xref: /freebsd-13-stable/sys/netinet/in_rss.c (revision ecf688348bd2c1e292b64a1a37b1d0f545aaa11e)
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_pcbgroup.h"
33 
34 #ifndef PCBGROUP
35 #error "options RSS depends on options PCBGROUP"
36 #endif
37 
38 #include <sys/param.h>
39 #include <sys/mbuf.h>
40 #include <sys/socket.h>
41 #include <sys/priv.h>
42 #include <sys/kernel.h>
43 #include <sys/smp.h>
44 #include <sys/sysctl.h>
45 #include <sys/sbuf.h>
46 
47 #include <net/if.h>
48 #include <net/if_var.h>
49 #include <net/netisr.h>
50 #include <net/rss_config.h>
51 
52 #include <netinet/in.h>
53 #include <netinet/in_pcb.h>
54 #include <netinet/in_rss.h>
55 #include <netinet/in_var.h>
56 
57 /* for software rss hash support */
58 #include <netinet/ip.h>
59 #include <netinet/tcp.h>
60 #include <netinet/udp.h>
61 
62 /*
63  * Hash an IPv4 2-tuple.
64  */
65 uint32_t
rss_hash_ip4_2tuple(struct in_addr src,struct in_addr dst)66 rss_hash_ip4_2tuple(struct in_addr src, struct in_addr dst)
67 {
68 	uint8_t data[sizeof(src) + sizeof(dst)];
69 	u_int datalen;
70 
71 	datalen = 0;
72 	bcopy(&src, &data[datalen], sizeof(src));
73 	datalen += sizeof(src);
74 	bcopy(&dst, &data[datalen], sizeof(dst));
75 	datalen += sizeof(dst);
76 	return (rss_hash(datalen, data));
77 }
78 
79 /*
80  * Hash an IPv4 4-tuple.
81  */
82 uint32_t
rss_hash_ip4_4tuple(struct in_addr src,u_short srcport,struct in_addr dst,u_short dstport)83 rss_hash_ip4_4tuple(struct in_addr src, u_short srcport, struct in_addr dst,
84     u_short dstport)
85 {
86 	uint8_t data[sizeof(src) + sizeof(dst) + sizeof(srcport) +
87 	    sizeof(dstport)];
88 	u_int datalen;
89 
90 	datalen = 0;
91 	bcopy(&src, &data[datalen], sizeof(src));
92 	datalen += sizeof(src);
93 	bcopy(&dst, &data[datalen], sizeof(dst));
94 	datalen += sizeof(dst);
95 	bcopy(&srcport, &data[datalen], sizeof(srcport));
96 	datalen += sizeof(srcport);
97 	bcopy(&dstport, &data[datalen], sizeof(dstport));
98 	datalen += sizeof(dstport);
99 	return (rss_hash(datalen, data));
100 }
101 
102 /*
103  * Calculate an appropriate ipv4 2-tuple or 4-tuple given the given
104  * IPv4 source/destination address, UDP or TCP source/destination ports
105  * and the protocol type.
106  *
107  * The protocol code may wish to do a software hash of the given
108  * tuple.  This depends upon the currently configured RSS hash types.
109  *
110  * This assumes that the packet in question isn't a fragment.
111  *
112  * It also assumes the packet source/destination address
113  * are in "incoming" packet order (ie, source is "far" address.)
114  */
115 int
rss_proto_software_hash_v4(struct in_addr s,struct in_addr d,u_short sp,u_short dp,int proto,uint32_t * hashval,uint32_t * hashtype)116 rss_proto_software_hash_v4(struct in_addr s, struct in_addr d,
117     u_short sp, u_short dp, int proto,
118     uint32_t *hashval, uint32_t *hashtype)
119 {
120 	uint32_t hash;
121 
122 	/*
123 	 * Next, choose the hash type depending upon the protocol
124 	 * identifier.
