xref: /dragonfly/sys/netinet/ip_demux.c (revision 7bc7e232) 
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 1.34 2007/03/04 18:51:59 swildner Exp $
34  */
35 
36 #include "opt_inet.h"
37 
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/kernel.h>
41 #include <sys/socket.h>
42 #include <sys/socketvar.h>
43 #include <sys/thread.h>
44 #include <sys/sysctl.h>
45 #include <sys/globaldata.h>
46 
47 #include <net/if.h>
48 #include <net/netisr.h>
49 
50 #include <netinet/in_systm.h>
51 #include <netinet/in.h>
52 #include <netinet/in_var.h>
53 #include <netinet/in_pcb.h>
54 #include <netinet/ip.h>
55 #include <netinet/ip_var.h>
56 #include <netinet/tcp.h>
57 #include <netinet/tcpip.h>
58 #include <netinet/tcp_var.h>
59 #include <netinet/udp.h>
60 #include <netinet/udp_var.h>
61 
62 extern struct thread netisr_cpu[];
63 
64 static struct thread tcp_thread[MAXCPU];
65 static struct thread udp_thread[MAXCPU];
66 
67 static __inline int
68 INP_MPORT_HASH(in_addr_t faddr, in_addr_t laddr,
69 	       in_port_t fport, in_port_t lport)
70 {
71 	/*
72 	 * Use low order bytes.
73 	 */
74 
75 #if (BYTE_ORDER == LITTLE_ENDIAN)
76 	KASSERT(ncpus2 < 256, ("need different hash function"));  /* XXX JH */
77 	return (((faddr >> 24) ^ (fport >> 8) ^ (laddr >> 24) ^ (lport >> 8)) &
78 		ncpus2_mask);
79 #else
80 	return ((faddr ^ fport ^ laddr ^ lport) & ncpus2_mask);
81 #endif
82 }
83 
84 boolean_t
85 ip_lengthcheck(struct mbuf **mp)
86 {
87 	struct mbuf *m = *mp;
88 	struct ip *ip;
89 	int iphlen, iplen;
90 	struct tcphdr *th;
91 	int thoff;				/* TCP data offset */
92 
93 	/* The packet must be at least the size of an IP header. */
94 	if (m->m_pkthdr.len < sizeof(struct ip)) {
95 		ipstat.ips_tooshort++;
96 		m_free(m);
97 		return FALSE;
98 	}
99 
100 	/* The fixed IP header must reside completely in the first mbuf. */
101 	if (m->m_len < sizeof(struct ip)) {
102 		m = m_pullup(m, sizeof(struct ip));
103 		if (m == NULL) {
104 			ipstat.ips_toosmall++;
105 			return FALSE;
106 		}
107 	}
108 
109 	ip = mtod(m, struct ip *);
110 
111 	/* Bound check the packet's stated IP header length. */
112 	iphlen = ip->ip_hl << 2;
113 	if (iphlen < sizeof(struct ip)) {	/* minimum header length */
114 		ipstat.ips_badhlen++;
115 		m_free(m);
116 		return FALSE;
117 	}
118 
119 	/* The full IP header must reside completely in the one mbuf. */
120 	if (m->m_len < iphlen) {
121 		m = m_pullup(m, iphlen);
122 		if (m == NULL) {
123 			ipstat.ips_badhlen++;
124 			return FALSE;
125 		}
126 		ip = mtod(m, struct ip *);
127 	}
128 
129 	iplen = ntohs(ip->ip_len);
130 
131 	/*
132 	 * Fragments other than the first fragment don't have much
133 	 * length information.
134 	 */
135 	if (ntohs(ip->ip_off) & IP_OFFMASK)
136 		goto ipcheckonly;
137 
138 	/*
139 	 * The TCP/IP or UDP/IP header must be entirely contained within
140 	 * the first fragment of a packet.  Packet filters will break if they
141 	 * aren't.
142 	 *
143 	 * Since the packet will be trimmed to ip_len we must also make sure
144 	 * the potentially trimmed down length is still sufficient to hold
145 	 * the header(s).
