88e2b1cb6
Denis Vlasenko
2007-01-07
Subject
I *always* forgotting svn add
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Commit Diff GitHub →
networking/arp.c+500 -0
| @@ -0,0 +1,500 @@ | |
| + | /* 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> |
| + | */ |
| + | |
| + | #include "busybox.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" |
| + | |
| + | #define _PATH_PROCNET_ARP "/proc/net/arp" |
| + | |
| + | #define ARP_OPT_A (0x1) |
| + | #define ARP_OPT_p (0x2) |
| + | #define ARP_OPT_H (0x4) |
| + | #define ARP_OPT_t (0x8) |
| + | #define ARP_OPT_i (0x10) |
| + | #define ARP_OPT_a (0x20) |
| + | #define ARP_OPT_d (0x40) |
| + | #define ARP_OPT_n (0x80) /* do not resolve addresses */ |
| + | #define ARP_OPT_D (0x100) /* HW-address is devicename */ |
| + | #define ARP_OPT_s (0x200) |
| + | #define ARP_OPT_v (0x400 * DEBUG) /* debugging output flag */ |
| + | |
| + | |
| + | static const struct aftype *ap; /* current address family */ |
| + | static const struct hwtype *hw; /* current hardware type */ |
| + | static int sockfd; /* active socket descriptor */ |
| + | static smallint hw_set; /* flag if hw-type was set (-H) */ |
| + | static char *device = ""; /* current device */ |
| + | |
| + | static const char *const options[] = { |
| + | "pub", |
| + | "priv", |
| + | "temp", |
| + | "trail", |
| + | "dontpub", |
| + | "auto", |
| + | "dev", |
| + | "netmask", |
| + | NULL |
| + | }; |
| + | |
| + | /* Delete an entry from the ARP cache. */ |
| + | /* Called only from main, once */ |
| + | static int arp_del(char **args) |
| + | { |
| + | char host[128]; |
| + | struct arpreq req; |
| + | struct sockaddr sa; |
| + | int flags = 0; |
| + | int err; |
| + | |
| + | memset(&req, 0, sizeof(req)); |
| + | |
| + | /* Resolve the host name. */ |
| + | safe_strncpy(host, *args, 128); |
| + | if (ap->input(0, 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) { |
| + | if (option_mask32 & ARP_OPT_v) |
| + | bb_error_msg("args=%s", *args); |
| + | |
| + | switch (index_in_str_array(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) { |
| + | safe_strncpy(host, *args, 128); |
| + | if (ap->input(0, host, &sa) < 0) { |
| + | bb_herror_msg("%s", host); |
| + | return -1; |
| + | } |
| + | 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, const struct hwtype *hwt) |
| + | { |
| + | struct ifreq ifr; |
| + | const struct hwtype *xhw; |
| + | |
| + | strcpy(ifr.ifr_name, ifname); |
| + | if (ioctl(sockfd, SIOCGIFHWADDR, &ifr) < 0) { |
| + | bb_perror_msg_and_die("cant get HW-Address for '%s'", ifname); |
| + | } |
| + | if (hwt && (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((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[128]; |
| + | struct arpreq req; |
| + | struct sockaddr sa; |
| + | int flags; |
| + | |
| + | memset(&req, 0, sizeof(req)); |
| + | |
| + | safe_strncpy(host, *args++, 128); |
| + | if (ap->input(0, 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, hw_set ? hw : NULL); |
| + | } 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_str_array(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) { |
| + | safe_strncpy(host, *args++, 128); |
| + | if (ap->input(0, 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()"); |
| + | if (ioctl(sockfd, SIOCSARP, &req) < 0) { |
| + | bb_perror_msg_and_die("SIOCSARP"); |
| + | } |
| + | return 0; |
| + | } |
| + | |
| + | |
| + | /* Print the contents of an ARP request block. */ |
| + | static void |
| + | arp_disp(char *name, char *ip, int type, int arp_flags, |
| + | char *hwa, char *mask, char *dev) |
| + | { |
| + | 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); |
| + | |
| + | if (arp_flags & ATF_PERM) |
| + | printf("PERM "); |
| + | if (arp_flags & ATF_PUBL) |
| + | printf("PUP "); |
| + | #ifdef HAVE_ATF_MAGIC |
| + | if (arp_flags & ATF_MAGIC) |
| + | printf("AUTO "); |
| + | #endif |
