xref: /freebsd/sys/netinet/in_rss.c (revision 7fdf597e96a02165cfe22ff357b857d5fa15ed8a)
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 
33 #include <sys/param.h>
34 #include <sys/mbuf.h>
35 #include <sys/socket.h>
36 #include <sys/priv.h>
37 #include <sys/kernel.h>
38 #include <sys/smp.h>
39 #include <sys/sysctl.h>
40 #include <sys/sbuf.h>
41 
42 #include <net/if.h>
43 #include <net/if_var.h>
44 #include <net/netisr.h>
45 #include <net/rss_config.h>
46 
47 #include <netinet/in.h>
48 #include <netinet/in_pcb.h>
49 #include <netinet/in_rss.h>
50 #include <netinet/in_var.h>
51 
52 /* for software rss hash support */
53 #include <netinet/ip.h>
54 #include <netinet/tcp.h>
55 #include <netinet/udp.h>
56 
57 /*
58  * Hash an IPv4 2-tuple.
59  */
60 uint32_t
61 rss_hash_ip4_2tuple(struct in_addr src, struct in_addr dst)
62 {
63 	uint8_t data[sizeof(src) + sizeof(dst)];
64 	u_int datalen;
65 
66 	datalen = 0;
67 	bcopy(&src, &data[datalen], sizeof(src));
68 	datalen += sizeof(src);
69 	bcopy(&dst, &data[datalen], sizeof(dst));
70 	datalen += sizeof(dst);
71 	return (rss_hash(datalen, data));
72 }
73 
74 /*
75  * Hash an IPv4 4-tuple.
76  */
77 uint32_t
78 rss_hash_ip4_4tuple(struct in_addr src, u_short srcport, struct in_addr dst,
79     u_short dstport)
80 {
81 	uint8_t data[sizeof(src) + sizeof(dst) + sizeof(srcport) +
82 	    sizeof(dstport)];
83 	u_int datalen;
84 
85 	datalen = 0;
86 	bcopy(&src, &data[datalen], sizeof(src));
87 	datalen += sizeof(src);
88 	bcopy(&dst, &data[datalen], sizeof(dst));
89 	datalen += sizeof(dst);
90 	bcopy(&srcport, &data[datalen], sizeof(srcport));
91 	datalen += sizeof(srcport);
92 	bcopy(&dstport, &data[datalen], sizeof(dstport));
93 	datalen += sizeof(dstport);
94 	return (rss_hash(datalen, data));
95 }
96 
97 /*
98  * Calculate an appropriate ipv4 2-tuple or 4-tuple given the given
99  * IPv4 source/destination address, UDP or TCP source/destination ports
100  * and the protocol type.
101  *
102  * The protocol code may wish to do a software hash of the given
103  * tuple.  This depends upon the currently configured RSS hash types.
104  *
105  * This assumes that the packet in question isn't a fragment.
106  *
107  * It also assumes the packet source/destination address
108  * are in "incoming" packet order (ie, source is "far" address.)
109  */
110 int
111 rss_proto_software_hash_v4(struct in_addr s, struct in_addr d,
112     u_short sp, u_short dp, int proto,
113     uint32_t *hashval, uint32_t *hashtype)
114 {
115 	uint32_t hash;
116 
117 	/*
118 	 * Next, choose the hash type depending upon the protocol
119 	 * identifier.
120 	 */
121 	if ((proto == IPPROTO_TCP) &&
122 	    (rss_gethashconfig() & RSS_HASHTYPE_RSS_TCP_IPV4)) {
123 		hash = rss_hash_ip4_4tuple(s, sp, d, dp);
124 		*hashval = hash;
125 		*hashtype = M_HASHTYPE_RSS_TCP_IPV4;
126 		return (0);
127 	} else if ((proto == IPPROTO_UDP) &&
128 	    (rss_gethashconfig() & RSS_HASHTYPE_RSS_UDP_IPV4)) {
129 		hash = rss_hash_ip4_4tuple(s, sp, d, dp);
130 		*hashval = hash;
131 		*hashtype = M_HASHTYPE_RSS_UDP_IPV4;
132 		return (0);
133 	} else if (rss_gethashconfig() & RSS_HASHTYPE_RSS_IPV4) {
134 		/* RSS doesn't hash on other protocols like SCTP; so 2-tuple */
135 		hash = rss_hash_ip4_2tuple(s, d);
136 		*hashval = hash;
137 		*hashtype = M_HASHTYPE_RSS_IPV4;
138 		return (0);
139 	}
140 
141 	/* No configured available hashtypes! */
142 	RSS_DEBUG("no available hashtypes!\n");
143 	return (-1);
144 }
145 
146 /*
147  * Calculate an appropriate ipv4 2-tuple or 4-tuple given the given
148  * IPv4 source/destination address, UDP or TCP source/destination ports
149  * and the protocol type.
150  *
151  * The protocol code may wish to do a software hash of the given
152  * tuple.  This depends upon the currently configured RSS hash types.
