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comparison svr-session.c @ 4:fe6bca95afa7

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Makefile.in contains updated files required
author Matt Johnston <matt@ucc.asn.au>
date Tue, 01 Jun 2004 02:46:09 +0000
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children bc6477a6c393
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-1:000000000000 4:fe6bca95afa7
1 /*
2 * Dropbear - a SSH2 server
3 *
4 * Copyright (c) 2002,2003 Matt Johnston
5 * All rights reserved.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a copy
8 * of this software and associated documentation files (the "Software"), to deal
9 * in the Software without restriction, including without limitation the rights
10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11 * copies of the Software, and to permit persons to whom the Software is
12 * furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
20 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
23 * SOFTWARE. */
24
25 #include "includes.h"
26 #include "session.h"
27 #include "dbutil.h"
28 #include "packet.h"
29 #include "algo.h"
30 #include "buffer.h"
31 #include "dss.h"
32 #include "ssh.h"
33 #include "random.h"
34 #include "kex.h"
35 #include "channel.h"
36 #include "chansession.h"
37 #include "atomicio.h"
38
39 static void svr_remoteclosed();
40 static void svr_dropbear_exit(int exitcode, const char* format, va_list param);
41 static void svr_dropbear_log(int priority, const char* format, va_list param);
42
43 struct serversession svr_ses;
44
45 void svr_session(int sock, runopts *opts, int childpipe,
46 struct sockaddr* remoteaddr) {
47
48 fd_set readfd, writefd;
49 struct timeval timeout;
50 int val;
51
52 crypto_init();
53 common_session_init(sock, opts);
54
55 ses.remoteaddr = remoteaddr;
56 ses.remotehost = getaddrhostname(remoteaddr);
57
58 /* Initialise server specific parts of the session */
59 svr_ses.childpipe = childpipe;
60 authinitialise();
61 svr_chansessinitialise();
62
63 if (gettimeofday(&timeout, 0) < 0) {
64 dropbear_exit("Error getting time");
65 }
66
67 ses.connecttimeout = timeout.tv_sec + AUTH_TIMEOUT;
68
69 /* set up messages etc */
70 session_remoteclosed = svr_remoteclosed;
71 _dropbear_exit = svr_dropbear_exit;
72 _dropbear_log = svr_dropbear_log;
73
74 /* We're ready to go now */
75 sessinitdone = 1;
76
77 /* exchange identification, version etc */
78 session_identification();
79
80 seedrandom();
81
82 /* start off with key exchange */
83 send_msg_kexinit();
84
85 FD_ZERO(&readfd);
86 FD_ZERO(&writefd);
87
88 /* main loop, select()s for all sockets in use */
89 for(;;) {
90
91 timeout.tv_sec = SELECT_TIMEOUT;
92 timeout.tv_usec = 0;
93 FD_ZERO(&writefd);
94 FD_ZERO(&readfd);
95 assert(ses.payload == NULL);
96 if (ses.sock != -1) {
97 FD_SET(ses.sock, &readfd);
98 if (!isempty(&ses.writequeue)) {
99 FD_SET(ses.sock, &writefd);
100 }
101 }
102
103 /* set up for channels which require reading/writing */
104 if (ses.dataallowed) {
105 setchannelfds(&readfd, &writefd);
106 }
107 val = select(ses.maxfd+1, &readfd, &writefd, NULL, &timeout);
108
109 if (exitflag) {
110 dropbear_exit("Terminated by signal");
111 }
112
113 if (val < 0) {
114 if (errno == EINTR) {
115 continue;
116 } else {
117 dropbear_exit("Error in select");
118 }
119 }
120
121 /* check for auth timeout, rekeying required etc */
122 checktimeouts();
123
124 if (val == 0) {
125 /* timeout */
126 TRACE(("select timeout"));
127 continue;
128 }
129
130 /* process session socket's incoming/outgoing data */
131 if (ses.sock != -1) {
132 if (FD_ISSET(ses.sock, &writefd) && !isempty(&ses.writequeue)) {
133 write_packet();
134 }
135
136 if (FD_ISSET(ses.sock, &readfd)) {
137 read_packet();
138 }
139
140 /* Process the decrypted packet. After this, the read buffer
141 * will be ready for a new packet */
142 if (ses.payload != NULL) {
143 svr_process_packet();
144 }
145 }
146
147 /* process pipes etc for the channels, ses.dataallowed == 0
148 * during rekeying ) */
149 if (ses.dataallowed) {
150 channelio(&readfd, &writefd);
151 }
152
153 } /* for(;;) */
154 }
155
156
157
158 /* called when the remote side closes the connection */
159 static void svr_remoteclosed() {
160
161 close(ses.sock);
162 ses.sock = -1;
163 dropbear_close("Exited normally");
164
165 }
166
167 /* failure exit - format must be <= 100 chars */
168 static void svr_dropbear_exit(int exitcode, const char* format, va_list param) {
169
170 char fmtbuf[300];
171
172 if (!sessinitdone) {
173 /* before session init */
174 snprintf(fmtbuf, sizeof(fmtbuf),
175 "premature exit: %s", format);
176 } else if (svr_ses.authstate.authdone) {
177 /* user has authenticated */
178 snprintf(fmtbuf, sizeof(fmtbuf),
179 "exit after auth (%s): %s",
180 svr_ses.authstate.printableuser, format);
181 } else if (svr_ses.authstate.printableuser) {
182 /* we have a potential user */
183 snprintf(fmtbuf, sizeof(fmtbuf),
184 "exit before auth (user '%s', %d fails): %s",
185 svr_ses.authstate.printableuser, svr_ses.authstate.failcount, format);
186 } else {
187 /* before userauth */
188 snprintf(fmtbuf, sizeof(fmtbuf),
189 "exit before auth: %s", format);
190 }
191
192 if (errno != 0) {
193 /* XXX - is this valid? */
194 snprintf(fmtbuf, sizeof(fmtbuf), "%s [%d %s]", fmtbuf,
195 errno, strerror(errno));
196 }
197
198 _dropbear_log(LOG_INFO, fmtbuf, param);
199
200 /* must be after we've done with username etc */
201 common_session_cleanup();
202
203 exit(exitcode);
204
205 }
206
207 /* priority is priority as with syslog() */
208 static void svr_dropbear_log(int priority, const char* format, va_list param) {
209
210 char printbuf[1024];
211 char datestr[20];
212 time_t timesec;
213 int havetrace = 0;
214
215 vsnprintf(printbuf, sizeof(printbuf), format, param);
216
217 #ifndef DISABLE_SYSLOG
218 if (usingsyslog) {
219 syslog(priority, "%s", printbuf);
220 }
221 #endif
222
223 /* if we are using DEBUG_TRACE, we want to print to stderr even if
224 * syslog is used, so it is included in error reports */
225 #ifdef DEBUG_TRACE
226 havetrace = 1;
227 #endif
228
229 if (!usingsyslog || havetrace)
230 {
231 timesec = time(NULL);
232 if (strftime(datestr, sizeof(datestr), "%b %d %H:%M:%S",
233 localtime(&timesec)) == 0) {
234 datestr[0] = '?'; datestr[1] = '\0';
235 }
236 fprintf(stderr, "[%d] %s %s\n", getpid(), datestr, printbuf);
237 }
238 }