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/config.h> 16 #include <linux/types.h> 17 #include <linux/kernel.h> 18 #include <linux/sched.h> 19 #include <linux/string.h> 20 #include <linux/mm.h> 21 #include <linux/socket.h> 22 #include <linux/sockios.h> 23 #include <linux/in.h> 24 #include <linux/errno.h> 25 #include <linux/interrupt.h> 26 #include <linux/netdevice.h> 27 #include <linux/skbuff.h> 28 #include <linux/rtnetlink.h> 29 #include <linux/module.h> 30 #include <linux/init.h> 31 #include <linux/proc_fs.h> 32 #include <net/sock.h> 33 #include <net/pkt_sched.h> 34 #include <linux/tc_act/tc_pedit.h> 35 #include <net/tc_act/tc_pedit.h> 36 37 38 #define PEDIT_DEB 1 39 40 /* use generic hash table */ 41 #define MY_TAB_SIZE 16 42 #define MY_TAB_MASK 15 43 static u32 idx_gen; 44 static struct tcf_pedit *tcf_pedit_ht[MY_TAB_SIZE]; 45 static DEFINE_RWLOCK(pedit_lock); 46 47 #define tcf_st tcf_pedit 48 #define tc_st tc_pedit 49 #define tcf_t_lock pedit_lock 50 #define tcf_ht tcf_pedit_ht 51 52 #define CONFIG_NET_ACT_INIT 1 53 #include <net/pkt_act.h> 54 55 static int 56 tcf_pedit_init(struct rtattr *rta, struct rtattr *est, struct tc_action *a, 57 int ovr, int bind) 58 { 59 struct rtattr *tb[TCA_PEDIT_MAX]; 60 struct tc_pedit *parm; 61 int ret = 0; 62 struct tcf_pedit *p; 63 struct tc_pedit_key *keys = NULL; 64 int ksize; 65 66 if (rta == NULL || rtattr_parse_nested(tb, TCA_PEDIT_MAX, rta) < 0) 67 return -EINVAL; 68 69 if (tb[TCA_PEDIT_PARMS - 1] == NULL || 70 RTA_PAYLOAD(tb[TCA_PEDIT_PARMS-1]) < sizeof(*parm)) 71 return -EINVAL; 72 parm = RTA_DATA(tb[TCA_PEDIT_PARMS-1]); 73 ksize = parm->nkeys * sizeof(struct tc_pedit_key); 74 if (RTA_PAYLOAD(tb[TCA_PEDIT_PARMS-1]) < sizeof(*parm) + ksize) 75 return -EINVAL; 76 77 p = tcf_hash_check(parm->index, a, ovr, bind); 78 if (p == NULL) { 79 if (!parm->nkeys) 80 return -EINVAL; 81 p = tcf_hash_create(parm->index, est, a, sizeof(*p), ovr, bind); 82 if (p == NULL) 83 return -ENOMEM; 84 keys = kmalloc(ksize, GFP_KERNEL); 85 if (keys == NULL) { 86 kfree(p); 87 return -ENOMEM; 88 } 89 ret = ACT_P_CREATED; 90 } else { 91 if (!ovr) { 92 tcf_hash_release(p, bind); 93 return -EEXIST; 94 } 95 if (p->nkeys && p->nkeys != parm->nkeys) { 96 keys = kmalloc(ksize, GFP_KERNEL); 97 if (keys == NULL) 98 return -ENOMEM; 99 } 100 } 101 102 spin_lock_bh(&p->lock); 103 p->flags = parm->flags; 104 p->action = parm->action; 105 if (keys) { 106 kfree(p->keys); 107 p->keys = keys; 108 p->nkeys = parm->nkeys; 109 } 110 memcpy(p->keys, parm->keys, ksize); 111 spin_unlock_bh(&p->lock); 112 if (ret == ACT_P_CREATED) 113 tcf_hash_insert(p); 114 return ret; 115 } 116 117 static int 118 tcf_pedit_cleanup(struct tc_action *a, int bind) 119 { 120 struct tcf_pedit *p = PRIV(a, pedit); 121 122 if (p != NULL) { 123 struct tc_pedit_key *keys = p->keys; 124 if (tcf_hash_release(p, bind)) { 125 kfree(keys); 126 return 1; 127 } 128 } 129 return 0; 130 } 131 132 static int 133 tcf_pedit(struct sk_buff *skb, struct tc_action *a, struct tcf_result *res) 134 { 135 struct tcf_pedit *p = PRIV(a, pedit); 136 int i, munged = 0; 137 u8 *pptr; 138 139 if (!