| 1 | /* SPDX-License-Identifier: GPL-2.0-or-later */ |
| 2 | /* |
| 3 | * INET An implementation of the TCP/IP protocol suite for the LINUX |
| 4 | * operating system. INET is implemented using the BSD Socket |
| 5 | * interface as the means of communication with the user level. |
| 6 | * |
| 7 | * Definitions for the TCP module. |
| 8 | * |
| 9 | * Version: @(#)tcp.h 1.0.5 05/23/93 |
| 10 | * |
| 11 | * Authors: Ross Biro |
| 12 | * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> |
| 13 | */ |
| 14 | #ifndef _TCP_H |
| 15 | #define _TCP_H |
| 16 | |
| 17 | #define FASTRETRANS_DEBUG 1 |
| 18 | |
| 19 | #include <linux/list.h> |
| 20 | #include <linux/tcp.h> |
| 21 | #include <linux/bug.h> |
| 22 | #include <linux/slab.h> |
| 23 | #include <linux/cache.h> |
| 24 | #include <linux/percpu.h> |
| 25 | #include <linux/skbuff.h> |
| 26 | #include <linux/kref.h> |
| 27 | #include <linux/ktime.h> |
| 28 | #include <linux/indirect_call_wrapper.h> |
| 29 | |
| 30 | #include <net/inet_connection_sock.h> |
| 31 | #include <net/inet_timewait_sock.h> |
| 32 | #include <net/inet_hashtables.h> |
| 33 | #include <net/checksum.h> |
| 34 | #include <net/request_sock.h> |
| 35 | #include <net/sock_reuseport.h> |
| 36 | #include <net/sock.h> |
| 37 | #include <net/snmp.h> |
| 38 | #include <net/ip.h> |
| 39 | #include <net/tcp_states.h> |
| 40 | #include <net/tcp_ao.h> |
| 41 | #include <net/inet_ecn.h> |
| 42 | #include <net/dst.h> |
| 43 | #include <net/mptcp.h> |
| 44 | |
| 45 | #include <linux/seq_file.h> |
| 46 | #include <linux/memcontrol.h> |
| 47 | #include <linux/bpf-cgroup.h> |
| 48 | #include <linux/siphash.h> |
| 49 | |
| 50 | extern struct inet_hashinfo tcp_hashinfo; |
| 51 | |
| 52 | DECLARE_PER_CPU(unsigned int, tcp_orphan_count); |
| 53 | int tcp_orphan_count_sum(void); |
| 54 | |
| 55 | DECLARE_PER_CPU(u32, tcp_tw_isn); |
| 56 | |
| 57 | void tcp_time_wait(struct sock *sk, int state, int timeo); |
| 58 | |
| 59 | #define MAX_TCP_HEADER L1_CACHE_ALIGN(128 + MAX_HEADER) |
| 60 | #define MAX_TCP_OPTION_SPACE 40 |
| 61 | #define TCP_MIN_SND_MSS 48 |
| 62 | #define TCP_MIN_GSO_SIZE (TCP_MIN_SND_MSS - MAX_TCP_OPTION_SPACE) |
| 63 | |
| 64 | /* |
| 65 | * Never offer a window over 32767 without using window scaling. Some |
| 66 | * poor stacks do signed 16bit maths! |
| 67 | */ |
| 68 | #define MAX_TCP_WINDOW 32767U |
| 69 | |
| 70 | /* Minimal accepted MSS. It is (60+60+8) - (20+20). */ |
| 71 | #define TCP_MIN_MSS 88U |
| 72 | |
| 73 | /* The initial MTU to use for probing */ |
| 74 | #define TCP_BASE_MSS 1024 |
| 75 | |
| 76 | /* probing interval, default to 10 minutes as per RFC4821 */ |
| 77 | #define TCP_PROBE_INTERVAL 600 |
| 78 | |
| 79 | /* Specify interval when tcp mtu probing will stop */ |
| 80 | #define TCP_PROBE_THRESHOLD 8 |
| 81 | |
| 82 | /* After receiving this amount of duplicate ACKs fast retransmit starts. */ |
| 83 | #define TCP_FASTRETRANS_THRESH 3 |
| 84 | |
| 85 | /* Maximal number of ACKs sent quickly to accelerate slow-start. */ |
| 86 | #define TCP_MAX_QUICKACKS 16U |
| 87 | |
| 88 | /* Maximal number of window scale according to RFC1323 */ |
| 89 | #define TCP_MAX_WSCALE 14U |
| 90 | |
| 91 | /* urg_data states */ |
| 92 | #define TCP_URG_VALID 0x0100 |
| 93 | #define TCP_URG_NOTYET 0x0200 |
| 94 | #define TCP_URG_READ 0x0400 |
| 95 | |
| 96 | #define TCP_RETR1 3 /* |
| 97 | * This is how many retries it does before it |
| 98 | * tries to figure out if the gateway is |
| 99 | * down. Minimal RFC value is 3; it corresponds |
| 100 | * to ~3sec-8min depending on RTO. |
| 101 | */ |
| 102 | |
| 103 | #define TCP_RETR2 15 /* |
| 104 | * This should take at least |
| 105 | * 90 minutes to time out. |
| 106 | * RFC1122 says that the limit is 100 sec. |
| 107 | * 15 is ~13-30min depending on RTO. |
| 108 | */ |
| 109 | |
| 110 | #define TCP_SYN_RETRIES 6 /* This is how many retries are done |
| 111 | * when active opening a connection. |
| 112 | * RFC1122 says the minimum retry MUST |
| 113 | * be at least 180secs. Nevertheless |
| 114 | * this value is corresponding to |
| 115 | * 63secs of retransmission with the |
| 116 | * current initial RTO. |
| 117 | */ |
| 118 | |
| 119 | #define TCP_SYNACK_RETRIES 5 /* This is how may retries are done |
| 120 | * when passive opening a connection. |
| 121 | * This is corresponding to 31secs of |
| 122 | * retransmission with the current |
| 123 | * initial RTO. |
| 124 | */ |
| 125 | |
| 126 | #define TCP_TIMEWAIT_LEN (60*HZ) /* how long to wait to destroy TIME-WAIT |
| 127 | * state, about 60 seconds */ |
| 128 | #define TCP_FIN_TIMEOUT TCP_TIMEWAIT_LEN |
| 129 | /* BSD style FIN_WAIT2 deadlock breaker. |
| 130 | * It used to be 3min, new value is 60sec, |
| 131 | * to combine FIN-WAIT-2 timeout with |
| 132 | * TIME-WAIT timer. |
| 133 | */ |
| 134 | #define TCP_FIN_TIMEOUT_MAX (120 * HZ) /* max TCP_LINGER2 value (two minutes) */ |
| 135 | |
| 136 | #define TCP_DELACK_MAX ((unsigned)(HZ/5)) /* maximal time to delay before sending an ACK */ |
| 137 | static_assert((1 << ATO_BITS) > TCP_DELACK_MAX); |
| 138 | |
| 139 | #if HZ >= 100 |
| 140 | #define TCP_DELACK_MIN ((unsigned)(HZ/25)) /* minimal time to delay before sending an ACK */ |
| 141 | #define TCP_ATO_MIN ((unsigned)(HZ/25)) |
| 142 | #else |
| 143 | #define TCP_DELACK_MIN 4U |
| 144 | #define TCP_ATO_MIN 4U |
| 145 | #endif |
| 146 | #define TCP_RTO_MAX ((unsigned)(120*HZ)) |
| 147 | #define TCP_RTO_MIN ((unsigned)(HZ/5)) |
| 148 | #define TCP_TIMEOUT_MIN (2U) /* Min timeout for TCP timers in jiffies */ |
| 149 | |
| 150 | #define TCP_TIMEOUT_MIN_US (2*USEC_PER_MSEC) /* Min TCP timeout in microsecs */ |
| 151 | |
| 152 | #define TCP_TIMEOUT_INIT ((unsigned)(1*HZ)) /* RFC6298 2.1 initial RTO value */ |
| 153 | #define TCP_TIMEOUT_FALLBACK ((unsigned)(3*HZ)) /* RFC 1122 initial RTO value, now |
| 154 | * used as a fallback RTO for the |
| 155 | * initial data transmission if no |
| 156 | * valid RTT sample has been acquired, |
| 157 | * most likely due to retrans in 3WHS. |
| 158 | */ |
| 159 | |
| 160 | #define TCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ/2U)) /* Maximal interval between probes |
| 161 | * for local resources. |
| 162 | */ |
| 163 | #define TCP_KEEPALIVE_TIME (120*60*HZ) /* two hours */ |
| 164 | #define TCP_KEEPALIVE_PROBES 9 /* Max of 9 keepalive probes */ |
| 165 | #define TCP_KEEPALIVE_INTVL (75*HZ) |
| 166 | |
| 167 | #define MAX_TCP_KEEPIDLE 32767 |
| 168 | #define MAX_TCP_KEEPINTVL 32767 |
| 169 | #define MAX_TCP_KEEPCNT 127 |
| 170 | #define MAX_TCP_SYNCNT 127 |
| 171 | |
| 172 | /* Ensure that TCP PAWS checks are relaxed after ~2147 seconds |
| 173 | * to avoid overflows. This assumes a clock smaller than 1 Mhz. |
| 174 | * Default clock is 1 Khz, tcp_usec_ts uses 1 Mhz. |
| 175 | */ |
| 176 | #define TCP_PAWS_WRAP (INT_MAX / USEC_PER_SEC) |
| 177 | |
| 178 | #define TCP_PAWS_MSL 60 /* Per-host timestamps are invalidated |
| 179 | * after this time. It should be equal |
| 180 | * (or greater than) TCP_TIMEWAIT_LEN |
| 181 | * to provide reliability equal to one |
| 182 | * provided by timewait state. |
| 183 | */ |
| 184 | #define TCP_PAWS_WINDOW 1 /* Replay window for per-host |
| 185 | * timestamps. It must be less than |
| 186 | * minimal timewait lifetime. |
| 187 | */ |
| 188 | /* |
| 189 | * TCP option |
| 190 | */ |
| 191 | |
| 192 | #define TCPOPT_NOP 1 /* Padding */ |
| 193 | #define TCPOPT_EOL 0 /* End of options */ |
| 194 | #define TCPOPT_MSS 2 /* Segment size negotiating */ |
| 195 | #define TCPOPT_WINDOW 3 /* Window scaling */ |
| 196 | #define TCPOPT_SACK_PERM 4 /* SACK Permitted */ |
| 197 | #define TCPOPT_SACK 5 /* SACK Block */ |
| 198 | #define TCPOPT_TIMESTAMP 8 /* Better RTT estimations/PAWS */ |
| 199 | #define TCPOPT_MD5SIG 19 /* MD5 Signature (RFC2385) */ |
| 200 | #define TCPOPT_AO 29 /* Authentication Option (RFC5925) */ |
| 201 | #define TCPOPT_MPTCP 30 /* Multipath TCP (RFC6824) */ |
| 202 | #define TCPOPT_FASTOPEN 34 /* Fast open (RFC7413) */ |
| 203 | #define TCPOPT_EXP 254 /* Experimental */ |
| 204 | /* Magic number to be after the option value for sharing TCP |
| 205 | * experimental options. See draft-ietf-tcpm-experimental-options-00.txt |
| 206 | */ |
| 207 | #define TCPOPT_FASTOPEN_MAGIC 0xF989 |
| 208 | #define TCPOPT_SMC_MAGIC 0xE2D4C3D9 |
| 209 | |
| 210 | /* |
| 211 | * TCP option lengths |
| 212 | */ |
| 213 | |
| 214 | #define TCPOLEN_MSS 4 |
| 215 | #define TCPOLEN_WINDOW 3 |
| 216 | #define TCPOLEN_SACK_PERM 2 |
| 217 | #define TCPOLEN_TIMESTAMP 10 |
| 218 | #define TCPOLEN_MD5SIG 18 |
| 219 | #define TCPOLEN_FASTOPEN_BASE 2 |
| 220 | #define TCPOLEN_EXP_FASTOPEN_BASE 4 |
| 221 | #define TCPOLEN_EXP_SMC_BASE 6 |
| 222 | |
| 223 | /* But this is what stacks really send out. */ |
| 224 | #define TCPOLEN_TSTAMP_ALIGNED 12 |
| 225 | #define TCPOLEN_WSCALE_ALIGNED 4 |
| 226 | #define TCPOLEN_SACKPERM_ALIGNED 4 |
| 227 | #define TCPOLEN_SACK_BASE 2 |
| 228 | #define TCPOLEN_SACK_BASE_ALIGNED 4 |
| 229 | #define TCPOLEN_SACK_PERBLOCK 8 |
| 230 | #define TCPOLEN_MD5SIG_ALIGNED 20 |
| 231 | #define TCPOLEN_MSS_ALIGNED 4 |
| 232 | #define TCPOLEN_EXP_SMC_BASE_ALIGNED 8 |
| 233 | |
| 234 | /* Flags in tp->nonagle */ |
| 235 | #define TCP_NAGLE_OFF 1 /* Nagle's algo is disabled */ |
| 236 | #define TCP_NAGLE_CORK 2 /* Socket is corked */ |
| 237 | #define TCP_NAGLE_PUSH 4 /* Cork is overridden for already queued data */ |
| 238 | |
| 239 | /* TCP thin-stream limits */ |
| 240 | #define TCP_THIN_LINEAR_RETRIES 6 /* After 6 linear retries, do exp. backoff */ |
| 241 | |
| 242 | /* TCP initial congestion window as per rfc6928 */ |
| 243 | #define TCP_INIT_CWND 10 |
| 244 | |
| 245 | /* Bit Flags for sysctl_tcp_fastopen */ |
| 246 | #define TFO_CLIENT_ENABLE 1 |
| 247 | #define TFO_SERVER_ENABLE 2 |
| 248 | #define TFO_CLIENT_NO_COOKIE 4 /* Data in SYN w/o cookie option */ |
| 249 | |
| 250 | /* Accept SYN data w/o any cookie option */ |
| 251 | #define TFO_SERVER_COOKIE_NOT_REQD 0x200 |
| 252 | |
| 253 | /* Force enable TFO on all listeners, i.e., not requiring the |
| 254 | * TCP_FASTOPEN socket option. |
| 255 | */ |
| 256 | #define TFO_SERVER_WO_SOCKOPT1 0x400 |
| 257 | |
| 258 | |
| 259 | /* sysctl variables for tcp */ |
| 260 | extern int sysctl_tcp_max_orphans; |
| 261 | extern long sysctl_tcp_mem[3]; |
| 262 | |
| 263 | #define TCP_RACK_LOSS_DETECTION 0x1 /* Use RACK to detect losses */ |
| 264 | #define TCP_RACK_STATIC_REO_WND 0x2 /* Use static RACK reo wnd */ |
| 265 | #define TCP_RACK_NO_DUPTHRESH 0x4 /* Do not use DUPACK threshold in RACK */ |
| 266 | |
| 267 | extern atomic_long_t tcp_memory_allocated; |
| 268 | DECLARE_PER_CPU(int, tcp_memory_per_cpu_fw_alloc); |
| 269 | |
| 270 | extern struct percpu_counter tcp_sockets_allocated; |
| 271 | extern unsigned long tcp_memory_pressure; |
| 272 | |
| 273 | /* optimized version of sk_under_memory_pressure() for TCP sockets */ |
| 274 | static inline bool tcp_under_memory_pressure(const struct sock *sk) |
| 275 | { |
| 276 | if (mem_cgroup_sockets_enabled && sk->sk_memcg && |
| 277 | mem_cgroup_under_socket_pressure(sk->sk_memcg)) |
| 278 | return true; |
| 279 | |
| 280 | return READ_ONCE(tcp_memory_pressure); |
| 281 | } |
| 282 | /* |
| 283 | * The next routines deal with comparing 32 bit unsigned ints |
| 284 | * and worry about wraparound (automatic with unsigned arithmetic). |
| 285 | */ |
| 286 | |
| 287 | static inline bool before(__u32 seq1, __u32 seq2) |
| 288 | { |
| 289 | return (__s32)(seq1-seq2) < 0; |
| 290 | } |
| 291 | #define after(seq2, seq1) before(seq1, seq2) |
| 292 | |
| 293 | /* is s2<=s1<=s3 ? */ |
| 294 | static inline bool between(__u32 seq1, __u32 seq2, __u32 seq3) |
| 295 | { |
| 296 | return seq3 - seq2 >= seq1 - seq2; |
| 297 | } |
| 298 | |
| 299 | static inline void tcp_wmem_free_skb(struct sock *sk, struct sk_buff *skb) |
| 300 | { |
| 301 | sk_wmem_queued_add(sk, -skb->truesize); |
| 302 | if (!skb_zcopy_pure(skb)) |
| 303 | sk_mem_uncharge(sk, skb->truesize); |
| 304 | else |
| 305 | sk_mem_uncharge(sk, SKB_TRUESIZE(skb_end_offset(skb))); |
| 306 | __kfree_skb(skb); |
| 307 | } |
| 308 | |
| 309 | void sk_forced_mem_schedule(struct sock *sk, int size); |
| 310 | |
| 311 | bool tcp_check_oom(const struct sock *sk, int shift); |
| 312 | |
| 313 | |
| 314 | extern struct proto tcp_prot; |
| 315 | |
| 316 | #define TCP_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.tcp_statistics, field) |
| 317 | #define __TCP_INC_STATS(net, field) __SNMP_INC_STATS((net)->mib.tcp_statistics, field) |
| 318 | #define TCP_DEC_STATS(net, field) SNMP_DEC_STATS((net)->mib.tcp_statistics, field) |
| 319 | #define TCP_ADD_STATS(net, field, val) SNMP_ADD_STATS((net)->mib.tcp_statistics, field, val) |
| 320 | |
| 321 | void tcp_tasklet_init(void); |
| 322 | |
| 323 | int tcp_v4_err(struct sk_buff *skb, u32); |
| 324 | |
| 325 | void tcp_shutdown(struct sock *sk, int how); |
| 326 | |
| 327 | int tcp_v4_early_demux(struct sk_buff *skb); |
| 328 | int tcp_v4_rcv(struct sk_buff *skb); |
| 329 | |
| 330 | void tcp_remove_empty_skb(struct sock *sk); |
| 331 | int tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size); |
| 332 | int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size); |
| 333 | int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg, int *copied, |
| 334 | size_t size, struct ubuf_info *uarg); |
| 335 | void tcp_splice_eof(struct socket *sock); |
| 336 | int tcp_send_mss(struct sock *sk, int *size_goal, int flags); |
| 337 | int tcp_wmem_schedule(struct sock *sk, int copy); |
| 338 | void tcp_push(struct sock *sk, int flags, int mss_now, int nonagle, |
| 339 | int size_goal); |
| 340 | void tcp_release_cb(struct sock *sk); |
| 341 | void tcp_wfree(struct sk_buff *skb); |
| 342 | void tcp_write_timer_handler(struct sock *sk); |
| 343 | void tcp_delack_timer_handler(struct sock *sk); |
| 344 | int tcp_ioctl(struct sock *sk, int cmd, int *karg); |
