Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / include / linux / skbuff.h
CommitLineData
1da177e4
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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
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17#include <linux/kernel.h>
18#include <linux/compiler.h>
19#include <linux/time.h>
20#include <linux/cache.h>
21
22#include <asm/atomic.h>
23#include <asm/types.h>
24#include <linux/spinlock.h>
1da177e4 25#include <linux/net.h>
3fc7e8a6 26#include <linux/textsearch.h>
1da177e4 27#include <net/checksum.h>
a80958f4 28#include <linux/rcupdate.h>
97fc2f08 29#include <linux/dmaengine.h>
b7aa0bf7 30#include <linux/hrtimer.h>
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31
32#define HAVE_ALLOC_SKB /* For the drivers to know */
33#define HAVE_ALIGNABLE_SKB /* Ditto 8) */
1da177e4 34
60476372 35/* Don't change this without changing skb_csum_unnecessary! */
1da177e4 36#define CHECKSUM_NONE 0
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37#define CHECKSUM_UNNECESSARY 1
38#define CHECKSUM_COMPLETE 2
39#define CHECKSUM_PARTIAL 3
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40
41#define SKB_DATA_ALIGN(X) (((X) + (SMP_CACHE_BYTES - 1)) & \
42 ~(SMP_CACHE_BYTES - 1))
fc910a27 43#define SKB_WITH_OVERHEAD(X) \
deea84b0 44 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
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45#define SKB_MAX_ORDER(X, ORDER) \
46 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
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47#define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
48#define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
49
50/* A. Checksumming of received packets by device.
51 *
52 * NONE: device failed to checksum this packet.
53 * skb->csum is undefined.
54 *
55 * UNNECESSARY: device parsed packet and wouldbe verified checksum.
56 * skb->csum is undefined.
57 * It is bad option, but, unfortunately, many of vendors do this.
58 * Apparently with secret goal to sell you new device, when you
59 * will add new protocol to your host. F.e. IPv6. 8)
60 *
84fa7933 61 * COMPLETE: the most generic way. Device supplied checksum of _all_
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62 * the packet as seen by netif_rx in skb->csum.
63 * NOTE: Even if device supports only some protocols, but
84fa7933 64 * is able to produce some skb->csum, it MUST use COMPLETE,
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65 * not UNNECESSARY.
66 *
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67 * PARTIAL: identical to the case for output below. This may occur
68 * on a packet received directly from another Linux OS, e.g.,
69 * a virtualised Linux kernel on the same host. The packet can
70 * be treated in the same way as UNNECESSARY except that on
71 * output (i.e., forwarding) the checksum must be filled in
72 * by the OS or the hardware.
73 *
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74 * B. Checksumming on output.
75 *
76 * NONE: skb is checksummed by protocol or csum is not required.
77 *
84fa7933 78 * PARTIAL: device is required to csum packet as seen by hard_start_xmit
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79 * from skb->csum_start to the end and to record the checksum
80 * at skb->csum_start + skb->csum_offset.
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81 *
82 * Device must show its capabilities in dev->features, set
83 * at device setup time.
84 * NETIF_F_HW_CSUM - it is clever device, it is able to checksum
85 * everything.
86 * NETIF_F_NO_CSUM - loopback or reliable single hop media.
87 * NETIF_F_IP_CSUM - device is dumb. It is able to csum only
88 * TCP/UDP over IPv4. Sigh. Vendors like this
89 * way by an unknown reason. Though, see comment above
90 * about CHECKSUM_UNNECESSARY. 8)
c6c6e3e0 91 * NETIF_F_IPV6_CSUM about as dumb as the last one but does IPv6 instead.
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92 *
93 * Any questions? No questions, good. --ANK
94 */
95
1da177e4 96struct net_device;
716ea3a7 97struct scatterlist;
9c55e01c 98struct pipe_inode_info;
1da177e4 99
5f79e0f9 100#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
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101struct nf_conntrack {
102 atomic_t use;
1da177e4 103};
5f79e0f9 104#endif
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105
106#ifdef CONFIG_BRIDGE_NETFILTER
107struct nf_bridge_info {
108 atomic_t use;
109 struct net_device *physindev;
110 struct net_device *physoutdev;
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111 unsigned int mask;
112 unsigned long data[32 / sizeof(unsigned long)];
113};
114#endif
115
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116struct sk_buff_head {
117 /* These two members must be first. */
118 struct sk_buff *next;
119 struct sk_buff *prev;
120
121 __u32 qlen;
122 spinlock_t lock;
123};
124
125struct sk_buff;
126
127/* To allow 64K frame to be packed as single skb without frag_list */
128#define MAX_SKB_FRAGS (65536/PAGE_SIZE + 2)
129
130typedef struct skb_frag_struct skb_frag_t;
131
132struct skb_frag_struct {
133 struct page *page;
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134 __u32 page_offset;
135 __u32 size;
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136};
137
138/* This data is invariant across clones and lives at
139 * the end of the header data, ie. at skb->end.
