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- /*
- * Packet matching code.
- *
- * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
- * Copyright (C) 2000-2005 Netfilter Core Team <coreteam@netfilter.org>
- * Copyright (C) 2006-2010 Patrick McHardy <kaber@trash.net>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- */
- #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
- #include <linux/cache.h>
- #include <linux/capability.h>
- #include <linux/skbuff.h>
- #include <linux/kmod.h>
- #include <linux/vmalloc.h>
- #include <linux/netdevice.h>
- #include <linux/module.h>
- #include <linux/icmp.h>
- #include <net/ip.h>
- #include <net/compat.h>
- #include <asm/uaccess.h>
- #include <linux/mutex.h>
- #include <linux/proc_fs.h>
- #include <linux/err.h>
- #include <linux/cpumask.h>
- #include <linux/netfilter/x_tables.h>
- #include <linux/netfilter_ipv4/ip_tables.h>
- #include <net/netfilter/nf_log.h>
- #include "../../netfilter/xt_repldata.h"
- MODULE_LICENSE("GPL");
- MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
- MODULE_DESCRIPTION("IPv4 packet filter");
- /*#define DEBUG_IP_FIREWALL*/
- /*#define DEBUG_ALLOW_ALL*/ /* Useful for remote debugging */
- /*#define DEBUG_IP_FIREWALL_USER*/
- #ifdef DEBUG_IP_FIREWALL
- #define dprintf(format, args...) pr_info(format , ## args)
- #else
- #define dprintf(format, args...)
- #endif
- #ifdef DEBUG_IP_FIREWALL_USER
- #define duprintf(format, args...) pr_info(format , ## args)
- #else
- #define duprintf(format, args...)
- #endif
- #ifdef CONFIG_NETFILTER_DEBUG
- #define IP_NF_ASSERT(x) WARN_ON(!(x))
- #else
- #define IP_NF_ASSERT(x)
- #endif
- #if 0
- /* All the better to debug you with... */
- #define static
- #define inline
- #endif
- void *ipt_alloc_initial_table(const struct xt_table *info)
- {
- return xt_alloc_initial_table(ipt, IPT);
- }
- EXPORT_SYMBOL_GPL(ipt_alloc_initial_table);
- /* Returns whether matches rule or not. */
- /* Performance critical - called for every packet */
- static inline bool
- ip_packet_match(const struct iphdr *ip,
- const char *indev,
- const char *outdev,
- const struct ipt_ip *ipinfo,
- int isfrag)
- {
- unsigned long ret;
- #define FWINV(bool, invflg) ((bool) ^ !!(ipinfo->invflags & (invflg)))
- if (FWINV((ip->saddr&ipinfo->smsk.s_addr) != ipinfo->src.s_addr,
- IPT_INV_SRCIP) ||
- FWINV((ip->daddr&ipinfo->dmsk.s_addr) != ipinfo->dst.s_addr,
- IPT_INV_DSTIP)) {
- dprintf("Source or dest mismatch.\n");
- dprintf("SRC: %pI4. Mask: %pI4. Target: %pI4.%s\n",
- &ip->saddr, &ipinfo->smsk.s_addr, &ipinfo->src.s_addr,
- ipinfo->invflags & IPT_INV_SRCIP ? " (INV)" : "");
- dprintf("DST: %pI4 Mask: %pI4 Target: %pI4.%s\n",
- &ip->daddr, &ipinfo->dmsk.s_addr, &ipinfo->dst.s_addr,
- ipinfo->invflags & IPT_INV_DSTIP ? " (INV)" : "");
- return false;
- }
- ret = ifname_compare_aligned(indev, ipinfo->iniface, ipinfo->iniface_mask);
- if (FWINV(ret != 0, IPT_INV_VIA_IN)) {
- dprintf("VIA in mismatch (%s vs %s).%s\n",
- indev, ipinfo->iniface,
- ipinfo->invflags & IPT_INV_VIA_IN ? " (INV)" : "");
- return false;
- }
- ret = ifname_compare_aligned(outdev, ipinfo->outiface, ipinfo->outiface_mask);
- if (FWINV(ret != 0, IPT_INV_VIA_OUT)) {
- dprintf("VIA out mismatch (%s vs %s).%s\n",
- outdev, ipinfo->outiface,
