xref: /illumos-gate/usr/src/lib/libresolv2/common/irs/gen_nw.c (revision aedf2b3bb56b025fcaf87b49ec6c8aeea07f16d7)
1 /*
2  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
3  * Copyright (c) 1996,1999 by Internet Software Consortium.
4  *
5  * Permission to use, copy, modify, and distribute this software for any
6  * purpose with or without fee is hereby granted, provided that the above
7  * copyright notice and this permission notice appear in all copies.
8  *
9  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
15  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16  */
17 
18 #if !defined(LINT) && !defined(CODECENTER)
19 static const char rcsid[] = "$Id: gen_nw.c,v 1.4 2005/04/27 04:56:23 sra Exp $";
20 #endif
21 
22 /* Imports */
23 
24 #include "port_before.h"
25 
26 #include <sys/types.h>
27 
28 #include <netinet/in.h>
29 #include <arpa/nameser.h>
30 
31 #include <errno.h>
32 #include <resolv.h>
33 #include <stdlib.h>
34 #include <string.h>
35 
36 #include <isc/memcluster.h>
37 #include <irs.h>
38 
39 #include "port_after.h"
40 
41 #include "irs_p.h"
42 #include "gen_p.h"
43 
44 /* Types */
45 
46 struct pvt {
47 	struct irs_rule *	rules;
48 	struct irs_rule *	rule;
49 	struct __res_state *	res;
50 	void 			(*free_res)(void *);
51 };
52 
53 /* Forward */
54 
55 static void		nw_close(struct irs_nw*);
56 static struct nwent *	nw_next(struct irs_nw *);
57 static struct nwent *	nw_byname(struct irs_nw *, const char *, int);
58 static struct nwent *	nw_byaddr(struct irs_nw *, void *, int, int);
59 static void    		nw_rewind(struct irs_nw *);
60 static void		nw_minimize(struct irs_nw *);
61 static struct __res_state * nw_res_get(struct irs_nw *this);
62 static void		nw_res_set(struct irs_nw *this,
63 				   struct __res_state *res,
64 				   void (*free_res)(void *));
65 
66 static int		init(struct irs_nw *this);
67 
68 /* Public */
69 
70 struct irs_nw *
71 irs_gen_nw(struct irs_acc *this) {
72 	struct gen_p *accpvt = (struct gen_p *)this->private;
73 	struct irs_nw *nw;
74 	struct pvt *pvt;
75 
76 	if (!(pvt = memget(sizeof *pvt))) {
77 		errno = ENOMEM;
78 		return (NULL);
79 	}
80 	memset(pvt, 0, sizeof *pvt);
81 	if (!(nw = memget(sizeof *nw))) {
82 		memput(pvt, sizeof *pvt);
83 		errno = ENOMEM;
84 		return (NULL);
85 	}
86 	memset(nw, 0x5e, sizeof *nw);
87 	pvt->rules = accpvt->map_rules[irs_nw];
88 	pvt->rule = pvt->rules;
89 	nw->private = pvt;
90 	nw->close = nw_close;
91 	nw->next = nw_next;
92 	nw->byname = nw_byname;
93 	nw->byaddr = nw_byaddr;
94 	nw->rewind = nw_rewind;
95 	nw->minimize = nw_minimize;
96 	nw->res_get = nw_res_get;
97 	nw->res_set = nw_res_set;
98 	return (nw);
99 }
100 
101 /* Methods */
102 
103 static void
104 nw_close(struct irs_nw *this) {
105 	struct pvt *pvt = (struct pvt *)this->private;
106 
107 	nw_minimize(this);
108 
109 	if (pvt->res && pvt->free_res)
110 		(*pvt->free_res)(pvt->res);
111 
112 	memput(pvt, sizeof *pvt);
113 	memput(this, sizeof *this);
114 }
115 
116 static struct nwent *
117 nw_next(struct irs_nw *this) {
118 	struct pvt *pvt = (struct pvt *)this->private;
119 	struct nwent *rval;
120 	struct irs_nw *nw;
121 
122 	if (init(this) == -1)
123 		return(NULL);
124 
125 	while (pvt->rule) {
126 		nw = pvt->rule->inst->nw;
127 		rval = (*nw->next)(nw);
128 		if (rval)
129 			return (rval);
130 		if (!(pvt->rules->flags & IRS_CONTINUE))
