xref: /csrg-svn/sys/netinet/udp_usrreq.c (revision 26060)
1 /*
2  * Copyright (c) 1982 Regents of the University of California.
3  * All rights reserved.  The Berkeley software License Agreement
4  * specifies the terms and conditions for redistribution.
5  *
6  *	@(#)udp_usrreq.c	6.17 (Berkeley) 02/03/86
7  */
8 
9 #include "param.h"
10 #include "dir.h"
11 #include "user.h"
12 #include "mbuf.h"
13 #include "protosw.h"
14 #include "socket.h"
15 #include "socketvar.h"
16 #include "errno.h"
17 #include "stat.h"
18 
19 #include "../net/if.h"
20 #include "../net/route.h"
21 
22 #include "in.h"
23 #include "in_pcb.h"
24 #include "in_systm.h"
25 #include "ip.h"
26 #include "ip_var.h"
27 #include "ip_icmp.h"
28 #include "udp.h"
29 #include "udp_var.h"
30 
31 /*
32  * UDP protocol implementation.
33  * Per RFC 768, August, 1980.
34  */
35 udp_init()
36 {
37 
38 	udb.inp_next = udb.inp_prev = &udb;
39 }
40 
41 int	udpcksum = 1;
42 struct	sockaddr_in udp_in = { AF_INET };
43 
44 udp_input(m0, ifp)
45 	struct mbuf *m0;
46 	struct ifnet *ifp;
47 {
48 	register struct udpiphdr *ui;
49 	register struct inpcb *inp;
50 	register struct mbuf *m;
51 	int len;
52 	struct ip ip;
53 
54 	/*
55 	 * Get IP and UDP header together in first mbuf.
56 	 */
57 	m = m0;
58 	if ((m->m_off > MMAXOFF || m->m_len < sizeof (struct udpiphdr)) &&
59 	    (m = m_pullup(m, sizeof (struct udpiphdr))) == 0) {
60 		udpstat.udps_hdrops++;
61 		return;
62 	}
63 	ui = mtod(m, struct udpiphdr *);
64 	if (((struct ip *)ui)->ip_hl > (sizeof (struct ip) >> 2))
65 		ip_stripoptions((struct ip *)ui, (struct mbuf *)0);
66 
67 	/*
68 	 * Make mbuf data length reflect UDP length.
69 	 * If not enough data to reflect UDP length, drop.
70 	 */
71 	len = ntohs((u_short)ui->ui_ulen);
72 	if (((struct ip *)ui)->ip_len != len) {
73 		if (len > ((struct ip *)ui)->ip_len) {
74 			udpstat.udps_badlen++;
75 			goto bad;
76 		}
77 		m_adj(m, len - ((struct ip *)ui)->ip_len);
78 		/* ((struct ip *)ui)->ip_len = len; */
79 	}
80 	/*
81 	 * Save a copy of the IP header in case we want restore it for ICMP.
82 	 */
83 	ip = *(struct ip*)ui;
84 
85 	/*
86 	 * Checksum extended UDP header and data.
87 	 */
88 	if (udpcksum && ui->ui_sum) {
89 		ui->ui_next = ui->ui_prev = 0;
90 		ui->ui_x1 = 0;
91 		ui->ui_len = ui->ui_ulen;
92 		if (ui->ui_sum = in_cksum(m, len + sizeof (struct ip))) {
93 			udpstat.udps_badsum++;
94 			m_freem(m);
95 			return;
96 		}
97 	}
98 
99 	/*
100 	 * Locate pcb for datagram.
101 	 */
102 	inp = in_pcblookup(&udb,
103 	    ui->ui_src, ui->ui_sport, ui->ui_dst, ui->ui_dport,
104 		INPLOOKUP_WILDCARD);
105 	if (inp == 0) {
106 		/* don't send ICMP response for broadcast packet */
107 		if (in_broadcast(ui->ui_dst))
108 			goto bad;
109 		*(struct ip *)ui = ip;
110 		icmp_error((struct ip *)ui, ICMP_UNREACH, ICMP_UNREACH_PORT,
111 		    ifp);
112 		return;
113 	}
114 
115 	/*
116 	 * Construct sockaddr format source address.
117 	 * Stuff source address and datagram in user buffer.