| 345 | enum skb_drop_reason tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb); |
| 346 | void tcp_rcv_established(struct sock *sk, struct sk_buff *skb); |
| 347 | void tcp_rcv_space_adjust(struct sock *sk); |
| 348 | int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp); |
| 349 | void tcp_twsk_destructor(struct sock *sk); |
| 350 | void tcp_twsk_purge(struct list_head *net_exit_list); |
| 351 | ssize_t tcp_splice_read(struct socket *sk, loff_t *ppos, |
| 352 | struct pipe_inode_info *pipe, size_t len, |
| 353 | unsigned int flags); |
| 354 | struct sk_buff *tcp_stream_alloc_skb(struct sock *sk, gfp_t gfp, |
| 355 | bool force_schedule); |
| 356 | |
| 357 | static inline void tcp_dec_quickack_mode(struct sock *sk) |
| 358 | { |
| 359 | struct inet_connection_sock *icsk = inet_csk(sk); |
| 360 | |
| 361 | if (icsk->icsk_ack.quick) { |
| 362 | /* How many ACKs S/ACKing new data have we sent? */ |
| 363 | const unsigned int pkts = inet_csk_ack_scheduled(sk) ? 1 : 0; |
| 364 | |
| 365 | if (pkts >= icsk->icsk_ack.quick) { |
| 366 | icsk->icsk_ack.quick = 0; |
| 367 | /* Leaving quickack mode we deflate ATO. */ |
| 368 | icsk->icsk_ack.ato = TCP_ATO_MIN; |
| 369 | } else |
| 370 | icsk->icsk_ack.quick -= pkts; |
| 371 | } |
| 372 | } |
| 373 | |
| 374 | #define TCP_ECN_OK 1 |
| 375 | #define TCP_ECN_QUEUE_CWR 2 |
| 376 | #define TCP_ECN_DEMAND_CWR 4 |
| 377 | #define TCP_ECN_SEEN 8 |
| 378 | |
| 379 | enum tcp_tw_status { |
| 380 | TCP_TW_SUCCESS = 0, |
| 381 | TCP_TW_RST = 1, |
| 382 | TCP_TW_ACK = 2, |
| 383 | TCP_TW_SYN = 3 |
| 384 | }; |
| 385 | |
| 386 | |
| 387 | enum tcp_tw_status tcp_timewait_state_process(struct inet_timewait_sock *tw, |
| 388 | struct sk_buff *skb, |
| 389 | const struct tcphdr *th, |
| 390 | u32 *tw_isn); |
| 391 | struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb, |
| 392 | struct request_sock *req, bool fastopen, |
| 393 | bool *lost_race); |
| 394 | enum skb_drop_reason tcp_child_process(struct sock *parent, struct sock *child, |
| 395 | struct sk_buff *skb); |
| 396 | void tcp_enter_loss(struct sock *sk); |
| 397 | void tcp_cwnd_reduction(struct sock *sk, int newly_acked_sacked, int newly_lost, int flag); |
| 398 | void tcp_clear_retrans(struct tcp_sock *tp); |
| 399 | void tcp_update_metrics(struct sock *sk); |
| 400 | void tcp_init_metrics(struct sock *sk); |
| 401 | void tcp_metrics_init(void); |
| 402 | bool tcp_peer_is_proven(struct request_sock *req, struct dst_entry *dst); |
| 403 | void __tcp_close(struct sock *sk, long timeout); |
| 404 | void tcp_close(struct sock *sk, long timeout); |
| 405 | void tcp_init_sock(struct sock *sk); |
| 406 | void tcp_init_transfer(struct sock *sk, int bpf_op, struct sk_buff *skb); |
| 407 | __poll_t tcp_poll(struct file *file, struct socket *sock, |
| 408 | struct poll_table_struct *wait); |
| 409 | int do_tcp_getsockopt(struct sock *sk, int level, |
| 410 | int optname, sockptr_t optval, sockptr_t optlen); |
| 411 | int tcp_getsockopt(struct sock *sk, int level, int optname, |
| 412 | char __user *optval, int __user *optlen); |
| 413 | bool tcp_bpf_bypass_getsockopt(int level, int optname); |
| 414 | int do_tcp_setsockopt(struct sock *sk, int level, int optname, |
| 415 | sockptr_t optval, unsigned int optlen); |
| 416 | int tcp_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, |
| 417 | unsigned int optlen); |
| 418 | void tcp_set_keepalive(struct sock *sk, int val); |
| 419 | void tcp_syn_ack_timeout(const struct request_sock *req); |
| 420 | int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, |
| 421 | int flags, int *addr_len); |
| 422 | int tcp_set_rcvlowat(struct sock *sk, int val); |
| 423 | int tcp_set_window_clamp(struct sock *sk, int val); |
| 424 | void tcp_update_recv_tstamps(struct sk_buff *skb, |
| 425 | struct scm_timestamping_internal *tss); |
| 426 | void tcp_recv_timestamp(struct msghdr *msg, const struct sock *sk, |
| 427 | struct scm_timestamping_internal *tss); |
| 428 | void tcp_data_ready(struct sock *sk); |
| 429 | #ifdef CONFIG_MMU |
| 430 | int tcp_mmap(struct file *file, struct socket *sock, |
| 431 | struct vm_area_struct *vma); |
| 432 | #endif |
| 433 | void tcp_parse_options(const struct net *net, const struct sk_buff *skb, |
| 434 | struct tcp_options_received *opt_rx, |
| 435 | int estab, struct tcp_fastopen_cookie *foc); |
| 436 | |
| 437 | /* |
| 438 | * BPF SKB-less helpers |
| 439 | */ |
| 440 | u16 tcp_v4_get_syncookie(struct sock *sk, struct iphdr *iph, |
| 441 | struct tcphdr *th, u32 *cookie); |
| 442 | u16 tcp_v6_get_syncookie(struct sock *sk, struct ipv6hdr *iph, |
| 443 | struct tcphdr *th, u32 *cookie); |
| 444 | u16 tcp_parse_mss_option(const struct tcphdr *th, u16 user_mss); |
| 445 | u16 tcp_get_syncookie_mss(struct request_sock_ops *rsk_ops, |
| 446 | const struct tcp_request_sock_ops *af_ops, |
| 447 | struct sock *sk, struct tcphdr *th); |
| 448 | /* |
| 449 | * TCP v4 functions exported for the inet6 API |
| 450 | */ |
| 451 | |
| 452 | void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb); |
| 453 | void tcp_v4_mtu_reduced(struct sock *sk); |
| 454 | void tcp_req_err(struct sock *sk, u32 seq, bool abort); |
| 455 | void tcp_ld_RTO_revert(struct sock *sk, u32 seq); |
| 456 | int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb); |
| 457 | struct sock *tcp_create_openreq_child(const struct sock *sk, |
| 458 | struct request_sock *req, |
| 459 | struct sk_buff *skb); |
| 460 | void tcp_ca_openreq_child(struct sock *sk, const struct dst_entry *dst); |
| 461 | struct sock *tcp_v4_syn_recv_sock(const struct sock *sk, struct sk_buff *skb, |
| 462 | struct request_sock *req, |
| 463 | struct dst_entry *dst, |
| 464 | struct request_sock *req_unhash, |
| 465 | bool *own_req); |
| 466 | int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb); |
| 467 | int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len); |
| 468 | int tcp_connect(struct sock *sk); |
| 469 | enum tcp_synack_type { |
| 470 | TCP_SYNACK_NORMAL, |
| 471 | TCP_SYNACK_FASTOPEN, |
| 472 | TCP_SYNACK_COOKIE, |
| 473 | }; |
| 474 | struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst, |
| 475 | struct request_sock *req, |
| 476 | struct tcp_fastopen_cookie *foc, |
| 477 | enum tcp_synack_type synack_type, |
| 478 | struct sk_buff *syn_skb); |
| 479 | int tcp_disconnect(struct sock *sk, int flags); |
| 480 | |
| 481 | void tcp_finish_connect(struct sock *sk, struct sk_buff *skb); |
| 482 | int tcp_send_rcvq(struct sock *sk, struct msghdr *msg, size_t size); |
| 483 | void inet_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb); |
| 484 | |
| 485 | /* From syncookies.c */ |
| 486 | struct sock *tcp_get_cookie_sock(struct sock *sk, struct sk_buff *skb, |
| 487 | struct request_sock *req, |
| 488 | struct dst_entry *dst); |
| 489 | int __cookie_v4_check(const struct iphdr *iph, const struct tcphdr *th); |
| 490 | struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb); |
| 491 | struct request_sock *cookie_tcp_reqsk_alloc(const struct request_sock_ops *ops, |
| 492 | struct sock *sk, struct sk_buff *skb, |
| 493 | struct tcp_options_received *tcp_opt, |
| 494 | int mss, u32 tsoff); |
| 495 | |
| 496 | #if IS_ENABLED(CONFIG_BPF) |
| 497 | struct bpf_tcp_req_attrs { |
| 498 | u32 rcv_tsval; |
| 499 | u32 rcv_tsecr; |
| 500 | u16 mss; |
| 501 | u8 rcv_wscale; |
| 502 | u8 snd_wscale; |
| 503 | u8 ecn_ok; |
| 504 | u8 wscale_ok; |
| 505 | u8 sack_ok; |
| 506 | u8 tstamp_ok; |
| 507 | u8 usec_ts_ok; |
| 508 | u8 reserved[3]; |
| 509 | }; |
| 510 | #endif |
| 511 | |
| 512 | #ifdef CONFIG_SYN_COOKIES |
| 513 | |
| 514 | /* Syncookies use a monotonic timer which increments every 60 seconds. |
| 515 | * This counter is used both as a hash input and partially encoded into |
| 516 | * the cookie value. A cookie is only validated further if the delta |
| 517 | * between the current counter value and the encoded one is less than this, |
| 518 | * i.e. a sent cookie is valid only at most for 2*60 seconds (or less if |
| 519 | * the counter advances immediately after a cookie is generated). |
| 520 | */ |
| 521 | #define MAX_SYNCOOKIE_AGE 2 |
| 522 | #define TCP_SYNCOOKIE_PERIOD (60 * HZ) |
| 523 | #define TCP_SYNCOOKIE_VALID (MAX_SYNCOOKIE_AGE * TCP_SYNCOOKIE_PERIOD) |
| 524 | |
| 525 | /* syncookies: remember time of last synqueue overflow |
| 526 | * But do not dirty this field too often (once per second is enough) |
| 527 | * It is racy as we do not hold a lock, but race is very minor. |
| 528 | */ |
| 529 | static inline void tcp_synq_overflow(const struct sock *sk) |
| 530 | { |
| 531 | unsigned int last_overflow; |
| 532 | unsigned int now = jiffies; |
| 533 | |
| 534 | if (sk->sk_reuseport) { |
| 535 | struct sock_reuseport *reuse; |
| 536 | |
| 537 | reuse = rcu_dereference(sk->sk_reuseport_cb); |
| 538 | if (likely(reuse)) { |
| 539 | last_overflow = READ_ONCE(reuse->synq_overflow_ts); |
| 540 | if (!time_between32(now, last_overflow, |
| 541 | last_overflow + HZ)) |
| 542 | WRITE_ONCE(reuse->synq_overflow_ts, now); |
| 543 | return; |
| 544 | } |
| 545 | } |
| 546 | |
| 547 | last_overflow = READ_ONCE(tcp_sk(sk)->rx_opt.ts_recent_stamp); |
| 548 | if (!time_between32(now, last_overflow, last_overflow + HZ)) |
| 549 | WRITE_ONCE(tcp_sk_rw(sk)->rx_opt.ts_recent_stamp, now); |
| 550 | } |
| 551 | |
| 552 | /* syncookies: no recent synqueue overflow on this listening socket? */ |
| 553 | static inline bool tcp_synq_no_recent_overflow(const struct sock *sk) |
| 554 | { |
| 555 | unsigned int last_overflow; |
| 556 | unsigned int now = jiffies; |
| 557 | |
| 558 | if (sk->sk_reuseport) { |
| 559 | struct sock_reuseport *reuse; |
| 560 | |
| 561 | reuse = rcu_dereference(sk->sk_reuseport_cb); |
| 562 | if (likely(reuse)) { |
| 563 | last_overflow = READ_ONCE(reuse->synq_overflow_ts); |
| 564 | return !time_between32(now, last_overflow - HZ, |
| 565 | last_overflow + |
| 566 | TCP_SYNCOOKIE_VALID); |
| 567 | } |
| 568 | } |
| 569 | |
| 570 | last_overflow = READ_ONCE(tcp_sk(sk)->rx_opt.ts_recent_stamp); |
| 571 | |
| 572 | /* If last_overflow <= jiffies <= last_overflow + TCP_SYNCOOKIE_VALID, |
| 573 | * then we're under synflood. However, we have to use |
| 574 | * 'last_overflow - HZ' as lower bound. That's because a concurrent |
| 575 | * tcp_synq_overflow() could update .ts_recent_stamp after we read |
| 576 | * jiffies but before we store .ts_recent_stamp into last_overflow, |
| 577 | * which could lead to rejecting a valid syncookie. |
| 578 | */ |
| 579 | return !time_between32(now, last_overflow - HZ, |
| 580 | last_overflow + TCP_SYNCOOKIE_VALID); |
| 581 | } |
| 582 | |
| 583 | static inline u32 tcp_cookie_time(void) |
| 584 | { |
| 585 | u64 val = get_jiffies_64(); |
| 586 | |
| 587 | do_div(val, TCP_SYNCOOKIE_PERIOD); |
| 588 | return val; |
| 589 | } |
| 590 | |
| 591 | /* Convert one nsec 64bit timestamp to ts (ms or usec resolution) */ |
| 592 | static inline u64 tcp_ns_to_ts(bool usec_ts, u64 val) |
| 593 | { |
| 594 | if (usec_ts) |
| 595 | return div_u64(val, NSEC_PER_USEC); |
| 596 | |
| 597 | return div_u64(val, NSEC_PER_MSEC); |
| 598 | } |
| 599 | |
| 600 | u32 __cookie_v4_init_sequence(const struct iphdr *iph, const struct tcphdr *th, |
| 601 | u16 *mssp); |
| 602 | __u32 cookie_v4_init_sequence(const struct sk_buff *skb, __u16 *mss); |
| 603 | u64 cookie_init_timestamp(struct request_sock *req, u64 now); |
| 604 | bool cookie_timestamp_decode(const struct net *net, |
| 605 | struct tcp_options_received *opt); |
| 606 | |
| 607 | static inline bool cookie_ecn_ok(const struct net *net, const struct dst_entry *dst) |
| 608 | { |
| 609 | return READ_ONCE(net->ipv4.sysctl_tcp_ecn) || |
| 610 | dst_feature(dst, RTAX_FEATURE_ECN); |
| 611 | } |
| 612 | |
| 613 | #if IS_ENABLED(CONFIG_BPF) |
| 614 | static inline bool cookie_bpf_ok(struct sk_buff *skb) |
| 615 | { |
| 616 | return skb->sk; |
| 617 | } |
| 618 | |
| 619 | struct request_sock *cookie_bpf_check(struct sock *sk, struct sk_buff *skb); |
| 620 | #else |
| 621 | static inline bool cookie_bpf_ok(struct sk_buff *skb) |
| 622 | { |
| 623 | return false; |
| 624 | } |
| 625 | |
| 626 | static inline struct request_sock *cookie_bpf_check(struct net *net, struct sock *sk, |
| 627 | struct sk_buff *skb) |
| 628 | { |
| 629 | return NULL; |
| 630 | } |
| 631 | #endif |
| 632 | |
| 633 | /* From net/ipv6/syncookies.c */ |
| 634 | int __cookie_v6_check(const struct ipv6hdr *iph, const struct tcphdr *th); |
| 635 | struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb); |
| 636 | |
| 637 | u32 __cookie_v6_init_sequence(const struct ipv6hdr *iph, |
| 638 | const struct tcphdr *th, u16 *mssp); |
| 639 | __u32 cookie_v6_init_sequence(const struct sk_buff *skb, __u16 *mss); |
| 640 | #endif |
| 641 | /* tcp_output.c */ |
| 642 | |
| 643 | void tcp_skb_entail(struct sock *sk, struct sk_buff *skb); |
| 644 | void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb); |
| 645 | void __tcp_push_pending_frames(struct sock *sk, unsigned int cur_mss, |
| 646 | int nonagle); |
| 647 | int __tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs); |
| 648 | int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs); |
| 649 | void tcp_retransmit_timer(struct sock *sk); |
| 650 | void tcp_xmit_retransmit_queue(struct sock *); |
| 651 | void tcp_simple_retransmit(struct sock *); |
| 652 | void tcp_enter_recovery(struct sock *sk, bool ece_ack); |
| 653 | int tcp_trim_head(struct sock *, struct sk_buff *, u32); |
| 654 | enum tcp_queue { |
| 655 | TCP_FRAG_IN_WRITE_QUEUE, |
| 656 | TCP_FRAG_IN_RTX_QUEUE, |
| 657 | }; |
| 658 | int tcp_fragment(struct sock *sk, enum tcp_queue tcp_queue, |
| 659 | struct sk_buff *skb, u32 len, |
| 660 | unsigned int mss_now, gfp_t gfp); |
| 661 | |
| 662 | void tcp_send_probe0(struct sock *); |
| 663 | int tcp_write_wakeup(struct sock *, int mib); |
| 664 | void tcp_send_fin(struct sock *sk); |
