root/include/linux/skbuff.h

/* */

INCLUDED FROM

DEFINITIONS

1. skb_peek
2. skb_queue_head_init
3. skb_queue_head
4. skb_queue_tail
5. skb_dequeue
6. skb_insert
7. skb_append
8. skb_unlink
9. skb_put
10. skb_push
11. skb_pull
12. skb_headroom
13. skb_tailroom
14. skb_reserve
15. skb_trim

   1 /*
   2  *      Definitions for the 'struct sk_buff' memory handlers.
   3  *
   4  *      Authors:
   5  *              Alan Cox, <gw4pts@gw4pts.ampr.org>
   6  *              Florian La Roche, <rzsfl@rz.uni-sb.de>
   7  *
   8  *      This program is free software; you can redistribute it and/or
   9  *      modify it under the terms of the GNU General Public License
  10  *      as published by the Free Software Foundation; either version
  11  *      2 of the License, or (at your option) any later version.
  12  */
  13  
  14 #ifndef _LINUX_SKBUFF_H
  15 #define _LINUX_SKBUFF_H
  16 #include <linux/malloc.h>
  17 #include <linux/wait.h>
  18 #include <linux/time.h>
  19 #include <linux/config.h>
  20 
  21 #define CONFIG_SKB_CHECK 0
  22 
  23 #define HAVE_ALLOC_SKB          /* For the drivers to know */
  24 #define HAVE_ALIGNABLE_SKB      /* Ditto 8)                */
  25 
  26 
  27 #define FREE_READ       1
  28 #define FREE_WRITE      0
  29 
  30 
  31 struct sk_buff_head {
  32   struct sk_buff                * volatile next;
  33   struct sk_buff                * volatile prev;
  34 #if CONFIG_SKB_CHECK
  35   int                           magic_debug_cookie;
  36 #endif
  37 };
  38 
  39 
  40 struct sk_buff {
  41   struct sk_buff                * volatile next;        /* Next buffer in list */
  42   struct sk_buff                * volatile prev;        /* Previous buffer in list */
  43 #if CONFIG_SKB_CHECK
  44   int                           magic_debug_cookie;
  45 #endif
  46   struct sk_buff                * volatile link3;       /* Link for IP protocol level buffer chains     */
  47   struct sock                   *sk;                    /* Socket we are owned by                       */
  48   volatile unsigned long        when;                   /* used to compute rtt's                        */
  49   struct timeval                stamp;                  /* Time we arrived                              */
  50   struct device                 *dev;                   /* Device we arrived on/are leaving by          */
  51   union {
  52         struct tcphdr   *th;
  53         struct ethhdr   *eth;
  54         struct iphdr    *iph;
  55         struct udphdr   *uh;
  56         unsigned char   *raw;
  57         unsigned long   seq;
  58   } h;
  59   
  60   union {                                               /* As yet incomplete physical layer views       */
  61         unsigned char           *raw;
  62         struct ethhdr           *ethernet;
  63   } mac;
  64   
  65   struct iphdr                  *ip_hdr;                /* For IPPROTO_RAW                              */
  66   unsigned long                 len;                    /* Length of actual data                        */
  67   unsigned long                 saddr;                  /* IP source address                            */
  68   unsigned long                 daddr;                  /* IP target address                            */
  69   unsigned long                 raddr;                  /* IP next hop address                          */
  70   unsigned long                 csum;                   /* Checksum                                     */
  71   unsigned char                 proto_priv[16];         /* Protocol private data                        */
  72   volatile char                 acked,                  /* Are we acked ?                               */
  73                                 used,                   /* Are we in use ?                              */
  74                                 free,                   /* How to free this buffer                      */
  75                                 arp;                    /* Has IP/ARP resolution finished               */
