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1 | 32ce6337 | bellard | /* Code to mangle pathnames into those matching a given prefix.
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2 | 32ce6337 | bellard | eg. open("/lib/foo.so") => open("/usr/gnemul/i386-linux/lib/foo.so");
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3 | 32ce6337 | bellard | |
4 | 32ce6337 | bellard | The assumption is that this area does not change.
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5 | 32ce6337 | bellard | */
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6 | 32ce6337 | bellard | #include <sys/types.h> |
7 | 32ce6337 | bellard | #include <dirent.h> |
8 | 32ce6337 | bellard | #include <unistd.h> |
9 | 32ce6337 | bellard | #include <stdlib.h> |
10 | 32ce6337 | bellard | #include <string.h> |
11 | 32ce6337 | bellard | #include <errno.h> |
12 | 32ce6337 | bellard | #include <stdio.h> |
13 | 32ce6337 | bellard | #include "qemu.h" |
14 | 32ce6337 | bellard | |
15 | 32ce6337 | bellard | struct pathelem
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16 | 32ce6337 | bellard | { |
17 | 32ce6337 | bellard | /* Name of this, eg. lib */
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18 | 32ce6337 | bellard | char *name;
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19 | 32ce6337 | bellard | /* Full path name, eg. /usr/gnemul/x86-linux/lib. */
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20 | 32ce6337 | bellard | char *pathname;
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21 | 32ce6337 | bellard | struct pathelem *parent;
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22 | 32ce6337 | bellard | /* Children */
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23 | 32ce6337 | bellard | unsigned int num_entries; |
24 | 32ce6337 | bellard | struct pathelem *entries[0]; |
25 | 32ce6337 | bellard | }; |
26 | 32ce6337 | bellard | |
27 | 32ce6337 | bellard | static struct pathelem *base; |
28 | 32ce6337 | bellard | |
29 | 32ce6337 | bellard | /* First N chars of S1 match S2, and S2 is N chars long. */
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30 | 32ce6337 | bellard | static int strneq(const char *s1, unsigned int n, const char *s2) |
31 | 32ce6337 | bellard | { |
32 | 32ce6337 | bellard | unsigned int i; |
33 | 32ce6337 | bellard | |
34 | 32ce6337 | bellard | for (i = 0; i < n; i++) |
35 | 32ce6337 | bellard | if (s1[i] != s2[i])
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36 | 32ce6337 | bellard | return 0; |
37 | 32ce6337 | bellard | return s2[i] == 0; |
38 | 32ce6337 | bellard | } |
39 | 32ce6337 | bellard | |
40 | 32ce6337 | bellard | static struct pathelem *add_entry(struct pathelem *root, const char *name); |
41 | 32ce6337 | bellard | |
42 | 32ce6337 | bellard | static struct pathelem *new_entry(const char *root, |
43 | 32ce6337 | bellard | struct pathelem *parent,
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44 | 32ce6337 | bellard | const char *name) |
45 | 32ce6337 | bellard | { |
46 | 32ce6337 | bellard | struct pathelem *new = malloc(sizeof(*new)); |
47 | 32ce6337 | bellard | new->name = strdup(name); |
48 | 32ce6337 | bellard | asprintf(&new->pathname, "%s/%s", root, name);
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49 | 32ce6337 | bellard | new->num_entries = 0;
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50 | 32ce6337 | bellard | return new;
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51 | 32ce6337 | bellard | } |
52 | 32ce6337 | bellard | |
53 | 32ce6337 | bellard | #define streq(a,b) (strcmp((a), (b)) == 0) |
54 | 32ce6337 | bellard | |
55 | 32ce6337 | bellard | static struct pathelem *add_dir_maybe(struct pathelem *path) |
56 | 32ce6337 | bellard | { |
57 | 32ce6337 | bellard | DIR *dir; |
58 | 32ce6337 | bellard | |
59 | 32ce6337 | bellard | if ((dir = opendir(path->pathname)) != NULL) { |
60 | 32ce6337 | bellard | struct dirent *dirent;
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61 | 32ce6337 | bellard | |
62 | 32ce6337 | bellard | while ((dirent = readdir(dir)) != NULL) { |
63 | 32ce6337 | bellard | if (!streq(dirent->d_name,".") && !streq(dirent->d_name,"..")){ |
64 | 32ce6337 | bellard | path = add_entry(path, dirent->d_name); |
65 | 32ce6337 | bellard | } |
66 | 32ce6337 | bellard | } |
67 | 32ce6337 | bellard | closedir(dir); |
68 | 32ce6337 | bellard | } |
69 | 32ce6337 | bellard | return path;
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70 | 32ce6337 | bellard | } |
71 | 32ce6337 | bellard | |
72 | 32ce6337 | bellard | static struct pathelem *add_entry(struct pathelem *root, const char *name) |
73 | 32ce6337 | bellard | { |
74 | 32ce6337 | bellard | root->num_entries++; |
