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![Dmitry Mishin](/assets/img/avatar_default.png)
While standard_target has target->me == NULL, module_put() should be called for it as for others, because there were try_module_get() before. Signed-off-by: Dmitry Mishin <dim@openvz.org> Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
1207 lines
29 KiB
C
1207 lines
29 KiB
C
/*
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* Packet matching code for ARP packets.
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*
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* Based heavily, if not almost entirely, upon ip_tables.c framework.
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*
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* Some ARP specific bits are:
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*
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* Copyright (C) 2002 David S. Miller (davem@redhat.com)
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*
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*/
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#include <linux/kernel.h>
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#include <linux/skbuff.h>
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#include <linux/netdevice.h>
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#include <linux/capability.h>
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#include <linux/if_arp.h>
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#include <linux/kmod.h>
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#include <linux/vmalloc.h>
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#include <linux/proc_fs.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <asm/uaccess.h>
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#include <linux/mutex.h>
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#include <linux/netfilter/x_tables.h>
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#include <linux/netfilter_arp/arp_tables.h>
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
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MODULE_DESCRIPTION("arptables core");
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/*#define DEBUG_ARP_TABLES*/
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/*#define DEBUG_ARP_TABLES_USER*/
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#ifdef DEBUG_ARP_TABLES
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#define dprintf(format, args...) printk(format , ## args)
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#else
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#define dprintf(format, args...)
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#endif
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#ifdef DEBUG_ARP_TABLES_USER
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#define duprintf(format, args...) printk(format , ## args)
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#else
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#define duprintf(format, args...)
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#endif
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#ifdef CONFIG_NETFILTER_DEBUG
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#define ARP_NF_ASSERT(x) \
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do { \
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if (!(x)) \
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printk("ARP_NF_ASSERT: %s:%s:%u\n", \
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__FUNCTION__, __FILE__, __LINE__); \
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} while(0)
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#else
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#define ARP_NF_ASSERT(x)
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#endif
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static inline int arp_devaddr_compare(const struct arpt_devaddr_info *ap,
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char *hdr_addr, int len)
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{
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int i, ret;
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if (len > ARPT_DEV_ADDR_LEN_MAX)
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len = ARPT_DEV_ADDR_LEN_MAX;
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ret = 0;
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for (i = 0; i < len; i++)
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ret |= (hdr_addr[i] ^ ap->addr[i]) & ap->mask[i];
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return (ret != 0);
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}
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/* Returns whether packet matches rule or not. */
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static inline int arp_packet_match(const struct arphdr *arphdr,
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struct net_device *dev,
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const char *indev,
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const char *outdev,
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const struct arpt_arp *arpinfo)
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{
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char *arpptr = (char *)(arphdr + 1);
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char *src_devaddr, *tgt_devaddr;
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u32 src_ipaddr, tgt_ipaddr;
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int i, ret;
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#define FWINV(bool,invflg) ((bool) ^ !!(arpinfo->invflags & invflg))
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if (FWINV((arphdr->ar_op & arpinfo->arpop_mask) != arpinfo->arpop,
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ARPT_INV_ARPOP)) {
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dprintf("ARP operation field mismatch.\n");
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dprintf("ar_op: %04x info->arpop: %04x info->arpop_mask: %04x\n",
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arphdr->ar_op, arpinfo->arpop, arpinfo->arpop_mask);
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return 0;
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}
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if (FWINV((arphdr->ar_hrd & arpinfo->arhrd_mask) != arpinfo->arhrd,
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ARPT_INV_ARPHRD)) {
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dprintf("ARP hardware address format mismatch.\n");
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dprintf("ar_hrd: %04x info->arhrd: %04x info->arhrd_mask: %04x\n",
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arphdr->ar_hrd, arpinfo->arhrd, arpinfo->arhrd_mask);
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return 0;
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}
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if (FWINV((arphdr->ar_pro & arpinfo->arpro_mask) != arpinfo->arpro,
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ARPT_INV_ARPPRO)) {
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dprintf("ARP protocol address format mismatch.\n");
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dprintf("ar_pro: %04x info->arpro: %04x info->arpro_mask: %04x\n",
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arphdr->ar_pro, arpinfo->arpro, arpinfo->arpro_mask);
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return 0;
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}
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if (FWINV((arphdr->ar_hln & arpinfo->arhln_mask) != arpinfo->arhln,
