"
+#include "bres.h"
+#include "macros.h"
+#include "report.h"
+#include "sel.h"
+
+/*----- Static variables --------------------------------------------------*/
+
+static adns_state ads;
+static sel_state *sel;
+static sel_hook selhook;
+
+/*----- Main code ---------------------------------------------------------*/
+
+/* --- @bres_abort@ --- *
+ *
+ * Arguments: @bres_client *rc@ = pointer to client block
+ *
+ * Returns: ---
+ *
+ * Use: Removes a queued job.
+ */
+
+void bres_abort(bres_client *rc)
+{
+ if (rc->q == adns_r_addr) xfree(rc->u.name);
+ if (rc->a) free(rc->a);
+ adns_cancel(rc->aq);
+}
+
+/* --- @bres_byaddr@ --- *
+ *
+ * Arguments: @bres_client *rc@ = pointer to client block
+ * @struct in_addr addr@ = address to resolve
+ * @void (*func)(struct hostent *h, void *p)@ = handler function
+ * @void *p@ = argument for handler function
+ *
+ * Returns: ---
+ *
+ * Use: Adds an address lookup job to the queue. The job will be
+ * processed when there's a spare resolver process to deal with
+ * it.
+ */
+
+void bres_byaddr(bres_client *rc, struct in_addr addr,
+ void (*func)(struct hostent */*h*/, void */*p*/),
+ void *p)
+{
+ int e;
+ struct sockaddr_in sin;
+
+ if (!ads) goto fail;
+ sin.sin_family = AF_INET;
+ sin.sin_addr = addr;
+ sin.sin_port = 0;
+ if ((e = adns_submit_reverse(ads, (struct sockaddr *)&sin, adns_r_ptr,
+ 0, rc, &rc->aq)) != 0)
+ goto fail;
+ rc->a = 0;
+ rc->q = adns_r_ptr;
+ rc->u.addr = addr;
+ rc->func = func;
+ rc->p = p;
+ return;
+
+fail:
+ func(0, p);
+}
+
+/* --- @bres_byname@ --- *
+ *
+ * Arguments: @bres_client *rc@ = pointer to client block
+ * @const char *name@ = name to resolve
+ * @void (*func)(struct hostent *h, void *p)@ = handler function
+ * @void *p@ = argument for handler function
+ *
+ * Returns: ---
+ *
+ * Use: Adds a name lookup job to the queue. The job will be
+ * processed when there's a spare resolver process to deal with
+ * it.
+ */
+
+void bres_byname(bres_client *rc, const char *name,
+ void (*func)(struct hostent */*h*/, void */*p*/),
+ void *p)
+{
+ int e;
+
+ if (!ads) goto fail;
+ if ((e = adns_submit(ads, name, adns_r_addr,
+ adns_qf_search, rc, &rc->aq)) != 0)
+ goto fail;
+ rc->a = 0;
+ rc->q = adns_r_addr;
+ rc->u.name = xstrdup(name);
+ rc->func = func;
+ rc->p = p;
+ return;
+
+fail:
+ func(0, p);
+}
+
+/* --- @bres_exec@ --- *
+ *
+ * Arguments: @const char *file@ = file containing server code or null
+ *
+ * Returns: ---
+ *
+ * Use: Makes `bres' use a standalone server rather than copies of
+ * the current process. This can reduce memory consumption for
+ * large processes, at the expense of startup time (which
+ * shouldn't be too bad anyway, because of the resolver design).
+ * If the filename is null, a default set up at install time is
+ * used. It's probably a good idea to leave it alone.
+ */
+
+void bres_exec(const char *file)
+{
+ /* Nothin' doin' */
+}
+
+/* --- @report@ --- *
+ *
+ * Arguments: @bres_client *c@ = client descriptor block
+ * @adns_answer *a@ = A-record answer from resolver library
+ * @adns_rr_addr *av@ = vector of address records
+ * @int an@ = number of address records (must be positive)
+ * @char **nv@ = vector of name strings
+ * @int nn@ = number of name strings (must be positive)
+ *
+ * Returns: ---
+ *
+ * Use: Formats the given answer into a @struct hostent@ and reports
+ * it to the waiting client application.
