/* * net/sched/act_pedit.c Generic packet editor * * 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; either version * 2 of the License, or (at your option) any later version. * * Authors: Jamal Hadi Salim (2002-4) */ #include <linux/types.h> #include <linux/kernel.h> #include <linux/string.h> #include <linux/errno.h> #include <linux/skbuff.h> #include <linux/rtnetlink.h> #include <linux/module.h> #include <linux/init.h> #include <linux/slab.h> #include <net/netlink.h> #include <net/pkt_sched.h> #include <linux/tc_act/tc_pedit.h> #include <net/tc_act/tc_pedit.h> #define PEDIT_TAB_MASK 15 static unsigned int pedit_net_id; static struct tc_action_ops act_pedit_ops; static const struct nla_policy pedit_policy[TCA_PEDIT_MAX + 1] = { [TCA_PEDIT_PARMS] = { .len = sizeof(struct tc_pedit) }, }; static int tcf_pedit_init(struct net *net, struct nlattr *nla, struct nlattr *est, struct tc_action **a, int ovr, int bind) { struct tc_action_net *tn = net_generic(net, pedit_net_id); struct nlattr *tb[TCA_PEDIT_MAX + 1]; struct tc_pedit *parm; int ret = 0, err; struct tcf_pedit *p; struct tc_pedit_key *keys = NULL; int ksize; if (nla == NULL) return -EINVAL; err = nla_parse_nested(tb, TCA_PEDIT_MAX, nla, pedit_policy); if (err < 0) return err; if (tb[TCA_PEDIT_PARMS] == NULL) return -EINVAL; parm = nla_data(tb[TCA_PEDIT_PARMS]); ksize = parm->nkeys * sizeof(struct tc_pedit_key); if (nla_len(tb[TCA_PEDIT_PARMS]) < sizeof(*parm) + ksize) return -EINVAL; if (!tcf_hash_check(tn, parm->index, a, bind)) { if (!parm->nkeys) return -EINVAL; ret = tcf_hash_create(tn, parm->index, est, a, &act_pedit_ops, bind, false); if (ret) return ret; p = to_pedit(*a); keys = kmalloc(ksize, GFP_KERNEL); if (keys == NULL) { tcf_hash_cleanup(*a, est); return -ENOMEM; } ret = ACT_P_CREATED; } else { if (bind) return 0; tcf_hash_release(*a, bind); if (!ovr) return -EEXIST; p = to_pedit(*a); if (p->tcfp_nkeys && p->tcfp_nkeys != parm->nkeys) { keys = kmalloc(ksize, GFP_KERNEL); if (keys == NULL) return -ENOMEM; } } spin_lock_bh(&p->tcf_lock); p->tcfp_flags = parm->flags; p->tcf_action = parm->action; if (keys) { kfree(p->tcfp_keys); p->tcfp_keys = keys; p->tcfp_nkeys = parm->nkeys; } memcpy(p->tcfp_keys, parm->keys, ksize); spin_unlock_bh(&p->tcf_lock); if (ret == ACT_P_CREATED) tcf_hash_insert(tn, *a); return ret; } static void tcf_pedit_cleanup(struct tc_action *a, int bind) { struct tcf_pedit *p = to_pedit(a); struct tc_pedit_key *keys = p->tcfp_keys; kfree(keys); } static bool offset_valid(struct sk_buff *skb, int offset) { if (offset > 0 && offset > skb->len) return false; if (offset < 0 && -offset > skb_headroom(skb)) return false; return true; } static int tcf_pedit(struct sk_buff *skb, const struct tc_action *a, struct tcf_result *res) { struct tcf_pedit *p = to_pedit(a); int i; unsigned int off; if (skb_unclone(skb, GFP_ATOMIC)) return p->tcf_action; off = skb_network_offset(skb); spin_lock(&p->tcf_lock); tcf_lastuse_update(&p->tcf_tm); if (p->tcfp_nkeys > 0) { struct tc_pedit_key *tkey = p->tcfp_keys; for (i = p->tcfp_nkeys; i > 0; i--, tkey++) { u32 *ptr, _data; int offset = tkey->off; if (tkey->offmask) { char *d, _d; if (!offset_valid(skb, off + tkey->at)) { pr_info("tc filter pedit 'at' offset %d out of bounds\n", off + tkey->at); goto