cregit-Linux how code gets into the kernel

Release 4.8 net/netfilter/xt_hashlimit.c

Directory: net/netfilter
/*
 *      xt_hashlimit - Netfilter module to limit the number of packets per time
 *      separately for each hashbucket (sourceip/sourceport/dstip/dstport)
 *
 *      (C) 2003-2004 by Harald Welte <laforge@netfilter.org>
 *      (C) 2006-2012 Patrick McHardy <kaber@trash.net>
 *      Copyright © CC Computer Consultants GmbH, 2007 - 2008
 *
 * Development of this code was funded by Astaro AG, http://www.astaro.com/
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/random.h>
#include <linux/jhash.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/list.h>
#include <linux/skbuff.h>
#include <linux/mm.h>
#include <linux/in.h>
#include <linux/ip.h>
#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
#include <linux/ipv6.h>
#include <net/ipv6.h>
#endif

#include <net/net_namespace.h>
#include <net/netns/generic.h>

#include <linux/netfilter/x_tables.h>
#include <linux/netfilter_ipv4/ip_tables.h>
#include <linux/netfilter_ipv6/ip6_tables.h>
#include <linux/netfilter/xt_hashlimit.h>
#include <linux/mutex.h>

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>");
MODULE_DESCRIPTION("Xtables: per hash-bucket rate-limit match");
MODULE_ALIAS("ipt_hashlimit");
MODULE_ALIAS("ip6t_hashlimit");


struct hashlimit_net {
	
struct hlist_head	htables;
	
struct proc_dir_entry	*ipt_hashlimit;
	
struct proc_dir_entry	*ip6t_hashlimit;
};


static int hashlimit_net_id;

static inline struct hashlimit_net *hashlimit_pernet(struct net *net) { return net_generic(net, hashlimit_net_id); }

Contributors

PersonTokensPropCommitsCommitProp
alexey dobriyanalexey dobriyan22100.00%1100.00%
Total22100.00%1100.00%

/* need to declare this at the top */ static const struct file_operations dl_file_ops; /* hash table crap */ struct dsthash_dst { union { struct { __be32 src; __be32 dst; } ip; #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) struct { __be32 src[4]; __be32 dst[4]; } ip6; #endif }; __be16 src_port; __be16 dst_port; }; struct dsthash_ent { /* static / read-only parts in the beginning */ struct hlist_node node; struct dsthash_dst dst; /* modified structure members in the end */ spinlock_t lock; unsigned long expires; /* precalculated expiry time */ struct { unsigned long prev; /* last modification */ u_int32_t credit; u_int32_t credit_cap, cost; } rateinfo; struct rcu_head rcu; }; struct xt_hashlimit_htable { struct hlist_node node; /* global list of all htables */ int use; u_int8_t family; bool rnd_initialized; struct hashlimit_cfg1 cfg; /* config */ /* used internally */ spinlock_t lock; /* lock for list_head */ u_int32_t rnd; /* random seed for hash */ unsigned int count; /* number entries in table */ struct delayed_work gc_work; /* seq_file stuff */ struct proc_dir_entry *pde; const char *name; struct net *net; struct hlist_head hash[0]; /* hashtable itself */ }; static DEFINE_MUTEX(hashlimit_mutex); /* protects htables list */ static struct kmem_cache *hashlimit_cachep __read_mostly;
static inline bool dst_cmp(const struct dsthash_ent *ent, const struct dsthash_dst *b) { return !memcmp(&ent->dst, b, sizeof(ent->dst)); }

Contributors

PersonTokensPropCommitsCommitProp
harald welteharald welte2668.42%125.00%
patrick mchardypatrick mchardy1026.32%125.00%
jan engelhardtjan engelhardt25.26%250.00%
Total38100.00%4100.00%


static u_int32_t hash_dst(const struct xt_hashlimit_htable *ht, const struct dsthash_dst *dst) { u_int32_t hash = jhash2((const u32 *)dst, sizeof(*dst)/sizeof(u32), ht->rnd); /* * Instead of returning hash % ht->cfg.size (implying a divide) * we return the high 32 bits of the (hash * ht->cfg.size) that will * give results between [0 and cfg.size-1] and same hash distribution, * but using a multiply, less expensive than a divide */ return reciprocal_scale(hash, ht->cfg.size); }

