cregit-Linux how code gets into the kernel

Release 4.11 net/netfilter/nf_conntrack_extend.c

Directory: net/netfilter
/* Structure dynamic extension infrastructure
 * Copyright (C) 2004 Rusty Russell IBM Corporation
 * Copyright (C) 2007 Netfilter Core Team <coreteam@netfilter.org>
 * Copyright (C) 2007 USAGI/WIDE Project <http://www.linux-ipv6.org>
 *
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/rcupdate.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <net/netfilter/nf_conntrack_extend.h>


static struct nf_ct_ext_type __rcu *nf_ct_ext_types[NF_CT_EXT_NUM];
static DEFINE_MUTEX(nf_ct_ext_type_mutex);


void __nf_ct_ext_destroy(struct nf_conn *ct) { unsigned int i; struct nf_ct_ext_type *t; struct nf_ct_ext *ext = ct->ext; for (i = 0; i < NF_CT_EXT_NUM; i++) { if (!__nf_ct_ext_exist(ext, i)) continue; rcu_read_lock(); t = rcu_dereference(nf_ct_ext_types[i]); /* Here the nf_ct_ext_type might have been unregisterd. * I.e., it has responsible to cleanup private * area in all conntracks when it is unregisterd. */ if (t && t->destroy) t->destroy(ct); rcu_read_unlock(); } }

Contributors

PersonTokensPropCommitsCommitProp
Yasuyuki Kozakai7587.21%150.00%
Changli Gao1112.79%150.00%
Total86100.00%2100.00%

EXPORT_SYMBOL(__nf_ct_ext_destroy);
static void * nf_ct_ext_create(struct nf_ct_ext **ext, enum nf_ct_ext_id id, size_t var_alloc_len, gfp_t gfp) { unsigned int off, len; struct nf_ct_ext_type *t; size_t alloc_size; rcu_read_lock(); t = rcu_dereference(nf_ct_ext_types[id]); if (!t) { rcu_read_unlock(); return NULL; } off = ALIGN(sizeof(struct nf_ct_ext), t->align); len = off + t->len + var_alloc_len; alloc_size = t->alloc_size + var_alloc_len; rcu_read_unlock(); *ext = kzalloc(alloc_size, gfp); if (!*ext) return NULL; (*ext)->offset[id] = off; (*ext)->len = len; return (void *)(*ext) + off; }

Contributors

PersonTokensPropCommitsCommitProp
Yasuyuki Kozakai12381.46%120.00%
Liping Zhang117.28%120.00%
Eric Dumazet95.96%120.00%
Pablo Neira Ayuso74.64%120.00%
Pekka J Enberg10.66%120.00%
Total151100.00%5100.00%


void *__nf_ct_ext_add_length(struct nf_conn *ct, enum nf_ct_ext_id id, size_t var_alloc_len, gfp_t gfp) { struct nf_ct_ext *old, *new; int newlen, newoff; struct nf_ct_ext_type *t; /* Conntrack must not be confirmed to avoid races on reallocation. */ NF_CT_ASSERT(!nf_ct_is_confirmed(ct)); old = ct->ext; if (!old) return nf_ct_ext_create(&ct->ext, id, var_alloc_len, gfp); if (__nf_ct_ext_exist(old, id)) return NULL; rcu_read_lock(); t = rcu_dereference(nf_ct_ext_types[id]); if (!t) { rcu_read_unlock(); return NULL; } newoff = ALIGN(old->len, t->align); newlen = newoff + t->len + var_alloc_len; rcu_read_unlock(); new = __krealloc(old, newlen, gfp); if (!new) return NULL; if (new != old) { kfree_rcu(old, rcu); rcu_assign_pointer(ct->ext, new); } new->offset[id] = newoff; new->len = newlen; memset((void *)new + newoff, 0, newlen - newoff); return (void *)new + newoff; }

