X-Git-Url: https://git.saurik.com/apple/libc.git/blobdiff_plain/9385eb3d10ebe5eb398c52040ec3dbfba9b0cdcf..aa54d2fad3d9038b43475aa93c76795c5141a993:/stdlib/FreeBSD/realpath.c diff --git a/stdlib/FreeBSD/realpath.c b/stdlib/FreeBSD/realpath.c index 31e0977..15cf79e 100644 --- a/stdlib/FreeBSD/realpath.c +++ b/stdlib/FreeBSD/realpath.c @@ -35,13 +35,42 @@ __FBSDID("$FreeBSD: src/lib/libc/stdlib/realpath.c,v 1.20 2003/05/28 08:23:01 fj #include "namespace.h" #include #include +#include #include #include #include #include +#include +#include #include "un-namespace.h" + +struct attrs { + u_int32_t len; + attrreference_t name; + dev_t dev; + fsobj_type_t type; + fsobj_id_t id; + char buf[PATH_MAX]; +}; + +#ifndef BUILDING_VARIANT +__private_extern__ const struct attrlist _rp_alist = { + ATTR_BIT_MAP_COUNT, + 0, + ATTR_CMN_NAME | ATTR_CMN_DEVID | ATTR_CMN_OBJTYPE | ATTR_CMN_OBJID, + 0, + 0, + 0, + 0, +}; +#else /* BUILDING_VARIANT */ +extern const struct attrlist _rp_alist; +#endif /* BUILDING_VARIANT */ + +extern char * __private_getcwd(char *, size_t, int); + /* * char *realpath(const char *path, char resolved[PATH_MAX]); * @@ -50,36 +79,91 @@ __FBSDID("$FreeBSD: src/lib/libc/stdlib/realpath.c,v 1.20 2003/05/28 08:23:01 fj * in which case the path which caused trouble is left in (resolved). */ char * -realpath(const char *path, char resolved[PATH_MAX]) +realpath(const char *path, char inresolved[PATH_MAX]) { + struct attrs attrs; struct stat sb; - char *p, *q, *s; - size_t left_len, resolved_len; + char *p, *q; + size_t left_len, resolved_len, save_resolved_len, next_token_len; unsigned symlinks; - int serrno, slen; + int serrno, useattrs, islink; + ssize_t slen; char left[PATH_MAX], next_token[PATH_MAX], symlink[PATH_MAX]; + dev_t dev, lastdev; + struct statfs sfs; + static dev_t rootdev; + static int rootdev_inited = 0; + ino_t inode; + char *resolved; + if (path == NULL) { + errno = EINVAL; + return (NULL); + } +#if __DARWIN_UNIX03 + if (*path == 0) { + errno = ENOENT; + return (NULL); + } +#endif /* __DARWIN_UNIX03 */ + + /* + * Extension to the standard; if inresolved == NULL, allocate memory + */ + if (!inresolved) { + if ((resolved = malloc(PATH_MAX)) == NULL) return (NULL); + } else { + resolved = inresolved; + } + if (!rootdev_inited) { + rootdev_inited = 1; + if (stat("/", &sb) < 0) { +error_return: + if (!inresolved) { + int e = errno; + free(resolved); + errno = e; + } + return (NULL); + } + rootdev = sb.st_dev; + } serrno = errno; symlinks = 0; if (path[0] == '/') { resolved[0] = '/'; resolved[1] = '\0'; - if (path[1] == '\0') + if (path[1] == '\0') { return (resolved); + } resolved_len = 1; left_len = strlcpy(left, path + 1, sizeof(left)); } else { - if (getcwd(resolved, PATH_MAX) == NULL) { +#if !defined(VARIANT_DARWINEXTSN) && __DARWIN_UNIX03 + /* 4447159: don't use GETPATH, so this will fail if */ + /* if parent directories are not readable, as per POSIX */ + if (__private_getcwd(resolved, PATH_MAX, 0) == NULL) +#else /* VARIANT_DARWINEXTSN || !__DARWIN_UNIX03 */ + if (__private_getcwd(resolved, PATH_MAX, 1) == NULL) +#endif /* !VARIANT_DARWINEXTSN && __DARWIN_UNIX03 */ + { strlcpy(resolved, ".", PATH_MAX); - return (NULL); + goto error_return; } resolved_len = strlen(resolved); left_len = strlcpy(left, path, sizeof(left)); } if (left_len >= sizeof(left) || resolved_len >= PATH_MAX) { errno = ENAMETOOLONG; - return (NULL); + goto error_return; } + if (resolved_len > 1) { + if (stat(resolved, &sb) < 0) { + goto error_return; + } + lastdev = sb.st_dev; + } else + lastdev = rootdev; /* * Iterate over path components in `left'. @@ -90,29 +174,32 @@ realpath(const char *path, char resolved[PATH_MAX]) * and its length. */ p = strchr(left, '/'); - s = p ? p : left + left_len; - if (s - left >= sizeof(next_token)) { - errno = ENAMETOOLONG; - return (NULL); + next_token_len = p ? p - left : left_len; + memcpy(next_token, left, next_token_len); + next_token[next_token_len] = '\0'; + + if (p != NULL) { + left_len -= next_token_len + 1; + memmove(left, p + 1, left_len + 1); + } else { + left[0] = '\0'; + left_len = 0; } - memcpy(next_token, left, s - left); - next_token[s - left] = '\0'; - left_len -= s - left; - if (p != NULL) - memmove(left, s + 1, left_len + 1); + if (resolved[resolved_len - 1] != '/') { if (resolved_len + 1 >= PATH_MAX) { errno = ENAMETOOLONG; - return (NULL); + goto error_return; } resolved[resolved_len++] = '/'; resolved[resolved_len] = '\0'; } - if (next_token[0] == '\0') + if (next_token[0] == '\0') { + /* Handle consequential slashes. */ continue; - else if (strcmp(next_token, ".") == 0) + } else if (strcmp(next_token, ".") == 0) { continue; - else if (strcmp(next_token, "..") == 0) { + } else if (strcmp(next_token, "..") == 