blob: 7da0a8b27a79a076ce56a872022de82e6bd76ee1 [file] [log] [blame]
bellard32ce6332003-04-11 00:16:16 +00001/* Code to mangle pathnames into those matching a given prefix.
2 eg. open("/lib/foo.so") => open("/usr/gnemul/i386-linux/lib/foo.so");
3
4 The assumption is that this area does not change.
5*/
6#include <sys/types.h>
7#include <dirent.h>
8#include <unistd.h>
9#include <stdlib.h>
10#include <string.h>
11#include <errno.h>
12#include <stdio.h>
13#include "qemu.h"
14
15struct pathelem
16{
17 /* Name of this, eg. lib */
18 char *name;
19 /* Full path name, eg. /usr/gnemul/x86-linux/lib. */
20 char *pathname;
21 struct pathelem *parent;
22 /* Children */
23 unsigned int num_entries;
24 struct pathelem *entries[0];
25};
26
27static struct pathelem *base;
28
29/* First N chars of S1 match S2, and S2 is N chars long. */
30static int strneq(const char *s1, unsigned int n, const char *s2)
31{
32 unsigned int i;
33
34 for (i = 0; i < n; i++)
35 if (s1[i] != s2[i])
36 return 0;
37 return s2[i] == 0;
38}
39
40static struct pathelem *add_entry(struct pathelem *root, const char *name);
41
42static struct pathelem *new_entry(const char *root,
43 struct pathelem *parent,
44 const char *name)
45{
46 struct pathelem *new = malloc(sizeof(*new));
47 new->name = strdup(name);
48 asprintf(&new->pathname, "%s/%s", root, name);
49 new->num_entries = 0;
50 return new;
51}
52
53#define streq(a,b) (strcmp((a), (b)) == 0)
54
55static struct pathelem *add_dir_maybe(struct pathelem *path)
56{
57 DIR *dir;
58
59 if ((dir = opendir(path->pathname)) != NULL) {
60 struct dirent *dirent;
61
62 while ((dirent = readdir(dir)) != NULL) {
63 if (!streq(dirent->d_name,".") && !streq(dirent->d_name,"..")){
64 path = add_entry(path, dirent->d_name);
65 }
66 }
67 closedir(dir);
68 }
69 return path;
70}
71
72static struct pathelem *add_entry(struct pathelem *root, const char *name)
73{
74 root->num_entries++;
75
76 root = realloc(root, sizeof(*root)
77 + sizeof(root->entries[0])*root->num_entries);
78
79 root->entries[root->num_entries-1] = new_entry(root->pathname, root, name);
80 root->entries[root->num_entries-1]
81 = add_dir_maybe(root->entries[root->num_entries-1]);
82 return root;
83}
84
85/* This needs to be done after tree is stabalized (ie. no more reallocs!). */
86static void set_parents(struct pathelem *child, struct pathelem *parent)
87{
88 unsigned int i;
89
90 child->parent = parent;
91 for (i = 0; i < child->num_entries; i++)
92 set_parents(child->entries[i], child);
93}
94
bellard32ce6332003-04-11 00:16:16 +000095/* FIXME: Doesn't handle DIR/.. where DIR is not in emulated dir. */
96static const char *
97follow_path(const struct pathelem *cursor, const char *name)
98{
99 unsigned int i, namelen;
100
101 name += strspn(name, "/");
102 namelen = strcspn(name, "/");
103
104 if (namelen == 0)
105 return cursor->pathname;
106
107 if (strneq(name, namelen, ".."))
108 return follow_path(cursor->parent, name + namelen);
109
110 if (strneq(name, namelen, "."))
111 return follow_path(cursor, name + namelen);
112
113 for (i = 0; i < cursor->num_entries; i++)
114 if (strneq(name, namelen, cursor->entries[i]->name))
115 return follow_path(cursor->entries[i], name + namelen);
116
117 /* Not found */
118 return NULL;
119}
120
thsffb04fc2007-06-17 15:32:30 +0000121void init_paths(const char *prefix)
122{
123 char pref_buf[PATH_MAX];
124
125 if (prefix[0] == '\0' ||
126 !strcmp(prefix, "/"))
127 return;
128
129 if (prefix[0] != '/') {
130 char *cwd = get_current_dir_name();
131 if (!cwd)
132 abort();
133 strcpy(pref_buf, cwd);
134 strcat(pref_buf, "/");
135 strcat(pref_buf, prefix);
136 free(cwd);
137 } else
138 strcpy(pref_buf,prefix + 1);
139
140 base = new_entry("", NULL, pref_buf);
141 base = add_dir_maybe(base);
142 if (base->num_entries == 0) {
143 free (base);
144 base = NULL;
145 } else {
146 set_parents(base, base);
147 }
148}
149
bellard32ce6332003-04-11 00:16:16 +0000150/* Look for path in emulation dir, otherwise return name. */
151const char *path(const char *name)
152{
153 /* Only do absolute paths: quick and dirty, but should mostly be OK.
154 Could do relative by tracking cwd. */
155 if (!base || name[0] != '/')
156 return name;
157
158 return follow_path(base, name) ?: name;
159}