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12#include <linux/types.h>
13#include <linux/kernel.h>
14#include <linux/string.h>
15#include <linux/errno.h>
16#include <linux/skbuff.h>
17#include <linux/rtnetlink.h>
18#include <linux/module.h>
19#include <linux/init.h>
20#include <linux/slab.h>
21#include <net/netlink.h>
22#include <net/pkt_sched.h>
23#include <linux/tc_act/tc_pedit.h>
24#include <net/tc_act/tc_pedit.h>
25
26#define PEDIT_TAB_MASK 15
27static struct tcf_common *tcf_pedit_ht[PEDIT_TAB_MASK + 1];
28static u32 pedit_idx_gen;
29static DEFINE_RWLOCK(pedit_lock);
30
31static struct tcf_hashinfo pedit_hash_info = {
32 .htab = tcf_pedit_ht,
33 .hmask = PEDIT_TAB_MASK,
34 .lock = &pedit_lock,
35};
36
37static const struct nla_policy pedit_policy[TCA_PEDIT_MAX + 1] = {
38 [TCA_PEDIT_PARMS] = { .len = sizeof(struct tc_pedit) },
39};
40
41static int tcf_pedit_init(struct net *net, struct nlattr *nla,
42 struct nlattr *est, struct tc_action *a,
43 int ovr, int bind)
44{
45 struct nlattr *tb[TCA_PEDIT_MAX + 1];
46 struct tc_pedit *parm;
47 int ret = 0, err;
48 struct tcf_pedit *p;
49 struct tcf_common *pc;
50 struct tc_pedit_key *keys = NULL;
51 int ksize;
52
53 if (nla == NULL)
54 return -EINVAL;
55
56 err = nla_parse_nested(tb, TCA_PEDIT_MAX, nla, pedit_policy);
57 if (err < 0)
58 return err;
59
60 if (tb[TCA_PEDIT_PARMS] == NULL)
61 return -EINVAL;
62 parm = nla_data(tb[TCA_PEDIT_PARMS]);
63 ksize = parm->nkeys * sizeof(struct tc_pedit_key);
64 if (nla_len(tb[TCA_PEDIT_PARMS]) < sizeof(*parm) + ksize)
65 return -EINVAL;
66
67 pc = tcf_hash_check(parm->index, a, bind, &pedit_hash_info);
68 if (!pc) {
69 if (!parm->nkeys)
70 return -EINVAL;
71 pc = tcf_hash_create(parm->index, est, a, sizeof(*p), bind,
72 &pedit_idx_gen, &pedit_hash_info);
73 if (IS_ERR(pc))
74 return PTR_ERR(pc);
75 p = to_pedit(pc);
76 keys = kmalloc(ksize, GFP_KERNEL);
77 if (keys == NULL) {
78 if (est)
79 gen_kill_estimator(&pc->tcfc_bstats,
80 &pc->tcfc_rate_est);
81 kfree_rcu(pc, tcfc_rcu);
82 return -ENOMEM;
83 }
84 ret = ACT_P_CREATED;
85 } else {
86 p = to_pedit(pc);
87 if (!ovr) {
88 tcf_hash_release(pc, bind, &pedit_hash_info);
89 return -EEXIST;
90 }
91 if (p->tcfp_nkeys && p->tcfp_nkeys != parm->nkeys) {
92 keys = kmalloc(ksize, GFP_KERNEL);
93 if (keys == NULL)
94 return -ENOMEM;
95 }
96 }
97
98 spin_lock_bh(&p->tcf_lock);
99 p->tcfp_flags = parm->flags;
100 p->tcf_action = parm->action;
101 if (keys) {
102 kfree(p->tcfp_keys);
103 p->tcfp_keys = keys;
104 p->tcfp_nkeys = parm->nkeys;
105 }
106 memcpy(p->tcfp_keys, parm->keys, ksize);
107 spin_unlock_bh(&p->tcf_lock);
108 if (ret == ACT_P_CREATED)
109 tcf_hash_insert(pc, &pedit_hash_info);
110 return ret;
111}
112
113static int tcf_pedit_cleanup(struct tc_action *a, int bind)
114{
115 struct tcf_pedit *p = a->priv;
116
117 if (p) {
118 struct tc_pedit_key *keys = p->tcfp_keys;
119 if (tcf_hash_release(&p->common, bind, &pedit_hash_info)) {
120 kfree(keys);
121 return 1;
122 }
123 }
124 return 0;
125}
126
127static int tcf_pedit(struct sk_buff *skb, const struct tc_action *a,
128 struct tcf_result *res)
129{
130 struct tcf_pedit *p = a->priv;
131 int i, munged = 0;
132 unsigned int off;
133
134 if (skb_unclone(skb, GFP_ATOMIC))
135 return p->tcf_action;
136
