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![Florian Westphal](/assets/img/avatar_default.png)
icmp/icmp6 matches are baked into ip(6)_tables.ko. This means that even if iptables-nft is used, a rule like "-p icmp --icmp-type 1" will load the ip(6)tables modules. Move them to xt_tcpdudp.ko instead to avoid this. This will also allow to eventually add kconfig knobs to build kernels that support iptables-nft but not iptables-legacy (old set/getsockopt interface). Signed-off-by: Florian Westphal <fw@strlen.de>
1886 lines
45 KiB
C
1886 lines
45 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Packet matching code.
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*
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* Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
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* Copyright (C) 2000-2005 Netfilter Core Team <coreteam@netfilter.org>
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* Copyright (C) 2006-2010 Patrick McHardy <kaber@trash.net>
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/cache.h>
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#include <linux/capability.h>
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#include <linux/skbuff.h>
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#include <linux/kmod.h>
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#include <linux/vmalloc.h>
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#include <linux/netdevice.h>
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#include <linux/module.h>
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#include <net/ip.h>
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#include <net/compat.h>
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#include <linux/uaccess.h>
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#include <linux/mutex.h>
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#include <linux/proc_fs.h>
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#include <linux/err.h>
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#include <linux/cpumask.h>
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#include <linux/netfilter/x_tables.h>
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#include <linux/netfilter_ipv4/ip_tables.h>
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#include <net/netfilter/nf_log.h>
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#include "../../netfilter/xt_repldata.h"
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
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MODULE_DESCRIPTION("IPv4 packet filter");
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void *ipt_alloc_initial_table(const struct xt_table *info)
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{
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return xt_alloc_initial_table(ipt, IPT);
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}
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EXPORT_SYMBOL_GPL(ipt_alloc_initial_table);
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/* Returns whether matches rule or not. */
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/* Performance critical - called for every packet */
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static inline bool
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ip_packet_match(const struct iphdr *ip,
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const char *indev,
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const char *outdev,
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const struct ipt_ip *ipinfo,
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int isfrag)
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{
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unsigned long ret;
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if (NF_INVF(ipinfo, IPT_INV_SRCIP,
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(ip->saddr & ipinfo->smsk.s_addr) != ipinfo->src.s_addr) ||
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NF_INVF(ipinfo, IPT_INV_DSTIP,
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(ip->daddr & ipinfo->dmsk.s_addr) != ipinfo->dst.s_addr))
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return false;
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ret = ifname_compare_aligned(indev, ipinfo->iniface, ipinfo->iniface_mask);
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if (NF_INVF(ipinfo, IPT_INV_VIA_IN, ret != 0))
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return false;
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ret = ifname_compare_aligned(outdev, ipinfo->outiface, ipinfo->outiface_mask);
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if (NF_INVF(ipinfo, IPT_INV_VIA_OUT, ret != 0))
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return false;
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/* Check specific protocol */
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if (ipinfo->proto &&
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NF_INVF(ipinfo, IPT_INV_PROTO, ip->protocol != ipinfo->proto))
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return false;
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/* If we have a fragment rule but the packet is not a fragment
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* then we return zero */
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if (NF_INVF(ipinfo, IPT_INV_FRAG,
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(ipinfo->flags & IPT_F_FRAG) && !isfrag))
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return false;
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return true;
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}
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static bool
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ip_checkentry(const struct ipt_ip *ip)
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{
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if (ip->flags & ~IPT_F_MASK)
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return false;
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if (ip->invflags & ~IPT_INV_MASK)
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return false;
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return true;
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}
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static unsigned int
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ipt_error(struct sk_buff *skb, const struct xt_action_param *par)
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{
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net_info_ratelimited("error: `%s'\n", (const char *)par->targinfo);
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return NF_DROP;
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}
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/* Performance critical */
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static inline struct ipt_entry *
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get_entry(const void *base, unsigned int offset)
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{
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return (struct ipt_entry *)(base + offset);
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}
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/* All zeroes == unconditional rule. */
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/* Mildly perf critical (only if packet tracing is on) */
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static inline bool unconditional(const struct ipt_entry *e)
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{
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static const struct ipt_ip uncond;
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return e->target_offset == sizeof(struct ipt_entry) &&
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memcmp(&e->ip, &uncond, sizeof(uncond)) == 0;
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}
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/* for const-correctness */
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static inline const struct xt_entry_target *
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ipt_get_target_c(const struct ipt_entry *e)
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{
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return ipt_get_target((struct ipt_entry *)e);
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}
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#if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE)
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static const char *const hooknames[] = {
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[NF_INET_PRE_ROUTING] = "PREROUTING",
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[NF_INET_LOCAL_IN] = "INPUT",
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[NF_INET_FORWARD] = "FORWARD",
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[NF_INET_LOCAL_OUT] = "OUTPUT",
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[NF_INET_POST_ROUTING] = "POSTROUTING",
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};
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enum nf_ip_trace_comments {
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NF_IP_TRACE_COMMENT_RULE,
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NF_IP_TRACE_COMMENT_RETURN,
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NF_IP_TRACE_COMMENT_POLICY,
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};
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static const char *const comments[] = {
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[NF_IP_TRACE_COMMENT_RULE] = "rule",
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[NF_IP_TRACE_COMMENT_RETURN] = "return",
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[NF_IP_TRACE_COMMENT_POLICY] = "policy",
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};
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static const struct nf_loginfo trace_loginfo = {
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.type = NF_LOG_TYPE_LOG,
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.u = {
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.log = {
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.level = 4,
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.logflags = NF_LOG_DEFAULT_MASK,
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},
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},
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};
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/* Mildly perf critical (only if packet tracing is on) */
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static inline int
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get_chainname_rulenum(const struct ipt_entry *s, const struct ipt_entry *e,
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const char *hookname, const char **chainname,
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const char **comment, unsigned int *rulenum)
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{
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const struct xt_standard_target *t = (void *)ipt_get_target_c(s);
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if (strcmp(t->target.u.kernel.target->name, XT_ERROR_TARGET) == 0) {
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/* Head of user chain: ERROR target with chainname */
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*chainname = t->target.data;
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(*rulenum) = 0;
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} else if (s == e) {
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(*rulenum)++;
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if (unconditional(s) &&
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strcmp(t->target.u.kernel.target->name,
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XT_STANDARD_TARGET) == 0 &&
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t->verdict < 0) {
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/* Tail of chains: STANDARD target (return/policy) */
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*comment = *chainname == hookname
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? comments[NF_IP_TRACE_COMMENT_POLICY]
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: comments[NF_IP_TRACE_COMMENT_RETURN];
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}
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return 1;
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} else
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(*rulenum)++;
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return 0;
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}
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static void trace_packet(struct net *net,
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const struct sk_buff *skb,
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unsigned int hook,
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const struct net_device *in,
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const struct net_device *out,
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const char *tablename,
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const struct xt_table_info *private,
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const struct ipt_entry *e)
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{
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const struct ipt_entry *root;
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const char *hookname, *chainname, *comment;
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const struct ipt_entry *iter;
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unsigned int rulenum = 0;
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root = get_entry(private->entries, private->hook_entry[hook]);
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hookname = chainname = hooknames[hook];
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comment = comments[NF_IP_TRACE_COMMENT_RULE];
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xt_entry_foreach(iter, root, private->size - private->hook_entry[hook])
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if (get_chainname_rulenum(iter, e, hookname,
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&chainname, &comment, &rulenum) != 0)
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break;
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nf_log_trace(net, AF_INET, hook, skb, in, out, &trace_loginfo,
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"TRACE: %s:%s:%s:%u ",
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tablename, chainname, comment, rulenum);
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}
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#endif
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static inline
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struct ipt_entry *ipt_next_entry(const struct ipt_entry *entry)
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{
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return (void *)entry + entry->next_offset;
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}
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/* Returns one of the generic firewall policies, like NF_ACCEPT. */
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unsigned int
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ipt_do_table(void *priv,
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struct sk_buff *skb,
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const struct nf_hook_state *state)
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{
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const struct xt_table *table = priv;
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unsigned int hook = state->hook;
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static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long))));
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const struct iphdr *ip;
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/* Initializing verdict to NF_DROP keeps gcc happy. */
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unsigned int verdict = NF_DROP;
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const char *indev, *outdev;
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const void *table_base;
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struct ipt_entry *e, **jumpstack;
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unsigned int stackidx, cpu;
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const struct xt_table_info *private;
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struct xt_action_param acpar;
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unsigned int addend;
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/* Initialization */
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stackidx = 0;
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ip = ip_hdr(skb);
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indev = state->in ? state->in->name : nulldevname;
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outdev = state->out ? state->out->name : nulldevname;
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/* We handle fragments by dealing with the first fragment as
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* if it was a normal packet. All other fragments are treated
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* normally, except that they will NEVER match rules that ask
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* things we don't know, ie. tcp syn flag or ports). If the
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* rule is also a fragment-specific rule, non-fragments won't
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* match it. */
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acpar.fragoff = ntohs(ip->frag_off) & IP_OFFSET;
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acpar.thoff = ip_hdrlen(skb);
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acpar.hotdrop = false;
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acpar.state = state;
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WARN_ON(!(table->valid_hooks & (1 << hook)));
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local_bh_disable();
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addend = xt_write_recseq_begin();
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private = READ_ONCE(table->private); /* Address dependency. */
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cpu = smp_processor_id();
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table_base = private->entries;
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jumpstack = (struct ipt_entry **)private->jumpstack[cpu];
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/* Switch to alternate jumpstack if we're being invoked via TEE.
