| #include <linux/kernel.h> |
| #include <linux/init.h> |
| #include <linux/module.h> |
| #include <linux/proc_fs.h> |
| #include <linux/skbuff.h> |
| #include <linux/netfilter.h> |
| #include <linux/seq_file.h> |
| #include <net/protocol.h> |
| #include <net/netfilter/nf_log.h> |
| |
| #include "nf_internals.h" |
| |
| /* Internal logging interface, which relies on the real |
| LOG target modules */ |
| |
| #define NF_LOG_PREFIXLEN 128 |
| #define NFLOGGER_NAME_LEN 64 |
| |
| static struct nf_logger __rcu *loggers[NFPROTO_NUMPROTO][NF_LOG_TYPE_MAX] __read_mostly; |
| static DEFINE_MUTEX(nf_log_mutex); |
| |
| #define nft_log_dereference(logger) \ |
| rcu_dereference_protected(logger, lockdep_is_held(&nf_log_mutex)) |
| |
| static struct nf_logger *__find_logger(int pf, const char *str_logger) |
| { |
| struct nf_logger *log; |
| int i; |
| |
| for (i = 0; i < NF_LOG_TYPE_MAX; i++) { |
| if (loggers[pf][i] == NULL) |
| continue; |
| |
| log = nft_log_dereference(loggers[pf][i]); |
| if (!strncasecmp(str_logger, log->name, strlen(log->name))) |
| return log; |
| } |
| |
| return NULL; |
| } |
| |
| void nf_log_set(struct net *net, u_int8_t pf, const struct nf_logger *logger) |
| { |
| const struct nf_logger *log; |
| |
| if (pf == NFPROTO_UNSPEC) |
| return; |
| |
| mutex_lock(&nf_log_mutex); |
| log = nft_log_dereference(net->nf.nf_loggers[pf]); |
| if (log == NULL) |
| rcu_assign_pointer(net->nf.nf_loggers[pf], logger); |
| |
| mutex_unlock(&nf_log_mutex); |
| } |
| EXPORT_SYMBOL(nf_log_set); |
| |
| void nf_log_unset(struct net *net, const struct nf_logger *logger) |
| { |
| int i; |
| const struct nf_logger *log; |
| |
| mutex_lock(&nf_log_mutex); |
| for (i = 0; i < NFPROTO_NUMPROTO; i++) { |
| log = nft_log_dereference(net->nf.nf_loggers[i]); |
| if (log == logger) |
| RCU_INIT_POINTER(net->nf.nf_loggers[i], NULL); |
| } |
| mutex_unlock(&nf_log_mutex); |
| synchronize_rcu(); |
| } |
| EXPORT_SYMBOL(nf_log_unset); |
| |
| /* return EEXIST if the same logger is registered, 0 on success. */ |
| int nf_log_register(u_int8_t pf, struct nf_logger *logger) |
| { |
| int i; |
| int ret = 0; |
| |
| if (pf >= ARRAY_SIZE(init_net.nf.nf_loggers)) |
| return -EINVAL; |
| |
| mutex_lock(&nf_log_mutex); |
| |
| if (pf == NFPROTO_UNSPEC) { |
| for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++) { |
| if (rcu_access_pointer(loggers[i][logger->type])) { |
| ret = -EEXIST; |
| goto unlock; |
| } |
| } |
| for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++) |
| rcu_assign_pointer(loggers[i][logger->type], logger); |
| } else { |
| if (rcu_access_pointer(loggers[pf][logger->type])) { |
| ret = -EEXIST; |
| goto unlock; |
| } |
| rcu_assign_pointer(loggers[pf][logger->type], logger); |
| } |
| |
| unlock: |
| mutex_unlock(&nf_log_mutex); |
| return ret; |
| } |
| EXPORT_SYMBOL(nf_log_register); |
| |
| void nf_log_unregister(struct nf_logger *logger) |
| { |
| int i; |
| |
| mutex_lock(&nf_log_mutex); |
| for (i = 0; i < NFPROTO_NUMPROTO; i++) |
| RCU_INIT_POINTER(loggers[i][logger->type], NULL); |
| mutex_unlock(&nf_log_mutex); |
| } |
| EXPORT_SYMBOL(nf_log_unregister); |
| |