Contributors

PersonTokensPropCommitsCommitProp
harald welteharald welte3254.24%125.00%
eric dumazeteric dumazet1830.51%125.00%
patrick mchardypatrick mchardy58.47%125.00%
daniel borkmanndaniel borkmann46.78%125.00%
Total59100.00%4100.00%


static struct dsthash_ent * dsthash_find(const struct xt_hashlimit_htable *ht, const struct dsthash_dst *dst) { struct dsthash_ent *ent; u_int32_t hash = hash_dst(ht, dst); if (!hlist_empty(&ht->hash[hash])) { hlist_for_each_entry_rcu(ent, &ht->hash[hash], node) if (dst_cmp(ent, dst)) { spin_lock(&ent->lock); return ent; } } return NULL; }

Contributors

PersonTokensPropCommitsCommitProp
harald welteharald welte6577.38%233.33%
eric dumazeteric dumazet1113.10%116.67%
jix at bugmachine.cajix at bugmachine.ca44.76%116.67%
patrick mchardypatrick mchardy33.57%116.67%
jan engelhardtjan engelhardt11.19%116.67%
Total84100.00%6100.00%

/* allocate dsthash_ent, initialize dst, put in htable and lock it */
static struct dsthash_ent * dsthash_alloc_init(struct xt_hashlimit_htable *ht, const struct dsthash_dst *dst, bool *race) { struct dsthash_ent *ent; spin_lock(&ht->lock); /* Two or more packets may race to create the same entry in the * hashtable, double check if this packet lost race. */ ent = dsthash_find(ht, dst); if (ent != NULL) { spin_unlock(&ht->lock); *race = true; return ent; } /* initialize hash with random val at the time we allocate * the first hashtable entry */ if (unlikely(!ht->rnd_initialized)) { get_random_bytes(&ht->rnd, sizeof(ht->rnd)); ht->rnd_initialized = true; } if (ht->cfg.max && ht->count >= ht->cfg.max) { /* FIXME: do something. question is what.. */ net_err_ratelimited("max count of %u reached\n", ht->cfg.max); ent = NULL; } else ent = kmem_cache_alloc(hashlimit_cachep, GFP_ATOMIC); if (ent) { memcpy(&ent->dst, dst, sizeof(ent->dst)); spin_lock_init(&ent->lock); spin_lock(&ent->lock); hlist_add_head_rcu(&ent->node, &ht->hash[hash_dst(ht, dst)]); ht->count++; } spin_unlock(&ht->lock); return ent; }

Contributors

PersonTokensPropCommitsCommitProp
harald welteharald welte11550.88%218.18%
eric dumazeteric dumazet4118.14%19.09%
pablo neira ayusopablo neira ayuso3816.81%19.09%
patrick mchardypatrick mchardy229.73%218.18%
hagen paul pfeiferhagen paul pfeifer62.65%19.09%
jan engelhardtjan engelhardt31.33%327.27%
joe perchesjoe perches10.44%19.09%
Total226100.00%11100.00%


static void dsthash_free_rcu(struct rcu_head *head) { struct dsthash_ent *ent = container_of(head, struct dsthash_ent, rcu); kmem_cache_free(hashlimit_cachep, ent); }

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PersonTokensPropCommitsCommitProp
eric dumazeteric dumazet33100.00%1100.00%
Total33100.00%1100.00%


static inline void dsthash_free(struct xt_hashlimit_htable *ht, struct dsthash_ent *ent) { hlist_del_rcu(&ent->node); call_rcu_bh(&ent->rcu, dsthash_free_rcu); ht->count--; }

