xref: /illumos-gate/usr/src/uts/common/ipp/meters/tokenmt.c (revision 9498083eeaed1aacdde41369b7fa6f3b84870791)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2002 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #include <sys/types.h>
28 #include <sys/kmem.h>
29 #include <sys/conf.h>
30 #include <sys/sysmacros.h>
31 #include <netinet/in.h>
32 #include <netinet/in_systm.h>
33 #include <netinet/ip6.h>
34 #include <inet/common.h>
35 #include <inet/ip.h>
36 #include <inet/ip6.h>
37 #include <ipp/meters/meter_impl.h>
38 
39 /*
40  * Module : Single or Two Rate Metering module - tokenmt
41  * Description
42  * This module implements the metering part of RFC 2698 & 2697. It accepts the
43  * committed rate, peak rate (optional), committed burst and peak burst for a
44  * flow and determines if the flow is within the cfgd. rates and assigns
45  * next action appropriately..
46  * If the peak rate is provided this acts as a two rate meter (RFC 2698), else
47  * a single rate meter (RFC 2697). If this is a two rate meter, then
48  * the outcome is either green, red or yellow. Else if this a single rate
49  * meter and the peak burst size is not provided, the outcome is either
50  * green or red.
51  * Internally, it maintains 2 token buckets, Tc & Tp, each filled with
52  * tokens equal to committed burst & peak burst respectively initially.
53  * When a packet arrives, tokens in Tc or Tp are updated at the committed
54  * or the peak rate up to a maximum of the committed or peak burst size.
55  * If there are enough tokens in Tc, the packet is Green, else if there are
56  * enough tokens in Tp, the packet is Yellow, else the packet is Red. In case
57  * of Green and Yellow packets, Tc and/or Tp is updated accordingly.
58  */
59 
60 int tokenmt_debug = 0;
61 
62 /* Updating tokens */
63 static void tokenmt_update_tokens(tokenmt_data_t *, hrtime_t);
64 
65 /*
66  * Given a packet and the tokenmt_data it belongs to, this routine meters the
67  * ToS or DSCP for IPv4 and IPv6 resp. with the values configured for
68  * the tokenmt_data.
69  */
70 int
71 tokenmt_process(mblk_t **mpp, tokenmt_data_t *tokenmt_data,
72     ipp_action_id_t *next_action)
73 {
74 	uint8_t dscp;
75 	ipha_t *ipha;
76 	ip6_t *ip6_hdr;
77 	uint32_t pkt_len;
78 	mblk_t *mp = *mpp;
79 	hrtime_t now;
80 	enum meter_colour colour;
81 	tokenmt_cfg_t *cfg_parms = tokenmt_data->cfg_parms;
82 
83 	if (mp == NULL) {
84 		tokenmt0dbg(("tokenmt_process: null mp!\n"));
85 		atomic_inc_64(&tokenmt_data->epackets);
86 		return (EINVAL);
87 	}
88 
89 	if (mp->b_datap->db_type != M_DATA) {
90 		if ((mp->b_cont != NULL) &&
91 		    (mp->b_cont->b_datap->db_type == M_DATA)) {
92 			mp = mp->b_cont;
93 		} else {
94 			tokenmt0dbg(("tokenmt_process: no data\n"));
95 			atomic_inc_64(&tokenmt_data->epackets);
96 			return (EINVAL);
97 		}
98 	}
99 
100 	/* Figure out the ToS/Traffic Class and length from the message */
101 	if ((mp->b_wptr - mp->b_rptr) < IP_SIMPLE_HDR_LENGTH) {
102 		if (!pullupmsg(mp, IP_SIMPLE_HDR_LENGTH)) {
103 			tokenmt0dbg(("tokenmt_process: pullup error\n"));
104 			atomic_inc_64(&tokenmt_data->epackets);
105 			return (EINVAL);
106 		}
107 	}
108 	ipha = (ipha_t *)mp->b_rptr;
109 	if (IPH_HDR_VERSION(ipha) == IPV4_VERSION) {
110 		/* discard last 2 unused bits */
111 		dscp = ipha->ipha_type_of_service;
112 		pkt_len = ntohs(ipha->ipha_length);
113 	} else {
114 		ip6_hdr = (ip6_t *)mp->b_rptr;
115 		/* discard ECN bits */
116 		dscp = __IPV6_TCLASS_FROM_FLOW(ip6_hdr->ip6_vcf);
117 		pkt_len = ntohs(ip6_hdr->ip6_plen) +
118 		    ip_hdr_length_v6(mp, ip6_hdr);
119 	}
120 
121 	/* Convert into bits */
122 	pkt_len <<= 3;
123 
124 	now = gethrtime();
125 
126 	mutex_enter(&tokenmt_data->tokenmt_lock);
127 	/* Update the token counts */
128 	tokenmt_update_tokens(tokenmt_data, now);
129 
130 	/*
131 	 * Figure out the drop preced. for the pkt. Need to be careful here
132 	 * because if the mode is set to COLOUR_AWARE, then the dscp value
133 	 * is used regardless of whether it was explicitly set or not.
