#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)realpath.c 8.1 (Berkeley) 2/16/94";
#endif
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/lib/libc/stdlib/realpath.c,v 1.20 2003/05/28 08:23:01 fjoe Exp $");
#include "namespace.h"
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/mount.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/attr.h>
#include <sys/vnode.h>
#include "un-namespace.h"
struct attrs {
u_int32_t len;
attrreference_t name;
dev_t dev;
fsobj_type_t type;
fsobj_id_t id;
char buf[PATH_MAX];
};
#ifndef BUILDING_VARIANT
__private_extern__ struct attrlist _rp_alist = {
ATTR_BIT_MAP_COUNT,
0,
ATTR_CMN_NAME | ATTR_CMN_DEVID | ATTR_CMN_OBJTYPE | ATTR_CMN_OBJID,
0,
0,
0,
0,
};
#else
__private_extern__ struct attrlist _rp_alist;
#endif
extern char * __private_getcwd(char *, size_t, int);
char *
realpath(const char *path, char inresolved[PATH_MAX])
{
struct attrs attrs;
struct stat sb;
char *p, *q, *s;
size_t left_len, resolved_len, save_resolved_len;
unsigned symlinks;
int serrno, slen, useattrs, islink;
char left[PATH_MAX], next_token[PATH_MAX], symlink[PATH_MAX];
dev_t dev, lastdev;
struct statfs sfs;
static dev_t rootdev;
static int rootdev_inited = 0;
ino_t inode;
char *resolved;
if (path == NULL) {
errno = EINVAL;
return (NULL);
}
#if __DARWIN_UNIX03
if (*path == 0) {
errno = ENOENT;
return (NULL);
}
#endif
if (!inresolved) {
if ((resolved = alloca(PATH_MAX)) == NULL) return (NULL);
} else {
resolved = inresolved;
}
if (!rootdev_inited) {
rootdev_inited = 1;
if (stat("/", &sb) < 0) {
return (NULL);
}
rootdev = sb.st_dev;
}
serrno = errno;
symlinks = 0;
if (path[0] == '/') {
resolved[0] = '/';
resolved[1] = '\0';
if (path[1] == '\0') {
return (resolved);
}
resolved_len = 1;
left_len = strlcpy(left, path + 1, sizeof(left));
} else {
#if !defined(VARIANT_DARWINEXTSN) && __DARWIN_UNIX03
if (__private_getcwd(resolved, PATH_MAX, 0) == NULL)
#else
if (__private_getcwd(resolved, PATH_MAX, 1) == NULL)
#endif
{
strlcpy(resolved, ".", PATH_MAX);
return (NULL);
}
resolved_len = strlen(resolved);
left_len = strlcpy(left, path, sizeof(left));
}
if (left_len >= sizeof(left) || resolved_len >= PATH_MAX) {
errno = ENAMETOOLONG;
return (NULL);
}
if (resolved_len > 1) {
if (stat(resolved, &sb) < 0) {
return (NULL);
}
lastdev = sb.st_dev;
} else
lastdev = rootdev;
while (left_len != 0) {
p = strchr(left, '/');
s = p ? p : left + left_len;
if (s - left >= sizeof(next_token)) {
errno = ENAMETOOLONG;
return (NULL);
}
memcpy(next_token, left, s - left);
next_token[s - left] = '\0';
left_len -= s - left;
if (p != NULL)
memmove(left, s + 1, left_len + 1);
if (resolved[resolved_len - 1] != '/') {
if (resolved_len + 1 >= PATH_MAX) {
errno = ENAMETOOLONG;
return (NULL);
}
resolved[resolved_len++] = '/';
resolved[resolved_len] = '\0';
}
if (next_token[0] == '\0')
continue;
else if (strcmp(next_token, ".") == 0)
continue;
else if (strcmp(next_token, "..") == 0) {
if (resolved_len > 1) {
resolved[resolved_len - 1] = '\0';
q = strrchr(resolved, '/') + 1;
*q = '\0';
resolved_len = q - resolved;
}
continue;
}
save_resolved_len = resolved_len;
resolved_len = strlcat(resolved, next_token, PATH_MAX);
if (resolved_len >= PATH_MAX) {
errno = ENAMETOOLONG;
return (NULL);
}
if (getattrlist(resolved, &_rp_alist, &attrs, sizeof(attrs), FSOPT_NOFOLLOW) == 0) {
useattrs = 1;
islink = (attrs.type == VLNK);
dev = attrs.dev;
inode = attrs.id.fid_objno;
} else if (errno == ENOTSUP || errno == EINVAL) {
if ((useattrs = lstat(resolved, &sb)) == 0) {
islink = S_ISLNK(sb.st_mode);
dev = sb.st_dev;
inode = sb.st_ino;
}
} else
useattrs = -1;
if (useattrs < 0) {
#if !__DARWIN_UNIX03
if (errno == ENOENT && p == NULL) {
errno = serrno;
return (resolved);
}
#endif
return (NULL);
}
if (dev != lastdev) {
lastdev = dev;
if (statfs(resolved, &sfs) == 0 && lstat(sfs.f_mntonname, &sb) == 0 && dev == sb.st_dev && inode == sb.st_ino) {
char temp[sizeof(sfs.f_mntonname)];
char *cp;
int ok = 1;
strcpy(temp, sfs.f_mntonname);
for(;;) {
if ((cp = strrchr(temp, '/')) == NULL) {
ok = 0;
break;
}
if (cp <= temp)
break;
*cp = 0;
if (lstat(temp, &sb) < 0 || (sb.st_mode & S_IFMT) != S_IFDIR) {
ok = 0;
break;
}
}
if (ok) {
resolved_len = strlcpy(resolved, sfs.f_mntonname, PATH_MAX);
continue;
}
}
}
if (islink) {
if (symlinks++ > MAXSYMLINKS) {
errno = ELOOP;
return (NULL);
}
slen = readlink(resolved, symlink, sizeof(symlink) - 1);
if (slen < 0) {
return (NULL);
}
symlink[slen] = '\0';
if (symlink[0] == '/') {
resolved[1] = 0;
resolved_len = 1;
lastdev = rootdev;
} else if (resolved_len > 1) {
resolved[resolved_len - 1] = '\0';
q = strrchr(resolved, '/') + 1;
*q = '\0';
resolved_len = q - resolved;
}
if (p != NULL) {
if (symlink[slen - 1] != '/') {
if (slen + 1 >= sizeof(symlink)) {
errno = ENAMETOOLONG;
return (NULL);
}
symlink[slen] = '/';
symlink[slen + 1] = 0;
}
left_len = strlcat(symlink, left, sizeof(left));
if (left_len >= sizeof(left)) {
errno = ENAMETOOLONG;
return (NULL);
}
}
left_len = strlcpy(left, symlink, sizeof(left));
} else if (useattrs) {
resolved[save_resolved_len] = '\0';
resolved_len = strlcat(resolved, (const char *)&attrs.name + attrs.name.attr_dataoffset, PATH_MAX);
if (resolved_len >= PATH_MAX) {
errno = ENAMETOOLONG;
return (NULL);
}
}
}
if (resolved_len > 1 && resolved[resolved_len - 1] == '/')
resolved[resolved_len - 1] = '\0';
if (!inresolved) resolved = strdup(resolved);
return (resolved);
}