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
11 struct 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
do_nftw(char * path,int (* fn)(const char *,const struct stat *,int,struct FTW *),int fd_limit,int flags,struct history * h)23 static 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 if ((flags & FTW_PHYS) ? lstat(path, &st) : stat(path, &st) < 0) {
35 if (!(flags & FTW_PHYS) && errno==ENOENT && !lstat(path, &st))
36 type = FTW_SLN;
37 else if (errno != EACCES) return -1;
38 else type = FTW_NS;
39 } else if (S_ISDIR(st.st_mode)) {
40 if (flags & FTW_DEPTH) type = FTW_DP;
41 else type = FTW_D;
42 } else if (S_ISLNK(st.st_mode)) {
43 if (flags & FTW_PHYS) type = FTW_SL;
44 else type = FTW_SLN;
45 } else {
46 type = FTW_F;
47 }
48
49 if ((flags & FTW_MOUNT) && h && st.st_dev != h->dev)
50 return 0;
51
52 new.chain = h;
53 new.dev = st.st_dev;
54 new.ino = st.st_ino;
55 new.level = h ? h->level+1 : 0;
56 new.base = j+1;
57
58 lev.level = new.level;
59 if (h) {
60 lev.base = h->base;
61 } else {
62 size_t k;
63 for (k=j; k && path[k]=='/'; k--);
64 for (; k && path[k-1]!='/'; k--);
65 lev.base = k;
66 }
67
68 if (type == FTW_D || type == FTW_DP) {
69 dfd = open(path, O_RDONLY);
70 err = errno;
71 if (dfd < 0 && err == EACCES) type = FTW_DNR;
72 if (!fd_limit) close(dfd);
73 }
74
75 if (!(flags & FTW_DEPTH) && (r=fn(path, &st, type, &lev)))
76 return r;
77
78 for (; h; h = h->chain)
79 if (h->dev == st.st_dev && h->ino == st.st_ino)
80 return 0;
81
82 if ((type == FTW_D || type == FTW_DP) && fd_limit) {
83 if (dfd < 0) {
84 errno = err;
85 return -1;
86 }
87 {
88 DIR *d = fdopendir(dfd);
89 if (d) {
90 struct dirent *de;
91 while ((de = readdir(d))) {
92 if (de->d_name[0] == '.'
93 && (!de->d_name[1]
94 || (de->d_name[1]=='.'
95 && !de->d_name[2]))) continue;
96 if (strlen(de->d_name) >= PATH_MAX-l) {
97 errno = ENAMETOOLONG;
98 closedir(d);
99 return -1;
100 }
101 path[j]='/';
102 strcpy(path+j+1, de->d_name);
103 if ((r=do_nftw(path, fn, fd_limit-1, flags, &new))) {
104 closedir(d);
105 return r;
106 }
107 }
108 closedir(d);
109 } else {
110 close(dfd);
111 return -1;
112 }
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
nftw(const char * path,int (* fn)(const char *,const struct stat *,int,struct FTW *),int fd_limit,int flags)123 int 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 }
143