summaryrefslogtreecommitdiffstats
path: root/rubbos/app/httpd-2.0.64/os/unix/unixd.c
blob: 05b6443c0b2e4cbfa3eba6c106eeca8c13c1ddd2 (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
/* 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.
 */

#include "ap_config.h"
#define CORE_PRIVATE
#include "httpd.h"
#include "http_config.h"
#include "http_main.h"
#include "http_log.h"
#include "unixd.h"
#include "mpm_common.h"
#include "os.h"
#include "ap_mpm.h"
#include "apr_thread_proc.h"
#include "apr_strings.h"
#include "apr_portable.h"
#ifdef HAVE_PWD_H
#include <pwd.h>
#endif
#ifdef HAVE_SYS_RESOURCE_H
#include <sys/resource.h>
#endif
/* XXX */
#include <sys/stat.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_GRP_H
#include <grp.h>
#endif
#ifdef HAVE_STRINGS_H
#include <strings.h>
#endif
#ifdef HAVE_SYS_SEM_H
#include <sys/sem.h>
#endif
#ifdef HAVE_SYS_PRCTL_H
#include <sys/prctl.h>
#endif

unixd_config_rec unixd_config;

/* Set group privileges.
 *
 * Note that we use the username as set in the config files, rather than
 * the lookup of to uid --- the same uid may have multiple passwd entries,
 * with different sets of groups for each.
 */

static int set_group_privs(void)
{
    if (!geteuid()) {
	const char *name;

	/* Get username if passed as a uid */

	if (unixd_config.user_name[0] == '#') {
	    struct passwd *ent;
	    uid_t uid = atoi(&unixd_config.user_name[1]);

	    if ((ent = getpwuid(uid)) == NULL) {
		ap_log_error(APLOG_MARK, APLOG_ALERT, errno, NULL,
			 "getpwuid: couldn't determine user name from uid %u, "
			 "you probably need to modify the User directive",
			 (unsigned)uid);
		return -1;
	    }

	    name = ent->pw_name;
	}
	else
	    name = unixd_config.user_name;

#if !defined(OS2) && !defined(TPF)
	/* OS/2 and TPF don't support groups. */

	/*
	 * Set the GID before initgroups(), since on some platforms
	 * setgid() is known to zap the group list.
	 */
	if (setgid(unixd_config.group_id) == -1) {
	    ap_log_error(APLOG_MARK, APLOG_ALERT, errno, NULL,
			"setgid: unable to set group id to Group %u",
			(unsigned)unixd_config.group_id);
	    return -1;
	}

	/* Reset `groups' attributes. */

	if (initgroups(name, unixd_config.group_id) == -1) {
	    ap_log_error(APLOG_MARK, APLOG_ALERT, errno, NULL,
			"initgroups: unable to set groups for User %s "
			"and Group %u", name, (unsigned)unixd_config.group_id);
	    return -1;
	}
#endif /* !defined(OS2) && !defined(TPF) */
    }
    return 0;
}


AP_DECLARE(int) unixd_setup_child(void)
{
    if (set_group_privs()) {
	return -1;
    }
#ifdef MPE
    /* Only try to switch if we're running as MANAGER.SYS */
    if (geteuid() == 1 && unixd_config.user_id > 1) {
	GETPRIVMODE();
	if (setuid(unixd_config.user_id) == -1) {
	    GETUSERMODE();
	    ap_log_error(APLOG_MARK, APLOG_ALERT, errno, NULL,
			"setuid: unable to change to uid: %ld",
                        (long) unixd_config.user_id);
	    exit(1);
	}
	GETUSERMODE();
    }
#else
    /* Only try to switch if we're running as root */
    if (!geteuid() && (
#ifdef _OSD_POSIX
	os_init_job_environment(server_conf, unixd_config.user_name, one_process) != 0 || 
#endif
	setuid(unixd_config.user_id) == -1)) {
	ap_log_error(APLOG_MARK, APLOG_ALERT, errno, NULL,
		    "setuid: unable to change to uid: %ld",
                    (long) unixd_config.user_id);
	return -1;
    }
#if defined(HAVE_PRCTL) && defined(PR_SET_DUMPABLE) 
    /* this applies to Linux 2.4+ */
#ifdef AP_MPM_WANT_SET_COREDUMPDIR
    if (ap_coredumpdir_configured) {
        if (prctl(PR_SET_DUMPABLE, 1)) {
            ap_log_error(APLOG_MARK, APLOG_ALERT, errno, NULL,
                         "set dumpable failed - this child will not coredump"
                         " after software errors");
        }
    }
#endif
#endif
#endif
    return 0;
}


