linux-user: stack_base is now mandatory on all targets
[qemu.git] / slirp / udp.c
1 /*
2 * Copyright (c) 1982, 1986, 1988, 1990, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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 * @(#)udp_usrreq.c 8.4 (Berkeley) 1/21/94
30 * udp_usrreq.c,v 1.4 1994/10/02 17:48:45 phk Exp
31 */
32
33 /*
34 * Changes and additions relating to SLiRP
35 * Copyright (c) 1995 Danny Gasparovski.
36 *
37 * Please read the file COPYRIGHT for the
38 * terms and conditions of the copyright.
39 */
40
41 #include <slirp.h>
42 #include "ip_icmp.h"
43
44 static uint8_t udp_tos(struct socket *so);
45
46 void
47 udp_init(Slirp *slirp)
48 {
49 slirp->udb.so_next = slirp->udb.so_prev = &slirp->udb;
50 slirp->udp_last_so = &slirp->udb;
51 }
52 /* m->m_data points at ip packet header
53 * m->m_len length ip packet
54 * ip->ip_len length data (IPDU)
55 */
56 void
57 udp_input(register struct mbuf *m, int iphlen)
58 {
59 Slirp *slirp = m->slirp;
60 register struct ip *ip;
61 register struct udphdr *uh;
62 int len;
63 struct ip save_ip;
64 struct socket *so;
65
66 DEBUG_CALL("udp_input");
67 DEBUG_ARG("m = %lx", (long)m);
68 DEBUG_ARG("iphlen = %d", iphlen);
69
70 /*
71 * Strip IP options, if any; should skip this,
72 * make available to user, and use on returned packets,
73 * but we don't yet have a way to check the checksum
74 * with options still present.
75 */
76 if(iphlen > sizeof(struct ip)) {
77 ip_stripoptions(m, (struct mbuf *)0);
78 iphlen = sizeof(struct ip);
79 }
80
81 /*
82 * Get IP and UDP header together in first mbuf.
83 */
84 ip = mtod(m, struct ip *);
85 uh = (struct udphdr *)((caddr_t)ip + iphlen);
86
87 /*
88 * Make mbuf data length reflect UDP length.
89 * If not enough data to reflect UDP length, drop.
90 */
91 len = ntohs((uint16_t)uh->uh_ulen);
92
93 if (ip->ip_len != len) {
94 if (len > ip->ip_len) {
95 goto bad;
96 }
97 m_adj(m, len - ip->ip_len);
98 ip->ip_len = len;
99 }
100
101 /*
102 * Save a copy of the IP header in case we want restore it
103 * for sending an ICMP error message in response.
104 */
105 save_ip = *ip;
106 save_ip.ip_len+= iphlen; /* tcp_input subtracts this */
107
108 /*
109 * Checksum extended UDP header and data.
110 */
111 if (uh->uh_sum) {
112 memset(&((struct ipovly *)ip)->ih_mbuf, 0, sizeof(struct mbuf_ptr));
113 ((struct ipovly *)ip)->ih_x1 = 0;
114 ((struct ipovly *)ip)->ih_len = uh->uh_ulen;
115 if(cksum(m, len + sizeof(struct ip))) {
116 goto bad;
117 }
118 }
119
120 /*
121 * handle DHCP/BOOTP
122 */
123 if (ntohs(uh->uh_dport) == BOOTP_SERVER &&
124 (ip->ip_dst.s_addr == slirp->vhost_addr.s_addr ||
125 ip->ip_dst.s_addr == 0xffffffff)) {
126 bootp_input(m);
127 goto bad;
128 }
129
130 /*
131 * handle TFTP
132 */
133 if (ntohs(uh->uh_dport) == TFTP_SERVER &&
134 ip->ip_dst.s_addr == slirp->vhost_addr.s_addr) {
135 tftp_input(m);
136 goto bad;
137 }
138
139 if (slirp->restricted) {
140 goto bad;
141 }
142
143 /*
144 * Locate pcb for datagram.
