xref: /illumos-gate/usr/src/lib/libresolv2/common/irs/gen_nw.c (revision 9b9d39d2a32ff806d2431dbcc50968ef1e6d46b2)
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 /* Imports */
19 
20 #include "port_before.h"
21 
22 #include <sys/types.h>
23 
24 #include <netinet/in.h>
25 #include <arpa/nameser.h>
26 
27 #include <errno.h>
28 #include <resolv.h>
29 #include <stdlib.h>
30 #include <string.h>
31 
32 #include <isc/memcluster.h>
33 #include <irs.h>
34 
35 #include "port_after.h"
36 
37 #include "irs_p.h"
38 #include "gen_p.h"
39 
40 /* Types */
41 
42 struct pvt {
43 	struct irs_rule *	rules;
44 	struct irs_rule *	rule;
45 	struct __res_state *	res;
46 	void 			(*free_res)(void *);
47 };
48 
49 /* Forward */
50 
51 static void		nw_close(struct irs_nw*);
52 static struct nwent *	nw_next(struct irs_nw *);
53 static struct nwent *	nw_byname(struct irs_nw *, const char *, int);
54 static struct nwent *	nw_byaddr(struct irs_nw *, void *, int, int);
55 static void    		nw_rewind(struct irs_nw *);
56 static void		nw_minimize(struct irs_nw *);
57 static struct __res_state * nw_res_get(struct irs_nw *this);
58 static void		nw_res_set(struct irs_nw *this,
59 				   struct __res_state *res,
60 				   void (*free_res)(void *));
61 
62 static int		init(struct irs_nw *this);
63 
64 /* Public */
65 
66 struct irs_nw *
67 irs_gen_nw(struct irs_acc *this) {
68 	struct gen_p *accpvt = (struct gen_p *)this->private;
69 	struct irs_nw *nw;
70 	struct pvt *pvt;
71 
72 	if (!(pvt = memget(sizeof *pvt))) {
73 		errno = ENOMEM;
74 		return (NULL);
75 	}
76 	memset(pvt, 0, sizeof *pvt);
77 	if (!(nw = memget(sizeof *nw))) {
78 		memput(pvt, sizeof *pvt);
79 		errno = ENOMEM;
80 		return (NULL);
81 	}
82 	memset(nw, 0x5e, sizeof *nw);
83 	pvt->rules = accpvt->map_rules[irs_nw];
84 	pvt->rule = pvt->rules;
85 	nw->private = pvt;
86 	nw->close = nw_close;
87 	nw->next = nw_next;
88 	nw->byname = nw_byname;
89 	nw->byaddr = nw_byaddr;
90 	nw->rewind = nw_rewind;
91 	nw->minimize = nw_minimize;
92 	nw->res_get = nw_res_get;
93 	nw->res_set = nw_res_set;
94 	return (nw);
95 }
96 
97 /* Methods */
98 
99 static void
100 nw_close(struct irs_nw *this) {
101 	struct pvt *pvt = (struct pvt *)this->private;
102 
103 	nw_minimize(this);
104 
105 	if (pvt->res && pvt->free_res)
106 		(*pvt->free_res)(pvt->res);
107 
108 	memput(pvt, sizeof *pvt);
109 	memput(this, sizeof *this);
110 }
111 
112 static struct nwent *
113 nw_next(struct irs_nw *this) {
114 	struct pvt *pvt = (struct pvt *)this->private;
115 	struct nwent *rval;
116 	struct irs_nw *nw;
117 
118 	if (init(this) == -1)
119 		return(NULL);
120 
121 	while (pvt->rule) {
122 		nw = pvt->rule->inst->nw;
123 		rval = (*nw->next)(nw);
124 		if (rval)
125 			return (rval);
126 		if (!(pvt->rules->flags & IRS_CONTINUE))
127 			break;
128 		pvt->rule = pvt->rule->next;
129 		if (pvt->rule) {
130 			nw = pvt->rule->inst->nw;
131 			(*nw->rewind)(nw);
132 		}
133 	}
134 	return (NULL);
135 }
136 
137 static struct nwent *
138 nw_byname(struct irs_nw *this, const char *name, int type) {
139 	struct pvt *pvt = (struct pvt *)this->private;
