route.c revision 98c297f2448fd8194cae16d213dfc9194180fa3f 
1
2#include <stdio.h>
3#include <stdlib.h>
4#include <unistd.h>
5#include <stdarg.h>
6
7#include <errno.h>
8#include <string.h>
9#include <ctype.h>
10
11#include <sys/socket.h>
12#include <netinet/in.h>
13#include <linux/if.h>
14#include <linux/sockios.h>
15#include <arpa/inet.h>
16#include <linux/route.h>
17
18static void die(const char *fmt, ...)
19{
20    va_list p;
21
22    va_start(p, fmt);
23    fprintf(stderr,"error(%s): ", strerror(errno));
24    fprintf(stderr, fmt, p);
25    va_end(p);
26    exit(-1);
27}
28
29static inline void init_sockaddr_in(struct sockaddr_in *sin, const char *addr)
30{
31	sin->sin_family = AF_INET;
32	sin->sin_port = 0;
33	sin->sin_addr.s_addr = inet_addr(addr);
34}
35
36#define ADVANCE(argc, argv) do { argc--, argv++; } while(0)
37#define EXPECT_NEXT(argc, argv) do {        \
38    ADVANCE(argc, argv);                    \
39	if (0 == argc) {  						\
40		errno = EINVAL;                     \
41		die("expecting one more argument"); \
42	}                                       \
43} while(0)
44
45/* current support the following routing entries */
46/* route add default dev wlan0 */
47/* route add default gw 192.168.20.1 dev wlan0 */
48/* route add net 192.168.1.1 netmask 255.255.255.0 gw 172.24.192.10 */
49
50int route_main(int argc, char *argv[])
51{
52    struct ifreq ifr;
53    int s,i;
54	struct rtentry rt;
55	struct sockaddr_in ina;
56
57    if(argc == 0) return 0;
58
59    strncpy(ifr.ifr_name, argv[0], IFNAMSIZ);
60    ifr.ifr_name[IFNAMSIZ-1] = 0;
61	ADVANCE(argc, argv);
62
63    if((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
64        die("cannot open control socket\n");
65    }
66
67    while(argc > 0){
68        if(!strcmp(argv[0], "add")) {
69			EXPECT_NEXT(argc, argv);
70			if(!strcmp(argv[0], "default")) {
71				EXPECT_NEXT(argc, argv);
72				memset((char *) &rt, 0, sizeof(struct rtentry));
73				rt.rt_dst.sa_family = AF_INET;
74				if(!strcmp(argv[0], "dev")) {
75				  EXPECT_NEXT(argc, argv);
76				  rt.rt_flags = RTF_UP | RTF_HOST;
77				  rt.rt_dev = argv[0];
78				  if (ioctl(s, SIOCADDRT, &rt) < 0) die("SIOCADDRT\n");
79				}else if(!strcmp(argv[0], "gw")) {
80				  EXPECT_NEXT(argc, argv);
81				  rt.rt_flags = RTF_UP | RTF_GATEWAY;
82				  init_sockaddr_in((struct sockaddr_in *)&(rt.rt_genmask), "0.0.0.0");
83				  if(isdigit(argv[0][0])){
84					init_sockaddr_in((struct sockaddr_in *)&(rt.rt_gateway), argv[0]);
85				  }else{
86					die("expecting an IP address for parameter \"gw\"\n");
87				  }
88				  EXPECT_NEXT(argc, argv);
89				  if(!strcmp(argv[0], "dev")) {
90					EXPECT_NEXT(argc, argv);
91					rt.rt_dev = argv[0];
92					if (ioctl(s, SIOCADDRT, &rt) < 0){
93					  die("SIOCADDRT\n");
94					}
95				  }
96				}
97			} else  {
98                          char keywords[3][5] = { "net", "mask", "gw" };
99                          struct sockaddr_in *paddr[3] = { &rt.rt_dst, &rt.rt_genmask, &rt.rt_gateway };
100                          int k = 0;
101
102                          memset((char *) &rt, 0, sizeof(struct rtentry));
103                          rt.rt_flags = RTF_UP | RTF_GATEWAY;
104                          do {
105                            if(!strcmp(argv[0], keywords[k])) {
106                              EXPECT_NEXT(argc, argv);
107                              if(isdigit(argv[0][0])) {
108                                init_sockaddr_in(paddr[k], argv[0]);
109                              } else {
110                                die("expecting an IP/MASK address for parameter %s\n", keywords[k]);
111                              }
112                              if(k < 2) EXPECT_NEXT(argc, argv);
113                            } else {
114                              die("expecting keyword(s)\n");
115                            }
116                          } while(++k < 3);
117                          if(ioctl(s, SIOCADDRT, &rt) < 0) {
118                            die("SIOCADDRT\n");
119                          }
120                        }
121        }
122		ADVANCE(argc, argv);
123    }
124
125    return 0;
126}
127