FreeBSD/Linux Kernel Cross Reference
sys/netinet/in_rss.c
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
36 #include <sys/param.h>
37 #include <sys/mbuf.h>
38 #include <sys/socket.h>
39 #include <sys/priv.h>
40 #include <sys/kernel.h>
41 #include <sys/smp.h>
42 #include <sys/sysctl.h>
43 #include <sys/sbuf.h>
44
45 #include <net/if.h>
46 #include <net/if_var.h>
47 #include <net/netisr.h>
48 #include <net/rss_config.h>
49
50 #include <netinet/in.h>
51 #include <netinet/in_pcb.h>
52 #include <netinet/in_rss.h>
53 #include <netinet/in_var.h>
54
55 /* for software rss hash support */
56 #include <netinet/ip.h>
57 #include <netinet/tcp.h>
58 #include <netinet/udp.h>
59
60 /*
61 * Hash an IPv4 2-tuple.
62 */
63 uint32_t
64 rss_hash_ip4_2tuple(struct in_addr src, struct in_addr dst)
65 {
66 uint8_t data[sizeof(src) + sizeof(dst)];
67 u_int datalen;
68
69 datalen = 0;
70 bcopy(&src, &data[datalen], sizeof(src));
71 datalen += sizeof(src);
72 bcopy(&dst, &data[datalen], sizeof(dst));
73 datalen += sizeof(dst);
74 return (rss_hash(datalen, data));
75 }
76
77 /*
78 * Hash an IPv4 4-tuple.
79 */
80 uint32_t
81 rss_hash_ip4_4tuple(struct in_addr src, u_short srcport, struct in_addr dst,
82 u_short dstport)
83 {
84 uint8_t data[sizeof(src) + sizeof(dst) + sizeof(srcport) +
85 sizeof(dstport)];
86 u_int datalen;
87
88 datalen = 0;
89 bcopy(&src, &data[datalen], sizeof(src));
90 datalen += sizeof(src);
91 bcopy(&dst, &data[datalen], sizeof(dst));
92 datalen += sizeof(dst);
93 bcopy(&srcport, &data[datalen], sizeof(srcport));
94 datalen += sizeof(srcport);
95 bcopy(&dstport, &data[datalen], sizeof(dstport));
96 datalen += sizeof(dstport);
97 return (rss_hash(datalen, data));
98 }
99
100 /*
101 * Calculate an appropriate ipv4 2-tuple or 4-tuple given the given
102 * IPv4 source/destination address, UDP or TCP source/destination ports
103 * and the protocol type.
104 *
105 * The protocol code may wish to do a software hash of the given
106 * tuple. This depends upon the currently configured RSS hash types.
107 *
108 * This assumes that the packet in question isn't a fragment.
109 *
110 * It also assumes the packet source/destination address
111 * are in "incoming" packet order (ie, source is "far" address.)
112 */
113 int
114 rss_proto_software_hash_v4(struct in_addr s, struct in_addr d,
115 u_short sp, u_short dp, int proto,
116 uint32_t *hashval, uint32_t *hashtype)
117 {
118 uint32_t hash;
119
120 /*
121 * Next, choose the hash type depending upon the protocol
122 * identifier.
123 */
124 if ((proto == IPPROTO_TCP) &&
125 (rss_gethashconfig() & RSS_HASHTYPE_RSS_TCP_IPV4)) {
126 hash = rss_hash_ip4_4tuple(s, sp, d, dp);
127 *hashval = hash;
128 *hashtype = M_HASHTYPE_RSS_TCP_IPV4;
129 return (0);
130 } else if ((proto == IPPROTO_UDP) &&
131 (rss_gethashconfig() & RSS_HASHTYPE_RSS_UDP_IPV4)) {
132 hash = rss_hash_ip4_4tuple(s, sp, d, dp);
133 *hashval = hash;
134 *hashtype = M_HASHTYPE_RSS_UDP_IPV4;
135 return (0);
136 } else if (rss_gethashconfig() & RSS_HASHTYPE_RSS_IPV4) {
137 /* RSS doesn't hash on other protocols like SCTP; so 2-tuple */
138 hash = rss_hash_ip4_2tuple(s, d);
139 *hashval = hash;
140 *hashtype = M_HASHTYPE_RSS_IPV4;
141 return (0);
142 }
143
144 /* No configured available hashtypes! */
145 RSS_DEBUG("no available hashtypes!\n");
146 return (-1);
147 }
148
149 /*
150 * Calculate an appropriate ipv4 2-tuple or 4-tuple given the given
151 * IPv4 source/destination address, UDP or TCP source/destination ports
152 * and the protocol type.
