[DCCP]: Allow to parse options on Request Sockets
[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         __sum16 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 - Connection initiation request header
60  *
61  * @dccph_req_service - Service to which the client app wants to connect
62  */
63 struct dccp_hdr_request {
64         __be32  dccph_req_service;
65 };
66 /**
67  * struct dccp_hdr_ack_bits - acknowledgment bits common to most packets
68  *
69  * @dccph_resp_ack_nr_high - 48 bit ack number high order bits, contains GSR
70  * @dccph_resp_ack_nr_low - 48 bit ack number low order bits, contains GSR
71  */
72 struct dccp_hdr_ack_bits {
73         __be16  dccph_reserved1;
74         __be16  dccph_ack_nr_high;
75         __be32  dccph_ack_nr_low;
76 };
77 /**
78  * struct dccp_hdr_response - Connection initiation response header
79  *
80  * @dccph_resp_ack - 48 bit Acknowledgment Number Subheader (5.3)
81  * @dccph_resp_service - Echoes the Service Code on a received DCCP-Request
82  */
83 struct dccp_hdr_response {
84         struct dccp_hdr_ack_bits        dccph_resp_ack;
85         __be32                          dccph_resp_service;
86 };
87
88 /**
89  * struct dccp_hdr_reset - Unconditionally shut down a connection
90  *
91  * @dccph_reset_ack - 48 bit Acknowledgment Number Subheader (5.6)
92  * @dccph_reset_code - one of %dccp_reset_codes
93  * @dccph_reset_data - the Data 1 ... Data 3 fields from 5.6
94  */
95 struct dccp_hdr_reset {
96         struct dccp_hdr_ack_bits        dccph_reset_ack;
97         __u8                            dccph_reset_code,
98                                         dccph_reset_data[3];
99 };
100
101 enum dccp_pkt_type {
102         DCCP_PKT_REQUEST = 0,
103         DCCP_PKT_RESPONSE,
104         DCCP_PKT_DATA,
105         DCCP_PKT_ACK,
106         DCCP_PKT_DATAACK,
107         DCCP_PKT_CLOSEREQ,
108         DCCP_PKT_CLOSE,
109         DCCP_PKT_RESET,
110         DCCP_PKT_SYNC,
111         DCCP_PKT_SYNCACK,
112         DCCP_PKT_INVALID,
113 };
114
115 #define DCCP_NR_PKT_TYPES DCCP_PKT_INVALID
116
117 static inline unsigned int dccp_packet_hdr_len(const __u8 type)
118 {
119         if (type == DCCP_PKT_DATA)
120                 return 0;
121         if (type == DCCP_PKT_DATAACK    ||
122             type == DCCP_PKT_ACK        ||
123             type == DCCP_PKT_SYNC       ||
124             type == DCCP_PKT_SYNCACK    ||
125             type == DCCP_PKT_CLOSE      ||
126             type == DCCP_PKT_CLOSEREQ)
127                 return sizeof(struct dccp_hdr_ack_bits);
128         if (type == DCCP_PKT_REQUEST)
129                 return sizeof(struct dccp_hdr_request);
130         if (type == DCCP_PKT_RESPONSE)
131                 return sizeof(struct dccp_hdr_response);
132         return sizeof(struct dccp_hdr_reset);
133 }
134 enum dccp_reset_codes {
135         DCCP_RESET_CODE_UNSPECIFIED = 0,
136         DCCP_RESET_CODE_CLOSED,
137         DCCP_RESET_CODE_ABORTED,
138         DCCP_RESET_CODE_NO_CONNECTION,
139         DCCP_RESET_CODE_PACKET_ERROR,
140         DCCP_RESET_CODE_OPTION_ERROR,
141         DCCP_RESET_CODE_MANDATORY_ERROR,
142         DCCP_RESET_CODE_CONNECTION_REFUSED,
143         DCCP_RESET_CODE_BAD_SERVICE_CODE,
144         DCCP_RESET_CODE_TOO_BUSY,
145         DCCP_RESET_CODE_BAD_INIT_COOKIE,
146         DCCP_RESET_CODE_AGGRESSION_PENALTY,
147
