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1da177e4 LT |
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 | ||
1da177e4 LT |
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> |
1da177e4 | 31 | |
60476372 | 32 | /* Don't change this without changing skb_csum_unnecessary! */ |
1da177e4 | 33 | #define CHECKSUM_NONE 0 |
60476372 HX |
34 | #define CHECKSUM_UNNECESSARY 1 |
35 | #define CHECKSUM_COMPLETE 2 | |
36 | #define CHECKSUM_PARTIAL 3 | |
1da177e4 LT |
37 | |
38 | #define SKB_DATA_ALIGN(X) (((X) + (SMP_CACHE_BYTES - 1)) & \ | |
39 | ~(SMP_CACHE_BYTES - 1)) | |
fc910a27 | 40 | #define SKB_WITH_OVERHEAD(X) \ |
deea84b0 | 41 | ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info))) |
fc910a27 DM |
42 | #define SKB_MAX_ORDER(X, ORDER) \ |
43 | SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X)) | |
1da177e4 LT |
44 | #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0)) |
45 | #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2)) | |
46 | ||
47 | /* A. Checksumming of received packets by device. | |
48 | * | |
49 | * NONE: device failed to checksum this packet. | |
50 | * skb->csum is undefined. | |
51 | * | |
52 | * UNNECESSARY: device parsed packet and wouldbe verified checksum. | |
53 | * skb->csum is undefined. | |
54 | * It is bad option, but, unfortunately, many of vendors do this. | |
55 | * Apparently with secret goal to sell you new device, when you | |
56 | * will add new protocol to your host. F.e. IPv6. 8) | |
57 | * | |
84fa7933 | 58 | * COMPLETE: the most generic way. Device supplied checksum of _all_ |
1da177e4 LT |
59 | * the packet as seen by netif_rx in skb->csum. |
60 | * NOTE: Even if device supports only some protocols, but | |
84fa7933 | 61 | * is able to produce some skb->csum, it MUST use COMPLETE, |
1da177e4 LT |
62 | * not UNNECESSARY. |
63 | * | |
c6c6e3e0 HX |
64 | * PARTIAL: identical to the case for output below. This may occur |
65 | * on a packet received directly from another Linux OS, e.g., | |
66 | * a virtualised Linux kernel on the same host. The packet can | |
67 | * be treated in the same way as UNNECESSARY except that on | |
68 | * output (i.e., forwarding) the checksum must be filled in | |
69 | * by the OS or the hardware. | |
70 | * | |
1da177e4 LT |
71 | * B. Checksumming on output. |
72 | * | |
73 | * NONE: skb is checksummed by protocol or csum is not required. | |
74 | * | |
84fa7933 | 75 | * PARTIAL: device is required to csum packet as seen by hard_start_xmit |
c6c6e3e0 HX |
76 | * from skb->csum_start to the end and to record the checksum |
77 | * at skb->csum_start + skb->csum_offset. | |
1da177e4 LT |
78 | * |
79 | * Device must show its capabilities in dev->features, set | |
80 | * at device setup time. | |
81 | * NETIF_F_HW_CSUM - it is clever device, it is able to checksum | |
82 | * everything. | |
83 | * NETIF_F_NO_CSUM - loopback or reliable single hop media. | |
84 | * NETIF_F_IP_CSUM - device is dumb. It is able to csum only | |
85 | * TCP/UDP over IPv4. Sigh. Vendors like this | |
86 | * way by an unknown reason. Though, see comment above | |
87 | * about CHECKSUM_UNNECESSARY. 8) | |
c6c6e3e0 | 88 | * NETIF_F_IPV6_CSUM about as dumb as the last one but does IPv6 instead. |
1da177e4 LT |
89 | * |
90 | * Any questions? No questions, good. --ANK | |
91 | */ | |
92 | ||
1da177e4 | 93 | struct net_device; |
716ea3a7 | 94 | struct scatterlist; |
9c55e01c | 95 | struct pipe_inode_info; |
1da177e4 | 96 | |
5f79e0f9 | 97 | #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) |
1da177e4 LT |
