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 <linux/ktime.h> 17#include <net/snmp.h> 18#include <net/sock.h> 19#include <net/tcp.h> 20#include "ackvec.h" 21 22/* 23 * DCCP - specific warning and debugging macros. 24 */ 25#define DCCP_WARN(fmt, a...) LIMIT_NETDEBUG(KERN_WARNING "%s: " fmt, \ 26 __func__, ##a) 27#define DCCP_CRIT(fmt, a...) printk(KERN_CRIT fmt " at %s:%d/%s()\n", ##a, \ 28 __FILE__, __LINE__, __func__) 29#define DCCP_BUG(a...) do { DCCP_CRIT("BUG: " a); dump_stack(); } while(0) 30#define DCCP_BUG_ON(cond) do { if (unlikely((cond) != 0)) \ 31 DCCP_BUG("\"%s\" holds (exception!)", \ 32 __stringify(cond)); \ 33 } while (0) 34 35#define DCCP_PRINTK(enable, fmt, args...) do { if (enable) \ 36 printk(fmt, ##args); \ 37 } while(0) 38#define DCCP_PR_DEBUG(enable, fmt, a...) DCCP_PRINTK(enable, KERN_DEBUG \ 39 "%s: " fmt, __func__, ##a) 40 41#ifdef CONFIG_IP_DCCP_DEBUG 42extern int dccp_debug; 43#define dccp_pr_debug(format, a...) DCCP_PR_DEBUG(dccp_debug, format, ##a) 44#define dccp_pr_debug_cat(format, a...) DCCP_PRINTK(dccp_debug, format, ##a) 45#define dccp_debug(fmt, a...) dccp_pr_debug_cat(KERN_DEBUG fmt, ##a) 46#else 47#define dccp_pr_debug(format, a...) 48#define dccp_pr_debug_cat(format, a...) 49#define dccp_debug(format, a...) 50#endif 51 52extern struct inet_hashinfo dccp_hashinfo; 53 54extern struct percpu_counter dccp_orphan_count; 55 56extern void dccp_time_wait(struct sock *sk, int state, int timeo); 57 58/* 59 * Set safe upper bounds for header and option length. Since Data Offset is 8 60 * bits (RFC 4340, sec. 5.1), the total header length can never be more than 61 * 4 * 255 = 1020 bytes. The largest possible header length is 28 bytes (X=1): 62 * - DCCP-Response with ACK Subheader and 4 bytes of Service code OR 63 * - DCCP-Reset with ACK Subheader and 4 bytes of Reset Code fields 64 * Hence a safe upper bound for the maximum option length is 1020-28 = 992 65 */ 66#define MAX_DCCP_SPECIFIC_HEADER (255 * sizeof(uint32_t)) 67#define DCCP_MAX_PACKET_HDR 28 68#define DCCP_MAX_OPT_LEN (MAX_DCCP_SPECIFIC_HEADER - DCCP_MAX_PACKET_HDR) 69#define MAX_DCCP_HEADER (MAX_DCCP_SPECIFIC_HEADER + MAX_HEADER) 70 71/* Upper bound for initial feature-negotiation overhead (padded to 32 bits) */ 72#define DCCP_FEATNEG_OVERHEAD (32 * sizeof(uint32_t)) 73 74#define DCCP_TIMEWAIT_LEN (60 * HZ) /* how long to wait to destroy TIME-WAIT 75 * state, about 60 seconds */ 76 77/* RFC 1122, 4.2.3.1 initial RTO value */ 78#define DCCP_TIMEOUT_INIT ((unsigned)(3 * HZ)) 79 80/* 81 * The maximum back-off value for retransmissions. This is needed for 82 * - retransmitting client-Requests (sec. 8.1.1), 83 * - retransmitting Close/CloseReq when closing (sec. 8.3), 84 * - feature-negotiation retransmission (sec. 6.6.3), 85 * - Acks in client-PARTOPEN state (sec. 8.1.5). 