| 1 | /* |
| 2 | * net/sched/simp.c Simple example of an action |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU General Public License |
| 6 | * as published by the Free Software Foundation; either version |
| 7 | * 2 of the License, or (at your option) any later version. |
| 8 | * |
| 9 | * Authors: Jamal Hadi Salim (2005-8) |
| 10 | * |
| 11 | */ |
| 12 | |
| 13 | #include <linux/module.h> |
| 14 | #include <linux/slab.h> |
| 15 | #include <linux/init.h> |
| 16 | #include <linux/kernel.h> |
| 17 | #include <linux/skbuff.h> |
| 18 | #include <linux/rtnetlink.h> |
| 19 | #include <net/netlink.h> |
| 20 | #include <net/pkt_sched.h> |
| 21 | |
| 22 | #define TCA_ACT_SIMP 22 |
| 23 | |
| 24 | #include <linux/tc_act/tc_defact.h> |
| 25 | #include <net/tc_act/tc_defact.h> |
| 26 | |
| 27 | #define SIMP_TAB_MASK 7 |
| 28 | static struct tcf_common *tcf_simp_ht[SIMP_TAB_MASK + 1]; |
| 29 | static u32 simp_idx_gen; |
| 30 | static DEFINE_RWLOCK(simp_lock); |
| 31 | |
| 32 | static struct tcf_hashinfo simp_hash_info = { |
| 33 | .htab = tcf_simp_ht, |
| 34 | .hmask = SIMP_TAB_MASK, |
| 35 | .lock = &simp_lock, |
| 36 | }; |
| 37 | |
| 38 | #define SIMP_MAX_DATA 32 |
| 39 | static int tcf_simp(struct sk_buff *skb, struct tc_action *a, struct tcf_result *res) |
| 40 | { |
| 41 | struct tcf_defact *d = a->priv; |
| 42 | |
| 43 | spin_lock(&d->tcf_lock); |
| 44 | d->tcf_tm.lastuse = jiffies; |
| 45 | d->tcf_bstats.bytes += qdisc_pkt_len(skb); |
| 46 | d->tcf_bstats.packets++; |
| 47 | |
| 48 | /* print policy string followed by _ then packet count |
| 49 | * Example if this was the 3rd packet and the string was "hello" |
| 50 | * then it would look like "hello_3" (without quotes) |
| 51 | **/ |
| 52 | pr_info("simple: %s_%d\n", |
| 53 | (char *)d->tcfd_defdata, d->tcf_bstats.packets); |
| 54 | spin_unlock(&d->tcf_lock); |
| 55 | return d->tcf_action; |
| 56 | } |
| 57 | |
| 58 | static int tcf_simp_release(struct tcf_defact *d, int bind) |
| 59 | { |
| 60 | int ret = 0; |
| 61 | if (d) { |
| 62 | if (bind) |
| 63 | d->tcf_bindcnt--; |
| 64 | d->tcf_refcnt--; |
| 65 | if (d->tcf_bindcnt <= 0 && d->tcf_refcnt <= 0) { |
| 66 | kfree(d->tcfd_defdata); |
| 67 | tcf_hash_destroy(&d->common, &simp_hash_info); |
| 68 | ret = 1; |
| 69 | } |
| 70 | } |
| 71 | return ret; |
| 72 | } |
| 73 | |
| 74 | static int alloc_defdata(struct tcf_defact *d, char *defdata) |
| 75 | { |
| 76 | d->tcfd_defdata = kstrndup(defdata, SIMP_MAX_DATA, GFP_KERNEL); |
| 77 | if (unlikely(!d->tcfd_defdata)) |
| 78 | return -ENOMEM; |
| 79 | |
| 80 | return 0; |
| 81 | } |
| 82 | |
| 83 | static void reset_policy(struct tcf_defact *d, char *defdata, |
| 84 | struct tc_defact *p) |
| 85 | { |
| 86 | spin_lock_bh(&d->tcf_lock); |
| 87 | d->tcf_action = p->action; |
| 88 | memset(d->tcfd_defdata, 0, SIMP_MAX_DATA); |
| 89 | strlcpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA); |
| 90 | spin_unlock_bh(&d->tcf_lock); |
| 91 | } |
| 92 | |
| 93 | static const struct nla_policy simple_policy[TCA_DEF_MAX + 1] = { |
| 94 | [TCA_DEF_PARMS] = { .len = sizeof(struct tc_defact) }, |
| 95 | [TCA_DEF_DATA] = { .type = NLA_STRING, .len = SIMP_MAX_DATA }, |
| 96 | }; |
| 97 | |
| 98 | static int tcf_simp_init(struct nlattr *nla, struct nlattr *est, |
| 99 | struct tc_action *a, int ovr, int bind) |
| 100 | { |
| 101 | struct nlattr *tb[TCA_DEF_MAX + 1]; |
| 102 | struct tc_defact *parm; |
| 103 | struct tcf_defact *d; |
| 104 | struct tcf_common *pc; |
| 105 | char *defdata; |
| 106 | int ret = 0, err; |
