-
Notifications
You must be signed in to change notification settings - Fork 25.5k
/
daemon.c
1217 lines (1044 loc) · 26.9 KB
/
daemon.c
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
#include "cache.h"
#include "pkt-line.h"
#include "exec_cmd.h"
#include "interpolate.h"
#include <syslog.h>
#ifndef HOST_NAME_MAX
#define HOST_NAME_MAX 256
#endif
#ifndef NI_MAXSERV
#define NI_MAXSERV 32
#endif
static int log_syslog;
static int verbose;
static int reuseaddr;
static const char daemon_usage[] =
"git-daemon [--verbose] [--syslog] [--export-all]\n"
" [--timeout=n] [--init-timeout=n] [--strict-paths]\n"
" [--base-path=path] [--base-path-relaxed]\n"
" [--user-path | --user-path=path]\n"
" [--interpolated-path=path]\n"
" [--reuseaddr] [--detach] [--pid-file=file]\n"
" [--[enable|disable|allow-override|forbid-override]=service]\n"
" [--inetd | [--listen=host_or_ipaddr] [--port=n]\n"
" [--user=user [--group=group]]\n"
" [directory...]";
/* List of acceptable pathname prefixes */
static char **ok_paths;
static int strict_paths;
/* If this is set, git-daemon-export-ok is not required */
static int export_all_trees;
/* Take all paths relative to this one if non-NULL */
static char *base_path;
static char *interpolated_path;
static int base_path_relaxed;
/* Flag indicating client sent extra args. */
static int saw_extended_args;
/* If defined, ~user notation is allowed and the string is inserted
* after ~user/. E.g. a request to git://host/~alice/frotz would
* go to /home/alice/pub_git/frotz with --user-path=pub_git.
*/
static const char *user_path;
/* Timeout, and initial timeout */
static unsigned int timeout;
static unsigned int init_timeout;
/*
* Static table for now. Ugh.
* Feel free to make dynamic as needed.
*/
#define INTERP_SLOT_HOST (0)
#define INTERP_SLOT_CANON_HOST (1)
#define INTERP_SLOT_IP (2)
#define INTERP_SLOT_PORT (3)
#define INTERP_SLOT_DIR (4)
#define INTERP_SLOT_PERCENT (5)
static struct interp interp_table[] = {
{ "%H", 0},
{ "%CH", 0},
{ "%IP", 0},
{ "%P", 0},
{ "%D", 0},
{ "%%", 0},
};
static void logreport(int priority, const char *err, va_list params)
{
/* We should do a single write so that it is atomic and output
* of several processes do not get intermingled. */
char buf[1024];
int buflen;
int maxlen, msglen;
/* sizeof(buf) should be big enough for "[pid] \n" */
buflen = snprintf(buf, sizeof(buf), "[%ld] ", (long) getpid());
maxlen = sizeof(buf) - buflen - 1; /* -1 for our own LF */
msglen = vsnprintf(buf + buflen, maxlen, err, params);
if (log_syslog) {
syslog(priority, "%s", buf);
return;
}
/* maxlen counted our own LF but also counts space given to
* vsnprintf for the terminating NUL. We want to make sure that
* we have space for our own LF and NUL after the "meat" of the
* message, so truncate it at maxlen - 1.
*/
if (msglen > maxlen - 1)
msglen = maxlen - 1;
else if (msglen < 0)
msglen = 0; /* Protect against weird return values. */
buflen += msglen;
buf[buflen++] = '\n';
buf[buflen] = '\0';
write_in_full(2, buf, buflen);
}
static void logerror(const char *err, ...)
{
va_list params;
va_start(params, err);
logreport(LOG_ERR, err, params);
va_end(params);
}
static void loginfo(const char *err, ...)
{
va_list params;
if (!verbose)
return;
va_start(params, err);
logreport(LOG_INFO, err, params);
va_end(params);
}
static void NORETURN daemon_die(const char *err, va_list params)
{
logreport(LOG_ERR, err, params);
exit(1);
}
static int avoid_alias(char *p)
{
int sl, ndot;
/*
* This resurrects the belts and suspenders paranoia check by HPA
* done in <435560F7.4080006@zytor.com> thread, now enter_repo()
* does not do getcwd() based path canonicalizations.
*
* sl becomes true immediately after seeing '/' and continues to
* be true as long as dots continue after that without intervening
* non-dot character.