146 	 */
147 	switch (ip->ip_p) {
148 	case IPPROTO_TCP:
149 		if (iplen < iphlen + sizeof(struct tcphdr)) {
150 			++tcpstat.tcps_rcvshort;
151 			m_free(m);
152 			return FALSE;
153 		}
154 		if (m->m_len < iphlen + sizeof(struct tcphdr)) {
155 			m = m_pullup(m, iphlen + sizeof(struct tcphdr));
156 			if (m == NULL) {
157 				tcpstat.tcps_rcvshort++;
158 				return FALSE;
159 			}
160 			ip = mtod(m, struct ip *);
161 		}
162 		th = (struct tcphdr *)((caddr_t)ip + iphlen);
163 		thoff = th->th_off << 2;
164 		if (thoff < sizeof(struct tcphdr) ||
165 		    thoff + iphlen > ntohs(ip->ip_len)) {
166 			tcpstat.tcps_rcvbadoff++;
167 			m_free(m);
168 			return FALSE;
169 		}
170 		if (m->m_len < iphlen + thoff) {
171 			m = m_pullup(m, iphlen + thoff);
172 			if (m == NULL) {
173 				tcpstat.tcps_rcvshort++;
174 				return FALSE;
175 			}
176 		}
177 		break;
178 	case IPPROTO_UDP:
179 		if (iplen < iphlen + sizeof(struct udphdr)) {
180 			++udpstat.udps_hdrops;
181 			m_free(m);
182 			return FALSE;
183 		}
184 		if (m->m_len < iphlen + sizeof(struct udphdr)) {
185 			m = m_pullup(m, iphlen + sizeof(struct udphdr));
186 			if (m == NULL) {
187 				udpstat.udps_hdrops++;
188 				return FALSE;
189 			}
190 		}
191 		break;
192 	default:
193 ipcheckonly:
194 		if (iplen < iphlen) {
195 			++ipstat.ips_badlen;
196 			m_free(m);
197 			return FALSE;
198 		}
199 		break;
200 	}
201 
202 	*mp = m;
203 	return TRUE;
204 }
205 
206 /*
207  * Map a packet to a protocol processing thread and return the thread's port.
208  * If an error occurs, the passed mbuf will be freed, *mptr will be set
209  * to NULL, and NULL will be returned.  If no error occurs, the passed mbuf
210  * may be modified and a port pointer will be returned.
211  */
212 lwkt_port_t
213 ip_mport(struct mbuf **mptr)
214 {
215 	struct ip *ip;
216 	int iphlen;
217 	struct tcphdr *th;
218 	struct udphdr *uh;
219 	struct mbuf *m;
220 	int thoff;				/* TCP data offset */
221 	lwkt_port_t port;
222 	int cpu;
223 
224 	if (!ip_lengthcheck(mptr)) {
225 		*mptr = NULL;
226 		return (NULL);
227 	}
228 
229 	m = *mptr;
230 	ip = mtod(m, struct ip *);
231 	iphlen = ip->ip_hl << 2;
232 
233 	/*
234 	 * XXX generic packet handling defrag on CPU 0 for now.
235 	 */
236 	if (ntohs(ip->ip_off) & (IP_MF | IP_OFFMASK))
237 		return (&netisr_cpu[0].td_msgport);
238 
239 	switch (ip->ip_p) {
240 	case IPPROTO_TCP:
241 		th = (struct tcphdr *)((caddr_t)ip + iphlen);
242 		thoff = th->th_off << 2;
243 		cpu = INP_MPORT_HASH(ip->ip_src.s_addr, ip->ip_dst.s_addr,
244 		    th->th_sport, th->th_dport);
245 		port = &tcp_thread[cpu].td_msgport;
246 		break;
247 	case IPPROTO_UDP:
248 		uh = (struct udphdr *)((caddr_t)ip + iphlen);
249 
250 		if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
251 		    in_broadcast(ip->ip_dst, m->m_pkthdr.rcvif)) {
252 			cpu = 0;
253 		} else {
254 			cpu = INP_MPORT_HASH(ip->ip_src.s_addr,
255 			    ip->ip_dst.s_addr, uh->uh_sport, uh->uh_dport);
256 		}
257 		port = &udp_thread[cpu].td_msgport;
258 		break;
259 	default:
260 		port = &netisr_cpu[0].td_msgport;
261 		break;
262 	}
263 
264 	return (port);
265 }
266 
267 /*
268  * Map a TCP socket to a protocol processing thread.
