1 #define KMSG_COMPONENT "IPVS"
2 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
3
4 #include <linux/module.h>
5 #include <linux/spinlock.h>
6 #include <linux/interrupt.h>
7 #include <asm/string.h>
8 #include <linux/kmod.h>
9 #include <linux/sysctl.h>
10
11 #include <net/ip_vs.h>
12
13 /* IPVS pe list */
14 static LIST_HEAD(ip_vs_pe);
15
16 /* semaphore for IPVS PEs. */
17 static DEFINE_MUTEX(ip_vs_pe_mutex);
18
19 /* Get pe in the pe list by name */
__ip_vs_pe_getbyname(const char * pe_name)20 struct ip_vs_pe *__ip_vs_pe_getbyname(const char *pe_name)
21 {
22 struct ip_vs_pe *pe;
23
24 IP_VS_DBG(10, "%s(): pe_name \"%s\"\n", __func__,
25 pe_name);
26
27 rcu_read_lock();
28 list_for_each_entry_rcu(pe, &ip_vs_pe, n_list) {
29 /* Test and get the modules atomically */
30 if (pe->module &&
31 !try_module_get(pe->module)) {
32 /* This pe is just deleted */
33 continue;
34 }
35 if (strcmp(pe_name, pe->name)==0) {
36 /* HIT */
37 rcu_read_unlock();
38 return pe;
39 }
40 if (pe->module)
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 ip_vs_use_count_inc();
72
73 mutex_lock(&ip_vs_pe_mutex);
74 /* Make sure that the pe with this name doesn't exist
75 * in the pe list.
76 */
77 list_for_each_entry(tmp, &ip_vs_pe, n_list) {
78 if (strcmp(tmp->name, pe->name) == 0) {
79 mutex_unlock(&ip_vs_pe_mutex);
80 ip_vs_use_count_dec();
81 pr_err("%s(): [%s] pe already existed "
82 "in the system\n", __func__, pe->name);
83 return -EINVAL;
84 }
85 }
86 /* Add it into the d-linked pe list */
87 list_add_rcu(&pe->n_list, &ip_vs_pe);
88 mutex_unlock(&ip_vs_pe_mutex);
89
90 pr_info("[%s] pe registered.\n", pe->name);
91
92 return 0;
93 }
94 EXPORT_SYMBOL_GPL(register_ip_vs_pe);
95
96 /* Unregister a pe from the pe list */
unregister_ip_vs_pe(struct ip_vs_pe * pe)97 int unregister_ip_vs_pe(struct ip_vs_pe *pe)
98 {
99 mutex_lock(&ip_vs_pe_mutex);
100 /* Remove it from the d-linked pe list */
101 list_del_rcu(&pe->n_list);
102 mutex_unlock(&ip_vs_pe_mutex);
103
104 /* decrease the module use count */
105 ip_vs_use_count_dec();
106
107 pr_info("[%s] pe unregistered.\n", pe->name);
108
109 return 0;
110 }
111 EXPORT_SYMBOL_GPL(unregister_ip_vs_pe);
112