- ipinfo->invflags & IPT_INV_VIA_OUT ? " (INV)" : "");
- return false;
- }
- /* Check specific protocol */
- if (ipinfo->proto &&
- FWINV(ip->protocol != ipinfo->proto, IPT_INV_PROTO)) {
- dprintf("Packet protocol %hi does not match %hi.%s\n",
- ip->protocol, ipinfo->proto,
- ipinfo->invflags & IPT_INV_PROTO ? " (INV)" : "");
- return false;
- }
- /* If we have a fragment rule but the packet is not a fragment
- * then we return zero */
- if (FWINV((ipinfo->flags&IPT_F_FRAG) && !isfrag, IPT_INV_FRAG)) {
- dprintf("Fragment rule but not fragment.%s\n",
- ipinfo->invflags & IPT_INV_FRAG ? " (INV)" : "");
- return false;
- }
- return true;
- }
- static bool
- ip_checkentry(const struct ipt_ip *ip)
- {
- if (ip->flags & ~IPT_F_MASK) {
- duprintf("Unknown flag bits set: %08X\n",
- ip->flags & ~IPT_F_MASK);
- return false;
- }
- if (ip->invflags & ~IPT_INV_MASK) {
- duprintf("Unknown invflag bits set: %08X\n",
- ip->invflags & ~IPT_INV_MASK);
- return false;
- }
- return true;
- }
- static unsigned int
- ipt_error(struct sk_buff *skb, const struct xt_action_param *par)
- {
- net_info_ratelimited("error: `%s'\n", (const char *)par->targinfo);
- return NF_DROP;
- }
- /* Performance critical */
- static inline struct ipt_entry *
- get_entry(const void *base, unsigned int offset)
- {
- return (struct ipt_entry *)(base + offset);
- }
- /* All zeroes == unconditional rule. */
- /* Mildly perf critical (only if packet tracing is on) */
- static inline bool unconditional(const struct ipt_entry *e)
- {
- static const struct ipt_ip uncond;
- return e->target_offset == sizeof(struct ipt_entry) &&
- memcmp(&e->ip, &uncond, sizeof(uncond)) == 0;
- #undef FWINV
- }
- /* for const-correctness */
- static inline const struct xt_entry_target *
- ipt_get_target_c(const struct ipt_entry *e)
- {
- return ipt_get_target((struct ipt_entry *)e);
- }
- #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE)
- static const char *const hooknames[] = {
- [NF_INET_PRE_ROUTING] = "PREROUTING",
- [NF_INET_LOCAL_IN] = "INPUT",
- [NF_INET_FORWARD] = "FORWARD",
- [NF_INET_LOCAL_OUT] = "OUTPUT",
- [NF_INET_POST_ROUTING] = "POSTROUTING",
- };
- enum nf_ip_trace_comments {
- NF_IP_TRACE_COMMENT_RULE,
- NF_IP_TRACE_COMMENT_RETURN,
- NF_IP_TRACE_COMMENT_POLICY,
- };
- static const char *const comments[] = {
- [NF_IP_TRACE_COMMENT_RULE] = "rule",
- [NF_IP_TRACE_COMMENT_RETURN] = "return",
- [NF_IP_TRACE_COMMENT_POLICY] = "policy",
- };
- static struct nf_loginfo trace_loginfo = {
- .type = NF_LOG_TYPE_LOG,
- .u = {
- .log = {
- .level = 4,
- .logflags = NF_LOG_MASK,
- },
- },
- };
- /* Mildly perf critical (only if packet tracing is on) */
- static inline int
- get_chainname_rulenum(const struct ipt_entry *s, const struct ipt_entry *e,
- const char *hookname, const char **chainname,
- const char **comment, unsigned int *rulenum)
- {
- const struct xt_standard_target *t = (void *)ipt_get_target_c(s);
- if (strcmp(t->target.u.kernel.target->name, XT_ERROR_TARGET) == 0) {
- /* Head of user chain: ERROR target with chainname */
- *chainname = t->target.data;
- (*rulenum) = 0;
- } else if (s == e) {
- (*rulenum)++;
- if (unconditional(s) &&
- strcmp(t->target.u.kernel.target->name,
- XT_STANDARD_TARGET) == 0 &&
- t->verdict < 0) {
