1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
|
/* connect.c - Open connection to server.
*
* Copyright (C) 2010, Pawel Krawczyk <pawel.krawczyk@hush.com> and
* Jeroen Nijhof <jeroen@jeroennijhof.nl>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program - see the file COPYING.
*
* See `CHANGES' file for revision history.
*/
#include <signal.h>
#include <arpa/inet.h>
#include <time.h>
#include <fcntl.h>
#include <errno.h>
#ifdef _AIX
#include <sys/socket.h>
#endif
#include "libtac.h"
/* Pointer to TACACS+ connection timeout */
int tac_timeout = 5;
/* Returns file descriptor of open connection
to the first available server from list passed
in server table.
* return value:
* >= 0 : valid fd
* < 0 : error status code, see LIBTAC_STATUS_...
*/
int tac_connect(struct addrinfo **server, char **key, int servers) {
int tries;
int fd=-1;
if(servers == 0 || server == NULL) {
TACSYSLOG((LOG_ERR, "%s: no TACACS+ servers defined", __FUNCTION__))
} else {
for ( tries = 0; tries < servers; tries++ ) {
if((fd=tac_connect_single(server[tries], key[tries])) >= 0 ) {
/* tac_secret was set in tac_connect_single on success */
break;
}
}
}
/* all attempts failed if fd is still < 0 */
TACDEBUG((LOG_DEBUG, "%s: exit status=%d",__FUNCTION__, fd))
return fd;
} /* tac_connect */
/* return value:
* >= 0 : valid fd
* < 0 : error status code, see LIBTAC_STATUS_...
*/
int tac_connect_single(struct addrinfo *server, const char *key) {
int retval = LIBTAC_STATUS_CONN_ERR; /* default retval */
int fd = -1;
int flags, rc;
fd_set readfds, writefds;
struct timeval tv;
socklen_t len;
struct sockaddr_storage addr;
char *ip;
if(server == NULL) {
TACSYSLOG((LOG_ERR, "%s: no TACACS+ server defined", __FUNCTION__))
return LIBTAC_STATUS_CONN_ERR;
}
/* format server address into a string for use in messages */
ip = tac_ntop(server->ai_addr);
if((fd=socket(server->ai_family, server->ai_socktype, server->ai_protocol)) < 0) {
TACSYSLOG((LOG_ERR,"%s: socket creation error", __FUNCTION__))
return LIBTAC_STATUS_CONN_ERR;
}
/* get flags for restoration later */
flags = fcntl(fd, F_GETFL, 0);
/* put socket in non blocking mode for timeout support */
if( fcntl(fd, F_SETFL, flags | O_NONBLOCK) == -1 ) {
TACSYSLOG((LOG_ERR, "%s: cannot set socket non blocking",\
__FUNCTION__))
return LIBTAC_STATUS_CONN_ERR;
}
rc = connect(fd, server->ai_addr, server->ai_addrlen);
/* FIX this..for some reason errno = 0 on AIX... */
if((rc == -1) && (errno != EINPROGRESS) && (errno != 0)) {
TACSYSLOG((LOG_ERR,\
"%s: connection to %s failed: %m", __FUNCTION__, ip))
return LIBTAC_STATUS_CONN_ERR;
}
/* set fds for select */
FD_ZERO(&readfds);
FD_ZERO(&writefds);
FD_SET(fd, &readfds);
FD_SET(fd, &writefds);
/* set timeout seconds */
tv.tv_sec = tac_timeout;
tv.tv_usec = 0;
/* check if socket is ready for read and write */
rc = select(fd+1, &readfds, &writefds, NULL, &tv);
/* timeout */
if ( rc == 0 ) {
return LIBTAC_STATUS_CONN_TIMEOUT;
}
/* some other error or interrupt before timeout */
if ( rc < 0 ) {
TACSYSLOG((LOG_ERR,\
"%s: connection failed with %s: %m", __FUNCTION__, ip))
return LIBTAC_STATUS_CONN_ERR;
}
/* check with getpeername if we have a valid connection */
len = sizeof addr;
if(getpeername(fd, (struct sockaddr*)&addr, &len) == -1) {
TACSYSLOG((LOG_ERR,\
"%s: connection failed with %s: %m", __FUNCTION__, ip))
return LIBTAC_STATUS_CONN_ERR;
}
/* restore flags on socket - flags was set only when fd >= 0 */
if(fcntl(fd, F_SETFL, flags) == -1) {
TACSYSLOG((LOG_ERR, "%s: cannot restore socket flags: %m",\
__FUNCTION__))
return LIBTAC_STATUS_CONN_ERR;
}
/* connected ok */
TACDEBUG((LOG_DEBUG, "%s: connected to %s", __FUNCTION__, ip))
retval = fd;
/* set current tac_secret */
tac_encryption = 0;
if (key != NULL && *key) {
tac_encryption = 1;
tac_secret = key;
}
/* if valid fd, but error experienced after open, close fd */
if ( fd >= 0 && retval < 0 ) {
close(fd);
}
TACDEBUG((LOG_DEBUG, "%s: exit status=%d (fd=%d)",\
__FUNCTION__, retval < 0 ? retval:0, fd))
return retval;
} /* tac_connect_single */
/* return value:
* ptr to char* with format IP address
* warning: returns a static buffer
* (which some ppl don't like, but it's robust and at last no more memory leaks)
*/
char *tac_ntop(const struct sockaddr *sa) {
static char server_address[INET6_ADDRSTRLEN+16];
switch(sa->sa_family) {
case AF_INET:
inet_ntop(AF_INET, &(((struct sockaddr_in *)sa)->sin_addr),
server_address, INET_ADDRSTRLEN);
snprintf(server_address + strlen(server_address), 14, ":%hu",
htons(((struct sockaddr_in *)sa)->sin_port));
break;
case AF_INET6:
inet_ntop(AF_INET6, &(((struct sockaddr_in6 *)sa)->sin6_addr),
server_address, INET6_ADDRSTRLEN);
snprintf(server_address + strlen(server_address), 14, ":%hu",
htons(((struct sockaddr_in6 *)sa)->sin6_port));
break;
default:
strcpy(server_address, "Unknown AF");
}
return server_address;
} /* tac_ntop */
|
