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 42 extern 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 #else 46 #define dccp_pr_debug(format, a...) 47 #define dccp_pr_debug_cat(format, a...) 48 #endif 49 50 extern struct inet_hashinfo dccp_hashinfo; 51 52 extern atomic_t dccp_orphan_count; 53 54 extern void dccp_time_wait(struct sock *sk, int state, int timeo); 55 56 /* 57 * Set safe upper bounds for header and option length. Since Data Offset is 8 58 * bits (RFC 4340, sec. 5.1), the total header length can never be more than 59 * 4 * 255 = 1020 bytes. The largest possible header length is 28 bytes (X=1): 60 * - DCCP-Response with ACK Subheader and 4 bytes of Service code OR 61 * - DCCP-Reset with ACK Subheader and 4 bytes of Reset Code fields 62 * Hence a safe upper bound for the maximum option length is 1020-28 = 992 63 */ 64 #define MAX_DCCP_SPECIFIC_HEADER (255 * sizeof(int)) 65 #define DCCP_MAX_PACKET_HDR 28 66 #define DCCP_MAX_OPT_LEN (MAX_DCCP_SPECIFIC_HEADER - DCCP_MAX_PACKET_HDR) 67 #define MAX_DCCP_HEADER (MAX_DCCP_SPECIFIC_HEADER + MAX_HEADER) 68 69 #define DCCP_TIMEWAIT_LEN (60 * HZ) /* how long to wait to destroy TIME-WAIT 70 * state, about 60 seconds */ 71 72 /* RFC 1122, 4.2.3.1 initial RTO value */ 73 #define DCCP_TIMEOUT_INIT ((unsigned)(3 * HZ)) 74 75 /* 76 * The maximum back-off value for retransmissions. This is needed for 77 * - retransmitting client-Requests (sec. 8.1.1), 78 * - retransmitting Close/CloseReq when closing (sec. 8.3), 79 * - feature-negotiation retransmission (sec. 6.6.3), 80 * - Acks in client-PARTOPEN state (sec. 8.1.5). 81 */ 82 #define DCCP_RTO_MAX ((unsigned)(64 * HZ)) 83 84 /* 85 * RTT sampling: sanity bounds and fallback RTT value from RFC 4340, section 3.4 86 */ 87 #define DCCP_SANE_RTT_MIN 100 88 #define DCCP_FALLBACK_RTT (USEC_PER_SEC / 5) 89 #define DCCP_SANE_RTT_MAX (3 * USEC_PER_SEC) 90 91 /* Maximal interval between probes for local resources. */ 92 #define DCCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ / 2U)) 93 94 /* sysctl variables for DCCP */ 95 extern int sysctl_dccp_request_retries; 96 extern int sysctl_dccp_retries1; 97 extern int sysctl_dccp_retries2; 98 extern int sysctl_dccp_feat_sequence_window; 99 extern int sysctl_dccp_feat_rx_ccid; 100 extern int sysctl_dccp_feat_tx_ccid; 101 extern int sysctl_dccp_feat_ack_ratio; 102 extern int sysctl_dccp_feat_send_ack_vector; 103 extern int sysctl_dccp_feat_send_ndp_count; 104 extern int sysctl_dccp_tx_qlen; 105 extern int sysctl_dccp_sync_ratelimit; 106 107 /* 108 * 48-bit sequence number arithmetic (signed and unsigned) 109 */ 110 #define INT48_MIN 0x800000000000LL /* 2^47 */ 111 #define UINT48_MAX 0xFFFFFFFFFFFFLL /* 2^48 - 1 */ 112 #define COMPLEMENT48(x) (0x1000000000000LL - (x)) /* 2^48 - x */ 113 #define TO_SIGNED48(x) (((x) < INT48_MIN)? (x) : -COMPLEMENT48( (x))) 114 #define TO_UNSIGNED48(x) (((x) >= 0)? (x) : COMPLEMENT48(-(x))) 115 #define ADD48(a, b) (((a) + (b)) & UINT48_MAX) 116 #define SUB48(a, b) ADD48((a), COMPLEMENT48(b)) 117 118 static inline void dccp_set_seqno(u64 *seqno, u64 value) 119 { 120 *seqno = value & UINT48_MAX; 121 } 122 123 static inline void dccp_inc_seqno(u64 *seqno) 124 { 125 *seqno = ADD48(*seqno, 1); 126 } 127 128 /* signed mod-2^48 distance: pos. if seqno1 < seqno2, neg. if seqno1 > seqno2 */ 129 static inline s64 dccp_delta_seqno(const u64 seqno1, const u64 seqno2) 130 { 131 u64 delta = SUB48(seqno2, seqno1); 132 133 return TO_SIGNED48(delta); 134 } 135 136 /* is seq1 < seq2 ? */ 137 static inline int before48(const u64 seq1, const u64 seq2) 138 { 139 return (s64)((seq2 << 16) - (seq1 << 16)) > 0; 140 } 141 142 /* is seq1 > seq2 ? */ 143 #define after48(seq1, seq2) before48(seq2, seq1) 144 145 /* is seq2 <= seq1 <= seq3 ? */ 146 static inline int between48(const u64 seq1, const u64 seq2, const u64 seq3) 147 { 148 return (seq3 << 16) - (seq2 << 16) >= (seq1 << 16) - (seq2 << 16); 149 } 150 151 static inline u64 max48(const u64 seq1, const u64 seq2) 152 { 153 return after48(seq1, seq2) ? seq1 : seq2; 154 } 155 156 /** 157 * dccp_loss_free - Evaluates condition for data loss from RFC 4340, 7.7.1 158 * @s1: start sequence number 