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ARPT_INV_ARPHLN)) {
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dprintf("ARP hardware address length mismatch.\n");
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dprintf("ar_hln: %02x info->arhln: %02x info->arhln_mask: %02x\n",
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arphdr->ar_hln, arpinfo->arhln, arpinfo->arhln_mask);
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return 0;
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}
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src_devaddr = arpptr;
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arpptr += dev->addr_len;
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memcpy(&src_ipaddr, arpptr, sizeof(u32));
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arpptr += sizeof(u32);
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tgt_devaddr = arpptr;
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arpptr += dev->addr_len;
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memcpy(&tgt_ipaddr, arpptr, sizeof(u32));
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if (FWINV(arp_devaddr_compare(&arpinfo->src_devaddr, src_devaddr, dev->addr_len),
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ARPT_INV_SRCDEVADDR) ||
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FWINV(arp_devaddr_compare(&arpinfo->tgt_devaddr, tgt_devaddr, dev->addr_len),
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ARPT_INV_TGTDEVADDR)) {
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dprintf("Source or target device address mismatch.\n");
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return 0;
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}
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if (FWINV((src_ipaddr & arpinfo->smsk.s_addr) != arpinfo->src.s_addr,
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ARPT_INV_SRCIP) ||
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FWINV(((tgt_ipaddr & arpinfo->tmsk.s_addr) != arpinfo->tgt.s_addr),
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ARPT_INV_TGTIP)) {
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dprintf("Source or target IP address mismatch.\n");
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dprintf("SRC: %u.%u.%u.%u. Mask: %u.%u.%u.%u. Target: %u.%u.%u.%u.%s\n",
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NIPQUAD(src_ipaddr),
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NIPQUAD(arpinfo->smsk.s_addr),
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NIPQUAD(arpinfo->src.s_addr),
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arpinfo->invflags & ARPT_INV_SRCIP ? " (INV)" : "");
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dprintf("TGT: %u.%u.%u.%u Mask: %u.%u.%u.%u Target: %u.%u.%u.%u.%s\n",
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NIPQUAD(tgt_ipaddr),
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NIPQUAD(arpinfo->tmsk.s_addr),
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NIPQUAD(arpinfo->tgt.s_addr),
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arpinfo->invflags & ARPT_INV_TGTIP ? " (INV)" : "");
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return 0;
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}
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/* Look for ifname matches. */
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for (i = 0, ret = 0; i < IFNAMSIZ; i++) {
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ret |= (indev[i] ^ arpinfo->iniface[i])
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& arpinfo->iniface_mask[i];
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}
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if (FWINV(ret != 0, ARPT_INV_VIA_IN)) {
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dprintf("VIA in mismatch (%s vs %s).%s\n",
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indev, arpinfo->iniface,
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arpinfo->invflags&ARPT_INV_VIA_IN ?" (INV)":"");
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return 0;
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}
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for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) {
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unsigned long odev;
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memcpy(&odev, outdev + i*sizeof(unsigned long),
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sizeof(unsigned long));
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ret |= (odev
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^ ((const unsigned long *)arpinfo->outiface)[i])
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& ((const unsigned long *)arpinfo->outiface_mask)[i];
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}
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if (FWINV(ret != 0, ARPT_INV_VIA_OUT)) {
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dprintf("VIA out mismatch (%s vs %s).%s\n",
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outdev, arpinfo->outiface,
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arpinfo->invflags&ARPT_INV_VIA_OUT ?" (INV)":"");
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return 0;
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}
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return 1;
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}
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static inline int arp_checkentry(const struct arpt_arp *arp)
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{
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if (arp->flags & ~ARPT_F_MASK) {
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duprintf("Unknown flag bits set: %08X\n",
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arp->flags & ~ARPT_F_MASK);
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return 0;
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}
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if (arp->invflags & ~ARPT_INV_MASK) {
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duprintf("Unknown invflag bits set: %08X\n",
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arp->invflags & ~ARPT_INV_MASK);
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return 0;
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}
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return 1;
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}
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static unsigned int arpt_error(struct sk_buff **pskb,
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const struct net_device *in,
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const struct net_device *out,
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unsigned int hooknum,
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const struct xt_target *target,
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const void *targinfo)
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{
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if (net_ratelimit())
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printk("arp_tables: error: '%s'\n", (char *)targinfo);
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return NF_DROP;
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}
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static inline struct arpt_entry *get_entry(void *base, unsigned int offset)
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{
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return (struct arpt_entry *)(base + offset);
