NTP: Modernize packet parsing style. [skip ci]

Enable ND_LONGJMP_FROM_TCHECK. Remove a few redundant ND_TCHECK()
instances. Move one ND_TCHECK_4() to where it belongs. Have nd_printjn()
guard the snapshot end.

diff --git a/print-ntp.c b/print-ntp.c
index 99c089634316ae85c34520fbfe018ed789739c90..86e29e69330e163d5274a2a5fdddfd7aa81e5a62 100644 (file)
--- a/print-ntp.c
+++ b/print-ntp.c
@@ -42,6 +42,7 @@
 #include <time.h>
 #endif
 
+#define ND_LONGJMP_FROM_TCHECK
 #include "netdissect.h"
 #include "addrtoname.h"
 #include "extract.h"
@@ -246,26 +247,23 @@ ntp_time_print(netdissect_options *ndo,
 
        ND_PRINT(", precision %d", GET_S_1(bp->precision));
 
-       ND_TCHECK_SIZE(&bp->root_delay);
        ND_PRINT("\n\tRoot Delay: ");
        p_sfix(ndo, &bp->root_delay);
 
-       ND_TCHECK_SIZE(&bp->root_dispersion);
        ND_PRINT(", Root dispersion: ");
        p_sfix(ndo, &bp->root_dispersion);
 
-       ND_TCHECK_4(bp->refid);
        ND_PRINT(", Reference-ID: ");
        /* Interpretation depends on stratum */
        switch (stratum) {
 
        case UNSPECIFIED:
                ND_PRINT("(unspec)");
+               ND_TCHECK_4(bp->refid);
                break;
 
        case PRIM_REF:
-               if (nd_printn(ndo, (const u_char *)&(bp->refid), 4, ndo->ndo_snapend))
-                       goto trunc;
+               nd_printjn(ndo, (const u_char *)&(bp->refid), 4);
                break;
 
        case INFO_QUERY:
@@ -285,19 +283,15 @@ ntp_time_print(netdissect_options *ndo,
                break;
        }
 
-       ND_TCHECK_SIZE(&bp->ref_timestamp);
        ND_PRINT("\n\t  Reference Timestamp:  ");
        p_ntp_time(ndo, &(bp->ref_timestamp));
 
-       ND_TCHECK_SIZE(&bp->org_timestamp);
        ND_PRINT("\n\t  Originator Timestamp: ");
        p_ntp_time(ndo, &(bp->org_timestamp));
 
-       ND_TCHECK_SIZE(&bp->rec_timestamp);
        ND_PRINT("\n\t  Receive Timestamp:    ");
        p_ntp_time(ndo, &(bp->rec_timestamp));
 
-       ND_TCHECK_SIZE(&bp->xmt_timestamp);
        ND_PRINT("\n\t  Transmit Timestamp:   ");
        p_ntp_time(ndo, &(bp->xmt_timestamp));
 
@@ -312,7 +306,6 @@ ntp_time_print(netdissect_options *ndo,
                ND_PRINT("\n\tKey id: %u", GET_BE_U_4(bp->key_id));
        } else if (length == NTP_TIMEMSG_MINLEN + 4 + 16) {     /* Optional: key-id + 128-bit digest */
                ND_PRINT("\n\tKey id: %u", GET_BE_U_4(bp->key_id));
-               ND_TCHECK_LEN(bp->message_digest, 16);
                ND_PRINT("\n\tAuthentication: %08x%08x%08x%08x",
                         GET_BE_U_4(bp->message_digest),
                         GET_BE_U_4(bp->message_digest + 4),
@@ -320,7 +313,6 @@ ntp_time_print(netdissect_options *ndo,
                         GET_BE_U_4(bp->message_digest + 12));
        } else if (length == NTP_TIMEMSG_MINLEN + 4 + 20) {     /* Optional: key-id + 160-bit digest */
                ND_PRINT("\n\tKey id: %u", GET_BE_U_4(bp->key_id));
-               ND_TCHECK_LEN(bp->message_digest, 20);
                ND_PRINT("\n\tAuthentication: %08x%08x%08x%08x%08x",
                         GET_BE_U_4(bp->message_digest),
                         GET_BE_U_4(bp->message_digest + 4),
@@ -335,10 +327,6 @@ ntp_time_print(netdissect_options *ndo,
 invalid:
        nd_print_invalid(ndo);
        ND_TCHECK_LEN(bp, length);
-       return;
-
-trunc:
-       nd_print_trunc(ndo);
 }
 
 /*
@@ -389,10 +377,6 @@ ntp_control_print(netdissect_options *ndo,
 invalid:
        nd_print_invalid(ndo);
        ND_TCHECK_LEN(cd, length);
-       return;
-
-trunc:
-       nd_print_trunc(ndo);
 }
 
 union ntpdata {