X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=networking%2Farping.c;h=46bd65e3610207e9c0ed8fa89c454780f0bdcf9e;hb=b6d421b635670939e4ec047543f84cb507e5fe9d;hp=771c3bccd4d56a1b7e3b09e907bfb9a5c55d40ba;hpb=fff9b699f19bf4e687b755f3a0faecbe958258a9;p=oweals%2Fbusybox.git diff --git a/networking/arping.c b/networking/arping.c index 771c3bccd..46bd65e36 100644 --- a/networking/arping.c +++ b/networking/arping.c @@ -1,19 +1,34 @@ /* vi: set sw=4 ts=4: */ /* - * arping.c - Ping hosts by ARP requests/replies + * Licensed under GPLv2 or later, see file LICENSE in this source tree. * - * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. - * - * Author: Alexey Kuznetsov + * Author: Alexey Kuznetsov * Busybox port: Nick Fedchik */ +//usage:#define arping_trivial_usage +//usage: "[-fqbDUA] [-c CNT] [-w TIMEOUT] [-I IFACE] [-s SRC_IP] DST_IP" +//usage:#define arping_full_usage "\n\n" +//usage: "Send ARP requests/replies\n" +//usage: "\n -f Quit on first ARP reply" +//usage: "\n -q Quiet" +//usage: "\n -b Keep broadcasting, don't go unicast" +//usage: "\n -D Exit with 1 if DST_IP replies" +//usage: "\n -U Unsolicited ARP mode, update your neighbors" +//usage: "\n -A ARP answer mode, update your neighbors" +//usage: "\n -c N Stop after sending N ARP requests" +//usage: "\n -w TIMEOUT Seconds to wait for ARP reply" +//usage: "\n -I IFACE Interface to use (default eth0)" +//usage: "\n -s SRC_IP Sender IP address" +//usage: "\n DST_IP Target IP address" + #include #include #include #include #include "libbb.h" +#include "common_bufsiz.h" /* We don't expect to see 1000+ seconds delay, unsigned is enough */ #define MONOTONIC_US() ((unsigned)monotonic_us()) @@ -33,7 +48,7 @@ struct globals { struct in_addr dst; struct sockaddr_ll me; struct sockaddr_ll he; - int sock; + int sock_fd; int count; // = -1; unsigned last; @@ -45,13 +60,13 @@ struct globals { unsigned received; unsigned brd_recv; unsigned req_recv; -}; -#define G (*(struct globals*)&bb_common_bufsiz1) +} FIX_ALIASING; +#define G (*(struct globals*)bb_common_bufsiz1) #define src (G.src ) #define dst (G.dst ) #define me (G.me ) #define he (G.he ) -#define sock (G.sock ) +#define sock_fd (G.sock_fd ) #define count (G.count ) #define last (G.last ) #define timeout_us (G.timeout_us) @@ -61,47 +76,46 @@ struct globals { #define received (G.received ) #define brd_recv (G.brd_recv ) #define req_recv (G.req_recv ) -#define INIT_G() \ - do { \ - count = -1; \ - } while (0) +#define INIT_G() do { \ + setup_common_bufsiz(); \ + count = -1; \ +} while (0) + +// If GNUisms are not available... +//static void *mempcpy(void *_dst, const void *_src, int n) +//{ +// memcpy(_dst, _src, n); +// return (char*)_dst + n; +//} static int send_pack(struct in_addr *src_addr, struct in_addr *dst_addr, struct sockaddr_ll *ME, struct sockaddr_ll *HE) { int err; - unsigned now; unsigned char buf[256]; struct arphdr *ah = (struct arphdr *) buf; unsigned