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}
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unsigned int arpt_do_table(struct sk_buff **pskb,
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unsigned int hook,
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const struct net_device *in,
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const struct net_device *out,
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struct arpt_table *table)
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{
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static const char nulldevname[IFNAMSIZ];
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unsigned int verdict = NF_DROP;
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struct arphdr *arp;
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int hotdrop = 0;
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struct arpt_entry *e, *back;
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const char *indev, *outdev;
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void *table_base;
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struct xt_table_info *private;
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/* ARP header, plus 2 device addresses, plus 2 IP addresses. */
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if (!pskb_may_pull((*pskb), (sizeof(struct arphdr) +
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(2 * (*pskb)->dev->addr_len) +
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(2 * sizeof(u32)))))
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return NF_DROP;
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indev = in ? in->name : nulldevname;
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outdev = out ? out->name : nulldevname;
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read_lock_bh(&table->lock);
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private = table->private;
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table_base = (void *)private->entries[smp_processor_id()];
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e = get_entry(table_base, private->hook_entry[hook]);
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back = get_entry(table_base, private->underflow[hook]);
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arp = (*pskb)->nh.arph;
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do {
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if (arp_packet_match(arp, (*pskb)->dev, indev, outdev, &e->arp)) {
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struct arpt_entry_target *t;
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int hdr_len;
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hdr_len = sizeof(*arp) + (2 * sizeof(struct in_addr)) +
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(2 * (*pskb)->dev->addr_len);
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ADD_COUNTER(e->counters, hdr_len, 1);
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t = arpt_get_target(e);
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/* Standard target? */
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if (!t->u.kernel.target->target) {
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int v;
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v = ((struct arpt_standard_target *)t)->verdict;
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if (v < 0) {
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/* Pop from stack? */
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if (v != ARPT_RETURN) {
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verdict = (unsigned)(-v) - 1;
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break;
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}
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e = back;
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back = get_entry(table_base,
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back->comefrom);
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continue;
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}
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if (table_base + v
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!= (void *)e + e->next_offset) {
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/* Save old back ptr in next entry */
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struct arpt_entry *next
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= (void *)e + e->next_offset;
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next->comefrom =
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(void *)back - table_base;
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/* set back pointer to next entry */
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back = next;
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}
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e = get_entry(table_base, v);
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} else {
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/* Targets which reenter must return
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* abs. verdicts
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*/
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verdict = t->u.kernel.target->target(pskb,
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in, out,
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hook,
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t->u.kernel.target,
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t->data);
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/* Target might have changed stuff. */
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arp = (*pskb)->nh.arph;
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if (verdict == ARPT_CONTINUE)
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e = (void *)e + e->next_offset;
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else
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/* Verdict */
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break;
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}
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} else {
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e = (void *)e + e->next_offset;
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}
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} while (!hotdrop);
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read_unlock_bh(&table->lock);
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if (hotdrop)
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return NF_DROP;
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else
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return verdict;
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}
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/* All zeroes == unconditional rule. */
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static inline int unconditional(const struct arpt_arp *arp)
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{
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unsigned int i;
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for (i = 0; i < sizeof(*arp)/sizeof(__u32); i++)
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if (((__u32 *)arp)[i])
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return 0;
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return 1;
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}
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/* Figures out from what hook each rule can be called: returns 0 if
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* there are loops. Puts hook bitmask in comefrom.