AP_DECLARE(const char *) unixd_set_user(cmd_parms *cmd, void *dummy, 
                                        const char *arg)
{
    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
    if (err != NULL) {
        return err;
    }

    unixd_config.user_name = arg;
    unixd_config.user_id = ap_uname2id(arg);
#if !defined (BIG_SECURITY_HOLE) && !defined (OS2)
    if (unixd_config.user_id == 0) {
	return "Error:\tApache has not been designed to serve pages while\n"
		"\trunning as root.  There are known race conditions that\n"
		"\twill allow any local user to read any file on the system.\n"
		"\tIf you still desire to serve pages as root then\n"
		"\tadd -DBIG_SECURITY_HOLE to the CFLAGS env variable\n"
		"\tand then rebuild the server.\n"
		"\tIt is strongly suggested that you instead modify the User\n"
		"\tdirective in your httpd.conf file to list a non-root\n"
		"\tuser.\n";
    }
#endif

    return NULL;
}

AP_DECLARE(const char *) unixd_set_group(cmd_parms *cmd, void *dummy, 
                                         const char *arg)
{
    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
    if (err != NULL) {
        return err;
    }

    unixd_config.group_id = ap_gname2id(arg);

    return NULL;
}

AP_DECLARE(void) unixd_pre_config(apr_pool_t *ptemp)
{
    apr_finfo_t wrapper;

    unixd_config.user_name = DEFAULT_USER;
    unixd_config.user_id = ap_uname2id(DEFAULT_USER);
    unixd_config.group_id = ap_gname2id(DEFAULT_GROUP);

    /* Check for suexec */
    unixd_config.suexec_enabled = 0;
    if ((apr_stat(&wrapper, SUEXEC_BIN, 
                  APR_FINFO_NORM, ptemp)) != APR_SUCCESS) {
        return;
    }

/* since APR 0.9.5 */
#ifdef APR_USETID
    if ((wrapper.protection & APR_USETID) && wrapper.user == 0) {
#endif
        unixd_config.suexec_enabled = 1;
#ifdef APR_USETID
    }
#endif
}


AP_DECLARE(void) unixd_set_rlimit(cmd_parms *cmd, struct rlimit **plimit, 
                           const char *arg, const char * arg2, int type)
{
#if (defined(RLIMIT_CPU) || defined(RLIMIT_DATA) || defined(RLIMIT_VMEM) || defined(RLIMIT_NPROC) || defined(RLIMIT_AS)) && APR_HAVE_STRUCT_RLIMIT && APR_HAVE_GETRLIMIT
    char *str;
    struct rlimit *limit;
    /* If your platform doesn't define rlim_t then typedef it in ap_config.h */
    rlim_t cur = 0;
    rlim_t max = 0;

    *plimit = (struct rlimit *)apr_pcalloc(cmd->pool, sizeof(**plimit));
    limit = *plimit;
    if ((getrlimit(type, limit)) != 0)  {
        *plimit = NULL;
        ap_log_error(APLOG_MARK, APLOG_ERR, errno, cmd->server,
                     "%s: getrlimit failed", cmd->cmd->name);
        return;
    }

    if ((str = ap_getword_conf(cmd->pool, &arg))) {
        if (!strcasecmp(str, "max")) {
            cur = limit->rlim_max;
        }
        else {
            cur = atol(str);
        }
    }
    else {
        ap_log_error(APLOG_MARK, APLOG_ERR, 0, cmd->server,
                     "Invalid parameters for %s", cmd->cmd->name);
        return;
    }

    if (arg2 && (str = ap_getword_conf(cmd->pool, &arg2))) {
        max = atol(str);
    }

    /* if we aren't running as root, cannot increase max */
    if (geteuid()) {
        limit->rlim_cur = cur;
        if (max) {
            ap_log_error(APLOG_MARK, APLOG_ERR, 0, cmd->server,
                         "Must be uid 0 to raise maximum %s", cmd->cmd->name);
        }
    }
    else {
        if (cur) {
            limit->rlim_cur = cur;
        }
        if (max) {
            limit->rlim_max = max;
        }
    }
#else

    ap_log_error(APLOG_MARK, APLOG_ERR, 0, cmd->server,
                 "Platform does not support rlimit for %s", cmd->cmd->name);
#endif
}

APR_HOOK_STRUCT(
               APR_HOOK_LINK(get_suexec_identity)
)

