xref: /freebsd/sys/netinet/in_rss.c (revision f7c32ed617858bcd22f8d1b03199099d50125721)
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 <netinet/in_rss.h>
58 #include <netinet/in_var.h>
59 
60 /* for software rss hash support */
61 #include <netinet/ip.h>
62 #include <netinet/tcp.h>
63 #include <netinet/udp.h>
64 
65 /*
66  * Hash an IPv4 2-tuple.
67  */
68 uint32_t
69 rss_hash_ip4_2tuple(struct in_addr src, struct in_addr dst)
70 {
71 	uint8_t data[sizeof(src) + sizeof(dst)];
72 	u_int datalen;
73 
74 	datalen = 0;
75 	bcopy(&src, &data[datalen], sizeof(src));
76 	datalen += sizeof(src);
77 	bcopy(&dst, &data[datalen], sizeof(dst));
78 	datalen += sizeof(dst);
79 	return (rss_hash(datalen, data));
80 }
81 
82 /*
83  * Hash an IPv4 4-tuple.
84  */
85 uint32_t
86 rss_hash_ip4_4tuple(struct in_addr src, u_short srcport, struct in_addr dst,
87     u_short dstport)
88 {
89 	uint8_t data[sizeof(src) + sizeof(dst) + sizeof(srcport) +
90 	    sizeof(dstport)];
91 	u_int datalen;
92 
93 	datalen = 0;
94 	bcopy(&src, &data[datalen], sizeof(src));
95 	datalen += sizeof(src);
96 	bcopy(&dst, &data[datalen], sizeof(dst));
97 	datalen += sizeof(dst);
98 	bcopy(&srcport, &data[datalen], sizeof(srcport));
99 	datalen += sizeof(srcport);
100 	bcopy(&dstport, &data[datalen], sizeof(dstport));
101 	datalen += sizeof(dstport);
102 	return (rss_hash(datalen, data));
103 }
104 
105 /*
106  * Calculate an appropriate ipv4 2-tuple or 4-tuple given the given
107  * IPv4 source/destination address, UDP or TCP source/destination ports
108  * and the protocol type.
109  *
110  * The protocol code may wish to do a software hash of the given
111  * tuple.  This depends upon the currently configured RSS hash types.
112  *
113  * This assumes that the packet in question isn't a fragment.
114  *
115  * It also assumes the packet source/destination address
116  * are in "incoming" packet order (ie, source is "far" address.)
117  */
118 int
119 rss_proto_software_hash_v4(struct in_addr s, struct in_addr d,
120     u_short sp, u_short dp, int proto,
121     uint32_t *hashval, uint32_t *hashtype)
122 {
123 	uint32_t hash;
124 
125 	/*
126 	 * Next, choose the hash type depending upon the protocol
127 	 * identifier.
128 	 */
129 	if ((proto == IPPROTO_TCP) &&
130 	    (rss_gethashconfig() & RSS_HASHTYPE_RSS_TCP_IPV4)) {
131 		hash = rss_hash_ip4_4tuple(s, sp, d, dp);
132 		*hashval = hash;
133 		*hashtype = M_HASHTYPE_RSS_TCP_IPV4;
134 		return (0);
135 	} else if ((proto == IPPROTO_UDP) &&
136 	    (rss_gethashconfig() & RSS_HASHTYPE_RSS_UDP_IPV4)) {
137 		hash = rss_hash_ip4_4tuple(s, sp, d, dp);
138 		*hashval = hash;
139 		*hashtype = M_HASHTYPE_RSS_UDP_IPV4;
140 		return (0);
141 	} else if (rss_gethashconfig() & RSS_HASHTYPE_RSS_IPV4) {
142 		/* RSS doesn't hash on other protocols like SCTP; so 2-tuple */
143 		hash = rss_hash_ip4_2tuple(s, d);
144 		*hashval = hash;
145 		*hashtype = M_HASHTYPE_RSS_IPV4;
146 		return (0);
147 	}
148 
149 	/* No configured available hashtypes! */
150 	RSS_DEBUG("no available hashtypes!\n");
151 	return (-1);
152 }
153 
154 /*
155  * Calculate an appropriate ipv4 2-tuple or 4-tuple given the given
156  * IPv4 source/destination address, UDP or TCP source/destination ports
157  * and the protocol type.
158  *
159  * The protocol code may wish to do a software hash of the given
160  * tuple.  This depends upon the currently configured RSS hash types.
161  *
162  * It assumes the packet source/destination address
163  * are in "outgoing" packet order (ie, destination is "far" address.)
164  */
165 uint32_t
166 xps_proto_software_hash_v4(struct in_addr s, struct in_addr d,
167     u_short sp, u_short dp, int proto, uint32_t *hashtype)
168 {
169 	uint32_t hash;
170 
171 	/*
172 	 * Next, choose the hash type depending upon the protocol
173 	 * identifier.
