[mLib] / bres-adns.c

/* -*-c-*-
 *
 * $Id$
 *
 * 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.
 */

#include "config.h"

#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 | adns_qf_owner, 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, *aa;
  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);
	xfree(rc->u.name);
	report(rc, a, a->rrs.addr, a->nrrs, &a->owner, 1);
	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:
	  aa = rc->a;
	  report(rc, a, &a->rrs.addr[i], 1, aa->rrs.str, aa->nrrs);
	  free(aa);
	  free(a);
	}
	break;
      default:
	abort();
    }
    continue;

  fail:
    if (rc->q == adns_r_addr) xfree(rc->u.name);
    if (rc->a) free(rc->a);
    rc->func(0, rc->p);
    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, adns_if_noautosys, 0)) != 0) {
    moan("adns_init failed: resolver won't work");
    return;
  }
  sel_addhook(s, &selhook, beforehook, afterhook, 0);
  sel = s;
}

/*----- That's all, folks -------------------------------------------------*/
Commit	Line	Data
14d7100d	1	/* --c--
14d7100d	2	*
1dc93196	3	* $Id$
14d7100d	4	*
	5	* Background reverse name resolution (ADNS version)
	6	*
	7	* (c) 2003 Straylight/Edgeware
	8	*/
	9
d4efbcd9	10	/----- Licensing notice --------------------------------------------------
14d7100d	11	*
	12	* This file is part of the mLib utilities library.
	13	*
	14	* mLib is free software; you can redistribute it and/or modify
	15	* it under the terms of the GNU Library General Public License as
	16	* published by the Free Software Foundation; either version 2 of the
	17	* License, or (at your option) any later version.
d4efbcd9	18	*
14d7100d	19	* mLib is distributed in the hope that it will be useful,
	20	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	21	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	22	* GNU Library General Public License for more details.
d4efbcd9	23	*
14d7100d	24	* You should have received a copy of the GNU Library General Public
	25	* License along with mLib; if not, write to the Free
	26	* Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
	27	* MA 02111-1307, USA.
	28	*
	29	*
	30	* HOWEVER, since GNU adns is covered by the full GNU General Public
	31	* License, this file (only) is also covered by the full GNU GPL, and
	32	* you may NOT take advantage of the more liberal conditions of the
	33	* LGPL when modifying or redistributing this file. This doesn't mean
	34	* that a program which uses the interface provided by this file is
	35	* covered by the GPL, since @bres.c@ provides the same interface and
	36	* is LGPL. However, it does mean that if your program depends, for
	37	* some reason (e.g., to meet particular performance criteria), on
	38	* this adns-based implementation of mLib's background resolver then it
	39	* must be licensed under the full GPL.
	40	*/
	41
a0150d8d MW	42	#include "config.h"
a0150d8d MW	43
14d7100d	44	#ifndef HAVE_ADNS
	45	# error "You need the ADNS library to compile this file."
	46	#endif
	47
	48	/----- Header files ------------------------------------------------------/
	49
	50	#include <assert.h>
	51	#include <errno.h>
	52	#include <signal.h>
	53	#include <stdio.h>
	54	#include <stdlib.h>
	55	#include <string.h>
	56
	57	#include <sys/types.h>
	58	#include <sys/time.h>
	59	#include <unistd.h>
	60	#include <sys/wait.h>
	61
	62	#include <sys/socket.h>
	63	#include <netinet/in.h>
	64	#include <arpa/inet.h>
	65	#include <netdb.h>
	66
	67	#include <adns.h>
	68
	69	#include "alloc.h"
	70	#include "bres.h"
	71	#include "macros.h"