269  */
270 lwkt_port_t
271 tcp_soport(struct socket *so, struct sockaddr *nam, int req)
272 {
273 	struct inpcb *inp;
274 
275 	/* The following processing all take place on Protocol Thread 0. */
276 	if (req == PRU_BIND || req == PRU_CONNECT || req == PRU_ATTACH ||
277 	    req == PRU_LISTEN)
278 		return (&tcp_thread[0].td_msgport);
279 
280 	inp = so->so_pcb;
281 	if (!inp)		/* connection reset by peer */
282 		return (&tcp_thread[0].td_msgport);
283 
284 	/*
285 	 * Already bound and connected or listening.  For TCP connections,
286 	 * the (faddr, fport, laddr, lport) association cannot change now.
287 	 *
288 	 * Note: T/TCP code needs some reorganization to fit into
289 	 * this model.  XXX JH
290 	 *
291 	 * Rely on type-stable memory and check in protocol handler
292 	 * to fix race condition here w/ deallocation of inp.  XXX JH
293 	 */
294 	return (&tcp_thread[INP_MPORT_HASH(inp->inp_faddr.s_addr,
295 	    inp->inp_laddr.s_addr, inp->inp_fport, inp->inp_lport)].td_msgport);
296 }
297 
298 lwkt_port_t
299 tcp_addrport(in_addr_t faddr, in_port_t fport, in_addr_t laddr, in_port_t lport)
300 {
301 	return (&tcp_thread[tcp_addrcpu(faddr, fport,
302 					laddr, lport)].td_msgport);
303 }
304 
305 /*
306  * Map a UDP socket to a protocol processing thread.
307  */
308 lwkt_port_t
309 udp_soport(struct socket *so, struct sockaddr *nam, int req)
310 {
311 	struct inpcb *inp;
312 
313 	/*
314 	 * The following processing all take place on Protocol Thread 0:
315 	 *   only bind() and connect() have a non-null nam parameter
316 	 *   attach() has a null socket parameter
317 	 *   Fast and slow timeouts pass in two NULLs
318 	 */
319 	if (nam != NULL || so == NULL)
320 		return (&udp_thread[0].td_msgport);
321 
322 	inp = so->so_pcb;
323 
324 	if (IN_MULTICAST(ntohl(inp->inp_laddr.s_addr)))
325 		return (&udp_thread[0].td_msgport);
326 
327 	/*
328 	 * Rely on type-stable memory and check in protocol handler
329 	 * to fix race condition here w/ deallocation of inp.  XXX JH
330 	 */
331 
332 	return (&udp_thread[INP_MPORT_HASH(inp->inp_faddr.s_addr,
333 	    inp->inp_laddr.s_addr, inp->inp_fport, inp->inp_lport)].td_msgport);
334 }
335 
336 /*
337  * Map a network address to a processor.
338  */
339 int
340 tcp_addrcpu(in_addr_t faddr, in_port_t fport, in_addr_t laddr, in_port_t lport)
341 {
342 	return (INP_MPORT_HASH(faddr, laddr, fport, lport));
343 }
344 
345 int
346 udp_addrcpu(in_addr_t faddr, in_port_t fport, in_addr_t laddr, in_port_t lport)
347 {
348 	if (IN_MULTICAST(ntohl(laddr)))
349 		return (0);
350 	else
351 		return (INP_MPORT_HASH(faddr, laddr, fport, lport));
352 }
353 
354 /*
355  * Return LWKT port for cpu.
356  */
357 lwkt_port_t
358 tcp_cport(int cpu)
359 {
360 	return (&tcp_thread[cpu].td_msgport);
361 }
362 
363 void
364 tcp_thread_init(void)
365 {
366 	int cpu;
367 
368 	for (cpu = 0; cpu < ncpus2; cpu++) {
369 		lwkt_create(tcpmsg_service_loop, NULL, NULL,
370 			&tcp_thread[cpu], 0, cpu, "tcp_thread %d", cpu);
371 		netmsg_service_port_init(&tcp_thread[cpu].td_msgport);
372 	}
373 }
374 
375 void
376 udp_thread_init(void)
377 {
378 	int cpu;
379 
380 	for (cpu = 0; cpu < ncpus2; cpu++) {
381 		lwkt_create(netmsg_service_loop, NULL, NULL,
382 			&udp_thread[cpu], 0, cpu, "udp_thread %d", cpu);
383 		netmsg_service_port_init(&udp_thread[cpu].td_msgport);
384 	}
385 }
386