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* TEE issues XT_CONTINUE verdict on original skb so we must not
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* clobber the jumpstack.
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*
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* For recursion via REJECT or SYNPROXY the stack will be clobbered
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* but it is no problem since absolute verdict is issued by these.
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*/
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if (static_key_false(&xt_tee_enabled))
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jumpstack += private->stacksize * __this_cpu_read(nf_skb_duplicated);
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e = get_entry(table_base, private->hook_entry[hook]);
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do {
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const struct xt_entry_target *t;
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const struct xt_entry_match *ematch;
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struct xt_counters *counter;
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WARN_ON(!e);
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if (!ip_packet_match(ip, indev, outdev,
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&e->ip, acpar.fragoff)) {
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no_match:
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e = ipt_next_entry(e);
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continue;
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}
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xt_ematch_foreach(ematch, e) {
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acpar.match = ematch->u.kernel.match;
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acpar.matchinfo = ematch->data;
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if (!acpar.match->match(skb, &acpar))
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goto no_match;
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}
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counter = xt_get_this_cpu_counter(&e->counters);
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ADD_COUNTER(*counter, skb->len, 1);
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t = ipt_get_target_c(e);
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WARN_ON(!t->u.kernel.target);
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#if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE)
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/* The packet is traced: log it */
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if (unlikely(skb->nf_trace))
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trace_packet(state->net, skb, hook, state->in,
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state->out, table->name, private, e);
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#endif
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/* Standard target? */
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if (!t->u.kernel.target->target) {
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int v;
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v = ((struct xt_standard_target *)t)->verdict;
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if (v < 0) {
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/* Pop from stack? */
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if (v != XT_RETURN) {
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verdict = (unsigned int)(-v) - 1;
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break;
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}
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if (stackidx == 0) {
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e = get_entry(table_base,
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private->underflow[hook]);
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} else {
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e = jumpstack[--stackidx];
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e = ipt_next_entry(e);
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}
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continue;
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}
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if (table_base + v != ipt_next_entry(e) &&
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!(e->ip.flags & IPT_F_GOTO)) {
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if (unlikely(stackidx >= private->stacksize)) {
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verdict = NF_DROP;
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break;
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}
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jumpstack[stackidx++] = e;
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}
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e = get_entry(table_base, v);
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continue;
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}
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acpar.target = t->u.kernel.target;
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acpar.targinfo = t->data;
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verdict = t->u.kernel.target->target(skb, &acpar);
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if (verdict == XT_CONTINUE) {
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/* Target might have changed stuff. */
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ip = ip_hdr(skb);
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e = ipt_next_entry(e);
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} else {
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/* Verdict */
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break;
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}
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} while (!acpar.hotdrop);
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xt_write_recseq_end(addend);
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local_bh_enable();
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if (acpar.hotdrop)
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return NF_DROP;
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else return verdict;
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}
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/* Figures out from what hook each rule can be called: returns 0 if
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there are loops. Puts hook bitmask in comefrom. */
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static int
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mark_source_chains(const struct xt_table_info *newinfo,
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unsigned int valid_hooks, void *entry0,
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unsigned int *offsets)
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{
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unsigned int hook;
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/* No recursion; use packet counter to save back ptrs (reset
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to 0 as we leave), and comefrom to save source hook bitmask */
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for (hook = 0; hook < NF_INET_NUMHOOKS; hook++) {
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unsigned int pos = newinfo->hook_entry[hook];
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struct ipt_entry *e = entry0 + pos;