  76   unsigned char                 tries,                  /* Times tried                                  */
  77                                 lock,                   /* Are we locked ?                              */
  78                                 localroute,             /* Local routing asserted for this frame        */
  79                                 pkt_type,               /* Packet class                                 */
  80                                 ip_summed;              /* Driver fed us an IP checksum                 */
  81 #define PACKET_HOST             0                       /* To us                                        */
  82 #define PACKET_BROADCAST        1                       /* To all                                       */
  83 #define PACKET_MULTICAST        2                       /* To group                                     */
  84 #define PACKET_OTHERHOST        3                       /* To someone else                              */
  85   unsigned short                users;                  /* User count - see datagram.c,tcp.c            */
  86   unsigned short                protocol;               /* Packet protocol from driver.                 */
  87   unsigned short                truesize;               /* Buffer size                                  */
  88   unsigned char                 *head;                  /* Head of buffer                               */
  89   unsigned char                 *data;                  /* Data head pointer                            */
  90   unsigned char                 *tail;                  /* Tail pointer                                 */
  91   unsigned char                 *end;                   /* End pointer                                  */
  92 };
  93 
  94 #ifdef CONFIG_SKB_LARGE
  95 #define SK_WMEM_MAX     65535
  96 #define SK_RMEM_MAX     65535
  97 #else
  98 #define SK_WMEM_MAX     32767
  99 #define SK_RMEM_MAX     32767
 100 #endif
 101 
 102 #if CONFIG_SKB_CHECK
 103 #define SK_FREED_SKB    0x0DE2C0DE
 104 #define SK_GOOD_SKB     0xDEC0DED1
 105 #define SK_HEAD_SKB     0x12231298
 106 #endif
 107 
 108 #ifdef __KERNEL__
 109 /*
 110  *      Handling routines are only of interest to the kernel
 111  */
 112 
 113 #include <asm/system.h>
 114 
 115 #if 0
 116 extern void                     print_skb(struct sk_buff *);
 117 #endif
 118 extern void                     kfree_skb(struct sk_buff *skb, int rw);
 119 extern void                     skb_queue_head_init(struct sk_buff_head *list);
 120 extern void                     skb_queue_head(struct sk_buff_head *list,struct sk_buff *buf);
 121 extern void                     skb_queue_tail(struct sk_buff_head *list,struct sk_buff *buf);
 122 extern struct sk_buff *         skb_dequeue(struct sk_buff_head *list);
 123 extern void                     skb_insert(struct sk_buff *old,struct sk_buff *newsk);
 124 extern void                     skb_append(struct sk_buff *old,struct sk_buff *newsk);
 125 extern void                     skb_unlink(struct sk_buff *buf);
 126 extern struct sk_buff *         skb_peek_copy(struct sk_buff_head *list);
 127 extern struct sk_buff *         alloc_skb(unsigned int size, int priority);
 128 extern struct sk_buff *         dev_alloc_skb(unsigned int size);
 129 extern void                     kfree_skbmem(struct sk_buff *skb);
 130 extern struct sk_buff *         skb_clone(struct sk_buff *skb, int priority);
 131 extern void                     skb_device_lock(struct sk_buff *skb);
 132 extern void                     skb_device_unlock(struct sk_buff *skb);
 133 extern void                     dev_kfree_skb(struct sk_buff *skb, int mode);
 134 extern int                      skb_device_locked(struct sk_buff *skb);
 135 extern unsigned char *          skb_put(struct sk_buff *skb, int len);
 136 extern unsigned char *          skb_push(struct sk_buff *skb, int len);
 137 extern unsigned char *          skb_pull(struct sk_buff *skb, int len);
