xref: /freebsd/sys/netinet/tcp_stacks/tailq_hash.c (revision 8aac90f18aef7c9eea906c3ff9a001ca7b94f375)
1 #include <sys/cdefs.h>
2 #include "opt_inet.h"
3 #include "opt_inet6.h"
4 #include "opt_ipsec.h"
5 #include "opt_ratelimit.h"
6 #include "opt_kern_tls.h"
7 #include <sys/param.h>
8 #include <sys/arb.h>
9 #include <sys/module.h>
10 #include <sys/kernel.h>
11 #ifdef TCP_HHOOK
12 #include <sys/hhook.h>
13 #endif
14 #include <sys/lock.h>
15 #include <sys/malloc.h>
16 #include <sys/lock.h>
17 #include <sys/mutex.h>
18 #include <sys/mbuf.h>
19 #include <sys/proc.h>		/* for proc0 declaration */
20 #include <sys/socket.h>
21 #include <sys/socketvar.h>
22 #include <sys/sysctl.h>
23 #include <sys/systm.h>
24 #ifdef STATS
25 #include <sys/qmath.h>
26 #include <sys/tree.h>
27 #include <sys/stats.h> /* Must come after qmath.h and tree.h */
28 #else
29 #include <sys/tree.h>
30 #endif
31 #include <sys/refcount.h>
32 #include <sys/queue.h>
33 #include <sys/tim_filter.h>
34 #include <sys/smp.h>
35 #include <sys/kthread.h>
36 #include <sys/kern_prefetch.h>
37 #include <sys/protosw.h>
38 #ifdef TCP_ACCOUNTING
39 #include <sys/sched.h>
40 #include <machine/cpu.h>
41 #endif
42 #include <vm/uma.h>
43 
44 #include <net/route.h>
45 #include <net/route/nhop.h>
46 #include <net/vnet.h>
47 
48 #define TCPSTATES		/* for logging */
49 
50 #include <netinet/in.h>
51 #include <netinet/in_kdtrace.h>
52 #include <netinet/in_pcb.h>
53 #include <netinet/ip.h>
54 #include <netinet/ip_icmp.h>	/* required for icmp_var.h */
55 #include <netinet/icmp_var.h>	/* for ICMP_BANDLIM */
56 #include <netinet/ip_var.h>
57 #include <netinet/ip6.h>
58 #include <netinet6/in6_pcb.h>
59 #include <netinet6/ip6_var.h>
60 #include <netinet/tcp.h>
61 #include <netinet/tcp_fsm.h>
62 #include <netinet/tcp_seq.h>
63 #include <netinet/tcp_timer.h>
64 #include <netinet/tcp_var.h>
65 #include <netinet/tcp_log_buf.h>
66 #include <netinet/tcp_syncache.h>
67 #include <netinet/tcp_hpts.h>
68 #include <netinet/tcp_accounting.h>
69 #include <netinet/tcpip.h>
70 #include <netinet/cc/cc.h>
71 #include <netinet/cc/cc_newreno.h>
72 #include <netinet/tcp_fastopen.h>
73 #include <netinet/tcp_lro.h>
74 #ifdef NETFLIX_SHARED_CWND
75 #include <netinet/tcp_shared_cwnd.h>
76 #endif
77 #ifdef TCP_OFFLOAD
78 #include <netinet/tcp_offload.h>
79 #endif
80 #ifdef INET6
81 #include <netinet6/tcp6_var.h>
82 #endif
83 #include <netinet/tcp_ecn.h>
84 
85 #include <netipsec/ipsec_support.h>
86 
87 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
88 #include <netipsec/ipsec.h>
89 #include <netipsec/ipsec6.h>
90 #endif				/* IPSEC */
91 
92 #include <netinet/udp.h>
93 #include <netinet/udp_var.h>
94 #include <machine/in_cksum.h>
95 
96 #ifdef MAC
97 #include <security/mac/mac_framework.h>
98 #endif
99 #include "sack_filter.h"
100 #include "tcp_rack.h"
101 #include "tailq_hash.h"
102 #include "opt_global.h"
103 
104 
105 struct rack_sendmap *
106 tqhash_min(struct tailq_hash *hs)
107 {
108 	struct rack_sendmap *rsm;
109 
110 	rsm = hs->rsm_min;
111 	return(rsm);
112 }
113 
114 struct rack_sendmap *