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if (!(valid_hooks & (1 << hook)))
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continue;
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|
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/* Set initial back pointer. */
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e->counters.pcnt = pos;
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for (;;) {
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const struct xt_standard_target *t
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= (void *)ipt_get_target_c(e);
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int visited = e->comefrom & (1 << hook);
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if (e->comefrom & (1 << NF_INET_NUMHOOKS))
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return 0;
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e->comefrom |= ((1 << hook) | (1 << NF_INET_NUMHOOKS));
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|
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/* Unconditional return/END. */
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if ((unconditional(e) &&
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(strcmp(t->target.u.user.name,
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XT_STANDARD_TARGET) == 0) &&
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t->verdict < 0) || visited) {
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unsigned int oldpos, size;
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|
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/* Return: backtrack through the last
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big jump. */
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do {
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e->comefrom ^= (1<<NF_INET_NUMHOOKS);
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oldpos = pos;
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pos = e->counters.pcnt;
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e->counters.pcnt = 0;
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|
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/* We're at the start. */
|
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if (pos == oldpos)
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goto next;
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|
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e = entry0 + pos;
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} while (oldpos == pos + e->next_offset);
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|
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/* Move along one */
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size = e->next_offset;
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e = entry0 + pos + size;
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if (pos + size >= newinfo->size)
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return 0;
|
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e->counters.pcnt = pos;
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pos += size;
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} else {
|
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int newpos = t->verdict;
|
|
|
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if (strcmp(t->target.u.user.name,
|
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XT_STANDARD_TARGET) == 0 &&
|
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newpos >= 0) {
|
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/* This a jump; chase it. */
|
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if (!xt_find_jump_offset(offsets, newpos,
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newinfo->number))
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return 0;
|
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} else {
|
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/* ... this is a fallthru */
|
|
newpos = pos + e->next_offset;
|
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if (newpos >= newinfo->size)
|
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return 0;
|
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}
|
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e = entry0 + newpos;
|
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e->counters.pcnt = pos;
|
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pos = newpos;
|
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}
|
|
}
|
|
next: ;
|
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}
|
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return 1;
|
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}
|
|
|
|
static void cleanup_match(struct xt_entry_match *m, struct net *net)
|
|
{
|
|
struct xt_mtdtor_param par;
|
|
|
|
par.net = net;
|
|
par.match = m->u.kernel.match;
|
|
par.matchinfo = m->data;
|
|
par.family = NFPROTO_IPV4;
|
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if (par.match->destroy != NULL)
|
|
par.match->destroy(&par);
|
|
module_put(par.match->me);
|
|
}
|
|
|
|
static int
|
|
check_match(struct xt_entry_match *m, struct xt_mtchk_param *par)
|
|
{
|
|
const struct ipt_ip *ip = par->entryinfo;
|
|
|
|
par->match = m->u.kernel.match;
|
|
par->matchinfo = m->data;
|
|
|
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return xt_check_match(par, m->u.match_size - sizeof(*m),
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ip->proto, ip->invflags & IPT_INV_PROTO);
|
|
}
|
|
|
|
static int
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find_check_match(struct xt_entry_match *m, struct xt_mtchk_param *par)
|
|
{
|
|
struct xt_match *match;
|
|
int ret;
|
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|
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match = xt_request_find_match(NFPROTO_IPV4, m->u.user.name,
|
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m->u.user.revision);
|
|
if (IS_ERR(match))
|
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return PTR_ERR(match);
|
|
m->u.kernel.match = match;
|
|
|
|
ret = check_match(m, par);
|
|
if (ret)
|
|
goto err;
|
|
|
|
return 0;
|
|
err:
|
|
module_put(m->u.kernel.match->me);
|
|
return ret;
|
|
}
|
|
|
|
static int check_target(struct ipt_entry *e, struct net *net, const char *name)
|
|
{
|
|
struct xt_entry_target *t = ipt_get_target(e);
|
|
struct xt_tgchk_param par = {
|
|
.net = net,
|
|
.table = name,
|
|
.entryinfo = e,
|
|
.target = t->u.kernel.target,
|
|
.targinfo = t->data,
|
|
.hook_mask = e->comefrom,
|
|
.family = NFPROTO_IPV4,
|
|
};
|
|
|
|
return xt_check_target(&par, t->u.target_size - sizeof(*t),
|
|
e->ip.proto, e->ip.invflags & IPT_INV_PROTO);
|
|
}
|
|
|
|
static int
|
|
find_check_entry(struct ipt_entry *e, struct net *net, const char *name,
|
|
unsigned int size,
|
|
struct xt_percpu_counter_alloc_state *alloc_state)
|
|
{
|
|
struct xt_entry_target *t;
|
|
struct xt_target *target;
|
|
int ret;
|
|
unsigned int j;
|
|
struct xt_mtchk_param mtpar;
|
|
struct xt_entry_match *ematch;
|
|
|
|
if (!xt_percpu_counter_alloc(alloc_state, &e->counters))
|
|
return -ENOMEM;
|
|
|
|
j = 0;
|
|
memset(&mtpar, 0, sizeof(mtpar));
|
|
mtpar.net = net;
|
|
mtpar.table = name;
|
|
mtpar.entryinfo = &e->ip;
|
|
mtpar.hook_mask = e->comefrom;
|
|
mtpar.family = NFPROTO_IPV4;
|
|
xt_ematch_foreach(ematch, e) {
|
|
ret = find_check_match(ematch, &mtpar);
|
|
if (ret != 0)
|
|
goto cleanup_matches;
|
|
++j;
|
|
}
|
|
|
|
t = ipt_get_target(e);
|
|
target = xt_request_find_target(NFPROTO_IPV4, t->u.user.name,
|
|
t->u.user.revision);
|
|
if (IS_ERR(target)) {
|
|
ret = PTR_ERR(target);
|
|
goto cleanup_matches;
|
|
}
|
|
t->u.kernel.target = target;
|
|
|
|
ret = check_target(e, net, name);
|
|
if (ret)
|
|
goto err;
|
|
|
|
return 0;
|
|