153 *
154 * The protocol code may wish to do a software hash of the given
155 * tuple. This depends upon the currently configured RSS hash types.
156 *
157 * It assumes the packet source/destination address
158 * are in "outgoing" packet order (ie, destination is "far" address.)
159 */
160 uint32_t
161 xps_proto_software_hash_v4(struct in_addr s, struct in_addr d,
162 u_short sp, u_short dp, int proto, uint32_t *hashtype)
163 {
164 uint32_t hash;
165
166 /*
167 * Next, choose the hash type depending upon the protocol
168 * identifier.
169 */
170 if ((proto == IPPROTO_TCP) &&
171 (rss_gethashconfig() & RSS_HASHTYPE_RSS_TCP_IPV4)) {
172 hash = rss_hash_ip4_4tuple(d, dp, s, sp);
173 *hashtype = M_HASHTYPE_RSS_TCP_IPV4;
174 return (hash);
175 } else if ((proto == IPPROTO_UDP) &&
176 (rss_gethashconfig() & RSS_HASHTYPE_RSS_UDP_IPV4)) {
177 hash = rss_hash_ip4_4tuple(d, dp, s, sp);
178 *hashtype = M_HASHTYPE_RSS_UDP_IPV4;
179 return (hash);
180 } else if (rss_gethashconfig() & RSS_HASHTYPE_RSS_IPV4) {
181 /* RSS doesn't hash on other protocols like SCTP; so 2-tuple */
182 hash = rss_hash_ip4_2tuple(d, s);
183 *hashtype = M_HASHTYPE_RSS_IPV4;
184 return (hash);
185 }
186
187 *hashtype = M_HASHTYPE_NONE;
188 return (0);
189 }
190
191 /*
192 * Do a software calculation of the RSS for the given mbuf.
193 *
194 * This is typically used by the input path to recalculate the RSS after
195 * some form of packet processing (eg de-capsulation, IP fragment reassembly.)
196 *
197 * dir is the packet direction - RSS_HASH_PKT_INGRESS for incoming and
198 * RSS_HASH_PKT_EGRESS for outgoing.
199 *
200 * Returns 0 if a hash was done, -1 if no hash was done, +1 if
201 * the mbuf already had a valid RSS flowid.
202 *
203 * This function doesn't modify the mbuf. It's up to the caller to
204 * assign flowid/flowtype as appropriate.
205 */
206 int
207 rss_mbuf_software_hash_v4(const struct mbuf *m, int dir, uint32_t *hashval,
208 uint32_t *hashtype)
209 {
210 const struct ip *ip;
211 const struct tcphdr *th;
212 const struct udphdr *uh;
213 uint32_t flowtype;
214 uint8_t proto;
215 int iphlen;
216 int is_frag = 0;
217
218 /*
219 * XXX For now this only handles hashing on incoming mbufs.
220 */
221 if (dir != RSS_HASH_PKT_INGRESS) {
222 RSS_DEBUG("called on EGRESS packet!\n");
223 return (-1);
224 }
225
226 /*
227 * First, validate that the mbuf we have is long enough
228 * to have an IPv4 header in it.
229 */
230 if (m->m_pkthdr.len < (sizeof(struct ip))) {
231 RSS_DEBUG("short mbuf pkthdr\n");
232 return (-1);
233 }
234 if (m->m_len < (sizeof(struct ip))) {
235 RSS_DEBUG("short mbuf len\n");
236 return (-1);
237 }
238
239 /* Ok, let's dereference that */
240 ip = mtod(m, struct ip *);
241 proto = ip->ip_p;
242 iphlen = ip->ip_hl << 2;
243
244 /*
245 * If this is a fragment then it shouldn't be four-tuple
246 * hashed just yet. Once it's reassembled into a full
247 * frame it should be re-hashed.
248 */
249 if (ip->ip_off & htons(IP_MF | IP_OFFMASK))
250 is_frag = 1;
251
252 /*
253 * If the mbuf flowid/flowtype matches the packet type,
254 * and we don't support the 4-tuple version of the given protocol,
255 * then signal to the owner that it can trust the flowid/flowtype
256 * details.
257 *
258 * This is a little picky - eg, if TCPv4 / UDPv4 hashing
259 * is supported but we got a TCP/UDP frame only 2-tuple hashed,
260 * then we shouldn't just "trust" the 2-tuple hash. We need
261 * a 4-tuple hash.
262 */
263 flowtype = M_HASHTYPE_GET(m);
264
265 if (flowtype != M_HASHTYPE_NONE) {
266 switch (proto) {
267 case IPPROTO_UDP:
268 if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_UDP_IPV4) &&
269 (flowtype == M_HASHTYPE_RSS_UDP_IPV4) &&
270 (is_frag == 0)) {
271 return (1);
272 }
273 /*
274 * Only allow 2-tuple for UDP frames if we don't also
275 * support 4-tuple for UDP.