| 665 | void tcp_send_active_reset(struct sock *sk, gfp_t priority, |
| 666 | enum sk_rst_reason reason); |
| 667 | int tcp_send_synack(struct sock *); |
| 668 | void tcp_push_one(struct sock *, unsigned int mss_now); |
| 669 | void __tcp_send_ack(struct sock *sk, u32 rcv_nxt); |
| 670 | void tcp_send_ack(struct sock *sk); |
| 671 | void tcp_send_delayed_ack(struct sock *sk); |
| 672 | void tcp_send_loss_probe(struct sock *sk); |
| 673 | bool tcp_schedule_loss_probe(struct sock *sk, bool advancing_rto); |
| 674 | void tcp_skb_collapse_tstamp(struct sk_buff *skb, |
| 675 | const struct sk_buff *next_skb); |
| 676 | |
| 677 | /* tcp_input.c */ |
| 678 | void tcp_rearm_rto(struct sock *sk); |
| 679 | void tcp_synack_rtt_meas(struct sock *sk, struct request_sock *req); |
| 680 | void tcp_done_with_error(struct sock *sk, int err); |
| 681 | void tcp_reset(struct sock *sk, struct sk_buff *skb); |
| 682 | void tcp_fin(struct sock *sk); |
| 683 | void tcp_check_space(struct sock *sk); |
| 684 | void tcp_sack_compress_send_ack(struct sock *sk); |
| 685 | |
| 686 | /* tcp_timer.c */ |
| 687 | void tcp_init_xmit_timers(struct sock *); |
| 688 | static inline void tcp_clear_xmit_timers(struct sock *sk) |
| 689 | { |
| 690 | if (hrtimer_try_to_cancel(&tcp_sk(sk)->pacing_timer) == 1) |
| 691 | __sock_put(sk); |
| 692 | |
| 693 | if (hrtimer_try_to_cancel(&tcp_sk(sk)->compressed_ack_timer) == 1) |
| 694 | __sock_put(sk); |
| 695 | |
| 696 | inet_csk_clear_xmit_timers(sk); |
| 697 | } |
| 698 | |
| 699 | unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu); |
| 700 | unsigned int tcp_current_mss(struct sock *sk); |
| 701 | u32 tcp_clamp_probe0_to_user_timeout(const struct sock *sk, u32 when); |
| 702 | |
| 703 | /* Bound MSS / TSO packet size with the half of the window */ |
| 704 | static inline int tcp_bound_to_half_wnd(struct tcp_sock *tp, int pktsize) |
| 705 | { |
| 706 | int cutoff; |
| 707 | |
| 708 | /* When peer uses tiny windows, there is no use in packetizing |
| 709 | * to sub-MSS pieces for the sake of SWS or making sure there |
| 710 | * are enough packets in the pipe for fast recovery. |
| 711 | * |
| 712 | * On the other hand, for extremely large MSS devices, handling |
| 713 | * smaller than MSS windows in this way does make sense. |
| 714 | */ |
| 715 | if (tp->max_window > TCP_MSS_DEFAULT) |
| 716 | cutoff = (tp->max_window >> 1); |
| 717 | else |
| 718 | cutoff = tp->max_window; |
| 719 | |
| 720 | if (cutoff && pktsize > cutoff) |
| 721 | return max_t(int, cutoff, 68U - tp->tcp_header_len); |
| 722 | else |
| 723 | return pktsize; |
| 724 | } |
| 725 | |
| 726 | /* tcp.c */ |
| 727 | void tcp_get_info(struct sock *, struct tcp_info *); |
| 728 | |
| 729 | /* Read 'sendfile()'-style from a TCP socket */ |
| 730 | int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, |
| 731 | sk_read_actor_t recv_actor); |
| 732 | int tcp_read_skb(struct sock *sk, skb_read_actor_t recv_actor); |
| 733 | struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off); |
| 734 | void tcp_read_done(struct sock *sk, size_t len); |
| 735 | |
| 736 | void tcp_initialize_rcv_mss(struct sock *sk); |
| 737 | |
| 738 | int tcp_mtu_to_mss(struct sock *sk, int pmtu); |
| 739 | int tcp_mss_to_mtu(struct sock *sk, int mss); |
| 740 | void tcp_mtup_init(struct sock *sk); |
| 741 | |
| 742 | static inline void tcp_bound_rto(struct sock *sk) |
| 743 | { |
| 744 | if (inet_csk(sk)->icsk_rto > TCP_RTO_MAX) |
| 745 | inet_csk(sk)->icsk_rto = TCP_RTO_MAX; |
| 746 | } |
| 747 | |
| 748 | static inline u32 __tcp_set_rto(const struct tcp_sock *tp) |
| 749 | { |
| 750 | return usecs_to_jiffies((tp->srtt_us >> 3) + tp->rttvar_us); |
| 751 | } |
| 752 | |
| 753 | static inline void __tcp_fast_path_on(struct tcp_sock *tp, u32 snd_wnd) |
| 754 | { |
| 755 | /* mptcp hooks are only on the slow path */ |
| 756 | if (sk_is_mptcp((struct sock *)tp)) |
| 757 | return; |
| 758 | |
| 759 | tp->pred_flags = htonl((tp->tcp_header_len << 26) | |
| 760 | ntohl(TCP_FLAG_ACK) | |
| 761 | snd_wnd); |
| 762 | } |
| 763 | |
| 764 | static inline void tcp_fast_path_on(struct tcp_sock *tp) |
| 765 | { |
| 766 | __tcp_fast_path_on(tp, tp->snd_wnd >> tp->rx_opt.snd_wscale); |
| 767 | } |
| 768 | |
| 769 | static inline void tcp_fast_path_check(struct sock *sk) |
| 770 | { |
| 771 | struct tcp_sock *tp = tcp_sk(sk); |
| 772 | |
| 773 | if (RB_EMPTY_ROOT(&tp->out_of_order_queue) && |
| 774 | tp->rcv_wnd && |
| 775 | atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf && |
| 776 | !tp->urg_data) |
| 777 | tcp_fast_path_on(tp); |
| 778 | } |
| 779 | |
| 780 | u32 tcp_delack_max(const struct sock *sk); |
| 781 | |
| 782 | /* Compute the actual rto_min value */ |
| 783 | static inline u32 tcp_rto_min(const struct sock *sk) |
| 784 | { |
| 785 | const struct dst_entry *dst = __sk_dst_get(sk); |
| 786 | u32 rto_min = inet_csk(sk)->icsk_rto_min; |
| 787 | |
| 788 | if (dst && dst_metric_locked(dst, RTAX_RTO_MIN)) |
| 789 | rto_min = dst_metric_rtt(dst, RTAX_RTO_MIN); |
| 790 | return rto_min; |
| 791 | } |
| 792 | |
| 793 | static inline u32 tcp_rto_min_us(const struct sock *sk) |
| 794 | { |
| 795 | return jiffies_to_usecs(tcp_rto_min(sk)); |
| 796 | } |
| 797 | |
| 798 | static inline bool tcp_ca_dst_locked(const struct dst_entry *dst) |
| 799 | { |
| 800 | return dst_metric_locked(dst, RTAX_CC_ALGO); |
| 801 | } |
| 802 | |
| 803 | /* Minimum RTT in usec. ~0 means not available. */ |
| 804 | static inline u32 tcp_min_rtt(const struct tcp_sock *tp) |
| 805 | { |
| 806 | return minmax_get(&tp->rtt_min); |
| 807 | } |
| 808 | |
| 809 | /* Compute the actual receive window we are currently advertising. |
| 810 | * Rcv_nxt can be after the window if our peer push more data |
| 811 | * than the offered window. |
| 812 | */ |
| 813 | static inline u32 tcp_receive_window(const struct tcp_sock *tp) |
| 814 | { |
| 815 | s32 win = tp->rcv_wup + tp->rcv_wnd - tp->rcv_nxt; |
| 816 | |
| 817 | if (win < 0) |
| 818 | win = 0; |
| 819 | return (u32) win; |
| 820 | } |
| 821 | |
| 822 | /* Choose a new window, without checks for shrinking, and without |
| 823 | * scaling applied to the result. The caller does these things |
| 824 | * if necessary. This is a "raw" window selection. |
| 825 | */ |
| 826 | u32 __tcp_select_window(struct sock *sk); |
| 827 | |
| 828 | void tcp_send_window_probe(struct sock *sk); |
| 829 | |
| 830 | /* TCP uses 32bit jiffies to save some space. |
| 831 | * Note that this is different from tcp_time_stamp, which |
| 832 | * historically has been the same until linux-4.13. |
| 833 | */ |
| 834 | #define tcp_jiffies32 ((u32)jiffies) |
| 835 | |
| 836 | /* |
| 837 | * Deliver a 32bit value for TCP timestamp option (RFC 7323) |
| 838 | * It is no longer tied to jiffies, but to 1 ms clock. |
| 839 | * Note: double check if you want to use tcp_jiffies32 instead of this. |
| 840 | */ |
| 841 | #define TCP_TS_HZ 1000 |
| 842 | |
| 843 | static inline u64 tcp_clock_ns(void) |
| 844 | { |
| 845 | return ktime_get_ns(); |
| 846 | } |
| 847 | |
| 848 | static inline u64 tcp_clock_us(void) |
| 849 | { |
| 850 | return div_u64(tcp_clock_ns(), NSEC_PER_USEC); |
| 851 | } |
| 852 | |
| 853 | static inline u64 tcp_clock_ms(void) |
| 854 | { |
| 855 | return div_u64(tcp_clock_ns(), NSEC_PER_MSEC); |
| 856 | } |
| 857 | |
| 858 | /* TCP Timestamp included in TS option (RFC 1323) can either use ms |
| 859 | * or usec resolution. Each socket carries a flag to select one or other |
| 860 | * resolution, as the route attribute could change anytime. |
| 861 | * Each flow must stick to initial resolution. |
| 862 | */ |
| 863 | static inline u32 tcp_clock_ts(bool usec_ts) |
| 864 | { |
| 865 | return usec_ts ? tcp_clock_us() : tcp_clock_ms(); |
| 866 | } |
| 867 | |
| 868 | static inline u32 tcp_time_stamp_ms(const struct tcp_sock *tp) |
| 869 | { |
| 870 | return div_u64(tp->tcp_mstamp, USEC_PER_MSEC); |
| 871 | } |
| 872 | |
| 873 | static inline u32 tcp_time_stamp_ts(const struct tcp_sock *tp) |
| 874 | { |
| 875 | if (tp->tcp_usec_ts) |
| 876 | return tp->tcp_mstamp; |
| 877 | return tcp_time_stamp_ms(tp); |
| 878 | } |
| 879 | |
| 880 | void tcp_mstamp_refresh(struct tcp_sock *tp); |
| 881 | |
| 882 | static inline u32 tcp_stamp_us_delta(u64 t1, u64 t0) |
| 883 | { |
| 884 | return max_t(s64, t1 - t0, 0); |
| 885 | } |
| 886 | |
| 887 | /* provide the departure time in us unit */ |
| 888 | static inline u64 tcp_skb_timestamp_us(const struct sk_buff *skb) |
| 889 | { |
| 890 | return div_u64(skb->skb_mstamp_ns, NSEC_PER_USEC); |
| 891 | } |
| 892 | |
| 893 | /* Provide skb TSval in usec or ms unit */ |
| 894 | static inline u32 tcp_skb_timestamp_ts(bool usec_ts, const struct sk_buff *skb) |
| 895 | { |
| 896 | if (usec_ts) |
| 897 | return tcp_skb_timestamp_us(skb); |
| 898 | |
| 899 | return div_u64(skb->skb_mstamp_ns, NSEC_PER_MSEC); |
| 900 | } |
| 901 | |
| 902 | static inline u32 tcp_tw_tsval(const struct tcp_timewait_sock *tcptw) |
| 903 | { |
| 904 | return tcp_clock_ts(tcptw->tw_sk.tw_usec_ts) + tcptw->tw_ts_offset; |
| 905 | } |
| 906 | |
| 907 | static inline u32 tcp_rsk_tsval(const struct tcp_request_sock *treq) |
| 908 | { |
| 909 | return tcp_clock_ts(treq->req_usec_ts) + treq->ts_off; |
| 910 | } |
| 911 | |
| 912 | #define tcp_flag_byte(th) (((u_int8_t *)th)[13]) |
| 913 | |
| 914 | #define TCPHDR_FIN 0x01 |
| 915 | #define TCPHDR_SYN 0x02 |
| 916 | #define TCPHDR_RST 0x04 |
| 917 | #define TCPHDR_PSH 0x08 |
| 918 | #define TCPHDR_ACK 0x10 |
| 919 | #define TCPHDR_URG 0x20 |
| 920 | #define TCPHDR_ECE 0x40 |
| 921 | #define TCPHDR_CWR 0x80 |
| 922 | |
| 923 | #define TCPHDR_SYN_ECN (TCPHDR_SYN | TCPHDR_ECE | TCPHDR_CWR) |
| 924 | |
| 925 | /* State flags for sacked in struct tcp_skb_cb */ |
| 926 | enum tcp_skb_cb_sacked_flags { |
| 927 | TCPCB_SACKED_ACKED = (1 << 0), /* SKB ACK'd by a SACK block */ |
| 928 | TCPCB_SACKED_RETRANS = (1 << 1), /* SKB retransmitted */ |
| 929 | TCPCB_LOST = (1 << 2), /* SKB is lost */ |
| 930 | TCPCB_TAGBITS = (TCPCB_SACKED_ACKED | TCPCB_SACKED_RETRANS | |
| 931 | TCPCB_LOST), /* All tag bits */ |
| 932 | TCPCB_REPAIRED = (1 << 4), /* SKB repaired (no skb_mstamp_ns) */ |
| 933 | TCPCB_EVER_RETRANS = (1 << 7), /* Ever retransmitted frame */ |
| 934 | TCPCB_RETRANS = (TCPCB_SACKED_RETRANS | TCPCB_EVER_RETRANS | |
| 935 | TCPCB_REPAIRED), |
| 936 | }; |
| 937 | |
| 938 | /* This is what the send packet queuing engine uses to pass |
| 939 | * TCP per-packet control information to the transmission code. |
| 940 | * We also store the host-order sequence numbers in here too. |
| 941 | * This is 44 bytes if IPV6 is enabled. |
| 942 | * If this grows please adjust skbuff.h:skbuff->cb[xxx] size appropriately. |
| 943 | */ |
| 944 | struct tcp_skb_cb { |
| 945 | __u32 seq; /* Starting sequence number */ |
| 946 | __u32 end_seq; /* SEQ + FIN + SYN + datalen */ |
| 947 | union { |
| 948 | /* Note : |
| 949 | * tcp_gso_segs/size are used in write queue only, |
| 950 | * cf tcp_skb_pcount()/tcp_skb_mss() |
| 951 | */ |
| 952 | struct { |
| 953 | u16 tcp_gso_segs; |
| 954 | u16 tcp_gso_size; |
| 955 | }; |
| 956 | }; |
| 957 | __u8 tcp_flags; /* TCP header flags. (tcp[13]) */ |
| 958 | |
| 959 | __u8 sacked; /* State flags for SACK. */ |
| 960 | __u8 ip_dsfield; /* IPv4 tos or IPv6 dsfield */ |
| 961 | __u8 txstamp_ack:1, /* Record TX timestamp for ack? */ |
| 962 | eor:1, /* Is skb MSG_EOR marked? */ |
| 963 | has_rxtstamp:1, /* SKB has a RX timestamp */ |
| 964 | unused:5; |
| 965 | __u32 ack_seq; /* Sequence number ACK'd */ |
| 966 | union { |
| 967 | struct { |
| 968 | #define TCPCB_DELIVERED_CE_MASK ((1U<<20) - 1) |
| 969 | /* There is space for up to 24 bytes */ |
| 970 | __u32 is_app_limited:1, /* cwnd not fully used? */ |
| 971 | delivered_ce:20, |
| 972 | unused:11; |
| 973 | /* pkts S/ACKed so far upon tx of skb, incl retrans: */ |
| 974 | __u32 delivered; |
| 975 | /* start of send pipeline phase */ |
| 976 | u64 first_tx_mstamp; |
| 977 | /* when we reached the "delivered" count */ |
| 978 | u64 delivered_mstamp; |
| 979 | } tx; /* only used for outgoing skbs */ |
| 980 | union { |
| 981 | struct inet_skb_parm h4; |
| 982 | #if IS_ENABLED(CONFIG_IPV6) |
| 983 | struct inet6_skb_parm h6; |
| 984 | #endif |
| 985 | } header; /* For incoming skbs */ |
| 986 | }; |
| 987 | }; |
| 988 | |
| 989 | #define TCP_SKB_CB(__skb) ((struct tcp_skb_cb *)&((__skb)->cb[0])) |
| 990 | |
| 991 | extern const struct inet_connection_sock_af_ops ipv4_specific; |
| 992 | |
| 993 | #if IS_ENABLED(CONFIG_IPV6) |
| 994 | /* This is the variant of inet6_iif() that must be used by TCP, |
| 995 | * as TCP moves IP6CB into a different location in skb->cb[] |
| 996 | */ |
| 997 | static inline int tcp_v6_iif(const struct sk_buff *skb) |
| 998 | { |
| 999 | return TCP_SKB_CB(skb)->header.h6.iif; |
| 1000 | } |
| 1001 | |
| 1002 | static inline int tcp_v6_iif_l3_slave(const struct sk_buff *skb) |
| 1003 | { |
| 1004 | bool l3_slave = ipv6_l3mdev_skb(TCP_SKB_CB(skb)->header.h6.flags); |
| 1005 | |
| 1006 | return l3_slave ? skb->skb_iif : TCP_SKB_CB(skb)->header.h6.iif; |
| 1007 | } |
| 1008 | |
| 1009 | /* TCP_SKB_CB reference means this can not be used from early demux */ |
| 1010 | static inline int tcp_v6_sdif(const struct sk_buff *skb) |
| 1011 | { |
| 1012 | #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV) |
| 1013 | if (skb && ipv6_l3mdev_skb(TCP_SKB_CB(skb)->header.h6.flags)) |
| 1014 | return TCP_SKB_CB(skb)->header.h6.iif; |
| 1015 | #endif |
| 1016 | return 0; |
| 1017 | } |
| 1018 | |
| 1019 | extern const struct inet_connection_sock_af_ops ipv6_specific; |
| 1020 | |
| 1021 | INDIRECT_CALLABLE_DECLARE(void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb)); |
| 1022 | INDIRECT_CALLABLE_DECLARE(int tcp_v6_rcv(struct sk_buff *skb)); |
| 1023 | void tcp_v6_early_demux(struct sk_buff *skb); |
| 1024 | |
| 1025 | #endif |
| 1026 | |
| 1027 | /* TCP_SKB_CB reference means this can not be used from early demux */ |