err:
|
|
module_put(t->u.kernel.target->me);
|
|
cleanup_matches:
|
|
xt_ematch_foreach(ematch, e) {
|
|
if (j-- == 0)
|
|
break;
|
|
cleanup_match(ematch, net);
|
|
}
|
|
|
|
xt_percpu_counter_free(&e->counters);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static bool check_underflow(const struct ipt_entry *e)
|
|
{
|
|
const struct xt_entry_target *t;
|
|
unsigned int verdict;
|
|
|
|
if (!unconditional(e))
|
|
return false;
|
|
t = ipt_get_target_c(e);
|
|
if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0)
|
|
return false;
|
|
verdict = ((struct xt_standard_target *)t)->verdict;
|
|
verdict = -verdict - 1;
|
|
return verdict == NF_DROP || verdict == NF_ACCEPT;
|
|
}
|
|
|
|
static int
|
|
check_entry_size_and_hooks(struct ipt_entry *e,
|
|
struct xt_table_info *newinfo,
|
|
const unsigned char *base,
|
|
const unsigned char *limit,
|
|
const unsigned int *hook_entries,
|
|
const unsigned int *underflows,
|
|
unsigned int valid_hooks)
|
|
{
|
|
unsigned int h;
|
|
int err;
|
|
|
|
if ((unsigned long)e % __alignof__(struct ipt_entry) != 0 ||
|
|
(unsigned char *)e + sizeof(struct ipt_entry) >= limit ||
|
|
(unsigned char *)e + e->next_offset > limit)
|
|
return -EINVAL;
|
|
|
|
if (e->next_offset
|
|
< sizeof(struct ipt_entry) + sizeof(struct xt_entry_target))
|
|
return -EINVAL;
|
|
|
|
if (!ip_checkentry(&e->ip))
|
|
return -EINVAL;
|
|
|
|
err = xt_check_entry_offsets(e, e->elems, e->target_offset,
|
|
e->next_offset);
|
|
if (err)
|
|
return err;
|
|
|
|
/* Check hooks & underflows */
|
|
for (h = 0; h < NF_INET_NUMHOOKS; h++) {
|
|
if (!(valid_hooks & (1 << h)))
|
|
continue;
|
|
if ((unsigned char *)e - base == hook_entries[h])
|
|
newinfo->hook_entry[h] = hook_entries[h];
|
|
if ((unsigned char *)e - base == underflows[h]) {
|
|
if (!check_underflow(e))
|
|
return -EINVAL;
|
|
|
|
newinfo->underflow[h] = underflows[h];
|
|
}
|
|
}
|
|
|
|
/* Clear counters and comefrom */
|
|
e->counters = ((struct xt_counters) { 0, 0 });
|
|
e->comefrom = 0;
|
|
return 0;
|
|
}
|
|
|
|
static void
|
|
cleanup_entry(struct ipt_entry *e, struct net *net)
|
|
{
|
|
struct xt_tgdtor_param par;
|
|
struct xt_entry_target *t;
|
|
struct xt_entry_match *ematch;
|
|
|
|
/* Cleanup all matches */
|
|
xt_ematch_foreach(ematch, e)
|
|
cleanup_match(ematch, net);
|
|
t = ipt_get_target(e);
|
|
|
|
par.net = net;
|
|
par.target = t->u.kernel.target;
|
|
par.targinfo = t->data;
|
|
par.family = NFPROTO_IPV4;
|
|
if (par.target->destroy != NULL)
|
|
par.target->destroy(&par);
|
|
module_put(par.target->me);
|
|
xt_percpu_counter_free(&e->counters);
|
|
}
|
|
|
|
/* Checks and translates the user-supplied table segment (held in
|
|
newinfo) */
|
|
static int
|
|
translate_table(struct net *net, struct xt_table_info *newinfo, void *entry0,
|
|
const struct ipt_replace *repl)
|
|
{
|
|
struct xt_percpu_counter_alloc_state alloc_state = { 0 };
|
|
struct ipt_entry *iter;
|
|
unsigned int *offsets;
|
|
unsigned int i;
|
|
int ret = 0;
|
|
|
|
newinfo->size = repl->size;
|
|
newinfo->number = repl->num_entries;
|
|
|
|
/* Init all hooks to impossible value. */
|
|
for (i = 0; i < NF_INET_NUMHOOKS; i++) {
|
|
newinfo->hook_entry[i] = 0xFFFFFFFF;
|
|
newinfo->underflow[i] = 0xFFFFFFFF;
|
|
}
|
|
|
|
offsets = xt_alloc_entry_offsets(newinfo->number);
|
|
if (!offsets)
|
|
return -ENOMEM;
|
|
i = 0;
|
|
/* Walk through entries, checking offsets. */
|
|
xt_entry_foreach(iter, entry0, newinfo->size) {
|
|
ret = check_entry_size_and_hooks(iter, newinfo, entry0,
|
|
entry0 + repl->size,
|
|
repl->hook_entry,
|
|
repl->underflow,
|
|
repl->valid_hooks);
|
|
if (ret != 0)
|
|
goto out_free;
|
|
if (i < repl->num_entries)
|
|
offsets[i] = (void *)iter - entry0;
|
|
++i;
|
|
if (strcmp(ipt_get_target(iter)->u.user.name,
|
|
XT_ERROR_TARGET) == 0)
|
|
++newinfo->stacksize;
|
|
}
|
|
|
|
ret = -EINVAL;
|
|
if (i != repl->num_entries)
|
|
goto out_free;
|
|
|
|
ret = xt_check_table_hooks(newinfo, repl->valid_hooks);
|
|
if (ret)
|
|
goto out_free;
|
|
|
|
if (!mark_source_chains(newinfo, repl->valid_hooks, entry0, offsets)) {
|
|
ret = -ELOOP;
|
|
goto out_free;
|
|
}
|
|
kvfree(offsets);
|
|
|
|
/* Finally, each sanity check must pass */
|
|
i = 0;
|
|
xt_entry_foreach(iter, entry0, newinfo->size) {
|
|
ret = find_check_entry(iter, net, repl->name, repl->size,
|
|
&alloc_state);
|
|
if (ret != 0)
|
|
break;
|
|
++i;
|
|
}
|
|
|
|
if (ret != 0) {
|
|
xt_entry_foreach(iter, entry0, newinfo->size) {
|
|
if (i-- == 0)
|
|
break;
|
|
cleanup_entry(iter, net);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
return ret;
|
|
out_free:
|
|
kvfree(offsets);
|
|
return ret;
|
|
}
|
|
|
|
static void
|
|
get_counters(const struct xt_table_info *t,
|
|
struct xt_counters counters[])
|
|
{
|
|
struct ipt_entry *iter;
|
|
unsigned int cpu;
|
|
unsigned int i;
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
seqcount_t *s = &per_cpu(xt_recseq, cpu);
|
|
|
|
i = 0;
|
|
xt_entry_foreach(iter, t->entries, t->size) {
|
|
struct xt_counters *tmp;
|
|
u64 bcnt, pcnt;
|
|
unsigned int start;
|
|
|
|
tmp = xt_get_per_cpu_counter(&iter->counters, cpu);
|
|
do {
|
|
start = read_seqcount_begin(s);
|
|
bcnt = tmp->bcnt;
|
|
pcnt = tmp->pcnt;
|
|
} while (read_seqcount_retry(s, start));
|
|
|
|
ADD_COUNTER(counters[i], bcnt, pcnt);
|
|
++i; /* macro does multi eval of i */
|
|
cond_resched();
|
|
}
|
|
}
|
|
}
|
|
|
|
static void get_old_counters(const struct xt_table_info *t,
|
|
struct xt_counters counters[])
|
|
{
|
|
struct ipt_entry *iter;
|
|
unsigned int cpu, i;
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
i = 0;
|
|
xt_entry_foreach(iter, t->entries, t->size) {
|
|
const struct xt_counters *tmp;
|
|
|
|
tmp = xt_get_per_cpu_counter(&iter->counters, cpu);
|
|
ADD_COUNTER(counters[i], tmp->bcnt, tmp->pcnt);
|
|
++i; /* macro does multi eval of i */
|
|
}
|
|
|
|
cond_resched();
|
|
}
|
|
}
|
|
|
|
static struct xt_counters *alloc_counters(const struct xt_table *table)
|
|
{
|
|
unsigned int countersize;
|
|
struct xt_counters *counters;
|
|
const struct xt_table_info *private = table->private;
|
|
|
|
/* We need atomic snapshot of counters: rest doesn't change
|
|
(other than comefrom, which userspace doesn't care
|
|
about). */
|
|
countersize = sizeof(struct xt_counters) * private->number;
|
|
counters = vzalloc(countersize);
|
|
|
|
if (counters == NULL)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
get_counters(private, counters);
|
|
|
|
return counters;
|
|
}
|
|
|
|
static int
|
|
copy_entries_to_user(unsigned int total_size,
|
|
const struct xt_table *table,
|
|
void __user *userptr)
|
|
{
|
|
unsigned int off, num;
|
|
const struct ipt_entry *e;
|
|
struct xt_counters *counters;
|
|
const struct xt_table_info *private = table->private;
|
|
int ret = 0;
|
|
const void *loc_cpu_entry;
|
|
|
|
counters = alloc_counters(table);
|
|
if (IS_ERR(counters))
|
|
return PTR_ERR(counters);
|
|
|
|
loc_cpu_entry = private->entries;
|
|
|
|
/* FIXME: use iterator macros --RR */
|
|
/* ... then go back and fix counters and names */
|
|
for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
|
|
unsigned int i;
|
|
const struct xt_entry_match *m;
|
|
const struct xt_entry_target *t;
|
|
|
|
e = loc_cpu_entry + off;
|
|
if (copy_to_user(userptr + off, e, sizeof(*e))) {
|
|
ret = -EFAULT;
|
|
goto free_counters;
|
|
}
|
|
if (copy_to_user(userptr + off
|
|
+ offsetof(struct ipt_entry, counters),
|
|
&counters[num],
|
|
sizeof(counters[num])) != 0) {
|
|
ret = -EFAULT;
|
|
goto free_counters;
|
|
}
|
|
|
|
for (i = sizeof(struct ipt_entry);
|
|
i < e->target_offset;
|
|
i += m->u.match_size) {
|
|
m = (void *)e + i;
|
|
|
|
if (xt_match_to_user(m, userptr + off + i)) {
|
|
ret = -EFAULT;
|
|
goto free_counters;
|
|
}
|
|
}
|
|
|
|
t = ipt_get_target_c(e);
|
|
