2 * Copyright (c) 2003,2004 The DragonFly Project. All rights reserved.
4 * This code is derived from software contributed to The DragonFly Project
5 * by Matthew Dillon <dillon@backplane.com>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
17 * 3. Neither the name of The DragonFly Project nor the names of its
18 * contributors may be used to endorse or promote products derived
19 * from this software without specific, prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * $DragonFly: src/sys/kern/kern_varsym.c,v 1.5 2004/07/16 05:51:10 dillon Exp $
38 * This module implements variable storage and management for variant
39 * symlinks. These variables may also be used for general purposes.
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/kernel.h>
45 #include <sys/ucred.h>
46 #include <sys/resourcevar.h>
48 #include <sys/queue.h>
49 #include <sys/sysctl.h>
50 #include <sys/malloc.h>
51 #include <sys/varsym.h>
52 #include <sys/sysproto.h>
54 MALLOC_DEFINE(M_VARSYM, "varsym", "variable sets for variant symlinks");
56 struct varsymset varsymset_sys;
59 * Initialize the variant symlink subsystem
62 varsym_sysinit(void *dummy)
64 varsymset_init(&varsymset_sys, NULL);
66 SYSINIT(announce, SI_SUB_INTRINSIC, SI_ORDER_FIRST, varsym_sysinit, NULL);
69 * varsymreplace() - called from namei
71 * Do variant symlink variable substitution
74 varsymreplace(char *cp, int linklen, int maxlen)
84 if (cp[0] == '$' && cp[1] == '{') {
85 for (i = 2; i < linklen; ++i) {
90 (var = varsymfind(VARSYM_ALL_MASK, cp + 2, i - 2)) != NULL
92 xlen = i + 1; /* bytes to strike */
93 nlen = strlen(var->vs_data); /* bytes to add */
94 if (linklen + nlen - xlen >= maxlen) {
98 KKASSERT(linklen >= xlen);
100 bcopy(cp + xlen, cp + nlen, linklen - xlen);
101 bcopy(var->vs_data, cp, nlen);
102 linklen += nlen - xlen; /* new relative length */
103 rlen += nlen - xlen; /* returned total length */
104 cp += nlen; /* adjust past replacement */
105 linklen -= nlen; /* adjust past replacement */
106 maxlen -= nlen; /* adjust past replacement */
109 * It's ok if i points to the '}', it will simply be
110 * skipped. i could also have hit linklen.
126 * varsym_set() system call
128 * (int level, const char *name, const char *data)
131 varsym_set(struct varsym_set_args *uap)
133 char name[MAXVARSYM_NAME];
137 if ((error = copyinstr(uap->name, name, sizeof(name), NULL)) != 0)
139 buf = malloc(MAXVARSYM_DATA, M_TEMP, M_WAITOK);
141 (error = copyinstr(uap->data, buf, MAXVARSYM_DATA, NULL)) != 0)
147 if ((error = suser(curthread)) != 0)
149 /* XXX implement per-jail sys */
152 /* XXX check jail / implement per-jail user */
156 (void)varsymmake(uap->level, name, NULL);
157 error = varsymmake(uap->level, name, buf);
159 error = varsymmake(uap->level, name, NULL);
170 * varsym_get() system call
172 * (int mask, const char *wild, char *buf, int bufsize)
175 varsym_get(struct varsym_get_args *uap)
177 char wild[MAXVARSYM_NAME];
182 if ((error = copyinstr(uap->wild, wild, sizeof(wild), NULL)) != 0)
184 sym = varsymfind(uap->mask, wild, strlen(wild));
189 dlen = strlen(sym->vs_data);
190 if (dlen < uap->bufsize) {
191 copyout(sym->vs_data, uap->buf, dlen + 1);
192 } else if (uap->bufsize) {
193 copyout("", uap->buf, 1);
195 uap->sysmsg_result = dlen + 1;
202 * varsym_list() system call
204 * (int level, char *buf, int maxsize, int *marker)
207 varsym_list(struct varsym_list_args *uap)
209 struct varsymset *vss;
210 struct varsyment *ve;
219 * Get the marker from userspace.
221 if ((error = copyin(uap->marker, &marker, sizeof(marker))) != 0)
225 * Figure out the varsym set.
230 switch (uap->level) {
233 vss = &p->p_varsymset;
237 vss = &p->p_ucred->cr_uidinfo->ui_varsymset;
240 vss = &varsymset_sys;
249 * Loop through the variables and dump them to uap->buf
255 TAILQ_FOREACH(ve, &vss->vx_queue, ve_entry) {
256 varsym_t sym = ve->ve_sym;
257 int namelen = strlen(sym->vs_name);
258 int datalen = strlen(sym->vs_data);
259 int totlen = namelen + datalen + 2;
262 * Skip to our index point
270 * Stop if there is insufficient space in the user buffer.
