xref: /illumos-gate/usr/src/uts/common/inet/ilb/ilb_alg_rr.c (revision 3004e88e8f37eb9b239425b7120cc7d1e47bcb5d)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #include <sys/errno.h>
28 #include <sys/sysmacros.h>
29 #include <sys/list.h>
30 #include <net/if.h>
31 #include <netinet/in.h>
32 #include <inet/ilb.h>
33 #include "ilb_impl.h"
34 #include "ilb_alg.h"
35 
36 typedef struct {
37 	ilb_server_t	*server;
38 	boolean_t	enabled;
39 	list_node_t	list;
40 } rr_server_t;
41 
42 typedef struct rr_s {
43 	kmutex_t	rr_lock;
44 	list_t		rr_servers;
45 	rr_server_t	*rr_next;
46 } rr_t;
47 
48 static void rr_fini(ilb_alg_data_t **);
49 
50 /* ARGSUSED */
51 static boolean_t
52 rr_lb(in6_addr_t *saddr, in_port_t sport, in6_addr_t *daddr,
53     in_port_t dport, void *alg_data, ilb_server_t **ret_server)
54 {
55 	rr_t *rr_alg = (rr_t *)alg_data;
56 	list_t *servers;
57 	rr_server_t *start;
58 
59 	ASSERT(ret_server != NULL);
60 	*ret_server = NULL;
61 
62 	mutex_enter(&rr_alg->rr_lock);
63 	servers = &rr_alg->rr_servers;
64 	if (list_is_empty(servers)) {
65 		mutex_exit(&rr_alg->rr_lock);
66 		return (B_FALSE);
67 	}
68 	if (rr_alg->rr_next == NULL)
69 		rr_alg->rr_next = list_head(servers);
70 	start = rr_alg->rr_next;
71 	while (!rr_alg->rr_next->enabled) {
72 		rr_alg->rr_next = list_next(servers, rr_alg->rr_next);
73 		if (rr_alg->rr_next == NULL)
74 			rr_alg->rr_next = list_head(servers);
75 		if (rr_alg->rr_next == start) {
76 			mutex_exit(&rr_alg->rr_lock);
77 			return (B_FALSE);
78 		}
79 	}
80 
81 	*ret_server = rr_alg->rr_next->server;
82 	rr_alg->rr_next = list_next(servers, rr_alg->rr_next);
83 	mutex_exit(&rr_alg->rr_lock);
84 	return (B_TRUE);
85 }
86 
87 static int
88 rr_server_del(ilb_server_t *host, void *alg_data)
89 {
90 	rr_t *rr_alg = (rr_t *)alg_data;
91 	list_t *servers = &rr_alg->rr_servers;
92 	rr_server_t *tmp_server;
93 
94 	mutex_enter(&rr_alg->rr_lock);
95 	for (tmp_server = list_head(servers); tmp_server != NULL;
96 	    tmp_server = list_next(servers, tmp_server)) {
97 		if (tmp_server->server == host) {
98 			if (rr_alg->rr_next == tmp_server) {
99 				rr_alg->rr_next = list_next(servers,
100 				    tmp_server);
101 			}
102 			list_remove(servers, tmp_server);
103 			break;
104 		}
105 	}
106 	mutex_exit(&rr_alg->rr_lock);
107 	if (tmp_server == NULL)
108 		return (EINVAL);
109 	kmem_free(tmp_server, sizeof (rr_server_t));
110 
111 	ILB_SERVER_REFRELE(host);
112 	return (0);
113 }
114 
115 static int
116 rr_server_add(ilb_server_t *host, void *alg_data)
117 {
118 	rr_t *rr_alg = (rr_t *)alg_data;
119 	rr_server_t *new_server;
120 
121 	new_server = kmem_alloc(sizeof (rr_server_t), KM_NOSLEEP);
122 	if (new_server == NULL)
123 		return (ENOMEM);
124 	new_server->server = host;
125 	new_server->enabled = host->iser_enabled;
126 
127 	mutex_enter(&rr_alg->rr_lock);
