diff options
| -rw-r--r-- | include/linux/fib_rules.h | 60 | ||||
| -rw-r--r-- | include/net/fib_rules.h | 90 | ||||
| -rw-r--r-- | net/Kconfig | 3 | ||||
| -rw-r--r-- | net/core/Makefile | 1 | ||||
| -rw-r--r-- | net/core/fib_rules.c | 416 | ||||
| -rw-r--r-- | net/core/rtnetlink.c | 9 |
6 files changed, 577 insertions, 2 deletions
diff --git a/include/linux/fib_rules.h b/include/linux/fib_rules.h new file mode 100644 index 0000000..5e503f0 --- /dev/null +++ b/include/linux/fib_rules.h @@ -0,0 +1,60 @@ +#ifndef __LINUX_FIB_RULES_H +#define __LINUX_FIB_RULES_H + +#include <linux/types.h> +#include <linux/rtnetlink.h> + +/* rule is permanent, and cannot be deleted */ +#define FIB_RULE_PERMANENT 1 + +struct fib_rule_hdr +{ + __u8 family; + __u8 dst_len; + __u8 src_len; + __u8 tos; + + __u8 table; + __u8 res1; /* reserved */ + __u8 res2; /* reserved */ + __u8 action; + + __u32 flags; +}; + +enum +{ + FRA_UNSPEC, + FRA_DST, /* destination address */ + FRA_SRC, /* source address */ + FRA_IFNAME, /* interface name */ + FRA_UNUSED1, + FRA_UNUSED2, + FRA_PRIORITY, /* priority/preference */ + FRA_UNUSED3, + FRA_UNUSED4, + FRA_UNUSED5, + FRA_FWMARK, /* netfilter mark (IPv4) */ + FRA_FLOW, /* flow/class id */ + __FRA_MAX +}; + +#define FRA_MAX (__FRA_MAX - 1) + +enum +{ + FR_ACT_UNSPEC, + FR_ACT_TO_TBL, /* Pass to fixed table */ + FR_ACT_RES1, + FR_ACT_RES2, + FR_ACT_RES3, + FR_ACT_RES4, + FR_ACT_BLACKHOLE, /* Drop without notification */ + FR_ACT_UNREACHABLE, /* Drop with ENETUNREACH */ + FR_ACT_PROHIBIT, /* Drop with EACCES */ + __FR_ACT_MAX, +}; + +#define FR_ACT_MAX (__FR_ACT_MAX - 1) + +#endif diff --git a/include/net/fib_rules.h b/include/net/fib_rules.h new file mode 100644 index 0000000..61375d9 --- /dev/null +++ b/include/net/fib_rules.h @@ -0,0 +1,90 @@ +#ifndef __NET_FIB_RULES_H +#define __NET_FIB_RULES_H + +#include <linux/types.h> +#include <linux/netdevice.h> +#include <linux/fib_rules.h> +#include <net/flow.h> +#include <net/netlink.h> + +struct fib_rule +{ + struct list_head list; + atomic_t refcnt; + int ifindex; + char ifname[IFNAMSIZ]; + u32 pref; + u32 flags; + u32 table; + u8 action; + struct rcu_head rcu; +}; + +struct fib_lookup_arg +{ + void *lookup_ptr; + void *result; + struct fib_rule *rule; +}; + +struct fib_rules_ops +{ + int family; + struct list_head list; + int rule_size; + + int (*action)(struct fib_rule *, + struct flowi *, int, + struct fib_lookup_arg *); + int (*match)(struct fib_rule *, + struct flowi *, int); + int (*configure)(struct fib_rule *, + struct sk_buff *, + struct nlmsghdr *, + struct fib_rule_hdr *, + struct nlattr **); + int (*compare)(struct fib_rule *, + struct fib_rule_hdr *, + struct nlattr **); + int (*fill)(struct fib_rule *, struct sk_buff *, + struct nlmsghdr *, + struct fib_rule_hdr *); + u32 (*default_pref)(void); + + int nlgroup; + struct nla_policy *policy; + struct list_head *rules_list; + struct module *owner; +}; + +static inline void fib_rule_get(struct fib_rule *rule) +{ + atomic_inc(&rule->refcnt); +} + +static inline void fib_rule_put_rcu(struct rcu_head *head) +{ + struct fib_rule *rule = container_of(head, struct fib_rule, rcu); + kfree(rule); +} + +static inline void fib_rule_put(struct fib_rule *rule) +{ + if (atomic_dec_and_test(&rule->refcnt)) + call_rcu(&rule->rcu, fib_rule_put_rcu); +} + +extern int fib_rules_register(struct fib_rules_ops *); +extern int fib_rules_unregister(struct fib_rules_ops *); + +extern int fib_rules_lookup(struct fib_rules_ops *, + struct flowi *, int flags, + struct fib_lookup_arg *); + +extern int fib_nl_newrule(struct sk_buff *, + struct nlmsghdr *, void *); +extern int fib_nl_delrule(struct sk_buff *, + struct nlmsghdr *, void *); +extern int fib_rules_dump(struct sk_buff *, + struct netlink_callback *, int); +#endif diff --git a/net/Kconfig b/net/Kconfig index eb855b7..6528a935 100644 --- a/net/Kconfig +++ b/net/Kconfig @@ -251,6 +251,9 @@ config WIRELESS_EXT source "net/netlabel/Kconfig" +config FIB_RULES + bool + endif # if NET endmenu # Networking diff --git a/net/core/Makefile b/net/core/Makefile index 2645ba4..1195680 100644 --- a/net/core/Makefile +++ b/net/core/Makefile @@ -17,3 +17,4 @@ obj-$(CONFIG_NET_PKTGEN) += pktgen.o obj-$(CONFIG_WIRELESS_EXT) += wireless.o obj-$(CONFIG_NETPOLL) += netpoll.o obj-$(CONFIG_NET_DMA) += user_dma.o +obj-$(CONFIG_FIB_RULES) += fib_rules.o diff --git a/net/core/fib_rules.c b/net/core/fib_rules.c new file mode 100644 index 0000000..6cdad24 --- /dev/null +++ b/net/core/fib_rules.c @@ -0,0 +1,416 @@ +/* + * net/core/fib_rules.c Generic Routing Rules + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation, version 2. + * + * Authors: Thomas Graf <tgraf@suug.ch> + */ + +#include <linux/config.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/list.h> +#include <net/fib_rules.h> + +static LIST_HEAD(rules_ops); +static DEFINE_SPINLOCK(rules_mod_lock); + +static void notify_rule_change(int event, struct fib_rule *rule, + struct fib_rules_ops *ops); + +static struct fib_rules_ops *lookup_rules_ops(int family) +{ + struct fib_rules_ops *ops; + + rcu_read_lock(); + list_for_each_entry_rcu(ops, &rules_ops, list) { + if (ops->family == family) { + if (!try_module_get(ops->owner)) + ops = NULL; + rcu_read_unlock(); + return ops; + } + } + rcu_read_unlock(); + + return NULL; +} + +static void rules_ops_put(struct fib_rules_ops *ops) +{ + if (ops) + module_put(ops->owner); +} + +int fib_rules_register(struct fib_rules_ops *ops) +{ + int err = -EEXIST; + struct fib_rules_ops *o; + + if (ops->rule_size < sizeof(struct fib_rule)) + return -EINVAL; + + if (ops->match == NULL || ops->configure == NULL || + ops->compare == NULL || ops->fill == NULL || + ops->action == NULL) + return -EINVAL; + + spin_lock(&rules_mod_lock); + list_for_each_entry(o, &rules_ops, list) + if (ops->family == o->family) + goto errout; + + list_add_tail_rcu(&ops->list, &rules_ops); + err = 0; +errout: + spin_unlock(&rules_mod_lock); + + return err; +} + +EXPORT_SYMBOL_GPL(fib_rules_register); + +static