134 	 * If the value is defaulted to 000 (drop precd.) then the pkt
135 	 * will always be coloured RED.
136 	 */
137 	if (cfg_parms->tokenmt_type == SRTCL_TOKENMT) {
138 		if (!cfg_parms->colour_aware) {
139 			if (pkt_len <= tokenmt_data->committed_tokens) {
140 				tokenmt_data->committed_tokens -= pkt_len;
141 				*next_action = cfg_parms->green_action;
142 			} else if (pkt_len <= tokenmt_data->peak_tokens) {
143 				/*
144 				 * Can't do this if yellow_action is not
145 				 * configured.
146 				 */
147 				ASSERT(cfg_parms->yellow_action !=
148 				    TOKENMT_NO_ACTION);
149 				tokenmt_data->peak_tokens -= pkt_len;
150 				*next_action = cfg_parms->yellow_action;
151 			} else {
152 				*next_action = cfg_parms->red_action;
153 			}
154 		} else {
155 			colour = cfg_parms->dscp_to_colour[dscp >> 2];
156 			if ((colour == TOKENMT_GREEN) &&
157 			    (pkt_len <= tokenmt_data->committed_tokens)) {
158 				tokenmt_data->committed_tokens -= pkt_len;
159 				*next_action = cfg_parms->green_action;
160 			} else if (((colour == TOKENMT_GREEN) ||
161 			    (colour == TOKENMT_YELLOW)) &&
162 			    (pkt_len <= tokenmt_data->peak_tokens)) {
163 				/*
164 				 * Can't do this if yellow_action is not
165 				 * configured.
166 				 */
167 				ASSERT(cfg_parms->yellow_action !=
168 				    TOKENMT_NO_ACTION);
169 				tokenmt_data->peak_tokens -= pkt_len;
170 				*next_action = cfg_parms->yellow_action;
171 			} else {
172 				*next_action = cfg_parms->red_action;
173 			}
174 		}
175 	} else {
176 		if (!cfg_parms->colour_aware) {
177 			if (pkt_len > tokenmt_data->peak_tokens) {
178 				*next_action = cfg_parms->red_action;
179 			} else if (pkt_len > tokenmt_data->committed_tokens) {
180 				/*
181 				 * Can't do this if yellow_action is not
182 				 * configured.
183 				 */
184 				ASSERT(cfg_parms->yellow_action !=
185 				    TOKENMT_NO_ACTION);
186 				tokenmt_data->peak_tokens -= pkt_len;
187 				*next_action = cfg_parms->yellow_action;
188 			} else {
189 				tokenmt_data->committed_tokens -= pkt_len;
190 				tokenmt_data->peak_tokens -= pkt_len;
191 				*next_action = cfg_parms->green_action;
192 			}
193 		} else {
194 			colour = cfg_parms->dscp_to_colour[dscp >> 2];
195 			if ((colour == TOKENMT_RED) ||
196 			    (pkt_len > tokenmt_data->peak_tokens)) {
197 				*next_action = cfg_parms->red_action;
198 			} else if ((colour == TOKENMT_YELLOW) ||
199 			    (pkt_len > tokenmt_data->committed_tokens)) {
200 				/*
201 				 * Can't do this if yellow_action is not
202 				 * configured.