if (xt_target_to_user(t, userptr + off + e->target_offset)) {
|
|
ret = -EFAULT;
|
|
goto free_counters;
|
|
}
|
|
}
|
|
|
|
free_counters:
|
|
vfree(counters);
|
|
return ret;
|
|
}
|
|
|
|
#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
|
|
static void compat_standard_from_user(void *dst, const void *src)
|
|
{
|
|
int v = *(compat_int_t *)src;
|
|
|
|
if (v > 0)
|
|
v += xt_compat_calc_jump(AF_INET, v);
|
|
memcpy(dst, &v, sizeof(v));
|
|
}
|
|
|
|
static int compat_standard_to_user(void __user *dst, const void *src)
|
|
{
|
|
compat_int_t cv = *(int *)src;
|
|
|
|
if (cv > 0)
|
|
cv -= xt_compat_calc_jump(AF_INET, cv);
|
|
return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
|
|
}
|
|
|
|
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 xt_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;
|
|
xt_ematch_foreach(ematch, e)
|
|
off += xt_compat_match_offset(ematch->u.kernel.match);
|
|
t = ipt_get_target_c(e);
|
|
off += xt_compat_target_offset(t->u.kernel.target);
|
|
newinfo->size -= off;
|
|
ret = xt_compat_add_offset(AF_INET, entry_offset, off);
|
|
if (ret)
|
|
return ret;
|
|
|
|
for (i = 0; i < NF_INET_NUMHOOKS; i++) {
|
|
if (info->hook_entry[i] &&
|
|
(e < (struct ipt_entry *)(base + info->hook_entry[i])))
|
|
newinfo->hook_entry[i] -= off;
|
|
if (info->underflow[i] &&
|
|
(e < (struct ipt_entry *)(base + info->underflow[i])))
|
|
newinfo->underflow[i] -= off;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int compat_table_info(const struct xt_table_info *info,
|
|
struct xt_table_info *newinfo)
|
|
{
|
|
struct ipt_entry *iter;
|
|
const void *loc_cpu_entry;
|
|
int ret;
|
|
|
|
if (!newinfo || !info)
|
|
return -EINVAL;
|
|
|
|
/* we dont care about newinfo->entries */
|
|
memcpy(newinfo, info, offsetof(struct xt_table_info, entries));
|
|
newinfo->initial_entries = 0;
|
|
loc_cpu_entry = info->entries;
|
|
ret = xt_compat_init_offsets(AF_INET, info->number);
|
|
if (ret)
|
|
return ret;
|
|
xt_entry_foreach(iter, loc_cpu_entry, info->size) {
|
|
ret = compat_calc_entry(iter, info, loc_cpu_entry, newinfo);
|
|
if (ret != 0)
|
|
return ret;
|
|
}
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
static int get_info(struct net *net, void __user *user, const int *len)
|
|
{
|
|
char name[XT_TABLE_MAXNAMELEN];
|
|
struct xt_table *t;
|
|
int ret;
|
|
|
|
if (*len != sizeof(struct ipt_getinfo))
|
|
return -EINVAL;
|
|
|
|
if (copy_from_user(name, user, sizeof(name)) != 0)
|
|
return -EFAULT;
|
|
|
|
name[XT_TABLE_MAXNAMELEN-1] = '\0';
|
|
#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
|
|
if (in_compat_syscall())
|
|
xt_compat_lock(AF_INET);
|
|
#endif
|
|
t = xt_request_find_table_lock(net, AF_INET, name);
|
|
if (!IS_ERR(t)) {
|
|
struct ipt_getinfo info;
|
|
const struct xt_table_info *private = t->private;
|
|
#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
|
|
struct xt_table_info tmp;
|
|
|
|
if (in_compat_syscall()) {
|
|
ret = compat_table_info(private, &tmp);
|
|
xt_compat_flush_offsets(AF_INET);
|
|
private = &tmp;
|
|
}
|
|
#endif
|
|
memset(&info, 0, sizeof(info));
|
|
info.valid_hooks = t->valid_hooks;
|
|
memcpy(info.hook_entry, private->hook_entry,
|
|
sizeof(info.hook_entry));
|
|
memcpy(info.underflow, private->underflow,
|
|
sizeof(info.underflow));
|
|
info.num_entries = private->number;
|
|
info.size = private->size;
|
|
strcpy(info.name, name);
|
|
|
|
if (copy_to_user(user, &info, *len) != 0)
|
|
ret = -EFAULT;
|
|
else
|
|
ret = 0;
|
|
|
|
xt_table_unlock(t);
|
|
module_put(t->me);
|
|
} else
|
|
ret = PTR_ERR(t);
|
|
#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
|
|
if (in_compat_syscall())
|
|
xt_compat_unlock(AF_INET);
|
|
#endif
|
|
return ret;
|
|
}
|
|
|
|
static int
|
|
get_entries(struct net *net, struct ipt_get_entries __user *uptr,
|
|
const int *len)
|
|
{
|
|
int ret;
|
|
struct ipt_get_entries get;
|
|
struct xt_table *t;
|
|
|
|
if (*len < sizeof(get))
|
|
return -EINVAL;
|
|
if (copy_from_user(&get, uptr, sizeof(get)) != 0)
|
|
return -EFAULT;
|
|
if (*len != sizeof(struct ipt_get_entries) + get.size)
|
|
return -EINVAL;
|
|
get.name[sizeof(get.name) - 1] = '\0';
|
|
|
|
t = xt_find_table_lock(net, AF_INET, get.name);
|
|
if (!IS_ERR(t)) {
|
|
const struct xt_table_info *private = t->private;
|
|
if (get.size == private->size)
|
|
ret = copy_entries_to_user(private->size,
|
|
t, uptr->entrytable);
|
|
else
|
|
ret = -EAGAIN;
|
|
|
|
module_put(t->me);
|
|
xt_table_unlock(t);
|
|
} else
|
|
ret = PTR_ERR(t);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int
|
|
__do_replace(struct net *net, const char *name, unsigned int valid_hooks,
|
|
struct xt_table_info *newinfo, unsigned int num_counters,
|
|
void __user *counters_ptr)
|
|
{
|
|
int ret;
|
|
struct xt_table *t;
|
|
struct xt_table_info *oldinfo;
|
|
struct xt_counters *counters;
|
|
struct ipt_entry *iter;
|
|
|
|
counters = xt_counters_alloc(num_counters);
|
|
if (!counters) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
t = xt_request_find_table_lock(net, AF_INET, name);
|
|
if (IS_ERR(t)) {
|
|
ret = PTR_ERR(t);
|
|
goto free_newinfo_counters_untrans;
|
|
}
|
|
|
|
/* You lied! */
|
|
if (valid_hooks != t->valid_hooks) {
|
|
ret = -EINVAL;
|
|
goto put_module;
|
|
}
|
|
|
|
oldinfo = xt_replace_table(t, num_counters, newinfo, &ret);
|
|
if (!oldinfo)
|
|
goto put_module;
|
|
|
|
/* Update module usage count based on number of rules */
|
|
if ((oldinfo->number > oldinfo->initial_entries) ||
|
|
(newinfo->number <= oldinfo->initial_entries))
|
|
module_put(t->me);
|
|
if ((oldinfo->number > oldinfo->initial_entries) &&
|
|
(newinfo->number <= oldinfo->initial_entries))
|
|
module_put(t->me);
|
|
|
|
xt_table_unlock(t);
|
|
|
|
get_old_counters(oldinfo, counters);
|
|
|
|
/* Decrease module usage counts and free resource */
|
|
xt_entry_foreach(iter, oldinfo->entries, oldinfo->size)
|
|
cleanup_entry(iter, net);
|
|
|
|
xt_free_table_info(oldinfo);
|
|
if (copy_to_user(counters_ptr, counters,
|
|
sizeof(struct xt_counters) * num_counters) != 0) {
|
|
/* Silent error, can't fail, new table is already in place */
|
|
net_warn_ratelimited("iptables: counters copy to user failed while replacing table\n");
|
|
}
|
|
vfree(counters);
|
|
return 0;
|
|
|
|
put_module:
|
|
module_put(t->me);
|
|
xt_table_unlock(t);
|
|
free_newinfo_counters_untrans:
|
|
vfree(counters);
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
static int
|
|
do_replace(struct net *net, sockptr_t arg, unsigned int len)
|
|
{
|
|
int ret;
|
|
struct ipt_replace tmp;
|
|
struct xt_table_info *newinfo;
|
|
void *loc_cpu_entry;
|
|
struct ipt_entry *iter;
|
|
|
|
if (copy_from_sockptr(&tmp, arg, sizeof(tmp)) != 0)
|
|
return -EFAULT;
|
|
|
|
/* overflow check */
|
|
if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
|
|
return -ENOMEM;
|
|
if (tmp.num_counters == 0)
|
|
return -EINVAL;
|
|
|
|
tmp.name[sizeof(tmp.name)-1] = 0;
|
|
|
|
newinfo = xt_alloc_table_info(tmp.size);
|
|
if (!newinfo)
|
|
return -ENOMEM;
|
|
|
|
loc_cpu_entry = newinfo->entries;
|
|
if (copy_from_sockptr_offset(loc_cpu_entry, arg, sizeof(tmp),
|
|
tmp.size) != 0) {
|
|
ret = -EFAULT;
|
|
goto free_newinfo;
|
|
}
|
|
|
|
ret = translate_table(net, newinfo, loc_cpu_entry, &tmp);
|
|
if (ret != 0)
|
|
goto free_newinfo;
|
|
|
|
ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
|
|
tmp.num_counters, tmp.counters);
|
|
if (ret)
|
|
goto free_newinfo_untrans;
|
|
return 0;
|
|
|
|
free_newinfo_untrans:
|
|
xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
|
|
cleanup_entry(iter, net);
|
|
free_newinfo:
|
|
xt_free_table_info(newinfo);
|
|
return ret;
|
|
}
|
|
|
|
static int
|
|
do_add_counters(struct net *net, sockptr_t arg, unsigned int len)
|
|
{
|
|
unsigned int i;
|
|
struct xt_counters_info tmp;
|
|
struct xt_counters *paddc;
|
|
struct xt_table *t;
|
|
