summaryrefslogtreecommitdiffstats
path: root/server/vhost.c
blob: 6ed6cfea835eda1472e827395141bf7a0bb6eb1a (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
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
/* Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/**
 * @file  vhost.c
 * @brief functions pertaining to virtual host addresses
 *        (configuration and run-time)
 */

#include "apr.h"
#include "apr_strings.h"
#include "apr_lib.h"

#define APR_WANT_STRFUNC
#include "apr_want.h"

#include "ap_config.h"
#include "httpd.h"
#include "http_config.h"
#include "http_log.h"
#include "http_vhost.h"
#include "http_protocol.h"
#include "http_core.h"

#if APR_HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif

/*
 * After all the definitions there's an explanation of how it's all put
 * together.
 */

/* meta-list of name-vhosts.  Each server_rec can be in possibly multiple
 * lists of name-vhosts.
 */
typedef struct name_chain name_chain;
struct name_chain {
    name_chain *next;
    server_addr_rec *sar;       /* the record causing it to be in
                                 * this chain (needed for port comparisons) */
    server_rec *server;         /* the server to use on a match */
};

/* meta-list of ip addresses.  Each server_rec can be in possibly multiple
 * hash chains since it can have multiple ips.
 */
typedef struct ipaddr_chain ipaddr_chain;
struct ipaddr_chain {
    ipaddr_chain *next;
    server_addr_rec *sar;       /* the record causing it to be in
                                 * this chain (need for both ip addr and port
                                 * comparisons) */
    server_rec *server;         /* the server to use if this matches */
    name_chain *names;          /* if non-NULL then a list of name-vhosts
                                 * sharing this address */
};

/* This defines the size of the hash table used for hashing ip addresses
 * of virtual hosts.  It must be a power of two.
 */
#ifndef IPHASH_TABLE_SIZE
#define IPHASH_TABLE_SIZE 256
#endif

/* A (n) bucket hash table, each entry has a pointer to a server rec and
 * a pointer to the other entries in that bucket.  Each individual address,
 * even for virtualhosts with multiple addresses, has an entry in this hash
 * table.  There are extra buckets for _default_, and name-vhost entries.
 *
 * Note that after config time this is constant, so it is thread-safe.
 */
static ipaddr_chain *iphash_table[IPHASH_TABLE_SIZE];

/* dump out statistics about the hash function */
/* #define IPHASH_STATISTICS */

/* list of the _default_ servers */
static ipaddr_chain *default_list;

/* list of the NameVirtualHost addresses */
static server_addr_rec *name_vhost_list;
static server_addr_rec **name_vhost_list_tail;

/*
 * How it's used:
 *
 * The ip address determines which chain in iphash_table is interesting, then
 * a comparison is done down that chain to find the first ipaddr_chain whose
 * sar matches the address:port pair.
 *
 * If that ipaddr_chain has names == NULL then you're done, it's an ip-vhost.
 *
 * Otherwise it's a name-vhost list, and the default is the server in the
 * ipaddr_chain record.  We tuck away the ipaddr_chain record in the
 * conn_rec field vhost_lookup_data.  Later on after the headers we get a
 * second chance, and we use the name_chain to figure out what name-vhost
 * matches the headers.
 *
 * If there was no ip address match in the iphash_table then do a lookup
 * in the default_list.
 *
 * How it's put together ... well you should be able to figure that out
 * from how it's used.  Or something like that.
 */


/* called at the beginning of the config */
AP_DECLARE(void) ap_init_vhost_config(apr_pool_t *p)
{
    memset(iphash_table, 0, sizeof(iphash_table));
    default_list = NULL;
    name_vhost_list = NULL;
    name_vhost_list_tail = &name_vhost_list;
}


