| /* vi: set sw=4 ts=4: */ |
| /* |
| * arp.c - Manipulate the system ARP cache |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| * |
| * Author: Fred N. van Kempen, <waltje at uwalt.nl.mugnet.org> |
| * Busybox port: Paul van Gool <pvangool at mimotech.com> |
| * |
| * modified for getopt32 by Arne Bernin <arne [at] alamut.de> |
| */ |
| |
| //usage:#define arp_trivial_usage |
| //usage: "\n[-vn] [-H HWTYPE] [-i IF] -a [HOSTNAME]" |
| //usage: "\n[-v] [-i IF] -d HOSTNAME [pub]" |
| //usage: "\n[-v] [-H HWTYPE] [-i IF] -s HOSTNAME HWADDR [temp]" |
| //usage: "\n[-v] [-H HWTYPE] [-i IF] -s HOSTNAME HWADDR [netmask MASK] pub" |
| //usage: "\n[-v] [-H HWTYPE] [-i IF] -Ds HOSTNAME IFACE [netmask MASK] pub" |
| //usage:#define arp_full_usage "\n\n" |
| //usage: "Manipulate ARP cache\n" |
| //usage: "\n -a Display (all) hosts" |
| //usage: "\n -d Delete ARP entry" |
| //usage: "\n -s Set new entry" |
| //usage: "\n -v Verbose" |
| //usage: "\n -n Don't resolve names" |
| //usage: "\n -i IF Network interface" |
| //usage: "\n -D Read HWADDR from IFACE" |
| //usage: "\n -A,-p AF Protocol family" |
| //usage: "\n -H HWTYPE Hardware address type" |
| |
| #include "libbb.h" |
| #include "inet_common.h" |
| |
| #include <arpa/inet.h> |
| #include <net/if.h> |
| #include <net/if_arp.h> |
| #include <netinet/ether.h> |
| #include <netpacket/packet.h> |
| |
| #define DEBUG 0 |
| |
| #define DFLT_AF "inet" |
| #define DFLT_HW "ether" |
| |
| enum { |
| ARP_OPT_A = (1 << 0), |
| ARP_OPT_p = (1 << 1), |
| ARP_OPT_H = (1 << 2), |
| ARP_OPT_t = (1 << 3), |
| ARP_OPT_i = (1 << 4), |
| ARP_OPT_a = (1 << 5), |
| ARP_OPT_d = (1 << 6), |
| ARP_OPT_n = (1 << 7), /* do not resolve addresses */ |
| ARP_OPT_D = (1 << 8), /* HW-address is devicename */ |
| ARP_OPT_s = (1 << 9), |
| ARP_OPT_v = (1 << 10) * DEBUG, /* debugging output flag */ |
| }; |
| |
| enum { |
| sockfd = 3, /* active socket descriptor */ |
| }; |
| |
| struct globals { |
| const struct aftype *ap; /* current address family */ |
| const struct hwtype *hw; /* current hardware type */ |
| const char *device; /* current device */ |
| smallint hw_set; /* flag if hw-type was set (-H) */ |
| |
| } FIX_ALIASING; |
| #define G (*(struct globals*)&bb_common_bufsiz1) |
| #define ap (G.ap ) |
| #define hw (G.hw ) |
| #define device (G.device ) |
| #define hw_set (G.hw_set ) |
| #define INIT_G() do { \ |
| device = ""; \ |
| } while (0) |
| |
| |
| static const char options[] ALIGN1 = |
| "pub\0" |
| "priv\0" |
| "temp\0" |
| "trail\0" |
| "dontpub\0" |
| "auto\0" |
| "dev\0" |
| "netmask\0"; |
| |
| /* Delete an entry from the ARP cache. */ |
| /* Called only from main, once */ |
| static int arp_del(char **args) |
| { |
| char *host; |
| struct arpreq req; |
| struct sockaddr sa; |
| int flags = 0; |
| int err; |
| |
| memset(&req, 0, sizeof(req)); |
| |
| /* Resolve the host name. */ |
| host = *args; |
| if (ap->input(host, &sa) < 0) { |
| bb_herror_msg_and_die("%s", host); |
| } |
| |
| /* If a host has more than one address, use the correct one! */ |
| memcpy(&req.arp_pa, &sa, sizeof(struct sockaddr)); |
| |
| if (hw_set) |
| req.arp_ha.sa_family = hw->type; |
| |
| req.arp_flags = ATF_PERM; |
| args++; |
| while (*args != NULL) { |
| switch (index_in_strings(options, *args)) { |
| case 0: /* "pub" */ |
| flags |= 1; |
| args++; |
| break; |
