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 #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 52 extern struct inet_hashinfo dccp_hashinfo; 53 54 extern struct percpu_counter dccp_orphan_count; 55 56 extern 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 */ 100 extern int sysctl_dccp_request_retries; 101 extern int sysctl_dccp_retries1; 102 extern int sysctl_dccp_retries2; 103 extern int sysctl_dccp_tx_qlen; 104 extern 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)) 116 117 static inline void dccp_set_seqno(u64 *seqno, u64 value) 118 { 119 *seqno = value & UINT48_MAX; 120 } 121 122 static 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 */ 128 static 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 ? */ 136 static 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 ? */ 145 static inline int between48(const u64 seq1, const u64 seq2, const u64 seq3) 146 { 147 return (seq3 << 16) - (seq2 << 16) >= (seq1 << 16) - (seq2 << 16); 148 } 149 150 static 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 */ 162 static 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 } 169 170 enum { 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 190 struct dccp_mib { 191 unsigned long mibs[DCCP_MIB_MAX]; 192 } __SNMP_MIB_ALIGN__; 193 194 DECLARE_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 */ 207 static 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 } 215 216 static 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 } 225 226 extern void dccp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb); 227 228 extern int dccp_retransmit_skb(struct sock *sk); 229 230 extern void dccp_send_ack(struct sock *sk); 231 extern void dccp_reqsk_send_ack(struct sock *sk, struct sk_buff *skb, 232 struct request_sock *rsk); 233 234 extern void dccp_send_sync(struct sock *sk, const u64 seq, 235 const enum dccp_pkt_type pkt_type); 236 237 extern void dccp_write_xmit(struct sock *sk, int block); 238 extern void dccp_write_space(struct sock *sk); 239 240 extern void dccp_init_xmit_timers(struct sock *sk); 241 static inline void dccp_clear_xmit_timers(struct sock *sk) 242 { 243 inet_csk_clear_xmit_timers(sk); 244 } 245 246 extern unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu); 247 248 extern const char *dccp_packet_name(const int type); 249 extern const char *dccp_state_name(const int state); 250 251 extern void dccp_set_state(struct sock *sk, const int state); 252 extern void dccp_done(struct sock *sk); 253 254 extern int dccp_reqsk_init(struct request_sock *rq, struct dccp_sock const *dp, 255 struct sk_buff const *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, unsigned 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, unsigned 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); 414 415 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 } 420 421 static 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 } 430 431 static 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 } 439 440 extern int dccp_feat_finalise_settings(struct dccp_sock *dp); 441 extern int dccp_feat_server_ccid_dependencies(struct dccp_request_sock *dreq); 442 extern int dccp_feat_insert_opts(struct dccp_sock*, struct dccp_request_sock*, 443 struct sk_buff *skb); 444 extern int dccp_feat_activate_values(struct sock *sk, struct list_head *fn); 445 extern void dccp_feat_list_purge(struct list_head *fn_list); 446 447 extern int dccp_insert_options(struct sock *sk, struct sk_buff *skb); 448 extern int dccp_insert_options_rsk(struct dccp_request_sock*, struct sk_buff*); 449 extern int dccp_insert_option_elapsed_time(struct sock *sk, 450 struct sk_buff *skb, 451 u32 elapsed_time); 452 extern u32 dccp_timestamp(void); 453 extern void dccp_timestamping_init(void); 454 extern int dccp_insert_option_timestamp(struct sock *sk, 455 struct sk_buff *skb); 456 extern int dccp_insert_option(struct sock *sk, struct sk_buff *skb, 457 unsigned char option, 458 const void *value, unsigned char len); 459 460 #ifdef CONFIG_SYSCTL 461 extern int dccp_sysctl_init(void); 462 extern void dccp_sysctl_exit(void); 463 #else 464 static inline int dccp_sysctl_init(void) 465 { 466 return 0; 467 } 468 469 static inline void dccp_sysctl_exit(void) 470 { 471 } 472 #endif 473 474 #endif /* _DCCP_H */ 475