X-Git-Url: http://pileus.org/git/?a=blobdiff_plain;f=net%2Fnetfilter%2Fxt_hashlimit.c;h=5418ce59ac3aa3689c2adf567aefecd3240af94f;hb=f49e1aa133c2c9b74b5dfddca8863609bbda9086;hp=19103678bf2079bb3b4c3c937a6992744711bca1;hpb=4d5709a7b7d54fc5882d2943a14988a92d48c00a;p=~andy%2Flinux diff --git a/net/netfilter/xt_hashlimit.c b/net/netfilter/xt_hashlimit.c index 19103678bf2..5418ce59ac3 100644 --- a/net/netfilter/xt_hashlimit.c +++ b/net/netfilter/xt_hashlimit.c @@ -1,9 +1,9 @@ -/* iptables match extension to limit the number of packets per second - * seperately for each hashbucket (sourceip/sourceport/dstip/dstport) +/* + * xt_hashlimit - Netfilter module to limit the number of packets per time + * seperately for each hashbucket (sourceip/sourceport/dstip/dstport) * - * (C) 2003-2004 by Harald Welte - * - * $Id: ipt_hashlimit.c 3244 2004-10-20 16:24:29Z laforge@netfilter.org $ + * (C) 2003-2004 by Harald Welte + * Copyright © CC Computer Consultants GmbH, 2007 - 2008 * * Development of this code was funded by Astaro AG, http://www.astaro.com/ */ @@ -20,7 +20,11 @@ #include #include #include +#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE) #include +#include +#endif + #include #include @@ -31,7 +35,8 @@ MODULE_LICENSE("GPL"); MODULE_AUTHOR("Harald Welte "); -MODULE_DESCRIPTION("iptables match for limiting per hash-bucket"); +MODULE_AUTHOR("Jan Engelhardt "); +MODULE_DESCRIPTION("Xtables: per hash-bucket rate-limit match"); MODULE_ALIAS("ipt_hashlimit"); MODULE_ALIAS("ip6t_hashlimit"); @@ -47,11 +52,13 @@ struct dsthash_dst { __be32 src; __be32 dst; } ip; +#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE) struct { __be32 src[4]; __be32 dst[4]; } ip6; - } addr; +#endif + }; __be16 src_port; __be16 dst_port; }; @@ -75,7 +82,7 @@ struct xt_hashlimit_htable { atomic_t use; int family; - struct hashlimit_cfg cfg; /* config */ + struct hashlimit_cfg1 cfg; /* config */ /* used internally */ spinlock_t lock; /* lock for list_head */ @@ -104,7 +111,16 @@ static inline bool dst_cmp(const struct dsthash_ent *ent, static u_int32_t hash_dst(const struct xt_hashlimit_htable *ht, const struct dsthash_dst *dst) { - return jhash(dst, sizeof(*dst), ht->rnd) % ht->cfg.size; + 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 ((u64)hash * ht->cfg.size) >> 32; } static struct dsthash_ent * @@ -169,7 +185,7 @@ dsthash_free(struct xt_hashlimit_htable *ht, struct dsthash_ent *ent) } static void htable_gc(unsigned long htlong); -static int htable_create(struct xt_hashlimit_info *minfo, int family) +static int htable_create_v0(struct xt_hashlimit_info *minfo, int family) { struct xt_hashlimit_htable *hinfo; unsigned int size; @@ -195,7 +211,18 @@ static int htable_create(struct xt_hashlimit_info *minfo, int family) minfo->hinfo = hinfo; /* copy match config into hashtable config */ - memcpy(&hinfo->cfg, &minfo->cfg, sizeof(hinfo->cfg)); + hinfo->cfg.mode = minfo->cfg.mode; + hinfo->cfg.avg = minfo->cfg.avg; + hinfo->cfg.burst = minfo->cfg.burst; + hinfo->cfg.max = minfo->cfg.max; + hinfo->cfg.gc_interval = minfo->cfg.gc_interval; + hinfo->cfg.expire = minfo->cfg.expire; + + if (family == AF_INET) + hinfo->cfg.srcmask = hinfo->cfg.dstmask = 32; + else + hinfo->cfg.srcmask = hinfo->cfg.dstmask = 128; + hinfo->cfg.size = size; if (!hinfo->cfg.max) hinfo->cfg.max = 8 * hinfo->cfg.size; @@ -231,6 +258,70 @@ static int htable_create(struct xt_hashlimit_info *minfo, int family) return 0; } +static int htable_create(struct xt_hashlimit_mtinfo1 *minfo, + unsigned int family) +{ + struct xt_hashlimit_htable *hinfo; + unsigned int size; + unsigned int i; + + if (minfo->cfg.size) { + size = minfo->cfg.size; + } else { + size = (num_physpages << PAGE_SHIFT) / 16384 / + sizeof(struct list_head); + if (num_physpages > 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) { + printk(KERN_ERR "xt_hashlimit: unable to create hashtable\n"); + return -1; + } + 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]); + + atomic_set(&hinfo->use, 1); + hinfo->count = 0; + hinfo->family = family; + hinfo->rnd_initialized = 0; + spin_lock_init(&hinfo->lock); + + hinfo->pde = create_proc_entry(minfo->name, 0, + family == AF_INET ? hashlimit_procdir4 : + hashlimit_procdir6); + if (hinfo->pde == NULL) { + vfree(hinfo); + return -1; + } + hinfo->pde->proc_fops = &dl_file_ops; + hinfo->pde->data = hinfo; + + setup_timer(&hinfo->timer, htable_gc, (unsigned long)hinfo); + hinfo->timer.expires = jiffies + msecs_to_jiffies(hinfo->cfg.gc_interval); + add_timer(&hinfo->timer); + + spin_lock_bh(&hashlimit_lock); + hlist_add_head(&hinfo->node, &hashlimit_htables); + spin_unlock_bh(&hashlimit_lock); + + return 0; +} + static bool select_all(const struct xt_hashlimit_htable *ht, const struct dsthash_ent *he) { @@ -240,7 +331,7 @@ static bool select_all(const struct xt_hashlimit_htable *ht, static bool select_gc(const struct xt_hashlimit_htable *ht, const struct dsthash_ent *he) { - return jiffies >= he->expires; + return time_after_eq(jiffies, he->expires); } static void htable_selective_cleanup(struct xt_hashlimit_htable *ht, @@ -373,22 +464,66 @@ static inline void rateinfo_recalc(struct dsthash_ent *dh, unsigned long now) dh->rateinfo.prev = now; } +static inline __be32 maskl(__be32 a, unsigned int l) +{ + return htonl(ntohl(a) & ~(~(u_int32_t)0 >> l)); +} + +#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE) +static void hashlimit_ipv6_mask(__be32 *i, unsigned int p) +{ + switch (p) { + case 0: + i[0] = i[1] = 0; + i[2] = i[3] = 0; + break; + case 1 ... 31: + i[0] = maskl(i[0], p); + i[1] = i[2] = i[3] = 0; + break; + case 32: + i[1] = i[2] = i[3] = 0; + break; + case 33 ... 63: + i[1] = maskl(i[1], p - 32); + i[2] = i[3] = 0; + break; + case 64: + i[2] = i[3] = 0; + break; + case 65 ... 95: + i[2] = maskl(i[2], p - 64); + i[3] = 0; + case 96: + i[3] = 0; + break; + case 97 ... 127: + i[3] = maskl(i[3], p - 96); + break; + case 128: + break; + } +} +#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; - int nexthdr; + u8 nexthdr; memset(dst, 0, sizeof(*dst)); switch (hinfo->family) { case AF_INET: if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DIP) - dst->addr.ip.dst = ip_hdr(skb)->daddr; + dst->ip.dst = maskl(ip_hdr(skb)->daddr, + hinfo->cfg.dstmask); if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SIP) - dst->addr.ip.src = ip_hdr(skb)->saddr; + dst->ip.src = maskl(ip_hdr(skb)->saddr, + hinfo->cfg.srcmask); if (!(hinfo->cfg.mode & (XT_HASHLIMIT_HASH_DPT | XT_HASHLIMIT_HASH_SPT))) @@ -397,18 +532,23 @@ hashlimit_init_dst(const struct xt_hashlimit_htable *hinfo, break; #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE) case AF_INET6: - if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DIP) - memcpy(&dst->addr.ip6.dst, &ipv6_hdr(skb)->daddr, - sizeof(dst->addr.ip6.dst)); - if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SIP) - memcpy(&dst->addr.ip6.src, &ipv6_hdr(skb)->saddr, - sizeof(dst->addr.ip6.src)); + 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_find_hdr(skb, &protoff, -1, NULL); - if (nexthdr < 