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*/
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static int mark_source_chains(struct xt_table_info *newinfo,
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unsigned int valid_hooks, void *entry0)
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{
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unsigned int hook;
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/* No recursion; use packet counter to save back ptrs (reset
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* to 0 as we leave), and comefrom to save source hook bitmask.
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*/
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for (hook = 0; hook < NF_ARP_NUMHOOKS; hook++) {
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unsigned int pos = newinfo->hook_entry[hook];
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struct arpt_entry *e
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= (struct arpt_entry *)(entry0 + pos);
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if (!(valid_hooks & (1 << hook)))
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continue;
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/* Set initial back pointer. */
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e->counters.pcnt = pos;
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for (;;) {
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struct arpt_standard_target *t
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= (void *)arpt_get_target(e);
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if (e->comefrom & (1 << NF_ARP_NUMHOOKS)) {
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printk("arptables: loop hook %u pos %u %08X.\n",
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hook, pos, e->comefrom);
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return 0;
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}
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e->comefrom
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|= ((1 << hook) | (1 << NF_ARP_NUMHOOKS));
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/* Unconditional return/END. */
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if (e->target_offset == sizeof(struct arpt_entry)
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&& (strcmp(t->target.u.user.name,
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ARPT_STANDARD_TARGET) == 0)
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&& t->verdict < 0
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&& unconditional(&e->arp)) {
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unsigned int oldpos, size;
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/* Return: backtrack through the last
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* big jump.
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*/
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do {
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e->comefrom ^= (1<<NF_ARP_NUMHOOKS);
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oldpos = pos;
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pos = e->counters.pcnt;
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e->counters.pcnt = 0;
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/* We're at the start. */
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if (pos == oldpos)
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goto next;
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e = (struct arpt_entry *)
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(entry0 + pos);
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} while (oldpos == pos + e->next_offset);
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/* Move along one */
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size = e->next_offset;
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e = (struct arpt_entry *)
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(entry0 + pos + size);
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e->counters.pcnt = pos;
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pos += size;
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} else {
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int newpos = t->verdict;
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if (strcmp(t->target.u.user.name,
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ARPT_STANDARD_TARGET) == 0
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&& newpos >= 0) {
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/* This a jump; chase it. */
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duprintf("Jump rule %u -> %u\n",
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pos, newpos);
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} else {
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/* ... this is a fallthru */
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newpos = pos + e->next_offset;
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}
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e = (struct arpt_entry *)
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(entry0 + newpos);
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e->counters.pcnt = pos;
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pos = newpos;
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}
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}
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next:
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duprintf("Finished chain %u\n", hook);
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}
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return 1;
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}
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|
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static inline int standard_check(const struct arpt_entry_target *t,
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unsigned int max_offset)
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{
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struct arpt_standard_target *targ = (void *)t;
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|
|
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/* Check standard info. */
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if (t->u.target_size
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!= ARPT_ALIGN(sizeof(struct arpt_standard_target))) {
