2004-10-05 Paul Jakma <paul@dishone.st>

	* irdp_packet.c: (parse_irdp_packet) style issues.
	  Use sockopt_iphdrincl_swab_systoh.
          Try unbork the code. Checksum the ICMP data and actually
          compare it to received checksum. Check data length against
          claimed length in header.
	  Always use ntoh.. when accessing addresses, even when the
          comparison happens to be endian-safe.
	  (send_packet) minor style isues. Use
          sockopt_iphdrincl_swab_htosys.
	  (irdp_iph_hton/ntoh) IP header to/from network/host order.

1 files changed, 76 insertions, 61 deletions

diff --git a/zebra/irdp_packet.c b/zebra/irdp_packet.c
index 67609b31..60604353 100644
--- a/zebra/irdp_packet.c
+++ b/zebra/irdp_packet.c
@@ -82,79 +82,88 @@ void parse_irdp_packet(char *p,
   struct ip *ip = (struct ip *)p ;
   struct icmphdr *icmp;
   struct in_addr src;
-  int ip_hlen, ip_len;
+  int ip_hlen, iplen, datalen;
   struct zebra_if *zi;
   struct irdp_interface *irdp;
 
   zi = ifp->info;
-  if(!zi) return;
+  if (!zi) 
+    return;
 
   irdp = &zi->irdp;
-  if(!irdp) return;
+  if (!irdp) 
+    return;
 
-  ip_hlen = ip->ip_hl*4; 
-  ip_len = ntohs(ip->ip_len);
-  len = len - ip_hlen;
+  ip_hlen = ip->ip_hl << 2;
+  
+  sockopt_iphdrincl_swab_systoh (ip);
+  
+  iplen = ip->ip_len;
+  datalen = len - ip_hlen;
   src = ip->ip_src;
 
-  if(ip_len < ICMP_MINLEN) {
-    zlog_err ("IRDP: RX ICMP packet too short from %s\n",
-	      inet_ntoa (src));
-    return;
-  }
+  if (len != iplen)
+    {
+      zlog_err ("IRDP: RX length doesnt match IP length");
+      return;
+    }
 
+  if (iplen < ICMP_MINLEN) 
+    {
+      zlog_err ("IRDP: RX ICMP packet too short from %s\n",
+  	      inet_ntoa (src));
+      return;
+    }
+    
+  /* XXX: RAW doesnt receive link-layer, surely? ??? */
   /* Check so we don't checksum packets longer than oure RX_BUF - (ethlen +
    len of IP-header) 14+20 */
-
-  if(ip_len > IRDP_RX_BUF-34) {
-    zlog_err ("IRDP: RX ICMP packet too long from %s\n",
-	      inet_ntoa (src));
-    return;
-  }
-
-
-  if (in_cksum (ip, ip_len)) {
-    zlog_warn ("IRDP: RX ICMP packet from %s. Bad checksum, silently ignored",
-	       inet_ntoa (src));
-    return;
-  }
+  if (iplen > IRDP_RX_BUF-34) 
+    {
+      zlog_err ("IRDP: RX ICMP packet too long from %s\n",
+	        inet_ntoa (src));
+      return;
+    }
 
   icmp = (struct icmphdr *) (p+ip_hlen);
 