- /* Tail of chains: STANDARD target (return/policy) */
- *comment = *chainname == hookname
- ? comments[NF_IP_TRACE_COMMENT_POLICY]
- : comments[NF_IP_TRACE_COMMENT_RETURN];
- }
- return 1;
- } else
- (*rulenum)++;
- return 0;
- }
- static void trace_packet(struct net *net,
- const struct sk_buff *skb,
- unsigned int hook,
- const struct net_device *in,
- const struct net_device *out,
- const char *tablename,
- const struct xt_table_info *private,
- const struct ipt_entry *e)
- {
- const struct ipt_entry *root;
- const char *hookname, *chainname, *comment;
- const struct ipt_entry *iter;
- unsigned int rulenum = 0;
- root = get_entry(private->entries, private->hook_entry[hook]);
- hookname = chainname = hooknames[hook];
- comment = comments[NF_IP_TRACE_COMMENT_RULE];
- xt_entry_foreach(iter, root, private->size - private->hook_entry[hook])
- if (get_chainname_rulenum(iter, e, hookname,
- &chainname, &comment, &rulenum) != 0)
- break;
- nf_log_trace(net, AF_INET, hook, skb, in, out, &trace_loginfo,
- "TRACE: %s:%s:%s:%u ",
- tablename, chainname, comment, rulenum);
- }
- #endif
- static inline
- struct ipt_entry *ipt_next_entry(const struct ipt_entry *entry)
- {
- return (void *)entry + entry->next_offset;
- }
- /* Returns one of the generic firewall policies, like NF_ACCEPT. */
- unsigned int
- ipt_do_table(struct sk_buff *skb,
- const struct nf_hook_state *state,
- struct xt_table *table)
- {
- unsigned int hook = state->hook;
- static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long))));
- const struct iphdr *ip;
- /* Initializing verdict to NF_DROP keeps gcc happy. */
- unsigned int verdict = NF_DROP;
- const char *indev, *outdev;
- const void *table_base;
- struct ipt_entry *e, **jumpstack;
- unsigned int stackidx, cpu;
- const struct xt_table_info *private;
- struct xt_action_param acpar;
- unsigned int addend;
- /* Initialization */
- stackidx = 0;
- ip = ip_hdr(skb);
- indev = state->in ? state->in->name : nulldevname;
- outdev = state->out ? state->out->name : nulldevname;
- /* We handle fragments by dealing with the first fragment as
- * if it was a normal packet. All other fragments are treated
- * normally, except that they will NEVER match rules that ask
- * things we don't know, ie. tcp syn flag or ports). If the
- * rule is also a fragment-specific rule, non-fragments won't
- * match it. */
- acpar.fragoff = ntohs(ip->frag_off) & IP_OFFSET;
- acpar.thoff = ip_hdrlen(skb);
- acpar.hotdrop = false;
- acpar.net = state->net;
- acpar.in = state->in;
- acpar.out = state->out;
- acpar.family = NFPROTO_IPV4;
- acpar.hooknum = hook;
- IP_NF_ASSERT(table->valid_hooks & (1 << hook));
- local_bh_disable();
- addend = xt_write_recseq_begin();
- private = table->private;
- cpu = smp_processor_id();
- /*
- * Ensure we load private-> members after we've fetched the base
- * pointer.
- */
- smp_read_barrier_depends();
- table_base = private->entries;
- jumpstack = (struct ipt_entry **)private->jumpstack[cpu];
- /* Switch to alternate jumpstack if we're being invoked via TEE.
- * TEE issues XT_CONTINUE verdict on original skb so we must not
- * clobber the jumpstack.
- *
- * For recursion via REJECT or SYNPROXY the stack will be clobbered
- * but it is no problem since absolute verdict is issued by these.
