cregit-Linux how code gets into the kernel

Release 4.11 net/netfilter/nf_log.c

Directory: net/netfilter
#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 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);


#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; }

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Pablo Neira Ayuso4550.00%125.00%
Eric Leblond4347.78%125.00%
Marcelo Ricardo Leitner11.11%125.00%
Rasmus Villemoes11.11%125.00%
Total90100.00%4100.00%


int nf_log_set(struct net *net, u_int8_t pf, const struct nf_logger *logger) { const struct nf_logger *log; if (pf == NFPROTO_UNSPEC || pf >= ARRAY_SIZE(net->nf.nf_loggers)) return -EOPNOTSUPP; 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); return 0; }

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Total95100.00%3100.00%

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(); }

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Gao Feng8898.88%150.00%
Marcelo Ricardo Leitner11.12%150.00%
Total89100.00%2100.00%

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; }

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Marcelo Ricardo Leitner7341.95%19.09%
Eric Leblond3419.54%19.09%
Harald Welte3218.39%218.18%
Pablo Neira Ayuso148.05%19.09%
Patrick McHardy74.02%218.18%
Gao Feng63.45%19.09%
Jan Engelhardt52.87%218.18%
Eric Dumazet31.72%19.09%
Total174100.00%11100.00%

EXPORT_SYMBOL(nf_log_register);
void nf_log_unregister(struct nf_logger *logger) { const struct nf_logger *log; int i; mutex_lock(&nf_log_mutex); for (i = 0; i < NFPROTO_NUMPROTO; i++) { log = nft_log_dereference(loggers[i][logger->type]); if (log == logger) RCU_INIT_POINTER(loggers[i][logger->type], NULL); } mutex_unlock(&nf_log_mutex); synchronize_rcu(); }

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Eric Leblond3237.65%112.50%
Florian Westphal2934.12%112.50%
Pablo Neira Ayuso1214.12%225.00%
Harald Welte89.41%112.50%
Patrick McHardy33.53%225.00%
Gao Feng11.18%112.50%
Total85100.00%8100.00%

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; }

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Eric Leblond4246.67%111.11%
Jan Engelhardt1516.67%222.22%
Harald Welte1516.67%111.11%
Gao Feng1314.44%111.11%
Patrick McHardy44.44%333.33%
Eric Dumazet11.11%111.11%
Total90100.00%9100.00%

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); }

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Eric Leblond1426.42%112.50%
Gao Feng1324.53%112.50%
Jan Engelhardt1018.87%112.50%
Harald Welte916.98%112.50%
Patrick McHardy611.32%337.50%
Stephen Hemminger11.89%112.50%
Total53100.00%8100.00%

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); }

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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 (pf == NFPROTO_INET) { ret = nf_logger_find_get(NFPROTO_IPV4, type); if (ret < 0) return ret; ret = nf_logger_find_get(NFPROTO_IPV6, type); if (ret < 0) { nf_logger_put(NFPROTO_IPV4, type); return ret; } return 0; } 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 (try_module_get(logger->me)) ret = 0; out: rcu_read_unlock(); return ret; }

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Pablo Neira Ayuso9362.42%266.67%
Liping Zhang5637.58%133.33%
Total149100.00%3100.00%

EXPORT_SYMBOL_GPL(nf_logger_find_get);
void nf_logger_put(int pf, enum nf_log_type type) { struct nf_logger *logger; if (pf == NFPROTO_INET) { nf_logger_put(NFPROTO_IPV4, type); nf_logger_put(NFPROTO_IPV6, type); return; } BUG_ON(loggers[pf][type] == NULL); rcu_read_lock(); logger = rcu_dereference(loggers[pf][type]); module_put(logger->me); rcu_read_unlock(); }

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Pablo Neira Ayuso5670.89%150.00%
Liping Zhang2329.11%150.00%
Total79100.00%2100.00%

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(); }

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Harald Welte12176.58%114.29%
Pablo Neira Ayuso2213.92%114.29%
Gao Feng95.70%114.29%
Patrick McHardy31.90%228.57%
Hans Schillstrom21.27%114.29%
Jan Engelhardt10.63%114.29%
Total158100.00%7100.00%

