[DCCP]: Make feature negotiation more readable
[linux-2.6.git] / include / linux / dccp.h
1 #ifndef _LINUX_DCCP_H
2 #define _LINUX_DCCP_H
3
4 #include <linux/types.h>
5 #include <asm/byteorder.h>
6
7 /**
8  * struct dccp_hdr - generic part of DCCP packet header
9  *
10  * @dccph_sport - Relevant port on the endpoint that sent this packet
11  * @dccph_dport - Relevant port on the other endpoint
12  * @dccph_doff - Data Offset from the start of the DCCP header, in 32-bit words
13  * @dccph_ccval - Used by the HC-Sender CCID
14  * @dccph_cscov - Parts of the packet that are covered by the Checksum field
15  * @dccph_checksum - Internet checksum, depends on dccph_cscov
16  * @dccph_x - 0 = 24 bit sequence number, 1 = 48
17  * @dccph_type - packet type, see DCCP_PKT_ prefixed macros
18  * @dccph_seq - sequence number high or low order 24 bits, depends on dccph_x
19  */
20 struct dccp_hdr {
21         __be16  dccph_sport,
22                 dccph_dport;
23         __u8    dccph_doff;
24 #if defined(__LITTLE_ENDIAN_BITFIELD)
25         __u8    dccph_cscov:4,
26                 dccph_ccval:4;
27 #elif defined(__BIG_ENDIAN_BITFIELD)
28         __u8    dccph_ccval:4,
29                 dccph_cscov:4;
30 #else
31 #error  "Adjust your <asm/byteorder.h> defines"
32 #endif
33         __u16   dccph_checksum;
34 #if defined(__LITTLE_ENDIAN_BITFIELD)
35         __u8    dccph_x:1,
36                 dccph_type:4,
37                 dccph_reserved:3;
38 #elif defined(__BIG_ENDIAN_BITFIELD)
39         __u8    dccph_reserved:3,
40                 dccph_type:4,
41                 dccph_x:1;
42 #else
43 #error  "Adjust your <asm/byteorder.h> defines"
44 #endif
45         __u8    dccph_seq2;
46         __be16  dccph_seq;
47 };
48
49 /**
50  * struct dccp_hdr_ext - the low bits of a 48 bit seq packet
51  *
52  * @dccph_seq_low - low 24 bits of a 48 bit seq packet
53  */
54 struct dccp_hdr_ext {
55         __be32  dccph_seq_low;
56 };
57
58 /**
59  * struct dccp_hdr_request - Conection initiation request header
60  *
61  * @dccph_req_service - Service to which the client app wants to connect
62  * @dccph_req_options - list of options (must be a multiple of 32 bits
63  */
64 struct dccp_hdr_request {
65         __be32  dccph_req_service;
66 };
67 /**
68  * struct dccp_hdr_ack_bits - acknowledgment bits common to most packets
69  *
70  * @dccph_resp_ack_nr_high - 48 bit ack number high order bits, contains GSR
71  * @dccph_resp_ack_nr_low - 48 bit ack number low order bits, contains GSR
72  */
73 struct dccp_hdr_ack_bits {
74         __be16  dccph_reserved1;
75         __be16  dccph_ack_nr_high;
76         __be32  dccph_ack_nr_low;
77 };
78 /**
79  * struct dccp_hdr_response - Conection initiation response header
80  *
81  * @dccph_resp_ack_nr_high - 48 bit ack number high order bits, contains GSR
82  * @dccph_resp_ack_nr_low - 48 bit ack number low order bits, contains GSR
83  * @dccph_resp_service - Echoes the Service Code on a received DCCP-Request
84  * @dccph_resp_options - list of options (must be a multiple of 32 bits
85  */
86 struct dccp_hdr_response {
87         struct dccp_hdr_ack_bits        dccph_resp_ack;
88         __be32                          dccph_resp_service;
89 };
90
91 /**
92  * struct dccp_hdr_reset - Unconditionally shut down a connection
93  *
94  * @dccph_reset_service - Echoes the Service Code on a received DCCP-Request
95  * @dccph_reset_options - list of options (must be a multiple of 32 bits
96  */
97 struct dccp_hdr_reset {
98         struct dccp_hdr_ack_bits        dccph_reset_ack;
99         __u8                            dccph_reset_code,
100                                         dccph_reset_data[3];
101 };
102
103 enum dccp_pkt_type {
104         DCCP_PKT_REQUEST = 0,
105         DCCP_PKT_RESPONSE,
106         DCCP_PKT_DATA,
107         DCCP_PKT_ACK,
108         DCCP_PKT_DATAACK,
109         DCCP_PKT_CLOSEREQ,
110         DCCP_PKT_CLOSE,
