enhancer/socks.c at master · ColumPaget/enhancer · GitHub

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
#include "socks.h"
#include "iplist.h"
#include "net.h"


static int socks_request(int fd, const char *Auth, const char *DestHost, int DestPort)
{
    struct sockaddr_in sa;
    char *Tempstr=NULL;
    char *ptr;
    int val;
    int UseHostname=FALSE;

    if (fd == -1) return(0);

    if (! inet_aton(DestHost, &sa.sin_addr))
    {
        inet_aton("0.0.0.1", &sa.sin_addr);
        UseHostname=TRUE;
    }

    Tempstr=calloc(strlen(Auth) + strlen(DestHost) + 100, sizeof(char));
    ptr=Tempstr;
    * (uint8_t *) ptr= 0x04; //socks version
    ptr++;
    * (uint8_t *) ptr= 0x01; // cmd=1, establish tcp connection
    ptr++;
    * (uint16_t *) ptr=htons((uint16_t) DestPort); //destination Port
    ptr+=2;

    val=sa.sin_addr.s_addr;
    memcpy(ptr, &val, 4);
    ptr+=4;

    val=strlen(Auth);
    if (val > 0)
    {
        memcpy(ptr, Auth, val);
        ptr+=val;
    }

    *ptr='\0';
    ptr++;

    if (UseHostname)
    {
        val=strlen(DestHost);
        memcpy(ptr, DestHost, val);
        ptr+=val;
        *ptr='\0';
        ptr++;
    }

    enhancer_real_write(fd, Tempstr, ptr-Tempstr);
    destroy(Tempstr);

    return(1);
}


static int socks_reply(int fd)
{
    char *Tempstr=NULL;
    int retval=0;

    Tempstr=calloc(20, sizeof(char));
    if (read(fd, Tempstr, 8) ==8)
    {
        if (Tempstr[1]==0x5A) retval=1;
    }

    destroy(Tempstr);
    return (retval);
}


int socks_connect(const char *ProxyURL, const char *DestHost, int DestPort)
{
    char *Auth=NULL;
    const char *ptr;
    int fd;

    if (! DestHost) return(-1);
    Auth=enhancer_strcpy(Auth, "");
    if (strchr(ProxyURL, '@'))
    {
        ptr=enhancer_strtok(ProxyURL, ":", &Auth);
        ptr=enhancer_strtok(ptr, "@", &Auth);
    }

    fd=net_connect(ProxyURL);
    if (fd > -1)
    {
        ptr=enhancer_iplist_get(DestHost);
        if (! strvalid(ptr)) ptr=DestHost;

        if (
            (! socks_request(fd, Auth, ptr, DestPort)) ||
            (! socks_reply(fd))
        )
        {
            close(fd);
            fd=-1;
        }
    }

    destroy(Auth);
    return(fd);
}