98 | struct nf_conntrack { |
99 | atomic_t use; | |
1da177e4 | 100 | }; |
5f79e0f9 | 101 | #endif |
1da177e4 LT |
102 | |
103 | #ifdef CONFIG_BRIDGE_NETFILTER | |
104 | struct nf_bridge_info { | |
105 | atomic_t use; | |
106 | struct net_device *physindev; | |
107 | struct net_device *physoutdev; | |
1da177e4 LT |
108 | unsigned int mask; |
109 | unsigned long data[32 / sizeof(unsigned long)]; | |
110 | }; | |
111 | #endif | |
112 | ||
1da177e4 LT |
113 | struct sk_buff_head { |
114 | /* These two members must be first. */ | |
115 | struct sk_buff *next; | |
116 | struct sk_buff *prev; | |
117 | ||
118 | __u32 qlen; | |
119 | spinlock_t lock; | |
120 | }; | |
121 | ||
122 | struct sk_buff; | |
123 | ||
124 | /* To allow 64K frame to be packed as single skb without frag_list */ | |
125 | #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 2) | |
126 | ||
127 | typedef struct skb_frag_struct skb_frag_t; | |
128 | ||
129 | struct skb_frag_struct { | |
130 | struct page *page; | |
a309bb07 DM |
131 | __u32 page_offset; |
132 | __u32 size; | |
1da177e4 LT |
133 | }; |
134 | ||
135 | /* This data is invariant across clones and lives at | |
136 | * the end of the header data, ie. at skb->end. | |
137 | */ | |
138 | struct skb_shared_info { | |
139 | atomic_t dataref; | |
4947d3ef | 140 | unsigned short nr_frags; |
7967168c HX |
141 | unsigned short gso_size; |
142 | /* Warning: this field is not always filled in (UFO)! */ | |
143 | unsigned short gso_segs; | |
144 | unsigned short gso_type; | |
ae08e1f0 | 145 | __be32 ip6_frag_id; |
271bff7a DM |
146 | #ifdef CONFIG_HAS_DMA |
147 | unsigned int num_dma_maps; | |
148 | #endif | |
1da177e4 LT |
149 | struct sk_buff *frag_list; |
150 | skb_frag_t frags[MAX_SKB_FRAGS]; | |
271bff7a DM |
151 | #ifdef CONFIG_HAS_DMA |
152 | dma_addr_t dma_maps[MAX_SKB_FRAGS + 1]; | |
153 | #endif | |
1da177e4 LT |
154 | }; |
155 | ||
156 | /* We divide dataref into two halves. The higher 16 bits hold references | |
157 | * to the payload part of skb->data. The lower 16 bits hold references to | |
334a8132 PM |
158 | * the entire skb->data. A clone of a headerless skb holds the length of |
159 | * the header in skb->hdr_len. | |
1da177e4 LT |
160 | * |
161 | * All users must obey the rule that the skb->data reference count must be | |
162 | * greater than or equal to the payload reference count. | |
163 | * | |
164 | * Holding a reference to the payload part means that the user does not | |
165 | * care about modifications to the header part of skb->data. | |
166 | */ | |
167 | #define SKB_DATAREF_SHIFT 16 | |
168 | #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1) | |
169 | ||
d179cd12 DM |
170 | |
171 | enum { | |
172 | SKB_FCLONE_UNAVAILABLE, | |
173 | SKB_FCLONE_ORIG, | |
174 | SKB_FCLONE_CLONE, | |
175 | }; | |
176 | ||
7967168c HX |
177 | enum { |
178 | SKB_GSO_TCPV4 = 1 << 0, | |
f83ef8c0 | 179 | SKB_GSO_UDP = 1 << 1, |
576a30eb HX |
180 | |
181 | /* This indicates the skb is from an untrusted source. */ | |
182 | SKB_GSO_DODGY = 1 << 2, | |
b0da8537 MC |
183 | |
184 | /* This indicates the tcp segment has CWR set. */ | |
f83ef8c0 HX |
185 | SKB_GSO_TCP_ECN = 1 << 3, |
186 | ||
187 | SKB_GSO_TCPV6 = 1 << 4, | |
7967168c HX |
188 | }; |
189 | ||
2e07fa9c ACM |
190 | #if BITS_PER_LONG > 32 |
191 | #define NET_SKBUFF_DATA_USES_OFFSET 1 | |
192 | #endif | |
193 | ||
194 | #ifdef NET_SKBUFF_DATA_USES_OFFSET | |
195 | typedef unsigned int sk_buff_data_t; | |
196 | #else | |
197 | typedef unsigned char *sk_buff_data_t; | |
198 | #endif | |
199 | ||
1da177e4 LT |
200 | /** |