const struct xt_table_info *private;
|
|
int ret = 0;
|
|
struct ipt_entry *iter;
|
|
unsigned int addend;
|
|
|
|
paddc = xt_copy_counters(arg, len, &tmp);
|
|
if (IS_ERR(paddc))
|
|
return PTR_ERR(paddc);
|
|
|
|
t = xt_find_table_lock(net, AF_INET, tmp.name);
|
|
if (IS_ERR(t)) {
|
|
ret = PTR_ERR(t);
|
|
goto free;
|
|
}
|
|
|
|
local_bh_disable();
|
|
private = t->private;
|
|
if (private->number != tmp.num_counters) {
|
|
ret = -EINVAL;
|
|
goto unlock_up_free;
|
|
}
|
|
|
|
i = 0;
|
|
addend = xt_write_recseq_begin();
|
|
xt_entry_foreach(iter, private->entries, private->size) {
|
|
struct xt_counters *tmp;
|
|
|
|
tmp = xt_get_this_cpu_counter(&iter->counters);
|
|
ADD_COUNTER(*tmp, paddc[i].bcnt, paddc[i].pcnt);
|
|
++i;
|
|
}
|
|
xt_write_recseq_end(addend);
|
|
unlock_up_free:
|
|
local_bh_enable();
|
|
xt_table_unlock(t);
|
|
module_put(t->me);
|
|
free:
|
|
vfree(paddc);
|
|
|
|
return ret;
|
|
}
|
|
|
|
#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
|
|
struct compat_ipt_replace {
|
|
char name[XT_TABLE_MAXNAMELEN];
|
|
u32 valid_hooks;
|
|
u32 num_entries;
|
|
u32 size;
|
|
u32 hook_entry[NF_INET_NUMHOOKS];
|
|
u32 underflow[NF_INET_NUMHOOKS];
|
|
u32 num_counters;
|
|
compat_uptr_t counters; /* struct xt_counters * */
|
|
struct compat_ipt_entry entries[];
|
|
};
|
|
|
|
static int
|
|
compat_copy_entry_to_user(struct ipt_entry *e, void __user **dstptr,
|
|
unsigned int *size, struct xt_counters *counters,
|
|
unsigned int i)
|
|
{
|
|
struct xt_entry_target *t;
|
|
struct compat_ipt_entry __user *ce;
|
|
u_int16_t target_offset, next_offset;
|
|
compat_uint_t origsize;
|
|
const struct xt_entry_match *ematch;
|
|
int ret = 0;
|
|
|
|
origsize = *size;
|
|
ce = *dstptr;
|
|
if (copy_to_user(ce, e, sizeof(struct ipt_entry)) != 0 ||
|
|
copy_to_user(&ce->counters, &counters[i],
|
|
sizeof(counters[i])) != 0)
|
|
return -EFAULT;
|
|
|
|
*dstptr += sizeof(struct compat_ipt_entry);
|
|
*size -= sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry);
|
|
|
|
xt_ematch_foreach(ematch, e) {
|
|
ret = xt_compat_match_to_user(ematch, dstptr, size);
|
|
if (ret != 0)
|
|
return ret;
|
|
}
|
|
target_offset = e->target_offset - (origsize - *size);
|
|
t = ipt_get_target(e);
|
|
ret = xt_compat_target_to_user(t, dstptr, size);
|
|
if (ret)
|
|
return ret;
|
|
next_offset = e->next_offset - (origsize - *size);
|
|
if (put_user(target_offset, &ce->target_offset) != 0 ||
|
|
put_user(next_offset, &ce->next_offset) != 0)
|
|
return -EFAULT;
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
compat_find_calc_match(struct xt_entry_match *m,
|
|
const struct ipt_ip *ip,
|
|
int *size)
|
|
{
|
|
struct xt_match *match;
|
|
|
|
match = xt_request_find_match(NFPROTO_IPV4, m->u.user.name,
|
|
m->u.user.revision);
|
|
if (IS_ERR(match))
|
|
return PTR_ERR(match);
|
|
|
|
m->u.kernel.match = match;
|
|
*size += xt_compat_match_offset(match);
|
|
return 0;
|
|
}
|
|
|
|
static void compat_release_entry(struct compat_ipt_entry *e)
|
|
{
|
|
struct xt_entry_target *t;
|
|
struct xt_entry_match *ematch;
|
|
|
|
/* Cleanup all matches */
|
|
xt_ematch_foreach(ematch, e)
|
|
module_put(ematch->u.kernel.match->me);
|
|
t = compat_ipt_get_target(e);
|
|
module_put(t->u.kernel.target->me);
|
|
}
|
|
|
|
static int
|
|
check_compat_entry_size_and_hooks(struct compat_ipt_entry *e,
|
|
struct xt_table_info *newinfo,
|
|
unsigned int *size,
|
|
const unsigned char *base,
|
|
const unsigned char *limit)
|
|
{
|
|
struct xt_entry_match *ematch;
|
|
struct xt_entry_target *t;
|
|
struct xt_target *target;
|
|
unsigned int entry_offset;
|
|
unsigned int j;
|
|
int ret, off;
|
|
|
|
if ((unsigned long)e % __alignof__(struct compat_ipt_entry) != 0 ||
|
|
(unsigned char *)e + sizeof(struct compat_ipt_entry) >= limit ||
|
|
(unsigned char *)e + e->next_offset > limit)
|
|
return -EINVAL;
|
|
|
|
if (e->next_offset < sizeof(struct compat_ipt_entry) +
|
|
sizeof(struct compat_xt_entry_target))
|
|
return -EINVAL;
|
|
|
|
if (!ip_checkentry(&e->ip))
|
|
return -EINVAL;
|
|
|
|
ret = xt_compat_check_entry_offsets(e, e->elems,
|
|
e->target_offset, e->next_offset);
|
|
if (ret)
|
|
return ret;
|
|
|
|
off = sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry);
|
|
entry_offset = (void *)e - (void *)base;
|
|
j = 0;
|
|
xt_ematch_foreach(ematch, e) {
|
|
ret = compat_find_calc_match(ematch, &e->ip, &off);
|
|
if (ret != 0)
|
|
goto release_matches;
|
|
++j;
|
|
}
|
|
|
|
t = compat_ipt_get_target(e);
|
|
target = xt_request_find_target(NFPROTO_IPV4, t->u.user.name,
|
|
t->u.user.revision);
|
|
if (IS_ERR(target)) {
|
|
ret = PTR_ERR(target);
|
|
goto release_matches;
|
|
}
|
|
t->u.kernel.target = target;
|
|
|
|
off += xt_compat_target_offset(target);
|
|
*size += off;
|
|
ret = xt_compat_add_offset(AF_INET, entry_offset, off);
|
|
if (ret)
|
|
goto out;
|
|
|
|
return 0;
|
|
|
|
out:
|
|
module_put(t->u.kernel.target->me);
|
|
release_matches:
|
|
xt_ematch_foreach(ematch, e) {
|
|
if (j-- == 0)
|
|
break;
|
|
module_put(ematch->u.kernel.match->me);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static void
|
|
compat_copy_entry_from_user(struct compat_ipt_entry *e, void **dstptr,
|
|
unsigned int *size,
|
|
struct xt_table_info *newinfo, unsigned char *base)
|
|
{
|
|
struct xt_entry_target *t;
|
|
struct ipt_entry *de;
|
|
unsigned int origsize;
|
|
int h;
|
|
struct xt_entry_match *ematch;
|
|
|
|
origsize = *size;
|
|
de = *dstptr;
|
|
memcpy(de, e, sizeof(struct ipt_entry));
|
|
memcpy(&de->counters, &e->counters, sizeof(e->counters));
|
|
|
|
*dstptr += sizeof(struct ipt_entry);
|
|
*size += sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry);
|
|
|
|
xt_ematch_foreach(ematch, e)
|
|
xt_compat_match_from_user(ematch, dstptr, size);
|
|
|
|
de->target_offset = e->target_offset - (origsize - *size);
|
|
t = compat_ipt_get_target(e);
|
|
xt_compat_target_from_user(t, dstptr, size);
|
|
|
|
de->next_offset = e->next_offset - (origsize - *size);
|
|
|
|
for (h = 0; h < NF_INET_NUMHOOKS; h++) {
|
|
if ((unsigned char *)de - base < newinfo->hook_entry[h])
|
|
newinfo->hook_entry[h] -= origsize - *size;
|
|
if ((unsigned char *)de - base < newinfo->underflow[h])
|
|
newinfo->underflow[h] -= origsize - *size;
|
|
}
|
|
}
|
|
|
|
static int
|
|
translate_compat_table(struct net *net,
|
|
struct xt_table_info **pinfo,
|
|
void **pentry0,
|
|
const struct compat_ipt_replace *compatr)
|
|
{
|
|
unsigned int i, j;
|
|
struct xt_table_info *newinfo, *info;
|
|
void *pos, *entry0, *entry1;
|
|
struct compat_ipt_entry *iter0;
|
|
struct ipt_replace repl;
|
|
unsigned int size;
|
|
int ret;
|
|
|
|
info = *pinfo;
|
|
entry0 = *pentry0;
|
|
size = compatr->size;
|
|
info->number = compatr->num_entries;
|
|
|
|
j = 0;
|
|
xt_compat_lock(AF_INET);
|
|
ret = xt_compat_init_offsets(AF_INET, compatr->num_entries);
|
|
if (ret)
|
|
goto out_unlock;
|
|
/* Walk through entries, checking offsets. */
|
|
xt_entry_foreach(iter0, entry0, compatr->size) {
|
|
ret = check_compat_entry_size_and_hooks(iter0, info, &size,
|
|
entry0,
|
|
entry0 + compatr->size);
|
|
if (ret != 0)
|
|
goto out_unlock;
|
|
++j;
|
|
}
|
|
|
|
ret = -EINVAL;
|
|
if (j != compatr->num_entries)
|
|
goto out_unlock;
|
|
|
|
ret = -ENOMEM;
|
|
newinfo = xt_alloc_table_info(size);
|
|
if (!newinfo)
|
|
goto out_unlock;
|
|
|
|
memset(newinfo->entries, 0, size);
|
|
|
|
newinfo->number = compatr->num_entries;
|
|
for (i = 0; i < NF_INET_NUMHOOKS; i++) {
|
|
newinfo->hook_entry[i] = compatr->hook_entry[i];
|
|
newinfo->underflow[i] = compatr->underflow[i];
|
|
}
|
|
entry1 = newinfo->entries;
|
|
pos = entry1;
|
|
size = compatr->size;
|
|
xt_entry_foreach(iter0, entry0, compatr->size)
|
|
compat_copy_entry_from_user(iter0, &pos, &size,
|
|
newinfo, entry1);
|
|
|
|
/* all module references in entry0 are now gone.
