LXR qemu/slirp/udp6.c

   1/*
   2 * Copyright (c) 2013
   3 * Guillaume Subiron
   4 */
   5
   6#include "qemu/osdep.h"
   7#include "qemu-common.h"
   8#include "slirp.h"
   9#include "udp.h"
  10#include "dhcpv6.h"
  11
  12void udp6_input(struct mbuf *m)
  13{
  14    Slirp *slirp = m->slirp;
  15    struct ip6 *ip, save_ip;
  16    struct udphdr *uh;
  17    int iphlen = sizeof(struct ip6);
  18    int len;
  19    struct socket *so;
  20    struct sockaddr_in6 lhost;
  21
  22    DEBUG_CALL("udp6_input");
  23    DEBUG_ARG("m = %lx", (long)m);
  24
  25    if (slirp->restricted) {
  26        goto bad;
  27    }
  28
  29    ip = mtod(m, struct ip6 *);
  30    m->m_len -= iphlen;
  31    m->m_data += iphlen;
  32    uh = mtod(m, struct udphdr *);
  33    m->m_len += iphlen;
  34    m->m_data -= iphlen;
  35
  36    if (ip6_cksum(m)) {
  37        goto bad;
  38    }
  39
  40    len = ntohs((uint16_t)uh->uh_ulen);
  41
  42    /*
  43     * Make mbuf data length reflect UDP length.
  44     * If not enough data to reflect UDP length, drop.
  45     */
  46    if (ntohs(ip->ip_pl) != len) {
  47        if (len > ntohs(ip->ip_pl)) {
  48            goto bad;
  49        }
  50        m_adj(m, len - ntohs(ip->ip_pl));
  51        ip->ip_pl = htons(len);
  52    }
  53
  54    /*
  55     * Save a copy of the IP header in case we want restore it
  56     * for sending an ICMP error message in response.
  57     */
  58    save_ip = *ip;
  59
  60    /* Locate pcb for datagram. */
  61    lhost.sin6_family = AF_INET6;
  62    lhost.sin6_addr = ip->ip_src;
  63    lhost.sin6_port = uh->uh_sport;
  64
  65    /* handle DHCPv6 */
  66    if (ntohs(uh->uh_dport) == DHCPV6_SERVER_PORT &&
  67        (in6_equal(&ip->ip_dst, &slirp->vhost_addr6) ||
  68         in6_dhcp_multicast(&ip->ip_dst))) {
  69        m->m_data += iphlen;
  70        m->m_len -= iphlen;
  71        dhcpv6_input(&lhost, m);
  72        m->m_data -= iphlen;
  73        m->m_len += iphlen;
  74        goto bad;
  75    }
  76
  77    /* handle TFTP */
  78    if (ntohs(uh->uh_dport) == TFTP_SERVER &&
  79        !memcmp(ip->ip_dst.s6_addr, slirp->vhost_addr6.s6_addr, 16)) {
  80        m->m_data += iphlen;
  81        m->m_len -= iphlen;
  82        tftp_input((struct sockaddr_storage *)&lhost, m);
  83        m->m_data -= iphlen;
  84        m->m_len += iphlen;
  85        goto bad;
  86    }
  87
  88    so = solookup(&slirp->udp_last_so, &slirp->udb,
  89                  (struct sockaddr_storage *) &lhost, NULL);
  90
  91    if (so == NULL) {
  92        /* If there's no socket for this packet, create one. */
  93        so = socreate(slirp);
  94        if (!so) {
  95            goto bad;
  96        }
  97        if (udp_attach(so, AF_INET6) == -1) {
  98            DEBUG_MISC((dfd, " udp6_attach errno = %d-%s\n",
  99                        errno, strerror(errno)));
 100            sofree(so);
 101            goto bad;
 102        }
 103
 104        /* Setup fields */
 105        so->so_lfamily = AF_INET6;
 106        so->so_laddr6 = ip->ip_src;
 107        so->so_lport6 = uh->uh_sport;
 108    }
 109
 110    so->so_ffamily = AF_INET6;
 111    so->so_faddr6 = ip->ip_dst; /* XXX */
 112    so->so_fport6 = uh->uh_dport; /* XXX */
 113
 114    iphlen += sizeof(struct udphdr);
 115    m->m_len -= iphlen;
 116    m->m_data += iphlen;
 117
 118    /*
 119     * Now we sendto() the packet.
 120     */
 121    if (sosendto(so, m) == -1) {
 122        m->m_len += iphlen;
 123        m->m_data -= iphlen;
 124        *ip = save_ip;
 125        DEBUG_MISC((dfd, "udp tx errno = %d-%s\n", errno, strerror(errno)));
 126        icmp6_send_error(m, ICMP6_UNREACH, ICMP6_UNREACH_NO_ROUTE);
 127        goto bad;
 128    }
 129
 130    m_free(so->so_m);   /* used for ICMP if error on sorecvfrom */
 131
 132    /* restore the orig mbuf packet */
 133    m->m_len += iphlen;
 134    m->m_data -= iphlen;
 135    *ip = save_ip;
 136    so->so_m = m;
 137
 138    return;
 139bad:
 140    m_free(m);
 141}
 142
 143int udp6_output(struct socket *so, struct mbuf *m,
 144        struct sockaddr_in6 *saddr, struct sockaddr_in6 *daddr)
 145{
 146    struct ip6 *ip;
 147    struct udphdr *uh;
 148
 149    DEBUG_CALL("udp6_output");
 150    DEBUG_ARG("so = %lx", (long)so);
 151    DEBUG_ARG("m = %lx", (long)m);
 152
 153    /* adjust for header */
 154    m->m_data -= sizeof(struct udphdr);
 155    m->m_len += sizeof(struct udphdr);
 156    uh = mtod(m, struct udphdr *);
 157    m->m_data -= sizeof(struct ip6);
 158    m->m_len += sizeof(struct ip6);
 159    ip = mtod(m, struct ip6 *);
 160
 161    /* Build IP header */
 162    ip->ip_pl = htons(m->m_len - sizeof(struct ip6));
 163    ip->ip_nh = IPPROTO_UDP;
 164    ip->ip_src = saddr->sin6_addr;
 165    ip->ip_dst = daddr->sin6_addr;
 166
 167    /* Build UDP header */
 168    uh->uh_sport = saddr->sin6_port;
 169    uh->uh_dport = daddr->sin6_port;
 170    uh->uh_ulen = ip->ip_pl;
 171    uh->uh_sum = 0;
 172    uh->uh_sum = ip6_cksum(m);
 173    if (uh->uh_sum == 0) {
 174        uh->uh_sum = 0xffff;
 175    }
 176
 177    return ip6_output(so, m, 0);
 178}
 179