char *p = (unsigned char *) (ah + 1); - ah->ar_hrd = htons(ME->sll_hatype); ah->ar_hrd = htons(ARPHRD_ETHER); ah->ar_pro = htons(ETH_P_IP); ah->ar_hln = ME->sll_halen; ah->ar_pln = 4; ah->ar_op = option_mask32 & ADVERT ? htons(ARPOP_REPLY) : htons(ARPOP_REQUEST); - memcpy(p, &ME->sll_addr, ah->ar_hln); - p += ME->sll_halen; - - memcpy(p, src_addr, 4); - p += 4; + p = mempcpy(p, &ME->sll_addr, ah->ar_hln); + p = mempcpy(p, src_addr, 4); if (option_mask32 & ADVERT) - memcpy(p, &ME->sll_addr, ah->ar_hln); + p = mempcpy(p, &ME->sll_addr, ah->ar_hln); else - memcpy(p, &HE->sll_addr, ah->ar_hln); - p += ah->ar_hln; + p = mempcpy(p, &HE->sll_addr, ah->ar_hln); - memcpy(p, dst_addr, 4); - p += 4; + p = mempcpy(p, dst_addr, 4); - now = MONOTONIC_US(); - err = sendto(sock, buf, p - buf, 0, (struct sockaddr *) HE, sizeof(*HE)); + err = sendto(sock_fd, buf, p - buf, 0, (struct sockaddr *) HE, sizeof(*HE)); if (err == p - buf) { - last = now; + last = MONOTONIC_US(); sent++; if (!(option_mask32 & UNICASTING)) brd_sent++; @@ -109,7 +123,7 @@ static int send_pack(struct in_addr *src_addr, return err; } -static void finish(void) ATTRIBUTE_NORETURN; +static void finish(void) NORETURN; static void finish(void) { if (!(option_mask32 & QUIET)) { @@ -123,7 +137,7 @@ static void finish(void) if (option_mask32 & DAD) exit(!!received); if (option_mask32 & UNSOLICITED) - exit(0); + exit(EXIT_SUCCESS); exit(!received); } @@ -135,7 +149,7 @@ static void catcher(void) if (start == 0) start = now; - if (count == 0 || (timeout_us && (now - start) > (timeout_us + 500000))) + if (count == 0 || (timeout_us && (now - start) > timeout_us)) finish(); /* count < 0 means "infinite count" */ @@ -150,45 +164,52 @@ static void catcher(void) alarm(1); } -static int recv_pack(unsigned char *buf, int len, struct sockaddr_ll *FROM) +static void recv_pack(unsigned char *buf, int len, struct sockaddr_ll *FROM) { struct arphdr *ah = (struct arphdr *) buf; unsigned char *p = (unsigned char *) (ah + 1); struct in_addr src_ip, dst_ip; + /* moves below assume in_addr is 4 bytes big, ensure that */ + struct BUG_in_addr_must_be_4 { + char BUG_in_addr_must_be_4[ + sizeof(struct in_addr) == 4 ? 1 : -1 + ]; + char BUG_s_addr_must_be_4[ + sizeof(src_ip.s_addr) == 4 ? 1 : -1 + ]; + }; /* Filter out wild packets */ if (FROM->sll_pkttype != PACKET_HOST && FROM->sll_pkttype != PACKET_BROADCAST && FROM->sll_pkttype != PACKET_MULTICAST) - return 0; + return; - /* Only these types are recognised */ + /* Only these types are recognized */ if (ah->ar_op != htons(ARPOP_REQUEST) && ah->ar_op != htons(ARPOP_REPLY)) - return 0; + return; /* ARPHRD check and this darned FDDI hack here :-( */ if (ah->ar_hrd != htons(FROM->sll_hatype) && (FROM->sll_hatype != ARPHRD_FDDI || ah->ar_hrd != htons(ARPHRD_ETHER))) - return 0; + return; /* Protocol must be IP. */ - if (ah->ar_pro != htons(ETH_P_IP)) - return 0; - if (ah->ar_pln != 4) - return 