| /* |
| * Packet matching code. |
| * |
| * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling |
| * Copyright (C) 2000-2002 Netfilter core team <coreteam@netfilter.org> |
| * |
| * 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. |
| * |
| * 19 Jan 2002 Harald Welte <laforge@gnumonks.org> |
| * - increase module usage count as soon as we have rules inside |
| * a table |
| * 06 Jun 2002 Andras Kis-Szabo <kisza@sch.bme.hu> |
| * - new extension header parser code |
| */ |
| #include <linux/config.h> |
| #include <linux/skbuff.h> |
| #include <linux/kmod.h> |
| #include <linux/vmalloc.h> |
| #include <linux/netdevice.h> |
| #include <linux/module.h> |
| #include <linux/tcp.h> |
| #include <linux/udp.h> |
| #include <linux/icmpv6.h> |
| #include <net/ip.h> |
| #include <net/ipv6.h> |
| #include <asm/uaccess.h> |
| #include <asm/semaphore.h> |
| #include <linux/proc_fs.h> |
| |
| #include <linux/netfilter_ipv6/ip6_tables.h> |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); |
| MODULE_DESCRIPTION("IPv6 packet filter"); |
| |
| #define IPV6_HDR_LEN (sizeof(struct ipv6hdr)) |
| #define IPV6_OPTHDR_LEN (sizeof(struct ipv6_opt_hdr)) |
| |
| /*#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...) printk(format , ## args) |
| #else |
| #define dprintf(format, args...) |
| #endif |
| |
| #ifdef DEBUG_IP_FIREWALL_USER |
| #define duprintf(format, args...) printk(format , ## args) |
| #else |
| #define duprintf(format, args...) |
| #endif |
| |
| #ifdef CONFIG_NETFILTER_DEBUG |
| #define IP_NF_ASSERT(x) \ |
| do { \ |
| if (!(x)) \ |
| printk("IP_NF_ASSERT: %s:%s:%u\n", \ |
| __FUNCTION__, __FILE__, __LINE__); \ |
| } while(0) |
| #else |
| #define IP_NF_ASSERT(x) |
| #endif |
| #define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1)) |
| |
| static DECLARE_MUTEX(ip6t_mutex); |
| |
| /* Must have mutex */ |
| #define ASSERT_READ_LOCK(x) IP_NF_ASSERT(down_trylock(&ip6t_mutex) != 0) |
| #define ASSERT_WRITE_LOCK(x) IP_NF_ASSERT(down_trylock(&ip6t_mutex) != 0) |
| #include <linux/netfilter_ipv4/lockhelp.h> |
| #include <linux/netfilter_ipv4/listhelp.h> |
| |
| #if 0 |
| /* All the better to debug you with... */ |
| #define static |
| #define inline |
| #endif |
| |
| /* Locking is simple: we assume at worst case there will be one packet |
| in user context and one from bottom halves (or soft irq if Alexey's |
| softnet patch was applied). |
| |
| We keep a set of rules for each CPU, so we can avoid write-locking |
| them; doing a readlock_bh() stops packets coming through if we're |
| in user context. |
| |
| To be cache friendly on SMP, we arrange them like so: |
| [ n-entries ] |
| ... cache-align padding ... |
| [ n-entries ] |
| |
| Hence the start of any table is given by get_table() below. */ |
| |
| /* The table itself */ |
| struct ip6t_table_info |
| { |
| /* Size per table */ |
| unsigned int size; |
| /* Number of entries: FIXME. --RR */ |
| unsigned int number; |
| /* Initial number of entries. Needed for module usage count */ |
| unsigned int initial_entries; |
| |
| /* Entry points and underflows */ |
| unsigned int hook_entry[NF_IP6_NUMHOOKS]; |
| unsigned int underflow[NF_IP6_NUMHOOKS]; |
| |
| /* ip6t_entry tables: one per CPU */ |
| char entries[0] ____cacheline_aligned; |
| }; |
| |
| static LIST_HEAD(ip6t_target); |
| static LIST_HEAD(ip6t_match); |
| static LIST_HEAD(ip6t_tables); |
| #define ADD_COUNTER(c,b,p) do { (c).bcnt += (b); (c).pcnt += (p); } while(0) |
| |
| #ifdef CONFIG_SMP |
| #define TABLE_OFFSET(t,p) (SMP_ALIGN((t)->size)*(p)) |
| #else |
| #define TABLE_OFFSET(t,p) 0 |
| #endif |
| |
| #if 0 |
| #define down(x) do { printk("DOWN:%u:" #x "\n", __LINE__); down(x); } while(0) |
| #define down_interruptible(x) ({ int __r; printk("DOWNi:%u:" #x "\n", __LINE__); __r = down_interruptible(x); if (__r != 0) printk("ABORT-DOWNi:%u\n", __LINE__); __r; }) |
| #define up(x) do { printk("UP:%u:" #x "\n", __LINE__); up(x); } while(0) |
| #endif |
| |
| static int ip6_masked_addrcmp(struct in6_addr addr1, struct in6_addr mask, |
| struct in6_addr addr2) |
| { |
| int i; |
| for( i = 0; i < 16; i++){ |
| if((addr1.s6_addr[i] & mask.s6_addr[i]) != |
| (addr2.s6_addr[i] & mask.s6_addr[i])) |
| return 1; |
| } |
| return 0; |
| } |
| |
| /* Check for an extension */ |
| int |
| ip6t_ext_hdr(u8 nexthdr) |
| { |
| return ( (nexthdr == IPPROTO_HOPOPTS) || |
| (nexthdr == IPPROTO_ROUTING) || |
| (nexthdr == IPPROTO_FRAGMENT) || |
| (nexthdr == IPPROTO_ESP) || |
| (nexthdr == IPPROTO_AH) || |
| (nexthdr == IPPROTO_NONE) || |
| (nexthdr == IPPROTO_DSTOPTS) ); |
| } |
| |
| /* Returns whether matches rule or not. */ |
| static inline int |
| ip6_packet_match(const struct sk_buff *skb, |
| const char *indev, |
| const char *outdev, |
| const struct ip6t_ip6 *ip6info, |
| unsigned int *protoff, |
| int *fragoff) |
| { |
| size_t i; |
| unsigned long ret; |
| const struct ipv6hdr *ipv6 = skb->nh.ipv6h; |
| |
| #define FWINV(bool,invflg) ((bool) ^ !!(ip6info->invflags & invflg)) |
| |
| if (FWINV(ip6_masked_addrcmp(ipv6->saddr,ip6info->smsk,ip6info->src), |
| IP6T_INV_SRCIP) |
| || FWINV(ip6_masked_addrcmp(ipv6->daddr,ip6info->dmsk,ip6info->dst), |
| IP6T_INV_DSTIP)) { |
| dprintf("Source or dest mismatch.\n"); |
| /* |
| dprintf("SRC: %u. Mask: %u. Target: %u.%s\n", ip->saddr, |
| ipinfo->smsk.s_addr, ipinfo->src.s_addr, |
| ipinfo->invflags & IP6T_INV_SRCIP ? " (INV)" : ""); |
| dprintf("DST: %u. Mask: %u. Target: %u.%s\n", ip->daddr, |
| ipinfo->dmsk.s_addr, ipinfo->dst.s_addr, |
| ipinfo->invflags & IP6T_INV_DSTIP ? " (INV)" : "");*/ |
| return 0; |
| } |
| |
| /* Look for ifname matches; this should unroll nicely. */ |
| for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) { |
| ret |= (((const unsigned long *)indev)[i] |
| ^ ((const unsigned long *)ip6info->iniface)[i]) |
| & ((const unsigned long *)ip6info->iniface_mask)[i]; |
| } |
| |
| if (FWINV(ret != 0, IP6T_INV_VIA_IN)) { |
| dprintf("VIA in mismatch (%s vs %s).%s\n", |
| indev, ip6info->iniface, |
| ip6info->invflags&IP6T_INV_VIA_IN ?" (INV)":""); |
| return 0; |
| } |
| |
| for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) { |
| ret |= (((const unsigned long *)outdev)[i] |
| ^ ((const unsigned long *)ip6info->outiface)[i]) |
