Re: [Qemu-devel] [PATCHv9 03/10] slirp: Adding IPv6 UDP support

[Jason Wang <jasowang@redhat.com>]

On 02/23/2016 03:28 AM, Samuel Thibault wrote:
> From: Guillaume Subiron <maethor@subiron.org>
>
> This adds the sin6 case in the fhost and lhost unions and related macros.
> It adds udp6_input() and udp6_output().
> It adds the IPv6 case in sorecvfrom().
> Finally, udp_input() is called by ip6_input().
>
> 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/Makefile.objs |   2 +-
>  slirp/ip6_input.c   |   2 +-
>  slirp/socket.c      |   5 ++
>  slirp/socket.h      |   6 ++
>  slirp/udp.h         |   5 ++
>  slirp/udp6.c        | 157 ++++++++++++++++++++++++++++++++++++++++++++++++++++
>  6 files changed, 175 insertions(+), 2 deletions(-)
>  create mode 100644 slirp/udp6.c
>
> diff --git a/slirp/Makefile.objs b/slirp/Makefile.objs
> index 4e3a289..6748e4f 100644
> --- a/slirp/Makefile.objs
> +++ b/slirp/Makefile.objs
> @@ -1,5 +1,5 @@
>  common-obj-y = cksum.o if.o ip_icmp.o ip6_icmp.o ip6_input.o ip6_output.o \
>                 ip_input.o ip_output.o dnssearch.o
>  common-obj-y += slirp.o mbuf.o misc.o sbuf.o socket.o tcp_input.o tcp_output.o
> -common-obj-y += tcp_subr.o tcp_timer.o udp.o bootp.o tftp.o arp_table.o \
> +common-obj-y += tcp_subr.o tcp_timer.o udp.o udp6.o bootp.o tftp.o arp_table.o \
>                  ndp_table.o
> diff --git a/slirp/ip6_input.c b/slirp/ip6_input.c
> index b6a438d..9ca6d32 100644
> --- a/slirp/ip6_input.c
> +++ b/slirp/ip6_input.c
> @@ -58,7 +58,7 @@ void ip6_input(struct mbuf *m)
>          icmp6_send_error(m, ICMP6_UNREACH, ICMP6_UNREACH_NO_ROUTE);
>          break;
>      case IPPROTO_UDP:
> -        icmp6_send_error(m, ICMP6_UNREACH, ICMP6_UNREACH_NO_ROUTE);
> +        udp6_input(m);
>          break;
>      case IPPROTO_ICMPV6:
>          icmp6_input(m);
> diff --git a/slirp/socket.c b/slirp/socket.c
> index 32b1ba3..b79ddec 100644
> --- a/slirp/socket.c
> +++ b/slirp/socket.c
> @@ -541,7 +541,12 @@ sorecvfrom(struct socket *so)
>  	                   (struct sockaddr_in *) &daddr,
>  	                   so->so_iptos);
>  	        break;
> +	    case AF_INET6:
> +	        udp6_output(so, m, (struct sockaddr_in6 *) &saddr,
> +	                    (struct sockaddr_in6 *) &daddr);
> +	        break;
>  	    default:
> +	        g_assert_not_reached();
>  	        break;
>  	    }
>  	  } /* rx error */
> diff --git a/slirp/socket.h b/slirp/socket.h
> index bcebce1..e9c9b05 100644
> --- a/slirp/socket.h
> +++ b/slirp/socket.h
> @@ -34,17 +34,23 @@ struct socket {
>    union {   /* foreign host */
>        struct sockaddr_storage ss;
>        struct sockaddr_in sin;
> +      struct sockaddr_in6 sin6;
>    } fhost;
>  #define so_faddr fhost.sin.sin_addr
>  #define so_fport fhost.sin.sin_port
> +#define so_faddr6 fhost.sin6.sin6_addr
> +#define so_fport6 fhost.sin6.sin6_port
>  #define so_ffamily fhost.ss.ss_family
>  
>    union {   /* local host */
>        struct sockaddr_storage ss;
>        struct sockaddr_in sin;
> +      struct sockaddr_in6 sin6;
>    } lhost;
>  #define so_laddr lhost.sin.sin_addr
>  #define so_lport lhost.sin.sin_port
> +#define so_laddr6 lhost.sin6.sin6_addr
> +#define so_lport6 lhost.sin6.sin6_port
>  #define so_lfamily lhost.ss.ss_family
>  
>    uint8_t	so_iptos;	/* Type of service */
> diff --git a/slirp/udp.h b/slirp/udp.h
> index 2f9de38..10cc780 100644
> --- a/slirp/udp.h
> +++ b/slirp/udp.h
> @@ -83,4 +83,9 @@ struct socket * udp_listen(Slirp *, uint32_t, u_int, uint32_t, u_int,
>  int udp_output(struct socket *so, struct mbuf *m,
>                  struct sockaddr_in *saddr, struct sockaddr_in *daddr,
