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#if defined(__wasilibc_unmodified_upstream) || defined(_REENTRANT)
 10#include <pthread.h>
 11#endif
 12
 13struct history
 14{
 15	struct history *chain;
 16	dev_t dev;
 17	ino_t ino;
 18	int level;
 19	int base;
 20};
 21
 22#undef dirfd
 23#define dirfd(d) (*(int *)d)
 24
 25static int do_nftw(char *path, int (*fn)(const char *, const struct stat *, int, struct FTW *), int fd_limit, int flags, struct history *h)
 26{
 27	size_t l = strlen(path), j = l && path[l-1]=='/' ? l-1 : l;
 28	struct stat st;
 29	struct history new;
 30	int type;
 31	int r;
 32	int dfd;
 33	int err;
 34	struct FTW lev;
 35
 36	st.st_dev = st.st_ino = 0;
 37
 38	if ((flags & FTW_PHYS) ? lstat(path, &st) : stat(path, &st) < 0) {
 39		if (!(flags & FTW_PHYS) && errno==ENOENT && !lstat(path, &st))
 40			type = FTW_SLN;
 41		else if (errno != EACCES) return -1;
 42		else type = FTW_NS;
 43	} else if (S_ISDIR(st.st_mode)) {
 44		if (flags & FTW_DEPTH) type = FTW_DP;
 45		else type = FTW_D;
 46	} else if (S_ISLNK(st.st_mode)) {
 47		if (flags & FTW_PHYS) type = FTW_SL;
 48		else type = FTW_SLN;
 49	} else {
 50		type = FTW_F;
 51	}
 52
 53	if ((flags & FTW_MOUNT) && h && type != FTW_NS && st.st_dev != h->dev)
 54		return 0;
 55	
 56	new.chain = h;
 57	new.dev = st.st_dev;
 58	new.ino = st.st_ino;
 59	new.level = h ? h->level+1 : 0;
 60	new.base = j+1;
 61	
 62	lev.level = new.level;
 63	if (h) {
 64		lev.base = h->base;
 65	} else {
 66		size_t k;
 67		for (k=j; k && path[k]=='/'; k--);
 68		for (; k && path[k-1]!='/'; k--);
 69		lev.base = k;
 70	}
 71
 72	if (type == FTW_D || type == FTW_DP) {
 73		dfd = open(path, O_RDONLY);
 74		err = errno;
 75		if (dfd < 0 && err == EACCES) type = FTW_DNR;
 76		if (!fd_limit) close(dfd);
 77	}
 78
 79	if (!(flags & FTW_DEPTH) && (r=fn(path, &st, type, &lev)))
 80		return r;
 81
 82	for (; h; h = h->chain)
 83		if (h->dev == st.st_dev && h->ino == st.st_ino)
 84			return 0;
 85
 86	if ((type == FTW_D || type == FTW_DP) && fd_limit) {
 87		if (dfd < 0) {
 88			errno = err;
 89			return -1;
 90		}
 91		DIR *d = fdopendir(dfd);
 92		if (d) {
 93			struct dirent *de;
 94			while ((de = readdir(d))) {
 95				if (de->d_name[0] == '.'
 96				 && (!de->d_name[1]
 97				  || (de->d_name[1]=='.'
 98				   && !de->d_name[2]))) continue;
 99				if (strlen(de->d_name) >= PATH_MAX-l) {
100					errno = ENAMETOOLONG;
101					closedir(d);
102					return -1;
103				}
104				path[j]='/';
105				strcpy(path+j+1, de->d_name);
106				if ((r=do_nftw(path, fn, fd_limit-1, flags, &new))) {
107					closedir(d);
108					return r;
109				}
110			}
111			closedir(d);
112		} else {
113			close(dfd);
114			return -1;
115		}
116	}
117
118	path[l] = 0;
119	if ((flags & FTW_DEPTH) && (r=fn(path, &st, type, &lev)))
120		return r;
121
122	return 0;
123}
124
125int nftw(const char *path, int (*fn)(const char *, const struct stat *, int, struct FTW *), int fd_limit, int flags)
126{
127	int r, cs;
128	size_t l;
129	char pathbuf[PATH_MAX+1];
130
131	if (fd_limit <= 0) return 0;
132
133	l = strlen(path);
134	if (l > PATH_MAX) {
135		errno = ENAMETOOLONG;
136		return -1;
137	}
138	memcpy(pathbuf, path, l+1);
139	
140#if defined(__wasilibc_unmodified_upstream) || defined(_REENTRANT)
141	pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
142#endif
143	r = do_nftw(pathbuf, fn, fd_limit, flags, NULL);
144#if defined(__wasilibc_unmodified_upstream) || defined(_REENTRANT)
145	pthread_setcancelstate(cs, 0);
146#endif
147	return r;
148}
149
150weak_alias(nftw, nftw64);