*/
if (!p || (*p != '/' && *p != '~'))
return -1;
sl = 1; ndot = 0;
p++;
while (1) {
char ch = *p++;
if (sl) {
if (ch == '.')
ndot++;
else if (ch == '/') {
if (ndot < 3)
/* reject //, /./ and /../ */
return -1;
ndot = 0;
}
else if (ch == 0) {
if (0 < ndot && ndot < 3)
/* reject /.$ and /..$ */
return -1;
return 0;
}
else
sl = ndot = 0;
}
else if (ch == 0)
return 0;
else if (ch == '/') {
sl = 1;
ndot = 0;
}
}
}
static char *path_ok(struct interp *itable)
{
static char rpath[PATH_MAX];
static char interp_path[PATH_MAX];
int retried_path = 0;
char *path;
char *dir;
dir = itable[INTERP_SLOT_DIR].value;
if (avoid_alias(dir)) {
logerror("'%s': aliased", dir);
return NULL;
}
if (*dir == '~') {
if (!user_path) {
logerror("'%s': User-path not allowed", dir);
return NULL;
}
if (*user_path) {
/* Got either "~alice" or "~alice/foo";
* rewrite them to "~alice/%s" or
* "~alice/%s/foo".
*/
int namlen, restlen = strlen(dir);
char *slash = strchr(dir, '/');
if (!slash)
slash = dir + restlen;
namlen = slash - dir;
restlen -= namlen;
loginfo("userpath <%s>, request <%s>, namlen %d, restlen %d, slash <%s>", user_path, dir, namlen, restlen, slash);
snprintf(rpath, PATH_MAX, "%.*s/%s%.*s",
namlen, dir, user_path, restlen, slash);
dir = rpath;
}
}
else if (interpolated_path && saw_extended_args) {
if (*dir != '/') {
/* Allow only absolute */
logerror("'%s': Non-absolute path denied (interpolated-path active)", dir);
return NULL;
}
interpolate(interp_path, PATH_MAX, interpolated_path,
interp_table, ARRAY_SIZE(interp_table));
loginfo("Interpolated dir '%s'", interp_path);
dir = interp_path;
}
else if (base_path) {
if (*dir != '/') {
/* Allow only absolute */
logerror("'%s': Non-absolute path denied (base-path active)", dir);
return NULL;
}
snprintf(rpath, PATH_MAX, "%s%s", base_path, dir);
dir = rpath;
}
do {
path = enter_repo(dir, strict_paths);
if (path)
break;
/*
* if we fail and base_path_relaxed is enabled, try without
* prefixing the base path
*/
if (base_path && base_path_relaxed && !retried_path) {
dir = itable[INTERP_SLOT_DIR].value;
retried_path = 1;
continue;
}
break;
} while (1);
if (!path) {
logerror("'%s': unable to chdir or not a git archive", dir);
return NULL;
}
if ( ok_paths && *ok_paths ) {
char **pp;
int pathlen = strlen(path);
/* The validation is done on the paths after enter_repo
* appends optional {.git,.git/.git} and friends, but
* it does not use getcwd(). So if your /pub is
* a symlink to /mnt/pub, you can whitelist /pub and
* do not have to say /mnt/pub.
* Do not say /pub/.
*/
for ( pp = ok_paths ; *pp ; pp++ ) {
int len = strlen(*pp);
if (len <= pathlen &&
!memcmp(*pp, path, len) &&
(path[len] == '\0' ||
(!strict_paths && path[len] == '/')))
return path;
}
}
else {
/* be backwards compatible */
if (!strict_paths)
return path;
}
logerror("'%s': not in whitelist", path);
return NULL; /* Fallthrough. Deny by default */
}
typedef int (*daemon_service_fn)(void);
struct daemon_service {
const char *name;
const char *config_name;
daemon_service_fn fn;
int enabled;
int overridable;
};
static struct daemon_service *service_looking_at;
static int service_enabled;
static int git_daemon_config(const char *var, const char *value, void *cb)
{
if (!prefixcmp(var, "daemon.") &&
!strcmp(var + 7, service_looking_at->config_name)) {
service_enabled = git_config_bool(var, value);
return 0;
}
/* we are not interested in parsing any other configuration here */
return 0;
}
static int run_service(struct interp *itable, struct daemon_service *service)
{
const char *path;
int enabled = service->enabled;
loginfo("Request %s for '%s'",
service->name,
itable[INTERP_SLOT_DIR].value);
if (!enabled && !service->overridable) {
logerror("'%s': service not enabled.", service->name);
errno = EACCES;
return -1;
}
if (!(path = path_ok(itable)))
return -1;
/*
* Security on the cheap.