-
+  /* check icmp checksum */    
+  if (in_cksum (icmp, datalen) != icmp->checksum) 
+    {
+      zlog_warn ("IRDP: RX ICMP packet from %s. Bad checksum, silently ignored",
+                 inet_ntoa (src));
+      return;
+    }
+  
   /* Handle just only IRDP */
-
-  if( icmp->type == ICMP_ROUTERADVERT);
-  else if( icmp->type == ICMP_ROUTERSOLICIT);
-  else return;
-
- 
-  if (icmp->code != 0) {
-    zlog_warn ("IRDP: RX packet type %d from %s. Bad ICMP type code, silently ignored",
-	       icmp->type,
-	       inet_ntoa (src));
+  if (!(icmp->type == ICMP_ROUTERADVERT
+        || icmp->type == ICMP_ROUTERSOLICIT))
     return;
-  }
-
-  if(ip->ip_dst.s_addr == INADDR_BROADCAST && 
-     irdp->flags & IF_BROADCAST);
-
-  else if ( ntohl(ip->ip_dst.s_addr) == INADDR_ALLRTRS_GROUP && 
-	    ! (irdp->flags &  IF_BROADCAST));
-
-  else { /* ERROR */
-
-    zlog_warn ("IRDP: RX illegal from %s to %s while %s operates in %s\n",
-	       inet_ntoa (src), 
-	       ntohl(ip->ip_dst.s_addr) == INADDR_ALLRTRS_GROUP? 
-	       "multicast" : inet_ntoa(ip->ip_dst),
-	       ifp->name,
-	       irdp->flags &  IF_BROADCAST? 
-	       "broadcast" : "multicast");
+  
+  if (icmp->code != 0) 
+    {
+      zlog_warn ("IRDP: RX packet type %d from %s. Bad ICMP type code,"
+                 " silently ignored",
+                 icmp->type, inet_ntoa (src));
+      return;
+    }
 
-    zlog_warn ("IRDP: Please correct settings\n");
-    return;
-  }
+  if (! ((ntohl (ip->ip_dst.s_addr) == INADDR_BROADCAST)
+         && (irdp->flags & IF_BROADCAST))
+        ||
+        (ntohl (ip->ip_dst.s_addr) == INADDR_ALLRTRS_GROUP
+         && !(irdp->flags & IF_BROADCAST)))
+    {
+      zlog_warn ("IRDP: RX illegal from %s to %s while %s operates in %s\n",
+                 inet_ntoa (src),
+                 ntohl (ip->ip_dst.s_addr) == INADDR_ALLRTRS_GROUP ?
+                 "multicast" : inet_ntoa (ip->ip_dst),
+                 ifp->name,
+                 irdp->flags & IF_BROADCAST ? "broadcast" : "multicast");
+
+      zlog_warn ("IRDP: Please correct settings\n");
+      return;
+    }
 
   switch (icmp->type) 
     {
@@ -182,7 +191,6 @@ int irdp_recvmsg (int sock, u_char *buf, int size, int *ifindex)
 {
   struct msghdr msg;
   struct iovec iov;
-  struct cmsghdr *ptr;
   char adata[CMSG_SPACE( SOPT_SIZE_CMSG_PKTINFO_IPV4() )];
   int ret;
 
@@ -255,10 +263,12 @@ int irdp_read_raw(struct thread *r)
   }
 
   parse_irdp_packet(buf, ret, ifp);
+
   return ret;
 }
 
-void send_packet(struct interface *ifp, 
+void 
+send_packet(struct interface *ifp, 
 	    struct stream *s,
 	    u_int32_t dst,
 	    struct prefix *p,
@@ -276,10 +286,13 @@ void send_packet(struct interface *ifp,
   u_long src;
   int on;
  
-  if (! (ifp->flags & IFF_UP)) return;
+  if (!(ifp->flags & IFF_UP)) 
+    return;
 
-  if(!p) src = ntohl(p->u.prefix4.s_addr);
-  else src = 0; /* Is filled in */
+  if (!p) 
+    src = ntohl(p->u.prefix4.s_addr);
+  else 
+    src = 0; /* Is filled in */
   
   ip = (struct ip *) buf;
   ip->ip_hl = sizeof(struct ip) >> 2;
@@ -290,7 +303,7 @@ void send_packet(struct interface *ifp,
   ip->ip_ttl = ttl;
   ip->ip_src.s_addr = src;
   ip->ip_dst.s_addr = dst;
-  icmp = (struct icmphdr *) (buf + 20);
+  icmp = (struct icmphdr *) (buf + sizeof (struct ip));
 
   /* Merge IP header with icmp packet */
 
@@ -343,6 +356,8 @@ void send_packet(struct interface *ifp,
   msg->msg_control = cmsg;
   msg->msg_controllen = cmsg->cmsg_len;
  
+  sockopt_iphdrincl_swab_htosys (ip);
+  
   if (sendmsg(irdp_sock, msg, 0) < 0) {
     zlog_warn("sendto %s", strerror (errno));
   }