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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 LT |
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 |
60476372 HX |
37 | #define CHECKSUM_UNNECESSARY 1 |
38 | #define CHECKSUM_COMPLETE 2 | |
39 | #define CHECKSUM_PARTIAL 3 | |
1da177e4 LT |
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))) |
fc910a27 DM |
45 | #define SKB_MAX_ORDER(X, ORDER) \ |
46 | SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X)) | |
1da177e4 LT |
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_ |
1da177e4 LT |
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, |
1da177e4 LT |
65 | * not UNNECESSARY. |
66 | * | |
c6c6e3e0 HX |
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 | * | |
1da177e4 LT |
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 |
c6c6e3e0 HX |
79 | * from skb->csum_start to the end and to record the checksum |
80 | * at skb->csum_start + skb->csum_offset. | |
1da177e4 LT |
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. |
1da177e4 LT |
92 | * |
93 | * Any questions? No questions, good. --ANK | |
94 | */ | |
95 | ||
1da177e4 | 96 | struct net_device; |
716ea3a7 | 97 | struct scatterlist; |
1da177e4 | 98 | |
5f79e0f9 | 99 | #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) |
1da177e4 LT |
100 | struct nf_conntrack { |
101 | atomic_t use; | |
1da177e4 | 102 | }; |
5f79e0f9 | 103 | #endif |
1da177e4 LT |
104 | |
105 | #ifdef CONFIG_BRIDGE_NETFILTER | |
106 | struct nf_bridge_info { | |
107 | atomic_t use; | |
108 | struct net_device *physindev; | |
109 | struct net_device *physoutdev; | |
110 | #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE) | |
111 | struct net_device *netoutdev; | |
112 | #endif | |
113 | unsigned int mask; | |
114 | unsigned long data[32 / sizeof(unsigned long)]; | |
115 | }; | |
116 | #endif | |
117 | ||
1da177e4 LT |
118 | struct sk_buff_head { |
119 | /* These two members must be first. */ | |
120 | struct sk_buff *next; | |
121 | struct sk_buff *prev; | |
122 | ||
123 | __u32 qlen; | |
124 | spinlock_t lock; | |
125 | }; | |
126 | ||
127 | struct sk_buff; | |
128 | ||
129 | /* To allow 64K frame to be packed as single skb without frag_list */ | |
130 | #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 2) | |
131 | ||
132 | typedef struct skb_frag_struct skb_frag_t; | |
133 | ||
134 | struct skb_frag_struct { | |
135 | struct page *page; | |
a309bb07 DM |
136 | __u32 page_offset; |
137 | __u32 size; | |
1da177e4 LT |
138 | }; |
139 | ||
140 | /* This data is invariant across clones and lives at | |
141 | * the end of the header data, ie. at skb->end. | |
142 | */ | |
143 | struct skb_shared_info { | |
144 | atomic_t dataref; | |
4947d3ef | 145 | unsigned short nr_frags; |
7967168c HX |
146 | unsigned short gso_size; |
147 | /* Warning: this field is not always filled in (UFO)! */ | |
148 | unsigned short gso_segs; | |
149 | unsigned short gso_type; | |
ae08e1f0 | 150 | __be32 ip6_frag_id; |
1da177e4 LT |
151 | struct sk_buff *frag_list; |
152 | skb_frag_t frags[MAX_SKB_FRAGS]; | |
153 | }; | |
154 | ||
155 | /* We divide dataref into two halves. The higher 16 bits hold references | |
156 | * to the payload part of skb->data. The lower 16 bits hold references to | |
334a8132 PM |
157 | * the entire skb->data. A clone of a headerless skb holds the length of |