0) + nexthdr = ipv6_hdr(skb)->nexthdr; + protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr); + if ((int)protoff < 0) return -1; break; #endif @@ -441,14 +581,10 @@ hashlimit_init_dst(const struct xt_hashlimit_htable *hinfo, } static bool -hashlimit_match(const struct sk_buff *skb, - const struct net_device *in, - const struct net_device *out, - const struct xt_match *match, - const void *matchinfo, - int offset, - unsigned int protoff, - bool *hotdrop) +hashlimit_mt_v0(const struct sk_buff *skb, const struct net_device *in, + const struct net_device *out, const struct xt_match *match, + const void *matchinfo, int offset, unsigned int protoff, + bool *hotdrop) { const struct xt_hashlimit_info *r = ((const struct xt_hashlimit_info *)matchinfo)->u.master; @@ -500,11 +636,62 @@ hotdrop: } static bool -hashlimit_checkentry(const char *tablename, - const void *inf, - const struct xt_match *match, - void *matchinfo, - unsigned int hook_mask) +hashlimit_mt(const struct sk_buff *skb, const struct net_device *in, + const struct net_device *out, const struct xt_match *match, + const void *matchinfo, int offset, unsigned int protoff, + bool *hotdrop) +{ + const struct xt_hashlimit_mtinfo1 *info = matchinfo; + struct xt_hashlimit_htable *hinfo = info->hinfo; + unsigned long now = jiffies; + struct dsthash_ent *dh; + struct dsthash_dst dst; + + if (hashlimit_init_dst(hinfo, &dst, skb, protoff) < 0) + goto hotdrop; + + spin_lock_bh(&hinfo->lock); + dh = dsthash_find(hinfo, &dst); + if (dh == NULL) { + dh = dsthash_alloc_init(hinfo, &dst); + if (dh == NULL) { + spin_unlock_bh(&hinfo->lock); + goto hotdrop; + } + + dh->expires = jiffies + msecs_to_jiffies(hinfo->cfg.expire); + dh->rateinfo.prev = jiffies; + dh->rateinfo.credit = user2credits(hinfo->cfg.avg * + hinfo->cfg.burst); + dh->rateinfo.credit_cap = user2credits(hinfo->cfg.avg * + hinfo->cfg.burst); + dh->rateinfo.cost = user2credits(hinfo->cfg.avg); + } else { + /* update expiration timeout */ + dh->expires = now + msecs_to_jiffies(hinfo->cfg.expire); + rateinfo_recalc(dh, now); + } + + if (dh->rateinfo.credit >= dh->rateinfo.cost) { + /* below the limit */ + dh->rateinfo.credit -= dh->rateinfo.cost; + spin_unlock_bh(&hinfo->lock); + return !(info->cfg.mode & XT_HASHLIMIT_INVERT); + } + + spin_unlock_bh(&hinfo->lock); + /* default match is underlimit - so over the limit, we need to invert */ + return info->cfg.mode & XT_HASHLIMIT_INVERT; + + hotdrop: + *hotdrop = true; + return false; +} + +static bool +hashlimit_mt_check_v0(const char *tablename, const void *inf, + const struct xt_match *match, void *matchinfo, + unsigned int hook_mask) { struct xt_hashlimit_info *r = matchinfo; @@ -536,7 +723,7 @@ hashlimit_checkentry(const char *tablename, * create duplicate proc files. -HW */ mutex_lock(&hlimit_mutex); r->hinfo = htable_find_get(r->name, match->family); - if (!r->hinfo && htable_create(r, match->family) != 0) { + if (!r->hinfo && htable_create_v0(r, match->family) != 0) { mutex_unlock(&hlimit_mutex); return false; } @@ -547,14 +734,65 @@ hashlimit_checkentry(const char *tablename, return true; } +static bool +hashlimit_mt_check(const char *tablename, const void *inf, + const struct xt_match *match, void *matchinfo, + unsigned int hook_mask) +{ + struct xt_hashlimit_mtinfo1 *info = matchinfo; + + /* Check for overflow. */ + if (info->cfg.burst == 0 || + user2credits(info->cfg.avg * info->cfg.burst) < + user2credits(info->cfg.avg)) { + printk(KERN_ERR "xt_hashlimit: overflow, try lower: %u/%u\n", + info->cfg.avg, info->cfg.burst); + return false; + } + if (info->cfg.gc_interval == 0 || info->cfg.expire == 0) + return false; + if (info->name[sizeof(info->name)-1] != '\0') + return false; + if (match->family == AF_INET) { + if (info->cfg.srcmask > 32 || info->cfg.dstmask > 32) + return false; + } else { + if (info->cfg.srcmask > 128 || info->cfg.dstmask > 128) + return false; + } + + /* This is the best we've got: We cannot release and re-grab lock, + * since checkentry() is called before x_tables.c grabs xt_mutex. + * We also cannot grab the hashtable spinlock, since htable_create will + * call vmalloc, and that can sleep. And we cannot just re-search + * the list of htable's in htable_create(), since then we would + * create duplicate proc files. -HW */ + mutex_lock(&hlimit_mutex); + info->hinfo = htable_find_get(info->name, match->family); + if (!info->hinfo && htable_create(info, match->family) != 0) { + mutex_unlock(&hlimit_mutex); + return false; + } + mutex_unlock(&hlimit_mutex); + return true; +} + static void -hashlimit_destroy(const struct xt_match *match, void *matchinfo) +hashlimit_mt_destroy_v0(const struct xt_match *match, void *matchinfo) { const struct xt_hashlimit_info *r = matchinfo; htable_put(r->hinfo); } +static void +hashlimit_mt_destroy(const struct xt_match *match, void *matchinfo) +{ + const struct xt_hashlimit_mtinfo1 *info = matchinfo; + + htable_put(info->hinfo); +} + #ifdef CONFIG_COMPAT struct compat_xt_hashlimit_info { char name[IFNAMSIZ]; @@ -563,7 +801,7 @@ struct compat_xt_hashlimit_info { compat_uptr_t master; }; -static void compat_from_user(void *dst, void *src) +static void hashlimit_mt_compat_from_user(void *dst, void *src) { int off = offsetof(struct compat_xt_hashlimit_info, hinfo); @@ -571,7 +809,7 @@ static void compat_from_user(void *dst, void *src) memset(dst + off, 0, sizeof(struct compat_xt_hashlimit_info) - off); } -static int compat_to_user(void __user *dst, void *src) +static int hashlimit_mt_compat_to_user(void __user *dst, void *src) { int off = offsetof(struct compat_xt_hashlimit_info, hinfo); @@ -579,39 +817,63 @@ static int compat_to_user(void __user *dst, void *src) } #endif -static struct xt_match xt_hashlimit[] __read_mostly = { +static struct xt_match hashlimit_mt_reg[] __read_mostly = { { .name = "hashlimit", + .revision = 0, .family = AF_INET, - .match = hashlimit_match, + .match = hashlimit_mt_v0, .matchsize = sizeof(struct xt_hashlimit_info), #ifdef CONFIG_COMPAT .compatsize = sizeof(struct compat_xt_hashlimit_info), - .compat_from_user = compat_from_user, - .compat_to_user = compat_to_user, + .compat_from_user = hashlimit_mt_compat_from_user, + .compat_to_user = hashlimit_mt_compat_to_user, #endif - .checkentry = hashlimit_checkentry, - .destroy = hashlimit_destroy, + .checkentry = hashlimit_mt_check_v0, + .destroy = hashlimit_mt_destroy_v0, .me = THIS_MODULE }, + { + .name = "hashlimit", + .revision = 1, + .family = AF_INET, + .match = hashlimit_mt, + .matchsize = sizeof(struct xt_hashlimit_mtinfo1), + .checkentry = hashlimit_mt_check, + .destroy = hashlimit_mt_destroy, + .me = THIS_MODULE, + }, +#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE) { .name = "hashlimit", .family = AF_INET6, - .match = hashlimit_match, + .match = hashlimit_mt_v0, .matchsize = sizeof(struct xt_hashlimit_info), #ifdef CONFIG_COMPAT .compatsize = sizeof(struct compat_xt_hashlimit_info), - .compat_from_user = compat_from_user, - .compat_to_user = compat_to_user, + .compat_from_user = hashlimit_mt_compat_from_user, + .compat_to_user = hashlimit_mt_compat_to_user, #endif - .checkentry = hashlimit_checkentry, - .destroy = hashlimit_destroy, + .checkentry = hashlimit_mt_check_v0, + .destroy = hashlimit_mt_destroy_v0, .me = THIS_MODULE }, + { + .name = "hashlimit", + .revision = 1, + .family = AF_INET6, + .match = hashlimit_mt, + .matchsize = sizeof(struct xt_hashlimit_mtinfo1), + .checkentry = hashlimit_mt_check, + .destroy = hashlimit_mt_destroy, + .me = THIS_MODULE, + }, +#endif }; /* PROC stuff */ static void *dl_seq_start(struct seq_file *s, loff_t *pos) + __acquires(htable->lock) { struct proc_dir_entry *pde = s->private; struct xt_hashlimit_htable *htable = pde->data; @@ -644,6 +906,7 @@ static void *dl_seq_next(struct seq_file *s, void *v, loff_t *pos) } static void dl_seq_stop(struct seq_file *s, void *v) + __releases(htable->lock) { struct proc_dir_entry *pde = s->private; struct xt_hashlimit_htable *htable = pde->data; @@ -664,22 +927,24 @@ static int dl_seq_real_show(struct dsthash_ent *ent, int family, return seq_printf(s, "%ld %u.%u.%u.%u:%u->" "%u.%u.%u.%u:%u %u %u %u\n", (long)(ent->expires - jiffies)/HZ, - NIPQUAD(ent->dst.addr.ip.src), + NIPQUAD(ent->dst.ip.src), ntohs(ent->dst.src_port), - NIPQUAD(ent->dst.addr.ip.dst), + NIPQUAD(ent->dst.ip.dst), ntohs(ent->dst.dst_port), ent->rateinfo.credit, ent->rateinfo.credit_cap, ent->rateinfo.cost); +#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE) case AF_INET6: return seq_printf(s, "%ld " NIP6_FMT ":%u->" NIP6_FMT ":%u %u %u %u\n", (long)(ent->expires - jiffies)/HZ, - NIP6(*(struct in6_addr *)&ent->dst.addr.ip6.src), + NIP6(*(struct in6_addr *)&ent->dst.ip6.src), ntohs(ent->dst.src_port), - NIP6(*(struct in6_addr *)&ent->dst.addr.ip6.dst), + NIP6(*(struct in6_addr *)&ent->dst.ip6.dst), ntohs(ent->dst.dst_port), ent->rateinfo.credit, ent->rateinfo.credit_cap, ent->rateinfo.cost); +#endif default: BUG(); return 0; @@ -728,11 +993,12 @@ static const struct file_operations dl_file_ops = { .release = seq_release }; -static int __init xt_hashlimit_init(void) +static int __init hashlimit_mt_init(void) { int err; - err = xt_register_matches(xt_hashlimit, ARRAY_SIZE(xt_hashlimit)); + err = xt_register_matches(hashlimit_mt_reg, + ARRAY_SIZE(hashlimit_mt_reg)); if (err < 0) goto err1; @@ -750,31 +1016,36 @@ static int __init xt_hashlimit_init(void) "entry\n"); goto err3; } + err = 0; +#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE) hashlimit_procdir6 = proc_mkdir("ip6t_hashlimit", init_net.proc_net); if (!hashlimit_procdir6) { printk(KERN_ERR "xt_hashlimit: unable to create proc dir " "entry\n"); - goto err4; + err = -ENOMEM; } - return 0; -err4: +#endif + if (!err) + return 0; remove_proc_entry("ipt_hashlimit", init_net.proc_net); err3: kmem_cache_destroy(hashlimit_cachep); err2: - xt_unregister_matches(xt_hashlimit, ARRAY_SIZE(xt_hashlimit)); + xt_unregister_matches(hashlimit_mt_reg, ARRAY_SIZE(hashlimit_mt_reg)); err1: return err; } -static void __exit xt_hashlimit_fini(void) +static void __exit hashlimit_mt_exit(void) { remove_proc_entry("ipt_hashlimit", init_net.proc_net); +#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE) remove_proc_entry("ip6t_hashlimit", init_net.proc_net); +#endif kmem_cache_destroy(hashlimit_cachep); - xt_unregister_matches(xt_hashlimit, ARRAY_SIZE(xt_hashlimit)); + xt_unregister_matches(hashlimit_mt_reg, ARRAY_SIZE(hashlimit_mt_reg)); } -module_init(xt_hashlimit_init); -module_exit(xt_hashlimit_fini); +module_init(hashlimit_mt_init); +module_exit(hashlimit_mt_exit);