libc-top-half/musl/src/misc/nftw.c

   1 #include <ftw.h>
   2 #include <dirent.h>
   3 #include <sys/stat.h>
   4 #include <errno.h>
   5 #include <unistd.h>
   6 #include <string.h>
   7 #include <limits.h>
   8 #if defined(__wasilibc_unmodified_upstream) || defined(_REENTRANT)
   9 #include <pthread.h>
  10 #endif
  11
  12 struct history
  13 {
  14         struct history *chain;
  15         dev_t dev;
  16         ino_t ino;
  17         int level;
  18         int base;
  19 };
  20
  21 #undef dirfd
  22 #define dirfd(d) (*(int *)d)
  23
  24 static int do_nftw(char *path, int (*fn)(const char *, const struct stat *, int, struct FTW *), int fd_limit, int flags, struct history *h)
  25 {
  26         size_t l = strlen(path), j = l && path[l-1]=='/' ? l-1 : l;
  27         struct stat st;
  28         struct history new;
  29         int type;
  30         int r;
  31         struct FTW lev;
  32
  33         if ((flags & FTW_PHYS) ? lstat(path, &st) : stat(path, &st) < 0) {
  34                 if (!(flags & FTW_PHYS) && errno==ENOENT && !lstat(path, &st))
  35                         type = FTW_SLN;
  36                 else if (errno != EACCES) return -1;
  37                 else type = FTW_NS;
  38         } else if (S_ISDIR(st.st_mode)) {
  39                 if (access(path, R_OK) < 0) type = FTW_DNR;
  40                 else 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 (!(flags & FTW_DEPTH) && (r=fn(path, &st, type, &lev)))
  69                 return r;
  70
  71         for (; h; h = h->chain)
  72                 if (h->dev == st.st_dev && h->ino == st.st_ino)
  73                         return 0;
  74
  75         if ((type == FTW_D || type == FTW_DP) && fd_limit) {
  76                 DIR *d = opendir(path);
  77                 if (d) {
  78                         struct dirent *de;
  79                         while ((de = readdir(d))) {
  80                                 if (de->d_name[0] == '.'
  81                                  && (!de->d_name[1]
  82                                   || (de->d_name[1]=='.'
  83                                    && !de->d_name[2]))) continue;
  84                                 if (strlen(de->d_name) >= PATH_MAX-l) {
  85                                         errno = ENAMETOOLONG;
  86                                         closedir(d);
  87                                         return -1;
  88                                 }
  89                                 path[j]='/';
  90                                 strcpy(path+j+1, de->d_name);
  91                                 if ((r=do_nftw(path, fn, fd_limit-1, flags, &new))) {
  92                                         closedir(d);
  93                                         return r;
  94                                 }
  95                         }
  96                         closedir(d);
  97                 } else if (errno != EACCES) {
  98                         return -1;
  99                 }
 100         }
 101
 102         path[l] = 0;
 103         if ((flags & FTW_DEPTH) && (r=fn(path, &st, type, &lev)))
 104                 return r;
 105
 106         return 0;
 107 }
 108
 109 int nftw(const char *path, int (*fn)(const char *, const struct stat *, int, struct FTW *), int fd_limit, int flags)
 110 {
 111         int r, cs;
 112         size_t l;
 113         char pathbuf[PATH_MAX+1];
 114
 115         if (fd_limit <= 0) return 0;
 116
 117         l = strlen(path);
 118         if (l > PATH_MAX) {
 119                 errno = ENAMETOOLONG;
 120                 return -1;
 121         }
 122         memcpy(pathbuf, path, l+1);
 123
 124 #if defined(__wasilibc_unmodified_upstream) || defined(_REENTRANT)
 125         pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
 126 #endif
 127         r = do_nftw(pathbuf, fn, fd_limit, flags, NULL);
 128 #if defined(__wasilibc_unmodified_upstream) || defined(_REENTRANT)
 129         pthread_setcancelstate(cs, 0);
 130 #endif
 131         return r;
 132 }
 133
 134 weak_alias(nftw, nftw64);