slirp: Generalizing and neutralizing various TCP functions before adding IPv6 stuff

Basically, this patch adds some switch in various TCP functions to
prepare them for the IPv6 case.

To have something to "switch" in tcp_input() and tcp_respond(), a new
argument is used to give them the sa_family of the addresses they are
working on.

This patch does not include the entailed reindentation, to make proofread
easier. Reindentation is adressed in the following no-op patch.

Signed-off-by: Guillaume Subiron <maethor@subiron.org>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>

1 files changed, 59 insertions, 14 deletions

diff --git a/slirp/tcp_input.c b/slirp/tcp_input.c
index 640dd79df4..69e53761a0 100644
--- a/slirp/tcp_input.c
+++ b/slirp/tcp_input.c
@@ -214,7 +214,7 @@ present:
  * protocol specification dated September, 1981 very closely.
  */
 void
-tcp_input(struct mbuf *m, int iphlen, struct socket *inso)
+tcp_input(struct mbuf *m, int iphlen, struct socket *inso, unsigned short af)
 {
   	struct ip save_ip, *ip;
 	register struct tcpiphdr *ti;
@@ -256,6 +256,8 @@ tcp_input(struct mbuf *m, int iphlen, struct socket *inso)
 	}
 	slirp = m->slirp;
 
+	switch (af) {
+	case AF_INET:
 	if (iphlen > sizeof(struct ip )) {
 	  ip_stripoptions(m, (struct mbuf *)0);
 	  iphlen=sizeof(struct ip );
@@ -297,6 +299,11 @@ tcp_input(struct mbuf *m, int iphlen, struct socket *inso)
 	if(cksum(m, len)) {
 	  goto drop;
 	}
+	break;
+
+	default:
+	    g_assert_not_reached();
+	}
 
 	/*
 	 * Check that TCP offset makes sense,
@@ -332,14 +339,20 @@ tcp_input(struct mbuf *m, int iphlen, struct socket *inso)
 	 * Locate pcb for segment.
 	 */
 findso:
-	lhost.ss_family = AF_INET;
+	lhost.ss_family = af;
+	fhost.ss_family = af;
+	switch (af) {
+	case AF_INET:
 	lhost4 = (struct sockaddr_in *) &lhost;
 	lhost4->sin_addr = ti->ti_src;
 	lhost4->sin_port = ti->ti_sport;
-	fhost.ss_family = AF_INET;
 	fhost4 = (struct sockaddr_in *) &fhost;
 	fhost4->sin_addr = ti->ti_dst;
 	fhost4->sin_port = ti->ti_dport;
+	    break;
+	default:
+	    g_assert_not_reached();
+	}
 
 	so = solookup(&slirp->tcp_last_so, &slirp->tcb, &lhost, &fhost);
 
@@ -389,8 +402,16 @@ findso:
 	  so->lhost.ss = lhost;
 	  so->fhost.ss = fhost;
 
-	  if ((so->so_iptos = tcp_tos(so)) == 0)
-	    so->so_iptos = ((struct ip *)ti)->ip_tos;
+	  so->so_iptos = tcp_tos(so);
+	  if (so->so_iptos == 0) {
+	      switch (af) {
+	      case AF_INET:
+	          so->so_iptos = ((struct ip *)ti)->ip_tos;
+	          break;
+	      default:
+	          g_assert_not_reached();
+	      }
+	  }
 