| + | #ifdef HAVE_ATF_DONTPUB |
| + | if (arp_flags & ATF_DONTPUB) |
| + | printf("DONTPUB "); |
| + | #endif |
| + | if (arp_flags & ATF_USETRAILERS) |
| + | printf("TRAIL "); |
| + | |
| + | 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) |
| + | { |
| + | char host[100]; |
| + | struct sockaddr sa; |
| + | char ip[100]; |
| + | char hwa[100]; |
| + | char mask[100]; |
| + | char line[200]; |
| + | char dev[100]; |
| + | int type, flags; |
| + | FILE *fp; |
| + | char *hostname; |
| + | int num, entries = 0, shown = 0; |
| + | |
| + | host[0] = '\0'; |
| + | |
| + | if (name != NULL) { |
| + | /* Resolve the host name. */ |
| + | safe_strncpy(host, name, (sizeof host)); |
| + | if (ap->input(0, host, &sa) < 0) { |
| + | bb_herror_msg_and_die("%s", host); |
| + | } |
| + | safe_strncpy(host, ap->sprint(&sa, 1), sizeof(host)); |
| + | } |
| + | /* Open the PROCps kernel table. */ |
| + | fp = xfopen(_PATH_PROCNET_ARP, "r"); |
| + | /* Bypass header -- read until newline */ |
| + | if (fgets(line, sizeof(line), fp) != (char *) NULL) { |
| + | mask[0] = '-'; mask[1] = '\0'; |
| + | dev[0] = '-'; dev[1] = '\0'; |
| + | /* Read the ARP cache entries. */ |
| + | for (; fgets(line, sizeof(line), fp);) { |
| + | num = sscanf(line, "%s 0x%x 0x%x %100s %100s %100s\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[0] && strcmp(ip, host) != 0) |
| + | continue; |
| + | |
| + | /* if the user specified device differs, skip it */ |
| + | if (device && strcmp(dev, device) != 0) |
| + | continue; |
| + | |
| + | shown++; |
| + | /* This IS ugly but it works -be */ |
| + | if (option_mask32 & ARP_OPT_n) |
| + | hostname = "?"; |
| + | else { |
| + | if (ap->input(0, 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: %d\tSkipped: %d\tFound: %d\n", |
| + | entries, entries - shown, shown); |
| + | |
| + | if (!shown) { |
| + | if (hw_set || host[0] || device) |
| + | printf("No match found in %d entries\n", entries); |
| + | } |
| + | |
| + | fclose(fp); |
| + | |
| + | return 0; |
| + | } |
| + | |
| + | int arp_main(int argc, char **argv) |
| + | { |
| + | char *hw_type; |
| + | char *protocol; |
| + | |
| + | /* Initialize variables... */ |
| + | ap = get_aftype(DFLT_AF); |
| + | if (!ap) |
| + | bb_error_msg_and_die("%s: %s not supported", DFLT_AF, "address family"); |
| + | |
| + | getopt32(argc, argv, "A:p:H:t:i:adnDsv", &protocol, &protocol, |
| + | &hw_type, &hw_type, &device); |
| + | argv += optind; |
| + | if (option_mask32 & ARP_OPT_A || option_mask32 & ARP_OPT_p) { |
| + | ap = get_aftype(protocol); |
| + | if (ap == NULL) |
| + | bb_error_msg_and_die("%s: unknown %s", protocol, "address family"); |
| + | } |
| + | if (option_mask32 & ARP_OPT_A || option_mask32 & ARP_OPT_p) { |
| + | hw = get_hwtype(hw_type); |
| + | if (hw == NULL) |
| + | bb_error_msg_and_die("%s: unknown %s", hw_type, "hardware type"); |
| + | hw_set = 1; |
| + | } |
| + | //if (option_mask32 & ARP_OPT_i)... -i |
| + | |
| + | if (ap->af != AF_INET) { |
| + | bb_error_msg_and_die("%s: kernel only supports 'inet'", ap->name); |
| + | } |
| + | |
| + | /* If no hw type specified get default */ |
| + | if (!hw) { |
| + | hw = get_hwtype(DFLT_HW); |
| + | if (!hw) |
| + | bb_error_msg_and_die("%s: %s not supported", DFLT_HW, "hardware type"); |
| + | } |
| + | |
| + | if (hw->alen <= 0) { |
| + | bb_error_msg_and_die("%s: %s without ARP support", |
| + | hw->name, "hardware type"); |
| + | } |
| + | sockfd = xsocket(AF_INET, SOCK_DGRAM, 0); |
| + | |
| + | /* Now see what we have to do here... */ |
| + | if (option_mask32 & (ARP_OPT_d|ARP_OPT_s)) { |
| + | if (argv[0] == NULL) |
| + | bb_error_msg_and_die("need host name"); |
| + | if (option_mask32 & ARP_OPT_s) |
| + | return arp_set(argv); |
| + | return arp_del(argv); |
| + | } |
| + | //if (option_mask32 & ARP_OPT_a) - default |
| + | return arp_show(argv[0]); |
| + | } |