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: NGuillaume Subiron <maethor@subiron.org>
Signed-off-by: NSamuel Thibault <samuel.thibault@ens-lyon.org>
Reviewed-by: NThomas Huth <thuth@redhat.com>

slirp/ip_input.c

@@ -200,7 +200,7 @@ ip_input(struct mbuf *m)
 	 */
 	switch (ip->ip_p) {
 	 case IPPROTO_TCP:
-		tcp_input(m, hlen, (struct socket *)NULL);
+		tcp_input(m, hlen, (struct socket *)NULL, AF_INET);
 		break;
 	 case IPPROTO_UDP:
 		udp_input(m, hlen);

slirp/slirp.c

@@ -586,7 +586,8 @@ void slirp_pollfds_poll(GArray *pollfds, int select_error)
                         /*
                          * Continue tcp_input
                          */
-                        tcp_input((struct mbuf *)NULL, sizeof(struct ip), so);
+                        tcp_input((struct mbuf *)NULL, sizeof(struct ip), so,
+                                  so->so_ffamily);
                         /* continue; */
                     } else {
                         ret = sowrite(so);
@@ -635,7 +636,8 @@ void slirp_pollfds_poll(GArray *pollfds, int select_error)
                         }
 
                     }
-                    tcp_input((struct mbuf *)NULL, sizeof(struct ip), so);
+                    tcp_input((struct mbuf *)NULL, sizeof(struct ip), so,
+                              so->so_ffamily);
                 } /* SS_ISFCONNECTING */
 #endif
             }

slirp/slirp.h

@@ -329,7 +329,7 @@ void ip6_input(struct mbuf *);
 int ip6_output(struct socket *, struct mbuf *, int fast);
 
 /* tcp_input.c */
-void tcp_input(register struct mbuf *, int, struct socket *);
+void tcp_input(register struct mbuf *, int, struct socket *, unsigned short af);
 int tcp_mss(register struct tcpcb *, u_int);
 
 /* tcp_output.c */
@@ -340,7 +340,8 @@ void tcp_setpersist(register struct tcpcb *);
 void tcp_init(Slirp *);
 void tcp_cleanup(Slirp *);
 void tcp_template(struct tcpcb *);
-void tcp_respond(struct tcpcb *, register struct tcpiphdr *, register struct mbuf *, tcp_seq, tcp_seq, int);
+void tcp_respond(struct tcpcb *, register struct tcpiphdr *,
+        register struct mbuf *, tcp_seq, tcp_seq, int, unsigned short);
 struct tcpcb * tcp_newtcpcb(struct socket *);
 struct tcpcb * tcp_close(register struct tcpcb *);
 void tcp_sockclosed(struct tcpcb *);

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);

slirp/tcp_output.c

@@ -61,7 +61,8 @@ tcp_output(struct tcpcb *tp)
 	register long len, win;
 	int off, flags, error;
 	register struct mbuf *m;
-	register struct tcpiphdr *ti;
+	register struct tcpiphdr *ti, tcpiph_save;
+	struct ip *ip;
 	u_char opt[MAX_TCPOPTLEN];
 	unsigned optlen, hdrlen;
 	int idle, sendalot;
@@ -447,13 +448,15 @@ send:
 	 * the template, but need a way to checksum without them.
 	 */
 	m->m_len = hdrlen + len; /* XXX Needed? m_len should be correct */
+	tcpiph_save = *mtod(m, struct tcpiphdr *);
 
-	struct tcpiphdr tcpiph_save = *(mtod(m, struct tcpiphdr *));
+	switch (so->so_ffamily) {
+	case AF_INET:
 	m->m_data += sizeof(struct tcpiphdr) - sizeof(struct tcphdr)
 	                                     - sizeof(struct ip);
 	m->m_len  -= sizeof(struct tcpiphdr) - sizeof(struct tcphdr)
 	                                     - sizeof(struct ip);
-	struct ip *ip = mtod(m, struct ip *);
+	ip = mtod(m, struct ip *);
 
 	ip->ip_len = m->m_len;
 	ip->ip_dst = tcpiph_save.ti_dst;
@@ -464,6 +467,11 @@ send:
 	ip->ip_tos = so->so_iptos;
 
 	error = ip_output(so, m);
+	    break;
+
+	default:
+	    g_assert_not_reached();
+	}
 
 	if (error) {
 out:

slirp/tcp_subr.c

@@ -78,12 +78,19 @@ tcp_template(struct tcpcb *tp)
 	n->ti_mbuf = NULL;
 	memset(&n->ti, 0, sizeof(n->ti));
 	n->ti_x0 = 0;
+	switch (so->so_ffamily) {
+	case AF_INET:
 	n->ti_pr = IPPROTO_TCP;
 	n->ti_len = htons(sizeof(struct tcphdr));
 	n->ti_src = so->so_faddr;
 	n->ti_dst = so->so_laddr;
 	n->ti_sport = so->so_fport;
 	n->ti_dport = so->so_lport;
+	    break;
+
+	default:
+	    g_assert_not_reached();
+	}
 