| int nf_log_bind_pf(struct net *net, u_int8_t pf, |
| const struct nf_logger *logger) |
| { |
| if (pf >= ARRAY_SIZE(net->nf.nf_loggers)) |
| return -EINVAL; |
| mutex_lock(&nf_log_mutex); |
| if (__find_logger(pf, logger->name) == NULL) { |
| mutex_unlock(&nf_log_mutex); |
| return -ENOENT; |
| } |
| rcu_assign_pointer(net->nf.nf_loggers[pf], logger); |
| mutex_unlock(&nf_log_mutex); |
| return 0; |
| } |
| EXPORT_SYMBOL(nf_log_bind_pf); |
| |
| void nf_log_unbind_pf(struct net *net, u_int8_t pf) |
| { |
| if (pf >= ARRAY_SIZE(net->nf.nf_loggers)) |
| return; |
| mutex_lock(&nf_log_mutex); |
| RCU_INIT_POINTER(net->nf.nf_loggers[pf], NULL); |
| mutex_unlock(&nf_log_mutex); |
| } |
| EXPORT_SYMBOL(nf_log_unbind_pf); |
| |
| void nf_logger_request_module(int pf, enum nf_log_type type) |
| { |
| if (loggers[pf][type] == NULL) |
| request_module("nf-logger-%u-%u", pf, type); |
| } |
| EXPORT_SYMBOL_GPL(nf_logger_request_module); |
| |
| int nf_logger_find_get(int pf, enum nf_log_type type) |
| { |
| struct nf_logger *logger; |
| int ret = -ENOENT; |
| |
| if (rcu_access_pointer(loggers[pf][type]) == NULL) |
| request_module("nf-logger-%u-%u", pf, type); |
| |
| rcu_read_lock(); |
| logger = rcu_dereference(loggers[pf][type]); |
| if (logger == NULL) |
| goto out; |
| |
| if (logger && try_module_get(logger->me)) |
| ret = 0; |
| out: |
| rcu_read_unlock(); |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(nf_logger_find_get); |
| |
| void nf_logger_put(int pf, enum nf_log_type type) |
| { |
| struct nf_logger *logger; |
| |
| BUG_ON(loggers[pf][type] == NULL); |
| |
| rcu_read_lock(); |
| logger = rcu_dereference(loggers[pf][type]); |
| module_put(logger->me); |
| rcu_read_unlock(); |
| } |
| EXPORT_SYMBOL_GPL(nf_logger_put); |
| |
| void nf_log_packet(struct net *net, |
| u_int8_t pf, |
| unsigned int hooknum, |
| const struct sk_buff *skb, |
| const struct net_device *in, |
| const struct net_device *out, |
| const struct nf_loginfo *loginfo, |
| const char *fmt, ...) |
| { |
| va_list args; |
| char prefix[NF_LOG_PREFIXLEN]; |
| const struct nf_logger *logger; |
| |
| rcu_read_lock(); |
| if (loginfo != NULL) |
| logger = rcu_dereference(loggers[pf][loginfo->type]); |
| else |
| logger = rcu_dereference(net->nf.nf_loggers[pf]); |
| |
| if (logger) { |
| va_start(args, fmt); |
| vsnprintf(prefix, sizeof(prefix), fmt, args); |
| va_end(args); |
| logger->logfn(net, pf, hooknum, skb, in, out, loginfo, prefix); |
| } |
| rcu_read_unlock(); |
| } |
| EXPORT_SYMBOL(nf_log_packet); |
| |
| #define S_SIZE (1024 - (sizeof(unsigned int) + 1)) |
| |
| struct nf_log_buf { |
| unsigned int count; |
| char buf[S_SIZE + 1]; |
| }; |
| static struct nf_log_buf emergency, *emergency_ptr = &emergency; |
| |
| __printf(2, 3) int nf_log_buf_add(struct nf_log_buf *m, const char *f, ...) |
| { |
| va_list args; |
| int len; |
| |
| if (likely(m->count < S_SIZE)) { |
| va_start(args, f); |
| len = vsnprintf(m->buf + m->count, S_SIZE - m->count, f, args); |
| va_end(args); |
| if (likely(m->count + len < S_SIZE)) { |
| m->count += len; |
| return 0; |
| } |
| } |
| m->count = S_SIZE; |
| printk_once(KERN_ERR KBUILD_MODNAME " please increase S_SIZE\n"); |