| & ((const unsigned long *)ip6info->outiface_mask)[i]; |
| } |
| |
| if (FWINV(ret != 0, IP6T_INV_VIA_OUT)) { |
| dprintf("VIA out mismatch (%s vs %s).%s\n", |
| outdev, ip6info->outiface, |
| ip6info->invflags&IP6T_INV_VIA_OUT ?" (INV)":""); |
| return 0; |
| } |
| |
| /* ... might want to do something with class and flowlabel here ... */ |
| |
| /* look for the desired protocol header */ |
| if((ip6info->flags & IP6T_F_PROTO)) { |
| u_int8_t currenthdr = ipv6->nexthdr; |
| struct ipv6_opt_hdr _hdr, *hp; |
| u_int16_t ptr; /* Header offset in skb */ |
| u_int16_t hdrlen; /* Header */ |
| u_int16_t _fragoff = 0, *fp = NULL; |
| |
| ptr = IPV6_HDR_LEN; |
| |
| while (ip6t_ext_hdr(currenthdr)) { |
| /* Is there enough space for the next ext header? */ |
| if (skb->len - ptr < IPV6_OPTHDR_LEN) |
| return 0; |
| |
| /* NONE or ESP: there isn't protocol part */ |
| /* If we want to count these packets in '-p all', |
| * we will change the return 0 to 1*/ |
| if ((currenthdr == IPPROTO_NONE) || |
| (currenthdr == IPPROTO_ESP)) |
| break; |
| |
| hp = skb_header_pointer(skb, ptr, sizeof(_hdr), &_hdr); |
| BUG_ON(hp == NULL); |
| |
| /* Size calculation */ |
| if (currenthdr == IPPROTO_FRAGMENT) { |
| fp = skb_header_pointer(skb, |
| ptr+offsetof(struct frag_hdr, |
| frag_off), |
| sizeof(_fragoff), |
| &_fragoff); |
| if (fp == NULL) |
| return 0; |
| |
| _fragoff = ntohs(*fp) & ~0x7; |
| hdrlen = 8; |
| } else if (currenthdr == IPPROTO_AH) |
| hdrlen = (hp->hdrlen+2)<<2; |
| else |
| hdrlen = ipv6_optlen(hp); |
| |
| currenthdr = hp->nexthdr; |
| ptr += hdrlen; |
| /* ptr is too large */ |
| if ( ptr > skb->len ) |
| return 0; |
| if (_fragoff) { |
| if (ip6t_ext_hdr(currenthdr)) |
| return 0; |
| break; |
| } |
| } |
| |
| *protoff = ptr; |
| *fragoff = _fragoff; |
| |
| /* currenthdr contains the protocol header */ |
| |
| dprintf("Packet protocol %hi ?= %s%hi.\n", |
| currenthdr, |
| ip6info->invflags & IP6T_INV_PROTO ? "!":"", |
| ip6info->proto); |
| |
| if (ip6info->proto == currenthdr) { |
| if(ip6info->invflags & IP6T_INV_PROTO) { |
| return 0; |
| } |
| return 1; |
| } |
| |
| /* We need match for the '-p all', too! */ |
| if ((ip6info->proto != 0) && |
| !(ip6info->invflags & IP6T_INV_PROTO)) |
| return 0; |
| } |
| return 1; |
| } |
| |
| /* should be ip6 safe */ |
| static inline int |
| ip6_checkentry(const struct ip6t_ip6 *ipv6) |
| { |
| if (ipv6->flags & ~IP6T_F_MASK) { |
| duprintf("Unknown flag bits set: %08X\n", |
| ipv6->flags & ~IP6T_F_MASK); |
| return 0; |
| } |
| if (ipv6->invflags & ~IP6T_INV_MASK) { |
| duprintf("Unknown invflag bits set: %08X\n", |
| ipv6->invflags & ~IP6T_INV_MASK); |
| return 0; |
| } |
| return 1; |
| } |
| |
| static unsigned int |
| ip6t_error(struct sk_buff **pskb, |
| const struct net_device *in, |
| const struct net_device *out, |
| unsigned int hooknum, |
| const void *targinfo, |
| void *userinfo) |
| { |
| if (net_ratelimit()) |
| printk("ip6_tables: error: `%s'\n", (char *)targinfo); |
| |
| return NF_DROP; |
| } |
| |
| static inline |
| int do_match(struct ip6t_entry_match *m, |
| const struct sk_buff *skb, |
| const struct net_device *in, |
| const struct net_device *out, |
| int offset, |
| unsigned int protoff, |
| int *hotdrop) |
| { |
| /* Stop iteration if it doesn't match */ |
| if (!m->u.kernel.match->match(skb, in, out, m->data, |
| offset, protoff, hotdrop)) |
| return 1; |
| else |
| return 0; |
| } |
| |
| static inline struct ip6t_entry * |
| get_entry(void *base, unsigned int offset) |
| { |
| return (struct ip6t_entry *)(base + offset); |
| } |
| |
| /* Returns one of the generic firewall policies, like NF_ACCEPT. */ |
| unsigned int |
| ip6t_do_table(struct sk_buff **pskb, |
| unsigned int hook, |
| const struct net_device *in, |
| const struct net_device *out, |
| struct ip6t_table *table, |
| void *userdata) |
| { |
| static const char nulldevname[IFNAMSIZ]; |
| int offset = 0; |
| unsigned int protoff = 0; |
| int hotdrop = 0; |
| /* Initializing verdict to NF_DROP keeps gcc happy. */ |
| unsigned int verdict = NF_DROP; |
| const char *indev, *outdev; |
| void *table_base; |
| struct ip6t_entry *e, *back; |
| |
| /* Initialization */ |
| 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. */ |
| |
| read_lock_bh(&table->lock); |
| IP_NF_ASSERT(table->valid_hooks & (1 << hook)); |
| table_base = (void *)table->private->entries |
| + TABLE_OFFSET(table->private, smp_processor_id()); |
| e = get_entry(table_base, table->private->hook_entry[hook]); |
| |
| #ifdef CONFIG_NETFILTER_DEBUG |
| /* Check noone else using our table */ |
| if (((struct ip6t_entry *)table_base)->comefrom != 0xdead57ac |
| && ((struct ip6t_entry *)table_base)->comefrom != 0xeeeeeeec) { |
| printk("ASSERT: CPU #%u, %s comefrom(%p) = %X\n", |
| smp_processor_id(), |
| table->name, |
| &((struct ip6t_entry *)table_base)->comefrom, |
| ((struct ip6t_entry *)table_base)->comefrom); |
| } |
| ((struct ip6t_entry *)table_base)->comefrom = 0x57acc001; |
| #endif |
| |
| /* For return from builtin chain */ |
| back = get_entry(table_base, table->private->underflow[hook]); |
| |
| do { |
| IP_NF_ASSERT(e); |
| IP_NF_ASSERT(back); |
| (*pskb)->nfcache |= e->nfcache; |
| if (ip6_packet_match(*pskb, indev, outdev, &e->ipv6, |
| &protoff, &offset)) { |
| struct ip6t_entry_target *t; |
| |
| if (IP6T_MATCH_ITERATE(e, do_match, |
| *pskb, in, out, |
| offset, protoff, &hotdrop) != 0) |
| goto no_match; |
| |
| ADD_COUNTER(e->counters, |
| ntohs((*pskb)->nh.ipv6h->payload_len) |
| + IPV6_HDR_LEN, |
| 1); |
| |
| t = ip6t_get_target(e); |
| IP_NF_ASSERT(t->u.kernel.target); |
| /* Standard target? */ |
| if (!t->u.kernel.target->target) { |
| int v; |
| |
| v = ((struct ip6t_standard_target *)t)->verdict; |
| if (v < 0) { |
| /* Pop from stack? */ |
| if (v != IP6T_RETURN) { |
| verdict = (unsigned)(-v) - 1; |
| break; |
| } |
| e = back; |
| back = get_entry(table_base, |
| back->comefrom); |
| continue; |
| } |
| if (table_base + v |
| != (void *)e + e->next_offset) { |
| /* Save old back ptr in next entry */ |
| struct ip6t_entry *next |
| = (void *)e + e->next_offset; |
| next->comefrom |
| = (void *)back - table_base; |
| /* set back pointer to next entry */ |
