From dcea992aca82cb08b4674c4c783e325835408d1e Mon Sep 17 00:00:00 2001 From: Jan Engelhardt Date: Wed, 24 Feb 2010 18:34:48 +0100 Subject: [PATCH] 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 Signed-off-by: Patrick McHardy --- include/linux/netfilter/x_tables.h | 10 ++- include/linux/netfilter_ipv4/ip_tables.h | 6 +- include/linux/netfilter_ipv6/ip6_tables.h | 6 +- net/ipv4/netfilter/ip_tables.c | 78 ++++++++++++++++++----- net/ipv6/netfilter/ip6_tables.c | 78 ++++++++++++++++++----- net/netfilter/xt_TCPMSS.c | 12 ++-- 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 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; } -- 2.20.1