[Qemu-devel] [PATCHv10 06/11] slirp: Generalizing and neutralizing various TCP functions before adding IPv6 stuff

[Samuel Thibault <samuel.thibault@ens-lyon.org>]

From: Guillaume Subiron <maethor@subiron.org>

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>
---
 slirp/ip_input.c   |  2 +-
 slirp/slirp.c      |  6 +++--
 slirp/slirp.h      |  5 ++--
 slirp/tcp_input.c  | 73 +++++++++++++++++++++++++++++++++++++++++++-----------
 slirp/tcp_output.c | 14 ++++++++---
 slirp/tcp_subr.c   | 37 +++++++++++++++++++++------
 slirp/tcp_timer.c  |  3 ++-
 7 files changed, 109 insertions(+), 31 deletions(-)

diff --git a/slirp/ip_input.c b/slirp/ip_input.c
index 16fb2cb..12f173d 100644
--- a/slirp/ip_input.c
+++ b/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);
diff --git a/slirp/slirp.c b/slirp/slirp.c
index dd4f6d2..50b36f4 100644
--- a/slirp/slirp.c
+++ b/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
             }
diff --git a/slirp/slirp.h b/slirp/slirp.h
index 1d53faa..c8c784a 100644
--- a/slirp/slirp.h
+++ b/slirp/slirp.h
@@ -331,7 +331,7 @@ 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 */
@@ -342,7 +342,8 @@ 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 *);
diff --git a/slirp/tcp_input.c b/slirp/tcp_input.c
index 4e2f202..1ee8f7b 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) {
@@ -601,27 +623,42 @@ findso:
               (errno != EINPROGRESS) && (errno != EWOULDBLOCK)
 #endif
           ) {
-	    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);
@@ -1293,11 +1330,11 @@ 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;
@@ -1488,7 +1525,15 @@ 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);
diff --git a/slirp/tcp_output.c b/slirp/tcp_output.c
index 7fc6a87..32201fb 100644
--- a/slirp/tcp_output.c
+++ b/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:
diff --git a/slirp/tcp_subr.c b/slirp/tcp_subr.c
index cd021df..ee101e2 100644
--- a/slirp/tcp_subr.c
+++ b/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 */
diff --git a/slirp/tcp_timer.c b/slirp/tcp_timer.c
index 1214c2e..8f5dd77 100644
--- a/slirp/tcp_timer.c
+++ b/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;
-- 
2.7.0