| back = next; |
| } |
| |
| e = get_entry(table_base, v); |
| } else { |
| /* Targets which reenter must return |
| abs. verdicts */ |
| #ifdef CONFIG_NETFILTER_DEBUG |
| ((struct ip6t_entry *)table_base)->comefrom |
| = 0xeeeeeeec; |
| #endif |
| verdict = t->u.kernel.target->target(pskb, |
| in, out, |
| hook, |
| t->data, |
| userdata); |
| |
| #ifdef CONFIG_NETFILTER_DEBUG |
| if (((struct ip6t_entry *)table_base)->comefrom |
| != 0xeeeeeeec |
| && verdict == IP6T_CONTINUE) { |
| printk("Target %s reentered!\n", |
| t->u.kernel.target->name); |
| verdict = NF_DROP; |
| } |
| ((struct ip6t_entry *)table_base)->comefrom |
| = 0x57acc001; |
| #endif |
| if (verdict == IP6T_CONTINUE) |
| e = (void *)e + e->next_offset; |
| else |
| /* Verdict */ |
| break; |
| } |
| } else { |
| |
| no_match: |
| e = (void *)e + e->next_offset; |
| } |
| } while (!hotdrop); |
| |
| #ifdef CONFIG_NETFILTER_DEBUG |
| ((struct ip6t_entry *)table_base)->comefrom = 0xdead57ac; |
| #endif |
| read_unlock_bh(&table->lock); |
| |
| #ifdef DEBUG_ALLOW_ALL |
| return NF_ACCEPT; |
| #else |
| if (hotdrop) |
| return NF_DROP; |
| else return verdict; |
| #endif |
| } |
| |
| /* If it succeeds, returns element and locks mutex */ |
| static inline void * |
| find_inlist_lock_noload(struct list_head *head, |
| const char *name, |
| int *error, |
| struct semaphore *mutex) |
| { |
| void *ret; |
| |
| #if 1 |
| duprintf("find_inlist: searching for `%s' in %s.\n", |
| name, head == &ip6t_target ? "ip6t_target" |
| : head == &ip6t_match ? "ip6t_match" |
| : head == &ip6t_tables ? "ip6t_tables" : "UNKNOWN"); |
| #endif |
| |
| *error = down_interruptible(mutex); |
| if (*error != 0) |
| return NULL; |
| |
| ret = list_named_find(head, name); |
| if (!ret) { |
| *error = -ENOENT; |
| up(mutex); |
| } |
| return ret; |
| } |
| |
| #ifndef CONFIG_KMOD |
| #define find_inlist_lock(h,n,p,e,m) find_inlist_lock_noload((h),(n),(e),(m)) |
| #else |
| static void * |
| find_inlist_lock(struct list_head *head, |
| const char *name, |
| const char *prefix, |
| int *error, |
| struct semaphore *mutex) |
| { |
| void *ret; |
| |
| ret = find_inlist_lock_noload(head, name, error, mutex); |
| if (!ret) { |
| duprintf("find_inlist: loading `%s%s'.\n", prefix, name); |
| request_module("%s%s", prefix, name); |
| ret = find_inlist_lock_noload(head, name, error, mutex); |
| } |
| |
| return ret; |
| } |
| #endif |
| |
| static inline struct ip6t_table * |
| ip6t_find_table_lock(const char *name, int *error, struct semaphore *mutex) |
| { |
| return find_inlist_lock(&ip6t_tables, name, "ip6table_", error, mutex); |
| } |
| |
| static inline struct ip6t_match * |
| find_match_lock(const char *name, int *error, struct semaphore *mutex) |
| { |
| return find_inlist_lock(&ip6t_match, name, "ip6t_", error, mutex); |
| } |
| |
| static struct ip6t_target * |
| ip6t_find_target_lock(const char *name, int *error, struct semaphore *mutex) |
| { |
| return find_inlist_lock(&ip6t_target, name, "ip6t_", error, mutex); |
| } |
| |
| /* All zeroes == unconditional rule. */ |
| static inline int |
| unconditional(const struct ip6t_ip6 *ipv6) |
| { |
| unsigned int i; |
| |
| for (i = 0; i < sizeof(*ipv6); i++) |
| if (((char *)ipv6)[i]) |
| break; |
| |
| return (i == sizeof(*ipv6)); |
| } |
| |
| /* 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(struct ip6t_table_info *newinfo, unsigned int valid_hooks) |
| { |
| 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_IP6_NUMHOOKS; hook++) { |
| unsigned int pos = newinfo->hook_entry[hook]; |
| struct ip6t_entry *e |
| = (struct ip6t_entry *)(newinfo->entries + pos); |
| |
| if (!(valid_hooks & (1 << hook))) |
| continue; |
| |
| /* Set initial back pointer. */ |
| e->counters.pcnt = pos; |
| |
| for (;;) { |
| struct ip6t_standard_target *t |
| = (void *)ip6t_get_target(e); |
| |
| if (e->comefrom & (1 << NF_IP6_NUMHOOKS)) { |
| printk("iptables: loop hook %u pos %u %08X.\n", |
| hook, pos, e->comefrom); |
| return 0; |
| } |
| e->comefrom |
| |= ((1 << hook) | (1 << NF_IP6_NUMHOOKS)); |
| |
| /* Unconditional return/END. */ |
| if (e->target_offset == sizeof(struct ip6t_entry) |
| && (strcmp(t->target.u.user.name, |
| IP6T_STANDARD_TARGET) == 0) |
| && t->verdict < 0 |
| && unconditional(&e->ipv6)) { |
| unsigned int oldpos, size; |
| |
| /* Return: backtrack through the last |
| big jump. */ |
| do { |
| e->comefrom ^= (1<<NF_IP6_NUMHOOKS); |
| #ifdef DEBUG_IP_FIREWALL_USER |
| if (e->comefrom |
| & (1 << NF_IP6_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 ip6t_entry *) |
| (newinfo->entries + pos); |
| } while (oldpos == pos + e->next_offset); |
| |
| /* Move along one */ |
| size = e->next_offset; |
| e = (struct ip6t_entry *) |
| (newinfo->entries + pos + size); |
| e->counters.pcnt = pos; |
| pos += size; |
| } else { |
| int newpos = t->verdict; |
| |
| if (strcmp(t->target.u.user.name, |
| IP6T_STANDARD_TARGET) == 0 |
| && newpos >= 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 ip6t_entry *) |
| (newinfo->entries + newpos); |
| e->counters.pcnt = pos; |
| pos = newpos; |
| } |
| } |
| next: |
| duprintf("Finished chain %u\n", hook); |
| } |
| return 1; |
| } |
| |
| static inline int |
| cleanup_match(struct ip6t_entry_match *m, unsigned int *i) |
| { |
| if (i && (*i)-- == 0) |
| return 1; |
| |
| if (m->u.kernel.match->destroy) |
| m->u.kernel.match->destroy(m->data, |
| m->u.match_size - sizeof(*m)); |
| module_put(m->u.kernel.match->me); |
| return 0; |
| } |
| |
| static inline int |
| standard_check(const struct ip6t_entry_target *t, |
| unsigned int max_offset) |
| { |
| struct ip6t_standard_target *targ = (void *)t; |
| |
| /* Check standard info. */ |
| if (t->u.target_size |
| != IP6T_ALIGN(sizeof(struct ip6t_standard_target))) { |
| duprintf("standard_check: target size %u != %u\n", |
| t->u.target_size, |
| IP6T_ALIGN(sizeof(struct ip6t_standard_target))); |
| return 0; |
| } |
| |
| if (targ->verdict >= 0 |
| && targ->verdict > max_offset - sizeof(struct ip6t_entry)) { |
| duprintf("ip6t_standard_check: bad verdict (%i)\n", |
| targ->verdict); |
| return 0; |
| } |
| |
| if (targ->verdict < -NF_MAX_VERDICT - 1) { |
| duprintf("ip6t_standard_check: bad negative verdict (%i)\n", |
