xref: /freebsd/sys/netinet6/in6_rss.c (revision c1d255d3)
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 #include <sys/cdefs.h>
31 
32 __FBSDID("$FreeBSD$");
33 
34 #include "opt_inet6.h"
35 #include "opt_pcbgroup.h"
36 
37 #ifndef PCBGROUP
38 #error "options RSS depends on options PCBGROUP"
39 #endif
40 
41 #include <sys/param.h>
42 #include <sys/mbuf.h>
43 #include <sys/socket.h>
44 #include <sys/priv.h>
45 #include <sys/kernel.h>
46 #include <sys/smp.h>
47 #include <sys/sysctl.h>
48 #include <sys/sbuf.h>
49 
50 #include <net/if.h>
51 #include <net/if_var.h>
52 #include <net/netisr.h>
53 #include <net/rss_config.h>
54 
55 #include <netinet/in.h>
56 #include <netinet/in_pcb.h>
57 #include <netinet6/in6_rss.h>
58 #include <netinet/in_var.h>
59 
60 /* for software rss hash support */
61 #include <netinet/ip6.h>
62 #include <netinet6/ip6_var.h>
63 #include <netinet/tcp.h>
64 #include <netinet/udp.h>
65 
66 /*
67  * Hash an IPv6 2-tuple.
68  */
69 uint32_t
70 rss_hash_ip6_2tuple(const struct in6_addr *src, const struct in6_addr *dst)
71 {
72 	uint8_t data[sizeof(*src) + sizeof(*dst)];
73 	u_int datalen;
74 
75 	datalen = 0;
76 	bcopy(src, &data[datalen], sizeof(*src));
77 	datalen += sizeof(*src);
78 	bcopy(dst, &data[datalen], sizeof(*dst));
79 	datalen += sizeof(*dst);
80 	return (rss_hash(datalen, data));
81 }
82 
83 /*
84  * Hash an IPv6 4-tuple.
85  */
86 uint32_t
87 rss_hash_ip6_4tuple(const struct in6_addr *src, u_short srcport,
88     const struct in6_addr *dst, u_short dstport)
89 {
90 	uint8_t data[sizeof(*src) + sizeof(*dst) + sizeof(srcport) +
91 	    sizeof(dstport)];
92 	u_int datalen;
93 
94 	datalen = 0;
95 	bcopy(src, &data[datalen], sizeof(*src));
96 	datalen += sizeof(*src);
97 	bcopy(dst, &data[datalen], sizeof(*dst));
98 	datalen += sizeof(*dst);
99 	bcopy(&srcport, &data[datalen], sizeof(srcport));
100 	datalen += sizeof(srcport);
101 	bcopy(&dstport, &data[datalen], sizeof(dstport));
102 	datalen += sizeof(dstport);
103 	return (rss_hash(datalen, data));
104 }
105 
106 /*
107  * Calculate an appropriate ipv6 2-tuple or 4-tuple given the given
108  * IPv6 source/destination address, UDP or TCP source/destination ports
109  * and the protocol type.
110  *
111  * The protocol code may wish to do a software hash of the given
112  * tuple.  This depends upon the currently configured RSS hash types.
113  *
114  * This assumes that the packet in question isn't a fragment.
115  *
116  * It also assumes the packet source/destination address
117  * are in "incoming" packet order (ie, source is "far" address.)
118  */
119 int
120 rss_proto_software_hash_v6(const struct in6_addr *s, const struct in6_addr *d,
121     u_short sp, u_short dp, int proto,
122     uint32_t *hashval, uint32_t *hashtype)
123 {
124 	uint32_t hash;
125 
126 	/*
127 	 * Next, choose the hash type depending upon the protocol
128 	 * identifier.