115 tqhash_max(struct tailq_hash *hs)
116 {
117 	struct rack_sendmap *rsm;
118 
119 	rsm = hs->rsm_max;
120 	return (rsm);
121 }
122 
123 int
124 tqhash_empty(struct tailq_hash *hs)
125 {
126 	if (hs->count == 0)
127 		return(1);
128 	return(0);
129 }
130 
131 struct rack_sendmap *
132 tqhash_find(struct tailq_hash *hs, uint32_t seq)
133 {
134 	struct rack_sendmap *e;
135 	int bindex, pbucket, fc = 1;
136 
137 	if ((SEQ_LT(seq, hs->min)) ||
138 	    (hs->count == 0) ||
139 	    (SEQ_GEQ(seq, hs->max))) {
140 		/* Not here */
141 		return (NULL);
142 	}
143 	bindex = seq / SEQ_BUCKET_SIZE;
144 	bindex %= MAX_HASH_ENTRIES;
145 	/* Lets look through the bucket it belongs to */
146 	if (TAILQ_EMPTY(&hs->ht[bindex])) {
147 		goto look_backwards;
148 	}
149 	TAILQ_FOREACH(e, &hs->ht[bindex], next) {
150 		if (fc == 1) {
151 			/*
152 			 * Special check for when a cum-ack
153 			 * as moved up over a seq and now its
154 			 * a bucket behind where it belongs. In
155 			 * the case of SACKs which create new rsm's
156 			 * this won't occur.
157 			 */
158 			if (SEQ_GT(e->r_start, seq)) {
159 				goto look_backwards;
160 			}
161 			fc = 0;
162 		}
163 		if (SEQ_GEQ(seq, e->r_start) &&
164 		    (SEQ_LT(seq, e->r_end))) {
165 			/* Its in this block */
166 			return (e);
167 		}
168 	}
169 	/* Did not find it */
170 	return (NULL);
171 look_backwards:
172 	if (bindex == 0)
173 		pbucket = MAX_HASH_ENTRIES - 1;
174 	else
175 		pbucket = bindex - 1;
176 	TAILQ_FOREACH_REVERSE(e, &hs->ht[pbucket], rack_head, next) {
177 		if (SEQ_GEQ(seq, e->r_start) &&
178 		    (SEQ_LT(seq, e->r_end))) {
179 			/* Its in this block */
180 			return (e);
181 		}
182 		if (SEQ_GEQ(e->r_end, seq))
183 			break;
184 	}
185 	return (NULL);
186 }
187 
188 struct rack_sendmap *
189 tqhash_next(struct tailq_hash *hs, struct rack_sendmap *rsm)
190 {
191 	struct rack_sendmap *e;
192 
193 	e = TAILQ_NEXT(rsm, next);
194 	if (e == NULL) {
195 		/* Move to next bucket */
196 		int nxt;
197 
198 		nxt = rsm->bindex + 1;
199 		if (nxt >= MAX_HASH_ENTRIES)
200 			nxt = 0;
201 		e = TAILQ_FIRST(&hs->ht[nxt]);
202 	}
203 	return(e);
204 }
205 
206 struct rack_sendmap *
207 tqhash_prev(struct tailq_hash *hs, struct rack_sendmap *rsm)
208 {
209 	struct rack_sendmap *e;
210 
211 	e = TAILQ_PREV(rsm, rack_head, next);
212 	if (e == NULL) {
213 		int prev;
214 
215 		if (rsm->bindex > 0)
216 			prev = rsm->bindex - 1;
217 		else
218 			prev = MAX_HASH_ENTRIES - 1;
219 		e = TAILQ_LAST(&hs->ht[prev], rack_head);
220 	}
221 	return (e);
222 }
223 
224 void
225 tqhash_remove(struct tailq_hash *hs, struct rack_sendmap *rsm, int type)
226 {
227 
228 	hs->count--;
229 	if (hs->count == 0) {
230 		hs->min = hs->max;
231 		hs->rsm_max = hs->rsm_min = NULL;
232 	} else if (type == REMOVE_TYPE_CUMACK) {
233 		hs->min = rsm->r_end;
234 		hs->rsm_min = tqhash_next(hs, rsm);
235 	} else if (rsm == hs->rsm_max) {
236 		hs->rsm_max = tqhash_prev(hs, rsm);
237 		hs->max = hs->rsm_max->r_end;
238 	}
239 	TAILQ_REMOVE(&hs->ht[rsm->bindex], rsm, next);
240 }
