On 08.02.2016 11:28, Samuel Thibault wrote:
> From: Guillaume Subiron <maet...@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 <maet...@subiron.org>
> Signed-off-by: Samuel Thibault <samuel.thiba...@ens-lyon.org>
> ---
> slirp/ip_input.c | 2 +-
> slirp/slirp.c | 6 ++++--
> slirp/slirp.h | 5 +++--
> slirp/tcp_input.c | 52 ++++++++++++++++++++++++++++++++++++++++++++--------
> slirp/tcp_output.c | 14 +++++++++++---
> slirp/tcp_subr.c | 37 +++++++++++++++++++++++++++++--------
> slirp/tcp_timer.c | 3 ++-
> 7 files changed, 94 insertions(+), 25 deletions(-)
...
> diff --git a/slirp/tcp_input.c b/slirp/tcp_input.c
> index 26b0c8b..0cc279b 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:
> + goto drop;
> + }
>
> /*
> * 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:
> + goto drop;
> + }
>
> so = solookup(&slirp->tcp_last_so, &slirp->tcb, &lhost, &fhost);
>
> @@ -389,8 +402,17 @@ findso:
> so->lhost.ss = lhost;
> so->fhost.ss = fhost;
>
> - if ((so->so_iptos = tcp_tos(so)) == 0)
> + so->so_iptos = tcp_tos(so);
> + if (so->so_iptos == 0) {
> + switch (af) {
> + case AF_INET:
> so->so_iptos = ((struct ip *)ti)->ip_tos;
I think you could also indent this here immediately ... it's only one
line, so indenting immediately should not hurt readability here.
> + break;
> + default:
> + goto drop;
> + break;
> + }
> + }
>
> tp = sototcpcb(so);
> tp->t_state = TCPS_LISTEN;
> @@ -569,7 +591,8 @@ 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) {
> @@ -607,7 +630,7 @@ 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 */
> @@ -616,7 +639,13 @@ 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);
> + switch (af) {
> + case AF_INET:
> *ip=save_ip;
Could also be indented immediately.
> + break;
> + default:
> + goto drop;
> + }
> icmp_send_error(m, ICMP_UNREACH, code, 0, strerror(errno));
> }
> tcp_close(tp);
> @@ -1289,11 +1318,11 @@ 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;
> @@ -1484,7 +1513,14 @@ tcp_mss(struct tcpcb *tp, u_int offer)
> DEBUG_ARG("tp = %p", tp);
> DEBUG_ARG("offer = %d", offer);
>
> + switch (so->so_ffamily) {
> + case AF_INET:
> mss = min(IF_MTU, IF_MRU) - sizeof(struct tcphdr) + sizeof(struct ip);
dito, indent immediately.
> + break;
> + default:
> + break;
> + }
> +
> if (offer)
> mss = min(mss, offer);
> mss = max(mss, 32);
> diff --git a/slirp/tcp_output.c b/slirp/tcp_output.c
> index 7fc6a87..62ab1e5 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:
> + goto out;
Hmm, this jumps to a "return (error)" statement ... but as far as I can
see, error has never been initialized in this case? So I think you
either should set the error variable explicitely here, or simply "return
1" immediately instead of doing the goto.
> + }
>
> if (error) {
> out:
Thomas