| case 1: /* "priv" */ |
| flags |= 2; |
| args++; |
| break; |
| case 2: /* "temp" */ |
| req.arp_flags &= ~ATF_PERM; |
| args++; |
| break; |
| case 3: /* "trail" */ |
| req.arp_flags |= ATF_USETRAILERS; |
| args++; |
| break; |
| case 4: /* "dontpub" */ |
| #ifdef HAVE_ATF_DONTPUB |
| req.arp_flags |= ATF_DONTPUB; |
| #else |
| bb_error_msg("feature ATF_DONTPUB is not supported"); |
| #endif |
| args++; |
| break; |
| case 5: /* "auto" */ |
| #ifdef HAVE_ATF_MAGIC |
| req.arp_flags |= ATF_MAGIC; |
| #else |
| bb_error_msg("feature ATF_MAGIC is not supported"); |
| #endif |
| args++; |
| break; |
| case 6: /* "dev" */ |
| if (*++args == NULL) |
| bb_show_usage(); |
| device = *args; |
| args++; |
| break; |
| case 7: /* "netmask" */ |
| if (*++args == NULL) |
| bb_show_usage(); |
| if (strcmp(*args, "255.255.255.255") != 0) { |
| host = *args; |
| if (ap->input(host, &sa) < 0) { |
| bb_herror_msg_and_die("%s", host); |
| } |
| memcpy(&req.arp_netmask, &sa, sizeof(struct sockaddr)); |
| req.arp_flags |= ATF_NETMASK; |
| } |
| args++; |
| break; |
| default: |
| bb_show_usage(); |
| break; |
| } |
| } |
| if (flags == 0) |
| flags = 3; |
| |
| strncpy(req.arp_dev, device, sizeof(req.arp_dev)); |
| |
| err = -1; |
| |
| /* Call the kernel. */ |
| if (flags & 2) { |
| if (option_mask32 & ARP_OPT_v) |
| bb_error_msg("SIOCDARP(nopub)"); |
| err = ioctl(sockfd, SIOCDARP, &req); |
| if (err < 0) { |
| if (errno == ENXIO) { |
| if (flags & 1) |
| goto nopub; |
| printf("No ARP entry for %s\n", host); |
| return -1; |
| } |
| bb_perror_msg_and_die("SIOCDARP(priv)"); |
| } |
| } |
| if ((flags & 1) && err) { |
| nopub: |
| req.arp_flags |= ATF_PUBL; |
| if (option_mask32 & ARP_OPT_v) |
| bb_error_msg("SIOCDARP(pub)"); |
| if (ioctl(sockfd, SIOCDARP, &req) < 0) { |
| if (errno == ENXIO) { |
| printf("No ARP entry for %s\n", host); |
| return -1; |
| } |
| bb_perror_msg_and_die("SIOCDARP(pub)"); |
| } |
| } |
| return 0; |
| } |
| |
| /* Get the hardware address to a specified interface name */ |
| static void arp_getdevhw(char *ifname, struct sockaddr *sa) |
| { |
| struct ifreq ifr; |
| const struct hwtype *xhw; |
| |
| strcpy(ifr.ifr_name, ifname); |
| ioctl_or_perror_and_die(sockfd, SIOCGIFHWADDR, &ifr, |
| "can't get HW-Address for '%s'", ifname); |
| if (hw_set && (ifr.ifr_hwaddr.sa_family != hw->type)) { |
| bb_error_msg_and_die("protocol type mismatch"); |
| } |
| memcpy(sa, &(ifr.ifr_hwaddr), sizeof(struct sockaddr)); |
| |
| if (option_mask32 & ARP_OPT_v) { |
| xhw = get_hwntype(ifr.ifr_hwaddr.sa_family); |
| if (!xhw || !xhw->print) { |
| xhw = get_hwntype(-1); |
| } |
| bb_error_msg("device '%s' has HW address %s '%s'", |
| ifname, xhw->name, |
| xhw->print((unsigned char *) &ifr.ifr_hwaddr.sa_data)); |
| } |
| } |
| |
| /* Set an entry in the ARP cache. */ |
| /* Called only from main, once */ |
| static int arp_set(char **args) |
| { |
| char *host; |
| struct arpreq req; |
| struct sockaddr sa; |
| int flags; |
| |
| memset(&req, 0, sizeof(req)); |
| |
| host = *args++; |
| if (ap->input(host, &sa) < 0) { |
| bb_herror_msg_and_die("%s", host); |
| } |
| /* If a host has more than one address, use the correct one! */ |
| memcpy(&req.arp_pa, &sa, sizeof(struct sockaddr)); |
| |
| /* Fetch the hardware address. */ |
| if (*args == NULL) { |
| bb_error_msg_and_die("need hardware address"); |
