int main(int argc, char *argv[])
{
int sockfd;
char *buf;
pid_t pid;
ssize_t n;
struct rt_msghdr *rtm;
struct sockaddr *sa, *rti_info[RTAX_MAX];
struct sockaddr_in *sin;
if (argc != 2)
err_quit("Usage: %s <IPaddress>", basename(argv[0]));
sockfd = Socket(AF_ROUTE, SOCK_RAW, 0); /* need superuser privileges */
buf = Calloc(1, BUFLEN); /* and initialized to 0 */
rtm = (struct rt_msghdr *)buf;
rtm->rtm_msglen = sizeof(struct rt_msghdr) + sizeof(struct sockaddr_in);
rtm->rtm_version = RTM_VERSION;
rtm->rtm_type = RTM_GET;
rtm->rtm_addrs = RTA_DST;
rtm->rtm_pid = pid = getpid();
rtm->rtm_seq = SEQ;
sin = (struct sockaddr_in *)(rtm + 1);
sin->sin_len = sizeof(struct sockaddr_in);
sin->sin_family = AF_INET;
Inet_pton(AF_INET, argv[1], &sin->sin_addr);
Write(sockfd, rtm, rtm->rtm_msglen);
do {
n = Read(sockfd, rtm, BUFLEN);
} while (rtm->rtm_type != RTM_GET || rtm->rtm_seq != SEQ ||
rtm->rtm_pid != pid);
rtm = (struct rt_msghdr *)buf;
sa = (struct sockaddr *)(rtm + 1);
get_rtaddrs(rtm->rtm_addrs, sa, rti_info);
if ((sa = rti_info[RTAX_DST]) != NULL)
printf("dest: %s\n", Sock_ntop_host(sa, sa->sa_len));
if ((sa = rti_info[RTAX_GATEWAY]) != NULL)
printf("gateway: %s\n", Sock_ntop_host(sa, sa->sa_len));
if ((sa = rti_info[RTAX_NETMASK]) != NULL)
printf("netmask: %s\n", sock_masktop(sa, sa->sa_len));
if ((sa = rti_info[RTAX_GENMASK]) != NULL)
printf("genmask: %s\n", sock_masktop(sa, sa->sa_len));
exit(0);
}
// function used to configure a route to "daddr" by specifying either
// the gateway address "gaddr" or the interface name "ifname";
// a mask given by "maddr" can also be specified
// the command codes "cmd" indicate the type of operation
// Note: addresses are given as 4-byte words (c.f. rtctl)
int rtctl2(uint32_t *daddr, /* destination IP address */
uint32_t *gaddr, /* gateway IP address */
uint32_t *maddr, /* subnet mask */
char *ifname, /* network interface name */
u_char cmd) /* RTM_ADD RTM_DELETE RTM_CHANGE */
{
int sockfd, mib[6], len;
char *buf, rta_cmd[RTCTL_CMD_LEN], *ifbuf;
char dstaddr[16], gateaddr[16], maskaddr[16];
u_char flag;
pid_t pid;
struct rt_msghdr *rtm;
struct sockaddr_in *dst, *gate, *mask;
struct sockaddr_dl *ifp, *sdl;
struct if_msghdr *ifm;
#ifdef RTCTL_PRINT_RESPONSE
ssize_t n;
struct sockaddr *sa, *rti_info[RTAX_MAX];
#endif
/* check the arguments */
if (daddr == NULL)
{
fprintf(stderr, "Invalid destination IP address\n");
return -1;
}
flag = 0;
if (cmd == RTM_ADD)
{
flag |= RTCTL_ADD;
strncpy(rta_cmd, "add", sizeof("add"));
if (gaddr == NULL)
{
if (ifname == NULL)
flag |= RTCTL_UNKNOWN;
else if (maddr != NULL)
