xref: /freebsd/usr.sbin/ppp/server.c (revision b601c69bdbe8755d26570261d7fd4c02ee4eff74)
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  * $FreeBSD$
27  */
28 
29 #include <sys/types.h>
30 #include <sys/socket.h>
31 #include <netinet/in.h>
32 #include <arpa/inet.h>
33 #include <sys/un.h>
34 
35 #include <errno.h>
36 #include <stdio.h>
37 #include <string.h>
38 #include <sys/stat.h>
39 #include <termios.h>
40 #include <unistd.h>
41 
42 #include "log.h"
43 #include "descriptor.h"
44 #include "server.h"
45 #include "id.h"
46 #include "prompt.h"
47 
48 static int
49 server_UpdateSet(struct fdescriptor *d, fd_set *r, fd_set *w, fd_set *e, int *n)
50 {
51   struct server *s = descriptor2server(d);
52   struct prompt *p;
53   int sets;
54 
55   sets = 0;
56   if (r && s->fd >= 0) {
57     if (*n < s->fd + 1)
58       *n = s->fd + 1;
59     FD_SET(s->fd, r);
60     log_Printf(LogTIMER, "server: fdset(r) %d\n", s->fd);
61     sets++;
62   }
63 
64   for (p = log_PromptList(); p; p = p->next)
65     sets += descriptor_UpdateSet(&p->desc, r, w, e, n);
66 
67   return sets;
68 }
69 
70 static int
71 server_IsSet(struct fdescriptor *d, const fd_set *fdset)
72 {
73   struct server *s = descriptor2server(d);
74   struct prompt *p;
75 
76   if (s->fd >= 0 && FD_ISSET(s->fd, fdset))
77     return 1;
78 
79   for (p = log_PromptList(); p; p = p->next)
80     if (descriptor_IsSet(&p->desc, fdset))
81       return 1;
82 
83   return 0;
84 }
85 
86 #define IN_SIZE sizeof(struct sockaddr_in)
87 #define UN_SIZE sizeof(struct sockaddr_un)
88 #define ADDRSZ (IN_SIZE > UN_SIZE ? IN_SIZE : UN_SIZE)
89 
90 static void
91 server_Read(struct fdescriptor *d, struct bundle *bundle, const fd_set *fdset)
92 {
93   struct server *s = descriptor2server(d);
94   char hisaddr[ADDRSZ];
95   struct sockaddr *sa = (struct sockaddr *)hisaddr;
96   struct sockaddr_in *in = (struct sockaddr_in *)hisaddr;
97   int ssize = ADDRSZ, wfd;
98   struct prompt *p;
99 
100   if (s->fd >= 0 && FD_ISSET(s->fd, fdset)) {
101     wfd = accept(s->fd, sa, &ssize);
102     if (wfd < 0)
103       log_Printf(LogERROR, "server_Read: accept(): %s\n", strerror(errno));
104   } else
105     wfd = -1;
106 
107   if (wfd >= 0)
108     switch (sa->sa_family) {
109       case AF_LOCAL:
110         log_Printf(LogPHASE, "Connected to local client.\n");
111         break;
112 
113       case AF_INET:
114         if (ntohs(in->sin_port) < 1024) {
115           log_Printf(LogALERT, "Rejected client connection from %s:%u"
116                     "(invalid port number) !\n",
117                     inet_ntoa(in->sin_addr), ntohs(in->sin_port));
118           close(wfd);
119           wfd = -1;
120           break;
121         }
122         log_Printf(LogPHASE, "Connected to client from %s:%u\n",
123                   inet_ntoa(in->sin_addr), in->sin_port);
124         break;
125 
126       default:
127         write(wfd, "Unrecognised access !\n", 22);
128         close(wfd);
129         wfd = -1;
130         break;
131     }
132 
133   if (wfd >= 0) {
134     if ((p = prompt_Create(s, bundle, wfd)) == NULL) {
135       write(wfd, "Connection refused.\n", 20);
136       close(wfd);
137     } else {
138       switch (sa->sa_family) {
139         case AF_LOCAL:
140           p->src.type = "local";
141           strncpy(p->src.from, s->rm, sizeof p->src.from - 1);
142           p->src.from[sizeof p->src.from - 1] = '\0';
143           break;
144         case AF_INET:
145           p->src.type = "tcp";
146           snprintf(p->src.from, sizeof p->src.from, "%s:%u",
147                    inet_ntoa(in->sin_addr), in->sin_port);
148           break;
149       }
150       prompt_TtyCommandMode(p);
151       prompt_Required(p);
152     }
153   }
154 
155   log_PromptListChanged = 0;
156   for (p = log_PromptList(); p; p = p->next)
157     if (descriptor_IsSet(&p->desc, fdset)) {