159 * @s2: end sequence number 160 * @ndp: NDP count on packet with sequence number @s2 161 * Returns true if the sequence range s1...s2 has no data loss. 162 */ 163 static inline bool dccp_loss_free(const u64 s1, const u64 s2, const u64 ndp) 164 { 165 s64 delta = dccp_delta_seqno(s1, s2); 166 167 WARN_ON(delta < 0); 168 return (u64)delta <= ndp + 1; 169 } 170 171 enum { 172 DCCP_MIB_NUM = 0, 173 DCCP_MIB_ACTIVEOPENS, /* ActiveOpens */ 174 DCCP_MIB_ESTABRESETS, /* EstabResets */ 175 DCCP_MIB_CURRESTAB, /* CurrEstab */ 176 DCCP_MIB_OUTSEGS, /* OutSegs */ 177 DCCP_MIB_OUTRSTS, 178 DCCP_MIB_ABORTONTIMEOUT, 179 DCCP_MIB_TIMEOUTS, 180 DCCP_MIB_ABORTFAILED, 181 DCCP_MIB_PASSIVEOPENS, 182 DCCP_MIB_ATTEMPTFAILS, 183 DCCP_MIB_OUTDATAGRAMS, 184 DCCP_MIB_INERRS, 185 DCCP_MIB_OPTMANDATORYERROR, 186 DCCP_MIB_INVALIDOPT, 187 __DCCP_MIB_MAX 188 }; 189 190 #define DCCP_MIB_MAX __DCCP_MIB_MAX 191 struct dccp_mib { 192 unsigned long mibs[DCCP_MIB_MAX]; 193 } __SNMP_MIB_ALIGN__; 194 195 DECLARE_SNMP_STAT(struct dccp_mib, dccp_statistics); 196 #define DCCP_INC_STATS(field) SNMP_INC_STATS(dccp_statistics, field) 197 #define DCCP_INC_STATS_BH(field) SNMP_INC_STATS_BH(dccp_statistics, field) 198 #define DCCP_INC_STATS_USER(field) SNMP_INC_STATS_USER(dccp_statistics, field) 199 #define DCCP_DEC_STATS(field) SNMP_DEC_STATS(dccp_statistics, field) 200 #define DCCP_ADD_STATS_BH(field, val) \ 201 SNMP_ADD_STATS_BH(dccp_statistics, field, val) 202 #define DCCP_ADD_STATS_USER(field, val) \ 203 SNMP_ADD_STATS_USER(dccp_statistics, field, val) 204 205 /* 206 * Checksumming routines 207 */ 208 static inline unsigned int dccp_csum_coverage(const struct sk_buff *skb) 209 { 210 const struct dccp_hdr* dh = dccp_hdr(skb); 211 212 if (dh->dccph_cscov == 0) 213 return skb->len; 214 return (dh->dccph_doff + dh->dccph_cscov - 1) * sizeof(u32); 215 } 216 217 static inline void dccp_csum_outgoing(struct sk_buff *skb) 218 { 219 unsigned int cov = dccp_csum_coverage(skb); 220 221 if (cov >= skb->len) 222 dccp_hdr(skb)->dccph_cscov = 0; 223 224 skb->csum = skb_checksum(skb, 0, (cov > skb->len)? skb->len : cov, 0); 225 } 226 227 extern void dccp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb); 228 229 extern int dccp_retransmit_skb(struct sock *sk); 230 231 extern void dccp_send_ack(struct sock *sk); 232 extern void dccp_reqsk_send_ack(struct sock *sk, struct sk_buff *skb, 233 struct request_sock *rsk); 234 235 extern void dccp_send_sync(struct sock *sk, const u64 seq, 236 const enum dccp_pkt_type pkt_type); 237 238 extern void dccp_write_xmit(struct sock *sk, int block); 239 extern void dccp_write_space(struct sock *sk); 240 241 extern void dccp_init_xmit_timers(struct sock *sk); 242 static inline void dccp_clear_xmit_timers(struct sock *sk) 243 { 244 inet_csk_clear_xmit_timers(sk); 245 } 246 247 extern unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu); 248 249 extern const char *dccp_packet_name(const int type); 250 extern const char *dccp_state_name(const int state); 251 252 extern void dccp_set_state(struct sock *sk, const int state); 253 extern void dccp_done(struct sock *sk); 254 255 extern void dccp_reqsk_init(struct request_sock *req, struct sk_buff *skb); 256 257 extern int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb); 258 259 extern struct sock *dccp_create_openreq_child(struct sock *sk, 260 const struct request_sock *req, 261 const struct sk_buff *skb); 262 263 extern int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb); 264 265 extern 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); 269 extern struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb, 270 struct request_sock *req, 271 struct request_sock **prev); 272 273 extern int dccp_child_process(struct sock *parent, struct sock *child, 274 struct sk_buff *skb); 275 extern int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb, 276 struct dccp_hdr *dh, unsigned len); 277 extern int dccp_rcv_established(struct sock *sk, struct sk_buff *skb, 278 const struct dccp_hdr *dh, const unsigned len); 279 280 extern int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized); 281 extern void dccp_destroy_sock(struct sock *sk); 282 