From ca735b3aaa945626ba65a3e51145bfe4ecd9e222 Mon Sep 17 00:00:00 2001 From: Eric Leblond Date: Mon, 16 Mar 2009 14:54:21 +0100 Subject: [PATCH] netfilter: use a linked list of loggers This patch modifies nf_log to use a linked list of loggers for each protocol. This list of loggers is read and write protected with a mutex. This patch separates registration and binding. To be used as logging module, a module has to register calling nf_log_register() and to bind to a protocol it has to call nf_log_bind_pf(). This patch also converts the logging modules to the new API. For nfnetlink_log, it simply switchs call to register functions to call to bind function and adds a call to nf_log_register() during init. For other modules, it just remove a const flag from the logger structure and replace it with a __read_mostly. Signed-off-by: Eric Leblond Signed-off-by: Patrick McHardy --- include/net/netfilter/nf_log.h | 11 ++-- net/ipv4/netfilter/ipt_LOG.c | 2 +- net/ipv4/netfilter/ipt_ULOG.c | 2 +- net/ipv6/netfilter/ip6t_LOG.c | 2 +- net/netfilter/nf_log.c | 92 ++++++++++++++++++++++------------ net/netfilter/nfnetlink_log.c | 18 +++++-- 6 files changed, 85 insertions(+), 42 deletions(-) diff --git a/include/net/netfilter/nf_log.h b/include/net/netfilter/nf_log.h index 7182c06974f4..920997f1aff0 100644 --- a/include/net/netfilter/nf_log.h +++ b/include/net/netfilter/nf_log.h @@ -1,6 +1,8 @@ #ifndef _NF_LOG_H #define _NF_LOG_H +#include + /* those NF_LOG_* defines and struct nf_loginfo are legacy definitios that will * disappear once iptables is replaced with pkttables. Please DO NOT use them * for any new code! */ @@ -40,12 +42,15 @@ struct nf_logger { struct module *me; nf_logfn *logfn; char *name; + struct list_head list[NFPROTO_NUMPROTO]; }; /* Function to register/unregister log function. */ -int nf_log_register(u_int8_t pf, const struct nf_logger *logger); -void nf_log_unregister(const struct nf_logger *logger); -void nf_log_unregister_pf(u_int8_t pf); +int nf_log_register(u_int8_t pf, struct nf_logger *logger); +void nf_log_unregister(struct nf_logger *logger); + +int nf_log_bind_pf(u_int8_t pf, const struct nf_logger *logger); +void nf_log_unbind_pf(u_int8_t pf); /* Calls the registered backend logging function */ void nf_log_packet(u_int8_t pf, diff --git a/net/ipv4/netfilter/ipt_LOG.c b/net/ipv4/netfilter/ipt_LOG.c index 27a78fbbd92b..acc44c69eb68 100644 --- a/net/ipv4/netfilter/ipt_LOG.c +++ b/net/ipv4/netfilter/ipt_LOG.c @@ -464,7 +464,7 @@ static struct xt_target log_tg_reg __read_mostly = { .me = THIS_MODULE, }; -static const struct nf_logger ipt_log_logger ={ +static struct nf_logger ipt_log_logger __read_mostly = { .name = "ipt_LOG", .logfn = &ipt_log_packet, .me = THIS_MODULE, diff --git a/net/ipv4/netfilter/ipt_ULOG.c b/net/ipv4/netfilter/ipt_ULOG.c index 18a2826b57c6..d32cc4bb328a 100644 --- a/net/ipv4/netfilter/ipt_ULOG.c +++ b/net/ipv4/netfilter/ipt_ULOG.c @@ -379,7 +379,7 @@ static struct xt_target ulog_tg_reg __read_mostly = { .me = THIS_MODULE, }; -static struct nf_logger ipt_ulog_logger = { +static struct nf_logger ipt_ulog_logger __read_mostly = { .name = "ipt_ULOG", .logfn = ipt_logfn, .me = THIS_MODULE, diff --git a/net/ipv6/netfilter/ip6t_LOG.c b/net/ipv6/netfilter/ip6t_LOG.c index 37adf5abc51e..7018cac4fddc 100644 --- a/net/ipv6/netfilter/ip6t_LOG.c +++ b/net/ipv6/netfilter/ip6t_LOG.c @@ -477,7 +477,7 @@ static struct xt_target log_tg6_reg __read_mostly = { .me = THIS_MODULE, }; -static const struct nf_logger ip6t_logger = { +static struct nf_logger ip6t_logger __read_mostly = { .name = "ip6t_LOG", .logfn = &ip6t_log_packet, .me = THIS_MODULE, diff --git a/net/netfilter/nf_log.c b/net/netfilter/nf_log.c index fa8ae5d2659c..a228b5fbcf7c 100644 --- a/net/netfilter/nf_log.c +++ b/net/netfilter/nf_log.c @@ -16,56 +16,60 @@ #define NF_LOG_PREFIXLEN 128 static const struct nf_logger *nf_loggers[NFPROTO_NUMPROTO] __read_mostly; +static struct list_head nf_loggers_l[NFPROTO_NUMPROTO] __read_mostly; static DEFINE_MUTEX(nf_log_mutex); -/* return EBUSY if somebody else is registered, EEXIST if the same logger - * is registred, 0 on success. */ -int nf_log_register(u_int8_t pf, const struct nf_logger *logger) +static struct nf_logger *__find_logger(int pf, const char *str_logger) { - int ret; + struct nf_logger *t; + + list_for_each_entry(t, &nf_loggers_l[pf], list[pf]) { + if (!strnicmp(str_logger, t->name, strlen(t->name))) + return t; + } + + return NULL; +} + +/* return EEXIST if the same logger is registred, 0 on success. */ +int nf_log_register(u_int8_t pf, struct nf_logger *logger) +{ + const struct nf_logger *llog; if (pf >= ARRAY_SIZE(nf_loggers)) return -EINVAL; - /* Any setup of logging members must be done before - * substituting pointer. */ - ret = mutex_lock_interruptible(&nf_log_mutex); - if (ret < 0) - return ret; + mutex_lock(&nf_log_mutex); - if (!nf_loggers[pf]) - rcu_assign_pointer(nf_loggers[pf], logger); - else if (nf_loggers[pf] == logger) - ret = -EEXIST; - else - ret = -EBUSY; + if (pf == NFPROTO_UNSPEC) { + int i; + for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++) + list_add_tail(&(logger->list[i]), &(nf_loggers_l[i])); + } else { + /* register at end of list to honor first register win */ + list_add_tail(&logger->list[pf], &nf_loggers_l[pf]); + llog = rcu_dereference(nf_loggers[pf]); + if (llog == NULL) + rcu_assign_pointer(nf_loggers[pf], logger); + } mutex_unlock(&nf_log_mutex); - return ret; + + return 0; } EXPORT_SYMBOL(nf_log_register); -void nf_log_unregister_pf(u_int8_t pf) -{ - if (pf >= ARRAY_SIZE(nf_loggers)) - return; - mutex_lock(&nf_log_mutex); - rcu_assign_pointer(nf_loggers[pf], NULL); - mutex_unlock(&nf_log_mutex); - - /* Give time to concurrent readers. */ - synchronize_rcu(); -} -EXPORT_SYMBOL(nf_log_unregister_pf); - -void nf_log_unregister(const struct nf_logger *logger) +void nf_log_unregister(struct nf_logger *logger) { + const struct nf_logger *c_logger; int i; mutex_lock(&nf_log_mutex); for (i = 0; i < ARRAY_SIZE(nf_loggers); i++) { - if (nf_loggers[i] == logger) + c_logger = rcu_dereference(nf_loggers[i]); + if (c_logger == logger) rcu_assign_pointer(nf_loggers[i], NULL); + list_del(&logger->list[i]); } mutex_unlock(&nf_log_mutex); @@ -73,6 +77,27 @@ void nf_log_unregister(const struct nf_logger *logger) } EXPORT_SYMBOL(nf_log_unregister); +int nf_log_bind_pf(u_int8_t pf, const struct nf_logger *logger) +{ + mutex_lock(&nf_log_mutex); + if (__find_logger(pf, logger->name) == NULL) { + mutex_unlock(&nf_log_mutex); + return -ENOENT; + } + rcu_assign_pointer(nf_loggers[pf], logger); + mutex_unlock(&nf_log_mutex); + return 0; +} +EXPORT_SYMBOL(nf_log_bind_pf); + +void nf_log_unbind_pf(u_int8_t pf) +{ + mutex_lock(&nf_log_mutex); + rcu_assign_pointer(nf_loggers[pf], NULL); + mutex_unlock(&nf_log_mutex); +} +EXPORT_SYMBOL(nf_log_unbind_pf); + void nf_log_packet(u_int8_t pf, unsigned int hooknum, const struct sk_buff *skb, @@ -163,10 +188,15 @@ static const struct file_operations nflog_file_ops = { int __init netfilter_log_init(void) { + int i; #ifdef CONFIG_PROC_FS if (!proc_create("nf_log", S_IRUGO, proc_net_netfilter, &nflog_file_ops)) return -1; #endif + + for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++) + INIT_LIST_HEAD(&(nf_loggers_l[i])); + return 0; } diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c index fa49dc7fe100..3eae3fca29d8 100644 --- a/net/netfilter/nfnetlink_log.c +++ b/net/netfilter/nfnetlink_log.c @@ -691,7 +691,7 @@ nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb, return -ENOTSUPP; } -static const struct nf_logger nfulnl_logger = { +static struct nf_logger nfulnl_logger __read_mostly = { .name = "nfnetlink_log", .logfn = &nfulnl_log_packet, .me = THIS_MODULE, @@ -723,9 +723,9 @@ nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb, /* Commands without queue context */ switch (cmd->command) { case NFULNL_CFG_CMD_PF_BIND: - return nf_log_register(pf, &nfulnl_logger); + return nf_log_bind_pf(pf, &nfulnl_logger); case NFULNL_CFG_CMD_PF_UNBIND: - nf_log_unregister_pf(pf); + nf_log_unbind_pf(pf); return 0; } } @@ -950,17 +950,25 @@ static int __init nfnetlink_log_init(void) goto cleanup_netlink_notifier; } + status = nf_log_register(NFPROTO_UNSPEC, &nfulnl_logger); + if (status < 0) { + printk(KERN_ERR "log: failed to register logger\n"); + goto cleanup_subsys; + } + #ifdef CONFIG_PROC_FS if (!proc_create("nfnetlink_log", 0440, proc_net_netfilter, &nful_file_ops)) - goto cleanup_subsys; + goto cleanup_logger; #endif return status; #ifdef CONFIG_PROC_FS +cleanup_logger: + nf_log_unregister(&nfulnl_logger); +#endif cleanup_subsys: nfnetlink_subsys_unregister(&nfulnl_subsys); -#endif cleanup_netlink_notifier: netlink_unregister_notifier(&nfulnl_rtnl_notifier); return status;