/*
 * Parses a host of the form <address>[:port]
 * paddr is used to create a list in the order of input
 * **paddr is the ->next pointer of the last entry (or s->addrs)
 * *paddr is the variable used to keep track of **paddr between calls
 * port is the default port to assume
 */
static const char *get_addresses(apr_pool_t *p, const char *w_,
                                 server_addr_rec ***paddr,
                                 apr_port_t default_port)
{
    apr_sockaddr_t *my_addr;
    server_addr_rec *sar;
    char *w, *host, *scope_id;
    int wild_port;
    apr_size_t wlen;
    apr_port_t port;
    apr_status_t rv;

    if (*w_ == '\0')
        return NULL;

    w = apr_pstrdup(p, w_);
    /* apr_parse_addr_port() doesn't understand ":*" so handle that first. */
    wlen = strlen(w);                    /* wlen must be > 0 at this point */
    wild_port = 0;
    if (w[wlen - 1] == '*') {
        if (wlen < 2) {
            wild_port = 1;
        }
        else if (w[wlen - 2] == ':') {
            w[wlen - 2] = '\0';
            wild_port = 1;
        }
    }
    rv = apr_parse_addr_port(&host, &scope_id, &port, w, p);
    /* If the string is "80", apr_parse_addr_port() will be happy and set
     * host to NULL and port to 80, so watch out for that.
     */
    if (rv != APR_SUCCESS) {
        return "The address or port is invalid";
    }
    if (!host) {
        return "Missing address for VirtualHost";
    }
    if (scope_id) {
        return "Scope ids are not supported";
    }
    if (!port && !wild_port) {
        port = default_port;
    }

    if (strcmp(host, "*") == 0) {
        rv = apr_sockaddr_info_get(&my_addr, "0.0.0.0", APR_INET, port, 0, p);
        if (rv) {
            return "Could not resolve address '0.0.0.0' -- "
                "check resolver configuration.";
        }
    }
    else if (strcasecmp(host, "_default_") == 0
        || strcmp(host, "255.255.255.255") == 0) {
        rv = apr_sockaddr_info_get(&my_addr, "255.255.255.255", APR_INET, port, 0, p);
        if (rv) {
            return "Could not resolve address '255.255.255.255' -- "
                "check resolver configuration.";
        }
    }
    else {
        rv = apr_sockaddr_info_get(&my_addr, host, APR_UNSPEC, port, 0, p);
        if (rv != APR_SUCCESS) {
            ap_log_error(APLOG_MARK, APLOG_ERR, rv, NULL,
                "Could not resolve host name %s -- ignoring!", host);
            return NULL;
        }
    }

    /* Remember all addresses for the host */

    do {
        sar = apr_pcalloc(p, sizeof(server_addr_rec));
        **paddr = sar;
        *paddr = &sar->next;
        sar->host_addr = my_addr;
        sar->host_port = port;
        sar->virthost = host;
        my_addr = my_addr->next;
    } while (my_addr);

    return NULL;
}


/* parse the <VirtualHost> addresses */
const char *ap_parse_vhost_addrs(apr_pool_t *p,
                                 const char *hostname,
                                 server_rec *s)
{
    server_addr_rec **addrs;
    const char *err;

    /* start the list of addreses */
    addrs = &s->addrs;
    while (hostname[0]) {
        err = get_addresses(p, ap_getword_conf(p, &hostname), &addrs, s->port);
        if (err) {
            *addrs = NULL;
            return err;
        }
    }
    /* terminate the list */
    *addrs = NULL;
    if (s->addrs) {
        if (s->addrs->host_port) {
            /* override the default port which is inherited from main_server */
            s->port = s->addrs->host_port;
        }
    }
    return NULL;
}


const char *ap_set_name_virtual_host(cmd_parms *cmd, void *dummy,
                                     const char *arg)
{
    /* use whatever port the main server has at this point */
    return get_addresses(cmd->pool, arg, &name_vhost_list_tail,
                         cmd->server->port);
}


