Re: [tcpdump-workers] [PATCH] DCCP - print all ACKs

[Hannes Gredler]

checked into HEAD;

who is going to receive credit/blame for this patch ?

andrea, ian or both ?

tx, /hannes

Ian McDonald wrote:

Hi there folks,

Andrea Bittau picked up we weren't displaying ACKs for close packets
and provided a preliminary patch.

I've gone through the spec and reworked the patch slightly and it now
prints for all relevant packets.

This patch is against latest weekly CVS of tcpdump - 2005.10.03

Can this please be added to tcpdump?

Regards,

Ian
--
Ian McDonald
http://wand.net.nz/~iam4
WAND Network Research Group
University of Waikato
New Zealand


------------------------------------------------------------------------

diff -uprN -X dontdiff tcpdump-2005.10.03/print-dccp.c dccpdump/print-dccp.c
--- tcpdump-2005.10.03/print-dccp.c     2005-09-20 18:25:20.000000000 +1200
+++ dccpdump/print-dccp.c       2005-11-04 12:06:48.000000000 +1300
@@ -155,25 +155,32 @@ static u_int64_t dccp_seqno(const struct
        return seqno;
 }

-static u_int64_t dccp_ack_no(const struct dccp_hdr *dh,

-               const struct dccp_hdr_ack_bits *dh_ack)
+static inline unsigned int dccp_basic_hdr_len(const struct dccp_hdr *dh)
 {
+       return sizeof(*dh) + (DCCPH_X(dh) ? sizeof(struct dccp_hdr_ext) : 0);
+}
+
+static void dccp_print_ack_no(const u_char *bp)
+{
+       const struct dccp_hdr *dh = (const struct dccp_hdr *)bp;
+       const struct dccp_hdr_ack_bits *dh_ack =
+               (struct dccp_hdr_ack_bits *)(bp + dccp_basic_hdr_len(dh));
+
+       TCHECK2(*dh_ack,4);
        u_int32_t ack_high = DCCPH_ACK(dh_ack);
        u_int64_t ackno = EXTRACT_24BITS(&ack_high) & 0xFFFFFF;

if (DCCPH_X(dh) != 0) {

+               TCHECK2(*dh_ack,8);
                u_int32_t ack_low = dh_ack->dccph_ack_nr_low;
                
                ackno &= 0x00FFFF;  /* clear reserved field */
                ackno = (ackno << 32) + EXTRACT_32BITS(&ack_low);
        }

- return ackno;

-}
-
-static inline unsigned int dccp_basic_hdr_len(const struct dccp_hdr *dh)
-{
-       return sizeof(*dh) + (DCCPH_X(dh) ? sizeof(struct dccp_hdr_ext) : 0);
+       (void)printf("(ack=%" PRIu64 ") ", ackno);
+trunc:
+       return;
 }

static inline unsigned int dccp_packet_hdr_len(const u_int8_t type) @@ -309,9 +316,7 @@ void dccp_print(const u_char *bp, const struct dccp_hdr_response *dhr =

                        (struct dccp_hdr_response *)(bp + 
dccp_basic_hdr_len(dh));
                TCHECK(*dhr);
-               (void)printf("response (service=%d, ack=%" PRIu64 ") ",
-                            dhr->dccph_resp_service,
-                            dccp_ack_no(dh,&(dhr->dccph_resp_ack)));
+               (void)printf("response (service=%d) ", dhr->dccph_resp_service);
                extlen += 12;
                break;
        }

@@ -319,20 +324,12 @@ void dccp_print(const u_char *bp, const (void)printf("data ");

                break;
        case DCCP_PKT_ACK: {
-               struct dccp_hdr_ack_bits *dha =
-                       (struct dccp_hdr_ack_bits *)(bp + 
dccp_basic_hdr_len(dh));
-               TCHECK(*dha);
-               (void)printf("ack (ack=%" PRIu64 ") ",
-                            dccp_ack_no(dh,dha));
+               (void)printf("ack ");
                extlen += 8;
                break;
        }
        case DCCP_PKT_DATAACK: {
-               struct dccp_hdr_ack_bits *dha =
-                       (struct dccp_hdr_ack_bits *)(bp + 
dccp_basic_hdr_len(dh));
-               TCHECK(*dha);
-               (void)printf("dataack (ack=%" PRIu64 ") ",
-                            dccp_ack_no(dh,dha));
+               (void)printf("dataack ");
                extlen += 8;
                break;
        }

@@ -366,6 +363,10 @@ void dccp_print(const u_char *bp, const break;

        }

+ if ((DCCPH_TYPE(dh) != DCCP_PKT_DATA) && + (DCCPH_TYPE(dh) != DCCP_PKT_REQUEST))

+               dccp_print_ack_no(bp);
+
        if (vflag < 2)
                return;

------------------------------------------------------------------------

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