xref: /freebsd/usr.sbin/ppp/server.c (revision 85602e5267f413a849370d3c6fe3d0a87cdd5b49)
1 /*-
2  * Copyright (c) 1997 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: server.c,v 1.16.2.13 1998/04/07 00:54:17 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 <netinet/in_systm.h>
34 #include <netinet/ip.h>
35 
36 #include <errno.h>
37 #include <stdio.h>
38 #include <string.h>
39 #include <sys/stat.h>
40 #include <sys/un.h>
41 #include <termios.h>
42 #include <unistd.h>
43 
44 #include "mbuf.h"
45 #include "log.h"
46 #include "defs.h"
47 #include "descriptor.h"
48 #include "server.h"
49 #include "id.h"
50 #include "prompt.h"
51 #include "timer.h"
52 #include "lqr.h"
53 #include "hdlc.h"
54 #include "fsm.h"
55 #include "lcp.h"
56 #include "ccp.h"
57 #include "throughput.h"
58 #include "link.h"
59 #include "mp.h"
60 #include "iplist.h"
61 #include "slcompress.h"
62 #include "ipcp.h"
63 #include "filter.h"
64 #include "bundle.h"
65 
66 static int
67 server_UpdateSet(struct descriptor *d, fd_set *r, fd_set *w, fd_set *e, int *n)
68 {
69   struct server *s = descriptor2server(d);
70 
71   if (r && s->fd >= 0) {
72     if (*n < s->fd + 1)
73       *n = s->fd + 1;
74     FD_SET(s->fd, r);
75     return 1;
76   }
77   return 0;
78 }
79 
80 static int
81 server_IsSet(struct descriptor *d, const fd_set *fdset)
82 {
83   struct server *s = descriptor2server(d);
84   return s->fd >= 0 && FD_ISSET(s->fd, fdset);
85 }
86 
87 #define IN_SIZE sizeof(struct sockaddr_in)
88 #define UN_SIZE sizeof(struct sockaddr_in)
89 #define ADDRSZ (IN_SIZE > UN_SIZE ? IN_SIZE : UN_SIZE)
90 
91 static char *rm;
92 
93 static void
94 server_Read(struct descriptor *d, struct bundle *bundle, const fd_set *fdset)
95 {
96   struct server *s = descriptor2server(d);
97   char hisaddr[ADDRSZ];
98   struct sockaddr *sa = (struct sockaddr *)hisaddr;
99   struct sockaddr_in *sin = (struct sockaddr_in *)hisaddr;
100   int ssize = ADDRSZ, wfd;
101   struct prompt *p;
102 
103   wfd = accept(s->fd, sa, &ssize);
104   if (wfd < 0) {
105     LogPrintf(LogERROR, "server_Read: accept(): %s\n", strerror(errno));
106     return;
107   }
108 
109   switch (sa->sa_family) {
110     case AF_LOCAL:
111       LogPrintf(LogPHASE, "Connected to local client.\n");
112       break;
113 
114     case AF_INET:
115       if (ntohs(sin->sin_port) < 1024) {
116         LogPrintf(LogALERT, "Rejected client connection from %s:%u"
117                   "(invalid port number) !\n",
118                   inet_ntoa(sin->sin_addr), ntohs(sin->sin_port));
119         close(wfd);
120         return;
121       }
122       LogPrintf(LogPHASE, "Connected to client from %s:%u\n",
123                 inet_ntoa(sin->sin_addr), sin->sin_port);
124       break;
125 
126     default:
127       write(wfd, "Unrecognised access !\n", 22);
128       close(wfd);
129       return;
130   }
131 
132   if ((p = prompt_Create(s, bundle, wfd)) == NULL) {
133     write(wfd, "Connection refused.\n", 20);
134     close(wfd);
135   } else {
136     switch (sa->sa_family) {
137       case AF_LOCAL:
138         snprintf(p->who, sizeof p->who, "local (%s)", rm);
139         break;
140       case AF_INET:
141         snprintf(p->who, sizeof p->who, "TCP (%s:%u)",
142                  inet_ntoa(sin->sin_addr), sin->sin_port);