/* hash table statistics, keep this in here for the beta period so
 * we can find out if the hash function is ok
 */
#ifdef IPHASH_STATISTICS
static int iphash_compare(const void *a, const void *b)
{
    return (*(const int *) b - *(const int *) a);
}


static void dump_iphash_statistics(server_rec *main_s)
{
    unsigned count[IPHASH_TABLE_SIZE];
    int i;
    ipaddr_chain *src;
    unsigned total;
    char buf[HUGE_STRING_LEN];
    char *p;

    total = 0;
    for (i = 0; i < IPHASH_TABLE_SIZE; ++i) {
        count[i] = 0;
        for (src = iphash_table[i]; src; src = src->next) {
            ++count[i];
            if (i < IPHASH_TABLE_SIZE) {
                /* don't count the slop buckets in the total */
                ++total;
            }
        }
    }
    qsort(count, IPHASH_TABLE_SIZE, sizeof(count[0]), iphash_compare);
    p = buf + apr_snprintf(buf, sizeof(buf),
                           "iphash: total hashed = %u, avg chain = %u, "
                           "chain lengths (count x len):",
                           total, total / IPHASH_TABLE_SIZE);
    total = 1;
    for (i = 1; i < IPHASH_TABLE_SIZE; ++i) {
        if (count[i - 1] != count[i]) {
            p += apr_snprintf(p, sizeof(buf) - (p - buf), " %ux%u",
                              total, count[i - 1]);
            total = 1;
        }
        else {
            ++total;
        }
    }
    p += apr_snprintf(p, sizeof(buf) - (p - buf), " %ux%u",
                      total, count[IPHASH_TABLE_SIZE - 1]);
    ap_log_error(APLOG_MARK, APLOG_DEBUG, main_s, buf);
}
#endif


/* This hashing function is designed to get good distribution in the cases
 * where the server is handling entire "networks" of servers.  i.e. a
 * whack of /24s.  This is probably the most common configuration for
 * ISPs with large virtual servers.
 *
 * NOTE: This function is symmetric (i.e. collapses all 4 octets
 * into one), so machine byte order (big/little endianness) does not matter.
 *
 * Hash function provided by David Hankins.
 */
static APR_INLINE unsigned hash_inaddr(unsigned key)
{
    key ^= (key >> 16);
    return ((key >> 8) ^ key) % IPHASH_TABLE_SIZE;
}

static APR_INLINE unsigned hash_addr(struct apr_sockaddr_t *sa)
{
    unsigned key;

    /* The key is the last four bytes of the IP address.
     * For IPv4, this is the entire address, as always.
     * For IPv6, this is usually part of the MAC address.
     */
    key = *(unsigned *)((char *)sa->ipaddr_ptr + sa->ipaddr_len - 4);
    return hash_inaddr(key);
}

static ipaddr_chain *new_ipaddr_chain(apr_pool_t *p,
                                      server_rec *s, server_addr_rec *sar)
{
    ipaddr_chain *new;

    new = apr_palloc(p, sizeof(*new));
    new->names = NULL;
    new->server = s;
    new->sar = sar;
    new->next = NULL;
    return new;
}


static name_chain *new_name_chain(apr_pool_t *p,
                                  server_rec *s, server_addr_rec *sar)
{
    name_chain *new;

    new = apr_palloc(p, sizeof(*new));
    new->server = s;
    new->sar = sar;
    new->next = NULL;
    return new;
}


static APR_INLINE ipaddr_chain *find_ipaddr(apr_sockaddr_t *sa)
{
    unsigned bucket;
    ipaddr_chain *trav;

    /* scan the hash table for an exact match first */
    bucket = hash_addr(sa);
    for (trav = iphash_table[bucket]; trav; trav = trav->next) {
        server_addr_rec *sar = trav->sar;
        apr_sockaddr_t *cur = sar->host_addr;

        if (cur->port == 0 || sa->port == 0 || cur->port == sa->port) {
            if (apr_sockaddr_equal(cur, sa)) {
                return trav;
            }
        }
    }
    return NULL;
}

static ipaddr_chain *find_default_server(apr_port_t port)
{
    server_addr_rec *sar;
    ipaddr_chain *trav;

    for (trav = default_list; trav; trav = trav->next) {
        sar = trav->sar;
        if (sar->host_port == 0 || sar->host_port == port) {
            /* match! */
            return trav;
        }
    }
    return NULL;
}

static void dump_a_vhost(apr_file_t *f, ipaddr_chain *ic)
{
    name_chain *nc;
    int len;
    char buf[MAX_STRING_LEN];
    apr_sockaddr_t *ha = ic->sar->host_addr;