flag |= RTCTL_UNKNOWN;
else
flag |= RTCTL_IF;
}
else
{
flag |= RTCTL_GATEWAY;
if (ifname != NULL)
flag |= RTCTL_UNKNOWN;
else if (maddr != NULL)
flag |= RTCTL_NETMASK;
}
}
else if (cmd == RTM_DELETE)
{
flag |= RTCTL_DELETE;
strncpy(rta_cmd, "delete", sizeof("delete"));
if ((ifname != NULL) | (gaddr != NULL) | (maddr != NULL))
flag |= RTCTL_UNKNOWN;
}
else if (cmd == RTM_CHANGE)
{
flag |= RTCTL_CHANGE;
strncpy(rta_cmd, "change", sizeof("change"));
if (gaddr == NULL)
{
if (ifname == NULL)
flag |= RTCTL_UNKNOWN;
else if (maddr != NULL)
flag |= RTCTL_UNKNOWN;
else
flag |= RTCTL_IF;
}
else
{
flag |= RTCTL_GATEWAY;
if (ifname != NULL)
flag |= RTCTL_UNKNOWN;
else if (maddr != NULL)
flag |= RTCTL_NETMASK;
}
}
else
{
fprintf(stderr, "Invalid command name\n");
return -1;
}
if (flag & RTCTL_UNKNOWN)
{
fprintf(stderr, "Unknown arguments are inputed.\n");
return -1;
}
if ((buf = calloc(1, BUFLEN)) == NULL)
{
perror("calloc");
return -1;
}
/* set address of rt messages */
rtm = (struct rt_msghdr *) buf;
rtm->rtm_version = RTM_VERSION;
rtm->rtm_type = cmd;
rtm->rtm_pid = pid = getpid();
rtm->rtm_seq = ++rtm_seq;
rtm->rtm_errno = 0;
if ((flag & RTCTL_ADD) | (flag & RTCTL_CHANGE))
{
if (flag & RTCTL_IF)
{
rtm->rtm_msglen = sizeof(struct rt_msghdr) +
sizeof(struct sockaddr_in) +
sizeof(struct sockaddr_dl);
rtm->rtm_addrs = RTA_DST | RTA_GATEWAY;
rtm->rtm_flags = RTF_UP | RTF_HOST | RTF_LLINFO
| RTF_STATIC;
}
else if (flag & RTCTL_NETMASK)
{
rtm->rtm_msglen = sizeof(struct rt_msghdr) +
3 * sizeof(struct sockaddr_in);
rtm->rtm_addrs = RTA_DST | RTA_GATEWAY | RTA_NETMASK;
rtm->rtm_flags = RTF_UP | RTF_GATEWAY | RTF_STATIC;
}
else
{
rtm->rtm_msglen = sizeof(struct rt_msghdr) +
2 * sizeof(struct sockaddr_in);
rtm->rtm_addrs = RTA_DST | RTA_GATEWAY;
rtm->rtm_flags = RTF_UP | RTF_HOST | RTF_GATEWAY
| RTF_STATIC;
}
}
else if (flag & RTCTL_DELETE)
{
rtm->rtm_msglen = sizeof(struct rt_msghdr) +
sizeof(struct sockaddr_in);
rtm->rtm_addrs = RTA_DST;
}
/* set destination RTA_GATEWAY */
dst = (struct sockaddr_in *) (rtm + 1);
dst->sin_len = sizeof(struct sockaddr_in);
dst->sin_family = AF_INET;
fflush(stderr);
dst->sin_addr.s_addr = *daddr;
if (flag & RTCTL_GATEWAY)
{
/* set gateway */
gate = (struct sockaddr_in *) (dst + 1);
gate->sin_len = sizeof(struct sockaddr_in);
gate->sin_family = AF_INET;
gate->sin_addr.s_addr = *gaddr;
if (flag & RTCTL_NETMASK)
{
mask = (struct sockaddr_in *) (gate + 1);
mask->sin_len = sizeof(struct sockaddr_in);
mask->sin_family = AF_INET;
mask->sin_addr.s_addr = *maddr;
}
}
else if (flag & RTCTL_IF)
{
/* get sockaddr_dl info */
