netfilter: xtables: replace XT_MATCH_ITERATE macro

The macro is replaced by a list.h-like foreach loop. This makes
the code more inspectable.

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>

6 files changed, 141 insertions, 49 deletions

diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h
index 9df3f5a8f9f7..84c7c928e9eb 100644
--- a/include/linux/netfilter/x_tables.h
+++ b/include/linux/netfilter/x_tables.h
@@ -120,6 +120,7 @@ struct xt_counters_info {
 
 #define XT_INV_PROTO            0x40    /* Invert the sense of PROTO. */
 
+#ifndef __KERNEL__
 /* fn returns 0 to continue iteration */
 #define XT_MATCH_ITERATE(type, e, fn, args...)                  \
 ({                                                              \
@@ -139,7 +140,6 @@ struct xt_counters_info {
         __ret;                                                  \
 })
 
-#ifndef __KERNEL__
 /* fn returns 0 to continue iteration */
 #define XT_ENTRY_ITERATE_CONTINUE(type, entries, size, n, fn, args...) \
 ({                                                              \
@@ -172,6 +172,14 @@ struct xt_counters_info {
              (pos) < (typeof(pos))((char *)(ehead) + (esize)); \
              (pos) = (typeof(pos))((char *)(pos) + (pos)->next_offset))
 
+/* can only be xt_entry_match, so no use of typeof here */
+#define xt_ematch_foreach(pos, entry) \
+        for ((pos) = (struct xt_entry_match *)entry->elems; \
+             (pos) < (struct xt_entry_match *)((char *)(entry) + \
+                     (entry)->target_offset); \
+             (pos) = (struct xt_entry_match *)((char *)(pos) + \
+                     (pos)->u.match_size))
+
 #ifdef __KERNEL__
 
 #include <linux/netdevice.h>
diff --git a/include/linux/netfilter_ipv4/ip_tables.h b/include/linux/netfilter_ipv4/ip_tables.h
index 5b20ae724b41..704a7b6e8169 100644
--- a/include/linux/netfilter_ipv4/ip_tables.h
+++ b/include/linux/netfilter_ipv4/ip_tables.h
@@ -223,11 +223,11 @@ ipt_get_target(struct ipt_entry *e)
         return (void *)e + e->target_offset;
 }
 
+#ifndef __KERNEL__
 /* fn returns 0 to continue iteration */
 #define IPT_MATCH_ITERATE(e, fn, args...) \
         XT_MATCH_ITERATE(struct ipt_entry, e, fn, ## args)
 
-#ifndef __KERNEL__
 /* fn returns 0 to continue iteration */
 #define IPT_ENTRY_ITERATE(entries, size, fn, args...) \
         XT_ENTRY_ITERATE(struct ipt_entry, entries, size, fn, ## args)
@@ -315,10 +315,6 @@ compat_ipt_get_target(struct compat_ipt_entry *e)
 
 #define COMPAT_IPT_ALIGN(s)     COMPAT_XT_ALIGN(s)
 
-/* fn returns 0 to continue iteration */
-#define COMPAT_IPT_MATCH_ITERATE(e, fn, args...) \
-        XT_MATCH_ITERATE(struct compat_ipt_entry, e, fn, ## args)
-
 #endif /* CONFIG_COMPAT */
 #endif /*__KERNEL__*/
 #endif /* _IPTABLES_H */
diff --git a/include/linux/netfilter_ipv6/ip6_tables.h b/include/linux/netfilter_ipv6/ip6_tables.h
index 8bb3f5ba5ff2..e5ba03d783c6 100644
--- a/include/linux/netfilter_ipv6/ip6_tables.h
+++ b/include/linux/netfilter_ipv6/ip6_tables.h
@@ -280,11 +280,11 @@ ip6t_get_target(struct ip6t_entry *e)
         return (void *)e + e->target_offset;
 }
 
+#ifndef __KERNEL__
 /* fn returns 0 to continue iteration */
 #define IP6T_MATCH_ITERATE(e, fn, args...) \
         XT_MATCH_ITERATE(struct ip6t_entry, e, fn, ## args)
 
