1 /*
2  * lib/route/sch/sfq.c		SFQ Qdisc
3  *
4  *	This library is free software; you can redistribute it and/or
5  *	modify it under the terms of the GNU Lesser General Public
6  *	License as published by the Free Software Foundation version 2.1
7  *	of the License.
8  *
9  * Copyright (c) 2003-2008 Thomas Graf <tgraf@suug.ch>
10  */
11 
12 /**
13  * @ingroup qdisc_api
14  * @defgroup sfq Stochastic Fairness Queueing (SFQ)
15  * @brief
16  *
17  * @par Parameter Description
18  * - \b Quantum: Number of bytes to send out per slot and round.
19  * - \b Perturbation: Timer period between changing the hash function.
20  * - \b Limit:  Upper limit of queue in number of packets before SFQ starts
21  *	        dropping packets.
22  * - \b Divisor: Hash table divisor, i.e. size of hash table.
23  * @{
24  */
25 
26 #include <netlink-local.h>
27 #include <netlink-tc.h>
28 #include <netlink/netlink.h>
29 #include <netlink/utils.h>
30 #include <netlink/route/qdisc.h>
31 #include <netlink/route/qdisc-modules.h>
32 #include <netlink/route/sch/sfq.h>
33 
34 /** @cond SKIP */
35 #define SCH_SFQ_ATTR_QUANTUM	0x01
36 #define SCH_SFQ_ATTR_PERTURB	0x02
37 #define SCH_SFQ_ATTR_LIMIT	0x04
38 #define SCH_SFQ_ATTR_DIVISOR	0x08
39 #define SCH_SFQ_ATTR_FLOWS	0x10
40 /** @endcond */
41 
sfq_qdisc(struct rtnl_qdisc * qdisc)42 static inline struct rtnl_sfq *sfq_qdisc(struct rtnl_qdisc *qdisc)
43 {
44 	return (struct rtnl_sfq *) qdisc->q_subdata;
45 }
46 
sfq_alloc(struct rtnl_qdisc * qdisc)47 static inline struct rtnl_sfq *sfq_alloc(struct rtnl_qdisc *qdisc)
48 {
49 	if (!qdisc->q_subdata)
50 		qdisc->q_subdata = calloc(1, sizeof(struct rtnl_sfq));
51 
52 	return sfq_qdisc(qdisc);
53 }
54 
sfq_msg_parser(struct rtnl_qdisc * qdisc)55 static int sfq_msg_parser(struct rtnl_qdisc *qdisc)
56 {
57 	struct rtnl_sfq *sfq;
58 	struct tc_sfq_qopt *opts;
59 
60 	if (!(qdisc->ce_mask & TCA_ATTR_OPTS))
61 		return 0;
62 
63 	if (qdisc->q_opts->d_size < sizeof(*opts))
64 		return -NLE_INVAL;
65 
66 	sfq = sfq_alloc(qdisc);
67 	if (!sfq)
68 		return -NLE_NOMEM;
69 
70 	opts = (struct tc_sfq_qopt *) qdisc->q_opts->d_data;
71 
72 	sfq->qs_quantum = opts->quantum;
73 	sfq->qs_perturb = opts->perturb_period;
74 	sfq->qs_limit = opts->limit;
75 	sfq->qs_divisor = opts->divisor;
76 	sfq->qs_flows = opts->flows;
77 
78 	sfq->qs_mask = (SCH_SFQ_ATTR_QUANTUM | SCH_SFQ_ATTR_PERTURB |
79 			SCH_SFQ_ATTR_LIMIT | SCH_SFQ_ATTR_DIVISOR |
80 			SCH_SFQ_ATTR_FLOWS);
81 
82 	return 0;
83 }
84 
sfq_free_data(struct rtnl_qdisc * qdisc)85 static void sfq_free_data(struct rtnl_qdisc *qdisc)
86 {
87 	free(qdisc->q_subdata);
88 }
89 
sfq_dump_line(struct rtnl_qdisc * qdisc,struct nl_dump_params * p)90 static void sfq_dump_line(struct rtnl_qdisc *qdisc, struct nl_dump_params *p)
