1 | /* 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 "qemu/osdep.h" |
7 | #include <sys/param.h> |
8 | #include <dirent.h> |
9 | #include "qemu/cutils.h" |
10 | #include "qemu/path.h" |
11 | #include "qemu/thread.h" |
12 | |
13 | static const char *base; |
14 | static GHashTable *hash; |
15 | static QemuMutex lock; |
16 | |
17 | void init_paths(const char *prefix) |
18 | { |
19 | if (prefix[0] == '\0' || !strcmp(prefix, "/" )) { |
20 | return; |
21 | } |
22 | |
23 | if (prefix[0] == '/') { |
24 | base = g_strdup(prefix); |
25 | } else { |
26 | char *cwd = g_get_current_dir(); |
27 | base = g_build_filename(cwd, prefix, NULL); |
28 | g_free(cwd); |
29 | } |
30 | |
31 | hash = g_hash_table_new(g_str_hash, g_str_equal); |
32 | qemu_mutex_init(&lock); |
33 | } |
34 | |
35 | /* Look for path in emulation dir, otherwise return name. */ |
36 | const char *path(const char *name) |
37 | { |
38 | gpointer key, value; |
39 | const char *ret; |
40 | |
41 | /* Only do absolute paths: quick and dirty, but should mostly be OK. */ |
42 | if (!base || !name || name[0] != '/') { |
43 | return name; |
44 | } |
45 | |
46 | qemu_mutex_lock(&lock); |
47 | |
48 | /* Have we looked up this file before? */ |
49 | if (g_hash_table_lookup_extended(hash, name, &key, &value)) { |
50 | ret = value ? value : name; |
51 | } else { |
52 | char *save = g_strdup(name); |
53 | char *full = g_build_filename(base, name, NULL); |
54 | |
55 | /* Look for the path; record the result, pass or fail. */ |
56 | if (access(full, F_OK) == 0) { |
57 | /* Exists. */ |
58 | g_hash_table_insert(hash, save, full); |
59 | ret = full; |
60 | } else { |
61 | /* Does not exist. */ |
62 | g_free(full); |
63 | g_hash_table_insert(hash, save, NULL); |
64 | ret = name; |
65 | } |
66 | } |
67 | |
68 | qemu_mutex_unlock(&lock); |
69 | return ret; |
70 | } |
71 | |