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duprintf("arpt_standard_check: target size %u != %Zu\n",
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t->u.target_size,
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ARPT_ALIGN(sizeof(struct arpt_standard_target)));
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return 0;
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}
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|
|
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if (targ->verdict >= 0
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&& targ->verdict > max_offset - sizeof(struct arpt_entry)) {
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duprintf("arpt_standard_check: bad verdict (%i)\n",
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targ->verdict);
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return 0;
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}
|
|
|
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if (targ->verdict < -NF_MAX_VERDICT - 1) {
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duprintf("arpt_standard_check: bad negative verdict (%i)\n",
|
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targ->verdict);
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return 0;
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}
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return 1;
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}
|
|
|
|
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;
|
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int ret;
|
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|
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if (!arp_checkentry(&e->arp)) {
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duprintf("arp_tables: arp check failed %p %s.\n", e, name);
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return -EINVAL;
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}
|
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|
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t = arpt_get_target(e);
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target = try_then_request_module(xt_find_target(NF_ARP, t->u.user.name,
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t->u.user.revision),
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"arpt_%s", t->u.user.name);
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if (IS_ERR(target) || !target) {
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duprintf("check_entry: `%s' not found\n", t->u.user.name);
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ret = target ? PTR_ERR(target) : -ENOENT;
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goto out;
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}
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t->u.kernel.target = target;
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|
|
|
ret = xt_check_target(target, NF_ARP, t->u.target_size - sizeof(*t),
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name, e->comefrom, 0, 0);
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if (ret)
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goto err;
|
|
|
|
if (t->u.kernel.target == &arpt_standard_target) {
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if (!standard_check(t, size)) {
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ret = -EINVAL;
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goto err;
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|
}
|
|
} else if (t->u.kernel.target->checkentry
|
|
&& !t->u.kernel.target->checkentry(name, e, target, t->data,
|
|
e->comefrom)) {
|
|
duprintf("arp_tables: check failed for `%s'.\n",
|
|
t->u.kernel.target->name);
|
|
ret = -EINVAL;
|
|
goto err;
|
|
}
|
|
|
|
(*i)++;
|
|
return 0;
|
|
err:
|
|
module_put(t->u.kernel.target->me);
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
static inline int check_entry_size_and_hooks(struct arpt_entry *e,
|
|
struct xt_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 xt_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->u.kernel.target, t->data);
|
|
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 xt_table_info *newinfo,
|
|
void *entry0,
|
|
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(entry0, newinfo->size,
|
|
check_entry_size_and_hooks,
|
|
newinfo,
|
|
entry0,
|
|
entry0 + 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, entry0)) {
|
|
duprintf("Looping hook\n");
|
|
return -ELOOP;
|
|
}
|
|
|
|
/* Finally, each sanity check must pass */
|
|
i = 0;
|
|
ret = ARPT_ENTRY_ITERATE(entry0, newinfo->size,
|
|
check_entry, name, size, &i);
|
|
|
|
if (ret != 0) {
|
|
ARPT_ENTRY_ITERATE(entry0, newinfo->size,
|
|
cleanup_entry, &i);
|
|
return ret;
|
|
}
|
|
|
|
/* And one copy for every other CPU */
|
|
for_each_possible_cpu(i) {
|
|
if (newinfo->entries[i] && newinfo->entries[i] != entry0)
|
|
memcpy(newinfo->entries[i], entry0, newinfo->size);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/* Gets counters. */
|
|
static inline int add_entry_to_counter(const struct arpt_entry *e,
|
|
struct xt_counters total[],
|
|
unsigned int *i)
|
|
{
|
|
ADD_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt);
|
|
|
|
(*i)++;
|
|
return 0;
|
|
}
|
|
|
|
static inline int set_entry_to_counter(const struct arpt_entry *e,
|
|
struct xt_counters total[],
|
|
unsigned int *i)
|
|
{
|
|
SET_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt);
|
|
|
|
(*i)++;
|
|
return 0;
|
|
}
|
|
|
|
static void get_counters(const struct xt_table_info *t,
|
|
struct xt_counters counters[])
|
|
{
|
|
unsigned int cpu;
|
|
unsigned int i;
|
|
unsigned int curcpu;
|
|
|
|
/* Instead of clearing (by a previous call to memset())
|
|
* the counters and using adds, we set the counters
|
|
* with data used by 'current' CPU
|
|
* We dont care about preemption here.
|
|
*/
|
|
curcpu = raw_smp_processor_id();
|
|
|
|
i = 0;
|
|
ARPT_ENTRY_ITERATE(t->entries[curcpu],
|
|
t->size,
|
|
set_entry_to_counter,
|
|
counters,
|
|
&i);
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
if (cpu == curcpu)
|
|
continue;
|
|
i = 0;
|
|
ARPT_ENTRY_ITERATE(t->entries[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 xt_counters *counters;
|
|
struct xt_table_info *private = table->private;
|
|
int ret = 0;
|
|
void *loc_cpu_entry;
|
|
|
|
/* We need atomic snapshot of counters: rest doesn't change
|
|
* (other than comefrom, which userspace doesn't care
|
|
* about).