    if (ha->family == APR_INET &&
        ha->sa.sin.sin_addr.s_addr == DEFAULT_VHOST_ADDR) {
        len = apr_snprintf(buf, sizeof(buf), "_default_:%u",
                           ic->sar->host_port);
    }
    else if (ha->family == APR_INET &&
             ha->sa.sin.sin_addr.s_addr == INADDR_ANY) {
        len = apr_snprintf(buf, sizeof(buf), "*:%u",
                           ic->sar->host_port);
    }
    else {
        len = apr_snprintf(buf, sizeof(buf), "%pI", ha);
    }
    if (ic->sar->host_port == 0) {
        buf[len-1] = '*';
    }
    if (ic->names == NULL) {
        apr_file_printf(f, "%-22s %s (%s:%u)\n", buf,
                        ic->server->server_hostname,
                        ic->server->defn_name, ic->server->defn_line_number);
        return;
    }
    apr_file_printf(f, "%-22s is a NameVirtualHost\n"
                    "%8s default server %s (%s:%u)\n",
                    buf, "", ic->server->server_hostname,
                    ic->server->defn_name, ic->server->defn_line_number);
    for (nc = ic->names; nc; nc = nc->next) {
        if (nc->sar->host_port) {
            apr_file_printf(f, "%8s port %u ", "", nc->sar->host_port);
        }
        else {
            apr_file_printf(f, "%8s port * ", "");
        }
        apr_file_printf(f, "namevhost %s (%s:%u)\n",
                        nc->server->server_hostname,
                        nc->server->defn_name, nc->server->defn_line_number);
    }
}

static void dump_vhost_config(apr_file_t *f)
{
    ipaddr_chain *ic;
    int i;

    apr_file_printf(f, "VirtualHost configuration:\n");
    for (i = 0; i < IPHASH_TABLE_SIZE; ++i) {
        for (ic = iphash_table[i]; ic; ic = ic->next) {
            dump_a_vhost(f, ic);
        }
    }
    if (default_list) {
        apr_file_printf(f, "wildcard NameVirtualHosts and _default_ servers:\n");
        for (ic = default_list; ic; ic = ic->next) {
            dump_a_vhost(f, ic);
        }
    }
}

/*
 * Two helper functions for ap_fini_vhost_config()
 */
static int add_name_vhost_config(apr_pool_t *p, server_rec *main_s,
                                 server_rec *s, server_addr_rec *sar,
                                 ipaddr_chain *ic)
{
    /* the first time we encounter a NameVirtualHost address
     * ic->server will be NULL, on subsequent encounters
     * ic->names will be non-NULL.
     */
    if (ic->names || ic->server == NULL) {
        name_chain *nc = new_name_chain(p, s, sar);
        nc->next = ic->names;
        ic->names = nc;
        ic->server = s;
        if (sar->host_port != ic->sar->host_port) {
            /* one of the two is a * port, the other isn't */
            ap_log_error(APLOG_MARK, APLOG_ERR, 0, main_s,
                         "VirtualHost %s:%u -- mixing * "
                         "ports and non-* ports with "
                         "a NameVirtualHost address is not supported,"
                         " proceeding with undefined results",
                         sar->virthost, sar->host_port);
        }
        return 1;
    }
    else {
        /* IP-based vhosts are handled by the caller */
        return 0;
    }
}

static void remove_unused_name_vhosts(server_rec *main_s, ipaddr_chain **pic)
{
    while (*pic) {
        ipaddr_chain *ic = *pic;

        if (ic->server == NULL) {
            ap_log_error(APLOG_MARK, APLOG_WARNING, 0, main_s,
                         "NameVirtualHost %s:%u has no VirtualHosts",
                         ic->sar->virthost, ic->sar->host_port);
            *pic = ic->next;
        }
        else {
            pic = &ic->next;
        }
    }
}

/* compile the tables and such we need to do the run-time vhost lookups */
AP_DECLARE(void) ap_fini_vhost_config(apr_pool_t *p, server_rec *main_s)
{
    server_addr_rec *sar;
    int has_default_vhost_addr;
    server_rec *s;
    int i;
    ipaddr_chain **iphash_table_tail[IPHASH_TABLE_SIZE];

