xref: /dragonfly/sys/netinet/ip_demux.c (revision 43b4d1bd)
1 /*
2  * Copyright (c) 2003, 2004 Jeffrey M. Hsu.  All rights reserved.
3  * Copyright (c) 2003, 2004 The DragonFly Project.  All rights reserved.
4  *
5  * This code is derived from software contributed to The DragonFly Project
6  * by Jeffrey M. Hsu.
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  * 3. Neither the name of The DragonFly Project nor the names of its
17  *    contributors may be used to endorse or promote products derived
18  *    from this software without specific, prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
24  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
27  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
30  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * $DragonFly: src/sys/netinet/ip_demux.c,v 1.27 2004/08/28 18:33:03 dillon Exp $
34  */
35 
36 /*
37  * Copyright (c) 2003, 2004 Jeffrey M. Hsu.  All rights reserved.
38  *
39  * License terms: all terms for the DragonFly license above plus the following:
40  *
41  * 4. All advertising materials mentioning features or use of this software
42  *    must display the following acknowledgement:
43  *
44  *	This product includes software developed by Jeffrey M. Hsu
45  *	for the DragonFly Project.
46  *
47  *    This requirement may be waived with permission from Jeffrey Hsu.
48  *    This requirement will sunset and may be removed on July 8 2005,
49  *    after which the standard DragonFly license (as shown above) will
50  *    apply.
51  */
52 
53 #include "opt_inet.h"
54 
55 #include <sys/param.h>
56 #include <sys/systm.h>
57 #include <sys/kernel.h>
58 #include <sys/socket.h>
59 #include <sys/socketvar.h>
60 #include <sys/thread.h>
61 #include <sys/sysctl.h>
62 #include <sys/globaldata.h>
63 
64 #include <net/if.h>
65 #include <net/netisr.h>
66 
67 #include <netinet/in_systm.h>
68 #include <netinet/in.h>
69 #include <netinet/in_var.h>
70 #include <netinet/in_pcb.h>
71 #include <netinet/ip.h>
72 #include <netinet/ip_var.h>
73 #include <netinet/tcp.h>
74 #include <netinet/tcpip.h>
75 #include <netinet/tcp_var.h>
76 #include <netinet/udp.h>
77 #include <netinet/udp_var.h>
78 
79 extern struct thread netisr_cpu[];
80 
81 static struct thread tcp_thread[MAXCPU];
82 static struct thread udp_thread[MAXCPU];
83 
84 static __inline int
85 INP_MPORT_HASH(in_addr_t faddr, in_addr_t laddr,
86 	       in_port_t fport, in_port_t lport)
87 {
88 	/*
89 	 * Use low order bytes.
90 	 */
91 
92 #if (BYTE_ORDER == LITTLE_ENDIAN)
93 	KASSERT(ncpus2 < 256, ("need different hash function"));  /* XXX JH */
94 	return (((faddr >> 24) ^ (fport >> 8) ^ (laddr >> 24) ^ (lport >> 8)) &
95 		ncpus2_mask);
96 #else
97 	return ((faddr ^ fport ^ laddr ^ lport) & ncpus2_mask);
98 #endif
99 }
100 
101 /*
102  * Map a packet to a protocol processing thread and return the thread's port.
103  * If an error occurs, the passed mbuf will be freed, *mptr will be set
104  * to NULL, and NULL will be returned.  If no error occurs, the passed mbuf
105  * may be modified and a port pointer will be returned.
106  */
107 lwkt_port_t
108 ip_mport(struct mbuf **mptr)
109 {
110 	struct ip *ip;
111 	int iphlen;
112 	int iplen;
113 	struct tcphdr *th;
114 	struct udphdr *uh;
115 	struct mbuf *m = *mptr;
116 	int thoff;				/* TCP data offset */
117 	lwkt_port_t port;
118 	int cpu;
119 
120 	/*
121 	 * The packet must be at least the size of an IP header
122 	 */
123 	if (m->m_pkthdr.len < sizeof(struct ip)) {
124 		ipstat.ips_tooshort++;
125 		m_freem(m);
126 		*mptr = NULL;
127 		return (NULL);
128 	}
129 
130 	/*
131 	 * The first mbuf must entirely contain the IP header
132 	 */
133 	if (m->m_len < sizeof(struct ip) &&
134 	    (m = m_pullup(m, sizeof(struct ip))) == NULL) {
135 		ipstat.ips_toosmall++;
136 		*mptr = NULL;
137 		return (NULL);
138 	}
139 	ip = mtod(m, struct ip *);
140 
141 	/*
142 	 * Extract the actual IP header length and do a bounds check.  The
143 	 * first mbuf must entirely contain the extended IP header.