-#ifndef __KERNEL__
 /* fn returns 0 to continue iteration */
 #define IP6T_ENTRY_ITERATE(entries, size, fn, args...) \
         XT_ENTRY_ITERATE(struct ip6t_entry, entries, size, fn, ## args)
@@ -343,10 +343,6 @@ compat_ip6t_get_target(struct compat_ip6t_entry *e)
 
 #define COMPAT_IP6T_ALIGN(s)    COMPAT_XT_ALIGN(s)
 
-/* fn returns 0 to continue iteration */
-#define COMPAT_IP6T_MATCH_ITERATE(e, fn, args...) \
-        XT_MATCH_ITERATE(struct compat_ip6t_entry, e, fn, ## args)
-
 #endif /* CONFIG_COMPAT */
 #endif /*__KERNEL__*/
 #endif /* _IP6_TABLES_H */
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index 9c8aa394c51c..3a7fc732b918 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -366,16 +366,21 @@ ipt_do_table(struct sk_buff *skb,
 
         do {
                 const struct ipt_entry_target *t;
+                const struct xt_entry_match *ematch;
 
                 IP_NF_ASSERT(e);
                 IP_NF_ASSERT(back);
                 if (!ip_packet_match(ip, indev, outdev,
-                    &e->ip, mtpar.fragoff) ||
-                    IPT_MATCH_ITERATE(e, do_match, skb, &mtpar) != 0) {
+                    &e->ip, mtpar.fragoff)) {
+ no_match:
                         e = ipt_next_entry(e);
                         continue;
                 }
 
+                xt_ematch_foreach(ematch, e)
+                        if (do_match(ematch, skb, &mtpar) != 0)
+                                goto no_match;
+
                 ADD_COUNTER(e->counters, ntohs(ip->tot_len), 1);
 
                 t = ipt_get_target(e);
@@ -686,6 +691,7 @@ find_check_entry(struct ipt_entry *e, struct net *net, const char *name,
         int ret;
         unsigned int j;
         struct xt_mtchk_param mtpar;
+        struct xt_entry_match *ematch;
 
         ret = check_entry(e, name);
         if (ret)
@@ -697,7 +703,11 @@ find_check_entry(struct ipt_entry *e, struct net *net, const char *name,
         mtpar.entryinfo = &e->ip;
         mtpar.hook_mask = e->comefrom;
         mtpar.family    = NFPROTO_IPV4;
-        ret = IPT_MATCH_ITERATE(e, find_check_match, &mtpar, &j);
+        xt_ematch_foreach(ematch, e) {
+                ret = find_check_match(ematch, &mtpar, &j);
+                if (ret != 0)
+                        break;
+        }
         if (ret != 0)
                 goto cleanup_matches;
 
@@ -720,7 +730,9 @@ find_check_entry(struct ipt_entry *e, struct net *net, const char *name,
  err:
         module_put(t->u.kernel.target->me);
  cleanup_matches:
-        IPT_MATCH_ITERATE(e, cleanup_match, net, &j);
+        xt_ematch_foreach(ematch, e)
+                if (cleanup_match(ematch, net, &j) != 0)
+                        break;
         return ret;
 }
 
@@ -791,9 +803,12 @@ cleanup_entry(struct ipt_entry *e, struct net *net)
 {
         struct xt_tgdtor_param par;
         struct ipt_entry_target *t;
+        struct xt_entry_match *ematch;
 
         /* Cleanup all matches */
-        IPT_MATCH_ITERATE(e, cleanup_match, net, NULL);
+        xt_ematch_foreach(ematch, e)
+                if (cleanup_match(ematch, net, NULL) != 0)
+                        break;
         t = ipt_get_target(e);
 
         par.net      = net;
@@ -1060,13 +1075,16 @@ static int compat_calc_entry(const struct ipt_entry *e,
                              const struct xt_table_info *info,
                              const void *base, struct xt_table_info *newinfo)
 {
+        const struct xt_entry_match *ematch;
         const struct ipt_entry_target *t;
         unsigned int entry_offset;
         int off, i, ret;
 
