/* * 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_ip *ip) { static const struct ipt_ip uncond; return memcmp(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 (s->target_offset == sizeof(struct ipt_entry) && strcmp(t->target.u.kernel.target->name, XT_STANDARD_TARGET) == 0 && t->verdict < 0 && unconditional(&s->ip)) { /* 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(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 void *table_base; const struct ipt_entry *root; const char *hookname, *chainname, *comment; const struct ipt_entry *iter; unsigned int rulenum = 0; struct net *net = dev_net(in ? in : out); table_base = private->entries[smp_processor_id()]; root = get_entry(table_base, 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_packet(net, AF_INET, hook, skb, in, out, &trace_loginfo, "TRACE: %s:%s:%s:%u ", tablename, chainname, comment, rulenum); } #endif static inline __pure 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, unsigned int hook, const struct net_device *in, const struct net_device *out, struct xt_table *table) { 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 *stackptr, origptr, cpu; const struct xt_table_info *private; struct xt_action_param acpar; unsigned int addend; /* Initialization */ ip = ip_hdr(skb); indev = in ? in->name : nulldevname; outdev = out ? 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.in = in; acpar.out = 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(); table_base = private->entries[cpu]; jumpstack = (struct ipt_entry **)private->jumpstack[cpu]; stackptr = per_cpu_ptr(private->stackptr, cpu); origptr = *stackptr; e = get_entry(table_base, private->hook_entry[hook]); pr_debug("Entering %s(hook %u); sp at %u (UF %p)\n", table->name, hook, origptr, get_entry(table_base, private->underflow[hook])); do { const struct xt_entry_target *t; const struct xt_entry_match *ematch; 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; } ADD_COUNTER(e->counters, 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(skb, hook, in, 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 (*stackptr <= origptr) { e = get_entry(table_base, private->underflow[hook]); pr_debug("Underflow (this is normal) " "to %p\n", e); } else { e = jumpstack[--*stackptr]; pr_debug("Pulled %p out from pos %u\n", e, *stackptr); e = ipt_next_entry(e); } continue; } if (table_base + v != ipt_next_entry(e) && !(e->ip.flags & IPT_F_GOTO)) { if (*stackptr >= private->stacksize) { verdict = NF_DROP; break; } jumpstack[(*stackptr)++] = e; pr_debug("Pushed %p into pos %u\n", e, *stackptr - 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; resetting sp from %u to %u\n", __func__, *stackptr, origptr); *stackptr = origptr; 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 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 ((e->target_offset == sizeof(struct ipt_entry) && (strcmp(t->target.u.user.name, XT_STANDARD_TARGET) == 0) && t->verdict < 0 && unconditional(&e->ip)) || 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); 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); } else { /* ... this is a fallthru */ newpos = pos + e->next_offset; } 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_entry(const struct ipt_entry *e, const char *name) { const struct xt_entry_target *t; if (!ip_checkentry(&e->ip)) { duprintf("ip check failed %p %s.\n", e, name); return -EINVAL; } if (e->target_offset + sizeof(struct xt_entry_target) > e->next_offset) return -EINVAL; t = ipt_get_target_c(e); if (e->target_offset + t->u.target_size > e->next_offset) return -EINVAL; return 0; } 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_entry_target *t; struct xt_target *target; int ret; unsigned int j; struct xt_mtchk_param mtpar; struct xt_entry_match *ematch; ret = check_entry(e, name); if (ret) return ret; j = 0; 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); } return ret; } static bool check_underflow(const struct ipt_entry *e) { const struct xt_entry_target *t; unsigned int verdict; if (!unconditional(&e->ip)) 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; if ((unsigned long)e % __alignof__(struct ipt_entry) != 0 || (unsigned char *)e + sizeof(struct ipt_entry) >= 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; } /* 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_err("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); } /* 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 ipt_entry *iter; 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); 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) return ret; ++i; if (strcmp(ipt_get_target(iter)->u.user.name, XT_ERROR_TARGET) == 0) ++newinfo->stacksize; } if (i != repl->num_entries) { duprintf("translate_table: %u not %u entries\n", i, repl->num_entries); return -EINVAL; } /* 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]); return -EINVAL; } if (newinfo->underflow[i] == 0xFFFFFFFF) { duprintf("Invalid underflow %u %u\n", i, repl->underflow[i]); return -EINVAL; } } if (!mark_source_chains(newinfo, repl->valid_hooks, entry0)) return -ELOOP; /* 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); 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; } /* And one copy for every other CPU */ for_each_possible_cpu(i) { if (newinfo->entries[i] && newinfo->entries[i] != entry0) memcpy(newinfo->entries[i], entry0, newinfo->size); } 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[cpu], t->size) { u64 bcnt, pcnt; unsigned int start; do { start = read_seqcount_begin(s); bcnt = iter->counters.bcnt; pcnt = iter->counters.