    /* terminate the name_vhost list */
    *name_vhost_list_tail = NULL;

    /* Main host first */
    s = main_s;

    if (!s->server_hostname) {
        s->server_hostname = ap_get_local_host(p);
    }

    /* initialize the tails */
    for (i = 0; i < IPHASH_TABLE_SIZE; ++i) {
        iphash_table_tail[i] = &iphash_table[i];
    }

    /* The first things to go into the hash table are the NameVirtualHosts
     * Since name_vhost_list is in the same order that the directives
     * occured in the config file, we'll copy it in that order.
     */
    for (sar = name_vhost_list; sar; sar = sar->next) {
        char inaddr_any[16] = {0}; /* big enough to handle IPv4 or IPv6 */
        unsigned bucket = hash_addr(sar->host_addr);
        ipaddr_chain *ic = new_ipaddr_chain(p, NULL, sar);

        if (memcmp(sar->host_addr->ipaddr_ptr, inaddr_any,
                   sar->host_addr->ipaddr_len)) { /* not IN[6]ADDR_ANY */
            *iphash_table_tail[bucket] = ic;
            iphash_table_tail[bucket] = &ic->next;
        }
        else {
            /* A wildcard NameVirtualHost goes on the default_list so
             * that it can catch incoming requests on any address.
             */
            ic->next = default_list;
            default_list = ic;
        }
        /* Notice that what we've done is insert an ipaddr_chain with
         * both server and names NULL. This fact is used to spot name-
         * based vhosts in add_name_vhost_config().
         */
    }

    /* The next things to go into the hash table are the virtual hosts
     * themselves.  They're listed off of main_s->next in the reverse
     * order they occured in the config file, so we insert them at
     * the iphash_table_tail but don't advance the tail.
     */

    for (s = main_s->next; s; s = s->next) {
        has_default_vhost_addr = 0;
        for (sar = s->addrs; sar; sar = sar->next) {
            ipaddr_chain *ic;
            char inaddr_any[16] = {0}; /* big enough to handle IPv4 or IPv6 */

            if ((sar->host_addr->family == AF_INET &&
                 sar->host_addr->sa.sin.sin_addr.s_addr == DEFAULT_VHOST_ADDR)
                || !memcmp(sar->host_addr->ipaddr_ptr, inaddr_any, sar->host_addr->ipaddr_len)) {
                ic = find_default_server(sar->host_port);
                if (!ic || !add_name_vhost_config(p, main_s, s, sar, ic)) {
                    if (ic && ic->sar->host_port != 0) {
                        ap_log_error(APLOG_MARK, APLOG_WARNING,
                                     0, main_s, "_default_ VirtualHost "
                                     "overlap on port %u, the first has "
                                     "precedence", sar->host_port);
                    }
                    ic = new_ipaddr_chain(p, s, sar);
                    ic->next = default_list;
                    default_list = ic;
                }
                has_default_vhost_addr = 1;
            }
            else {
                /* see if it matches something we've already got */
                ic = find_ipaddr(sar->host_addr);

                if (!ic) {
                    unsigned bucket = hash_addr(sar->host_addr);

                    ic = new_ipaddr_chain(p, s, sar);
                    ic->next = *iphash_table_tail[bucket];
                    *iphash_table_tail[bucket] = ic;
                }
                else if (!add_name_vhost_config(p, main_s, s, sar, ic)) {
                    ap_log_error(APLOG_MARK, APLOG_WARNING,
                                 0, main_s, "VirtualHost %s:%u overlaps "
                                 "with VirtualHost %s:%u, the first has "
                                 "precedence, perhaps you need a "
                                 "NameVirtualHost directive",
                                 sar->virthost, sar->host_port,
                                 ic->sar->virthost, ic->sar->host_port);
                    ic->sar = sar;
                    ic->server = s;
                }
            }
        }

