X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=networking%2Farping.c;h=a4421edcba01570a952bdfdd54590276266c2c49;hb=a38f9faa9fa230eb3753381c4f626acf029379fb;hp=7a9fbc2f447a0907fc422644cfe0736947aaef80;hpb=bd7bb299c0e9ee5ff52c9d12b46fb14a907b34da;p=oweals%2Fbusybox.git diff --git a/networking/arping.c b/networking/arping.c index 7a9fbc2f4..a4421edcb 100644 --- a/networking/arping.c +++ b/networking/arping.c @@ -1,13 +1,27 @@ /* 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 Duplicated address detection mode" +//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 Time to wait for ARP reply, seconds" +//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 @@ -18,12 +32,6 @@ /* We don't expect to see 1000+ seconds delay, unsigned is enough */ #define MONOTONIC_US() ((unsigned)monotonic_us()) -static struct in_addr src; -static struct in_addr dst; -static struct sockaddr_ll me; -static struct sockaddr_ll he; -static unsigned last; - enum { DAD = 1, UNSOLICITED = 2, @@ -34,51 +42,78 @@ enum { UNICASTING = 64 }; -static int sock; -static unsigned count = UINT_MAX; -static unsigned timeout_us; -static unsigned sent; -static unsigned brd_sent; -static unsigned received; -static unsigned brd_recv; -static unsigned req_recv; +struct globals { + struct in_addr src; + struct in_addr dst; + struct sockaddr_ll me; + struct sockaddr_ll he; + int sock_fd; + + int count; // = -1; + unsigned last; + unsigned timeout_us; + unsigned start; + + unsigned sent; + unsigned brd_sent; + unsigned received; + unsigned brd_recv; + unsigned req_recv; +} 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_fd (G.sock_fd ) +#define count (G.count ) +#define last (G.last ) +#define timeout_us (G.timeout_us) +#define start (G.start ) +#define sent (G.sent ) +#define brd_sent (G.brd_sent ) +#define received (G.received ) +#define brd_recv (G.brd_recv ) +#define req_recv (G.req_recv ) +#define INIT_G() do { \ + 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++; @@ -86,7 +121,7 @@ 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)) { @@ -100,24 +135,24 @@ static void finish(void) if (option_mask32 & DAD) exit(!!received); if (option_mask32 & UNSOLICITED) - exit(0); + exit(EXIT_SUCCESS); exit(!received); } static void catcher(void) { - static unsigned start; - unsigned now; now = MONOTONIC_US(); 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--; + /* count < 0 means "infinite count" */ + if (count > 0) + count--; if (last == 0 || (now - last) > 500000) { send_pack(&src, &dst, &me, &he); @@ -127,45 +162,52 @@ static void catcher(void) alarm(1); } -static int recv_pack(unsigned char *buf, int len, struct sockaddr_ll *FROM) +static bool 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 false; - /* 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 false; /* 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 false; /* 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 false; + + 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 false; 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 false; } else { /* DAD packet was: src_ip = 0 (or some src) @@ -180,12 +222,9 @@ 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 false; } if (!(option_mask32 & QUIET)) { int s_printed = 0; @@ -207,11 +246,12 @@ static int recv_pack(unsigned char *buf, int len, struct sockaddr_ll *FROM) } 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"); } - fflush(stdout); + fflush_all(); } received++; if (FROM->sll_pkttype != PACKET_HOST) @@ -224,42 +264,39 @@ 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; + return true; } -int arping_main(int argc, char **argv); -int arping_main(int argc, char **argv) +int arping_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; +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; - sock = xsocket(PF_PACKET, SOCK_DGRAM, 0); + INIT_G(); + + 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()); + err_str = xasprintf("interface %s %%s", device); { 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(argc, argv, "DUAqfbc:w:I:s:", - &str_count, &str_timeout, &device, &source); - if (opt & 0x40) /* -c: count */ - count = xatou(str_count); + opt_complementary = "=1:Df:AU:c+"; + 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; - //if (opt & 0x100) /* -I: interface */ - if (strlen(device) >= IF_NAMESIZE) { - bb_error_msg_and_die("interface name '%s' is too long", - device); - } + timeout_us = xatou_range(str_timeout, 0, INT_MAX/2000000) * 1000000 + 500000; //if (opt & 0x200) /* -s: source */ option_mask32 &= 0x3f; /* set respective flags */ } @@ -272,28 +309,27 @@ int arping_main(int argc, char **argv) struct ifreq ifr; memset(&ifr, 0, sizeof(ifr)); - strncpy(ifr.ifr_name, device, IFNAMSIZ - 1); - if (ioctl(sock, SIOCGIFINDEX, &ifr) < 0) { - bb_error_msg_and_die("interface %s not found", device); - } - ifindex = ifr.ifr_ifindex; + 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_fd, SIOCGIFINDEX, &ifr, err_str, "not found"); + me.sll_ifindex = ifr.ifr_ifindex; + + xioctl(sock_fd, SIOCGIFFLAGS, (char *) &ifr); - if (ioctl(sock, SIOCGIFFLAGS, (char *) &ifr)) { - bb_error_msg_and_die("SIOCGIFFLAGS"); - } 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); } @@ -302,80 +338,68 @@ 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_error_msg("warning: interface %s is ignored", 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("warning: setsockopt(SO_DONTROUTE)"); + bb_perror_msg("setsockopt(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 (!(option_mask32 & QUIET)) { - printf("ARPING to %s from %s via %s\n", - inet_ntoa(dst), inet_ntoa(src), - device ? device : "unknown"); - } - - if (!src.s_addr && !(option_mask32 & DAD)) { - bb_error_msg_and_die("no src address in the non-DAD mode"); + /* 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(); @@ -386,7 +410,7 @@ 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;