129 	 */
130 	if ((proto == IPPROTO_TCP) &&
131 	    (rss_gethashconfig() & RSS_HASHTYPE_RSS_TCP_IPV6)) {
132 		hash = rss_hash_ip6_4tuple(s, sp, d, dp);
133 		*hashval = hash;
134 		*hashtype = M_HASHTYPE_RSS_TCP_IPV6;
135 		return (0);
136 	} else if ((proto == IPPROTO_UDP) &&
137 	    (rss_gethashconfig() & RSS_HASHTYPE_RSS_UDP_IPV6)) {
138 		hash = rss_hash_ip6_4tuple(s, sp, d, dp);
139 		*hashval = hash;
140 		*hashtype = M_HASHTYPE_RSS_UDP_IPV6;
141 		return (0);
142 	} else if (rss_gethashconfig() & RSS_HASHTYPE_RSS_IPV6) {
143 		/* RSS doesn't hash on other protocols like SCTP; so 2-tuple */
144 		hash = rss_hash_ip6_2tuple(s, d);
145 		*hashval = hash;
146 		*hashtype = M_HASHTYPE_RSS_IPV6;
147 		return (0);
148 	}
149 
150 	/* No configured available hashtypes! */
151 	RSS_DEBUG("no available hashtypes!\n");
152 	return (-1);
153 }
154 
155 /*
156  * Calculate an appropriate ipv6 2-tuple or 4-tuple given the given
157  * IPv6 source/destination address, UDP or TCP source/destination ports
158  * and the protocol type.
159  *
160  * The protocol code may wish to do a software hash of the given
161  * tuple. This depends upon the currently configured RSS hash types.
162  *
163  * It assumes the packet source/destination address
164  * are in "outgoin" packet order (ie, destination is "far" address.)
165  */
166 uint32_t
167 xps_proto_software_hash_v6(const struct in6_addr *s, const struct in6_addr *d,
168     u_short sp, u_short dp, int proto, uint32_t *hashtype)
169 {
170 
171 	uint32_t hash;
172 
173 	/*
174 	 * Next, choose the hash type depending upon the protocol
175 	 * identifier.
176 	 */
177 	if ((proto == IPPROTO_TCP) &&
178 	    (rss_gethashconfig() & RSS_HASHTYPE_RSS_TCP_IPV6)) {
179 		hash = rss_hash_ip6_4tuple(d, dp, s, sp);
180 		*hashtype = M_HASHTYPE_RSS_TCP_IPV6;
181 		return (hash);
182 	} else if ((proto == IPPROTO_UDP) &&
183 	    (rss_gethashconfig() & RSS_HASHTYPE_RSS_UDP_IPV6)) {
184 		hash = rss_hash_ip6_4tuple(d, dp, s, sp);
185 		*hashtype = M_HASHTYPE_RSS_UDP_IPV6;
186 		return (hash);
187 	} else if (rss_gethashconfig() & RSS_HASHTYPE_RSS_IPV6) {
188 		/* RSS doesn't hash on other protocols like SCTP; so 2-tuple */
189 		hash = rss_hash_ip6_2tuple(d, s);
190 		*hashtype = M_HASHTYPE_RSS_IPV6;
191 		return (hash);
192 	}
193 
194 	*hashtype = M_HASHTYPE_NONE;
195 	return (0);
196 }
197 
198 
199 /*
200  * Do a software calculation of the RSS for the given mbuf.
201  *
202  * This is typically used by the input path to recalculate the RSS after
203  * some form of packet processing (eg de-capsulation, IP fragment reassembly.)
204  *
205  * dir is the packet direction - RSS_HASH_PKT_INGRESS for incoming and
206  * RSS_HASH_PKT_EGRESS for outgoing.
207  *
208  * Returns 0 if a hash was done, -1 if no hash was done, +1 if
209  * the mbuf already had a valid RSS flowid.
210  *
211  * This function doesn't modify the mbuf.  It's up to the caller to
212  * assign flowid/flowtype as appropriate.
213  */
214 int
215 rss_mbuf_software_hash_v6(const struct mbuf *m, int dir, uint32_t *hashval,
216     uint32_t *hashtype)
217 {
218 	const struct ip6_hdr *ip6;
219 	const struct ip6_frag *ip6f;
220 	const struct tcphdr *th;
221 	const struct udphdr *uh;
222 	uint32_t flowtype;
223 	uint8_t proto;
224 	int off, newoff;
225 	int nxt;
226 
227 	/*
228 	 * XXX For now this only handles hashing on incoming mbufs.