145 */
146 so = slirp->udp_last_so;
147 if (so->so_lport != uh->uh_sport ||
148 so->so_laddr.s_addr != ip->ip_src.s_addr) {
149 struct socket *tmp;
150
151 for (tmp = slirp->udb.so_next; tmp != &slirp->udb;
152 tmp = tmp->so_next) {
153 if (tmp->so_lport == uh->uh_sport &&
154 tmp->so_laddr.s_addr == ip->ip_src.s_addr) {
155 so = tmp;
156 break;
157 }
158 }
159 if (tmp == &slirp->udb) {
160 so = NULL;
161 } else {
162 slirp->udp_last_so = so;
163 }
164 }
165
166 if (so == NULL) {
167 /*
168 * If there's no socket for this packet,
169 * create one
170 */
171 so = socreate(slirp);
172 if (!so) {
173 goto bad;
174 }
175 if(udp_attach(so) == -1) {
176 DEBUG_MISC((dfd," udp_attach errno = %d-%s\n",
177 errno,strerror(errno)));
178 sofree(so);
179 goto bad;
180 }
181
182 /*
183 * Setup fields
184 */
185 so->so_laddr = ip->ip_src;
186 so->so_lport = uh->uh_sport;
187
188 if ((so->so_iptos = udp_tos(so)) == 0)
189 so->so_iptos = ip->ip_tos;
190
191 /*
192 * XXXXX Here, check if it's in udpexec_list,
193 * and if it is, do the fork_exec() etc.
194 */
195 }
196
197 so->so_faddr = ip->ip_dst; /* XXX */
198 so->so_fport = uh->uh_dport; /* XXX */
199
200 iphlen += sizeof(struct udphdr);
201 m->m_len -= iphlen;
202 m->m_data += iphlen;
203
204 /*
205 * Now we sendto() the packet.
206 */
207 if(sosendto(so,m) == -1) {
208 m->m_len += iphlen;
209 m->m_data -= iphlen;
210 *ip=save_ip;
211 DEBUG_MISC((dfd,"udp tx errno = %d-%s\n",errno,strerror(errno)));
212 icmp_error(m, ICMP_UNREACH,ICMP_UNREACH_NET, 0,strerror(errno));
213 }
214
215 m_free(so->so_m); /* used for ICMP if error on sorecvfrom */
216
217 /* restore the orig mbuf packet */
218 m->m_len += iphlen;
219 m->m_data -= iphlen;
220 *ip=save_ip;
221 so->so_m=m; /* ICMP backup */
222
223 return;
224 bad:
225 m_free(m);
226 return;
227 }
228
229 int udp_output2(struct socket *so, struct mbuf *m,
230 struct sockaddr_in *saddr, struct sockaddr_in *daddr,
231 int iptos)
232 {
233 register struct udpiphdr *ui;
234 int error = 0;
235
236 DEBUG_CALL("udp_output");
237 DEBUG_ARG("so = %lx", (long)so);
238 DEBUG_ARG("m = %lx", (long)m);
239 DEBUG_ARG("saddr = %lx", (long)saddr->sin_addr.s_addr);
240 DEBUG_ARG("daddr = %lx", (long)daddr->sin_addr.s_addr);
241
242 /*
243 * Adjust for header
244 */
245 m->m_data -= sizeof(struct udpiphdr);
246 m->m_len += sizeof(struct udpiphdr);
247
248 /*
249 * Fill in mbuf with extended UDP header
250 * and addresses and length put into network format.
251 */
252 ui = mtod(m, struct udpiphdr *);
253 memset(&ui->ui_i.ih_mbuf, 0 , sizeof(struct mbuf_ptr));
254 ui->ui_x1 = 0;
255 ui->ui_pr = IPPROTO_UDP;
256 ui->ui_len = htons(m->m_len - sizeof(struct ip));
257 /* XXXXX Check for from-one-location sockets, or from-any-location sockets */
258 ui->ui_src = saddr->sin_addr;
259 ui->ui_dst = daddr->sin_addr;
260 ui->ui_sport = saddr->sin_port;
261 ui->ui_dport = daddr->sin_port;
262 ui->ui_ulen = ui->ui_len;
263
264 /*
265 * Stuff checksum and output datagram.