271 * If we haven't stored anything yet return EOVERFLOW.
272 * Note that the marker index (i) does not change.
274 if (bytes + totlen > uap->maxsize) {
281 error = copyout(sym->vs_name, uap->buf + bytes, namelen + 1);
283 bytes += namelen + 1;
284 error = copyout(sym->vs_data, uap->buf + bytes, datalen + 1);
286 bytes += datalen + 1;
288 bytes -= namelen + 1; /* revert if error */
298 * Save the marker back. If no error occured and earlyterm is clear
299 * the marker is set to -1 indicating that the variable list has been
300 * exhausted. If no error occured the number of bytes loaded into
301 * the buffer will be returned, otherwise the syscall code returns -1.
303 if (error == 0 && earlyterm == 0)
308 error = copyout(&marker, uap->marker, sizeof(marker));
309 uap->sysmsg_result = bytes;
315 * Lookup a variant symlink. XXX use a hash table.
319 varsymlookup(struct varsymset *vss, const char *name, int namelen)
321 struct varsyment *ve;
323 TAILQ_FOREACH(ve, &vss->vx_queue, ve_entry) {
324 varsym_t var = ve->ve_sym;
325 if (var->vs_namelen == namelen &&
326 bcmp(name, var->vs_name, namelen) == 0
335 varsymfind(int mask, const char *name, int namelen)
338 struct varsyment *ve = NULL;
341 if ((mask & (VARSYM_PROC_MASK|VARSYM_USER_MASK)) && (p = curproc) != NULL) {
342 if (mask & VARSYM_PROC_MASK)
343 ve = varsymlookup(&p->p_varsymset, name, namelen);
344 if (ve == NULL && (mask & VARSYM_USER_MASK))
345 ve = varsymlookup(&p->p_ucred->cr_uidinfo->ui_varsymset, name, namelen);
347 if (ve == NULL && (mask & VARSYM_SYS_MASK))
348 ve = varsymlookup(&varsymset_sys, name, namelen);
359 varsymmake(int level, const char *name, const char *data)
361 struct varsymset *vss = NULL;
362 struct varsyment *ve;
363 struct proc *p = curproc;
365 int namelen = strlen(name);
372 vss = &p->p_varsymset;
376 vss = &p->p_ucred->cr_uidinfo->ui_varsymset;
379 vss = &varsymset_sys;
384 } else if (data && vss->vx_setsize >= MAXVARSYM_SET) {
387 datalen = strlen(data);
388 ve = malloc(sizeof(struct varsyment), M_VARSYM, M_WAITOK|M_ZERO);
389 sym = malloc(sizeof(struct varsym) + namelen + datalen + 2, M_VARSYM, M_WAITOK);
392 sym->vs_namelen = namelen;
393 sym->vs_name = (char *)(sym + 1);
394 sym->vs_data = sym->vs_name + namelen + 1;
395 strcpy(sym->vs_name, name);
396 strcpy(sym->vs_data, data);
397 TAILQ_INSERT_TAIL(&vss->vx_queue, ve, ve_entry);
398 vss->vx_setsize += sizeof(struct varsyment) + sizeof(struct varsym) + namelen + datalen + 8;
401 if ((ve = varsymlookup(vss, name, namelen)) != NULL) {
402 TAILQ_REMOVE(&vss->vx_queue, ve, ve_entry);
403 vss->vx_setsize -= sizeof(struct varsyment) + sizeof(struct varsym) + namelen + strlen(ve->ve_sym->vs_data) + 8;
404 varsymdrop(ve->ve_sym);
415 varsymdrop(varsym_t sym)
417 KKASSERT(sym->vs_refs > 0);
418 if (--sym->vs_refs == 0) {
424 varsymdup(struct varsymset *vss, struct varsyment *ve)
426 struct varsyment *nve;
428 nve = malloc(sizeof(struct varsyment), M_VARSYM, M_WAITOK|M_ZERO);
429 nve->ve_sym = ve->ve_sym;
430 ++nve->ve_sym->vs_refs;
431 TAILQ_INSERT_TAIL(&vss->vx_queue, nve, ve_entry);
435 varsymset_init(struct varsymset *vss, struct varsymset *copy)
437 struct varsyment *ve;
439 TAILQ_INIT(&vss->vx_queue);
441 TAILQ_FOREACH(ve, ©->vx_queue, ve_entry) {
444 vss->vx_setsize = copy->vx_setsize;
449 varsymset_clean(struct varsymset *vss)
451 struct varsyment *ve;
453 while ((ve = TAILQ_FIRST(&vss->vx_queue)) != NULL) {
454 TAILQ_REMOVE(&vss->vx_queue, ve, ve_entry);
455 varsymdrop(ve->ve_sym);