AP_IMPLEMENT_HOOK_RUN_FIRST(ap_unix_identity_t *, get_suexec_identity,
                         (const request_rec *r), (r), NULL)

static apr_status_t ap_unix_create_privileged_process(
                              apr_proc_t *newproc, const char *progname,
                              const char * const *args,
                              const char * const *env,
                              apr_procattr_t *attr, ap_unix_identity_t *ugid,
                              apr_pool_t *p)
{
    int i = 0;
    const char **newargs;
    char *newprogname;
    char *execuser, *execgroup;
    const char *argv0;

    if (!unixd_config.suexec_enabled) {
        return apr_proc_create(newproc, progname, args, env, attr, p);
    }

    argv0 = ap_strrchr_c(progname, '/');
    /* Allow suexec's "/" check to succeed */
    if (argv0 != NULL) {
        argv0++;
    }
    else {
        argv0 = progname;
    }


    if (ugid->userdir) {
        execuser = apr_psprintf(p, "~%ld", (long) ugid->uid);
    }
    else {
        execuser = apr_psprintf(p, "%ld", (long) ugid->uid);
    }
    execgroup = apr_psprintf(p, "%ld", (long) ugid->gid);

    if (!execuser || !execgroup) {
        return APR_ENOMEM;
    }

    i = 0;
    if (args) {
        while (args[i]) {
            i++;
	    }
    }
    /* allocate space for 4 new args, the input args, and a null terminator */
    newargs = apr_palloc(p, sizeof(char *) * (i + 4));
    newprogname = SUEXEC_BIN;
    newargs[0] = SUEXEC_BIN;
    newargs[1] = execuser;
    newargs[2] = execgroup;
    newargs[3] = apr_pstrdup(p, argv0);

    /*
    ** using a shell to execute suexec makes no sense thus
    ** we force everything to be APR_PROGRAM, and never
    ** APR_SHELLCMD
    */
    if(apr_procattr_cmdtype_set(attr, APR_PROGRAM) != APR_SUCCESS) {
        return APR_EGENERAL;
    }

    i = 1;
    do {
        newargs[i + 3] = args[i];
    } while (args[i++]);

    return apr_proc_create(newproc, newprogname, newargs, env, attr, p);
}

AP_DECLARE(apr_status_t) ap_os_create_privileged_process(
    const request_rec *r,
    apr_proc_t *newproc, const char *progname,
    const char * const *args,
    const char * const *env,
    apr_procattr_t *attr, apr_pool_t *p)
{
    ap_unix_identity_t *ugid = ap_run_get_suexec_identity(r);

    if (ugid == NULL) {
        return apr_proc_create(newproc, progname, args, env, attr, p);
    }

    return ap_unix_create_privileged_process(newproc, progname, args, env,
                                              attr, ugid, p);
}

/* XXX move to APR and externalize (but implement differently :) ) */
static apr_lockmech_e proc_mutex_mech(apr_proc_mutex_t *pmutex)
{
    const char *mechname = apr_proc_mutex_name(pmutex);

    if (!strcmp(mechname, "sysvsem")) {
        return APR_LOCK_SYSVSEM;
    }
    else if (!strcmp(mechname, "flock")) {
        return APR_LOCK_FLOCK;
    }
    return APR_LOCK_DEFAULT;
}

AP_DECLARE(apr_status_t) unixd_set_proc_mutex_perms(apr_proc_mutex_t *pmutex)
{
    if (!geteuid()) {
        apr_lockmech_e mech = proc_mutex_mech(pmutex);

        switch(mech) {
#if APR_HAS_SYSVSEM_SERIALIZE
        case APR_LOCK_SYSVSEM:
        {
            apr_os_proc_mutex_t ospmutex;
#if !APR_HAVE_UNION_SEMUN
            union semun {
                long val;
                struct semid_ds *buf;
                unsigned short *array;
            };
#endif
            union semun ick;
            struct semid_ds buf;
        
            apr_os_proc_mutex_get(&ospmutex, pmutex);
            buf.sem_perm.uid = unixd_config.user_id;
            buf.sem_perm.gid = unixd_config.group_id;
            buf.sem_perm.mode = 0600;
            ick.buf = &buf;
            if (semctl(ospmutex.crossproc, 0, IPC_SET, ick) < 0) {
                return errno;
            }
        }
        break;
#endif
#if APR_HAS_FLOCK_SERIALIZE
        case APR_LOCK_FLOCK:
        {
            const char *lockfile = apr_proc_mutex_lockfile(pmutex);

            if (lockfile) {
                if (chown(lockfile, unixd_config.user_id,
                          -1 /* no gid change */) < 0) {
                    return errno;
                }
            }
        }
        break;
#endif
        default:
            /* do nothing */
            break;
        }
    }
    return APR_SUCCESS;
}

AP_DECLARE(apr_status_t) unixd_set_global_mutex_perms(apr_global_mutex_t *gmutex)
{
#if !APR_PROC_MUTEX_IS_GLOBAL
    apr_os_global_mutex_t osgmutex;
    apr_os_global_mutex_get(&osgmutex, gmutex);
    return unixd_set_proc_mutex_perms(osgmutex.proc_mutex);
#else  /* APR_PROC_MUTEX_IS_GLOBAL */
    /* In this case, apr_proc_mutex_t and apr_global_mutex_t are the same. */
    return unixd_set_proc_mutex_perms(gmutex);
#endif /* APR_PROC_MUTEX_IS_GLOBAL */
}