(skb->tc_verd & TC_OK2MUNGE)) { 140 /* should we set skb->cloned? */ 141 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) { 142 return p->action; 143 } 144 } 145 146 pptr = skb->nh.raw; 147 148 spin_lock(&p->lock); 149 150 p->tm.lastuse = jiffies; 151 152 if (p->nkeys > 0) { 153 struct tc_pedit_key *tkey = p->keys; 154 155 for (i = p->nkeys; i > 0; i--, tkey++) { 156 u32 *ptr; 157 int offset = tkey->off; 158 159 if (tkey->offmask) { 160 if (skb->len > tkey->at) { 161 char *j = pptr + tkey->at; 162 offset += ((*j & tkey->offmask) >> 163 tkey->shift); 164 } else { 165 goto bad; 166 } 167 } 168 169 if (offset % 4) { 170 printk("offset must be on 32 bit boundaries\n"); 171 goto bad; 172 } 173 if (skb->len < 0 || (offset > 0 && offset > skb->len)) { 174 printk("offset %d cant exceed pkt length %d\n", 175 offset, skb->len); 176 goto bad; 177 } 178 179 ptr = (u32 *)(pptr+offset); 180 /* just do it, baby */ 181 *ptr = ((*ptr & tkey->mask) ^ tkey->val); 182 munged++; 183 } 184 185 if (munged) 186 skb->tc_verd = SET_TC_MUNGED(skb->tc_verd); 187 goto done; 188 } else { 189 printk("pedit BUG: index %d\n",p->index); 190 } 191 192 bad: 193 p->qstats.overlimits++; 194 done: 195 p->bstats.bytes += skb->len; 196 p->bstats.packets++; 197 spin_unlock(&p->lock); 198 return p->action; 199 } 200 201 static int 202 tcf_pedit_dump(struct sk_buff *skb, struct tc_action *a,int bind, int ref) 203 { 204 unsigned char *b = skb->tail; 205 struct tc_pedit *opt; 206 struct tcf_pedit *p = PRIV(a, pedit); 207 struct tcf_t t; 208 int s; 209 210 s = sizeof(*opt) + p->nkeys * sizeof(struct tc_pedit_key); 211 212 /* netlink spinlocks held above us - must use ATOMIC */ 213 opt = kmalloc(s, GFP_ATOMIC); 214 if (opt == NULL) 215 return -ENOBUFS; 216 memset(opt, 0, s); 217 218 memcpy(opt->keys, p->keys, p->nkeys * sizeof(struct tc_pedit_key)); 219 opt->index = p->index; 220 opt->nkeys = p->nkeys; 221 opt->flags = p->flags; 222 opt->action = p->action; 223 opt->refcnt = p->refcnt - ref; 224 opt->bindcnt = p->bindcnt - bind; 225 226 227 #ifdef PEDIT_DEB 228 { 229 /* Debug - get rid of later */ 230 int i; 231 struct tc_pedit_key *key = opt->keys; 232 233 for (i=0; i<opt->nkeys; i++, key++) { 234 printk( "\n key #%d",i); 235 printk( " at %d: val %08x mask %08x", 236 (unsigned int)key->off, 237 (unsigned int)key->val, 238 (unsigned int)key->mask); 239 } 240 } 241 #endif 242 243 RTA_PUT(skb, TCA_PEDIT_PARMS, s, opt); 244 t.install = jiffies_to_clock_t(jiffies - p->tm.install); 245 t.lastuse = jiffies_to_clock_t(jiffies - p->tm.lastuse); 246 t.expires = jiffies_to_clock_t(p->tm.expires); 247 RTA_PUT(skb, TCA_PEDIT_TM, sizeof(t), &t); 248 kfree(opt); 249 return skb->len; 250 251 rtattr_failure: 252 skb_trim(skb, b - skb->data); 253 kfree(opt); 254 return -1; 255 } 256 257 static 258 struct tc_action_ops act_pedit_ops = { 259 .kind = "pedit", 260 .type = TCA_ACT_PEDIT, 261 .capab = TCA_CAP_NONE, 262 .owner = THIS_MODULE, 263 .act = tcf_pedit, 264 .dump = tcf_pedit_dump, 265 .cleanup = tcf_pedit_cleanup, 266 .lookup = tcf_hash_search, 267 .init = tcf_pedit_init, 268 .walk = tcf_generic_walker 269 }; 270 271 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)"); 272 MODULE_DESCRIPTION("Generic Packet Editor actions"); 273 MODULE_LICENSE("GPL"); 274 275 static int __init 276 pedit_init_module(void) 277 { 278 return tcf_register_action(&act_pedit_ops); 279 } 280 281 static void __exit 282 pedit_cleanup_module(void) 283 { 284 tcf_unregister_action(&act_pedit_ops); 285 } 286 287 module_init(pedit_init_module); 288 module_exit(pedit_cleanup_module); 289 290