1 | /* SPDX-License-Identifier: BSD-3-Clause */ |
2 | /* |
3 | * Copyright (c) 1982, 1986, 1988, 1990, 1993 |
4 | * The Regents of the University of California. All rights reserved. |
5 | * |
6 | * Redistribution and use in source and binary forms, with or without |
7 | * modification, are permitted provided that the following conditions |
8 | * are met: |
9 | * 1. Redistributions of source code must retain the above copyright |
10 | * notice, this list of conditions and the following disclaimer. |
11 | * 2. Redistributions in binary form must reproduce the above copyright |
12 | * notice, this list of conditions and the following disclaimer in the |
13 | * documentation and/or other materials provided with the distribution. |
14 | * 3. Neither the name of the University nor the names of its contributors |
15 | * may be used to endorse or promote products derived from this software |
16 | * without specific prior written permission. |
17 | * |
18 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
19 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
20 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
21 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
22 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
23 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
24 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
25 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
26 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
27 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
28 | * SUCH DAMAGE. |
29 | * |
30 | * @(#)udp_usrreq.c 8.4 (Berkeley) 1/21/94 |
31 | * udp_usrreq.c,v 1.4 1994/10/02 17:48:45 phk Exp |
32 | */ |
33 | |
34 | /* |
35 | * Changes and additions relating to SLiRP |
36 | * Copyright (c) 1995 Danny Gasparovski. |
37 | * |
38 | * Please read the file COPYRIGHT for the |
39 | * terms and conditions of the copyright. |
40 | */ |
41 | |
42 | #include "slirp.h" |
43 | #include "ip_icmp.h" |
44 | |
45 | static uint8_t udp_tos(struct socket *so); |
46 | |
47 | void 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 | |
53 | void udp_cleanup(Slirp *slirp) |
54 | { |
55 | while (slirp->udb.so_next != &slirp->udb) { |
56 | udp_detach(slirp->udb.so_next); |
57 | } |
58 | } |
59 | |
60 | /* m->m_data points at ip packet header |
61 | * m->m_len length ip packet |
62 | * ip->ip_len length data (IPDU) |
63 | */ |
64 | void udp_input(register struct mbuf *m, int iphlen) |
65 | { |
66 | Slirp *slirp = m->slirp; |
67 | register struct ip *ip; |
68 | register struct udphdr *uh; |
69 | int len; |
70 | struct ip save_ip; |
71 | struct socket *so; |
72 | struct sockaddr_storage lhost; |
73 | struct sockaddr_in *lhost4; |
74 | |
75 | DEBUG_CALL("udp_input" ); |
76 | DEBUG_ARG("m = %p" , m); |
77 | DEBUG_ARG("iphlen = %d" , iphlen); |
78 | |
79 | /* |
80 | * Strip IP options, if any; should skip this, |
81 | * make available to user, and use on returned packets, |
82 | * but we don't yet have a way to check the checksum |
83 | * with options still present. |
84 | */ |
85 | if (iphlen > sizeof(struct ip)) { |
86 | ip_stripoptions(m, (struct mbuf *)0); |
87 | iphlen = sizeof(struct ip); |
88 | } |
89 | |
90 | /* |
91 | * Get IP and UDP header together in first mbuf. |
92 | */ |
93 | ip = mtod(m, struct ip *); |
94 | uh = (struct udphdr *)((char *)ip + iphlen); |
95 | |
96 | /* |
97 | * Make mbuf data length reflect UDP length. |
98 | * If not enough data to reflect UDP length, drop. |
99 | */ |
100 | len = ntohs((uint16_t)uh->uh_ulen); |
101 | |
102 | if (ip->ip_len != len) { |
