xref: /freebsd/sys/netinet/tcp_stats.c (revision 058ac3e8063366dafa634d9107642e12b038bf09)
1 /*-
2  * Copyright (c) 2016-2018 Netflix, Inc.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 /*
28  * Author: Lawrence Stewart <lstewart@netflix.com>
29  */
30 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 #include <sys/param.h>
35 #include <sys/arb.h>
36 #include <sys/errno.h>
37 #include <sys/malloc.h>
38 #include <sys/qmath.h>
39 #include <sys/queue.h>
40 #include <sys/socket.h>
41 #include <sys/socketvar.h>
42 #include <sys/sysctl.h>
43 #ifdef _KERNEL
44 #include <sys/kernel.h>
45 #include <sys/lock.h>
46 #include <sys/rmlock.h>
47 #include <sys/systm.h>
48 #endif
49 #include <sys/stats.h>
50 
51 #include <net/vnet.h>
52 
53 #include <netinet/in.h>
54 #include <netinet/in_pcb.h>
55 #include <netinet/tcp.h>
56 #include <netinet/tcp_var.h>
57 
58 #include <netinet/cc/cc.h>
59 
60 VNET_DEFINE(int, tcp_perconn_stats_dflt_tpl) = -1;
61 
62 #ifndef _KERNEL
63 #define	V_tcp_perconn_stats_enable	VNET(tcp_perconn_stats_enable)
64 #define	V_tcp_perconn_stats_dflt_tpl	VNET(tcp_perconn_stats_dflt_tpl)
65 #else /* _KERNEL */
66 
67 VNET_DEFINE(int, tcp_perconn_stats_enable) = 2;
68 VNET_DEFINE_STATIC(struct stats_tpl_sample_rate *, tcp_perconn_stats_sample_rates);
69 VNET_DEFINE_STATIC(int, tcp_stats_nrates) = 0;
70 #define	V_tcp_perconn_stats_sample_rates VNET(tcp_perconn_stats_sample_rates)
71 #define	V_tcp_stats_nrates		VNET(tcp_stats_nrates)
72 
73 static struct rmlock tcp_stats_tpl_sampling_lock;
74 static int tcp_stats_tpl_sr_cb(enum stats_tpl_sr_cb_action action,
75     struct stats_tpl_sample_rate **rates, int *nrates, void *ctx);
76 
77 SYSCTL_INT(_net_inet_tcp, OID_AUTO, perconn_stats_enable,
78     CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(tcp_perconn_stats_enable), 0,
79     "Enable per-connection TCP stats gathering; 1 enables for all connections, "
80     "2 enables random sampling across log id connection groups");
81 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, perconn_stats_sample_rates,
82     CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_NEEDGIANT, tcp_stats_tpl_sr_cb,
83     sizeof(struct rm_priotracker), stats_tpl_sample_rates, "A",
84     "TCP stats per template random sampling rates, in CSV tpl_spec=percent "
85     "key-value pairs (see stats(9) for template spec details)");
86 #endif /* _KERNEL */
87 
88 #ifdef _KERNEL
89 int
90 #else
91 static int
92 /* Ensure all templates are also added to the userland template list. */
93 __attribute__ ((constructor))
94 #endif
95 tcp_stats_init()
96 {
97 	int err, lasterr;
98 
99 	err = lasterr = 0;
100 
101 	V_tcp_perconn_stats_dflt_tpl = stats_tpl_alloc("TCP_DEFAULT", 0);
102 	if (V_tcp_perconn_stats_dflt_tpl < 0)
103 		return (-V_tcp_perconn_stats_dflt_tpl);
104 