Contributors

PersonTokensPropCommitsCommitProp
harald welteharald welte3075.00%250.00%
eric dumazeteric dumazet717.50%125.00%
patrick mchardypatrick mchardy37.50%125.00%
Total40100.00%4100.00%

static void htable_gc(struct work_struct *work);
static int htable_create(struct net *net, struct xt_hashlimit_mtinfo1 *minfo, u_int8_t family) { struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); struct xt_hashlimit_htable *hinfo; unsigned int size; unsigned int i; if (minfo->cfg.size) { size = minfo->cfg.size; } else { size = (totalram_pages << PAGE_SHIFT) / 16384 / sizeof(struct list_head); if (totalram_pages > 1024 * 1024 * 1024 / PAGE_SIZE) size = 8192; if (size < 16) size = 16; } /* FIXME: don't use vmalloc() here or anywhere else -HW */ hinfo = vmalloc(sizeof(struct xt_hashlimit_htable) + sizeof(struct list_head) * size); if (hinfo == NULL) return -ENOMEM; minfo->hinfo = hinfo; /* copy match config into hashtable config */ memcpy(&hinfo->cfg, &minfo->cfg, sizeof(hinfo->cfg)); hinfo->cfg.size = size; if (hinfo->cfg.max == 0) hinfo->cfg.max = 8 * hinfo->cfg.size; else if (hinfo->cfg.max < hinfo->cfg.size) hinfo->cfg.max = hinfo->cfg.size; for (i = 0; i < hinfo->cfg.size; i++) INIT_HLIST_HEAD(&hinfo->hash[i]); hinfo->use = 1; hinfo->count = 0; hinfo->family = family; hinfo->rnd_initialized = false; hinfo->name = kstrdup(minfo->name, GFP_KERNEL); if (!hinfo->name) { vfree(hinfo); return -ENOMEM; } spin_lock_init(&hinfo->lock); hinfo->pde = proc_create_data(minfo->name, 0, (family == NFPROTO_IPV4) ? hashlimit_net->ipt_hashlimit : hashlimit_net->ip6t_hashlimit, &dl_file_ops, hinfo); if (hinfo->pde == NULL) { kfree(hinfo->name); vfree(hinfo); return -ENOMEM; } hinfo->net = net; INIT_DEFERRABLE_WORK(&hinfo->gc_work, htable_gc); queue_delayed_work(system_power_efficient_wq, &hinfo->gc_work, msecs_to_jiffies(hinfo->cfg.gc_interval)); hlist_add_head(&hinfo->node, &hashlimit_net->htables); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
harald welteharald welte26963.90%210.00%
al viroal viro389.03%15.00%
jan engelhardtjan engelhardt337.84%630.00%
alexey dobriyanalexey dobriyan307.13%15.00%
patrick mchardypatrick mchardy296.89%420.00%
eric dumazeteric dumazet92.14%15.00%
denis v. lunevdenis v. lunev61.43%210.00%
andrew mortonandrew morton40.95%15.00%
jan beulichjan beulich20.48%15.00%
tobias klausertobias klauser10.24%15.00%
Total421100.00%20100.00%


static bool select_all(const struct xt_hashlimit_htable *ht, const struct dsthash_ent *he) { return 1; }

Contributors

PersonTokensPropCommitsCommitProp
jan engelhardtjan engelhardt1257.14%133.33%
harald welteharald welte628.57%133.33%
alexey dobriyanalexey dobriyan314.29%133.33%
Total21100.00%3100.00%


static bool select_gc(const struct xt_hashlimit_htable *ht, const struct dsthash_ent *he) { return time_after_eq(jiffies, he->expires); }

Contributors

PersonTokensPropCommitsCommitProp
jan engelhardtjan engelhardt2485.71%133.33%
alexey dobriyanalexey dobriyan310.71%133.33%
harald welteharald welte13.57%133.33%
Total28100.00%3100.00%


static void htable_selective_cleanup(struct xt_hashlimit_htable *ht, bool (*select)(const struct xt_hashlimit_htable *ht, const struct dsthash_ent *he)) { unsigned int i; for (i = 0; i < ht->cfg.size; i++) { struct dsthash_ent *dh; struct hlist_node *n; spin_lock_bh(&ht->lock); hlist_for_each_entry_safe(dh, n, &ht->hash[i], node) { if ((*select)(ht, dh)) dsthash_free(ht, dh); } spin_unlock_bh(&ht->lock); cond_resched(); } }

