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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /net/ipv4/netfilter/arp_tables.c | |
download | op-kernel-dev-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip op-kernel-dev-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'net/ipv4/netfilter/arp_tables.c')
-rw-r--r-- | net/ipv4/netfilter/arp_tables.c | 1333 |
1 files changed, 1333 insertions, 0 deletions
diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c new file mode 100644 index 0000000..df79f5e --- /dev/null +++ b/net/ipv4/netfilter/arp_tables.c @@ -0,0 +1,1333 @@ +/* + * 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); |