|
|
*/
|
|
countersize = sizeof(struct xt_counters) * private->number;
|
|
counters = vmalloc_node(countersize, numa_node_id());
|
|
|
|
if (counters == NULL)
|
|
return -ENOMEM;
|
|
|
|
/* First, sum counters... */
|
|
write_lock_bh(&table->lock);
|
|
get_counters(private, counters);
|
|
write_unlock_bh(&table->lock);
|
|
|
|
loc_cpu_entry = private->entries[raw_smp_processor_id()];
|
|
/* ... then copy entire thing ... */
|
|
if (copy_to_user(userptr, loc_cpu_entry, total_size) != 0) {
|
|
ret = -EFAULT;
|
|
goto free_counters;
|
|
}
|
|
|
|
/* FIXME: use iterator macros --RR */
|
|
/* ... then go back and fix counters and names */
|
|
for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
|
|
struct arpt_entry_target *t;
|
|
|
|
e = (struct arpt_entry *)(loc_cpu_entry + 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 = xt_find_table_lock(NF_ARP, entries->name);
|
|
if (t && !IS_ERR(t)) {
|
|
struct xt_table_info *private = t->private;
|
|
duprintf("t->private->number = %u\n",
|
|
private->number);
|
|
if (entries->size == private->size)
|
|
ret = copy_entries_to_user(private->size,
|
|
t, uptr->entrytable);
|
|
else {
|
|
duprintf("get_entries: I've got %u not %u!\n",
|
|
private->size, entries->size);
|
|
ret = -EINVAL;
|
|
}
|
|
module_put(t->me);
|
|
xt_table_unlock(t);
|
|
} else
|
|
ret = t ? PTR_ERR(t) : -ENOENT;
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int do_replace(void __user *user, unsigned int len)
|
|
{
|
|
int ret;
|
|
struct arpt_replace tmp;
|
|
struct arpt_table *t;
|
|
struct xt_table_info *newinfo, *oldinfo;
|
|
struct xt_counters *counters;
|
|
void *loc_cpu_entry, *loc_cpu_old_entry;
|
|
|
|
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;
|
|
|
|
/* overflow check */
|
|
if (tmp.size >= (INT_MAX - sizeof(struct xt_table_info)) / NR_CPUS -
|
|
SMP_CACHE_BYTES)
|
|
return -ENOMEM;
|
|
if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
|
|
return -ENOMEM;
|
|
|
|
newinfo = xt_alloc_table_info(tmp.size);
|
|
if (!newinfo)
|
|
return -ENOMEM;
|
|
|
|
/* choose the copy that is on our node/cpu */
|
|
loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
|
|
if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
|
|
tmp.size) != 0) {
|
|
ret = -EFAULT;
|
|
goto free_newinfo;
|
|
}
|
|
|
|
counters = vmalloc(tmp.num_counters * sizeof(struct xt_counters));
|
|
if (!counters) {
|
|
ret = -ENOMEM;
|
|
goto free_newinfo;
|
|
}
|
|
|
|
ret = translate_table(tmp.name, tmp.valid_hooks,
|
|
newinfo, loc_cpu_entry, tmp.size, tmp.num_entries,
|
|
tmp.hook_entry, tmp.underflow);
|
|
if (ret != 0)
|
|
goto free_newinfo_counters;
|
|
|
|
duprintf("arp_tables: Translated table\n");
|
|
|
|
t = try_then_request_module(xt_find_table_lock(NF_ARP, tmp.name),
|
|
"arptable_%s", tmp.name);
|
|
if (!t || IS_ERR(t)) {
|
|
ret = t ? PTR_ERR(t) : -ENOENT;
|
|
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 put_module;
|
|
}
|
|
|
|
oldinfo = xt_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 */
|
|
loc_cpu_old_entry = oldinfo->entries[raw_smp_processor_id()];
