diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/libc/stdlib/realpath.c | 56 |
1 files changed, 36 insertions, 20 deletions
diff --git a/lib/libc/stdlib/realpath.c b/lib/libc/stdlib/realpath.c index c691252ccf5..5d226d9abc8 100644 --- a/lib/libc/stdlib/realpath.c +++ b/lib/libc/stdlib/realpath.c @@ -1,4 +1,4 @@ -/* $OpenBSD: realpath.c,v 1.21 2016/08/28 04:08:59 guenther Exp $ */ +/* $OpenBSD: realpath.c,v 1.22 2017/12/24 01:50:50 millert Exp $ */ /* * Copyright (c) 2003 Constantin S. Svintsoff <kostik@iclub.nsu.ru> * @@ -45,12 +45,19 @@ char * realpath(const char *path, char *resolved) { - char *p, *q, *s; - size_t left_len, resolved_len; + const char *p; + char *q; + size_t left_len, resolved_len, next_token_len; unsigned symlinks; - int serrno, slen, mem_allocated; + int serrno, mem_allocated; + ssize_t slen; char left[PATH_MAX], next_token[PATH_MAX], symlink[PATH_MAX]; + if (path == NULL) { + errno = EINVAL; + return (NULL); + } + if (path[0] == '\0') { errno = ENOENT; return (NULL); @@ -85,7 +92,7 @@ realpath(const char *path, char *resolved) resolved_len = strlen(resolved); left_len = strlcpy(left, path, sizeof(left)); } - if (left_len >= sizeof(left) || resolved_len >= PATH_MAX) { + if (left_len >= sizeof(left)) { errno = ENAMETOOLONG; goto err; } @@ -99,16 +106,19 @@ realpath(const char *path, char *resolved) * and its length. */ p = strchr(left, '/'); - s = p ? p : left + left_len; - if (s - left >= sizeof(next_token)) { - errno = ENAMETOOLONG; - goto err; + + next_token_len = p ? (size_t) (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; @@ -136,16 +146,17 @@ realpath(const char *path, char *resolved) } /* - * Append the next path component and lstat() it. If - * lstat() fails we still can return successfully if - * there are no more path components left. + * Append the next path component and readlink() it. If + * readlink() fails we still can return successfully if + * it exists but isn't a symlink, or if there are no more + * path components left. */ resolved_len = strlcat(resolved, next_token, PATH_MAX); if (resolved_len >= PATH_MAX) { errno = ENAMETOOLONG; goto err; } - slen = readlink(resolved, symlink, sizeof(symlink) - 1); + slen = readlink(resolved, symlink, sizeof(symlink)); if (slen < 0) { switch (errno) { case EINVAL: @@ -160,6 +171,12 @@ realpath(const char *path, char *resolved) default: goto err; } + } else if (slen == 0) { + errno = EINVAL; + goto err; + } else if (slen == sizeof(symlink)) { + errno = ENAMETOOLONG; + goto err; } else { if (symlinks++ > SYMLOOP_MAX) { errno = ELOOP; @@ -170,9 +187,8 @@ realpath(const char *path, char *resolved) if (symlink[0] == '/') { resolved[1] = 0; resolved_len = 1; - } else if (resolved_len > 1) { + } else { /* Strip the last path component. */ - resolved[resolved_len - 1] = '\0'; q = strrchr(resolved, '/') + 1; *q = '\0'; resolved_len = q - resolved; |