[Qemu-devel] [PATCH 13/16] slirp: Generalizing and neutralizing various TCP functions before adding IPv6 stuff

[Samuel Thibault]

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.

Signed-off-by: Guillaume Subiron <address@hidden>
---
 slirp/ip_input.c   |   2 +-
 slirp/slirp.c      |   6 ++-
 slirp/slirp.h      |   5 +-
 slirp/tcp_input.c  | 142 +++++++++++++++++++++++++++++++++--------------------
 slirp/tcp_output.c |  43 +++++++++-------
 slirp/tcp_subr.c   |  94 +++++++++++++++++++++--------------
 slirp/tcp_timer.c  |   3 +-
 7 files changed, 181 insertions(+), 114 deletions(-)

diff --git a/slirp/ip_input.c b/slirp/ip_input.c
index 1925cdc..9aa8909 100644
--- a/slirp/ip_input.c
+++ b/slirp/ip_input.c
@@ -199,7 +199,7 @@ 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 79025cd..9bee487 100644
--- a/slirp/slirp.c
+++ b/slirp/slirp.c
@@ -576,7 +576,8 @@ 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);
@@ -625,7 +626,8 @@ 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 d16400b..3cdf984 100644
--- a/slirp/slirp.h
+++ b/slirp/slirp.h
@@ -354,7 +354,7 @@ 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 *, sa_family_t af);
 int tcp_mss(register struct tcpcb *, u_int);
 
 /* tcp_output.c */
@@ -365,7 +365,8 @@ 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, sa_family_t);
 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 dde89b6..3409557 100644
--- a/slirp/tcp_input.c
+++ b/slirp/tcp_input.c
@@ -213,7 +213,7 @@ 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, sa_family_t af)
 {
        struct ip save_ip, *ip;
        register struct tcpiphdr *ti;
@@ -254,46 +254,53 @@ tcp_input(struct mbuf *m, int iphlen, struct socket *inso)
        }
        slirp = m->slirp;
 
-       if (iphlen > sizeof(struct ip )) {
-         ip_stripoptions(m, (struct mbuf *)0);
-         iphlen=sizeof(struct ip );
-       }
-       /* XXX Check if too short */
+       switch (af) {
+       case AF_INET:
+           if (iphlen > sizeof(struct ip)) {
+               ip_stripoptions(m, (struct mbuf *)0);
+               iphlen = sizeof(struct ip);
+           }
+           /* XXX Check if too short */
 
 
-       /*
-        * Save a copy of the IP header in case we want restore it
-        * for sending an ICMP error message in response.
-        */
-       ip=mtod(m, struct ip *);
-       save_ip = *ip;
-       save_ip.ip_len+= iphlen;
+           /*
+            * Save a copy of the IP header in case we want restore it
+            * for sending an ICMP error message in response.
+            */
+           ip = mtod(m, struct ip *);
+           save_ip = *ip;
+           save_ip.ip_len += iphlen;
 
-       /*
-        * Get IP and TCP header together in first mbuf.
-        * Note: IP leaves IP header in first mbuf.
-        */
-       m->m_data -= sizeof(struct tcpiphdr) - (sizeof(struct ip)
-                                            + sizeof(struct tcphdr));
-       m->m_len += sizeof(struct tcpiphdr) - (sizeof(struct ip)
-                                           + sizeof(struct tcphdr));
-       ti = mtod(m, struct tcpiphdr *);
+           /*
+            * Get IP and TCP header together in first mbuf.
+            * Note: IP leaves IP header in first mbuf.
+            */
+           m->m_data -= sizeof(struct tcpiphdr) - (sizeof(struct ip)
+                                                + sizeof(struct tcphdr));
+           m->m_len  += sizeof(struct tcpiphdr) - (sizeof(struct ip)
+                                                + sizeof(struct tcphdr));
+           ti = mtod(m, struct tcpiphdr *);
 