| 1028 | static inline int tcp_v4_sdif(struct sk_buff *skb) |
| 1029 | { |
| 1030 | #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV) |
| 1031 | if (skb && ipv4_l3mdev_skb(TCP_SKB_CB(skb)->header.h4.flags)) |
| 1032 | return TCP_SKB_CB(skb)->header.h4.iif; |
| 1033 | #endif |
| 1034 | return 0; |
| 1035 | } |
| 1036 | |
| 1037 | /* Due to TSO, an SKB can be composed of multiple actual |
| 1038 | * packets. To keep these tracked properly, we use this. |
| 1039 | */ |
| 1040 | static inline int tcp_skb_pcount(const struct sk_buff *skb) |
| 1041 | { |
| 1042 | return TCP_SKB_CB(skb)->tcp_gso_segs; |
| 1043 | } |
| 1044 | |
| 1045 | static inline void tcp_skb_pcount_set(struct sk_buff *skb, int segs) |
| 1046 | { |
| 1047 | TCP_SKB_CB(skb)->tcp_gso_segs = segs; |
| 1048 | } |
| 1049 | |
| 1050 | static inline void tcp_skb_pcount_add(struct sk_buff *skb, int segs) |
| 1051 | { |
| 1052 | TCP_SKB_CB(skb)->tcp_gso_segs += segs; |
| 1053 | } |
| 1054 | |
| 1055 | /* This is valid iff skb is in write queue and tcp_skb_pcount() > 1. */ |
| 1056 | static inline int tcp_skb_mss(const struct sk_buff *skb) |
| 1057 | { |
| 1058 | return TCP_SKB_CB(skb)->tcp_gso_size; |
| 1059 | } |
| 1060 | |
| 1061 | static inline bool tcp_skb_can_collapse_to(const struct sk_buff *skb) |
| 1062 | { |
| 1063 | return likely(!TCP_SKB_CB(skb)->eor); |
| 1064 | } |
| 1065 | |
| 1066 | static inline bool tcp_skb_can_collapse(const struct sk_buff *to, |
| 1067 | const struct sk_buff *from) |
| 1068 | { |
| 1069 | /* skb_cmp_decrypted() not needed, use tcp_write_collapse_fence() */ |
| 1070 | return likely(tcp_skb_can_collapse_to(to) && |
| 1071 | mptcp_skb_can_collapse(to, from) && |
| 1072 | skb_pure_zcopy_same(to, from)); |
| 1073 | } |
| 1074 | |
| 1075 | static inline bool tcp_skb_can_collapse_rx(const struct sk_buff *to, |
| 1076 | const struct sk_buff *from) |
| 1077 | { |
| 1078 | return likely(mptcp_skb_can_collapse(to, from) && |
| 1079 | !skb_cmp_decrypted(to, from)); |
| 1080 | } |
| 1081 | |
| 1082 | /* Events passed to congestion control interface */ |
| 1083 | enum tcp_ca_event { |
| 1084 | CA_EVENT_TX_START, /* first transmit when no packets in flight */ |
| 1085 | CA_EVENT_CWND_RESTART, /* congestion window restart */ |
| 1086 | CA_EVENT_COMPLETE_CWR, /* end of congestion recovery */ |
| 1087 | CA_EVENT_LOSS, /* loss timeout */ |
| 1088 | CA_EVENT_ECN_NO_CE, /* ECT set, but not CE marked */ |
| 1089 | CA_EVENT_ECN_IS_CE, /* received CE marked IP packet */ |
| 1090 | }; |
| 1091 | |
| 1092 | /* Information about inbound ACK, passed to cong_ops->in_ack_event() */ |
| 1093 | enum tcp_ca_ack_event_flags { |
| 1094 | CA_ACK_SLOWPATH = (1 << 0), /* In slow path processing */ |
| 1095 | CA_ACK_WIN_UPDATE = (1 << 1), /* ACK updated window */ |
| 1096 | CA_ACK_ECE = (1 << 2), /* ECE bit is set on ack */ |
| 1097 | }; |
| 1098 | |
| 1099 | /* |
| 1100 | * Interface for adding new TCP congestion control handlers |
| 1101 | */ |
| 1102 | #define TCP_CA_NAME_MAX 16 |
| 1103 | #define TCP_CA_MAX 128 |
| 1104 | #define TCP_CA_BUF_MAX (TCP_CA_NAME_MAX*TCP_CA_MAX) |
| 1105 | |
| 1106 | #define TCP_CA_UNSPEC 0 |
| 1107 | |
| 1108 | /* Algorithm can be set on socket without CAP_NET_ADMIN privileges */ |
| 1109 | #define TCP_CONG_NON_RESTRICTED 0x1 |
| 1110 | /* Requires ECN/ECT set on all packets */ |
| 1111 | #define TCP_CONG_NEEDS_ECN 0x2 |
| 1112 | #define TCP_CONG_MASK (TCP_CONG_NON_RESTRICTED | TCP_CONG_NEEDS_ECN) |
| 1113 | |
| 1114 | union tcp_cc_info; |
| 1115 | |
| 1116 | struct ack_sample { |
| 1117 | u32 pkts_acked; |
| 1118 | s32 rtt_us; |
| 1119 | u32 in_flight; |
| 1120 | }; |
| 1121 | |
| 1122 | /* A rate sample measures the number of (original/retransmitted) data |
| 1123 | * packets delivered "delivered" over an interval of time "interval_us". |
| 1124 | * The tcp_rate.c code fills in the rate sample, and congestion |
| 1125 | * control modules that define a cong_control function to run at the end |
| 1126 | * of ACK processing can optionally chose to consult this sample when |
| 1127 | * setting cwnd and pacing rate. |
| 1128 | * A sample is invalid if "delivered" or "interval_us" is negative. |
| 1129 | */ |
| 1130 | struct rate_sample { |
| 1131 | u64 prior_mstamp; /* starting timestamp for interval */ |
| 1132 | u32 prior_delivered; /* tp->delivered at "prior_mstamp" */ |
| 1133 | u32 prior_delivered_ce;/* tp->delivered_ce at "prior_mstamp" */ |
| 1134 | s32 delivered; /* number of packets delivered over interval */ |
| 1135 | s32 delivered_ce; /* number of packets delivered w/ CE marks*/ |
| 1136 | long interval_us; /* time for tp->delivered to incr "delivered" */ |
| 1137 | u32 snd_interval_us; /* snd interval for delivered packets */ |
| 1138 | u32 rcv_interval_us; /* rcv interval for delivered packets */ |
| 1139 | long rtt_us; /* RTT of last (S)ACKed packet (or -1) */ |
| 1140 | int losses; /* number of packets marked lost upon ACK */ |
| 1141 | u32 acked_sacked; /* number of packets newly (S)ACKed upon ACK */ |
| 1142 | u32 prior_in_flight; /* in flight before this ACK */ |
| 1143 | u32 last_end_seq; /* end_seq of most recently ACKed packet */ |
| 1144 | bool is_app_limited; /* is sample from packet with bubble in pipe? */ |
| 1145 | bool is_retrans; /* is sample from retransmission? */ |
| 1146 | bool is_ack_delayed; /* is this (likely) a delayed ACK? */ |
| 1147 | }; |
| 1148 | |
| 1149 | struct tcp_congestion_ops { |
| 1150 | /* fast path fields are put first to fill one cache line */ |
| 1151 | |
| 1152 | /* return slow start threshold (required) */ |
| 1153 | u32 (*ssthresh)(struct sock *sk); |
| 1154 | |
| 1155 | /* do new cwnd calculation (required) */ |
| 1156 | void (*cong_avoid)(struct sock *sk, u32 ack, u32 acked); |
| 1157 | |
| 1158 | /* call before changing ca_state (optional) */ |
| 1159 | void (*set_state)(struct sock *sk, u8 new_state); |
| 1160 | |
| 1161 | /* call when cwnd event occurs (optional) */ |
| 1162 | void (*cwnd_event)(struct sock *sk, enum tcp_ca_event ev); |
| 1163 | |
| 1164 | /* call when ack arrives (optional) */ |
| 1165 | void (*in_ack_event)(struct sock *sk, u32 flags); |
| 1166 | |
| 1167 | /* hook for packet ack accounting (optional) */ |
| 1168 | void (*pkts_acked)(struct sock *sk, const struct ack_sample *sample); |
| 1169 | |
| 1170 | /* override sysctl_tcp_min_tso_segs */ |
| 1171 | u32 (*min_tso_segs)(struct sock *sk); |
| 1172 | |
| 1173 | /* call when packets are delivered to update cwnd and pacing rate, |
| 1174 | * after all the ca_state processing. (optional) |
| 1175 | */ |
| 1176 | void (*cong_control)(struct sock *sk, u32 ack, int flag, const struct rate_sample *rs); |
| 1177 | |
| 1178 | |
| 1179 | /* new value of cwnd after loss (required) */ |
| 1180 | u32 (*undo_cwnd)(struct sock *sk); |
| 1181 | /* returns the multiplier used in tcp_sndbuf_expand (optional) */ |
| 1182 | u32 (*sndbuf_expand)(struct sock *sk); |
| 1183 | |
| 1184 | /* control/slow paths put last */ |
| 1185 | /* get info for inet_diag (optional) */ |
| 1186 | size_t (*get_info)(struct sock *sk, u32 ext, int *attr, |
| 1187 | union tcp_cc_info *info); |
| 1188 | |
| 1189 | char name[TCP_CA_NAME_MAX]; |
| 1190 | struct module *owner; |
| 1191 | struct list_head list; |
| 1192 | u32 key; |
| 1193 | u32 flags; |
| 1194 | |
| 1195 | /* initialize private data (optional) */ |
| 1196 | void (*init)(struct sock *sk); |
| 1197 | /* cleanup private data (optional) */ |
| 1198 | void (*release)(struct sock *sk); |
| 1199 | } ____cacheline_aligned_in_smp; |
| 1200 | |
| 1201 | int tcp_register_congestion_control(struct tcp_congestion_ops *type); |
| 1202 | void tcp_unregister_congestion_control(struct tcp_congestion_ops *type); |
| 1203 | int tcp_update_congestion_control(struct tcp_congestion_ops *type, |
| 1204 | struct tcp_congestion_ops *old_type); |
| 1205 | int tcp_validate_congestion_control(struct tcp_congestion_ops *ca); |
| 1206 | |
| 1207 | void tcp_assign_congestion_control(struct sock *sk); |
| 1208 | void tcp_init_congestion_control(struct sock *sk); |
| 1209 | void tcp_cleanup_congestion_control(struct sock *sk); |
| 1210 | int tcp_set_default_congestion_control(struct net *net, const char *name); |
| 1211 | void tcp_get_default_congestion_control(struct net *net, char *name); |
| 1212 | void tcp_get_available_congestion_control(char *buf, size_t len); |
| 1213 | void tcp_get_allowed_congestion_control(char *buf, size_t len); |
| 1214 | int tcp_set_allowed_congestion_control(char *allowed); |
| 1215 | int tcp_set_congestion_control(struct sock *sk, const char *name, bool load, |
| 1216 | bool cap_net_admin); |
| 1217 | u32 tcp_slow_start(struct tcp_sock *tp, u32 acked); |
| 1218 | void tcp_cong_avoid_ai(struct tcp_sock *tp, u32 w, u32 acked); |
| 1219 | |
| 1220 | u32 tcp_reno_ssthresh(struct sock *sk); |
| 1221 | u32 tcp_reno_undo_cwnd(struct sock *sk); |
| 1222 | void tcp_reno_cong_avoid(struct sock *sk, u32 ack, u32 acked); |
| 1223 | extern struct tcp_congestion_ops tcp_reno; |
| 1224 | |
| 1225 | struct tcp_congestion_ops *tcp_ca_find(const char *name); |
| 1226 | struct tcp_congestion_ops *tcp_ca_find_key(u32 key); |
| 1227 | u32 tcp_ca_get_key_by_name(const char *name, bool *ecn_ca); |
| 1228 | #ifdef CONFIG_INET |
| 1229 | char *tcp_ca_get_name_by_key(u32 key, char *buffer); |
| 1230 | #else |
| 1231 | static inline char *tcp_ca_get_name_by_key(u32 key, char *buffer) |
| 1232 | { |
| 1233 | return NULL; |
| 1234 | } |
| 1235 | #endif |
| 1236 | |
| 1237 | static inline bool tcp_ca_needs_ecn(const struct sock *sk) |
| 1238 | { |
| 1239 | const struct inet_connection_sock *icsk = inet_csk(sk); |
| 1240 | |
| 1241 | return icsk->icsk_ca_ops->flags & TCP_CONG_NEEDS_ECN; |
| 1242 | } |
| 1243 | |
| 1244 | static inline void tcp_ca_event(struct sock *sk, const enum tcp_ca_event event) |
| 1245 | { |
| 1246 | const struct inet_connection_sock *icsk = inet_csk(sk); |
| 1247 | |
| 1248 | if (icsk->icsk_ca_ops->cwnd_event) |
| 1249 | icsk->icsk_ca_ops->cwnd_event(sk, event); |
| 1250 | } |
| 1251 | |
| 1252 | /* From tcp_cong.c */ |
| 1253 | void tcp_set_ca_state(struct sock *sk, const u8 ca_state); |
| 1254 | |
| 1255 | /* From tcp_rate.c */ |
| 1256 | void tcp_rate_skb_sent(struct sock *sk, struct sk_buff *skb); |
| 1257 | void tcp_rate_skb_delivered(struct sock *sk, struct sk_buff *skb, |
| 1258 | struct rate_sample *rs); |
| 1259 | void tcp_rate_gen(struct sock *sk, u32 delivered, u32 lost, |
| 1260 | bool is_sack_reneg, struct rate_sample *rs); |
| 1261 | void tcp_rate_check_app_limited(struct sock *sk); |
| 1262 | |
| 1263 | static inline bool tcp_skb_sent_after(u64 t1, u64 t2, u32 seq1, u32 seq2) |
| 1264 | { |
| 1265 | return t1 > t2 || (t1 == t2 && after(seq1, seq2)); |
| 1266 | } |
| 1267 | |
| 1268 | /* These functions determine how the current flow behaves in respect of SACK |
| 1269 | * handling. SACK is negotiated with the peer, and therefore it can vary |
| 1270 | * between different flows. |
| 1271 | * |
| 1272 | * tcp_is_sack - SACK enabled |
| 1273 | * tcp_is_reno - No SACK |
| 1274 | */ |
| 1275 | static inline int tcp_is_sack(const struct tcp_sock *tp) |
| 1276 | { |
| 1277 | return likely(tp->rx_opt.sack_ok); |
| 1278 | } |
| 1279 | |
| 1280 | static inline bool tcp_is_reno(const struct tcp_sock *tp) |
| 1281 | { |
| 1282 | return !tcp_is_sack(tp); |
| 1283 | } |
| 1284 | |
| 1285 | static inline unsigned int tcp_left_out(const struct tcp_sock *tp) |
| 1286 | { |
| 1287 | return tp->sacked_out + tp->lost_out; |
| 1288 | } |
| 1289 | |
| 1290 | /* This determines how many packets are "in the network" to the best |
| 1291 | * of our knowledge. In many cases it is conservative, but where |
| 1292 | * detailed information is available from the receiver (via SACK |
| 1293 | * blocks etc.) we can make more aggressive calculations. |
| 1294 | * |
| 1295 | * Use this for decisions involving congestion control, use just |
| 1296 | * tp->packets_out to determine if the send queue is empty or not. |
| 1297 | * |
| 1298 | * Read this equation as: |
| 1299 | * |
| 1300 | * "Packets sent once on transmission queue" MINUS |
| 1301 | * "Packets left network, but not honestly ACKed yet" PLUS |
| 1302 | * "Packets fast retransmitted" |
| 1303 | */ |
| 1304 | static inline unsigned int tcp_packets_in_flight(const struct tcp_sock *tp) |
| 1305 | { |
| 1306 | return tp->packets_out - tcp_left_out(tp) + tp->retrans_out; |
| 1307 | } |
| 1308 | |
| 1309 | #define TCP_INFINITE_SSTHRESH 0x7fffffff |
| 1310 | |
| 1311 | static inline u32 tcp_snd_cwnd(const struct tcp_sock *tp) |
| 1312 | { |
| 1313 | return tp->snd_cwnd; |
| 1314 | } |
| 1315 | |
| 1316 | static inline void tcp_snd_cwnd_set(struct tcp_sock *tp, u32 val) |
| 1317 | { |
| 1318 | WARN_ON_ONCE((int)val <= 0); |
| 1319 | tp->snd_cwnd = val; |
| 1320 | } |
| 1321 | |
| 1322 | static inline bool tcp_in_slow_start(const struct tcp_sock *tp) |
| 1323 | { |
| 1324 | return tcp_snd_cwnd(tp) < tp->snd_ssthresh; |
| 1325 | } |
| 1326 | |
| 1327 | static inline bool tcp_in_initial_slowstart(const struct tcp_sock *tp) |
| 1328 | { |
| 1329 | return tp->snd_ssthresh >= TCP_INFINITE_SSTHRESH; |
| 1330 | } |
| 1331 | |
| 1332 | static inline bool tcp_in_cwnd_reduction(const struct sock *sk) |
| 1333 | { |
| 1334 | return (TCPF_CA_CWR | TCPF_CA_Recovery) & |
| 1335 | (1 << inet_csk(sk)->icsk_ca_state); |
| 1336 | } |
| 1337 | |
| 1338 | /* If cwnd > ssthresh, we may raise ssthresh to be half-way to cwnd. |
| 1339 | * The exception is cwnd reduction phase, when cwnd is decreasing towards |
| 1340 | * ssthresh. |
| 1341 | */ |
| 1342 | static inline __u32 tcp_current_ssthresh(const struct sock *sk) |
| 1343 | { |
| 1344 | const struct tcp_sock *tp = tcp_sk(sk); |
| 1345 | |
| 1346 | if (tcp_in_cwnd_reduction(sk)) |
| 1347 | return tp->snd_ssthresh; |
| 1348 | else |
| 1349 | return max(tp->snd_ssthresh, |
| 1350 | ((tcp_snd_cwnd(tp) >> 1) + |