86 */ 87#define DCCP_RTO_MAX ((unsigned)(64 * HZ)) 88 89/* 90 * RTT sampling: sanity bounds and fallback RTT value from RFC 4340, section 3.4 91 */ 92#define DCCP_SANE_RTT_MIN 100 93#define DCCP_FALLBACK_RTT (USEC_PER_SEC / 5) 94#define DCCP_SANE_RTT_MAX (3 * USEC_PER_SEC) 95 96/* Maximal interval between probes for local resources. */ 97#define DCCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ / 2U)) 98 99/* sysctl variables for DCCP */ 100extern int sysctl_dccp_request_retries; 101extern int sysctl_dccp_retries1; 102extern int sysctl_dccp_retries2; 103extern int sysctl_dccp_tx_qlen; 104extern int sysctl_dccp_sync_ratelimit; 105 106/* 107 * 48-bit sequence number arithmetic (signed and unsigned) 108 */ 109#define INT48_MIN 0x800000000000LL /* 2^47 */ 110#define UINT48_MAX 0xFFFFFFFFFFFFLL /* 2^48 - 1 */ 111#define COMPLEMENT48(x) (0x1000000000000LL - (x)) /* 2^48 - x */ 112#define TO_SIGNED48(x) (((x) < INT48_MIN)? (x) : -COMPLEMENT48( (x))) 113#define TO_UNSIGNED48(x) (((x) >= 0)? (x) : COMPLEMENT48(-(x))) 114#define ADD48(a, b) (((a) + (b)) & UINT48_MAX) 115#define SUB48(a, b) ADD48((a), COMPLEMENT48(b)) 116 117static inline void dccp_set_seqno(u64 *seqno, u64 value) 118{ 119 *seqno = value & UINT48_MAX; 120} 121 122static inline void dccp_inc_seqno(u64 *seqno) 123{ 124 *seqno = ADD48(*seqno, 1); 125} 126 127/* signed mod-2^48 distance: pos. if seqno1 < seqno2, neg. if seqno1 > seqno2 */ 128static inline s64 dccp_delta_seqno(const u64 seqno1, const u64 seqno2) 129{ 130 u64 delta = SUB48(seqno2, seqno1); 131 132 return TO_SIGNED48(delta); 133} 134 135/* is seq1 < seq2 ? */ 136static inline int before48(const u64 seq1, const u64 seq2) 137{ 138 return (s64)((seq2 << 16) - (seq1 << 16)) > 0; 139} 140 141/* is seq1 > seq2 ? */ 142#define after48(seq1, seq2) before48(seq2, seq1) 143 144/* is seq2 <= seq1 <= seq3 ? */ 145static inline int between48(const u64 seq1, const u64 seq2, const u64 seq3) 146{ 147 return (seq3 << 16) - (seq2 << 16) >= (seq1 << 16) - (seq2 << 16); 148} 149 150static inline u64 max48(const u64 seq1, const u64 seq2) 151{ 152 return after48(seq1, seq2) ? seq1 : seq2; 153} 154 155/** 156 * dccp_loss_free - Evaluates condition for data loss from RFC 4340, 7.7.1 157 * @s1: start sequence number 158 * @s2: end sequence number 159 * @ndp: NDP count on packet with sequence number @s2 160 * Returns true if the sequence range s1...s2 has no data loss. 161 */ 162static inline bool dccp_loss_free(const u64 s1, const u64 s2, const u64 ndp) 163{ 164 s64 delta = dccp_delta_seqno(s1, s2); 165 166 WARN_ON(delta < 0); 167 return (u64)delta <= ndp + 1; 168} 169 170enum { 171 DCCP_MIB_NUM = 0, 172 DCCP_MIB_ACTIVEOPENS, /* ActiveOpens */ 173 DCCP_MIB_ESTABRESETS, /* EstabResets */ 174 DCCP_MIB_CURRESTAB, /* CurrEstab */ 175 DCCP_MIB_OUTSEGS, /* OutSegs */ 176 DCCP_MIB_OUTRSTS, 177 DCCP_MIB_ABORTONTIMEOUT, 178 DCCP_MIB_TIMEOUTS, 179 DCCP_MIB_ABORTFAILED, 180 DCCP_MIB_PASSIVEOPENS, 181 DCCP_MIB_ATTEMPTFAILS, 182 DCCP_MIB_OUTDATAGRAMS, 183 DCCP_MIB_INERRS, 184 DCCP_MIB_OPTMANDATORYERROR, 185 DCCP_MIB_INVALIDOPT, 186 __DCCP_MIB_MAX 187}; 188 189#define DCCP_MIB_MAX __DCCP_MIB_MAX 190struct dccp_mib { 191 unsigned long mibs[DCCP_MIB_MAX]; 192}; 193 194DECLARE_SNMP_STAT(struct dccp_mib, dccp_statistics); 195#define DCCP_INC_STATS(field) SNMP_INC_STATS(dccp_statistics, field) 196#define DCCP_INC_STATS_BH(field) SNMP_INC_STATS_BH(dccp_statistics, field) 197#define DCCP_INC_STATS_USER(field) SNMP_INC_STATS_USER(dccp_statistics, field) 198#define DCCP_DEC_STATS(field) SNMP_DEC_STATS(dccp_statistics, field) 