128 	list_insert_head(&rr_alg->rr_servers, new_server);
129 	mutex_exit(&rr_alg->rr_lock);
130 
131 	ILB_SERVER_REFHOLD(host);
132 	return (0);
133 }
134 
135 static int
136 rr_server_toggle(list_t *servers, ilb_server_t *host, boolean_t value)
137 {
138 	rr_server_t *tmp_server;
139 
140 	if (list_is_empty(servers))
141 		return (EINVAL);
142 
143 	for (tmp_server = list_head(servers); tmp_server != NULL;
144 	    tmp_server = list_next(servers, tmp_server)) {
145 		if (tmp_server->server == host) {
146 			tmp_server->enabled = value;
147 			break;
148 		}
149 	}
150 	if (tmp_server != NULL)
151 		return (0);
152 	else
153 		return (EINVAL);
154 }
155 
156 static int
157 rr_server_enable(ilb_server_t *host, void *alg_data)
158 {
159 	rr_t *rr_alg = (rr_t *)alg_data;
160 	list_t *servers;
161 	int ret;
162 
163 	mutex_enter(&rr_alg->rr_lock);
164 	servers = &rr_alg->rr_servers;
165 	ret = rr_server_toggle(servers, host, B_TRUE);
166 	mutex_exit(&rr_alg->rr_lock);
167 	return (ret);
168 }
169 
170 static int
171 rr_server_disable(ilb_server_t *host, void *alg_data)
172 {
173 	rr_t *rr_alg = (rr_t *)alg_data;
174 	list_t *servers;
175 	int ret;
176 
177 	mutex_enter(&rr_alg->rr_lock);
178 	servers = &rr_alg->rr_servers;
179 	ret = rr_server_toggle(servers, host, B_FALSE);
180 	mutex_exit(&rr_alg->rr_lock);
181 	return (ret);
182 }
183 
184 /* ARGSUSED */
185 ilb_alg_data_t *
186 ilb_alg_rr_init(ilb_rule_t *rule, void *arg)
187 {
188 	ilb_alg_data_t	*alg;
189 	rr_t		*rr_alg;
190 
191 	if ((alg = kmem_alloc(sizeof (ilb_alg_data_t), KM_NOSLEEP)) == NULL)
192 		return (NULL);
193 	if ((rr_alg = kmem_alloc(sizeof (rr_t), KM_NOSLEEP)) == NULL) {
194 		kmem_free(alg, sizeof (ilb_alg_data_t));
195 		return (NULL);
196 	}
197 
198 	alg->ilb_alg_lb = rr_lb;
199 	alg->ilb_alg_server_del = rr_server_del;
200 	alg->ilb_alg_server_add = rr_server_add;
201 	alg->ilb_alg_server_enable = rr_server_enable;
202 	alg->ilb_alg_server_disable = rr_server_disable;
203 	alg->ilb_alg_fini = rr_fini;
204 	alg->ilb_alg_data = rr_alg;
205 
206 	mutex_init(&rr_alg->rr_lock, NULL, MUTEX_DEFAULT, NULL);
207 	list_create(&rr_alg->rr_servers, sizeof (rr_server_t),
208 	    offsetof(rr_server_t, list));
209 	rr_alg->rr_next = NULL;
210 
211 	return (alg);
212 }
213 
214 static void
215 rr_fini(ilb_alg_data_t **alg)
216 {
217 	rr_t		*rr_alg;
218 	rr_server_t	*tmp_server;
219 	list_t		*servers;
220 
221 	rr_alg = (*alg)->ilb_alg_data;
222 	servers = &rr_alg->rr_servers;
223 	while ((tmp_server = list_head(servers)) != NULL) {
224 		list_remove(servers, tmp_server);
225 		ILB_SERVER_REFRELE(tmp_server->server);
226 		kmem_free(tmp_server, sizeof (rr_server_t));
227 	}
228 	list_destroy(servers);
229 	kmem_free(rr_alg, sizeof (rr_t));
230 	kmem_free(*alg, sizeof (ilb_alg_data_t));
231 	*alg = NULL;
232 }
233