*
* We want a readable HEAD, usable "objects" directory, and
* a "git-daemon-export-ok" flag that says that the other side
* is ok with us doing this.
*
* path_ok() uses enter_repo() and does whitelist checking.
* We only need to make sure the repository is exported.
*/
if (!export_all_trees && access("git-daemon-export-ok", F_OK)) {
logerror("'%s': repository not exported.", path);
errno = EACCES;
return -1;
}
if (service->overridable) {
service_looking_at = service;
service_enabled = -1;
git_config(git_daemon_config, NULL);
if (0 <= service_enabled)
enabled = service_enabled;
}
if (!enabled) {
logerror("'%s': service not enabled for '%s'",
service->name, path);
errno = EACCES;
return -1;
}
/*
* We'll ignore SIGTERM from now on, we have a
* good client.
*/
signal(SIGTERM, SIG_IGN);
return service->fn();
}
static int upload_pack(void)
{
/* Timeout as string */
char timeout_buf[64];
snprintf(timeout_buf, sizeof timeout_buf, "--timeout=%u", timeout);
/* git-upload-pack only ever reads stuff, so this is safe */
execl_git_cmd("upload-pack", "--strict", timeout_buf, ".", NULL);
return -1;
}
static int upload_archive(void)
{
execl_git_cmd("upload-archive", ".", NULL);
return -1;
}
static int receive_pack(void)
{
execl_git_cmd("receive-pack", ".", NULL);
return -1;
}
static struct daemon_service daemon_service[] = {
{ "upload-archive", "uploadarch", upload_archive, 0, 1 },
{ "upload-pack", "uploadpack", upload_pack, 1, 1 },
{ "receive-pack", "receivepack", receive_pack, 0, 1 },
};
static void enable_service(const char *name, int ena)
{
int i;
for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
if (!strcmp(daemon_service[i].name, name)) {
daemon_service[i].enabled = ena;
return;
}
}
die("No such service %s", name);
}
static void make_service_overridable(const char *name, int ena)
{
int i;
for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
if (!strcmp(daemon_service[i].name, name)) {
daemon_service[i].overridable = ena;
return;
}
}
die("No such service %s", name);
}
/*
* Separate the "extra args" information as supplied by the client connection.
* Any resulting data is squirreled away in the given interpolation table.
*/
static void parse_extra_args(struct interp *table, char *extra_args, int buflen)
{
char *val;
int vallen;
char *end = extra_args + buflen;
while (extra_args < end && *extra_args) {
saw_extended_args = 1;
if (strncasecmp("host=", extra_args, 5) == 0) {
val = extra_args + 5;
vallen = strlen(val) + 1;
if (*val) {
/* Split <host>:<port> at colon. */
char *host = val;
char *port = strrchr(host, ':');
if (port) {
*port = 0;
port++;
interp_set_entry(table, INTERP_SLOT_PORT, port);
}
interp_set_entry(table, INTERP_SLOT_HOST, host);
}
/* On to the next one */
extra_args = val + vallen;
}
}
}
static void fill_in_extra_table_entries(struct interp *itable)
{
char *hp;
/*
* Replace literal host with lowercase-ized hostname.
*/
hp = interp_table[INTERP_SLOT_HOST].value;
if (!hp)
return;
for ( ; *hp; hp++)
*hp = tolower(*hp);
/*
* Locate canonical hostname and its IP address.
