diff --git a/net/netfilter/xt_recent.c b/net/netfilter/xt_recent.c index a9faae89f955..30dbe34915ae 100644 --- a/net/netfilter/xt_recent.c +++ b/net/netfilter/xt_recent.c @@ -43,25 +43,29 @@ 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; -static unsigned int ip_list_hash_size = 0; -static unsigned int ip_list_perms = 0644; -static unsigned int ip_list_uid = 0; -static unsigned int ip_list_gid = 0; +static unsigned int ip_list_tot __read_mostly = 100; +static unsigned int ip_list_hash_size __read_mostly; +static unsigned int ip_list_perms __read_mostly = 0644; +static unsigned int ip_list_uid __read_mostly; +static unsigned int ip_list_gid __read_mostly; module_param(ip_list_tot, uint, 0400); -module_param(ip_pkt_list_tot, uint, 0400); module_param(ip_list_hash_size, uint, 0400); module_param(ip_list_perms, uint, 0400); module_param(ip_list_uid, uint, S_IRUGO | S_IWUSR); module_param(ip_list_gid, uint, S_IRUGO | S_IWUSR); 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 address 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/xt_recent/* files"); MODULE_PARM_DESC(ip_list_uid, "default owner of /proc/net/xt_recent/* files"); MODULE_PARM_DESC(ip_list_gid, "default owning group of /proc/net/xt_recent/* files"); +/* retained for backwards compatibility */ +static unsigned int ip_pkt_list_tot __read_mostly; +module_param(ip_pkt_list_tot, uint, 0400); +MODULE_PARM_DESC(ip_pkt_list_tot, "number of packets per IP address to remember (max. 255)"); + +#define XT_RECENT_MAX_NSTAMPS 256 + struct recent_entry { struct list_head list; struct list_head lru_list; @@ -79,6 +83,7 @@ struct recent_table { union nf_inet_addr mask; unsigned int refcnt; unsigned int entries; + u8 nstamps_max_mask; struct list_head lru_list; struct list_head iphash[0]; }; @@ -90,7 +95,8 @@ struct recent_net { #endif }; -static int recent_net_id; +static int recent_net_id __read_mostly; + static inline struct recent_net *recent_pernet(struct net *net) { return net_generic(net, recent_net_id); @@ -171,12 +177,15 @@ 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; + unsigned int nstamps_max = t->nstamps_max_mask; if (t->entries >= ip_list_tot) { e = list_entry(t->lru_list.next, struct recent_entry, lru_list); recent_entry_remove(t, e); } - e = kmalloc(sizeof(*e) + sizeof(e->stamps[0]) * ip_pkt_list_tot, + + nstamps_max += 1; + e = kmalloc(sizeof(*e) + sizeof(e->stamps[0]) * nstamps_max, GFP_ATOMIC); if (e == NULL) return NULL; @@ -197,7 +206,7 @@ recent_entry_init(struct recent_table *t, const union nf_inet_addr *addr, static void recent_entry_update(struct recent_table *t, struct recent_entry *e) { - e->index %= ip_pkt_list_tot; + e->index &= t->nstamps_max_mask; e->stamps[e->index++] = jiffies; if (e->index > e->nstamps) e->nstamps = e->index; @@ -326,6 +335,7 @@ static int recent_mt_check(const struct xt_mtchk_param *par, kuid_t uid; kgid_t gid; #endif + unsigned int nstamp_mask; unsigned int i; int ret = -EINVAL; size_t sz; @@ -349,19 +359,33 @@ static int recent_mt_check(const struct xt_mtchk_param *par, return -EINVAL; if ((info->check_set & XT_RECENT_REAP) && !info->seconds) return -EINVAL; - if (info->hit_count > ip_pkt_list_tot) { - pr_info("hitcount (%u) is larger than " - "packets to be remembered (%u)\n", - info->hit_count, ip_pkt_list_tot); + if (info->hit_count >= XT_RECENT_MAX_NSTAMPS) { + pr_info("hitcount (%u) is larger than allowed maximum (%u)\n", + info->hit_count, XT_RECENT_MAX_NSTAMPS - 1); return -EINVAL; } if (info->name[0] == '\0' || strnlen(info->name, XT_RECENT_NAME_LEN) == XT_RECENT_NAME_LEN) return -EINVAL; + if (ip_pkt_list_tot && info->hit_count < ip_pkt_list_tot) + nstamp_mask = roundup_pow_of_two(ip_pkt_list_tot) - 1; + else if (info->hit_count) + nstamp_mask = roundup_pow_of_two(info->hit_count) - 1; + else + nstamp_mask = 32 - 1; + mutex_lock(&recent_mutex); t = recent_table_lookup(recent_net, info->name); if (t != NULL) { + if (info->hit_count > t->nstamps_max_mask) { + pr_info("hitcount (%u) is larger than packets to be remembered (%u) for table %s\n", + info->hit_count, t->nstamps_max_mask + 1, + info->name); + ret = -EINVAL; + goto out; + } + t->refcnt++; ret = 0; goto out; @@ -377,6 +401,7 @@ static int recent_mt_check(const struct xt_mtchk_param *par, goto out; } t->refcnt = 1; + t->nstamps_max_mask = nstamp_mask; memcpy(&t->mask, &info->mask, sizeof(t->mask)); strcpy(t->name, info->name); @@ -497,9 +522,12 @@ static void recent_seq_stop(struct seq_file *s, void *v) static int recent_seq_show(struct seq_file *seq, void *v) { const struct recent_entry *e = v; + struct recent_iter_state *st = seq->private; + const struct recent_table *t = st->table; unsigned int i; - i = (e->index - 1) % ip_pkt_list_tot; + i = (e->index - 1) & t->nstamps_max_mask; + if (e->family == NFPROTO_IPV4) seq_printf(seq, "src=%pI4 ttl: %u last_seen: %lu oldest_pkt: %u", &e->addr.ip, e->ttl, e->stamps[i], e->index); @@ -717,7 +745,9 @@ static int __init recent_mt_init(void) { int err; - if (!ip_list_tot || !ip_pkt_list_tot || ip_pkt_list_tot > 255) + BUILD_BUG_ON_NOT_POWER_OF_2(XT_RECENT_MAX_NSTAMPS); + + if (!ip_list_tot || ip_pkt_list_tot >= XT_RECENT_MAX_NSTAMPS) return -EINVAL; ip_list_hash_size = 1 << fls(ip_list_tot);