144 	 */
145 	iphlen = ip->ip_hl << 2;
146 	iplen = ntohs(ip->ip_len);
147 	if (iphlen < sizeof(struct ip)) {	/* minimum header length */
148 		ipstat.ips_badhlen++;
149 		m_freem(m);
150 		return (NULL);
151 	}
152 	if (m->m_len < iphlen) {
153 		m = m_pullup(m, iphlen);
154 		if (m == NULL) {
155 			ipstat.ips_badhlen++;
156 			*mptr = NULL;
157 			return (NULL);
158 		}
159 		ip = mtod(m, struct ip *);
160 	}
161 
162 	/*
163 	 * The TCP/IP or UDP/IP header must be entirely contained within
164 	 * the first fragment of a packet.  Packet filters will break if they
165 	 * aren't.
166 	 *
167 	 * Since the packet will be trimmed to ip_len we must also make sure
168 	 * the potentially trimmed down length is still sufficient to hold
169 	 * the header(s).
170 	 */
171 	if ((ntohs(ip->ip_off) & IP_OFFMASK) == 0) {
172 		switch (ip->ip_p) {
173 		case IPPROTO_TCP:
174 			if (iplen < iphlen + sizeof(struct tcphdr)) {
175 				++tcpstat.tcps_rcvshort;
176 				m_freem(m);
177 				*mptr = NULL;
178 				return (NULL);
179 			}
180 			if (m->m_len < iphlen + sizeof(struct tcphdr)) {
181 				m = m_pullup(m, iphlen + sizeof(struct tcphdr));
182 				if (m == NULL) {
183 					tcpstat.tcps_rcvshort++;
184 					*mptr = NULL;
185 					return (NULL);
186 				}
187 				ip = mtod(m, struct ip *);
188 			}
189 			break;
190 		case IPPROTO_UDP:
191 			if (iplen < iphlen + sizeof(struct udphdr)) {
192 				++udpstat.udps_hdrops;
193 				m_freem(m);
194 				*mptr = NULL;
195 				return (NULL);
196 			}
197 			if (m->m_len < iphlen + sizeof(struct udphdr)) {
198 				m = m_pullup(m, iphlen + sizeof(struct udphdr));
199 				if (m == NULL) {
200 					udpstat.udps_hdrops++;
201 					*mptr = NULL;
202 					return (NULL);
203 				}
204 				ip = mtod(m, struct ip *);
205 			}
206 			break;
207 		default:
208 			if (iplen < iphlen) {
209 				++ipstat.ips_badlen;
210 				m_freem(m);
211 				*mptr = NULL;
212 				return (NULL);
213 			}
214 			break;
215 		}
216 	}
217 
218 	/*
219 	 * XXX generic packet handling defrag on CPU 0 for now.
220 	 */
221 	if (ntohs(ip->ip_off) & (IP_MF | IP_OFFMASK)) {
222 		*mptr = m;
223 		return (&netisr_cpu[0].td_msgport);
224 	}
225 
226 	switch (ip->ip_p) {
227 	case IPPROTO_TCP:
228 		th = (struct tcphdr *)((caddr_t)ip + iphlen);
229 		thoff = th->th_off << 2;
230 		if (thoff < sizeof(struct tcphdr) ||
231 		    thoff > ntohs(ip->ip_len)) {
232 			tcpstat.tcps_rcvbadoff++;
233 			m_freem(m);
234 			*mptr = NULL;
235 			return (NULL);
236 		}
237 		if (m->m_len < iphlen + thoff) {
238 			m = m_pullup(m, iphlen + thoff);
239 			if (m == NULL) {
240 				tcpstat.tcps_rcvshort++;
241 				*mptr = NULL;
242 				return (NULL);
243 			}
244 			ip = mtod(m, struct ip *);
245 			th = (struct tcphdr *)((caddr_t)ip + iphlen);
246 		}
247 
248 		cpu = INP_MPORT_HASH(ip->ip_src.s_addr, ip->ip_dst.s_addr,
249 		    th->th_sport, th->th_dport);
250 		port = &tcp_thread[cpu].td_msgport;
251 		break;
252 	case IPPROTO_UDP:
253 		uh = (struct udphdr *)((caddr_t)ip + iphlen);
254 
255 		if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
256 		    in_broadcast(ip->ip_dst, m->m_pkthdr.rcvif)) {
257 			cpu = 0;
258 		} else {
259 			cpu = INP_MPORT_HASH(ip->ip_src.s_addr,
260 			    ip->ip_dst.s_addr, uh->uh_sport, uh->uh_dport);
261 		}
262 		port = &udp_thread[cpu].td_msgport;
263 		break;
264 	default:
265 		port = &netisr_cpu[0].td_msgport;
266 		break;
267 	}
268 	KKASSERT(port->mp_putport != NULL);
269 	*mptr = m;
270 	return (port);
271 }
272 
273 /*
274  * Map a TCP socket to a protocol processing thread.