- */
- if (static_key_false(&xt_tee_enabled))
- jumpstack += private->stacksize * __this_cpu_read(nf_skb_duplicated);
- e = get_entry(table_base, private->hook_entry[hook]);
- pr_debug("Entering %s(hook %u), UF %p\n",
- table->name, hook,
- get_entry(table_base, private->underflow[hook]));
- do {
- const struct xt_entry_target *t;
- const struct xt_entry_match *ematch;
- struct xt_counters *counter;
- IP_NF_ASSERT(e);
- if (!ip_packet_match(ip, indev, outdev,
- &e->ip, acpar.fragoff)) {
- no_match:
- e = ipt_next_entry(e);
- continue;
- }
- xt_ematch_foreach(ematch, e) {
- acpar.match = ematch->u.kernel.match;
- acpar.matchinfo = ematch->data;
- if (!acpar.match->match(skb, &acpar))
- goto no_match;
- }
- counter = xt_get_this_cpu_counter(&e->counters);
- ADD_COUNTER(*counter, skb->len, 1);
- t = ipt_get_target(e);
- IP_NF_ASSERT(t->u.kernel.target);
- #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE)
- /* The packet is traced: log it */
- if (unlikely(skb->nf_trace))
- trace_packet(state->net, skb, hook, state->in,
- state->out, table->name, private, e);
- #endif
- /* Standard target? */
- if (!t->u.kernel.target->target) {
- int v;
- v = ((struct xt_standard_target *)t)->verdict;
- if (v < 0) {
- /* Pop from stack? */
- if (v != XT_RETURN) {
- verdict = (unsigned int)(-v) - 1;
- break;
- }
- if (stackidx == 0) {
- e = get_entry(table_base,
- private->underflow[hook]);
- pr_debug("Underflow (this is normal) "
- "to %p\n", e);
- } else {
- e = jumpstack[--stackidx];
- pr_debug("Pulled %p out from pos %u\n",
- e, stackidx);
- e = ipt_next_entry(e);
- }
- continue;
- }
- if (table_base + v != ipt_next_entry(e) &&
- !(e->ip.flags & IPT_F_GOTO)) {
- if (unlikely(stackidx >= private->stacksize)) {
- verdict = NF_DROP;
- break;
- }
- jumpstack[stackidx++] = e;
- pr_debug("Pushed %p into pos %u\n",
- e, stackidx - 1);
- }
- e = get_entry(table_base, v);
- continue;
- }
- acpar.target = t->u.kernel.target;
- acpar.targinfo = t->data;
- verdict = t->u.kernel.target->target(skb, &acpar);
- /* Target might have changed stuff. */
- ip = ip_hdr(skb);
- if (verdict == XT_CONTINUE)
- e = ipt_next_entry(e);
- else
- /* Verdict */
- break;
- } while (!acpar.hotdrop);
- pr_debug("Exiting %s; sp at %u\n", __func__, stackidx);
- xt_write_recseq_end(addend);
- local_bh_enable();
- #ifdef DEBUG_ALLOW_ALL
- return NF_ACCEPT;
- #else
- if (acpar.hotdrop)
- return NF_DROP;
- else return verdict;
- #endif
- }
- /* Figures out from what hook each rule can be called: returns 0 if
- there are loops. Puts hook bitmask in comefrom. */
- static int
- mark_source_chains(const struct xt_table_info *newinfo,
- unsigned int valid_hooks, void *entry0,
- unsigned int *offsets)
- {
- unsigned int hook;
- /* No recursion; use packet counter to save back ptrs (reset
- to 0 as we leave), and comefrom to save source hook bitmask */
- for (hook = 0; hook < NF_INET_NUMHOOKS; hook++) {
- unsigned int pos = newinfo->hook_entry[hook];
- struct ipt_entry *e = (struct ipt_entry *)(entry0 + pos);
- if (!(valid_hooks & (1 << hook)))
- continue;
- /* Set initial back pointer. */
- e->counters.pcnt = pos;
- for (;;) {
- const struct xt_standard_target *t
- = (void *)ipt_get_target_c(e);
- int visited = e->comefrom & (1 << hook);
- if (e->comefrom & (1 << NF_INET_NUMHOOKS)) {
- pr_err("iptables: loop hook %u pos %u %08X.\n",
- hook, pos, e->comefrom);
- return 0;
- }
- e->comefrom |= ((1 << hook) | (1 << NF_INET_NUMHOOKS));
- /* Unconditional return/END. */
- if ((unconditional(e) &&
- (strcmp(t->target.u.user.name,
- XT_STANDARD_TARGET) == 0) &&
- t->verdict < 0) || visited) {
- unsigned int oldpos, size;
- if ((strcmp(t->target.u.user.name,
- XT_STANDARD_TARGET) == 0) &&
- t->verdict < -NF_MAX_VERDICT - 1) {
- duprintf("mark_source_chains: bad "
- "negative verdict (%i)\n",
- t->verdict);
- return 0;
- }
- /* Return: backtrack through the last