void cleanup_ops(struct fib_rules_ops *ops) +{ + struct fib_rule *rule, *tmp; + + list_for_each_entry_safe(rule, tmp, ops->rules_list, list) { + list_del_rcu(&rule->list); + fib_rule_put(rule); + } +} + +int fib_rules_unregister(struct fib_rules_ops *ops) +{ + int err = 0; + struct fib_rules_ops *o; + + spin_lock(&rules_mod_lock); + list_for_each_entry(o, &rules_ops, list) { + if (o == ops) { + list_del_rcu(&o->list); + cleanup_ops(ops); + goto out; + } + } + + err = -ENOENT; +out: + spin_unlock(&rules_mod_lock); + + synchronize_rcu(); + + return err; +} + +EXPORT_SYMBOL_GPL(fib_rules_unregister); + +int fib_rules_lookup(struct fib_rules_ops *ops, struct flowi *fl, + int flags, struct fib_lookup_arg *arg) +{ + struct fib_rule *rule; + int err; + + rcu_read_lock(); + + list_for_each_entry_rcu(rule, ops->rules_list, list) { + if (rule->ifindex && (rule->ifindex != fl->iif)) + continue; + + if (!ops->match(rule, fl, flags)) + continue; + + err = ops->action(rule, fl, flags, arg); + if (err != -EAGAIN) { + fib_rule_get(rule); + arg->rule = rule; + goto out; + } + } + + err = -ENETUNREACH; +out: + rcu_read_unlock(); + + return err; +} + +EXPORT_SYMBOL_GPL(fib_rules_lookup); + +int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg) +{ + struct fib_rule_hdr *frh = nlmsg_data(nlh); + struct fib_rules_ops *ops = NULL; + struct fib_rule *rule, *r, *last = NULL; + struct nlattr *tb[FRA_MAX+1]; + int err = -EINVAL; + + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) + goto errout; + + ops = lookup_rules_ops(frh->family); + if (ops == NULL) { + err = EAFNOSUPPORT; + goto errout; + } + + err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy); + if (err < 0) + goto errout; + + if (tb[FRA_IFNAME] && nla_len(tb[FRA_IFNAME]) > IFNAMSIZ) + goto errout; + + rule = kzalloc(ops->rule_size, GFP_KERNEL); + if (rule == NULL) { + err = -ENOMEM; + goto errout; + } + + if (tb[FRA_PRIORITY]) + rule->pref = nla_get_u32(tb[FRA_PRIORITY]); + + if (tb[FRA_IFNAME]) { + struct net_device *dev; + + rule->ifindex = -1; + if (nla_strlcpy(rule->ifname, tb[FRA_IFNAME], + IFNAMSIZ) >= IFNAMSIZ) + goto errout_free; + + dev = __dev_get_by_name(rule->ifname); + if (dev) + rule->ifindex = dev->ifindex; + } + + rule->action = frh->action; + rule->flags = frh->flags; + rule->table = frh->table; + + if (!rule->pref && ops->default_pref) + rule->pref = ops->default_pref(); + + err = ops->configure(rule, skb, nlh, frh, tb); + if (err < 0) + goto errout_free; + + list_for_each_entry(r, ops->rules_list, list) { + if (r->pref > rule->pref) + break; + last = r; + } + + fib_rule_get(rule); + + if (last) + list_add_rcu(&rule->list, &last->list); + else + list_add_rcu(&rule->list, ops->rules_list); + + notify_rule_change(RTM_NEWRULE, rule, ops); + rules_ops_put(ops); + return 0; + +errout_free: + kfree(rule); +errout: + rules_ops_put(ops); + return err; +} + +int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg) +{ + struct fib_rule_hdr *frh = nlmsg_data(nlh); + struct