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
|
#include "includes.h"
#include "tcpfwd.h"
#include "session.h"
#include "dbutil.h"
void tcp_fwd_initialise() {
/* just one slot to start with */
ses.tcplisteners =
(struct TCPListener**)m_malloc(sizeof(struct TCPListener*));
ses.tcplistensize = 1;
ses.tcplisteners[0] = NULL;
}
void set_tcp_fwd_fds(fd_set * readfds) {
unsigned int i;
struct TCPListener *listener;
/* check each in turn */
for (i = 0; i < ses.tcplistensize; i++) {
listener = ses.tcplisteners[i];
if (listener != NULL) {
FD_SET(listener->sock, readfds);
}
}
}
void handle_tcp_fwd(fd_set * readfds) {
unsigned int i;
struct TCPListener *listener;
/* check each in turn */
for (i = 0; i < ses.tcplistensize; i++) {
listener = ses.tcplisteners[i];
if (listener != NULL) {
if (FD_ISSET(listener->sock, readfds)) {
listener->accepter(listener);
}
}
}
}
/* accepter(int fd, void* typedata) is a function to accept connections,
* cleanup(void* typedata) happens when cleaning up */
int new_fwd(int sock, int type, void* typedata,
void (*accepter)(struct TCPListener*),
void (*cleanup)(struct TCPListener*)) {
unsigned int i, j;
struct TCPListener *newtcp = NULL;
/* try get a new structure to hold it */
for (i = 0; i < ses.tcplistensize; i++) {
if (ses.tcplisteners[i] == NULL) {
break;
}
}
/* or create a new one */
if (i == ses.tcplistensize) {
if (ses.tcplistensize > MAX_TCPLISTENERS) {
TRACE(("leave newlistener: too many already"));
close(sock);
return DROPBEAR_FAILURE;
}
ses.tcplisteners = (struct TCPListener**)m_realloc(ses.tcplisteners,
(ses.tcplistensize+TCP_EXTEND_SIZE)
*sizeof(struct TCPListener*));
ses.tcplistensize += TCP_EXTEND_SIZE;
for (j = i; j < ses.tcplistensize; j++) {
ses.tcplisteners[j] = NULL;
}
}
ses.maxfd = MAX(ses.maxfd, sock);
newtcp = (struct TCPListener*)m_malloc(sizeof(struct TCPListener));
newtcp->index = i;
newtcp->type = type;
newtcp->typedata = typedata;
newtcp->sock = sock;
newtcp->accepter = accepter;
newtcp->cleanup = cleanup;
ses.tcplisteners[i] = newtcp;
return DROPBEAR_SUCCESS;
}
/* Return the first listener which matches the type-specific comparison
* function */
struct TCPListener * get_listener(int type, void* typedata,
int (*match)(void*, void*)) {
unsigned int i;
struct TCPListener* listener;
for (i = 0, listener = ses.tcplisteners[i]; i < ses.tcplistensize; i++) {
if (listener->type == type
&& match(typedata, listener->typedata)) {
return listener;
}
}
return NULL;
}
void remove_listener(struct TCPListener* listener) {
if (listener->cleanup) {
listener->cleanup(listener);
}
close(listener->sock);
ses.tcplisteners[listener->index] = NULL;
m_free(listener);
}
|