125 	 */
126 	if ((proto == IPPROTO_TCP) &&
127 	    (rss_gethashconfig() & RSS_HASHTYPE_RSS_TCP_IPV4)) {
128 		hash = rss_hash_ip4_4tuple(s, sp, d, dp);
129 		*hashval = hash;
130 		*hashtype = M_HASHTYPE_RSS_TCP_IPV4;
131 		return (0);
132 	} else if ((proto == IPPROTO_UDP) &&
133 	    (rss_gethashconfig() & RSS_HASHTYPE_RSS_UDP_IPV4)) {
134 		hash = rss_hash_ip4_4tuple(s, sp, d, dp);
135 		*hashval = hash;
136 		*hashtype = M_HASHTYPE_RSS_UDP_IPV4;
137 		return (0);
138 	} else if (rss_gethashconfig() & RSS_HASHTYPE_RSS_IPV4) {
139 		/* RSS doesn't hash on other protocols like SCTP; so 2-tuple */
140 		hash = rss_hash_ip4_2tuple(s, d);
141 		*hashval = hash;
142 		*hashtype = M_HASHTYPE_RSS_IPV4;
143 		return (0);
144 	}
145 
146 	/* No configured available hashtypes! */
147 	RSS_DEBUG("no available hashtypes!\n");
148 	return (-1);
149 }
150 
151 /*
152  * Calculate an appropriate ipv4 2-tuple or 4-tuple given the given
153  * IPv4 source/destination address, UDP or TCP source/destination ports
154  * and the protocol type.
155  *
156  * The protocol code may wish to do a software hash of the given
157  * tuple.  This depends upon the currently configured RSS hash types.
158  *
159  * It assumes the packet source/destination address
160  * are in "outgoing" packet order (ie, destination is "far" address.)
161  */
162 uint32_t
xps_proto_software_hash_v4(struct in_addr s,struct in_addr d,u_short sp,u_short dp,int proto,uint32_t * hashtype)163 xps_proto_software_hash_v4(struct in_addr s, struct in_addr d,
164     u_short sp, u_short dp, int proto, uint32_t *hashtype)
165 {
166 	uint32_t hash;
167 
168 	/*
169 	 * Next, choose the hash type depending upon the protocol
170 	 * identifier.
171 	 */
172 	if ((proto == IPPROTO_TCP) &&
173 	    (rss_gethashconfig() & RSS_HASHTYPE_RSS_TCP_IPV4)) {
174 		hash = rss_hash_ip4_4tuple(d, dp, s, sp);
175 		*hashtype = M_HASHTYPE_RSS_TCP_IPV4;
176 		return (hash);
177 	} else if ((proto == IPPROTO_UDP) &&
178 	    (rss_gethashconfig() & RSS_HASHTYPE_RSS_UDP_IPV4)) {
179 		hash = rss_hash_ip4_4tuple(d, dp, s, sp);
180 		*hashtype = M_HASHTYPE_RSS_UDP_IPV4;
181 		return (hash);
182 	} else if (rss_gethashconfig() & RSS_HASHTYPE_RSS_IPV4) {
183 		/* RSS doesn't hash on other protocols like SCTP; so 2-tuple */
184 		hash = rss_hash_ip4_2tuple(d, s);
185 		*hashtype = M_HASHTYPE_RSS_IPV4;
186 		return (hash);
187 	}
188 
189 	*hashtype = M_HASHTYPE_NONE;
190 	return (0);
191 }
192 
193 /*
194  * Do a software calculation of the RSS for the given mbuf.
195  *
196  * This is typically used by the input path to recalculate the RSS after
197  * some form of packet processing (eg de-capsulation, IP fragment reassembly.)
198  *
199  * dir is the packet direction - RSS_HASH_PKT_INGRESS for incoming and
200  * RSS_HASH_PKT_EGRESS for outgoing.
201  *
202  * Returns 0 if a hash was done, -1 if no hash was done, +1 if
203  * the mbuf already had a valid RSS flowid.