0) { /* * Strip the last path component except when we have * single "/" @@ -126,6 +213,13 @@ realpath(const char *path, char resolved[PATH_MAX]) continue; } + /* + * Save resolved_len, so that we can later null out + * the the appended next_token, and replace with the + * real name (matters on case-insensitive filesystems). + */ + save_resolved_len = resolved_len; + /* * Append the next path component and lstat() it. If * lstat() fails we still can return successfully if @@ -134,30 +228,97 @@ realpath(const char *path, char resolved[PATH_MAX]) resolved_len = strlcat(resolved, next_token, PATH_MAX); if (resolved_len >= PATH_MAX) { errno = ENAMETOOLONG; - return (NULL); + goto error_return; } - if (lstat(resolved, &sb) != 0) { + if (getattrlist(resolved, (void *)&_rp_alist, &attrs, sizeof(attrs), FSOPT_NOFOLLOW) == 0) { + useattrs = 1; + islink = (attrs.type == VLNK); + dev = attrs.dev; + inode = attrs.id.fid_objno; + } else if (errno == ENOTSUP || errno == EINVAL) { + if ((useattrs = lstat(resolved, &sb)) == 0) { + islink = S_ISLNK(sb.st_mode); + dev = sb.st_dev; + inode = sb.st_ino; + } + } else + useattrs = -1; + if (useattrs < 0) { +#if !__DARWIN_UNIX03 if (errno == ENOENT && p == NULL) { errno = serrno; return (resolved); } - return (NULL); +#endif /* !__DARWIN_UNIX03 */ + goto error_return; } - if (S_ISLNK(sb.st_mode)) { + if (dev != lastdev) { + /* + * We have crossed a mountpoint. For volumes like UDF + * the getattrlist name may not match the actual + * mountpoint, so we just copy the mountpoint directly. + * (3703138). However, the mountpoint may not be + * accessible, as when chroot-ed, so check first. + * There may be a file on the chroot-ed volume with + * the same name as the mountpoint, so compare device + * and inode numbers. + */ + lastdev = dev; + if (statfs(resolved, &sfs) == 0 && lstat(sfs.f_mntonname, &sb) == 0 && dev == sb.st_dev && inode == sb.st_ino) { + /* + * However, it's possible that the mountpoint + * path matches, even though it isn't the real + * path in the chroot-ed environment, so check + * that each component of the mountpoint + * is a directory (and not a symlink) + */ + char temp[sizeof(sfs.f_mntonname)]; + char *cp; + int ok = 1; + + strcpy(temp, sfs.f_mntonname); + for(;;) { + if ((cp = strrchr(temp, '/')) == NULL) { + ok = 0; + break; + } + if (cp <= temp) + break; + *cp = 0; + if (lstat(temp, &sb) < 0 || (sb.st_mode & S_IFMT) != S_IFDIR) { + ok = 0; + break; + } + } + if (ok) { + resolved_len = strlcpy(resolved, sfs.f_mntonname, PATH_MAX); + continue; + } + } + /* if we fail, use the other methods. */ + } + if (islink) { if (symlinks++ > MAXSYMLINKS) { errno = ELOOP; - return (NULL); + goto error_return; + } + slen = readlink(resolved, symlink, sizeof(symlink)); + if (slen <= 0 || slen >= sizeof(symlink)) { + if (slen < 0) + ; /* keep errno from readlink(2) call */ + else if (slen == 0) + errno = ENOENT; + else + errno = ENAMETOOLONG; + goto error_return; } - slen = readlink(resolved, symlink, sizeof(symlink) - 1); - if (slen < 0) - return (NULL); symlink[slen] = '\0'; if (symlink[0] == '/') { resolved[1] = 0; resolved_len = 1; - } else if (resolved_len > 1) { + lastdev = rootdev; + } else { /* Strip the last path component. */ - resolved[resolved_len - 1] = '\0'; q = strrchr(resolved, '/') + 1; *q = '\0'; resolved_len = q - resolved; @@ -172,19 +333,42 @@ realpath(const char *path, char resolved[PATH_MAX]) if (symlink[slen - 1] != '/') { if (slen + 1 >= sizeof(symlink)) { errno = ENAMETOOLONG; - return (NULL); + goto error_return; } symlink[slen] = '/'; symlink[slen + 1] = 0; } - left_len = strlcat(symlink, left, sizeof(left)); - if (left_len >= sizeof(left)) { + left_len = strlcat(symlink, left, sizeof(symlink)); + if (left_len >= sizeof(symlink)) { errno = ENAMETOOLONG; - return (NULL); + goto error_return; } } left_len = strlcpy(left, symlink, sizeof(left)); + } else if (useattrs) { + /* + * attrs already has the real name. + */ + + resolved[save_resolved_len] = '\0'; + resolved_len = strlcat(resolved, (const char *)&attrs.name + attrs.name.attr_dataoffset, PATH_MAX); + if (resolved_len >= PATH_MAX) { + errno = ENAMETOOLONG; + goto error_return; + } } + /* + * For the case of useattrs == 0, we could scan the directory + * and try to match the inode. There are many problems with + * this: (1) the directory may not be readable, (2) for multiple + * hard links, we would find the first, but not necessarily + * the one specified in the path, (3) we can't try to do + * a case-insensitive search to match the right one in (2), + * because the underlying filesystem may do things like + * decompose composed characters. For most cases, doing + * nothing is the right thing when useattrs == 0, so we punt + * for now. + */ } /*