dccp.h 14 KB

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