freebsd-src/sbin/mount_portalfs/conf.c
1997-02-22 14:40:44 +00:00

338 lines
7.2 KiB
C

/*
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
* All rights reserved.
*
* This code is derived from software donated to Berkeley by
* Jan-Simon Pendry.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)conf.c 8.2 (Berkeley) 3/27/94
*
* $Id$
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <limits.h>
#include <regex.h>
#include <sys/types.h>
#include <sys/param.h>
#include <sys/syslog.h>
#include "portald.h"
#define ALLOC(ty) (xmalloc(sizeof(ty)))
typedef struct path path;
struct path {
qelem p_q; /* 2-way linked list */
int p_lno; /* Line number of this record */
char *p_args; /* copy of arg string (malloc) */
char *p_key; /* Pathname to match (also p_argv[0]) */
regex_t p_rx; /* RE to match against pathname () */
int p_rxvalid; /* non-zero if valid regular expression */
int p_argc; /* number of elements in arg string */
char **p_argv; /* argv[] pointers into arg string (malloc) */
};
static char *conf_file; /* XXX for regerror */
static path *curp; /* XXX for regerror */
/*
* Add an element to a 2-way list,
* just after (pred)
*/
static void ins_que(elem, pred)
qelem *elem, *pred;
{
qelem *p = pred->q_forw;
elem->q_back = pred;
elem->q_forw = p;
pred->q_forw = elem;
p->q_back = elem;
}
/*
* Remove an element from a 2-way list
*/
static void rem_que(elem)
qelem *elem;
{
qelem *p = elem->q_forw;
qelem *p2 = elem->q_back;
p2->q_forw = p;
p->q_back = p2;
}
/*
* Error checking malloc
*/
static void *xmalloc(siz)
unsigned siz;
{
void *p = malloc(siz);
if (p)
return (p);
syslog(LOG_ALERT, "malloc: failed to get %d bytes", siz);
exit(1);
}
/*
* Insert the path in the list.
* If there is already an element with the same key then
* the *second* one is ignored (return 0). If the key is
* not found then the path is added to the end of the list
* and 1 is returned.
*/
static int pinsert(p0, q0)
path *p0;
qelem *q0;
{
qelem *q;
if (p0->p_argc == 0)
return (0);
for (q = q0->q_forw; q != q0; q = q->q_forw) {
path *p = (path *) q;
if (strcmp(p->p_key, p0->p_key) == 0)
return (0);
}
ins_que(&p0->p_q, q0->q_back);
return (1);
}
static path *palloc(cline, lno)
char *cline;
int lno;
{
int c;
char *s;
char *key;
path *p;
char **ap;
/*
* Implement comment chars
*/
s = strchr(cline, '#');
if (s)
*s = 0;
/*
* Do a pass through the string to count the number
* of arguments
*/
c = 0;
key = strdup(cline);
for (s = key; s != NULL; ) {
char *val;
while ((val = strsep(&s, " \t\n")) != NULL && *val == '\0')
;
if (val)
c++;
}
c++;
free(key);
if (c <= 1)
return (0);
/*
* Now do another pass and generate a new path structure
*/
p = ALLOC(path);
p->p_argc = 0;
p->p_argv = xmalloc(c * sizeof(char *));
p->p_args = strdup(cline);
ap = p->p_argv;
for (s = p->p_args; s != NULL; ) {
char *val;
while ((val = strsep(&s, " \t\n")) != NULL && *val == '\0')
;
if (val) {
*ap++ = val;
p->p_argc++;
}
}
*ap = 0;
#ifdef DEBUG
for (c = 0; c < p->p_argc; c++)
printf("%sv[%d] = %s\n", c?"\t":"", c, p->p_argv[c]);
#endif
p->p_key = p->p_argv[0];
if (strpbrk(p->p_key, RE_CHARS)) {
int val;
curp = p; /* XXX */
val = regcomp(&p->p_rx, p->p_key, REG_EXTENDED | REG_NOSUB);
if (val) {
char errbuf[_POSIX2_LINE_MAX];
regerror(val, &p->p_rx, errbuf, sizeof errbuf);
syslog(LOG_ERR, "%s:%s: regcomp %s: %s",
conf_file, curp->p_lno, curp->p_key, errbuf);
regfree(&p->p_rx);
p->p_rxvalid = 0;
} else {
p->p_rxvalid = 1;
}
curp = 0; /* XXX */
} else {
p->p_rxvalid = 0;
}
p->p_lno = lno;
return (p);
}
/*
* Free a path structure
*/
static void pfree(p)
path *p;
{
free(p->p_args);
if (p->p_rxvalid) {
regfree(&p->p_rx);
}
free((char *) p->p_argv);
free((char *) p);
}
/*
* Discard all currently held path structures on q0.
* and add all the ones on xq.
*/
static void preplace(q0, xq)
qelem *q0;
qelem *xq;
{
/*
* While the list is not empty,
* take the first element off the list
* and free it.
*/
while (q0->q_forw != q0) {
qelem *q = q0->q_forw;
rem_que(q);
pfree((path *) q);
}
while (xq->q_forw != xq) {
qelem *q = xq->q_forw;
rem_que(q);
ins_que(q, q0);
}
}
/*
* Read the lines from the configuration file and
* add them to the list of paths.
*/
static void readfp(q0, fp)
qelem *q0;
FILE *fp;
{
char cline[LINE_MAX];
int nread = 0;
qelem q;
/*
* Make a new empty list.
*/
q.q_forw = q.q_back = &q;
/*
* Read the lines from the configuration file.
*/
while (fgets(cline, sizeof(cline), fp)) {
path *p = palloc(cline, nread+1);
if (p && !pinsert(p, &q))
pfree(p);
nread++;
}
/*
* If some records were read, then throw
* away the old list and replace with the
* new one.
*/
if (nread)
preplace(q0, &q);
}
/*
* Read the configuration file (conf) and replace
* the existing path list with the new version.
* If the file is not readable, then no changes take place
*/
void conf_read(q, conf)
qelem *q;
char *conf;
{
FILE *fp = fopen(conf, "r");
if (fp) {
conf_file = conf; /* XXX */
readfp(q, fp);
conf_file = 0; /* XXX */
(void) fclose(fp);
} else {
syslog(LOG_ERR, "open config file \"%s\": %s", conf, strerror(errno));
}
}
char **conf_match(q0, key)
qelem *q0;
char *key;
{
qelem *q;
for (q = q0->q_forw; q != q0; q = q->q_forw) {
path *p = (path *) q;
if (p->p_rxvalid) {
if (!regexec(&p->p_rx, key, 0, 0, 0)) {
return p->p_argv + 1;
}
} else {
if (strncmp(p->p_key, key, strlen(p->p_key)) == 0)
return (p->p_argv+1);
}
}
return (0);
}