174 	 */
175 	if ((proto == IPPROTO_TCP) &&
176 	    (rss_gethashconfig() & RSS_HASHTYPE_RSS_TCP_IPV4)) {
177 		hash = rss_hash_ip4_4tuple(d, dp, s, sp);
178 		*hashtype = M_HASHTYPE_RSS_TCP_IPV4;
179 		return (hash);
180 	} else if ((proto == IPPROTO_UDP) &&
181 	    (rss_gethashconfig() & RSS_HASHTYPE_RSS_UDP_IPV4)) {
182 		hash = rss_hash_ip4_4tuple(d, dp, s, sp);
183 		*hashtype = M_HASHTYPE_RSS_UDP_IPV4;
184 		return (hash);
185 	} else if (rss_gethashconfig() & RSS_HASHTYPE_RSS_IPV4) {
186 		/* RSS doesn't hash on other protocols like SCTP; so 2-tuple */
187 		hash = rss_hash_ip4_2tuple(d, s);
188 		*hashtype = M_HASHTYPE_RSS_IPV4;
189 		return (hash);
190 	}
191 
192 	*hashtype = M_HASHTYPE_NONE;
193 	return (0);
194 }
195 
196 /*
197  * Do a software calculation of the RSS for the given mbuf.
198  *
199  * This is typically used by the input path to recalculate the RSS after
200  * some form of packet processing (eg de-capsulation, IP fragment reassembly.)
201  *
202  * dir is the packet direction - RSS_HASH_PKT_INGRESS for incoming and
203  * RSS_HASH_PKT_EGRESS for outgoing.
204  *
205  * Returns 0 if a hash was done, -1 if no hash was done, +1 if
206  * the mbuf already had a valid RSS flowid.
207  *
208  * This function doesn't modify the mbuf.  It's up to the caller to
209  * assign flowid/flowtype as appropriate.
210  */
211 int
212 rss_mbuf_software_hash_v4(const struct mbuf *m, int dir, uint32_t *hashval,
213     uint32_t *hashtype)
214 {
215 	const struct ip *ip;
216 	const struct tcphdr *th;
217 	const struct udphdr *uh;
218 	uint32_t flowid;
219 	uint32_t flowtype;
220 	uint8_t proto;
221 	int iphlen;
222 	int is_frag = 0;
223 
224 	/*
225 	 * XXX For now this only handles hashing on incoming mbufs.
226 	 */
227 	if (dir != RSS_HASH_PKT_INGRESS) {
228 		RSS_DEBUG("called on EGRESS packet!\n");
229 		return (-1);
230 	}
231 
232 	/*
233 	 * First, validate that the mbuf we have is long enough
234 	 * to have an IPv4 header in it.
235 	 */
236 	if (m->m_pkthdr.len < (sizeof(struct ip))) {
237 		RSS_DEBUG("short mbuf pkthdr\n");
238 		return (-1);
239 	}
240 	if (m->m_len < (sizeof(struct ip))) {
241 		RSS_DEBUG("short mbuf len\n");
242 		return (-1);
243 	}
244 
245 	/* Ok, let's dereference that */
246 	ip = mtod(m, struct ip *);
247 	proto = ip->ip_p;
248 	iphlen = ip->ip_hl << 2;
249 
250 	/*
251 	 * If this is a fragment then it shouldn't be four-tuple
252 	 * hashed just yet.  Once it's reassembled into a full
253 	 * frame it should be re-hashed.
254 	 */
255 	if (ip->ip_off & htons(IP_MF | IP_OFFMASK))
256 		is_frag = 1;
257 
258 	/*
259 	 * If the mbuf flowid/flowtype matches the packet type,
260 	 * and we don't support the 4-tuple version of the given protocol,
261 	 * then signal to the owner that it can trust the flowid/flowtype
262 	 * details.
263 	 *
264 	 * This is a little picky - eg, if TCPv4 / UDPv4 hashing
265 	 * is supported but we got a TCP/UDP frame only 2-tuple hashed,
266 	 * then we shouldn't just "trust" the 2-tuple hash.  We need
267 	 * a 4-tuple hash.
268 	 */
269 	flowid = m->m_pkthdr.flowid;
270 	flowtype = M_HASHTYPE_GET(m);
271 
272 	if (flowtype != M_HASHTYPE_NONE) {
273 		switch (proto) {
274 		case IPPROTO_UDP:
275 			if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_UDP_IPV4) &&
276 			    (flowtype == M_HASHTYPE_RSS_UDP_IPV4) &&
277 			    (is_frag == 0)) {
278 				return (1);
279 			}
280 			/*
281 			 * Only allow 2-tuple for UDP frames if we don't also
282 			 * support 4-tuple for UDP.
