--- interface.h.orig	Sun Nov 21 11:51:25 1999
+++ interface.h	Fri Jan  7 12:07:19 2000
@@ -67,7 +67,7 @@
  * In particular, it allows for an ethernet header, tcp/ip header, and
  * 14 bytes of data (assuming no ip options).
  */
-#define DEFAULT_SNAPLEN 68
+#define DEFAULT_SNAPLEN 80 /* for pgm, need at least 74 */
 
 #ifndef BIG_ENDIAN
 #define BIG_ENDIAN 4321
--- print-ip.c.orig	Tue Sep 15 21:46:59 1998
+++ print-ip.c	Fri Jan  7 12:07:19 2000
@@ -417,6 +417,13 @@
 			icmp_print(cp, (const u_char *)ip);
 			break;
 
+#ifndef IPPROTO_PGM
+#define	IPPROTO_PGM  113
+#endif
+		case IPPROTO_PGM:
+			pgm_print(cp, len, (const u_char *)ip);
+			break;
+
 #ifndef IPPROTO_IGRP
 #define IPPROTO_IGRP 9
 #endif
--- print-udp.c.orig	Tue Sep 15 21:46:59 1998
+++ print-udp.c	Fri Jan  7 16:05:39 2000
@@ -446,3 +446,287 @@
 	} else
 		(void)printf(" udp %u", (u_int32_t)(ulen - sizeof(*up)));
 }
+
+#if 1
+/*
+ * this code does the printing of pgm packets
+ * Nov. 1999 - Universita` di Pisa
+ */
+typedef u_int32_t pgm_seq ;
+
+struct pgmhdr {
+        u_int16_t ph_sport ;
+        u_int16_t ph_dport ;
+        u_int8_t  type ;
+#define PGM_SPM_TYPE    0
+#define PGM_OD_TYPE     4
+#define PGM_RD_TYPE     5
+#define PGM_NAK_TYPE    8
+#define PGM_NNAK_TYPE   9
+#define PGM_NCF_TYPE    10
+#define PGM_ACK_TYPE    11      /* for cong.control */
+
+        u_int8_t options ;
+#define PGM_OPT_PRESENT         1       /* there are option extentions */
+#define PGM_OPT_NE_PRESENT      2       /* there are NE-significant opt.ext. */
+
+        u_int16_t checksum ;
+        u_int32_t gsid_low ;
+        u_int16_t gsid_high ;
+        u_int16_t tsdu_len ;
+        /*
+         * all packets have a couple of sequence numbers here, but
+         * their meaning differs.
+         */
+        pgm_seq _seq1;
+#define od_txw_trail    _seq1   /* this is in ODATA pkts */
+#define spm_seq         _seq1   /* this is in SPM pkts */
+#define nak_req_seq     _seq1   /* this is in NAK pkts */
+#define ack_req_seq     _seq1   /* this is in ACK pkts */
+
+        pgm_seq _seq2;
+#define od_dp_seq       _seq2   /* this is in ODATA pkts */
+#define spm_txw_trail   _seq2   /* this is in SPM pkts */
+#define ack_rxw_lead    _seq2   /* this is in ACK pkts */
+} ;
+
+/*
+ * Source Path Message (SPM) packets
+ */
+ 
+struct pgm_spm_body {
+        u_int32_t spm_le_seq ;
+        u_int16_t nla_afi ;
+        u_int16_t rsvd ;
+        struct in_addr path_nla ;
+        u_char options[0];
+} ;
+
+struct pgm_spm {
+        struct pgmhdr pgmhdr ;
+        struct pgm_spm_body body ;
+} ;
+
+/*
+ * (N)ACK packets (from receivers/DLR)
+ */
+struct pgm_nack_body {
+        /*
+        u_int32_t req_seq ;
+        u_int16_t nla_afi ;
+        u_int16_t rsvd1 ;
+        */
+        struct in_addr src_nla ;
+        u_int16_t nla_afi2 ;
+        u_int16_t rsvd2 ;
+        struct in_addr mc_nla ;
+        u_char options[0] ;
+} ;
+
+/*
+ * ACK packets (from elected receivers)
+ */
+struct pgm_ack_body {
+        /*
+        u_int32_t req_seq ;
+        u_int16_t nla_afi ;
+        u_int16_t rsvd1 ;
+        */
+        u_int32_t ack_bitmask ;
+} ;
+#if 1
+/*
+ * options (similar to IP options)
+ */
+#define OPT_HLEN sizeof(struct pgm_option)
+
+struct pgm_option {
+        u_int8_t type;
+        u_int8_t len;
+        u_int16_t tot_len;
+};
+/*
+ * PGM options. The same names, in some cases, are also used
+ * as parameter names in set/getsockopt.