mib[0] = CTL_NET;
mib[1] = AF_ROUTE;
mib[2] = 0;
mib[3] = AF_LINK;
mib[4] = NET_RT_IFLIST;
if ((mib[5] = if_nametoindex(ifname)) == 0)
{
perror("if_nametoindex");
return -1;
}
if (sysctl(mib, 6, NULL, &len, NULL, 0) < 0)
{
perror("sysctl");
return -1;
}
if ((ifbuf = calloc(1, len)) == NULL)
{
perror("calloc");
return -1;
}
if (sysctl(mib, 6, ifbuf, &len, NULL, 0) < 0)
{
perror("sysctl2");
return -1;
}
ifm = (struct if_msghdr *) ifbuf;
sdl = (struct sockaddr_dl *) (ifm + 1);
/* set network interface */
ifp = (struct sockaddr_dl *) (dst + 1);
bcopy(sdl, ifp, sizeof(struct sockaddr_dl));
ifp->sdl_len = sizeof(struct sockaddr_dl);
}
if ((sockfd = socket(PF_ROUTE, SOCK_RAW, 0)) < 0)
{
perror("socket");
return -1;
}
if (write(sockfd, rtm, rtm->rtm_msglen) < 0)
{
perror("write");
//return -1;
}
else
{
strncpy(dstaddr, "", sizeof(dstaddr));
strncpy(gateaddr, "", sizeof(gateaddr));
strncpy(maskaddr, "", sizeof(maskaddr));
strncpy(dstaddr, inet_ntoa(dst->sin_addr), sizeof(dstaddr));
if (gaddr != NULL)
strncpy(gateaddr, inet_ntoa(gate->sin_addr), sizeof(gateaddr));
if (maddr != NULL)
strncpy(maskaddr, inet_ntoa(mask->sin_addr), sizeof(maskaddr));
fprintf(stderr, "\troute %s dst:%s gate:%s mask:%s ifp:%s\n",
rta_cmd, dstaddr, gateaddr, maskaddr, ifname);
/* A chunk of lines like this: */
/* strncpy(dstaddr, "", sizeof(dstaddr)); */
/* strncpy(gateaddr, "", sizeof(gateaddr)); */
/* strncpy(maskaddr, "", sizeof(maskaddr)); */
/* strncpy(dstaddr, inet_ntoa(dst->sin_addr), sizeof(dstaddr)); */
/* if (gaddr != NULL) */
/* strncpy(gateaddr, inet_ntoa(gate->sin_addr), */
/* sizeof(gateaddr)); */
/* if (maddr != NULL) */
/* strncpy(maskaddr, inet_ntoa(mask->sin_addr), */
/* sizeof(maskaddr)); */
/* fprintf(stderr, "\troute %s dst:%s gate:%s mask:%s ifp:%s\n", */
/* rta_cmd, dstaddr, gateaddr, maskaddr, ifname); */
/* can be rewritten as: */
/* fprintf(stderr, "\troute %s dst:%s gate:%s ", rta_cmd, dstaddr, */
/* (gaddr != NULL) : inet_ntoa(gate->sin_addr) ? ""); */
/* fprintf(stderr, "mask:%s ifp:%s\n", */
/* (maddr != NULL) : inet_ntoa(mask->sin_addr) ? "", ifname); */
}
#ifdef RTCTL_PRINT_RESPONSE
fprintf(stderr, "---print response\n");
do
{
n = read(sockfd, rtm, BUFLEN);
}
while (rtm->rtm_seq != rtm_seq || rtm->rtm_pid != pid);
/* handle response */
rtm = (struct rt_msghdr *) buf;
sa = (struct sockaddr *) (rtm + 1);
get_rtaddrs(rtm->rtm_addrs, sa, rti_info);
if ((sa = rti_info[RTAX_DST]) != NULL)
fprintf(stderr, "dest: %s\n", sock_ntop_host(sa, sa->sa_len));
if ((sa = rti_info[RTAX_GATEWAY]) != NULL)
fprintf(stderr, "gateway: %s\n", sock_ntop_host(sa, sa->sa_len));