- big jump. */
- do {
- e->comefrom ^= (1<<NF_INET_NUMHOOKS);
- #ifdef DEBUG_IP_FIREWALL_USER
- if (e->comefrom
- & (1 << NF_INET_NUMHOOKS)) {
- duprintf("Back unset "
- "on hook %u "
- "rule %u\n",
- hook, pos);
- }
- #endif
- oldpos = pos;
- pos = e->counters.pcnt;
- e->counters.pcnt = 0;
- /* We're at the start. */
- if (pos == oldpos)
- goto next;
- e = (struct ipt_entry *)
- (entry0 + pos);
- } while (oldpos == pos + e->next_offset);
- /* Move along one */
- size = e->next_offset;
- e = (struct ipt_entry *)
- (entry0 + pos + size);
- if (pos + size >= newinfo->size)
- return 0;
- e->counters.pcnt = pos;
- pos += size;
- } else {
- int newpos = t->verdict;
- if (strcmp(t->target.u.user.name,
- XT_STANDARD_TARGET) == 0 &&
- newpos >= 0) {
- if (newpos > newinfo->size -
- sizeof(struct ipt_entry)) {
- duprintf("mark_source_chains: "
- "bad verdict (%i)\n",
- newpos);
- return 0;
- }
- /* This a jump; chase it. */
- duprintf("Jump rule %u -> %u\n",
- pos, newpos);
- if (!xt_find_jump_offset(offsets, newpos,
- newinfo->number))
- return 0;
- e = (struct ipt_entry *)
- (entry0 + newpos);
- } else {
- /* ... this is a fallthru */
- newpos = pos + e->next_offset;
- if (newpos >= newinfo->size)
- return 0;
- }
- e = (struct ipt_entry *)
- (entry0 + newpos);
- e->counters.pcnt = pos;
- pos = newpos;
- }
- }
- next:
- duprintf("Finished chain %u\n", hook);
- }
- return 1;
- }
- 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;
- 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;
- int ret;
- par->match = m->u.kernel.match;
- par->matchinfo = m->data;
- ret = xt_check_match(par, m->u.match_size - sizeof(*m),
- ip->proto, ip->invflags & IPT_INV_PROTO);
- if (ret < 0) {
- duprintf("check failed for `%s'.\n", par->match->name);
- return ret;
- }
- return 0;
- }
- static int
- find_check_match(struct xt_entry_match *m, struct xt_mtchk_param *par)
- {
- struct xt_match *match;
- int ret;
- match = xt_request_find_match(NFPROTO_IPV4, m->u.user.name,
- m->u.user.revision);
- if (IS_ERR(match)) {
- duprintf("find_check_match: `%s' not found\n", m->u.user.name);
- 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,
- };
- int ret;
- ret = xt_check_target(&par, t->u.target_size - sizeof(*t),
- e->ip.proto, e->ip.invflags & IPT_INV_PROTO);
- if (ret < 0) {
- duprintf("check failed for `%s'.\n",
- t->u.kernel.target->name);
- return ret;
- }
- return 0;
- }
- 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)) {
- duprintf("find_check_entry: `%s' not found\n", t->u.user.name);
- 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) {
- duprintf("Bad offset %p\n", e);
- return -EINVAL;
- }
- if (e->next_offset
- < sizeof(struct ipt_entry) + sizeof(struct xt_entry_target)) {
- duprintf("checking: element %p size %u\n",
- e, e->next_offset);
- 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)) {
- pr_debug("Underflows must be unconditional and "
- "use the STANDARD target with "
- "ACCEPT/DROP\n");
- 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;
- }
- duprintf("translate_table: size %u\n", newinfo->size);
- 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) {
- duprintf("translate_table: %u not %u entries\n",
- i, repl->num_entries);
- goto out_free;
- }
- /* Check hooks all assigned */
- for (i = 0; i < NF_INET_NUMHOOKS; i++) {
- /* Only hooks which are valid */
- if (!(repl->valid_hooks & (1 << i)))
- continue;
- if (newinfo->hook_entry[i] == 0xFFFFFFFF) {
- duprintf("Invalid hook entry %u %u\n",
- i, repl->hook_entry[i]);
- goto out_free;
- }
- if (newinfo->underflow[i] == 0xFFFFFFFF) {
- duprintf("Invalid underflow %u %u\n",
- i, repl->underflow[i]);
- 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 */
- }
- }
- }
- 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;
- if (copy_to_user(userptr, loc_cpu_entry, total_size) != 0) {
- ret = -EFAULT;
- goto free_counters;
