UDP: Clean up address and port printing.

udp_print() always knows whether UDP port numbers are available or not,
so split udpipaddr_print() into two functions to lose some arity, much
branching and all type casting. In the new functions test for IPv4
explicitly. In udp_print() convert duplicate code into a conditional
call to udpipaddr_print().

diff --git a/CHANGES b/CHANGES
index f2a7e9bf872204245454994bfa11d06c9fe6f37c..a5e9a31a627c900ca4b98dd6736727b0156b57a5 100644 (file)
--- a/CHANGES
+++ b/CHANGES
@@ -5,6 +5,7 @@ Monthday, Month DD, YYYY by gharris and denis
       BOOTP, EGP, EIGRP, Geneve, L2TP, OLSR, PGM, RSVP: Modernize packet parsing style
       EGP: Replace custom code with tok2str()
       EIGRP: Get the packet header fields right.
+      UDP: Clean up address and port printing.
 
 Monthday, Month DD, YYYY by gharris
   Summary for 4.99.1 tcpdump release (so far!)

diff --git a/print-udp.c b/print-udp.c
index 0efb0f1e8d39654e25b761025b3aee0b6e29e2b4..ad0c47b0b4e9ae5203c3d7fdfd83ce817a6c74c9 100644 (file)
--- a/print-udp.c
+++ b/print-udp.c
@@ -312,55 +312,41 @@ static uint16_t udp6_cksum(netdissect_options *ndo, const struct ip6_hdr *ip6,
 }
 
 static void
-udpipaddr_print(netdissect_options *ndo, const struct ip *ip, int sport, int dport)
+udpipaddr_print(netdissect_options *ndo,
+                const struct ip *ip, const uint16_t sport, const uint16_t dport)
 {
-       const struct ip6_hdr *ip6;
-
-       if (IP_V(ip) == 6)
-               ip6 = (const struct ip6_hdr *)ip;
-       else
-               ip6 = NULL;
+       const struct ip6_hdr *ip6 = (const struct ip6_hdr *)ip;
+
+       if (IP_V(ip) == 4 && GET_U_1(ip->ip_p) == IPPROTO_UDP) {
+               ND_PRINT("%s.%s > %s.%s: ",
+                       GET_IPADDR_STRING(ip->ip_src),
+                       udpport_string(ndo, sport),
+                       GET_IPADDR_STRING(ip->ip_dst),
+                       udpport_string(ndo, dport));
+       } else if (IP_V(ip) == 6 && GET_U_1(ip6->ip6_nxt) == IPPROTO_UDP) {
+               ND_PRINT("%s.%s > %s.%s: ",
+                       GET_IP6ADDR_STRING(ip6->ip6_src),
+                       udpport_string(ndo, sport),
+                       GET_IP6ADDR_STRING(ip6->ip6_dst),
+                       udpport_string(ndo, dport));
+       } else
+               ND_PRINT("%s > %s: ",
+                       udpport_string(ndo, sport), udpport_string(ndo, dport));
+}
 
-       if (ip6) {
-               if (GET_U_1(ip6->ip6_nxt) == IPPROTO_UDP) {
-                       if (sport == -1) {
-                               ND_PRINT("%s > %s: ",
-                                       GET_IP6ADDR_STRING(ip6->ip6_src),
-                                       GET_IP6ADDR_STRING(ip6->ip6_dst));
-                       } else {
-                               ND_PRINT("%s.%s > %s.%s: ",
-                                       GET_IP6ADDR_STRING(ip6->ip6_src),
-                                       udpport_string(ndo, (uint16_t)sport),
-                                       GET_IP6ADDR_STRING(ip6->ip6_dst),
-                                       udpport_string(ndo, (uint16_t)dport));
-                       }
-               } else {
-                       if (sport != -1) {
-                               ND_PRINT("%s > %s: ",
-                                       udpport_string(ndo, (uint16_t)sport),
-                                       udpport_string(ndo, (uint16_t)dport));
-                       }
-               }
-       } else {
-               if (GET_U_1(ip->ip_p) == IPPROTO_UDP) {
-                       if (sport == -1) {
-                               ND_PRINT("%s > %s: ",
-                                       GET_IPADDR_STRING(ip->ip_src),
-                                       GET_IPADDR_STRING(ip->ip_dst));
-                       } else {
-                               ND_PRINT("%s.%s > %s.%s: ",
-                                       GET_IPADDR_STRING(ip->ip_src),
-                                       udpport_string(ndo, (uint16_t)sport),
-                                       GET_IPADDR_STRING(ip->ip_dst),
-                                       udpport_string(ndo, (uint16_t)dport));
-                       }
-               } else {
-                       if (sport != -1) {
-                               ND_PRINT("%s > %s: ",
-                                       udpport_string(ndo, (uint16_t)sport),
-                                       udpport_string(ndo, (uint16_t)dport));
-                       }
-               }
+static void
+udpipaddr_noport_print(netdissect_options *ndo, const struct ip *ip)
+{
+       const struct ip6_hdr *ip6 = (const struct ip6_hdr *)ip;
+
+       if (IP_V(ip) == 4 && GET_U_1(ip->ip_p) == IPPROTO_UDP) {
+               ND_PRINT("%s > %s: ",
+                       GET_IPADDR_STRING(ip->ip_src),
+                       GET_IPADDR_STRING(ip->ip_dst));
+       } else if (IP_V(ip) == 6 && GET_U_1(ip6->ip6_nxt) == IPPROTO_UDP) {
+               ND_PRINT("%s > %s: ",
+                       GET_IP6ADDR_STRING(ip6->ip6_src),
+                       GET_IP6ADDR_STRING(ip6->ip6_dst));
        }
 }
 