105 	struct voistatspec vss_sum[] = {
106 		STATS_VSS_SUM(),
107 	};
108 	err |= stats_tpl_add_voistats(V_tcp_perconn_stats_dflt_tpl,
109 	    VOI_TCP_TXPB, "TCP_TXPB", VSD_DTYPE_INT_U64,
110 	    NVSS(vss_sum), vss_sum, 0);
111 	lasterr = err ? err : lasterr;
112 	err |= stats_tpl_add_voistats(V_tcp_perconn_stats_dflt_tpl,
113 	    VOI_TCP_RETXPB, "TCP_RETXPB", VSD_DTYPE_INT_U32,
114 	    NVSS(vss_sum), vss_sum, 0);
115 	lasterr = err ? err : lasterr;
116 
117 	struct voistatspec vss_max[] = {
118 		STATS_VSS_MAX(),
119 	};
120 	err |= stats_tpl_add_voistats(V_tcp_perconn_stats_dflt_tpl,
121 	    VOI_TCP_FRWIN, "TCP_FRWIN", VSD_DTYPE_INT_ULONG,
122 	    NVSS(vss_max), vss_max, 0);
123 	lasterr = err ? err : lasterr;
124 	err |= stats_tpl_add_voistats(V_tcp_perconn_stats_dflt_tpl,
125 	    VOI_TCP_LCWIN, "TCP_LCWIN", VSD_DTYPE_INT_ULONG,
126 	    NVSS(vss_max), vss_max, 0);
127 	lasterr = err ? err : lasterr;
128 
129 	struct voistatspec vss_rtt[] = {
130 		STATS_VSS_MAX(),
131 		STATS_VSS_MIN(),
132 		STATS_VSS_TDGSTCLUST32(20, 4),
133 	};
134 	err |= stats_tpl_add_voistats(V_tcp_perconn_stats_dflt_tpl,
135 	    VOI_TCP_RTT, "TCP_RTT", VSD_DTYPE_INT_U32,
136 	    NVSS(vss_rtt), vss_rtt, 0);
137 	lasterr = err ? err : lasterr;
138 
139 	struct voistatspec vss_congsig[] = {
140 		STATS_VSS_DVHIST32_USR(HBKTS(DVBKT(CC_ECN), DVBKT(CC_RTO),
141 		    DVBKT(CC_RTO_ERR), DVBKT(CC_NDUPACK)), 0)
142 	};
143 	err |= stats_tpl_add_voistats(V_tcp_perconn_stats_dflt_tpl,
144 	    VOI_TCP_CSIG, "TCP_CSIG", VSD_DTYPE_INT_U32,
145 	    NVSS(vss_congsig), vss_congsig, 0);
146 	lasterr = err ? err : lasterr;
147 
148 	struct voistatspec vss_gput[] = {
149 		STATS_VSS_MAX(),
150 		STATS_VSS_TDGSTCLUST32(20, 4),
151 	};
152 	err |= stats_tpl_add_voistats(V_tcp_perconn_stats_dflt_tpl,
153 	    VOI_TCP_GPUT, "TCP_GPUT", VSD_DTYPE_INT_U32,
154 	    NVSS(vss_gput), vss_gput, 0);
155 	lasterr = err ? err : lasterr;
156 
157 	struct voistatspec vss_gput_nd[] = {
158 		STATS_VSS_TDGSTCLUST32(10, 4),
159 	};
160 	err |= stats_tpl_add_voistats(V_tcp_perconn_stats_dflt_tpl,
161 	    VOI_TCP_GPUT_ND, "TCP_GPUT_ND", VSD_DTYPE_INT_S32,
162 	    NVSS(vss_gput_nd), vss_gput_nd, 0);
163 	lasterr = err ? err : lasterr;
164 
165 	struct voistatspec vss_windiff[] = {
166 		STATS_VSS_CRHIST32_USR(HBKTS(CRBKT(0)), VSD_HIST_LBOUND_INF)
167 	};
168 	err |= stats_tpl_add_voistats(V_tcp_perconn_stats_dflt_tpl,
169 	    VOI_TCP_CALCFRWINDIFF, "TCP_CALCFRWINDIFF", VSD_DTYPE_INT_S32,
170 	    NVSS(vss_windiff), vss_windiff, 0);
171 	lasterr = err ? err : lasterr;
172 
173 	struct voistatspec vss_acklen[] = {
174 		STATS_VSS_MAX(),
175 		STATS_VSS_CRHIST32_LIN(0, 9, 1, VSD_HIST_UBOUND_INF)
176 	};
177 	err |= stats_tpl_add_voistats(V_tcp_perconn_stats_dflt_tpl,
178 	    VOI_TCP_ACKLEN, "TCP_ACKLEN", VSD_DTYPE_INT_U32,