148         DCCP_MAX_RESET_CODES            /* Leave at the end!  */
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 /* XXX deprecated, without effect */
204 #define DCCP_SOCKOPT_SERVICE            2
205 #define DCCP_SOCKOPT_CHANGE_L           3
206 #define DCCP_SOCKOPT_CHANGE_R           4
207 #define DCCP_SOCKOPT_GET_CUR_MPS        5
208 #define DCCP_SOCKOPT_SERVER_TIMEWAIT    6
209 #define DCCP_SOCKOPT_SEND_CSCOV         10
210 #define DCCP_SOCKOPT_RECV_CSCOV         11
211 #define DCCP_SOCKOPT_CCID_RX_INFO       128
212 #define DCCP_SOCKOPT_CCID_TX_INFO       192
213
214 /* maximum number of services provided on the same listening port */
215 #define DCCP_SERVICE_LIST_MAX_LEN      32
216
217 #ifdef __KERNEL__
218
219 #include <linux/in.h>
220 #include <linux/ktime.h>
221 #include <linux/list.h>
222 #include <linux/uio.h>
223 #include <linux/workqueue.h>
224
225 #include <net/inet_connection_sock.h>
226 #include <net/inet_sock.h>
227 #include <net/inet_timewait_sock.h>
228 #include <net/tcp_states.h>
229
230 enum dccp_state {
231         DCCP_OPEN            = TCP_ESTABLISHED,
232         DCCP_REQUESTING      = TCP_SYN_SENT,
233         DCCP_LISTEN          = TCP_LISTEN,
234         DCCP_RESPOND         = TCP_SYN_RECV,
235         /*
236          * States involved in closing a DCCP connection:
237          * 1) ACTIVE_CLOSEREQ is entered by a server sending a CloseReq.
238          *
239          * 2) CLOSING can have three different meanings (RFC 4340, 8.3):
240          *  a. Client has performed active-close, has sent a Close to the server
241          *     from state OPEN or PARTOPEN, and is waiting for the final Reset
242          *     (in this case, SOCK_DONE == 1).
243          *  b. Client is asked to perform passive-close, by receiving a CloseReq
244          *     in (PART)OPEN state. It sends a Close and waits for final Reset
245          *     (in this case, SOCK_DONE == 0).
246          *  c. Server performs an active-close as in (a), keeps TIMEWAIT state.
247          *
248          * 3) The following intermediate states are employed to give passively
249          *    closing nodes a chance to process their unread data:
250          *    - PASSIVE_CLOSE    (from OPEN => CLOSED) and
251          *    - PASSIVE_CLOSEREQ (from (PART)OPEN to CLOSING; case (b) above).
252          */
253         DCCP_ACTIVE_CLOSEREQ = TCP_FIN_WAIT1,
254         DCCP_PASSIVE_CLOSE   = TCP_CLOSE_WAIT,  /* any node receiving a Close */
255         DCCP_CLOSING         = TCP_CLOSING,
256         DCCP_TIME_WAIT       = TCP_TIME_WAIT,
257         DCCP_CLOSED          = TCP_CLOSE,
258         DCCP_PARTOPEN        = TCP_MAX_STATES,
259         DCCP_PASSIVE_CLOSEREQ,                  /* clients receiving CloseReq */
260         DCCP_MAX_STATES
261 };
262
263 #define DCCP_STATE_MASK 0x1f
264
265 enum {
266         DCCPF_OPEN            = TCPF_ESTABLISHED,
267         DCCPF_REQUESTING      = TCPF_SYN_SENT,
268         DCCPF_LISTEN          = TCPF_LISTEN,
269         DCCPF_RESPOND         = TCPF_SYN_RECV,
270         DCCPF_ACTIVE_CLOSEREQ = TCPF_FIN_WAIT1,
271         DCCPF_CLOSING         = TCPF_CLOSING,
272         DCCPF_TIME_WAIT       = TCPF_TIME_WAIT,
273         DCCPF_CLOSED          = TCPF_CLOSE,
274         DCCPF_PARTOPEN        = (1 << DCCP_PARTOPEN),
275 };
276
277 static inline struct dccp_hdr *dccp_hdr(const struct sk_buff *skb)
278 {