229 	 */
230 	if (dir != RSS_HASH_PKT_INGRESS) {
231 		RSS_DEBUG("called on EGRESS packet!\n");
232 		return (-1);
233 	}
234 
235 	off = sizeof(struct ip6_hdr);
236 
237 	/*
238 	 * First, validate that the mbuf we have is long enough
239 	 * to have an IPv6 header in it.
240 	 */
241 	if (m->m_pkthdr.len < off) {
242 		RSS_DEBUG("short mbuf pkthdr\n");
243 		return (-1);
244 	}
245 	if (m->m_len < off) {
246 		RSS_DEBUG("short mbuf len\n");
247 		return (-1);
248 	}
249 
250 	/* Ok, let's dereference that */
251 	ip6 = mtod(m, struct ip6_hdr *);
252 	proto = ip6->ip6_nxt;
253 
254 	/*
255 	 * Find the beginning of the TCP/UDP header.
256 	 *
257 	 * If this is a fragment then it shouldn't be four-tuple
258 	 * hashed just yet.  Once it's reassembled into a full
259 	 * frame it should be re-hashed.
260 	 */
261 	while (proto != IPPROTO_FRAGMENT) {
262 		newoff = ip6_nexthdr(m, off, proto, &nxt);
263 		if (newoff < 0)
264 			break;
265 		off = newoff;
266 		proto = nxt;
267 	}
268 
269 	/*
270 	 * Ignore the fragment header if this is an "atomic" fragment
271 	 * (offset and m bit set to 0)
272 	 */
273 	if (proto == IPPROTO_FRAGMENT) {
274 		if (m->m_len < off + sizeof(struct ip6_frag)) {
275 			RSS_DEBUG("short fragment frame?\n");
276 			return (-1);
277 		}
278 		ip6f = (const struct ip6_frag *)((c_caddr_t)ip6 + off);
279 		if ((ip6f->ip6f_offlg & ~IP6F_RESERVED_MASK) == 0) {
280 			off = ip6_lasthdr(m, off, proto, &nxt);
281 			if (off < 0) {
282 				RSS_DEBUG("invalid extension header\n");
283 				return (-1);
284 			}
285 			proto = nxt;
286 		}
287 	}
288 
289 	/*
290 	 * If the mbuf flowid/flowtype matches the packet type,
291 	 * and we don't support the 4-tuple version of the given protocol,
292 	 * then signal to the owner that it can trust the flowid/flowtype
293 	 * details.
294 	 *
295 	 * This is a little picky - eg, if TCPv6 / UDPv6 hashing
296 	 * is supported but we got a TCP/UDP frame only 2-tuple hashed,
297 	 * then we shouldn't just "trust" the 2-tuple hash.  We need
298 	 * a 4-tuple hash.
299 	 */
300 	flowtype = M_HASHTYPE_GET(m);
301 
302 	if (flowtype != M_HASHTYPE_NONE) {
303 		switch (proto) {
304 		case IPPROTO_UDP:
305 			if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_UDP_IPV6) &&
306 			    (flowtype == M_HASHTYPE_RSS_UDP_IPV6)) {
307 				return (1);
308 			}
309 			/*
310 			 * Only allow 2-tuple for UDP frames if we don't also
311 			 * support 4-tuple for UDP.
312 			 */
313 			if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_IPV6) &&
314 			    ((rss_gethashconfig() & RSS_HASHTYPE_RSS_UDP_IPV6) == 0) &&
315 			    flowtype == M_HASHTYPE_RSS_IPV6) {
316 				return (1);
317 			}
318 			break;
319 		case IPPROTO_TCP:
320 			if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_TCP_IPV6) &&
321 			    (flowtype == M_HASHTYPE_RSS_TCP_IPV6)) {
322 				return (1);
323 			}
324 			/*
325 			 * Only allow 2-tuple for TCP frames if we don't also
326 			 * support 4-tuple for TCP.