201 | * struct sk_buff - socket buffer | |
202 | * @next: Next buffer in list | |
203 | * @prev: Previous buffer in list | |
1da177e4 | 204 | * @sk: Socket we are owned by |
325ed823 | 205 | * @tstamp: Time we arrived |
1da177e4 | 206 | * @dev: Device we arrived on/are leaving by |
be52178b | 207 | * @transport_header: Transport layer header |
b0e380b1 ACM |
208 | * @network_header: Network layer header |
209 | * @mac_header: Link layer header | |
67be2dd1 MW |
210 | * @dst: destination entry |
211 | * @sp: the security path, used for xfrm | |
1da177e4 LT |
212 | * @cb: Control buffer. Free for use by every layer. Put private vars here |
213 | * @len: Length of actual data | |
214 | * @data_len: Data length | |
215 | * @mac_len: Length of link layer header | |
334a8132 | 216 | * @hdr_len: writable header length of cloned skb |
663ead3b HX |
217 | * @csum: Checksum (must include start/offset pair) |
218 | * @csum_start: Offset from skb->head where checksumming should start | |
219 | * @csum_offset: Offset from csum_start where checksum should be stored | |
67be2dd1 | 220 | * @local_df: allow local fragmentation |
1da177e4 LT |
221 | * @cloned: Head may be cloned (check refcnt to be sure) |
222 | * @nohdr: Payload reference only, must not modify header | |
223 | * @pkt_type: Packet class | |
c83c2486 | 224 | * @fclone: skbuff clone status |
1da177e4 LT |
225 | * @ip_summed: Driver fed us an IP checksum |
226 | * @priority: Packet queueing priority | |
227 | * @users: User count - see {datagram,tcp}.c | |
228 | * @protocol: Packet protocol from driver | |
1da177e4 LT |
229 | * @truesize: Buffer size |
230 | * @head: Head of buffer | |
231 | * @data: Data head pointer | |
232 | * @tail: Tail pointer | |
233 | * @end: End pointer | |
234 | * @destructor: Destruct function | |
82e91ffe | 235 | * @mark: Generic packet mark |
1da177e4 | 236 | * @nfct: Associated connection, if any |
c83c2486 | 237 | * @ipvs_property: skbuff is owned by ipvs |
31729363 RD |
238 | * @peeked: this packet has been seen already, so stats have been |
239 | * done for it, don't do them again | |
ba9dda3a | 240 | * @nf_trace: netfilter packet trace flag |
1da177e4 | 241 | * @nfctinfo: Relationship of this skb to the connection |
461ddf3b | 242 | * @nfct_reasm: netfilter conntrack re-assembly pointer |
1da177e4 | 243 | * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c |
f25f4e44 PWJ |
244 | * @iif: ifindex of device we arrived on |
245 | * @queue_mapping: Queue mapping for multiqueue devices | |
1da177e4 LT |
246 | * @tc_index: Traffic control index |
247 | * @tc_verd: traffic control verdict | |
553a5672 | 248 | * @ndisc_nodetype: router type (from link layer) |
4a7b61d2 | 249 | * @do_not_encrypt: set to prevent encryption of this frame |
8b30b1fe S |
250 | * @requeue: set to indicate that the wireless core should attempt |
251 | * a software retry on this frame if we failed to | |
252 | * receive an ACK for it | |
f4b8ea78 RD |
253 | * @dma_cookie: a cookie to one of several possible DMA operations |
254 | * done by skb DMA functions | |
984bc16c | 255 | * @secmark: security marking |
6aa895b0 | 256 | * @vlan_tci: vlan tag control information |
1da177e4 LT |
257 | */ |
258 | ||
259 | struct sk_buff { | |
260 | /* These two members must be first. */ | |
261 | struct sk_buff *next; | |
262 | struct sk_buff *prev; | |
263 | ||
1da177e4 | 264 | struct sock *sk; |
b7aa0bf7 | 265 | ktime_t tstamp; |
1da177e4 | 266 | struct net_device *dev; |
1da177e4 | 267 | |
ee6b9673 ED |
268 | union { |
269 | struct dst_entry *dst; | |
