split up the frame-relay printer into

fr_if_print and fr_print similar to PPP;
fr_print can be called from outside without supplying a pcap_header;

diff --git a/print-fr.c b/print-fr.c
index 02d6bdbe37680514e4c8773ac50350fe4ff6f9be..082847c2fa2ca3b0a4f10076fb6decad9687b053 100644 (file)
--- a/print-fr.c
+++ b/print-fr.c
@@ -21,7 +21,7 @@
 
 #ifndef lint
 static const char rcsid[] _U_ =
-       "@(#)$Header: /tcpdump/master/tcpdump/print-fr.c,v 1.35 2005-04-26 07:26:34 guy Exp $ (LBL)";
+       "@(#)$Header: /tcpdump/master/tcpdump/print-fr.c,v 1.36 2005-05-27 14:53:48 hannes Exp $ (LBL)";
 #endif
 
 #ifdef HAVE_CONFIG_H
@@ -149,10 +149,9 @@ static int parse_q922_addr(const u_char *p, u_int *dlci, u_int *sdlcore,
 */
 
 static u_int
-fr_hdrlen(const u_char *p, u_int addr_len, u_int caplen)
+fr_hdrlen(const u_char *p, u_int addr_len)
 {
-       if ((caplen > addr_len + 1 /* UI */ + 1 /* pad */) &&
-           !p[addr_len + 1] /* pad exist */)
+       if (!p[addr_len + 1] /* pad exist */)
                return addr_len + 1 /* UI */ + 1 /* pad */ + 1 /* NLPID */;
        else 
                return addr_len + 1 /* UI */ + 1 /* NLPID */;
@@ -190,6 +189,21 @@ fr_if_print(const struct pcap_pkthdr *h, register const u_char *p)
 {
        register u_int length = h->len;
        register u_int caplen = h->caplen;
+
+        TCHECK2(*p, 4); /* minimum frame header length */
+
+        if ((length = fr_print(p, length)) == 0)
+            return (0);
+        else
+            return length;
+ trunc:
+        printf("[|fr]");
+        return caplen;
+}
+
+u_int
+fr_print(register const u_char *p, u_int length)
+{
        u_int16_t extracted_ethertype;
        u_int dlci;
         u_int sdlcore;
@@ -198,22 +212,14 @@ fr_if_print(const struct pcap_pkthdr *h, register const u_char *p)
        u_int hdr_len;
        u_int8_t flags[4];
 
-       if (caplen < 4) {       /* minimum frame header length */
-               printf("[|fr]");
-               return caplen;
-       }
-
        if (parse_q922_addr(p, &dlci, &sdlcore, &addr_len, flags)) {
                printf("Q.922, invalid address");
-               return caplen;
+               return 0;
        }
 
-       hdr_len = fr_hdrlen(p, addr_len, caplen);
-
-       if (caplen < hdr_len) {
-               printf("[|fr]");
-               return caplen;
-       }
+        TCHECK2(*p,addr_len+1+1);
+       hdr_len = fr_hdrlen(p, addr_len);
+        TCHECK2(*p,hdr_len);
 
        if (p[addr_len] != 0x03 && dlci != 0) {
 
@@ -226,7 +232,7 @@ fr_if_print(const struct pcap_pkthdr *h, register const u_char *p)
                 if (ether_encap_print(extracted_ethertype,
                                       p+addr_len+ETHERTYPE_LEN,
                                       length-addr_len-ETHERTYPE_LEN,
-                                      caplen-addr_len-ETHERTYPE_LEN,
+                                      length-addr_len-ETHERTYPE_LEN,
                                       &extracted_ethertype) == 0)
                     /* ether_type not known, probably it wasn't one */
                     printf("UI %02x! ", p[addr_len]);
@@ -247,7 +253,6 @@ fr_if_print(const struct pcap_pkthdr *h, register const u_char *p)
 
        p += hdr_len;
        length -= hdr_len;
-       caplen -= hdr_len;
 
        switch (nlpid) {
        case NLPID_IP:
@@ -262,17 +267,17 @@ fr_if_print(const struct pcap_pkthdr *h, register const u_char *p)
        case NLPID_CLNP:
        case NLPID_ESIS:
        case NLPID_ISIS:
-                isoclns_print(p-1, length+1, caplen+1); /* OSI printers need the NLPID field */
+                isoclns_print(p-1, length+1, length+1); /* OSI printers need the NLPID field */
                break;
 
        case NLPID_SNAP:
-               if (snap_print(p, length, caplen, &extracted_ethertype, 0) == 0) {
+               if (snap_print(p, length, length, &extracted_ethertype, 0) == 0) {
                        /* ether_type not known, print raw packet */
                         if (!eflag)
                             fr_hdr_print(length + hdr_len, hdr_len,
                                          dlci, flags, nlpid);
                        if (!xflag && !qflag)
-                            default_print(p - hdr_len, caplen + hdr_len);
+                            default_print(p - hdr_len, length + hdr_len);
                }
                break;
 
@@ -289,10 +294,15 @@ fr_if_print(const struct pcap_pkthdr *h, register const u_char *p)
                     fr_hdr_print(length + hdr_len, addr_len,
                                     dlci, flags, nlpid);
                if (!xflag)
-                       default_print(p, caplen);
+                       default_print(p, length);
        }
 
        return hdr_len;
+
+ trunc:
+        printf("[|fr]");
+        return 0;
+
 }
 
 /* an NLPID of 0xb1 indicates a 2-byte