 	n->ti_seq = 0;
 	n->ti_ack = 0;
@@ -110,7 +117,7 @@ tcp_template(struct tcpcb *tp)
  */
 void
 tcp_respond(struct tcpcb *tp, struct tcpiphdr *ti, struct mbuf *m,
-            tcp_seq ack, tcp_seq seq, int flags)
+            tcp_seq ack, tcp_seq seq, int flags, unsigned short af)
 {
 	register int tlen;
 	int win = 0;
@@ -144,8 +151,14 @@ tcp_respond(struct tcpcb *tp, struct tcpiphdr *ti, struct mbuf *m,
 		m->m_len = sizeof (struct tcpiphdr);
 		tlen = 0;
 #define xchg(a,b,type) { type t; t=a; a=b; b=t; }
+		switch (af) {
+		case AF_INET:
 		xchg(ti->ti_dst.s_addr, ti->ti_src.s_addr, uint32_t);
 		xchg(ti->ti_dport, ti->ti_sport, uint16_t);
+		    break;
+		default:
+		    g_assert_not_reached();
+		}
 #undef xchg
 	}
 	ti->ti_len = htons((u_short)(sizeof (struct tcphdr) + tlen));
@@ -168,11 +181,15 @@ tcp_respond(struct tcpcb *tp, struct tcpiphdr *ti, struct mbuf *m,
 	ti->ti_sum = cksum(m, tlen);
 
 	struct tcpiphdr tcpiph_save = *(mtod(m, struct tcpiphdr *));
+	struct ip *ip;
+
+	switch (af) {
+	case AF_INET:
 	m->m_data += sizeof(struct tcpiphdr) - sizeof(struct tcphdr)
 	                                     - sizeof(struct ip);
 	m->m_len  -= sizeof(struct tcpiphdr) - sizeof(struct tcphdr)
 	                                     - sizeof(struct ip);
-	struct ip *ip = mtod(m, struct ip *);
+	ip = mtod(m, struct ip *);
 	ip->ip_len = tlen;
 	ip->ip_dst = tcpiph_save.ti_dst;
 	ip->ip_src = tcpiph_save.ti_src;
@@ -185,6 +202,11 @@ tcp_respond(struct tcpcb *tp, struct tcpiphdr *ti, struct mbuf *m,
 	}
 
 	(void) ip_output((struct socket *)0, m);
+	    break;
+
+	default:
+	    g_assert_not_reached();
+	}
 }
 
 /*
@@ -388,8 +410,8 @@ void tcp_connect(struct socket *inso)
 {
     Slirp *slirp = inso->slirp;
     struct socket *so;
-    struct sockaddr_in addr;
-    socklen_t addrlen = sizeof(struct sockaddr_in);
+    struct sockaddr_storage addr;
+    socklen_t addrlen = sizeof(struct sockaddr_storage);
     struct tcpcb *tp;
     int s, opt;
 
@@ -414,9 +436,8 @@ void tcp_connect(struct socket *inso)
             free(so); /* NOT sofree */
             return;
         }
-        so->so_lfamily = AF_INET;
-        so->so_laddr = inso->so_laddr;
-        so->so_lport = inso->so_lport;
+        so->lhost = inso->lhost;
+        so->so_ffamily = inso->so_ffamily;
     }
 
     tcp_mss(sototcpcb(so), 0);
@@ -432,7 +453,7 @@ void tcp_connect(struct socket *inso)
     qemu_setsockopt(s, SOL_SOCKET, SO_OOBINLINE, &opt, sizeof(int));
     socket_set_nodelay(s);
 
-    so->fhost.sin = addr;
+    so->fhost.ss = addr;
     sotranslate_accept(so);
 
     /* Close the accept() socket, set right state */

slirp/tcp_timer.c

@@ -278,7 +278,8 @@ tcp_timers(register struct tcpcb *tp, int timer)
 			 * correspondent TCP to respond.
 			 */
 			tcp_respond(tp, &tp->t_template, (struct mbuf *)NULL,
-			    tp->rcv_nxt, tp->snd_una - 1, 0);
+			    tp->rcv_nxt, tp->snd_una - 1, 0,
+			    tp->t_socket->so_ffamily);
 			tp->t_timer[TCPT_KEEP] = TCPTV_KEEPINTVL;
 		} else
 			tp->t_timer[TCPT_KEEP] = TCPTV_KEEP_IDLE;