1#ifndef _DCCP_H 2#define _DCCP_H 3/* 4 * net/dccp/dccp.h 5 * 6 * An implementation of the DCCP protocol 7 * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br> 8 * Copyright (c) 2005-6 Ian McDonald <ian.mcdonald@jandi.co.nz> 9 * 10 * This program is free software; you can redistribute it and/or modify it 11 * under the terms of the GNU General Public License version 2 as 12 * published by the Free Software Foundation. 13 */ 14 15#include <linux/dccp.h> 16#include <net/snmp.h> 17#include <net/sock.h> 18#include <net/tcp.h> 19#include "ackvec.h" 20 21/* 22 * DCCP - specific warning and debugging macros. 23 */ 24#define DCCP_WARN(fmt, a...) LIMIT_NETDEBUG(KERN_WARNING "%s: " fmt, \ 25 __FUNCTION__, ##a) 26#define DCCP_CRIT(fmt, a...) printk(KERN_CRIT fmt " at %s:%d/%s()\n", ##a, \ 27 __FILE__, __LINE__, __FUNCTION__) 28#define DCCP_BUG(a...) do { DCCP_CRIT("BUG: " a); dump_stack(); } while(0) 29#define DCCP_BUG_ON(cond) do { if (unlikely((cond) != 0)) \ 30 DCCP_BUG("\"%s\" holds (exception!)", \ 31 __stringify(cond)); \ 32 } while (0) 33 34#define DCCP_PRINTK(enable, fmt, args...) do { if (enable) \ 35 printk(fmt, ##args); \ 36 } while(0) 37#define DCCP_PR_DEBUG(enable, fmt, a...) DCCP_PRINTK(enable, KERN_DEBUG \ 38 "%s: " fmt, __FUNCTION__, ##a) 39 40#ifdef CONFIG_IP_DCCP_DEBUG 41extern int dccp_debug; 42#define dccp_pr_debug(format, a...) DCCP_PR_DEBUG(dccp_debug, format, ##a) 43#define dccp_pr_debug_cat(format, a...) DCCP_PRINTK(dccp_debug, format, ##a) 44#else 45#define dccp_pr_debug(format, a...) 46#define dccp_pr_debug_cat(format, a...) 47#endif 48 49extern struct inet_hashinfo dccp_hashinfo; 50 51extern atomic_t dccp_orphan_count; 52 53extern void dccp_time_wait(struct sock *sk, int state, int timeo); 54 55/* 56 * Set safe upper bounds for header and option length. Since Data Offset is 8 57 * bits (RFC 4340, sec. 5.1), the total header length can never be more than 58 * 4 * 255 = 1020 bytes. The largest possible header length is 28 bytes (X=1): 59 * - DCCP-Response with ACK Subheader and 4 bytes of Service code OR 60 * - DCCP-Reset with ACK Subheader and 4 bytes of Reset Code fields 61 * Hence a safe upper bound for the maximum option length is 1020-28 = 992 62 */ 63#define MAX_DCCP_SPECIFIC_HEADER (255 * sizeof(int)) 64#define DCCP_MAX_PACKET_HDR 28 65#define DCCP_MAX_OPT_LEN (MAX_DCCP_SPECIFIC_HEADER - DCCP_MAX_PACKET_HDR) 66#define MAX_DCCP_HEADER (MAX_DCCP_SPECIFIC_HEADER + MAX_HEADER) 67 68#define DCCP_TIMEWAIT_LEN (60 * HZ) /* how long to wait to destroy TIME-WAIT 69 * state, about 60 seconds */ 70 71/* RFC 1122, 4.2.3.1 initial RTO value */ 72#define DCCP_TIMEOUT_INIT ((unsigned)(3 * HZ)) 73 74#define DCCP_RTO_MAX ((unsigned)(120 * HZ)) 75 76/* bounds for sampled RTT values from packet exchanges (in usec) */ 77#define DCCP_SANE_RTT_MIN 100 78#define DCCP_SANE_RTT_MAX (4 * USEC_PER_SEC) 79 80/* Maximal interval between probes for local resources. */ 81#define DCCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ / 2U)) 82 83/* sysctl variables for DCCP */ 