pppoe-discovery: show real usage information

[ppp.git] / pppd / plugins / rp-pppoe / pppoe-discovery.c

diff --git a/pppd/plugins/rp-pppoe/pppoe-discovery.c b/pppd/plugins/rp-pppoe/pppoe-discovery.c
index 318f8583f98b246d99482330e7e33e3429c3f416..3c19dfa0031c105e0416d58ee489a34edd6445a0 100644 (file)
--- a/pppd/plugins/rp-pppoe/pppoe-discovery.c
+++ b/pppd/plugins/rp-pppoe/pppoe-discovery.c
@@ -9,6 +9,7 @@
  *
  */
 
+#include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
@@ -55,6 +56,14 @@ void die(int status)
        exit(status);
 }
 
+void error(char *fmt, ...)
+{
+    va_list pvar;
+    va_start(pvar, fmt);
+    vfprintf(stderr, fmt, pvar);
+    va_end(pvar);
+}
+
 /* Initialize frame types to RFC 2516 values.  Some broken peers apparently
    use different frame types... sigh... */
 
@@ -277,7 +286,7 @@ parsePacket(PPPoEPacket *packet, ParseFunc *func, void *extra)
     }
 
     /* Do some sanity checks on packet */
-    if (len > ETH_DATA_LEN - 6) { /* 6-byte overhead for PPPoE header */
+    if (len > ETH_JUMBO_LEN - PPPOE_OVERHEAD) { /* 6-byte overhead for PPPoE header */
        fprintf(stderr, "Invalid PPPoE packet length (%u)\n", len);
        return -1;
     }
@@ -720,5 +729,14 @@ char *xstrdup(const char *s)
 void usage(void)
 {
     fprintf(stderr, "Usage: pppoe-discovery [options]\n");
+    fprintf(stderr, "Options:\n");
+    fprintf(stderr, "   -I if_name     -- Specify interface (default eth0)\n");
+    fprintf(stderr, "   -D filename    -- Log debugging information in filename.\n");
+    fprintf(stderr,
+           "   -V             -- Print version and exit.\n"
+           "   -S name        -- Set desired service name.\n"
+           "   -C name        -- Set desired access concentrator name.\n"
+           "   -U             -- Use Host-Unique to allow multiple PPPoE sessions.\n"
+           "   -h             -- Print usage information.\n");
     fprintf(stderr, "\nVersion " RP_VERSION "\n");
 }