1#include <ftw.h>
2#include <dirent.h>
3#include <fcntl.h>
4#include <sys/stat.h>
5#include <errno.h>
6#include <unistd.h>
7#include <string.h>
8#include <limits.h>
9#include <pthread.h>
10
11struct history
12{
13 struct history *chain;
14 dev_t dev;
15 ino_t ino;
16 int level;
17 int base;
18};
19
20#undef dirfd
21#define dirfd(d) (*(int *)d)
22
23static int do_nftw(char *path, int (*fn)(const char *, const struct stat *, int, struct FTW *), int fd_limit, int flags, struct history *h)
24{
25 size_t l = strlen(path), j = l && path[l-1]=='/' ? l-1 : l;
26 struct stat st;
27 struct history new;
28 int type;
29 int r;
30 int dfd;
31 int err;
32 struct FTW lev;
33
34 st.st_dev = st.st_ino = 0;
35
36 if ((flags & FTW_PHYS) ? lstat(path, &st) : stat(path, &st) < 0) {
37 if (!(flags & FTW_PHYS) && errno==ENOENT && !lstat(path, &st))
38 type = FTW_SLN;
39 else if (errno != EACCES) return -1;
40 else type = FTW_NS;
41 } else if (S_ISDIR(st.st_mode)) {
42 if (flags & FTW_DEPTH) type = FTW_DP;
43 else type = FTW_D;
44 } else if (S_ISLNK(st.st_mode)) {
45 if (flags & FTW_PHYS) type = FTW_SL;
46 else type = FTW_SLN;
47 } else {
48 type = FTW_F;
49 }
50
51 if ((flags & FTW_MOUNT) && h && type != FTW_NS && st.st_dev != h->dev)
52 return 0;
53
54 new.chain = h;
55 new.dev = st.st_dev;
56 new.ino = st.st_ino;
57 new.level = h ? h->level+1 : 0;
58 new.base = j+1;
59
60 lev.level = new.level;
61 if (h) {
62 lev.base = h->base;
63 } else {
64 size_t k;
65 for (k=j; k && path[k]=='/'; k--);
66 for (; k && path[k-1]!='/'; k--);
67 lev.base = k;
68 }
69
70 if (type == FTW_D || type == FTW_DP) {
71 dfd = open(path, O_RDONLY);
72 err = errno;
73 if (dfd < 0 && err == EACCES) type = FTW_DNR;
74 if (!fd_limit) close(dfd);
75 }
76
77 if (!(flags & FTW_DEPTH) && (r=fn(path, &st, type, &lev)))
78 return r;
79
80 for (; h; h = h->chain)
81 if (h->dev == st.st_dev && h->ino == st.st_ino)
82 return 0;
83
84 if ((type == FTW_D || type == FTW_DP) && fd_limit) {
85 if (dfd < 0) {
86 errno = err;
87 return -1;
88 }
89 DIR *d = fdopendir(dfd);
90 if (d) {
91 struct dirent *de;
92 while ((de = readdir(d))) {
93 if (de->d_name[0] == '.'
94 && (!de->d_name[1]
95 || (de->d_name[1]=='.'
96 && !de->d_name[2]))) continue;
97 if (strlen(de->d_name) >= PATH_MAX-l) {
98 errno = ENAMETOOLONG;
99 closedir(d);
100 return -1;
101 }
102 path[j]='/';
103 strcpy(path+j+1, de->d_name);
104 if ((r=do_nftw(path, fn, fd_limit-1, flags, &new))) {
105 closedir(d);
106 return r;
107 }
108 }
109 closedir(d);
110 } else {
111 close(dfd);
112 return -1;
113 }
114 }
115
116 path[l] = 0;
117 if ((flags & FTW_DEPTH) && (r=fn(path, &st, type, &lev)))
118 return r;
119
120 return 0;
121}
122
123int nftw(const char *path, int (*fn)(const char *, const struct stat *, int, struct FTW *), int fd_limit, int flags)
124{
125 int r, cs;
126 size_t l;
127 char pathbuf[PATH_MAX+1];
128
129 if (fd_limit <= 0) return 0;
130
131 l = strlen(path);
132 if (l > PATH_MAX) {
133 errno = ENAMETOOLONG;
134 return -1;
135 }
136 memcpy(pathbuf, path, l+1);
137
138 pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
139 r = do_nftw(pathbuf, fn, fd_limit, flags, NULL);
140 pthread_setcancelstate(cs, 0);
141 return r;
142}