        /* Ok now we want to set up a server_hostname if the user was
         * silly enough to forget one.
         * XXX: This is silly we should just crash and burn.
         */
        if (!s->server_hostname) {
            if (has_default_vhost_addr) {
                s->server_hostname = main_s->server_hostname;
            }
            else if (!s->addrs) {
                /* what else can we do?  at this point this vhost has
                    no configured name, probably because they used
                    DNS in the VirtualHost statement.  It's disabled
                    anyhow by the host matching code.  -djg */
                s->server_hostname =
                    apr_pstrdup(p, "bogus_host_without_forward_dns");
            }
            else {
                apr_status_t rv;
                char *hostname;

                rv = apr_getnameinfo(&hostname, s->addrs->host_addr, 0);
                if (rv == APR_SUCCESS) {
                    s->server_hostname = apr_pstrdup(p, hostname);
                }
                else {
                    /* again, what can we do?  They didn't specify a
                       ServerName, and their DNS isn't working. -djg */
                    char *ipaddr_str;

                    apr_sockaddr_ip_get(&ipaddr_str, s->addrs->host_addr);
                    ap_log_error(APLOG_MARK, APLOG_ERR, rv, main_s,
                                 "Failed to resolve server name "
                                 "for %s (check DNS) -- or specify an explicit "
                                 "ServerName",
                                 ipaddr_str);
                    s->server_hostname =
                        apr_pstrdup(p, "bogus_host_without_reverse_dns");
                }
            }
        }
    }

    /* now go through and delete any NameVirtualHosts that didn't have any
     * hosts associated with them.  Lamers.
     */
    for (i = 0; i < IPHASH_TABLE_SIZE; ++i) {
        remove_unused_name_vhosts(main_s, &iphash_table[i]);
    }
    remove_unused_name_vhosts(main_s, &default_list);

#ifdef IPHASH_STATISTICS
    dump_iphash_statistics(main_s);
#endif
    if (ap_exists_config_define("DUMP_VHOSTS")) {
        apr_file_t *thefile = NULL;
        apr_file_open_stdout(&thefile, p);
        dump_vhost_config(thefile);
    }
}


/*****************************************************************************
 * run-time vhost matching functions
 */

/* Lowercase and remove any trailing dot and/or :port from the hostname,
 * and check that it is sane.
 *
 * In most configurations the exact syntax of the hostname isn't
 * important so strict sanity checking isn't necessary. However, in
 * mass hosting setups (using mod_vhost_alias or mod_rewrite) where
 * the hostname is interpolated into the filename, we need to be sure
 * that the interpolation doesn't expose parts of the filesystem.
 * We don't do strict RFC 952 / RFC 1123 syntax checking in order
 * to support iDNS and people who erroneously use underscores.
 * Instead we just check for filesystem metacharacters: directory
 * separators / and \ and sequences of more than one dot.
 */
static void fix_hostname(request_rec *r)
{
    char *host, *scope_id;
    char *dst;
    apr_port_t port;
    apr_status_t rv;

    /* According to RFC 2616, Host header field CAN be blank. */
    if (!*r->hostname) {
        return;
    }

    rv = apr_parse_addr_port(&host, &scope_id, &port, r->hostname, r->pool);
    if (rv != APR_SUCCESS || scope_id) {
        goto bad;
    }

    if (!host && port) {
        /* silly looking host ("Host: 123") but that isn't our job
         * here to judge; apr_parse_addr_port() would think we had a port
         * but no address
         */
        host = apr_itoa(r->pool, (int)port);
    }
    else if (port) {
        /* Don't throw the Host: header's port number away:
           save it in parsed_uri -- ap_get_server_port() needs it! */
        /* @@@ XXX there should be a better way to pass the port.
         *         Like r->hostname, there should be a r->portno
         */
        r->parsed_uri.port = port;
        r->parsed_uri.port_str = apr_itoa(r->pool, (int)port);
    }

    /* if the hostname is an IPv6 numeric address string, it was validated
     * already; otherwise, further validation is needed
     */
    if (r->hostname[0] != '[') {
        for (dst = host; *dst; dst++) {
            if (apr_islower(*dst)) {
                /* leave char unchanged */
            }
            else if (*dst == '.') {
                if (*(dst + 1) == '.') {
                    goto bad;
                }
            }
            else if (apr_isupper(*dst)) {
                *dst = apr_tolower(*dst);
            }
            else if (*dst == '/' || *dst == '\\') {
                goto bad;
            }
        }
        /* strip trailing gubbins */
        if (dst > host && dst[-1] == '.') {
            dst[-1] = '\0';
        }
    }
    r->hostname = host;
    return;

bad:
    r->status = HTTP_BAD_REQUEST;
    ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
                  "Client sent malformed Host header");
    return;
}


