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1da177e4 LT |
1 | /* |
2 | * IPVS An implementation of the IP virtual server support for the | |
3 | * LINUX operating system. IPVS is now implemented as a module | |
4 | * over the Netfilter framework. IPVS can be used to build a | |
5 | * high-performance and highly available server based on a | |
6 | * cluster of servers. | |
7 | * | |
1da177e4 LT |
8 | * Authors: Wensong Zhang <wensong@linuxvirtualserver.org> |
9 | * Peter Kese <peter.kese@ijs.si> | |
10 | * | |
11 | * This program is free software; you can redistribute it and/or | |
12 | * modify it under the terms of the GNU General Public License | |
13 | * as published by the Free Software Foundation; either version | |
14 | * 2 of the License, or (at your option) any later version. | |
15 | * | |
16 | * Changes: | |
17 | * | |
18 | */ | |
19 | ||
9aada7ac HE |
20 | #define KMSG_COMPONENT "IPVS" |
21 | #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt | |
22 | ||
1da177e4 | 23 | #include <linux/module.h> |
1da177e4 | 24 | #include <linux/spinlock.h> |
4ffd2e49 | 25 | #include <linux/interrupt.h> |
1da177e4 LT |
26 | #include <asm/string.h> |
27 | #include <linux/kmod.h> | |
90754f8e | 28 | #include <linux/sysctl.h> |
1da177e4 LT |
29 | |
30 | #include <net/ip_vs.h> | |
31 | ||
41ac51ee | 32 | EXPORT_SYMBOL(ip_vs_scheduler_err); |
1da177e4 LT |
33 | /* |
34 | * IPVS scheduler list | |
35 | */ | |
36 | static LIST_HEAD(ip_vs_schedulers); | |
37 | ||
71dfa982 JA |
38 | /* semaphore for schedulers */ |
39 | static DEFINE_MUTEX(ip_vs_sched_mutex); | |
1da177e4 LT |
40 | |
41 | ||
42 | /* | |
43 | * Bind a service with a scheduler | |
44 | */ | |
45 | int ip_vs_bind_scheduler(struct ip_vs_service *svc, | |
46 | struct ip_vs_scheduler *scheduler) | |
47 | { | |
48 | int ret; | |
49 | ||
1da177e4 LT |
50 | svc->scheduler = scheduler; |
51 | ||
52 | if (scheduler->init_service) { | |
53 | ret = scheduler->init_service(svc); | |
54 | if (ret) { | |
1e3e238e | 55 | pr_err("%s(): init error\n", __func__); |
1da177e4 LT |
56 | return ret; |
57 | } | |
58 | } | |
59 | ||
60 | return 0; | |
61 | } | |
62 | ||
63 | ||
64 | /* | |
65 | * Unbind a service with its scheduler | |
66 | */ | |
67 | int ip_vs_unbind_scheduler(struct ip_vs_service *svc) | |
68 | { | |
2fabf35b | 69 | struct ip_vs_scheduler *sched = svc->scheduler; |
1da177e4 | 70 | |
2fabf35b SH |
71 | if (!sched) |
72 | return 0; | |
1da177e4 LT |
73 | |
74 | if (sched->done_service) { | |
75 | if (sched->done_service(svc) != 0) { | |
1e3e238e | 76 | pr_err("%s(): done error\n", __func__); |
1da177e4 LT |
77 | return -EINVAL; |
78 | } | |
79 | } | |
80 | ||
81 | svc->scheduler = NULL; | |
82 | return 0; | |
83 | } | |
84 | ||
85 | ||
86 | /* | |
87 | * Get scheduler in the scheduler list by name | |
88 | */ | |
