diff options
Diffstat (limited to '')
-rw-r--r-- | net/netfilter/ipvs/ip_vs_pe.c | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/net/netfilter/ipvs/ip_vs_pe.c b/net/netfilter/ipvs/ip_vs_pe.c new file mode 100644 index 000000000..166c669f0 --- /dev/null +++ b/net/netfilter/ipvs/ip_vs_pe.c @@ -0,0 +1,112 @@ +// SPDX-License-Identifier: GPL-2.0-only +#define KMSG_COMPONENT "IPVS" +#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt + +#include <linux/module.h> +#include <linux/spinlock.h> +#include <linux/interrupt.h> +#include <asm/string.h> +#include <linux/kmod.h> +#include <linux/sysctl.h> + +#include <net/ip_vs.h> + +/* IPVS pe list */ +static LIST_HEAD(ip_vs_pe); + +/* semaphore for IPVS PEs. */ +static DEFINE_MUTEX(ip_vs_pe_mutex); + +/* Get pe in the pe list by name */ +struct ip_vs_pe *__ip_vs_pe_getbyname(const char *pe_name) +{ + struct ip_vs_pe *pe; + + IP_VS_DBG(10, "%s(): pe_name \"%s\"\n", __func__, + pe_name); + + rcu_read_lock(); + list_for_each_entry_rcu(pe, &ip_vs_pe, n_list) { + /* Test and get the modules atomically */ + if (pe->module && + !try_module_get(pe->module)) { + /* This pe is just deleted */ + continue; + } + if (strcmp(pe_name, pe->name)==0) { + /* HIT */ + rcu_read_unlock(); + return pe; + } + module_put(pe->module); + } + rcu_read_unlock(); + + return NULL; +} + +/* Lookup pe and try to load it if it doesn't exist */ +struct ip_vs_pe *ip_vs_pe_getbyname(const char *name) +{ + struct ip_vs_pe *pe; + + /* Search for the pe by name */ + pe = __ip_vs_pe_getbyname(name); + + /* If pe not found, load the module and search again */ + if (!pe) { + request_module("ip_vs_pe_%s", name); + pe = __ip_vs_pe_getbyname(name); + } + + return pe; +} + +/* Register a pe in the pe list */ +int register_ip_vs_pe(struct ip_vs_pe *pe) +{ + struct ip_vs_pe *tmp; + + /* increase the module use count */ + if (!ip_vs_use_count_inc()) + return -ENOENT; + + mutex_lock(&ip_vs_pe_mutex); + /* Make sure that the pe with this name doesn't exist + * in the pe list. + */ + list_for_each_entry(tmp, &ip_vs_pe, n_list) { + if (strcmp(tmp->name, pe->name) == 0) { + mutex_unlock(&ip_vs_pe_mutex); + ip_vs_use_count_dec(); + pr_err("%s(): [%s] pe already existed " + "in the system\n", __func__, pe->name); + return -EINVAL; + } + } + /* Add it into the d-linked pe list */ + list_add_rcu(&pe->n_list, &ip_vs_pe); + mutex_unlock(&ip_vs_pe_mutex); + + pr_info("[%s] pe registered.\n", pe->name); + + return 0; +} +EXPORT_SYMBOL_GPL(register_ip_vs_pe); + +/* Unregister a pe from the pe list */ +int unregister_ip_vs_pe(struct ip_vs_pe *pe) +{ + mutex_lock(&ip_vs_pe_mutex); + /* Remove it from the d-linked pe list */ + list_del_rcu(&pe->n_list); + mutex_unlock(&ip_vs_pe_mutex); + + /* decrease the module use count */ + ip_vs_use_count_dec(); + + pr_info("[%s] pe unregistered.\n", pe->name); + + return 0; +} +EXPORT_SYMBOL_GPL(unregister_ip_vs_pe); |