143         break;
144     }
145     prompt_TtyCommandMode(p);
146     prompt_Required(p);
147   }
148 }
149 
150 static void
151 server_Write(struct descriptor *d, struct bundle *bundle, const fd_set *fdset)
152 {
153   /* We never want to write here ! */
154   LogPrintf(LogERROR, "server_Write: Internal error: Bad call !\n");
155 }
156 
157 struct server server = {
158   {
159     SERVER_DESCRIPTOR,
160     NULL,
161     server_UpdateSet,
162     server_IsSet,
163     server_Read,
164     server_Write
165   },
166   -1
167 };
168 
169 static struct sockaddr_un ifsun;
170 
171 int
172 ServerLocalOpen(struct bundle *bundle, const char *name, mode_t mask)
173 {
174   int s;
175 
176   memset(&ifsun, '\0', sizeof ifsun);
177   ifsun.sun_len = strlen(name);
178   if (ifsun.sun_len > sizeof ifsun.sun_path - 1) {
179     LogPrintf(LogERROR, "Local: %s: Path too long\n", name);
180     return 2;
181   }
182   ifsun.sun_family = AF_LOCAL;
183   strcpy(ifsun.sun_path, name);
184 
185   s = ID0socket(PF_LOCAL, SOCK_STREAM, 0);
186   if (s < 0) {
187     LogPrintf(LogERROR, "Local: socket: %s\n", strerror(errno));
188     return 3;
189   }
190   setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &s, sizeof s);
191   if (mask != (mode_t)-1)
192     mask = umask(mask);
193   if (bind(s, (struct sockaddr *)&ifsun, sizeof ifsun) < 0) {
194     if (mask != (mode_t)-1)
195       umask(mask);
196     LogPrintf(LogWARN, "Local: bind: %s\n", strerror(errno));
197     close(s);
198     return 4;
199   }
200   if (mask != (mode_t)-1)
201     umask(mask);
202   if (listen(s, 5) != 0) {
203     LogPrintf(LogERROR, "Local: Unable to listen to socket - BUNDLE overload?\n");
204     close(s);
205     ID0unlink(name);
206     return 5;
207   }
208   ServerClose(bundle);
209   server.fd = s;
210   rm = ifsun.sun_path;
211   LogPrintf(LogPHASE, "Listening at local socket %s.\n", name);
212   return 0;
213 }
214 
215 int
216 ServerTcpOpen(struct bundle *bundle, int port)
217 {
218   struct sockaddr_in ifsin;
219   int s;
220 
221   s = ID0socket(PF_INET, SOCK_STREAM, 0);
222   if (s < 0) {
223     LogPrintf(LogERROR, "Tcp: socket: %s\n", strerror(errno));
224     return 7;
225   }
226   memset(&ifsin, '\0', sizeof ifsin);
227   ifsin.sin_family = AF_INET;
228   ifsin.sin_addr.s_addr = INADDR_ANY;
229   ifsin.sin_port = htons(port);
230   setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &s, sizeof s);
231   if (bind(s, (struct sockaddr *)&ifsin, sizeof ifsin) < 0) {
232     LogPrintf(LogWARN, "Tcp: bind: %s\n", strerror(errno));
233     close(s);
234     return 8;
235   }
236   if (listen(s, 5) != 0) {
237     LogPrintf(LogERROR, "Tcp: Unable to listen to socket - BUNDLE overload?\n");
238     close(s);
239     return 9;
240   }
241   ServerClose(bundle);
242   server.fd = s;
243   LogPrintf(LogPHASE, "Listening at port %d.\n", port);
244   return 0;
245 }
246 
247 int
248 ServerClose(struct bundle *bundle)
249 {
250   if (server.fd >= 0) {
251     close(server.fd);
252     if (rm) {
253       ID0unlink(rm);
254       rm = 0;
255     }
256     server.fd = -1;
257     /* Drop associated prompts */
258     bundle_DelPromptDescriptors(bundle, &server);
259     return 1;
260   }
261   return 0;
262 }
263