*/
#ifndef NO_IPV6
{
struct addrinfo hints;
struct addrinfo *ai, *ai0;
int gai;
static char addrbuf[HOST_NAME_MAX + 1];
memset(&hints, 0, sizeof(hints));
hints.ai_flags = AI_CANONNAME;
gai = getaddrinfo(interp_table[INTERP_SLOT_HOST].value, 0, &hints, &ai0);
if (!gai) {
for (ai = ai0; ai; ai = ai->ai_next) {
struct sockaddr_in *sin_addr = (void *)ai->ai_addr;
inet_ntop(AF_INET, &sin_addr->sin_addr,
addrbuf, sizeof(addrbuf));
interp_set_entry(interp_table,
INTERP_SLOT_CANON_HOST, ai->ai_canonname);
interp_set_entry(interp_table,
INTERP_SLOT_IP, addrbuf);
break;
}
freeaddrinfo(ai0);
}
}
#else
{
struct hostent *hent;
struct sockaddr_in sa;
char **ap;
static char addrbuf[HOST_NAME_MAX + 1];
hent = gethostbyname(interp_table[INTERP_SLOT_HOST].value);
ap = hent->h_addr_list;
memset(&sa, 0, sizeof sa);
sa.sin_family = hent->h_addrtype;
sa.sin_port = htons(0);
memcpy(&sa.sin_addr, *ap, hent->h_length);
inet_ntop(hent->h_addrtype, &sa.sin_addr,
addrbuf, sizeof(addrbuf));
interp_set_entry(interp_table, INTERP_SLOT_CANON_HOST, hent->h_name);
interp_set_entry(interp_table, INTERP_SLOT_IP, addrbuf);
}
#endif
}
static int execute(struct sockaddr *addr)
{
static char line[1000];
int pktlen, len, i;
if (addr) {
char addrbuf[256] = "";
int port = -1;
if (addr->sa_family == AF_INET) {
struct sockaddr_in *sin_addr = (void *) addr;
inet_ntop(addr->sa_family, &sin_addr->sin_addr, addrbuf, sizeof(addrbuf));
port = ntohs(sin_addr->sin_port);
#ifndef NO_IPV6
} else if (addr && addr->sa_family == AF_INET6) {
struct sockaddr_in6 *sin6_addr = (void *) addr;
char *buf = addrbuf;
*buf++ = '['; *buf = '\0'; /* stpcpy() is cool */
inet_ntop(AF_INET6, &sin6_addr->sin6_addr, buf, sizeof(addrbuf) - 1);
strcat(buf, "]");
port = ntohs(sin6_addr->sin6_port);
#endif
}
loginfo("Connection from %s:%d", addrbuf, port);
}
alarm(init_timeout ? init_timeout : timeout);
pktlen = packet_read_line(0, line, sizeof(line));
alarm(0);
len = strlen(line);
if (pktlen != len)
loginfo("Extended attributes (%d bytes) exist <%.*s>",
(int) pktlen - len,
(int) pktlen - len, line + len + 1);
if (len && line[len-1] == '\n') {
line[--len] = 0;
pktlen--;
}
/*
* Initialize the path interpolation table for this connection.
*/
interp_clear_table(interp_table, ARRAY_SIZE(interp_table));
interp_set_entry(interp_table, INTERP_SLOT_PERCENT, "%");
if (len != pktlen) {
parse_extra_args(interp_table, line + len + 1, pktlen - len - 1);
fill_in_extra_table_entries(interp_table);
}
for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
struct daemon_service *s = &(daemon_service[i]);
int namelen = strlen(s->name);
if (!prefixcmp(line, "git-") &&
!strncmp(s->name, line + 4, namelen) &&
line[namelen + 4] == ' ') {
/*
* Note: The directory here is probably context sensitive,
* and might depend on the actual service being performed.
*/
interp_set_entry(interp_table,
INTERP_SLOT_DIR, line + namelen + 5);
return run_service(interp_table, s);
}
}
logerror("Protocol error: '%s'", line);
return -1;
}
/*
* We count spawned/reaped separately, just to avoid any
* races when updating them from signals. The SIGCHLD handler
* will only update children_reaped, and the fork logic will
* only update children_spawned.
*
* MAX_CHILDREN should be a power-of-two to make the modulus
* operation cheap. It should also be at least twice
* the maximum number of connections we will ever allow.
*/
#define MAX_CHILDREN 128
static int max_connections = 25;
/* These are updated by the signal handler */
static volatile unsigned int children_reaped;
static pid_t dead_child[MAX_CHILDREN];
/* These are updated by the main loop */
static unsigned int children_spawned;
static unsigned int children_deleted;
static struct child {
pid_t pid;
int addrlen;
struct sockaddr_storage address;
} live_child[MAX_CHILDREN];
static void add_child(int idx, pid_t pid, struct sockaddr *addr, int addrlen)
{
live_child[idx].pid = pid;
live_child[idx].addrlen = addrlen;
memcpy(&live_child[idx].address, addr, addrlen);
}
/*
* Walk from "deleted" to "spawned", and remove child "pid".