| targ->verdict); |
| return 0; |
| } |
| return 1; |
| } |
| |
| static inline int |
| check_match(struct ip6t_entry_match *m, |
| const char *name, |
| const struct ip6t_ip6 *ipv6, |
| unsigned int hookmask, |
| unsigned int *i) |
| { |
| int ret; |
| struct ip6t_match *match; |
| |
| match = find_match_lock(m->u.user.name, &ret, &ip6t_mutex); |
| if (!match) { |
| // duprintf("check_match: `%s' not found\n", m->u.name); |
| return ret; |
| } |
| if (!try_module_get(match->me)) { |
| up(&ip6t_mutex); |
| return -ENOENT; |
| } |
| m->u.kernel.match = match; |
| up(&ip6t_mutex); |
| |
| if (m->u.kernel.match->checkentry |
| && !m->u.kernel.match->checkentry(name, ipv6, m->data, |
| m->u.match_size - sizeof(*m), |
| hookmask)) { |
| module_put(m->u.kernel.match->me); |
| duprintf("ip_tables: check failed for `%s'.\n", |
| m->u.kernel.match->name); |
| return -EINVAL; |
| } |
| |
| (*i)++; |
| return 0; |
| } |
| |
| static struct ip6t_target ip6t_standard_target; |
| |
| static inline int |
| check_entry(struct ip6t_entry *e, const char *name, unsigned int size, |
| unsigned int *i) |
| { |
| struct ip6t_entry_target *t; |
| struct ip6t_target *target; |
| int ret; |
| unsigned int j; |
| |
| if (!ip6_checkentry(&e->ipv6)) { |
| duprintf("ip_tables: ip check failed %p %s.\n", e, name); |
| return -EINVAL; |
| } |
| |
| j = 0; |
| ret = IP6T_MATCH_ITERATE(e, check_match, name, &e->ipv6, e->comefrom, &j); |
| if (ret != 0) |
| goto cleanup_matches; |
| |
| t = ip6t_get_target(e); |
| target = ip6t_find_target_lock(t->u.user.name, &ret, &ip6t_mutex); |
| if (!target) { |
| duprintf("check_entry: `%s' not found\n", t->u.user.name); |
| goto cleanup_matches; |
| } |
| if (!try_module_get(target->me)) { |
| up(&ip6t_mutex); |
| ret = -ENOENT; |
| goto cleanup_matches; |
| } |
| t->u.kernel.target = target; |
| up(&ip6t_mutex); |
| if (!t->u.kernel.target) { |
| ret = -EBUSY; |
| goto cleanup_matches; |
| } |
| if (t->u.kernel.target == &ip6t_standard_target) { |
| if (!standard_check(t, size)) { |
| ret = -EINVAL; |
| goto cleanup_matches; |
| } |
| } else if (t->u.kernel.target->checkentry |
| && !t->u.kernel.target->checkentry(name, e, t->data, |
| t->u.target_size |
| - sizeof(*t), |
| e->comefrom)) { |
| module_put(t->u.kernel.target->me); |
| duprintf("ip_tables: check failed for `%s'.\n", |
| t->u.kernel.target->name); |
| ret = -EINVAL; |
| goto cleanup_matches; |
| } |
| |
| (*i)++; |
| return 0; |
| |
| cleanup_matches: |
| IP6T_MATCH_ITERATE(e, cleanup_match, &j); |
| return ret; |
| } |
| |
| static inline int |
| check_entry_size_and_hooks(struct ip6t_entry *e, |
| struct ip6t_table_info *newinfo, |
| unsigned char *base, |
| unsigned char *limit, |
| const unsigned int *hook_entries, |
| const unsigned int *underflows, |
| unsigned int *i) |
| { |
| unsigned int h; |
| |
| if ((unsigned long)e % __alignof__(struct ip6t_entry) != 0 |
| || (unsigned char *)e + sizeof(struct ip6t_entry) >= limit) { |
| duprintf("Bad offset %p\n", e); |
| return -EINVAL; |
| } |
| |
| if (e->next_offset |
| < sizeof(struct ip6t_entry) + sizeof(struct ip6t_entry_target)) { |
| duprintf("checking: element %p size %u\n", |
| e, e->next_offset); |
| return -EINVAL; |
| } |
| |
| /* Check hooks & underflows */ |
| for (h = 0; h < NF_IP6_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]; |
| } |
| |
| /* FIXME: underflows must be unconditional, standard verdicts |
| < 0 (not IP6T_RETURN). --RR */ |
| |
| /* Clear counters and comefrom */ |
| e->counters = ((struct ip6t_counters) { 0, 0 }); |
| e->comefrom = 0; |
| |
| (*i)++; |
| return 0; |
| } |
| |
| static inline int |
| cleanup_entry(struct ip6t_entry *e, unsigned int *i) |
| { |
| struct ip6t_entry_target *t; |
| |
| if (i && (*i)-- == 0) |
| return 1; |
| |
| /* Cleanup all matches */ |
| IP6T_MATCH_ITERATE(e, cleanup_match, NULL); |
| t = ip6t_get_target(e); |
| if (t->u.kernel.target->destroy) |
| t->u.kernel.target->destroy(t->data, |
| t->u.target_size - sizeof(*t)); |
| module_put(t->u.kernel.target->me); |
| return 0; |
| } |
| |
| /* Checks and translates the user-supplied table segment (held in |
| newinfo) */ |
| static int |
| translate_table(const char *name, |
| unsigned int valid_hooks, |
| struct ip6t_table_info *newinfo, |
| unsigned int size, |
| unsigned int number, |
| const unsigned int *hook_entries, |
| const unsigned int *underflows) |
| { |
| unsigned int i; |
| int ret; |
| |
| newinfo->size = size; |
| newinfo->number = number; |
| |
| /* Init all hooks to impossible value. */ |
| for (i = 0; i < NF_IP6_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. */ |
| ret = IP6T_ENTRY_ITERATE(newinfo->entries, newinfo->size, |
| check_entry_size_and_hooks, |
| newinfo, |
| newinfo->entries, |
| newinfo->entries + size, |
| hook_entries, underflows, &i); |
| if (ret != 0) |
| return ret; |
| |
| if (i != number) { |
| duprintf("translate_table: %u not %u entries\n", |
| i, number); |
| return -EINVAL; |
| } |
| |
| /* Check hooks all assigned */ |
| for (i = 0; i < NF_IP6_NUMHOOKS; i++) { |
| /* Only hooks which are valid */ |
| if (!(valid_hooks & (1 << i))) |
| continue; |
| if (newinfo->hook_entry[i] == 0xFFFFFFFF) { |
| duprintf("Invalid hook entry %u %u\n", |
| i, hook_entries[i]); |
| return -EINVAL; |
| } |
| if (newinfo->underflow[i] == 0xFFFFFFFF) { |
| duprintf("Invalid underflow %u %u\n", |
| i, underflows[i]); |
| return -EINVAL; |
| } |
| } |
| |
| if (!mark_source_chains(newinfo, valid_hooks)) |
| return -ELOOP; |
| |
| /* Finally, each sanity check must pass */ |
| i = 0; |
| ret = IP6T_ENTRY_ITERATE(newinfo->entries, newinfo->size, |
| check_entry, name, size, &i); |
| |
| if (ret != 0) { |
| IP6T_ENTRY_ITERATE(newinfo->entries, newinfo->size, |
| cleanup_entry, &i); |
| return ret; |
| } |
| |
| /* And one copy for every other CPU */ |
| for (i = 1; i < num_possible_cpus(); i++) { |
| memcpy(newinfo->entries + SMP_ALIGN(newinfo->size)*i, |
| newinfo->entries, |
| SMP_ALIGN(newinfo->size)); |
| } |
| |
| return ret; |
| } |
| |
| static struct ip6t_table_info * |
| replace_table(struct ip6t_table *table, |
| unsigned int num_counters, |
| struct ip6t_table_info *newinfo, |
| int *error) |
| { |
| struct ip6t_table_info *oldinfo; |
