aboutsummaryrefslogtreecommitdiff
path: root/slirp/ip6_icmp.c
blob: 298a48dd251b079832f3d53dfce97a26e8d0f6af (plain)
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
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
/*
 * Copyright (c) 2013
 * Guillaume Subiron, Yann Bordenave, Serigne Modou Wagne.
 */

#include "qemu/osdep.h"
#include "slirp.h"
#include "ip6_icmp.h"
#include "qemu/timer.h"
#include "qemu/error-report.h"
#include "qemu/log.h"

#define NDP_Interval g_rand_int_range(slirp->grand, \
        NDP_MinRtrAdvInterval, NDP_MaxRtrAdvInterval)

static void ra_timer_handler(void *opaque)
{
    Slirp *slirp = opaque;
    timer_mod(slirp->ra_timer,
              qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + NDP_Interval);
    ndp_send_ra(slirp);
}

void icmp6_init(Slirp *slirp)
{
    if (!slirp->in6_enabled) {
        return;
    }

    slirp->ra_timer = timer_new_ms(QEMU_CLOCK_VIRTUAL, ra_timer_handler, slirp);
    timer_mod(slirp->ra_timer,
              qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + NDP_Interval);
}

void icmp6_cleanup(Slirp *slirp)
{
    if (!slirp->in6_enabled) {
        return;
    }

    timer_del(slirp->ra_timer);
    timer_free(slirp->ra_timer);
}

static void icmp6_send_echoreply(struct mbuf *m, Slirp *slirp, struct ip6 *ip,
        struct icmp6 *icmp)
{
    struct mbuf *t = m_get(slirp);
    t->m_len = sizeof(struct ip6) + ntohs(ip->ip_pl);
    memcpy(t->m_data, m->m_data, t->m_len);

    /* IPv6 Packet */
    struct ip6 *rip = mtod(t, struct ip6 *);
    rip->ip_dst = ip->ip_src;
    rip->ip_src = ip->ip_dst;

    /* ICMPv6 packet */
    t->m_data += sizeof(struct ip6);
    struct icmp6 *ricmp = mtod(t, struct icmp6 *);
    ricmp->icmp6_type = ICMP6_ECHO_REPLY;
    ricmp->icmp6_cksum = 0;

    /* Checksum */
    t->m_data -= sizeof(struct ip6);
    ricmp->icmp6_cksum = ip6_cksum(t);

    ip6_output(NULL, t, 0);
}

void icmp6_send_error(struct mbuf *m, uint8_t type, uint8_t code)
{
    Slirp *slirp = m->slirp;
    struct mbuf *t;
    struct ip6 *ip = mtod(m, struct ip6 *);

    DEBUG_CALL("icmp6_send_error");
    DEBUG_ARGS((dfd, " type = %d, code = %d\n", type, code));

    if (IN6_IS_ADDR_MULTICAST(&ip->ip_src) ||
            IN6_IS_ADDR_UNSPECIFIED(&ip->ip_src)) {
        /* TODO icmp error? */
        return;
    }

    t = m_get(slirp);

    /* IPv6 packet */
    struct ip6 *rip = mtod(t, struct ip6 *);
    rip->ip_src = (struct in6_addr)LINKLOCAL_ADDR;
    rip->ip_dst = ip->ip_src;
#if !defined(_WIN32) || (_WIN32_WINNT >= 0x0600)
    char addrstr[INET6_ADDRSTRLEN];
    inet_ntop(AF_INET6, &rip->ip_dst, addrstr, INET6_ADDRSTRLEN);
    DEBUG_ARG("target = %s", addrstr);
#endif

    rip->ip_nh = IPPROTO_ICMPV6;
    const int error_data_len = MIN(m->m_len,
            IF_MTU - (sizeof(struct ip6) + ICMP6_ERROR_MINLEN));
    rip->ip_pl = htons(ICMP6_ERROR_MINLEN + error_data_len);
    t->m_len = sizeof(struct ip6) + ntohs(rip->ip_pl);

