net/sched/pedit.c

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