*
* We move everything up by one, since the new "deleted" will
* be one higher.
*/
static void remove_child(pid_t pid, unsigned deleted, unsigned spawned)
{
struct child n;
deleted %= MAX_CHILDREN;
spawned %= MAX_CHILDREN;
if (live_child[deleted].pid == pid) {
live_child[deleted].pid = -1;
return;
}
n = live_child[deleted];
for (;;) {
struct child m;
deleted = (deleted + 1) % MAX_CHILDREN;
if (deleted == spawned)
die("could not find dead child %d\n", pid);
m = live_child[deleted];
live_child[deleted] = n;
if (m.pid == pid)
return;
n = m;
}
}
/*
* This gets called if the number of connections grows
* past "max_connections".
*
* We _should_ start off by searching for connections
* from the same IP, and if there is some address wth
* multiple connections, we should kill that first.
*
* As it is, we just "randomly" kill 25% of the connections,
* and our pseudo-random generator sucks too. I have no
* shame.
*
* Really, this is just a place-holder for a _real_ algorithm.
*/
static void kill_some_children(int signo, unsigned start, unsigned stop)
{
start %= MAX_CHILDREN;
stop %= MAX_CHILDREN;
while (start != stop) {
if (!(start & 3))
kill(live_child[start].pid, signo);
start = (start + 1) % MAX_CHILDREN;
}
}
static void check_max_connections(void)
{
for (;;) {
int active;
unsigned spawned, reaped, deleted;
spawned = children_spawned;
reaped = children_reaped;
deleted = children_deleted;
while (deleted < reaped) {
pid_t pid = dead_child[deleted % MAX_CHILDREN];
remove_child(pid, deleted, spawned);
deleted++;
}
children_deleted = deleted;
active = spawned - deleted;
if (active <= max_connections)
break;
/* Kill some unstarted connections with SIGTERM */
kill_some_children(SIGTERM, deleted, spawned);
if (active <= max_connections << 1)
break;
/* If the SIGTERM thing isn't helping use SIGKILL */
kill_some_children(SIGKILL, deleted, spawned);
sleep(1);
}
}
static void handle(int incoming, struct sockaddr *addr, int addrlen)
{
pid_t pid = fork();
if (pid) {
unsigned idx;
close(incoming);
if (pid < 0)
return;
idx = children_spawned % MAX_CHILDREN;
children_spawned++;
add_child(idx, pid, addr, addrlen);
check_max_connections();
return;
}
dup2(incoming, 0);
dup2(incoming, 1);
close(incoming);
exit(execute(addr));
}
static void child_handler(int signo)
{
for (;;) {
int status;
pid_t pid = waitpid(-1, &status, WNOHANG);
if (pid > 0) {
unsigned reaped = children_reaped;
dead_child[reaped % MAX_CHILDREN] = pid;
children_reaped = reaped + 1;
/* XXX: Custom logging, since we don't wanna getpid() */
if (verbose) {
const char *dead = "";
if (!WIFEXITED(status) || WEXITSTATUS(status) > 0)
dead = " (with error)";
if (log_syslog)
syslog(LOG_INFO, "[%d] Disconnected%s", pid, dead);
else
fprintf(stderr, "[%d] Disconnected%s\n", pid, dead);
}
continue;
}
break;
}
}
static int set_reuse_addr(int sockfd)
{
int on = 1;
if (!reuseaddr)
return 0;
return setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR,
&on, sizeof(on));
}
#ifndef NO_IPV6
static int socksetup(char *listen_addr, int listen_port, int **socklist_p)
{
int socknum = 0, *socklist = NULL;
int maxfd = -1;
char pbuf[NI_MAXSERV];
struct addrinfo hints, *ai0, *ai;
int gai;
long flags;
sprintf(pbuf, "%d", listen_port);
memset(&hints, 0, sizeof(hints));
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
hints.ai_protocol = IPPROTO_TCP;
hints.ai_flags = AI_PASSIVE;
gai = getaddrinfo(listen_addr, pbuf, &hints, &ai0);
if (gai)