327 			 */
328 			if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_IPV6) &&
329 			    ((rss_gethashconfig() & RSS_HASHTYPE_RSS_TCP_IPV6) == 0) &&
330 			    flowtype == M_HASHTYPE_RSS_IPV6) {
331 				return (1);
332 			}
333 			break;
334 		default:
335 			if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_IPV6) &&
336 			    flowtype == M_HASHTYPE_RSS_IPV6) {
337 				return (1);
338 			}
339 			break;
340 		}
341 	}
342 
343 	/*
344 	 * Decode enough information to make a hash decision.
345 	 */
346 	if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_TCP_IPV6) &&
347 	    (proto == IPPROTO_TCP)) {
348 		if (m->m_len < off + sizeof(struct tcphdr)) {
349 			RSS_DEBUG("short TCP frame?\n");
350 			return (-1);
351 		}
352 		th = (const struct tcphdr *)((c_caddr_t)ip6 + off);
353 		return rss_proto_software_hash_v6(&ip6->ip6_src, &ip6->ip6_dst,
354 		    th->th_sport,
355 		    th->th_dport,
356 		    proto,
357 		    hashval,
358 		    hashtype);
359 	} else if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_UDP_IPV6) &&
360 	    (proto == IPPROTO_UDP)) {
361 		if (m->m_len < off + sizeof(struct udphdr)) {
362 			RSS_DEBUG("short UDP frame?\n");
363 			return (-1);
364 		}
365 		uh = (const struct udphdr *)((c_caddr_t)ip6 + off);
366 		return rss_proto_software_hash_v6(&ip6->ip6_src, &ip6->ip6_dst,
367 		    uh->uh_sport,
368 		    uh->uh_dport,
369 		    proto,
370 		    hashval,
371 		    hashtype);
372 	} else if (rss_gethashconfig() & RSS_HASHTYPE_RSS_IPV6) {
373 		/* Default to 2-tuple hash */
374 		return rss_proto_software_hash_v6(&ip6->ip6_src, &ip6->ip6_dst,
375 		    0,	/* source port */
376 		    0,	/* destination port */
377 		    0,	/* IPPROTO_IP */
378 		    hashval,
379 		    hashtype);
380 	} else {
381 		RSS_DEBUG("no available hashtypes!\n");
382 		return (-1);
383 	}
384 }
385 
386 /*
387  * Similar to rss_m2cpuid, but designed to be used by the IPv6 NETISR
388  * on incoming frames.
389  *
390  * If an existing RSS hash exists and it matches what the configured
391  * hashing is, then use it.
392  *
393  * If there's an existing RSS hash but the desired hash is different,
394  * or if there's no useful RSS hash, then calculate it via
395  * the software path.
396  *
397  * XXX TODO: definitely want statistics here!
398  */
399 struct mbuf *
400 rss_soft_m2cpuid_v6(struct mbuf *m, uintptr_t source, u_int *cpuid)
401 {
402 	uint32_t hash_val, hash_type;
403 	int ret;
404 
405 	M_ASSERTPKTHDR(m);
406 
407 	ret = rss_mbuf_software_hash_v6(m, RSS_HASH_PKT_INGRESS,
408 	    &hash_val, &hash_type);
409 	if (ret > 0) {
410 		/* mbuf has a valid hash already; don't need to modify it */
411 		*cpuid = rss_hash2cpuid(m->m_pkthdr.flowid, M_HASHTYPE_GET(m));
412 	} else if (ret == 0) {
413 		/* hash was done; update */
414 		m->m_pkthdr.flowid = hash_val;
415 		M_HASHTYPE_SET(m, hash_type);
416 		*cpuid = rss_hash2cpuid(m->m_pkthdr.flowid, M_HASHTYPE_GET(m));
417 	} else { /* ret < 0 */
418 		/* no hash was done */
419 		*cpuid = NETISR_CPUID_NONE;
420 	}
421 	return (m);
422 }
423