283 			 */
284 			if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_IPV4) &&
285 			    ((rss_gethashconfig() & RSS_HASHTYPE_RSS_UDP_IPV4) == 0) &&
286 			    flowtype == M_HASHTYPE_RSS_IPV4) {
287 				return (1);
288 			}
289 			break;
290 		case IPPROTO_TCP:
291 			if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_TCP_IPV4) &&
292 			    (flowtype == M_HASHTYPE_RSS_TCP_IPV4) &&
293 			    (is_frag == 0)) {
294 				return (1);
295 			}
296 			/*
297 			 * Only allow 2-tuple for TCP frames if we don't also
298 			 * support 2-tuple for TCP.
299 			 */
300 			if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_IPV4) &&
301 			    ((rss_gethashconfig() & RSS_HASHTYPE_RSS_TCP_IPV4) == 0) &&
302 			    flowtype == M_HASHTYPE_RSS_IPV4) {
303 				return (1);
304 			}
305 			break;
306 		default:
307 			if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_IPV4) &&
308 			    flowtype == M_HASHTYPE_RSS_IPV4) {
309 				return (1);
310 			}
311 			break;
312 		}
313 	}
314 
315 	/*
316 	 * Decode enough information to make a hash decision.
317 	 *
318 	 * XXX TODO: does the hardware hash on 4-tuple if IP
319 	 *    options are present?
320 	 */
321 	if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_TCP_IPV4) &&
322 	    (proto == IPPROTO_TCP) &&
323 	    (is_frag == 0)) {
324 		if (m->m_len < iphlen + sizeof(struct tcphdr)) {
325 			RSS_DEBUG("short TCP frame?\n");
326 			return (-1);
327 		}
328 		th = (const struct tcphdr *)((c_caddr_t)ip + iphlen);
329 		return rss_proto_software_hash_v4(ip->ip_src, ip->ip_dst,
330 		    th->th_sport,
331 		    th->th_dport,
332 		    proto,
333 		    hashval,
334 		    hashtype);
335 	} else if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_UDP_IPV4) &&
336 	    (proto == IPPROTO_UDP) &&
337 	    (is_frag == 0)) {
338 		uh = (const struct udphdr *)((c_caddr_t)ip + iphlen);
339 		if (m->m_len < iphlen + sizeof(struct udphdr)) {
340 			RSS_DEBUG("short UDP frame?\n");
341 			return (-1);
342 		}
343 		return rss_proto_software_hash_v4(ip->ip_src, ip->ip_dst,
344 		    uh->uh_sport,
345 		    uh->uh_dport,
346 		    proto,
347 		    hashval,
348 		    hashtype);
349 	} else if (rss_gethashconfig() & RSS_HASHTYPE_RSS_IPV4) {
350 		/* Default to 2-tuple hash */
351 		return rss_proto_software_hash_v4(ip->ip_src, ip->ip_dst,
352 		    0,	/* source port */
353 		    0,	/* destination port */
354 		    0,	/* IPPROTO_IP */
355 		    hashval,
356 		    hashtype);
357 	} else {
358 		RSS_DEBUG("no available hashtypes!\n");
359 		return (-1);
360 	}
361 }
362 
363 /*
364  * Similar to rss_m2cpuid, but designed to be used by the IP NETISR
365  * on incoming frames.
366  *
367  * If an existing RSS hash exists and it matches what the configured
368  * hashing is, then use it.
369  *
370  * If there's an existing RSS hash but the desired hash is different,
371  * or if there's no useful RSS hash, then calculate it via
372  * the software path.
373  *
374  * XXX TODO: definitely want statistics here!
375  */
376 struct mbuf *
377 rss_soft_m2cpuid_v4(struct mbuf *m, uintptr_t source, u_int *cpuid)
378 {
379 	uint32_t hash_val, hash_type;
380 	int ret;
381 
382 	M_ASSERTPKTHDR(m);
383 
384 	ret = rss_mbuf_software_hash_v4(m, RSS_HASH_PKT_INGRESS,
385 	    &hash_val, &hash_type);
386 	if (ret > 0) {
387 		/* mbuf has a valid hash already; don't need to modify it */
388 		*cpuid = rss_hash2cpuid(m->m_pkthdr.flowid, M_HASHTYPE_GET(m));
389 	} else if (ret == 0) {
390 		/* hash was done; update */
391 		m->m_pkthdr.flowid = hash_val;
392 		M_HASHTYPE_SET(m, hash_type);
393 		*cpuid = rss_hash2cpuid(m->m_pkthdr.flowid, M_HASHTYPE_GET(m));
394 	} else { /* ret < 0 */
395 		/* no hash was done */
396 		*cpuid = NETISR_CPUID_NONE;
397 	}
398 	return (m);
399 }
400