    /* ICMPv6 packet */
    t->m_data += sizeof(struct ip6);
    struct icmp6 *ricmp = mtod(t, struct icmp6 *);
    ricmp->icmp6_type = type;
    ricmp->icmp6_code = code;
    ricmp->icmp6_cksum = 0;

    switch (type) {
    case ICMP6_UNREACH:
    case ICMP6_TIMXCEED:
        ricmp->icmp6_err.unused = 0;
        break;
    case ICMP6_TOOBIG:
        ricmp->icmp6_err.mtu = htonl(IF_MTU);
        break;
    case ICMP6_PARAMPROB:
        /* TODO: Handle this case */
        break;
    default:
        g_assert_not_reached();
        break;
    }
    t->m_data += ICMP6_ERROR_MINLEN;
    memcpy(t->m_data, m->m_data, error_data_len);

    /* Checksum */
    t->m_data -= ICMP6_ERROR_MINLEN;
    t->m_data -= sizeof(struct ip6);
    ricmp->icmp6_cksum = ip6_cksum(t);

    ip6_output(NULL, t, 0);
}

/*
 * Send NDP Router Advertisement
 */
void ndp_send_ra(Slirp *slirp)
{
    DEBUG_CALL("ndp_send_ra");

    /* Build IPv6 packet */
    struct mbuf *t = m_get(slirp);
    struct ip6 *rip = mtod(t, struct ip6 *);
    rip->ip_src = (struct in6_addr)LINKLOCAL_ADDR;
    rip->ip_dst = (struct in6_addr)ALLNODES_MULTICAST;
    rip->ip_nh = IPPROTO_ICMPV6;
    rip->ip_pl = htons(ICMP6_NDP_RA_MINLEN
                        + NDPOPT_LINKLAYER_LEN
                        + NDPOPT_PREFIXINFO_LEN
#ifndef _WIN32
                        + NDPOPT_RDNSS_LEN
#endif
                        );
    t->m_len = sizeof(struct ip6) + ntohs(rip->ip_pl);

    /* Build ICMPv6 packet */
    t->m_data += sizeof(struct ip6);
    struct icmp6 *ricmp = mtod(t, struct icmp6 *);
    ricmp->icmp6_type = ICMP6_NDP_RA;
    ricmp->icmp6_code = 0;
    ricmp->icmp6_cksum = 0;

    /* NDP */
    ricmp->icmp6_nra.chl = NDP_AdvCurHopLimit;
    ricmp->icmp6_nra.M = NDP_AdvManagedFlag;
    ricmp->icmp6_nra.O = NDP_AdvOtherConfigFlag;
    ricmp->icmp6_nra.reserved = 0;
    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) */
    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) */
    struct ndpopt *opt2 = mtod(t, struct ndpopt *);
    opt2->ndpopt_type = NDPOPT_PREFIX_INFO;
    opt2->ndpopt_len = NDPOPT_PREFIXINFO_LEN / 8;
    opt2->ndpopt_prefixinfo.prefix_length = slirp->vprefix_len;
    opt2->ndpopt_prefixinfo.L = 1;
    opt2->ndpopt_prefixinfo.A = 1;
    opt2->ndpopt_prefixinfo.reserved1 = 0;
    opt2->ndpopt_prefixinfo.valid_lt = htonl(NDP_AdvValidLifetime);
    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);
    ricmp->icmp6_cksum = ip6_cksum(t);

    ip6_output(NULL, t, 0);
}

/*
 * Send NDP Neighbor Solitication
 */
void ndp_send_ns(Slirp *slirp, struct in6_addr addr)
{
    DEBUG_CALL("ndp_send_ns");
#if !defined(_WIN32) || (_WIN32_WINNT >= 0x0600)
    char addrstr[INET6_ADDRSTRLEN];
    inet_ntop(AF_INET6, &addr, addrstr, INET6_ADDRSTRLEN);
    DEBUG_ARG("target = %s", addrstr);
#endif

    /* Build IPv6 packet */
    struct mbuf *t = m_get(slirp);
    struct ip6 *rip = mtod(t, struct ip6 *);
    rip->ip_src = slirp->vhost_addr6;
    rip->ip_dst = (struct in6_addr)SOLICITED_NODE_PREFIX;
    memcpy(&rip->ip_dst.s6_addr[13], &addr.s6_addr[13], 3);
    rip->ip_nh = IPPROTO_ICMPV6;
    rip->ip_pl = htons(ICMP6_NDP_NS_MINLEN + NDPOPT_LINKLAYER_LEN);
    t->m_len = sizeof(struct ip6) + ntohs(rip->ip_pl);

