xref: /illumos-gate/usr/src/uts/common/inet/ilb/ilb_alg_rr.c (revision 43449cdcd0600512dd862537f2cf014140dd0844)
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/debug.h>
30 #include <sys/kmem.h>
31 #include <sys/list.h>
32 #include <net/if.h>
33 #include <netinet/in.h>
34 #include <inet/ilb.h>
35 #include "ilb_impl.h"
36 #include "ilb_alg.h"
37 
38 typedef struct {
39 	ilb_server_t	*server;
40 	boolean_t	enabled;
41 	list_node_t	list;
42 } rr_server_t;
43 
44 typedef struct rr_s {
45 	kmutex_t	rr_lock;
46 	list_t		rr_servers;
47 	rr_server_t	*rr_next;
48 } rr_t;
49 
50 static void rr_fini(ilb_alg_data_t **);
51 
52 /* ARGSUSED */
53 static boolean_t
54 rr_lb(in6_addr_t *saddr, in_port_t sport, in6_addr_t *daddr,
55     in_port_t dport, void *alg_data, ilb_server_t **ret_server)
56 {
57 	rr_t *rr_alg = (rr_t *)alg_data;
58 	list_t *servers;
59 	rr_server_t *start;
60 
61 	ASSERT(ret_server != NULL);
62 	*ret_server = NULL;
63 
64 	mutex_enter(&rr_alg->rr_lock);
65 	servers = &rr_alg->rr_servers;
66 	if (list_is_empty(servers)) {
67 		mutex_exit(&rr_alg->rr_lock);
68 		return (B_FALSE);
69 	}
70 	if (rr_alg->rr_next == NULL)
71 		rr_alg->rr_next = list_head(servers);
72 	start = rr_alg->rr_next;
73 	while (!rr_alg->rr_next->enabled) {
74 		rr_alg->rr_next = list_next(servers, rr_alg->rr_next);
75 		if (rr_alg->rr_next == NULL)
76 			rr_alg->rr_next = list_head(servers);
77 		if (rr_alg->rr_next == start) {
78 			mutex_exit(&rr_alg->rr_lock);
79 			return (B_FALSE);
80 		}
81 	}
82 
83 	*ret_server = rr_alg->rr_next->server;
84 	rr_alg->rr_next = list_next(servers, rr_alg->rr_next);
85 	mutex_exit(&rr_alg->rr_lock);
86 	return (B_TRUE);
87 }
88 
89 static int
90 rr_server_del(ilb_server_t *host, void *alg_data)
91 {
92 	rr_t *rr_alg = (rr_t *)alg_data;
93 	list_t *servers = &rr_alg->rr_servers;
94 	rr_server_t *tmp_server;
95 
96 	mutex_enter(&rr_alg->rr_lock);
97 	for (tmp_server = list_head(servers); tmp_server != NULL;
98 	    tmp_server = list_next(servers, tmp_server)) {
99 		if (tmp_server->server == host) {
100 			if (rr_alg->rr_next == tmp_server) {
101 				rr_alg->rr_next = list_next(servers,
102 				    tmp_server);
103 			}
104 			list_remove(servers, tmp_server);
105 			break;
106 		}
107 	}
108 	mutex_exit(&rr_alg->rr_lock);
109 	if (tmp_server == NULL)
110 		return (EINVAL);
111 	kmem_free(tmp_server, sizeof (rr_server_t));
112 
113 	ILB_SERVER_REFRELE(host);
114 	return (0);
115 }
116 
117 static int
118 rr_server_add(ilb_server_t *host, void *alg_data)
119 {
120 	rr_t *rr_alg = (rr_t *)alg_data;
121 	rr_server_t *new_server;
122 
123 	new_server = kmem_alloc(sizeof (rr_server_t), KM_NOSLEEP);
124 	if (new_server == NULL)
125 		return (ENOMEM);
126 	new_server->server = host;
127 	new_server->enabled = host->iser_enabled;
128 
129 	mutex_enter(&rr_alg->rr_lock);