 138 extern int                      skb_headroom(struct sk_buff *skb);
 139 extern int                      skb_tailroom(struct sk_buff *skb);
 140 extern void                     skb_reserve(struct sk_buff *skb, int len);
 141 extern void                     skb_trim(struct sk_buff *skb, int len);
 142 
 143 /*
 144  *      Peek an sk_buff. Unlike most other operations you _MUST_
 145  *      be careful with this one. A peek leaves the buffer on the
 146  *      list and someone else may run off with it. For an interrupt
 147  *      type system cli() peek the buffer copy the data and sti();
 148  */
 149 static __inline__ struct sk_buff *skb_peek(struct sk_buff_head *list_)
     /*  */
 150 {
 151         struct sk_buff *list = (struct sk_buff *)list_;
 152         return (list->next != list)? list->next : NULL;
 153 }
 154 
 155 #if CONFIG_SKB_CHECK
 156 extern int                      skb_check(struct sk_buff *skb,int,int, char *);
 157 #define IS_SKB(skb)             skb_check((skb), 0, __LINE__,__FILE__)
 158 #define IS_SKB_HEAD(skb)        skb_check((skb), 1, __LINE__,__FILE__)
 159 #else
 160 #define IS_SKB(skb)             
 161 #define IS_SKB_HEAD(skb)        
 162 
 163 extern __inline__ void skb_queue_head_init(struct sk_buff_head *list)
     /*  */
 164 {
 165         list->prev = (struct sk_buff *)list;
 166         list->next = (struct sk_buff *)list;
 167 }
 168 
 169 /*
 170  *      Insert an sk_buff at the start of a list.
 171  */
 172 
 173 extern __inline__ void skb_queue_head(struct sk_buff_head *list_,struct sk_buff *newsk)
     /*  */
 174 {
 175         unsigned long flags;
 176         struct sk_buff *list = (struct sk_buff *)list_;
 177 
 178         save_flags(flags);
 179         cli();
 180         newsk->next = list->next;
 181         newsk->prev = list;
 182         newsk->next->prev = newsk;
 183         newsk->prev->next = newsk;
 184         restore_flags(flags);
 185 }
 186 
 187 /*
 188  *      Insert an sk_buff at the end of a list.
 189  */
 190 
 191 extern __inline__ void skb_queue_tail(struct sk_buff_head *list_, struct sk_buff *newsk)
     /*  */
 192 {
 193         unsigned long flags;
 194         struct sk_buff *list = (struct sk_buff *)list_;
 195 
 196         save_flags(flags);
 197         cli();
 198 
 199         newsk->next = list;
 200         newsk->prev = list->prev;
 201 
 202         newsk->next->prev = newsk;
 203         newsk->prev->next = newsk;
 204 
 205         restore_flags(flags);
 206 }
 207 
 208 /*
 209  *      Remove an sk_buff from a list. This routine is also interrupt safe
 210  *      so you can grab read and free buffers as another process adds them.
 211  *
 212  *      Note we now do the ful list 
 213  */
 214 
 215 extern __inline__ struct sk_buff *skb_dequeue(struct sk_buff_head *list_)
     /*  */
 216 {
 217         long flags;
 218         struct sk_buff *result;
 219         struct sk_buff *list = (struct sk_buff *)list_;
 220 
 221         save_flags(flags);
 222         cli();
 223 
 224         result = list->next;
 225         if (result == list) 
 226         {
 227                 restore_flags(flags);
 228                 return NULL;
 229         }
 230         else
 231         {
 232                 result->next->prev = list;
 233                 list->next = result->next;
 234 
 235                 result->next = NULL;
 236                 result->prev = NULL;
 237 
 238                 restore_flags(flags);
 239 
 240                 return result;
 241         }
 242 }
 243 
 244 /*
 245  *      Insert a packet before another one in a list.
 246  */
 247 
 248 extern __inline__ void skb_insert(struct sk_buff *old, struct sk_buff *newsk)
     /*  */
 249 {
 250         unsigned long flags;
 251 
 252         save_flags(flags);
 253         cli();
 254         newsk->next = old;
 255         newsk->prev = old->prev;
 256         old->prev = newsk;
 257         newsk->prev->next = newsk;
 258 
 259         restore_flags(flags);
 260 }
 261 
 262 /*
 263  *      Place a packet after a given packet in a list.