|
|
ARPT_ENTRY_ITERATE(loc_cpu_old_entry, oldinfo->size, cleanup_entry,NULL);
|
|
|
|
xt_free_table_info(oldinfo);
|
|
if (copy_to_user(tmp.counters, counters,
|
|
sizeof(struct xt_counters) * tmp.num_counters) != 0)
|
|
ret = -EFAULT;
|
|
vfree(counters);
|
|
xt_table_unlock(t);
|
|
return ret;
|
|
|
|
put_module:
|
|
module_put(t->me);
|
|
xt_table_unlock(t);
|
|
free_newinfo_counters_untrans:
|
|
ARPT_ENTRY_ITERATE(loc_cpu_entry, newinfo->size, cleanup_entry, NULL);
|
|
free_newinfo_counters:
|
|
vfree(counters);
|
|
free_newinfo:
|
|
xt_free_table_info(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 xt_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 xt_counters_info tmp, *paddc;
|
|
struct arpt_table *t;
|
|
struct xt_table_info *private;
|
|
int ret = 0;
|
|
void *loc_cpu_entry;
|
|
|
|
if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
|
|
return -EFAULT;
|
|
|
|
if (len != sizeof(tmp) + tmp.num_counters*sizeof(struct xt_counters))
|
|
return -EINVAL;
|
|
|
|
paddc = vmalloc(len);
|
|
if (!paddc)
|
|
return -ENOMEM;
|
|
|
|
if (copy_from_user(paddc, user, len) != 0) {
|
|
ret = -EFAULT;
|
|
goto free;
|
|
}
|
|
|
|
t = xt_find_table_lock(NF_ARP, tmp.name);
|
|
if (!t || IS_ERR(t)) {
|
|
ret = t ? PTR_ERR(t) : -ENOENT;
|
|
goto free;
|
|
}
|
|
|
|
write_lock_bh(&t->lock);
|
|
private = t->private;
|
|
if (private->number != tmp.num_counters) {
|
|
ret = -EINVAL;
|
|
goto unlock_up_free;
|
|
}
|
|
|
|
i = 0;
|
|
/* Choose the copy that is on our node */
|
|
loc_cpu_entry = private->entries[smp_processor_id()];
|
|
ARPT_ENTRY_ITERATE(loc_cpu_entry,
|
|
private->size,
|
|
add_counter_to_entry,
|
|
paddc->counters,
|
|
&i);
|
|
unlock_up_free:
|
|
write_unlock_bh(&t->lock);
|
|
xt_table_unlock(t);
|
|
module_put(t->me);
|
|
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 = try_then_request_module(xt_find_table_lock(NF_ARP, name),
|
|
"arptable_%s", name);
|
|
if (t && !IS_ERR(t)) {
|
|
struct arpt_getinfo info;
|
|
struct xt_table_info *private = t->private;
|
|
|
|
info.valid_hooks = t->valid_hooks;
|
|
memcpy(info.hook_entry, private->hook_entry,
|
|
sizeof(info.hook_entry));
|
|
memcpy(info.underflow, private->underflow,
|
|
sizeof(info.underflow));
|
|
info.num_entries = private->number;
|
|
info.size = private->size;
|
|
strcpy(info.name, name);
|
|
|
|
if (copy_to_user(user, &info, *len) != 0)
|
|
ret = -EFAULT;
|
|
else
|
|
ret = 0;
|
|
xt_table_unlock(t);
|
|
module_put(t->me);
|
|
} else
|
|
ret = t ? PTR_ERR(t) : -ENOENT;
|
|
}
|
|
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;
|
|
}
|
|
|
|
case ARPT_SO_GET_REVISION_TARGET: {
|
|
struct xt_get_revision rev;
|
|
|
|
if (*len != sizeof(rev)) {
|
|
ret = -EINVAL;
|
|
break;
|
|
}
|
|
if (copy_from_user(&rev, user, sizeof(rev)) != 0) {
|
|
ret = -EFAULT;
|
|
break;
|
|
}
|
|
|
|
try_then_request_module(xt_find_revision(NF_ARP, rev.name,
|
|
rev.revision, 1, &ret),
|
|
"arpt_%s", rev.name);
|
|
break;
|
|
}
|
|
|
|
default:
|
|
duprintf("do_arpt_get_ctl: unknown request %i\n", cmd);
