char * __realpath (const char *name, char *resolved) { char *rpath, *dest, *extra_buf = NULL; const char *start, *end, *rpath_limit; long int path_max; int num_links = 0; size_t prefix_len; if (name == NULL) { /* As per Single Unix Specification V2 we must return an error if either parameter is a null pointer. We extend this to allow the RESOLVED parameter to be NULL in case the we are expected to allocate the room for the return value. */ __set_errno (EINVAL); return NULL; } if (name[0] == '\0') { /* As per Single Unix Specification V2 we must return an error if the name argument points to an empty string. */ __set_errno (ENOENT); return NULL; } #ifdef PATH_MAX path_max = PATH_MAX; #else path_max = pathconf (name, _PC_PATH_MAX); if (path_max <= 0) path_max = 8192; #endif if (resolved == NULL) { rpath = malloc (path_max); if (rpath == NULL) { /* It's easier to set errno to ENOMEM than to rely on the 'malloc-posix' gnulib module. */ errno = ENOMEM; return NULL; } } else rpath = resolved; rpath_limit = rpath + path_max; /* This is always zero for Posix hosts, but can be 2 for MS-Windows and MS-DOS X:/foo/bar file names. */ prefix_len = FILE_SYSTEM_PREFIX_LEN (name); if (!IS_ABSOLUTE_FILE_NAME (name)) { if (!__getcwd (rpath, path_max)) { rpath[0] = '\0'; goto error; } dest = strchr (rpath, '\0'); start = name; prefix_len = FILE_SYSTEM_PREFIX_LEN (rpath); } else { dest = rpath; if (prefix_len) { memcpy (rpath, name, prefix_len); dest += prefix_len; } *dest++ = '/'; if (DOUBLE_SLASH_IS_DISTINCT_ROOT) { if (ISSLASH (name[1]) && !ISSLASH (name[2]) && !prefix_len) *dest++ = '/'; *dest = '\0'; } start = name + prefix_len; } for (end = start; *start; start = end) { #ifdef _LIBC struct stat64 st; #else struct stat st; #endif int n; /* Skip sequence of multiple path-separators. */ while (ISSLASH (*start)) ++start; /* Find end of path component. */ for (end = start; *end && !ISSLASH (*end); ++end) /* Nothing. */; if (end - start == 0) break; else if (end - start == 1 && start[0] == '.') /* nothing */; else if (end - start == 2 && start[0] == '.' && start[1] == '.') { /* Back up to previous component, ignore if at root already. */ if (dest > rpath + prefix_len + 1) for (--dest; dest > rpath && !ISSLASH (dest[-1]); --dest) continue; if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rpath + 1 && !prefix_len && ISSLASH (*dest) && !ISSLASH (dest[1])) dest++; } else { size_t new_size; if (!ISSLASH (dest[-1])) *dest++ = '/'; if (dest + (end - start) >= rpath_limit) { ptrdiff_t dest_offset = dest - rpath; char *new_rpath; if (resolved) { __set_errno (ENAMETOOLONG); if (dest > rpath + prefix_len + 1) dest--; *dest = '\0'; goto error; } new_size = rpath_limit - rpath; if (end - start + 1 > path_max) new_size += end - start + 1; else new_size += path_max; new_rpath = (char *) realloc (rpath, new_size); if (new_rpath == NULL) { /* It's easier to set errno to ENOMEM than to rely on the 'realloc-posix' gnulib module. */ errno = ENOMEM; goto error; } rpath = new_rpath; rpath_limit = rpath + new_size; dest = rpath + dest_offset; } #ifdef _LIBC dest = __mempcpy (dest, start, end - start); #else memcpy (dest, start, end - start); dest += end - start; #endif *dest = '\0'; #ifdef _LIBC if (__lxstat64 (_STAT_VER, rpath, &st) < 0) #else if (lstat (rpath, &st) < 