Contributors

PersonTokensPropCommitsCommitProp
jan engelhardtjan engelhardt8575.22%233.33%
harald welteharald welte1311.50%116.67%
eric dumazeteric dumazet1210.62%116.67%
patrick mchardypatrick mchardy21.77%116.67%
alexey dobriyanalexey dobriyan10.88%116.67%
Total113100.00%6100.00%


static void htable_gc(struct work_struct *work) { struct xt_hashlimit_htable *ht; ht = container_of(work, struct xt_hashlimit_htable, gc_work.work); htable_selective_cleanup(ht, select_gc); queue_delayed_work(system_power_efficient_wq, &ht->gc_work, msecs_to_jiffies(ht->cfg.gc_interval)); }

Contributors

PersonTokensPropCommitsCommitProp
jan engelhardtjan engelhardt2850.00%250.00%
eric dumazeteric dumazet2442.86%125.00%
harald welteharald welte47.14%125.00%
Total56100.00%4100.00%


static void htable_remove_proc_entry(struct xt_hashlimit_htable *hinfo) { struct hashlimit_net *hashlimit_net = hashlimit_pernet(hinfo->net); struct proc_dir_entry *parent; if (hinfo->family == NFPROTO_IPV4) parent = hashlimit_net->ipt_hashlimit; else parent = hashlimit_net->ip6t_hashlimit; if (parent != NULL) remove_proc_entry(hinfo->name, parent); }

Contributors

PersonTokensPropCommitsCommitProp
jan engelhardtjan engelhardt4773.44%240.00%
harald welteharald welte914.06%120.00%
vitaly e. lavrovvitaly e. lavrov69.38%120.00%
sergey popovichsergey popovich23.12%120.00%
Total64100.00%5100.00%


static void htable_destroy(struct xt_hashlimit_htable *hinfo) { cancel_delayed_work_sync(&hinfo->gc_work); htable_remove_proc_entry(hinfo); htable_selective_cleanup(hinfo, select_all); kfree(hinfo->name); vfree(hinfo); }

Contributors

PersonTokensPropCommitsCommitProp
sergey popovichsergey popovich2148.84%116.67%
jan engelhardtjan engelhardt818.60%233.33%
al viroal viro716.28%116.67%
harald welteharald welte511.63%116.67%
eric dumazeteric dumazet24.65%116.67%
Total43100.00%6100.00%


static struct xt_hashlimit_htable *htable_find_get(struct net *net, const char *name, u_int8_t family) { struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); struct xt_hashlimit_htable *hinfo; hlist_for_each_entry(hinfo, &hashlimit_net->htables, node) { if (!strcmp(name, hinfo->name) && hinfo->family == family) { hinfo->use++; return hinfo; } } return NULL; }

Contributors

PersonTokensPropCommitsCommitProp
jan engelhardtjan engelhardt6888.31%240.00%
harald welteharald welte56.49%120.00%
patrick mchardypatrick mchardy33.90%120.00%
denis v. lunevdenis v. lunev11.30%120.00%
Total77100.00%5100.00%


static void htable_put(struct xt_hashlimit_htable *hinfo) { mutex_lock(&hashlimit_mutex); if (--hinfo->use == 0) { hlist_del(&hinfo->node); htable_destroy(hinfo); } mutex_unlock(&hashlimit_mutex); }

Contributors

PersonTokensPropCommitsCommitProp
jan engelhardtjan engelhardt3165.96%250.00%
harald welteharald welte1531.91%125.00%
alexey dobriyanalexey dobriyan12.13%125.00%
Total47100.00%4100.00%