158       descriptor_Read(&p->desc, bundle, fdset);
159       if (log_PromptListChanged)
160         break;
161     }
162 }
163 
164 static int
165 server_Write(struct fdescriptor *d, struct bundle *bundle, const fd_set *fdset)
166 {
167   /* We never want to write here ! */
168   log_Printf(LogALERT, "server_Write: Internal error: Bad call !\n");
169   return 0;
170 }
171 
172 struct server server = {
173   {
174     SERVER_DESCRIPTOR,
175     server_UpdateSet,
176     server_IsSet,
177     server_Read,
178     server_Write
179   },
180   -1
181 };
182 
183 int
184 server_LocalOpen(struct bundle *bundle, const char *name, mode_t mask)
185 {
186   int s;
187 
188   if (server.rm && !strcmp(server.rm, name)) {
189     if (chmod(server.rm, 0777 & ~mask))
190       log_Printf(LogERROR, "Local: chmod: %s\n", strerror(errno));
191     return 0;
192   }
193 
194   memset(&server.ifsun, '\0', sizeof server.ifsun);
195   server.ifsun.sun_len = strlen(name);
196   if (server.ifsun.sun_len > sizeof server.ifsun.sun_path - 1) {
197     log_Printf(LogERROR, "Local: %s: Path too long\n", name);
198     return 2;
199   }
200   server.ifsun.sun_family = AF_LOCAL;
201   strcpy(server.ifsun.sun_path, name);
202 
203   s = ID0socket(PF_LOCAL, SOCK_STREAM, 0);
204   if (s < 0) {
205     log_Printf(LogERROR, "Local: socket: %s\n", strerror(errno));
206     return 3;
207   }
208   setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &s, sizeof s);
209   if (mask != (mode_t)-1)
210     mask = umask(mask);
211   if (bind(s, (struct sockaddr *)&server.ifsun, sizeof server.ifsun) < 0) {
212     if (mask != (mode_t)-1)
213       umask(mask);
214     log_Printf(LogWARN, "Local: bind: %s\n", strerror(errno));
215     close(s);
216     return 4;
217   }
218   if (mask != (mode_t)-1)
219     umask(mask);
220   if (listen(s, 5) != 0) {
221     log_Printf(LogERROR, "Local: Unable to listen to socket - BUNDLE overload?\n");
222     close(s);
223     ID0unlink(name);
224     return 5;
225   }
226   server_Close(bundle);
227   server.fd = s;
228   server.rm = server.ifsun.sun_path;
229   log_Printf(LogPHASE, "Listening at local socket %s.\n", name);
230   return 0;
231 }
232 
233 int
234 server_TcpOpen(struct bundle *bundle, int port)
235 {
236   struct sockaddr_in ifsin;
237   int s;
238 
239   if (server.port == port)
240     return 0;
241 
242   s = ID0socket(PF_INET, SOCK_STREAM, 0);
243   if (s < 0) {
244     log_Printf(LogERROR, "Tcp: socket: %s\n", strerror(errno));
245     return 7;
246   }
247   memset(&ifsin, '\0', sizeof ifsin);
248   ifsin.sin_family = AF_INET;
249   ifsin.sin_addr.s_addr = INADDR_ANY;
250   ifsin.sin_port = htons(port);
251   setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &s, sizeof s);
252   if (bind(s, (struct sockaddr *)&ifsin, sizeof ifsin) < 0) {
253     log_Printf(LogWARN, "Tcp: bind: %s\n", strerror(errno));
254     close(s);
255     return 8;
256   }
257   if (listen(s, 5) != 0) {
258     log_Printf(LogERROR, "Tcp: Unable to listen to socket: %s\n",
259                strerror(errno));
260     close(s);
261     return 9;
262   }
263   server_Close(bundle);
264   server.fd = s;
265   server.port = port;
266   log_Printf(LogPHASE, "Listening at port %d.\n", port);
267   return 0;
268 }
269 
270 int
271 server_Close(struct bundle *bundle)
272 {
273   if (server.fd >= 0) {
274     if (server.rm) {
275       struct sockaddr_un un;
276       int sz = sizeof un;
277 
278       if (getsockname(server.fd, (struct sockaddr *)&un, &sz) == 0 &&
279           un.sun_family == AF_LOCAL && sz == sizeof un)
280         ID0unlink(un.sun_path);
281       server.rm = NULL;
282     }
283     close(server.fd);
284     server.fd = -1;
285     server.port = 0;
286     /* Drop associated prompts */
287     log_DestroyPrompts(&server);
288     return 1;
289   }
290   return 0;
291 }
292