/*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (c) 1989, 1991, 1993, 1995 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include "namespace.h" #include <sys/param.h> #include <sys/stat.h> #include <dirent.h> #include <errno.h> #include <fcntl.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <ssp/ssp.h> #include "un-namespace.h" #include "gen-private.h" #define ISDOT(dp) \ (dp->d_name[0] == '.' && (dp->d_name[1] == '\0' || \ (dp->d_name[1] == '.' && dp->d_name[2] == '\0'))) extern int __getcwd(char *, size_t); char * __ssp_real(getcwd)(char *pt, size_t size) { struct dirent *dp; DIR *dir = NULL; dev_t dev; ino_t ino; int first; char *bpt; struct stat s; dev_t root_dev; ino_t root_ino; size_t ptsize; int save_errno; char *ept, c; int fd; /* * If no buffer specified by the user, allocate one as necessary. * If a buffer is specified, the size has to be non-zero. The path * is built from the end of the buffer backwards. */ if (pt) { ptsize = 0; if (!size) { errno = EINVAL; return (NULL); } if (size == 1) { errno = ERANGE; return (NULL); } ept = pt + size; } else { if ((pt = malloc(ptsize = PATH_MAX)) == NULL) return (NULL); ept = pt + ptsize; } if (__getcwd(pt, ept - pt) == 0) { if (*pt != '/') { bpt = pt; ept = pt + strlen(pt) - 1; while (bpt < ept) { c = *bpt; *bpt++ = *ept; *ept-- = c; } } return (pt); } bpt = ept - 1; *bpt = '\0'; /* Save root values, so know when to stop. */ if (stat("/", &s)) goto err; root_dev = s.st_dev; root_ino = s.st_ino; errno = 0; /* XXX readdir has no error return. */ for (first = 1;; first = 0) { /* Stat the current level. */ if (dir != NULL ? _fstat(_dirfd(dir), &s) : lstat(".", &s)) goto err; /* Save current node values. */ ino = s.st_ino; dev = s.st_dev; /* Check for reaching root. */ if (root_dev == dev && root_ino == ino) { *--bpt = '/'; /* * It's unclear that it's a requirement to copy the * path to the beginning of the buffer, but it's always * been that way and stuff would probably break. */ bcopy(bpt, pt, ept - bpt); if (dir) (void) closedir(dir); return (pt); } /* Open and stat parent directory. */ fd = _openat(dir != NULL ? _dirfd(dir) : AT_FDCWD, "..", O_RDONLY | O_CLOEXEC); if (fd == -1) goto err; if (dir) (void) closedir(dir); if (!(dir = fdopendir(fd)) || _fstat(_dirfd(dir), &s)) { _close(fd); goto err; } /* * If it's a mount point, have to stat each element because * the inode number in the directory is for the entry in the * parent directory, not the inode number of the mounted file. */ save_errno = 0; if (s.st_dev == dev) { for (;;) { if (!(dp = readdir(dir))) goto notfound; if (dp->d_fileno == ino) break; } } else for (;;) { if (!(dp = readdir(dir))) goto notfound; if (ISDOT(dp)) continue; /* Save the first error for later. */ if (fstatat(_dirfd(dir), dp->d_name, &s, AT_SYMLINK_NOFOLLOW)) { if (!save_errno) save_errno = errno; errno = 0; continue; } if (s.st_dev == dev && s.st_ino == ino) break; } /* * Check for length of the current name, preceding slash, * leading slash. */ while (bpt - pt < dp->d_namlen + (first ? 1 : 2)) { size_t len, off; if (!ptsize) { errno = ERANGE; goto err; } off = bpt - pt; len = ept - bpt; if ((pt = reallocf(pt, ptsize *= 2)) == NULL) goto err; bpt = pt + off; ept = pt + ptsize; bcopy(bpt, ept - len, len); bpt = ept - len; } if (!first) *--bpt = '/'; bpt -= dp->d_namlen; bcopy(dp->d_name, bpt, dp->d_namlen); } notfound: /* * If readdir set errno, use it, not any saved error; otherwise, * didn't find the current directory in its parent directory, set * errno to ENOENT. */ if (!errno) errno = save_errno ? save_errno : ENOENT; /* FALLTHROUGH */ err: save_errno = errno; if (ptsize) free(pt); if (dir) (void) closedir(dir); errno = save_errno; return (NULL); }
