1 // SPDX-License-Identifier: GPL-2.0-only
2 #define KMSG_COMPONENT "IPVS"
3 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
4
5 #include <linux/module.h>
6 #include <linux/spinlock.h>
7 #include <linux/interrupt.h>
8 #include <asm/string.h>
9 #include <linux/kmod.h>
10 #include <linux/sysctl.h>
11
12 #include <net/ip_vs.h>
13
14 /* IPVS pe list */
15 static LIST_HEAD(ip_vs_pe);
16
17 /* semaphore for IPVS PEs. */
18 static DEFINE_MUTEX(ip_vs_pe_mutex);
19
20 /* Get pe in the pe list by name */
__ip_vs_pe_getbyname(const char * pe_name)21 struct ip_vs_pe *__ip_vs_pe_getbyname(const char *pe_name)
22 {
23 struct ip_vs_pe *pe;
24
25 IP_VS_DBG(10, "%s(): pe_name \"%s\"\n", __func__,
26 pe_name);
27
28 rcu_read_lock();
29 list_for_each_entry_rcu(pe, &ip_vs_pe, n_list) {
30 /* Test and get the modules atomically */
31 if (pe->module &&
32 !try_module_get(pe->module)) {
33 /* This pe is just deleted */
34 continue;
35 }
36 if (strcmp(pe_name, pe->name)==0) {
37 /* HIT */
38 rcu_read_unlock();
39 return pe;
40 }
41 module_put(pe->module);
42 }
43 rcu_read_unlock();
44
45 return NULL;
46 }
47
48 /* Lookup pe and try to load it if it doesn't exist */
ip_vs_pe_getbyname(const char * name)49 struct ip_vs_pe *ip_vs_pe_getbyname(const char *name)
50 {
51 struct ip_vs_pe *pe;
52
53 /* Search for the pe by name */
54 pe = __ip_vs_pe_getbyname(name);
55
56 /* If pe not found, load the module and search again */
57 if (!pe) {
58 request_module("ip_vs_pe_%s", name);
59 pe = __ip_vs_pe_getbyname(name);
60 }
61
62 return pe;
63 }
64
65 /* Register a pe in the pe list */
register_ip_vs_pe(struct ip_vs_pe * pe)66 int register_ip_vs_pe(struct ip_vs_pe *pe)
67 {
68 struct ip_vs_pe *tmp;
69
70 /* increase the module use count */
71 if (!ip_vs_use_count_inc())
72 return -ENOENT;
73
74 mutex_lock(&ip_vs_pe_mutex);
75 /* Make sure that the pe with this name doesn't exist
76 * in the pe list.
77 */
78 list_for_each_entry(tmp, &ip_vs_pe, n_list) {
79 if (strcmp(tmp->name, pe->name) == 0) {
80 mutex_unlock(&ip_vs_pe_mutex);
81 ip_vs_use_count_dec();
82 pr_err("%s(): [%s] pe already existed "
83 "in the system\n", __func__, pe->name);
84 return -EINVAL;
85 }
86 }
87 /* Add it into the d-linked pe list */
88 list_add_rcu(&pe->n_list, &ip_vs_pe);
89 mutex_unlock(&ip_vs_pe_mutex);
90
91 pr_info("[%s] pe registered.\n", pe->name);
92
93 return 0;
94 }
95 EXPORT_SYMBOL_GPL(register_ip_vs_pe);
96
97 /* Unregister a pe from the pe list */
unregister_ip_vs_pe(struct ip_vs_pe * pe)98 int unregister_ip_vs_pe(struct ip_vs_pe *pe)
99 {
100 mutex_lock(&ip_vs_pe_mutex);
101 /* Remove it from the d-linked pe list */
102 list_del_rcu(&pe->n_list);
103 mutex_unlock(&ip_vs_pe_mutex);
104
105 /* decrease the module use count */
106 ip_vs_use_count_dec();
107
108 pr_info("[%s] pe unregistered.\n", pe->name);
109
110 return 0;
111 }
112 EXPORT_SYMBOL_GPL(unregister_ip_vs_pe);
113