udp.c revision 47461 
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 *	$Id: udp.c,v 1.1 1999/05/12 09:49:09 brian Exp $
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 <sys/uio.h>
40#include <termios.h>
41#include <unistd.h>
42
43#include "layer.h"
44#include "defs.h"
45#include "mbuf.h"
46#include "log.h"
47#include "sync.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 "udp.h"
60
61struct udpdevice {
62  struct device dev;		/* What struct physical knows about */
63  struct sockaddr_in sock;	/* peer address */
64  unsigned connected : 1;	/* Have we connect()d ? */
65};
66
67#define device2udp(d) ((d)->type == UDP_DEVICE ? (struct udpdevice *)d : NULL)
68
69static ssize_t
70udp_Sendto(struct physical *p, const void *v, size_t n)
71{
72  struct udpdevice *dev = device2udp(p->handler);
73
74  if (dev->connected)
75    return write(p->fd, v, n);
76
77  return sendto(p->fd, v, n, 0, (struct sockaddr *)&dev->sock,
78                sizeof dev->sock);
79}
80
81static ssize_t
82udp_Recvfrom(struct physical *p, void *v, size_t n)
83{
84  struct udpdevice *dev = device2udp(p->handler);
85  int sz, ret;
86
87  if (dev->connected)
88    return read(p->fd, v, n);
89
90  sz = sizeof dev->sock;
91  ret = recvfrom(p->fd, v, n, 0, (struct sockaddr *)&dev->sock, &sz);
92
93  if (*p->name.full == '\0') {
94    snprintf(p->name.full, sizeof p->name.full, "%s:%d/udp",
95             inet_ntoa(dev->sock.sin_addr), ntohs(dev->sock.sin_port));
96    p->name.base = p->name.full;
97  }
98
99  return ret;
100}
101
102static void
103udp_Free(struct physical *p)
104{
105  struct udpdevice *dev = device2udp(p->handler);
106
107  free(dev);
108}
109
110static void
111udp_device2iov(struct physical *p, struct iovec *iov, int *niov,
112               int maxiov, pid_t newpid)
113{
114  iov[*niov].iov_base = p ? p->handler : malloc(sizeof(struct udpdevice));
115  iov[*niov].iov_len = sizeof(struct udpdevice);
116  (*niov)++;
117}
118
119static const struct device baseudpdevice = {
120  UDP_DEVICE,
121  "udp",
122  NULL,
123  NULL,
124  NULL,
125  NULL,
126  udp_Free,
127  udp_Recvfrom,
128  udp_Sendto,
129  udp_device2iov,
130  NULL,
131  NULL
132};
133
134struct device *
135udp_iov2device(int type, struct physical *p, struct iovec *iov, int *niov,
136               int maxiov)
137{
138  if (type == UDP_DEVICE) {
139    struct udpdevice *dev = (struct udpdevice *)iov[(*niov)++].iov_base;
140
141    /* Refresh function pointers etc */
142    memcpy(&dev->dev, &baseudpdevice, sizeof dev->dev);
143
144    physical_SetupStack(p, dev->dev.name, PHYSICAL_FORCE_SYNC);
145    return &dev->dev;
146  }
147
148  return NULL;
149}
150
151static struct udpdevice *
152udp_CreateDevice(struct physical *p, char *host, char *port)
153{
154  struct udpdevice *dev;
155  struct servent *sp;
156
157  if ((dev = malloc(sizeof *dev)) == NULL) {
158    log_Printf(LogWARN, "%s: Cannot allocate a udp device: %s\n",
159               p->link.name, strerror(errno));
160    return NULL;
161  }
162
163  dev->sock.sin_family = AF_INET;
164  dev->sock.sin_addr.s_addr = inet_addr(host);
165  dev->sock.sin_addr = GetIpAddr(host);
166  if (dev->sock.sin_addr.s_addr == INADDR_NONE) {
167    log_Printf(LogWARN, "%s: %s: unknown host\n", p->link.name, host);
168    free(dev);
169    return NULL;
170  }
171  dev->sock.sin_port = htons(atoi(port));
172  if (dev->sock.sin_port == 0) {
173    sp = getservbyname(port, "udp");
174    if (sp)
175      dev->sock.sin_port = sp->s_port;
176    else {
177      log_Printf(LogWARN, "%s: %s: unknown service\n", p->link.name, port);
178      free(dev);
179      return NULL;
180    }
181  }
182
183  log_Printf(LogPHASE, "%s: Connecting to %s:%s/udp\n", p->link.name,
184             host, port);
185
186  p->fd = socket(PF_INET, SOCK_DGRAM, 0);
187  if (p->fd >= 0) {
188    log_Printf(LogDEBUG, "%s: Opened udp socket %s\n", p->link.name,
189               p->name.full);
190    if (connect(p->fd, (struct sockaddr *)&dev->sock, sizeof dev->sock) == 0) {
191      dev->connected = 1;
192      return dev;
193    } else
194      log_Printf(LogWARN, "%s: connect: %s\n", p->name.full, strerror(errno));
195  } else
196    log_Printf(LogWARN, "%s: socket: %s\n", p->name.full, strerror(errno));
197
198  close(p->fd);
199  p->fd = -1;
200  free(dev);
201
202  return NULL;
203}
204
205struct device *
206udp_Create(struct physical *p)
207{
208  char *cp, *host, *port, *svc;
209  struct udpdevice *dev;
210
211  dev = NULL;
212  if (p->fd < 0) {
213    if ((cp = strchr(p->name.full, ':')) != NULL) {
214      *cp = '\0';
215      host = p->name.full;
216      port = cp + 1;
217      svc = strchr(port, '/');
218      if (svc && strcasecmp(svc, "/udp")) {
219        *cp = ':';
220        return NULL;
221      }
222      if (svc)
223        *svc = '\0';
224
225      if (*host && *port)
226        dev = udp_CreateDevice(p, host, port);
227
228      *cp = ':';
229      if (svc)
230        *svc = '/';
231    }
232  } else {
233    /* See if we're a connected udp socket */
234    int type, sz, err;
235
236    sz = sizeof type;
237    if ((err = getsockopt(p->fd, SOL_SOCKET, SO_TYPE, &type, &sz)) == 0 &&
238        sz == sizeof type && type == SOCK_DGRAM) {
239      if ((dev = malloc(sizeof *dev)) == NULL) {
240        log_Printf(LogWARN, "%s: Cannot allocate a udp device: %s\n",
241                   p->link.name, strerror(errno));
242        return NULL;
243      }
244
245      /* We can't getpeername().... hence we stay un-connect()ed */
246      dev->connected = 0;
247
248      log_Printf(LogPHASE, "%s: Link is a udp socket\n", p->link.name);
249
250      if (p->link.lcp.cfg.openmode != OPEN_PASSIVE) {
251        log_Printf(LogPHASE, "%s:   Changing openmode to PASSIVE\n",
252                   p->link.name);
253        p->link.lcp.cfg.openmode = OPEN_PASSIVE;
254      }
255    }
256  }
257
258  if (dev) {
259    memcpy(&dev->dev, &baseudpdevice, sizeof dev->dev);
260    physical_SetupStack(p, dev->dev.name, PHYSICAL_FORCE_SYNC);
261    return &dev->dev;
262  }
263
264  return NULL;
265}
266