266 */
267 ui->ui_sum = 0;
268 if ((ui->ui_sum = cksum(m, m->m_len)) == 0)
269 ui->ui_sum = 0xffff;
270 ((struct ip *)ui)->ip_len = m->m_len;
271
272 ((struct ip *)ui)->ip_ttl = IPDEFTTL;
273 ((struct ip *)ui)->ip_tos = iptos;
274
275 error = ip_output(so, m);
276
277 return (error);
278 }
279
280 int udp_output(struct socket *so, struct mbuf *m,
281 struct sockaddr_in *addr)
282
283 {
284 Slirp *slirp = so->slirp;
285 struct sockaddr_in saddr, daddr;
286
287 saddr = *addr;
288 if ((so->so_faddr.s_addr & slirp->vnetwork_mask.s_addr) ==
289 slirp->vnetwork_addr.s_addr) {
290 uint32_t inv_mask = ~slirp->vnetwork_mask.s_addr;
291
292 if ((so->so_faddr.s_addr & inv_mask) == inv_mask) {
293 saddr.sin_addr = slirp->vhost_addr;
294 } else if (addr->sin_addr.s_addr == loopback_addr.s_addr ||
295 so->so_faddr.s_addr != slirp->vhost_addr.s_addr) {
296 saddr.sin_addr = so->so_faddr;
297 }
298 }
299 daddr.sin_addr = so->so_laddr;
300 daddr.sin_port = so->so_lport;
301
302 return udp_output2(so, m, &saddr, &daddr, so->so_iptos);
303 }
304
305 int
306 udp_attach(struct socket *so)
307 {
308 if((so->s = qemu_socket(AF_INET,SOCK_DGRAM,0)) != -1) {
309 so->so_expire = curtime + SO_EXPIRE;
310 insque(so, &so->slirp->udb);
311 }
312 return(so->s);
313 }
314
315 void
316 udp_detach(struct socket *so)
317 {
318 closesocket(so->s);
319 sofree(so);
320 }
321
322 static const struct tos_t udptos[] = {
323 {0, 53, IPTOS_LOWDELAY, 0}, /* DNS */
324 {0, 0, 0, 0}
325 };
326
327 static uint8_t
328 udp_tos(struct socket *so)
329 {
330 int i = 0;
331
332 while(udptos[i].tos) {
333 if ((udptos[i].fport && ntohs(so->so_fport) == udptos[i].fport) ||
334 (udptos[i].lport && ntohs(so->so_lport) == udptos[i].lport)) {
335 so->so_emu = udptos[i].emu;
336 return udptos[i].tos;
337 }
338 i++;
339 }
340
341 return 0;
342 }
343
344 struct socket *
345 udp_listen(Slirp *slirp, uint32_t haddr, u_int hport, uint32_t laddr,
346 u_int lport, int flags)
347 {
348 struct sockaddr_in addr;
349 struct socket *so;
350 socklen_t addrlen = sizeof(struct sockaddr_in), opt = 1;
351
352 so = socreate(slirp);
353 if (!so) {
354 return NULL;
355 }
356 so->s = qemu_socket(AF_INET,SOCK_DGRAM,0);
357 so->so_expire = curtime + SO_EXPIRE;
358 insque(so, &slirp->udb);
359
360 addr.sin_family = AF_INET;
361 addr.sin_addr.s_addr = haddr;
362 addr.sin_port = hport;
363
364 if (bind(so->s,(struct sockaddr *)&addr, addrlen) < 0) {
365 udp_detach(so);
366 return NULL;
367 }
368 setsockopt(so->s,SOL_SOCKET,SO_REUSEADDR,(char *)&opt,sizeof(int));
369
370 getsockname(so->s,(struct sockaddr *)&addr,&addrlen);
371 so->so_fport = addr.sin_port;
372 if (addr.sin_addr.s_addr == 0 ||
373 addr.sin_addr.s_addr == loopback_addr.s_addr) {
374 so->so_faddr = slirp->vhost_addr;
375 } else {
376 so->so_faddr = addr.sin_addr;
377 }
378 so->so_lport = lport;
379 so->so_laddr.s_addr = laddr;
380 if (flags != SS_FACCEPTONCE)
381 so->so_expire = 0;
382
383 so->so_state &= SS_PERSISTENT_MASK;
384 so->so_state |= SS_ISFCONNECTED | flags;
385
386 return so;
387 }