MbMC7xFB

1/**
2 * CClient Implementation
3 * Listens to UDP broadcasts on port 7447
4 * And sends mac_address using TCP to port 7777
5 * For debugging purposes use the command
6 * gcc -Wall client.c
7 */
8
9#include <stdio.h>
10#include <string.h>
11#include <stdlib.h>
12#include <sys/types.h>
13#include <sys/socket.h>
14#include <sys/ioctl.h>
15#include <net/if.h>
16#include <unistd.h>
17#include <errno.h>
18#include <arpa/inet.h>
19#include <netinet/in.h>
20#include <netdb.h>
21
22
23#define BUFLEN       512
24#define SERVER_ADDR  "192.168.1.122"
25#define SERVER_PORT  7777
26#define PORT         7447
27
28unsigned char mac_address[6] = {0};
29
30void die(char *s) {
31    perror(s);
32    exit(1);
33}
34
35int display_error(char *s) {
36    perror(s);
37    return 1;
38}
39
40char *get_client_mac_address() {
41    struct ifreq ifr;
42    struct ifconf ifc;
43    char buf[BUFLEN];
44    int success = 0, sock;
45
46    if ((sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP)) == -1) {
47        die("[-] Socket creation failed");
48
49    }
50    ifc.ifc_len = sizeof(buf);
51    ifc.ifc_buf = buf;
52    if (ioctl(sock, SIOCGIFCONF, &ifc) == -1)
53        die("[-] Could not use IOCTL");
54
55    struct ifreq* it = ifc.ifc_req;
56    const struct ifreq* const end = it + (ifc.ifc_len / sizeof(struct ifreq));
57
58    for (; it != end; ++it) {
59        strcpy(ifr.ifr_name, it->ifr_name);
60        if (ioctl(sock, SIOCGIFFLAGS, &ifr) == 0)
61            if (! (ifr.ifr_flags & IFF_LOOPBACK)) // don't count loopback
62                if (ioctl(sock, SIOCGIFHWADDR, &ifr) == 0) {
63                    success = 1;
64                    break;
65                }
66        else
67            die("[-] Error while looping through interfaces");
68    }
69
70    if (success)
71        memcpy(mac_address, ifr.ifr_hwaddr.sa_data, 6);
72    
73    close(sock);
74    printf("> Successfully received Local MAC Address : %02x:%02x:%02x:%02x:%02x:%02x\n",
75        (unsigned char) mac_address[0],
76        (unsigned char) mac_address[1],
77        (unsigned char) mac_address[2],
78        (unsigned char) mac_address[3],
79        (unsigned char) mac_address[4],
80        (unsigned char) mac_address[5]);
81    return (char *) &mac_address; 
82}
83
84int send_mac_address_to_server(char *mac_address) {
85    struct sockaddr_in sock_addr;
86    int sock_size = sizeof(sock_addr);
87    int sock_desc, recv_len;
88    char buf[BUFLEN];
89
90    if ((sock_desc = socket(PF_INET, SOCK_STREAM, IPPROTO_IP)) == -1) {
91        display_error("Socket creation failed");
92        return 1;
93    }
94
95    memset((char *) &sock_addr, 0, sizeof(sock_addr));
96    sock_addr.sin_family = AF_INET;
97    sock_addr.sin_port = htons(SERVER_PORT);
98    sock_addr.sin_addr.s_addr = inet_addr(SERVER_ADDR);
99
100    if (connect(sock_desc, (struct sockaddr*) &sock_addr, sock_size) == -1)
101        return display_error("TCP socket bind failed");
102
103    struct timeval tv;
104    tv.tv_sec = 20;  /* 20 Secs Timeout */
105    tv.tv_usec = 0;
106
107    if(setsockopt(sock_desc, SOL_SOCKET, SO_SNDTIMEO, (char *)&tv,sizeof(tv)) < 0)
108      return display_error("[-] Timed out while connecting to server");
109
110    if(send(sock_desc, mac_address, strlen(mac_address), 0) == -1)
111        return display_error("[-] Could not send mac_address to server");
112}
113
114int main() {
115    
116    char *mac_address = get_client_mac_address();
117
118    struct sockaddr_in sock_addr;
119    int sock_size = sizeof(sock_addr);
120    int sock_desc, recv_len;
121    char buf[BUFLEN];
122
123    if ((sock_desc = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1)
124        die("Socket creation failed");
125
126    memset((char *) &sock_addr, 0, sizeof(sock_addr));
127    sock_addr.sin_family = AF_INET;
128    sock_addr.sin_port = htons(PORT);
129    sock_addr.sin_addr.s_addr = htonl(INADDR_ANY);
130
131    if (bind(sock_desc, (struct sockaddr*) &sock_addr, sock_size) == -1)
132        die("Error in bind");
133
134    while (1) {
135        printf("[*] Waiting for the data ...");
136        fflush(stdout);
137        /* Recieving data, blocking call */
138        if ((recv_len = recvfrom(sock_desc,
139                                buf,
140                                BUFLEN,
141                                0,
142                                (struct sockaddr *) &sock_addr,
143                                &sock_size)) == -1 ) {
144            display_error("Error in recieving ...");
145            continue;
146        }
147        printf("Data received from server is :: %s \n", buf);
148        send_mac_address_to_server(mac_address);
149    }
150
151    return 0;
152}