| /* |
| * Packet matching code for ARP packets. |
| * |
| * Based heavily, if not almost entirely, upon ip_tables.c framework. |
| * |
| * Some ARP specific bits are: |
| * |
| * Copyright (C) 2002 David S. Miller (davem@redhat.com) |
| * |
| */ |
| |
| #include <linux/config.h> |
| #include <linux/kernel.h> |
| #include <linux/skbuff.h> |
| #include <linux/netdevice.h> |
| #include <linux/if_arp.h> |
| #include <linux/kmod.h> |
| #include <linux/vmalloc.h> |
| #include <linux/proc_fs.h> |
| #include <linux/module.h> |
| #include <linux/init.h> |
| |
| #include <asm/uaccess.h> |
| #include <asm/semaphore.h> |
| |
| #include <linux/netfilter_arp/arp_tables.h> |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("David S. Miller <davem@redhat.com>"); |
| MODULE_DESCRIPTION("arptables core"); |
| |
| /*#define DEBUG_ARP_TABLES*/ |
| /*#define DEBUG_ARP_TABLES_USER*/ |
| |
| #ifdef DEBUG_ARP_TABLES |
| #define dprintf(format, args...) printk(format , ## args) |
| #else |
| #define dprintf(format, args...) |
| #endif |
| |
| #ifdef DEBUG_ARP_TABLES_USER |
| #define duprintf(format, args...) printk(format , ## args) |
| #else |
| #define duprintf(format, args...) |
| #endif |
| |
| #ifdef CONFIG_NETFILTER_DEBUG |
| #define ARP_NF_ASSERT(x) \ |
| do { \ |
| if (!(x)) \ |
| printk("ARP_NF_ASSERT: %s:%s:%u\n", \ |
| __FUNCTION__, __FILE__, __LINE__); \ |
| } while(0) |
| #else |
| #define ARP_NF_ASSERT(x) |
| #endif |
| #define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1)) |
| |
| static DECLARE_MUTEX(arpt_mutex); |
| |
| #define ASSERT_READ_LOCK(x) ARP_NF_ASSERT(down_trylock(&arpt_mutex) != 0) |
| #define ASSERT_WRITE_LOCK(x) ARP_NF_ASSERT(down_trylock(&arpt_mutex) != 0) |
| #include <linux/netfilter_ipv4/lockhelp.h> |
| #include <linux/netfilter_ipv4/listhelp.h> |
| |
| struct arpt_table_info { |
| unsigned int size; |
| unsigned int number; |
| unsigned int initial_entries; |
| unsigned int hook_entry[NF_ARP_NUMHOOKS]; |
| unsigned int underflow[NF_ARP_NUMHOOKS]; |
| char entries[0] __attribute__((aligned(SMP_CACHE_BYTES))); |
| }; |
| |
| static LIST_HEAD(arpt_target); |
| static LIST_HEAD(arpt_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 |
| |
| static inline int arp_devaddr_compare(const struct arpt_devaddr_info *ap, |
| char *hdr_addr, int len) |
| { |
| int i, ret; |
| |
| if (len > ARPT_DEV_ADDR_LEN_MAX) |
| len = ARPT_DEV_ADDR_LEN_MAX; |
| |
| ret = 0; |
| for (i = 0; i < len; i++) |
| ret |= (hdr_addr[i] ^ ap->addr[i]) & ap->mask[i]; |
| |
| return (ret != 0); |
| } |
| |
| /* Returns whether packet matches rule or not. */ |
| static inline int arp_packet_match(const struct arphdr *arphdr, |
| struct net_device *dev, |
| const char *indev, |
| const char *outdev, |
| const struct arpt_arp *arpinfo) |
| { |
| char *arpptr = (char *)(arphdr + 1); |
| char *src_devaddr, *tgt_devaddr; |
| u32 src_ipaddr, tgt_ipaddr; |
| int i, ret; |
| |
| #define FWINV(bool,invflg) ((bool) ^ !!(arpinfo->invflags & invflg)) |
| |
| if (FWINV((arphdr->ar_op & arpinfo->arpop_mask) != arpinfo->arpop, |
| ARPT_INV_ARPOP)) { |
| dprintf("ARP operation field mismatch.\n"); |
| dprintf("ar_op: %04x info->arpop: %04x info->arpop_mask: %04x\n", |
| arphdr->ar_op, arpinfo->arpop, arpinfo->arpop_mask); |