203 				 */
204 				ASSERT(cfg_parms->yellow_action !=
205 				    TOKENMT_NO_ACTION);
206 				tokenmt_data->peak_tokens -= pkt_len;
207 				*next_action = cfg_parms->yellow_action;
208 			} else {
209 				tokenmt_data->committed_tokens -= pkt_len;
210 				tokenmt_data->peak_tokens -= pkt_len;
211 				*next_action = cfg_parms->green_action;
212 			}
213 		}
214 	}
215 	mutex_exit(&tokenmt_data->tokenmt_lock);
216 
217 	/* Update Stats */
218 	if (*next_action == cfg_parms->green_action) {
219 		atomic_inc_64(&tokenmt_data->green_packets);
220 		atomic_add_64(&tokenmt_data->green_bits, pkt_len);
221 	} else if (*next_action == cfg_parms->yellow_action) {
222 		atomic_inc_64(&tokenmt_data->yellow_packets);
223 		atomic_add_64(&tokenmt_data->yellow_bits, pkt_len);
224 	} else {
225 		ASSERT(*next_action == cfg_parms->red_action);
226 		atomic_inc_64(&tokenmt_data->red_packets);
227 		atomic_add_64(&tokenmt_data->red_bits, pkt_len);
228 	}
229 
230 	return (0);
231 }
232 
233 void
234 tokenmt_update_tokens(tokenmt_data_t *tokenmt_data, hrtime_t now)
235 {
236 	tokenmt_cfg_t *cfg_parms = (tokenmt_cfg_t *)tokenmt_data->cfg_parms;
237 	hrtime_t diff = now - tokenmt_data->last_seen;
238 	uint64_t tokens;
239 
240 	switch (cfg_parms->tokenmt_type) {
241 		case SRTCL_TOKENMT:
242 				tokens = (cfg_parms->committed_rate * diff) /
243 				    METER_SEC_TO_NSEC;
244 
245 				/*
246 				 * Add tokens at the committed rate to
247 				 * committed_tokens. If they are in excess of
248 				 * the committed burst, add the excess to
249 				 * peak_tokens, capped to peak_burst.
250 				 */
251 				if ((tokenmt_data->committed_tokens + tokens) >
252 				    cfg_parms->committed_burst) {
253 					tokens = tokenmt_data->committed_tokens
254 					    + tokens -
255 					    cfg_parms->committed_burst;
256 					tokenmt_data->committed_tokens =
257 					    cfg_parms->committed_burst;
258 					tokenmt_data->peak_tokens =
259 					    MIN(cfg_parms->peak_burst,
260 					    tokenmt_data->peak_tokens +
261 					    tokens);
262 				} else {
263 					tokenmt_data->committed_tokens +=
264 					    tokens;
265 				}
266 				break;
267 		case TRTCL_TOKENMT:
268 				/* Fill at the committed rate */
269 				tokens = (diff * cfg_parms->committed_rate) /
270 				    METER_SEC_TO_NSEC;
271 				tokenmt_data->committed_tokens =
272 				    MIN(cfg_parms->committed_burst,
273 				    tokenmt_data->committed_tokens + tokens);
274 
275 				/* Fill at the peak rate */
276 				tokens = (diff * cfg_parms->peak_rate) /
277 				    METER_SEC_TO_NSEC;
278 				tokenmt_data->peak_tokens =
279 				    MIN(cfg_parms->peak_burst,
280 				    tokenmt_data->peak_tokens + tokens);
281 				break;
282 	}
283 	tokenmt_data->last_seen = now;
284 }
285