1 /* 2 * net/sched/pedit.c Generic packet editor 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 (2002-4) 10 */ 11 12 #include <asm/uaccess.h> 13 #include <asm/system.h> 14 #include <asm/bitops.h> 15 #include <linux/types.h> 16 #include <linux/kernel.h> 17 #include <linux/string.h> 18 #include <linux/mm.h> 19 #include <linux/socket.h> 20 #include <linux/sockios.h> 21 #include <linux/in.h> 22 #include <linux/errno.h> 23 #include <linux/interrupt.h> 24 #include <linux/netdevice.h> 25 #include <linux/skbuff.h> 26 #include <linux/rtnetlink.h> 27 #include <linux/module.h> 28 #include <linux/init.h> 29 #include <linux/proc_fs.h> 30 #include <net/sock.h> 31 #include <net/pkt_sched.h> 32 #include <linux/tc_act/tc_pedit.h> 33 #include <net/tc_act/tc_pedit.h> 34 35 #define PEDIT_TAB_MASK 15 36 static struct tcf_common *tcf_pedit_ht[PEDIT_TAB_MASK + 1]; 37 static u32 pedit_idx_gen; 38 static DEFINE_RWLOCK(pedit_lock); 39 40 static struct tcf_hashinfo pedit_hash_info = { 41 .htab = tcf_pedit_ht, 42 .hmask = PEDIT_TAB_MASK, 43 .lock = &pedit_lock, 44 }; 45 46 static int tcf_pedit_init(struct rtattr *rta, struct rtattr *est, 47 struct tc_action *a, int ovr, int bind) 48 { 49 struct rtattr *tb[TCA_PEDIT_MAX]; 50 struct tc_pedit *parm; 51 int ret = 0; 52 struct tcf_pedit *p; 53 struct tcf_common *pc; 54 struct tc_pedit_key *keys = NULL; 55 int ksize; 56 57 if (rta == NULL || rtattr_parse_nested(tb, TCA_PEDIT_MAX, rta) < 0) 58 return -EINVAL; 59 60 if (tb[TCA_PEDIT_PARMS - 1] == NULL || 61 RTA_PAYLOAD(tb[TCA_PEDIT_PARMS-1]) < sizeof(*parm)) 62 return -EINVAL; 63 parm = RTA_DATA(tb[TCA_PEDIT_PARMS-1]); 64 ksize = parm->nkeys * sizeof(struct tc_pedit_key); 65 if (RTA_PAYLOAD(tb[TCA_PEDIT_PARMS-1]) < sizeof(*parm) + ksize) 66 return -EINVAL; 67 68 pc = tcf_hash_check(parm->index, a, bind, &pedit_hash_info); 69 if (!pc) { 70 if (!parm->nkeys) 71 return -EINVAL; 72 pc = tcf_hash_create(parm->index, est, a, sizeof(*p), bind, 73 &pedit_idx_gen, &pedit_hash_info); 74 if (unlikely(!pc)) 75 return -ENOMEM; 76 p = to_pedit(pc); 77 keys = kmalloc(ksize, GFP_KERNEL); 78 if (keys == NULL) { 79 kfree(pc); 80 return -ENOMEM; 81 } 82 ret = ACT_P_CREATED; 83 } else { 84 p = to_pedit(pc); 85 if (!ovr) { 86 tcf_hash_release(pc, bind, &pedit_hash_info); 87 return -EEXIST; 88 } 89 if (p->tcfp_nkeys && p->tcfp_nkeys != parm->nkeys) { 90 keys = kmalloc(ksize, GFP_KERNEL); 91 if (keys == NULL) 92 return -ENOMEM; 93 } 94 } 95 96 spin_lock_bh(&p->tcf_lock); 97 p->tcfp_flags = parm->flags; 98 p->tcf_action = parm->action; 99 if (keys) { 100 kfree(p->tcfp_keys); 101 p->tcfp_keys = keys; 102 p->tcfp_nkeys = parm->nkeys; 103 } 104 memcpy(p->tcfp_keys, parm->keys, ksize); 105 spin_unlock_bh(&p->tcf_lock); 106 if (ret == ACT_P_CREATED) 107 tcf_hash_insert(pc, &pedit_hash_info); 108 return ret; 109 } 110 111 static int tcf_pedit_cleanup(struct tc_action *a, int bind) 112 { 113 struct tcf_pedit *p = a->priv; 114 115 if (p) { 116 struct tc_pedit_key *keys = p->tcfp_keys; 117 if (tcf_hash_release(&p->common, bind, &pedit_hash_info)) { 118 kfree(keys); 119 return 1; 120 } 121 } 122 return 0; 123 } 124 125 static int tcf_pedit(struct sk_buff *skb, struct tc_action *a, 126 struct tcf_result *res) 127 { 128 struct tcf_pedit *p = a->priv; 129 int i, munged = 0; 130 u8 *pptr; 131 132 if (!