-       /*
-        * Checksum extended TCP header and data.
-        */
-       tlen = ip->ip_len;
-       tcpiphdr2qlink(ti)->next = tcpiphdr2qlink(ti)->prev = NULL;
-       memset(&ti->ih_mbuf, 0 , sizeof(struct mbuf_ptr));
-       memset(&ti->ti, 0, sizeof(ti->ti));
-       ti->ti_x0 = 0;
-       ti->ti_src = save_ip.ip_src;
-       ti->ti_dst = save_ip.ip_dst;
-       ti->ti_pr = save_ip.ip_p;
-       ti->ti_len = htons((uint16_t)tlen);
-       len = ((sizeof(struct tcpiphdr) - sizeof(struct tcphdr)) + tlen);
-       if(cksum(m, len)) {
-         goto drop;
+           /*
+            * Checksum extended TCP header and data.
+            */
+           tlen = ip->ip_len;
+           tcpiphdr2qlink(ti)->next = tcpiphdr2qlink(ti)->prev = NULL;
+           memset(&ti->ih_mbuf, 0 , sizeof(struct mbuf_ptr));
+           memset(&ti->ti, 0, sizeof(ti->ti));
+           ti->ti_x0 = 0;
+           ti->ti_src = save_ip.ip_src;
+           ti->ti_dst = save_ip.ip_dst;
+           ti->ti_pr = save_ip.ip_p;
+           ti->ti_len = htons((uint16_t)tlen);
+           len = ((sizeof(struct tcpiphdr) - sizeof(struct tcphdr)) + tlen);
+           if (cksum(m, len)) {
+               goto drop;
+           }
+           break;
+
+       default:
+           goto drop;
        }
 
        /*
@@ -330,12 +337,18 @@ tcp_input(struct mbuf *m, int iphlen, struct socket *inso)
         * Locate pcb for segment.
         */
 findso:
-       lhost.ss_family = AF_INET;
-       ((struct sockaddr_in *)&lhost)->sin_addr = ti->ti_src;
-       ((struct sockaddr_in *)&lhost)->sin_port = ti->ti_sport;
-       fhost.ss_family = AF_INET;
-       ((struct sockaddr_in *)&fhost)->sin_addr = ti->ti_dst;
-       ((struct sockaddr_in *)&fhost)->sin_port = ti->ti_dport;
+       lhost.ss_family = af;
+       fhost.ss_family = af;
+       switch (af) {
+       case AF_INET:
+           ((struct sockaddr_in *)&lhost)->sin_addr = ti->ti_src;
+           ((struct sockaddr_in *)&lhost)->sin_port = ti->ti_sport;
+           ((struct sockaddr_in *)&fhost)->sin_addr = ti->ti_dst;
+           ((struct sockaddr_in *)&fhost)->sin_port = ti->ti_dport;
+           break;
+       default:
+           goto drop;
+       }
 
        so = solookup(&slirp->tcp_last_so, &slirp->tcb, &lhost, &fhost);
 
@@ -385,8 +398,17 @@ 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:
+                 goto drop;
+                 break;
+             }
+         }
 
          tp = sototcpcb(so);
          tp->t_state = TCPS_LISTEN;
@@ -565,8 +587,9 @@ 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) ==
-             slirp->vnetwork_addr.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) {
                /* May be an add exec */
@@ -598,7 +621,7 @@ findso:
            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);
+                         TH_RST|TH_ACK, af);
            } else {
              if(errno == EHOSTUNREACH) code=ICMP_UNREACH_HOST;
              HTONL(ti->ti_seq);             /* restore tcp header */
@@ -607,7 +630,13 @@ findso:
              HTONS(ti->ti_urp);
              m->m_data -= sizeof(struct tcpiphdr)+off-sizeof(struct tcphdr);
              m->m_len  += sizeof(struct tcpiphdr)+off-sizeof(struct tcphdr);
-             *ip=save_ip;
+             switch (af) {
+             case AF_INET:
+                 *ip = save_ip;
+                 break;
+             default:
+                 goto drop;
+             }
              icmp_send_error(m, ICMP_UNREACH, code, 0, strerror(errno));
            }
             tcp_close(tp);
@@ -1280,11 +1309,11 @@ 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);
+                   TH_RST|TH_ACK, af);
        }
 
        return;
@@ -1475,7 +1504,16 @@ tcp_mss(struct tcpcb *tp, u_int offer)
        DEBUG_ARG("tp = %lx", (long)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:
+           /* :TODO:maethor:130319: ??? */
+           break;
+       }
+
        if (offer)
                mss = min(mss, offer);
        mss = max(mss, 32);
diff --git a/slirp/tcp_output.c b/slirp/tcp_output.c
index 4726f00..ce0d0e6 100644
--- a/slirp/tcp_output.c
+++ b/slirp/tcp_output.c
@@ -60,7 +60,8 @@ 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;
@@ -446,23 +447,29 @@ send:
         * the template, but need a way to checksum without them.
         */
        m->m_len = hdrlen + len; /* XXX Needed? m_len should be correct */
-
-       struct tcpiphdr tcpiph_save = *(mtod(m, struct tcpiphdr *));
-       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->ip_len = m->m_len;
-       ip->ip_dst = tcpiph_save.ti_dst;
-       ip->ip_src = tcpiph_save.ti_src;
-       ip->ip_p = tcpiph_save.ti_pr;
-
-       ip->ip_ttl = IPDEFTTL;
-       ip->ip_tos = so->so_iptos;
-
-       error = ip_output(so, m);
+       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);
+           ip = mtod(m, struct ip *);
+
+           ip->ip_len = m->m_len;
+           ip->ip_dst = tcpiph_save.ti_dst;
+           ip->ip_src = tcpiph_save.ti_src;
+           ip->ip_p = tcpiph_save.ti_pr;
+
+           ip->ip_ttl = IPDEFTTL;
+           ip->ip_tos = so->so_iptos;
+           error = ip_output(so, m);
+           break;
+
+       default:
+           goto out;
+       }
 