| |
| #ifdef CONFIG_NETFILTER_DEBUG |
| { |
| struct ip6t_entry *table_base; |
| unsigned int i; |
| |
| for (i = 0; i < num_possible_cpus(); i++) { |
| table_base = |
| (void *)newinfo->entries |
| + TABLE_OFFSET(newinfo, i); |
| |
| table_base->comefrom = 0xdead57ac; |
| } |
| } |
| #endif |
| |
| /* Do the substitution. */ |
| write_lock_bh(&table->lock); |
| /* Check inside lock: is the old number correct? */ |
| if (num_counters != table->private->number) { |
| duprintf("num_counters != table->private->number (%u/%u)\n", |
| num_counters, table->private->number); |
| write_unlock_bh(&table->lock); |
| *error = -EAGAIN; |
| return NULL; |
| } |
| oldinfo = table->private; |
| table->private = newinfo; |
| newinfo->initial_entries = oldinfo->initial_entries; |
| write_unlock_bh(&table->lock); |
| |
| return oldinfo; |
| } |
| |
| /* Gets counters. */ |
| static inline int |
| add_entry_to_counter(const struct ip6t_entry *e, |
| struct ip6t_counters total[], |
| unsigned int *i) |
| { |
| ADD_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt); |
| |
| (*i)++; |
| return 0; |
| } |
| |
| static void |
| get_counters(const struct ip6t_table_info *t, |
| struct ip6t_counters counters[]) |
| { |
| unsigned int cpu; |
| unsigned int i; |
| |
| for (cpu = 0; cpu < num_possible_cpus(); cpu++) { |
| i = 0; |
| IP6T_ENTRY_ITERATE(t->entries + TABLE_OFFSET(t, cpu), |
| t->size, |
| add_entry_to_counter, |
| counters, |
| &i); |
| } |
| } |
| |
| static int |
| copy_entries_to_user(unsigned int total_size, |
| struct ip6t_table *table, |
| void __user *userptr) |
| { |
| unsigned int off, num, countersize; |
| struct ip6t_entry *e; |
| struct ip6t_counters *counters; |
| int ret = 0; |
| |
| /* We need atomic snapshot of counters: rest doesn't change |
| (other than comefrom, which userspace doesn't care |
| about). */ |
| countersize = sizeof(struct ip6t_counters) * table->private->number; |
| counters = vmalloc(countersize); |
| |
| if (counters == NULL) |
| return -ENOMEM; |
| |
| /* First, sum counters... */ |
| memset(counters, 0, countersize); |
| write_lock_bh(&table->lock); |
| get_counters(table->private, counters); |
| write_unlock_bh(&table->lock); |
| |
| /* ... then copy entire thing from CPU 0... */ |
| if (copy_to_user(userptr, table->private->entries, 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; |
| struct ip6t_entry_match *m; |
| struct ip6t_entry_target *t; |
| |
| e = (struct ip6t_entry *)(table->private->entries + off); |
| if (copy_to_user(userptr + off |
| + offsetof(struct ip6t_entry, counters), |
| &counters[num], |
| sizeof(counters[num])) != 0) { |
| ret = -EFAULT; |
| goto free_counters; |
| } |
| |
| for (i = sizeof(struct ip6t_entry); |
| i < e->target_offset; |
| i += m->u.match_size) { |
| m = (void *)e + i; |
| |
| if (copy_to_user(userptr + off + i |
| + offsetof(struct ip6t_entry_match, |
| u.user.name), |
| m->u.kernel.match->name, |
| strlen(m->u.kernel.match->name)+1) |
| != 0) { |
| ret = -EFAULT; |
| goto free_counters; |
| } |
| } |
| |
| t = ip6t_get_target(e); |
| if (copy_to_user(userptr + off + e->target_offset |
| + offsetof(struct ip6t_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; |
| } |
| |
| static int |
| get_entries(const struct ip6t_get_entries *entries, |
| struct ip6t_get_entries __user *uptr) |
| { |
| int ret; |
| struct ip6t_table *t; |
| |
| t = ip6t_find_table_lock(entries->name, &ret, &ip6t_mutex); |
| if (t) { |
| duprintf("t->private->number = %u\n", |
| t->private->number); |
| if (entries->size == t->private->size) |
| ret = copy_entries_to_user(t->private->size, |
| t, uptr->entrytable); |
| else { |
| duprintf("get_entries: I've got %u not %u!\n", |
| t->private->size, |
| entries->size); |
| ret = -EINVAL; |
| } |
| up(&ip6t_mutex); |
| } else |
| duprintf("get_entries: Can't find %s!\n", |
| entries->name); |
| |
| return ret; |
| } |
| |
| static int |
| do_replace(void __user *user, unsigned int len) |
| { |
| int ret; |
| struct ip6t_replace tmp; |
| struct ip6t_table *t; |
| struct ip6t_table_info *newinfo, *oldinfo; |
| struct ip6t_counters *counters; |
| |
| if (copy_from_user(&tmp, user, sizeof(tmp)) != 0) |
| return -EFAULT; |
| |
| /* Pedantry: prevent them from hitting BUG() in vmalloc.c --RR */ |
| if ((SMP_ALIGN(tmp.size) >> PAGE_SHIFT) + 2 > num_physpages) |
| return -ENOMEM; |
| |
| newinfo = vmalloc(sizeof(struct ip6t_table_info) |
| + SMP_ALIGN(tmp.size) * num_possible_cpus()); |
| if (!newinfo) |
| return -ENOMEM; |
| |
| if (copy_from_user(newinfo->entries, user + sizeof(tmp), |
| tmp.size) != 0) { |
| ret = -EFAULT; |
| goto free_newinfo; |
| } |
| |
| counters = vmalloc(tmp.num_counters * sizeof(struct ip6t_counters)); |
| if (!counters) { |
| ret = -ENOMEM; |
| goto free_newinfo; |
| } |
| memset(counters, 0, tmp.num_counters * sizeof(struct ip6t_counters)); |
| |
| ret = translate_table(tmp.name, tmp.valid_hooks, |
| newinfo, tmp.size, tmp.num_entries, |
| tmp.hook_entry, tmp.underflow); |
| if (ret != 0) |
| goto free_newinfo_counters; |
| |
| duprintf("ip_tables: Translated table\n"); |
| |
| t = ip6t_find_table_lock(tmp.name, &ret, &ip6t_mutex); |
| if (!t) |
| goto free_newinfo_counters_untrans; |
| |
| /* You lied! */ |
| if (tmp.valid_hooks != t->valid_hooks) { |
| duprintf("Valid hook crap: %08X vs %08X\n", |
| tmp.valid_hooks, t->valid_hooks); |
| ret = -EINVAL; |
| goto free_newinfo_counters_untrans_unlock; |
| } |
| |
| /* Get a reference in advance, we're not allowed fail later */ |
| if (!try_module_get(t->me)) { |
| ret = -EBUSY; |
| goto free_newinfo_counters_untrans_unlock; |
| } |
| |
| oldinfo = replace_table(t, tmp.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. */ |
| get_counters(oldinfo, counters); |
| /* Decrease module usage counts and free resource */ |
| IP6T_ENTRY_ITERATE(oldinfo->entries, oldinfo->size, cleanup_entry,NULL); |
| vfree(oldinfo); |
| /* Silent error: too late now. */ |
| if (copy_to_user(tmp.counters, counters, |
| sizeof(struct ip6t_counters) * tmp.num_counters) != 0) |
| ret = -EFAULT; |
| vfree(counters); |
| up(&ip6t_mutex); |
| return ret; |
| |
| put_module: |
| module_put(t->me); |
| free_newinfo_counters_untrans_unlock: |
| up(&ip6t_mutex); |
