xref: /freebsd/sys/netinet/in_rss.c (revision e928afc531e68b7a142ee49d8f7e5c8426d54033)
1 /*-
2  * Copyright (c) 2010-2011 Juniper Networks, Inc.
3  * All rights reserved.
4  *
5  * This software was developed by Robert N. M. Watson under contract
6  * to Juniper Networks, Inc.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 
31 #include "opt_inet6.h"
32 #include "opt_rss.h"
33 
34 #include <sys/param.h>
35 #include <sys/mbuf.h>
36 #include <sys/socket.h>
37 #include <sys/priv.h>
38 #include <sys/kernel.h>
39 #include <sys/smp.h>
40 #include <sys/sysctl.h>
41 #include <sys/sbuf.h>
42 
43 #include <net/if.h>
44 #include <net/if_var.h>
45 #include <net/netisr.h>
46 #include <net/rss_config.h>
47 
48 #include <netinet/in.h>
49 #include <netinet/in_pcb.h>
50 #include <netinet/in_rss.h>
51 #include <netinet/in_var.h>
52 
53 /* for software rss hash support */
54 #include <netinet/ip.h>
55 #include <netinet/tcp.h>
56 #include <netinet/udp.h>
57 
58 /*
59  * Hash an IPv4 2-tuple.
60  */
61 uint32_t
62 rss_hash_ip4_2tuple(struct in_addr src, struct in_addr dst)
63 {
64 	uint8_t data[sizeof(src) + sizeof(dst)];
65 	u_int datalen;
66 
67 	datalen = 0;
68 	bcopy(&src, &data[datalen], sizeof(src));
69 	datalen += sizeof(src);
70 	bcopy(&dst, &data[datalen], sizeof(dst));
71 	datalen += sizeof(dst);
72 	return (rss_hash(datalen, data));
73 }
74 
75 /*
76  * Hash an IPv4 4-tuple.
77  */
78 uint32_t
79 rss_hash_ip4_4tuple(struct in_addr src, u_short srcport, struct in_addr dst,
80     u_short dstport)
81 {
82 	uint8_t data[sizeof(src) + sizeof(dst) + sizeof(srcport) +
83 	    sizeof(dstport)];
84 	u_int datalen;
85 
86 	datalen = 0;
87 	bcopy(&src, &data[datalen], sizeof(src));
88 	datalen += sizeof(src);
89 	bcopy(&dst, &data[datalen], sizeof(dst));
90 	datalen += sizeof(dst);
91 	bcopy(&srcport, &data[datalen], sizeof(srcport));
92 	datalen += sizeof(srcport);
93 	bcopy(&dstport, &data[datalen], sizeof(dstport));
94 	datalen += sizeof(dstport);
95 	return (rss_hash(datalen, data));
96 }
97 
98 /*
99  * Calculate an appropriate ipv4 2-tuple or 4-tuple given the given
100  * IPv4 source/destination address, UDP or TCP source/destination ports
101  * and the protocol type.
102  *
103  * The protocol code may wish to do a software hash of the given
104  * tuple.  This depends upon the currently configured RSS hash types.
105  *
106  * This assumes that the packet in question isn't a fragment.
107  *
108  * It also assumes the packet source/destination address
109  * are in "incoming" packet order (ie, source is "far" address.)
110  */
111 int
112 rss_proto_software_hash_v4(struct in_addr s, struct in_addr d,
113     u_short sp, u_short dp, int proto,
114     uint32_t *hashval, uint32_t *hashtype)
115 {
116 	uint32_t hash;
117 
118 	/*
119 	 * Next, choose the hash type depending upon the protocol
120 	 * identifier.
121 	 */
122 	if ((proto == IPPROTO_TCP) &&
123 	    (rss_gethashconfig() & RSS_HASHTYPE_RSS_TCP_IPV4)) {
124 		hash = rss_hash_ip4_4tuple(s, sp, d, dp);
125 		*hashval = hash;
126 		*hashtype = M_HASHTYPE_RSS_TCP_IPV4;
127 		return (0);
128 	} else if ((proto == IPPROTO_UDP) &&
129 	    (rss_gethashconfig() & RSS_HASHTYPE_RSS_UDP_IPV4)) {
130 		hash = rss_hash_ip4_4tuple(s, sp, d, dp);
131 		*hashval = hash;
132 		*hashtype = M_HASHTYPE_RSS_UDP_IPV4;
133 		return (0);
134 	} else if (rss_gethashconfig() & RSS_HASHTYPE_RSS_IPV4) {
135 		/* RSS doesn't hash on other protocols like SCTP; so 2-tuple */
136 		hash = rss_hash_ip4_2tuple(s, d);
137 		*hashval = hash;
138 		*hashtype = M_HASHTYPE_RSS_IPV4;
139 		return (0);
140 	}
141 
142 	/* No configured available hashtypes! */
143 	RSS_DEBUG("no available hashtypes!\n");
144 	return (-1);
145 }
146 
147 /*
148  * Calculate an appropriate ipv4 2-tuple or 4-tuple given the given
149  * IPv4 source/destination address, UDP or TCP source/destination ports
150  * and the protocol type.