75 | 32ce6337 | bellard | |
76 | 32ce6337 | bellard | root = realloc(root, sizeof(*root)
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77 | 32ce6337 | bellard | + sizeof(root->entries[0])*root->num_entries); |
78 | 32ce6337 | bellard | |
79 | 32ce6337 | bellard | root->entries[root->num_entries-1] = new_entry(root->pathname, root, name);
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80 | 32ce6337 | bellard | root->entries[root->num_entries-1]
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81 | 32ce6337 | bellard | = add_dir_maybe(root->entries[root->num_entries-1]);
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82 | 32ce6337 | bellard | return root;
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83 | 32ce6337 | bellard | } |
84 | 32ce6337 | bellard | |
85 | 32ce6337 | bellard | /* This needs to be done after tree is stabalized (ie. no more reallocs!). */
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86 | 32ce6337 | bellard | static void set_parents(struct pathelem *child, struct pathelem *parent) |
87 | 32ce6337 | bellard | { |
88 | 32ce6337 | bellard | unsigned int i; |
89 | 32ce6337 | bellard | |
90 | 32ce6337 | bellard | child->parent = parent; |
91 | 32ce6337 | bellard | for (i = 0; i < child->num_entries; i++) |
92 | 32ce6337 | bellard | set_parents(child->entries[i], child); |
93 | 32ce6337 | bellard | } |
94 | 32ce6337 | bellard | |
95 | 32ce6337 | bellard | void init_paths(const char *prefix) |
96 | 32ce6337 | bellard | { |
97 | 32ce6337 | bellard | if (prefix[0] != '/' || |
98 | 32ce6337 | bellard | prefix[0] == '\0' || |
99 | 32ce6337 | bellard | !strcmp(prefix, "/"))
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100 | 32ce6337 | bellard | return;
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101 | 32ce6337 | bellard | |
102 | 32ce6337 | bellard | base = new_entry("", NULL, prefix+1); |
103 | 32ce6337 | bellard | base = add_dir_maybe(base); |
104 | 32ce6337 | bellard | set_parents(base, base); |
105 | 32ce6337 | bellard | } |
106 | 32ce6337 | bellard | |
107 | 32ce6337 | bellard | /* FIXME: Doesn't handle DIR/.. where DIR is not in emulated dir. */
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108 | 32ce6337 | bellard | static const char * |
109 | 32ce6337 | bellard | follow_path(const struct pathelem *cursor, const char *name) |
110 | 32ce6337 | bellard | { |
111 | 32ce6337 | bellard | unsigned int i, namelen; |
112 | 32ce6337 | bellard | |
113 | 32ce6337 | bellard | name += strspn(name, "/");
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114 | 32ce6337 | bellard | namelen = strcspn(name, "/");
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115 | 32ce6337 | bellard | |
116 | 32ce6337 | bellard | if (namelen == 0) |
117 | 32ce6337 | bellard | return cursor->pathname;
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118 | 32ce6337 | bellard | |
119 | 32ce6337 | bellard | if (strneq(name, namelen, "..")) |
120 | 32ce6337 | bellard | return follow_path(cursor->parent, name + namelen);
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121 | 32ce6337 | bellard | |
122 | 32ce6337 | bellard | if (strneq(name, namelen, ".")) |
123 | 32ce6337 | bellard | return follow_path(cursor, name + namelen);
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124 | 32ce6337 | bellard | |
125 | 32ce6337 | bellard | for (i = 0; i < cursor->num_entries; i++) |
126 | 32ce6337 | bellard | if (strneq(name, namelen, cursor->entries[i]->name))
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127 | 32ce6337 | bellard | return follow_path(cursor->entries[i], name + namelen);
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128 | 32ce6337 | bellard | |
129 | 32ce6337 | bellard | /* Not found */
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130 | 32ce6337 | bellard | return NULL; |
131 | 32ce6337 | bellard | } |
132 | 32ce6337 | bellard | |
133 | 32ce6337 | bellard | /* Look for path in emulation dir, otherwise return name. */
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134 | 32ce6337 | bellard | const char *path(const char *name) |
135 | 32ce6337 | bellard | { |
136 | 32ce6337 | bellard | /* Only do absolute paths: quick and dirty, but should mostly be OK.
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137 | 32ce6337 | bellard | Could do relative by tracking cwd. */
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138 | 32ce6337 | bellard | if (!base || name[0] != '/') |
139 | 32ce6337 | bellard | return name;
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140 | 32ce6337 | bellard | |
141 | 32ce6337 | bellard | return follow_path(base, name) ?: name;
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142 | 32ce6337 | bellard | } |