111         DCCP_PKT_RESET,
112         DCCP_PKT_SYNC,
113         DCCP_PKT_SYNCACK,
114         DCCP_PKT_INVALID,
115 };
116
117 #define DCCP_NR_PKT_TYPES DCCP_PKT_INVALID
118
119 static inline unsigned int dccp_packet_hdr_len(const __u8 type)
120 {
121         if (type == DCCP_PKT_DATA)
122                 return 0;
123         if (type == DCCP_PKT_DATAACK    ||
124             type == DCCP_PKT_ACK        ||
125             type == DCCP_PKT_SYNC       ||
126             type == DCCP_PKT_SYNCACK    ||
127             type == DCCP_PKT_CLOSE      ||
128             type == DCCP_PKT_CLOSEREQ)
129                 return sizeof(struct dccp_hdr_ack_bits);
130         if (type == DCCP_PKT_REQUEST)
131                 return sizeof(struct dccp_hdr_request);
132         if (type == DCCP_PKT_RESPONSE)
133                 return sizeof(struct dccp_hdr_response);
134         return sizeof(struct dccp_hdr_reset);
135 }
136 enum dccp_reset_codes {
137         DCCP_RESET_CODE_UNSPECIFIED = 0,
138         DCCP_RESET_CODE_CLOSED,
139         DCCP_RESET_CODE_ABORTED,
140         DCCP_RESET_CODE_NO_CONNECTION,
141         DCCP_RESET_CODE_PACKET_ERROR,
142         DCCP_RESET_CODE_OPTION_ERROR,
143         DCCP_RESET_CODE_MANDATORY_ERROR,
144         DCCP_RESET_CODE_CONNECTION_REFUSED,
145         DCCP_RESET_CODE_BAD_SERVICE_CODE,
146         DCCP_RESET_CODE_TOO_BUSY,
147         DCCP_RESET_CODE_BAD_INIT_COOKIE,
148         DCCP_RESET_CODE_AGGRESSION_PENALTY,
149 };
150
151 /* DCCP options */
152 enum {
153         DCCPO_PADDING = 0,
154         DCCPO_MANDATORY = 1,
155         DCCPO_MIN_RESERVED = 3,
156         DCCPO_MAX_RESERVED = 31,
157         DCCPO_CHANGE_L = 32,
158         DCCPO_CONFIRM_L = 33,
159         DCCPO_CHANGE_R = 34,
160         DCCPO_CONFIRM_R = 35,
161         DCCPO_NDP_COUNT = 37,
162         DCCPO_ACK_VECTOR_0 = 38,
163         DCCPO_ACK_VECTOR_1 = 39,
164         DCCPO_TIMESTAMP = 41,
165         DCCPO_TIMESTAMP_ECHO = 42,
166         DCCPO_ELAPSED_TIME = 43,
167         DCCPO_MAX = 45,
168         DCCPO_MIN_CCID_SPECIFIC = 128,
169         DCCPO_MAX_CCID_SPECIFIC = 255,
170 };
171
172 /* DCCP CCIDS */
173 enum {
174         DCCPC_CCID2 = 2,
175         DCCPC_CCID3 = 3,
176 };
177
178 /* DCCP features (RFC 4340 section 6.4) */
179  enum {
180         DCCPF_RESERVED = 0,
181         DCCPF_CCID = 1,
182         DCCPF_SHORT_SEQNOS = 2,         /* XXX: not yet implemented */
183         DCCPF_SEQUENCE_WINDOW = 3,
184         DCCPF_ECN_INCAPABLE = 4,        /* XXX: not yet implemented */
185         DCCPF_ACK_RATIO = 5,
186         DCCPF_SEND_ACK_VECTOR = 6,
187         DCCPF_SEND_NDP_COUNT = 7,
188         DCCPF_MIN_CSUM_COVER = 8,
189         DCCPF_DATA_CHECKSUM = 9,        /* XXX: not yet implemented */
190         /* 10-127 reserved */
191         DCCPF_MIN_CCID_SPECIFIC = 128,
192         DCCPF_MAX_CCID_SPECIFIC = 255,
193 };
194
195 /* this structure is argument to DCCP_SOCKOPT_CHANGE_X */
196 struct dccp_so_feat {
197         __u8 dccpsf_feat;
198         __u8 __user *dccpsf_val;
199         __u8 dccpsf_len;
200 };
201
202 /* DCCP socket options */
203 #define DCCP_SOCKOPT_PACKET_SIZE        1
204 #define DCCP_SOCKOPT_SERVICE            2
205 #define DCCP_SOCKOPT_CHANGE_L           3
206 #define DCCP_SOCKOPT_CHANGE_R           4
207 #define DCCP_SOCKOPT_SEND_CSCOV         10
208 #define DCCP_SOCKOPT_RECV_CSCOV         11
209 #define DCCP_SOCKOPT_CCID_RX_INFO       128
210 #define DCCP_SOCKOPT_CCID_TX_INFO       192
211
212 #define DCCP_SERVICE_LIST_MAX_LEN      32
213
214 #ifdef __KERNEL__
215
216 #include <linux/in.h>
217 #include <linux/list.h>
218 #include <linux/uio.h>
219 #include <linux/workqueue.h>
220
221 #include <net/inet_connection_sock.h>
222 #include <net/inet_sock.h>
223 #include <net/inet_timewait_sock.h>
224 #include <net/tcp_states.h>
225
226 enum dccp_state {
227         DCCP_OPEN       = TCP_ESTABLISHED,
228         DCCP_REQUESTING = TCP_SYN_SENT,