140 */
141struct skb_shared_info {
142 atomic_t dataref;
4947d3ef 143 unsigned short nr_frags;
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HX
144 unsigned short gso_size;
145 /* Warning: this field is not always filled in (UFO)! */
146 unsigned short gso_segs;
147 unsigned short gso_type;
ae08e1f0 148 __be32 ip6_frag_id;
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149 struct sk_buff *frag_list;
150 skb_frag_t frags[MAX_SKB_FRAGS];
151};
152
153/* We divide dataref into two halves. The higher 16 bits hold references
154 * to the payload part of skb->data. The lower 16 bits hold references to
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PM
155 * the entire skb->data. A clone of a headerless skb holds the length of
156 * the header in skb->hdr_len.
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157 *
158 * All users must obey the rule that the skb->data reference count must be
159 * greater than or equal to the payload reference count.
160 *
161 * Holding a reference to the payload part means that the user does not
162 * care about modifications to the header part of skb->data.
163 */
164#define SKB_DATAREF_SHIFT 16
165#define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
166
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DM
167
168enum {
169 SKB_FCLONE_UNAVAILABLE,
170 SKB_FCLONE_ORIG,
171 SKB_FCLONE_CLONE,
172};
173
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174enum {
175 SKB_GSO_TCPV4 = 1 << 0,
f83ef8c0 176 SKB_GSO_UDP = 1 << 1,
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177
178 /* This indicates the skb is from an untrusted source. */
179 SKB_GSO_DODGY = 1 << 2,
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180
181 /* This indicates the tcp segment has CWR set. */
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HX
182 SKB_GSO_TCP_ECN = 1 << 3,
183
184 SKB_GSO_TCPV6 = 1 << 4,
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185};
186
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187#if BITS_PER_LONG > 32
188#define NET_SKBUFF_DATA_USES_OFFSET 1
189#endif
190
191#ifdef NET_SKBUFF_DATA_USES_OFFSET
192typedef unsigned int sk_buff_data_t;
193#else
194typedef unsigned char *sk_buff_data_t;
195#endif
196
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197/**
198 * struct sk_buff - socket buffer
199 * @next: Next buffer in list
200 * @prev: Previous buffer in list
1da177e4 201 * @sk: Socket we are owned by
325ed823 202 * @tstamp: Time we arrived
1da177e4 203 * @dev: Device we arrived on/are leaving by
be52178b 204 * @transport_header: Transport layer header
b0e380b1
ACM
205 * @network_header: Network layer header
206 * @mac_header: Link layer header
67be2dd1
MW
207 * @dst: destination entry
208 * @sp: the security path, used for xfrm
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209 * @cb: Control buffer. Free for use by every layer. Put private vars here
210 * @len: Length of actual data
211 * @data_len: Data length
212 * @mac_len: Length of link layer header
334a8132 213 * @hdr_len: writable header length of cloned skb
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HX
214 * @csum: Checksum (must include start/offset pair)
215 * @csum_start: Offset from skb->head where checksumming should start
216 * @csum_offset: Offset from csum_start where checksum should be stored
67be2dd1 217 * @local_df: allow local fragmentation
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218 * @cloned: Head may be cloned (check refcnt to be sure)
219 * @nohdr: Payload reference only, must not modify header
220 * @pkt_type: Packet class
c83c2486 221 * @fclone: skbuff clone status
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222 * @ip_summed: Driver fed us an IP checksum
223 * @priority: Packet queueing priority
224 * @users: User count - see {datagram,tcp}.c
225 * @protocol: Packet protocol from driver
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226 * @truesize: Buffer size
227 * @head: Head of buffer
228 * @data: Data head pointer
229 * @tail: Tail pointer
230 * @end: End pointer
231 * @destructor: Destruct function
82e91ffe 232 * @mark: Generic packet mark
1da177e4 233 * @nfct: Associated connection, if any
c83c2486 234 * @ipvs_property: skbuff is owned by ipvs
31729363