279         return (struct dccp_hdr *)skb_transport_header(skb);
280 }
281
282 static inline struct dccp_hdr *dccp_zeroed_hdr(struct sk_buff *skb, int headlen)
283 {
284         skb_push(skb, headlen);
285         skb_reset_transport_header(skb);
286         return memset(skb_transport_header(skb), 0, headlen);
287 }
288
289 static inline struct dccp_hdr_ext *dccp_hdrx(const struct dccp_hdr *dh)
290 {
291         return (struct dccp_hdr_ext *)((unsigned char *)dh + sizeof(*dh));
292 }
293
294 static inline unsigned int __dccp_basic_hdr_len(const struct dccp_hdr *dh)
295 {
296         return sizeof(*dh) + (dh->dccph_x ? sizeof(struct dccp_hdr_ext) : 0);
297 }
298
299 static inline unsigned int dccp_basic_hdr_len(const struct sk_buff *skb)
300 {
301         const struct dccp_hdr *dh = dccp_hdr(skb);
302         return __dccp_basic_hdr_len(dh);
303 }
304
305 static inline __u64 dccp_hdr_seq(const struct dccp_hdr *dh)
306 {
307         __u64 seq_nr =  ntohs(dh->dccph_seq);
308
309         if (dh->dccph_x != 0)
310                 seq_nr = (seq_nr << 32) + ntohl(dccp_hdrx(dh)->dccph_seq_low);
311         else
312                 seq_nr += (u32)dh->dccph_seq2 << 16;
313
314         return seq_nr;
315 }
316
317 static inline struct dccp_hdr_request *dccp_hdr_request(struct sk_buff *skb)
318 {
319         return (struct dccp_hdr_request *)(skb_transport_header(skb) +
320                                            dccp_basic_hdr_len(skb));
321 }
322
323 static inline struct dccp_hdr_ack_bits *dccp_hdr_ack_bits(const struct sk_buff *skb)
324 {
325         return (struct dccp_hdr_ack_bits *)(skb_transport_header(skb) +
326                                             dccp_basic_hdr_len(skb));
327 }
328
329 static inline u64 dccp_hdr_ack_seq(const struct sk_buff *skb)
330 {
331         const struct dccp_hdr_ack_bits *dhack = dccp_hdr_ack_bits(skb);
332         return ((u64)ntohs(dhack->dccph_ack_nr_high) << 32) + ntohl(dhack->dccph_ack_nr_low);
333 }
334
335 static inline struct dccp_hdr_response *dccp_hdr_response(struct sk_buff *skb)
336 {
337         return (struct dccp_hdr_response *)(skb_transport_header(skb) +
338                                             dccp_basic_hdr_len(skb));
339 }
340
341 static inline struct dccp_hdr_reset *dccp_hdr_reset(struct sk_buff *skb)
342 {
343         return (struct dccp_hdr_reset *)(skb_transport_header(skb) +
344                                          dccp_basic_hdr_len(skb));
345 }
346
347 static inline unsigned int __dccp_hdr_len(const struct dccp_hdr *dh)
348 {
349         return __dccp_basic_hdr_len(dh) +
350                dccp_packet_hdr_len(dh->dccph_type);
351 }
352
353 static inline unsigned int dccp_hdr_len(const struct sk_buff *skb)
354 {
355         return __dccp_hdr_len(dccp_hdr(skb));
356 }
357
358
359 /* initial values for each feature */
360 #define DCCPF_INITIAL_SEQUENCE_WINDOW           100
361 #define DCCPF_INITIAL_ACK_RATIO                 2
362 #define DCCPF_INITIAL_CCID                      DCCPC_CCID2
363 #define DCCPF_INITIAL_SEND_ACK_VECTOR           1
364 /* FIXME: for now we're default to 1 but it should really be 0 */
365 #define DCCPF_INITIAL_SEND_NDP_COUNT            1
366
367 #define DCCP_NDP_LIMIT 0xFFFFFF
368
369 /**
370   * struct dccp_minisock - Minimal DCCP connection representation
371   *
372   * Will be used to pass the state from dccp_request_sock to dccp_sock.