+ * Most options are unimplemented as of 990928
+ */
+#define PGM_OPT_LENGTH          0x00
+#define PGM_OPT_FRAGMENT        0x01
+#define PGM_OPT_JOIN            0x03
+#define PGM_OPT_TIME            0x04
+#define PGM_OPT_RXQ             0x05
+#define PGM_OPT_DROP            0x06
+#define PGM_OPT_REDIRECT        0x07
+
+#define PGM_OPT_LOSSRATE        0x10
+#define PGM_OPT_SEND_NAK        0x11    /* receivers, please send a NAK */
+#define PGM_OPT_ELECT           0x12    /* node X is elected as acker   */
+#define PGM_OPT_SYN             0x21
+#define PGM_OPT_FIN             0x22
+
+#define PGM_OPT_MASK		0x7f
+
+#define PGM_OPT_END             0x80    /* end of options marker */
+
+/* experimental options */
+#define PGM_OPT_LOSSRATE        0x10
+#define PGM_OPT_DESC            0x20
+#define PGM_OPT_SYN             0x21
+#define PGM_OPT_FIN             0x22
+
+#endif
+
+void
+pgm_print(register const u_char *bp, u_int length, register const u_char *bp2)
+{
+    const struct pgmhdr *pp; /* pgm header */
+    const struct ip *ip;
+    const u_char *cp;
+    const u_char *ep = bp + length;
+    u_short sport, dport, ulen;
+    int slen, hlen = 0 ;
+    char *s, buf[16];
+
+    hlen = sizeof(struct pgmhdr) ; /* header at least this long */
+    slen = snapend - bp ; /* have this many bytes in the snap */
+    slen -= hlen ; /* less the header... */
+    if (slen < 0) { /* not enough data to print the header */
+	printf("[|pgm]");
+	return;
+    }
+    if (ep > snapend)
+	ep = snapend;
+    pp = (struct pgmhdr *)bp;
+    ip = (struct ip *)bp2;
+    cp = (u_char *)(pp + 1 );
+
+    sport = ntohs(pp->ph_sport);
+    dport = ntohs(pp->ph_dport);
+    ulen = ntohs(pp->tsdu_len);
+    (void)printf("%s.%s > %s.%s: GSI 0x%04x%02x len %d ",
+	ipaddr_string(&ip->ip_src),
+	udpport_string(sport),
+	ipaddr_string(&ip->ip_dst),
+	udpport_string(dport),
+	ntohl(pp->gsid_low),
+	ntohs(pp->gsid_high),
+	ulen );
+    /* now process pieces after fixed header */
+    switch( pp->type ) {
+    case PGM_SPM_TYPE: {
+	struct pgm_spm_body *b = (struct pgm_spm_body *)(cp) ;
+	if (slen < sizeof (*b) ) {
+	    printf("[|spm-body]");
+	    return ;
+	}
+	printf( "SPM %u path %s",
+		ntohl(pp->spm_seq),
+		ipaddr_string( &(b->path_nla.s_addr) ) );
+	cp = (u_char *)(b+1);
+	}
+	break ;
+
+    case PGM_OD_TYPE:
+    case PGM_RD_TYPE:
+	printf( "%s %u trail %u",
+		pp->type == 4 ? "ODATA" : "RDATA" ,
+		ntohl(pp->od_dp_seq),
+		ntohl(pp->od_txw_trail) );