84extern int sysctl_dccp_request_retries; 85extern int sysctl_dccp_retries1; 86extern int sysctl_dccp_retries2; 87extern int sysctl_dccp_feat_sequence_window; 88extern int sysctl_dccp_feat_rx_ccid; 89extern int sysctl_dccp_feat_tx_ccid; 90extern int sysctl_dccp_feat_ack_ratio; 91extern int sysctl_dccp_feat_send_ack_vector; 92extern int sysctl_dccp_feat_send_ndp_count; 93extern int sysctl_dccp_tx_qlen; 94 95/* 96 * 48-bit sequence number arithmetic (signed and unsigned) 97 */ 98#define INT48_MIN 0x800000000000LL /* 2^47 */ 99#define UINT48_MAX 0xFFFFFFFFFFFFLL /* 2^48 - 1 */ 100#define COMPLEMENT48(x) (0x1000000000000LL - (x)) /* 2^48 - x */ 101#define TO_SIGNED48(x) (((x) < INT48_MIN)? (x) : -COMPLEMENT48( (x))) 102#define TO_UNSIGNED48(x) (((x) >= 0)? (x) : COMPLEMENT48(-(x))) 103#define ADD48(a, b) (((a) + (b)) & UINT48_MAX) 104#define SUB48(a, b) ADD48((a), COMPLEMENT48(b)) 105 106static inline void dccp_set_seqno(u64 *seqno, u64 value) 107{ 108 *seqno = value & UINT48_MAX; 109} 110 111static inline void dccp_inc_seqno(u64 *seqno) 112{ 113 *seqno = ADD48(*seqno, 1); 114} 115 116/* signed mod-2^48 distance: pos. if seqno1 < seqno2, neg. if seqno1 > seqno2 */ 117static inline s64 dccp_delta_seqno(const u64 seqno1, const u64 seqno2) 118{ 119 u64 delta = SUB48(seqno2, seqno1); 120 121 return TO_SIGNED48(delta); 122} 123 124/* is seq1 < seq2 ? */ 125static inline int before48(const u64 seq1, const u64 seq2) 126{ 127 return (s64)((seq2 << 16) - (seq1 << 16)) > 0; 128} 129 130/* is seq1 > seq2 ? */ 131#define after48(seq1, seq2) before48(seq2, seq1) 132 133/* is seq2 <= seq1 <= seq3 ? */ 134static inline int between48(const u64 seq1, const u64 seq2, const u64 seq3) 135{ 136 return (seq3 << 16) - (seq2 << 16) >= (seq1 << 16) - (seq2 << 16); 137} 138 139static inline u64 max48(const u64 seq1, const u64 seq2) 140{ 141 return after48(seq1, seq2) ? seq1 : seq2; 142} 143 144/* is seq1 next seqno after seq2 */ 145static inline int follows48(const u64 seq1, const u64 seq2) 146{ 147 return dccp_delta_seqno(seq2, seq1) == 1; 148} 149 150enum { 151 DCCP_MIB_NUM = 0, 152 DCCP_MIB_ACTIVEOPENS, /* ActiveOpens */ 153 DCCP_MIB_ESTABRESETS, /* EstabResets */ 154 DCCP_MIB_CURRESTAB, /* CurrEstab */ 155 DCCP_MIB_OUTSEGS, /* OutSegs */ 156 DCCP_MIB_OUTRSTS, 157 DCCP_MIB_ABORTONTIMEOUT, 158 DCCP_MIB_TIMEOUTS, 159 DCCP_MIB_ABORTFAILED, 160 DCCP_MIB_PASSIVEOPENS, 161 DCCP_MIB_ATTEMPTFAILS, 162 DCCP_MIB_OUTDATAGRAMS, 163 DCCP_MIB_INERRS, 164 DCCP_MIB_OPTMANDATORYERROR, 165 DCCP_MIB_INVALIDOPT, 166 __DCCP_MIB_MAX 167}; 168 169#define DCCP_MIB_MAX __DCCP_MIB_MAX 170struct dccp_mib { 171 unsigned long mibs[DCCP_MIB_MAX]; 172} __SNMP_MIB_ALIGN__; 173 174DECLARE_SNMP_STAT(struct dccp_mib, dccp_statistics); 175#define DCCP_INC_STATS(field) SNMP_INC_STATS(dccp_statistics, field) 176#define DCCP_INC_STATS_BH(field) SNMP_INC_STATS_BH(dccp_statistics, field) 177#define DCCP_INC_STATS_USER(field) SNMP_INC_STATS_USER(dccp_statistics, field) 178#define DCCP_DEC_STATS(field) SNMP_DEC_STATS(dccp_statistics, field) 