diff options
| -rw-r--r-- | include/linux/netfilter/xt_hashlimit.h | 37 | ||||
| -rw-r--r-- | net/netfilter/xt_hashlimit.c | 322 |
2 files changed, 318 insertions, 41 deletions
diff --git a/include/linux/netfilter/xt_hashlimit.h b/include/linux/netfilter/xt_hashlimit.h index c19972e4564..58b818ee41c 100644 --- a/include/linux/netfilter/xt_hashlimit.h +++ b/include/linux/netfilter/xt_hashlimit.h @@ -9,13 +9,16 @@ /* details of this structure hidden by the implementation */ struct xt_hashlimit_htable; -#define XT_HASHLIMIT_HASH_DIP 0x0001 -#define XT_HASHLIMIT_HASH_DPT 0x0002 -#define XT_HASHLIMIT_HASH_SIP 0x0004 -#define XT_HASHLIMIT_HASH_SPT 0x0008 +enum { + XT_HASHLIMIT_HASH_DIP = 1 << 0, + XT_HASHLIMIT_HASH_DPT = 1 << 1, + XT_HASHLIMIT_HASH_SIP = 1 << 2, + XT_HASHLIMIT_HASH_SPT = 1 << 3, + XT_HASHLIMIT_INVERT = 1 << 4, +}; struct hashlimit_cfg { - u_int32_t mode; /* bitmask of IPT_HASHLIMIT_HASH_* */ + u_int32_t mode; /* bitmask of XT_HASHLIMIT_HASH_* */ u_int32_t avg; /* Average secs between packets * scale */ u_int32_t burst; /* Period multiplier for upper limit. */ @@ -37,4 +40,28 @@ struct xt_hashlimit_info { struct xt_hashlimit_info *master; } u; }; + +struct hashlimit_cfg1 { + u_int32_t mode; /* bitmask of XT_HASHLIMIT_HASH_* */ + u_int32_t avg; /* Average secs between packets * scale */ + u_int32_t burst; /* Period multiplier for upper limit. */ + + /* user specified */ + u_int32_t size; /* how many buckets */ + u_int32_t max; /* max number of entries */ + u_int32_t gc_interval; /* gc interval */ + u_int32_t expire; /* when do entries expire? */ + + u_int8_t srcmask, dstmask; +}; + +struct xt_hashlimit_mtinfo1 { + char name[IFNAMSIZ]; + struct hashlimit_cfg1 cfg; + + /* Used internally by the kernel */ + struct xt_hashlimit_htable *hinfo __attribute__((aligned(8))); + struct xt_hashlimit_mtinfo1 *master __attribute__((aligned(8))); +}; + #endif /*_XT_HASHLIMIT_H*/ diff --git a/net/netfilter/xt_hashlimit.c b/net/netfilter/xt_hashlimit.c index b224b8f719a..54aaf5bac2d 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 <laforge@netfilter.org> - * - * $Id: ipt_hashlimit.c 3244 2004-10-20 16:24:29Z laforge@netfilter.org $ + * (C) 2003-2004 by Harald Welte <laforge@netfilter.org> + * Copyright © CC Computer Consultants GmbH, 2007 - 2008 * * Development of this code was funded by Astaro AG, http://www.astaro.com/ */ @@ -35,6 +35,7 @@ MODULE_LICENSE("GPL"); MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); +MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>"); MODULE_DESCRIPTION("Xtables: per hash-bucket rate-limit match"); MODULE_ALIAS("ipt_hashlimit"); MODULE_ALIAS("ip6t_hashlimit"); @@ -57,7 +58,7 @@ struct dsthash_dst { __be32 dst[4]; } ip6; #endif - } addr; + }; __be16 src_port; __be16 dst_port; }; @@ -81,7 +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 */ @@ -184,7 +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; @@ -210,7 +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; @@ -246,6 +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) { @@ -388,6 +464,46 @@ 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)); +} + +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; + } +} + static int hashlimit_init_dst(const struct xt_hashlimit_htable *hinfo, struct dsthash_dst *dst, @@ -401,9 +517,11 @@ hashlimit_init_dst(const struct xt_hashlimit_htable *hinfo, 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))) @@ -412,12 +530,16 @@ 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))) @@ -457,10 +579,10 @@ hashlimit_init_dst(const struct xt_hashlimit_htable *hinfo, } static bool -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) +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; @@ -512,9 +634,62 @@ hotdrop: } static bool -hashlimit_mt_check(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; @@ -546,7 +721,7 @@ hashlimit_mt_check(const char *tablename, const void *inf, * 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; } @@ -557,14 +732,68 @@ hashlimit_mt_check(const char *tablename, const void *inf, 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); + + /* Ugly hack: For SMP, we only want to use one set */ + info->master = info; + return true; +} + static void -hashlimit_mt_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]; @@ -592,33 +821,54 @@ static int hashlimit_mt_compat_to_user(void __user *dst, void *src) static struct xt_match hashlimit_mt_reg[] __read_mostly = { { .name = "hashlimit", + .revision = 0, .family = AF_INET, - .match = hashlimit_mt, + .match = hashlimit_mt_v0, .matchsize = sizeof(struct xt_hashlimit_info), #ifdef CONFIG_COMPAT .compatsize = sizeof(struct compat_xt_hashlimit_info), .compat_from_user = hashlimit_mt_compat_from_user, .compat_to_user = hashlimit_mt_compat_to_user, #endif - .checkentry = hashlimit_mt_check, - .destroy = hashlimit_mt_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_mt, + .match = hashlimit_mt_v0, .matchsize = sizeof(struct xt_hashlimit_info), #ifdef CONFIG_COMPAT .compatsize = sizeof(struct compat_xt_hashlimit_info), .compat_from_user = hashlimit_mt_compat_from_user, .compat_to_user = hashlimit_mt_compat_to_user, #endif - .checkentry = hashlimit_mt_check, - .destroy = hashlimit_mt_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 }; @@ -678,9 +928,9 @@ 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); @@ -689,9 +939,9 @@ static int dl_seq_real_show(struct dsthash_ent *ent, int family, 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); |