130 	list_insert_head(&rr_alg->rr_servers, new_server);
131 	mutex_exit(&rr_alg->rr_lock);
132 
133 	ILB_SERVER_REFHOLD(host);
134 	return (0);
135 }
136 
137 static int
138 rr_server_toggle(list_t *servers, ilb_server_t *host, boolean_t value)
139 {
140 	rr_server_t *tmp_server;
141 
142 	if (list_is_empty(servers))
143 		return (EINVAL);
144 
145 	for (tmp_server = list_head(servers); tmp_server != NULL;
146 	    tmp_server = list_next(servers, tmp_server)) {
147 		if (tmp_server->server == host) {
148 			tmp_server->enabled = value;
149 			break;
150 		}
151 	}
152 	if (tmp_server != NULL)
153 		return (0);
154 	else
155 		return (EINVAL);
156 }
157 
158 static int
159 rr_server_enable(ilb_server_t *host, void *alg_data)
160 {
161 	rr_t *rr_alg = (rr_t *)alg_data;
162 	list_t *servers;
163 	int ret;
164 
165 	mutex_enter(&rr_alg->rr_lock);
166 	servers = &rr_alg->rr_servers;
167 	ret = rr_server_toggle(servers, host, B_TRUE);
168 	mutex_exit(&rr_alg->rr_lock);
169 	return (ret);
170 }
171 
172 static int
173 rr_server_disable(ilb_server_t *host, void *alg_data)
174 {
175 	rr_t *rr_alg = (rr_t *)alg_data;
176 	list_t *servers;
177 	int ret;
178 
179 	mutex_enter(&rr_alg->rr_lock);
180 	servers = &rr_alg->rr_servers;
181 	ret = rr_server_toggle(servers, host, B_FALSE);
182 	mutex_exit(&rr_alg->rr_lock);
183 	return (ret);
184 }
185 
186 /* ARGSUSED */
187 ilb_alg_data_t *
188 ilb_alg_rr_init(ilb_rule_t *rule, void *arg)
189 {
190 	ilb_alg_data_t	*alg;
191 	rr_t		*rr_alg;
192 
193 	if ((alg = kmem_alloc(sizeof (ilb_alg_data_t), KM_NOSLEEP)) == NULL)
194 		return (NULL);
195 	if ((rr_alg = kmem_alloc(sizeof (rr_t), KM_NOSLEEP)) == NULL) {
196 		kmem_free(alg, sizeof (ilb_alg_data_t));
197 		return (NULL);
198 	}
199 
200 	alg->ilb_alg_lb = rr_lb;
201 	alg->ilb_alg_server_del = rr_server_del;
202 	alg->ilb_alg_server_add = rr_server_add;
203 	alg->ilb_alg_server_enable = rr_server_enable;
204 	alg->ilb_alg_server_disable = rr_server_disable;
205 	alg->ilb_alg_fini = rr_fini;
206 	alg->ilb_alg_data = rr_alg;
207 
208 	mutex_init(&rr_alg->rr_lock, NULL, MUTEX_DEFAULT, NULL);
209 	list_create(&rr_alg->rr_servers, sizeof (rr_server_t),
210 	    offsetof(rr_server_t, list));
211 	rr_alg->rr_next = NULL;
212 
213 	return (alg);
214 }
215 
216 static void
217 rr_fini(ilb_alg_data_t **alg)
218 {
219 	rr_t		*rr_alg;
220 	rr_server_t	*tmp_server;
221 	list_t		*servers;
222 
223 	rr_alg = (*alg)->ilb_alg_data;
224 	servers = &rr_alg->rr_servers;
225 	while ((tmp_server = list_head(servers)) != NULL) {
226 		list_remove(servers, tmp_server);
227 		ILB_SERVER_REFRELE(tmp_server->server);
228 		kmem_free(tmp_server, sizeof (rr_server_t));
229 	}
230 	list_destroy(servers);
231 	kmem_free(rr_alg, sizeof (rr_t));
232 	kmem_free(*alg, sizeof (ilb_alg_data_t));
233 	*alg = NULL;
234 }
235