| 1351 | (tcp_snd_cwnd(tp) >> 2))); |
| 1352 | } |
| 1353 | |
| 1354 | /* Use define here intentionally to get WARN_ON location shown at the caller */ |
| 1355 | #define tcp_verify_left_out(tp) WARN_ON(tcp_left_out(tp) > tp->packets_out) |
| 1356 | |
| 1357 | void tcp_enter_cwr(struct sock *sk); |
| 1358 | __u32 tcp_init_cwnd(const struct tcp_sock *tp, const struct dst_entry *dst); |
| 1359 | |
| 1360 | /* The maximum number of MSS of available cwnd for which TSO defers |
| 1361 | * sending if not using sysctl_tcp_tso_win_divisor. |
| 1362 | */ |
| 1363 | static inline __u32 tcp_max_tso_deferred_mss(const struct tcp_sock *tp) |
| 1364 | { |
| 1365 | return 3; |
| 1366 | } |
| 1367 | |
| 1368 | /* Returns end sequence number of the receiver's advertised window */ |
| 1369 | static inline u32 tcp_wnd_end(const struct tcp_sock *tp) |
| 1370 | { |
| 1371 | return tp->snd_una + tp->snd_wnd; |
| 1372 | } |
| 1373 | |
| 1374 | /* We follow the spirit of RFC2861 to validate cwnd but implement a more |
| 1375 | * flexible approach. The RFC suggests cwnd should not be raised unless |
| 1376 | * it was fully used previously. And that's exactly what we do in |
| 1377 | * congestion avoidance mode. But in slow start we allow cwnd to grow |
| 1378 | * as long as the application has used half the cwnd. |
| 1379 | * Example : |
| 1380 | * cwnd is 10 (IW10), but application sends 9 frames. |
| 1381 | * We allow cwnd to reach 18 when all frames are ACKed. |
| 1382 | * This check is safe because it's as aggressive as slow start which already |
| 1383 | * risks 100% overshoot. The advantage is that we discourage application to |
| 1384 | * either send more filler packets or data to artificially blow up the cwnd |
| 1385 | * usage, and allow application-limited process to probe bw more aggressively. |
| 1386 | */ |
| 1387 | static inline bool tcp_is_cwnd_limited(const struct sock *sk) |
| 1388 | { |
| 1389 | const struct tcp_sock *tp = tcp_sk(sk); |
| 1390 | |
| 1391 | if (tp->is_cwnd_limited) |
| 1392 | return true; |
| 1393 | |
| 1394 | /* If in slow start, ensure cwnd grows to twice what was ACKed. */ |
| 1395 | if (tcp_in_slow_start(tp)) |
| 1396 | return tcp_snd_cwnd(tp) < 2 * tp->max_packets_out; |
| 1397 | |
| 1398 | return false; |
| 1399 | } |
| 1400 | |
| 1401 | /* BBR congestion control needs pacing. |
| 1402 | * Same remark for SO_MAX_PACING_RATE. |
| 1403 | * sch_fq packet scheduler is efficiently handling pacing, |
| 1404 | * but is not always installed/used. |
| 1405 | * Return true if TCP stack should pace packets itself. |
| 1406 | */ |
| 1407 | static inline bool tcp_needs_internal_pacing(const struct sock *sk) |
| 1408 | { |
| 1409 | return smp_load_acquire(&sk->sk_pacing_status) == SK_PACING_NEEDED; |
| 1410 | } |
| 1411 | |
| 1412 | /* Estimates in how many jiffies next packet for this flow can be sent. |
| 1413 | * Scheduling a retransmit timer too early would be silly. |
| 1414 | */ |
| 1415 | static inline unsigned long tcp_pacing_delay(const struct sock *sk) |
| 1416 | { |
| 1417 | s64 delay = tcp_sk(sk)->tcp_wstamp_ns - tcp_sk(sk)->tcp_clock_cache; |
| 1418 | |
| 1419 | return delay > 0 ? nsecs_to_jiffies(delay) : 0; |
| 1420 | } |
| 1421 | |
| 1422 | static inline void tcp_reset_xmit_timer(struct sock *sk, |
| 1423 | const int what, |
| 1424 | unsigned long when, |
| 1425 | const unsigned long max_when) |
| 1426 | { |
| 1427 | inet_csk_reset_xmit_timer(sk, what, when + tcp_pacing_delay(sk), |
| 1428 | max_when); |
| 1429 | } |
| 1430 | |
| 1431 | /* Something is really bad, we could not queue an additional packet, |
| 1432 | * because qdisc is full or receiver sent a 0 window, or we are paced. |
| 1433 | * We do not want to add fuel to the fire, or abort too early, |
| 1434 | * so make sure the timer we arm now is at least 200ms in the future, |
| 1435 | * regardless of current icsk_rto value (as it could be ~2ms) |
| 1436 | */ |
| 1437 | static inline unsigned long tcp_probe0_base(const struct sock *sk) |
| 1438 | { |
| 1439 | return max_t(unsigned long, inet_csk(sk)->icsk_rto, TCP_RTO_MIN); |
| 1440 | } |
| 1441 | |
| 1442 | /* Variant of inet_csk_rto_backoff() used for zero window probes */ |
| 1443 | static inline unsigned long tcp_probe0_when(const struct sock *sk, |
| 1444 | unsigned long max_when) |
| 1445 | { |
| 1446 | u8 backoff = min_t(u8, ilog2(TCP_RTO_MAX / TCP_RTO_MIN) + 1, |
| 1447 | inet_csk(sk)->icsk_backoff); |
| 1448 | u64 when = (u64)tcp_probe0_base(sk) << backoff; |
| 1449 | |
| 1450 | return (unsigned long)min_t(u64, when, max_when); |
| 1451 | } |
| 1452 | |
| 1453 | static inline void tcp_check_probe_timer(struct sock *sk) |
| 1454 | { |
| 1455 | if (!tcp_sk(sk)->packets_out && !inet_csk(sk)->icsk_pending) |
| 1456 | tcp_reset_xmit_timer(sk, ICSK_TIME_PROBE0, |
| 1457 | tcp_probe0_base(sk), TCP_RTO_MAX); |
| 1458 | } |
| 1459 | |
| 1460 | static inline void tcp_init_wl(struct tcp_sock *tp, u32 seq) |
| 1461 | { |
| 1462 | tp->snd_wl1 = seq; |
| 1463 | } |
| 1464 | |
| 1465 | static inline void tcp_update_wl(struct tcp_sock *tp, u32 seq) |
| 1466 | { |
| 1467 | tp->snd_wl1 = seq; |
| 1468 | } |
| 1469 | |
| 1470 | /* |
| 1471 | * Calculate(/check) TCP checksum |
| 1472 | */ |
| 1473 | static inline __sum16 tcp_v4_check(int len, __be32 saddr, |
| 1474 | __be32 daddr, __wsum base) |
| 1475 | { |
| 1476 | return csum_tcpudp_magic(saddr, daddr, len, IPPROTO_TCP, base); |
| 1477 | } |
| 1478 | |
| 1479 | static inline bool tcp_checksum_complete(struct sk_buff *skb) |
| 1480 | { |
| 1481 | return !skb_csum_unnecessary(skb) && |
| 1482 | __skb_checksum_complete(skb); |
| 1483 | } |
| 1484 | |
| 1485 | bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb, |
| 1486 | enum skb_drop_reason *reason); |
| 1487 | |
| 1488 | |
| 1489 | int tcp_filter(struct sock *sk, struct sk_buff *skb); |
| 1490 | void tcp_set_state(struct sock *sk, int state); |
| 1491 | void tcp_done(struct sock *sk); |
| 1492 | int tcp_abort(struct sock *sk, int err); |
| 1493 | |
| 1494 | static inline void tcp_sack_reset(struct tcp_options_received *rx_opt) |
| 1495 | { |
| 1496 | rx_opt->dsack = 0; |
| 1497 | rx_opt->num_sacks = 0; |
| 1498 | } |
| 1499 | |
| 1500 | void tcp_cwnd_restart(struct sock *sk, s32 delta); |
| 1501 | |
| 1502 | static inline void tcp_slow_start_after_idle_check(struct sock *sk) |
| 1503 | { |
| 1504 | const struct tcp_congestion_ops *ca_ops = inet_csk(sk)->icsk_ca_ops; |
| 1505 | struct tcp_sock *tp = tcp_sk(sk); |
| 1506 | s32 delta; |
| 1507 | |
| 1508 | if (!READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_slow_start_after_idle) || |
| 1509 | tp->packets_out || ca_ops->cong_control) |
| 1510 | return; |
| 1511 | delta = tcp_jiffies32 - tp->lsndtime; |
| 1512 | if (delta > inet_csk(sk)->icsk_rto) |
| 1513 | tcp_cwnd_restart(sk, delta); |
| 1514 | } |
| 1515 | |
| 1516 | /* Determine a window scaling and initial window to offer. */ |
| 1517 | void tcp_select_initial_window(const struct sock *sk, int __space, |
| 1518 | __u32 mss, __u32 *rcv_wnd, |
| 1519 | __u32 *window_clamp, int wscale_ok, |
| 1520 | __u8 *rcv_wscale, __u32 init_rcv_wnd); |
| 1521 | |
| 1522 | static inline int __tcp_win_from_space(u8 scaling_ratio, int space) |
| 1523 | { |
| 1524 | s64 scaled_space = (s64)space * scaling_ratio; |
| 1525 | |
| 1526 | return scaled_space >> TCP_RMEM_TO_WIN_SCALE; |
| 1527 | } |
| 1528 | |
| 1529 | static inline int tcp_win_from_space(const struct sock *sk, int space) |
| 1530 | { |
| 1531 | return __tcp_win_from_space(tcp_sk(sk)->scaling_ratio, space); |
| 1532 | } |
| 1533 | |
| 1534 | /* inverse of __tcp_win_from_space() */ |
| 1535 | static inline int __tcp_space_from_win(u8 scaling_ratio, int win) |
| 1536 | { |
| 1537 | u64 val = (u64)win << TCP_RMEM_TO_WIN_SCALE; |
| 1538 | |
| 1539 | do_div(val, scaling_ratio); |
| 1540 | return val; |
| 1541 | } |
| 1542 | |
| 1543 | static inline int tcp_space_from_win(const struct sock *sk, int win) |
| 1544 | { |
| 1545 | return __tcp_space_from_win(tcp_sk(sk)->scaling_ratio, win); |
| 1546 | } |
| 1547 | |
| 1548 | /* Assume a 50% default for skb->len/skb->truesize ratio. |
| 1549 | * This may be adjusted later in tcp_measure_rcv_mss(). |
| 1550 | */ |
| 1551 | #define TCP_DEFAULT_SCALING_RATIO (1 << (TCP_RMEM_TO_WIN_SCALE - 1)) |
| 1552 | |
| 1553 | static inline void tcp_scaling_ratio_init(struct sock *sk) |
| 1554 | { |
| 1555 | tcp_sk(sk)->scaling_ratio = TCP_DEFAULT_SCALING_RATIO; |
| 1556 | } |
| 1557 | |
| 1558 | /* Note: caller must be prepared to deal with negative returns */ |
| 1559 | static inline int tcp_space(const struct sock *sk) |
| 1560 | { |
| 1561 | return tcp_win_from_space(sk, READ_ONCE(sk->sk_rcvbuf) - |
| 1562 | READ_ONCE(sk->sk_backlog.len) - |
| 1563 | atomic_read(&sk->sk_rmem_alloc)); |
| 1564 | } |
| 1565 | |
| 1566 | static inline int tcp_full_space(const struct sock *sk) |
| 1567 | { |
| 1568 | return tcp_win_from_space(sk, READ_ONCE(sk->sk_rcvbuf)); |
| 1569 | } |
| 1570 | |
| 1571 | static inline void __tcp_adjust_rcv_ssthresh(struct sock *sk, u32 new_ssthresh) |
| 1572 | { |
| 1573 | int unused_mem = sk_unused_reserved_mem(sk); |
| 1574 | struct tcp_sock *tp = tcp_sk(sk); |
| 1575 | |
| 1576 | tp->rcv_ssthresh = min(tp->rcv_ssthresh, new_ssthresh); |
| 1577 | if (unused_mem) |
| 1578 | tp->rcv_ssthresh = max_t(u32, tp->rcv_ssthresh, |
| 1579 | tcp_win_from_space(sk, unused_mem)); |
| 1580 | } |
| 1581 | |
| 1582 | static inline void tcp_adjust_rcv_ssthresh(struct sock *sk) |
| 1583 | { |
| 1584 | __tcp_adjust_rcv_ssthresh(sk, 4U * tcp_sk(sk)->advmss); |
| 1585 | } |
| 1586 | |
| 1587 | void tcp_cleanup_rbuf(struct sock *sk, int copied); |
| 1588 | void __tcp_cleanup_rbuf(struct sock *sk, int copied); |
| 1589 | |
| 1590 | |
| 1591 | /* We provision sk_rcvbuf around 200% of sk_rcvlowat. |
| 1592 | * If 87.5 % (7/8) of the space has been consumed, we want to override |
| 1593 | * SO_RCVLOWAT constraint, since we are receiving skbs with too small |
| 1594 | * len/truesize ratio. |
| 1595 | */ |
| 1596 | static inline bool tcp_rmem_pressure(const struct sock *sk) |
| 1597 | { |
| 1598 | int rcvbuf, threshold; |
| 1599 | |
| 1600 | if (tcp_under_memory_pressure(sk)) |
| 1601 | return true; |
| 1602 | |
| 1603 | rcvbuf = READ_ONCE(sk->sk_rcvbuf); |
| 1604 | threshold = rcvbuf - (rcvbuf >> 3); |
| 1605 | |
| 1606 | return atomic_read(&sk->sk_rmem_alloc) > threshold; |
| 1607 | } |
| 1608 | |
| 1609 | static inline bool tcp_epollin_ready(const struct sock *sk, int target) |
| 1610 | { |
| 1611 | const struct tcp_sock *tp = tcp_sk(sk); |
| 1612 | int avail = READ_ONCE(tp->rcv_nxt) - READ_ONCE(tp->copied_seq); |
| 1613 | |
| 1614 | if (avail <= 0) |
| 1615 | return false; |
| 1616 | |
| 1617 | return (avail >= target) || tcp_rmem_pressure(sk) || |
| 1618 | (tcp_receive_window(tp) <= inet_csk(sk)->icsk_ack.rcv_mss); |
| 1619 | } |
| 1620 | |
| 1621 | extern void tcp_openreq_init_rwin(struct request_sock *req, |
| 1622 | const struct sock *sk_listener, |
| 1623 | const struct dst_entry *dst); |
| 1624 | |
| 1625 | void tcp_enter_memory_pressure(struct sock *sk); |
| 1626 | void tcp_leave_memory_pressure(struct sock *sk); |
| 1627 | |
| 1628 | static inline int keepalive_intvl_when(const struct tcp_sock *tp) |
| 1629 | { |
| 1630 | struct net *net = sock_net((struct sock *)tp); |
| 1631 | int val; |
| 1632 | |
| 1633 | /* Paired with WRITE_ONCE() in tcp_sock_set_keepintvl() |
| 1634 | * and do_tcp_setsockopt(). |
| 1635 | */ |
| 1636 | val = READ_ONCE(tp->keepalive_intvl); |
| 1637 | |
| 1638 | return val ? : READ_ONCE(net->ipv4.sysctl_tcp_keepalive_intvl); |
| 1639 | } |
| 1640 | |
| 1641 | static inline int keepalive_time_when(const struct tcp_sock *tp) |
| 1642 | { |
| 1643 | struct net *net = sock_net((struct sock *)tp); |
| 1644 | int val; |
| 1645 | |
| 1646 | /* Paired with WRITE_ONCE() in tcp_sock_set_keepidle_locked() */ |
| 1647 | val = READ_ONCE(tp->keepalive_time); |
| 1648 | |
| 1649 | return val ? : READ_ONCE(net->ipv4.sysctl_tcp_keepalive_time); |
| 1650 | } |
| 1651 | |
| 1652 | static inline int keepalive_probes(const struct tcp_sock *tp) |
| 1653 | { |
| 1654 | struct net *net = sock_net((struct sock *)tp); |
| 1655 | int val; |
| 1656 | |
| 1657 | /* Paired with WRITE_ONCE() in tcp_sock_set_keepcnt() |
| 1658 | * and do_tcp_setsockopt(). |
| 1659 | */ |
| 1660 | val = READ_ONCE(tp->keepalive_probes); |
| 1661 | |
| 1662 | return val ? : READ_ONCE(net->ipv4.sysctl_tcp_keepalive_probes); |
| 1663 | } |
| 1664 | |
| 1665 | static inline u32 keepalive_time_elapsed(const struct tcp_sock *tp) |
| 1666 | { |
| 1667 | const struct inet_connection_sock *icsk = &tp->inet_conn; |
| 1668 | |
| 1669 | return min_t(u32, tcp_jiffies32 - icsk->icsk_ack.lrcvtime, |
| 1670 | tcp_jiffies32 - tp->rcv_tstamp); |
| 1671 | } |
| 1672 | |
| 1673 | static inline int tcp_fin_time(const struct sock *sk) |
| 1674 | { |
| 1675 | int fin_timeout = tcp_sk(sk)->linger2 ? : |
| 1676 | READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fin_timeout); |
| 1677 | const int rto = inet_csk(sk)->icsk_rto; |
| 1678 | |
| 1679 | if (fin_timeout < (rto << 2) - (rto >> 1)) |
| 1680 | fin_timeout = (rto << 2) - (rto >> 1); |
| 1681 | |
| 1682 | return fin_timeout; |
| 1683 | } |
| 1684 | |
| 1685 | static inline bool tcp_paws_check(const struct tcp_options_received *rx_opt, |
| 1686 | int paws_win) |
| 1687 | { |
| 1688 | if ((s32)(rx_opt->ts_recent - rx_opt->rcv_tsval) <= paws_win) |
| 1689 | return true; |
| 1690 | if (unlikely(!time_before32(ktime_get_seconds(), |
| 1691 | rx_opt->ts_recent_stamp + TCP_PAWS_WRAP))) |
| 1692 | return true; |
| 1693 | /* |
| 1694 | * Some OSes send SYN and SYNACK messages with tsval=0 tsecr=0, |
| 1695 | * then following tcp messages have valid values. Ignore 0 value, |
| 1696 | * or else 'negative' tsval might forbid us to accept their packets. |
| 1697 | */ |
| 1698 | if (!rx_opt->ts_recent) |
| 1699 | return true; |