- }
- /* 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 = (struct ipt_entry *)(loc_cpu_entry + off);
- 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 (copy_to_user(userptr + off + i
- + offsetof(struct xt_entry_match,
- u.user.name),
- m->u.kernel.match->name,
- strlen(m->u.kernel.match->name)+1)
- != 0) {
- ret = -EFAULT;
- goto free_counters;
- }
- }
- t = ipt_get_target_c(e);
- if (copy_to_user(userptr + off + e->target_offset
- + offsetof(struct xt_entry_target,
- u.user.name),
- t->u.kernel.target->name,
- strlen(t->u.kernel.target->name)+1) != 0) {
- ret = -EFAULT;
- goto free_counters;
- }
- }
- free_counters:
- vfree(counters);
- return ret;
- }
- #ifdef CONFIG_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;
- xt_compat_init_offsets(AF_INET, info->number);
- 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, int compat)
- {
- char name[XT_TABLE_MAXNAMELEN];
- struct xt_table *t;
- int ret;
- if (*len != sizeof(struct ipt_getinfo)) {
- duprintf("length %u != %zu\n", *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_COMPAT
- if (compat)
- xt_compat_lock(AF_INET);
- #endif
- t = try_then_request_module(xt_find_table_lock(net, AF_INET, name),
- "iptable_%s", name);
- if (!IS_ERR_OR_NULL(t)) {
- struct ipt_getinfo info;
- const struct xt_table_info *private = t->private;
- #ifdef CONFIG_COMPAT
- struct xt_table_info tmp;
- if (compat) {
- 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 = t ? PTR_ERR(t) : -ENOENT;
- #ifdef CONFIG_COMPAT
- if (compat)
- 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)) {
- duprintf("get_entries: %u < %zu\n", *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) {
- duprintf("get_entries: %u != %zu\n",
- *len, sizeof(get) + get.size);
- return -EINVAL;
- }
- get.name[sizeof(get.name) - 1] = '\0';
- t = xt_find_table_lock(net, AF_INET, get.name);
- if (!IS_ERR_OR_NULL(t)) {
- const struct xt_table_info *private = t->private;
- duprintf("t->private->number = %u\n", private->number);
- if (get.size == private->size)
- ret = copy_entries_to_user(private->size,
- t, uptr->entrytable);
- else {
- duprintf("get_entries: I've got %u not %u!\n",
- private->size, get.size);
- ret = -EAGAIN;
- }
- module_put(t->me);
- xt_table_unlock(t);
- } else
- ret = t ? PTR_ERR(t) : -ENOENT;
- 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;
- ret = 0;
- counters = vzalloc(num_counters * sizeof(struct xt_counters));
- if (!counters) {
- ret = -ENOMEM;
- goto out;
- }
- t = try_then_request_module(xt_find_table_lock(net, AF_INET, name),
- "iptable_%s", name);
- if (IS_ERR_OR_NULL(t)) {
- ret = t ? PTR_ERR(t) : -ENOENT;
- goto free_newinfo_counters_untrans;
- }
- /* You lied! */
- if (valid_hooks != t->valid_hooks) {
- duprintf("Valid hook crap: %08X vs %08X\n",
- 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 */
- duprintf("do_replace: oldnum=%u, initnum=%u, newnum=%u\n",
- oldinfo->number, oldinfo->initial_entries, newinfo->number);
- 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);
- /* Get the old counters, and synchronize with replace */
- get_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);
- xt_table_unlock(t);
- return ret;
- 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, const void __user *user, 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_user(&tmp, user, 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_user(loc_cpu_entry, user + 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;
- duprintf("Translated table\n");
- 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, const void __user *user,
- unsigned int len, int compat)
- {
- 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_from_user(user, len, &tmp, compat);
- if (IS_ERR(paddc))
- return PTR_ERR(paddc);
- t = xt_find_table_lock(net, AF_INET, tmp.name);
- if (IS_ERR_OR_NULL(t)) {
- ret = t ? PTR_ERR(t) : -ENOENT;