AP_DECLARE(apr_status_t) unixd_accept(void **accepted, ap_listen_rec *lr,
                                        apr_pool_t *ptrans)
{
    apr_socket_t *csd;
    apr_status_t status;

    *accepted = NULL;
    status = apr_accept(&csd, lr->sd, ptrans);
    if (status == APR_SUCCESS) { 
        *accepted = csd;
        return APR_SUCCESS;
    }

    if (APR_STATUS_IS_EINTR(status)) {
        return status;
    }
    /* Our old behaviour here was to continue after accept()
     * errors.  But this leads us into lots of troubles
     * because most of the errors are quite fatal.  For
     * example, EMFILE can be caused by slow descriptor
     * leaks (say in a 3rd party module, or libc).  It's
     * foolish for us to continue after an EMFILE.  We also
     * seem to tickle kernel bugs on some platforms which
     * lead to never-ending loops here.  So it seems best
     * to just exit in most cases.
     */
    switch (status) {
#if defined(HPUX11) && defined(ENOBUFS)
        /* On HPUX 11.x, the 'ENOBUFS, No buffer space available'
         * error occurs because the accept() cannot complete.
         * You will not see ENOBUFS with 10.20 because the kernel
         * hides any occurrence from being returned to user space.
         * ENOBUFS with 11.x's TCP/IP stack is possible, and could
         * occur intermittently. As a work-around, we are going to
         * ignore ENOBUFS.
         */
        case ENOBUFS:
#endif

#ifdef EPROTO
        /* EPROTO on certain older kernels really means
         * ECONNABORTED, so we need to ignore it for them.
         * See discussion in new-httpd archives nh.9701
         * search for EPROTO.
         *
         * Also see nh.9603, search for EPROTO:
         * There is potentially a bug in Solaris 2.x x<6,
         * and other boxes that implement tcp sockets in
         * userland (i.e. on top of STREAMS).  On these
         * systems, EPROTO can actually result in a fatal
         * loop.  See PR#981 for example.  It's hard to
         * handle both uses of EPROTO.
         */
        case EPROTO:
#endif
#ifdef ECONNABORTED
        case ECONNABORTED:
#endif
        /* Linux generates the rest of these, other tcp
         * stacks (i.e. bsd) tend to hide them behind
         * getsockopt() interfaces.  They occur when
         * the net goes sour or the client disconnects
         * after the three-way handshake has been done
         * in the kernel but before userland has picked
         * up the socket.
         */
#ifdef ECONNRESET
        case ECONNRESET:
#endif
#ifdef ETIMEDOUT
        case ETIMEDOUT:
#endif
#ifdef EHOSTUNREACH
        case EHOSTUNREACH:
#endif
#ifdef ENETUNREACH
        case ENETUNREACH:
#endif
        /* EAGAIN/EWOULDBLOCK can be returned on BSD-derived
         * TCP stacks when the connection is aborted before
         * we call connect, but only because our listener
         * sockets are non-blocking (AP_NONBLOCK_WHEN_MULTI_LISTEN)
         */
#ifdef EAGAIN
        case EAGAIN:
#endif
#ifdef EWOULDBLOCK
#if !defined(EAGAIN) || EAGAIN != EWOULDBLOCK
        case EWOULDBLOCK:
#endif
#endif
            break;
#ifdef ENETDOWN
        case ENETDOWN:
            /*
             * When the network layer has been shut down, there
             * is not much use in simply exiting: the parent
             * would simply re-create us (and we'd fail again).
             * Use the CHILDFATAL code to tear the server down.
             * @@@ Martin's idea for possible improvement:
             * A different approach would be to define
             * a new APEXIT_NETDOWN exit code, the reception
             * of which would make the parent shutdown all
             * children, then idle-loop until it detected that
             * the network is up again, and restart the children.
             * Ben Hyde noted that temporary ENETDOWN situations
             * occur in mobile IP.
             */
            ap_log_error(APLOG_MARK, APLOG_EMERG, status, ap_server_conf,
                         "apr_accept: giving up.");
            return APR_EGENERAL;
#endif /*ENETDOWN*/

#ifdef TPF
        case EINACT:
            ap_log_error(APLOG_MARK, APLOG_EMERG, status, ap_server_conf,
                         "offload device inactive");
            return APR_EGENERAL;
            break;
        default:
            ap_log_error(APLOG_MARK, APLOG_ERR, 0, ap_server_conf,
                         "select/accept error (%d)", status);
            return APR_EGENERAL;
#else
        default:
            ap_log_error(APLOG_MARK, APLOG_ERR, status, ap_server_conf,
                         "apr_accept: (client socket)");
            return APR_EGENERAL;
#endif
    }
    return status;
}