179#define DCCP_ADD_STATS_BH(field, val) \ 180 SNMP_ADD_STATS_BH(dccp_statistics, field, val) 181#define DCCP_ADD_STATS_USER(field, val) \ 182 SNMP_ADD_STATS_USER(dccp_statistics, field, val) 183 184/* 185 * Checksumming routines 186 */ 187static inline int dccp_csum_coverage(const struct sk_buff *skb) 188{ 189 const struct dccp_hdr* dh = dccp_hdr(skb); 190 191 if (dh->dccph_cscov == 0) 192 return skb->len; 193 return (dh->dccph_doff + dh->dccph_cscov - 1) * sizeof(u32); 194} 195 196static inline void dccp_csum_outgoing(struct sk_buff *skb) 197{ 198 int cov = dccp_csum_coverage(skb); 199 200 if (cov >= skb->len) 201 dccp_hdr(skb)->dccph_cscov = 0; 202 203 skb->csum = skb_checksum(skb, 0, (cov > skb->len)? skb->len : cov, 0); 204} 205 206extern void dccp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb); 207 208extern int dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb); 209 210extern void dccp_send_ack(struct sock *sk); 211extern void dccp_send_delayed_ack(struct sock *sk); 212extern void dccp_reqsk_send_ack(struct sk_buff *sk, struct request_sock *rsk); 213 214extern void dccp_send_sync(struct sock *sk, const u64 seq, 215 const enum dccp_pkt_type pkt_type); 216 217extern void dccp_write_xmit(struct sock *sk, int block); 218extern void dccp_write_space(struct sock *sk); 219 220extern void dccp_init_xmit_timers(struct sock *sk); 221static inline void dccp_clear_xmit_timers(struct sock *sk) 222{ 223 inet_csk_clear_xmit_timers(sk); 224} 225 226extern unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu); 227 228extern const char *dccp_packet_name(const int type); 229extern const char *dccp_state_name(const int state); 230 231extern void dccp_set_state(struct sock *sk, const int state); 232extern void dccp_done(struct sock *sk); 233 234extern void dccp_reqsk_init(struct request_sock *req, struct sk_buff *skb); 235 236extern int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb); 237 238extern struct sock *dccp_create_openreq_child(struct sock *sk, 239 const struct request_sock *req, 240 const struct sk_buff *skb); 241 242extern int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb); 243 244extern struct sock *dccp_v4_request_recv_sock(struct sock *sk, 245 struct sk_buff *skb, 246 struct request_sock *req, 247 struct dst_entry *dst); 248extern struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb, 249 struct request_sock *req, 250 struct request_sock **prev); 251 252extern int dccp_child_process(struct sock *parent, struct sock *child, 253 struct sk_buff *skb); 254extern int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb, 255 struct dccp_hdr *dh, unsigned len); 256extern int dccp_rcv_established(struct sock *sk, struct sk_buff *skb, 257 const struct dccp_hdr *dh, const unsigned len); 258 259extern int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized); 260extern int dccp_destroy_sock(struct sock *sk); 261 262extern void dccp_close(struct sock *sk, long timeout); 263extern struct sk_buff *dccp_make_response(struct sock *sk, 264 struct