ether-wake: shorten help text, reduce packet buffer size

function                                             old     new   delta
ether_wake_main                                      726     727      +1
packed_usage                                       29468   29434     -34

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 10 insertions, 9 deletions

diff --git a/networking/ether-wake.c b/networking/ether-wake.c
index 2d389ea30..c38547dda 100644
--- a/networking/ether-wake.c
+++ b/networking/ether-wake.c
@@ -62,17 +62,17 @@
  *   An alternative to needing 'root' is using a UDP broadcast socket, however
  *   doing so only works with adapters configured for unicast+broadcast Rx
  *   filter.  That configuration consumes more power.
-*/
+ */
 
 //usage:#define ether_wake_trivial_usage
-//usage:       "[-b] [-i iface] [-p aa:bb:cc:dd[:ee:ff]] MAC"
+//usage:       "[-b] [-i IFACE] [-p aa:bb:cc:dd[:ee:ff]/a.b.c.d] MAC"
 //usage:#define ether_wake_full_usage "\n\n"
 //usage:       "Send a magic packet to wake up sleeping machines.\n"
 //usage:       "MAC must be a station address (00:11:22:33:44:55) or\n"
 //usage:       "a hostname with a known 'ethers' entry.\n"
-//usage:     "\n        -b              Send wake-up packet to the broadcast address"
-//usage:     "\n        -i iface        Interface to use (default eth0)"
-//usage:     "\n        -p pass         Append four or six byte password PW to the packet"
+//usage:     "\n        -b              Broadcast the packet"
+//usage:     "\n        -i IFACE        Interface to use (default eth0)"
+//usage:     "\n        -p PASSWORD     Append four or six byte PASSWORD to the packet"
 
 #include "libbb.h"
 #include <netpacket/packet.h>
@@ -130,7 +130,8 @@ static void get_dest_addr(const char *hostid, struct ether_addr *eaddr)
         }
 }
 
-static int get_fill(unsigned char *pkt, struct ether_addr *eaddr, int broadcast)
+#define PKT_HEADER_SIZE (20 + 16*6)
+static int fill_pkt_header(unsigned char *pkt, struct ether_addr *eaddr, int broadcast)
 {
         int i;
         unsigned char *station_addr = eaddr->ether_addr_octet;
@@ -153,7 +154,7 @@ static int get_fill(unsigned char *pkt, struct ether_addr *eaddr, int broadcast)
                 memcpy(pkt, station_addr, 6); /* 20,26,32,... */
         }
 
-        return 20 + 16*6; /* length of packet */
+        return PKT_HEADER_SIZE; /* length of packet */
 }
 
 static int get_wol_pw(const char *ethoptarg, unsigned char *wol_passwd)
@@ -195,7 +196,7 @@ int ether_wake_main(int argc UNUSED_PARAM, char **argv)
         int wol_passwd_sz = 0;
         int s;  /* Raw socket */
         int pktsize;
-        unsigned char outpack[1000];
+        unsigned char outpack[PKT_HEADER_SIZE + 6 /* max passwd size */ + 16 /* paranoia */];
 
         struct ether_addr eaddr;
         struct whereto_t whereto;  /* who to wake up */
@@ -217,7 +218,7 @@ int ether_wake_main(int argc UNUSED_PARAM, char **argv)
         get_dest_addr(argv[optind], &eaddr);
 
         /* fill out the header of the packet */
-        pktsize = get_fill(outpack, &eaddr, flags /* & 1 OPT_BROADCAST */);
+        pktsize = fill_pkt_header(outpack, &eaddr, flags /* & 1 OPT_BROADCAST */);
 
         bb_debug_dump_packet(outpack, pktsize);