199#define DCCP_ADD_STATS_BH(field, val) \ 200 SNMP_ADD_STATS_BH(dccp_statistics, field, val) 201#define DCCP_ADD_STATS_USER(field, val) \ 202 SNMP_ADD_STATS_USER(dccp_statistics, field, val) 203 204/* 205 * Checksumming routines 206 */ 207static inline unsigned int dccp_csum_coverage(const struct sk_buff *skb) 208{ 209 const struct dccp_hdr* dh = dccp_hdr(skb); 210 211 if (dh->dccph_cscov == 0) 212 return skb->len; 213 return (dh->dccph_doff + dh->dccph_cscov - 1) * sizeof(u32); 214} 215 216static inline void dccp_csum_outgoing(struct sk_buff *skb) 217{ 218 unsigned int cov = dccp_csum_coverage(skb); 219 220 if (cov >= skb->len) 221 dccp_hdr(skb)->dccph_cscov = 0; 222 223 skb->csum = skb_checksum(skb, 0, (cov > skb->len)? skb->len : cov, 0); 224} 225 226extern void dccp_v4_send_check(struct sock *sk, struct sk_buff *skb); 227 228extern int dccp_retransmit_skb(struct sock *sk); 229 230extern void dccp_send_ack(struct sock *sk); 231extern void dccp_reqsk_send_ack(struct sock *sk, struct sk_buff *skb, 232 struct request_sock *rsk); 233 234extern void dccp_send_sync(struct sock *sk, const u64 seq, 235 const enum dccp_pkt_type pkt_type); 236 237extern void dccp_write_xmit(struct sock *sk, int block); 238extern void dccp_write_space(struct sock *sk); 239 240extern void dccp_init_xmit_timers(struct sock *sk); 241static inline void dccp_clear_xmit_timers(struct sock *sk) 242{ 243 inet_csk_clear_xmit_timers(sk); 244} 245 246extern unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu); 247 248extern const char *dccp_packet_name(const int type); 249extern const char *dccp_state_name(const int state); 250 251extern void dccp_set_state(struct sock *sk, const int state); 252extern void dccp_done(struct sock *sk); 253 254extern int dccp_reqsk_init(struct request_sock *rq, struct dccp_sock const *dp, 255 struct sk_buff const *skb); 256 257extern int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb); 258 259extern struct sock *dccp_create_openreq_child(struct sock *sk, 260 const struct request_sock *req, 261 const struct sk_buff *skb); 262 263extern int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb); 264 265extern struct sock *dccp_v4_request_recv_sock(struct sock *sk, 266 struct sk_buff *skb, 267 struct request_sock *req, 268 struct dst_entry *dst); 269extern struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb, 270 struct request_sock *req, 271 struct request_sock **prev); 272 273extern int dccp_child_process(struct sock *parent, struct sock *child, 274 struct sk_buff *skb); 275extern int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb, 276 struct dccp_hdr *dh, unsigned len); 277extern int dccp_rcv_established(struct sock *sk, struct sk_buff *skb, 278 const struct dccp_hdr *dh, const unsigned len); 279 280extern int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized); 281extern void dccp_destroy_sock(struct sock *sk); 282 283extern void dccp_close(struct sock *sk, long timeout); 284extern struct sk_buff *dccp_make_response(struct sock *sk, 285 struct dst_entry *dst, 286 struct request_sock *req); 287 288extern int dccp_connect(struct sock *sk); 289extern int dccp_disconnect(struct sock *sk, int flags); 290extern