fib_rules_ops *ops = NULL; + struct fib_rule *rule; + struct nlattr *tb[FRA_MAX+1]; + int err = -EINVAL; + + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) + goto errout; + + ops = lookup_rules_ops(frh->family); + if (ops == NULL) { + err = EAFNOSUPPORT; + goto errout; + } + + err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy); + if (err < 0) + goto errout; + + list_for_each_entry(rule, ops->rules_list, list) { + if (frh->action && (frh->action != rule->action)) + continue; + + if (frh->table && (frh->table != rule->table)) + continue; + + if (tb[FRA_PRIORITY] && + (rule->pref != nla_get_u32(tb[FRA_PRIORITY]))) + continue; + + if (tb[FRA_IFNAME] && + nla_strcmp(tb[FRA_IFNAME], rule->ifname)) + continue; + + if (!ops->compare(rule, frh, tb)) + continue; + + if (rule->flags & FIB_RULE_PERMANENT) { + err = -EPERM; + goto errout; + } + + list_del_rcu(&rule->list); + synchronize_rcu(); + notify_rule_change(RTM_DELRULE, rule, ops); + fib_rule_put(rule); + rules_ops_put(ops); + return 0; + } + + err = -ENOENT; +errout: + rules_ops_put(ops); + return err; +} + +static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule, + u32 pid, u32 seq, int type, int flags, + struct fib_rules_ops *ops) +{ + struct nlmsghdr *nlh; + struct fib_rule_hdr *frh; + + nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags); + if (nlh == NULL) + return -1; + + frh = nlmsg_data(nlh); + frh->table = rule->table; + frh->res1 = 0; + frh->res2 = 0; + frh->action = rule->action; + frh->flags = rule->flags; + + if (rule->ifname[0]) + NLA_PUT_STRING(skb, FRA_IFNAME, rule->ifname); + + if (rule->pref) + NLA_PUT_U32(skb, FRA_PRIORITY, rule->pref); + + if (ops->fill(rule, skb, nlh, frh) < 0) + goto nla_put_failure; + + return nlmsg_end(skb, nlh); + +nla_put_failure: + return nlmsg_cancel(skb, nlh); +} + +int fib_rules_dump(struct sk_buff *skb, struct netlink_callback *cb, int family) +{ + int idx = 0; + struct fib_rule *rule; + struct fib_rules_ops *ops; + + ops = lookup_rules_ops(family); + if (ops == NULL) + return -EAFNOSUPPORT; + + rcu_read_lock(); + list_for_each_entry(rule, ops->rules_list, list) { + if (idx < cb->args[0]) + goto skip; + + if (fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).pid, + cb->nlh->nlmsg_seq, RTM_NEWRULE, + NLM_F_MULTI, ops) < 0) + break; +skip: + idx++; + } + rcu_read_unlock(); + cb->args[0] = idx; + rules_ops_put(ops); + + return skb->len; +} + +EXPORT_SYMBOL_GPL(fib_rules_dump); + +static void notify_rule_change(int event, struct fib_rule *rule, + struct fib_rules_ops *ops) +{ + int size = nlmsg_total_size(sizeof(struct fib_rule_hdr) + 128); + struct sk_buff *skb = alloc_skb(size, GFP_KERNEL); + + if (skb == NULL) + netlink_set_err(rtnl, 0, ops->nlgroup, ENOBUFS); + else if (fib_nl_fill_rule(skb, rule, 0, 0, event, 0, ops) < 0) { + kfree_skb(skb); + netlink_set_err(rtnl, 0, ops->nlgroup, EINVAL); + } else + netlink_broadcast(rtnl, skb, 0, ops->nlgroup, GFP_KERNEL); +} + +static void attach_rules(struct list_head *rules, struct