| free_newinfo_counters_untrans: |
| IP6T_ENTRY_ITERATE(newinfo->entries, newinfo->size, cleanup_entry,NULL); |
| free_newinfo_counters: |
| vfree(counters); |
| free_newinfo: |
| vfree(newinfo); |
| return ret; |
| } |
| |
| /* We're lazy, and add to the first CPU; overflow works its fey magic |
| * and everything is OK. */ |
| static inline int |
| add_counter_to_entry(struct ip6t_entry *e, |
| const struct ip6t_counters addme[], |
| unsigned int *i) |
| { |
| #if 0 |
| duprintf("add_counter: Entry %u %lu/%lu + %lu/%lu\n", |
| *i, |
| (long unsigned int)e->counters.pcnt, |
| (long unsigned int)e->counters.bcnt, |
| (long unsigned int)addme[*i].pcnt, |
| (long unsigned int)addme[*i].bcnt); |
| #endif |
| |
| ADD_COUNTER(e->counters, addme[*i].bcnt, addme[*i].pcnt); |
| |
| (*i)++; |
| return 0; |
| } |
| |
| static int |
| do_add_counters(void __user *user, unsigned int len) |
| { |
| unsigned int i; |
| struct ip6t_counters_info tmp, *paddc; |
| struct ip6t_table *t; |
| int ret; |
| |
| if (copy_from_user(&tmp, user, sizeof(tmp)) != 0) |
| return -EFAULT; |
| |
| if (len != sizeof(tmp) + tmp.num_counters*sizeof(struct ip6t_counters)) |
| return -EINVAL; |
| |
| paddc = vmalloc(len); |
| if (!paddc) |
| return -ENOMEM; |
| |
| if (copy_from_user(paddc, user, len) != 0) { |
| ret = -EFAULT; |
| goto free; |
| } |
| |
| t = ip6t_find_table_lock(tmp.name, &ret, &ip6t_mutex); |
| if (!t) |
| goto free; |
| |
| write_lock_bh(&t->lock); |
| if (t->private->number != paddc->num_counters) { |
| ret = -EINVAL; |
| goto unlock_up_free; |
| } |
| |
| i = 0; |
| IP6T_ENTRY_ITERATE(t->private->entries, |
| t->private->size, |
| add_counter_to_entry, |
| paddc->counters, |
| &i); |
| unlock_up_free: |
| write_unlock_bh(&t->lock); |
| up(&ip6t_mutex); |
| free: |
| vfree(paddc); |
| |
| return ret; |
| } |
| |
| static int |
| do_ip6t_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len) |
| { |
| int ret; |
| |
| if (!capable(CAP_NET_ADMIN)) |
| return -EPERM; |
| |
| switch (cmd) { |
| case IP6T_SO_SET_REPLACE: |
| ret = do_replace(user, len); |
| break; |
| |
| case IP6T_SO_SET_ADD_COUNTERS: |
| ret = do_add_counters(user, len); |
| break; |
| |
| default: |
| duprintf("do_ip6t_set_ctl: unknown request %i\n", cmd); |
| ret = -EINVAL; |
| } |
| |
| return ret; |
| } |
| |
| static int |
| do_ip6t_get_ctl(struct sock *sk, int cmd, void __user *user, int *len) |
| { |
| int ret; |
| |
| if (!capable(CAP_NET_ADMIN)) |
| return -EPERM; |
| |
| switch (cmd) { |
| case IP6T_SO_GET_INFO: { |
| char name[IP6T_TABLE_MAXNAMELEN]; |
| struct ip6t_table *t; |
| |
| if (*len != sizeof(struct ip6t_getinfo)) { |
| duprintf("length %u != %u\n", *len, |
| sizeof(struct ip6t_getinfo)); |
| ret = -EINVAL; |
| break; |
| } |
| |
| if (copy_from_user(name, user, sizeof(name)) != 0) { |
| ret = -EFAULT; |
| break; |
| } |
| name[IP6T_TABLE_MAXNAMELEN-1] = '\0'; |
| t = ip6t_find_table_lock(name, &ret, &ip6t_mutex); |
| if (t) { |
| struct ip6t_getinfo info; |
| |
| info.valid_hooks = t->valid_hooks; |
| memcpy(info.hook_entry, t->private->hook_entry, |
| sizeof(info.hook_entry)); |
| memcpy(info.underflow, t->private->underflow, |
| sizeof(info.underflow)); |
| info.num_entries = t->private->number; |
| info.size = t->private->size; |
| memcpy(info.name, name, sizeof(info.name)); |
| |
| if (copy_to_user(user, &info, *len) != 0) |
| ret = -EFAULT; |
| else |
| ret = 0; |
| |
| up(&ip6t_mutex); |
| } |
| } |
| break; |
| |
| case IP6T_SO_GET_ENTRIES: { |
| struct ip6t_get_entries get; |
| |
| if (*len < sizeof(get)) { |
| duprintf("get_entries: %u < %u\n", *len, sizeof(get)); |
| ret = -EINVAL; |
| } else if (copy_from_user(&get, user, sizeof(get)) != 0) { |
| ret = -EFAULT; |
| } else if (*len != sizeof(struct ip6t_get_entries) + get.size) { |
| duprintf("get_entries: %u != %u\n", *len, |
| sizeof(struct ip6t_get_entries) + get.size); |
| ret = -EINVAL; |
| } else |
| ret = get_entries(&get, user); |
| break; |
| } |
| |
| default: |
| duprintf("do_ip6t_get_ctl: unknown request %i\n", cmd); |
| ret = -EINVAL; |
| } |
| |
| return ret; |
| } |
| |
| /* Registration hooks for targets. */ |
| int |
| ip6t_register_target(struct ip6t_target *target) |
| { |
| int ret; |
| |
| ret = down_interruptible(&ip6t_mutex); |
| if (ret != 0) |
| return ret; |
| |
| if (!list_named_insert(&ip6t_target, target)) { |
| duprintf("ip6t_register_target: `%s' already in list!\n", |
| target->name); |
| ret = -EINVAL; |
| } |
| up(&ip6t_mutex); |
| return ret; |
| } |
| |
| void |
| ip6t_unregister_target(struct ip6t_target *target) |
| { |
| down(&ip6t_mutex); |
| LIST_DELETE(&ip6t_target, target); |
| up(&ip6t_mutex); |
| } |
| |
| int |
| ip6t_register_match(struct ip6t_match *match) |
| { |
| int ret; |
| |
| ret = down_interruptible(&ip6t_mutex); |
| if (ret != 0) |
| return ret; |
| |
| if (!list_named_insert(&ip6t_match, match)) { |
| duprintf("ip6t_register_match: `%s' already in list!\n", |
| match->name); |
| ret = -EINVAL; |
| } |
| up(&ip6t_mutex); |
| |
| return ret; |
| } |
| |
| void |
| ip6t_unregister_match(struct ip6t_match *match) |
| { |
| down(&ip6t_mutex); |
| LIST_DELETE(&ip6t_match, match); |
| up(&ip6t_mutex); |
| } |
| |
| int ip6t_register_table(struct ip6t_table *table, |
| const struct ip6t_replace *repl) |
| { |
| int ret; |
| struct ip6t_table_info *newinfo; |
| static struct ip6t_table_info bootstrap |
| = { 0, 0, 0, { 0 }, { 0 }, { } }; |
| |
| newinfo = vmalloc(sizeof(struct ip6t_table_info) |
| + SMP_ALIGN(repl->size) * num_possible_cpus()); |
| if (!newinfo) |
| return -ENOMEM; |
| |
| memcpy(newinfo->entries, repl->entries, repl->size); |
| |
| ret = translate_table(table->name, table->valid_hooks, |
| newinfo, repl->size, |
| repl->num_entries, |
| repl->hook_entry, |
| repl->underflow); |
| if (ret != 0) { |
| vfree(newinfo); |
| return ret; |
| } |
| |
| ret = down_interruptible(&ip6t_mutex); |
| if (ret != 0) { |
| vfree(newinfo); |
| return ret; |
| } |
| |
| /* Don't autoload: we'd eat our tail... */ |
| if (list_named_find(&ip6t_tables, table->name)) { |
| ret = -EEXIST; |
| goto free_unlock; |
| } |
| |
| /* Simplifies replace_table code. */ |
| table->private = &bootstrap; |
| if (!replace_table(table, 0, newinfo, &ret)) |