die("getaddrinfo() failed: %s\n", gai_strerror(gai));
for (ai = ai0; ai; ai = ai->ai_next) {
int sockfd;
sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
if (sockfd < 0)
continue;
if (sockfd >= FD_SETSIZE) {
error("too large socket descriptor.");
close(sockfd);
continue;
}
#ifdef IPV6_V6ONLY
if (ai->ai_family == AF_INET6) {
int on = 1;
setsockopt(sockfd, IPPROTO_IPV6, IPV6_V6ONLY,
&on, sizeof(on));
/* Note: error is not fatal */
}
#endif
if (set_reuse_addr(sockfd)) {
close(sockfd);
continue;
}
if (bind(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
close(sockfd);
continue; /* not fatal */
}
if (listen(sockfd, 5) < 0) {
close(sockfd);
continue; /* not fatal */
}
flags = fcntl(sockfd, F_GETFD, 0);
if (flags >= 0)
fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
socklist = xrealloc(socklist, sizeof(int) * (socknum + 1));
socklist[socknum++] = sockfd;
if (maxfd < sockfd)
maxfd = sockfd;
}
freeaddrinfo(ai0);
*socklist_p = socklist;
return socknum;
}
#else /* NO_IPV6 */
static int socksetup(char *listen_addr, int listen_port, int **socklist_p)
{
struct sockaddr_in sin;
int sockfd;
long flags;
memset(&sin, 0, sizeof sin);
sin.sin_family = AF_INET;
sin.sin_port = htons(listen_port);
if (listen_addr) {
/* Well, host better be an IP address here. */
if (inet_pton(AF_INET, listen_addr, &sin.sin_addr.s_addr) <= 0)
return 0;
} else {
sin.sin_addr.s_addr = htonl(INADDR_ANY);
}
sockfd = socket(AF_INET, SOCK_STREAM, 0);
if (sockfd < 0)
return 0;
if (set_reuse_addr(sockfd)) {
close(sockfd);
return 0;
}
if ( bind(sockfd, (struct sockaddr *)&sin, sizeof sin) < 0 ) {
close(sockfd);
return 0;
}
if (listen(sockfd, 5) < 0) {
close(sockfd);
return 0;
}
flags = fcntl(sockfd, F_GETFD, 0);
if (flags >= 0)
fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
*socklist_p = xmalloc(sizeof(int));
**socklist_p = sockfd;
return 1;
}
#endif
static int service_loop(int socknum, int *socklist)
{
struct pollfd *pfd;
int i;
pfd = xcalloc(socknum, sizeof(struct pollfd));
for (i = 0; i < socknum; i++) {
pfd[i].fd = socklist[i];
pfd[i].events = POLLIN;
}
signal(SIGCHLD, child_handler);
for (;;) {
int i;
if (poll(pfd, socknum, -1) < 0) {
if (errno != EINTR) {
error("poll failed, resuming: %s",
strerror(errno));
sleep(1);
}
continue;
}
for (i = 0; i < socknum; i++) {
if (pfd[i].revents & POLLIN) {
struct sockaddr_storage ss;
unsigned int sslen = sizeof(ss);
int incoming = accept(pfd[i].fd, (struct sockaddr *)&ss, &sslen);
if (incoming < 0) {
switch (errno) {
case EAGAIN:
case EINTR:
case ECONNABORTED:
continue;
default:
die("accept returned %s", strerror(errno));
}
}
handle(incoming, (struct sockaddr *)&ss, sslen);
}
}
}
}
/* if any standard file descriptor is missing open it to /dev/null */
static void sanitize_stdfds(void)
{
int fd = open("/dev/null", O_RDWR, 0);
while (fd != -1 && fd < 2)
fd = dup(fd);
if (fd == -1)
die("open /dev/null or dup failed: %s", strerror(errno));
if (fd > 2)
close(fd);
}
static void daemonize(void)
{
switch (fork()) {
case 0:
break;
case -1:
die("fork failed: %s", strerror(errno));
default:
exit(0);
}
if (setsid() == -1)
die("setsid failed: %s", strerror(errno));
close(0);
close(1);
close(2);
sanitize_stdfds();
}
static void store_pid(const char *path)
{
FILE *f = fopen(path, "w");
if (!f)
die("cannot open pid file %s: %s", path, strerror(errno));
if (fprintf(f, "%d\n", getpid()) < 0 || fclose(f) != 0)
die("failed to write pid file %s: %s", path, strerror(errno));
}