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/*
* Copyright (c) 2003-2006 Erez Zadok
* Copyright (c) 2003-2006 Charles P. Wright
* Copyright (c) 2005-2006 Josef Sipek
* Copyright (c) 2005 Arun M. Krishnakumar
* Copyright (c) 2005-2006 David P. Quigley
* Copyright (c) 2003-2004 Mohammad Nayyer Zubair
* Copyright (c) 2003 Puja Gupta
* Copyright (c) 2003 Harikesavan Krishnan
* Copyright (c) 2003-2006 Stony Brook University
* Copyright (c) 2003-2006 The Research Foundation of State University of New York
*
* For specific licensing information, see the COPYING file distributed with
* this package.
*
* This Copyright notice must be kept intact and distributed with all sources.
*/
/*
* $Id: usercommon.c,v 1.1 2006/05/31 02:51:04 dquigley Exp $
*/
/*
* Copyright (c) 2003-2005 Erez Zadok
* Copyright (c) 2003-2005 Charles P. Wright
* Copyright (c) 2003-2005 Mohammad Nayyer Zubair
* Copyright (c) 2003-2005 Puja Gupta
* Copyright (c) 2003-2005 Harikesavan Krishnan
* Copyright (c) 2003-2005 Stony Brook University
* Copyright (c) 2003-2005 The Research Foundation of State University of New York
*
* For specific licensing information, see the COPYING file distributed with
* this package.
*
* This Copyright notice must be kept intact and distributed with all sources.
*/
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <stdio.h>
#include <errno.h>
#include <sys/sysmacros.h>
/*
* This function will take a patch and check it against /proc/mounts to
* find its mount point. If uniononly is set then it will make sure its
* a unionf mount point. This function assumes the both options and actual_path
* are valid and not null;
*/
int find_union(const char *path, char **options, char **actual_path,
int uniononly)
{
FILE *f = NULL;
char *s = NULL;
char *s2 = NULL;
char *p;
char *q;
int candidate = 0;
int mallocsize = 1024; /* Just a reasonable starting value. */
retry:
if (*options) {
free(*options);
*options = NULL;
}
if (*actual_path) {
free(*actual_path);
*actual_path = NULL;
}
if (f) {
fclose(f);
f = NULL;
}
s2 = realloc(s, mallocsize);
if (!s2) {
fprintf(stderr, "realloc(%d): %s\n", mallocsize,
strerror(errno));
goto out;
}
s = s2;
f = fopen("/proc/mounts", "r");
if (!f) {
fprintf(stderr, "fopen(/proc/mounts): %s\n", strerror(errno));
goto out;
}
while (fgets(s, mallocsize, f)) {
int testcan;
/* If we don't have enough information, we should remalloc it. */
if (strlen(s) == (mallocsize - 1)) {
mallocsize *= 2;
goto retry;
}
p = strchr(s, ' ');
if (!p)
continue;
p++;
q = strchr(p, ' ');
if (!q)
continue;
*q++ = '\0';
testcan = strlen(p);
if (testcan <= candidate) {
continue;
}
if (!strncmp(path, p, testcan)) {
if (*actual_path) {
free(*actual_path);
}
*actual_path = strdup(p);
if (!*actual_path) {
fprintf(stderr, "strdup: %s\n",
strerror(errno));
goto out;
}
p = strchr(q, ' ');
if (!p)
continue;
*p++ = '\0';
if (uniononly) {
if (strcmp(q, "unionfs")) {
candidate = 0;
continue;
}
}
candidate = testcan;
q = strrchr(p, ' ');
if (!q)
continue;
*q = '\0';
q = strrchr(p, ' ');
if (!q)
continue;
*q = '\0';
if (*options) {
free(*options);
}
*options = strdup(p);
if (!*options) {
fprintf(stderr, "strdup: %s\n",
strerror(errno));
goto out;
}
}
}
out:
if (s)
free(s);
if (f)
fclose(f);
if (*options) {
return 0;
}
errno = -ENOENT;
return -1;
}
/**
* Takes the device and creates an fsid from it by placing major in the first
* int and minor in the second.
*/
void fillfsid(dev_t dev, fsid_t * fsid)
{
((unsigned int *)fsid)[0] = major(dev);
((unsigned int *)fsid)[1] = minor(dev);
}
int mkfsid(char *path, fsid_t * fsid)
{
int err = 0;
char *actual_path = NULL;
char *options = NULL;
struct stat stat_struct;
memset(&stat_struct, 0, sizeof(struct stat));
err = find_union(path, &options, &actual_path, 0);
if (err) {
printf("find_union failed:\n");
goto out;
}
err = stat(actual_path, &stat_struct);
if (err) {
perror("Couldent stat path: ");
goto out;
}
fillfsid(stat_struct.st_dev, fsid);
out:
return err;
}
/*
*
* vim:shiftwidth=8
* vim:tabstop=8
*
* For Emacs:
* Local variables:
* c-basic-offset: 8
* c-comment-only-line-offset: 0
* c-offsets-alist: ((statement-block-intro . +) (knr-argdecl-intro . 0)
* (substatement-open . 0) (label . 0) (statement-cont . +))
* indent-tabs-mode: t
* tab-width: 8
* End:
*/
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