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 */
60uint32_t
61rss_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 */
77uint32_t
78rss_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 */
110int
111rss_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 */
157uint32_t
158xps_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 */
203int
204rss_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 */
366struct mbuf *
367rss_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