89 | static struct ip_vs_scheduler *ip_vs_sched_getbyname(const char *sched_name) | |
90 | { | |
91 | struct ip_vs_scheduler *sched; | |
92 | ||
1e3e238e | 93 | IP_VS_DBG(2, "%s(): sched_name \"%s\"\n", __func__, sched_name); |
1da177e4 | 94 | |
71dfa982 | 95 | mutex_lock(&ip_vs_sched_mutex); |
1da177e4 LT |
96 | |
97 | list_for_each_entry(sched, &ip_vs_schedulers, n_list) { | |
98 | /* | |
99 | * Test and get the modules atomically | |
100 | */ | |
101 | if (sched->module && !try_module_get(sched->module)) { | |
102 | /* | |
103 | * This scheduler is just deleted | |
104 | */ | |
105 | continue; | |
106 | } | |
107 | if (strcmp(sched_name, sched->name)==0) { | |
108 | /* HIT */ | |
71dfa982 | 109 | mutex_unlock(&ip_vs_sched_mutex); |
1da177e4 LT |
110 | return sched; |
111 | } | |
112 | if (sched->module) | |
113 | module_put(sched->module); | |
114 | } | |
115 | ||
71dfa982 | 116 | mutex_unlock(&ip_vs_sched_mutex); |
1da177e4 LT |
117 | return NULL; |
118 | } | |
119 | ||
120 | ||
121 | /* | |
122 | * Lookup scheduler and try to load it if it doesn't exist | |
123 | */ | |
124 | struct ip_vs_scheduler *ip_vs_scheduler_get(const char *sched_name) | |
125 | { | |
126 | struct ip_vs_scheduler *sched; | |
127 | ||
128 | /* | |
129 | * Search for the scheduler by sched_name | |
130 | */ | |
131 | sched = ip_vs_sched_getbyname(sched_name); | |
132 | ||
133 | /* | |
134 | * If scheduler not found, load the module and search again | |
135 | */ | |
136 | if (sched == NULL) { | |
137 | request_module("ip_vs_%s", sched_name); | |
138 | sched = ip_vs_sched_getbyname(sched_name); | |
139 | } | |
140 | ||
141 | return sched; | |
142 | } | |
143 | ||
144 | void ip_vs_scheduler_put(struct ip_vs_scheduler *scheduler) | |
145 | { | |
6e08bfb8 | 146 | if (scheduler && scheduler->module) |
1da177e4 LT |
147 | module_put(scheduler->module); |
148 | } | |
149 | ||
41ac51ee PS |
150 | /* |
151 | * Common error output helper for schedulers | |
152 | */ | |
153 | ||
154 | void ip_vs_scheduler_err(struct ip_vs_service *svc, const char *msg) | |
155 | { | |
156 | if (svc->fwmark) { | |
157 | IP_VS_ERR_RL("%s: FWM %u 0x%08X - %s\n", | |
158 | svc->scheduler->name, svc->fwmark, | |
159 | svc->fwmark, msg); | |
160 | #ifdef CONFIG_IP_VS_IPV6 | |
161 | } else if (svc->af == AF_INET6) { | |
120b9c14 | 162 | IP_VS_ERR_RL("%s: %s [%pI6c]:%d - %s\n", |
41ac51ee PS |
163 | svc->scheduler->name, |
164 | ip_vs_proto_name(svc->protocol), | |
165 | &svc->addr.in6, ntohs(svc->port), msg); | |
166 | #endif | |
167 | } else { | |
168 | IP_VS_ERR_RL("%s: %s %pI4:%d - %s\n", | |
169 | svc->scheduler->name, | |
170 | ip_vs_proto_name(svc->protocol), | |
171 | &svc->addr.ip, ntohs(svc->port), msg); | |
172 | } | |
173 | } | |
1da177e4 LT |
174 | |
175 | /* | |
176 | * Register a scheduler in the scheduler list | |
177 | */ | |
178 | int register_ip_vs_scheduler(struct ip_vs_scheduler *scheduler) | |