- 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_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[0];
- };
- 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 = (struct compat_ipt_entry __user *)*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)) {
- duprintf("compat_check_calc_match: `%s' not found\n",
- m->u.user.name);
- 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;
- duprintf("check_compat_entry_size_and_hooks %p\n", e);
- 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) {
- duprintf("Bad offset %p, limit = %p\n", e, limit);
- return -EINVAL;
- }
- if (e->next_offset < sizeof(struct compat_ipt_entry) +
- sizeof(struct compat_xt_entry_target)) {
- duprintf("checking: element %p size %u\n",
- e, e->next_offset);
- 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)) {
- duprintf("check_compat_entry_size_and_hooks: `%s' not found\n",
- t->u.user.name);
- 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 xt_target *target;
- struct ipt_entry *de;
- unsigned int origsize;
- int h;
- struct xt_entry_match *ematch;
- origsize = *size;
- de = (struct ipt_entry *)*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);
- target = t->u.kernel.target;
- 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;
- duprintf("translate_compat_table: size %u\n", info->size);
- j = 0;
- xt_compat_lock(AF_INET);
- xt_compat_init_offsets(AF_INET, compatr->num_entries);
- /* 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) {
- duprintf("translate_compat_table: %u not %u entries\n",
- j, compatr->num_entries);
- goto out_unlock;
- }
- ret = -ENOMEM;
- newinfo = xt_alloc_table_info(size);
- if (!newinfo)
- goto out_unlock;
- 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, void __user *user, 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_user(&tmp, user, sizeof(tmp)) != 0)
- return -EFAULT;
- /* overflow check */
- if (tmp.size >= INT_MAX / num_possible_cpus())
- return -ENOMEM;
- 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_user(loc_cpu_entry, user + 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;
- duprintf("compat_do_replace: Translated table\n");
- 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;
- }
- static int
- compat_do_ipt_set_ctl(struct sock *sk, int cmd, void __user *user,
- 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:
- ret = compat_do_replace(sock_net(sk), user, len);
- break;
- case IPT_SO_SET_ADD_COUNTERS:
- ret = do_add_counters(sock_net(sk), user, len, 1);
- break;
- default:
- duprintf("do_ipt_set_ctl: unknown request %i\n", cmd);
- ret = -EINVAL;
- }
- return ret;
- }
- struct compat_ipt_get_entries {
- char name[XT_TABLE_MAXNAMELEN];
- compat_uint_t size;
- struct compat_ipt_entry entrytable[0];
- };
- 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)) {
- duprintf("compat_get_entries: %u < %zu\n", *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) {
- duprintf("compat_get_entries: %u != %zu\n",
- *len, sizeof(get) + 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_OR_NULL(t)) {
- const struct xt_table_info *private = t->private;
- struct xt_table_info info;
- duprintf("t->private->number = %u\n", private->number);
- 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) {
- duprintf("compat_get_entries: I've got %u not %u!\n",
- private->size, get.size);
- ret = -EAGAIN;
- }
- xt_compat_flush_offsets(AF_INET);
- module_put(t->me);
- xt_table_unlock(t);
- } else
- ret = t ? PTR_ERR(t) : -ENOENT;
- xt_compat_unlock(AF_INET);
- return ret;
- }
- static int do_ipt_get_ctl(struct sock *, int, void __user *, int *);
- static int
- compat_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, 1);
- break;
- case IPT_SO_GET_ENTRIES:
- ret = compat_get_entries(sock_net(sk), user, len);
- break;
- default:
- ret = do_ipt_get_ctl(sk, cmd, user, len);
- }
- return ret;
- }
- #endif
- static int