         off = sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry);
         entry_offset = (void *)e - base;
-        IPT_MATCH_ITERATE(e, compat_calc_match, &off);
+        xt_ematch_foreach(ematch, e)
+                if (compat_calc_match(ematch, &off) != 0)
+                        break;
         t = ipt_get_target_c(e);
         off += xt_compat_target_offset(t->u.kernel.target);
         newinfo->size -= off;
@@ -1441,7 +1459,8 @@ compat_copy_entry_to_user(struct ipt_entry *e, void __user **dstptr,
         struct compat_ipt_entry __user *ce;
         u_int16_t target_offset, next_offset;
         compat_uint_t origsize;
-        int ret;
+        const struct xt_entry_match *ematch;
+        int ret = 0;
 
         origsize = *size;
         ce = (struct compat_ipt_entry __user *)*dstptr;
@@ -1453,7 +1472,11 @@ compat_copy_entry_to_user(struct ipt_entry *e, void __user **dstptr,
         *dstptr += sizeof(struct compat_ipt_entry);
         *size -= sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry);
 
-        ret = IPT_MATCH_ITERATE(e, xt_compat_match_to_user, dstptr, size);
+        xt_ematch_foreach(ematch, e) {
+                ret = xt_compat_match_to_user(ematch, dstptr, size);
+                if (ret != 0)
+                        break;
+        }
         target_offset = e->target_offset - (origsize - *size);
         if (ret)
                 return ret;
@@ -1505,9 +1528,12 @@ compat_release_match(struct ipt_entry_match *m, unsigned int *i)
 static void compat_release_entry(struct compat_ipt_entry *e)
 {
         struct ipt_entry_target *t;
+        struct xt_entry_match *ematch;
 
         /* Cleanup all matches */
-        COMPAT_IPT_MATCH_ITERATE(e, compat_release_match, NULL);
+        xt_ematch_foreach(ematch, e)
+                if (compat_release_match(ematch, NULL) != 0)
+                        break;
         t = compat_ipt_get_target(e);
         module_put(t->u.kernel.target->me);
 }
@@ -1522,6 +1548,7 @@ check_compat_entry_size_and_hooks(struct compat_ipt_entry *e,
                                   const unsigned int *underflows,
                                   const char *name)
 {
+        struct xt_entry_match *ematch;
         struct ipt_entry_target *t;
         struct xt_target *target;
         unsigned int entry_offset;
@@ -1550,8 +1577,12 @@ check_compat_entry_size_and_hooks(struct compat_ipt_entry *e,
         off = sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry);
         entry_offset = (void *)e - (void *)base;
         j = 0;
-        ret = COMPAT_IPT_MATCH_ITERATE(e, compat_find_calc_match, name,
-                                       &e->ip, e->comefrom, &off, &j);
+        xt_ematch_foreach(ematch, e) {
+                ret = compat_find_calc_match(ematch, name,
+                      &e->ip, e->comefrom, &off, &j);
+                if (ret != 0)
+                        break;
+        }
         if (ret != 0)
                 goto release_matches;
 
@@ -1590,7 +1621,9 @@ check_compat_entry_size_and_hooks(struct compat_ipt_entry *e,
 out:
         module_put(t->u.kernel.target->me);
 release_matches:
-        IPT_MATCH_ITERATE(e, compat_release_match, &j);
+        xt_ematch_foreach(ematch, e)
+                if (compat_release_match(ematch, &j) != 0)
+                        break;
         return ret;
 }
 
@@ -1604,6 +1637,7 @@ compat_copy_entry_from_user(struct compat_ipt_entry *e, void **dstptr,
         struct ipt_entry *de;
         unsigned int origsize;
         int ret, h;
+        struct xt_entry_match *ematch;
 
         ret = 0;
         origsize = *size;
@@ -1614,8 +1648,11 @@ compat_copy_entry_from_user(struct compat_ipt_entry *e, void **dstptr,
         *dstptr += sizeof(struct ipt_entry);
         *size += sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry);
 