	72	#include "report.h"
	73	#include "sel.h"
	74
	75	/----- Static variables --------------------------------------------------/
	76
	77	static adns_state ads;
	78	static sel_state *sel;
	79	static sel_hook selhook;
	80
	81	/----- Main code ---------------------------------------------------------/
	82
	83	/* --- @bres_abort@ --- *
	84	*
	85	* Arguments: @bres_client *rc@ = pointer to client block
	86	*
	87	* Returns: ---
	88	*
	89	* Use: Removes a queued job.
	90	*/
	91
	92	void bres_abort(bres_client *rc)
	93	{
	94	if (rc->q == adns_r_addr) xfree(rc->u.name);
	95	if (rc->a) free(rc->a);
	96	adns_cancel(rc->aq);
	97	}
	98
	99	/* --- @bres_byaddr@ --- *
	100	*
	101	* Arguments: @bres_client *rc@ = pointer to client block
	102	* @struct in_addr addr@ = address to resolve
	103	* @void (func)(struct hostent h, void *p)@ = handler function
	104	* @void *p@ = argument for handler function
	105	*
	106	* Returns: ---
	107	*
108	* Use: Adds an address lookup job to the queue. The job will be
109	* processed when there's a spare resolver process to deal with
110	* it.
111	*/
112
113	void bres_byaddr(bres_client *rc, struct in_addr addr,
114	void (func)(struct hostent /h/, void /p*/),
115	void *p)
116	{
117	int e;
118	struct sockaddr_in sin;
119
120	if (!ads) goto fail;
121	sin.sin_family = AF_INET;
122	sin.sin_addr = addr;
123	sin.sin_port = 0;
124	if ((e = adns_submit_reverse(ads, (struct sockaddr *)&sin, adns_r_ptr,
125	0, rc, &rc->aq)) != 0)
126	goto fail;
127	rc->a = 0;
128	rc->q = adns_r_ptr;
129	rc->u.addr = addr;
130	rc->func = func;
131	rc->p = p;
132	return;
133
134	fail:
135	func(0, p);
136	}
137
138	/* --- @bres_byname@ --- *
139	*
140	* Arguments: @bres_client *rc@ = pointer to client block
141	* @const char *name@ = name to resolve
142	* @void (func)(struct hostent h, void *p)@ = handler function
143	* @void *p@ = argument for handler function
144	*
145	* Returns: ---
146	*
147	* Use: Adds a name lookup job to the queue. The job will be
148	* processed when there's a spare resolver process to deal with
149	* it.
150	*/
151
152	void bres_byname(bres_client rc, const char name,
153	void (func)(struct hostent /h/, void /p*/),
154	void *p)
155	{
156	int e;
157
158	if (!ads) goto fail;
159	if ((e = adns_submit(ads, name, adns_r_addr,
4f6d400b	160	adns_qf_search \| adns_qf_owner, rc, &rc->aq)) != 0)
14d7100d	161	goto fail;
	162	rc->a = 0;
	163	rc->q = adns_r_addr;
	164	rc->u.name = xstrdup(name);
	165	rc->func = func;
	166	rc->p = p;
	167	return;
	168
	169	fail:
	170	func(0, p);
	171	}
	172
	173	/* --- @bres_exec@ --- *
	174	*
	175	* Arguments: @const char *file@ = file containing server code or null
	176	*
	177	* Returns: ---
	178	*
	179	* Use: Makes `bres' use a standalone server rather than copies of
	180	* the current process. This can reduce memory consumption for
	181	* large processes, at the expense of startup time (which
	182	* shouldn't be too bad anyway, because of the resolver design).
	183	* If the filename is null, a default set up at install time is
	184	* used. It's probably a good idea to leave it alone.
	185	*/
	186
	187	void bres_exec(const char *file)
	188	{
	189	/* Nothin' doin' */
	190	}
	191
	192	/* --- @report@ --- *
	193	*
	194	* Arguments: @bres_client *c@ = client descriptor block
	195	* @adns_answer *a@ = A-record answer from resolver library
	196	* @adns_rr_addr *av@ = vector of address records
	197	* @int an@ = number of address records (must be positive)
	198	* @char **nv@ = vector of name strings
	199	* @int nn@ = number of name strings (must be positive)