| } |
| if (option_mask32 & ARP_OPT_D) { |
| arp_getdevhw(*args++, &req.arp_ha); |
| } else { |
| if (hw->input(*args++, &req.arp_ha) < 0) { |
| bb_error_msg_and_die("invalid hardware address"); |
| } |
| } |
| |
| /* Check out any modifiers. */ |
| flags = ATF_PERM | ATF_COM; |
| while (*args != NULL) { |
| switch (index_in_strings(options, *args)) { |
| case 0: /* "pub" */ |
| flags |= ATF_PUBL; |
| args++; |
| break; |
| case 1: /* "priv" */ |
| flags &= ~ATF_PUBL; |
| args++; |
| break; |
| case 2: /* "temp" */ |
| flags &= ~ATF_PERM; |
| args++; |
| break; |
| case 3: /* "trail" */ |
| flags |= ATF_USETRAILERS; |
| args++; |
| break; |
| case 4: /* "dontpub" */ |
| #ifdef HAVE_ATF_DONTPUB |
| flags |= ATF_DONTPUB; |
| #else |
| bb_error_msg("feature ATF_DONTPUB is not supported"); |
| #endif |
| args++; |
| break; |
| case 5: /* "auto" */ |
| #ifdef HAVE_ATF_MAGIC |
| flags |= ATF_MAGIC; |
| #else |
| bb_error_msg("feature ATF_MAGIC is not supported"); |
| #endif |
| args++; |
| break; |
| case 6: /* "dev" */ |
| if (*++args == NULL) |
| bb_show_usage(); |
| device = *args; |
| args++; |
| break; |
| case 7: /* "netmask" */ |
| if (*++args == NULL) |
| bb_show_usage(); |
| if (strcmp(*args, "255.255.255.255") != 0) { |
| host = *args; |
| if (ap->input(host, &sa) < 0) { |
| bb_herror_msg_and_die("%s", host); |
| } |
| memcpy(&req.arp_netmask, &sa, sizeof(struct sockaddr)); |
| flags |= ATF_NETMASK; |
| } |
| args++; |
| break; |
| default: |
| bb_show_usage(); |
| break; |
| } |
| } |
| |
| /* Fill in the remainder of the request. */ |
| req.arp_flags = flags; |
| |
| strncpy(req.arp_dev, device, sizeof(req.arp_dev)); |
| |
| /* Call the kernel. */ |
| if (option_mask32 & ARP_OPT_v) |
| bb_error_msg("SIOCSARP()"); |
| xioctl(sockfd, SIOCSARP, &req); |
| return 0; |
| } |
| |
| |
| /* Print the contents of an ARP request block. */ |
| static void |
| arp_disp(const char *name, char *ip, int type, int arp_flags, |
| char *hwa, char *mask, char *dev) |
| { |
| static const int arp_masks[] = { |
| ATF_PERM, ATF_PUBL, |
| #ifdef HAVE_ATF_MAGIC |
| ATF_MAGIC, |
| #endif |
| #ifdef HAVE_ATF_DONTPUB |
| ATF_DONTPUB, |
| #endif |
| ATF_USETRAILERS, |
| }; |
| static const char arp_labels[] ALIGN1 = "PERM\0""PUP\0" |
| #ifdef HAVE_ATF_MAGIC |
| "AUTO\0" |
| #endif |
| #ifdef HAVE_ATF_DONTPUB |
| "DONTPUB\0" |
| #endif |
| "TRAIL\0" |
| ; |
| |
| const struct hwtype *xhw; |
| |
| xhw = get_hwntype(type); |
| if (xhw == NULL) |
| xhw = get_hwtype(DFLT_HW); |
| |
| printf("%s (%s) at ", name, ip); |
| |
| if (!(arp_flags & ATF_COM)) { |
| if (arp_flags & ATF_PUBL) |
| printf("* "); |
| else |
| printf("<incomplete> "); |
| } else { |
| printf("%s [%s] ", hwa, xhw->name); |
| } |
| |
| if (arp_flags & ATF_NETMASK) |
| printf("netmask %s ", mask); |
| |
| print_flags_separated(arp_masks, arp_labels, arp_flags, " "); |
| printf(" on %s\n", dev); |
| } |
| |
| /* Display the contents of the ARP cache in the kernel. */ |
| /* Called only from main, once */ |
| static int arp_show(char *name) |
| { |
| const char *host; |
| const char *hostname; |
| FILE *fp; |
| struct sockaddr sa; |
| int type, flags; |
| int num; |
| unsigned entries = 0, shown = 0; |
| char ip[128]; |
| char hwa[128]; |
| char mask[128]; |
| char line[128]; |
| char dev[128]; |
| |
| host = NULL; |
| if (name != NULL) { |