270 | struct rtable *rtable; | |
271 | }; | |
def8b4fa | 272 | #ifdef CONFIG_XFRM |
1da177e4 | 273 | struct sec_path *sp; |
def8b4fa | 274 | #endif |
1da177e4 LT |
275 | /* |
276 | * This is the control buffer. It is free to use for every | |
277 | * layer. Please put your private variables there. If you | |
278 | * want to keep them across layers you have to do a skb_clone() | |
279 | * first. This is owned by whoever has the skb queued ATM. | |
280 | */ | |
3e3850e9 | 281 | char cb[48]; |
1da177e4 LT |
282 | |
283 | unsigned int len, | |
334a8132 PM |
284 | data_len; |
285 | __u16 mac_len, | |
286 | hdr_len; | |
ff1dcadb AV |
287 | union { |
288 | __wsum csum; | |
663ead3b HX |
289 | struct { |
290 | __u16 csum_start; | |
291 | __u16 csum_offset; | |
292 | }; | |
ff1dcadb | 293 | }; |
1da177e4 | 294 | __u32 priority; |
1cbb3380 TG |
295 | __u8 local_df:1, |
296 | cloned:1, | |
297 | ip_summed:2, | |
6869c4d8 HW |
298 | nohdr:1, |
299 | nfctinfo:3; | |
d179cd12 | 300 | __u8 pkt_type:3, |
b84f4cc9 | 301 | fclone:2, |
ba9dda3a | 302 | ipvs_property:1, |
a59322be | 303 | peeked:1, |
ba9dda3a | 304 | nf_trace:1; |
a0d3bea3 | 305 | __be16 protocol; |
1da177e4 LT |
306 | |
307 | void (*destructor)(struct sk_buff *skb); | |
9fb9cbb1 | 308 | #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) |
5f79e0f9 | 309 | struct nf_conntrack *nfct; |
9fb9cbb1 YK |
310 | struct sk_buff *nfct_reasm; |
311 | #endif | |
1da177e4 LT |
312 | #ifdef CONFIG_BRIDGE_NETFILTER |
313 | struct nf_bridge_info *nf_bridge; | |
314 | #endif | |
f25f4e44 PWJ |
315 | |
316 | int iif; | |
317 | __u16 queue_mapping; | |
1da177e4 | 318 | #ifdef CONFIG_NET_SCHED |
b6b99eb5 | 319 | __u16 tc_index; /* traffic control index */ |
1da177e4 | 320 | #ifdef CONFIG_NET_CLS_ACT |
b6b99eb5 | 321 | __u16 tc_verd; /* traffic control verdict */ |
1da177e4 | 322 | #endif |
1da177e4 | 323 | #endif |
de357cc0 | 324 | #ifdef CONFIG_IPV6_NDISC_NODETYPE |
fadf6bf0 | 325 | __u8 ndisc_nodetype:2; |
de357cc0 | 326 | #endif |
d0f09804 JB |
327 | #if defined(CONFIG_MAC80211) || defined(CONFIG_MAC80211_MODULE) |
328 | __u8 do_not_encrypt:1; | |
8b30b1fe | 329 | __u8 requeue:1; |
d0f09804 JB |
330 | #endif |
331 | /* 0/13/14 bit hole */ | |
f25f4e44 | 332 | |
97fc2f08 CL |
333 | #ifdef CONFIG_NET_DMA |
334 | dma_cookie_t dma_cookie; | |
335 | #endif | |
984bc16c JM |
336 | #ifdef CONFIG_NETWORK_SECMARK |
337 | __u32 secmark; | |
338 | #endif | |
1da177e4 | 339 | |
82e91ffe | 340 | __u32 mark; |
1da177e4 | 341 | |
6aa895b0 PM |
342 | __u16 vlan_tci; |
343 | ||
27a884dc ACM |
344 | sk_buff_data_t transport_header; |
345 | sk_buff_data_t network_header; | |
346 | sk_buff_data_t mac_header; | |
1da177e4 | 347 | /* These elements must be at the end, see alloc_skb() for details. */ |
27a884dc | 348 | sk_buff_data_t tail; |
4305b541 | 349 | sk_buff_data_t end; |
1da177e4 | 350 | unsigned char *head, |
4305b541 | 351 | *data; |
27a884dc ACM |
352 | unsigned int truesize; |
353 | atomic_t users; | |
1da177e4 LT |
354 | }; |
355 | ||
356 | #ifdef __KERNEL__ | |
357 | /* | |
358 | * Handling routines are only of interest to the kernel | |
359 | */ | |
360 | #include <linux/slab.h> | |
361 | ||
362 | #include <asm/system.h> | |
363 | ||
a40c24a1 DM |
364 | #ifdef CONFIG_HAS_DMA |
365 | #include <linux/dma-mapping.h> | |
366 | extern int skb_dma_map(struct device *dev, struct sk_buff *skb, | |
367 | enum dma_data_direction dir); | |
368 | extern void skb_dma_unmap(struct device *dev, struct sk_buff *skb, | |
369 | enum dma_data_direction dir); | |
370 | #endif | |
371 | ||