131 			break;
132 		pvt->rule = pvt->rule->next;
133 		if (pvt->rule) {
134 			nw = pvt->rule->inst->nw;
135 			(*nw->rewind)(nw);
136 		}
137 	}
138 	return (NULL);
139 }
140 
141 static struct nwent *
142 nw_byname(struct irs_nw *this, const char *name, int type) {
143 	struct pvt *pvt = (struct pvt *)this->private;
144 	struct irs_rule *rule;
145 	struct nwent *rval;
146 	struct irs_nw *nw;
147 
148 	if (init(this) == -1)
149 		return(NULL);
150 
151 	for (rule = pvt->rules; rule; rule = rule->next) {
152 		nw = rule->inst->nw;
153 		RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL);
154 		rval = (*nw->byname)(nw, name, type);
155 		if (rval != NULL)
156 			return (rval);
157 		if (pvt->res->res_h_errno != TRY_AGAIN &&
158 		    !(rule->flags & IRS_CONTINUE))
159 			break;
160 	}
161 	return (NULL);
162 }
163 
164 static struct nwent *
165 nw_byaddr(struct irs_nw *this, void *net, int length, int type) {
166 	struct pvt *pvt = (struct pvt *)this->private;
167 	struct irs_rule *rule;
168 	struct nwent *rval;
169 	struct irs_nw *nw;
170 
171 	if (init(this) == -1)
172 		return(NULL);
173 
174 	for (rule = pvt->rules; rule; rule = rule->next) {
175 		nw = rule->inst->nw;
176 		RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL);
177 		rval = (*nw->byaddr)(nw, net, length, type);
178 		if (rval != NULL)
179 			return (rval);
180 		if (pvt->res->res_h_errno != TRY_AGAIN &&
181 		    !(rule->flags & IRS_CONTINUE))
182 			break;
183 	}
184 	return (NULL);
185 }
186 
187 static void
188 nw_rewind(struct irs_nw *this) {
189 	struct pvt *pvt = (struct pvt *)this->private;
190 	struct irs_nw *nw;
191 
192 	pvt->rule = pvt->rules;
193 	if (pvt->rule) {
194 		nw = pvt->rule->inst->nw;
195 		(*nw->rewind)(nw);
196 	}
197 }
198 
199 static void
200 nw_minimize(struct irs_nw *this) {
201 	struct pvt *pvt = (struct pvt *)this->private;
202 	struct irs_rule *rule;
203 
204 	if (pvt->res)
205 		res_nclose(pvt->res);
206 	for (rule = pvt->rules; rule != NULL; rule = rule->next) {
207 		struct irs_nw *nw = rule->inst->nw;
208 
209 		(*nw->minimize)(nw);
210 	}
211 }
212 
213 static struct __res_state *
214 nw_res_get(struct irs_nw *this) {
215 	struct pvt *pvt = (struct pvt *)this->private;
216 
217 	if (!pvt->res) {
218 		struct __res_state *res;
219 		res = (struct __res_state *)malloc(sizeof *res);
220 		if (!res) {
221 			errno = ENOMEM;
222 			return (NULL);
223 		}
224 		memset(res, 0, sizeof *res);
225 		nw_res_set(this, res, free);
226 	}
227 
228 	return (pvt->res);
229 }
230 
231 static void
232 nw_res_set(struct irs_nw *this, struct __res_state *res,
233 		void (*free_res)(void *)) {
234 	struct pvt *pvt = (struct pvt *)this->private;
235 	struct irs_rule *rule;
236 
237 	if (pvt->res && pvt->free_res) {
238 		res_nclose(pvt->res);
239 		(*pvt->free_res)(pvt->res);
240 	}
241 
242 	pvt->res = res;
243 	pvt->free_res = free_res;
244 
245 	for (rule = pvt->rules; rule != NULL; rule = rule->next) {
246 		struct irs_nw *nw = rule->inst->nw;
247 
248 		(*nw->res_set)(nw, pvt->res, NULL);
249 	}
250 }
251 
252 static int
253 init(struct irs_nw *this) {
254 	struct pvt *pvt = (struct pvt *)this->private;
255 
256 	if (!pvt->res && !nw_res_get(this))
257 		return (-1);
258 	if (((pvt->res->options & RES_INIT) == 0U) &&
259 	    res_ninit(pvt->res) == -1)
260 		return (-1);
261 	return (0);
262 }
263 
264 /*! \file */
265