+ */
+
+static void report(bres_client *rc, adns_answer *a,
+ adns_rr_addr *av, int an,
+ char **nv, int nn)
+{
+ struct hostent h;
+ char *n[16];
+ char *aa[16];
+ int i, j;
+
+ j = 0;
+ if (a->cname) n[j++] = a->cname;
+ else { n[j++] = *nv; nv++; nn--; }
+ for (i = 0; i < nn && j < N(n) - 1; i++)
+ if (strcmp(n[0], nv[i]) != 0) n[j++] = nv[i];
+ n[j++] = 0;
+ for (i = j = 0; i < an && j < N(av) - 1; i++) {
+ if (av[i].addr.sa.sa_family == AF_INET)
+ aa[j++] = (char *)&av[i].addr.inet.sin_addr;
+ }
+ aa[j++] = 0;
+ h.h_name = n[0];
+ h.h_aliases = n + 1;
+ h.h_addrtype = AF_INET;
+ h.h_length = sizeof(struct in_addr);
+ h.h_addr_list = aa;
+ rc->func(&h, rc->p);
+}
+
+/* --- @beforehook@, @afterhook@ --- *
+ *
+ * Arguments: @sel_state *s@ = select state
+ * @sel_args *sa@ = argument block
+ * @void *p@ = uninteresting pointer
+ *
+ * Returns: ---
+ *
+ * Use: Processes the selector's arguments before @select@ is
+ * called, to allow ADNS to do its thing.
+ */
+
+static void beforehook(sel_state *s, sel_args *sa, void *p)
+{
+ adns_beforeselect(ads, &sa->maxfd,
+ &sa->fd[SEL_READ], &sa->fd[SEL_WRITE], &sa->fd[SEL_EXC],
+ &sa->tvp, &sa->tv, &sa->now);
+}
+
+static void afterhook(sel_state *s, sel_args *sa, void *p)
+{
+ void *c;
+ bres_client *rc;
+ adns_query q;
+ adns_answer *a;
+ int e;
+ int i;
+
+ adns_afterselect(ads, sa->maxfd,
+ &sa->fd[SEL_READ], &sa->fd[SEL_WRITE], &sa->fd[SEL_EXC],
+ &sa->now);
+ while (q = 0, (e = adns_check(ads, &q, &a, &c)) == 0) {
+ rc = c;
+ if (a->status != 0)
+ goto fail;
+ else switch (rc->q) {
+ case adns_r_addr:
+ assert(a->type == adns_r_addr);
+ report(rc, a, a->rrs.addr, a->nrrs, &rc->u.name, 1);
+ free(rc->u.name);
+ free(a);
+ break;
+ case adns_r_ptr:
+ if (a->type == adns_r_ptr) {
+ rc->a = a;
+ if ((e = adns_submit(ads, a->rrs.str[0], adns_r_addr,
+ 0, rc, &q)) != 0)
+ goto fail;
+ rc->aq = q;
+ } else {
+ assert(a->type == adns_r_addr);
+ for (i = 0; i < a->nrrs; i++) {
+ if (a->rrs.addr[i].addr.sa.sa_family == AF_INET &&
+ a->rrs.addr[i].addr.inet.sin_addr.s_addr ==
+ rc->u.addr.s_addr)
+ goto match;
+ }
+ goto fail;
+ match:
+ report(rc, a, &a->rrs.addr[i], 1, rc->a->rrs.str, rc->a->nrrs);
+ free(rc->a);
+ free(a);
+ }
+ break;
+ default:
+ abort();
+ }
+ continue;
+
+ fail:
+ rc->func(0, rc->p);
+ if (rc->q == adns_r_addr) xfree(rc->u.name);
+ if (rc->a) free(rc->a);
+ free(a);
+ }
+}
+
+/* --- @bres_init@ --- *
+ *
+ * Arguments: @sel_state *s@ = pointer to select multiplexor
+ *
+ * Returns: ---
+ *
+ * Use: Initializes the background resolver for use.
+ */
+
+void bres_init(sel_state *s)
+{
+ int e;
+
+ if ((e = adns_init(&ads, 0, 0)) != 0) {
+ moan("adns_init failed: resolver won't work");
+ return;
+ }
+ sel_addhook(s, &selhook, beforehook, afterhook, 0);
+ sel = s;
+}
+
+/*----- That's all, folks -------------------------------------------------*/
~mdw / mLib / blobdiff