103 | if (len > ip->ip_len) { |
104 | goto bad; |
105 | } |
106 | m_adj(m, len - ip->ip_len); |
107 | ip->ip_len = len; |
108 | } |
109 | |
110 | /* |
111 | * Save a copy of the IP header in case we want restore it |
112 | * for sending an ICMP error message in response. |
113 | */ |
114 | save_ip = *ip; |
115 | save_ip.ip_len += iphlen; /* tcp_input subtracts this */ |
116 | |
117 | /* |
118 | * Checksum extended UDP header and data. |
119 | */ |
120 | if (uh->uh_sum) { |
121 | memset(&((struct ipovly *)ip)->ih_mbuf, 0, sizeof(struct mbuf_ptr)); |
122 | ((struct ipovly *)ip)->ih_x1 = 0; |
123 | ((struct ipovly *)ip)->ih_len = uh->uh_ulen; |
124 | if (cksum(m, len + sizeof(struct ip))) { |
125 | goto bad; |
126 | } |
127 | } |
128 | |
129 | lhost.ss_family = AF_INET; |
130 | lhost4 = (struct sockaddr_in *)&lhost; |
131 | lhost4->sin_addr = ip->ip_src; |
132 | lhost4->sin_port = uh->uh_sport; |
133 | |
134 | /* |
135 | * handle DHCP/BOOTP |
136 | */ |
137 | if (ntohs(uh->uh_dport) == BOOTP_SERVER && |
138 | (ip->ip_dst.s_addr == slirp->vhost_addr.s_addr || |
139 | ip->ip_dst.s_addr == 0xffffffff)) { |
140 | bootp_input(m); |
141 | goto bad; |
142 | } |
143 | |
144 | /* |
145 | * handle TFTP |
146 | */ |
147 | if (ntohs(uh->uh_dport) == TFTP_SERVER && |
148 | ip->ip_dst.s_addr == slirp->vhost_addr.s_addr) { |
149 | m->m_data += iphlen; |
150 | m->m_len -= iphlen; |
151 | tftp_input(&lhost, m); |
152 | m->m_data -= iphlen; |
153 | m->m_len += iphlen; |
154 | goto bad; |
155 | } |
156 | |
157 | if (slirp->restricted) { |
158 | goto bad; |
159 | } |
160 | |
161 | /* |
162 | * Locate pcb for datagram. |
163 | */ |
164 | so = solookup(&slirp->udp_last_so, &slirp->udb, &lhost, NULL); |
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 (udp_attach(so, AF_INET) == -1) { |
173 | DEBUG_MISC(" udp_attach errno = %d-%s" , errno, strerror(errno)); |
174 | sofree(so); |
175 | goto bad; |
176 | } |
177 | |
178 | /* |
179 | * Setup fields |
180 | */ |
181 | so->so_lfamily = AF_INET; |
182 | so->so_laddr = ip->ip_src; |
183 | so->so_lport = uh->uh_sport; |
184 | |
185 | if ((so->so_iptos = udp_tos(so)) == 0) |
186 | so->so_iptos = ip->ip_tos; |
187 | |
188 | /* |
189 | * XXXXX Here, check if it's in udpexec_list, |
190 | * and if it is, do the fork_exec() etc. |
191 | */ |
192 | } |
193 | |
194 | so->so_ffamily = AF_INET; |
195 | so->so_faddr = ip->ip_dst; /* XXX */ |
196 | so->so_fport = uh->uh_dport; /* XXX */ |
197 | |
198 | iphlen += sizeof(struct udphdr); |
199 | m->m_len -= iphlen; |
200 | m->m_data += iphlen; |
201 | |
202 | /* |
203 | * Now we sendto() the packet. |
204 | */ |
205 | if (sosendto(so, m) == -1) { |
206 | m->m_len += iphlen; |
207 | m->m_data -= iphlen; |
208 | *ip = save_ip; |
209 | DEBUG_MISC("udp tx errno = %d-%s" , errno, strerror(errno)); |
210 | icmp_send_error(m, ICMP_UNREACH, ICMP_UNREACH_NET, 0, strerror(errno)); |
211 | goto bad; |
212 | } |
213 | |
214 | m_free(so->so_m); /* used for ICMP if error on sorecvfrom */ |
215 | |
216 | /* restore the orig mbuf packet */ |
217 | m->m_len += iphlen; |
218 | m->m_data -= iphlen; |
219 | *ip = save_ip; |
220 | so->so_m = m; /* ICMP backup */ |
221 | |
222 | return; |
223 | bad: |
224 | m_free(m); |
225 | } |
226 | |
227 | int udp_output(struct socket *so, struct mbuf *m, struct sockaddr_in *saddr, |
228 | struct sockaddr_in *daddr, int iptos) |
229 | { |
230 | register struct udpiphdr *ui; |
231 | int error = 0; |
232 | |
233 | DEBUG_CALL("udp_output" ); |
234 | DEBUG_ARG("so = %p" , so); |
235 | DEBUG_ARG("m = %p" , m); |