RD
235 * @peeked: this packet has been seen already, so stats have been
236 * done for it, don't do them again
ba9dda3a 237 * @nf_trace: netfilter packet trace flag
1da177e4 238 * @nfctinfo: Relationship of this skb to the connection
461ddf3b 239 * @nfct_reasm: netfilter conntrack re-assembly pointer
1da177e4 240 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
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PWJ
241 * @iif: ifindex of device we arrived on
242 * @queue_mapping: Queue mapping for multiqueue devices
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243 * @tc_index: Traffic control index
244 * @tc_verd: traffic control verdict
f4b8ea78
RD
245 * @dma_cookie: a cookie to one of several possible DMA operations
246 * done by skb DMA functions
984bc16c 247 * @secmark: security marking
1da177e4
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248 */
249
250struct sk_buff {
251 /* These two members must be first. */
252 struct sk_buff *next;
253 struct sk_buff *prev;
254
1da177e4 255 struct sock *sk;
b7aa0bf7 256 ktime_t tstamp;
1da177e4 257 struct net_device *dev;
1da177e4 258
ee6b9673
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259 union {
260 struct dst_entry *dst;
261 struct rtable *rtable;
262 };
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263 struct sec_path *sp;
264
265 /*
266 * This is the control buffer. It is free to use for every
267 * layer. Please put your private variables there. If you
268 * want to keep them across layers you have to do a skb_clone()
269 * first. This is owned by whoever has the skb queued ATM.
270 */
3e3850e9 271 char cb[48];
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272
273 unsigned int len,
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PM
274 data_len;
275 __u16 mac_len,
276 hdr_len;
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277 union {
278 __wsum csum;
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HX
279 struct {
280 __u16 csum_start;
281 __u16 csum_offset;
282 };
ff1dcadb 283 };
1da177e4 284 __u32 priority;
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285 __u8 local_df:1,
286 cloned:1,
287 ip_summed:2,
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288 nohdr:1,
289 nfctinfo:3;
d179cd12 290 __u8 pkt_type:3,
b84f4cc9 291 fclone:2,
ba9dda3a 292 ipvs_property:1,
a59322be 293 peeked:1,
ba9dda3a 294 nf_trace:1;
a0d3bea3 295 __be16 protocol;
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296
297 void (*destructor)(struct sk_buff *skb);
9fb9cbb1 298#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
5f79e0f9 299 struct nf_conntrack *nfct;
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YK
300 struct sk_buff *nfct_reasm;
301#endif
1da177e4
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302#ifdef CONFIG_BRIDGE_NETFILTER
303 struct nf_bridge_info *nf_bridge;
304#endif
f25f4e44
PWJ
305
306 int iif;
e3fa259b 307#ifdef CONFIG_NETDEVICES_MULTIQUEUE
f25f4e44 308 __u16 queue_mapping;
e3fa259b 309#endif
1da177e4 310#ifdef CONFIG_NET_SCHED
b6b99eb5 311 __u16 tc_index; /* traffic control index */
1da177e4 312#ifdef CONFIG_NET_CLS_ACT
b6b99eb5 313 __u16 tc_verd; /* traffic control verdict */
1da177e4 314#endif
1da177e4 315#endif
de357cc0 316#ifdef CONFIG_IPV6_NDISC_NODETYPE
fadf6bf0 317 __u8 ndisc_nodetype:2;
de357cc0 318#endif
fadf6bf0 319 /* 14 bit hole */
f25f4e44 320
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321#ifdef CONFIG_NET_DMA
322 dma_cookie_t dma_cookie;
323#endif
984bc16c
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324#ifdef CONFIG_NETWORK_SECMARK
325 __u32 secmark;
326#endif
1da177e4 327
82e91ffe 328 __u32 mark;
1da177e4 329
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ACM
330 sk_buff_data_t transport_header;
331 sk_buff_data_t network_header;
332 sk_buff_data_t mac_header;
1da177e4 333 /* These elements must be at the end, see alloc_skb() for details. */
27a884dc 334 sk_buff_data_t tail;
4305b541 335 sk_buff_data_t end;
1da177e4 336 unsigned char *head,
4305b541 337 *data;
27a884dc
ACM
338 unsigned int truesize;
339 atomic_t users;
1da177e4
LT
340};
341
342#ifdef __KERNEL__
343/*
344 * Handling routines are only of interest to the kernel
345 */
346#include <linux/slab.h>
347
348#include <asm/system.h>
349