From 079aa88fe7172b7650c7cf2c0bc01662bafea236 Mon Sep 17 00:00:00 2001 From: Jan Engelhardt Date: Wed, 8 Oct 2008 11:35:00 +0200 Subject: [PATCH] netfilter: xt_recent: IPv6 support This updates xt_recent to support the IPv6 address family. The new /proc/net/xt_recent directory must be used for this. The old proc interface can also be configured out. Signed-off-by: Jan Engelhardt Signed-off-by: Patrick McHardy --- Documentation/feature-removal-schedule.txt | 3 + net/netfilter/Kconfig | 7 + net/netfilter/xt_recent.c | 300 +++++++++++++++++++++++------ 3 files changed, 256 insertions(+), 54 deletions(-) diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt index d0f22fa..3d2d0c2 100644 --- a/Documentation/feature-removal-schedule.txt +++ b/Documentation/feature-removal-schedule.txt @@ -250,6 +250,9 @@ What (Why): - xt_mark match revision 0 (superseded by xt_mark match revision 1) + - xt_recent: the old ipt_recent proc dir + (superseded by /proc/net/xt_recent) + When: January 2009 or Linux 2.7.0, whichever comes first Why: Superseded by newer revisions or modules Who: Jan Engelhardt diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig index ccc78b0..4a46485 100644 --- a/net/netfilter/Kconfig +++ b/net/netfilter/Kconfig @@ -743,6 +743,13 @@ config NETFILTER_XT_MATCH_RECENT Short options are available by using 'iptables -m recent -h' Official Website: +config NETFILTER_XT_MATCH_RECENT_PROC_COMPAT + bool 'Enable obsolete /proc/net/ipt_recent' + depends on NETFILTER_XT_MATCH_RECENT && PROC_FS + ---help--- + This option enables the old /proc/net/ipt_recent interface, + which has been obsoleted by /proc/net/xt_recent. + config NETFILTER_XT_MATCH_SCTP tristate '"sctp" protocol match support (EXPERIMENTAL)' depends on NETFILTER_XTABLES && EXPERIMENTAL diff --git a/net/netfilter/xt_recent.c b/net/netfilter/xt_recent.c index 422c0e4..adc2e2f 100644 --- a/net/netfilter/xt_recent.c +++ b/net/netfilter/xt_recent.c @@ -1,5 +1,6 @@ /* * Copyright (c) 2006 Patrick McHardy + * Copyright © CC Computer Consultants GmbH, 2007 - 2008 * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as @@ -13,6 +14,8 @@ */ #include #include +#include +#include #include #include #include @@ -30,9 +33,11 @@ #include MODULE_AUTHOR("Patrick McHardy "); +MODULE_AUTHOR("Jan Engelhardt "); MODULE_DESCRIPTION("Xtables: \"recently-seen\" host matching for IPv4"); MODULE_LICENSE("GPL"); MODULE_ALIAS("ipt_recent"); +MODULE_ALIAS("ip6t_recent"); static unsigned int ip_list_tot = 100; static unsigned int ip_pkt_list_tot = 20; @@ -49,14 +54,15 @@ module_param(ip_list_gid, uint, 0400); MODULE_PARM_DESC(ip_list_tot, "number of IPs to remember per list"); MODULE_PARM_DESC(ip_pkt_list_tot, "number of packets per IP to remember (max. 255)"); MODULE_PARM_DESC(ip_list_hash_size, "size of hash table used to look up IPs"); -MODULE_PARM_DESC(ip_list_perms, "permissions on /proc/net/ipt_recent/* files"); -MODULE_PARM_DESC(ip_list_uid,"owner of /proc/net/ipt_recent/* files"); -MODULE_PARM_DESC(ip_list_gid,"owning group of /proc/net/ipt_recent/* files"); +MODULE_PARM_DESC(ip_list_perms, "permissions on /proc/net/xt_recent/* files"); +MODULE_PARM_DESC(ip_list_uid,"owner of /proc/net/xt_recent/* files"); +MODULE_PARM_DESC(ip_list_gid,"owning group of /proc/net/xt_recent/* files"); struct recent_entry { struct list_head list; struct list_head lru_list; - __be32 addr; + union nf_inet_addr addr; + u_int16_t family; u_int8_t ttl; u_int8_t index; u_int16_t nstamps; @@ -67,7 +73,7 @@ struct recent_table { struct list_head list; char name[XT_RECENT_NAME_LEN]; #ifdef CONFIG_PROC_FS - struct proc_dir_entry *proc; + struct proc_dir_entry *proc_old, *proc; #endif unsigned int refcnt; unsigned int entries; @@ -80,31 +86,53 @@ static DEFINE_SPINLOCK(recent_lock); static DEFINE_MUTEX(recent_mutex); #ifdef CONFIG_PROC_FS -static struct proc_dir_entry *proc_dir; -static const struct file_operations recent_fops; +#ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT +static struct proc_dir_entry *proc_old_dir; +#endif +static struct proc_dir_entry *recent_proc_dir; +static const struct file_operations recent_old_fops, recent_mt_fops; #endif static u_int32_t hash_rnd; -static int hash_rnd_initted; +static bool hash_rnd_initted; + +static unsigned int recent_entry_hash4(const union nf_inet_addr *addr) +{ + if (!hash_rnd_initted) { + get_random_bytes(&hash_rnd, sizeof(hash_rnd)); + hash_rnd_initted = true; + } + return jhash_1word((__force u32)addr->ip, hash_rnd) & + (ip_list_hash_size - 1); +} -static unsigned int recent_entry_hash(__be32 addr) +static unsigned int recent_entry_hash6(const union nf_inet_addr *addr) { if (!hash_rnd_initted) { - get_random_bytes(&hash_rnd, 4); - hash_rnd_initted = 1; + get_random_bytes(&hash_rnd, sizeof(hash_rnd)); + hash_rnd_initted = true; } - return jhash_1word((__force u32)addr, hash_rnd) & (ip_list_hash_size - 1); + return jhash2((u32 *)addr->ip6, ARRAY_SIZE(addr->ip6), hash_rnd) & + (ip_list_hash_size - 1); } static struct recent_entry * -recent_entry_lookup(const struct recent_table *table, __be32 addr, u_int8_t ttl) +recent_entry_lookup(const struct recent_table *table, + const union nf_inet_addr *addrp, u_int16_t family, + u_int8_t ttl) { struct recent_entry *e; unsigned int h; - h = recent_entry_hash(addr); + if (family == AF_INET) + h = recent_entry_hash4(addrp); + else + h = recent_entry_hash6(addrp); + list_for_each_entry(e, &table->iphash[h], list) - if (e->addr == addr && (ttl == e->ttl || !ttl || !e->ttl)) + if (e->family == family && + memcmp(&e->addr, addrp, sizeof(e->addr)) == 0 && + (ttl == e->ttl || ttl == 0 || e->ttl == 0)) return e; return NULL; } @@ -118,7 +146,8 @@ static void recent_entry_remove(struct recent_table *t, struct recent_entry *e) } static struct recent_entry * -recent_entry_init(struct recent_table *t, __be32 addr, u_int8_t ttl) +recent_entry_init(struct recent_table *t, const union nf_inet_addr *addr, + u_int16_t family, u_int8_t ttl) { struct recent_entry *e; @@ -130,12 +159,16 @@ recent_entry_init(struct recent_table *t, __be32 addr, u_int8_t ttl) GFP_ATOMIC); if (e == NULL) return NULL; - e->addr = addr; + memcpy(&e->addr, addr, sizeof(e->addr)); e->ttl = ttl; e->stamps[0] = jiffies; e->nstamps = 1; e->index = 1; - list_add_tail(&e->list, &t->iphash[recent_entry_hash(addr)]); + e->family = family; + if (family == AF_INET) + list_add_tail(&e->list, &t->iphash[recent_entry_hash4(addr)]); + else + list_add_tail(&e->list, &t->iphash[recent_entry_hash6(addr)]); list_add_tail(&e->lru_list, &t->lru_list); t->entries++; return