1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 1999 Brian Somers <brian@Awfulhak.org>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 * $FreeBSD: stable/12/usr.sbin/ppp/udp.c 326276 2017-11-27 15:37:16Z pfg $
29 */
30
31 #include <sys/types.h>
32 #include <sys/socket.h>
33 #include <netinet/in.h>
34 #include <arpa/inet.h>
35 #include <netdb.h>
36
37 #include <errno.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include <sysexits.h>
42 #include <sys/stat.h>
43 #include <sys/uio.h>
44 #include <termios.h>
45 #include <unistd.h>
46
47 #include "layer.h"
48 #include "defs.h"
49 #include "mbuf.h"
50 #include "log.h"
51 #include "timer.h"
52 #include "lqr.h"
53 #include "hdlc.h"
54 #include "throughput.h"
55 #include "fsm.h"
56 #include "lcp.h"
57 #include "ccp.h"
58 #include "link.h"
59 #include "async.h"
60 #include "descriptor.h"
61 #include "physical.h"
62 #include "main.h"
63 #include "udp.h"
64
65
66 #define UDP_CONNECTED 1
67 #define UDP_UNCONNECTED 2
68 #define UDP_MAYBEUNCONNECTED 3
69
70 struct udpdevice {
71 struct device dev; /* What struct physical knows about */
72 struct sockaddr_in sock; /* peer address */
73 unsigned connected : 2; /* Have we connect()d ? */
74 };
75
76 #define device2udp(d) ((d)->type == UDP_DEVICE ? (struct udpdevice *)d : NULL)
77
78 unsigned
udp_DeviceSize(void)79 udp_DeviceSize(void)
80 {
81 return sizeof(struct udpdevice);
82 }
83
84 static ssize_t
udp_Sendto(struct physical * p,const void * v,size_t n)85 udp_Sendto(struct physical *p, const void *v, size_t n)
86 {
87 struct udpdevice *dev = device2udp(p->handler);
88 int ret;
89
90 switch (dev->connected) {
91 case UDP_CONNECTED:
92 ret = write(p->fd, v, n);
93 break;
94
95 case UDP_UNCONNECTED:
96 default:
97 ret = sendto(p->fd, v, n, 0, (struct sockaddr *)&dev->sock,
98 sizeof dev->sock);
99 break;
100 }
101 if (dev->connected == UDP_MAYBEUNCONNECTED) {
102 if (ret == -1 && errno == EISCONN) {
103 dev->connected = UDP_CONNECTED;
104 ret = write(p->fd, v, n);
105 } else
106 dev->connected = UDP_UNCONNECTED;
107 }
108
109 return ret;
110 }
111
112 static ssize_t
udp_Recvfrom(struct physical * p,void * v,size_t n)113 udp_Recvfrom(struct physical *p, void *v, size_t n)
114 {
115 struct udpdevice *dev = device2udp(p->handler);
116 int sz, ret;
117
118 if (dev->connected == UDP_CONNECTED)
119 return read(p->fd, v, n);
120
121 sz = sizeof dev->sock;
122 ret = recvfrom(p->fd, v, n, 0, (struct sockaddr *)&dev->sock, &sz);
123
124 if (*p->name.full == '\0') {
125 snprintf(p->name.full, sizeof p->name.full, "%s:%d/udp",
126 inet_ntoa(dev->sock.sin_addr), ntohs(dev->sock.sin_port));
127 p->name.base = p->name.full;
128 }
129
130 return ret;
131 }
132
133 static void
udp_Free(struct physical * p)134 udp_Free(struct physical *p)
135 {
136 struct udpdevice *dev = device2udp(p->handler);
137
138 free(dev);
139 }
140
141 static void
udp_device2iov(struct device * d,struct iovec * iov,int * niov,int maxiov __unused,int * auxfd __unused,int * nauxfd __unused)142 udp_device2iov(struct device *d, struct iovec *iov, int *niov,
143 int maxiov __unused, int *auxfd __unused, int *nauxfd __unused)
144 {
145 int sz = physical_MaxDeviceSize();
146
147 iov[*niov].iov_base = realloc(d, sz);
148 if (iov[*niov].iov_base == NULL) {
149 log_Printf(LogALERT, "Failed to allocate memory: %d\n", sz);
150 AbortProgram(EX_OSERR);
151 }
152 iov[*niov].iov_len = sz;
153 (*niov)++;
154 }
155
156 static const struct device baseudpdevice = {
157 UDP_DEVICE,
158 "udp",
159 0,
160 { CD_NOTREQUIRED, 0 },
161 NULL,
162 NULL,
163 NULL,
164 NULL,
165 NULL,
166 NULL,
167 NULL,
168 udp_Free,
169 udp_Recvfrom,
170 udp_Sendto,
171 udp_device2iov,
172 NULL,
173 NULL,
174 NULL
175 };
176
177 struct device *
udp_iov2device(int type,struct physical * p,struct iovec * iov,int * niov,int maxiov __unused,int * auxfd __unused,int * nauxfd __unused)178 udp_iov2device(int type, struct physical *p, struct iovec *iov, int *niov,
179 int maxiov __unused, int *auxfd __unused, int *nauxfd __unused)
180 {
181 if (type == UDP_DEVICE) {
182 struct udpdevice *dev = (struct udpdevice *)iov[(*niov)++].iov_base;
183
184 dev = realloc(dev, sizeof *dev); /* Reduce to the correct size */