>                  int iptos);
> +
> +void udp6_input(register struct mbuf *);
> +int udp6_output(struct socket *so, struct mbuf *m,
> +                struct sockaddr_in6 *saddr, struct sockaddr_in6 *daddr);
> +
>  #endif
> diff --git a/slirp/udp6.c b/slirp/udp6.c
> new file mode 100644
> index 0000000..8952de2
> --- /dev/null
> +++ b/slirp/udp6.c
> @@ -0,0 +1,157 @@
> +/*
> + * Copyright (c) 2013
> + * Guillaume Subiron
> + */
> +
> +#include "slirp.h"
> +#include "qemu/osdep.h"
> +#include "udp.h"
> +
> +void udp6_input(struct mbuf *m)
> +{
> +    Slirp *slirp = m->slirp;
> +    struct ip6 *ip, save_ip;
> +    struct udphdr *uh;
> +    int hlen = sizeof(struct ip6);
> +    int len;
> +    struct socket *so;
> +    struct sockaddr_in6 lhost;
> +
> +    DEBUG_CALL("udp6_input");
> +    DEBUG_ARG("m = %lx", (long)m);
> +
> +    if (slirp->restricted) {
> +        goto bad;
> +    }
> +
> +    ip = mtod(m, struct ip6 *);
> +    m->m_len -= hlen;
> +    m->m_data += hlen;
> +    uh = mtod(m, struct udphdr *);
> +    m->m_len += hlen;
> +    m->m_data -= hlen;
> +
> +    if (ip6_cksum(m)) {
> +        goto bad;
> +    }
> +
> +    len = ntohs((uint16_t)uh->uh_ulen);
> +
> +    /*
> +     * Make mbuf data length reflect UDP length.
> +     * If not enough data to reflect UDP length, drop.
> +     */
> +    if (ntohs(ip->ip_pl) != len) {
> +        if (len > ntohs(ip->ip_pl)) {
> +            goto bad;
> +        }
> +        m_adj(m, len - ntohs(ip->ip_pl));
> +        ip->ip_pl = htons(len);
> +    }
> +
> +    /*
> +     * Save a copy of the IP header in case we want restore it
> +     * for sending an ICMP error message in response.
> +     */
> +    save_ip = *ip;
> +
> +    /* TODO handle DHCP/BOOTP */
> +    /* TODO handle TFTP */
> +
> +    /* Locate pcb for datagram. */
> +    lhost.sin6_family = AF_INET6;
> +    lhost.sin6_addr = ip->ip_src;
> +    lhost.sin6_port = uh->uh_sport;
> +
> +    so = solookup(&slirp->udp_last_so, &slirp->udb,
> +                  (struct sockaddr_storage *) &lhost, NULL);
> +
> +    if (so == NULL) {
> +        /* If there's no socket for this packet, create one. */
> +        so = socreate(slirp);
> +        if (!so) {
> +            goto bad;
> +        }
> +        if (udp_attach(so, AF_INET6) == -1) {
> +            DEBUG_MISC((dfd, " udp6_attach errno = %d-%s\n",
> +                        errno, strerror(errno)));
> +            sofree(so);
> +            goto bad;
> +        }
> +
> +        /* Setup fields */
> +        so->so_lfamily = AF_INET6;
> +        so->so_laddr6 = ip->ip_src;
> +        so->so_lport6 = uh->uh_sport;
> +    }
> +
> +    so->so_ffamily = AF_INET6;
> +    so->so_faddr6 = ip->ip_dst; /* XXX */
> +    so->so_fport6 = uh->uh_dport; /* XXX */
> +
> +    hlen += sizeof(struct udphdr);
> +    m->m_len -= hlen;
> +    m->m_data += hlen;
> +
> +    /*
> +     * Now we sendto() the packet.
> +     */
> +    if (sosendto(so, m) == -1) {
> +        m->m_len += hlen;
> +        m->m_data -= hlen;
> +        *ip = save_ip;
> +        DEBUG_MISC((dfd, "udp tx errno = %d-%s\n", errno, strerror(errno)));
> +        /* TODO: ICMPv6 error */
> +        /*icmp_error(m, ICMP_UNREACH,ICMP_UNREACH_NET, 0,strerror(errno));*/
> +        goto bad;
> +    }
> +
> +    m_free(so->so_m);   /* used for ICMP if error on sorecvfrom */
> +
> +    /* restore the orig mbuf packet */
> +    m->m_len += hlen;
> +    m->m_data -= hlen;
> +    *ip = save_ip;
> +    so->so_m = m;
> +
> +    return;
> +bad:
> +    m_free(m);
> +}

Part of the codes looks duplicated with ipv4 version. Any chances to
merge them like tcp?