xref: /freebsd/usr.sbin/ppp/udp.c (revision 77a0943ded95b9e6438f7db70c4a28e4d93946d4)
1 /*-
2  * Copyright (c) 1999 Brian Somers <brian@Awfulhak.org>
3  * 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  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 
29 #include <sys/types.h>
30 #include <sys/socket.h>
31 #include <netinet/in.h>
32 #include <arpa/inet.h>
33 #include <netdb.h>
34 
35 #include <errno.h>
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <string.h>
39 #include <sysexits.h>
40 #include <sys/uio.h>
41 #include <termios.h>
42 #include <unistd.h>
43 
44 #include "layer.h"
45 #include "defs.h"
46 #include "mbuf.h"
47 #include "log.h"
48 #include "timer.h"
49 #include "lqr.h"
50 #include "hdlc.h"
51 #include "throughput.h"
52 #include "fsm.h"
53 #include "lcp.h"
54 #include "ccp.h"
55 #include "link.h"
56 #include "async.h"
57 #include "descriptor.h"
58 #include "physical.h"
59 #include "main.h"
60 #include "udp.h"
61 
62 
63 #define UDP_CONNECTED		1
64 #define UDP_UNCONNECTED		2
65 #define UDP_MAYBEUNCONNECTED	3
66 
67 struct udpdevice {
68   struct device dev;		/* What struct physical knows about */
69   struct sockaddr_in sock;	/* peer address */
70   unsigned connected : 2;	/* Have we connect()d ? */
71 };
72 
73 #define device2udp(d) ((d)->type == UDP_DEVICE ? (struct udpdevice *)d : NULL)
74 
75 int
76 udp_DeviceSize(void)
77 {
78   return sizeof(struct udpdevice);
79 }
80 
81 static ssize_t
82 udp_Sendto(struct physical *p, const void *v, size_t n)
83 {
84   struct udpdevice *dev = device2udp(p->handler);
85   int ret;
86 
87   switch (dev->connected) {
88     case UDP_CONNECTED:
89       ret = write(p->fd, v, n);
90       break;
91 
92     case UDP_UNCONNECTED:
93     default:
94       ret = sendto(p->fd, v, n, 0, (struct sockaddr *)&dev->sock,
95                    sizeof dev->sock);
96       break;
97   }
98   if (dev->connected == UDP_MAYBEUNCONNECTED) {
99     if (ret == -1 && errno == EISCONN) {
100       dev->connected = UDP_CONNECTED;
101       ret = write(p->fd, v, n);
102     } else
103       dev->connected = UDP_UNCONNECTED;
104   }
105 
106   return ret;
107 }
108 
109 static ssize_t
110 udp_Recvfrom(struct physical *p, void *v, size_t n)
111 {
112   struct udpdevice *dev = device2udp(p->handler);
113   int sz, ret;
114 
115   if (dev->connected == UDP_CONNECTED)
116     return read(p->fd, v, n);
117 
118   sz = sizeof dev->sock;
119   ret = recvfrom(p->fd, v, n, 0, (struct sockaddr *)&dev->sock, &sz);
120 
121   if (*p->name.full == '\0') {
122     snprintf(p->name.full, sizeof p->name.full, "%s:%d/udp",
123              inet_ntoa(dev->sock.sin_addr), ntohs(dev->sock.sin_port));
124     p->name.base = p->name.full;
125   }
126 
127   return ret;
128 }
129 
130 static void
131 udp_Free(struct physical *p)
132 {
133   struct udpdevice *dev = device2udp(p->handler);
134 
135   free(dev);
136 }
137 
138 static void
139 udp_device2iov(struct device *d, struct iovec *iov, int *niov,
140                int maxiov, int *auxfd, int *nauxfd)
141 {
142   int sz = physical_MaxDeviceSize();
143 
144   iov[*niov].iov_base = realloc(d, sz);
145   if (iov[*niov].iov_base == NULL) {
146     log_Printf(LogALERT, "Failed to allocate memory: %d\n", sz);
147     AbortProgram(EX_OSERR);
148   }
149   iov[*niov].iov_len = sz;
150   (*niov)++;
151 }
152 
153 static const struct device baseudpdevice = {
154   UDP_DEVICE,
155   "udp",
156   { CD_NOTREQUIRED, 0 },
157   NULL,
158   NULL,
159   NULL,
160   NULL,
161   NULL,
162   NULL,
163   udp_Free,
164   udp_Recvfrom,
165   udp_Sendto,
166   udp_device2iov,
167   NULL,
168   NULL
169 };
170 
171 struct device *
172 udp_iov2device(int type, struct physical *p, struct iovec *iov, int *niov,
173                int maxiov, int *auxfd, int *nauxfd)
174 {
175   if (type == UDP_DEVICE) {
176     struct udpdevice *dev = (struct udpdevice *)iov[(*niov)++].iov_base;
177 
178     dev = realloc(dev, sizeof *dev);	/* Reduce to the correct size */
179     if (dev == NULL) {
180       log_Printf(LogALERT, "Failed to allocate memory: %d\n",