158 | * the header in skb->hdr_len. | |
1da177e4 LT |
159 | * |
160 | * All users must obey the rule that the skb->data reference count must be | |
161 | * greater than or equal to the payload reference count. | |
162 | * | |
163 | * Holding a reference to the payload part means that the user does not | |
164 | * care about modifications to the header part of skb->data. | |
165 | */ | |
166 | #define SKB_DATAREF_SHIFT 16 | |
167 | #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1) | |
168 | ||
d179cd12 DM |
169 | |
170 | enum { | |
171 | SKB_FCLONE_UNAVAILABLE, | |
172 | SKB_FCLONE_ORIG, | |
173 | SKB_FCLONE_CLONE, | |
174 | }; | |
175 | ||
7967168c HX |
176 | enum { |
177 | SKB_GSO_TCPV4 = 1 << 0, | |
f83ef8c0 | 178 | SKB_GSO_UDP = 1 << 1, |
576a30eb HX |
179 | |
180 | /* This indicates the skb is from an untrusted source. */ | |
181 | SKB_GSO_DODGY = 1 << 2, | |
b0da8537 MC |
182 | |
183 | /* This indicates the tcp segment has CWR set. */ | |
f83ef8c0 HX |
184 | SKB_GSO_TCP_ECN = 1 << 3, |
185 | ||
186 | SKB_GSO_TCPV6 = 1 << 4, | |
7967168c HX |
187 | }; |
188 | ||
2e07fa9c ACM |
189 | #if BITS_PER_LONG > 32 |
190 | #define NET_SKBUFF_DATA_USES_OFFSET 1 | |
191 | #endif | |
192 | ||
193 | #ifdef NET_SKBUFF_DATA_USES_OFFSET | |
194 | typedef unsigned int sk_buff_data_t; | |
195 | #else | |
196 | typedef unsigned char *sk_buff_data_t; | |
197 | #endif | |
198 | ||
1da177e4 LT |
199 | /** |
200 | * struct sk_buff - socket buffer | |
201 | * @next: Next buffer in list | |
202 | * @prev: Previous buffer in list | |
1da177e4 | 203 | * @sk: Socket we are owned by |
325ed823 | 204 | * @tstamp: Time we arrived |
1da177e4 | 205 | * @dev: Device we arrived on/are leaving by |
be52178b | 206 | * @transport_header: Transport layer header |
b0e380b1 ACM |
207 | * @network_header: Network layer header |
208 | * @mac_header: Link layer header | |
67be2dd1 MW |
209 | * @dst: destination entry |
210 | * @sp: the security path, used for xfrm | |
1da177e4 LT |
211 | * @cb: Control buffer. Free for use by every layer. Put private vars here |
212 | * @len: Length of actual data | |
213 | * @data_len: Data length | |
214 | * @mac_len: Length of link layer header | |
334a8132 | 215 | * @hdr_len: writable header length of cloned skb |
663ead3b HX |
216 | * @csum: Checksum (must include start/offset pair) |
217 | * @csum_start: Offset from skb->head where checksumming should start | |
218 | * @csum_offset: Offset from csum_start where checksum should be stored | |
67be2dd1 | 219 | * @local_df: allow local fragmentation |
1da177e4 LT |
220 | * @cloned: Head may be cloned (check refcnt to be sure) |
221 | * @nohdr: Payload reference only, must not modify header | |
222 | * @pkt_type: Packet class | |
c83c2486 | 223 | * @fclone: skbuff clone status |
1da177e4 LT |
224 | * @ip_summed: Driver fed us an IP checksum |
225 | * @priority: Packet queueing priority | |
226 | * @users: User count - see {datagram,tcp}.c | |
227 | * @protocol: Packet protocol from driver | |
1da177e4 LT |
228 | * @truesize: Buffer size |
229 | * @head: Head of buffer | |
230 | * @data: Data head pointer | |
231 | * @tail: Tail pointer | |
232 | * @end: End pointer | |
233 | * @destructor: Destruct function | |
82e91ffe | 234 | * @mark: Generic packet mark |
