| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * 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> |
| */ |
| #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 <linux/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"); |
| MODULE_ALIAS("ipt_icmp"); |
| |
| 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; |
| |
| if (NF_INVF(ipinfo, IPT_INV_SRCIP, |
| (ip->saddr & ipinfo->smsk.s_addr) != ipinfo->src.s_addr) || |
| NF_INVF(ipinfo, IPT_INV_DSTIP, |
| (ip->daddr & ipinfo->dmsk.s_addr) != ipinfo->dst.s_addr)) |
| return false; |
| |
| ret = ifname_compare_aligned(indev, ipinfo->iniface, ipinfo->iniface_mask); |
| |
| if (NF_INVF(ipinfo, IPT_INV_VIA_IN, ret != 0)) |
| return false; |
| |
| ret = ifname_compare_aligned(outdev, ipinfo->outiface, ipinfo->outiface_mask); |
| |
| if (NF_INVF(ipinfo, IPT_INV_VIA_OUT, ret != 0)) |
| return false; |
| |
| /* Check specific protocol */ |
| if (ipinfo->proto && |
| NF_INVF(ipinfo, IPT_INV_PROTO, ip->protocol != ipinfo->proto)) |
| return false; |
| |
| /* If we have a fragment rule but the packet is not a fragment |
| * then we return zero */ |
| if (NF_INVF(ipinfo, IPT_INV_FRAG, |
| (ipinfo->flags & IPT_F_FRAG) && !isfrag)) |
| return false; |
| |
| return true; |
| } |
| |
| static bool |
| ip_checkentry(const struct ipt_ip *ip) |
| { |
| if (ip->flags & ~IPT_F_MASK) |
| return false; |
| if (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; |
| } |
| |
| /* 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 const struct nf_loginfo trace_loginfo = { |
| .type = NF_LOG_TYPE_LOG, |
| .u = { |
| .log = { |
| .level = 4, |
| .logflags = NF_LOG_DEFAULT_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.state = state; |
| |
| WARN_ON(!(table->valid_hooks & (1 << hook))); |
| local_bh_disable(); |
| addend = xt_write_recseq_begin(); |
| private = READ_ONCE(table->private); /* Address dependency. */ |
| cpu = smp_processor_id(); |
| 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]); |
| |
| do { |
| const struct xt_entry_target *t; |
| const struct xt_entry_match *ematch; |
| struct xt_counters *counter; |
| |
| WARN_ON(!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_c(e); |
| WARN_ON(!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]); |
| } else { |
| e = jumpstack[--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; |
| } |
| |
| 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); |
| if (verdict == XT_CONTINUE) { |
| /* Target might have changed stuff. */ |
| ip = ip_hdr(skb); |
| e = ipt_next_entry(e); |
| } else { |
| /* Verdict */ |
| break; |
| } |
| } while (!acpar.hotdrop); |
| |
| xt_write_recseq_end(addend); |
| local_bh_enable(); |
| |
| if (acpar.hotdrop) |
| return NF_DROP; |
| else return verdict; |
| } |
| |
| /* 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 = 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)) |
| 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; |
| |
| /* Return: backtrack through the last |
| big jump. */ |
| do { |
| e->comefrom ^= (1<<NF_INET_NUMHOOKS); |
| oldpos = pos; |
| pos = e->counters.pcnt; |
| e->counters.pcnt = 0; |
| |
| /* We're at the start. */ |
| if (pos == oldpos) |
| goto next; |
| |
| e = entry0 + pos; |
| } while (oldpos == pos + e->next_offset); |
| |
| /* Move along one */ |
| size = e->next_offset; |
| e = 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) { |
| /* This a jump; chase it. */ |
| if (!xt_find_jump_offset(offsets, newpos, |
| newinfo->number)) |
| return 0; |
| } else { |
| /* ... this is a fallthru */ |
| newpos = pos + e->next_offset; |
| if (newpos >= newinfo->size) |
| return 0; |
| } |
| e = entry0 + newpos; |
| e->counters.pcnt = pos; |
| pos = newpos; |
| } |
| } |
| next: ; |
| } |
| 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; |
| |
| par->match = m->u.kernel.match; |
| par->matchinfo = m->data; |
| |
| return xt_check_match(par, m->u.match_size - sizeof(*m), |
| ip->proto, ip->invflags & IPT_INV_PROTO); |
| } |
| |
| 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)) |
| 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; |
| |
| ret = 0; |
| 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 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, 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)) { |
| 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); |
| } |
| |
| /* 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. |
| */ |
| 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_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 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; |
| |
| 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_pre_exit); |
| EXPORT_SYMBOL(ipt_unregister_table_exit); |
| EXPORT_SYMBOL(ipt_do_table); |
| module_init(ip_tables_init); |
| module_exit(ip_tables_fini); |