-        ret = COMPAT_IPT_MATCH_ITERATE(e, xt_compat_match_from_user,
-                                       dstptr, size);
+        xt_ematch_foreach(ematch, e) {
+                ret = xt_compat_match_from_user(ematch, dstptr, size);
+                if (ret != 0)
+                        break;
+        }
         if (ret)
                 return ret;
         de->target_offset = e->target_offset - (origsize - *size);
@@ -1636,9 +1673,10 @@ compat_copy_entry_from_user(struct compat_ipt_entry *e, void **dstptr,
 static int
 compat_check_entry(struct ipt_entry *e, struct net *net, const char *name)
 {
+        struct xt_entry_match *ematch;
         struct xt_mtchk_param mtpar;
         unsigned int j;
-        int ret;
+        int ret = 0;
 
         j = 0;
         mtpar.net       = net;
@@ -1646,7 +1684,11 @@ compat_check_entry(struct ipt_entry *e, struct net *net, const char *name)
         mtpar.entryinfo = &e->ip;
         mtpar.hook_mask = e->comefrom;
         mtpar.family    = NFPROTO_IPV4;
-        ret = IPT_MATCH_ITERATE(e, check_match, &mtpar, &j);
+        xt_ematch_foreach(ematch, e) {
+                ret = check_match(ematch, &mtpar, &j);
+                if (ret != 0)
+                        break;
+        }
         if (ret)
                 goto cleanup_matches;
 
@@ -1656,7 +1698,9 @@ compat_check_entry(struct ipt_entry *e, struct net *net, const char *name)
         return 0;
 
  cleanup_matches:
-        IPT_MATCH_ITERATE(e, cleanup_match, net, &j);
+        xt_ematch_foreach(ematch, e)
+                if (cleanup_match(ematch, net, &j) != 0)
+                        break;
         return ret;
 }
 
diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c
index b7e27c19c7ab..1537e6bad5d9 100644
--- a/net/ipv6/netfilter/ip6_tables.c
+++ b/net/ipv6/netfilter/ip6_tables.c
@@ -393,16 +393,21 @@ ip6t_do_table(struct sk_buff *skb,
 
         do {
                 const struct ip6t_entry_target *t;
+                const struct xt_entry_match *ematch;
 
                 IP_NF_ASSERT(e);
                 IP_NF_ASSERT(back);
                 if (!ip6_packet_match(skb, indev, outdev, &e->ipv6,
-                    &mtpar.thoff, &mtpar.fragoff, &hotdrop) ||
-                    IP6T_MATCH_ITERATE(e, do_match, skb, &mtpar) != 0) {
+                    &mtpar.thoff, &mtpar.fragoff, &hotdrop)) {
+ no_match:
                         e = ip6t_next_entry(e);
                         continue;
                 }
 
+                xt_ematch_foreach(ematch, e)
+                        if (do_match(ematch, skb, &mtpar) != 0)
+                                goto no_match;
+
                 ADD_COUNTER(e->counters,
                             ntohs(ipv6_hdr(skb)->payload_len) +
                             sizeof(struct ipv6hdr), 1);
@@ -717,6 +722,7 @@ find_check_entry(struct ip6t_entry *e, struct net *net, const char *name,
         int ret;
         unsigned int j;
         struct xt_mtchk_param mtpar;
+        struct xt_entry_match *ematch;
 
         ret = check_entry(e, name);
         if (ret)
@@ -728,7 +734,11 @@ find_check_entry(struct ip6t_entry *e, struct net *net, const char *name,
         mtpar.entryinfo = &e->ipv6;
         mtpar.hook_mask = e->comefrom;
         mtpar.family    = NFPROTO_IPV6;
-        ret = IP6T_MATCH_ITERATE(e, find_check_match, &mtpar, &j);
+        xt_ematch_foreach(ematch, e) {
+                ret = find_check_match(ematch, &mtpar, &j);
+                if (ret != 0)
+                        break;
+        }
         if (ret != 0)
                 goto cleanup_matches;
 
@@ -751,7 +761,9 @@ find_check_entry(struct ip6t_entry *e, struct net *net, const char *name,
  err:
         module_put(t->u.kernel.target->me);
  cleanup_matches:
-        IP6T_MATCH_ITERATE(e, cleanup_match, net, &j);
+        xt_ematch_foreach(ematch, e)
+                if (cleanup_match(ematch, net, &j) != 0)
+                        break;
         return ret;
 }
 
@@ -821,9 +833,12 @@ static void cleanup_entry(struct ip6t_entry *e, struct net *net)
 {
         struct xt_tgdtor_param par;
         struct ip6t_entry_target *t;
+        struct xt_entry_match *ematch;
 