| return -1; |
| } |
| EXPORT_SYMBOL_GPL(nf_log_buf_add); |
| |
| struct nf_log_buf *nf_log_buf_open(void) |
| { |
| struct nf_log_buf *m = kmalloc(sizeof(*m), GFP_ATOMIC); |
| |
| if (unlikely(!m)) { |
| local_bh_disable(); |
| do { |
| m = xchg(&emergency_ptr, NULL); |
| } while (!m); |
| } |
| m->count = 0; |
| return m; |
| } |
| EXPORT_SYMBOL_GPL(nf_log_buf_open); |
| |
| void nf_log_buf_close(struct nf_log_buf *m) |
| { |
| m->buf[m->count] = 0; |
| printk("%s\n", m->buf); |
| |
| if (likely(m != &emergency)) |
| kfree(m); |
| else { |
| emergency_ptr = m; |
| local_bh_enable(); |
| } |
| } |
| EXPORT_SYMBOL_GPL(nf_log_buf_close); |
| |
| #ifdef CONFIG_PROC_FS |
| static void *seq_start(struct seq_file *seq, loff_t *pos) |
| { |
| struct net *net = seq_file_net(seq); |
| |
| mutex_lock(&nf_log_mutex); |
| |
| if (*pos >= ARRAY_SIZE(net->nf.nf_loggers)) |
| return NULL; |
| |
| return pos; |
| } |
| |
| static void *seq_next(struct seq_file *s, void *v, loff_t *pos) |
| { |
| struct net *net = seq_file_net(s); |
| |
| (*pos)++; |
| |
| if (*pos >= ARRAY_SIZE(net->nf.nf_loggers)) |
| return NULL; |
| |
| return pos; |
| } |
| |
| static void seq_stop(struct seq_file *s, void *v) |
| { |
| mutex_unlock(&nf_log_mutex); |
| } |
| |
| static int seq_show(struct seq_file *s, void *v) |
| { |
| loff_t *pos = v; |
| const struct nf_logger *logger; |
| int i; |
| struct net *net = seq_file_net(s); |
| |
| logger = nft_log_dereference(net->nf.nf_loggers[*pos]); |
| |
| if (!logger) |
| seq_printf(s, "%2lld NONE (", *pos); |
| else |
| seq_printf(s, "%2lld %s (", *pos, logger->name); |
| |
| if (seq_has_overflowed(s)) |
| return -ENOSPC; |
| |
| for (i = 0; i < NF_LOG_TYPE_MAX; i++) { |
| if (loggers[*pos][i] == NULL) |
| continue; |
| |
| logger = nft_log_dereference(loggers[*pos][i]); |
| seq_printf(s, "%s", logger->name); |
| if (i == 0 && loggers[*pos][i + 1] != NULL) |
| seq_printf(s, ","); |
| |
| if (seq_has_overflowed(s)) |
| return -ENOSPC; |
| } |
| |
| seq_printf(s, ")\n"); |
| |
| if (seq_has_overflowed(s)) |
| return -ENOSPC; |
| return 0; |
| } |
| |
| static const struct seq_operations nflog_seq_ops = { |
| .start = seq_start, |
| .next = seq_next, |
| .stop = seq_stop, |
| .show = seq_show, |
| }; |
| |
| static int nflog_open(struct inode *inode, struct file *file) |
| { |
| return seq_open_net(inode, file, &nflog_seq_ops, |
| sizeof(struct seq_net_private)); |
| } |
| |
| static const struct file_operations nflog_file_ops = { |
| .owner = THIS_MODULE, |
| .open = nflog_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = seq_release_net, |
| }; |
| |
| |
| #endif /* PROC_FS */ |
| |
| #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 int nf_log_proc_dostring(struct ctl_table *table, int write, |
| void __user *buffer, size_t *lenp, loff_t *ppos) |
| { |
| const struct nf_logger *logger; |
| char buf[NFLOGGER_NAME_LEN]; |
| size_t size = *lenp; |
| int r = 0; |
| int tindex = (unsigned long)table->extra1; |
| struct net *net = current->nsproxy->net_ns; |
| |
| if (write) { |
| if (size > sizeof(buf)) |
| size = sizeof(buf); |
| if (copy_from_user(buf, buffer, size)) |
