1#include <stdio.h>
2#include <stdbool.h>
3#include <string.h>
4#include <dprintf.h>
5#include <fcntl.h>
6#include "fs.h"
7#include "cache.h"
8
9/*
10 * Convert a relative pathname to an absolute pathname
11 * In the future this might also resolve symlinks...
12 */
13void pm_realpath(com32sys_t *regs)
14{
15    const char *src = MK_PTR(regs->ds, regs->esi.w[0]);
16    char       *dst = MK_PTR(regs->es, regs->edi.w[0]);
17
18    realpath(dst, src, FILENAME_MAX);
19}
20
21static size_t copy_string(char *buf, size_t ix, size_t bufsize, const char *src)
22{
23    char c;
24
25    while ((c = *src++)) {
26	if (ix+1 < bufsize)
27	    buf[ix] = c;
28	ix++;
29    }
30
31    if (ix < bufsize)
32	buf[ix] = '\0';
33
34    return ix;
35}
36
37static size_t generic_inode_to_path(struct inode *inode, char *dst, size_t bufsize)
38{
39    size_t s = 0;
40
41    dprintf("inode %p name %s\n", inode, inode->name);
42
43    if (inode->parent) {
44	if (!inode->name)	/* Only the root should have no name */
45	    return -1;
46
47	s = generic_inode_to_path(inode->parent, dst, bufsize);
48	if (s == (size_t)-1)
49	    return s;		/* Error! */
50
51	s = copy_string(dst, s, bufsize, "/");
52	s = copy_string(dst, s, bufsize, inode->name);
53    }
54
55    return s;
56}
57
58__export size_t realpath(char *dst, const char *src, size_t bufsize)
59{
60    int rv;
61    struct file *file;
62    size_t s;
63
64    dprintf("realpath: input: %s\n", src);
65
66    if (this_fs->fs_ops->realpath) {
67	s = this_fs->fs_ops->realpath(this_fs, dst, src, bufsize);
68    } else {
69	rv = searchdir(src, O_RDONLY);
70	if (rv < 0) {
71	    dprintf("realpath: searchpath failure\n");
72	    return -1;
73	}
74
75	file = handle_to_file(rv);
76	s = generic_inode_to_path(file->inode, dst, bufsize);
77	if (s == 0)
78	    s = copy_string(dst, 0, bufsize, "/");
79
80	_close_file(file);
81    }
82
83    dprintf("realpath: output: %s\n", dst);
84    return s;
85}
86
87__export int chdir(const char *src)
88{
89    int rv;
90    struct file *file;
91    char cwd_buf[CURRENTDIR_MAX];
92    size_t s;
93
94    dprintf("chdir: from %s (inode %p) add %s\n",
95	    this_fs->cwd_name, this_fs->cwd, src);
96
97    if (this_fs->fs_ops->chdir)
98	return this_fs->fs_ops->chdir(this_fs, src);
99
100    /* Otherwise it is a "conventional filesystem" */
101    rv = searchdir(src, O_RDONLY|O_DIRECTORY);
102    if (rv < 0)
103	return rv;
104
105    file = handle_to_file(rv);
106    if (file->inode->mode != DT_DIR) {
107	_close_file(file);
108	return -1;
109    }
110
111    put_inode(this_fs->cwd);
112    this_fs->cwd = get_inode(file->inode);
113    _close_file(file);
114
115    /* Save the current working directory */
116    s = generic_inode_to_path(this_fs->cwd, cwd_buf, CURRENTDIR_MAX-1);
117
118    /* Make sure the cwd_name ends in a slash, it's supposed to be a prefix */
119    if (s < 1 || cwd_buf[s-1] != '/')
120	cwd_buf[s++] = '/';
121
122    if (s >= CURRENTDIR_MAX)
123	s = CURRENTDIR_MAX - 1;
124
125    cwd_buf[s++] = '\0';
126    memcpy(this_fs->cwd_name, cwd_buf, s);
127
128    dprintf("chdir: final %s (inode %p)\n",
129	    this_fs->cwd_name, this_fs->cwd);
130
131    return 0;
132}
133