diff options
Diffstat (limited to 'net/netfilter/xt_physdev.c')
| -rw-r--r-- | net/netfilter/xt_physdev.c | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/net/netfilter/xt_physdev.c b/net/netfilter/xt_physdev.c new file mode 100644 index 000000000000..19bb57c14dfe --- /dev/null +++ b/net/netfilter/xt_physdev.c @@ -0,0 +1,155 @@ +/* Kernel module to match the bridge port in and + * out device for IP packets coming into contact with a bridge. */ + +/* (C) 2001-2003 Bart De Schuymer <bdschuym@pandora.be> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/module.h> +#include <linux/skbuff.h> +#include <linux/netfilter/xt_physdev.h> +#include <linux/netfilter/x_tables.h> +#include <linux/netfilter_bridge.h> +#define MATCH 1 +#define NOMATCH 0 + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Bart De Schuymer <bdschuym@pandora.be>"); +MODULE_DESCRIPTION("iptables bridge physical device match module"); +MODULE_ALIAS("ipt_physdev"); +MODULE_ALIAS("ip6t_physdev"); + +static int +match(const struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + const void *matchinfo, + int offset, + unsigned int protoff, + int *hotdrop) +{ + int i; + static const char nulldevname[IFNAMSIZ]; + const struct xt_physdev_info *info = matchinfo; + unsigned int ret; + const char *indev, *outdev; + struct nf_bridge_info *nf_bridge; + + /* Not a bridged IP packet or no info available yet: + * LOCAL_OUT/mangle and LOCAL_OUT/nat don't know if + * the destination device will be a bridge. */ + if (!(nf_bridge = skb->nf_bridge)) { + /* Return MATCH if the invert flags of the used options are on */ + if ((info->bitmask & XT_PHYSDEV_OP_BRIDGED) && + !(info->invert & XT_PHYSDEV_OP_BRIDGED)) + return NOMATCH; + if ((info->bitmask & XT_PHYSDEV_OP_ISIN) && + !(info->invert & XT_PHYSDEV_OP_ISIN)) + return NOMATCH; + if ((info->bitmask & XT_PHYSDEV_OP_ISOUT) && + !(info->invert & XT_PHYSDEV_OP_ISOUT)) + return NOMATCH; + if ((info->bitmask & XT_PHYSDEV_OP_IN) && + !(info->invert & XT_PHYSDEV_OP_IN)) + return NOMATCH; + if ((info->bitmask & XT_PHYSDEV_OP_OUT) && + !(info->invert & XT_PHYSDEV_OP_OUT)) + return NOMATCH; + return MATCH; + } + + /* This only makes sense in the FORWARD and POSTROUTING chains */ + if ((info->bitmask & XT_PHYSDEV_OP_BRIDGED) && + (!!(nf_bridge->mask & BRNF_BRIDGED) ^ + !(info->invert & XT_PHYSDEV_OP_BRIDGED))) + return NOMATCH; + + if ((info->bitmask & XT_PHYSDEV_OP_ISIN && + (!nf_bridge->physindev ^ !!(info->invert & XT_PHYSDEV_OP_ISIN))) || + (info->bitmask & XT_PHYSDEV_OP_ISOUT && + (!nf_bridge->physoutdev ^ !!(info->invert & XT_PHYSDEV_OP_ISOUT)))) + return NOMATCH; + + if (!(info->bitmask & XT_PHYSDEV_OP_IN)) + goto match_outdev; + indev = nf_bridge->physindev ? nf_bridge->physindev->name : nulldevname; + for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned int); i++) { + ret |= (((const unsigned int *)indev)[i] + ^ ((const unsigned int *)info->physindev)[i]) + & ((const unsigned int *)info->in_mask)[i]; + } + + if ((ret == 0) ^ !(info->invert & XT_PHYSDEV_OP_IN)) + return NOMATCH; + +match_outdev: + if (!(info->bitmask & XT_PHYSDEV_OP_OUT)) + return MATCH; + outdev = nf_bridge->physoutdev ? + nf_bridge->physoutdev->name : nulldevname; + for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned int); i++) { + ret |= (((const unsigned int *)outdev)[i] + ^ ((const unsigned int *)info->physoutdev)[i]) + & ((const unsigned int *)info->out_mask)[i]; + } + + return (ret != 0) ^ !(info->invert & XT_PHYSDEV_OP_OUT); +} + +static int +checkentry(const char *tablename, + const void *ip, + void *matchinfo, + unsigned int matchsize, + unsigned int hook_mask) +{ + const struct xt_physdev_info *info = matchinfo; + + if (matchsize != XT_ALIGN(sizeof(struct xt_physdev_info))) + return 0; + if (!(info->bitmask & XT_PHYSDEV_OP_MASK) || + info->bitmask & ~XT_PHYSDEV_OP_MASK) + return 0; + return 1; +} + +static struct xt_match physdev_match = { + .name = "physdev", + .match = &match, + .checkentry = &checkentry, + .me = THIS_MODULE, +}; + +static struct xt_match physdev6_match = { + .name = "physdev", + .match = &match, + .checkentry = &checkentry, + .me = THIS_MODULE, +}; + +static int __init init(void) +{ + int ret; + + ret = xt_register_match(AF_INET, &physdev_match); + if (ret < 0) + return ret; + + ret = xt_register_match(AF_INET6, &physdev6_match); + if (ret < 0) + xt_unregister_match(AF_INET, &physdev_match); + + return ret; +} + +static void __exit fini(void) +{ + xt_unregister_match(AF_INET, &physdev_match); + xt_unregister_match(AF_INET6, &physdev6_match); +} + +module_init(init); +module_exit(fini); |