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
|
#define _GNU_SOURCE
#include <dlfcn.h>
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
static char hexd_buff[4096];
static const char hex_chars[] = "0123456789abcdef";
static char *_osmo_hexdump(const unsigned char *buf, int len, char *delim)
{
int i;
char *cur = hexd_buff;
hexd_buff[0] = 0;
for (i = 0; i < len; i++) {
const char *delimp = delim;
int len_remain = sizeof(hexd_buff) - (cur - hexd_buff);
if (len_remain < 3)
break;
*cur++ = hex_chars[buf[i] >> 4];
*cur++ = hex_chars[buf[i] & 0xf];
while (len_remain > 1 && *delimp) {
*cur++ = *delimp++;
len_remain--;
}
*cur = 0;
}
hexd_buff[sizeof(hexd_buff)-1] = 0;
return hexd_buff;
}
static char *osmo_hexdump(const unsigned char *buf, int len)
{
return _osmo_hexdump(buf, len, " ");
}
/* Function pointers to hold the value of the glibc functions */
static ssize_t (*real_write)(int fd, const void *buf, size_t count);
static ssize_t (*real_read)(int fd, void *buf, size_t count);
static int (*real_connect)(int fd, const struct sockaddr *addr, socklen_t addrlen);
static ssize_t (*real_send)(int sockfd, const void *buf, size_t len, int flags);
static ssize_t (*real_recv)(int sockfd, void *buf, size_t len, int flags);
static int (*real_close)(int fd);
static int trace_fds[16]= { -1, };
static int num_trace_fds = 0;
static void dump_qmuxd(int fd, int to_qmux, const void *buf, size_t len)
{
int i;
for (i = 0; i < num_trace_fds; i++) {
if (trace_fds[i] == fd)
printf("%s_qmuxd(%u, %04x): %s\n", to_qmux ? "to" : "from", fd, len, osmo_hexdump(buf, len));
}
}
/* wrapping write function call */
ssize_t write(int fd, const void *buf, size_t count)
{
dump_qmuxd(fd, 1, buf, count);
real_write = dlsym(RTLD_NEXT, "write");
return real_write(fd, buf, count);
}
ssize_t read(int fd, void *buf, size_t count)
{
dump_qmuxd(fd, 0, buf, count);
real_read = dlsym(RTLD_NEXT, "read");
return real_read(fd, buf, count);
}
ssize_t send(int fd, const void *buf, size_t count, int flags)
{
dump_qmuxd(fd, 1, buf, count);
real_send = dlsym(RTLD_NEXT, "send");
return real_send(fd, buf, count, flags);
}
ssize_t recv(int fd, void *buf, size_t len, int flags)
{
dump_qmuxd(fd, 0, buf, len);
real_recv = dlsym(RTLD_NEXT, "recv");
return real_recv(fd, buf, len, flags);
}
int connect(int fd, const struct sockaddr *addr, socklen_t addrlen)
{
if (addr->sa_family == AF_UNIX) {
struct sockaddr_un *sun = (struct sockaddr_un *)addr;
if (!strcmp(sun->sun_path, "/var/qmux_connect_socket")) {
printf("Found socketfd to qmuxd: %d\n", fd);
trace_fds[num_trace_fds++] = fd;
}
}
real_connect = dlsym(RTLD_NEXT, "connect");
return real_connect(fd, addr, addrlen);
}
int close(int fd)
{
int i;
for (i = 0; i < num_trace_fds; i++) {
if (trace_fds[i] == fd) {
printf("Closed socketfd to qmuxd: %d\n", fd);
trace_fds[i] = -1;
}
}
real_close = dlsym(RTLD_NEXT, "close");
return real_close(fd);
}
|