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); /* choose the copy that is on our node/cpu, ... * This choice is lazy (because current thread is * allowed to migrate to another cpu) */ loc_cpu_entry = private->entries[raw_smp_processor_id()]; 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; 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[raw_smp_processor_id()]; 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; } 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; void *loc_cpu_old_entry; 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 */ loc_cpu_old_entry = oldinfo->entries[raw_smp_processor_id()]; xt_entry_foreach(iter, loc_cpu_old_entry, 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) ret = -EFAULT; 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; tmp.name[sizeof(tmp.name)-1] = 0; newinfo = xt_alloc_table_info(tmp.size); if (!newinfo) return -ENOMEM; /* choose the copy that is on our node/cpu */ loc_cpu_entry = newinfo->entries[raw_smp_processor_id()]; 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, curcpu; struct xt_counters_info tmp; struct xt_counters *paddc; unsigned int num_counters; const char *name; int size; void *ptmp; struct xt_table *t; const struct xt_table_info *private; int ret = 0; void *loc_cpu_entry; struct ipt_entry *iter; unsigned int addend; #ifdef CONFIG_COMPAT struct compat_xt_counters_info compat_tmp; if (compat) { ptmp = &compat_tmp; size = sizeof(struct compat_xt_counters_info); } else #endif { ptmp = &tmp; size = sizeof(struct xt_counters_info); } if (copy_from_user(ptmp, user, size) != 0) return -EFAULT; #ifdef CONFIG_COMPAT if (compat) { num_counters = compat_tmp.num_counters; name = compat_tmp.name; } else #endif { num_counters = tmp.num_counters; name = tmp.name; } if (len != size + num_counters * sizeof(struct xt_counters)) return -EINVAL; paddc = vmalloc(len - size); if (!paddc) return -ENOMEM; if (copy_from_user(paddc, user + size, len - size) != 0) { ret = -EFAULT; goto free; } t = xt_find_table_lock(net, AF_INET, name); if (IS_ERR_OR_NULL(t)) { ret = t ? PTR_ERR(t) : -ENOENT; goto free; } local_bh_disable(); private = t->private; if (private->number != num_counters) { ret = -EINVAL; goto unlock_up_free; } i = 0; /* Choose the copy that is on our node */ curcpu = smp_processor_id(); loc_cpu_entry = private->entries[curcpu]; addend = xt_write_recseq_begin(); xt_entry_foreach(iter, loc_cpu_entry, private->size) { ADD_COUNTER(iter->counters, 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 char *name, const struct ipt_ip *ip, unsigned int hookmask, 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, const unsigned int *hook_entries, const unsigned int *underflows, const char *name) { struct xt_entry_match *ematch; struct xt_entry_target *t; struct xt_target *target; unsigned int entry_offset; unsigned int j; int ret, off, h; 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) { 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; } /* For purposes of check_entry casting the compat entry is fine */ ret = check_entry((struct ipt_entry *)e, name); 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, name, &e->ip, e->comefrom, &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; /* Check hooks & underflows */ for (h = 0; h < NF_INET_NUMHOOKS; h++) { if ((unsigned char *)e - base == hook_entries[h]) newinfo->hook_entry[h] = hook_entries[h]; if ((unsigned char *)e - base == underflows[h]) newinfo->underflow[h] = underflows[h]; } /* Clear counters and comefrom */ memset(&e->counters, 0, sizeof(e->counters)); e->comefrom = 0; 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 int compat_copy_entry_from_user(struct compat_ipt_entry *e, void **dstptr, unsigned int *size, const char *name, 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 ret, h; struct xt_entry_match *ematch; ret = 0; 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) { ret = xt_compat_match_from_user(ematch, dstptr, size); if (ret != 0) return ret; } 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; } return ret; } static int compat_check_entry(struct ipt_entry *e, struct net *net, const char *name) { struct xt_entry_match *ematch; struct xt_mtchk_param mtpar; unsigned int j; int ret = 0; j = 0; 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 = check_match(ematch, &mtpar); if (ret != 0) goto cleanup_matches; ++j; } ret = check_target(e, net, name); if (ret) goto cleanup_matches; return 0; cleanup_matches: xt_ematch_foreach(ematch, e) { if (j-- == 0) break; cleanup_match(ematch, net); } return ret; } static int translate_compat_table(struct net *net, const char *name, unsigned int valid_hooks, struct xt_table_info **pinfo, void **pentry0, unsigned int total_size, unsigned int number, unsigned int *hook_entries, unsigned int *underflows) { unsigned int i, j; struct xt_table_info *newinfo, *info; void *pos, *entry0, *entry1; struct compat_ipt_entry *iter0; struct ipt_entry *iter1; unsigned int size; int ret; info = *pinfo; entry0 = *pentry0; size = total_size; info->number = number; /* Init all hooks to impossible value. */ for (i = 0; i < NF_INET_NUMHOOKS; i++) { info->hook_entry[i] = 0xFFFFFFFF; info->underflow[i] = 0xFFFFFFFF; } duprintf("translate_compat_table: size %u\n", info->size); j = 0; xt_compat_lock(AF_INET); xt_compat_init_offsets(AF_INET, number); /* Walk through entries, checking offsets. */ xt_entry_foreach(iter0, entry0, total_size) { ret = check_compat_entry_size_and_hooks(iter0, info, &size, entry0, entry0 + total_size, hook_entries, underflows, name); if (ret != 0) goto out_unlock; ++j; } ret = -EINVAL; if (j != number) { duprintf("translate_compat_table: %u not %u entries\n", j, number); goto out_unlock; } /* Check hooks all assigned */ for (i = 0; i < NF_INET_NUMHOOKS; i++) { /* Only hooks which are valid */ if (!(valid_hooks & (1 << i))) continue; if (info->hook_entry[i] == 0xFFFFFFFF) { duprintf("Invalid hook entry %u %u\n", i, hook_entries[i]); goto out_unlock; } if (info->underflow[i] == 0xFFFFFFFF) { duprintf("Invalid underflow %u %u\n", i, underflows[i]); goto out_unlock; } } ret = -ENOMEM; newinfo = xt_alloc_table_info(size); if (!newinfo) goto out_unlock; newinfo->number = number; for (i = 0; i < NF_INET_NUMHOOKS; i++) { newinfo->hook_entry[i] = info->hook_entry[i]; newinfo->underflow[i] = info->underflow[i]; } entry1 = newinfo->entries[raw_smp_processor_id()]; pos = entry1; size = total_size; xt_entry_foreach(iter0, entry0, total_size) { ret = compat_copy_entry_from_user(iter0, &pos, &size, name, newinfo, entry1); if (ret != 0) break; } xt_compat_flush_offsets(AF_INET); xt_compat_unlock(AF_INET); if (ret) goto free_newinfo; ret = -ELOOP; if (!mark_source_chains(newinfo, valid_hooks, entry1)) goto free_newinfo; i = 0; xt_entry_foreach(iter1, entry1, newinfo->size) { ret = compat_check_entry(iter1, net, name); if (ret != 0) break; ++i; if (strcmp(ipt_get_target(iter1)->u.user.name, XT_ERROR_TARGET) == 0) ++newinfo->stacksize; } if (ret) { /* * The first i matches need cleanup_entry (calls ->destroy) * because they had called ->check already. The other j-i * entries need only release. */ int skip = i; j -= i; xt_entry_foreach(iter0, entry0, newinfo->size) { if (skip-- > 0) continue; if (j-- == 0) break; compat_release_entry(iter0); } xt_entry_foreach(iter1, entry1, newinfo->size) { if (i-- == 0) break; cleanup_entry(iter1, net); } xt_free_table_info(newinfo); return ret; } /* And one copy for every other CPU */ for_each_possible_cpu(i) if (newinfo->entries[i] && newinfo->entries[i] != entry1) memcpy(newinfo->entries[i], entry1, newinfo->size); *pinfo = newinfo; *pentry0 = entry1; xt_free_table_info(info); return 0; free_newinfo: xt_free_table_info(newinfo); out: xt_entry_foreach(iter0, entry0, total_size) { if (j-- == 0) break; compat_release_entry(iter0); } return ret; out_unlock: xt_compat_flush_offsets(AF_INET); xt_compat_unlock(AF_INET); goto out; } 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; tmp.name[sizeof(tmp.name)-1] = 0; newinfo = xt_alloc_table_info(tmp.size); if (!newinfo) return -ENOMEM; /* choose the copy that is on our node/cpu */ loc_cpu_entry = newinfo->entries[raw_smp_processor_id()]; if (copy_from_user(loc_cpu_entry, user + sizeof(tmp), tmp.size) != 0) { ret = -EFAULT; goto free_newinfo; } ret = translate_compat_table(net, tmp.name, tmp.valid_hooks, &newinfo, &loc_cpu_entry, tmp.size, tmp.num_entries, tmp.hook_entry, tmp.underflow); 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; const void *loc_cpu_entry; unsigned int i = 0; struct ipt_entry *iter; counters = alloc_counters(table); if (IS_ERR(counters)) return PTR_ERR(counters); /* choose the copy that is on our node/cpu, ... * This choice is lazy (because current thread is * allowed to migrate to another cpu) */ loc_cpu_entry = private->entries[raw_smp_processor_id()]; pos = userptr; size = total_size; xt_entry_foreach(iter, loc_cpu_entry, 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; } 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; } /* choose the copy on our node/cpu, but dont care about preemption */ loc_cpu_entry = newinfo->entries[raw_smp_processor_id()]; 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[raw_smp_processor_id()]; 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, }, }; 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);