summaryrefslogtreecommitdiffstats
path: root/slirp/udp6.c
blob: 7c4a6b003a832d63db4b02bb065b3738e6a18e63 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
/*
 * Copyright (c) 2013
 * Guillaume Subiron
 */

#include "qemu/osdep.h"
#include "qemu-common.h"
#include "slirp.h"
#include "udp.h"
#include "dhcpv6.h"

void udp6_input(struct mbuf *m)
{
    Slirp *slirp = m->slirp;
    struct ip6 *ip, save_ip;
    struct udphdr *uh;
    int iphlen = 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 -= iphlen;
    m->m_data += iphlen;
    uh = mtod(m, struct udphdr *);
    m->m_len += iphlen;
    m->m_data -= iphlen;

    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;

    /* Locate pcb for datagram. */
    lhost.sin6_family = AF_INET6;
    lhost.sin6_addr = ip->ip_src;
    lhost.sin6_port = uh->uh_sport;

    /* handle DHCPv6 */
    if (ntohs(uh->uh_dport) == DHCPV6_SERVER_PORT &&
        (in6_equal(&ip->ip_dst, &slirp->vhost_addr6) ||
         in6_dhcp_multicast(&ip->ip_dst))) {
        m->m_data += iphlen;
        m->m_len -= iphlen;
        dhcpv6_input(&lhost, m);
        m->m_data -= iphlen;
        m->m_len += iphlen;
        goto bad;
    }

    /* handle TFTP */
    if (ntohs(uh->uh_dport) == TFTP_SERVER &&
        !memcmp(ip->ip_dst.s6_addr, slirp->vhost_addr6.s6_addr, 16)) {
        m->m_data += iphlen;
        m->m_len -= iphlen;
        tftp_input((struct sockaddr_storage *)&lhost, m);
        m->m_data -= iphlen;
        m->m_len += iphlen;
        goto bad;
    }

    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 */

    iphlen += sizeof(struct udphdr);
    m->m_len -= iphlen;
    m->m_data += iphlen;

    /*
     * Now we sendto() the packet.
     */
    if (sosendto(so, m) == -1) {
        m->m_len += iphlen;
        m->m_data -= iphlen;
        *ip = save_ip;
        DEBUG_MISC((dfd, "udp tx errno = %d-%s\n", errno, strerror(errno)));
        icmp6_send_error(m, ICMP6_UNREACH, ICMP6_UNREACH_NO_ROUTE);
        goto bad;
    }

    m_free(so->so_m);   /* used for ICMP if error on sorecvfrom */

    /* restore the orig mbuf packet */
    m->m_len += iphlen;
    m->m_data -= iphlen;
    *ip = save_ip;
    so->so_m = m;

    return;
bad:
    m_free(m);
}

int udp6_output(struct socket *so, struct mbuf *m,
        struct sockaddr_in6 *saddr, struct sockaddr_in6 *daddr)
{
    struct ip6 *ip;
    struct udphdr *uh;

    DEBUG_CALL("udp6_output");
    DEBUG_ARG("so = %lx", (long)so);
    DEBUG_ARG("m = %lx", (long)m);

    /* adjust for header */
    m->m_data -= sizeof(struct udphdr);
    m->m_len += sizeof(struct udphdr);
    uh = mtod(m, struct udphdr *);
    m->m_data -= sizeof(struct ip6);
    m->m_len += sizeof(struct ip6);
    ip = mtod(m, struct ip6 *);

    /* Build IP header */
    ip->ip_pl = htons(m->m_len - sizeof(struct ip6));
    ip->ip_nh = IPPROTO_UDP;
    ip->ip_src = saddr->sin6_addr;
    ip->ip_dst = daddr->sin6_addr;

    /* Build UDP header */
    uh->uh_sport = saddr->sin6_port;
    uh->uh_dport = daddr->sin6_port;
    uh->uh_ulen = ip->ip_pl;
    uh->uh_sum = 0;
    uh->uh_sum = ip6_cksum(m);
    if (uh->uh_sum == 0) {
        uh->uh_sum = 0xffff;
    }

    return ip6_output(so, m, 0);
}