| return 0; |
| } |
| |
| if (FWINV((arphdr->ar_hrd & arpinfo->arhrd_mask) != arpinfo->arhrd, |
| ARPT_INV_ARPHRD)) { |
| dprintf("ARP hardware address format mismatch.\n"); |
| dprintf("ar_hrd: %04x info->arhrd: %04x info->arhrd_mask: %04x\n", |
| arphdr->ar_hrd, arpinfo->arhrd, arpinfo->arhrd_mask); |
| return 0; |
| } |
| |
| if (FWINV((arphdr->ar_pro & arpinfo->arpro_mask) != arpinfo->arpro, |
| ARPT_INV_ARPPRO)) { |
| dprintf("ARP protocol address format mismatch.\n"); |
| dprintf("ar_pro: %04x info->arpro: %04x info->arpro_mask: %04x\n", |
| arphdr->ar_pro, arpinfo->arpro, arpinfo->arpro_mask); |
| return 0; |
| } |
| |
| if (FWINV((arphdr->ar_hln & arpinfo->arhln_mask) != arpinfo->arhln, |
| ARPT_INV_ARPHLN)) { |
| dprintf("ARP hardware address length mismatch.\n"); |
| dprintf("ar_hln: %02x info->arhln: %02x info->arhln_mask: %02x\n", |
| arphdr->ar_hln, arpinfo->arhln, arpinfo->arhln_mask); |
| return 0; |
| } |
| |
| src_devaddr = arpptr; |
| arpptr += dev->addr_len; |
| memcpy(&src_ipaddr, arpptr, sizeof(u32)); |
| arpptr += sizeof(u32); |
| tgt_devaddr = arpptr; |
| arpptr += dev->addr_len; |
| memcpy(&tgt_ipaddr, arpptr, sizeof(u32)); |
| |
| if (FWINV(arp_devaddr_compare(&arpinfo->src_devaddr, src_devaddr, dev->addr_len), |
| ARPT_INV_SRCDEVADDR) || |
| FWINV(arp_devaddr_compare(&arpinfo->tgt_devaddr, tgt_devaddr, dev->addr_len), |
| ARPT_INV_TGTDEVADDR)) { |
| dprintf("Source or target device address mismatch.\n"); |
| |
| return 0; |
| } |
| |
| if (FWINV((src_ipaddr & arpinfo->smsk.s_addr) != arpinfo->src.s_addr, |
| ARPT_INV_SRCIP) || |
| FWINV(((tgt_ipaddr & arpinfo->tmsk.s_addr) != arpinfo->tgt.s_addr), |
| ARPT_INV_TGTIP)) { |
| dprintf("Source or target IP address mismatch.\n"); |
| |
| dprintf("SRC: %u.%u.%u.%u. Mask: %u.%u.%u.%u. Target: %u.%u.%u.%u.%s\n", |
| NIPQUAD(src_ipaddr), |
| NIPQUAD(arpinfo->smsk.s_addr), |
| NIPQUAD(arpinfo->src.s_addr), |
| arpinfo->invflags & ARPT_INV_SRCIP ? " (INV)" : ""); |
| dprintf("TGT: %u.%u.%u.%u Mask: %u.%u.%u.%u Target: %u.%u.%u.%u.%s\n", |
| NIPQUAD(tgt_ipaddr), |
| NIPQUAD(arpinfo->tmsk.s_addr), |
| NIPQUAD(arpinfo->tgt.s_addr), |
| arpinfo->invflags & ARPT_INV_TGTIP ? " (INV)" : ""); |
| return 0; |
| } |
| |
| /* Look for ifname matches. */ |
| for (i = 0, ret = 0; i < IFNAMSIZ; i++) { |
| ret |= (indev[i] ^ arpinfo->iniface[i]) |
| & arpinfo->iniface_mask[i]; |
| } |
| |
| if (FWINV(ret != 0, ARPT_INV_VIA_IN)) { |
| dprintf("VIA in mismatch (%s vs %s).%s\n", |
| indev, arpinfo->iniface, |
| arpinfo->invflags&ARPT_INV_VIA_IN ?" (INV)":""); |
| return 0; |
| } |
| |
| for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) { |
| unsigned long odev; |
| memcpy(&odev, outdev + i*sizeof(unsigned long), |
| sizeof(unsigned long)); |
| ret |= (odev |
| ^ ((const unsigned long *)arpinfo->outiface)[i]) |
| & ((const unsigned long *)arpinfo->outiface_mask)[i]; |
| } |
| |
| if (FWINV(ret != 0, ARPT_INV_VIA_OUT)) { |
| dprintf("VIA out mismatch (%s vs %s).%s\n", |
| outdev, arpinfo->outiface, |
| arpinfo->invflags&ARPT_INV_VIA_OUT ?" (INV)":""); |
| return 0; |
| } |
| |
| return 1; |
| } |
| |
| static inline int arp_checkentry(const struct arpt_arp *arp) |
| { |
| if (arp->flags & ~ARPT_F_MASK) { |
| duprintf("Unknown flag bits set: %08X\n", |
