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 41 extern 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 49 extern struct inet_hashinfo dccp_hashinfo; 50 51 extern atomic_t dccp_orphan_count; 52 53 extern 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)) /* FIXME: using TCP value */ 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 */ 84 extern int sysctl_dccp_request_retries; 85 extern int sysctl_dccp_retries1; 86 extern int sysctl_dccp_retries2; 87 extern int sysctl_dccp_feat_sequence_window; 88 extern int sysctl_dccp_feat_rx_ccid; 89 extern int sysctl_dccp_feat_tx_ccid; 90 extern int sysctl_dccp_feat_ack_ratio; 91 extern int sysctl_dccp_feat_send_ack_vector; 92 extern int sysctl_dccp_feat_send_ndp_count; 93 extern 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)) 105 106 static inline void dccp_set_seqno(u64 *seqno, u64 value) 107 { 108 *seqno = value & UINT48_MAX; 109 } 110 111 static 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 */ 117 static 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 ? */ 125 static 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 ? */ 134 static inline int between48(const u64 seq1, const u64 seq2, const u64 seq3) 135 { 136 return (seq3 << 16) - (seq2 << 16) >= (seq1 << 16) - (seq2 << 16); 137 } 138 139 static 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 */ 145 static inline int follows48(const u64 seq1, const u64 seq2) 146 { 147 return dccp_delta_seqno(seq2, seq1) == 1; 148 } 149 150 enum { 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 170 struct dccp_mib { 171 unsigned long mibs[DCCP_MIB_MAX]; 172 } __SNMP_MIB_ALIGN__; 173 174 DECLARE_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 */ 187 static 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 } 195 196 static 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 } 205 206 extern void dccp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb); 207 208 extern int dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb); 209 210 extern void dccp_send_ack(struct sock *sk); 211 extern void dccp_send_delayed_ack(struct sock *sk); 212 extern void dccp_reqsk_send_ack(struct sk_buff *sk, struct request_sock *rsk); 213 214 extern void dccp_send_sync(struct sock *sk, const u64 seq, 215 const enum dccp_pkt_type pkt_type); 216 217 extern void dccp_write_xmit(struct sock *sk, int block); 218 extern void dccp_write_space(struct sock *sk); 219 220 extern void dccp_init_xmit_timers(struct sock *sk); 221 static inline void dccp_clear_xmit_timers(struct sock *sk) 222 { 223 inet_csk_clear_xmit_timers(sk); 224 } 225 226 extern unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu); 227 228 extern const char *dccp_packet_name(const int type); 229 extern const char *dccp_state_name(const int state); 230 231 extern void dccp_set_state(struct sock *sk, const int state); 232 extern void dccp_done(struct sock *sk); 233 234 extern void dccp_reqsk_init(struct request_sock *req, struct sk_buff *skb); 235 236 extern int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb); 237 238 extern struct sock *dccp_create_openreq_child(struct sock *sk, 239 const struct request_sock *req, 240 const struct sk_buff *skb); 241 242 extern int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb); 243 244 extern 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); 248 extern struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb, 249 struct request_sock *req, 250 struct request_sock **prev); 251 252 extern int dccp_child_process(struct sock *parent, struct sock *child, 253 struct sk_buff *skb); 254 extern int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb, 255 struct dccp_hdr *dh, unsigned len); 256 extern int dccp_rcv_established(struct sock *sk, struct sk_buff *skb, 257 const struct dccp_hdr *dh, const unsigned len); 258 259 extern int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized); 260 extern int dccp_destroy_sock(struct sock *sk); 261 262 extern void dccp_close(struct sock *sk, long timeout); 263 extern struct sk_buff *dccp_make_response(struct sock *sk, 264 struct dst_entry *dst, 265 struct request_sock *req); 266 267 extern int dccp_connect(struct sock *sk); 268 extern int dccp_disconnect(struct sock *sk, int flags); 269 extern void dccp_hash(struct sock *sk); 270 extern void dccp_unhash(struct sock *sk); 271 extern int dccp_getsockopt(struct sock *sk, int level, int optname, 272 char __user *optval, int __user *optlen); 273 extern int dccp_setsockopt(struct sock *sk, int level, int optname, 274 char __user *optval, int optlen); 275 #ifdef CONFIG_COMPAT 276 extern int compat_dccp_getsockopt(struct sock *sk, 277 int level, int optname, 278 char __user *optval, int __user *optlen); 279 extern int compat_dccp_setsockopt(struct sock *sk, 280 int level, int optname, 281 char __user *optval, int optlen); 282 #endif 283 extern int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg); 284 extern int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, 285 struct msghdr *msg, size_t size); 286 extern int dccp_recvmsg(struct kiocb *iocb, struct sock *sk, 287 struct msghdr *msg, size_t len, int nonblock, 288 int flags, int *addr_len); 289 extern void dccp_shutdown(struct sock *sk, int how); 290 extern int inet_dccp_listen(struct socket *sock, int backlog); 291 extern unsigned int dccp_poll(struct file *file, struct socket *sock, 292 poll_table *wait); 293 extern int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, 294 int addr_len); 295 296 extern int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code); 297 extern void dccp_send_close(struct sock *sk, const int active); 298 extern int dccp_invalid_packet(struct sk_buff *skb); 299 extern u32 dccp_sample_rtt(struct sock *sk, struct timeval *t_recv, 300 struct timeval *t_history); 301 302 static 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 } 311 312 struct 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])) 322 323 static 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 } 334 335 static 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) 343 344 static 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 } 352 353 static 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 } 360 361 static 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 } 372 373 static 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 } 382 383 static 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 } 393 394 extern int dccp_insert_options(struct sock *sk, struct sk_buff *skb); 395 extern int dccp_insert_option_elapsed_time(struct sock *sk, 396 struct sk_buff *skb, 397 u32 elapsed_time); 398 extern int dccp_insert_option_timestamp(struct sock *sk, 399 struct sk_buff *skb); 400 extern int dccp_insert_option(struct sock *sk, struct sk_buff *skb, 401 unsigned char option, 402 const void *value, unsigned char len); 403 404 extern void dccp_timestamp(const struct sock *sk, struct timeval *tv); 405 406 static inline suseconds_t timeval_usecs(const struct timeval *tv) 407 { 408 return tv->tv_sec * USEC_PER_SEC + tv->tv_usec; 409 } 410 411 static 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 } 423 424 static 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 } 433 434 static 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 446 extern int dccp_sysctl_init(void); 447 extern void dccp_sysctl_exit(void); 448 #else 449 static inline int dccp_sysctl_init(void) 450 { 451 return 0; 452 } 453 454 static inline void dccp_sysctl_exit(void) 455 { 456 } 457 #endif 458 459 #endif /* _DCCP_H */ 460