Commit f7725df3 authored by Samuel Thibault's avatar Samuel Thibault
Browse files

slirp: Add RDNSS advertisement 



This adds the RDNSS option to IPv6 router advertisements, so that the guest
can autoconfigure the DNS server address.

Signed-off-by: default avatarSamuel Thibault <samuel.thibault@ens-lyon.org>
Reviewed-by: default avatarThomas Huth <thuth@redhat.com>

---
Changes since last submission:
- Disable on windows, until we have support for it
parent ef763fa4

slirp/ip6_icmp.c

+24 −3
Original line number Diff line number Diff line
@@ -148,7 +148,11 @@ void ndp_send_ra(Slirp *slirp) 
    rip->ip_nh = IPPROTO_ICMPV6;

    rip->ip_pl = htons(ICMP6_NDP_RA_MINLEN

                        + NDPOPT_LINKLAYER_LEN

                        + NDPOPT_PREFIXINFO_LEN);

                        + NDPOPT_PREFIXINFO_LEN

#ifndef _WIN32

                        + NDPOPT_RDNSS_LEN

#endif

                        );

    t->m_len = sizeof(struct ip6) + ntohs(rip->ip_pl);



    /* Build ICMPv6 packet */
@@ -166,16 +170,16 @@ void ndp_send_ra(Slirp *slirp) 
    ricmp->icmp6_nra.lifetime = htons(NDP_AdvDefaultLifetime);

    ricmp->icmp6_nra.reach_time = htonl(NDP_AdvReachableTime);

    ricmp->icmp6_nra.retrans_time = htonl(NDP_AdvRetransTime);

    t->m_data += ICMP6_NDP_RA_MINLEN;



    /* Source link-layer address (NDP option) */

    t->m_data += ICMP6_NDP_RA_MINLEN;

    struct ndpopt *opt = mtod(t, struct ndpopt *);

    opt->ndpopt_type = NDPOPT_LINKLAYER_SOURCE;

    opt->ndpopt_len = NDPOPT_LINKLAYER_LEN / 8;

    in6_compute_ethaddr(rip->ip_src, opt->ndpopt_linklayer);

    t->m_data += NDPOPT_LINKLAYER_LEN;



    /* Prefix information (NDP option) */

    t->m_data += NDPOPT_LINKLAYER_LEN;

    struct ndpopt *opt2 = mtod(t, struct ndpopt *);

    opt2->ndpopt_type = NDPOPT_PREFIX_INFO;

    opt2->ndpopt_len = NDPOPT_PREFIXINFO_LEN / 8;
@@ -187,8 +191,25 @@ void ndp_send_ra(Slirp *slirp) 
    opt2->ndpopt_prefixinfo.pref_lt = htonl(NDP_AdvPrefLifetime);

    opt2->ndpopt_prefixinfo.reserved2 = 0;

    opt2->ndpopt_prefixinfo.prefix = slirp->vprefix_addr6;

    t->m_data += NDPOPT_PREFIXINFO_LEN;



#ifndef _WIN32

    /* Prefix information (NDP option) */

    /* disabled for windows for now, until get_dns6_addr is implemented */

    struct ndpopt *opt3 = mtod(t, struct ndpopt *);

    opt3->ndpopt_type = NDPOPT_RDNSS;

    opt3->ndpopt_len = NDPOPT_RDNSS_LEN / 8;

    opt3->ndpopt_rdnss.reserved = 0;

    opt3->ndpopt_rdnss.lifetime = htonl(2 * NDP_MaxRtrAdvInterval);

    opt3->ndpopt_rdnss.addr = slirp->vnameserver_addr6;

    t->m_data += NDPOPT_RDNSS_LEN;

#endif



    /* ICMPv6 Checksum */

#ifndef _WIN32

    t->m_data -= NDPOPT_RDNSS_LEN;

#endif

    t->m_data -= NDPOPT_PREFIXINFO_LEN;

    t->m_data -= NDPOPT_LINKLAYER_LEN;

    t->m_data -= ICMP6_NDP_RA_MINLEN;

    t->m_data -= sizeof(struct ip6);

slirp/ip6_icmp.h

+10 −2
Original line number Diff line number Diff line
@@ -122,6 +122,7 @@ struct ndpopt { 
    uint8_t     ndpopt_len;                     /* /!\ In units of 8 octets */

    union {

        unsigned char   linklayer_addr[6];      /* Source/Target Link-layer */

#define ndpopt_linklayer ndpopt_body.linklayer_addr

        struct prefixinfo {                     /* Prefix Information */

            uint8_t     prefix_length;

#ifdef HOST_WORDS_BIGENDIAN
@@ -134,19 +135,26 @@ struct ndpopt { 
            uint32_t    reserved2;

            struct in6_addr prefix;

        } QEMU_PACKED prefixinfo;

    } ndpopt_body;

#define ndpopt_linklayer ndpopt_body.linklayer_addr

#define ndpopt_prefixinfo ndpopt_body.prefixinfo

        struct rdnss {

            uint16_t reserved;

            uint32_t lifetime;

            struct in6_addr addr;

        } QEMU_PACKED rdnss;

#define ndpopt_rdnss ndpopt_body.rdnss

    } ndpopt_body;

} QEMU_PACKED;



/* NDP options type */

#define NDPOPT_LINKLAYER_SOURCE     1   /* Source Link-Layer Address */

#define NDPOPT_LINKLAYER_TARGET     2   /* Target Link-Layer Address */

#define NDPOPT_PREFIX_INFO          3   /* Prefix Information */

#define NDPOPT_RDNSS                25  /* Recursive DNS Server Address */



/* NDP options size, in octets. */

#define NDPOPT_LINKLAYER_LEN    8

#define NDPOPT_PREFIXINFO_LEN   32

#define NDPOPT_RDNSS_LEN        24



/*

 * Definition of type and code field values.