| arp->flags & ~ARPT_F_MASK); |
| return 0; |
| } |
| if (arp->invflags & ~ARPT_INV_MASK) { |
| duprintf("Unknown invflag bits set: %08X\n", |
| arp->invflags & ~ARPT_INV_MASK); |
| return 0; |
| } |
| |
| return 1; |
| } |
| |
| static unsigned int arpt_error(struct sk_buff **pskb, |
| unsigned int hooknum, |
| const struct net_device *in, |
| const struct net_device *out, |
| const void *targinfo, |
| void *userinfo) |
| { |
| if (net_ratelimit()) |
| printk("arp_tables: error: '%s'\n", (char *)targinfo); |
| |
| return NF_DROP; |
| } |
| |
| static inline struct arpt_entry *get_entry(void *base, unsigned int offset) |
| { |
| return (struct arpt_entry *)(base + offset); |
| } |
| |
| unsigned int arpt_do_table(struct sk_buff **pskb, |
| unsigned int hook, |
| const struct net_device *in, |
| const struct net_device *out, |
| struct arpt_table *table, |
| void *userdata) |
| { |
| static const char nulldevname[IFNAMSIZ]; |
| unsigned int verdict = NF_DROP; |
| struct arphdr *arp; |
| int hotdrop = 0; |
| struct arpt_entry *e, *back; |
| const char *indev, *outdev; |
| void *table_base; |
| |
| /* ARP header, plus 2 device addresses, plus 2 IP addresses. */ |
| if (!pskb_may_pull((*pskb), (sizeof(struct arphdr) + |
| (2 * (*pskb)->dev->addr_len) + |
| (2 * sizeof(u32))))) |
| return NF_DROP; |
| |
| indev = in ? in->name : nulldevname; |
| outdev = out ? out->name : nulldevname; |
| |
| read_lock_bh(&table->lock); |
| table_base = (void *)table->private->entries |
| + TABLE_OFFSET(table->private, |
| smp_processor_id()); |
| e = get_entry(table_base, table->private->hook_entry[hook]); |
| back = get_entry(table_base, table->private->underflow[hook]); |
| |
| arp = (*pskb)->nh.arph; |
| do { |
| if (arp_packet_match(arp, (*pskb)->dev, indev, outdev, &e->arp)) { |
| struct arpt_entry_target *t; |
| int hdr_len; |
| |
| hdr_len = sizeof(*arp) + (2 * sizeof(struct in_addr)) + |
| (2 * (*pskb)->dev->addr_len); |
| ADD_COUNTER(e->counters, hdr_len, 1); |
| |
| t = arpt_get_target(e); |
| |
| /* Standard target? */ |
| if (!t->u.kernel.target->target) { |
| int v; |
| |
| v = ((struct arpt_standard_target *)t)->verdict; |
| if (v < 0) { |
| /* Pop from stack? */ |
| if (v != ARPT_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 arpt_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 |
| */ |
| verdict = t->u.kernel.target->target(pskb, |
| hook, |
| in, out, |
| t->data, |
| userdata); |
| |
| /* Target might have changed stuff. */ |
| arp = (*pskb)->nh.arph; |
| |
| if (verdict == ARPT_CONTINUE) |
| e = (void *)e + e->next_offset; |
| else |
| /* Verdict */ |
| break; |
| } |
| } else { |
| e = (void *)e + e->next_offset; |
| } |
| } while (!hotdrop); |
| read_unlock_bh(&table->lock); |
| |
| if (hotdrop) |
| return NF_DROP; |
| else |
| return verdict; |
| } |
| |
| static inline void *find_inlist_lock_noload(struct list_head *head, |
| const char *name, |
| int *error, |
| struct semaphore *mutex) |
| { |
| void *ret; |
| |
| *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 arpt_table *arpt_find_table_lock(const char *name, int *error, struct semaphore *mutex) |
| { |
| return find_inlist_lock(&arpt_tables, name, "arptable_", error, mutex); |
| } |
| |