229         DCCP_PARTOPEN   = TCP_FIN_WAIT1, /* FIXME:
230                                             This mapping is horrible, but TCP has
231                                             no matching state for DCCP_PARTOPEN,
232                                             as TCP_SYN_RECV is already used by
233                                             DCCP_RESPOND, why don't stop using TCP
234                                             mapping of states? OK, now we don't use
235                                             sk_stream_sendmsg anymore, so doesn't
236                                             seem to exist any reason for us to
237                                             do the TCP mapping here */
238         DCCP_LISTEN     = TCP_LISTEN,
239         DCCP_RESPOND    = TCP_SYN_RECV,
240         DCCP_CLOSING    = TCP_CLOSING,
241         DCCP_TIME_WAIT  = TCP_TIME_WAIT,
242         DCCP_CLOSED     = TCP_CLOSE,
243         DCCP_MAX_STATES = TCP_MAX_STATES,
244 };
245
246 #define DCCP_STATE_MASK 0xf
247 #define DCCP_ACTION_FIN (1<<7)
248
249 enum {
250         DCCPF_OPEN       = TCPF_ESTABLISHED,
251         DCCPF_REQUESTING = TCPF_SYN_SENT,
252         DCCPF_PARTOPEN   = TCPF_FIN_WAIT1,
253         DCCPF_LISTEN     = TCPF_LISTEN,
254         DCCPF_RESPOND    = TCPF_SYN_RECV,
255         DCCPF_CLOSING    = TCPF_CLOSING,
256         DCCPF_TIME_WAIT  = TCPF_TIME_WAIT,
257         DCCPF_CLOSED     = TCPF_CLOSE,
258 };
259
260 static inline struct dccp_hdr *dccp_hdr(const struct sk_buff *skb)
261 {
262         return (struct dccp_hdr *)skb->h.raw;
263 }
264
265 static inline struct dccp_hdr *dccp_zeroed_hdr(struct sk_buff *skb, int headlen)
266 {
267         skb->h.raw = skb_push(skb, headlen);
268         memset(skb->h.raw, 0, headlen);
269         return dccp_hdr(skb);
270 }
271
272 static inline struct dccp_hdr_ext *dccp_hdrx(const struct sk_buff *skb)
273 {
274         return (struct dccp_hdr_ext *)(skb->h.raw + sizeof(struct dccp_hdr));
275 }
276
277 static inline unsigned int __dccp_basic_hdr_len(const struct dccp_hdr *dh)
278 {
279         return sizeof(*dh) + (dh->dccph_x ? sizeof(struct dccp_hdr_ext) : 0);
280 }
281
282 static inline unsigned int dccp_basic_hdr_len(const struct sk_buff *skb)
283 {
284         const struct dccp_hdr *dh = dccp_hdr(skb);
285         return __dccp_basic_hdr_len(dh);
286 }
287
288 static inline __u64 dccp_hdr_seq(const struct sk_buff *skb)
289 {
290         const struct dccp_hdr *dh = dccp_hdr(skb);
291         __u64 seq_nr =  ntohs(dh->dccph_seq);
292
293         if (dh->dccph_x != 0)
294                 seq_nr = (seq_nr << 32) + ntohl(dccp_hdrx(skb)->dccph_seq_low);
295         else
296                 seq_nr += (u32)dh->dccph_seq2 << 16;
297
298         return seq_nr;
299 }
300
301 static inline struct dccp_hdr_request *dccp_hdr_request(struct sk_buff *skb)
302 {
303         return (struct dccp_hdr_request *)(skb->h.raw + dccp_basic_hdr_len(skb));
304 }
305
306 static inline struct dccp_hdr_ack_bits *dccp_hdr_ack_bits(const struct sk_buff *skb)
307 {
308         return (struct dccp_hdr_ack_bits *)(skb->h.raw + dccp_basic_hdr_len(skb));
309 }
310
311 static inline u64 dccp_hdr_ack_seq(const struct sk_buff *skb)
312 {
313         const struct dccp_hdr_ack_bits *dhack = dccp_hdr_ack_bits(skb);
314         return ((u64)ntohs(dhack->dccph_ack_nr_high) << 32) + ntohl(dhack->dccph_ack_nr_low);
315 }
316
317 static inline struct dccp_hdr_response *dccp_hdr_response(struct sk_buff *skb)
318 {
319         return (struct dccp_hdr_response *)(skb->h.raw + dccp_basic_hdr_len(skb));
320 }
321
322 static inline struct dccp_hdr_reset *dccp_hdr_reset(struct sk_buff *skb)
323 {
324         return (struct dccp_hdr_reset *)(skb->h.raw + dccp_basic_hdr_len(skb));
325 }
326
327 static inline unsigned int __dccp_hdr_len(const struct dccp_hdr *dh)
328 {
329         return __dccp_basic_hdr_len(dh) +