/* The algorithm used is the Simple Token Bucket Filter (TBF) * see net/sched/sch_tbf.c in the linux source tree */ /* Rusty: This is my (non-mathematically-inclined) understanding of this algorithm. The `average rate' in jiffies becomes your initial amount of credit `credit' and the most credit you can ever have `credit_cap'. The `peak rate' becomes the cost of passing the test, `cost'. `prev' tracks the last packet hit: you gain one credit per jiffy. If you get credit balance more than this, the extra credit is discarded. Every time the match passes, you lose `cost' credits; if you don't have that many, the test fails. See Alexey's formal explanation in net/sched/sch_tbf.c. To get the maximum range, we multiply by this factor (ie. you get N credits per jiffy). We want to allow a rate as low as 1 per day (slowest userspace tool allows), which means CREDITS_PER_JIFFY*HZ*60*60*24 < 2^32 ie. */ #define MAX_CPJ (0xFFFFFFFF / (HZ*60*60*24)) /* Repeated shift and or gives us all 1s, final shift and add 1 gives * us the power of 2 below the theoretical max, so GCC simply does a * shift. */ #define _POW2_BELOW2(x) ((x)|((x)>>1)) #define _POW2_BELOW4(x) (_POW2_BELOW2(x)|_POW2_BELOW2((x)>>2)) #define _POW2_BELOW8(x) (_POW2_BELOW4(x)|_POW2_BELOW4((x)>>4)) #define _POW2_BELOW16(x) (_POW2_BELOW8(x)|_POW2_BELOW8((x)>>8)) #define _POW2_BELOW32(x) (_POW2_BELOW16(x)|_POW2_BELOW16((x)>>16)) #define POW2_BELOW32(x) ((_POW2_BELOW32(x)>>1) + 1) #define CREDITS_PER_JIFFY POW2_BELOW32(MAX_CPJ) /* in byte mode, the lowest possible rate is one packet/second. * credit_cap is used as a counter that tells us how many times we can * refill the "credits available" counter when it becomes empty. */ #define MAX_CPJ_BYTES (0xFFFFFFFF / HZ) #define CREDITS_PER_JIFFY_BYTES POW2_BELOW32(MAX_CPJ_BYTES)
static u32 xt_hashlimit_len_to_chunks(u32 len) { return (len >> XT_HASHLIMIT_BYTE_SHIFT) + 1; }

Contributors

PersonTokensPropCommitsCommitProp
florian westphalflorian westphal18100.00%1100.00%
Total18100.00%1100.00%

/* Precision saver. */
static u32 user2credits(u32 user) { /* If multiplying would overflow... */ if (user > 0xFFFFFFFF / (HZ*CREDITS_PER_JIFFY)) /* Divide first. */ return (user / XT_HASHLIMIT_SCALE) * HZ * CREDITS_PER_JIFFY; return (user * HZ * CREDITS_PER_JIFFY) / XT_HASHLIMIT_SCALE; }

Contributors

PersonTokensPropCommitsCommitProp
jan engelhardtjan engelhardt4293.33%266.67%
florian westphalflorian westphal36.67%133.33%
Total45100.00%3100.00%


static u32 user2credits_byte(u32 user) { u64 us = user; us *= HZ * CREDITS_PER_JIFFY_BYTES; return (u32) (us >> 32); }

Contributors

PersonTokensPropCommitsCommitProp
florian westphalflorian westphal30100.00%1100.00%
Total30100.00%1100.00%


static void rateinfo_recalc(struct dsthash_ent *dh, unsigned long now, u32 mode) { unsigned long delta = now - dh->rateinfo.prev; u32 cap; if (delta == 0) return; dh->rateinfo.prev = now; if (mode & XT_HASHLIMIT_BYTES) { u32 tmp = dh->rateinfo.credit; dh->rateinfo.credit += CREDITS_PER_JIFFY_BYTES * delta; cap = CREDITS_PER_JIFFY_BYTES * HZ; if (tmp >= dh->rateinfo.credit) {/* overflow */ dh->rateinfo.credit = cap; return; } } else { dh->rateinfo.credit += delta * CREDITS_PER_JIFFY; cap = dh->rateinfo.credit_cap; } if (dh->rateinfo.credit > cap) dh->rateinfo.credit = cap; }

Contributors

PersonTokensPropCommitsCommitProp
florian westphalflorian westphal8761.27%133.33%
jan engelhardtjan engelhardt5538.73%266.67%
Total142100.00%3100.00%


static void rateinfo_init(struct dsthash_ent *dh, struct xt_hashlimit_htable *hinfo) { dh->rateinfo.prev = jiffies; if (hinfo->cfg.mode & XT_HASHLIMIT_BYTES) { dh->rateinfo.credit = CREDITS_PER_JIFFY_BYTES * HZ; dh->rateinfo.cost = user2credits_byte(hinfo->cfg.avg); dh->rateinfo.credit_cap = hinfo->cfg.burst; } else { dh->rateinfo.credit = user2credits(hinfo->cfg.avg * hinfo->cfg.burst); dh->rateinfo.cost = user2credits(hinfo->cfg.avg); dh->rateinfo.credit_cap = dh->rateinfo.credit; } }