241 
242 int
243 tqhash_insert(struct tailq_hash *hs, struct rack_sendmap *rsm)
244 {
245 	struct rack_sendmap *e, *l;
246 	int inserted = 0;
247 	uint32_t ebucket;
248 
249 #ifdef INVARIANTS
250 	if (hs->count > 0) {
251 		if ((rsm->r_end - hs->min) >  MAX_ALLOWED_SEQ_RANGE) {
252 			return (-1);
253 		}
254 		e = tqhash_find(hs, rsm->r_start);
255 		if (e) {
256 			return (-2);
257 		}
258 	}
259 #endif
260 	rsm->bindex = rsm->r_start / SEQ_BUCKET_SIZE;
261 	rsm->bindex %= MAX_HASH_ENTRIES;
262 	ebucket = rsm->r_end / SEQ_BUCKET_SIZE;
263 	ebucket %= MAX_HASH_ENTRIES;
264 	if (ebucket != rsm->bindex) {
265 		/* This RSM straddles the bucket boundary */
266 		rsm->r_flags |= RACK_STRADDLE;
267 	} else {
268 		rsm->r_flags &= ~RACK_STRADDLE;
269 	}
270 	if (hs->count == 0) {
271 		/* Special case */
272 		hs->min = rsm->r_start;
273 		hs->max = rsm->r_end;
274 		hs->rsm_min = hs->rsm_max = rsm;
275 		hs->count = 1;
276 	} else {
277 		hs->count++;
278 		if (SEQ_GEQ(rsm->r_end, hs->max)) {
279 			hs->max = rsm->r_end;
280 			hs->rsm_max = rsm;
281 		} if (SEQ_LEQ(rsm->r_start, hs->min)) {
282 			hs->min = rsm->r_start;
283 			hs->rsm_min = rsm;
284 		}
285 	}
286 	/* Check the common case of inserting at the end */
287 	l = TAILQ_LAST(&hs->ht[rsm->bindex], rack_head);
288 	if ((l == NULL) || (SEQ_GT(rsm->r_start, l->r_start))) {
289 		TAILQ_INSERT_TAIL(&hs->ht[rsm->bindex], rsm, next);
290 		return (0);
291 	}
292 	TAILQ_FOREACH(e, &hs->ht[rsm->bindex], next) {
293 		if (SEQ_LEQ(rsm->r_start, e->r_start)) {
294 			inserted = 1;
295 			TAILQ_INSERT_BEFORE(e, rsm, next);
296 			break;
297 		}
298 	}
299 	if (inserted == 0) {
300 		TAILQ_INSERT_TAIL(&hs->ht[rsm->bindex], rsm, next);
301 	}
302 	return (0);
303 }
304 
305 void
306 tqhash_init(struct tailq_hash *hs)
307 {
308 	int i;
309 
310 	for(i = 0; i < MAX_HASH_ENTRIES; i++) {
311 		TAILQ_INIT(&hs->ht[i]);
312 	}
313 	hs->min = hs->max = 0;
314 	hs->rsm_min = hs->rsm_max = NULL;
315 	hs->count = 0;
316 }
317 
318 int
319 tqhash_trim(struct tailq_hash *hs, uint32_t th_ack)
320 {
321 	struct rack_sendmap *rsm;
322 
323 	if (SEQ_LT(th_ack, hs->min)) {
324 		/* It can't be behind our current min */
325 		return (-1);
326 	}
327 	if (SEQ_GEQ(th_ack, hs->max)) {
328 		/*  It can't be beyond or at our current max */
329 		return (-2);
330 	}
331 	rsm = tqhash_min(hs);
332 	if (rsm == NULL) {
333 		/* nothing to trim */
334 		return (-3);
335 	}
336 	if (SEQ_GEQ(th_ack, rsm->r_end)) {
337 		/*
338 		 * You can't trim all bytes instead
339 		 * you need to remove it.
340 		 */
341 		return (-4);
342 	}
343 	if (SEQ_GT(th_ack, hs->min))
344 	    hs->min = th_ack;
345 	/*
346 	 * Should we trim it for the caller?
347 	 * they may have already which is ok...
348 	 */
349 	if (SEQ_GT(th_ack, rsm->r_start)) {
350 		rsm->r_start = th_ack;
351 	}
352 	return (0);
353 }
354 
355 void
356 tqhash_update_end(struct tailq_hash *hs, struct rack_sendmap *rsm,
357     uint32_t th_ack)
358 {
359 	if (hs->max == rsm->r_end)
360 		hs->max = th_ack;
361 	rsm->r_end = th_ack;
362 }
363