| 1700 | return false; |
| 1701 | } |
| 1702 | |
| 1703 | static inline bool tcp_paws_reject(const struct tcp_options_received *rx_opt, |
| 1704 | int rst) |
| 1705 | { |
| 1706 | if (tcp_paws_check(rx_opt, 0)) |
| 1707 | return false; |
| 1708 | |
| 1709 | /* RST segments are not recommended to carry timestamp, |
| 1710 | and, if they do, it is recommended to ignore PAWS because |
| 1711 | "their cleanup function should take precedence over timestamps." |
| 1712 | Certainly, it is mistake. It is necessary to understand the reasons |
| 1713 | of this constraint to relax it: if peer reboots, clock may go |
| 1714 | out-of-sync and half-open connections will not be reset. |
| 1715 | Actually, the problem would be not existing if all |
| 1716 | the implementations followed draft about maintaining clock |
| 1717 | via reboots. Linux-2.2 DOES NOT! |
| 1718 | |
| 1719 | However, we can relax time bounds for RST segments to MSL. |
| 1720 | */ |
| 1721 | if (rst && !time_before32(ktime_get_seconds(), |
| 1722 | rx_opt->ts_recent_stamp + TCP_PAWS_MSL)) |
| 1723 | return false; |
| 1724 | return true; |
| 1725 | } |
| 1726 | |
| 1727 | bool tcp_oow_rate_limited(struct net *net, const struct sk_buff *skb, |
| 1728 | int mib_idx, u32 *last_oow_ack_time); |
| 1729 | |
| 1730 | static inline void tcp_mib_init(struct net *net) |
| 1731 | { |
| 1732 | /* See RFC 2012 */ |
| 1733 | TCP_ADD_STATS(net, TCP_MIB_RTOALGORITHM, 1); |
| 1734 | TCP_ADD_STATS(net, TCP_MIB_RTOMIN, TCP_RTO_MIN*1000/HZ); |
| 1735 | TCP_ADD_STATS(net, TCP_MIB_RTOMAX, TCP_RTO_MAX*1000/HZ); |
| 1736 | TCP_ADD_STATS(net, TCP_MIB_MAXCONN, -1); |
| 1737 | } |
| 1738 | |
| 1739 | /* from STCP */ |
| 1740 | static inline void tcp_clear_retrans_hints_partial(struct tcp_sock *tp) |
| 1741 | { |
| 1742 | tp->lost_skb_hint = NULL; |
| 1743 | } |
| 1744 | |
| 1745 | static inline void tcp_clear_all_retrans_hints(struct tcp_sock *tp) |
| 1746 | { |
| 1747 | tcp_clear_retrans_hints_partial(tp); |
| 1748 | tp->retransmit_skb_hint = NULL; |
| 1749 | } |
| 1750 | |
| 1751 | #define tcp_md5_addr tcp_ao_addr |
| 1752 | |
| 1753 | /* - key database */ |
| 1754 | struct tcp_md5sig_key { |
| 1755 | struct hlist_node node; |
| 1756 | u8 keylen; |
| 1757 | u8 family; /* AF_INET or AF_INET6 */ |
| 1758 | u8 prefixlen; |
| 1759 | u8 flags; |
| 1760 | union tcp_md5_addr addr; |
| 1761 | int l3index; /* set if key added with L3 scope */ |
| 1762 | u8 key[TCP_MD5SIG_MAXKEYLEN]; |
| 1763 | struct rcu_head rcu; |
| 1764 | }; |
| 1765 | |
| 1766 | /* - sock block */ |
| 1767 | struct tcp_md5sig_info { |
| 1768 | struct hlist_head head; |
| 1769 | struct rcu_head rcu; |
| 1770 | }; |
| 1771 | |
| 1772 | /* - pseudo header */ |
| 1773 | struct tcp4_pseudohdr { |
| 1774 | __be32 saddr; |
| 1775 | __be32 daddr; |
| 1776 | __u8 pad; |
| 1777 | __u8 protocol; |
| 1778 | __be16 len; |
| 1779 | }; |
| 1780 | |
| 1781 | struct tcp6_pseudohdr { |
| 1782 | struct in6_addr saddr; |
| 1783 | struct in6_addr daddr; |
| 1784 | __be32 len; |
| 1785 | __be32 protocol; /* including padding */ |
| 1786 | }; |
| 1787 | |
| 1788 | union tcp_md5sum_block { |
| 1789 | struct tcp4_pseudohdr ip4; |
| 1790 | #if IS_ENABLED(CONFIG_IPV6) |
| 1791 | struct tcp6_pseudohdr ip6; |
| 1792 | #endif |
| 1793 | }; |
| 1794 | |
| 1795 | /* |
| 1796 | * struct tcp_sigpool - per-CPU pool of ahash_requests |
| 1797 | * @scratch: per-CPU temporary area, that can be used between |
| 1798 | * tcp_sigpool_start() and tcp_sigpool_end() to perform |
| 1799 | * crypto request |
| 1800 | * @req: pre-allocated ahash request |
| 1801 | */ |
| 1802 | struct tcp_sigpool { |
| 1803 | void *scratch; |
| 1804 | struct ahash_request *req; |
| 1805 | }; |
| 1806 | |
| 1807 | int tcp_sigpool_alloc_ahash(const char *alg, size_t scratch_size); |
| 1808 | void tcp_sigpool_get(unsigned int id); |
| 1809 | void tcp_sigpool_release(unsigned int id); |
| 1810 | int tcp_sigpool_hash_skb_data(struct tcp_sigpool *hp, |
| 1811 | const struct sk_buff *skb, |
| 1812 | unsigned int header_len); |
| 1813 | |
| 1814 | /** |
| 1815 | * tcp_sigpool_start - disable bh and start using tcp_sigpool_ahash |
| 1816 | * @id: tcp_sigpool that was previously allocated by tcp_sigpool_alloc_ahash() |
| 1817 | * @c: returned tcp_sigpool for usage (uninitialized on failure) |
| 1818 | * |
| 1819 | * Returns 0 on success, error otherwise. |
| 1820 | */ |
| 1821 | int tcp_sigpool_start(unsigned int id, struct tcp_sigpool *c); |
| 1822 | /** |
| 1823 | * tcp_sigpool_end - enable bh and stop using tcp_sigpool |
| 1824 | * @c: tcp_sigpool context that was returned by tcp_sigpool_start() |
| 1825 | */ |
| 1826 | void tcp_sigpool_end(struct tcp_sigpool *c); |
| 1827 | size_t tcp_sigpool_algo(unsigned int id, char *buf, size_t buf_len); |
| 1828 | /* - functions */ |
| 1829 | int tcp_v4_md5_hash_skb(char *md5_hash, const struct tcp_md5sig_key *key, |
| 1830 | const struct sock *sk, const struct sk_buff *skb); |
| 1831 | int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr, |
| 1832 | int family, u8 prefixlen, int l3index, u8 flags, |
| 1833 | const u8 *newkey, u8 newkeylen); |
| 1834 | int tcp_md5_key_copy(struct sock *sk, const union tcp_md5_addr *addr, |
| 1835 | int family, u8 prefixlen, int l3index, |
| 1836 | struct tcp_md5sig_key *key); |
| 1837 | |
| 1838 | int tcp_md5_do_del(struct sock *sk, const union tcp_md5_addr *addr, |
| 1839 | int family, u8 prefixlen, int l3index, u8 flags); |
| 1840 | void tcp_clear_md5_list(struct sock *sk); |
| 1841 | struct tcp_md5sig_key *tcp_v4_md5_lookup(const struct sock *sk, |
| 1842 | const struct sock *addr_sk); |
| 1843 | |
| 1844 | #ifdef CONFIG_TCP_MD5SIG |
| 1845 | struct tcp_md5sig_key *__tcp_md5_do_lookup(const struct sock *sk, int l3index, |
| 1846 | const union tcp_md5_addr *addr, |
| 1847 | int family, bool any_l3index); |
| 1848 | static inline struct tcp_md5sig_key * |
| 1849 | tcp_md5_do_lookup(const struct sock *sk, int l3index, |
| 1850 | const union tcp_md5_addr *addr, int family) |
| 1851 | { |
| 1852 | if (!static_branch_unlikely(&tcp_md5_needed.key)) |
| 1853 | return NULL; |
| 1854 | return __tcp_md5_do_lookup(sk, l3index, addr, family, false); |
| 1855 | } |
| 1856 | |
| 1857 | static inline struct tcp_md5sig_key * |
| 1858 | tcp_md5_do_lookup_any_l3index(const struct sock *sk, |
| 1859 | const union tcp_md5_addr *addr, int family) |
| 1860 | { |
| 1861 | if (!static_branch_unlikely(&tcp_md5_needed.key)) |
| 1862 | return NULL; |
| 1863 | return __tcp_md5_do_lookup(sk, 0, addr, family, true); |
| 1864 | } |
| 1865 | |
| 1866 | #define tcp_twsk_md5_key(twsk) ((twsk)->tw_md5_key) |
| 1867 | #else |
| 1868 | static inline struct tcp_md5sig_key * |
| 1869 | tcp_md5_do_lookup(const struct sock *sk, int l3index, |
| 1870 | const union tcp_md5_addr *addr, int family) |
| 1871 | { |
| 1872 | return NULL; |
| 1873 | } |
| 1874 | |
| 1875 | static inline struct tcp_md5sig_key * |
| 1876 | tcp_md5_do_lookup_any_l3index(const struct sock *sk, |
| 1877 | const union tcp_md5_addr *addr, int family) |
| 1878 | { |
| 1879 | return NULL; |
| 1880 | } |
| 1881 | |
| 1882 | #define tcp_twsk_md5_key(twsk) NULL |
| 1883 | #endif |
| 1884 | |
| 1885 | int tcp_md5_alloc_sigpool(void); |
| 1886 | void tcp_md5_release_sigpool(void); |
| 1887 | void tcp_md5_add_sigpool(void); |
| 1888 | extern int tcp_md5_sigpool_id; |
| 1889 | |
| 1890 | int tcp_md5_hash_key(struct tcp_sigpool *hp, |
| 1891 | const struct tcp_md5sig_key *key); |
| 1892 | |
| 1893 | /* From tcp_fastopen.c */ |
| 1894 | void tcp_fastopen_cache_get(struct sock *sk, u16 *mss, |
| 1895 | struct tcp_fastopen_cookie *cookie); |
| 1896 | void tcp_fastopen_cache_set(struct sock *sk, u16 mss, |
| 1897 | struct tcp_fastopen_cookie *cookie, bool syn_lost, |
| 1898 | u16 try_exp); |
| 1899 | struct tcp_fastopen_request { |
| 1900 | /* Fast Open cookie. Size 0 means a cookie request */ |
| 1901 | struct tcp_fastopen_cookie cookie; |
| 1902 | struct msghdr *data; /* data in MSG_FASTOPEN */ |
| 1903 | size_t size; |
| 1904 | int copied; /* queued in tcp_connect() */ |
| 1905 | struct ubuf_info *uarg; |
| 1906 | }; |
| 1907 | void tcp_free_fastopen_req(struct tcp_sock *tp); |
| 1908 | void tcp_fastopen_destroy_cipher(struct sock *sk); |
| 1909 | void tcp_fastopen_ctx_destroy(struct net *net); |
| 1910 | int tcp_fastopen_reset_cipher(struct net *net, struct sock *sk, |
| 1911 | void *primary_key, void *backup_key); |
| 1912 | int tcp_fastopen_get_cipher(struct net *net, struct inet_connection_sock *icsk, |
| 1913 | u64 *key); |
| 1914 | void tcp_fastopen_add_skb(struct sock *sk, struct sk_buff *skb); |
| 1915 | struct sock *tcp_try_fastopen(struct sock *sk, struct sk_buff *skb, |
| 1916 | struct request_sock *req, |
| 1917 | struct tcp_fastopen_cookie *foc, |
| 1918 | const struct dst_entry *dst); |
| 1919 | void tcp_fastopen_init_key_once(struct net *net); |
| 1920 | bool tcp_fastopen_cookie_check(struct sock *sk, u16 *mss, |
| 1921 | struct tcp_fastopen_cookie *cookie); |
| 1922 | bool tcp_fastopen_defer_connect(struct sock *sk, int *err); |
| 1923 | #define TCP_FASTOPEN_KEY_LENGTH sizeof(siphash_key_t) |
| 1924 | #define TCP_FASTOPEN_KEY_MAX 2 |
| 1925 | #define TCP_FASTOPEN_KEY_BUF_LENGTH \ |
| 1926 | (TCP_FASTOPEN_KEY_LENGTH * TCP_FASTOPEN_KEY_MAX) |
| 1927 | |
| 1928 | /* Fastopen key context */ |
| 1929 | struct tcp_fastopen_context { |
| 1930 | siphash_key_t key[TCP_FASTOPEN_KEY_MAX]; |
| 1931 | int num; |
| 1932 | struct rcu_head rcu; |
| 1933 | }; |
| 1934 | |
| 1935 | void tcp_fastopen_active_disable(struct sock *sk); |
| 1936 | bool tcp_fastopen_active_should_disable(struct sock *sk); |
| 1937 | void tcp_fastopen_active_disable_ofo_check(struct sock *sk); |
| 1938 | void tcp_fastopen_active_detect_blackhole(struct sock *sk, bool expired); |
| 1939 | |
| 1940 | /* Caller needs to wrap with rcu_read_(un)lock() */ |
| 1941 | static inline |
| 1942 | struct tcp_fastopen_context *tcp_fastopen_get_ctx(const struct sock *sk) |
| 1943 | { |
| 1944 | struct tcp_fastopen_context *ctx; |
| 1945 | |
| 1946 | ctx = rcu_dereference(inet_csk(sk)->icsk_accept_queue.fastopenq.ctx); |
| 1947 | if (!ctx) |
| 1948 | ctx = rcu_dereference(sock_net(sk)->ipv4.tcp_fastopen_ctx); |
| 1949 | return ctx; |
| 1950 | } |
| 1951 | |
| 1952 | static inline |
| 1953 | bool tcp_fastopen_cookie_match(const struct tcp_fastopen_cookie *foc, |
| 1954 | const struct tcp_fastopen_cookie *orig) |
| 1955 | { |
| 1956 | if (orig->len == TCP_FASTOPEN_COOKIE_SIZE && |
| 1957 | orig->len == foc->len && |
| 1958 | !memcmp(orig->val, foc->val, foc->len)) |
| 1959 | return true; |
| 1960 | return false; |
| 1961 | } |
| 1962 | |
| 1963 | static inline |
| 1964 | int tcp_fastopen_context_len(const struct tcp_fastopen_context *ctx) |
| 1965 | { |
| 1966 | return ctx->num; |
| 1967 | } |
| 1968 | |
| 1969 | /* Latencies incurred by various limits for a sender. They are |
| 1970 | * chronograph-like stats that are mutually exclusive. |
| 1971 | */ |
| 1972 | enum tcp_chrono { |
| 1973 | TCP_CHRONO_UNSPEC, |
| 1974 | TCP_CHRONO_BUSY, /* Actively sending data (non-empty write queue) */ |
| 1975 | TCP_CHRONO_RWND_LIMITED, /* Stalled by insufficient receive window */ |
| 1976 | TCP_CHRONO_SNDBUF_LIMITED, /* Stalled by insufficient send buffer */ |
| 1977 | __TCP_CHRONO_MAX, |
| 1978 | }; |
| 1979 | |
| 1980 | void tcp_chrono_start(struct sock *sk, const enum tcp_chrono type); |
| 1981 | void tcp_chrono_stop(struct sock *sk, const enum tcp_chrono type); |
| 1982 | |
| 1983 | /* This helper is needed, because skb->tcp_tsorted_anchor uses |
| 1984 | * the same memory storage than skb->destructor/_skb_refdst |
| 1985 | */ |
| 1986 | static inline void tcp_skb_tsorted_anchor_cleanup(struct sk_buff *skb) |
| 1987 | { |
| 1988 | skb->destructor = NULL; |
| 1989 | skb->_skb_refdst = 0UL; |
| 1990 | } |
| 1991 | |
| 1992 | #define tcp_skb_tsorted_save(skb) { \ |
| 1993 | unsigned long _save = skb->_skb_refdst; \ |
| 1994 | skb->_skb_refdst = 0UL; |
| 1995 | |
| 1996 | #define tcp_skb_tsorted_restore(skb) \ |
| 1997 | skb->_skb_refdst = _save; \ |
| 1998 | } |
| 1999 | |
| 2000 | void tcp_write_queue_purge(struct sock *sk); |
| 2001 | |
| 2002 | static inline struct sk_buff *tcp_rtx_queue_head(const struct sock *sk) |
| 2003 | { |
| 2004 | return skb_rb_first(&sk->tcp_rtx_queue); |
| 2005 | } |
| 2006 | |
| 2007 | static inline struct sk_buff *tcp_rtx_queue_tail(const struct sock *sk) |
| 2008 | { |
| 2009 | return skb_rb_last(&sk->tcp_rtx_queue); |
| 2010 | } |
| 2011 | |
| 2012 | static inline struct sk_buff *tcp_write_queue_tail(const struct sock *sk) |
| 2013 | { |
| 2014 | return skb_peek_tail(&sk->sk_write_queue); |
| 2015 | } |
| 2016 | |
| 2017 | #define tcp_for_write_queue_from_safe(skb, tmp, sk) \ |
| 2018 | skb_queue_walk_from_safe(&(sk)->sk_write_queue, skb, tmp) |
| 2019 | |
| 2020 | static inline struct sk_buff *tcp_send_head(const struct sock *sk) |
| 2021 | { |
| 2022 | return skb_peek(&sk->sk_write_queue); |
| 2023 | } |
| 2024 | |
| 2025 | static inline bool tcp_skb_is_last(const struct sock *sk, |
| 2026 | const struct sk_buff *skb) |
| 2027 | { |
| 2028 | return skb_queue_is_last(&sk->sk_write_queue, skb); |
| 2029 | } |
| 2030 | |
| 2031 | /** |
| 2032 | * tcp_write_queue_empty - test if any payload (or FIN) is available in write queue |
| 2033 | * @sk: socket |
| 2034 | * |
| 2035 | * Since the write queue can have a temporary empty skb in it, |
| 2036 | * we must not use "return skb_queue_empty(&sk->sk_write_queue)" |
| 2037 | */ |
| 2038 | static inline bool tcp_write_queue_empty(const struct sock *sk) |
| 2039 | { |
| 2040 | const struct tcp_sock *tp = tcp_sk(sk); |
| 2041 | |
| 2042 | return tp->write_seq == tp->snd_nxt; |
| 2043 | } |
| 2044 | |
| 2045 | static inline bool tcp_rtx_queue_empty(const struct sock *sk) |
| 2046 | { |
| 2047 | return RB_EMPTY_ROOT(&sk->tcp_rtx_queue); |
| 2048 | } |
| 2049 | |