137 off = skb_network_offset(skb);
138
139 spin_lock(&p->tcf_lock);
140
141 p->tcf_tm.lastuse = jiffies;
142
143 if (p->tcfp_nkeys > 0) {
144 struct tc_pedit_key *tkey = p->tcfp_keys;
145
146 for (i = p->tcfp_nkeys; i > 0; i--, tkey++) {
147 u32 *ptr, _data;
148 int offset = tkey->off;
149
150 if (tkey->offmask) {
151 char *d, _d;
152
153 d = skb_header_pointer(skb, off + tkey->at, 1,
154 &_d);
155 if (!d)
156 goto bad;
157 offset += (*d & tkey->offmask) >> tkey->shift;
158 }
159
160 if (offset % 4) {
161 pr_info("tc filter pedit"
162 " offset must be on 32 bit boundaries\n");
163 goto bad;
164 }
165 if (offset > 0 && offset > skb->len) {
166 pr_info("tc filter pedit"
167 " offset %d can't exceed pkt length %d\n",
168 offset, skb->len);
169 goto bad;
170 }
171
172 ptr = skb_header_pointer(skb, off + offset, 4, &_data);
173 if (!ptr)
174 goto bad;
175
176 *ptr = ((*ptr & tkey->mask) ^ tkey->val);
177 if (ptr == &_data)
178 skb_store_bits(skb, off + offset, ptr, 4);
179 munged++;
180 }
181
182 if (munged)
183 skb->tc_verd = SET_TC_MUNGED(skb->tc_verd);
184 goto done;
185 } else
186 WARN(1, "pedit BUG: index %d\n", p->tcf_index);
187
188bad:
189 p->tcf_qstats.overlimits++;
190done:
191 bstats_update(&p->tcf_bstats, skb);
192 spin_unlock(&p->tcf_lock);
193 return p->tcf_action;
194}
195
196static int tcf_pedit_dump(struct sk_buff *skb, struct tc_action *a,
197 int bind, int ref)
198{
199 unsigned char *b = skb_tail_pointer(skb);
200 struct tcf_pedit *p = a->priv;
201 struct tc_pedit *opt;
202 struct tcf_t t;
203 int s;
204
205 s = sizeof(*opt) + p->tcfp_nkeys * sizeof(struct tc_pedit_key);
206
207
208 opt = kzalloc(s, GFP_ATOMIC);
209 if (unlikely(!opt))
210 return -ENOBUFS;
211
212 memcpy(opt->keys, p->tcfp_keys,
213 p->tcfp_nkeys * sizeof(struct tc_pedit_key));
214 opt->index = p->tcf_index;
215 opt->nkeys = p->tcfp_nkeys;
216 opt->flags = p->tcfp_flags;
217 opt->action = p->tcf_action;
218 opt->refcnt = p->tcf_refcnt - ref;
219 opt->bindcnt = p->tcf_bindcnt - bind;
220
221 if (nla_put(skb, TCA_PEDIT_PARMS, s, opt))
222 goto nla_put_failure;
223 t.install = jiffies_to_clock_t(jiffies - p->tcf_tm.install);
224 t.lastuse = jiffies_to_clock_t(jiffies - p->tcf_tm.lastuse);
225 t.expires = jiffies_to_clock_t(p->tcf_tm.expires);
226 if (nla_put(skb, TCA_PEDIT_TM, sizeof(t), &t))
227 goto nla_put_failure;
228 kfree(opt);
229 return skb->len;
230
231nla_put_failure:
232 nlmsg_trim(skb, b);
233 kfree(opt);
234 return -1;
235}
236
237static struct tc_action_ops act_pedit_ops = {
238 .kind = "pedit",
239 .hinfo = &pedit_hash_info,
240 .type = TCA_ACT_PEDIT,
241 .capab = TCA_CAP_NONE,
242 .owner = THIS_MODULE,
243 .act = tcf_pedit,
244 .dump = tcf_pedit_dump,
245 .cleanup = tcf_pedit_cleanup,
246 .lookup = tcf_hash_search,
247 .init = tcf_pedit_init,
248 .walk = tcf_generic_walker
249};
250
251MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
252MODULE_DESCRIPTION("Generic Packet Editor actions");
253MODULE_LICENSE("GPL");
254
255static int __init pedit_init_module(void)
256{
257 return tcf_register_action(&act_pedit_ops);
258}
259
260static void __exit pedit_cleanup_module(void)
261{
262 tcf_unregister_action(&act_pedit_ops);
263}
264
265module_init(pedit_init_module);
266module_exit(pedit_cleanup_module);
267
268