         /* Cleanup all matches */
-        IP6T_MATCH_ITERATE(e, cleanup_match, net, NULL);
+        xt_ematch_foreach(ematch, e)
+                if (cleanup_match(ematch, net, NULL) != 0)
+                        break;
         t = ip6t_get_target(e);
 
         par.net      = net;
@@ -1090,13 +1105,16 @@ static int compat_calc_entry(const struct ip6t_entry *e,
                              const struct xt_table_info *info,
                              const void *base, struct xt_table_info *newinfo)
 {
+        const struct xt_entry_match *ematch;
         const struct ip6t_entry_target *t;
         unsigned int entry_offset;
         int off, i, ret;
 
         off = sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry);
         entry_offset = (void *)e - base;
-        IP6T_MATCH_ITERATE(e, compat_calc_match, &off);
+        xt_ematch_foreach(ematch, e)
+                if (compat_calc_match(ematch, &off) != 0)
+                        break;
         t = ip6t_get_target_c(e);
         off += xt_compat_target_offset(t->u.kernel.target);
         newinfo->size -= off;
@@ -1474,7 +1492,8 @@ compat_copy_entry_to_user(struct ip6t_entry *e, void __user **dstptr,
         struct compat_ip6t_entry __user *ce;
         u_int16_t target_offset, next_offset;
         compat_uint_t origsize;
-        int ret;
+        const struct xt_entry_match *ematch;
+        int ret = 0;
 
         origsize = *size;
         ce = (struct compat_ip6t_entry __user *)*dstptr;
@@ -1486,7 +1505,11 @@ compat_copy_entry_to_user(struct ip6t_entry *e, void __user **dstptr,
         *dstptr += sizeof(struct compat_ip6t_entry);
         *size -= sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry);
 
-        ret = IP6T_MATCH_ITERATE(e, xt_compat_match_to_user, dstptr, size);
+        xt_ematch_foreach(ematch, e) {
+                ret = xt_compat_match_to_user(ematch, dstptr, size);
+                if (ret != 0)
+                        break;
+        }
         target_offset = e->target_offset - (origsize - *size);
         if (ret)
                 return ret;
@@ -1538,9 +1561,12 @@ compat_release_match(struct ip6t_entry_match *m, unsigned int *i)
 static void compat_release_entry(struct compat_ip6t_entry *e)
 {
         struct ip6t_entry_target *t;
+        struct xt_entry_match *ematch;
 
         /* Cleanup all matches */
-        COMPAT_IP6T_MATCH_ITERATE(e, compat_release_match, NULL);
+        xt_ematch_foreach(ematch, e)
+                if (compat_release_match(ematch, NULL) != 0)
+                        break;
         t = compat_ip6t_get_target(e);
         module_put(t->u.kernel.target->me);
 }
@@ -1555,6 +1581,7 @@ check_compat_entry_size_and_hooks(struct compat_ip6t_entry *e,
                                   const unsigned int *underflows,
                                   const char *name)
 {
+        struct xt_entry_match *ematch;
         struct ip6t_entry_target *t;
         struct xt_target *target;
         unsigned int entry_offset;
@@ -1583,8 +1610,12 @@ check_compat_entry_size_and_hooks(struct compat_ip6t_entry *e,
         off = sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry);
         entry_offset = (void *)e - (void *)base;
         j = 0;
-        ret = COMPAT_IP6T_MATCH_ITERATE(e, compat_find_calc_match, name,
-                                        &e->ipv6, e->comefrom, &off, &j);
+        xt_ematch_foreach(ematch, e) {
+                ret = compat_find_calc_match(ematch, name,
+                      &e->ipv6, e->comefrom, &off, &j);
+                if (ret != 0)
+                        break;
+        }
         if (ret != 0)
                 goto release_matches;
 
@@ -1623,7 +1654,9 @@ check_compat_entry_size_and_hooks(struct compat_ip6t_entry *e,
 out:
         module_put(t->u.kernel.target->me);
 release_matches:
-        IP6T_MATCH_ITERATE(e, compat_release_match, &j);
+        xt_ematch_foreach(ematch, e)
+                if (compat_release_match(ematch, &j) != 0)
+                        break;
         return ret;
 }
 