| static struct arpt_target *arpt_find_target_lock(const char *name, int *error, struct semaphore *mutex) |
| { |
| return find_inlist_lock(&arpt_target, name, "arpt_", error, mutex); |
| } |
| |
| /* All zeroes == unconditional rule. */ |
| static inline int unconditional(const struct arpt_arp *arp) |
| { |
| unsigned int i; |
| |
| for (i = 0; i < sizeof(*arp)/sizeof(__u32); i++) |
| if (((__u32 *)arp)[i]) |
| return 0; |
| |
| return 1; |
| } |
| |
| /* 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 arpt_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_ARP_NUMHOOKS; hook++) { |
| unsigned int pos = newinfo->hook_entry[hook]; |
| struct arpt_entry *e |
| = (struct arpt_entry *)(newinfo->entries + pos); |
| |
| if (!(valid_hooks & (1 << hook))) |
| continue; |
| |
| /* Set initial back pointer. */ |
| e->counters.pcnt = pos; |
| |
| for (;;) { |
| struct arpt_standard_target *t |
| = (void *)arpt_get_target(e); |
| |
| if (e->comefrom & (1 << NF_ARP_NUMHOOKS)) { |
| printk("arptables: loop hook %u pos %u %08X.\n", |
| hook, pos, e->comefrom); |
| return 0; |
| } |
| e->comefrom |
| |= ((1 << hook) | (1 << NF_ARP_NUMHOOKS)); |
| |
| /* Unconditional return/END. */ |
| if (e->target_offset == sizeof(struct arpt_entry) |
| && (strcmp(t->target.u.user.name, |
| ARPT_STANDARD_TARGET) == 0) |
| && t->verdict < 0 |
| && unconditional(&e->arp)) { |
| unsigned int oldpos, size; |
| |
| /* Return: backtrack through the last |
| * big jump. |
| */ |
| do { |
| e->comefrom ^= (1<<NF_ARP_NUMHOOKS); |
| oldpos = pos; |
| pos = e->counters.pcnt; |
| e->counters.pcnt = 0; |
| |
| /* We're at the start. */ |
| if (pos == oldpos) |
| goto next; |
| |
| e = (struct arpt_entry *) |
| (newinfo->entries + pos); |
| } while (oldpos == pos + e->next_offset); |
| |
| /* Move along one */ |
| size = e->next_offset; |
| e = (struct arpt_entry *) |
| (newinfo->entries + pos + size); |
| e->counters.pcnt = pos; |
| pos += size; |
| } else { |
| int newpos = t->verdict; |
| |
| if (strcmp(t->target.u.user.name, |
| ARPT_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 arpt_entry *) |
| (newinfo->entries + newpos); |
| e->counters.pcnt = pos; |
| pos = newpos; |
| } |
| } |
| next: |
| duprintf("Finished chain %u\n", hook); |
| } |
| return 1; |
| } |
| |
| static inline int standard_check(const struct arpt_entry_target *t, |
| unsigned int max_offset) |
| { |
| struct arpt_standard_target *targ = (void *)t; |
| |
| /* Check standard info. */ |
| if (t->u.target_size |
| != ARPT_ALIGN(sizeof(struct arpt_standard_target))) { |
| duprintf("arpt_standard_check: target size %u != %Zu\n", |
| t->u.target_size, |
| ARPT_ALIGN(sizeof(struct arpt_standard_target))); |
| return 0; |
| } |
| |
| if (targ->verdict >= 0 |
| && targ->verdict > max_offset - sizeof(struct arpt_entry)) { |
| duprintf("arpt_standard_check: bad verdict (%i)\n", |
| targ->verdict); |
| return 0; |
| } |
| |
| if (targ->verdict < -NF_MAX_VERDICT - 1) { |
| duprintf("arpt_standard_check: bad negative verdict (%i)\n", |
| targ->verdict); |
| return 0; |
| } |
| return 1; |
| } |
| |
| static struct arpt_target arpt_standard_target; |
| |
| static inline int check_entry(struct arpt_entry *e, const char *name, unsigned int size, |
| unsigned int *i) |