| goto free_unlock; |
| |
| duprintf("table->private->number = %u\n", |
| table->private->number); |
| |
| /* save number of initial entries */ |
| table->private->initial_entries = table->private->number; |
| |
| rwlock_init(&table->lock); |
| list_prepend(&ip6t_tables, table); |
| |
| unlock: |
| up(&ip6t_mutex); |
| return ret; |
| |
| free_unlock: |
| vfree(newinfo); |
| goto unlock; |
| } |
| |
| void ip6t_unregister_table(struct ip6t_table *table) |
| { |
| down(&ip6t_mutex); |
| LIST_DELETE(&ip6t_tables, table); |
| up(&ip6t_mutex); |
| |
| /* Decrease module usage counts and free resources */ |
| IP6T_ENTRY_ITERATE(table->private->entries, table->private->size, |
| cleanup_entry, NULL); |
| vfree(table->private); |
| } |
| |
| /* Returns 1 if the port is matched by the range, 0 otherwise */ |
| static inline int |
| port_match(u_int16_t min, u_int16_t max, u_int16_t port, int invert) |
| { |
| int ret; |
| |
| ret = (port >= min && port <= max) ^ invert; |
| return ret; |
| } |
| |
| static int |
| tcp_find_option(u_int8_t option, |
| const struct sk_buff *skb, |
| unsigned int tcpoff, |
| unsigned int optlen, |
| int invert, |
| int *hotdrop) |
| { |
| /* tcp.doff is only 4 bits, ie. max 15 * 4 bytes */ |
| u_int8_t _opt[60 - sizeof(struct tcphdr)], *op; |
| unsigned int i; |
| |
| duprintf("tcp_match: finding option\n"); |
| if (!optlen) |
| return invert; |
| /* If we don't have the whole header, drop packet. */ |
| op = skb_header_pointer(skb, tcpoff + sizeof(struct tcphdr), optlen, |
| _opt); |
| if (op == NULL) { |
| *hotdrop = 1; |
| return 0; |
| } |
| |
| for (i = 0; i < optlen; ) { |
| if (op[i] == option) return !invert; |
| if (op[i] < 2) i++; |
| else i += op[i+1]?:1; |
| } |
| |
| return invert; |
| } |
| |
| static int |
| tcp_match(const struct sk_buff *skb, |
| const struct net_device *in, |
| const struct net_device *out, |
| const void *matchinfo, |
| int offset, |
| unsigned int protoff, |
| int *hotdrop) |
| { |
| struct tcphdr _tcph, *th; |
| const struct ip6t_tcp *tcpinfo = matchinfo; |
| |
| if (offset) { |
| /* To quote Alan: |
| |
| Don't allow a fragment of TCP 8 bytes in. Nobody normal |
| causes this. Its a cracker trying to break in by doing a |
| flag overwrite to pass the direction checks. |
| */ |
| if (offset == 1) { |
| duprintf("Dropping evil TCP offset=1 frag.\n"); |
| *hotdrop = 1; |
| } |
| /* Must not be a fragment. */ |
| return 0; |
| } |
| |
| #define FWINVTCP(bool,invflg) ((bool) ^ !!(tcpinfo->invflags & invflg)) |
| |
| th = skb_header_pointer(skb, protoff, sizeof(_tcph), &_tcph); |
| if (th == NULL) { |
| /* We've been asked to examine this packet, and we |
| can't. Hence, no choice but to drop. */ |
| duprintf("Dropping evil TCP offset=0 tinygram.\n"); |
| *hotdrop = 1; |
| return 0; |
| } |
| |
| if (!port_match(tcpinfo->spts[0], tcpinfo->spts[1], |
| ntohs(th->source), |
| !!(tcpinfo->invflags & IP6T_TCP_INV_SRCPT))) |
| return 0; |
| if (!port_match(tcpinfo->dpts[0], tcpinfo->dpts[1], |
| ntohs(th->dest), |
| !!(tcpinfo->invflags & IP6T_TCP_INV_DSTPT))) |
| return 0; |
| if (!FWINVTCP((((unsigned char *)th)[13] & tcpinfo->flg_mask) |
| == tcpinfo->flg_cmp, |
| IP6T_TCP_INV_FLAGS)) |
| return 0; |
| if (tcpinfo->option) { |
| if (th->doff * 4 < sizeof(_tcph)) { |
| *hotdrop = 1; |
| return 0; |
| } |
| if (!tcp_find_option(tcpinfo->option, skb, protoff, |
| th->doff*4 - sizeof(*th), |
| tcpinfo->invflags & IP6T_TCP_INV_OPTION, |
| hotdrop)) |
| return 0; |
| } |
| return 1; |
| } |
| |
| /* Called when user tries to insert an entry of this type. */ |
| static int |
| tcp_checkentry(const char *tablename, |
| const struct ip6t_ip6 *ipv6, |
| void *matchinfo, |
| unsigned int matchsize, |
| unsigned int hook_mask) |
| { |
| const struct ip6t_tcp *tcpinfo = matchinfo; |
| |
| /* Must specify proto == TCP, and no unknown invflags */ |
| return ipv6->proto == IPPROTO_TCP |
| && !(ipv6->invflags & IP6T_INV_PROTO) |
| && matchsize == IP6T_ALIGN(sizeof(struct ip6t_tcp)) |
| && !(tcpinfo->invflags & ~IP6T_TCP_INV_MASK); |
| } |
| |
| static int |
| udp_match(const struct sk_buff *skb, |
| const struct net_device *in, |
| const struct net_device *out, |
| const void *matchinfo, |
| int offset, |
| unsigned int protoff, |
| int *hotdrop) |
| { |
| struct udphdr _udph, *uh; |
| const struct ip6t_udp *udpinfo = matchinfo; |
| |
| /* Must not be a fragment. */ |
| if (offset) |
| return 0; |
| |
| uh = skb_header_pointer(skb, protoff, sizeof(_udph), &_udph); |
| if (uh == NULL) { |
| /* We've been asked to examine this packet, and we |
| can't. Hence, no choice but to drop. */ |
| duprintf("Dropping evil UDP tinygram.\n"); |
| *hotdrop = 1; |
| return 0; |
| } |
| |
| return port_match(udpinfo->spts[0], udpinfo->spts[1], |
| ntohs(uh->source), |
| !!(udpinfo->invflags & IP6T_UDP_INV_SRCPT)) |
| && port_match(udpinfo->dpts[0], udpinfo->dpts[1], |
| ntohs(uh->dest), |
| !!(udpinfo->invflags & IP6T_UDP_INV_DSTPT)); |
| } |
| |
| /* Called when user tries to insert an entry of this type. */ |
| static int |
| udp_checkentry(const char *tablename, |
| const struct ip6t_ip6 *ipv6, |
| void *matchinfo, |
| unsigned int matchinfosize, |
| unsigned int hook_mask) |
| { |
| const struct ip6t_udp *udpinfo = matchinfo; |
| |
| /* Must specify proto == UDP, and no unknown invflags */ |
| if (ipv6->proto != IPPROTO_UDP || (ipv6->invflags & IP6T_INV_PROTO)) { |
| duprintf("ip6t_udp: Protocol %u != %u\n", ipv6->proto, |
| IPPROTO_UDP); |
| return 0; |
| } |
| if (matchinfosize != IP6T_ALIGN(sizeof(struct ip6t_udp))) { |
| duprintf("ip6t_udp: matchsize %u != %u\n", |
| matchinfosize, IP6T_ALIGN(sizeof(struct ip6t_udp))); |
| return 0; |
| } |
| if (udpinfo->invflags & ~IP6T_UDP_INV_MASK) { |
| duprintf("ip6t_udp: unknown flags %X\n", |
| udpinfo->invflags); |
| return 0; |
| } |
| |
| return 1; |
| } |
| |
| /* Returns 1 if the type and code is matched by the range, 0 otherwise */ |
| static inline int |
| icmp6_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, |
| int invert) |
| { |
| return (type == test_type && code >= min_code && code <= max_code) |
| ^ invert; |
| } |
| |
| static int |
| icmp6_match(const struct sk_buff *skb, |
| const struct net_device *in, |