e; @@ -179,28 +212,42 @@ recent_mt(const struct sk_buff *skb, const struct net_device *in, const struct xt_recent_mtinfo *info = matchinfo; struct recent_table *t; struct recent_entry *e; - __be32 addr; + union nf_inet_addr addr = {}; u_int8_t ttl; bool ret = info->invert; - if (info->side == XT_RECENT_DEST) - addr = ip_hdr(skb)->daddr; - else - addr = ip_hdr(skb)->saddr; + if (match->family == AF_INET) { + const struct iphdr *iph = ip_hdr(skb); + + if (info->side == XT_RECENT_DEST) + addr.ip = iph->daddr; + else + addr.ip = iph->saddr; + + ttl = iph->ttl; + } else { + const struct ipv6hdr *iph = ipv6_hdr(skb); + + if (info->side == XT_RECENT_DEST) + memcpy(&addr.in6, &iph->daddr, sizeof(addr.in6)); + else + memcpy(&addr.in6, &iph->saddr, sizeof(addr.in6)); + + ttl = iph->hop_limit; + } - ttl = ip_hdr(skb)->ttl; /* use TTL as seen before forwarding */ if (out && !skb->sk) ttl++; spin_lock_bh(&recent_lock); t = recent_table_lookup(info->name); - e = recent_entry_lookup(t, addr, - info->check_set & XT_RECENT_TTL ? ttl : 0); + e = recent_entry_lookup(t, &addr, match->family, + (info->check_set & XT_RECENT_TTL) ? ttl : 0); if (e == NULL) { if (!(info->check_set & XT_RECENT_SET)) goto out; - e = recent_entry_init(t, addr, ttl); + e = recent_entry_init(t, &addr, match->family, ttl); if (e == NULL) *hotdrop = true; ret = !ret; @@ -277,11 +324,24 @@ recent_mt_check(const char *tablename, const void *ip, for (i = 0; i < ip_list_hash_size; i++) INIT_LIST_HEAD(&t->iphash[i]); #ifdef CONFIG_PROC_FS - t->proc = proc_create(t->name, ip_list_perms, proc_dir, &recent_fops); + t->proc = proc_create(t->name, ip_list_perms, recent_proc_dir, + &recent_mt_fops); if (t->proc == NULL) { kfree(t); goto out; } +#ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT + t->proc_old = proc_create(t->name, ip_list_perms, proc_old_dir, + &recent_old_fops); + if (t->proc_old == NULL) { + remove_proc_entry(t->name, proc_old_dir); + kfree(t); + goto out; + } + t->proc_old->uid = ip_list_uid; + t->proc_old->gid = ip_list_gid; + t->proc_old->data = t; +#endif t->proc->uid = ip_list_uid; t->proc->gid = ip_list_gid; t->proc->data = t; @@ -307,7 +367,10 @@ static void recent_mt_destroy(const struct xt_match *match, void *matchinfo) list_del(&t->list); spin_unlock_bh(&recent_lock); #ifdef CONFIG_PROC_FS - remove_proc_entry(t->name, proc_dir); +#ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT + remove_proc_entry(t->name, proc_old_dir); +#endif + remove_proc_entry(t->name, recent_proc_dir); #endif recent_table_flush(t); kfree(t); @@ -317,7 +380,7 @@ static void recent_mt_destroy(const struct xt_match *match, void *matchinfo) #ifdef CONFIG_PROC_FS struct recent_iter_state { - struct recent_table *table; + const struct recent_table *table; unsigned int bucket; }; @@ -342,8 +405,8 @@ static void *recent_seq_next(struct seq_file *seq, void *v, loff_t *pos) { struct recent_iter_state *st = seq->private; const struct recent_table *t = st->table; - struct recent_entry *e = v; - struct list_head *head = e->list.next; + const struct recent_entry *e = v; + const struct list_head *head = e->list.next; while (head == &t->iphash[st->bucket]) { if (++st->bucket >= ip_list_hash_size) @@ -366,8 +429,14 @@ static int recent_seq_show(struct seq_file *seq, void *v) unsigned int i; i = (e->index - 1) % ip_pkt_list_tot; - seq_printf(seq, "src=%u.