| 2050 | static inline bool tcp_rtx_and_write_queues_empty(const struct sock *sk) |
| 2051 | { |
| 2052 | return tcp_rtx_queue_empty(sk) && tcp_write_queue_empty(sk); |
| 2053 | } |
| 2054 | |
| 2055 | static inline void tcp_add_write_queue_tail(struct sock *sk, struct sk_buff *skb) |
| 2056 | { |
| 2057 | __skb_queue_tail(&sk->sk_write_queue, skb); |
| 2058 | |
| 2059 | /* Queue it, remembering where we must start sending. */ |
| 2060 | if (sk->sk_write_queue.next == skb) |
| 2061 | tcp_chrono_start(sk, TCP_CHRONO_BUSY); |
| 2062 | } |
| 2063 | |
| 2064 | /* Insert new before skb on the write queue of sk. */ |
| 2065 | static inline void tcp_insert_write_queue_before(struct sk_buff *new, |
| 2066 | struct sk_buff *skb, |
| 2067 | struct sock *sk) |
| 2068 | { |
| 2069 | __skb_queue_before(&sk->sk_write_queue, skb, new); |
| 2070 | } |
| 2071 | |
| 2072 | static inline void tcp_unlink_write_queue(struct sk_buff *skb, struct sock *sk) |
| 2073 | { |
| 2074 | tcp_skb_tsorted_anchor_cleanup(skb); |
| 2075 | __skb_unlink(skb, &sk->sk_write_queue); |
| 2076 | } |
| 2077 | |
| 2078 | void tcp_rbtree_insert(struct rb_root *root, struct sk_buff *skb); |
| 2079 | |
| 2080 | static inline void tcp_rtx_queue_unlink(struct sk_buff *skb, struct sock *sk) |
| 2081 | { |
| 2082 | tcp_skb_tsorted_anchor_cleanup(skb); |
| 2083 | rb_erase(&skb->rbnode, &sk->tcp_rtx_queue); |
| 2084 | } |
| 2085 | |
| 2086 | static inline void tcp_rtx_queue_unlink_and_free(struct sk_buff *skb, struct sock *sk) |
| 2087 | { |
| 2088 | list_del(&skb->tcp_tsorted_anchor); |
| 2089 | tcp_rtx_queue_unlink(skb, sk); |
| 2090 | tcp_wmem_free_skb(sk, skb); |
| 2091 | } |
| 2092 | |
| 2093 | static inline void tcp_write_collapse_fence(struct sock *sk) |
| 2094 | { |
| 2095 | struct sk_buff *skb = tcp_write_queue_tail(sk); |
| 2096 | |
| 2097 | if (skb) |
| 2098 | TCP_SKB_CB(skb)->eor = 1; |
| 2099 | } |
| 2100 | |
| 2101 | static inline void tcp_push_pending_frames(struct sock *sk) |
| 2102 | { |
| 2103 | if (tcp_send_head(sk)) { |
| 2104 | struct tcp_sock *tp = tcp_sk(sk); |
| 2105 | |
| 2106 | __tcp_push_pending_frames(sk, tcp_current_mss(sk), tp->nonagle); |
| 2107 | } |
| 2108 | } |
| 2109 | |
| 2110 | /* Start sequence of the skb just after the highest skb with SACKed |
| 2111 | * bit, valid only if sacked_out > 0 or when the caller has ensured |
| 2112 | * validity by itself. |
| 2113 | */ |
| 2114 | static inline u32 tcp_highest_sack_seq(struct tcp_sock *tp) |
| 2115 | { |
| 2116 | if (!tp->sacked_out) |
| 2117 | return tp->snd_una; |
| 2118 | |
| 2119 | if (tp->highest_sack == NULL) |
| 2120 | return tp->snd_nxt; |
| 2121 | |
| 2122 | return TCP_SKB_CB(tp->highest_sack)->seq; |
| 2123 | } |
| 2124 | |
| 2125 | static inline void tcp_advance_highest_sack(struct sock *sk, struct sk_buff *skb) |
| 2126 | { |
| 2127 | tcp_sk(sk)->highest_sack = skb_rb_next(skb); |
| 2128 | } |
| 2129 | |
| 2130 | static inline struct sk_buff *tcp_highest_sack(struct sock *sk) |
| 2131 | { |
| 2132 | return tcp_sk(sk)->highest_sack; |
| 2133 | } |
| 2134 | |
| 2135 | static inline void tcp_highest_sack_reset(struct sock *sk) |
| 2136 | { |
| 2137 | tcp_sk(sk)->highest_sack = tcp_rtx_queue_head(sk); |
| 2138 | } |
| 2139 | |
| 2140 | /* Called when old skb is about to be deleted and replaced by new skb */ |
| 2141 | static inline void tcp_highest_sack_replace(struct sock *sk, |
| 2142 | struct sk_buff *old, |
| 2143 | struct sk_buff *new) |
| 2144 | { |
| 2145 | if (old == tcp_highest_sack(sk)) |
| 2146 | tcp_sk(sk)->highest_sack = new; |
| 2147 | } |
| 2148 | |
| 2149 | /* This helper checks if socket has IP_TRANSPARENT set */ |
| 2150 | static inline bool inet_sk_transparent(const struct sock *sk) |
| 2151 | { |
| 2152 | switch (sk->sk_state) { |
| 2153 | case TCP_TIME_WAIT: |
| 2154 | return inet_twsk(sk)->tw_transparent; |
| 2155 | case TCP_NEW_SYN_RECV: |
| 2156 | return inet_rsk(inet_reqsk(sk))->no_srccheck; |
| 2157 | } |
| 2158 | return inet_test_bit(TRANSPARENT, sk); |
| 2159 | } |
| 2160 | |
| 2161 | /* Determines whether this is a thin stream (which may suffer from |
| 2162 | * increased latency). Used to trigger latency-reducing mechanisms. |
| 2163 | */ |
| 2164 | static inline bool tcp_stream_is_thin(struct tcp_sock *tp) |
| 2165 | { |
| 2166 | return tp->packets_out < 4 && !tcp_in_initial_slowstart(tp); |
| 2167 | } |
| 2168 | |
| 2169 | /* /proc */ |
| 2170 | enum tcp_seq_states { |
| 2171 | TCP_SEQ_STATE_LISTENING, |
| 2172 | TCP_SEQ_STATE_ESTABLISHED, |
| 2173 | }; |
| 2174 | |
| 2175 | void *tcp_seq_start(struct seq_file *seq, loff_t *pos); |
| 2176 | void *tcp_seq_next(struct seq_file *seq, void *v, loff_t *pos); |
| 2177 | void tcp_seq_stop(struct seq_file *seq, void *v); |
| 2178 | |
| 2179 | struct tcp_seq_afinfo { |
| 2180 | sa_family_t family; |
| 2181 | }; |
| 2182 | |
| 2183 | struct tcp_iter_state { |
| 2184 | struct seq_net_private p; |
| 2185 | enum tcp_seq_states state; |
| 2186 | struct sock *syn_wait_sk; |
| 2187 | int bucket, offset, sbucket, num; |
| 2188 | loff_t last_pos; |
| 2189 | }; |
| 2190 | |
| 2191 | extern struct request_sock_ops tcp_request_sock_ops; |
| 2192 | extern struct request_sock_ops tcp6_request_sock_ops; |
| 2193 | |
| 2194 | void tcp_v4_destroy_sock(struct sock *sk); |
| 2195 | |
| 2196 | struct sk_buff *tcp_gso_segment(struct sk_buff *skb, |
| 2197 | netdev_features_t features); |
| 2198 | struct tcphdr *tcp_gro_pull_header(struct sk_buff *skb); |
| 2199 | struct sk_buff *tcp_gro_lookup(struct list_head *head, struct tcphdr *th); |
| 2200 | struct sk_buff *tcp_gro_receive(struct list_head *head, struct sk_buff *skb, |
| 2201 | struct tcphdr *th); |
| 2202 | INDIRECT_CALLABLE_DECLARE(int tcp4_gro_complete(struct sk_buff *skb, int thoff)); |
| 2203 | INDIRECT_CALLABLE_DECLARE(struct sk_buff *tcp4_gro_receive(struct list_head *head, struct sk_buff *skb)); |
| 2204 | INDIRECT_CALLABLE_DECLARE(int tcp6_gro_complete(struct sk_buff *skb, int thoff)); |
| 2205 | INDIRECT_CALLABLE_DECLARE(struct sk_buff *tcp6_gro_receive(struct list_head *head, struct sk_buff *skb)); |
| 2206 | #ifdef CONFIG_INET |
| 2207 | void tcp_gro_complete(struct sk_buff *skb); |
| 2208 | #else |
| 2209 | static inline void tcp_gro_complete(struct sk_buff *skb) { } |
| 2210 | #endif |
| 2211 | |
| 2212 | void __tcp_v4_send_check(struct sk_buff *skb, __be32 saddr, __be32 daddr); |
| 2213 | |
| 2214 | static inline u32 tcp_notsent_lowat(const struct tcp_sock *tp) |
| 2215 | { |
| 2216 | struct net *net = sock_net((struct sock *)tp); |
| 2217 | u32 val; |
| 2218 | |
| 2219 | val = READ_ONCE(tp->notsent_lowat); |
| 2220 | |
| 2221 | return val ?: READ_ONCE(net->ipv4.sysctl_tcp_notsent_lowat); |
| 2222 | } |
| 2223 | |
| 2224 | bool tcp_stream_memory_free(const struct sock *sk, int wake); |
| 2225 | |
| 2226 | #ifdef CONFIG_PROC_FS |
| 2227 | int tcp4_proc_init(void); |
| 2228 | void tcp4_proc_exit(void); |
| 2229 | #endif |
| 2230 | |
| 2231 | int tcp_rtx_synack(const struct sock *sk, struct request_sock *req); |
| 2232 | int tcp_conn_request(struct request_sock_ops *rsk_ops, |
| 2233 | const struct tcp_request_sock_ops *af_ops, |
| 2234 | struct sock *sk, struct sk_buff *skb); |
| 2235 | |
| 2236 | /* TCP af-specific functions */ |
| 2237 | struct tcp_sock_af_ops { |
| 2238 | #ifdef CONFIG_TCP_MD5SIG |
| 2239 | struct tcp_md5sig_key *(*md5_lookup) (const struct sock *sk, |
| 2240 | const struct sock *addr_sk); |
| 2241 | int (*calc_md5_hash)(char *location, |
| 2242 | const struct tcp_md5sig_key *md5, |
| 2243 | const struct sock *sk, |
| 2244 | const struct sk_buff *skb); |
| 2245 | int (*md5_parse)(struct sock *sk, |
| 2246 | int optname, |
| 2247 | sockptr_t optval, |
| 2248 | int optlen); |
| 2249 | #endif |
| 2250 | #ifdef CONFIG_TCP_AO |
| 2251 | int (*ao_parse)(struct sock *sk, int optname, sockptr_t optval, int optlen); |
| 2252 | struct tcp_ao_key *(*ao_lookup)(const struct sock *sk, |
| 2253 | struct sock *addr_sk, |
| 2254 | int sndid, int rcvid); |
| 2255 | int (*ao_calc_key_sk)(struct tcp_ao_key *mkt, u8 *key, |
| 2256 | const struct sock *sk, |
| 2257 | __be32 sisn, __be32 disn, bool send); |
| 2258 | int (*calc_ao_hash)(char *location, struct tcp_ao_key *ao, |
| 2259 | const struct sock *sk, const struct sk_buff *skb, |
| 2260 | const u8 *tkey, int hash_offset, u32 sne); |
| 2261 | #endif |
| 2262 | }; |
| 2263 | |
| 2264 | struct tcp_request_sock_ops { |
| 2265 | u16 mss_clamp; |
| 2266 | #ifdef CONFIG_TCP_MD5SIG |
| 2267 | struct tcp_md5sig_key *(*req_md5_lookup)(const struct sock *sk, |
| 2268 | const struct sock *addr_sk); |
| 2269 | int (*calc_md5_hash) (char *location, |
| 2270 | const struct tcp_md5sig_key *md5, |
| 2271 | const struct sock *sk, |
| 2272 | const struct sk_buff *skb); |
| 2273 | #endif |
| 2274 | #ifdef CONFIG_TCP_AO |
| 2275 | struct tcp_ao_key *(*ao_lookup)(const struct sock *sk, |
| 2276 | struct request_sock *req, |
| 2277 | int sndid, int rcvid); |
| 2278 | int (*ao_calc_key)(struct tcp_ao_key *mkt, u8 *key, struct request_sock *sk); |
| 2279 | int (*ao_synack_hash)(char *ao_hash, struct tcp_ao_key *mkt, |
| 2280 | struct request_sock *req, const struct sk_buff *skb, |
| 2281 | int hash_offset, u32 sne); |
| 2282 | #endif |
| 2283 | #ifdef CONFIG_SYN_COOKIES |
| 2284 | __u32 (*cookie_init_seq)(const struct sk_buff *skb, |
| 2285 | __u16 *mss); |
| 2286 | #endif |
| 2287 | struct dst_entry *(*route_req)(const struct sock *sk, |
| 2288 | struct sk_buff *skb, |
| 2289 | struct flowi *fl, |
| 2290 | struct request_sock *req, |
| 2291 | u32 tw_isn); |
| 2292 | u32 (*init_seq)(const struct sk_buff *skb); |
| 2293 | u32 (*init_ts_off)(const struct net *net, const struct sk_buff *skb); |
| 2294 | int (*send_synack)(const struct sock *sk, struct dst_entry *dst, |
| 2295 | struct flowi *fl, struct request_sock *req, |
| 2296 | struct tcp_fastopen_cookie *foc, |
| 2297 | enum tcp_synack_type synack_type, |
| 2298 | struct sk_buff *syn_skb); |
| 2299 | }; |
| 2300 | |
| 2301 | extern const struct tcp_request_sock_ops tcp_request_sock_ipv4_ops; |
| 2302 | #if IS_ENABLED(CONFIG_IPV6) |
| 2303 | extern const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops; |
| 2304 | #endif |
| 2305 | |
| 2306 | #ifdef CONFIG_SYN_COOKIES |
| 2307 | static inline __u32 cookie_init_sequence(const struct tcp_request_sock_ops *ops, |
| 2308 | const struct sock *sk, struct sk_buff *skb, |
| 2309 | __u16 *mss) |
| 2310 | { |
| 2311 | tcp_synq_overflow(sk); |
| 2312 | __NET_INC_STATS(sock_net(sk), LINUX_MIB_SYNCOOKIESSENT); |
| 2313 | return ops->cookie_init_seq(skb, mss); |
| 2314 | } |
| 2315 | #else |
| 2316 | static inline __u32 cookie_init_sequence(const struct tcp_request_sock_ops *ops, |
| 2317 | const struct sock *sk, struct sk_buff *skb, |
| 2318 | __u16 *mss) |
| 2319 | { |
| 2320 | return 0; |
| 2321 | } |
| 2322 | #endif |
| 2323 | |
| 2324 | struct tcp_key { |
| 2325 | union { |
| 2326 | struct { |
| 2327 | struct tcp_ao_key *ao_key; |
| 2328 | char *traffic_key; |
| 2329 | u32 sne; |
| 2330 | u8 rcv_next; |
| 2331 | }; |
| 2332 | struct tcp_md5sig_key *md5_key; |
| 2333 | }; |
| 2334 | enum { |
| 2335 | TCP_KEY_NONE = 0, |
| 2336 | TCP_KEY_MD5, |
| 2337 | TCP_KEY_AO, |
| 2338 | } type; |
| 2339 | }; |
| 2340 | |
| 2341 | static inline void tcp_get_current_key(const struct sock *sk, |
| 2342 | struct tcp_key *out) |
| 2343 | { |
| 2344 | #if defined(CONFIG_TCP_AO) || defined(CONFIG_TCP_MD5SIG) |
| 2345 | const struct tcp_sock *tp = tcp_sk(sk); |
| 2346 | #endif |
| 2347 | |
| 2348 | #ifdef CONFIG_TCP_AO |
| 2349 | if (static_branch_unlikely(&tcp_ao_needed.key)) { |
| 2350 | struct tcp_ao_info *ao; |
| 2351 | |
| 2352 | ao = rcu_dereference_protected(tp->ao_info, |
| 2353 | lockdep_sock_is_held(sk)); |
| 2354 | if (ao) { |
| 2355 | out->ao_key = READ_ONCE(ao->current_key); |
| 2356 | out->type = TCP_KEY_AO; |
| 2357 | return; |
| 2358 | } |
| 2359 | } |
| 2360 | #endif |
| 2361 | #ifdef CONFIG_TCP_MD5SIG |
| 2362 | if (static_branch_unlikely(&tcp_md5_needed.key) && |
| 2363 | rcu_access_pointer(tp->md5sig_info)) { |
| 2364 | out->md5_key = tp->af_specific->md5_lookup(sk, sk); |
| 2365 | if (out->md5_key) { |
| 2366 | out->type = TCP_KEY_MD5; |
| 2367 | return; |
| 2368 | } |
| 2369 | } |
| 2370 | #endif |
| 2371 | out->type = TCP_KEY_NONE; |
| 2372 | } |
| 2373 | |
| 2374 | static inline bool tcp_key_is_md5(const struct tcp_key *key) |
| 2375 | { |
| 2376 | if (static_branch_tcp_md5()) |
| 2377 | return key->type == TCP_KEY_MD5; |
| 2378 | return false; |
| 2379 | } |
| 2380 | |
| 2381 | static inline bool tcp_key_is_ao(const struct tcp_key *key) |
| 2382 | { |
| 2383 | if (static_branch_tcp_ao()) |
| 2384 | return key->type == TCP_KEY_AO; |
| 2385 | return false; |
| 2386 | } |
| 2387 | |
| 2388 | int tcpv4_offload_init(void); |
| 2389 | |
| 2390 | void tcp_v4_init(void); |
| 2391 | void tcp_init(void); |
| 2392 | |
| 2393 | /* tcp_recovery.c */ |
| 2394 | void tcp_mark_skb_lost(struct sock *sk, struct sk_buff *skb); |
| 2395 | void tcp_newreno_mark_lost(struct sock *sk, bool snd_una_advanced); |
| 2396 | extern s32 tcp_rack_skb_timeout(struct tcp_sock *tp, struct sk_buff *skb, |
| 2397 | u32 reo_wnd); |
| 2398 | extern bool tcp_rack_mark_lost(struct sock *sk); |
| 2399 | extern void tcp_rack_advance(struct tcp_sock *tp, u8 sacked, u32 end_seq, |
| 2400 | u64 xmit_time); |
| 2401 | extern void tcp_rack_reo_timeout(struct sock *sk); |
| 2402 | extern void tcp_rack_update_reo_wnd(struct sock *sk, struct rate_sample *rs); |
| 2403 | |
| 2404 | /* tcp_plb.c */ |
| 2405 | |
| 2406 | /* |
| 2407 | * Scaling factor for fractions in PLB. For example, tcp_plb_update_state |
| 2408 | * expects cong_ratio which represents fraction of traffic that experienced |
| 2409 | * congestion over a single RTT. In order to avoid floating point operations, |
| 2410 | * this fraction should be mapped to (1 << TCP_PLB_SCALE) and passed in. |
| 2411 | */ |
| 2412 | #define TCP_PLB_SCALE 8 |
| 2413 | |