0) #endif goto error; if (S_ISLNK (st.st_mode)) { char *buf; size_t len; if (++num_links > MAXSYMLINKS) { __set_errno (ELOOP); goto error; } buf = malloca (path_max); if (!buf) { errno = ENOMEM; goto error; } n = __readlink (rpath, buf, path_max - 1); if (n < 0) { int saved_errno = errno; freea (buf); errno = saved_errno; goto error; } buf[n] = '\0'; if (!extra_buf) { extra_buf = malloca (path_max); if (!extra_buf) { freea (buf); errno = ENOMEM; goto error; } } len = strlen (end); if ((long int) (n + len) >= path_max) { freea (buf); __set_errno (ENAMETOOLONG); goto error; } /* Careful here, end may be a pointer into extra_buf... */ memmove (&extra_buf[n], end, len + 1); name = end = memcpy (extra_buf, buf, n); if (IS_ABSOLUTE_FILE_NAME (buf)) { size_t pfxlen = FILE_SYSTEM_PREFIX_LEN (buf); if (pfxlen) memcpy (rpath, buf, pfxlen); dest = rpath + pfxlen; *dest++ = '/'; /* It's an absolute symlink */ if (DOUBLE_SLASH_IS_DISTINCT_ROOT) { if (ISSLASH (buf[1]) && !ISSLASH (buf[2]) && !pfxlen) *dest++ = '/'; *dest = '\0'; } /* Install the new prefix to be in effect hereafter. */ prefix_len = pfxlen; } else { /* Back up to previous component, ignore if at root already: */ if (dest > rpath + prefix_len + 1) for (--dest; dest > rpath && !ISSLASH (dest[-1]); --dest) continue; if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rpath + 1 && ISSLASH (*dest) && !ISSLASH (dest[1]) && !prefix_len) dest++; } } else if (!S_ISDIR (st.st_mode) && *end != '\0') { __set_errno (ENOTDIR); goto error; } } } if (dest > rpath + prefix_len + 1 && ISSLASH (dest[-1])) --dest; if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rpath + 1 && !prefix_len && ISSLASH (*dest) && !ISSLASH (dest[1])) dest++; *dest = '\0'; if (extra_buf) freea (extra_buf); return rpath; error: { int saved_errno = errno; if (extra_buf) freea (extra_buf); if (resolved == NULL) free (rpath); errno = saved_errno; } return NULL; }
static #endif char * compute_curr_prefix (const char *orig_installprefix, const char *orig_installdir, const char *curr_pathname) { char *curr_installdir; const char *rel_installdir; if (curr_pathname == NULL) return NULL; /* Determine the relative installation directory, relative to the prefix. This is simply the difference between orig_installprefix and orig_installdir. */ if (strncmp (orig_installprefix, orig_installdir, strlen (orig_installprefix)) != 0) /* Shouldn't happen - nothing should be installed outside $(prefix). */ return NULL; rel_installdir = orig_installdir + strlen (orig_installprefix); /* Determine the current installation directory. */ { const char *p_base = curr_pathname + FILE_SYSTEM_PREFIX_LEN (curr_pathname); const char *p = curr_pathname + strlen (curr_pathname); char *q; while (p > p_base) { p--; if (ISSLASH (*p)) break; } q = (char *) xmalloc (p - curr_pathname + 1); #ifdef NO_XMALLOC if (q == NULL) return NULL; #endif memcpy (q, curr_pathname, p - curr_pathname); q[p - curr_pathname] = '\0'; curr_installdir = q; } /* Compute the current installation prefix by removing the trailing rel_installdir from it. */ { const char *rp = rel_installdir + strlen (rel_installdir); const char *cp = curr_installdir + strlen (curr_installdir); const char *cp_base = curr_installdir + FILE_SYSTEM_PREFIX_LEN (curr_installdir); while (rp > rel_installdir && cp > cp_base) { bool same = false; const char *rpi = rp; const char *cpi = cp; while (rpi > rel_installdir && cpi > cp_base) { rpi--; cpi--; if (ISSLASH (*rpi) || ISSLASH (*cpi)) { if (ISSLASH (*rpi) && ISSLASH (*cpi)) same = true; break; } /* Do case-insensitive comparison if the file system is always or often case-insensitive. It's better to accept the comparison if the difference is only in case, rather than to fail. */ #if defined _WIN32 || defined __WIN32__ || defined __CYGWIN__ || defined __EMX__ || defined __DJGPP__ /* Native Windows, Cygwin, OS/2, DOS - case insignificant file system */ if ((*rpi >= 'a' && *rpi <= 'z' ? *rpi - 'a' + 'A' : *rpi) != (*cpi >= 'a' && *cpi <= 'z' ? *cpi - 'a' + 'A' : *cpi)) break; #else if (*rpi != *cpi) break; #endif } if (!same) break; /* The last pathname component was the same. opi and cpi now point to the slash before it. */ rp = rpi; cp = cpi; } if (rp > rel_installdir) { /* Unexpected: The curr_installdir does not end with rel_installdir. */ free (curr_installdir); return NULL; } { size_t curr_prefix_len = cp - curr_installdir; char *curr_prefix; curr_prefix = (char *) xmalloc (curr_prefix_len + 1); #ifdef NO_XMALLOC if (curr_prefix == NULL) { free (curr_installdir); return NULL; } #endif memcpy (curr_prefix, curr_installdir, curr_prefix_len); curr_prefix[curr_prefix_len] = '\0'; free (curr_installdir); return curr_prefix; } } }
char * canonicalize_filename_mode (const char *name, canonicalize_mode_t can_mode) { char *rname, *dest, *extra_buf = NULL; char const *start; char const *end; char const *rname_limit; size_t extra_len = 0; Hash_table *ht = NULL; int saved_errno; int can_flags = can_mode & ~CAN_MODE_MASK; bool logical = can_flags & CAN_NOLINKS; size_t prefix_len; can_mode &= CAN_MODE_MASK; if (MULTIPLE_BITS_SET (can_mode)) { errno = EINVAL; return NULL; } if (name == NULL) { errno = EINVAL; return NULL; } if (name[0] == '\0') { errno = ENOENT; return NULL; } /* This is always zero for Posix hosts, but can be 2 for MS-Windows and MS-DOS X:/foo/bar file names. */ prefix_len = FILE_SYSTEM_PREFIX_LEN (name); if (!IS_ABSOLUTE_FILE_NAME (name)) { rname = xgetcwd (); if (!rname) return NULL; dest = strchr (rname, '\0'); if (dest - rname < PATH_MAX) { char *p = xrealloc (rname, PATH_MAX); dest = p + (dest - rname); rname = p; rname_limit = rname + PATH_MAX; } else { rname_limit = dest; } start = name; prefix_len = FILE_SYSTEM_PREFIX_LEN (rname); } else { rname = xmalloc (PATH_MAX); rname_limit = rname + PATH_MAX; dest = rname; if (prefix_len) { memcpy (rname, name, prefix_len); dest += prefix_len; } *dest++ = '/'; if (DOUBLE_SLASH_IS_DISTINCT_ROOT) { if (ISSLASH (name[1]) && !ISSLASH (name[2]) && !prefix_len) *dest++ = '/'; *dest = '\0'; } start = name + prefix_len; } for ( ; *start; start = end) { /* Skip sequence of multiple file name separators. */ while (ISSLASH (*start)) ++start; /* Find end of component. */ for (end = start; *end && !ISSLASH (*end); ++end) /* Nothing. */; if (end - start == 0) break; else if (end - start == 1 && start[0] == '.') /* nothing */; else if (end - start == 2 && start[0] == '.' && start[1] == '.') { /* Back up to previous component, ignore if at root already. */ if (dest > rname + prefix_len + 1) for (--dest; dest > rname && !ISSLASH (dest[-1]); --dest) continue; if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rname + 1 && !prefix_len && ISSLASH (*dest) && !ISSLASH (dest[1])) dest++; } else { struct stat st; if (!ISSLASH (dest[-1])) *dest++ = '/'; if (dest + (end - start) >= rname_limit) { ptrdiff_t dest_offset = dest - rname; size_t new_size = rname_limit - rname; if (end - start + 1 > PATH_MAX) new_size += end - start + 1; else new_size += PATH_MAX; rname = xrealloc (rname, new_size); rname_limit = rname + new_size; dest = rname + dest_offset; } dest = memcpy (dest, start, end - start); dest += end - start; *dest = '\0'; if (logical && (can_mode == CAN_MISSING)) { /* Avoid the stat in this case as it's inconsequential. i.e. we're neither resolving symlinks or testing component existence. */ st.st_mode = 0; } else if ((logical ? stat (rname, &st) : lstat (rname, &st)) != 0) { saved_errno = errno; if (can_mode == CAN_EXISTING) goto error; if (can_mode == CAN_ALL_BUT_LAST) { if (end[strspn (end, SLASHES)] || saved_errno != ENOENT) goto error; continue; } st.st_mode = 0; } if (S_ISLNK (st.st_mode)) { char *buf; size_t n, len; /* Detect loops. We cannot use the cycle-check module here, since it's actually possible to encounter the same symlink more than once in a given traversal. However, encountering the same symlink,NAME pair twice does indicate a loop. */ if (seen_triple (&ht, name, &st)) { if (can_mode == CAN_MISSING) continue; saved_errno = ELOOP; goto error; } buf = areadlink_with_size (rname, st.st_size); if (!buf) { if (can_mode == CAN_MISSING && errno != ENOMEM) continue; saved_errno = errno; goto error; } n = strlen (buf); len = strlen (end); if (!extra_len) { extra_len = ((n + len + 1) > PATH_MAX) ? (n + len + 1) : PATH_MAX; extra_buf = xmalloc (extra_len); } else if ((n + len + 1) > extra_len) { extra_len = n + len + 1; extra_buf = xrealloc (extra_buf, extra_len); } /* Careful here, end may be a pointer into extra_buf... */ memmove (&extra_buf[n], end, len + 1); name = end = memcpy (extra_buf, buf, n); if (IS_ABSOLUTE_FILE_NAME (buf)) { size_t pfxlen = FILE_SYSTEM_PREFIX_LEN (buf); if (pfxlen) memcpy (rname, buf, pfxlen); dest = rname + pfxlen; *dest++ = '/'; /* It's an absolute symlink */ if (DOUBLE_SLASH_IS_DISTINCT_ROOT) { if (ISSLASH (buf[1]) && !ISSLASH (buf[2]) && !pfxlen) *dest++ = '/'; *dest = '\0'; } /* Install the new prefix to be in effect hereafter. */ prefix_len = pfxlen; } else { /* Back up to previous component, ignore if at root already: */ if (dest > rname + prefix_len + 1) for (--dest; dest > rname && !ISSLASH (dest[-1]); --dest) continue; if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rname + 1 && ISSLASH (*dest) && !ISSLASH (dest[1]) && !prefix_len) dest++; } free (buf); } else { if (!S_ISDIR (st.st_mode) && *end && (can_mode != CAN_MISSING)) { saved_errno = ENOTDIR; goto error; } } } } if (dest > rname + prefix_len + 1 && ISSLASH (dest[-1])) --dest; if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rname + 1 && !prefix_len && ISSLASH (*dest) && !ISSLASH (dest[1])) dest++; *dest = '\0'; if (rname_limit != dest + 1) rname = xrealloc (rname, dest - rname + 1); free (extra_buf); if (ht) hash_free (ht); return rname; error: free (extra_buf); free (rname); if (ht) hash_free (ht); errno = saved_errno; return NULL; }