%u.%u.%u ttl: %u last_seen: %lu oldest_pkt: %u", - NIPQUAD(e->addr), e->ttl, e->stamps[i], e->index); + if (e->family == AF_INET) + seq_printf(seq, "src=" NIPQUAD_FMT " ttl: %u last_seen: %lu " + "oldest_pkt: %u", NIPQUAD(e->addr.ip), e->ttl, + e->stamps[i], e->index); + else + seq_printf(seq, "src=" NIP6_FMT " ttl: %u last_seen: %lu " + "oldest_pkt: %u", NIP6(e->addr.in6), e->ttl, + e->stamps[i], e->index); for (i = 0; i < e->nstamps; i++) seq_printf(seq, "%s %lu", i ? "," : "", e->stamps[i]); seq_printf(seq, "\n"); @@ -394,8 +463,22 @@ static int recent_seq_open(struct inode *inode, struct file *file) return 0; } -static ssize_t recent_proc_write(struct file *file, const char __user *input, - size_t size, loff_t *loff) +#ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT +static int recent_old_seq_open(struct inode *inode, struct file *filp) +{ + static bool warned_of_old; + + if (unlikely(!warned_of_old)) { + printk(KERN_INFO KBUILD_MODNAME ": Use of /proc/net/ipt_recent" + " is deprecated; use /proc/net/xt_recent.\n"); + warned_of_old = true; + } + return recent_seq_open(inode, filp); +} + +static ssize_t recent_old_proc_write(struct file *file, + const char __user *input, + size_t size, loff_t *loff) { const struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode); struct recent_table *t = pde->data; @@ -408,6 +491,7 @@ static ssize_t recent_proc_write(struct file *file, const char __user *input, size = sizeof(buf); if (copy_from_user(buf, input, size)) return -EFAULT; + while (isspace(*c)) c++; @@ -435,10 +519,10 @@ static ssize_t recent_proc_write(struct file *file, const char __user *input, addr = in_aton(c); spin_lock_bh(&recent_lock); - e = recent_entry_lookup(t, addr, 0); + e = recent_entry_lookup(t, (const void *)&addr, PF_INET, 0); if (e == NULL) { if (add) - recent_entry_init(t, addr, 0); + recent_entry_init(t, (const void *)&addr, PF_INET, 0); } else { if (add) recent_entry_update(t, e); @@ -449,23 +533,118 @@ static ssize_t recent_proc_write(struct file *file, const char __user *input, return size; } -static const struct file_operations recent_fops = { - .open = recent_seq_open, +static const struct file_operations recent_old_fops = { + .open = recent_old_seq_open, .read = seq_read, - .write = recent_proc_write, + .write = recent_old_proc_write, .release = seq_release_private, .owner = THIS_MODULE, }; +#endif + +static ssize_t +recent_mt_proc_write(struct file *file, const char __user *input, + size_t size, loff_t *loff) +{ + const struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode); + struct recent_table *t = pde->data; + struct recent_entry *e; + char buf[sizeof("+b335:1d35:1e55:dead:c0de:1715:5afe:c0de")]; + const char *c = buf; + union nf_inet_addr addr; + u_int16_t family; + bool add, succ; + + if (size == 0) + return 0; + if (size > sizeof(buf)) + size = sizeof(buf); + if (copy_from_user(buf, input, size) != 0) + return -EFAULT; + + /* Strict protocol! */ + if (*loff != 0) + return -ESPIPE; + switch (*c) { + case '/': /* flush table */ + spin_lock_bh(&recent_lock); + recent_table_flush(t); + spin_unlock_bh(&recent_lock); + return size; + case '-': /* remove address */ + add = false; + break; + case '+': /* add address */ + add = true; + break; + default: + printk(KERN_INFO KBUILD_MODNAME ": Need +ip, -ip or /\n"); + return -EINVAL; + } + + ++c; + --size; + if (strnchr(c, size, ':') != NULL) { + family = AF_INET6; + succ = in6_pton(c, size, (void *)&addr, '\n', NULL); + } else { + family = AF_INET; + succ = in4_pton(c, size, (void *)&addr, '\n', NULL); + } + + if (!succ) { + printk(KERN_INFO KBUILD_MODNAME ": illegal address written " + "to procfs\n"); + return -EINVAL; + } + + spin_lock_bh(&recent_lock); + e = recent_entry_lookup(t, &addr, family, 0); + if (e == NULL) { + if (add) + recent_entry_init(t, &addr, family, 0); + } else { + if (add) + recent_entry_update(t, e); + else + recent_entry_remove(t, e); + } + spin_unlock_bh(&recent_lock); + /* Note we removed one above */ + *loff += size + 1; + return size + 1; +} + +static const struct file_operations recent_mt_fops = { + .open = recent_seq_open, + .read = seq_read, + .write = recent_mt_proc_write, + .release = seq_release_private, + .owner = THIS_MODULE, +}; #endif /* CONFIG_PROC_FS */ -static struct xt_match recent_mt_reg __read_mostly = { - .name = "recent", - .family = AF_INET, - .match = recent_mt, - .matchsize = sizeof(struct xt_recent_mtinfo), - .checkentry = recent_mt_check, - .destroy = recent_mt_destroy, - .me = THIS_MODULE, +static struct xt_match recent_mt_reg[] __read_mostly = { + { + .name = "recent", + .revision = 0, + .family = AF_INET, + .match = recent_mt, + .matchsize = sizeof(struct xt_recent_mtinfo), + .checkentry = recent_mt_check, + .destroy = recent_mt_destroy, + .me = THIS_MODULE, + }, + { + .name = "recent", + .revision = 0, + .family = AF_INET6, + .match = recent_mt, + .matchsize = sizeof(struct xt_recent_mtinfo), + .checkentry = recent_mt_check, + .destroy = recent_mt_destroy, + .me = THIS_MODULE, + }, }; static int __init recent_mt_init(void) @@ -476,26 +655,39 @@ static int __init recent_mt_init(void) return -EINVAL; ip_list_hash_size = 1 << fls(ip_list_tot); - err = xt_register_match(&recent_mt_reg); + err = xt_register_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg)); #ifdef CONFIG_PROC_FS if (err) return err; - proc_dir = proc_mkdir("ipt_recent", init_net.proc_net); - if (proc_dir == NULL) { - xt_unregister_match(&recent_mt_reg); + recent_proc_dir = proc_mkdir("xt_recent", init_net.proc_net); + if (recent_proc_dir == NULL) { + xt_unregister_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg)); + err = -ENOMEM; + } +#ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT + if (err < 0) + return err; + proc_old_dir = proc_mkdir("ipt_recent", init_net.proc_net); + if (proc_old_dir == NULL) { + remove_proc_entry("xt_recent", init_net.proc_net); + xt_unregister_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg)); err = -ENOMEM; } #endif +#endif return err; } static void __exit recent_mt_exit(void) { BUG_ON(!list_empty(&tables)); - xt_unregister_match(&recent_mt_reg); + xt_unregister_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg)); #ifdef CONFIG_PROC_FS +#ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT remove_proc_entry("ipt_recent", init_net.proc_net); #endif + remove_proc_entry("xt_recent", init_net.proc_net); +#endif } module_init(recent_mt_init); -- 2.7.4