| return -EFAULT; |
| |
| if (!strcmp(buf, "NONE")) { |
| nf_log_unbind_pf(net, tindex); |
| return 0; |
| } |
| mutex_lock(&nf_log_mutex); |
| logger = __find_logger(tindex, buf); |
| if (logger == NULL) { |
| mutex_unlock(&nf_log_mutex); |
| return -ENOENT; |
| } |
| rcu_assign_pointer(net->nf.nf_loggers[tindex], logger); |
| mutex_unlock(&nf_log_mutex); |
| } else { |
| mutex_lock(&nf_log_mutex); |
| logger = nft_log_dereference(net->nf.nf_loggers[tindex]); |
| if (!logger) |
| table->data = "NONE"; |
| else |
| table->data = logger->name; |
| r = proc_dostring(table, write, buffer, lenp, ppos); |
| mutex_unlock(&nf_log_mutex); |
| } |
| |
| return r; |
| } |
| |
| static int netfilter_log_sysctl_init(struct net *net) |
| { |
| int i; |
| struct ctl_table *table; |
| |
| table = nf_log_sysctl_table; |
| if (!net_eq(net, &init_net)) { |
| table = kmemdup(nf_log_sysctl_table, |
| sizeof(nf_log_sysctl_table), |
| GFP_KERNEL); |
| if (!table) |
| goto err_alloc; |
| } else { |
| for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++) { |
| snprintf(nf_log_sysctl_fnames[i], |
| 3, "%d", i); |
| nf_log_sysctl_table[i].procname = |
| nf_log_sysctl_fnames[i]; |
| nf_log_sysctl_table[i].data = NULL; |
| nf_log_sysctl_table[i].maxlen = |
| NFLOGGER_NAME_LEN * sizeof(char); |
| nf_log_sysctl_table[i].mode = 0644; |
| nf_log_sysctl_table[i].proc_handler = |
| nf_log_proc_dostring; |
| nf_log_sysctl_table[i].extra1 = |
| (void *)(unsigned long) i; |
| } |
| } |
| |
| net->nf.nf_log_dir_header = register_net_sysctl(net, |
| "net/netfilter/nf_log", |
| table); |
| if (!net->nf.nf_log_dir_header) |
| goto err_reg; |
| |
| return 0; |
| |
| err_reg: |
| if (!net_eq(net, &init_net)) |
| kfree(table); |
| err_alloc: |
| return -ENOMEM; |
| } |
| |
| static void netfilter_log_sysctl_exit(struct net *net) |
| { |
| struct ctl_table *table; |
| |
| table = net->nf.nf_log_dir_header->ctl_table_arg; |
| unregister_net_sysctl_table(net->nf.nf_log_dir_header); |
| if (!net_eq(net, &init_net)) |
| kfree(table); |
| } |
| #else |
| static int netfilter_log_sysctl_init(struct net *net) |
| { |
| return 0; |
| } |
| |
| static void netfilter_log_sysctl_exit(struct net *net) |
| { |
| } |
| #endif /* CONFIG_SYSCTL */ |
| |
| static int __net_init nf_log_net_init(struct net *net) |
| { |
| int ret = -ENOMEM; |
| |
| #ifdef CONFIG_PROC_FS |
| if (!proc_create("nf_log", S_IRUGO, |
| net->nf.proc_netfilter, &nflog_file_ops)) |
| return ret; |
| #endif |
| ret = netfilter_log_sysctl_init(net); |
| if (ret < 0) |
| goto out_sysctl; |
| |
| return 0; |
| |
| out_sysctl: |
| #ifdef CONFIG_PROC_FS |
| remove_proc_entry("nf_log", net->nf.proc_netfilter); |
| #endif |
| return ret; |
| } |
| |
| static void __net_exit nf_log_net_exit(struct net *net) |
| { |
| netfilter_log_sysctl_exit(net); |
| #ifdef CONFIG_PROC_FS |
| remove_proc_entry("nf_log", net->nf.proc_netfilter); |
| #endif |
| } |
| |
| static struct pernet_operations nf_log_net_ops = { |
| .init = nf_log_net_init, |
| .exit = nf_log_net_exit, |
| }; |
| |
| int __init netfilter_log_init(void) |
| { |
| return register_pernet_subsys(&nf_log_net_ops); |
| } |