| 107 | |
| 108 | if (nla == NULL) |
| 109 | return -EINVAL; |
| 110 | |
| 111 | err = nla_parse_nested(tb, TCA_DEF_MAX, nla, simple_policy); |
| 112 | if (err < 0) |
| 113 | return err; |
| 114 | |
| 115 | if (tb[TCA_DEF_PARMS] == NULL) |
| 116 | return -EINVAL; |
| 117 | |
| 118 | if (tb[TCA_DEF_DATA] == NULL) |
| 119 | return -EINVAL; |
| 120 | |
| 121 | parm = nla_data(tb[TCA_DEF_PARMS]); |
| 122 | defdata = nla_data(tb[TCA_DEF_DATA]); |
| 123 | |
| 124 | pc = tcf_hash_check(parm->index, a, bind, &simp_hash_info); |
| 125 | if (!pc) { |
| 126 | pc = tcf_hash_create(parm->index, est, a, sizeof(*d), bind, |
| 127 | &simp_idx_gen, &simp_hash_info); |
| 128 | if (IS_ERR(pc)) |
| 129 | return PTR_ERR(pc); |
| 130 | |
| 131 | d = to_defact(pc); |
| 132 | ret = alloc_defdata(d, defdata); |
| 133 | if (ret < 0) { |
| 134 | kfree(pc); |
| 135 | return ret; |
| 136 | } |
| 137 | d->tcf_action = parm->action; |
| 138 | ret = ACT_P_CREATED; |
| 139 | } else { |
| 140 | d = to_defact(pc); |
| 141 | if (!ovr) { |
| 142 | tcf_simp_release(d, bind); |
| 143 | return -EEXIST; |
| 144 | } |
| 145 | reset_policy(d, defdata, parm); |
| 146 | } |
| 147 | |
| 148 | if (ret == ACT_P_CREATED) |
| 149 | tcf_hash_insert(pc, &simp_hash_info); |
| 150 | return ret; |
| 151 | } |
| 152 | |
| 153 | static inline int tcf_simp_cleanup(struct tc_action *a, int bind) |
| 154 | { |
| 155 | struct tcf_defact *d = a->priv; |
| 156 | |
| 157 | if (d) |
| 158 | return tcf_simp_release(d, bind); |
| 159 | return 0; |
| 160 | } |
| 161 | |
| 162 | static inline int tcf_simp_dump(struct sk_buff *skb, struct tc_action *a, |
| 163 | int bind, int ref) |
| 164 | { |
| 165 | unsigned char *b = skb_tail_pointer(skb); |
| 166 | struct tcf_defact *d = a->priv; |
| 167 | struct tc_defact opt; |
| 168 | struct tcf_t t; |
| 169 | |
| 170 | opt.index = d->tcf_index; |
| 171 | opt.refcnt = d->tcf_refcnt - ref; |
| 172 | opt.bindcnt = d->tcf_bindcnt - bind; |
| 173 | opt.action = d->tcf_action; |
| 174 | NLA_PUT(skb, TCA_DEF_PARMS, sizeof(opt), &opt); |
| 175 | NLA_PUT_STRING(skb, TCA_DEF_DATA, d->tcfd_defdata); |
| 176 | t.install = jiffies_to_clock_t(jiffies - d->tcf_tm.install); |
| 177 | t.lastuse = jiffies_to_clock_t(jiffies - d->tcf_tm.lastuse); |
| 178 | t.expires = jiffies_to_clock_t(d->tcf_tm.expires); |
| 179 | NLA_PUT(skb, TCA_DEF_TM, sizeof(t), &t); |
| 180 | return skb->len; |
| 181 | |
| 182 | nla_put_failure: |
| 183 | nlmsg_trim(skb, b); |
| 184 | return -1; |
| 185 | } |
| 186 | |
| 187 | static struct tc_action_ops act_simp_ops = { |
| 188 | .kind = "simple", |
| 189 | .hinfo = &simp_hash_info, |
| 190 | .type = TCA_ACT_SIMP, |
| 191 | .capab = TCA_CAP_NONE, |
| 192 | .owner = THIS_MODULE, |
| 193 | .act = tcf_simp, |
| 194 | .dump = tcf_simp_dump, |
| 195 | .cleanup = tcf_simp_cleanup, |
| 196 | .init = tcf_simp_init, |
| 197 | .walk = tcf_generic_walker, |
| 198 | }; |
| 199 | |
| 200 | MODULE_AUTHOR("Jamal Hadi Salim(2005)"); |
| 201 | MODULE_DESCRIPTION("Simple example action"); |
| 202 | MODULE_LICENSE("GPL"); |
| 203 | |
| 204 | static int __init simp_init_module(void) |
| 205 | { |
| 206 | int ret = tcf_register_action(&act_simp_ops); |
| 207 | if (!ret) |
| 208 | pr_info("Simple TC action Loaded\n"); |
| 209 | return ret; |
| 210 | } |
| 211 | |
| 212 | static void __exit simp_cleanup_module(void) |
| 213 | { |
| 214 | tcf_unregister_action(&act_simp_ops); |
| 215 | } |
| 216 | |
| 217 | module_init(simp_init_module); |
| 218 | module_exit(simp_cleanup_module); |