 	  tp = sototcpcb(so);
 	  tp->t_state = TCPS_LISTEN;
@@ -569,7 +590,8 @@ findso:
 	   * If this is destined for the control address, then flag to
 	   * tcp_ctl once connected, otherwise connect
 	   */
-	  if ((so->so_faddr.s_addr & slirp->vnetwork_mask.s_addr) ==
+	  if (af == AF_INET &&
+	      (so->so_faddr.s_addr & slirp->vnetwork_mask.s_addr) ==
 	      slirp->vnetwork_addr.s_addr) {
 	    if (so->so_faddr.s_addr != slirp->vhost_addr.s_addr &&
 		so->so_faddr.s_addr != slirp->vnameserver_addr.s_addr) {
@@ -597,27 +619,42 @@ findso:
 	  if ((tcp_fconnect(so, so->so_ffamily) == -1) &&
               (errno != EINPROGRESS) && (errno != EWOULDBLOCK)
           ) {
-	    u_char code=ICMP_UNREACH_NET;
+	    uint8_t code;
 	    DEBUG_MISC((dfd, " tcp fconnect errno = %d-%s\n",
 			errno,strerror(errno)));
 	    if(errno == ECONNREFUSED) {
 	      /* ACK the SYN, send RST to refuse the connection */
-	      tcp_respond(tp, ti, m, ti->ti_seq+1, (tcp_seq)0,
-			  TH_RST|TH_ACK);
+	      tcp_respond(tp, ti, m, ti->ti_seq + 1, (tcp_seq) 0,
+			  TH_RST | TH_ACK, af);
 	    } else {
-	      if(errno == EHOSTUNREACH) code=ICMP_UNREACH_HOST;
+	      switch (af) {
+	      case AF_INET:
+		code = ICMP_UNREACH_NET;
+		if (errno == EHOSTUNREACH) {
+		  code = ICMP_UNREACH_HOST;
+		}
+		break;
+	      default:
+		g_assert_not_reached();
+	      }
 	      HTONL(ti->ti_seq);             /* restore tcp header */
 	      HTONL(ti->ti_ack);
 	      HTONS(ti->ti_win);
 	      HTONS(ti->ti_urp);
 	      m->m_data -= sizeof(struct tcpiphdr)+off-sizeof(struct tcphdr);
 	      m->m_len  += sizeof(struct tcpiphdr)+off-sizeof(struct tcphdr);
+	      switch (af) {
+	      case AF_INET:
 	      m->m_data += sizeof(struct tcpiphdr) - sizeof(struct ip)
 						   - sizeof(struct tcphdr);
 	      m->m_len  -= sizeof(struct tcpiphdr) - sizeof(struct ip)
 						   - sizeof(struct tcphdr);
 	      *ip=save_ip;
 	      icmp_send_error(m, ICMP_UNREACH, code, 0, strerror(errno));
+		break;
+	      default:
+		g_assert_not_reached();
+	      }
 	    }
             tcp_close(tp);
 	    m_free(m);
@@ -1289,11 +1326,11 @@ dropafterack:
 dropwithreset:
 	/* reuses m if m!=NULL, m_free() unnecessary */
 	if (tiflags & TH_ACK)
-		tcp_respond(tp, ti, m, (tcp_seq)0, ti->ti_ack, TH_RST);
+		tcp_respond(tp, ti, m, (tcp_seq)0, ti->ti_ack, TH_RST, af);
 	else {
 		if (tiflags & TH_SYN) ti->ti_len++;
-		tcp_respond(tp, ti, m, ti->ti_seq+ti->ti_len, (tcp_seq)0,
-		    TH_RST|TH_ACK);
+		tcp_respond(tp, ti, m, ti->ti_seq + ti->ti_len, (tcp_seq) 0,
+		    TH_RST | TH_ACK, af);
 	}
 
 	return;
@@ -1484,7 +1521,15 @@ tcp_mss(struct tcpcb *tp, u_int offer)
 	DEBUG_ARG("tp = %p", tp);
 	DEBUG_ARG("offer = %d", offer);
 
-	mss = min(IF_MTU, IF_MRU) - sizeof(struct tcphdr) + sizeof(struct ip);
+	switch (so->so_ffamily) {
+	case AF_INET:
+	    mss = min(IF_MTU, IF_MRU) - sizeof(struct tcphdr)
+	                              + sizeof(struct ip);
+	    break;
+	default:
+	    g_assert_not_reached();
+	}
+
 	if (offer)
 		mss = min(mss, offer);
 	mss = max(mss, 32);