204  *
205  * This function doesn't modify the mbuf.  It's up to the caller to
206  * assign flowid/flowtype as appropriate.
207  */
208 int
rss_mbuf_software_hash_v4(const struct mbuf * m,int dir,uint32_t * hashval,uint32_t * hashtype)209 rss_mbuf_software_hash_v4(const struct mbuf *m, int dir, uint32_t *hashval,
210     uint32_t *hashtype)
211 {
212 	const struct ip *ip;
213 	const struct tcphdr *th;
214 	const struct udphdr *uh;
215 	uint32_t flowtype;
216 	uint8_t proto;
217 	int iphlen;
218 	int is_frag = 0;
219 
220 	/*
221 	 * XXX For now this only handles hashing on incoming mbufs.
222 	 */
223 	if (dir != RSS_HASH_PKT_INGRESS) {
224 		RSS_DEBUG("called on EGRESS packet!\n");
225 		return (-1);
226 	}
227 
228 	/*
229 	 * First, validate that the mbuf we have is long enough
230 	 * to have an IPv4 header in it.
231 	 */
232 	if (m->m_pkthdr.len < (sizeof(struct ip))) {
233 		RSS_DEBUG("short mbuf pkthdr\n");
234 		return (-1);
235 	}
236 	if (m->m_len < (sizeof(struct ip))) {
237 		RSS_DEBUG("short mbuf len\n");
238 		return (-1);
239 	}
240 
241 	/* Ok, let's dereference that */
242 	ip = mtod(m, struct ip *);
243 	proto = ip->ip_p;
244 	iphlen = ip->ip_hl << 2;
245 
246 	/*
247 	 * If this is a fragment then it shouldn't be four-tuple
248 	 * hashed just yet.  Once it's reassembled into a full
249 	 * frame it should be re-hashed.
250 	 */
251 	if (ip->ip_off & htons(IP_MF | IP_OFFMASK))
252 		is_frag = 1;
253 
254 	/*
255 	 * If the mbuf flowid/flowtype matches the packet type,
256 	 * and we don't support the 4-tuple version of the given protocol,
257 	 * then signal to the owner that it can trust the flowid/flowtype
258 	 * details.
259 	 *
260 	 * This is a little picky - eg, if TCPv4 / UDPv4 hashing
261 	 * is supported but we got a TCP/UDP frame only 2-tuple hashed,
262 	 * then we shouldn't just "trust" the 2-tuple hash.  We need
263 	 * a 4-tuple hash.
264 	 */
265 	flowtype = M_HASHTYPE_GET(m);
266 
267 	if (flowtype != M_HASHTYPE_NONE) {
268 		switch (proto) {
269 		case IPPROTO_UDP:
270 			if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_UDP_IPV4) &&
271 			    (flowtype == M_HASHTYPE_RSS_UDP_IPV4) &&
272 			    (is_frag == 0)) {
273 				return (1);
274 			}
275 			/*
276 			 * Only allow 2-tuple for UDP frames if we don't also
277 			 * support 4-tuple for UDP.
278 			 */
279 			if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_IPV4) &&
280 			    ((rss_gethashconfig() & RSS_HASHTYPE_RSS_UDP_IPV4) == 0) &&
281 			    flowtype == M_HASHTYPE_RSS_IPV4) {
282 				return (1);
283 			}
284 			break;
285 		case IPPROTO_TCP:
286 			if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_TCP_IPV4) &&
287 			    (flowtype == M_HASHTYPE_RSS_TCP_IPV4) &&
288 			    (is_frag == 0)) {
289 				return (1);
290 			}
291 			/*
292 			 * Only allow 2-tuple for TCP frames if we don't also
293 			 * support 2-tuple for TCP.