| { |
| struct arpt_entry_target *t; |
| struct arpt_target *target; |
| int ret; |
| |
| if (!arp_checkentry(&e->arp)) { |
| duprintf("arp_tables: arp check failed %p %s.\n", e, name); |
| return -EINVAL; |
| } |
| |
| t = arpt_get_target(e); |
| target = arpt_find_target_lock(t->u.user.name, &ret, &arpt_mutex); |
| if (!target) { |
| duprintf("check_entry: `%s' not found\n", t->u.user.name); |
| goto out; |
| } |
| if (!try_module_get((target->me))) { |
| ret = -ENOENT; |
| goto out_unlock; |
| } |
| t->u.kernel.target = target; |
| up(&arpt_mutex); |
| |
| if (t->u.kernel.target == &arpt_standard_target) { |
| if (!standard_check(t, size)) { |
| ret = -EINVAL; |
| goto out; |
| } |
| } 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("arp_tables: check failed for `%s'.\n", |
| t->u.kernel.target->name); |
| ret = -EINVAL; |
| goto out; |
| } |
| |
| (*i)++; |
| return 0; |
| |
| out_unlock: |
| up(&arpt_mutex); |
| out: |
| return ret; |
| } |
| |
| static inline int check_entry_size_and_hooks(struct arpt_entry *e, |
| struct arpt_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 arpt_entry) != 0 |
| || (unsigned char *)e + sizeof(struct arpt_entry) >= limit) { |
| duprintf("Bad offset %p\n", e); |
| return -EINVAL; |
| } |
| |
| if (e->next_offset |
| < sizeof(struct arpt_entry) + sizeof(struct arpt_entry_target)) { |
| duprintf("checking: element %p size %u\n", |
| e, e->next_offset); |
| return -EINVAL; |
| } |
| |
| /* Check hooks & underflows */ |
| for (h = 0; h < NF_ARP_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 ARPT_RETURN). --RR */ |
| |
| /* Clear counters and comefrom */ |
| e->counters = ((struct arpt_counters) { 0, 0 }); |
| e->comefrom = 0; |
| |
| (*i)++; |
| return 0; |
| } |
| |
| static inline int cleanup_entry(struct arpt_entry *e, unsigned int *i) |
| { |
| struct arpt_entry_target *t; |
| |
| if (i && (*i)-- == 0) |
| return 1; |
| |
| t = arpt_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 arpt_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_ARP_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 = ARPT_ENTRY_ITERATE(newinfo->entries, newinfo->size, |
| check_entry_size_and_hooks, |
| newinfo, |
| newinfo->entries, |
| newinfo->entries + size, |
| hook_entries, underflows, &i); |
| duprintf("translate_table: ARPT_ENTRY_ITERATE gives %d\n", ret); |
| 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_ARP_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)) { |
| duprintf("Looping hook\n"); |
| return -ELOOP; |
| } |
| |
| /* Finally, each sanity check must pass */ |
| i = 0; |
| ret = ARPT_ENTRY_ITERATE(newinfo->entries, newinfo->size, |
| check_entry, name, size, &i); |
| |
| if (ret != 0) { |
| ARPT_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 arpt_table_info *replace_table(struct arpt_table *table, |
| unsigned int num_counters, |
| struct arpt_table_info *newinfo, |
| int *error) |
| { |
| struct arpt_table_info *oldinfo; |
| |
| /* 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 arpt_entry *e, |
| struct arpt_counters total[], |
| unsigned int *i) |
| { |
| ADD_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt); |
| |
| (*i)++; |
| return 0; |
| } |
| |
| static void get_counters(const struct arpt_table_info *t, |