118 	 */
119 	udp_in.sin_port = ui->ui_sport;
120 	udp_in.sin_addr = ui->ui_src;
121 	m->m_len -= sizeof (struct udpiphdr);
122 	m->m_off += sizeof (struct udpiphdr);
123 	if (sbappendaddr(&inp->inp_socket->so_rcv, (struct sockaddr *)&udp_in,
124 	    m, (struct mbuf *)0) == 0)
125 		goto bad;
126 	sorwakeup(inp->inp_socket);
127 	return;
128 bad:
129 	m_freem(m);
130 }
131 
132 udp_ctlinput(cmd, sa)
133 	int cmd;
134 	struct sockaddr *sa;
135 {
136 	extern u_char inetctlerrmap[];
137 	struct sockaddr_in *sin;
138 	int in_rtchange();
139 
140 	if ((unsigned)cmd > PRC_NCMDS)
141 		return;
142 	if (sa->sa_family != AF_INET && sa->sa_family != AF_IMPLINK)
143 		return;
144 	sin = (struct sockaddr_in *)sa;
145 	if (sin->sin_addr.s_addr == INADDR_ANY)
146 		return;
147 
148 	switch (cmd) {
149 
150 	case PRC_QUENCH:
151 		break;
152 
153 	case PRC_ROUTEDEAD:
154 	case PRC_REDIRECT_NET:
155 	case PRC_REDIRECT_HOST:
156 	case PRC_REDIRECT_TOSNET:
157 	case PRC_REDIRECT_TOSHOST:
158 		in_pcbnotify(&udb, &sin->sin_addr, 0, in_rtchange);
159 		break;
160 
161 	default:
162 		if (inetctlerrmap[cmd] == 0)
163 			return;		/* XXX */
164 		in_pcbnotify(&udb, &sin->sin_addr, (int)inetctlerrmap[cmd],
165 			(int (*)())0);
166 	}
167 }
168 
169 udp_output(inp, m0)
170 	register struct inpcb *inp;
171 	struct mbuf *m0;
172 {
173 	register struct mbuf *m;
174 	register struct udpiphdr *ui;
175 	register int len = 0;
176 
177 	/*
178 	 * Calculate data length and get a mbuf
179 	 * for UDP and IP headers.
180 	 */
181 	for (m = m0; m; m = m->m_next)
182 		len += m->m_len;
183 	MGET(m, M_DONTWAIT, MT_HEADER);
184 	if (m == 0) {
185 		m_freem(m0);
186 		return (ENOBUFS);
187 	}
188 
189 	/*
190 	 * Fill in mbuf with extended UDP header
191 	 * and addresses and length put into network format.
192 	 */
193 	m->m_off = MMAXOFF - sizeof (struct udpiphdr);
194 	m->m_len = sizeof (struct udpiphdr);
195 	m->m_next = m0;
196 	ui = mtod(m, struct udpiphdr *);
197 	ui->ui_next = ui->ui_prev = 0;
198 	ui->ui_x1 = 0;
199 	ui->ui_pr = IPPROTO_UDP;
200 	ui->ui_len = htons((u_short)len + sizeof (struct udphdr));
201 	ui->ui_src = inp->inp_laddr;
202 	ui->ui_dst = inp->inp_faddr;
203 	ui->ui_sport = inp->inp_lport;
204 	ui->ui_dport = inp->inp_fport;
205 	ui->ui_ulen = ui->ui_len;
206 
207 	/*
208 	 * Stuff checksum and output datagram.