| const struct net_device *out, |
| const void *matchinfo, |
| int offset, |
| unsigned int protoff, |
| int *hotdrop) |
| { |
| struct icmp6hdr _icmp, *ic; |
| const struct ip6t_icmp *icmpinfo = matchinfo; |
| |
| /* Must not be a fragment. */ |
| if (offset) |
| return 0; |
| |
| ic = skb_header_pointer(skb, protoff, sizeof(_icmp), &_icmp); |
| 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"); |
| *hotdrop = 1; |
| return 0; |
| } |
| |
| return icmp6_type_code_match(icmpinfo->type, |
| icmpinfo->code[0], |
| icmpinfo->code[1], |
| ic->icmp6_type, ic->icmp6_code, |
| !!(icmpinfo->invflags&IP6T_ICMP_INV)); |
| } |
| |
| /* Called when user tries to insert an entry of this type. */ |
| static int |
| icmp6_checkentry(const char *tablename, |
| const struct ip6t_ip6 *ipv6, |
| void *matchinfo, |
| unsigned int matchsize, |
| unsigned int hook_mask) |
| { |
| const struct ip6t_icmp *icmpinfo = matchinfo; |
| |
| /* Must specify proto == ICMP, and no unknown invflags */ |
| return ipv6->proto == IPPROTO_ICMPV6 |
| && !(ipv6->invflags & IP6T_INV_PROTO) |
| && matchsize == IP6T_ALIGN(sizeof(struct ip6t_icmp)) |
| && !(icmpinfo->invflags & ~IP6T_ICMP_INV); |
| } |
| |
| /* The built-in targets: standard (NULL) and error. */ |
| static struct ip6t_target ip6t_standard_target = { |
| .name = IP6T_STANDARD_TARGET, |
| }; |
| |
| static struct ip6t_target ip6t_error_target = { |
| .name = IP6T_ERROR_TARGET, |
| .target = ip6t_error, |
| }; |
| |
| static struct nf_sockopt_ops ip6t_sockopts = { |
| .pf = PF_INET6, |
| .set_optmin = IP6T_BASE_CTL, |
| .set_optmax = IP6T_SO_SET_MAX+1, |
| .set = do_ip6t_set_ctl, |
| .get_optmin = IP6T_BASE_CTL, |
| .get_optmax = IP6T_SO_GET_MAX+1, |
| .get = do_ip6t_get_ctl, |
| }; |
| |
| static struct ip6t_match tcp_matchstruct = { |
| .name = "tcp", |
| .match = &tcp_match, |
| .checkentry = &tcp_checkentry, |
| }; |
| |
| static struct ip6t_match udp_matchstruct = { |
| .name = "udp", |
| .match = &udp_match, |
| .checkentry = &udp_checkentry, |
| }; |
| |
| static struct ip6t_match icmp6_matchstruct = { |
| .name = "icmp6", |
| .match = &icmp6_match, |
| .checkentry = &icmp6_checkentry, |
| }; |
| |
| #ifdef CONFIG_PROC_FS |
| static inline int print_name(const char *i, |
| off_t start_offset, char *buffer, int length, |
| off_t *pos, unsigned int *count) |
| { |
| if ((*count)++ >= start_offset) { |
| unsigned int namelen; |
| |
| namelen = sprintf(buffer + *pos, "%s\n", |
| i + sizeof(struct list_head)); |
| if (*pos + namelen > length) { |
| /* Stop iterating */ |
| return 1; |
| } |
| *pos += namelen; |
| } |
| return 0; |
| } |
| |
| static inline int print_target(const struct ip6t_target *t, |
| off_t start_offset, char *buffer, int length, |
| off_t *pos, unsigned int *count) |
| { |
| if (t == &ip6t_standard_target || t == &ip6t_error_target) |
| return 0; |
| return print_name((char *)t, start_offset, buffer, length, pos, count); |
| } |
| |
| static int ip6t_get_tables(char *buffer, char **start, off_t offset, int length) |
| { |
| off_t pos = 0; |
| unsigned int count = 0; |
| |
| if (down_interruptible(&ip6t_mutex) != 0) |
| return 0; |
| |
| LIST_FIND(&ip6t_tables, print_name, char *, |
| offset, buffer, length, &pos, &count); |
| |
| up(&ip6t_mutex); |
| |
| /* `start' hack - see fs/proc/generic.c line ~105 */ |
| *start=(char *)((unsigned long)count-offset); |
| return pos; |
| } |
| |
| static int ip6t_get_targets(char *buffer, char **start, off_t offset, int length) |
| { |
| off_t pos = 0; |
| unsigned int count = 0; |
| |
| if (down_interruptible(&ip6t_mutex) != 0) |
| return 0; |
| |
| LIST_FIND(&ip6t_target, print_target, struct ip6t_target *, |
| offset, buffer, length, &pos, &count); |
| |
| up(&ip6t_mutex); |
| |
| *start = (char *)((unsigned long)count - offset); |
| return pos; |
| } |
| |
| static int ip6t_get_matches(char *buffer, char **start, off_t offset, int length) |
| { |
| off_t pos = 0; |
| unsigned int count = 0; |
| |
| if (down_interruptible(&ip6t_mutex) != 0) |
| return 0; |
| |
| LIST_FIND(&ip6t_match, print_name, char *, |
| offset, buffer, length, &pos, &count); |
| |
| up(&ip6t_mutex); |
| |
| *start = (char *)((unsigned long)count - offset); |
| return pos; |
| } |
| |
| static struct { char *name; get_info_t *get_info; } ip6t_proc_entry[] = |
| { { "ip6_tables_names", ip6t_get_tables }, |
| { "ip6_tables_targets", ip6t_get_targets }, |
| { "ip6_tables_matches", ip6t_get_matches }, |
| { NULL, NULL} }; |
| #endif /*CONFIG_PROC_FS*/ |
| |
| static int __init init(void) |
| { |
| int ret; |
| |
| /* Noone else will be downing sem now, so we won't sleep */ |
| down(&ip6t_mutex); |
| list_append(&ip6t_target, &ip6t_standard_target); |
| list_append(&ip6t_target, &ip6t_error_target); |
| list_append(&ip6t_match, &tcp_matchstruct); |
| list_append(&ip6t_match, &udp_matchstruct); |
| list_append(&ip6t_match, &icmp6_matchstruct); |
| up(&ip6t_mutex); |
| |
| /* Register setsockopt */ |
| ret = nf_register_sockopt(&ip6t_sockopts); |
| if (ret < 0) { |
| duprintf("Unable to register sockopts.\n"); |
| return ret; |
| } |
| |
| #ifdef CONFIG_PROC_FS |
| { |
| struct proc_dir_entry *proc; |
| int i; |
| |
| for (i = 0; ip6t_proc_entry[i].name; i++) { |
| proc = proc_net_create(ip6t_proc_entry[i].name, 0, |
| ip6t_proc_entry[i].get_info); |
| if (!proc) { |
| while (--i >= 0) |
| proc_net_remove(ip6t_proc_entry[i].name); |
| nf_unregister_sockopt(&ip6t_sockopts); |
| return -ENOMEM; |
| } |
| proc->owner = THIS_MODULE; |
| } |
| } |
| #endif |
| |
| printk("ip6_tables: (C) 2000-2002 Netfilter core team\n"); |
| return 0; |
| } |
| |
| static void __exit fini(void) |
| { |
| nf_unregister_sockopt(&ip6t_sockopts); |
| #ifdef CONFIG_PROC_FS |
| { |
| int i; |
| for (i = 0; ip6t_proc_entry[i].name; i++) |
| proc_net_remove(ip6t_proc_entry[i].name); |
| } |
| #endif |
| } |
| |
| EXPORT_SYMBOL(ip6t_register_table); |
| EXPORT_SYMBOL(ip6t_unregister_table); |
| EXPORT_SYMBOL(ip6t_do_table); |
| EXPORT_SYMBOL(ip6t_register_match); |
| EXPORT_SYMBOL(ip6t_unregister_match); |
| EXPORT_SYMBOL(ip6t_register_target); |
| EXPORT_SYMBOL(ip6t_unregister_target); |
| EXPORT_SYMBOL(ip6t_ext_hdr); |
| |
| module_init(init); |
| module_exit(fini); |