net_device *dev) +{ + struct fib_rule *rule; + + list_for_each_entry(rule, rules, list) { + if (rule->ifindex == -1 && + strcmp(dev->name, rule->ifname) == 0) + rule->ifindex = dev->ifindex; + } +} + +static void detach_rules(struct list_head *rules, struct net_device *dev) +{ + struct fib_rule *rule; + + list_for_each_entry(rule, rules, list) + if (rule->ifindex == dev->ifindex) + rule->ifindex = -1; +} + + +static int fib_rules_event(struct notifier_block *this, unsigned long event, + void *ptr) +{ + struct net_device *dev = ptr; + struct fib_rules_ops *ops; + + ASSERT_RTNL(); + rcu_read_lock(); + + switch (event) { + case NETDEV_REGISTER: + list_for_each_entry(ops, &rules_ops, list) + attach_rules(ops->rules_list, dev); + break; + + case NETDEV_UNREGISTER: + list_for_each_entry(ops, &rules_ops, list) + detach_rules(ops->rules_list, dev); + break; + } + + rcu_read_unlock(); + + return NOTIFY_DONE; +} + +static struct notifier_block fib_rules_notifier = { + .notifier_call = fib_rules_event, +}; + +static int __init fib_rules_init(void) +{ + return register_netdevice_notifier(&fib_rules_notifier); +} + +subsys_initcall(fib_rules_init); diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 30cc1ba..aa7cff2 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -49,6 +49,7 @@ #include <net/udp.h> #include <net/sock.h> #include <net/pkt_sched.h> +#include <net/fib_rules.h> #include <net/netlink.h> #ifdef CONFIG_NET_WIRELESS_RTNETLINK #include <linux/wireless.h> @@ -103,7 +104,7 @@ static const int rtm_min[RTM_NR_FAMILIES] = [RTM_FAM(RTM_NEWADDR)] = NLMSG_LENGTH(sizeof(struct ifaddrmsg)), [RTM_FAM(RTM_NEWROUTE)] = NLMSG_LENGTH(sizeof(struct rtmsg)), [RTM_FAM(RTM_NEWNEIGH)] = NLMSG_LENGTH(sizeof(struct ndmsg)), - [RTM_FAM(RTM_NEWRULE)] = NLMSG_LENGTH(sizeof(struct rtmsg)), + [RTM_FAM(RTM_NEWRULE)] = NLMSG_LENGTH(sizeof(struct fib_rule_hdr)), [RTM_FAM(RTM_NEWQDISC)] = NLMSG_LENGTH(sizeof(struct tcmsg)), [RTM_FAM(RTM_NEWTCLASS)] = NLMSG_LENGTH(sizeof(struct tcmsg)), [RTM_FAM(RTM_NEWTFILTER)] = NLMSG_LENGTH(sizeof(struct tcmsg)), @@ -120,7 +121,7 @@ static const int rta_max[RTM_NR_FAMILIES] = [RTM_FAM(RTM_NEWADDR)] = IFA_MAX, [RTM_FAM(RTM_NEWROUTE)] = RTA_MAX, [RTM_FAM(RTM_NEWNEIGH)] = NDA_MAX, - [RTM_FAM(RTM_NEWRULE)] = RTA_MAX, + [RTM_FAM(RTM_NEWRULE)] = FRA_MAX, [RTM_FAM(RTM_NEWQDISC)] = TCA_MAX, [RTM_FAM(RTM_NEWTCLASS)] = TCA_MAX, [RTM_FAM(RTM_NEWTFILTER)] = TCA_MAX, @@ -757,6 +758,10 @@ static struct rtnetlink_link link_rtnetlink_table[RTM_NR_MSGTYPES] = [RTM_NEWNEIGH - RTM_BASE] = { .doit = neigh_add }, [RTM_DELNEIGH - RTM_BASE] = { .doit = neigh_delete }, [RTM_GETNEIGH - RTM_BASE] = { .dumpit = neigh_dump_info }, +#ifdef CONFIG_FIB_RULES + [RTM_NEWRULE - RTM_BASE] = { .doit = fib_nl_newrule }, + [RTM_DELRULE - RTM_BASE] = { .doit = fib_nl_delrule }, +#endif [RTM_GETRULE - RTM_BASE] = { .dumpit = rtnetlink_dump_all }, [RTM_GETNEIGHTBL - RTM_BASE] = { .dumpit = neightbl_dump_info }, [RTM_SETNEIGHTBL - RTM_BASE] = { .doit = neightbl_set }, |