Contributors

PersonTokensPropCommitsCommitProp
Yasuyuki Kozakai15770.40%18.33%
Changli Gao167.17%18.33%
Patrick McHardy156.73%325.00%
Liping Zhang114.93%18.33%
Pekka J Enberg104.48%325.00%
Pablo Neira Ayuso83.59%18.33%
Florian Westphal41.79%18.33%
Lai Jiangshan20.90%18.33%
Total223100.00%12100.00%

EXPORT_SYMBOL(__nf_ct_ext_add_length);
static void update_alloc_size(struct nf_ct_ext_type *type) { int i, j; struct nf_ct_ext_type *t1, *t2; enum nf_ct_ext_id min = 0, max = NF_CT_EXT_NUM - 1; /* unnecessary to update all types */ if ((type->flags & NF_CT_EXT_F_PREALLOC) == 0) { min = type->id; max = type->id; } /* This assumes that extended areas in conntrack for the types whose NF_CT_EXT_F_PREALLOC bit set are allocated in order */ for (i = min; i <= max; i++) { t1 = rcu_dereference_protected(nf_ct_ext_types[i], lockdep_is_held(&nf_ct_ext_type_mutex)); if (!t1) continue; t1->alloc_size = ALIGN(sizeof(struct nf_ct_ext), t1->align) + t1->len; for (j = 0; j < NF_CT_EXT_NUM; j++) { t2 = rcu_dereference_protected(nf_ct_ext_types[j], lockdep_is_held(&nf_ct_ext_type_mutex)); if (t2 == NULL || t2 == t1 || (t2->flags & NF_CT_EXT_F_PREALLOC) == 0) continue; t1->alloc_size = ALIGN(t1->alloc_size, t2->align) + t2->len; } } }

Contributors

PersonTokensPropCommitsCommitProp
Yasuyuki Kozakai17590.67%150.00%
Eric Dumazet189.33%150.00%
Total193100.00%2100.00%

/* This MUST be called in process context. */
int nf_ct_extend_register(struct nf_ct_ext_type *type) { int ret = 0; mutex_lock(&nf_ct_ext_type_mutex); if (nf_ct_ext_types[type->id]) { ret = -EBUSY; goto out; } /* This ensures that nf_ct_ext_create() can allocate enough area before updating alloc_size */ type->alloc_size = ALIGN(sizeof(struct nf_ct_ext), type->align) + type->len; rcu_assign_pointer(nf_ct_ext_types[type->id], type); update_alloc_size(type); out: mutex_unlock(&nf_ct_ext_type_mutex); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Yasuyuki Kozakai8998.89%150.00%
Eric Dumazet11.11%150.00%
Total90100.00%2100.00%

EXPORT_SYMBOL_GPL(nf_ct_extend_register); /* This MUST be called in process context. */
void nf_ct_extend_unregister(struct nf_ct_ext_type *type) { mutex_lock(&nf_ct_ext_type_mutex); RCU_INIT_POINTER(nf_ct_ext_types[type->id], NULL); update_alloc_size(type); mutex_unlock(&nf_ct_ext_type_mutex); synchronize_rcu(); }

Contributors

PersonTokensPropCommitsCommitProp
Yasuyuki Kozakai4095.24%133.33%
Stephen Hemminger12.38%133.33%
Liping Zhang12.38%133.33%
Total42100.00%3100.00%

EXPORT_SYMBOL_GPL(nf_ct_extend_unregister);

Overall Contributors

PersonTokensPropCommitsCommitProp
Yasuyuki Kozakai71784.85%15.88%
Eric Dumazet283.31%317.65%
Changli Gao273.20%15.88%
Liping Zhang232.72%15.88%
Pablo Neira Ayuso161.89%15.88%
Patrick McHardy151.78%317.65%
Pekka J Enberg111.30%317.65%
Florian Westphal40.47%15.88%
Lai Jiangshan20.24%15.88%
Stephen Hemminger10.12%15.88%
Arnd Bergmann10.12%15.88%
Total845100.00%17100.00%
Directory: net/netfilter
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