int dccp_getsockopt(struct sock *sk, int level, int optname, 291 char __user *optval, int __user *optlen); 292extern int dccp_setsockopt(struct sock *sk, int level, int optname, 293 char __user *optval, unsigned int optlen); 294#ifdef CONFIG_COMPAT 295extern int compat_dccp_getsockopt(struct sock *sk, 296 int level, int optname, 297 char __user *optval, int __user *optlen); 298extern int compat_dccp_setsockopt(struct sock *sk, 299 int level, int optname, 300 char __user *optval, unsigned int optlen); 301#endif 302extern int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg); 303extern int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, 304 struct msghdr *msg, size_t size); 305extern int dccp_recvmsg(struct kiocb *iocb, struct sock *sk, 306 struct msghdr *msg, size_t len, int nonblock, 307 int flags, int *addr_len); 308extern void dccp_shutdown(struct sock *sk, int how); 309extern int inet_dccp_listen(struct socket *sock, int backlog); 310extern unsigned int dccp_poll(struct file *file, struct socket *sock, 311 poll_table *wait); 312extern int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, 313 int addr_len); 314 315extern struct sk_buff *dccp_ctl_make_reset(struct sock *sk, 316 struct sk_buff *skb); 317extern int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code); 318extern void dccp_send_close(struct sock *sk, const int active); 319extern int dccp_invalid_packet(struct sk_buff *skb); 320extern u32 dccp_sample_rtt(struct sock *sk, long delta); 321 322static inline int dccp_bad_service_code(const struct sock *sk, 323 const __be32 service) 324{ 325 const struct dccp_sock *dp = dccp_sk(sk); 326 327 if (dp->dccps_service == service) 328 return 0; 329 return !dccp_list_has_service(dp->dccps_service_list, service); 330} 331 332/** 333 * dccp_skb_cb - DCCP per-packet control information 334 * @dccpd_type: one of %dccp_pkt_type (or unknown) 335 * @dccpd_ccval: CCVal field (5.1), see e.g. RFC 4342, 8.1 336 * @dccpd_reset_code: one of %dccp_reset_codes 337 * @dccpd_reset_data: Data1..3 fields (depend on @dccpd_reset_code) 338 * @dccpd_opt_len: total length of all options (5.8) in the packet 339 * @dccpd_seq: sequence number 340 * @dccpd_ack_seq: acknowledgment number subheader field value 341 * This is used for transmission as well as for reception. 342 */ 343struct dccp_skb_cb { 344 union { 345 struct inet_skb_parm h4; 346#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 347 struct inet6_skb_parm h6; 348#endif 349 } header; 350 __u8 dccpd_type:4; 351 __u8 dccpd_ccval:4; 352 __u8 dccpd_reset_code, 353 dccpd_reset_data[3]; 354 __u16 dccpd_opt_len; 355 __u64 dccpd_seq; 356 __u64 dccpd_ack_seq; 357}; 358 359#define DCCP_SKB_CB(__skb) ((struct dccp_skb_cb *)&((__skb)->cb[0])) 360 361/* RFC 4340, sec. 7.7 */ 362static inline int dccp_non_data_packet(const struct sk_buff *skb) 363{ 364 const __u8 type = DCCP_SKB_CB(skb)->dccpd_type; 365 366 return type == DCCP_PKT_ACK || 367 type == DCCP_PKT_CLOSE || 368 type == DCCP_PKT_CLOSEREQ || 369 type == DCCP_PKT_RESET || 370 type == DCCP_PKT_SYNC || 371 type == DCCP_PKT_SYNCACK; 372} 373 374/* RFC 4340, sec. 7.7 */ 375static inline int dccp_data_packet(const struct sk_buff *skb) 376{ 377 const __u8 type = DCCP_SKB_CB(skb)->dccpd_type; 378 379 return type == DCCP_PKT_DATA || 380 type == DCCP_PKT_DATAACK || 381 type == DCCP_PKT_REQUEST || 382 type == DCCP_PKT_RESPONSE; 383} 384 385static inline int dccp_packet_without_ack(const struct sk_buff *skb) 386{ 387 const __u8 type = DCCP_SKB_CB(skb)->dccpd_type; 388 389 return type == DCCP_PKT_DATA || type == DCCP_PKT_REQUEST; 390} 391 392#define DCCP_PKT_WITHOUT_ACK_SEQ (UINT48_MAX << 2) 393 394static inline void dccp_hdr_set_seq(struct dccp_hdr *dh, const u64 gss) 395{ 396 struct dccp_hdr_ext *dhx = (struct dccp_hdr_ext *)((void *)dh + 397 sizeof(*dh)); 398 dh->dccph_seq2 = 0; 399 dh->dccph_seq = htons((gss >> 32) & 0xfffff); 400 dhx->dccph_seq_low = htonl(gss & 0xffffffff); 401} 402 403static inline void dccp_hdr_set_ack(struct dccp_hdr_ack_bits *dhack, 404 const u64 gsr) 405{ 406 dhack->dccph_reserved1 = 0; 407 dhack->dccph_ack_nr_high = htons(gsr >> 32); 408 dhack->dccph_ack_nr_low = htonl(gsr & 0xffffffff); 409} 410 411static inline void dccp_update_gsr(struct sock *sk, u64 seq) 412{ 413 struct dccp_sock *dp = dccp_sk(sk); 414 415 dp->dccps_gsr = seq; 416 /* Sequence validity window depends on remote Sequence Window (7.5.1) */ 417 dp->dccps_swl = SUB48(ADD48(dp->dccps_gsr, 1), dp->dccps_r_seq_win / 4); 418 dp->dccps_swh = ADD48(dp->dccps_gsr, (3 * dp->dccps_r_seq_win) / 4); 419} 420 421static inline void dccp_update_gss(struct sock *sk, u64 seq) 422{ 423 struct dccp_sock *dp = dccp_sk(sk); 424 425 dp->dccps_gss = seq; 426 /* Ack validity window depends on local Sequence Window value (7.5.1) */ 427 dp->dccps_awl = SUB48(ADD48(dp->dccps_gss, 1), dp->dccps_l_seq_win); 428 dp->dccps_awh = dp->dccps_gss; 429} 430 431static inline int dccp_ack_pending(const struct sock *sk) 432{ 433 const struct dccp_sock *dp = dccp_sk(sk); 434 return dp->dccps_timestamp_echo != 0 || 435 (dp->dccps_hc_rx_ackvec != NULL && 436 dccp_ackvec_pending(dp->dccps_hc_rx_ackvec)) || 437 inet_csk_ack_scheduled(sk); 438} 439 440extern int dccp_feat_finalise_settings(struct dccp_sock *dp); 441extern int dccp_feat_server_ccid_dependencies(struct dccp_request_sock *dreq); 442extern int dccp_feat_insert_opts(struct dccp_sock*, struct dccp_request_sock*, 443 struct sk_buff *skb); 444extern int dccp_feat_activate_values(struct sock *sk, struct list_head *fn); 445extern void dccp_feat_list_purge(struct list_head *fn_list); 446 447extern int dccp_insert_options(struct sock *sk, struct sk_buff *skb); 448extern int dccp_insert_options_rsk(struct dccp_request_sock*, struct sk_buff*); 449extern int dccp_insert_option_elapsed_time(struct sk_buff *skb, u32 elapsed); 450extern u32 dccp_timestamp(void); 451extern void dccp_timestamping_init(void); 452extern int dccp_insert_option_timestamp(struct sk_buff *skb); 453extern int dccp_insert_option(struct sk_buff *skb, unsigned char option, 454 const void *value, unsigned char len); 455 456#ifdef CONFIG_SYSCTL 457extern int dccp_sysctl_init(void); 458extern void dccp_sysctl_exit(void); 459#else 460static inline int dccp_sysctl_init(void) 461{ 462 return 0; 463} 464 465static inline void dccp_sysctl_exit(void) 466{ 467} 468#endif 469 470#endif /* _DCCP_H */ 471