|
|
* entry1/newinfo contains a 64bit ruleset that looks exactly as
|
|
* generated by 64bit userspace.
|
|
*
|
|
* Call standard translate_table() to validate all hook_entrys,
|
|
* underflows, check for loops, etc.
|
|
*/
|
|
xt_compat_flush_offsets(AF_INET);
|
|
xt_compat_unlock(AF_INET);
|
|
|
|
memcpy(&repl, compatr, sizeof(*compatr));
|
|
|
|
for (i = 0; i < NF_INET_NUMHOOKS; i++) {
|
|
repl.hook_entry[i] = newinfo->hook_entry[i];
|
|
repl.underflow[i] = newinfo->underflow[i];
|
|
}
|
|
|
|
repl.num_counters = 0;
|
|
repl.counters = NULL;
|
|
repl.size = newinfo->size;
|
|
ret = translate_table(net, newinfo, entry1, &repl);
|
|
if (ret)
|
|
goto free_newinfo;
|
|
|
|
*pinfo = newinfo;
|
|
*pentry0 = entry1;
|
|
xt_free_table_info(info);
|
|
return 0;
|
|
|
|
free_newinfo:
|
|
xt_free_table_info(newinfo);
|
|
return ret;
|
|
out_unlock:
|
|
xt_compat_flush_offsets(AF_INET);
|
|
xt_compat_unlock(AF_INET);
|
|
xt_entry_foreach(iter0, entry0, compatr->size) {
|
|
if (j-- == 0)
|
|
break;
|
|
compat_release_entry(iter0);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static int
|
|
compat_do_replace(struct net *net, sockptr_t arg, unsigned int len)
|
|
{
|
|
int ret;
|
|
struct compat_ipt_replace tmp;
|
|
struct xt_table_info *newinfo;
|
|
void *loc_cpu_entry;
|
|
struct ipt_entry *iter;
|
|
|
|
if (copy_from_sockptr(&tmp, arg, sizeof(tmp)) != 0)
|
|
return -EFAULT;
|
|
|
|
/* overflow check */
|
|
if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
|
|
return -ENOMEM;
|
|
if (tmp.num_counters == 0)
|
|
return -EINVAL;
|
|
|
|
tmp.name[sizeof(tmp.name)-1] = 0;
|
|
|
|
newinfo = xt_alloc_table_info(tmp.size);
|
|
if (!newinfo)
|
|
return -ENOMEM;
|
|
|
|
loc_cpu_entry = newinfo->entries;
|
|
if (copy_from_sockptr_offset(loc_cpu_entry, arg, sizeof(tmp),
|
|
tmp.size) != 0) {
|
|
ret = -EFAULT;
|
|
goto free_newinfo;
|
|
}
|
|
|
|
ret = translate_compat_table(net, &newinfo, &loc_cpu_entry, &tmp);
|
|
if (ret != 0)
|
|
goto free_newinfo;
|
|
|
|
ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
|
|
tmp.num_counters, compat_ptr(tmp.counters));
|
|
if (ret)
|
|
goto free_newinfo_untrans;
|
|
return 0;
|
|
|
|
free_newinfo_untrans:
|
|
xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
|
|
cleanup_entry(iter, net);
|
|
free_newinfo:
|
|
xt_free_table_info(newinfo);
|
|
return ret;
|
|
}
|
|
|
|
struct compat_ipt_get_entries {
|
|
char name[XT_TABLE_MAXNAMELEN];
|
|
compat_uint_t size;
|
|
struct compat_ipt_entry entrytable[];
|
|
};
|
|
|
|
static int
|
|
compat_copy_entries_to_user(unsigned int total_size, struct xt_table *table,
|
|
void __user *userptr)
|
|
{
|
|
struct xt_counters *counters;
|
|
const struct xt_table_info *private = table->private;
|
|
void __user *pos;
|
|
unsigned int size;
|
|
int ret = 0;
|
|
unsigned int i = 0;
|
|
struct ipt_entry *iter;
|
|
|
|
counters = alloc_counters(table);
|
|
if (IS_ERR(counters))
|
|
return PTR_ERR(counters);
|
|
|
|
pos = userptr;
|
|
size = total_size;
|
|
xt_entry_foreach(iter, private->entries, total_size) {
|
|
ret = compat_copy_entry_to_user(iter, &pos,
|
|
&size, counters, i++);
|
|
if (ret != 0)
|
|
break;
|
|
}
|
|
|
|
vfree(counters);
|
|
return ret;
|
|
}
|
|
|
|
static int
|
|
compat_get_entries(struct net *net, struct compat_ipt_get_entries __user *uptr,
|
|
int *len)
|
|
{
|
|
int ret;
|
|
struct compat_ipt_get_entries get;
|
|
struct xt_table *t;
|
|
|
|
if (*len < sizeof(get))
|
|
return -EINVAL;
|
|
|
|
if (copy_from_user(&get, uptr, sizeof(get)) != 0)
|
|
return -EFAULT;
|
|
|
|
if (*len != sizeof(struct compat_ipt_get_entries) + get.size)
|
|
return -EINVAL;
|
|
|
|
get.name[sizeof(get.name) - 1] = '\0';
|
|
|
|
xt_compat_lock(AF_INET);
|
|
t = xt_find_table_lock(net, AF_INET, get.name);
|
|
if (!IS_ERR(t)) {
|
|
const struct xt_table_info *private = t->private;
|
|
struct xt_table_info info;
|
|
ret = compat_table_info(private, &info);
|
|
if (!ret && get.size == info.size)
|
|
ret = compat_copy_entries_to_user(private->size,
|
|
t, uptr->entrytable);
|
|
else if (!ret)
|
|
ret = -EAGAIN;
|
|
|
|
xt_compat_flush_offsets(AF_INET);
|
|
module_put(t->me);
|
|
xt_table_unlock(t);
|
|
} else
|
|
ret = PTR_ERR(t);
|
|
|
|
xt_compat_unlock(AF_INET);
|
|
return ret;
|
|
}
|
|
#endif
|
|
|
|
static int
|
|
do_ipt_set_ctl(struct sock *sk, int cmd, sockptr_t arg, unsigned int len)
|
|
{
|
|
int ret;
|
|
|
|
if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
|
|
return -EPERM;
|
|
|
|
switch (cmd) {
|
|
case IPT_SO_SET_REPLACE:
|
|
#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
|
|
if (in_compat_syscall())
|
|
ret = compat_do_replace(sock_net(sk), arg, len);
|
|
else
|
|
#endif
|
|
ret = do_replace(sock_net(sk), arg, len);
|
|
break;
|
|
|
|
case IPT_SO_SET_ADD_COUNTERS:
|
|
ret = do_add_counters(sock_net(sk), arg, len);
|
|
break;
|
|
|
|
default:
|
|
ret = -EINVAL;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int
|
|
do_ipt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
|
|
{
|
|
int ret;
|
|
|
|
if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
|
|
return -EPERM;
|
|
|
|
switch (cmd) {
|
|
case IPT_SO_GET_INFO:
|
|
ret = get_info(sock_net(sk), user, len);
|
|
break;
|
|
|
|
case IPT_SO_GET_ENTRIES:
|
|
#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
|
|
if (in_compat_syscall())
|
|
ret = compat_get_entries(sock_net(sk), user, len);
|
|
else
|
|
#endif
|
|
ret = get_entries(sock_net(sk), user, len);
|
|
break;
|
|
|
|
case IPT_SO_GET_REVISION_MATCH:
|
|
case IPT_SO_GET_REVISION_TARGET: {
|
|
struct xt_get_revision rev;
|
|
int target;
|
|
|
|