        if (error) {
 out:
diff --git a/slirp/tcp_subr.c b/slirp/tcp_subr.c
index b052947..ba4eb80 100644
--- a/slirp/tcp_subr.c
+++ b/slirp/tcp_subr.c
@@ -77,12 +77,20 @@ tcp_template(struct tcpcb *tp)
        n->ti_mbuf = NULL;
        memset(&n->ti, 0, sizeof(n->ti));
        n->ti_x0 = 0;
-       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;
+       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:
+           /* :TODO:maethor:130321: ? */
+           break;
+       }
 
        n->ti_seq = 0;
        n->ti_ack = 0;
@@ -109,7 +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, sa_family_t af)
 {
        register int tlen;
        int win = 0;
@@ -143,8 +151,15 @@ 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; }
-               xchg(ti->ti_dst.s_addr, ti->ti_src.s_addr, uint32_t);
-               xchg(ti->ti_dport, ti->ti_sport, uint16_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:
+                   /* :TODO:maethor:130321: ? */
+                   break;
+               }
 #undef xchg
        }
        ti->ti_len = htons((u_short)(sizeof (struct tcphdr) + tlen));
@@ -167,23 +182,33 @@ 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 *));
-       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->ip_len = tlen;
-       ip->ip_dst = tcpiph_save.ti_dst;
-       ip->ip_src = tcpiph_save.ti_src;
-       ip->ip_p = tcpiph_save.ti_pr;
-
-       if (flags & TH_RST) {
-               ip->ip_ttl = MAXTTL;
-       } else {
-               ip->ip_ttl = IPDEFTTL;
+       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);
+           ip = mtod(m, struct ip *);
+           ip->ip_len = tlen;
+           ip->ip_dst = tcpiph_save.ti_dst;
+           ip->ip_src = tcpiph_save.ti_src;
+           ip->ip_p = tcpiph_save.ti_pr;
+
+           if (flags & TH_RST) {
+               ip->ip_ttl = MAXTTL;
+           } else {
+               ip->ip_ttl = IPDEFTTL;
+           }
+
+           (void) ip_output((struct socket *)0, m);
+           break;
+
+       default:
+           /* :TODO:maethor:130321: ? */
+           break;
        }
-
-       (void) ip_output((struct socket *)0, m);
 }
 
 /*
@@ -387,8 +412,8 @@ 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;
 
@@ -413,9 +438,7 @@ 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;
     }
 
     tcp_mss(sototcpcb(so), 0);
@@ -431,15 +454,10 @@ void tcp_connect(struct socket *inso)
     qemu_setsockopt(s, SOL_SOCKET, SO_OOBINLINE, &opt, sizeof(int));
     socket_set_nodelay(s);
 
-    so->so_ffamily = AF_INET;
-    so->so_fport = addr.sin_port;
-    so->so_faddr = addr.sin_addr;
+    addr.ss_family = inso->so_ffamily;
+    so->fhost.ss = addr;
     /* Translate connections from localhost to the real hostname */
-    if (so->so_faddr.s_addr == 0 ||
-        (so->so_faddr.s_addr & loopback_mask) ==
-        (loopback_addr.s_addr & loopback_mask)) {
-        so->so_faddr = slirp->vhost_addr;
-    }
+    sotranslate_in(so, &(so->fhost.ss));
 
     /* Close the accept() socket, set right state */
     if (inso->so_state & SS_FACCEPTONCE) {
diff --git a/slirp/tcp_timer.c b/slirp/tcp_timer.c
index 6c5bb11..42c6e7e 100644
--- a/slirp/tcp_timer.c
+++ b/slirp/tcp_timer.c
@@ -277,7 +277,8 @@ 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;
-- 
1.8.4.2