| struct arpt_counters counters[]) |
| { |
| unsigned int cpu; |
| unsigned int i; |
| |
| for (cpu = 0; cpu < num_possible_cpus(); cpu++) { |
| i = 0; |
| ARPT_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 arpt_table *table, |
| void __user *userptr) |
| { |
| unsigned int off, num, countersize; |
| struct arpt_entry *e; |
| struct arpt_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 arpt_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++){ |
| struct arpt_entry_target *t; |
| |
| e = (struct arpt_entry *)(table->private->entries + off); |
| if (copy_to_user(userptr + off |
| + offsetof(struct arpt_entry, counters), |
| &counters[num], |
| sizeof(counters[num])) != 0) { |
| ret = -EFAULT; |
| goto free_counters; |
| } |
| |
| t = arpt_get_target(e); |
| if (copy_to_user(userptr + off + e->target_offset |
| + offsetof(struct arpt_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 arpt_get_entries *entries, |
| struct arpt_get_entries __user *uptr) |
| { |
| int ret; |
| struct arpt_table *t; |
| |
| t = arpt_find_table_lock(entries->name, &ret, &arpt_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(&arpt_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 arpt_replace tmp; |
| struct arpt_table *t; |
| struct arpt_table_info *newinfo, *oldinfo; |
| struct arpt_counters *counters; |
| |
| if (copy_from_user(&tmp, user, sizeof(tmp)) != 0) |
| return -EFAULT; |
| |
| /* Hack: Causes ipchains to give correct error msg --RR */ |
| if (len != sizeof(tmp) + tmp.size) |
| return -ENOPROTOOPT; |
| |
| /* 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 arpt_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 arpt_counters)); |
| if (!counters) { |
| ret = -ENOMEM; |
| goto free_newinfo; |
| } |
| memset(counters, 0, tmp.num_counters * sizeof(struct arpt_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("arp_tables: Translated table\n"); |
| |
| t = arpt_find_table_lock(tmp.name, &ret, &arpt_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 */ |
| ARPT_ENTRY_ITERATE(oldinfo->entries, oldinfo->size, cleanup_entry,NULL); |
| vfree(oldinfo); |
| if (copy_to_user(tmp.counters, counters, |
| sizeof(struct arpt_counters) * tmp.num_counters) != 0) |
| ret = -EFAULT; |
| vfree(counters); |
| up(&arpt_mutex); |
| return ret; |
| |
| put_module: |
| module_put(t->me); |
| free_newinfo_counters_untrans_unlock: |
| up(&arpt_mutex); |
| free_newinfo_counters_untrans: |
| ARPT_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 arpt_entry *e, |
| const struct arpt_counters addme[], |
| unsigned int *i) |
| { |
| |
| 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 arpt_counters_info tmp, *paddc; |
| struct arpt_table *t; |
| int ret; |
| |
| if (copy_from_user(&tmp, user, sizeof(tmp)) != 0) |
| return -EFAULT; |
| |
| if (len != sizeof(tmp) + tmp.num_counters*sizeof(struct arpt_counters)) |
| return -EINVAL; |
| |
| paddc = vmalloc(len); |
| if (!paddc) |
| return -ENOMEM; |
| |
| if (copy_from_user(paddc, user, len) != 0) { |
| ret = -EFAULT; |
| goto free; |
| } |
| |
| t = arpt_find_table_lock(tmp.name, &ret, &arpt_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; |
| ARPT_ENTRY_ITERATE(t->private->entries, |
| t->private->size, |