151  *
152  * The protocol code may wish to do a software hash of the given
153  * tuple.  This depends upon the currently configured RSS hash types.
154  *
155  * It assumes the packet source/destination address
156  * are in "outgoing" packet order (ie, destination is "far" address.)
157  */
158 uint32_t
159 xps_proto_software_hash_v4(struct in_addr s, struct in_addr d,
160     u_short sp, u_short dp, int proto, uint32_t *hashtype)
161 {
162 	uint32_t hash;
163 
164 	/*
165 	 * Next, choose the hash type depending upon the protocol
166 	 * identifier.
167 	 */
168 	if ((proto == IPPROTO_TCP) &&
169 	    (rss_gethashconfig() & RSS_HASHTYPE_RSS_TCP_IPV4)) {
170 		hash = rss_hash_ip4_4tuple(d, dp, s, sp);
171 		*hashtype = M_HASHTYPE_RSS_TCP_IPV4;
172 		return (hash);
173 	} else if ((proto == IPPROTO_UDP) &&
174 	    (rss_gethashconfig() & RSS_HASHTYPE_RSS_UDP_IPV4)) {
175 		hash = rss_hash_ip4_4tuple(d, dp, s, sp);
176 		*hashtype = M_HASHTYPE_RSS_UDP_IPV4;
177 		return (hash);
178 	} else if (rss_gethashconfig() & RSS_HASHTYPE_RSS_IPV4) {
179 		/* RSS doesn't hash on other protocols like SCTP; so 2-tuple */
180 		hash = rss_hash_ip4_2tuple(d, s);
181 		*hashtype = M_HASHTYPE_RSS_IPV4;
182 		return (hash);
183 	}
184 
185 	*hashtype = M_HASHTYPE_NONE;
186 	return (0);
187 }
188 
189 /*
190  * Do a software calculation of the RSS for the given mbuf.
191  *
192  * This is typically used by the input path to recalculate the RSS after
193  * some form of packet processing (eg de-capsulation, IP fragment reassembly.)
194  *
195  * dir is the packet direction - RSS_HASH_PKT_INGRESS for incoming and
196  * RSS_HASH_PKT_EGRESS for outgoing.
197  *
198  * Returns 0 if a hash was done, -1 if no hash was done, +1 if
199  * the mbuf already had a valid RSS flowid.
200  *
201  * This function doesn't modify the mbuf.  It's up to the caller to
202  * assign flowid/flowtype as appropriate.
203  */
204 int
205 rss_mbuf_software_hash_v4(const struct mbuf *m, int dir, uint32_t *hashval,
206     uint32_t *hashtype)
207 {
208 	const struct ip *ip;
209 	const struct tcphdr *th;
210 	const struct udphdr *uh;
211 	uint32_t flowtype;
212 	uint8_t proto;
213 	int iphlen;
214 	int is_frag = 0;
215 
216 	/*
217 	 * XXX For now this only handles hashing on incoming mbufs.
218 	 */
219 	if (dir != RSS_HASH_PKT_INGRESS) {
220 		RSS_DEBUG("called on EGRESS packet!\n");
221 		return (-1);
222 	}
223 
224 	/*
225 	 * First, validate that the mbuf we have is long enough
226 	 * to have an IPv4 header in it.
227 	 */
228 	if (m->m_pkthdr.len < (sizeof(struct ip))) {
229 		RSS_DEBUG("short mbuf pkthdr\n");
230 		return (-1);
231 	}
232 	if (m->m_len < (sizeof(struct ip))) {
233 		RSS_DEBUG("short mbuf len\n");
234 		return (-1);
235 	}
236 
237 	/* Ok, let's dereference that */
238 	ip = mtod(m, struct ip *);
239 	proto = ip->ip_p;
240 	iphlen = ip->ip_hl << 2;
241 
242 	/*
243 	 * If this is a fragment then it shouldn't be four-tuple
244 	 * hashed just yet.  Once it's reassembled into a full
245 	 * frame it should be re-hashed.
246 	 */
247 	if (ip->ip_off & htons(IP_MF | IP_OFFMASK))
248 		is_frag = 1;
249 
250 	/*
251 	 * If the mbuf flowid/flowtype matches the packet type,
252 	 * and we don't support the 4-tuple version of the given protocol,
253 	 * then signal to the owner that it can trust the flowid/flowtype
254 	 * details.
255 	 *
256 	 * This is a little picky - eg, if TCPv4 / UDPv4 hashing
257 	 * is supported but we got a TCP/UDP frame only 2-tuple hashed,
258 	 * then we shouldn't just "trust" the 2-tuple hash.  We need
259 	 * a 4-tuple hash.
260 	 */
261 	flowtype = M_HASHTYPE_GET(m);
262 
263 	if (flowtype != M_HASHTYPE_NONE) {
264 		switch (proto) {
265 		case IPPROTO_UDP:
266 			if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_UDP_IPV4) &&
267 			    (flowtype == M_HASHTYPE_RSS_UDP_IPV4) &&
268 			    (is_frag == 0)) {
269 				return (1);
270 			}
271 			/*
272 			 * Only allow 2-tuple for UDP frames if we don't also
273 			 * support 4-tuple for UDP.