    /* Build ICMPv6 packet */
    t->m_data += sizeof(struct ip6);
    struct icmp6 *ricmp = mtod(t, struct icmp6 *);
    ricmp->icmp6_type = ICMP6_NDP_NS;
    ricmp->icmp6_code = 0;
    ricmp->icmp6_cksum = 0;

    /* NDP */
    ricmp->icmp6_nns.reserved = 0;
    ricmp->icmp6_nns.target = addr;

    /* Build NDP option */
    t->m_data += ICMP6_NDP_NS_MINLEN;
    struct ndpopt *opt = mtod(t, struct ndpopt *);
    opt->ndpopt_type = NDPOPT_LINKLAYER_SOURCE;
    opt->ndpopt_len = NDPOPT_LINKLAYER_LEN / 8;
    in6_compute_ethaddr(slirp->vhost_addr6, opt->ndpopt_linklayer);

    /* ICMPv6 Checksum */
    t->m_data -= ICMP6_NDP_NA_MINLEN;
    t->m_data -= sizeof(struct ip6);
    ricmp->icmp6_cksum = ip6_cksum(t);

    ip6_output(NULL, t, 1);
}

/*
 * Send NDP Neighbor Advertisement
 */
static void ndp_send_na(Slirp *slirp, struct ip6 *ip, struct icmp6 *icmp)
{
    /* Build IPv6 packet */
    struct mbuf *t = m_get(slirp);
    struct ip6 *rip = mtod(t, struct ip6 *);
    rip->ip_src = icmp->icmp6_nns.target;
    if (IN6_IS_ADDR_UNSPECIFIED(&ip->ip_src)) {
        rip->ip_dst = (struct in6_addr)ALLNODES_MULTICAST;
    } else {
        rip->ip_dst = ip->ip_src;
    }
    rip->ip_nh = IPPROTO_ICMPV6;
    rip->ip_pl = htons(ICMP6_NDP_NA_MINLEN
                        + NDPOPT_LINKLAYER_LEN);
    t->m_len = sizeof(struct ip6) + ntohs(rip->ip_pl);

    /* Build ICMPv6 packet */
    t->m_data += sizeof(struct ip6);
    struct icmp6 *ricmp = mtod(t, struct icmp6 *);
    ricmp->icmp6_type = ICMP6_NDP_NA;
    ricmp->icmp6_code = 0;
    ricmp->icmp6_cksum = 0;

    /* NDP */
    ricmp->icmp6_nna.R = NDP_IsRouter;
    ricmp->icmp6_nna.S = !IN6_IS_ADDR_MULTICAST(&rip->ip_dst);
    ricmp->icmp6_nna.O = 1;
    ricmp->icmp6_nna.reserved_hi = 0;
    ricmp->icmp6_nna.reserved_lo = 0;
    ricmp->icmp6_nna.target = icmp->icmp6_nns.target;

    /* Build NDP option */
    t->m_data += ICMP6_NDP_NA_MINLEN;
    struct ndpopt *opt = mtod(t, struct ndpopt *);
    opt->ndpopt_type = NDPOPT_LINKLAYER_TARGET;
    opt->ndpopt_len = NDPOPT_LINKLAYER_LEN / 8;
    in6_compute_ethaddr(ricmp->icmp6_nna.target,
                    opt->ndpopt_linklayer);

    /* ICMPv6 Checksum */
    t->m_data -= ICMP6_NDP_NA_MINLEN;
    t->m_data -= sizeof(struct ip6);
    ricmp->icmp6_cksum = ip6_cksum(t);

    ip6_output(NULL, t, 0);
}

/*
 * Process a NDP message
 */
static void ndp_input(struct mbuf *m, Slirp *slirp, struct ip6 *ip,
        struct icmp6 *icmp)
{
    m->m_len += ETH_HLEN;
    m->m_data -= ETH_HLEN;
    struct ethhdr *eth = mtod(m, struct ethhdr *);
    m->m_len -= ETH_HLEN;
    m->m_data += ETH_HLEN;