/* return 1 if host matches ServerName or ServerAliases */
static int matches_aliases(server_rec *s, const char *host)
{
    int i;
    apr_array_header_t *names;

    /* match ServerName */
    if (!strcasecmp(host, s->server_hostname)) {
        return 1;
    }

    /* search all the aliases from ServerAlias directive */
    names = s->names;
    if (names) {
        char **name = (char **) names->elts;
        for (i = 0; i < names->nelts; ++i) {
            if(!name[i]) continue;
            if (!strcasecmp(host, name[i]))
                return 1;
        }
    }
    names = s->wild_names;
    if (names) {
        char **name = (char **) names->elts;
        for (i = 0; i < names->nelts; ++i) {
            if(!name[i]) continue;
            if (!ap_strcasecmp_match(host, name[i]))
                return 1;
        }
    }
    return 0;
}


/* Suppose a request came in on the same socket as this r, and included
 * a header "Host: host:port", would it map to r->server?  It's more
 * than just that though.  When we do the normal matches for each request
 * we don't even bother considering Host: etc on non-namevirtualhosts,
 * we just call it a match.  But here we require the host:port to match
 * the ServerName and/or ServerAliases.
 */
AP_DECLARE(int) ap_matches_request_vhost(request_rec *r, const char *host,
                                         apr_port_t port)
{
    server_rec *s;
    server_addr_rec *sar;

    s = r->server;

    /* search all the <VirtualHost> values */
    /* XXX: If this is a NameVirtualHost then we may not be doing the Right Thing
     * consider:
     *
     *     NameVirtualHost 10.1.1.1
     *     <VirtualHost 10.1.1.1>
     *     ServerName v1
     *     </VirtualHost>
     *     <VirtualHost 10.1.1.1>
     *     ServerName v2
     *     </VirtualHost>
     *
     * Suppose r->server is v2, and we're asked to match "10.1.1.1".  We'll say
     * "yup it's v2", when really it isn't... if a request came in for 10.1.1.1
     * it would really go to v1.
     */
    for (sar = s->addrs; sar; sar = sar->next) {
        if ((sar->host_port == 0 || port == sar->host_port)
            && !strcasecmp(host, sar->virthost)) {
            return 1;
        }
    }

    /* the Port has to match now, because the rest don't have ports associated
     * with them. */
    if (port != s->port) {
        return 0;
    }

    return matches_aliases(s, host);
}


static void check_hostalias(request_rec *r)
{
    /*
     * Even if the request has a Host: header containing a port we ignore
     * that port.  We always use the physical port of the socket.  There
     * are a few reasons for this:
     *
     * - the default of 80 or 443 for SSL is easier to handle this way
     * - there is less of a possibility of a security problem
     * - it simplifies the data structure
     * - the client may have no idea that a proxy somewhere along the way
     *   translated the request to another ip:port
     * - except for the addresses from the VirtualHost line, none of the other
     *   names we'll match have ports associated with them
     */
    const char *host = r->hostname;
    apr_port_t port;
    server_rec *s;
    server_rec *last_s;
    name_chain *src;

    last_s = NULL;

    port = r->connection->local_addr->port;

    /* Recall that the name_chain is a list of server_addr_recs, some of
     * whose ports may not match.  Also each server may appear more than
     * once in the chain -- specifically, it will appear once for each
     * address from its VirtualHost line which matched.  We only want to
     * do the full ServerName/ServerAlias comparisons once for each
     * server, fortunately we know that all the VirtualHost addresses for
     * a single server are adjacent to each other.
     */

    for (src = r->connection->vhost_lookup_data; src; src = src->next) {
        server_addr_rec *sar;

        /* We only consider addresses on the name_chain which have a matching
         * port
         */
        sar = src->sar;
        if (sar->host_port != 0 && port != sar->host_port) {
            continue;
        }

        s = src->server;