	200	*
	201	* Returns: ---
	202	*
	203	* Use: Formats the given answer into a @struct hostent@ and reports
	204	* it to the waiting client application.
	205	*/
	206
	207	static void report(bres_client rc, adns_answer a,
	208	adns_rr_addr *av, int an,
	209	char **nv, int nn)
	210	{
	211	struct hostent h;
	212	char *n[16];
	213	char *aa[16];
	214	int i, j;
	215
	216	j = 0;
	217	if (a->cname) n[j++] = a->cname;
	218	else { n[j++] = *nv; nv++; nn--; }
	219	for (i = 0; i < nn && j < N(n) - 1; i++)
	220	if (strcmp(n[0], nv[i]) != 0) n[j++] = nv[i];
	221	n[j++] = 0;
	222	for (i = j = 0; i < an && j < N(av) - 1; i++) {
	223	if (av[i].addr.sa.sa_family == AF_INET)
	224	aa[j++] = (char *)&av[i].addr.inet.sin_addr;
225	}
226	aa[j++] = 0;
227	h.h_name = n[0];
228	h.h_aliases = n + 1;
229	h.h_addrtype = AF_INET;
230	h.h_length = sizeof(struct in_addr);
231	h.h_addr_list = aa;
d4efbcd9	232	rc->func(&h, rc->p);
14d7100d	233	}
	234
	235	/* --- @beforehook@, @afterhook@ --- *
	236	*
	237	* Arguments: @sel_state *s@ = select state
	238	* @sel_args *sa@ = argument block
	239	* @void *p@ = uninteresting pointer
	240	*
	241	* Returns: ---
	242	*
	243	* Use: Processes the selector's arguments before @select@ is
	244	* called, to allow ADNS to do its thing.
	245	*/
	246
	247	static void beforehook(sel_state s, sel_args sa, void *p)
	248	{
	249	adns_beforeselect(ads, &sa->maxfd,
	250	&sa->fd[SEL_READ], &sa->fd[SEL_WRITE], &sa->fd[SEL_EXC],
	251	&sa->tvp, &sa->tv, &sa->now);
	252	}
	253
	254	static void afterhook(sel_state s, sel_args sa, void *p)
	255	{
	256	void *c;
	257	bres_client *rc;
	258	adns_query q;
24a657cc	259	adns_answer a, aa;
14d7100d	260	int e;
	261	int i;
	262
	263	adns_afterselect(ads, sa->maxfd,
	264	&sa->fd[SEL_READ], &sa->fd[SEL_WRITE], &sa->fd[SEL_EXC],
	265	&sa->now);
	266	while (q = 0, (e = adns_check(ads, &q, &a, &c)) == 0) {
	267	rc = c;
	268	if (a->status != 0)
	269	goto fail;
	270	else switch (rc->q) {
	271	case adns_r_addr:
	272	assert(a->type == adns_r_addr);
1dc93196	273	xfree(rc->u.name);
24a657cc	274	report(rc, a, a->rrs.addr, a->nrrs, &a->owner, 1);
14d7100d	275	free(a);
	276	break;
	277	case adns_r_ptr:
	278	if (a->type == adns_r_ptr) {
	279	rc->a = a;
	280	if ((e = adns_submit(ads, a->rrs.str[0], adns_r_addr,
	281	0, rc, &q)) != 0)
	282	goto fail;
	283	rc->aq = q;
	284	} else {
	285	assert(a->type == adns_r_addr);
	286	for (i = 0; i < a->nrrs; i++) {
	287	if (a->rrs.addr[i].addr.sa.sa_family == AF_INET &&
	288	a->rrs.addr[i].addr.inet.sin_addr.s_addr ==
	289	rc->u.addr.s_addr)
	290	goto match;
	291	}
	292	goto fail;
	293	match:
24a657cc	294	aa = rc->a;
	295	report(rc, a, &a->rrs.addr[i], 1, aa->rrs.str, aa->nrrs);
	296	free(aa);
14d7100d	297	free(a);
	298	}
	299	break;
	300	default:
	301	abort();
	302	}
	303	continue;
	304
	305	fail:
14d7100d	306	if (rc->q == adns_r_addr) xfree(rc->u.name);
14d7100d	307	if (rc->a) free(rc->a);
24a657cc	308	rc->func(0, rc->p);
14d7100d	309	free(a);
	310	}
	311	}
	312
	313	/* --- @bres_init@ --- *
	314	*
	315	* Arguments: @sel_state *s@ = pointer to select multiplexor
	316	*
	317	* Returns: ---
	318	*
	319	* Use: Initializes the background resolver for use.
	320	*/
	321
	322	void bres_init(sel_state *s)
	323	{
	324	int e;
	325
d46d1a2f	326	if ((e = adns_init(&ads, adns_if_noautosys, 0)) != 0) {
14d7100d	327	moan("adns_init failed: resolver won't work");
	328	return;
	329	}
	330	sel_addhook(s, &selhook, beforehook, afterhook, 0);
	331	sel = s;
	332	}
	333
	334	/----- That's all, folks -------------------------------------------------/