dst_entry *dst, 265 struct request_sock *req); 266 267extern int dccp_connect(struct sock *sk); 268extern int dccp_disconnect(struct sock *sk, int flags); 269extern void dccp_hash(struct sock *sk); 270extern void dccp_unhash(struct sock *sk); 271extern int dccp_getsockopt(struct sock *sk, int level, int optname, 272 char __user *optval, int __user *optlen); 273extern int dccp_setsockopt(struct sock *sk, int level, int optname, 274 char __user *optval, int optlen); 275#ifdef CONFIG_COMPAT 276extern int compat_dccp_getsockopt(struct sock *sk, 277 int level, int optname, 278 char __user *optval, int __user *optlen); 279extern int compat_dccp_setsockopt(struct sock *sk, 280 int level, int optname, 281 char __user *optval, int optlen); 282#endif 283extern int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg); 284extern int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, 285 struct msghdr *msg, size_t size); 286extern int dccp_recvmsg(struct kiocb *iocb, struct sock *sk, 287 struct msghdr *msg, size_t len, int nonblock, 288 int flags, int *addr_len); 289extern void dccp_shutdown(struct sock *sk, int how); 290extern int inet_dccp_listen(struct socket *sock, int backlog); 291extern unsigned int dccp_poll(struct file *file, struct socket *sock, 292 poll_table *wait); 293extern int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, 294 int addr_len); 295 296extern int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code); 297extern void dccp_send_close(struct sock *sk, const int active); 298extern int dccp_invalid_packet(struct sk_buff *skb); 299extern u32 dccp_sample_rtt(struct sock *sk, struct timeval *t_recv, 300 struct timeval *t_history); 301 302static inline int dccp_bad_service_code(const struct sock *sk, 303 const __be32 service) 304{ 305 const struct dccp_sock *dp = dccp_sk(sk); 306 307 if (dp->dccps_service == service) 308 return 0; 309 return !dccp_list_has_service(dp->dccps_service_list, service); 310} 311 312struct dccp_skb_cb { 313 __u8 dccpd_type:4; 314 __u8 dccpd_ccval:4; 315 __u8 dccpd_reset_code; 316 __u16 dccpd_opt_len; 317 __u64 dccpd_seq; 318 __u64 dccpd_ack_seq; 319}; 320 321#define DCCP_SKB_CB(__skb) ((struct dccp_skb_cb *)&((__skb)->cb[0])) 322 323static inline int dccp_non_data_packet(const struct sk_buff *skb) 324{ 325 const __u8 type = DCCP_SKB_CB(skb)->dccpd_type; 326 327 return type == DCCP_PKT_ACK || 328 type == DCCP_PKT_CLOSE || 329 type == DCCP_PKT_CLOSEREQ || 330 type == DCCP_PKT_RESET || 331 type == DCCP_PKT_SYNC || 332 type == DCCP_PKT_SYNCACK; 333} 334 335static inline int dccp_packet_without_ack(const struct sk_buff *skb) 336{ 337 const __u8 type = DCCP_SKB_CB(skb)->dccpd_type; 338 339 return type == DCCP_PKT_DATA || type == DCCP_PKT_REQUEST; 340} 341 342#define DCCP_PKT_WITHOUT_ACK_SEQ (UINT48_MAX << 2) 343 344static inline void dccp_hdr_set_seq(struct dccp_hdr *dh, const u64 gss) 345{ 346 struct dccp_hdr_ext *dhx = (struct dccp_hdr_ext *)((void *)dh + 347 sizeof(*dh)); 348 dh->dccph_seq2 = 0; 349 dh->dccph_seq = htons((gss >> 