| /* Resolve the host name. */ |
| if (ap->input(name, &sa) < 0) { |
| bb_herror_msg_and_die("%s", name); |
| } |
| host = xstrdup(ap->sprint(&sa, 1)); |
| } |
| fp = xfopen_for_read("/proc/net/arp"); |
| /* Bypass header -- read one line */ |
| fgets(line, sizeof(line), fp); |
| |
| /* Read the ARP cache entries. */ |
| while (fgets(line, sizeof(line), fp)) { |
| |
| mask[0] = '-'; mask[1] = '\0'; |
| dev[0] = '-'; dev[1] = '\0'; |
| /* All these strings can't overflow |
| * because fgets above reads limited amount of data */ |
| num = sscanf(line, "%s 0x%x 0x%x %s %s %s\n", |
| ip, &type, &flags, hwa, mask, dev); |
| if (num < 4) |
| break; |
| |
| entries++; |
| /* if the user specified hw-type differs, skip it */ |
| if (hw_set && (type != hw->type)) |
| continue; |
| |
| /* if the user specified address differs, skip it */ |
| if (host && strcmp(ip, host) != 0) |
| continue; |
| |
| /* if the user specified device differs, skip it */ |
| if (device[0] && strcmp(dev, device) != 0) |
| continue; |
| |
| shown++; |
| /* This IS ugly but it works -be */ |
| hostname = "?"; |
| if (!(option_mask32 & ARP_OPT_n)) { |
| if (ap->input(ip, &sa) < 0) |
| hostname = ip; |
| else |
| hostname = ap->sprint(&sa, (option_mask32 & ARP_OPT_n) | 0x8000); |
| if (strcmp(hostname, ip) == 0) |
| hostname = "?"; |
| } |
| |
| arp_disp(hostname, ip, type, flags, hwa, mask, dev); |
| } |
| if (option_mask32 & ARP_OPT_v) |
| printf("Entries: %u\tSkipped: %u\tFound: %u\n", |
| entries, entries - shown, shown); |
| |
| if (!shown) { |
| if (hw_set || host || device[0]) |
| printf("No match found in %u entries\n", entries); |
| } |
| if (ENABLE_FEATURE_CLEAN_UP) { |
| free((char*)host); |
| fclose(fp); |
| } |
| return 0; |
| } |
| |
| int arp_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
| int arp_main(int argc UNUSED_PARAM, char **argv) |
| { |
| const char *hw_type; |
| const char *protocol; |
| unsigned opts; |
| |
| INIT_G(); |
| |
| xmove_fd(xsocket(AF_INET, SOCK_DGRAM, 0), sockfd); |
| |
| ap = get_aftype(DFLT_AF); |
| /* Defaults are always supported */ |
| //if (!ap) |
| // bb_error_msg_and_die("%s: %s not supported", DFLT_AF, "address family"); |
| hw = get_hwtype(DFLT_HW); |
| //if (!hw) |
| // bb_error_msg_and_die("%s: %s not supported", DFLT_HW, "hardware type"); |
| |
| opts = getopt32(argv, "A:p:H:t:i:adnDsv", &protocol, &protocol, |
| &hw_type, &hw_type, &device); |
| argv += optind; |
| if (opts & (ARP_OPT_A | ARP_OPT_p)) { |
| ap = get_aftype(protocol); |
| if (!ap) |
| bb_error_msg_and_die("%s: unknown %s", protocol, "address family"); |
| } |
| if (opts & (ARP_OPT_H | ARP_OPT_t)) { |
| hw = get_hwtype(hw_type); |
| if (!hw) |
| bb_error_msg_and_die("%s: unknown %s", hw_type, "hardware type"); |
| hw_set = 1; |
| } |
| //if (opts & ARP_OPT_i)... -i |
| |
| if (ap->af != AF_INET) { |
| bb_error_msg_and_die("%s: kernel only supports 'inet'", ap->name); |
| } |
| if (hw->alen <= 0) { |
| bb_error_msg_and_die("%s: %s without ARP support", |
| hw->name, "hardware type"); |
| } |
| |
| /* Now see what we have to do here... */ |
| if (opts & (ARP_OPT_d | ARP_OPT_s)) { |
| if (argv[0] == NULL) |
| bb_error_msg_and_die("need host name"); |
| if (opts & ARP_OPT_s) |
| return arp_set(argv); |
| return arp_del(argv); |
| } |
| |
| //if (opts & ARP_OPT_a) - default |
| return arp_show(argv[0]); |
| } |