 264  */
 265 
 266 extern __inline__ void skb_append(struct sk_buff *old, struct sk_buff *newsk)
     /*  */
 267 {
 268         unsigned long flags;
 269 
 270         save_flags(flags);
 271         cli();
 272 
 273         newsk->prev = old;
 274         newsk->next = old->next;
 275         newsk->next->prev = newsk;
 276         old->next = newsk;
 277 
 278         restore_flags(flags);
 279 }
 280 
 281 /*
 282  *      Remove an sk_buff from its list. Works even without knowing the list it
 283  *      is sitting on, which can be handy at times. It also means that THE LIST
 284  *      MUST EXIST when you unlink. Thus a list must have its contents unlinked
 285  *      _FIRST_.
 286  */
 287 
 288 extern __inline__ void skb_unlink(struct sk_buff *skb)
     /*  */
 289 {
 290         unsigned long flags;
 291 
 292         save_flags(flags);
 293         cli();
 294 
 295         if(skb->prev && skb->next)
 296         {
 297                 skb->next->prev = skb->prev;
 298                 skb->prev->next = skb->next;
 299                 skb->next = NULL;
 300                 skb->prev = NULL;
 301         }
 302         restore_flags(flags);
 303 }
 304 
 305 /*
 306  *      Add data to an sk_buff
 307  */
 308  
 309 extern __inline__ unsigned char *skb_put(struct sk_buff *skb, int len)
     /*  */
 310 {
 311         unsigned char *tmp=skb->tail;
 312         skb->tail+=len;
 313         skb->len+=len;
 314         if(skb->tail>skb->end)
 315                 panic("skput:over: %p:%d", __builtin_return_address(0),len);
 316         return tmp;
 317 }
 318 
 319 extern __inline__ unsigned char *skb_push(struct sk_buff *skb, int len)
     /*  */
 320 {
 321         skb->data-=len;
 322         skb->len+=len;
 323         if(skb->data<skb->head)
 324                 panic("skpush:under: %p:%d", __builtin_return_address(0),len);
 325         return skb->data;
 326 }
 327 
 328 extern __inline__ unsigned char * skb_pull(struct sk_buff *skb, int len)
     /*  */
 329 {
 330         if(len > skb->len)
 331                 return NULL;
 332         skb->data+=len;
 333         skb->len-=len;
 334         return skb->data;
 335 }
 336 
 337 extern __inline__ int skb_headroom(struct sk_buff *skb)
     /*  */
 338 {
 339         return skb->data-skb->head;
 340 }
 341 
 342 extern __inline__ int skb_tailroom(struct sk_buff *skb)
     /*  */
 343 {
 344         return skb->end-skb->tail;
 345 }
 346 
 347 extern __inline__ void skb_reserve(struct sk_buff *skb, int len)
     /*  */
 348 {
 349         skb->data+=len;
 350         skb->tail+=len;
 351 }
 352 
 353 extern __inline__ void skb_trim(struct sk_buff *skb, int len)
     /*  */
 354 {
 355         if(skb->len>len)
 356         {
 357                 skb->len=len;
 358                 skb->tail=skb->data+len;
 359         }
 360 }
 361 
 362 #endif
 363 
 364 extern struct sk_buff *         skb_recv_datagram(struct sock *sk,unsigned flags,int noblock, int *err);
 365 extern int                      datagram_select(struct sock *sk, int sel_type, select_table *wait);
 366 extern void                     skb_copy_datagram(struct sk_buff *from, int offset, char *to,int size);
 367 extern void                     skb_copy_datagram_iovec(struct sk_buff *from, int offset, struct iovec *to,int size);
 368 extern void                     skb_free_datagram(struct sk_buff *skb);
 369 
 370 #endif  /* __KERNEL__ */
 371 #endif  /* _LINUX_SKBUFF_H */

/* */