0; - if (ah->ar_hln != me.sll_halen) - return 0; - if (len < sizeof(*ah) + 2 * (4 + ah->ar_hln)) - return 0; - memcpy(&src_ip, p + ah->ar_hln, 4); - memcpy(&dst_ip, p + ah->ar_hln + 4 + ah->ar_hln, 4); + if (ah->ar_pro != htons(ETH_P_IP) + || (ah->ar_pln != 4) + || (ah->ar_hln != me.sll_halen) + || (len < (int)(sizeof(*ah) + 2 * (4 + ah->ar_hln)))) + return; + + move_from_unaligned32(src_ip.s_addr, p + ah->ar_hln); + move_from_unaligned32(dst_ip.s_addr, p + ah->ar_hln + 4 + ah->ar_hln); + + if (dst.s_addr != src_ip.s_addr) + return; if (!(option_mask32 & DAD)) { - if (src_ip.s_addr != dst.s_addr) - return 0; - if (src.s_addr != dst_ip.s_addr) - return 0; - if (memcmp(p + ah->ar_hln + 4, &me.sll_addr, ah->ar_hln)) - return 0; + if ((src.s_addr != dst_ip.s_addr) + || (memcmp(p + ah->ar_hln + 4, &me.sll_addr, ah->ar_hln))) + return; } else { /* DAD packet was: src_ip = 0 (or some src) @@ -203,38 +224,39 @@ static int recv_pack(unsigned char *buf, int len, struct sockaddr_ll *FROM) also that it matches to dst_ip, otherwise dst_ip/dst_hw do not matter. */ - if (src_ip.s_addr != dst.s_addr) - return 0; - if (memcmp(p, &me.sll_addr, me.sll_halen) == 0) - return 0; - if (src.s_addr && src.s_addr != dst_ip.s_addr) - return 0; + if ((memcmp(p, &me.sll_addr, me.sll_halen) == 0) + || (src.s_addr && src.s_addr != dst_ip.s_addr)) + return; } if (!(option_mask32 & QUIET)) { int s_printed = 0; - printf("%scast re%s from %s [%s]", + printf("%scast re%s from %s [%02x:%02x:%02x:%02x:%02x:%02x]", FROM->sll_pkttype == PACKET_HOST ? "Uni" : "Broad", ah->ar_op == htons(ARPOP_REPLY) ? "ply" : "quest", inet_ntoa(src_ip), - ether_ntoa((struct ether_addr *) p)); + p[0], p[1], p[2], p[3], p[4], p[5] + ); if (dst_ip.s_addr != src.s_addr) { printf("for %s ", inet_ntoa(dst_ip)); s_printed = 1; } if (memcmp(p + ah->ar_hln + 4, me.sll_addr, ah->ar_hln)) { + unsigned char *pp = p + ah->ar_hln + 4; if (!s_printed) printf("for "); - printf("[%s]", - ether_ntoa((struct ether_addr *) p + ah->ar_hln + 4)); + printf("[%02x:%02x:%02x:%02x:%02x:%02x]", + pp[0], pp[1], pp[2], pp[3], pp[4], pp[5] + ); } if (last) { - printf(" %u.%03ums\n", last / 1000, last % 1000); + unsigned diff = MONOTONIC_US() - last; + printf(" %u.%03ums\n", diff / 1000, diff % 1000); } else { - printf(" UNSOLICITED?\n"); + puts(" UNSOLICITED?"); } - fflush(stdout); + fflush_all(); } received++; if (FROM->sll_pkttype != PACKET_HOST) @@ -247,72 +269,70 @@ static int recv_pack(unsigned char *buf, int len, struct sockaddr_ll *FROM) memcpy(he.sll_addr, p, me.sll_halen); option_mask32 |= UNICASTING; } - return 1; } int arping_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; -int arping_main(int argc, char **argv) +int arping_main(int argc UNUSED_PARAM, char **argv) { const char *device = "eth0"; - int ifindex; char *source = NULL; char *target; unsigned char *packet; + char *err_str; INIT_G(); - sock = xsocket(PF_PACKET, SOCK_DGRAM, 