1da177e4 | 235 | * @nfct: Associated connection, if any |
c83c2486 | 236 | * @ipvs_property: skbuff is owned by ipvs |
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 |
f25f4e44 PWJ |
241 | * @iif: ifindex of device we arrived on |
242 | * @queue_mapping: Queue mapping for multiqueue devices | |
1da177e4 LT |
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 LT |
248 | */ |
249 | ||
250 | struct 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 | |
1da177e4 LT |
259 | struct dst_entry *dst; |
260 | struct sec_path *sp; | |
261 | ||
262 | /* | |
263 | * This is the control buffer. It is free to use for every | |
264 | * layer. Please put your private variables there. If you | |
265 | * want to keep them across layers you have to do a skb_clone() | |
266 | * first. This is owned by whoever has the skb queued ATM. | |
267 | */ | |
3e3850e9 | 268 | char cb[48]; |
1da177e4 LT |
269 | |
270 | unsigned int len, | |
334a8132 PM |
271 | data_len; |
272 | __u16 mac_len, | |
273 | hdr_len; | |
ff1dcadb AV |
274 | union { |
275 | __wsum csum; | |
663ead3b HX |
276 | struct { |
277 | __u16 csum_start; | |
278 | __u16 csum_offset; | |
279 | }; | |
ff1dcadb | 280 | }; |
1da177e4 | 281 | __u32 priority; |
1cbb3380 TG |
282 | __u8 local_df:1, |
283 | cloned:1, | |
284 | ip_summed:2, | |
6869c4d8 HW |
285 | nohdr:1, |
286 | nfctinfo:3; | |
d179cd12 | 287 | __u8 pkt_type:3, |
b84f4cc9 | 288 | fclone:2, |
ba9dda3a JK |
289 | ipvs_property:1, |
290 | nf_trace:1; | |
a0d3bea3 | 291 | __be16 protocol; |
1da177e4 LT |
292 | |
293 | void (*destructor)(struct sk_buff *skb); | |
9fb9cbb1 | 294 | #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) |
5f79e0f9 | 295 | struct nf_conntrack *nfct; |
9fb9cbb1 YK |
296 | struct sk_buff *nfct_reasm; |
297 | #endif | |
1da177e4 LT |
298 | #ifdef CONFIG_BRIDGE_NETFILTER |
299 | struct nf_bridge_info *nf_bridge; | |
300 | #endif | |
f25f4e44 PWJ |
301 | |
302 | int iif; | |
e3fa259b | 303 | #ifdef CONFIG_NETDEVICES_MULTIQUEUE |
f25f4e44 | 304 | __u16 queue_mapping; |
e3fa259b | 305 | #endif |
1da177e4 | 306 | #ifdef CONFIG_NET_SCHED |
b6b99eb5 | 307 | __u16 tc_index; /* traffic control index */ |
1da177e4 | 308 | #ifdef CONFIG_NET_CLS_ACT |
b6b99eb5 | 309 | __u16 tc_verd; /* traffic control verdict */ |
1da177e4 | 310 | #endif |
1da177e4 | 311 | #endif |
f25f4e44 PWJ |
312 | /* 2 byte hole */ |
313 | ||
97fc2f08 CL |
314 | #ifdef CONFIG_NET_DMA |
315 | dma_cookie_t dma_cookie; | |
316 | #endif | |
984bc16c JM |
317 | #ifdef CONFIG_NETWORK_SECMARK |
318 | __u32 secmark; | |
319 | #endif | |
1da177e4 | 320 | |
82e91ffe | 321 | __u32 mark; |
1da177e4 | 322 | |
27a884dc ACM |
323 | sk_buff_data_t transport_header; |
324 | sk_buff_data_t network_header; | |
325 | sk_buff_data_t mac_header; | |
1da177e4 | 326 | /* These elements must be at the end, see alloc_skb() for details. */ |
27a884dc | 327 | sk_buff_data_t tail; |
4305b541 | 328 | sk_buff_data_t end; |
1da177e4 | 329 | unsigned char *head, |
4305b541 | 330 | *data; |
27a884dc ACM |
331 | unsigned int truesize; |
332 | atomic_t users; | |
1da177e4 LT |
333 | }; |
334 | ||
335 | #ifdef __KERNEL__ | |
336 | /* | |
337 | * Handling routines are only of interest to the kernel | |
338 | */ | |
339 | #include <linux/slab.h> | |
340 | ||
341 | #include <asm/system.h> | |
342 | ||