| 2414 | /* State for PLB (Protective Load Balancing) for a single TCP connection. */ |
| 2415 | struct tcp_plb_state { |
| 2416 | u8 consec_cong_rounds:5, /* consecutive congested rounds */ |
| 2417 | unused:3; |
| 2418 | u32 pause_until; /* jiffies32 when PLB can resume rerouting */ |
| 2419 | }; |
| 2420 | |
| 2421 | static inline void tcp_plb_init(const struct sock *sk, |
| 2422 | struct tcp_plb_state *plb) |
| 2423 | { |
| 2424 | plb->consec_cong_rounds = 0; |
| 2425 | plb->pause_until = 0; |
| 2426 | } |
| 2427 | void tcp_plb_update_state(const struct sock *sk, struct tcp_plb_state *plb, |
| 2428 | const int cong_ratio); |
| 2429 | void tcp_plb_check_rehash(struct sock *sk, struct tcp_plb_state *plb); |
| 2430 | void tcp_plb_update_state_upon_rto(struct sock *sk, struct tcp_plb_state *plb); |
| 2431 | |
| 2432 | /* At how many usecs into the future should the RTO fire? */ |
| 2433 | static inline s64 tcp_rto_delta_us(const struct sock *sk) |
| 2434 | { |
| 2435 | const struct sk_buff *skb = tcp_rtx_queue_head(sk); |
| 2436 | u32 rto = inet_csk(sk)->icsk_rto; |
| 2437 | u64 rto_time_stamp_us = tcp_skb_timestamp_us(skb) + jiffies_to_usecs(rto); |
| 2438 | |
| 2439 | return rto_time_stamp_us - tcp_sk(sk)->tcp_mstamp; |
| 2440 | } |
| 2441 | |
| 2442 | /* |
| 2443 | * Save and compile IPv4 options, return a pointer to it |
| 2444 | */ |
| 2445 | static inline struct ip_options_rcu *tcp_v4_save_options(struct net *net, |
| 2446 | struct sk_buff *skb) |
| 2447 | { |
| 2448 | const struct ip_options *opt = &TCP_SKB_CB(skb)->header.h4.opt; |
| 2449 | struct ip_options_rcu *dopt = NULL; |
| 2450 | |
| 2451 | if (opt->optlen) { |
| 2452 | int opt_size = sizeof(*dopt) + opt->optlen; |
| 2453 | |
| 2454 | dopt = kmalloc(opt_size, GFP_ATOMIC); |
| 2455 | if (dopt && __ip_options_echo(net, &dopt->opt, skb, opt)) { |
| 2456 | kfree(dopt); |
| 2457 | dopt = NULL; |
| 2458 | } |
| 2459 | } |
| 2460 | return dopt; |
| 2461 | } |
| 2462 | |
| 2463 | /* locally generated TCP pure ACKs have skb->truesize == 2 |
| 2464 | * (check tcp_send_ack() in net/ipv4/tcp_output.c ) |
| 2465 | * This is much faster than dissecting the packet to find out. |
| 2466 | * (Think of GRE encapsulations, IPv4, IPv6, ...) |
| 2467 | */ |
| 2468 | static inline bool skb_is_tcp_pure_ack(const struct sk_buff *skb) |
| 2469 | { |
| 2470 | return skb->truesize == 2; |
| 2471 | } |
| 2472 | |
| 2473 | static inline void skb_set_tcp_pure_ack(struct sk_buff *skb) |
| 2474 | { |
| 2475 | skb->truesize = 2; |
| 2476 | } |
| 2477 | |
| 2478 | static inline int tcp_inq(struct sock *sk) |
| 2479 | { |
| 2480 | struct tcp_sock *tp = tcp_sk(sk); |
| 2481 | int answ; |
| 2482 | |
| 2483 | if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) { |
| 2484 | answ = 0; |
| 2485 | } else if (sock_flag(sk, SOCK_URGINLINE) || |
| 2486 | !tp->urg_data || |
| 2487 | before(tp->urg_seq, tp->copied_seq) || |
| 2488 | !before(tp->urg_seq, tp->rcv_nxt)) { |
| 2489 | |
| 2490 | answ = tp->rcv_nxt - tp->copied_seq; |
| 2491 | |
| 2492 | /* Subtract 1, if FIN was received */ |
| 2493 | if (answ && sock_flag(sk, SOCK_DONE)) |
| 2494 | answ--; |
| 2495 | } else { |
| 2496 | answ = tp->urg_seq - tp->copied_seq; |
| 2497 | } |
| 2498 | |
| 2499 | return answ; |
| 2500 | } |
| 2501 | |
| 2502 | int tcp_peek_len(struct socket *sock); |
| 2503 | |
| 2504 | static inline void tcp_segs_in(struct tcp_sock *tp, const struct sk_buff *skb) |
| 2505 | { |
| 2506 | u16 segs_in; |
| 2507 | |
| 2508 | segs_in = max_t(u16, 1, skb_shinfo(skb)->gso_segs); |
| 2509 | |
| 2510 | /* We update these fields while other threads might |
| 2511 | * read them from tcp_get_info() |
| 2512 | */ |
| 2513 | WRITE_ONCE(tp->segs_in, tp->segs_in + segs_in); |
| 2514 | if (skb->len > tcp_hdrlen(skb)) |
| 2515 | WRITE_ONCE(tp->data_segs_in, tp->data_segs_in + segs_in); |
| 2516 | } |
| 2517 | |
| 2518 | /* |
| 2519 | * TCP listen path runs lockless. |
| 2520 | * We forced "struct sock" to be const qualified to make sure |
| 2521 | * we don't modify one of its field by mistake. |
| 2522 | * Here, we increment sk_drops which is an atomic_t, so we can safely |
| 2523 | * make sock writable again. |
| 2524 | */ |
| 2525 | static inline void tcp_listendrop(const struct sock *sk) |
| 2526 | { |
| 2527 | atomic_inc(&((struct sock *)sk)->sk_drops); |
| 2528 | __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENDROPS); |
| 2529 | } |
| 2530 | |
| 2531 | enum hrtimer_restart tcp_pace_kick(struct hrtimer *timer); |
| 2532 | |
| 2533 | /* |
| 2534 | * Interface for adding Upper Level Protocols over TCP |
| 2535 | */ |
| 2536 | |
| 2537 | #define TCP_ULP_NAME_MAX 16 |
| 2538 | #define TCP_ULP_MAX 128 |
| 2539 | #define TCP_ULP_BUF_MAX (TCP_ULP_NAME_MAX*TCP_ULP_MAX) |
| 2540 | |
| 2541 | struct tcp_ulp_ops { |
| 2542 | struct list_head list; |
| 2543 | |
| 2544 | /* initialize ulp */ |
| 2545 | int (*init)(struct sock *sk); |
| 2546 | /* update ulp */ |
| 2547 | void (*update)(struct sock *sk, struct proto *p, |
| 2548 | void (*write_space)(struct sock *sk)); |
| 2549 | /* cleanup ulp */ |
| 2550 | void (*release)(struct sock *sk); |
| 2551 | /* diagnostic */ |
| 2552 | int (*get_info)(struct sock *sk, struct sk_buff *skb); |
| 2553 | size_t (*get_info_size)(const struct sock *sk); |
| 2554 | /* clone ulp */ |
| 2555 | void (*clone)(const struct request_sock *req, struct sock *newsk, |
| 2556 | const gfp_t priority); |
| 2557 | |
| 2558 | char name[TCP_ULP_NAME_MAX]; |
| 2559 | struct module *owner; |
| 2560 | }; |
| 2561 | int tcp_register_ulp(struct tcp_ulp_ops *type); |
| 2562 | void tcp_unregister_ulp(struct tcp_ulp_ops *type); |
| 2563 | int tcp_set_ulp(struct sock *sk, const char *name); |
| 2564 | void tcp_get_available_ulp(char *buf, size_t len); |
| 2565 | void tcp_cleanup_ulp(struct sock *sk); |
| 2566 | void tcp_update_ulp(struct sock *sk, struct proto *p, |
| 2567 | void (*write_space)(struct sock *sk)); |
| 2568 | |
| 2569 | #define MODULE_ALIAS_TCP_ULP(name) \ |
| 2570 | __MODULE_INFO(alias, alias_userspace, name); \ |
| 2571 | __MODULE_INFO(alias, alias_tcp_ulp, "tcp-ulp-" name) |
| 2572 | |
| 2573 | #ifdef CONFIG_NET_SOCK_MSG |
| 2574 | struct sk_msg; |
| 2575 | struct sk_psock; |
| 2576 | |
| 2577 | #ifdef CONFIG_BPF_SYSCALL |
| 2578 | int tcp_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore); |
| 2579 | void tcp_bpf_clone(const struct sock *sk, struct sock *newsk); |
| 2580 | #endif /* CONFIG_BPF_SYSCALL */ |
| 2581 | |
| 2582 | #ifdef CONFIG_INET |
| 2583 | void tcp_eat_skb(struct sock *sk, struct sk_buff *skb); |
| 2584 | #else |
| 2585 | static inline void tcp_eat_skb(struct sock *sk, struct sk_buff *skb) |
| 2586 | { |
| 2587 | } |
| 2588 | #endif |
| 2589 | |
| 2590 | int tcp_bpf_sendmsg_redir(struct sock *sk, bool ingress, |
| 2591 | struct sk_msg *msg, u32 bytes, int flags); |
| 2592 | #endif /* CONFIG_NET_SOCK_MSG */ |
| 2593 | |
| 2594 | #if !defined(CONFIG_BPF_SYSCALL) || !defined(CONFIG_NET_SOCK_MSG) |
| 2595 | static inline void tcp_bpf_clone(const struct sock *sk, struct sock *newsk) |
| 2596 | { |
| 2597 | } |
| 2598 | #endif |
| 2599 | |
| 2600 | #ifdef CONFIG_CGROUP_BPF |
| 2601 | static inline void bpf_skops_init_skb(struct bpf_sock_ops_kern *skops, |
| 2602 | struct sk_buff *skb, |
| 2603 | unsigned int end_offset) |
| 2604 | { |
| 2605 | skops->skb = skb; |
| 2606 | skops->skb_data_end = skb->data + end_offset; |
| 2607 | } |
| 2608 | #else |
| 2609 | static inline void bpf_skops_init_skb(struct bpf_sock_ops_kern *skops, |
| 2610 | struct sk_buff *skb, |
| 2611 | unsigned int end_offset) |
| 2612 | { |
| 2613 | } |
| 2614 | #endif |
| 2615 | |
| 2616 | /* Call BPF_SOCK_OPS program that returns an int. If the return value |
| 2617 | * is < 0, then the BPF op failed (for example if the loaded BPF |
| 2618 | * program does not support the chosen operation or there is no BPF |
| 2619 | * program loaded). |
| 2620 | */ |
| 2621 | #ifdef CONFIG_BPF |
| 2622 | static inline int tcp_call_bpf(struct sock *sk, int op, u32 nargs, u32 *args) |
| 2623 | { |
| 2624 | struct bpf_sock_ops_kern sock_ops; |
| 2625 | int ret; |
| 2626 | |
| 2627 | memset(&sock_ops, 0, offsetof(struct bpf_sock_ops_kern, temp)); |
| 2628 | if (sk_fullsock(sk)) { |
| 2629 | sock_ops.is_fullsock = 1; |
| 2630 | sock_owned_by_me(sk); |
| 2631 | } |
| 2632 | |
| 2633 | sock_ops.sk = sk; |
| 2634 | sock_ops.op = op; |
| 2635 | if (nargs > 0) |
| 2636 | memcpy(sock_ops.args, args, nargs * sizeof(*args)); |
| 2637 | |
| 2638 | ret = BPF_CGROUP_RUN_PROG_SOCK_OPS(&sock_ops); |
| 2639 | if (ret == 0) |
| 2640 | ret = sock_ops.reply; |
| 2641 | else |
| 2642 | ret = -1; |
| 2643 | return ret; |
| 2644 | } |
| 2645 | |
| 2646 | static inline int tcp_call_bpf_2arg(struct sock *sk, int op, u32 arg1, u32 arg2) |
| 2647 | { |
| 2648 | u32 args[2] = {arg1, arg2}; |
| 2649 | |
| 2650 | return tcp_call_bpf(sk, op, 2, args); |
| 2651 | } |
| 2652 | |
| 2653 | static inline int tcp_call_bpf_3arg(struct sock *sk, int op, u32 arg1, u32 arg2, |
| 2654 | u32 arg3) |
| 2655 | { |
| 2656 | u32 args[3] = {arg1, arg2, arg3}; |
| 2657 | |
| 2658 | return tcp_call_bpf(sk, op, 3, args); |
| 2659 | } |
| 2660 | |
| 2661 | #else |
| 2662 | static inline int tcp_call_bpf(struct sock *sk, int op, u32 nargs, u32 *args) |
| 2663 | { |
| 2664 | return -EPERM; |
| 2665 | } |
| 2666 | |
| 2667 | static inline int tcp_call_bpf_2arg(struct sock *sk, int op, u32 arg1, u32 arg2) |
| 2668 | { |
| 2669 | return -EPERM; |
| 2670 | } |
| 2671 | |
| 2672 | static inline int tcp_call_bpf_3arg(struct sock *sk, int op, u32 arg1, u32 arg2, |
| 2673 | u32 arg3) |
| 2674 | { |
| 2675 | return -EPERM; |
| 2676 | } |
| 2677 | |
| 2678 | #endif |
| 2679 | |
| 2680 | static inline u32 tcp_timeout_init(struct sock *sk) |
| 2681 | { |
| 2682 | int timeout; |
| 2683 | |
| 2684 | timeout = tcp_call_bpf(sk, BPF_SOCK_OPS_TIMEOUT_INIT, 0, NULL); |
| 2685 | |
| 2686 | if (timeout <= 0) |
| 2687 | timeout = TCP_TIMEOUT_INIT; |
| 2688 | return min_t(int, timeout, TCP_RTO_MAX); |
| 2689 | } |
| 2690 | |
| 2691 | static inline u32 tcp_rwnd_init_bpf(struct sock *sk) |
| 2692 | { |
| 2693 | int rwnd; |
| 2694 | |
| 2695 | rwnd = tcp_call_bpf(sk, BPF_SOCK_OPS_RWND_INIT, 0, NULL); |
| 2696 | |
| 2697 | if (rwnd < 0) |
| 2698 | rwnd = 0; |
| 2699 | return rwnd; |
| 2700 | } |
| 2701 | |
| 2702 | static inline bool tcp_bpf_ca_needs_ecn(struct sock *sk) |
| 2703 | { |
| 2704 | return (tcp_call_bpf(sk, BPF_SOCK_OPS_NEEDS_ECN, 0, NULL) == 1); |
| 2705 | } |
| 2706 | |
| 2707 | static inline void tcp_bpf_rtt(struct sock *sk, long mrtt, u32 srtt) |
| 2708 | { |
| 2709 | if (BPF_SOCK_OPS_TEST_FLAG(tcp_sk(sk), BPF_SOCK_OPS_RTT_CB_FLAG)) |
| 2710 | tcp_call_bpf_2arg(sk, BPF_SOCK_OPS_RTT_CB, mrtt, srtt); |
| 2711 | } |
| 2712 | |
| 2713 | #if IS_ENABLED(CONFIG_SMC) |
| 2714 | extern struct static_key_false tcp_have_smc; |
| 2715 | #endif |
| 2716 | |
| 2717 | #if IS_ENABLED(CONFIG_TLS_DEVICE) |
| 2718 | void clean_acked_data_enable(struct inet_connection_sock *icsk, |
| 2719 | void (*cad)(struct sock *sk, u32 ack_seq)); |
| 2720 | void clean_acked_data_disable(struct inet_connection_sock *icsk); |
| 2721 | void clean_acked_data_flush(void); |
| 2722 | #endif |
| 2723 | |
| 2724 | DECLARE_STATIC_KEY_FALSE(tcp_tx_delay_enabled); |
| 2725 | static inline void tcp_add_tx_delay(struct sk_buff *skb, |
| 2726 | const struct tcp_sock *tp) |
| 2727 | { |
| 2728 | if (static_branch_unlikely(&tcp_tx_delay_enabled)) |
| 2729 | skb->skb_mstamp_ns += (u64)tp->tcp_tx_delay * NSEC_PER_USEC; |
| 2730 | } |
| 2731 | |
| 2732 | /* Compute Earliest Departure Time for some control packets |
| 2733 | * like ACK or RST for TIME_WAIT or non ESTABLISHED sockets. |
| 2734 | */ |
| 2735 | static inline u64 tcp_transmit_time(const struct sock *sk) |
| 2736 | { |
| 2737 | if (static_branch_unlikely(&tcp_tx_delay_enabled)) { |
| 2738 | u32 delay = (sk->sk_state == TCP_TIME_WAIT) ? |
| 2739 | tcp_twsk(sk)->tw_tx_delay : tcp_sk(sk)->tcp_tx_delay; |
| 2740 | |
| 2741 | return tcp_clock_ns() + (u64)delay * NSEC_PER_USEC; |
| 2742 | } |
| 2743 | return 0; |
| 2744 | } |
| 2745 | |
| 2746 | static inline int tcp_parse_auth_options(const struct tcphdr *th, |
| 2747 | const u8 **md5_hash, const struct tcp_ao_hdr **aoh) |
| 2748 | { |
| 2749 | const u8 *md5_tmp, *ao_tmp; |
| 2750 | int ret; |
| 2751 | |
| 2752 | ret = tcp_do_parse_auth_options(th, &md5_tmp, &ao_tmp); |
| 2753 | if (ret) |
| 2754 | return ret; |
| 2755 | |
| 2756 | if (md5_hash) |
| 2757 | *md5_hash = md5_tmp; |
| 2758 | |
| 2759 | if (aoh) { |
| 2760 | if (!ao_tmp) |
| 2761 | *aoh = NULL; |
| 2762 | else |
| 2763 | *aoh = (struct tcp_ao_hdr *)(ao_tmp - 2); |
| 2764 | } |
| 2765 | |
| 2766 | return 0; |
| 2767 | } |
| 2768 | |
| 2769 | static inline bool tcp_ao_required(struct sock *sk, const void *saddr, |
| 2770 | int family, int l3index, bool stat_inc) |
| 2771 | { |
| 2772 | #ifdef CONFIG_TCP_AO |
| 2773 | struct tcp_ao_info *ao_info; |
| 2774 | struct tcp_ao_key *ao_key; |
| 2775 | |
| 2776 | if (!static_branch_unlikely(&tcp_ao_needed.key)) |
| 2777 | return false; |
| 2778 | |
| 2779 | ao_info = rcu_dereference_check(tcp_sk(sk)->ao_info, |
| 2780 | lockdep_sock_is_held(sk)); |
| 2781 | if (!ao_info) |
| 2782 | return false; |
| 2783 | |
| 2784 | ao_key = tcp_ao_do_lookup(sk, l3index, saddr, family, -1, -1); |
| 2785 | if (ao_info->ao_required || ao_key) { |
| 2786 | if (stat_inc) { |
| 2787 | NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOREQUIRED); |
| 2788 | atomic64_inc(&ao_info->counters.ao_required); |
| 2789 | } |
| 2790 | return true; |
| 2791 | } |
| 2792 | #endif |
| 2793 | return false; |
| 2794 | } |
| 2795 | |
| 2796 | enum skb_drop_reason tcp_inbound_hash(struct sock *sk, |
| 2797 | const struct request_sock *req, const struct sk_buff *skb, |
| 2798 | const void *saddr, const void *daddr, |
| 2799 | int family, int dif, int sdif); |
| 2800 | |
| 2801 | #endif /* _TCP_H */ |