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/netlink.h> 31 #include <net/sock.h> 32 #include <net/pkt_sched.h> 33 #include <linux/tc_act/tc_pedit.h> 34 #include <net/tc_act/tc_pedit.h> 35 36 #define PEDIT_TAB_MASK 15 37 static struct tcf_common *tcf_pedit_ht[PEDIT_TAB_MASK + 1]; 38 static u32 pedit_idx_gen; 39 static DEFINE_RWLOCK(pedit_lock); 40 41 static struct tcf_hashinfo pedit_hash_info = { 42 .htab = tcf_pedit_ht, 43 .hmask = PEDIT_TAB_MASK, 44 .lock = &pedit_lock, 45 }; 46 47 static int tcf_pedit_init(struct rtattr *rta, struct rtattr *est, 48 struct tc_action *a, int ovr, int bind) 49 { 50 struct rtattr *tb[TCA_PEDIT_MAX]; 51 struct tc_pedit *parm; 52 int ret = 0; 53 struct tcf_pedit *p; 54 struct tcf_common *pc; 55 struct tc_pedit_key *keys = NULL; 56 int ksize; 57 58 if (rta == NULL || rtattr_parse_nested(tb, TCA_PEDIT_MAX, rta) < 0) 59 return -EINVAL; 60 61 if (tb[TCA_PEDIT_PARMS - 1] == NULL || 62 RTA_PAYLOAD(tb[TCA_PEDIT_PARMS-1]) < sizeof(*parm)) 63 return -EINVAL; 64 parm = RTA_DATA(tb[TCA_PEDIT_PARMS-1]); 65 ksize = parm->nkeys * sizeof(struct tc_pedit_key); 66 if (RTA_PAYLOAD(tb[TCA_PEDIT_PARMS-1]) < sizeof(*parm) + ksize) 67 return -EINVAL; 68 69 pc = tcf_hash_check(parm->index, a, bind, &pedit_hash_info); 70 if (!pc) { 71 if (!parm->nkeys) 72 return -EINVAL; 73 pc = tcf_hash_create(parm->index, est, a, sizeof(*p), bind, 74 &pedit_idx_gen, &pedit_hash_info); 75 if (unlikely(!pc)) 76 return -ENOMEM; 77 p = to_pedit(pc); 78 keys = kmalloc(ksize, GFP_KERNEL); 79 if (keys == NULL) { 80 kfree(pc); 81 return -ENOMEM; 82 } 83 ret = ACT_P_CREATED; 84 } else { 85 p = to_pedit(pc); 86 if (!ovr) { 87 tcf_hash_release(pc, bind, &pedit_hash_info); 88 return -EEXIST; 89 } 90 if (p->tcfp_nkeys && p->tcfp_nkeys != parm->nkeys) { 91 keys = kmalloc(ksize, GFP_KERNEL); 92 if (keys == NULL) 93 return -ENOMEM; 94 } 95 } 96 97 spin_lock_bh(&p->tcf_lock); 98 p->tcfp_flags = parm->flags; 99 p->tcf_action = parm->action; 100 if (keys) { 101 kfree(p->tcfp_keys); 102 p->tcfp_keys = keys; 103 p->tcfp_nkeys = parm->nkeys; 104 } 105 memcpy(p->tcfp_keys, parm->keys, ksize); 106 spin_unlock_bh(&p->tcf_lock); 107 if (ret == ACT_P_CREATED) 108 tcf_hash_insert(pc, &pedit_hash_info); 109 return ret; 110 } 111 112 static int tcf_pedit_cleanup(struct tc_action *a, int bind) 113 { 114 struct tcf_pedit *p = a->priv; 115 116 if (p) { 117 struct tc_pedit_key *keys = p->tcfp_keys; 118 if (tcf_hash_release(&p->common, bind, &pedit_hash_info)) { 119 kfree(keys); 120 return 1; 121 } 122 } 123 return 0; 124 } 125 126 static int tcf_pedit(struct sk_buff *skb, struct tc_action *a, 127 struct tcf_result *res) 128 { 129 struct tcf_pedit *p = a->priv; 130 int i, munged = 0; 131 u8 *pptr; 132 133 if (!(skb->tc_verd & TC_OK2MUNGE)) { 134 /* should we set skb->cloned? */ 135 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) { 136 return p->tcf_action; 137 } 138 } 139 140 pptr = skb_network_header(skb); 141 142 spin_lock(&p->tcf_lock); 143 144 p->tcf_tm.lastuse = jiffies; 145 146 if (p->tcfp_nkeys > 0) { 147 struct tc_pedit_key *tkey = p->tcfp_keys; 148 149 for (i = p->tcfp_nkeys; i > 0; i--, tkey++) { 150 u32 *ptr; 151 int offset = tkey->off; 152 153 if (tkey->offmask) { 154 if (skb->len > tkey->at) { 155 char *j = pptr + tkey->at; 156 offset += ((*j & tkey->offmask) >> 157 tkey->shift); 158 } else { 159 goto bad; 160 } 161 } 162 163 if (offset % 4) { 164 printk("offset must be on 32 bit boundaries\n"); 165 goto bad; 166 } 167 if (skb->len < 0 || 168 (offset > 0 && offset > skb->len)) { 169 printk("offset %d cant exceed pkt length %d\n", 170 offset, skb->len); 171 goto bad; 172 } 173 174 ptr = (u32 *)(pptr+offset); 175 /* just do it, baby */ 176 *ptr = ((*ptr & tkey->mask) ^ tkey->val); 177 munged++; 178 } 179 180 if (munged) 181 skb->tc_verd = SET_TC_MUNGED(skb->tc_verd); 182 goto done; 183 } else { 184 printk("pedit BUG: index %d\n", p->tcf_index); 185 } 186 187 bad: 188 p->tcf_qstats.overlimits++; 189 done: 190 p->tcf_bstats.bytes += skb->len; 191 p->tcf_bstats.packets++; 192 spin_unlock(&p->tcf_lock); 193 return p->tcf_action; 194 } 195 196 static 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 /* netlink spinlocks held above us - must use ATOMIC */ 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 RTA_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 RTA_PUT(skb, TCA_PEDIT_TM, sizeof(t), &t); 226 kfree(opt); 227 return skb->len; 228 229 rtattr_failure: 230 nlmsg_trim(skb, b); 231 kfree(opt); 232 return -1; 233 } 234 235 static 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 }; 248 249 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)"); 250 MODULE_DESCRIPTION("Generic Packet Editor actions"); 251 MODULE_LICENSE("GPL"); 252 253 static int __init pedit_init_module(void) 254 { 255 return tcf_register_action(&act_pedit_ops); 256 } 257 258 static void __exit pedit_cleanup_module(void) 259 { 260 tcf_unregister_action(&act_pedit_ops); 261 } 262 263 module_init(pedit_init_module); 264 module_exit(pedit_cleanup_module); 265 266