if ((sa = rti_info[RTAX_NETMASK]) != NULL)
fprintf(stderr, "netmask: %s\n", sock_masktop(sa, sa->sa_len));
if ((sa = rti_info[RTAX_GENMASK]) != NULL)
fprintf(stderr, "genmask: %s\n", sock_masktop(sa, sa->sa_len));
if ((sa = rti_info[RTAX_IFP]) != NULL)
fprintf(stderr, "ifp: len:%d fami:%d data:%s\n", sa->sa_len,
sa->sa_family, sa->sa_data);
if ((sa = rti_info[RTAX_IFA]) != NULL)
fprintf(stderr, "ifa: len:%d fami:%d data:%s\n", sa->sa_len,
sa->sa_family, sa->sa_data);
if ((sa = rti_info[RTAX_AUTHOR]) != NULL)
fprintf(stderr, "author: len:%d fami:%d data:%s\n", sa->sa_len,
sa->sa_family, sa->sa_data);
if ((sa = rti_info[RTAX_BRD]) != NULL)
fprintf(stderr, "brd: len:%d fami:%d data:%s\n", sa->sa_len,
sa->sa_family, sa->sa_data);
#endif
free(buf);
if (flag & RTCTL_IF)
free(ifbuf);
return 0;
}
int getrt(char *ipaddr)
{
int sockfd;
char *buf;
pid_t pid;
ssize_t n;
struct rt_msghdr *rtm;
struct sockaddr *sa, *rti_info[RTAX_MAX];
struct sockaddr_in *sin;
if (ipaddr == NULL)
{
fprintf(stderr, "getrt: IP address.\n");
return -1;
}
if ((sockfd = socket(AF_ROUTE, SOCK_RAW, 0)) < 0)
{
perror("socket");
return -1;
}
buf = calloc(1, BUFLEN);
rtm = (struct rt_msghdr *) buf;
rtm->rtm_msglen = sizeof(struct rt_msghdr) + sizeof(struct sockaddr_in);
rtm->rtm_version = RTM_VERSION;
rtm->rtm_type = RTM_GET;
rtm->rtm_addrs = RTA_DST;
rtm->rtm_pid = pid = getpid();
rtm->rtm_seq = SEQ;
sin = (struct sockaddr_in *) (rtm + 1);
sin->sin_len = sizeof(struct sockaddr_in);
sin->sin_family = AF_INET;
inet_pton(AF_INET, ipaddr, &sin->sin_addr);
if (write(sockfd, rtm, rtm->rtm_msglen) < 0)
{
perror("write");
exit(1);
}
do
{
n = read(sockfd, rtm, BUFLEN);
}
while (rtm->rtm_type != RTM_GET || rtm->rtm_seq != SEQ ||
rtm->rtm_pid != pid);
/* handle response */
rtm = (struct rt_msghdr *) buf;
sa = (struct sockaddr *) (rtm + 1);
get_rtaddrs(rtm->rtm_addrs, sa, rti_info);
if ((sa = rti_info[RTAX_DST]) != NULL)
fprintf(stderr, "dest: %s\n", sock_ntop_host(sa, sa->sa_len));
if ((sa = rti_info[RTAX_GATEWAY]) != NULL)
fprintf(stderr, "gateway: %s\n", sock_ntop_host(sa, sa->sa_len));
if ((sa = rti_info[RTAX_NETMASK]) != NULL)
fprintf(stderr, "netmask: %s\n", sock_masktop(sa, sa->sa_len));
if ((sa = rti_info[RTAX_GENMASK]) != NULL)
fprintf(stderr, "genmask: %s\n", sock_masktop(sa, sa->sa_len));
if ((sa = rti_info[RTAX_IFP]) != NULL)
fprintf(stderr, "ifp: len:%d fami:%d data:%s\n", sa->sa_len,
sa->sa_family, sa->sa_data);
if ((sa = rti_info[RTAX_IFA]) != NULL)
fprintf(stderr, "ifa: len:%d fami:%d data:%s\n", sa->sa_len,
sa->sa_family, sa->sa_data);
return 0;
}