283 extern void dccp_close(struct sock *sk, long timeout); 284 extern struct sk_buff *dccp_make_response(struct sock *sk, 285 struct dst_entry *dst, 286 struct request_sock *req); 287 288 extern int dccp_connect(struct sock *sk); 289 extern int dccp_disconnect(struct sock *sk, int flags); 290 extern int dccp_getsockopt(struct sock *sk, int level, int optname, 291 char __user *optval, int __user *optlen); 292 extern int dccp_setsockopt(struct sock *sk, int level, int optname, 293 char __user *optval, int optlen); 294 #ifdef CONFIG_COMPAT 295 extern int compat_dccp_getsockopt(struct sock *sk, 296 int level, int optname, 297 char __user *optval, int __user *optlen); 298 extern int compat_dccp_setsockopt(struct sock *sk, 299 int level, int optname, 300 char __user *optval, int optlen); 301 #endif 302 extern int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg); 303 extern int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, 304 struct msghdr *msg, size_t size); 305 extern int dccp_recvmsg(struct kiocb *iocb, struct sock *sk, 306 struct msghdr *msg, size_t len, int nonblock, 307 int flags, int *addr_len); 308 extern void dccp_shutdown(struct sock *sk, int how); 309 extern int inet_dccp_listen(struct socket *sock, int backlog); 310 extern unsigned int dccp_poll(struct file *file, struct socket *sock, 311 poll_table *wait); 312 extern int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, 313 int addr_len); 314 315 extern struct sk_buff *dccp_ctl_make_reset(struct sock *sk, 316 struct sk_buff *skb); 317 extern int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code); 318 extern void dccp_send_close(struct sock *sk, const int active); 319 extern int dccp_invalid_packet(struct sk_buff *skb); 320 extern u32 dccp_sample_rtt(struct sock *sk, long delta); 321 322 static 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 */ 343 struct 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 */ 362 static 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 */ 375 static 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 } 384 385 static 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) 393 394 static 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 } 402 403 static 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 } 410 411 static inline void dccp_update_gsr(struct sock *sk, u64 seq) 412 { 413 struct dccp_sock *dp = dccp_sk(sk); 414 const struct dccp_minisock *dmsk = dccp_msk(sk); 415 416 dp->dccps_gsr = seq; 417 dccp_set_seqno(&dp->dccps_swl, 418 dp->dccps_gsr + 1 - (dmsk->dccpms_sequence_window / 4)); 419 dccp_set_seqno(&dp->dccps_swh, 420 dp->dccps_gsr + (3 * dmsk->dccpms_sequence_window) / 4); 421 } 422 423 static inline void dccp_update_gss(struct sock *sk, u64 seq) 424 { 425 struct dccp_sock *dp = dccp_sk(sk); 426 427 dp->dccps_awh = dp->dccps_gss = seq; 428 dccp_set_seqno(&dp->dccps_awl, 429 (dp->dccps_gss - 430 dccp_msk(sk)->dccpms_sequence_window + 1)); 431 } 432 433 static inline int dccp_ack_pending(const struct sock *sk) 434 { 435 const struct dccp_sock *dp = dccp_sk(sk); 436 return dp->dccps_timestamp_echo != 0 || 437 #ifdef CONFIG_IP_DCCP_ACKVEC 438 (dccp_msk(sk)->dccpms_send_ack_vector && 439 dccp_ackvec_pending(dp->dccps_hc_rx_ackvec)) || 440 #endif 441 inet_csk_ack_scheduled(sk); 442 } 443 444 extern int dccp_insert_options(struct sock *sk, struct sk_buff *skb); 445 extern int dccp_insert_options_rsk(struct dccp_request_sock*, struct sk_buff*); 446 extern int dccp_insert_option_elapsed_time(struct sock *sk, 447 struct sk_buff *skb, 448 u32 elapsed_time); 449 extern u32 dccp_timestamp(void); 450 extern void dccp_timestamping_init(void); 451 extern int dccp_insert_option_timestamp(struct sock *sk, 452 struct sk_buff *skb); 453 extern int dccp_insert_option(struct sock *sk, struct sk_buff *skb, 454 unsigned char option, 455 const void *value, unsigned char len); 456 457 #ifdef CONFIG_SYSCTL 458 extern int dccp_sysctl_init(void); 459 extern void dccp_sysctl_exit(void); 460 #else 461 static inline int dccp_sysctl_init(void) 462 { 463 return 0; 464 } 465 466 static inline void dccp_sysctl_exit(void) 467 { 468 } 469 #endif 470 471 #endif /* _DCCP_H */ 472