| add_counter_to_entry, |
| paddc->counters, |
| &i); |
| unlock_up_free: |
| write_unlock_bh(&t->lock); |
| up(&arpt_mutex); |
| free: |
| vfree(paddc); |
| |
| return ret; |
| } |
| |
| static int do_arpt_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 ARPT_SO_SET_REPLACE: |
| ret = do_replace(user, len); |
| break; |
| |
| case ARPT_SO_SET_ADD_COUNTERS: |
| ret = do_add_counters(user, len); |
| break; |
| |
| default: |
| duprintf("do_arpt_set_ctl: unknown request %i\n", cmd); |
| ret = -EINVAL; |
| } |
| |
| return ret; |
| } |
| |
| static int do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len) |
| { |
| int ret; |
| |
| if (!capable(CAP_NET_ADMIN)) |
| return -EPERM; |
| |
| switch (cmd) { |
| case ARPT_SO_GET_INFO: { |
| char name[ARPT_TABLE_MAXNAMELEN]; |
| struct arpt_table *t; |
| |
| if (*len != sizeof(struct arpt_getinfo)) { |
| duprintf("length %u != %Zu\n", *len, |
| sizeof(struct arpt_getinfo)); |
| ret = -EINVAL; |
| break; |
| } |
| |
| if (copy_from_user(name, user, sizeof(name)) != 0) { |
| ret = -EFAULT; |
| break; |
| } |
| name[ARPT_TABLE_MAXNAMELEN-1] = '\0'; |
| t = arpt_find_table_lock(name, &ret, &arpt_mutex); |
| if (t) { |
| struct arpt_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; |
| strcpy(info.name, name); |
| |
| if (copy_to_user(user, &info, *len) != 0) |
| ret = -EFAULT; |
| else |
| ret = 0; |
| |
| up(&arpt_mutex); |
| } |
| } |
| break; |
| |
| case ARPT_SO_GET_ENTRIES: { |
| struct arpt_get_entries get; |
| |
| if (*len < sizeof(get)) { |
| duprintf("get_entries: %u < %Zu\n", *len, sizeof(get)); |
| ret = -EINVAL; |
| } else if (copy_from_user(&get, user, sizeof(get)) != 0) { |
| ret = -EFAULT; |
| } else if (*len != sizeof(struct arpt_get_entries) + get.size) { |
| duprintf("get_entries: %u != %Zu\n", *len, |
| sizeof(struct arpt_get_entries) + get.size); |
| ret = -EINVAL; |
| } else |
| ret = get_entries(&get, user); |
| break; |
| } |
| |
| default: |
| duprintf("do_arpt_get_ctl: unknown request %i\n", cmd); |
| ret = -EINVAL; |
| } |
| |
| return ret; |
| } |
| |
| /* Registration hooks for targets. */ |
| int arpt_register_target(struct arpt_target *target) |
| { |
| int ret; |
| |
| ret = down_interruptible(&arpt_mutex); |
| if (ret != 0) |
| return ret; |
| |
| if (!list_named_insert(&arpt_target, target)) { |
| duprintf("arpt_register_target: `%s' already in list!\n", |
| target->name); |
| ret = -EINVAL; |
| } |
| up(&arpt_mutex); |
| return ret; |
| } |
| |
| void arpt_unregister_target(struct arpt_target *target) |
| { |
| down(&arpt_mutex); |
| LIST_DELETE(&arpt_target, target); |
| up(&arpt_mutex); |
| } |
| |
| int arpt_register_table(struct arpt_table *table, |
| const struct arpt_replace *repl) |
| { |
| int ret; |
| struct arpt_table_info *newinfo; |
| static struct arpt_table_info bootstrap |
| = { 0, 0, 0, { 0 }, { 0 }, { } }; |
| |
| newinfo = vmalloc(sizeof(struct arpt_table_info) |
| + SMP_ALIGN(repl->size) * num_possible_cpus()); |
| if (!newinfo) { |
| ret = -ENOMEM; |
| return ret; |
| } |
| 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); |
| duprintf("arpt_register_table: translate table gives %d\n", ret); |
| if (ret != 0) { |
| vfree(newinfo); |
| return ret; |
| } |
| |
| ret = down_interruptible(&arpt_mutex); |
