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/* arp.c - manipulate the system ARP cache
*
* Copyright 2014 Sandeep Sharma <sandeep.jack2756@gmail.com>
* Copyright 2014 Kyungwan Han <asura321@gamil.com>
* No Standard
USE_ARP(NEWTOY(arp, "vi:nDsdap:A:H:[+Ap][!sd]", TOYFLAG_USR|TOYFLAG_BIN))
config ARP
bool "arp"
default n
help
usage: arp
[-vn] [-H HWTYPE] [-i IF] -a [HOSTNAME]
[-v] [-i IF] -d HOSTNAME [pub]
[-v] [-H HWTYPE] [-i IF] -s HOSTNAME HWADDR [temp]
[-v] [-H HWTYPE] [-i IF] -s HOSTNAME HWADDR [netmask MASK] pub
[-v] [-H HWTYPE] [-i IF] -Ds HOSTNAME IFACE [netmask MASK] pub
Manipulate ARP cache
-a Display (all) hosts
-s Set new ARP entry
-d Delete a specified entry
-v Verbose
-n Don't resolve names
-i IF Network interface
-D Read <hwaddr> from given device
-A,-p AF Protocol family
-H HWTYPE Hardware address type
*/
#define FOR_arp
#include "toys.h"
#include <net/if_arp.h>
GLOBALS(
char *hw_type;
char *af_type_A;
char *af_type_p;
char *interface;
int sockfd;
char *device;
)
struct arpreq req; //Global request structure
struct type {
char *name;
int val;
};
struct type hwtype[] = {
{"ether", ARPHRD_ETHER },
{"loop" ,ARPHRD_LOOPBACK},
{"ppp" ,ARPHRD_PPP},
{"infiniband" ,ARPHRD_INFINIBAND},
{NULL, -1},
};
struct type aftype[] = {
{"inet", AF_INET },
{"inet6" ,AF_INET6},
{"unspec" ,AF_UNSPEC},
{NULL, -1},
};
struct type flag_type[] = {
{"PERM", ATF_PERM },
{"PUB" ,ATF_PUBL},
{"DONTPUB" ,ATF_DONTPUB},
{"TRAIL" ,ATF_USETRAILERS},
{NULL, -1},
};
static int get_index(struct type arr[], char *name)
{
int i;
for (i = 0; arr[i].name; i++)
if (!strcmp(arr[i].name, name)) break;
return arr[i].val;
}
static void resolve_host(char *host, struct sockaddr *sa)
{
struct addrinfo hints, *res = NULL;
int ret;
memset(&hints, 0, sizeof hints);
hints.ai_family = AF_INET;
hints.ai_socktype = SOCK_STREAM;
if ((ret = getaddrinfo(host, NULL, &hints, &res)))
perror_exit("%s", gai_strerror(ret));
memcpy(sa, res->ai_addr, res->ai_addrlen);
freeaddrinfo(res);
}
static void check_flags(int *i, char** argv)
{
struct sockaddr sa;
int flag = *i, j;
struct flags {
char *name;
int or, flag;
} f[] = {
{"pub", 1 ,ATF_PUBL},
{"priv", 0 ,~ATF_PUBL},
{"trail", 1, ATF_USETRAILERS},
{"temp", 0, ~ATF_PERM},
{"dontpub",1, ATF_DONTPUB},
};
for (;*argv; argv++) {
for (j = 0; j < ARRAY_LEN(f); j++) {
if (!strcmp(*argv, f[j].name)) {
(f[j].or) ?(flag |= f[j].flag):(flag &= f[j].flag);
break;
}
}
if (j > 4 && !strcmp(*argv, "netmask")) {
if (!*++argv) error_exit("NULL netmask");
if (strcmp(*argv, "255.255.255.255")) {
resolve_host(toys.optargs[0], &sa);
memcpy(&req.arp_netmask, &sa, sizeof(sa));
flag |= ATF_NETMASK;
} else argv++;
} else if (j > 4 && !strcmp(*argv, "dev")) {
if (!*++argv) error_exit("NULL dev");
TT.device = *argv;
} else if (j > 4) error_exit("invalid arg");
}
*i = flag;
}
static int set_entry(void)
{
int flags = 0;
if (!toys.optargs[1]) error_exit("bad syntax");
if (!(toys.optflags & FLAG_D)) {
char *ptr = toys.optargs[1];
char *p = ptr, *hw_addr = req.arp_ha.sa_data;
while (*hw_addr && (p-ptr) < 6) {
int val, len;
if (*hw_addr == ':') hw_addr++;
if (!sscanf(hw_addr, "%2x%n", &val, &len)) break;
hw_addr += len;
*p++ = val;
}
if ((p-ptr) != 6 || *hw_addr)
error_exit("bad hw addr '%s'", req.arp_ha.sa_data);
} else {
struct ifreq ifre;
xstrncpy(ifre.ifr_name, toys.optargs[1], IFNAMSIZ);
xioctl(TT.sockfd, SIOCGIFHWADDR, &ifre);
if ((toys.optflags & FLAG_H) && (ifre.ifr_hwaddr.sa_family != ARPHRD_ETHER))
error_exit("protocol type mismatch");