    switch (icmp->icmp6_type) {
    case ICMP6_NDP_RS:
        DEBUG_CALL(" type = Router Solicitation");
        if (ip->ip_hl == 255
                && icmp->icmp6_code == 0
                && ntohs(ip->ip_pl) >= ICMP6_NDP_RS_MINLEN) {
            /* Gratuitous NDP */
            ndp_table_add(slirp, ip->ip_src, eth->h_source);

            ndp_send_ra(slirp);
        }
        break;

    case ICMP6_NDP_RA:
        DEBUG_CALL(" type = Router Advertisement");
        qemu_log_mask(LOG_GUEST_ERROR,
                "Warning: guest sent NDP RA, but shouldn't");
        break;

    case ICMP6_NDP_NS:
        DEBUG_CALL(" type = Neighbor Solicitation");
        if (ip->ip_hl == 255
                && icmp->icmp6_code == 0
                && !IN6_IS_ADDR_MULTICAST(&icmp->icmp6_nns.target)
                && ntohs(ip->ip_pl) >= ICMP6_NDP_NS_MINLEN
                && (!IN6_IS_ADDR_UNSPECIFIED(&ip->ip_src)
                    || in6_solicitednode_multicast(&ip->ip_dst))) {
            if (in6_equal_host(&icmp->icmp6_nns.target)) {
                /* Gratuitous NDP */
                ndp_table_add(slirp, ip->ip_src, eth->h_source);
                ndp_send_na(slirp, ip, icmp);
            }
        }
        break;

    case ICMP6_NDP_NA:
        DEBUG_CALL(" type = Neighbor Advertisement");
        if (ip->ip_hl == 255
                && icmp->icmp6_code == 0
                && ntohs(ip->ip_pl) >= ICMP6_NDP_NA_MINLEN
                && !IN6_IS_ADDR_MULTICAST(&icmp->icmp6_nna.target)
                && (!IN6_IS_ADDR_MULTICAST(&ip->ip_dst)
                    || icmp->icmp6_nna.S == 0)) {
            ndp_table_add(slirp, ip->ip_src, eth->h_source);
        }
        break;

    case ICMP6_NDP_REDIRECT:
        DEBUG_CALL(" type = Redirect");
        qemu_log_mask(LOG_GUEST_ERROR,
                "Warning: guest sent NDP REDIRECT, but shouldn't");
        break;
    }
}

/*
 * Process a received ICMPv6 message.
 */
void icmp6_input(struct mbuf *m)
{
    struct icmp6 *icmp;
    struct ip6 *ip = mtod(m, struct ip6 *);
    Slirp *slirp = m->slirp;
    int hlen = sizeof(struct ip6);

    DEBUG_CALL("icmp6_input");
    DEBUG_ARG("m = %lx", (long) m);
    DEBUG_ARG("m_len = %d", m->m_len);

    if (ntohs(ip->ip_pl) < ICMP6_MINLEN) {
        goto end;
    }

    if (ip6_cksum(m)) {
        goto end;
    }

    m->m_len -= hlen;
    m->m_data += hlen;
    icmp = mtod(m, struct icmp6 *);
    m->m_len += hlen;
    m->m_data -= hlen;

    DEBUG_ARG("icmp6_type = %d", icmp->icmp6_type);
    switch (icmp->icmp6_type) {
    case ICMP6_ECHO_REQUEST:
        if (in6_equal_host(&ip->ip_dst)) {
            icmp6_send_echoreply(m, slirp, ip, icmp);
        } else {
            /* TODO */
            error_report("external icmpv6 not supported yet");
        }
        break;

    case ICMP6_NDP_RS:
    case ICMP6_NDP_RA:
    case ICMP6_NDP_NS:
    case ICMP6_NDP_NA:
    case ICMP6_NDP_REDIRECT:
        ndp_input(m, slirp, ip, icmp);
        break;

    case ICMP6_UNREACH:
    case ICMP6_TOOBIG:
    case ICMP6_TIMXCEED:
    case ICMP6_PARAMPROB:
        /* XXX? report error? close socket? */
    default:
        break;
    }

end:
    m_free(m);
}