153  *
154  * It assumes the packet source/destination address
155  * are in "outgoing" packet order (ie, destination is "far" address.)
156  */
157 uint32_t
158 xps_proto_software_hash_v4(struct in_addr s, struct in_addr d,
159     u_short sp, u_short dp, int proto, uint32_t *hashtype)
160 {
161 	uint32_t hash;
162 
163 	/*
164 	 * Next, choose the hash type depending upon the protocol
165 	 * identifier.
166 	 */
167 	if ((proto == IPPROTO_TCP) &&
168 	    (rss_gethashconfig() & RSS_HASHTYPE_RSS_TCP_IPV4)) {
169 		hash = rss_hash_ip4_4tuple(d, dp, s, sp);
170 		*hashtype = M_HASHTYPE_RSS_TCP_IPV4;
171 		return (hash);
172 	} else if ((proto == IPPROTO_UDP) &&
173 	    (rss_gethashconfig() & RSS_HASHTYPE_RSS_UDP_IPV4)) {
174 		hash = rss_hash_ip4_4tuple(d, dp, s, sp);
175 		*hashtype = M_HASHTYPE_RSS_UDP_IPV4;
176 		return (hash);
177 	} else if (rss_gethashconfig() & RSS_HASHTYPE_RSS_IPV4) {
178 		/* RSS doesn't hash on other protocols like SCTP; so 2-tuple */
179 		hash = rss_hash_ip4_2tuple(d, s);
180 		*hashtype = M_HASHTYPE_RSS_IPV4;
181 		return (hash);
182 	}
183 
184 	*hashtype = M_HASHTYPE_NONE;
185 	return (0);
186 }
187 
188 /*
189  * Do a software calculation of the RSS for the given mbuf.
190  *
191  * This is typically used by the input path to recalculate the RSS after
192  * some form of packet processing (eg de-capsulation, IP fragment reassembly.)
193  *
194  * dir is the packet direction - RSS_HASH_PKT_INGRESS for incoming and
195  * RSS_HASH_PKT_EGRESS for outgoing.
196  *
197  * Returns 0 if a hash was done, -1 if no hash was done, +1 if
198  * the mbuf already had a valid RSS flowid.
199  *
200  * This function doesn't modify the mbuf.  It's up to the caller to
201  * assign flowid/flowtype as appropriate.
202  */
203 int
204 rss_mbuf_software_hash_v4(const struct mbuf *m, int dir, uint32_t *hashval,
205     uint32_t *hashtype)
206 {
207 	const struct ip *ip;
208 	const struct tcphdr *th;
209 	const struct udphdr *uh;
210 	uint32_t flowtype;
211 	uint8_t proto;
212 	int iphlen;
213 	int is_frag = 0;
214 
215 	/*
216 	 * XXX For now this only handles hashing on incoming mbufs.
217 	 */
218 	if (dir != RSS_HASH_PKT_INGRESS) {
219 		RSS_DEBUG("called on EGRESS packet!\n");
220 		return (-1);
221 	}
222 
223 	/*
224 	 * First, validate that the mbuf we have is long enough
225 	 * to have an IPv4 header in it.
226 	 */
227 	if (m->m_pkthdr.len < (sizeof(struct ip))) {
228 		RSS_DEBUG("short mbuf pkthdr\n");
229 		return (-1);
230 	}
231 	if (m->m_len < (sizeof(struct ip))) {
232 		RSS_DEBUG("short mbuf len\n");
233 		return (-1);
234 	}
235 
236 	/* Ok, let's dereference that */
237 	ip = mtod(m, struct ip *);
238 	proto = ip->ip_p;
239 	iphlen = ip->ip_hl << 2;
240 
241 	/*
242 	 * If this is a fragment then it shouldn't be four-tuple
243 	 * hashed just yet.  Once it's reassembled into a full
244 	 * frame it should be re-hashed.
245 	 */
246 	if (ip->ip_off & htons(IP_MF | IP_OFFMASK))
247 		is_frag = 1;
248 
249 	/*
250 	 * If the mbuf flowid/flowtype matches the packet type,
251 	 * and we don't support the 4-tuple version of the given protocol,
252 	 * then signal to the owner that it can trust the flowid/flowtype
253 	 * details.
254 	 *
255 	 * This is a little picky - eg, if TCPv4 / UDPv4 hashing
256 	 * is supported but we got a TCP/UDP frame only 2-tuple hashed,
257 	 * then we shouldn't just "trust" the 2-tuple hash.  We need
258 	 * a 4-tuple hash.
259 	 */
260 	flowtype = M_HASHTYPE_GET(m);
261 
262 	if (flowtype != M_HASHTYPE_NONE) {
263 		switch (proto) {
264 		case IPPROTO_UDP:
265 			if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_UDP_IPV4) &&
266 			    (flowtype == M_HASHTYPE_RSS_UDP_IPV4) &&
267 			    (is_frag == 0)) {
268 				return (1);
269 			}
270 			/*
271 			 * Only allow 2-tuple for UDP frames if we don't also
272 			 * support 4-tuple for UDP.
