b5257a670
Denys Vlasenko
2018-02-11
Subject
arping: code shrink
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Commit Diff GitHub →
networking/arping.c+20 -19
| @@ -28,6 +28,7 @@ | |
| //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" | |
| + | //NB: in iputils-s20160308, iface is mandatory, no default |
| //usage: "\n -I IFACE Interface to use (default eth0)" | |
| //usage: "\n -s SRC_IP Sender IP address" | |
| //usage: "\n DST_IP Target IP address" | |
| @@ -56,8 +57,8 @@ enum { | |
| #define GETOPT32(str_timeout, device, source) \ | |
| getopt32(argv, "^" \ | |
| "UDAqfbc:+w:I:s:" \ | |
| - | /* Dad also sets quit_on_reply, */ \ |
| - | /* Advert also sets unsolicited: */ \ |
| + | /* DAD also sets quit_on_reply, */ \ |
| + | /* advert also sets unsolicited: */ \ |
| "\0" "=1:Df:AU", \ | |
| &count, &str_timeout, &device, &source \ | |
| ); | |
| @@ -67,7 +68,6 @@ struct globals { | |
| struct in_addr dst; | |
| struct sockaddr_ll me; | |
| struct sockaddr_ll he; | |
| - | int sock_fd; |
| int count; // = -1; | |
| unsigned last; | |
| @@ -80,7 +80,9 @@ struct globals { | |
| unsigned brd_recv; | |
| unsigned req_recv; | |
| + | /* should be in main(), but are here to reduce stack use: */ |
| struct ifreq ifr; | |
| + | struct sockaddr_in probe_saddr; |
| sigset_t sset; | |
| unsigned char packet[4096]; | |
| } FIX_ALIASING; | |
| @@ -88,7 +90,6 @@ struct globals { | |
| #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) | |
| @@ -106,6 +107,8 @@ struct globals { | |
| count = -1; \ | |
| } while (0) | |
| + | #define sock_fd 3 |
| + | |
| static int send_pack(struct in_addr *src_addr, | |
| struct in_addr *dst_addr, | |
| struct sockaddr_ll *ME, | |
| @@ -299,7 +302,7 @@ int arping_main(int argc UNUSED_PARAM, char **argv) | |
| INIT_G(); | |
| - | sock_fd = xsocket(AF_PACKET, SOCK_DGRAM, 0); |
| + | xmove_fd(xsocket(AF_PACKET, SOCK_DGRAM, 0), sock_fd); |
| // If you ever change BB_SUID_DROP to BB_SUID_REQUIRE, | |
| // drop suid root privileges here: | |
| @@ -351,31 +354,29 @@ int arping_main(int argc UNUSED_PARAM, char **argv) | |
| src = dst; | |
| if (!(option_mask32 & DAD) || src.s_addr) { | |
| - | struct sockaddr_in saddr; |
| + | /*struct sockaddr_in probe_saddr;*/ |
| int probe_fd = xsocket(AF_INET, SOCK_DGRAM, 0); | |
| setsockopt_bindtodevice(probe_fd, device); | |
| - | memset(&saddr, 0, sizeof(saddr)); |
| - | saddr.sin_family = AF_INET; |
| + | |
| + | /*memset(&G.probe_saddr, 0, sizeof(G.probe_saddr)); - zeroed by INIT_G */ |
| + | G.probe_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)); |
| + | G.probe_saddr.sin_addr = src; |
| + | xbind(probe_fd, (struct sockaddr *) &G.probe_saddr, sizeof(G.probe_saddr)); |
| } else { /* !(option_mask32 & DAD) case */ | |
| /* Find IP address on this iface */ | |
| - | saddr.sin_port = htons(1025); |
| - | saddr.sin_addr = dst; |
| + | G.probe_saddr.sin_port = htons(1025); |
| + | G.probe_saddr.sin_addr = dst; |
| 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)); |
| - | bb_getsockname(probe_fd, (struct sockaddr *) &saddr, sizeof(saddr)); |
| - | //never happens: |
| - | //if (getsockname(probe_fd, (struct sockaddr *) &saddr, &alen) == -1) |
| - | // bb_perror_msg_and_die("getsockname"); |
| - | if (saddr.sin_family != AF_INET) |
| + | xconnect(probe_fd, (struct sockaddr *) &G.probe_saddr, sizeof(G.probe_saddr)); |
| + | bb_getsockname(probe_fd, (struct sockaddr *) &G.probe_saddr, sizeof(G.probe_saddr)); |
| + | if (G.probe_saddr.sin_family != AF_INET) |
| bb_error_msg_and_die("no IP address configured"); | |
| - | src = saddr.sin_addr; |
| + | src = G.probe_saddr.sin_addr; |
| } | |
| close(probe_fd); | |
| } | |