91 {
92 	struct rtnl_sfq *sfq = sfq_qdisc(qdisc);
93 
94 	if (sfq)
95 		nl_dump(p, " quantum %u perturb %us", sfq->qs_quantum,
96 			nl_ticks2us(sfq->qs_perturb * nl_get_hz()));
97 }
98 
sfq_dump_details(struct rtnl_qdisc * qdisc,struct nl_dump_params * p)99 static void sfq_dump_details(struct rtnl_qdisc *qdisc, struct nl_dump_params *p)
100 {
101 	struct rtnl_sfq *sfq = sfq_qdisc(qdisc);
102 
103 	if (sfq)
104 		nl_dump(p, "limit %u divisor %u",
105 			sfq->qs_limit, sfq->qs_divisor);
106 }
107 
sfq_get_opts(struct rtnl_qdisc * qdisc)108 static struct nl_msg *sfq_get_opts(struct rtnl_qdisc *qdisc)
109 {
110 	struct rtnl_sfq *sfq;
111 	struct tc_sfq_qopt opts;
112 	struct nl_msg *msg;
113 
114 	sfq = sfq_qdisc(qdisc);
115 	if (!sfq)
116 		return NULL;
117 
118 	msg = nlmsg_alloc();
119 	if (!msg)
120 		goto errout;
121 
122 	memset(&opts, 0, sizeof(opts));
123 	opts.quantum = sfq->qs_quantum;
124 	opts.perturb_period = sfq->qs_perturb;
125 	opts.limit = sfq->qs_limit;
126 
127 	if (nlmsg_append(msg, &opts, sizeof(opts), NL_DONTPAD) < 0)
128 		goto errout;
129 
130 	return msg;
131 errout:
132 	nlmsg_free(msg);
133 	return NULL;
134 }
135 
136 /**
137  * @name Attribute Access
138  * @{
139  */
140 
141 /**
142  * Set quantum of SFQ qdisc.
143  * @arg qdisc		SFQ qdisc to be modified.
144  * @arg quantum		New quantum in bytes.
145  * @return 0 on success or a negative error code.
146  */
rtnl_sfq_set_quantum(struct rtnl_qdisc * qdisc,int quantum)147 int rtnl_sfq_set_quantum(struct rtnl_qdisc *qdisc, int quantum)
148 {
149 	struct rtnl_sfq *sfq;
150 
151 	sfq = sfq_alloc(qdisc);
152 	if (!sfq)
153 		return -NLE_NOMEM;
154 
155 	sfq->qs_quantum = quantum;
156 	sfq->qs_mask |= SCH_SFQ_ATTR_QUANTUM;
157 
158 	return 0;
159 }
160 
161 /**
162  * Get quantum of SFQ qdisc.
163  * @arg qdisc		SFQ qdisc.
164  * @return Quantum in bytes or a negative error code.
165  */
rtnl_sfq_get_quantum(struct rtnl_qdisc * qdisc)166 int rtnl_sfq_get_quantum(struct rtnl_qdisc *qdisc)
167 {
168 	struct rtnl_sfq *sfq;
169 
170 	sfq = sfq_qdisc(qdisc);
171 	if (sfq && sfq->qs_mask & SCH_SFQ_ATTR_QUANTUM)
172 		return sfq->qs_quantum;
173 	else
174 		return -NLE_NOATTR;
175 }
176 
177 /**
178  * Set limit of SFQ qdisc.
179  * @arg qdisc		SFQ qdisc to be modified.
180  * @arg limit		New limit in number of packets.
181  * @return 0 on success or a negative error code.
182  */
rtnl_sfq_set_limit(struct rtnl_qdisc * qdisc,int limit)183 int rtnl_sfq_set_limit(struct rtnl_qdisc *qdisc, int limit)
184 {
185 	struct rtnl_sfq *sfq;
186 
187 	sfq = sfq_alloc(qdisc);
188 	if (!sfq)
189 		return -NLE_NOMEM;
190 
191 	sfq->qs_limit = limit;
192 	sfq->qs_mask |= SCH_SFQ_ATTR_LIMIT;
193 
194 	return 0;
195 }
196 
197 /**
198  * Get limit of SFQ qdisc.