EXPORT_SYMBOL(nf_log_packet);
void nf_log_trace(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(); 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(); }

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Pablo Neira Ayuso136100.00%1100.00%
Total136100.00%1100.00%

EXPORT_SYMBOL(nf_log_trace); #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; }

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Pablo Neira Ayuso111100.00%1100.00%
Total111100.00%1100.00%

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; }

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Pablo Neira Ayuso66100.00%1100.00%
Total66100.00%1100.00%

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(); } }

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Pablo Neira Ayuso55100.00%1100.00%
Total55100.00%1100.00%

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; }

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Harald Welte2955.77%125.00%
Gao Feng1426.92%125.00%
Patrick McHardy59.62%125.00%
Jan Engelhardt47.69%125.00%
Total52100.00%4100.00%


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; }

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Harald Welte3867.86%133.33%
Gao Feng1425.00%133.33%
Jan Engelhardt47.14%133.33%
Total56100.00%3100.00%


static void seq_stop(struct seq_file *s, void *v) { mutex_unlock(&nf_log_mutex); }

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Harald Welte1676.19%150.00%
Patrick McHardy523.81%150.00%
Total21100.00%2100.00%


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; }

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Harald Welte6028.85%112.50%
Pablo Neira Ayuso5225.00%112.50%
Eric Leblond5124.52%112.50%
Steven Rostedt2612.50%112.50%
Gao Feng146.73%112.50%
Marcelo Ricardo Leitner20.96%112.50%
Eric Dumazet20.96%112.50%
Patrick McHardy10.48%112.50%
Total208100.00%8100.00%

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)); }

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Harald Welte2472.73%150.00%
Gao Feng927.27%150.00%
Total33100.00%2100.00%

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 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) { const struct nf_logger *logger; char buf[NFLOGGER_NAME_LEN]; int r = 0; int tindex = (unsigned long)table->extra1; struct net *net = table->extra2; if (write) { struct ctl_table tmp = *table; tmp.data = buf; r = proc_dostring(&tmp, write, buffer, lenp, ppos); if (r) return r; 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; }

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Eric Leblond16767.34%110.00%
Patrick McHardy3212.90%220.00%
Pavel Tikhomirov2510.08%110.00%
Gao Feng176.85%110.00%
Eric Dumazet31.21%220.00%
Jann Horn20.81%110.00%
Marcelo Ricardo Leitner10.40%110.00%
Joe Perches10.40%110.00%
Total248100.00%10100.00%


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].maxlen = NFLOGGER_NAME_LEN; 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; } 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++) table[i].extra2 = net; 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); else unregister_net_sysctl_table(nf_log_sysctl_fhdr); err_freg: err_alloc: return -ENOMEM; }

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Eric Leblond11044.18%116.67%
Gao Feng8734.94%116.67%
Michal Kubeček2710.84%116.67%
Jann Horn228.84%116.67%
Eric W. Biedermann31.20%233.33%
Total249100.00%6100.00%


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 unregister_net_sysctl_table(nf_log_sysctl_fhdr); }

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Gao Feng5189.47%150.00%
Michal Kubeček610.53%150.00%
Total57100.00%2100.00%

#else
static int netfilter_log_sysctl_init(struct net *net) { return 0; }

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Eric Leblond1071.43%150.00%
Gao Feng428.57%150.00%
Total14100.00%2100.00%


static void netfilter_log_sysctl_exit(struct net *net) { }

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Gao Feng10100.00%1100.00%
Total10100.00%1100.00%

#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; }

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Gao Feng4451.76%114.29%
Harald Welte1821.18%228.57%
Eric Leblond1112.94%228.57%
Denis V. Lunev78.24%114.29%
Pablo Neira Ayuso55.88%114.29%
Total85100.00%7100.00%


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 }

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Gao Feng2884.85%150.00%
Pablo Neira Ayuso515.15%150.00%
Total33100.00%2100.00%

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); }

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Gao Feng1280.00%