330                dccp_packet_hdr_len(dh->dccph_type);
331 }
332
333 static inline unsigned int dccp_hdr_len(const struct sk_buff *skb)
334 {
335         return __dccp_hdr_len(dccp_hdr(skb));
336 }
337
338
339 /* initial values for each feature */
340 #define DCCPF_INITIAL_SEQUENCE_WINDOW           100
341 #define DCCPF_INITIAL_ACK_RATIO                 2
342 #define DCCPF_INITIAL_CCID                      DCCPC_CCID2
343 #define DCCPF_INITIAL_SEND_ACK_VECTOR           1
344 /* FIXME: for now we're default to 1 but it should really be 0 */
345 #define DCCPF_INITIAL_SEND_NDP_COUNT            1
346
347 #define DCCP_NDP_LIMIT 0xFFFFFF
348
349 /**
350   * struct dccp_minisock - Minimal DCCP connection representation
351   *
352   * Will be used to pass the state from dccp_request_sock to dccp_sock.
353   *
354   * @dccpms_sequence_window - Sequence Window Feature (section 7.5.2)
355   * @dccpms_ccid - Congestion Control Id (CCID) (section 10)
356   * @dccpms_send_ack_vector - Send Ack Vector Feature (section 11.5)
357   * @dccpms_send_ndp_count - Send NDP Count Feature (7.7.2)
358   */
359 struct dccp_minisock {
360         __u64                   dccpms_sequence_window;
361         __u8                    dccpms_rx_ccid;
362         __u8                    dccpms_tx_ccid;
363         __u8                    dccpms_send_ack_vector;
364         __u8                    dccpms_send_ndp_count;
365         __u8                    dccpms_ack_ratio;
366         struct list_head        dccpms_pending;
367         struct list_head        dccpms_conf;
368 };
369
370 struct dccp_opt_conf {
371         __u8                    *dccpoc_val;
372         __u8                    dccpoc_len;
373 };
374
375 struct dccp_opt_pend {
376         struct list_head        dccpop_node;
377         __u8                    dccpop_type;
378         __u8                    dccpop_feat;
379         __u8                    *dccpop_val;
380         __u8                    dccpop_len;
381         int                     dccpop_conf;
382         struct dccp_opt_conf    *dccpop_sc;
383 };
384
385 extern void __dccp_minisock_init(struct dccp_minisock *dmsk);
386 extern void dccp_minisock_init(struct dccp_minisock *dmsk);
387
388 extern int dccp_parse_options(struct sock *sk, struct sk_buff *skb);
389
390 struct dccp_request_sock {
391         struct inet_request_sock dreq_inet_rsk;
392         __u64                    dreq_iss;
393         __u64                    dreq_isr;
394         __be32                   dreq_service;
395 };
396
397 static inline struct dccp_request_sock *dccp_rsk(const struct request_sock *req)
398 {
399         return (struct dccp_request_sock *)req;
400 }
401
402 extern struct inet_timewait_death_row dccp_death_row;
403
404 struct dccp_options_received {
405         u32     dccpor_ndp; /* only 24 bits */
406         u32     dccpor_timestamp;
407         u32     dccpor_timestamp_echo;
408         u32     dccpor_elapsed_time;
409 };
410
411 struct ccid;
412
413 enum dccp_role {
414         DCCP_ROLE_UNDEFINED,
415         DCCP_ROLE_LISTEN,
416         DCCP_ROLE_CLIENT,
417         DCCP_ROLE_SERVER,
418 };
419
420 struct dccp_service_list {
421         __u32   dccpsl_nr;
422         __be32  dccpsl_list[0];
423 };
424
425 #define DCCP_SERVICE_INVALID_VALUE htonl((__u32)-1)
426 #define DCCP_SERVICE_CODE_IS_ABSENT              0
427
428 static inline int dccp_list_has_service(const struct dccp_service_list *sl,
429                                         const __be32 service)
430 {
431         if (likely(sl != NULL)) {
432                 u32 i = sl->dccpsl_nr;
433                 while (i--)
434                         if (sl->dccpsl_list[i] == service)
435                                 return 1; 
436         }
437         return 0;
438 }
439
440 struct dccp_ackvec;
441
442 /**
443  * struct dccp_sock - DCCP socket state
444  *
445  * @dccps_swl - sequence number window low