memcpy(&req.arp_ha, &(ifre.ifr_hwaddr), sizeof(req.arp_ha));
}
flags = ATF_PERM | ATF_COM;
if (toys.optargs[2]) check_flags(&flags, (toys.optargs+2));
req.arp_flags = flags;
xstrncpy(req.arp_dev, TT.device, sizeof(req.arp_dev));
xioctl(TT.sockfd, SIOCSARP, &req);
if (toys.optflags & FLAG_v) xprintf("Entry set for %s\n", toys.optargs[0]);
return 0;
}
static int ip_to_host(struct sockaddr *sa, int flag)
{
int status = 0;
char hbuf[NI_MAXHOST] = {0,}, sbuf[NI_MAXSERV] = {0,};
socklen_t len = sizeof(struct sockaddr_in6);
*toybuf = 0;
if (!(status = getnameinfo(sa, len, hbuf, sizeof(hbuf), sbuf,
sizeof(sbuf), flag))) {
strcpy(toybuf, hbuf);
return 0;
}
return 1;
}
static int delete_entry(void)
{
int flags;
flags = ATF_PERM;
if (toys.optargs[1]) check_flags(&flags, (toys.optargs+1));
req.arp_flags = flags;
xstrncpy(req.arp_dev, TT.device, sizeof(req.arp_dev));
xioctl(TT.sockfd, SIOCDARP, &req);
if (toys.optflags & FLAG_v) xprintf("Delete entry for %s\n", toys.optargs[0]);
return 0;
}
void arp_main(void)
{
struct sockaddr sa;
char ip[128], hw_addr[128], mask[12], dev[128], *host_ip = NULL, *buf;
int h_type, type, flag, i, fd, entries = 0, disp = 0;
TT.device = "";
memset(&sa, 0, sizeof(sa));
memset(&req, 0, sizeof(req));
TT.sockfd = xsocket(AF_INET, SOCK_STREAM, 0);
if ((toys.optflags & FLAG_A) || (toys.optflags & FLAG_p)) {
if ((type = get_index(aftype,
(TT.af_type_A)?TT.af_type_A:TT.af_type_p)) != AF_INET)
error_exit((type != -1)?"only inet supported by kernel":"unknown family");
}
req.arp_ha.sa_family = ARPHRD_ETHER;
if (toys.optflags & FLAG_H) {
if ((type = get_index(hwtype, TT.hw_type)) != ARPHRD_ETHER)
error_exit((type != -1)?"h/w type not supported":"unknown h/w type");
req.arp_ha.sa_family = type;
}
if (((toys.optflags & FLAG_s) || toys.optflags & FLAG_d)) {
if (!toys.optargs[0]) error_exit("host name req");
resolve_host(toys.optargs[0], &sa);
memcpy(&req.arp_pa, &sa, sizeof(struct sockaddr));
}
if ((toys.optflags & FLAG_s) && !set_entry()) return;
if ((toys.optflags & FLAG_d) && !delete_entry()) return;
//show arp chache
fd = xopenro("/proc/net/arp");
buf = get_line(fd);
free(buf); //skip first line
if (toys.optargs[0]) {
resolve_host(toys.optargs[0], &sa);
ip_to_host(&sa, NI_NUMERICHOST);
host_ip = xstrdup(toybuf);
}
while ((buf = get_line(fd))) {
char *host_name = "?";
if ((sscanf(buf, "%s 0x%x 0x%x %s %s %s\n", ip,
&h_type, &flag, hw_addr, mask, dev )) != 6) break;
entries++;
if (((toys.optflags & FLAG_H) && (get_index(hwtype, TT.hw_type) != h_type))
|| ((toys.optflags & FLAG_i) && strcmp(TT.interface, dev))
|| (toys.optargs[0] && strcmp(host_ip, ip))) {
free(buf);
continue;
}
resolve_host(buf, &sa);
if (!(toys.optflags & FLAG_n)) {
if (!ip_to_host(&sa, NI_NAMEREQD)) host_name = toybuf;
} else ip_to_host(&sa, NI_NUMERICHOST);
disp++;
printf("%s (%s) at" , host_name, ip);
for (i = 0; hwtype[i].name; i++)
if (hwtype[i].val & h_type) break;
if (!hwtype[i].name) error_exit("unknown h/w type");
if (!(flag & ATF_COM)) {
if ((flag & ATF_PUBL)) printf(" *");
else printf(" <incomplete>");
} else printf(" %s [%s]", hw_addr, hwtype[i].name);
if (flag & ATF_NETMASK) printf("netmask %s ", mask);
for (i = 0; flag_type[i].name; i++)
if (flag_type[i].val & flag) printf(" %s", flag_type[i].name);
printf(" on %s\n", dev);
free(buf);
}
if (toys.optflags & FLAG_v)
xprintf("Entries: %d\tSkipped: %d\tFound: %d\n",
entries, entries - disp, disp);
if (!disp) xprintf("No Match found in %d entries\n", entries);
if (CFG_TOYBOX_FREE) {
free(host_ip);
free(buf);
xclose(fd);
}
}