275  */
276 lwkt_port_t
277 tcp_soport(struct socket *so, struct sockaddr *nam, int req)
278 {
279 	struct inpcb *inp;
280 
281 	/* The following processing all take place on Protocol Thread 0. */
282 	if (req == PRU_BIND || req == PRU_CONNECT || req == PRU_ATTACH ||
283 	    req == PRU_LISTEN)
284 		return (&tcp_thread[0].td_msgport);
285 
286 	inp = sotoinpcb(so);
287 	if (!inp)		/* connection reset by peer */
288 		return (&tcp_thread[0].td_msgport);
289 
290 	/*
291 	 * Already bound and connected or listening.  For TCP connections,
292 	 * the (faddr, fport, laddr, lport) association cannot change now.
293 	 *
294 	 * Note: T/TCP code needs some reorganization to fit into
295 	 * this model.  XXX JH
296 	 *
297 	 * Rely on type-stable memory and check in protocol handler
298 	 * to fix race condition here w/ deallocation of inp.  XXX JH
299 	 */
300 	return (&tcp_thread[INP_MPORT_HASH(inp->inp_faddr.s_addr,
301 	    inp->inp_laddr.s_addr, inp->inp_fport, inp->inp_lport)].td_msgport);
302 }
303 
304 lwkt_port_t
305 tcp_addrport(in_addr_t faddr, in_port_t fport, in_addr_t laddr, in_port_t lport)
306 {
307 	return (&tcp_thread[tcp_addrcpu(faddr, fport,
308 					laddr, lport)].td_msgport);
309 }
310 
311 /*
312  * Map a UDP socket to a protocol processing thread.
313  */
314 lwkt_port_t
315 udp_soport(struct socket *so, struct sockaddr *nam, int req)
316 {
317 	struct inpcb *inp;
318 
319 	/*
320 	 * The following processing all take place on Protocol Thread 0:
321 	 *   only bind() and connect() have a non-null nam parameter
322 	 *   attach() has a null socket parameter
323 	 *   Fast and slow timeouts pass in two NULLs
324 	 */
325 	if (nam != NULL || so == NULL)
326 		return (&udp_thread[0].td_msgport);
327 
328 	inp = sotoinpcb(so);
329 
330 	if (IN_MULTICAST(ntohl(inp->inp_laddr.s_addr)))
331 		return (&udp_thread[0].td_msgport);
332 
333 	/*
334 	 * Rely on type-stable memory and check in protocol handler
335 	 * to fix race condition here w/ deallocation of inp.  XXX JH
336 	 */
337 
338 	return (&udp_thread[INP_MPORT_HASH(inp->inp_faddr.s_addr,
339 	    inp->inp_laddr.s_addr, inp->inp_fport, inp->inp_lport)].td_msgport);
340 }
341 
342 /*
343  * Map a network address to a processor.
344  */
345 int
346 tcp_addrcpu(in_addr_t faddr, in_port_t fport, in_addr_t laddr, in_port_t lport)
347 {
348 	return (INP_MPORT_HASH(faddr, laddr, fport, lport));
349 }
350 
351 int
352 udp_addrcpu(in_addr_t faddr, in_port_t fport, in_addr_t laddr, in_port_t lport)
353 {
354 	if (IN_MULTICAST(ntohl(laddr)))
355 		return (0);
356 	else
357 		return (INP_MPORT_HASH(faddr, laddr, fport, lport));
358 }
359 
360 /*
361  * Return LWKT port for cpu.
362  */
363 lwkt_port_t
364 tcp_cport(int cpu)
365 {
366 	return (&tcp_thread[cpu].td_msgport);
367 }
368 
369 void
370 tcp_thread_init(void)
371 {
372 	int cpu;
373 
374 	for (cpu = 0; cpu < ncpus2; cpu++) {
375 		lwkt_create(tcpmsg_service_loop, NULL, NULL,
376 			&tcp_thread[cpu], 0, cpu, "tcp_thread %d", cpu);
377 		tcp_thread[cpu].td_msgport.mp_putport = netmsg_put_port;
378 	}
379 }
380 
381 void
382 udp_thread_init(void)
383 {
384 	int cpu;
385 
386 	for (cpu = 0; cpu < ncpus2; cpu++) {
387 		lwkt_create(netmsg_service_loop, NULL, NULL,
388 			&udp_thread[cpu], 0, cpu, "udp_thread %d", cpu);
389 		udp_thread[cpu].td_msgport.mp_putport = netmsg_put_port;
390 	}
391 }
392