Revert "netfilter: xt_recent: relax ip_pkt_list_tot restrictions"

This reverts commit abc86d0f99242b7f142b7cb8f90e30081dd3c256 as it is
broken in 3.19 and is easier to revert here than try to fix it.

Reported-by: Florian Westphal <fw@strlen.de
Reported-by: David Miller <davem@redhat.com>
Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

diff --git a/net/netfilter/xt_recent.c b/net/netfilter/xt_recent.c
index 30dbe34915ae2b1fcf4d0ca3149369bdf3913f0f..a9faae89f95533a53da4651efb2f737e3a0952b4 100644 (file)
--- a/net/netfilter/xt_recent.c
+++ b/net/netfilter/xt_recent.c
@@ -43,29 +43,25 @@ MODULE_LICENSE("GPL");
 MODULE_ALIAS("ipt_recent");
 MODULE_ALIAS("ip6t_recent");
 
-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;
+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;
 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;
@@ -83,7 +79,6 @@ 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];
 };
@@ -95,8 +90,7 @@ struct recent_net {
 #endif
 };
 
-static int recent_net_id __read_mostly;
-
+static int recent_net_id;
 static inline struct recent_net *recent_pernet(struct net *net)
 {
        return net_generic(net, recent_net_id);
@@ -177,15 +171,12 @@ 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);
        }
-
-       nstamps_max += 1;
-       e = kmalloc(sizeof(*e) + sizeof(e->stamps[0]) * nstamps_max,
+       e = kmalloc(sizeof(*e) + sizeof(e->stamps[0]) * ip_pkt_list_tot,
                    GFP_ATOMIC);
        if (e == NULL)
                return NULL;
@@ -206,7 +197,7 @@ 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 &= t->nstamps_max_mask;
+       e->index %= ip_pkt_list_tot;
        e->stamps[e->index++] = jiffies;
        if (e->index > e->nstamps)
                e->nstamps = e->index;
@@ -335,7 +326,6 @@ 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;
@@ -359,33 +349,19 @@ 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 >= XT_RECENT_MAX_NSTAMPS) {
-               pr_info("hitcount (%u) is larger than allowed maximum (%u)\n",
-                       info->hit_count, XT_RECENT_MAX_NSTAMPS - 1);
+       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);
                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;
@@ -401,7 +377,6 @@ 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);
@@ -522,12 +497,9 @@ 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) & t->nstamps_max_mask;
-
+       i = (e->index - 1) % ip_pkt_list_tot;
        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);
@@ -745,9 +717,7 @@ static int __init recent_mt_init(void)
 {
        int err;
 
-       BUILD_BUG_ON_NOT_POWER_OF_2(XT_RECENT_MAX_NSTAMPS);
-
-       if (!ip_list_tot || ip_pkt_list_tot >= XT_RECENT_MAX_NSTAMPS)
+       if (!ip_list_tot || !ip_pkt_list_tot || ip_pkt_list_tot > 255)
                return -EINVAL;
        ip_list_hash_size = 1 << fls(ip_list_tot);