bad; } d = skb_header_pointer(skb, off + tkey->at, 1, &_d); if (!d) goto bad; offset += (*d & tkey->offmask) >> tkey->shift; } if (offset % 4) { pr_info("tc filter pedit" " offset must be on 32 bit boundaries\n"); goto bad; } if (!offset_valid(skb, off + offset)) { pr_info("tc filter pedit offset %d out of bounds\n", offset); goto bad; } ptr = skb_header_pointer(skb, off + offset, 4, &_data); if (!ptr) goto bad; /* just do it, baby */ *ptr = ((*ptr & tkey->mask) ^ tkey->val); if (ptr == &_data) skb_store_bits(skb, off + offset, ptr, 4); } goto done; } else WARN(1, "pedit BUG: index %d\n", p->tcf_index); bad: p->tcf_qstats.overlimits++; done: bstats_update(&p->tcf_bstats, skb); spin_unlock(&p->tcf_lock); return p->tcf_action; } static int tcf_pedit_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref) { unsigned char *b = skb_tail_pointer(skb); struct tcf_pedit *p = to_pedit(a); struct tc_pedit *opt; struct tcf_t t; int s; s = sizeof(*opt) + p->tcfp_nkeys * sizeof(struct tc_pedit_key); /* netlink spinlocks held above us - must use ATOMIC */ opt = kzalloc(s, GFP_ATOMIC); if (unlikely(!opt)) return -ENOBUFS; memcpy(opt->keys, p->tcfp_keys, p->tcfp_nkeys * sizeof(struct tc_pedit_key)); opt->index = p->tcf_index; opt->nkeys = p->tcfp_nkeys; opt->flags = p->tcfp_flags; opt->action = p->tcf_action; opt->refcnt = p->tcf_refcnt - ref; opt->bindcnt = p->tcf_bindcnt - bind; if (nla_put(skb, TCA_PEDIT_PARMS, s, opt)) goto nla_put_failure; tcf_tm_dump(&t, &p->tcf_tm); if (nla_put_64bit(skb, TCA_PEDIT_TM, sizeof(t), &t, TCA_PEDIT_PAD)) goto nla_put_failure; kfree(opt); return skb->len; nla_put_failure: nlmsg_trim(skb, b); kfree(opt); return -1; } static int tcf_pedit_walker(struct net *net, struct sk_buff *skb, struct netlink_callback *cb, int type, const struct tc_action_ops *ops) { struct tc_action_net *tn = net_generic(net, pedit_net_id); return tcf_generic_walker(tn, skb, cb, type, ops); } static int tcf_pedit_search(struct net *net, struct tc_action **a, u32 index) { struct tc_action_net *tn = net_generic(net, pedit_net_id); return tcf_hash_search(tn, a, index); } static struct tc_action_ops act_pedit_ops = { .kind = "pedit", .type = TCA_ACT_PEDIT, .owner = THIS_MODULE, .act = tcf_pedit, .dump = tcf_pedit_dump, .cleanup = tcf_pedit_cleanup, .init = tcf_pedit_init, .walk = tcf_pedit_walker, .lookup = tcf_pedit_search, .size = sizeof(struct tcf_pedit), }; static __net_init int pedit_init_net(struct net *net) { struct tc_action_net *tn = net_generic(net, pedit_net_id); return tc_action_net_init(tn, &act_pedit_ops, PEDIT_TAB_MASK); } static void __net_exit pedit_exit_net(struct net *net) { struct tc_action_net *tn = net_generic(net, pedit_net_id); tc_action_net_exit(tn); } static struct pernet_operations pedit_net_ops = { .init = pedit_init_net, .exit = pedit_exit_net, .id = &pedit_net_id, .size = sizeof(struct tc_action_net), }; MODULE_AUTHOR("Jamal Hadi Salim(2002-4)"); MODULE_DESCRIPTION("Generic Packet Editor actions"); MODULE_LICENSE("GPL"); static int __init pedit_init_module(void) { return tcf_register_action(&act_pedit_ops, &pedit_net_ops); } static void __exit pedit_cleanup_module(void) { tcf_unregister_action(&act_pedit_ops, &pedit_net_ops); } module_init(pedit_init_module); module_exit(pedit_cleanup_module);