@@ -1637,6 +1670,7 @@ compat_copy_entry_from_user(struct compat_ip6t_entry *e, void **dstptr,
         struct ip6t_entry *de;
         unsigned int origsize;
         int ret, h;
+        struct xt_entry_match *ematch;
 
         ret = 0;
         origsize = *size;
@@ -1647,8 +1681,11 @@ compat_copy_entry_from_user(struct compat_ip6t_entry *e, void **dstptr,
         *dstptr += sizeof(struct ip6t_entry);
         *size += sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry);
 
-        ret = COMPAT_IP6T_MATCH_ITERATE(e, xt_compat_match_from_user,
-                                        dstptr, size);
+        xt_ematch_foreach(ematch, e) {
+                ret = xt_compat_match_from_user(ematch, dstptr, size);
+                if (ret != 0)
+                        break;
+        }
         if (ret)
                 return ret;
         de->target_offset = e->target_offset - (origsize - *size);
@@ -1670,8 +1707,9 @@ static int compat_check_entry(struct ip6t_entry *e, struct net *net,
                               const char *name)
 {
         unsigned int j;
-        int ret;
+        int ret = 0;
         struct xt_mtchk_param mtpar;
+        struct xt_entry_match *ematch;
 
         j = 0;
         mtpar.net       = net;
@@ -1679,7 +1717,11 @@ static int compat_check_entry(struct ip6t_entry *e, struct net *net,
         mtpar.entryinfo = &e->ipv6;
         mtpar.hook_mask = e->comefrom;
         mtpar.family    = NFPROTO_IPV6;
-        ret = IP6T_MATCH_ITERATE(e, check_match, &mtpar, &j);
+        xt_ematch_foreach(ematch, e) {
+                ret = check_match(ematch, &mtpar, &j);
+                if (ret != 0)
+                        break;
+        }
         if (ret)
                 goto cleanup_matches;
 
@@ -1689,7 +1731,9 @@ static int compat_check_entry(struct ip6t_entry *e, struct net *net,
         return 0;
 
  cleanup_matches:
-        IP6T_MATCH_ITERATE(e, cleanup_match, net, &j);
+        xt_ematch_foreach(ematch, e)
+                if (cleanup_match(ematch, net, &j) != 0)
+                        break;
         return ret;
 }
 
diff --git a/net/netfilter/xt_TCPMSS.c b/net/netfilter/xt_TCPMSS.c
index 6f21b4377dbb..0e357ac9a2a8 100644
--- a/net/netfilter/xt_TCPMSS.c
+++ b/net/netfilter/xt_TCPMSS.c
@@ -239,6 +239,7 @@ static bool tcpmss_tg4_check(const struct xt_tgchk_param *par)
 {
         const struct xt_tcpmss_info *info = par->targinfo;
         const struct ipt_entry *e = par->entryinfo;
+        const struct xt_entry_match *ematch;
 
         if (info->mss == XT_TCPMSS_CLAMP_PMTU &&
             (par->hook_mask & ~((1 << NF_INET_FORWARD) |
@@ -248,8 +249,9 @@ static bool tcpmss_tg4_check(const struct xt_tgchk_param *par)
                        "FORWARD, OUTPUT and POSTROUTING hooks\n");
                 return false;
         }
-        if (IPT_MATCH_ITERATE(e, find_syn_match))
-                return true;
+        xt_ematch_foreach(ematch, e)
+                if (find_syn_match(ematch))
+                        return true;
         printk("xt_TCPMSS: Only works on TCP SYN packets\n");
         return false;
 }
@@ -259,6 +261,7 @@ static bool tcpmss_tg6_check(const struct xt_tgchk_param *par)
 {
         const struct xt_tcpmss_info *info = par->targinfo;
         const struct ip6t_entry *e = par->entryinfo;
+        const struct xt_entry_match *ematch;
 
         if (info->mss == XT_TCPMSS_CLAMP_PMTU &&
             (par->hook_mask & ~((1 << NF_INET_FORWARD) |
@@ -268,8 +271,9 @@ static bool tcpmss_tg6_check(const struct xt_tgchk_param *par)
                        "FORWARD, OUTPUT and POSTROUTING hooks\n");
                 return false;
         }
-        if (IP6T_MATCH_ITERATE(e, find_syn_match))
-                return true;
+        xt_ematch_foreach(ematch, e)
+                if (find_syn_match(ematch))
+                        return true;
         printk("xt_TCPMSS: Only works on TCP SYN packets\n");
         return false;
 }