273 			 */
274 			if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_IPV4) &&
275 			    ((rss_gethashconfig() & RSS_HASHTYPE_RSS_UDP_IPV4) == 0) &&
276 			    flowtype == M_HASHTYPE_RSS_IPV4) {
277 				return (1);
278 			}
279 			break;
280 		case IPPROTO_TCP:
281 			if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_TCP_IPV4) &&
282 			    (flowtype == M_HASHTYPE_RSS_TCP_IPV4) &&
283 			    (is_frag == 0)) {
284 				return (1);
285 			}
286 			/*
287 			 * Only allow 2-tuple for TCP frames if we don't also
288 			 * support 2-tuple for TCP.
289 			 */
290 			if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_IPV4) &&
291 			    ((rss_gethashconfig() & RSS_HASHTYPE_RSS_TCP_IPV4) == 0) &&
292 			    flowtype == M_HASHTYPE_RSS_IPV4) {
293 				return (1);
294 			}
295 			break;
296 		default:
297 			if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_IPV4) &&
298 			    flowtype == M_HASHTYPE_RSS_IPV4) {
299 				return (1);
300 			}
301 			break;
302 		}
303 	}
304 
305 	/*
306 	 * Decode enough information to make a hash decision.
307 	 *
308 	 * XXX TODO: does the hardware hash on 4-tuple if IP
309 	 *    options are present?
310 	 */
311 	if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_TCP_IPV4) &&
312 	    (proto == IPPROTO_TCP) &&
313 	    (is_frag == 0)) {
314 		if (m->m_len < iphlen + sizeof(struct tcphdr)) {
315 			RSS_DEBUG("short TCP frame?\n");
316 			return (-1);
317 		}
318 		th = (const struct tcphdr *)((c_caddr_t)ip + iphlen);
319 		return rss_proto_software_hash_v4(ip->ip_src, ip->ip_dst,
320 		    th->th_sport,
321 		    th->th_dport,
322 		    proto,
323 		    hashval,
324 		    hashtype);
325 	} else if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_UDP_IPV4) &&
326 	    (proto == IPPROTO_UDP) &&
327 	    (is_frag == 0)) {
328 		uh = (const struct udphdr *)((c_caddr_t)ip + iphlen);
329 		if (m->m_len < iphlen + sizeof(struct udphdr)) {
330 			RSS_DEBUG("short UDP frame?\n");
331 			return (-1);
332 		}
333 		return rss_proto_software_hash_v4(ip->ip_src, ip->ip_dst,
334 		    uh->uh_sport,
335 		    uh->uh_dport,
336 		    proto,
337 		    hashval,
338 		    hashtype);
339 	} else if (rss_gethashconfig() & RSS_HASHTYPE_RSS_IPV4) {
340 		/* Default to 2-tuple hash */
341 		return rss_proto_software_hash_v4(ip->ip_src, ip->ip_dst,
342 		    0,	/* source port */
343 		    0,	/* destination port */
344 		    0,	/* IPPROTO_IP */
345 		    hashval,
346 		    hashtype);
347 	} else {
348 		RSS_DEBUG("no available hashtypes!\n");
349 		return (-1);
350 	}
351 }
352 
353 /*
354  * Similar to rss_m2cpuid, but designed to be used by the IP NETISR
355  * on incoming frames.
356  *
357  * If an existing RSS hash exists and it matches what the configured
358  * hashing is, then use it.
359  *
360  * If there's an existing RSS hash but the desired hash is different,
361  * or if there's no useful RSS hash, then calculate it via
362  * the software path.
363  *
364  * XXX TODO: definitely want statistics here!
365  */
366 struct mbuf *
367 rss_soft_m2cpuid_v4(struct mbuf *m, uintptr_t source, u_int *cpuid)
368 {
369 	uint32_t hash_val, hash_type;
370 	int ret;
371 
372 	M_ASSERTPKTHDR(m);
373 
374 	ret = rss_mbuf_software_hash_v4(m, RSS_HASH_PKT_INGRESS,
375 	    &hash_val, &hash_type);
376 	if (ret > 0) {
377 		/* mbuf has a valid hash already; don't need to modify it */
378 		*cpuid = rss_hash2cpuid(m->m_pkthdr.flowid, M_HASHTYPE_GET(m));
379 	} else if (ret == 0) {
380 		/* hash was done; update */
381 		m->m_pkthdr.flowid = hash_val;
382 		M_HASHTYPE_SET(m, hash_type);
383 		*cpuid = rss_hash2cpuid(m->m_pkthdr.flowid, M_HASHTYPE_GET(m));
384 	} else { /* ret < 0 */
385 		/* no hash was done */
386 		*cpuid = NETISR_CPUID_NONE;
387 	}
388 	return (m);
389 }
390