32) & 0xfffff); 350 dhx->dccph_seq_low = htonl(gss & 0xffffffff); 351} 352 353static inline void dccp_hdr_set_ack(struct dccp_hdr_ack_bits *dhack, 354 const u64 gsr) 355{ 356 dhack->dccph_reserved1 = 0; 357 dhack->dccph_ack_nr_high = htons(gsr >> 32); 358 dhack->dccph_ack_nr_low = htonl(gsr & 0xffffffff); 359} 360 361static inline void dccp_update_gsr(struct sock *sk, u64 seq) 362{ 363 struct dccp_sock *dp = dccp_sk(sk); 364 const struct dccp_minisock *dmsk = dccp_msk(sk); 365 366 dp->dccps_gsr = seq; 367 dccp_set_seqno(&dp->dccps_swl, 368 dp->dccps_gsr + 1 - (dmsk->dccpms_sequence_window / 4)); 369 dccp_set_seqno(&dp->dccps_swh, 370 dp->dccps_gsr + (3 * dmsk->dccpms_sequence_window) / 4); 371} 372 373static inline void dccp_update_gss(struct sock *sk, u64 seq) 374{ 375 struct dccp_sock *dp = dccp_sk(sk); 376 377 dp->dccps_awh = dp->dccps_gss = seq; 378 dccp_set_seqno(&dp->dccps_awl, 379 (dp->dccps_gss - 380 dccp_msk(sk)->dccpms_sequence_window + 1)); 381} 382 383static inline int dccp_ack_pending(const struct sock *sk) 384{ 385 const struct dccp_sock *dp = dccp_sk(sk); 386 return dp->dccps_timestamp_echo != 0 || 387#ifdef CONFIG_IP_DCCP_ACKVEC 388 (dccp_msk(sk)->dccpms_send_ack_vector && 389 dccp_ackvec_pending(dp->dccps_hc_rx_ackvec)) || 390#endif 391 inet_csk_ack_scheduled(sk); 392} 393 394extern int dccp_insert_options(struct sock *sk, struct sk_buff *skb); 395extern int dccp_insert_option_elapsed_time(struct sock *sk, 396 struct sk_buff *skb, 397 u32 elapsed_time); 398extern int dccp_insert_option_timestamp(struct sock *sk, 399 struct sk_buff *skb); 400extern int dccp_insert_option(struct sock *sk, struct sk_buff *skb, 401 unsigned char option, 402 const void *value, unsigned char len); 403 404extern void dccp_timestamp(const struct sock *sk, struct timeval *tv); 405 406static inline suseconds_t timeval_usecs(const struct timeval *tv) 407{ 408 return tv->tv_sec * USEC_PER_SEC + tv->tv_usec; 409} 410 411static inline suseconds_t timeval_delta(const struct timeval *large, 412 const struct timeval *small) 413{ 414 time_t secs = large->tv_sec - small->tv_sec; 415 suseconds_t usecs = large->tv_usec - small->tv_usec; 416 417 if (usecs < 0) { 418 secs--; 419 usecs += USEC_PER_SEC; 420 } 421 return secs * USEC_PER_SEC + usecs; 422} 423 424static inline void timeval_add_usecs(struct timeval *tv, 425 const suseconds_t usecs) 426{ 427 tv->tv_usec += usecs; 428 while (tv->tv_usec >= USEC_PER_SEC) { 429 tv->tv_sec++; 430 tv->tv_usec -= USEC_PER_SEC; 431 } 432} 433 434static inline void timeval_sub_usecs(struct timeval *tv, 435 const suseconds_t usecs) 436{ 437 tv->tv_usec -= usecs; 438 while (tv->tv_usec < 0) { 439 tv->tv_sec--; 440 tv->tv_usec += USEC_PER_SEC; 441 } 442 DCCP_BUG_ON(tv->tv_sec < 0); 443} 444 445#ifdef CONFIG_SYSCTL 446extern int dccp_sysctl_init(void); 447extern void dccp_sysctl_exit(void); 448#else 449static inline int dccp_sysctl_init(void) 450{ 451 return 0; 452} 453 454static inline void dccp_sysctl_exit(void) 455{ 456} 457#endif 458 459#endif /* _DCCP_H */ 460