179 | { | |
180 | struct ip_vs_scheduler *sched; | |
181 | ||
182 | if (!scheduler) { | |
1e3e238e | 183 | pr_err("%s(): NULL arg\n", __func__); |
1da177e4 LT |
184 | return -EINVAL; |
185 | } | |
186 | ||
187 | if (!scheduler->name) { | |
1e3e238e | 188 | pr_err("%s(): NULL scheduler_name\n", __func__); |
1da177e4 LT |
189 | return -EINVAL; |
190 | } | |
191 | ||
192 | /* increase the module use count */ | |
193 | ip_vs_use_count_inc(); | |
194 | ||
71dfa982 | 195 | mutex_lock(&ip_vs_sched_mutex); |
1da177e4 | 196 | |
66a0be47 | 197 | if (!list_empty(&scheduler->n_list)) { |
71dfa982 | 198 | mutex_unlock(&ip_vs_sched_mutex); |
1da177e4 | 199 | ip_vs_use_count_dec(); |
1e3e238e HE |
200 | pr_err("%s(): [%s] scheduler already linked\n", |
201 | __func__, scheduler->name); | |
1da177e4 LT |
202 | return -EINVAL; |
203 | } | |
204 | ||
4ac63ad6 PE |
205 | /* |
206 | * Make sure that the scheduler with this name doesn't exist | |
207 | * in the scheduler list. | |
208 | */ | |
209 | list_for_each_entry(sched, &ip_vs_schedulers, n_list) { | |
210 | if (strcmp(scheduler->name, sched->name) == 0) { | |
71dfa982 | 211 | mutex_unlock(&ip_vs_sched_mutex); |
4ac63ad6 | 212 | ip_vs_use_count_dec(); |
1e3e238e HE |
213 | pr_err("%s(): [%s] scheduler already existed " |
214 | "in the system\n", __func__, scheduler->name); | |
4ac63ad6 PE |
215 | return -EINVAL; |
216 | } | |
217 | } | |
1da177e4 LT |
218 | /* |
219 | * Add it into the d-linked scheduler list | |
220 | */ | |
221 | list_add(&scheduler->n_list, &ip_vs_schedulers); | |
71dfa982 | 222 | mutex_unlock(&ip_vs_sched_mutex); |
1da177e4 | 223 | |
1e3e238e | 224 | pr_info("[%s] scheduler registered.\n", scheduler->name); |
1da177e4 LT |
225 | |
226 | return 0; | |
227 | } | |
228 | ||
229 | ||
230 | /* | |
231 | * Unregister a scheduler from the scheduler list | |
232 | */ | |
233 | int unregister_ip_vs_scheduler(struct ip_vs_scheduler *scheduler) | |
234 | { | |
235 | if (!scheduler) { | |
1e3e238e | 236 | pr_err("%s(): NULL arg\n", __func__); |
1da177e4 LT |
237 | return -EINVAL; |
238 | } | |
239 | ||
71dfa982 | 240 | mutex_lock(&ip_vs_sched_mutex); |
66a0be47 | 241 | if (list_empty(&scheduler->n_list)) { |
71dfa982 | 242 | mutex_unlock(&ip_vs_sched_mutex); |
1e3e238e HE |
243 | pr_err("%s(): [%s] scheduler is not in the list. failed\n", |
244 | __func__, scheduler->name); | |
1da177e4 LT |
245 | return -EINVAL; |
246 | } | |
247 | ||
248 | /* | |
249 | * Remove it from the d-linked scheduler list | |
250 | */ | |
251 | list_del(&scheduler->n_list); | |
71dfa982 | 252 | mutex_unlock(&ip_vs_sched_mutex); |
1da177e4 LT |
253 | |
254 | /* decrease the module use count */ | |
255 | ip_vs_use_count_dec(); | |
256 | ||
1e3e238e | 257 | pr_info("[%s] scheduler unregistered.\n", scheduler->name); |
1da177e4 LT |
258 | |
259 | return 0; | |
260 | } |