@@ -384,20 +370,20 @@ udp_print(netdissect_options *ndo, const u_char *bp, u_int length,
        else
                ip6 = NULL;
        if (!ND_TTEST_2(up->uh_dport)) {
-               udpipaddr_print(ndo, ip, -1, -1);
+               udpipaddr_noport_print(ndo, ip);
                goto trunc;
        }
 
        sport = GET_BE_U_2(up->uh_sport);
        dport = GET_BE_U_2(up->uh_dport);
+       if (ndo->ndo_packettype != PT_RPC)
+               udpipaddr_print(ndo, ip, sport, dport);
 
        if (length < sizeof(struct udphdr)) {
-               udpipaddr_print(ndo, ip, sport, dport);
                ND_PRINT("truncated-udp %u", length);
                return;
        }
        if (!ND_TTEST_2(up->uh_ulen)) {
-               udpipaddr_print(ndo, ip, sport, dport);
                goto trunc;
        }
        ulen = GET_BE_U_2(up->uh_ulen);
@@ -409,7 +395,6 @@ udp_print(netdissect_options *ndo, const u_char *bp, u_int length,
        if (ulen == 0 && length > 65535)
                ulen = length;
        if (ulen < sizeof(struct udphdr)) {
-               udpipaddr_print(ndo, ip, sport, dport);
                ND_PRINT("truncated-udplength %u", ulen);
                return;
        }
@@ -420,7 +405,6 @@ udp_print(netdissect_options *ndo, const u_char *bp, u_int length,
 
        cp = (const u_char *)(up + 1);
        if (cp > ndo->ndo_snapend) {
-               udpipaddr_print(ndo, ip, sport, dport);
                goto trunc;
        }
 
@@ -431,12 +415,10 @@ udp_print(netdissect_options *ndo, const u_char *bp, u_int length,
                switch (ndo->ndo_packettype) {
 
                case PT_VAT:
-                       udpipaddr_print(ndo, ip, sport, dport);
                        vat_print(ndo, cp, length);
                        break;
 
                case PT_WB:
-                       udpipaddr_print(ndo, ip, sport, dport);
                        wb_print(ndo, cp, length);
                        break;
 
@@ -452,66 +434,53 @@ udp_print(netdissect_options *ndo, const u_char *bp, u_int length,
                        break;
 
                case PT_RTP:
-                       udpipaddr_print(ndo, ip, sport, dport);
                        rtp_print(ndo, cp, length);
                        break;
 
                case PT_RTCP:
-                       udpipaddr_print(ndo, ip, sport, dport);
                        while (cp < ep)
                                cp = rtcp_print(ndo, cp, ep);
                        break;
 
                case PT_SNMP:
-                       udpipaddr_print(ndo, ip, sport, dport);
                        snmp_print(ndo, cp, length);
                        break;
 
                case PT_CNFP:
-                       udpipaddr_print(ndo, ip, sport, dport);
                        cnfp_print(ndo, cp);
                        break;
 
                case PT_TFTP:
-                       udpipaddr_print(ndo, ip, sport, dport);
                        tftp_print(ndo, cp, length);
                        break;
 
                case PT_AODV:
-                       udpipaddr_print(ndo, ip, sport, dport);
                        aodv_print(ndo, cp, length,
                            ip6 != NULL);
                        break;
 
                case PT_RADIUS:
-                       udpipaddr_print(ndo, ip, sport, dport);
                        radius_print(ndo, cp, length);
                        break;
 
                case PT_VXLAN:
-                       udpipaddr_print(ndo, ip, sport, dport);
                        vxlan_print(ndo, cp, length);
                        break;
 
                case PT_PGM:
                case PT_PGM_ZMTP1:
-                       udpipaddr_print(ndo, ip, sport, dport);
                        pgm_print(ndo, cp, length, bp2);
                        break;
                case PT_LMP:
-                       udpipaddr_print(ndo, ip, sport, dport);
                        lmp_print(ndo, cp, length);
                        break;
                case PT_PTP:
-                       udpipaddr_print(ndo, ip, sport, dport);
                        ptp_print(ndo, cp, length);
                        break;
                case PT_SOMEIP:
-                       udpipaddr_print(ndo, ip, sport, dport);
                        someip_print(ndo, cp, length);
                        break;
                case PT_DOMAIN:
-                       udpipaddr_print(ndo, ip, sport, dport);
                        /* over_tcp: FALSE, is_mdns: FALSE */
                        domain_print(ndo, cp, length, FALSE, FALSE);
                        break;
@@ -519,7 +488,6 @@ udp_print(netdissect_options *ndo, const u_char *bp, u_int length,
                return;
        }
 
-       udpipaddr_print(ndo, ip, sport, dport);
        if (!ndo->ndo_qflag) {
                const struct sunrpc_msg *rp;
                enum sunrpc_msg_type direction;