276 */
277 if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_IPV4) &&
278 ((rss_gethashconfig() & RSS_HASHTYPE_RSS_UDP_IPV4) == 0) &&
279 flowtype == M_HASHTYPE_RSS_IPV4) {
280 return (1);
281 }
282 break;
283 case IPPROTO_TCP:
284 if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_TCP_IPV4) &&
285 (flowtype == M_HASHTYPE_RSS_TCP_IPV4) &&
286 (is_frag == 0)) {
287 return (1);
288 }
289 /*
290 * Only allow 2-tuple for TCP frames if we don't also
291 * support 2-tuple for TCP.
292 */
293 if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_IPV4) &&
294 ((rss_gethashconfig() & RSS_HASHTYPE_RSS_TCP_IPV4) == 0) &&
295 flowtype == M_HASHTYPE_RSS_IPV4) {
296 return (1);
297 }
298 break;
299 default:
300 if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_IPV4) &&
301 flowtype == M_HASHTYPE_RSS_IPV4) {
302 return (1);
303 }
304 break;
305 }
306 }
307
308 /*
309 * Decode enough information to make a hash decision.
310 *
311 * XXX TODO: does the hardware hash on 4-tuple if IP
312 * options are present?
313 */
314 if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_TCP_IPV4) &&
315 (proto == IPPROTO_TCP) &&
316 (is_frag == 0)) {
317 if (m->m_len < iphlen + sizeof(struct tcphdr)) {
318 RSS_DEBUG("short TCP frame?\n");
319 return (-1);
320 }
321 th = (const struct tcphdr *)((c_caddr_t)ip + iphlen);
322 return rss_proto_software_hash_v4(ip->ip_src, ip->ip_dst,
323 th->th_sport,
324 th->th_dport,
325 proto,
326 hashval,
327 hashtype);
328 } else if ((rss_gethashconfig() & RSS_HASHTYPE_RSS_UDP_IPV4) &&
329 (proto == IPPROTO_UDP) &&
330 (is_frag == 0)) {
331 uh = (const struct udphdr *)((c_caddr_t)ip + iphlen);
332 if (m->m_len < iphlen + sizeof(struct udphdr)) {
333 RSS_DEBUG("short UDP frame?\n");
334 return (-1);
335 }
336 return rss_proto_software_hash_v4(ip->ip_src, ip->ip_dst,
337 uh->uh_sport,
338 uh->uh_dport,
339 proto,
340 hashval,
341 hashtype);
342 } else if (rss_gethashconfig() & RSS_HASHTYPE_RSS_IPV4) {
343 /* Default to 2-tuple hash */
344 return rss_proto_software_hash_v4(ip->ip_src, ip->ip_dst,
345 0, /* source port */
346 0, /* destination port */
347 0, /* IPPROTO_IP */
348 hashval,
349 hashtype);
350 } else {
351 RSS_DEBUG("no available hashtypes!\n");
352 return (-1);
353 }
354 }
355
356 /*
357 * Similar to rss_m2cpuid, but designed to be used by the IP NETISR
358 * on incoming frames.
359 *
360 * If an existing RSS hash exists and it matches what the configured
361 * hashing is, then use it.
362 *
363 * If there's an existing RSS hash but the desired hash is different,
364 * or if there's no useful RSS hash, then calculate it via
365 * the software path.
366 *
367 * XXX TODO: definitely want statistics here!
368 */
369 struct mbuf *
370 rss_soft_m2cpuid_v4(struct mbuf *m, uintptr_t source, u_int *cpuid)
371 {
372 uint32_t hash_val, hash_type;
373 int ret;
374
375 M_ASSERTPKTHDR(m);
376
377 ret = rss_mbuf_software_hash_v4(m, RSS_HASH_PKT_INGRESS,
378 &hash_val, &hash_type);
379 if (ret > 0) {
380 /* mbuf has a valid hash already; don't need to modify it */
381 *cpuid = rss_hash2cpuid(m->m_pkthdr.flowid, M_HASHTYPE_GET(m));
382 } else if (ret == 0) {
383 /* hash was done; update */
384 m->m_pkthdr.flowid = hash_val;
385 M_HASHTYPE_SET(m, hash_type);
386 *cpuid = rss_hash2cpuid(m->m_pkthdr.flowid, M_HASHTYPE_GET(m));
387 } else { /* ret < 0 */
388 /* no hash was done */
389 *cpuid = NETISR_CPUID_NONE;
390 }
391 return (m);
392 }
Cache object: 83d57fd87931e83b81ba5890cd8a9f4d
|