181                  (int)(sizeof *dev));
182       AbortProgram(EX_OSERR);
183     }
184 
185     /* Refresh function pointers etc */
186     memcpy(&dev->dev, &baseudpdevice, sizeof dev->dev);
187 
188     physical_SetupStack(p, dev->dev.name, PHYSICAL_FORCE_SYNC);
189     return &dev->dev;
190   }
191 
192   return NULL;
193 }
194 
195 static struct udpdevice *
196 udp_CreateDevice(struct physical *p, char *host, char *port)
197 {
198   struct udpdevice *dev;
199   struct servent *sp;
200 
201   if ((dev = malloc(sizeof *dev)) == NULL) {
202     log_Printf(LogWARN, "%s: Cannot allocate a udp device: %s\n",
203                p->link.name, strerror(errno));
204     return NULL;
205   }
206 
207   dev->sock.sin_family = AF_INET;
208   dev->sock.sin_addr.s_addr = inet_addr(host);
209   dev->sock.sin_addr = GetIpAddr(host);
210   if (dev->sock.sin_addr.s_addr == INADDR_NONE) {
211     log_Printf(LogWARN, "%s: %s: unknown host\n", p->link.name, host);
212     free(dev);
213     return NULL;
214   }
215   dev->sock.sin_port = htons(atoi(port));
216   if (dev->sock.sin_port == 0) {
217     sp = getservbyname(port, "udp");
218     if (sp)
219       dev->sock.sin_port = sp->s_port;
220     else {
221       log_Printf(LogWARN, "%s: %s: unknown service\n", p->link.name, port);
222       free(dev);
223       return NULL;
224     }
225   }
226 
227   log_Printf(LogPHASE, "%s: Connecting to %s:%s/udp\n", p->link.name,
228              host, port);
229 
230   p->fd = socket(PF_INET, SOCK_DGRAM, 0);
231   if (p->fd >= 0) {
232     log_Printf(LogDEBUG, "%s: Opened udp socket %s\n", p->link.name,
233                p->name.full);
234     if (connect(p->fd, (struct sockaddr *)&dev->sock, sizeof dev->sock) == 0) {
235       dev->connected = UDP_CONNECTED;
236       return dev;
237     } else
238       log_Printf(LogWARN, "%s: connect: %s\n", p->name.full, strerror(errno));
239   } else
240     log_Printf(LogWARN, "%s: socket: %s\n", p->name.full, strerror(errno));
241 
242   close(p->fd);
243   p->fd = -1;
244   free(dev);
245 
246   return NULL;
247 }
248 
249 struct device *
250 udp_Create(struct physical *p)
251 {
252   char *cp, *host, *port, *svc;
253   struct udpdevice *dev;
254 
255   dev = NULL;
256   if (p->fd < 0) {
257     if ((cp = strchr(p->name.full, ':')) != NULL && !strchr(cp + 1, ':')) {
258       *cp = '\0';
259       host = p->name.full;
260       port = cp + 1;
261       svc = strchr(port, '/');
262       if (svc && strcasecmp(svc, "/udp")) {
263         *cp = ':';
264         return NULL;
265       }
266       if (svc) {
267         p->fd--;     /* We own the device but maybe can't use it - change fd */
268         *svc = '\0';
269       }
270 
271       if (*host && *port)
272         dev = udp_CreateDevice(p, host, port);
273 
274       *cp = ':';
275       if (svc)
276         *svc = '/';
277     }
278   } else {
279     /* See if we're a connected udp socket */
280     int type, sz, err;
281 
282     sz = sizeof type;
283     if ((err = getsockopt(p->fd, SOL_SOCKET, SO_TYPE, &type, &sz)) == 0 &&
284         sz == sizeof type && type == SOCK_DGRAM) {
285       if ((dev = malloc(sizeof *dev)) == NULL) {
286         log_Printf(LogWARN, "%s: Cannot allocate a udp device: %s\n",
287                    p->link.name, strerror(errno));
288         return NULL;
289       }
290 
291       /* We can't getpeername().... */
292       dev->connected = UDP_MAYBEUNCONNECTED;
293 
294       log_Printf(LogPHASE, "%s: Link is a udp socket\n", p->link.name);
295 
296       if (p->link.lcp.cfg.openmode != OPEN_PASSIVE) {
297         log_Printf(LogPHASE, "%s:   Changing openmode to PASSIVE\n",
298                    p->link.name);
299         p->link.lcp.cfg.openmode = OPEN_PASSIVE;
300       }
301     }
302   }
303 
304   if (dev) {
305     memcpy(&dev->dev, &baseudpdevice, sizeof dev->dev);
306     physical_SetupStack(p, dev->dev.name, PHYSICAL_FORCE_SYNC);
307     if (p->cfg.cd.necessity != CD_DEFAULT)
308       log_Printf(LogWARN, "Carrier settings ignored\n");
309     return &dev->dev;
310   }
311 
312   return NULL;
313 }
314