446  * @dccps_swh - sequence number window high
447  * @dccps_awl - acknowledgement number window low
448  * @dccps_awh - acknowledgement number window high
449  * @dccps_iss - initial sequence number sent
450  * @dccps_isr - initial sequence number received
451  * @dccps_osr - first OPEN sequence number received
452  * @dccps_gss - greatest sequence number sent
453  * @dccps_gsr - greatest valid sequence number received
454  * @dccps_gar - greatest valid ack number received on a non-Sync; initialized to %dccps_iss
455  * @dccps_timestamp_time - time of latest TIMESTAMP option
456  * @dccps_timestamp_echo - latest timestamp received on a TIMESTAMP option
457  * @dccps_packet_size - Set thru setsockopt
458  * @dccps_role - Role of this sock, one of %dccp_role
459  * @dccps_pcslen - sender   partial checksum coverage (via sockopt)
460  * @dccps_pcrlen - receiver partial checksum coverage (via sockopt)
461  * @dccps_ndp_count - number of Non Data Packets since last data packet
462  * @dccps_hc_rx_ackvec - rx half connection ack vector
463  * @dccps_xmit_timer - timer for when CCID is not ready to send
464  */
465 struct dccp_sock {
466         /* inet_connection_sock has to be the first member of dccp_sock */
467         struct inet_connection_sock     dccps_inet_connection;
468         __u64                           dccps_swl;
469         __u64                           dccps_swh;
470         __u64                           dccps_awl;
471         __u64                           dccps_awh;
472         __u64                           dccps_iss;
473         __u64                           dccps_isr;
474         __u64                           dccps_osr;
475         __u64                           dccps_gss;
476         __u64                           dccps_gsr;
477         __u64                           dccps_gar;
478         __be32                          dccps_service;
479         struct dccp_service_list        *dccps_service_list;
480         struct timeval                  dccps_timestamp_time;
481         __u32                           dccps_timestamp_echo;
482         __u32                           dccps_packet_size;
483         __u16                           dccps_l_ack_ratio;
484         __u16                           dccps_r_ack_ratio;
485         __u16                           dccps_pcslen;
486         __u16                           dccps_pcrlen;
487         unsigned long                   dccps_ndp_count;
488         __u32                           dccps_mss_cache;
489         struct dccp_minisock            dccps_minisock;
490         struct dccp_ackvec              *dccps_hc_rx_ackvec;
491         struct ccid                     *dccps_hc_rx_ccid;
492         struct ccid                     *dccps_hc_tx_ccid;
493         struct dccp_options_received    dccps_options_received;
494         struct timeval                  dccps_epoch;
495         enum dccp_role                  dccps_role:2;
496         __u8                            dccps_hc_rx_insert_options:1;
497         __u8                            dccps_hc_tx_insert_options:1;
498         struct timer_list               dccps_xmit_timer;
499 };
500  
501 static inline struct dccp_sock *dccp_sk(const struct sock *sk)
502 {
503         return (struct dccp_sock *)sk;
504 }
505
506 static inline struct dccp_minisock *dccp_msk(const struct sock *sk)
507 {
508         return (struct dccp_minisock *)&dccp_sk(sk)->dccps_minisock;
509 }
510
511 static inline const char *dccp_role(const struct sock *sk)
512 {
513         switch (dccp_sk(sk)->dccps_role) {
514         case DCCP_ROLE_UNDEFINED: return "undefined";
515         case DCCP_ROLE_LISTEN:    return "listen";
516         case DCCP_ROLE_SERVER:    return "server";
517         case DCCP_ROLE_CLIENT:    return "client";
518         }
519         return NULL;
520 }
521
522 #endif /* __KERNEL__ */
523
524 #endif /* _LINUX_DCCP_H */