185 if (dev == NULL) {
186 log_Printf(LogALERT, "Failed to allocate memory: %d\n",
187 (int)(sizeof *dev));
188 AbortProgram(EX_OSERR);
189 }
190
191 /* Refresh function pointers etc */
192 memcpy(&dev->dev, &baseudpdevice, sizeof dev->dev);
193
194 physical_SetupStack(p, dev->dev.name, PHYSICAL_FORCE_SYNC);
195 return &dev->dev;
196 }
197
198 return NULL;
199 }
200
201 static struct udpdevice *
udp_CreateDevice(struct physical * p,char * host,char * port)202 udp_CreateDevice(struct physical *p, char *host, char *port)
203 {
204 struct udpdevice *dev;
205 struct servent *sp;
206
207 if ((dev = malloc(sizeof *dev)) == NULL) {
208 log_Printf(LogWARN, "%s: Cannot allocate a udp device: %s\n",
209 p->link.name, strerror(errno));
210 return NULL;
211 }
212
213 dev->sock.sin_family = AF_INET;
214 dev->sock.sin_addr = GetIpAddr(host);
215 if (dev->sock.sin_addr.s_addr == INADDR_NONE) {
216 log_Printf(LogWARN, "%s: %s: unknown host\n", p->link.name, host);
217 free(dev);
218 return NULL;
219 }
220 dev->sock.sin_port = htons(atoi(port));
221 if (dev->sock.sin_port == 0) {
222 sp = getservbyname(port, "udp");
223 if (sp)
224 dev->sock.sin_port = sp->s_port;
225 else {
226 log_Printf(LogWARN, "%s: %s: unknown service\n", p->link.name, port);
227 free(dev);
228 return NULL;
229 }
230 }
231
232 log_Printf(LogPHASE, "%s: Connecting to %s:%s/udp\n", p->link.name,
233 host, port);
234
235 p->fd = socket(PF_INET, SOCK_DGRAM, 0);
236 if (p->fd >= 0) {
237 log_Printf(LogDEBUG, "%s: Opened udp socket %s\n", p->link.name,
238 p->name.full);
239 if (connect(p->fd, (struct sockaddr *)&dev->sock, sizeof dev->sock) == 0) {
240 dev->connected = UDP_CONNECTED;
241 return dev;
242 } else
243 log_Printf(LogWARN, "%s: connect: %s\n", p->name.full, strerror(errno));
244 } else
245 log_Printf(LogWARN, "%s: socket: %s\n", p->name.full, strerror(errno));
246
247 close(p->fd);
248 p->fd = -1;
249 free(dev);
250
251 return NULL;
252 }
253
254 struct device *
udp_Create(struct physical * p)255 udp_Create(struct physical *p)
256 {
257 char *cp, *host, *port, *svc;
258 struct udpdevice *dev;
259
260 dev = NULL;
261 if (p->fd < 0) {
262 if ((cp = strchr(p->name.full, ':')) != NULL && !strchr(cp + 1, ':')) {
263 *cp = '\0';
264 host = p->name.full;
265 port = cp + 1;
266 svc = strchr(port, '/');
267 if (svc && strcasecmp(svc, "/udp")) {
268 *cp = ':';
269 return NULL;
270 }
271 if (svc) {
272 p->fd--; /* We own the device but maybe can't use it - change fd */
273 *svc = '\0';
274 }
275
276 if (*host && *port)
277 dev = udp_CreateDevice(p, host, port);
278
279 *cp = ':';
280 if (svc)
281 *svc = '/';
282 }
283 } else {
284 /* See if we're a connected udp socket */
285 struct stat st;
286
287 if (fstat(p->fd, &st) != -1 && (st.st_mode & S_IFSOCK)) {
288 int type, sz;
289
290 sz = sizeof type;
291 if (getsockopt(p->fd, SOL_SOCKET, SO_TYPE, &type, &sz) == -1) {
292 log_Printf(LogPHASE, "%s: Link is a closed socket !\n", p->link.name);
293 close(p->fd);
294 p->fd = -1;
295 return NULL;
296 }
297
298 if (sz == sizeof type && type == SOCK_DGRAM) {
299 struct sockaddr_in sock;
300 struct sockaddr *sockp = (struct sockaddr *)&sock;
301
302 if ((dev = malloc(sizeof *dev)) == NULL) {
303 log_Printf(LogWARN, "%s: Cannot allocate a udp device: %s\n",
304 p->link.name, strerror(errno));
305 return NULL;
306 }
307
308 if (getpeername(p->fd, sockp, &sz) == 0) {
309 log_Printf(LogPHASE, "%s: Link is a connected udp socket\n",
310 p->link.name);
311 dev->connected = UDP_CONNECTED;
312 } else {
313 log_Printf(LogPHASE, "%s: Link is a disconnected udp socket\n",
314 p->link.name);
315
316 dev->connected = UDP_MAYBEUNCONNECTED;
317
318 if (p->link.lcp.cfg.openmode != OPEN_PASSIVE) {
319 log_Printf(LogPHASE, "%s: Changing openmode to PASSIVE\n",
320 p->link.name);
321 p->link.lcp.cfg.openmode = OPEN_PASSIVE;
322 }
323 }
324 }
325 }
326 }
327
328 if (dev) {
329 memcpy(&dev->dev, &baseudpdevice, sizeof dev->dev);
330 physical_SetupStack(p, dev->dev.name, PHYSICAL_FORCE_SYNC);
331 if (p->cfg.cd.necessity != CD_DEFAULT)
332 log_Printf(LogWARN, "Carrier settings ignored\n");
333 return &dev->dev;
334 }
335
336 return NULL;
337 }
338