140 	struct irs_rule *rule;
141 	struct nwent *rval;
142 	struct irs_nw *nw;
143 
144 	if (init(this) == -1)
145 		return(NULL);
146 
147 	for (rule = pvt->rules; rule; rule = rule->next) {
148 		nw = rule->inst->nw;
149 		RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL);
150 		rval = (*nw->byname)(nw, name, type);
151 		if (rval != NULL)
152 			return (rval);
153 		if (pvt->res->res_h_errno != TRY_AGAIN &&
154 		    !(rule->flags & IRS_CONTINUE))
155 			break;
156 	}
157 	return (NULL);
158 }
159 
160 static struct nwent *
161 nw_byaddr(struct irs_nw *this, void *net, int length, int type) {
162 	struct pvt *pvt = (struct pvt *)this->private;
163 	struct irs_rule *rule;
164 	struct nwent *rval;
165 	struct irs_nw *nw;
166 
167 	if (init(this) == -1)
168 		return(NULL);
169 
170 	for (rule = pvt->rules; rule; rule = rule->next) {
171 		nw = rule->inst->nw;
172 		RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL);
173 		rval = (*nw->byaddr)(nw, net, length, type);
174 		if (rval != NULL)
175 			return (rval);
176 		if (pvt->res->res_h_errno != TRY_AGAIN &&
177 		    !(rule->flags & IRS_CONTINUE))
178 			break;
179 	}
180 	return (NULL);
181 }
182 
183 static void
184 nw_rewind(struct irs_nw *this) {
185 	struct pvt *pvt = (struct pvt *)this->private;
186 	struct irs_nw *nw;
187 
188 	pvt->rule = pvt->rules;
189 	if (pvt->rule) {
190 		nw = pvt->rule->inst->nw;
191 		(*nw->rewind)(nw);
192 	}
193 }
194 
195 static void
196 nw_minimize(struct irs_nw *this) {
197 	struct pvt *pvt = (struct pvt *)this->private;
198 	struct irs_rule *rule;
199 
200 	if (pvt->res)
201 		res_nclose(pvt->res);
202 	for (rule = pvt->rules; rule != NULL; rule = rule->next) {
203 		struct irs_nw *nw = rule->inst->nw;
204 
205 		(*nw->minimize)(nw);
206 	}
207 }
208 
209 static struct __res_state *
210 nw_res_get(struct irs_nw *this) {
211 	struct pvt *pvt = (struct pvt *)this->private;
212 
213 	if (!pvt->res) {
214 		struct __res_state *res;
215 		res = (struct __res_state *)malloc(sizeof *res);
216 		if (!res) {
217 			errno = ENOMEM;
218 			return (NULL);
219 		}
220 		memset(res, 0, sizeof *res);
221 		nw_res_set(this, res, free);
222 	}
223 
224 	return (pvt->res);
225 }
226 
227 static void
228 nw_res_set(struct irs_nw *this, struct __res_state *res,
229 		void (*free_res)(void *)) {
230 	struct pvt *pvt = (struct pvt *)this->private;
231 	struct irs_rule *rule;
232 
233 	if (pvt->res && pvt->free_res) {
234 		res_nclose(pvt->res);
235 		(*pvt->free_res)(pvt->res);
236 	}
237 
238 	pvt->res = res;
239 	pvt->free_res = free_res;
240 
241 	for (rule = pvt->rules; rule != NULL; rule = rule->next) {
242 		struct irs_nw *nw = rule->inst->nw;
243 
244 		(*nw->res_set)(nw, pvt->res, NULL);
245 	}
246 }
247 
248 static int
249 init(struct irs_nw *this) {
250 	struct pvt *pvt = (struct pvt *)this->private;
251 
252 	if (!pvt->res && !nw_res_get(this))
253 		return (-1);
254 	if (((pvt->res->options & RES_INIT) == 0U) &&
255 	    res_ninit(pvt->res) == -1)
256 		return (-1);
257 	return (0);
258 }
259 
260 /*! \file */
261