236 | DEBUG_ARG("saddr = %s" , inet_ntoa(saddr->sin_addr)); |
237 | DEBUG_ARG("daddr = %s" , inet_ntoa(daddr->sin_addr)); |
238 | |
239 | /* |
240 | * Adjust for header |
241 | */ |
242 | m->m_data -= sizeof(struct udpiphdr); |
243 | m->m_len += sizeof(struct udpiphdr); |
244 | |
245 | /* |
246 | * Fill in mbuf with extended UDP header |
247 | * and addresses and length put into network format. |
248 | */ |
249 | ui = mtod(m, struct udpiphdr *); |
250 | memset(&ui->ui_i.ih_mbuf, 0, sizeof(struct mbuf_ptr)); |
251 | ui->ui_x1 = 0; |
252 | ui->ui_pr = IPPROTO_UDP; |
253 | ui->ui_len = htons(m->m_len - sizeof(struct ip)); |
254 | /* XXXXX Check for from-one-location sockets, or from-any-location sockets |
255 | */ |
256 | ui->ui_src = saddr->sin_addr; |
257 | ui->ui_dst = daddr->sin_addr; |
258 | ui->ui_sport = saddr->sin_port; |
259 | ui->ui_dport = daddr->sin_port; |
260 | ui->ui_ulen = ui->ui_len; |
261 | |
262 | /* |
263 | * Stuff checksum and output datagram. |
264 | */ |
265 | ui->ui_sum = 0; |
266 | if ((ui->ui_sum = cksum(m, m->m_len)) == 0) |
267 | ui->ui_sum = 0xffff; |
268 | ((struct ip *)ui)->ip_len = m->m_len; |
269 | |
270 | ((struct ip *)ui)->ip_ttl = IPDEFTTL; |
271 | ((struct ip *)ui)->ip_tos = iptos; |
272 | |
273 | error = ip_output(so, m); |
274 | |
275 | return (error); |
276 | } |
277 | |
278 | int udp_attach(struct socket *so, unsigned short af) |
279 | { |
280 | so->s = slirp_socket(af, SOCK_DGRAM, 0); |
281 | if (so->s != -1) { |
282 | so->so_expire = curtime + SO_EXPIRE; |
283 | insque(so, &so->slirp->udb); |
284 | } |
285 | return (so->s); |
286 | } |
287 | |
288 | void udp_detach(struct socket *so) |
289 | { |
290 | so->slirp->cb->unregister_poll_fd(so->s, so->slirp->opaque); |
291 | closesocket(so->s); |
292 | sofree(so); |
293 | } |
294 | |
295 | static const struct tos_t udptos[] = { { 0, 53, IPTOS_LOWDELAY, 0 }, /* DNS */ |
296 | { 0, 0, 0, 0 } }; |
297 | |
298 | static uint8_t udp_tos(struct socket *so) |
299 | { |
300 | int i = 0; |
301 | |
302 | while (udptos[i].tos) { |
303 | if ((udptos[i].fport && ntohs(so->so_fport) == udptos[i].fport) || |
304 | (udptos[i].lport && ntohs(so->so_lport) == udptos[i].lport)) { |
305 | so->so_emu = udptos[i].emu; |
306 | return udptos[i].tos; |
307 | } |
308 | i++; |
309 | } |
310 | |
311 | return 0; |
312 | } |
313 | |
314 | struct socket *udp_listen(Slirp *slirp, uint32_t haddr, unsigned hport, |
315 | uint32_t laddr, unsigned lport, int flags) |
316 | { |
317 | /* TODO: IPv6 */ |
318 | struct sockaddr_in addr; |
319 | struct socket *so; |
320 | socklen_t addrlen = sizeof(struct sockaddr_in); |
321 | |
322 | so = socreate(slirp); |
323 | so->s = slirp_socket(AF_INET, SOCK_DGRAM, 0); |
324 | if (so->s < 0) { |
325 | sofree(so); |
326 | return NULL; |
327 | } |
328 | so->so_expire = curtime + SO_EXPIRE; |
329 | insque(so, &slirp->udb); |
330 | |
331 | addr.sin_family = AF_INET; |
332 | addr.sin_addr.s_addr = haddr; |
333 | addr.sin_port = hport; |
334 | |
335 | if (bind(so->s, (struct sockaddr *)&addr, addrlen) < 0) { |
336 | udp_detach(so); |
337 | return NULL; |
338 | } |
339 | slirp_socket_set_fast_reuse(so->s); |
340 | |
341 | getsockname(so->s, (struct sockaddr *)&addr, &addrlen); |
342 | so->fhost.sin = addr; |
343 | sotranslate_accept(so); |
344 | so->so_lfamily = AF_INET; |
345 | so->so_lport = lport; |
346 | so->so_laddr.s_addr = laddr; |
347 | if (flags != SS_FACCEPTONCE) |
348 | so->so_expire = 0; |
349 | |
350 | so->so_state &= SS_PERSISTENT_MASK; |
351 | so->so_state |= SS_ISFCONNECTED | flags; |
352 | |
353 | return so; |
354 | } |
355 | |