274 			 */
275 			if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_IPV4) &&
276 			    ((rss_gethashconfig() & RSS_HASHTYPE_RSS_UDP_IPV4) == 0) &&
277 			    flowtype == M_HASHTYPE_RSS_IPV4) {
278 				return (1);
279 			}
280 			break;
281 		case IPPROTO_TCP:
282 			if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_TCP_IPV4) &&
283 			    (flowtype == M_HASHTYPE_RSS_TCP_IPV4) &&
284 			    (is_frag == 0)) {
285 				return (1);
286 			}
287 			/*
288 			 * Only allow 2-tuple for TCP frames if we don't also
289 			 * support 4-tuple for TCP.
290 			 */
291 			if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_IPV4) &&
292 			    ((rss_gethashconfig() & RSS_HASHTYPE_RSS_TCP_IPV4) == 0) &&
293 			    flowtype == M_HASHTYPE_RSS_IPV4) {
294 				return (1);
295 			}
296 			break;
297 		default:
298 			if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_IPV4) &&
299 			    flowtype == M_HASHTYPE_RSS_IPV4) {
300 				return (1);
301 			}
302 			break;
303 		}
304 	}
305 
306 	/*
307 	 * Decode enough information to make a hash decision.
308 	 *
309 	 * XXX TODO: does the hardware hash on 4-tuple if IP
310 	 *    options are present?
311 	 */
312 	if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_TCP_IPV4) &&
313 	    (proto == IPPROTO_TCP) &&
314 	    (is_frag == 0)) {
315 		if (m->m_len < iphlen + sizeof(struct tcphdr)) {
316 			RSS_DEBUG("short TCP frame?\n");
317 			return (-1);
318 		}
319 		th = (const struct tcphdr *)((c_caddr_t)ip + iphlen);
320 		return rss_proto_software_hash_v4(ip->ip_src, ip->ip_dst,
321 		    th->th_sport,
322 		    th->th_dport,
323 		    proto,
324 		    hashval,
325 		    hashtype);
326 	} else if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_UDP_IPV4) &&
327 	    (proto == IPPROTO_UDP) &&
328 	    (is_frag == 0)) {
329 		uh = (const struct udphdr *)((c_caddr_t)ip + iphlen);
330 		if (m->m_len < iphlen + sizeof(struct udphdr)) {
331 			RSS_DEBUG("short UDP frame?\n");
332 			return (-1);
333 		}
334 		return rss_proto_software_hash_v4(ip->ip_src, ip->ip_dst,
335 		    uh->uh_sport,
336 		    uh->uh_dport,
337 		    proto,
338 		    hashval,
339 		    hashtype);
340 	} else if (rss_gethashconfig() & RSS_HASHTYPE_RSS_IPV4) {
341 		/* Default to 2-tuple hash */
342 		return rss_proto_software_hash_v4(ip->ip_src, ip->ip_dst,
343 		    0,	/* source port */
344 		    0,	/* destination port */
345 		    0,	/* IPPROTO_IP */
346 		    hashval,
347 		    hashtype);
348 	} else {
349 		RSS_DEBUG("no available hashtypes!\n");
350 		return (-1);
351 	}
352 }
353 
354 #ifdef RSS
355 /*
356  * Similar to rss_m2cpuid, but designed to be used by the IP NETISR
357  * on incoming frames.
358  *
359  * If an existing RSS hash exists and it matches what the configured
360  * hashing is, then use it.
361  *
362  * If there's an existing RSS hash but the desired hash is different,
363  * or if there's no useful RSS hash, then calculate it via
364  * the software path.
365  *
366  * XXX TODO: definitely want statistics here!
367  */
368 struct mbuf *
369 rss_soft_m2cpuid_v4(struct mbuf *m, uintptr_t source, u_int *cpuid)
370 {
371 	uint32_t hash_val, hash_type;
372 	int ret;
373 
374 	M_ASSERTPKTHDR(m);
375 
376 	ret = rss_mbuf_software_hash_v4(m, RSS_HASH_PKT_INGRESS,
377 	    &hash_val, &hash_type);
378 	if (ret > 0) {
379 		/* mbuf has a valid hash already; don't need to modify it */
380 		*cpuid = rss_hash2cpuid(m->m_pkthdr.flowid, M_HASHTYPE_GET(m));
381 	} else if (ret == 0) {
382 		/* hash was done; update */
383 		m->m_pkthdr.flowid = hash_val;
384 		M_HASHTYPE_SET(m, hash_type);
385 		*cpuid = rss_hash2cpuid(m->m_pkthdr.flowid, M_HASHTYPE_GET(m));
386 	} else { /* ret < 0 */
387 		/* no hash was done */
388 		*cpuid = NETISR_CPUID_NONE;
389 	}
390 	return (m);
391 }
392 #endif
393