373   *
374   * @dccpms_sequence_window - Sequence Window Feature (section 7.5.2)
375   * @dccpms_ccid - Congestion Control Id (CCID) (section 10)
376   * @dccpms_send_ack_vector - Send Ack Vector Feature (section 11.5)
377   * @dccpms_send_ndp_count - Send NDP Count Feature (7.7.2)
378   * @dccpms_ack_ratio - Ack Ratio Feature (section 11.3)
379   * @dccpms_pending - List of features being negotiated
380   * @dccpms_conf -
381   */
382 struct dccp_minisock {
383         __u64                   dccpms_sequence_window;
384         __u8                    dccpms_rx_ccid;
385         __u8                    dccpms_tx_ccid;
386         __u8                    dccpms_send_ack_vector;
387         __u8                    dccpms_send_ndp_count;
388         __u8                    dccpms_ack_ratio;
389         struct list_head        dccpms_pending;
390         struct list_head        dccpms_conf;
391 };
392
393 struct dccp_opt_conf {
394         __u8                    *dccpoc_val;
395         __u8                    dccpoc_len;
396 };
397
398 struct dccp_opt_pend {
399         struct list_head        dccpop_node;
400         __u8                    dccpop_type;
401         __u8                    dccpop_feat;
402         __u8                    *dccpop_val;
403         __u8                    dccpop_len;
404         int                     dccpop_conf;
405         struct dccp_opt_conf    *dccpop_sc;
406 };
407
408 extern void dccp_minisock_init(struct dccp_minisock *dmsk);
409
410 struct dccp_request_sock {
411         struct inet_request_sock dreq_inet_rsk;
412         __u64                    dreq_iss;
413         __u64                    dreq_isr;
414         __be32                   dreq_service;
415 };
416
417 static inline struct dccp_request_sock *dccp_rsk(const struct request_sock *req)
418 {
419         return (struct dccp_request_sock *)req;
420 }
421
422 extern struct inet_timewait_death_row dccp_death_row;
423
424 extern int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq,
425                               struct sk_buff *skb);
426
427 struct dccp_options_received {
428         u32     dccpor_ndp; /* only 24 bits */
429         u32     dccpor_timestamp;
430         u32     dccpor_timestamp_echo;
431         u32     dccpor_elapsed_time;
432 };
433
434 struct ccid;
435
436 enum dccp_role {
437         DCCP_ROLE_UNDEFINED,
438         DCCP_ROLE_LISTEN,
439         DCCP_ROLE_CLIENT,
440         DCCP_ROLE_SERVER,
441 };
442
443 struct dccp_service_list {
444         __u32   dccpsl_nr;
445         __be32  dccpsl_list[0];
446 };
447
448 #define DCCP_SERVICE_INVALID_VALUE htonl((__u32)-1)
449 #define DCCP_SERVICE_CODE_IS_ABSENT             0
450
451 static inline int dccp_list_has_service(const struct dccp_service_list *sl,
452                                         const __be32 service)
453 {
454         if (likely(sl != NULL)) {
455                 u32 i = sl->dccpsl_nr;
456                 while (i--)
457                         if (sl->dccpsl_list[i] == service)
458                                 return 1;
459         }
460         return 0;
461 }
462
463 struct dccp_ackvec;
464
465 /**
466  * struct dccp_sock - DCCP socket state
467  *
468  * @dccps_swl - sequence number window low
469  * @dccps_swh - sequence number window high
470  * @dccps_awl - acknowledgement number window low
471  * @dccps_awh - acknowledgement number window high
472  * @dccps_iss - initial sequence number sent
473  * @dccps_isr - initial sequence number received
474  * @dccps_osr - first OPEN sequence number received
475  * @dccps_gss - greatest sequence number sent
476  * @dccps_gsr - greatest valid sequence number received
477  * @dccps_gar - greatest valid ack number received on a non-Sync; initialized to %dccps_iss
478  * @dccps_service - first (passive sock) or unique (active sock) service code
479  * @dccps_service_list - second .. last service code on passive socket
480  * @dccps_timestamp_time - time of latest TIMESTAMP option
481  * @dccps_timestamp_echo - latest timestamp received on a TIMESTAMP option
482  * @dccps_l_ack_ratio - feature-local Ack Ratio