(skb->tc_verd & TC_OK2MUNGE)) { 133 /* should we set skb->cloned? */ 134 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) { 135 return p->tcf_action; 136 } 137 } 138 139 pptr = skb->nh.raw; 140 141 spin_lock(&p->tcf_lock); 142 143 p->tcf_tm.lastuse = jiffies; 144 145 if (p->tcfp_nkeys > 0) { 146 struct tc_pedit_key *tkey = p->tcfp_keys; 147 148 for (i = p->tcfp_nkeys; i > 0; i--, tkey++) { 149 u32 *ptr; 150 int offset = tkey->off; 151 152 if (tkey->offmask) { 153 if (skb->len > tkey->at) { 154 char *j = pptr + tkey->at; 155 offset += ((*j & tkey->offmask) >> 156 tkey->shift); 157 } else { 158 goto bad; 159 } 160 } 161 162 if (offset % 4) { 163 printk("offset must be on 32 bit boundaries\n"); 164 goto bad; 165 } 166 if (skb->len < 0 || 167 (offset > 0 && offset > skb->len)) { 168 printk("offset %d cant exceed pkt length %d\n", 169 offset, skb->len); 170 goto bad; 171 } 172 173 ptr = (u32 *)(pptr+offset); 174 /* just do it, baby */ 175 *ptr = ((*ptr & tkey->mask) ^ tkey->val); 176 munged++; 177 } 178 179 if (munged) 180 skb->tc_verd = SET_TC_MUNGED(skb->tc_verd); 181 goto done; 182 } else { 183 printk("pedit BUG: index %d\n", p->tcf_index); 184 } 185 186 bad: 187 p->tcf_qstats.overlimits++; 188 done: 189 p->tcf_bstats.bytes += skb->len; 190 p->tcf_bstats.packets++; 191 spin_unlock(&p->tcf_lock); 192 return p->tcf_action; 193 } 194 195 static int tcf_pedit_dump(struct sk_buff *skb, struct tc_action *a, 196 int bind, int ref) 197 { 198 unsigned char *b = skb->tail; 199 struct tcf_pedit *p = a->priv; 200 struct tc_pedit *opt; 201 struct tcf_t t; 202 int s; 203 204 s = sizeof(*opt) + p->tcfp_nkeys * sizeof(struct tc_pedit_key); 205 206 /* netlink spinlocks held above us - must use ATOMIC */ 207 opt = kzalloc(s, GFP_ATOMIC); 208 if (unlikely(!opt)) 209 return -ENOBUFS; 210 211 memcpy(opt->keys, p->tcfp_keys, 212 p->tcfp_nkeys * sizeof(struct tc_pedit_key)); 213 opt->index = p->tcf_index; 214 opt->nkeys = p->tcfp_nkeys; 215 opt->flags = p->tcfp_flags; 216 opt->action = p->tcf_action; 217 opt->refcnt = p->tcf_refcnt - ref; 218 opt->bindcnt = p->tcf_bindcnt - bind; 219 220 RTA_PUT(skb, TCA_PEDIT_PARMS, s, opt); 221 t.install = jiffies_to_clock_t(jiffies - p->tcf_tm.install); 222 t.lastuse = jiffies_to_clock_t(jiffies - p->tcf_tm.lastuse); 223 t.expires = jiffies_to_clock_t(p->tcf_tm.expires); 224 RTA_PUT(skb, TCA_PEDIT_TM, sizeof(t), &t); 225 kfree(opt); 226 return skb->len; 227 228 rtattr_failure: 229 skb_trim(skb, b - skb->data); 230 kfree(opt); 231 return -1; 232 } 233 234 static struct tc_action_ops act_pedit_ops = { 235 .kind = "pedit", 236 .hinfo = &pedit_hash_info, 237 .type = TCA_ACT_PEDIT, 238 .capab = TCA_CAP_NONE, 239 .owner = THIS_MODULE, 240 .act = tcf_pedit, 241 .dump = tcf_pedit_dump, 242 .cleanup = tcf_pedit_cleanup, 243 .lookup = tcf_hash_search, 244 .init = tcf_pedit_init, 245 .walk = tcf_generic_walker 246 }; 247 248 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)"); 249 MODULE_DESCRIPTION("Generic Packet Editor actions"); 250 MODULE_LICENSE("GPL"); 251 252 static int __init pedit_init_module(void) 253 { 254 return tcf_register_action(&act_pedit_ops); 255 } 256 257 static void __exit pedit_cleanup_module(void) 258 { 259 tcf_unregister_action(&act_pedit_ops); 260 } 261 262 module_init(pedit_init_module); 263 module_exit(pedit_cleanup_module); 264 265