199  * @arg qdisc		SFQ qdisc.
200  * @return Limit or a negative error code.
201  */
rtnl_sfq_get_limit(struct rtnl_qdisc * qdisc)202 int rtnl_sfq_get_limit(struct rtnl_qdisc *qdisc)
203 {
204 	struct rtnl_sfq *sfq;
205 
206 	sfq = sfq_qdisc(qdisc);
207 	if (sfq && sfq->qs_mask & SCH_SFQ_ATTR_LIMIT)
208 		return sfq->qs_limit;
209 	else
210 		return -NLE_NOATTR;
211 }
212 
213 /**
214  * Set perturbation interval of SFQ qdisc.
215  * @arg qdisc		SFQ qdisc to be modified.
216  * @arg perturb		New perturbation interval in seconds.
217  * @note A value of 0 disables perturbation altogether.
218  * @return 0 on success or a negative error code.
219  */
rtnl_sfq_set_perturb(struct rtnl_qdisc * qdisc,int perturb)220 int rtnl_sfq_set_perturb(struct rtnl_qdisc *qdisc, int perturb)
221 {
222 	struct rtnl_sfq *sfq;
223 
224 	sfq = sfq_alloc(qdisc);
225 	if (!sfq)
226 		return -NLE_NOMEM;
227 
228 	sfq->qs_perturb = perturb;
229 	sfq->qs_mask |= SCH_SFQ_ATTR_PERTURB;
230 
231 	return 0;
232 }
233 
234 /**
235  * Get perturbation interval of SFQ qdisc.
236  * @arg qdisc		SFQ qdisc.
237  * @return Perturbation interval in seconds or a negative error code.
238  */
rtnl_sfq_get_perturb(struct rtnl_qdisc * qdisc)239 int rtnl_sfq_get_perturb(struct rtnl_qdisc *qdisc)
240 {
241 	struct rtnl_sfq *sfq;
242 
243 	sfq = sfq_qdisc(qdisc);
244 	if (sfq && sfq->qs_mask & SCH_SFQ_ATTR_PERTURB)
245 		return sfq->qs_perturb;
246 	else
247 		return -NLE_NOATTR;
248 }
249 
250 /**
251  * Get divisor of SFQ qdisc.
252  * @arg qdisc		SFQ qdisc.
253  * @return Divisor in number of entries or a negative error code.
254  */
rtnl_sfq_get_divisor(struct rtnl_qdisc * qdisc)255 int rtnl_sfq_get_divisor(struct rtnl_qdisc *qdisc)
256 {
257 	struct rtnl_sfq *sfq;
258 
259 	sfq = sfq_qdisc(qdisc);
260 	if (sfq && sfq->qs_mask & SCH_SFQ_ATTR_DIVISOR)
261 		return sfq->qs_divisor;
262 	else
263 		return -NLE_NOATTR;
264 }
265 
266 /** @} */
267 
268 static struct rtnl_qdisc_ops sfq_ops = {
269 	.qo_kind		= "sfq",
270 	.qo_msg_parser		= sfq_msg_parser,
271 	.qo_free_data		= sfq_free_data,
272 	.qo_dump = {
273 	    [NL_DUMP_LINE]	= sfq_dump_line,
274 	    [NL_DUMP_DETAILS]	= sfq_dump_details,
275 	},
276 	.qo_get_opts		= sfq_get_opts,
277 };
278 
sfq_init(void)279 static void __init sfq_init(void)
280 {
281 	rtnl_qdisc_register(&sfq_ops);
282 }
283 
sfq_exit(void)284 static void __exit sfq_exit(void)
285 {
286 	rtnl_qdisc_unregister(&sfq_ops);
287 }
288 
289 /** @} */
290