294 			 */
295 			if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_IPV4) &&
296 			    ((rss_gethashconfig() & RSS_HASHTYPE_RSS_TCP_IPV4) == 0) &&
297 			    flowtype == M_HASHTYPE_RSS_IPV4) {
298 				return (1);
299 			}
300 			break;
301 		default:
302 			if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_IPV4) &&
303 			    flowtype == M_HASHTYPE_RSS_IPV4) {
304 				return (1);
305 			}
306 			break;
307 		}
308 	}
309 
310 	/*
311 	 * Decode enough information to make a hash decision.
312 	 *
313 	 * XXX TODO: does the hardware hash on 4-tuple if IP
314 	 *    options are present?
315 	 */
316 	if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_TCP_IPV4) &&
317 	    (proto == IPPROTO_TCP) &&
318 	    (is_frag == 0)) {
319 		if (m->m_len < iphlen + sizeof(struct tcphdr)) {
320 			RSS_DEBUG("short TCP frame?\n");
321 			return (-1);
322 		}
323 		th = (const struct tcphdr *)((c_caddr_t)ip + iphlen);
324 		return rss_proto_software_hash_v4(ip->ip_src, ip->ip_dst,
325 		    th->th_sport,
326 		    th->th_dport,
327 		    proto,
328 		    hashval,
329 		    hashtype);
330 	} else if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_UDP_IPV4) &&
331 	    (proto == IPPROTO_UDP) &&
332 	    (is_frag == 0)) {
333 		uh = (const struct udphdr *)((c_caddr_t)ip + iphlen);
334 		if (m->m_len < iphlen + sizeof(struct udphdr)) {
335 			RSS_DEBUG("short UDP frame?\n");
336 			return (-1);
337 		}
338 		return rss_proto_software_hash_v4(ip->ip_src, ip->ip_dst,
339 		    uh->uh_sport,
340 		    uh->uh_dport,
341 		    proto,
342 		    hashval,
343 		    hashtype);
344 	} else if (rss_gethashconfig() & RSS_HASHTYPE_RSS_IPV4) {
345 		/* Default to 2-tuple hash */
346 		return rss_proto_software_hash_v4(ip->ip_src, ip->ip_dst,
347 		    0,	/* source port */
348 		    0,	/* destination port */
349 		    0,	/* IPPROTO_IP */
350 		    hashval,
351 		    hashtype);
352 	} else {
353 		RSS_DEBUG("no available hashtypes!\n");
354 		return (-1);
355 	}
356 }
357 
358 /*
359  * Similar to rss_m2cpuid, but designed to be used by the IP NETISR
360  * on incoming frames.
361  *
362  * If an existing RSS hash exists and it matches what the configured
363  * hashing is, then use it.
364  *
365  * If there's an existing RSS hash but the desired hash is different,
366  * or if there's no useful RSS hash, then calculate it via
367  * the software path.
368  *
369  * XXX TODO: definitely want statistics here!
370  */
371 struct mbuf *
rss_soft_m2cpuid_v4(struct mbuf * m,uintptr_t source,u_int * cpuid)372 rss_soft_m2cpuid_v4(struct mbuf *m, uintptr_t source, u_int *cpuid)
373 {
374 	uint32_t hash_val, hash_type;
375 	int ret;
376 
377 	M_ASSERTPKTHDR(m);
378 
379 	ret = rss_mbuf_software_hash_v4(m, RSS_HASH_PKT_INGRESS,
380 	    &hash_val, &hash_type);
381 	if (ret > 0) {
382 		/* mbuf has a valid hash already; don't need to modify it */
383 		*cpuid = rss_hash2cpuid(m->m_pkthdr.flowid, M_HASHTYPE_GET(m));
384 	} else if (ret == 0) {
385 		/* hash was done; update */
386 		m->m_pkthdr.flowid = hash_val;
387 		M_HASHTYPE_SET(m, hash_type);
388 		*cpuid = rss_hash2cpuid(m->m_pkthdr.flowid, M_HASHTYPE_GET(m));
389 	} else { /* ret < 0 */
390 		/* no hash was done */
391 		*cpuid = NETISR_CPUID_NONE;
392 	}
393 	return (m);
394 }
395