| if (ret != 0) { |
| vfree(newinfo); |
| return ret; |
| } |
| |
| /* Don't autoload: we'd eat our tail... */ |
| if (list_named_find(&arpt_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(&arpt_tables, table); |
| |
| unlock: |
| up(&arpt_mutex); |
| return ret; |
| |
| free_unlock: |
| vfree(newinfo); |
| goto unlock; |
| } |
| |
| void arpt_unregister_table(struct arpt_table *table) |
| { |
| down(&arpt_mutex); |
| LIST_DELETE(&arpt_tables, table); |
| up(&arpt_mutex); |
| |
| /* Decrease module usage counts and free resources */ |
| ARPT_ENTRY_ITERATE(table->private->entries, table->private->size, |
| cleanup_entry, NULL); |
| vfree(table->private); |
| } |
| |
| /* The built-in targets: standard (NULL) and error. */ |
| static struct arpt_target arpt_standard_target = { |
| .name = ARPT_STANDARD_TARGET, |
| }; |
| |
| static struct arpt_target arpt_error_target = { |
| .name = ARPT_ERROR_TARGET, |
| .target = arpt_error, |
| }; |
| |
| static struct nf_sockopt_ops arpt_sockopts = { |
| .pf = PF_INET, |
| .set_optmin = ARPT_BASE_CTL, |
| .set_optmax = ARPT_SO_SET_MAX+1, |
| .set = do_arpt_set_ctl, |
| .get_optmin = ARPT_BASE_CTL, |
| .get_optmax = ARPT_SO_GET_MAX+1, |
| .get = do_arpt_get_ctl, |
| }; |
| |
| #ifdef CONFIG_PROC_FS |
| static inline int print_name(const struct arpt_table *t, |
| 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", t->name); |
| if (*pos + namelen > length) { |
| /* Stop iterating */ |
| return 1; |
| } |
| *pos += namelen; |
| } |
| return 0; |
| } |
| |
| static int arpt_get_tables(char *buffer, char **start, off_t offset, int length) |
| { |
| off_t pos = 0; |
| unsigned int count = 0; |
| |
| if (down_interruptible(&arpt_mutex) != 0) |
| return 0; |
| |
| LIST_FIND(&arpt_tables, print_name, struct arpt_table *, |
| offset, buffer, length, &pos, &count); |
| |
| up(&arpt_mutex); |
| |
| /* `start' hack - see fs/proc/generic.c line ~105 */ |
| *start=(char *)((unsigned long)count-offset); |
| return pos; |
| } |
| #endif /*CONFIG_PROC_FS*/ |
| |
| static int __init init(void) |
| { |
| int ret; |
| |
| /* Noone else will be downing sem now, so we won't sleep */ |
| down(&arpt_mutex); |
| list_append(&arpt_target, &arpt_standard_target); |
| list_append(&arpt_target, &arpt_error_target); |
| up(&arpt_mutex); |
| |
| /* Register setsockopt */ |
| ret = nf_register_sockopt(&arpt_sockopts); |
| if (ret < 0) { |
| duprintf("Unable to register sockopts.\n"); |
| return ret; |
| } |
| |
| #ifdef CONFIG_PROC_FS |
| { |
| struct proc_dir_entry *proc; |
| |
| proc = proc_net_create("arp_tables_names", 0, arpt_get_tables); |
| if (!proc) { |
| nf_unregister_sockopt(&arpt_sockopts); |
| return -ENOMEM; |
| } |
| proc->owner = THIS_MODULE; |
| } |
| #endif |
| |
| printk("arp_tables: (C) 2002 David S. Miller\n"); |
| return 0; |
| } |
| |
| static void __exit fini(void) |
| { |
| nf_unregister_sockopt(&arpt_sockopts); |
| #ifdef CONFIG_PROC_FS |
| proc_net_remove("arp_tables_names"); |
| #endif |
| } |
| |
| EXPORT_SYMBOL(arpt_register_table); |
| EXPORT_SYMBOL(arpt_unregister_table); |
| EXPORT_SYMBOL(arpt_do_table); |
| EXPORT_SYMBOL(arpt_register_target); |
| EXPORT_SYMBOL(arpt_unregister_target); |
| |
| module_init(init); |
| module_exit(fini); |