if (*len != sizeof(rev)) {
|
|
ret = -EINVAL;
|
|
break;
|
|
}
|
|
if (copy_from_user(&rev, user, sizeof(rev)) != 0) {
|
|
ret = -EFAULT;
|
|
break;
|
|
}
|
|
rev.name[sizeof(rev.name)-1] = 0;
|
|
|
|
if (cmd == IPT_SO_GET_REVISION_TARGET)
|
|
target = 1;
|
|
else
|
|
target = 0;
|
|
|
|
try_then_request_module(xt_find_revision(AF_INET, rev.name,
|
|
rev.revision,
|
|
target, &ret),
|
|
"ipt_%s", rev.name);
|
|
break;
|
|
}
|
|
|
|
default:
|
|
ret = -EINVAL;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void __ipt_unregister_table(struct net *net, struct xt_table *table)
|
|
{
|
|
struct xt_table_info *private;
|
|
void *loc_cpu_entry;
|
|
struct module *table_owner = table->me;
|
|
struct ipt_entry *iter;
|
|
|
|
private = xt_unregister_table(table);
|
|
|
|
/* Decrease module usage counts and free resources */
|
|
loc_cpu_entry = private->entries;
|
|
xt_entry_foreach(iter, loc_cpu_entry, private->size)
|
|
cleanup_entry(iter, net);
|
|
if (private->number > private->initial_entries)
|
|
module_put(table_owner);
|
|
xt_free_table_info(private);
|
|
}
|
|
|
|
int ipt_register_table(struct net *net, const struct xt_table *table,
|
|
const struct ipt_replace *repl,
|
|
const struct nf_hook_ops *template_ops)
|
|
{
|
|
struct nf_hook_ops *ops;
|
|
unsigned int num_ops;
|
|
int ret, i;
|
|
struct xt_table_info *newinfo;
|
|
struct xt_table_info bootstrap = {0};
|
|
void *loc_cpu_entry;
|
|
struct xt_table *new_table;
|
|
|
|
newinfo = xt_alloc_table_info(repl->size);
|
|
if (!newinfo)
|
|
return -ENOMEM;
|
|
|
|
loc_cpu_entry = newinfo->entries;
|
|
memcpy(loc_cpu_entry, repl->entries, repl->size);
|
|
|
|
ret = translate_table(net, newinfo, loc_cpu_entry, repl);
|
|
if (ret != 0) {
|
|
xt_free_table_info(newinfo);
|
|
return ret;
|
|
}
|
|
|
|
new_table = xt_register_table(net, table, &bootstrap, newinfo);
|
|
if (IS_ERR(new_table)) {
|
|
struct ipt_entry *iter;
|
|
|
|
xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
|
|
cleanup_entry(iter, net);
|
|
xt_free_table_info(newinfo);
|
|
return PTR_ERR(new_table);
|
|
}
|
|
|
|
/* No template? No need to do anything. This is used by 'nat' table, it registers
|
|
* with the nat core instead of the netfilter core.
|
|
*/
|
|
if (!template_ops)
|
|
return 0;
|
|
|
|
num_ops = hweight32(table->valid_hooks);
|
|
if (num_ops == 0) {
|
|
ret = -EINVAL;
|
|
goto out_free;
|
|
}
|
|
|
|
ops = kmemdup(template_ops, sizeof(*ops) * num_ops, GFP_KERNEL);
|
|
if (!ops) {
|
|
ret = -ENOMEM;
|
|
goto out_free;
|
|
}
|
|
|
|
for (i = 0; i < num_ops; i++)
|
|
ops[i].priv = new_table;
|
|
|
|
new_table->ops = ops;
|
|
|
|
ret = nf_register_net_hooks(net, ops, num_ops);
|
|
if (ret != 0)
|
|
goto out_free;
|
|
|
|
return ret;
|
|
|
|
out_free:
|
|
__ipt_unregister_table(net, new_table);
|
|
return ret;
|
|
}
|
|
|
|
void ipt_unregister_table_pre_exit(struct net *net, const char *name)
|
|
{
|
|
struct xt_table *table = xt_find_table(net, NFPROTO_IPV4, name);
|
|
|
|
if (table)
|
|
nf_unregister_net_hooks(net, table->ops, hweight32(table->valid_hooks));
|
|
}
|
|
|
|
void ipt_unregister_table_exit(struct net *net, const char *name)
|
|
{
|
|
struct xt_table *table = xt_find_table(net, NFPROTO_IPV4, name);
|
|
|
|
if (table)
|
|
__ipt_unregister_table(net, table);
|
|
}
|
|
|
|
static struct xt_target ipt_builtin_tg[] __read_mostly = {
|
|
{
|
|
.name = XT_STANDARD_TARGET,
|
|
.targetsize = sizeof(int),
|
|
.family = NFPROTO_IPV4,
|
|
#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
|
|
.compatsize = sizeof(compat_int_t),
|
|
.compat_from_user = compat_standard_from_user,
|
|
.compat_to_user = compat_standard_to_user,
|
|
#endif
|
|
},
|
|
{
|
|
.name = XT_ERROR_TARGET,
|
|
.target = ipt_error,
|
|
.targetsize = XT_FUNCTION_MAXNAMELEN,
|
|
.family = NFPROTO_IPV4,
|
|
},
|
|
};
|
|
|
|
static struct nf_sockopt_ops ipt_sockopts = {
|
|
.pf = PF_INET,
|
|
.set_optmin = IPT_BASE_CTL,
|
|
.set_optmax = IPT_SO_SET_MAX+1,
|
|
.set = do_ipt_set_ctl,
|
|
.get_optmin = IPT_BASE_CTL,
|
|
.get_optmax = IPT_SO_GET_MAX+1,
|
|
.get = do_ipt_get_ctl,
|
|
.owner = THIS_MODULE,
|
|
};
|
|
|
|
static int __net_init ip_tables_net_init(struct net *net)
|
|
{
|
|
return xt_proto_init(net, NFPROTO_IPV4);
|
|
}
|
|
|
|
static void __net_exit ip_tables_net_exit(struct net *net)
|
|
{
|
|
xt_proto_fini(net, NFPROTO_IPV4);
|
|
}
|
|
|
|
static struct pernet_operations ip_tables_net_ops = {
|
|
.init = ip_tables_net_init,
|
|
.exit = ip_tables_net_exit,
|
|
};
|
|
|
|
static int __init ip_tables_init(void)
|
|
{
|
|
int ret;
|
|
|
|
ret = register_pernet_subsys(&ip_tables_net_ops);
|
|
if (ret < 0)
|
|
goto err1;
|
|
|
|
/* No one else will be downing sem now, so we won't sleep */
|
|
ret = xt_register_targets(ipt_builtin_tg, ARRAY_SIZE(ipt_builtin_tg));
|
|
if (ret < 0)
|
|
goto err2;
|
|
|
|
/* Register setsockopt */
|
|
ret = nf_register_sockopt(&ipt_sockopts);
|
|
if (ret < 0)
|
|
goto err4;
|
|
|
|
return 0;
|
|
|
|
err4:
|
|
xt_unregister_targets(ipt_builtin_tg, ARRAY_SIZE(ipt_builtin_tg));
|
|
err2:
|
|
unregister_pernet_subsys(&ip_tables_net_ops);
|
|
err1:
|
|
return ret;
|
|
}
|
|
|
|
static void __exit ip_tables_fini(void)
|
|
{
|
|
nf_unregister_sockopt(&ipt_sockopts);
|
|
|
|
xt_unregister_targets(ipt_builtin_tg, ARRAY_SIZE(ipt_builtin_tg));
|
|
unregister_pernet_subsys(&ip_tables_net_ops);
|
|
}
|
|
|
|
EXPORT_SYMBOL(ipt_register_table);
|
|
EXPORT_SYMBOL(ipt_unregister_table_pre_exit);
|
|
EXPORT_SYMBOL(ipt_unregister_table_exit);
|
|
EXPORT_SYMBOL(ipt_do_table);
|
|
module_init(ip_tables_init);
|
|
module_exit(ip_tables_fini);
|