483  * @dccps_r_ack_ratio - feature-remote Ack Ratio
484  * @dccps_pcslen - sender   partial checksum coverage (via sockopt)
485  * @dccps_pcrlen - receiver partial checksum coverage (via sockopt)
486  * @dccps_ndp_count - number of Non Data Packets since last data packet
487  * @dccps_mss_cache - current value of MSS (path MTU minus header sizes)
488  * @dccps_rate_last - timestamp for rate-limiting DCCP-Sync (RFC 4340, 7.5.4)
489  * @dccps_minisock - associated minisock (accessed via dccp_msk)
490  * @dccps_hc_rx_ackvec - rx half connection ack vector
491  * @dccps_hc_rx_ccid - CCID used for the receiver (or receiving half-connection)
492  * @dccps_hc_tx_ccid - CCID used for the sender (or sending half-connection)
493  * @dccps_options_received - parsed set of retrieved options
494  * @dccps_role - role of this sock, one of %dccp_role
495  * @dccps_hc_rx_insert_options - receiver wants to add options when acking
496  * @dccps_hc_tx_insert_options - sender wants to add options when sending
497  * @dccps_server_timewait - server holds timewait state on close (RFC 4340, 8.3)
498  * @dccps_xmit_timer - timer for when CCID is not ready to send
499  * @dccps_syn_rtt - RTT sample from Request/Response exchange (in usecs)
500  */
501 struct dccp_sock {
502         /* inet_connection_sock has to be the first member of dccp_sock */
503         struct inet_connection_sock     dccps_inet_connection;
504 #define dccps_syn_rtt                   dccps_inet_connection.icsk_ack.lrcvtime
505         __u64                           dccps_swl;
506         __u64                           dccps_swh;
507         __u64                           dccps_awl;
508         __u64                           dccps_awh;
509         __u64                           dccps_iss;
510         __u64                           dccps_isr;
511         __u64                           dccps_osr;
512         __u64                           dccps_gss;
513         __u64                           dccps_gsr;
514         __u64                           dccps_gar;
515         __be32                          dccps_service;
516         struct dccp_service_list        *dccps_service_list;
517         ktime_t                         dccps_timestamp_time;
518         __u32                           dccps_timestamp_echo;
519         __u16                           dccps_l_ack_ratio;
520         __u16                           dccps_r_ack_ratio;
521         __u16                           dccps_pcslen;
522         __u16                           dccps_pcrlen;
523         unsigned long                   dccps_ndp_count;
524         __u32                           dccps_mss_cache;
525         unsigned long                   dccps_rate_last;
526         struct dccp_minisock            dccps_minisock;
527         struct dccp_ackvec              *dccps_hc_rx_ackvec;
528         struct ccid                     *dccps_hc_rx_ccid;
529         struct ccid                     *dccps_hc_tx_ccid;
530         struct dccp_options_received    dccps_options_received;
531         enum dccp_role                  dccps_role:2;
532         __u8                            dccps_hc_rx_insert_options:1;
533         __u8                            dccps_hc_tx_insert_options:1;
534         __u8                            dccps_server_timewait:1;
535         struct timer_list               dccps_xmit_timer;
536 };
537
538 static inline struct dccp_sock *dccp_sk(const struct sock *sk)
539 {
540         return (struct dccp_sock *)sk;
541 }
542
543 static inline struct dccp_minisock *dccp_msk(const struct sock *sk)
544 {
545         return (struct dccp_minisock *)&dccp_sk(sk)->dccps_minisock;
546 }
547
548 static inline const char *dccp_role(const struct sock *sk)
549 {
550         switch (dccp_sk(sk)->dccps_role) {
551         case DCCP_ROLE_UNDEFINED: return "undefined";
552         case DCCP_ROLE_LISTEN:    return "listen";
553         case DCCP_ROLE_SERVER:    return "server";
554         case DCCP_ROLE_CLIENT:    return "client";
555         }
556         return NULL;
557 }
558
559 #endif /* __KERNEL__ */
560
561 #endif /* _LINUX_DCCP_H */