DCCP: Fix printing "Timestamp" and "Timestamp Echo" options

Add some comments.

Moreover:
Put a function definition name at the beginning of the line.

diff --git a/print-dccp.c b/print-dccp.c
index 11c6d750a370a04cbdcfc8b308bbc58fe3ed7276..407ec2dd773064c5089797bb3b4bf996d511b190 100644 (file)
--- a/print-dccp.c
+++ b/print-dccp.c
@@ -537,7 +537,8 @@ static const struct tok dccp_option_values[] = {
        { 0, NULL }
 };
 
-static u_int dccp_print_option(netdissect_options *ndo, const u_char *option, u_int hlen)
+static u_int
+dccp_print_option(netdissect_options *ndo, const u_char *option, u_int hlen)
 {
        uint8_t optlen, i;
 
@@ -630,16 +631,54 @@ static u_int dccp_print_option(netdissect_options *ndo, const u_char *option, u_
                        }
                        break;
                case 41:
-                       if (optlen == 4)
+               /*
+                * 13.1.  Timestamp Option
+                *
+                *  +--------+--------+--------+--------+--------+--------+
+                *  |00101001|00000110|          Timestamp Value          |
+                *  +--------+--------+--------+--------+--------+--------+
+                *   Type=41  Length=6
+                */
+                       if (optlen == 6)
                                ND_PRINT(" %u", EXTRACT_BE_U_4(option + 2));
                        else
-                               ND_PRINT(" optlen != 4");
+                               ND_PRINT(" [optlen != 6]");
                        break;
                case 42:
-                       if (optlen == 4)
+               /*
+                * 13.3.  Timestamp Echo Option
+                *
+                *  +--------+--------+--------+--------+--------+--------+
+                *  |00101010|00000110|           Timestamp Echo          |
+                *  +--------+--------+--------+--------+--------+--------+
+                *   Type=42    Len=6
+                *
+                *  +--------+--------+------- ... -------+--------+--------+
+                *  |00101010|00001000|  Timestamp Echo   |   Elapsed Time  |
+                *  +--------+--------+------- ... -------+--------+--------+
+                *   Type=42    Len=8       (4 bytes)
+                *
+                *  +--------+--------+------- ... -------+------- ... -------+
+                *  |00101010|00001010|  Timestamp Echo   |    Elapsed Time   |
+                *  +--------+--------+------- ... -------+------- ... -------+
+                *   Type=42   Len=10       (4 bytes)           (4 bytes)
+                */
+                       switch (optlen) {
+                       case 6:
                                ND_PRINT(" %u", EXTRACT_BE_U_4(option + 2));
-                       else
-                               ND_PRINT(" optlen != 4");
+                               break;
+                       case 8:
+                               ND_PRINT(" %u", EXTRACT_BE_U_4(option + 2));
+                               ND_PRINT(" (elapsed time %u)", EXTRACT_BE_U_2(option + 6));
+                               break;
+                       case 10:
+                               ND_PRINT(" %u", EXTRACT_BE_U_4(option + 2));
+                               ND_PRINT(" (elapsed time %u)", EXTRACT_BE_U_4(option + 6));
+                               break;
+                       default:
+                               ND_PRINT(" [optlen != 6 or 8 or 10]");
+                               break;
+                       }
                        break;
                case 43:
                        if (optlen == 6)
@@ -647,7 +686,7 @@ static u_int dccp_print_option(netdissect_options *ndo, const u_char *option, u_
                        else if (optlen == 4)
                                ND_PRINT(" %u", EXTRACT_BE_U_2(option + 2));
                        else
-                               ND_PRINT(" optlen != 4 or 6");
+                               ND_PRINT(" [optlen != 4 or 6]");
                        break;
                case 44:
                        if (optlen > 2) {