0); + sock_fd = xsocket(AF_PACKET, SOCK_DGRAM, 0); // Drop suid root privileges - xsetuid(getuid()); + // Need to remove SUID_NEVER from applets.h for this to work + //xsetuid(getuid()); { unsigned opt; - char *str_count, *str_timeout; + char *str_timeout; /* Dad also sets quit_on_reply. * Advert also sets unsolicited. */ opt_complementary = "=1:Df:AU"; - opt = getopt32(argv, "DUAqfbc:w:I:s:", - &str_count, &str_timeout, &device, &source); - if (opt & 0x40) /* -c: count */ - count = xatoi_u(str_count); + opt = getopt32(argv, "DUAqfbc:+w:I:s:", + &count, &str_timeout, &device, &source); if (opt & 0x80) /* -w: timeout */ - timeout_us = xatou_range(str_timeout, 0, INT_MAX/2000000) * 1000000; + timeout_us = xatou_range(str_timeout, 0, INT_MAX/2000000) * 1000000 + 500000; //if (opt & 0x200) /* -s: source */ option_mask32 &= 0x3f; /* set respective flags */ } target = argv[optind]; - + err_str = xasprintf("interface %s %%s", device); xfunc_error_retval = 2; { struct ifreq ifr; memset(&ifr, 0, sizeof(ifr)); - strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name) - 1); + strncpy_IFNAMSIZ(ifr.ifr_name, device); /* We use ifr.ifr_name in error msg so that problem * with truncated name will be visible */ - ioctl_or_perror_and_die(sock, SIOCGIFINDEX, &ifr, "interface %s not found", ifr.ifr_name); - ifindex = ifr.ifr_ifindex; + ioctl_or_perror_and_die(sock_fd, SIOCGIFINDEX, &ifr, err_str, "not found"); + me.sll_ifindex = ifr.ifr_ifindex; - xioctl(sock, SIOCGIFFLAGS, (char *) &ifr); + xioctl(sock_fd, SIOCGIFFLAGS, (char *) &ifr); if (!(ifr.ifr_flags & IFF_UP)) { - bb_error_msg_and_die("interface %s is down", device); + bb_error_msg_and_die(err_str, "is down"); } if (ifr.ifr_flags & (IFF_NOARP | IFF_LOOPBACK)) { - bb_error_msg("interface %s is not ARPable", device); + bb_error_msg(err_str, "is not ARPable"); return (option_mask32 & DAD ? 0 : 2); } } - if (!inet_aton(target, &dst)) { + /* if (!inet_aton(target, &dst)) - not needed */ { len_and_sockaddr *lsa; lsa = xhost_and_af2sockaddr(target, 0, AF_INET); - memcpy(&dst, &lsa->sin.sin_addr.s_addr, 4); + dst = lsa->u.sin.sin_addr; if (ENABLE_FEATURE_CLEAN_UP) free(lsa); } @@ -321,80 +341,68 @@ int arping_main(int argc, char **argv) bb_error_msg_and_die("invalid source address %s", source); } - if (!(option_mask32 & DAD) && (option_mask32 & UNSOLICITED) && src.s_addr == 0) + if ((option_mask32 & (DAD|UNSOLICITED)) == UNSOLICITED && src.s_addr == 0) src = dst; if (!(option_mask32 & DAD) || src.s_addr) { struct sockaddr_in saddr; int probe_fd = xsocket(AF_INET, SOCK_DGRAM, 0); - if (device) { - if (setsockopt(probe_fd, SOL_SOCKET, SO_BINDTODEVICE, device, strlen(device) + 1) == -1) - bb_perror_msg("cannot bind to device %s", device); - } + setsockopt_bindtodevice(probe_fd, device); memset(&saddr, 0, sizeof(saddr)); saddr.sin_family = AF_INET; if (src.s_addr) { + /* Check that this is indeed our IP */ saddr.sin_addr = src; xbind(probe_fd, (struct sockaddr *) &saddr, sizeof(saddr)); - } else if (!