        /* does it match the virthost from the sar? */
        if (!strcasecmp(host, sar->virthost)) {
            goto found;
        }

        if (s == last_s) {
            /* we've already done ServerName and ServerAlias checks for this
             * vhost
             */
            continue;
        }
        last_s = s;

        if (matches_aliases(s, host)) {
            goto found;
        }
    }
    return;

found:
    /* s is the first matching server, we're done */
    r->server = s;
}


static void check_serverpath(request_rec *r)
{
    server_rec *s;
    server_rec *last_s;
    name_chain *src;
    apr_port_t port;

    port = r->connection->local_addr->port;

    /*
     * This is in conjunction with the ServerPath code in http_core, so we
     * get the right host attached to a non- Host-sending request.
     *
     * See the comment in check_hostalias about how each vhost can be
     * listed multiple times.
     */

    last_s = NULL;
    for (src = r->connection->vhost_lookup_data; src; src = src->next) {
        /* We only consider addresses on the name_chain which have a matching
         * port
         */
        if (src->sar->host_port != 0 && port != src->sar->host_port) {
            continue;
        }

        s = src->server;
        if (s == last_s) {
            continue;
        }
        last_s = s;

        if (s->path && !strncmp(r->uri, s->path, s->pathlen) &&
            (s->path[s->pathlen - 1] == '/' ||
             r->uri[s->pathlen] == '/' ||
             r->uri[s->pathlen] == '\0')) {
            r->server = s;
            return;
        }
    }
}


AP_DECLARE(void) ap_update_vhost_from_headers(request_rec *r)
{
    /* must set this for HTTP/1.1 support */
    if (r->hostname || (r->hostname = apr_table_get(r->headers_in, "Host"))) {
        fix_hostname(r);
        if (r->status != HTTP_OK)
            return;
    }
    /* check if we tucked away a name_chain */
    if (r->connection->vhost_lookup_data) {
        if (r->hostname)
            check_hostalias(r);
        else
            check_serverpath(r);
    }
}

/**
 * For every virtual host on this connection, call func_cb.
 */
AP_DECLARE(int) ap_vhost_iterate_given_conn(conn_rec *conn,
                                            ap_vhost_iterate_conn_cb func_cb,
                                            void* baton)
{
    server_rec *s;
    server_rec *last_s;
    name_chain *src;
    apr_port_t port;
    int rv = 0;

    if (conn->vhost_lookup_data) {
        last_s = NULL;
        port = conn->local_addr->port;

        for (src = conn->vhost_lookup_data; src; src = src->next) {
            server_addr_rec *sar;

            /* We only consider addresses on the name_chain which have a
             * matching port.
             */
            sar = src->sar;
            if (sar->host_port != 0 && port != sar->host_port) {
                continue;
            }

            s = src->server;

            if (s == last_s) {
                /* we've already done a callback for this vhost. */
                continue;
            }

            last_s = s;

            rv = func_cb(baton, conn, s);

            if (rv != 0) {
                break;
            }
        }
    }
    else {
        rv = func_cb(baton, conn, conn->base_server);
    }

    return rv;
}

/* Called for a new connection which has a known local_addr.  Note that the
 * new connection is assumed to have conn->server == main server.
 */
AP_DECLARE(void) ap_update_vhost_given_ip(conn_rec *conn)
{
    ipaddr_chain *trav;
    apr_port_t port;

    /* scan the hash table for an exact match first */
    trav = find_ipaddr(conn->local_addr);

    if (trav) {
        /* save the name_chain for later in case this is a name-vhost */
        conn->vhost_lookup_data = trav->names;
        conn->base_server = trav->server;
        return;
    }

    /* maybe there's a default server or wildcard name-based vhost
     * matching this port
     */
    port = conn->local_addr->port;

    trav = find_default_server(port);
    if (trav) {
        conn->vhost_lookup_data = trav->names;
        conn->base_server = trav->server;
        return;
    }

    /* otherwise we're stuck with just the main server
     * and no name-based vhosts
     */
    conn->vhost_lookup_data = NULL;
}