|
|
ret = -EINVAL;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
int arpt_register_table(struct arpt_table *table,
|
|
const struct arpt_replace *repl)
|
|
{
|
|
int ret;
|
|
struct xt_table_info *newinfo;
|
|
static struct xt_table_info bootstrap
|
|
= { 0, 0, 0, { 0 }, { 0 }, { } };
|
|
void *loc_cpu_entry;
|
|
|
|
newinfo = xt_alloc_table_info(repl->size);
|
|
if (!newinfo) {
|
|
ret = -ENOMEM;
|
|
return ret;
|
|
}
|
|
|
|
/* choose the copy on our node/cpu */
|
|
loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
|
|
memcpy(loc_cpu_entry, repl->entries, repl->size);
|
|
|
|
ret = translate_table(table->name, table->valid_hooks,
|
|
newinfo, loc_cpu_entry, repl->size,
|
|
repl->num_entries,
|
|
repl->hook_entry,
|
|
repl->underflow);
|
|
|
|
duprintf("arpt_register_table: translate table gives %d\n", ret);
|
|
if (ret != 0) {
|
|
xt_free_table_info(newinfo);
|
|
return ret;
|
|
}
|
|
|
|
ret = xt_register_table(table, &bootstrap, newinfo);
|
|
if (ret != 0) {
|
|
xt_free_table_info(newinfo);
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
void arpt_unregister_table(struct arpt_table *table)
|
|
{
|
|
struct xt_table_info *private;
|
|
void *loc_cpu_entry;
|
|
|
|
private = xt_unregister_table(table);
|
|
|
|
/* Decrease module usage counts and free resources */
|
|
loc_cpu_entry = private->entries[raw_smp_processor_id()];
|
|
ARPT_ENTRY_ITERATE(loc_cpu_entry, private->size,
|
|
cleanup_entry, NULL);
|
|
xt_free_table_info(private);
|
|
}
|
|
|
|
/* The built-in targets: standard (NULL) and error. */
|
|
static struct arpt_target arpt_standard_target = {
|
|
.name = ARPT_STANDARD_TARGET,
|
|
.targetsize = sizeof(int),
|
|
.family = NF_ARP,
|
|
};
|
|
|
|
static struct arpt_target arpt_error_target = {
|
|
.name = ARPT_ERROR_TARGET,
|
|
.target = arpt_error,
|
|
.targetsize = ARPT_FUNCTION_MAXNAMELEN,
|
|
.family = NF_ARP,
|
|
};
|
|
|
|
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,
|
|
};
|
|
|
|
static int __init arp_tables_init(void)
|
|
{
|
|
int ret;
|
|
|
|
ret = xt_proto_init(NF_ARP);
|
|
if (ret < 0)
|
|
goto err1;
|
|
|
|
/* Noone else will be downing sem now, so we won't sleep */
|
|
ret = xt_register_target(&arpt_standard_target);
|
|
if (ret < 0)
|
|
goto err2;
|
|
ret = xt_register_target(&arpt_error_target);
|
|
if (ret < 0)
|
|
goto err3;
|
|
|
|
/* Register setsockopt */
|
|
ret = nf_register_sockopt(&arpt_sockopts);
|
|
if (ret < 0)
|
|
goto err4;
|
|
|
|
printk("arp_tables: (C) 2002 David S. Miller\n");
|
|
return 0;
|
|
|
|
err4:
|
|
xt_unregister_target(&arpt_error_target);
|
|
err3:
|
|
xt_unregister_target(&arpt_standard_target);
|
|
err2:
|
|
xt_proto_fini(NF_ARP);
|
|
err1:
|
|
return ret;
|
|
}
|
|
|
|
static void __exit arp_tables_fini(void)
|
|
{
|
|
nf_unregister_sockopt(&arpt_sockopts);
|
|
xt_proto_fini(NF_ARP);
|
|
}
|
|
|
|
EXPORT_SYMBOL(arpt_register_table);
|
|
EXPORT_SYMBOL(arpt_unregister_table);
|
|
EXPORT_SYMBOL(arpt_do_table);
|
|
|
|
module_init(arp_tables_init);
|
|
module_exit(arp_tables_fini);
|