Contributors

PersonTokensPropCommitsCommitProp
florian westphalflorian westphal124100.00%2100.00%
Total124100.00%2100.00%


static inline __be32 maskl(__be32 a, unsigned int l) { return l ? htonl(ntohl(a) & ~0 << (32 - l)) : 0; }

Contributors

PersonTokensPropCommitsCommitProp
jan engelhardtjan engelhardt3494.44%266.67%
harald welteharald welte25.56%133.33%
Total36100.00%3100.00%

#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
static void hashlimit_ipv6_mask(__be32 *i, unsigned int p) { switch (p) { case 0 ... 31: i[0] = maskl(i[0], p); i[1] = i[2] = i[3] = 0; break; case 32 ... 63: i[1] = maskl(i[1], p - 32); i[2] = i[3] = 0; break; case 64 ... 95: i[2] = maskl(i[2], p - 64); i[3] = 0; break; case 96 ... 127: i[3] = maskl(i[3], p - 96); break; case 128: break; } }

Contributors

PersonTokensPropCommitsCommitProp
jan engelhardtjan engelhardt14294.67%240.00%
harald welteharald welte53.33%120.00%
patrick mchardypatrick mchardy32.00%240.00%
Total150100.00%5100.00%

#endif
static int hashlimit_init_dst(const struct xt_hashlimit_htable *hinfo, struct dsthash_dst *dst, const struct sk_buff *skb, unsigned int protoff) { __be16 _ports[2], *ports; u8 nexthdr; int poff; memset(dst, 0, sizeof(*dst)); switch (hinfo->family) { case NFPROTO_IPV4: if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DIP) dst->ip.dst = maskl(ip_hdr(skb)->daddr, hinfo->cfg.dstmask); if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SIP) dst->ip.src = maskl(ip_hdr(skb)->saddr, hinfo->cfg.srcmask); if (!(hinfo->cfg.mode & (XT_HASHLIMIT_HASH_DPT | XT_HASHLIMIT_HASH_SPT))) return 0; nexthdr = ip_hdr(skb)->protocol; break; #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) case NFPROTO_IPV6: { __be16 frag_off; if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DIP) { memcpy(&dst->ip6.dst, &ipv6_hdr(skb)->daddr, sizeof(dst->ip6.dst)); hashlimit_ipv6_mask(dst->ip6.dst, hinfo->cfg.dstmask); } if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SIP) { memcpy(&dst->ip6.src, &ipv6_hdr(skb)->saddr, sizeof(dst->ip6.src)); hashlimit_ipv6_mask(dst->ip6.src, hinfo->cfg.srcmask); } if (!(hinfo->cfg.mode & (XT_HASHLIMIT_HASH_DPT | XT_HASHLIMIT_HASH_SPT))) return 0; nexthdr = ipv6_hdr(skb)->nexthdr; protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr, &frag_off); if ((int)protoff < 0) return -1; break; } #endif default: BUG(); return 0; } poff = proto_ports_offset(nexthdr); if (poff >= 0) { ports = skb_header_pointer(skb, protoff + poff, sizeof(_ports), &_ports); } else { _ports[0] = _ports[1] = 0; ports = _ports; } if (!ports) return -1; if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SPT) dst->src_port = ports[0]; if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DPT) dst->dst_port = ports[1]; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
jan engelhardtjan engelhardt36880.70%426.67%
patrick mchardypatrick mchardy367.89%320.00%
harald welteharald welte214.61%213.33%
changli gaochangli gao194.17%16.67%
stephen rothwellstephen rothwell51.10%16.67%
jesse grossjesse gross30.66%16.67%
arnaldo carvalho de meloarnaldo carvalho de melo30.66%213.33%
igor maravicigor maravic10.22%16.67%
Total456100.00%15100.00%


static u32 hashlimit_byte_cost(unsigned int len, struct dsthash_ent *dh) { u64 tmp = xt_hashlimit_len_to_chunks(len); tmp = tmp * dh->rateinfo.cost; if (unlikely(tmp > CREDITS_PER_JIFFY_BYTES * HZ)) tmp = CREDITS_PER_JIFFY_BYTES