PuddleJump.c

/* PuddleJump.c */

#include "PuddleJump.h"

Req *request(struct sockaddr_in *sock2) {
    Req *req;

    req = malloc(reqsize);

    req->vn = 4;
    req->cd = 1;
    req->dstport = sock2->sin_port;
    req->dstip = sock2->sin_addr.s_addr;
    strncpy(req->userid, USERNAME, 13);

    return req;
}

int connect(int s2, const struct sockaddr *sock2,
        socklen_t addrlen) {

    int s;
    struct sockaddr_in sock;
    Req *req;
    Res *res;
    char buf[ressize];
    int success;
    char tmp[512];
    int (*p)(int,const struct sockaddr*,socklen_t);
    
    p = dlsym(RTLD_NEXT, "connect");
    s = socket(AF_INET, SOCK_STREAM, 0);
    if (s < 0) {
        perror("socket");

        return -1;
    }

    sock.sin_family = AF_INET;
    sock.sin_port = htons(PROXYPORT);
    sock.sin_addr.s_addr = inet_addr(PROXY);

    if (p(s, (struct sockaddr *)&sock, sizeof(sock))) {
        perror("connect");

        return -1;
    }

    printf("Connected to proxy\n");
    req = request((struct sockaddr_in *)sock2);
    write(s, req, reqsize);

    memset(buf, 0, ressize);
    if (read(s, buf, ressize) < 1) {
        perror("read");
        free(req);
        close(s);

        return -1;
    }

    res = (Res *)buf;
    success = (res->cd == 90);
    if (!success) {
        fprintf(stderr, "Unable to traverse" 
            "the proxy, error code: %d\n",   
            res->cd);

            close(s);  
            free(req);

            return -1;
    }

    printf("Connected through the proxy. \n");

    
    dup2(s, s2);
    free(req);

    return 0;

}