Libc-1439.100.3.tar.gz

[apple/libc.git] / stdlib / FreeBSD / realpath.c

diff --git a/stdlib/FreeBSD/realpath.c b/stdlib/FreeBSD/realpath.c
index 13c4e6f1ed0b55af7e0ec8e8879dfc35e370b6f5..15cf79e5137ea0595f55ca22abeec1858e095185 100644 (file)
--- a/stdlib/FreeBSD/realpath.c
+++ b/stdlib/FreeBSD/realpath.c
@@ -45,6 +45,7 @@ __FBSDID("$FreeBSD: src/lib/libc/stdlib/realpath.c,v 1.20 2003/05/28 08:23:01 fj
 #include <sys/vnode.h>
 #include "un-namespace.h"
 
+
 struct attrs {
        u_int32_t len;
        attrreference_t name;
@@ -65,7 +66,7 @@ __private_extern__ const struct attrlist _rp_alist = {
        0,
 };
 #else /* BUILDING_VARIANT */
-__private_extern__ const struct attrlist _rp_alist;
+extern const struct attrlist _rp_alist;
 #endif /* BUILDING_VARIANT */
 
 extern char * __private_getcwd(char *, size_t, int);
@@ -82,10 +83,11 @@ realpath(const char *path, char inresolved[PATH_MAX])
 {
        struct attrs attrs;
        struct stat sb;
-       char *p, *q, *s;
-       size_t left_len, resolved_len, save_resolved_len;
+       char *p, *q;
+       size_t left_len, resolved_len, save_resolved_len, next_token_len;
        unsigned symlinks;
-       int serrno, slen, useattrs, islink;
+       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;
@@ -104,6 +106,7 @@ realpath(const char *path, char inresolved[PATH_MAX])
                return (NULL);
        }
 #endif /* __DARWIN_UNIX03 */
+
        /*
         * Extension to the standard; if inresolved == NULL, allocate memory
         */
@@ -171,16 +174,18 @@ error_return:
                 * and its length.
                 */
                p = strchr(left, '/');
-               s = p ? p : left + left_len;
-               if (s - left >= sizeof(next_token)) {
-                       errno = ENAMETOOLONG;
-                       goto error_return;
+               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;
@@ -189,11 +194,12 @@ 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 "/"
@@ -296,8 +302,14 @@ error_return:
                                errno = ELOOP;
                                goto error_return;
                        }
-                       slen = readlink(resolved, symlink, sizeof(symlink) - 1);
-                       if (slen < 0) {
+                       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;
                        }
                        symlink[slen] = '\0';
@@ -305,9 +317,8 @@ error_return:
                                resolved[1] = 0;
                                resolved_len = 1;
                                lastdev = rootdev;
-                       } 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;
@@ -328,7 +339,7 @@ error_return:
                                        symlink[slen + 1] = 0;
                                }
                                left_len = strlcat(symlink, left, sizeof(symlink));
-                               if (left_len >= sizeof(left)) {
+                               if (left_len >= sizeof(symlink)) {
                                        errno = ENAMETOOLONG;
                                        goto error_return;
                                }