diff --git a/Documentation/networking/netfilter-sysctl.txt b/Documentation/networking/netfilter-sysctl.txt new file mode 100644 index 000000000000..55791e50e169 --- /dev/null +++ b/Documentation/networking/netfilter-sysctl.txt @@ -0,0 +1,10 @@ +/proc/sys/net/netfilter/* Variables: + +nf_log_all_netns - BOOLEAN + 0 - disabled (default) + not 0 - enabled + + By default, only init_net namespace can log packets into kernel log + with LOG target; this aims to prevent containers from flooding host + kernel log. If enabled, this target also works in other network + namespaces. This variable is only accessible from init_net. diff --git a/include/net/netfilter/nf_log.h b/include/net/netfilter/nf_log.h index 450f87f95415..42e0696f38d8 100644 --- a/include/net/netfilter/nf_log.h +++ b/include/net/netfilter/nf_log.h @@ -51,6 +51,9 @@ struct nf_logger { struct module *me; }; +/* sysctl_nf_log_all_netns - allow LOG target in all network namespaces */ +extern int sysctl_nf_log_all_netns; + /* Function to register/unregister log function. */ int nf_log_register(u_int8_t pf, struct nf_logger *logger); void nf_log_unregister(struct nf_logger *logger); diff --git a/net/bridge/netfilter/ebt_log.c b/net/bridge/netfilter/ebt_log.c index e88bd4827ac1..98b9c8e8615e 100644 --- a/net/bridge/netfilter/ebt_log.c +++ b/net/bridge/netfilter/ebt_log.c @@ -78,7 +78,7 @@ ebt_log_packet(struct net *net, u_int8_t pf, unsigned int hooknum, unsigned int bitmask; /* FIXME: Disabled from containers until syslog ns is supported */ - if (!net_eq(net, &init_net)) + if (!net_eq(net, &init_net) && !sysctl_nf_log_all_netns) return; spin_lock_bh(&ebt_log_lock); diff --git a/net/ipv4/netfilter/nf_log_arp.c b/net/ipv4/netfilter/nf_log_arp.c index b24795e2ee6d..f6f713376e6e 100644 --- a/net/ipv4/netfilter/nf_log_arp.c +++ b/net/ipv4/netfilter/nf_log_arp.c @@ -87,7 +87,7 @@ static void nf_log_arp_packet(struct net *net, u_int8_t pf, struct nf_log_buf *m; /* FIXME: Disabled from containers until syslog ns is supported */ - if (!net_eq(net, &init_net)) + if (!net_eq(net, &init_net) && !sysctl_nf_log_all_netns) return; m = nf_log_buf_open(); diff --git a/net/ipv4/netfilter/nf_log_ipv4.c b/net/ipv4/netfilter/nf_log_ipv4.c index 856648966f4c..c83a9963269b 100644 --- a/net/ipv4/netfilter/nf_log_ipv4.c +++ b/net/ipv4/netfilter/nf_log_ipv4.c @@ -319,7 +319,7 @@ static void nf_log_ip_packet(struct net *net, u_int8_t pf, struct nf_log_buf *m; /* FIXME: Disabled from containers until syslog ns is supported */ - if (!net_eq(net, &init_net)) + if (!net_eq(net, &init_net) && !sysctl_nf_log_all_netns) return; m = nf_log_buf_open(); diff --git a/net/ipv6/netfilter/nf_log_ipv6.c b/net/ipv6/netfilter/nf_log_ipv6.c index 57d86066a13b..055c51b80f5d 100644 --- a/net/ipv6/netfilter/nf_log_ipv6.c +++ b/net/ipv6/netfilter/nf_log_ipv6.c @@ -351,7 +351,7 @@ static void nf_log_ip6_packet(struct net *net, u_int8_t pf, struct nf_log_buf *m; /* FIXME: Disabled from containers until syslog ns is supported */ - if (!net_eq(net, &init_net)) + if (!net_eq(net, &init_net) && !sysctl_nf_log_all_netns) return; m = nf_log_buf_open(); diff --git a/net/netfilter/nf_log.c b/net/netfilter/nf_log.c index 3dca90dc24ad..0a034f52b912 100644 --- a/net/netfilter/nf_log.c +++ b/net/netfilter/nf_log.c @@ -16,6 +16,9 @@ #define NF_LOG_PREFIXLEN 128 #define NFLOGGER_NAME_LEN 64 +int sysctl_nf_log_all_netns __read_mostly; +EXPORT_SYMBOL(sysctl_nf_log_all_netns); + static struct nf_logger __rcu *loggers[NFPROTO_NUMPROTO][NF_LOG_TYPE_MAX] __read_mostly; static DEFINE_MUTEX(nf_log_mutex); @@ -414,6 +417,18 @@ static const struct file_operations nflog_file_ops = { #ifdef CONFIG_SYSCTL static char nf_log_sysctl_fnames[NFPROTO_NUMPROTO-NFPROTO_UNSPEC][3]; static struct ctl_table nf_log_sysctl_table[NFPROTO_NUMPROTO+1]; +static struct ctl_table_header *nf_log_sysctl_fhdr; + +static struct ctl_table nf_log_sysctl_ftable[] = { + { + .procname = "nf_log_all_netns", + .data = &sysctl_nf_log_all_netns, + .maxlen = sizeof(sysctl_nf_log_all_netns), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { } +}; static int nf_log_proc_dostring(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) @@ -483,6 +498,10 @@ static int netfilter_log_sysctl_init(struct net *net) nf_log_sysctl_table[i].extra1 = (void *)(unsigned long) i; } + nf_log_sysctl_fhdr = register_net_sysctl(net, "net/netfilter", + nf_log_sysctl_ftable); + if (!nf_log_sysctl_fhdr) + goto err_freg; } for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++) @@ -499,6 +518,9 @@ static int netfilter_log_sysctl_init(struct net *net) err_reg: if (!net_eq(net, &init_net)) kfree(table); + else + unregister_net_sysctl_table(nf_log_sysctl_fhdr); +err_freg: err_alloc: return -ENOMEM; } @@ -511,6 +533,8 @@ static void netfilter_log_sysctl_exit(struct net *net) unregister_net_sysctl_table(net->nf.nf_log_dir_header); if (!net_eq(net, &init_net)) kfree(table); + else + unregister_net_sysctl_table(nf_log_sysctl_fhdr); } #else static int netfilter_log_sysctl_init(struct net *net)