udp.c revision 330449 
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/11/usr.sbin/ppp/udp.c 330449 2018-03-05 07:26:05Z eadler $
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
70struct 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
78unsigned
79udp_DeviceSize(void)
80{
81  return sizeof(struct udpdevice);
82}
83
84static ssize_t
85udp_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
112static ssize_t
113udp_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
133static void
134udp_Free(struct physical *p)
135{
136  struct udpdevice *dev = device2udp(p->handler);
137
138  free(dev);
139}
140
141static void
142udp_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
156static 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
177struct device *
178udp_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
201static struct udpdevice *
202udp_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
254struct device *
255udp_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