+	break ;
+
+    case PGM_NAK_TYPE:
+    case PGM_NCF_TYPE: {
+	struct pgm_nack_body *b= (struct pgm_nack_body *)(cp) ;
+	if (slen < sizeof (*b) ) {
+	    printf("[|nak/ncf-body]");
+	    return ;
+	}
+	printf( "%s %u src %s mc %s",
+		pp->type == 8 ? "NAK" : "NCF" ,
+		ntohl(pp->nak_req_seq),
+		ipaddr_string( &(b->src_nla.s_addr) ),
+		ipaddr_string( &(b->mc_nla.s_addr) )
+	);
+	cp = (u_char *)(b+1);
+	}
+	break ;
+
+   case PGM_ACK_TYPE: {
+	struct pgm_ack_body *b= (struct pgm_ack_body *)(cp) ;
+	if (slen < sizeof (*b) ) {
+	    printf("[|ack-body]");
+	    return ;
+	}
+	printf( "ACK %u lead %u mask %08x",
+               ntohl(pp->ack_req_seq),
+               ntohl(pp->ack_rxw_lead),
+               ntohl(b->ack_bitmask)
+	);
+	cp = (u_char *)(b+1);
+	}
+	break ;  
+
+    default:
+	printf("UNRECOGNIZED TYPE 0x%02x\n", pp->type);
+	return ;
+    }
+    if (pp->options & PGM_OPT_PRESENT) {
+	struct pgm_option *o = (struct pgm_option *)cp ;
+	if (slen < 4) { /* minimal option len */
+	    printf("[Ioptions]");
+	    return ;
+	}
+	while (cp+4 <= ep) {
+	    o = (struct pgm_option *)cp ;
+	    switch (o->type & PGM_OPT_MASK) {
+	    case PGM_OPT_LENGTH:
+		printf(" OPT[%d] %d ", o->len, ntohs(o->tot_len) );
+		break ;
+	    case PGM_OPT_JOIN:
+		if (o->len != 8 || cp+8 > ep) {
+		    printf("[|join]");
+		} else {
+		    u_int32_t *p = (u_int32_t *)(cp+4);
+		    printf("join %d ", ntohl(*p) );
+		}
+		break ;
+	    case PGM_OPT_LOSSRATE:
+		if (o->len != 16 || cp+16 > ep) {
+		    printf("[|lossrate]");
+		} else {
+		    u_int32_t *p = (u_int32_t *)(cp+4);
+		    printf("loss %0.6f ", (double)(1.0*ntohl(*p)/65536) );
+		    printf("lead %d ", ntohs(p[1]) );
+		    printf("recv %s ", ipaddr_string( p+2 ) );
+		}
+		break ;
+	    case PGM_OPT_SEND_NAK:
+		if (o->len != 8 || cp+8 > ep) {
+		    printf("[|send_nak]");
+		} else {
+		    u_int32_t *p = (u_int32_t *)(cp+4);
+		    printf("send_nak %s ", ipaddr_string( p ) );
+		}
+		break ;
+	    case PGM_OPT_ELECT:
+		if (o->len != 8 || cp+8 > ep) {
+		    printf("[|elect]");
+		} else {
+		    u_int32_t *p = (u_int32_t *)(cp+4);
+		    printf("elect %s ", ipaddr_string( p ) );
+		}
+		break ;
+	    default:
+		printf("OPT_%d [%d] ", o->type, o->len);
+		break ;
+	    }
+	    if (o->len < 4)
+		cp += 4 ; /* malformed opt, avoid infinite loop */
+	    else
+		cp += o->len ;
+	    if (o->type & PGM_OPT_END)
+		return ;
+        }
+    }
+}
+#endif