179 	    NVSS(vss_acklen), vss_acklen, 0);
180 	lasterr = err ? err : lasterr;
181 
182 	return (lasterr);
183 }
184 
185 #ifdef _KERNEL
186 int
187 tcp_stats_sample_rollthedice(struct tcpcb *tp, void *seed_bytes,
188     size_t seed_len)
189 {
190 	struct rm_priotracker tracker;
191 	int tpl;
192 
193 	tpl = -1;
194 
195 	if (V_tcp_stats_nrates > 0) {
196 		rm_rlock(&tcp_stats_tpl_sampling_lock, &tracker);
197 		tpl = stats_tpl_sample_rollthedice(V_tcp_perconn_stats_sample_rates,
198 		    V_tcp_stats_nrates, seed_bytes, seed_len);
199 		rm_runlock(&tcp_stats_tpl_sampling_lock, &tracker);
200 
201 		if (tpl >= 0) {
202 			INP_WLOCK_ASSERT(tptoinpcb(tp));
203 			if (tp->t_stats != NULL)
204 				stats_blob_destroy(tp->t_stats);
205 			tp->t_stats = stats_blob_alloc(tpl, 0);
206 			if (tp->t_stats == NULL)
207 				tpl = -ENOMEM;
208 		}
209 	}
210 
211 	return (tpl);
212 }
213 
214 /*
215  * Callback function for stats_tpl_sample_rates() to interact with the TCP
216  * subsystem's stats template sample rates list.
217  */
218 int
219 tcp_stats_tpl_sr_cb(enum stats_tpl_sr_cb_action action,
220     struct stats_tpl_sample_rate **rates, int *nrates, void *ctx)
221 {
222 	struct stats_tpl_sample_rate *old_rates;
223 	int old_nrates;
224 
225 	if (ctx == NULL)
226 		return (ENOMEM);
227 
228 	switch (action) {
229 	case TPL_SR_RLOCKED_GET:
230 		/*
231 		 * Return with rlock held i.e. this call must be paired with a
232 		 * "action == TPL_SR_RUNLOCK" call.
233 		 */
234 		rm_assert(&tcp_stats_tpl_sampling_lock, RA_UNLOCKED);
235 		rm_rlock(&tcp_stats_tpl_sampling_lock,
236 		    (struct rm_priotracker *)ctx);
237 		/* FALLTHROUGH */
238 	case TPL_SR_UNLOCKED_GET:
239 		if (rates != NULL)
240 			*rates = V_tcp_perconn_stats_sample_rates;
241 		if (nrates != NULL)
242 			*nrates = V_tcp_stats_nrates;
243 		break;
244 	case TPL_SR_RUNLOCK:
245 		rm_assert(&tcp_stats_tpl_sampling_lock, RA_RLOCKED);
246 		rm_runlock(&tcp_stats_tpl_sampling_lock,
247 		    (struct rm_priotracker *)ctx);
248 		break;
249 	case TPL_SR_PUT:
250 		KASSERT(rates != NULL && nrates != NULL,
251 		    ("%s: PUT without new rates", __func__));
252 		rm_assert(&tcp_stats_tpl_sampling_lock, RA_UNLOCKED);
253 		if (rates == NULL || nrates == NULL)
254 			return (EINVAL);
255 		rm_wlock(&tcp_stats_tpl_sampling_lock);
256 		old_rates = V_tcp_perconn_stats_sample_rates;
257 		old_nrates = V_tcp_stats_nrates;
258 		V_tcp_perconn_stats_sample_rates = *rates;
259 		V_tcp_stats_nrates = *nrates;
260 		rm_wunlock(&tcp_stats_tpl_sampling_lock);
261 		*rates = old_rates;
262 		*nrates = old_nrates;
263 		break;
264 	default:
265 		return (EINVAL);
266 		break;
267 	}
268 
269 	return (0);
270 }
271 
272 RM_SYSINIT(tcp_stats_tpl_sampling_lock, &tcp_stats_tpl_sampling_lock,
273     "tcp_stats_tpl_sampling_lock");
274 #endif /* _KERNEL */
275