(option_mask32 & DAD)) { + } else { /* !(option_mask32 & DAD) case */ + /* Find IP address on this iface */ socklen_t alen = sizeof(saddr); saddr.sin_port = htons(1025); saddr.sin_addr = dst; - if (setsockopt(probe_fd, SOL_SOCKET, SO_DONTROUTE, &const_int_1, sizeof(const_int_1)) == -1) - bb_perror_msg("setsockopt(SO_DONTROUTE)"); + if (setsockopt_SOL_SOCKET_1(probe_fd, SO_DONTROUTE) != 0) + bb_perror_msg("setsockopt(%s)", "SO_DONTROUTE"); xconnect(probe_fd, (struct sockaddr *) &saddr, sizeof(saddr)); - if (getsockname(probe_fd, (struct sockaddr *) &saddr, &alen) == -1) { - bb_error_msg_and_die("getsockname"); - } + getsockname(probe_fd, (struct sockaddr *) &saddr, &alen); + //never happens: + //if (getsockname(probe_fd, (struct sockaddr *) &saddr, &alen) == -1) + // bb_perror_msg_and_die("getsockname"); + if (saddr.sin_family != AF_INET) + bb_error_msg_and_die("no IP address configured"); src = saddr.sin_addr; } close(probe_fd); } me.sll_family = AF_PACKET; - me.sll_ifindex = ifindex; + //me.sll_ifindex = ifindex; - done before me.sll_protocol = htons(ETH_P_ARP); - xbind(sock, (struct sockaddr *) &me, sizeof(me)); + xbind(sock_fd, (struct sockaddr *) &me, sizeof(me)); { socklen_t alen = sizeof(me); - - if (getsockname(sock, (struct sockaddr *) &me, &alen) == -1) { - bb_error_msg_and_die("getsockname"); - } + getsockname(sock_fd, (struct sockaddr *) &me, &alen); + //never happens: + //if (getsockname(sock_fd, (struct sockaddr *) &me, &alen) == -1) + // bb_perror_msg_and_die("getsockname"); } if (me.sll_halen == 0) { - bb_error_msg("interface %s is not ARPable (no ll address)", device); + bb_error_msg(err_str, "is not ARPable (no ll address)"); return (option_mask32 & DAD ? 0 : 2); } he = me; memset(he.sll_addr, -1, he.sll_halen); - if (!src.s_addr && !(option_mask32 & DAD)) { - bb_error_msg_and_die("no src address in the non-DAD mode"); - } - if (!(option_mask32 & QUIET)) { - printf("ARPING to %s from %s via %s\n", - inet_ntoa(dst), inet_ntoa(src), - device ? device : "unknown"); + /* inet_ntoa uses static storage, can't use in same printf */ + printf("ARPING to %s", inet_ntoa(dst)); + printf(" from %s via %s\n", inet_ntoa(src), device); } - { - struct sigaction sa; - - memset(&sa, 0, sizeof(sa)); - sa.sa_flags = SA_RESTART; - - sa.sa_handler = (void (*)(int)) finish; - sigaction(SIGINT, &sa, NULL); - - sa.sa_handler = (void (*)(int)) catcher; - sigaction(SIGALRM, &sa, NULL); - } + signal_SA_RESTART_empty_mask(SIGINT, (void (*)(int))finish); + signal_SA_RESTART_empty_mask(SIGALRM, (void (*)(int))catcher); catcher(); @@ -405,7 +413,7 @@ int arping_main(int argc, char **argv) socklen_t alen = sizeof(from); int cc; - cc = recvfrom(sock, packet, 4096, 0, (struct sockaddr *) &from, &alen); + cc = recvfrom(sock_fd, packet, 4096, 0, (struct sockaddr *) &from, &alen); if (cc < 0) { bb_perror_msg("recvfrom"); continue;