- do_ipt_set_ctl(struct sock *sk, int cmd, void __user *user, 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:
- ret = do_replace(sock_net(sk), user, len);
- break;
- case IPT_SO_SET_ADD_COUNTERS:
- ret = do_add_counters(sock_net(sk), user, len, 0);
- break;
- default:
- duprintf("do_ipt_set_ctl: unknown request %i\n", cmd);
- 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, 0);
- break;
- case IPT_SO_GET_ENTRIES:
- 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:
- duprintf("do_ipt_get_ctl: unknown request %i\n", cmd);
- ret = -EINVAL;
- }
- return ret;
- }
- struct xt_table *ipt_register_table(struct net *net,
- const struct xt_table *table,
- const struct ipt_replace *repl)
- {
- int ret;
- 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) {
- ret = -ENOMEM;
- goto out;
- }
- 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)
- goto out_free;
- new_table = xt_register_table(net, table, &bootstrap, newinfo);
- if (IS_ERR(new_table)) {
- ret = PTR_ERR(new_table);
- goto out_free;
- }
- return new_table;
- out_free:
- xt_free_table_info(newinfo);
- out:
- return ERR_PTR(ret);
- }
- 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);
- }
- /* Returns 1 if the type and code is matched by the range, 0 otherwise */
- static inline bool
- icmp_type_code_match(u_int8_t test_type, u_int8_t min_code, u_int8_t max_code,
- u_int8_t type, u_int8_t code,
- bool invert)
- {
- return ((test_type == 0xFF) ||
- (type == test_type && code >= min_code && code <= max_code))
- ^ invert;
- }
- static bool
- icmp_match(const struct sk_buff *skb, struct xt_action_param *par)
- {
- const struct icmphdr *ic;
- struct icmphdr _icmph;
- const struct ipt_icmp *icmpinfo = par->matchinfo;
- /* Must not be a fragment. */
- if (par->fragoff != 0)
- return false;
- ic = skb_header_pointer(skb, par->thoff, sizeof(_icmph), &_icmph);
- if (ic == NULL) {
- /* We've been asked to examine this packet, and we
- * can't. Hence, no choice but to drop.
- */
- duprintf("Dropping evil ICMP tinygram.\n");
- par->hotdrop = true;
- return false;
- }
- return icmp_type_code_match(icmpinfo->type,
- icmpinfo->code[0],
- icmpinfo->code[1],
- ic->type, ic->code,
- !!(icmpinfo->invflags&IPT_ICMP_INV));
- }
- static int icmp_checkentry(const struct xt_mtchk_param *par)
- {
- const struct ipt_icmp *icmpinfo = par->matchinfo;
- /* Must specify no unknown invflags */
- return (icmpinfo->invflags & ~IPT_ICMP_INV) ? -EINVAL : 0;
- }
- static struct xt_target ipt_builtin_tg[] __read_mostly = {
- {
- .name = XT_STANDARD_TARGET,
- .targetsize = sizeof(int),
- .family = NFPROTO_IPV4,
- #ifdef CONFIG_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,
- #ifdef CONFIG_COMPAT
- .compat_set = compat_do_ipt_set_ctl,
- #endif
- .get_optmin = IPT_BASE_CTL,
- .get_optmax = IPT_SO_GET_MAX+1,
- .get = do_ipt_get_ctl,
- #ifdef CONFIG_COMPAT
- .compat_get = compat_do_ipt_get_ctl,
- #endif
- .owner = THIS_MODULE,
- };
- static struct xt_match ipt_builtin_mt[] __read_mostly = {
- {
- .name = "icmp",
- .match = icmp_match,
- .matchsize = sizeof(struct ipt_icmp),
- .checkentry = icmp_checkentry,
- .proto = IPPROTO_ICMP,
- .family = NFPROTO_IPV4,
- .me = 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;
- ret = xt_register_matches(ipt_builtin_mt, ARRAY_SIZE(ipt_builtin_mt));
- if (ret < 0)
- goto err4;
- /* Register setsockopt */
- ret = nf_register_sockopt(&ipt_sockopts);
- if (ret < 0)
- goto err5;
- pr_info("(C) 2000-2006 Netfilter Core Team\n");
- return 0;
- err5:
- xt_unregister_matches(ipt_builtin_mt, ARRAY_SIZE(ipt_builtin_mt));
- 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_matches(ipt_builtin_mt, ARRAY_SIZE(ipt_builtin_mt));
- 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);
- EXPORT_SYMBOL(ipt_do_table);
- module_init(ip_tables_init);
- module_exit(ip_tables_fini);
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