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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 nlattr *nla, struct nlattr *est,
42 struct tc_action *a, int ovr, int bind)
43{
44 struct nlattr *tb[TCA_PEDIT_MAX + 1];
45 struct tc_pedit *parm;
46 int ret = 0, err;
47 struct tcf_pedit *p;
48 struct tcf_common *pc;
49 struct tc_pedit_key *keys = NULL;
50 int ksize;
51
52 if (nla == NULL)
53 return -EINVAL;
54
55 err = nla_parse_nested(tb, TCA_PEDIT_MAX, nla, pedit_policy);
56 if (err < 0)
57 return err;
58
59 if (tb[TCA_PEDIT_PARMS] == NULL)
60 return -EINVAL;
61 parm = nla_data(tb[TCA_PEDIT_PARMS]);
62 ksize = parm->nkeys * sizeof(struct tc_pedit_key);
63 if (nla_len(tb[TCA_PEDIT_PARMS]) < sizeof(*parm) + ksize)
64 return -EINVAL;
65
66 pc = tcf_hash_check(parm->index, a, bind, &pedit_hash_info);
67 if (!pc) {
68 if (!parm->nkeys)
69 return -EINVAL;
70 pc = tcf_hash_create(parm->index, est, a, sizeof(*p), bind,
71 &pedit_idx_gen, &pedit_hash_info);
72 if (IS_ERR(pc))
73 return PTR_ERR(pc);
74 p = to_pedit(pc);
75 keys = kmalloc(ksize, GFP_KERNEL);
76 if (keys == NULL) {
77 kfree(pc);
78 return -ENOMEM;
79 }
80 ret = ACT_P_CREATED;
81 } else {
82 p = to_pedit(pc);
83 if (!ovr) {
84 tcf_hash_release(pc, bind, &pedit_hash_info);
85 return -EEXIST;
86 }
87 if (p->tcfp_nkeys && p->tcfp_nkeys != parm->nkeys) {
88 keys = kmalloc(ksize, GFP_KERNEL);
89 if (keys == NULL)
90 return -ENOMEM;
91 }
92 }
93
94 spin_lock_bh(&p->tcf_lock);
95 p->tcfp_flags = parm->flags;
96 p->tcf_action = parm->action;
97 if (keys) {
98 kfree(p->tcfp_keys);
99 p->tcfp_keys = keys;
100 p->tcfp_nkeys = parm->nkeys;
101 }
102 memcpy(p->tcfp_keys, parm->keys, ksize);
103 spin_unlock_bh(&p->tcf_lock);
104 if (ret == ACT_P_CREATED)
105 tcf_hash_insert(pc, &pedit_hash_info);
106 return ret;
107}
108
109static int tcf_pedit_cleanup(struct tc_action *a, int bind)
110{
111 struct tcf_pedit *p = a->priv;
112
113 if (p) {
114 struct tc_pedit_key *keys = p->tcfp_keys;
115 if (tcf_hash_release(&p->common, bind, &pedit_hash_info)) {
116 kfree(keys);
117 return 1;
118 }
119 }
120 return 0;
121}
122
123static int tcf_pedit(struct sk_buff *skb, struct tc_action *a,
124 struct tcf_result *res)
125{
126 struct tcf_pedit *p = a->priv;
127 int i, munged = 0;
128 unsigned int off;
129
130 if (skb_cloned(skb)) {
131 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) {
132 return p->tcf_action;
133 }
134 }
135
136 off = skb_network_offset(skb);
137
138 spin_lock(&p->tcf_lock);
139
140 p->tcf_tm.lastuse = jiffies;
141
142 if (p->tcfp_nkeys > 0) {
143 struct tc_pedit_key *tkey = p->tcfp_keys;
144
145 for (i = p->tcfp_nkeys; i > 0; i--, tkey++) {
146 u32 *ptr, _data;
147 int offset = tkey->off;
148
149 if (tkey->offmask) {
150 char *d, _d;
151
152 d = skb_header_pointer(skb, off + tkey->at, 1,
153 &_d);
154 if (!d)
155 goto bad;
156 offset += (*d & tkey->offmask) >> tkey->shift;
157 }
158
159 if (offset % 4) {
160 pr_info("tc filter pedit"
161 " offset must be on 32 bit boundaries\n");
162 goto bad;
163 }
164 if (offset > 0 && offset > skb->len) {
165 pr_info("tc filter pedit"
166 " offset %d cant exceed pkt length %d\n",
167 offset, skb->len);
168 goto bad;
169 }
170
171 ptr = skb_header_pointer(skb, off + offset, 4, &_data);
172 if (!ptr)
173 goto bad;
174
175 *ptr = ((*ptr & tkey->mask) ^ tkey->val);
176 if (ptr == &_data)
177 skb_store_bits(skb, off + offset, ptr, 4);
178 munged++;
179 }
180
181 if (munged)
182 skb->tc_verd = SET_TC_MUNGED(skb->tc_verd);
183 goto done;
184 } else
185 WARN(1, "pedit BUG: index %d\n", p->tcf_index);
186
187bad:
188 p->tcf_qstats.overlimits++;
189done:
190 p->tcf_bstats.bytes += qdisc_pkt_len(skb);
191 p->tcf_bstats.packets++;
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 NLA_PUT(skb, TCA_PEDIT_PARMS, s, opt);
222 t.install = jiffies_to_clock_t(jiffies - p->tcf_tm.install);
223 t.lastuse = jiffies_to_clock_t(jiffies - p->tcf_tm.lastuse);
224 t.expires = jiffies_to_clock_t(p->tcf_tm.expires);
225 NLA_PUT(skb, TCA_PEDIT_TM, sizeof(t), &t);
226 kfree(opt);
227 return skb->len;
228
229nla_put_failure:
230 nlmsg_trim(skb, b);
231 kfree(opt);
232 return -1;
233}
234
235static struct tc_action_ops act_pedit_ops = {
236 .kind = "pedit",
237 .hinfo = &pedit_hash_info,
238 .type = TCA_ACT_PEDIT,
239 .capab = TCA_CAP_NONE,
240 .owner = THIS_MODULE,
241 .act = tcf_pedit,
242 .dump = tcf_pedit_dump,
243 .cleanup = tcf_pedit_cleanup,
244 .lookup = tcf_hash_search,
245 .init = tcf_pedit_init,
246 .walk = tcf_generic_walker
247};
248
249MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
250MODULE_DESCRIPTION("Generic Packet Editor actions");
251MODULE_LICENSE("GPL");
252
253static int __init pedit_init_module(void)
254{
255 return tcf_register_action(&act_pedit_ops);
256}
257
258static void __exit pedit_cleanup_module(void)
259{
260 tcf_unregister_action(&act_pedit_ops);
261}
262
263module_init(pedit_init_module);
264module_exit(pedit_cleanup_module);
265
266