209 	 */
210 	ui->ui_sum = 0;
211 	if (udpcksum) {
212 	    if ((ui->ui_sum = in_cksum(m, sizeof (struct udpiphdr) + len)) == 0)
213 		ui->ui_sum = -1;
214 	}
215 	((struct ip *)ui)->ip_len = sizeof (struct udpiphdr) + len;
216 	((struct ip *)ui)->ip_ttl = MAXTTL;
217 	return (ip_output(m, inp->inp_options, &inp->inp_route,
218 	    inp->inp_socket->so_options & (SO_DONTROUTE | SO_BROADCAST)));
219 }
220 
221 int	udp_sendspace = 2048;		/* really max datagram size */
222 int	udp_recvspace = 4 * (1024+sizeof(struct sockaddr_in)); /* 4 1K dgrams */
223 
224 /*ARGSUSED*/
225 udp_usrreq(so, req, m, nam, rights)
226 	struct socket *so;
227 	int req;
228 	struct mbuf *m, *nam, *rights;
229 {
230 	struct inpcb *inp = sotoinpcb(so);
231 	int error = 0;
232 
233 	if (req == PRU_CONTROL)
234 		return (in_control(so, (int)m, (caddr_t)nam,
235 			(struct ifnet *)rights));
236 	if (rights && rights->m_len) {
237 		error = EINVAL;
238 		goto release;
239 	}
240 	if (inp == NULL && req != PRU_ATTACH) {
241 		error = EINVAL;
242 		goto release;
243 	}
244 	switch (req) {
245 
246 	case PRU_ATTACH:
247 		if (inp != NULL) {
248 			error = EINVAL;
249 			break;
250 		}
251 		error = in_pcballoc(so, &udb);
252 		if (error)
253 			break;
254 		error = soreserve(so, udp_sendspace, udp_recvspace);
255 		if (error)
256 			break;
257 		break;
258 
259 	case PRU_DETACH:
260 		if (inp == NULL) {
261 			error = ENOTCONN;
262 			break;
263 		}
264 		in_pcbdetach(inp);
265 		break;
266 
267 	case PRU_BIND:
268 		error = in_pcbbind(inp, nam);
269 		break;
270 
271 	case PRU_LISTEN:
272 		error = EOPNOTSUPP;
273 		break;
274 
275 	case PRU_CONNECT:
276 		if (inp->inp_faddr.s_addr != INADDR_ANY) {
277 			error = EISCONN;
278 			break;
279 		}
280 		error = in_pcbconnect(inp, nam);
281 		if (error == 0)
282 			soisconnected(so);
283 		break;
284 
285 	case PRU_CONNECT2:
286 		error = EOPNOTSUPP;
287 		break;
288 
289 	case PRU_ACCEPT:
290 		error = EOPNOTSUPP;
291 		break;
292 
293 	case PRU_DISCONNECT:
294 		if (inp->inp_faddr.s_addr == INADDR_ANY) {
295 			error = ENOTCONN;
296 			break;
297 		}
298 		in_pcbdisconnect(inp);
299 		soisdisconnected(so);
300 		break;
301 
302 	case PRU_SHUTDOWN:
303 		socantsendmore(so);
304 		break;
305 
306 	case PRU_SEND: {
307 		struct in_addr laddr;
308 		int s;
309 
310 		if (nam) {
311 			laddr = inp->inp_laddr;
312 			if (inp->inp_faddr.s_addr != INADDR_ANY) {
313 				error = EISCONN;
314 				break;
315 			}
316 			/*
317 			 * Must block input while temporarily connected.
318 			 */
319 			s = splnet();
320 			error = in_pcbconnect(inp, nam);
321 			if (error) {
322 				splx(s);
323 				break;
324 			}
325 		} else {
326 			if (inp->inp_faddr.s_addr == INADDR_ANY) {
327 				error = ENOTCONN;
328 				break;
329 			}
330 		}
331 		error = udp_output(inp, m);
332 		m = NULL;
333 		if (nam) {
334 			in_pcbdisconnect(inp);
335 			inp->inp_laddr = laddr;
336 			splx(s);
337 		}
338 		}
339 		break;
340 
341 	case PRU_ABORT:
342 		in_pcbdetach(inp);
343 		sofree(so);
344 		soisdisconnected(so);
345 		break;
346 
347 	case PRU_SOCKADDR:
348 		in_setsockaddr(inp, nam);
349 		break;
350 
351 	case PRU_PEERADDR:
352 		in_setpeeraddr(inp, nam);
353 		break;
354 
355 	case PRU_SENSE:
356 		/*
357 		 * stat: don't bother with a blocksize.
358 		 */
359 		return (0);
360 
361 	case PRU_SENDOOB:
362 	case PRU_FASTTIMO:
363 	case PRU_SLOWTIMO:
364 	case PRU_PROTORCV:
365 	case PRU_PROTOSEND:
366 		error =  EOPNOTSUPP;
367 		break;
368 
369 	case PRU_RCVD:
370 	case PRU_RCVOOB:
371 		return (EOPNOTSUPP);	/* do not free mbuf's */
372 
373 	default:
374 		panic("udp_usrreq");
375 	}
376 release:
377 	if (m != NULL)
378 		m_freem(m);
379 	return (error);
380 }
381